# CommandSection

title: CAVEATS
content:
Not all X Font Servers fully support the <i>GetFont</i> request for all font properties, which might lead to incomplete BDF output for certain fonts or servers. This command is part of the older X.Org font server utilities and might not be present by default on modern Linux distributions that primarily rely on Fontconfig/FreeType for font management.


title: ENVIRONMENT VARIABLES
content:
The <b>FONTSERVER</b> environment variable can be used to specify the default font server if the <i>-s</i> option is not provided. Its value should be in the format <i>hostname:port</i>.


title: OUTPUT FORMAT
content:
The output generated by <b>fstobdf</b> is in the Bitmap Distribution Format (BDF), a standard ASCII representation of bitmap fonts. This format can then be used by other font utilities or for direct inclusion in font packages.


title: HISTORY
content:
The <i>fstobdf</i> command emerged as part of the X Window System's font infrastructure, specifically tied to the X Font Server (xfs). In the early days of X, fonts were managed centrally by font servers, and utilities like <i>fstobdf</i> were crucial for manipulating and converting these server-side fonts. Its development aligns with the X11R5 and X11R6 eras of the X Window System when xfs was a prominent component for serving bitmap fonts to X clients. While modern X environments often rely more on client-side font rendering libraries like FreeType and Fontconfig, <i>fstobdf</i> remains available for legacy systems or specific use cases involving X Font Servers.


title: DESCRIPTION
content:
<I>fstopgm</I> is a specialized command-line utility from the Netpbm toolkit. Its primary function is to convert image files in the Sun FrameStore (FST) format into the Portable Graymap (PGM) format.<br><br>The FST format is a proprietary image format historically associated with Sun Microsystems workstations and their FrameStore image database system. PGM is a simple, common grayscale image format part of the Netpbm family, widely used for basic image manipulation and processing due to its straightforward structure.<br><br>This tool is essential for users needing to process or view old Sun FrameStore images using modern image tools or for integration into standard image processing workflows that leverage Netpbm's interoperability. It typically reads the FST image from a specified file or standard input and writes the resulting PGM data to standard output, making it suitable for use in Unix pipelines.


title: CAVEATS
content:
<I>fstopgm</I> is part of the Netpbm package; it must be installed for <I>fstopgm</I> to be available.<br>The Sun FrameStore (FST) format is relatively obscure today, primarily used on older Sun systems.<br>Conversion to PGM implies a grayscale output. Any color information present in the original FST file (if the format supports it, though FST is often grayscale) will be lost or converted to intensity values.<br>Output is written to standard output by default, which can be redirected to a file.


title: STANDARD I/O USAGE
content:
<I>fstopgm</I> follows the Unix convention of reading from standard input if no <I>fstopfile</I> is specified, and writing the resulting PGM image to standard output. This design makes it highly suitable for use in command-line pipelines. For instance, an <I>fstop</I> file can be piped directly into <I>fstopgm</I>, or its output can be piped to another Netpbm utility for further processing.


title: HISTORY
content:
<I>fstopgm</I> is a component of the Netpbm project, an extensive toolkit for graphic file conversion that originated from Jef Poskanzer's Pbmplus package in the late 1980s and early 1990s.<br><br>Netpbm commands, including <I>fstopgm</I>, are designed to adhere to the Unix philosophy of small, specialized tools that do one thing well and can be easily combined using pipes. The utility reflects the historical need to convert between various image formats prevalent in different computing environments, particularly as Sun Microsystems workstations were common during the period of Netpbm's initial development.


title: PARAMETERS
content:
<b>-a, --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Trim all mounted filesystems that support the discard operation. Requires root privileges.<br><br><b>-o, --offset <offset></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Byte offset to start trimming from within the filesystem.<br><br><b>-l, --length <length></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of bytes to trim, or 0 to trim to the end of the device.<br><br><b>-m, --minimum <minimum-bytes></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The minimum contiguous free range (in bytes) to discard. Smaller ranges will be ignored.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the number of discarded bytes and other details during operation.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress verbose output. Overrides -v.<br><br><b>-s, --secure</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a secure discard. This attempts to erase data on discarded blocks more thoroughly but is often slower and less commonly supported by all hardware.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
The <b>fstrim</b> command is used on Linux systems to discard unused blocks on a mounted filesystem. It sends <I>TRIM</I> or <I>DISCARD</I> commands to the underlying storage device for blocks that are no longer in use by the filesystem. This operation is critically important for <I>Solid State Drives</I> (SSDs) and other thin-provisioned storage technologies.<br><br>Unlike traditional Hard Disk Drives (HDDs) that overwrite data, SSDs need to erase blocks before new data can be written to them. If the operating system doesn't inform the SSD which blocks are free, the SSD might perform unnecessary erase cycles on blocks it believes are still in use, leading to performance degradation over time and reduced lifespan. <br><br><b>fstrim</b> helps maintain optimal SSD performance by notifying the drive about free blocks, allowing the SSD's internal garbage collection mechanisms to work efficiently. It can be run manually or as a scheduled service (e.g., via cron or systemd) to keep drives performing well.


title: CAVEATS
content:
Running <b>fstrim</b> can be I/O intensive and might temporarily impact system performance, especially on large filesystems or older SSDs. <br><br>Not all filesystems or storage devices fully support the <I>TRIM</I> or <I>DISCARD</I> operation; <b>fstrim</b> will only work on those that do. Filesystems typically include <I>ext4</I>, <I>XFS</I>, <I>Btrfs</I>, and <I>F2FS</I>. <br><br>The <I>-s</I> (--secure) option performs a secure discard, which aims to permanently erase data from discarded blocks. This operation is often slower, less commonly supported by all hardware, and should be used with extreme caution as it involves data destruction. <br><br><b>fstrim</b> requires root privileges to execute successfully.


title: SCHEDULING <B>FSTRIM</B>
content:
While <b>fstrim</b> can be run manually, it is most commonly scheduled to run periodically using <I>cron</I> jobs or <I>systemd timers</I> (e.g., <I>fstrim.timer</I> on many distributions). This ensures that SSDs are regularly trimmed without requiring manual intervention, helping to maintain long-term performance and drive health. For most desktop users, the default weekly <I>fstrim.timer</I> is sufficient.


title: ONLINE DISCARD VS. OFFLINE <B>FSTRIM</B>
content:
Some modern filesystems (like <I>ext4</I> with the <I>discard</I> mount option, or <I>Btrfs</I>) can perform online, continuous discard operations. This means blocks are trimmed as soon as they are freed. While convenient, enabling continuous discard can sometimes lead to noticeable performance overhead and increased wear, especially on older SSDs. For this reason, many users and distributions prefer periodic offline <b>fstrim</b> runs over continuous online discarding.


title: HISTORY
content:
The concept of <I>TRIM</I> originated from the need to improve performance and lifespan of <I>Solid State Drives</I> (SSDs). The TRIM command itself was standardized as part of the <I>ATA Command Set</I> to allow an operating system to inform a NAND flash SSD which data blocks are no longer in use and can be internally erased. <br><br>Linux kernel support for the TRIM/DISCARD operation was introduced gradually, primarily via the <I>FITRIM ioctl</I>. The <b>fstrim</b> utility was developed as a user-space command-line tool to expose this kernel functionality, making it accessible for manual execution or automated scheduling. Early usage often involved infrequent, full-disk trims, but with the advent of more advanced SSDs and filesystem features, continuous or frequent smaller trims (e.g., via <I>systemd's fstrim.timer</I>) became more common for maintaining optimal performance without significant overhead.


title: SYNOPSIS
content:
The functionality of <i>fstrim-all</i> is commonly achieved by invoking the <b>fstrim</b> command with the <b>--all</b> option:<br><b>fstrim --all</b> [<i>OPTIONS</i>]<br><br>Alternatively, it is often managed by systemd services:<br><b>systemctl start fstrim.service</b><br><b>systemctl enable --now fstrim.timer</b>


title: PARAMETERS
content:
<b><b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs the TRIM operation on all mounted filesystems that support it and are not explicitly excluded (e.g., via <i>noauto-trim</i> in <i>/etc/fstab</i>). This is the core of 'fstrim-all' functionality.<br><br><b><b>--fstab</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restricts the processing of all filesystems to those defined in <i>/etc/fstab</i>. This option is commonly used in systemd units to ensure only relevant filesystems are trimmed.<br><br><b><b>--verbose</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints detailed information about the progress and results of the TRIM operation for each filesystem.<br><br><b><b>--quiet</b>, <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses output, showing nothing unless an error occurs. Useful for cron jobs or systemd services where verbose output is not desired.<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs information in JSON format, facilitating programmatic parsing and integration with other tools.<br><br><b><b>--dry-run</b>, <b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a simulated TRIM operation without actually discarding any blocks. It shows what would be done, useful for testing configurations.<br><br>


title: DESCRIPTION
content:
<i>fstrim-all</i> conceptually represents the process of performing the TRIM operation on all mounted filesystems that support it. This is crucial for Solid State Drives (SSDs) and other flash-based storage devices. The TRIM command (also known as a 'discard' operation) allows the operating system to inform the SSD which data blocks are no longer considered 'in use' by the filesystem. When blocks are deleted by the user, the operating system simply marks them as free, but the SSD controller doesn't know this until explicitly told via TRIM.<br><br>By periodically performing TRIM, the SSD can internally erase these unused blocks, keeping its internal block management (garbage collection) efficient. This prevents 'write amplification' (where the SSD has to read, modify, and rewrite larger blocks than necessary) and helps maintain consistent performance over time, extending the drive's lifespan. Without TRIM, SSDs can experience significant performance degradation as they run out of pre-erased blocks.<br><br>While not a direct standalone command on most modern Linux systems, <i>fstrim-all</i> functionality is typically implemented via a systemd timer (<code>fstrim.timer</code>) that triggers a service (<code>fstrim.service</code>), which in turn executes the <code>fstrim --all --fstab</code> command weekly or as configured. This automates the process across all suitable filesystems, ensuring optimal SSD health without manual intervention.


title: CAVEATS
content:
<ul><li><b>Requires SSD/Flash Storage:</b> TRIM is only relevant for Solid State Drives (SSDs) and other flash-based storage devices. It has no effect on traditional Hard Disk Drives (HDDs).</li><li><b>Filesystem Support:</b> The filesystem must support the TRIM operation (e.g., ext4, XFS, Btrfs, F2FS). Older filesystems or certain configurations may not be compatible.</li><li><b>Performance Impact:</b> While beneficial in the long run, the TRIM operation itself can temporarily consume system resources and might cause a brief pause or performance dip, especially on very busy or fragmented filesystems, or if performed too frequently.</li><li><b>Root Privileges:</b> Executing <i>fstrim</i> (and thus <i>fstrim-all</i> functionality) requires root privileges.</li><li><b>Not Always Needed with 'discard' Mount Option:</b> If a filesystem is mounted with the <code>discard</code> option (e.g., <code>/dev/sda1 /mnt/data ext4 defaults,discard 0 0</code>), TRIM commands are sent to the drive immediately upon block deallocation. While this can provide real-time optimization, it might introduce minor latency for individual deletion operations. Periodic <i>fstrim</i> is still often recommended even with <code>discard</code> enabled, as it can catch blocks freed before <code>discard</code> was enabled or aggregate trims more efficiently.</li></ul>


title: HISTORY
content:
The TRIM command was standardized as part of the ATA-8 ACS-2 specification to address the unique characteristics of flash-based storage. Linux kernel support for TRIM operations was introduced around version 2.6.33. Subsequently, the <i>fstrim</i> utility was developed and integrated into the <i>util-linux</i> package, providing a command-line interface for manual or scheduled TRIM operations.<br><br>In modern Linux distributions, the functionality associated with 'fstrim-all' evolved from traditional cron jobs (e.g., a script in <i>/etc/cron.weekly/fstrim</i>) to more robust and flexible <i>systemd</i> units. The introduction of <code>fstrim.timer</code> and <code>fstrim.service</code> in systemd allowed for standardized, event-driven scheduling of the TRIM operation across all relevant filesystems, making automated, periodic TRIM a common and recommended practice for systems utilizing SSDs.


title: PARAMETERS
content:
<b>-0, --print0</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the null character as a path separator for output, suitable for 'xargs -0'.<br><br><b>-d, --debounce <milliseconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Debounce events within the specified time window to avoid multiple triggers for a single logical change.<br><br><b>-e, --exclude <regex></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude paths matching the specified extended regular expression from monitoring.<br><br><b>-E, --include <regex></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include only paths matching the specified extended regular expression for monitoring.<br><br><b>-f, --format <format_string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output format using a format string. Supports placeholders like '%p' (path), '%f' (flags).<br><br><b>-l, --latency <seconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the latency for coalescing events. Events occurring within this period are grouped (default: 0.1 seconds).<br><br><b>-m, --monitor <monitor_type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the monitor type to use (e.g., 'inotify', 'kqueue', 'fsevents', 'poll'). <b>fswatch</b> typically auto-detects the best one.<br><br><b>-n, --max-events <count></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exit after a specified number of events have been received. Useful for single-shot operations.<br><br><b>-o, --one-shot</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exit after the first event has been received. Alias for <b>--max-events 1</b>.<br><br><b>-r, --recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitor directories recursively, including all subdirectories and their contents.<br><br><b>-t, --event-type <type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter events by type. Can be used multiple times (e.g., <b>-t Created -t Updated</b>). Valid types include 'Created', 'Updated', 'Removed', 'Renamed', 'AttributeModified'.<br><br><b>-x, --exclude-recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude paths recursively from monitoring, preventing traversal into excluded directories.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, showing more details about events, monitor types, and internal operations.<br><br><b>PATH...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more paths (files or directories) to monitor. If no paths are specified, the current directory is monitored.<br><br>


title: DESCRIPTION
content:
<b>fswatch</b> is a powerful, cross-platform command-line utility designed to monitor changes in files and directories in real-time. It leverages native file system event APIs specific to the operating system it runs on, such as <i>inotify</i> on Linux, <i>kqueue</i> on macOS and BSD, and <i>FSEvents</i> on macOS. This allows <b>fswatch</b> to efficiently detect modifications, creations, deletions, and attribute changes without constant polling, thus minimizing CPU and resource consumption.<br><br>It's commonly used in development workflows for tasks like automatically recompiling code, restarting development servers, running test suites upon code changes, or triggering synchronization scripts. By default, <b>fswatch</b> prints the path of the changed file to standard output, making it easy to pipe its output to other commands or scripts for further processing. Its versatility and efficiency make it an invaluable tool for automation and continuous integration setups.


title: CAVEATS
content:
While highly efficient, <b>fswatch</b> does have some limitations:<br><br><b>Resource Limits:</b> On Linux, the <i>inotify</i> subsystem has limits (e.g., <i>max_user_watches</i>, <i>max_queued_events</i>) which can be hit when monitoring an extremely large number of files or deeply nested directories. These limits can usually be increased via <i>sysctl</i>.<br><br><b>Temporary Files:</b> Some text editors save changes by writing to a temporary file and then renaming or replacing the original. This can lead to <i>Created</i> and <i>Removed</i> events instead of just an <i>Updated</i> event for the original file.<br><br><b>Symlinks:</b> Behavior with symbolic links can be complex, especially with recursive monitoring and exclusion/inclusion patterns, requiring careful configuration.<br><br><b>Polling Fallback:</b> If native file system event APIs are unavailable or fail, <b>fswatch</b> may fall back to less efficient polling, which consumes more resources and might not detect changes instantaneously.


title: EVENT TYPES
content:
<b>fswatch</b> can report various types of file system events, allowing for fine-grained control over what triggers an action. Common event types include: <i>Created</i>, <i>Updated</i>, <i>Removed</i>, <i>Renamed</i>, <i>MovedFrom</i>, <i>MovedTo</i>, <i>AttributeModified</i> (e.g., permissions, timestamps), and <i>SizeModified</i>. You can filter for specific event types using the <b>-t</b> or <b>--event-type</b> option, specifying one or more types to receive only relevant notifications.


title: CROSS-PLATFORM NATURE
content:
One of <b>fswatch</b>'s key strengths is its broad cross-platform compatibility. It intelligently selects the most efficient native API available on the host operating system: <br><i>inotify</i> on Linux<br><i>kqueue</i> on macOS and BSD systems<br><i>FSEvents</i> on macOS<br><i>ReadDirectoryChangesW</i> on Windows<br>This ensures optimal performance and resource usage regardless of the environment, making it a reliable tool for development and automation across diverse systems.


title: HISTORY
content:
<b>fswatch</b> was developed to provide a unified, cross-platform interface for file system event monitoring. It was designed to overcome the limitations of platform-specific tools and offer a consistent way for developers to react to file changes, especially important in a world where projects are often developed across different operating systems. Its initial development aimed to leverage the most efficient native APIs available on each system, making it more performant than simple polling solutions. While precise historical dates might be hard to pinpoint without diving deep into its source repository, its design philosophy is rooted in providing a robust and flexible tool for modern development workflows requiring automation and continuous integration.


title: PARAMETERS
content:
<b>--device <device></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the V4L2 device file (e.g., <I>/dev/video0</I>).<br><br><b>--resolution <width>x<height></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the capture resolution (e.g., <I>640x480</I>).<br><br><b>--input <index></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select a specific input on the device (e.g., for multi-input cards).<br><br><b>--format <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force a specific input format if the camera supports multiple.<br><br><b>--jpeg <quality></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set JPEG compression quality (0-100, 100 is best).<br><br><b>--png <compression></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set PNG compression level (0-9, 9 is best).<br><br><b>--bmp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in BMP format.<br><br><b>--no-banner</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable the informational banner overlaid on the image.<br><br><b>--banner-colour <#RRGGBB></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the banner background color using a hexadecimal RGB code.<br><br><b>--line-colour <#RRGGBB></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the banner line color.<br><br><b>--text-colour <#RRGGBB></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the banner text color.<br><br><b>--font <fontname></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the font for banner text (e.g., <I>arial:10</I>).<br><br><b>--title <text></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the main title text displayed on the banner.<br><br><b>--subtitle <text></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the subtitle text displayed on the banner.<br><br><b>--info <text></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set additional info text on the banner.<br><br><b>--timestamp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the current date and time on the banner.<br><br><b>--gmt</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use Greenwich Mean Time for the timestamp.<br><br><b>--no-timestamp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable the timestamp.<br><br><b>--top-banner</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Place the banner at the top of the image.<br><br><b>--bottom-banner</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Place the banner at the bottom of the image (default).<br><br><b>--no-overlay</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable all text and banner overlays.<br><br><b>--crop <WxH,X,Y></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Crop the image before saving (e.g., <I>320x240,0,0</I>).<br><br><b>--rotate <angle></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rotate the image by 90, 180, or 270 degrees clockwise.<br><br><b>--flip <H|V></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Flip the image horizontally (<I>H</I>) or vertically (<I>V</I>).<br><br><b>--greyscale</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert the captured image to greyscale.<br><br><b>--set <control>=<value></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a V4L2 control (e.g., <I>brightness=20</I>). Use <I>--list-controls</I> to see available options.<br><br><b>--list-controls</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List available V4L2 controls and their current values for the device.<br><br><b>--list-formats</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List supported video formats for the device.<br><br><b>--skip <frames></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip a specified number of initial frames (e.g., for camera warm-up).<br><br><b>--delay <seconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wait for a specified duration before capturing the image.<br><br><b>--loop <seconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continuously capture images at specified intervals (e.g., <I>60</I> for every minute).<br><br><b>--background</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in the background, typically used with <I>--loop</I>.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<b>fswebcam</b> is a small, simple webcam application for Linux. It captures images from a Video4Linux2 (V4L2) device, such as a USB webcam, and saves them to a local file. It supports various image formats like JPEG, PNG, and BMP. Beyond basic image capture, <b>fswebcam</b> offers features to customize the output, including adding text banners, timestamps, and adjusting image properties like brightness, contrast, and resolution.<br><br>It's often used in scripts for time-lapse photography, security monitoring, or simply taking a quick snapshot from a command line. Its straightforward syntax and lightweight nature make it a popular choice for embedded systems and server environments where a full GUI application is not practical or desired. It can also handle multiple cameras and offers options for controlling focus, exposure, and white balance if supported by the camera.


title: CAVEATS
content:
<b>fswebcam</b> relies heavily on underlying V4L2 drivers; compatibility and available features (like specific <I>--set</I> controls) can vary significantly between different webcams and Linux distributions.<br><br>Error messages can sometimes be cryptic if the device or driver encounters issues. For consistent results, especially with time-lapse photography, it's often advisable to disable camera auto-settings (e.g., auto-exposure, auto-white-balance) using <I>--set</I> options or <I>v4l2-ctl</I>.


title: IMAGE FILE NAMING WITH DATE/TIME
content:
The <I>image_file</I> argument can include <I>strftime</I>-like format specifiers to automatically name files based on the current date and time. This is particularly useful when using the <I>--loop</I> option for time-lapse captures.<br>For example: <I>fswebcam --loop 60 /var/www/webcam/%Y-%m-%d_%H%M%S.jpg</I> will save a new JPEG every minute with a unique timestamped filename.


title: DEVICE DISCOVERY
content:
If the <I>--device</I> option is not specified, <I>fswebcam</I> will attempt to open <I>/dev/video0</I> by default. If that fails, it will try other common device paths such as <I>/dev/video1</I>, <I>/dev/video2</I>, and so on, until a working V4L2 device is found.


title: HISTORY
content:
<b>fswebcam</b> was developed by Philip Perry. It was initially released as <I>webcam</I> in 2004, then renamed to <I>fswebcam</I> (Free Software Webcam) in 2007. The project's goal was to provide a simple, lightweight, and efficient command-line tool for capturing images from webcams, particularly suited for environments without a graphical interface, such as servers or embedded Linux devices.


title: SYNOPSIS
content:
<b>ftp</b> [<b>-v</b>] [<b>-n</b>] [<b>-i</b>] [<b>-d</b>] [<b>-g</b>] [<b>-k</b>] [<b>-x</b>] [<b>-a</b>] [<b>-t</b>] [<i>host</i>]<br><br>Once connected to a host, <i>ftp</i> provides its own interactive prompt to issue further commands.


title: PARAMETERS
content:
<b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose mode, showing all responses from the remote server.<br><br><b><b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents auto-login upon initial connection. Users must manually issue the <i>open</i> command.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Turns off interactive prompting during multiple file transfers (e.g., with <i>mget</i> or <i>mput</i>).<br><br><b><b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debugging output, displaying all internal debugging information.<br><br><b><b>-g</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables filename globbing for <i>mget</i> and <i>mput</i> commands, treating wildcards literally.<br><br><b><b>-k</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses Kerberos 4 authentication for connecting to the remote host.<br><br><b><b>-x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses Kerberos 5 authentication for connecting to the remote host.<br><br><b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically attempts anonymous FTP login upon connection.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables packet tracing for network debugging.<br><br><b><i>host</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The hostname or IP address of the remote FTP server to connect to. If not provided, <i>ftp</i> enters interactive mode awaiting an <i>open</i> command.<br><br>


title: DESCRIPTION
content:
The <i>ftp</i> command provides a user interface to the File Transfer Protocol (FTP), allowing users to transfer files between a local host and a remote host. It operates in an interactive mode, where users can issue commands to navigate directories, list files, upload, download, and manage file transfer modes (ASCII or binary). While historically a primary method for transferring files, its use has diminished due to inherent security vulnerabilities, such as transmitting passwords and data in plain text. It is still useful for connecting to older FTP servers or for automated scripts where security is less of a concern or handled by other means.


title: CAVEATS
content:
The primary caveat of using <i>ftp</i> is its inherent lack of security. Passwords and data are transmitted in clear text, making them vulnerable to eavesdropping. <br>Firewall configurations can sometimes complicate <i>ftp</i> connections, especially when using active mode, requiring specific port ranges to be open on the client side. <br>For secure file transfers, modern alternatives like <i>sftp</i> (SSH File Transfer Protocol) or <i>scp</i> are strongly recommended over <i>ftp</i>.


title: INTERACTIVE COMMANDS
content:
Once connected to an FTP server, the <i>ftp</i> program provides a rich set of interactive commands for file operations. Common commands include: <br><i>ls</i>: List files on the remote server.<br><i>cd</i>: Change directory on the remote server.<br><i>lcd</i>: Change directory on the local machine.<br><i>get</i>: Download a file from the remote server.<br><i>put</i>: Upload a file to the remote server.<br><i>mget</i>/<i>mput</i>: Download/upload multiple files.<br><i>binary</i>/<i>ascii</i>: Set transfer mode (important for data integrity).<br><i>passive</i>: Toggle passive mode, often necessary for traversing firewalls.<br><i>quit</i>: Exit the <i>ftp</i> session.


title: LOGIN AND AUTHENTICATION
content:
When connecting to an FTP server, <i>ftp</i> will prompt for a username and password unless anonymous login is enabled (often by using 'anonymous' as the username and an email address as the password) or specified via options. The <i>ftp</i> command itself does not store credentials; they are entered at the prompt or handled by Kerberos if specified.


title: HISTORY
content:
FTP (File Transfer Protocol) is one of the oldest and most fundamental network protocols for transferring files, dating back to 1971. Its original specification, RFC 114, was superseded by RFC 959 in 1985, which remains the standard for the protocol today. The <i>ftp</i> client command has been a ubiquitous part of Unix-like operating systems since the early days of the internet. While its fundamental functionality hasn't changed much, its widespread general use has declined significantly due to the rise of more secure protocols like SFTP and HTTPS, which encrypt data and authentication credentials.


title: PARAMETERS
content:
<b><I>--help</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><I>--version</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the program's version number and exits.<br><br><b><I>--alias</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the shell alias definition required for proper integration.<br><br><b><I>--force-command <I>COMMAND</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the correction of a specific <I>COMMAND</I> instead of the last executed one.<br><br><b><I>--</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Marks the end of options; arguments following this will be treated as positional arguments.<br><br>


title: DESCRIPTION
content:
<I>The Fuck</I> is a popular command-line tool that automatically corrects previous mistyped or incorrect commands. Designed to be invoked immediately after a command failure, it analyzes the user's shell history and the error message of the preceding command to suggest a probable correction.<br><br>For instance, if you type "<I>git sttus</I>", and it fails, typing "<I>fuck</I>" immediately after will likely suggest "<I>git status</I>". It supports a wide range of common command errors across various tools like Git, Docker, APT, pacman, and many others, significantly improving productivity by reducing the need to manually retype commands. Its intelligence comes from a collection of "rules" that detect common mistakes and propose fixes. The user can then choose to apply the suggested fix, ignore it, or quit.


title: CAVEATS
content:
<B>Dependency on Python</B>: Requires Python 3 to be installed on the system.<br><br><B>Shell Integration</B>: Needs proper shell alias setup (e.g., in <I>.bashrc</I>, <I>.zshrc</I>) to function correctly, typically as <I>eval $(thefuck --alias)</I>.<br><br><B>Potential for Incorrect Suggestions</B>: While generally accurate, it might occasionally suggest a wrong command, requiring user vigilance.<br><br><B>Security Considerations</B>: As it executes commands, ensure rules are from trusted sources.<br><br><B>Not a Standard Utility</B>: It's an external tool and not part of core Linux distributions; it must be installed separately.


title: <B>INSTALLATION</B>
content:
<I>The Fuck</I> is typically installed via pip, the Python package installer. The command for installation is usually <I>pip install thefuck</I>. After installation, shell-specific setup (e.g., adding an alias to your shell configuration file) is required for seamless use.


title: <B>CONFIGURATION</B>
content:
Users can customize <I>The Fuck</I>'s behavior through a configuration file, typically located at <I>~/.thefuck/settings.py</I>. This file allows specifying which rules to enable or disable, setting up priority for rules, defining custom commands, and configuring other aspects like auto-correction and logging.


title: <B>HOW IT WORKS</B>
content:
When <I>fuck</I> is executed, it retrieves the last command from the shell's history and analyzes its exit status. It then iterates through its collection of predefined "rules" (Python functions) to identify a potential correction. Each rule attempts to fix a specific type of error (e.g., <I>git</I> typos, <I>sudo</I> prefix, missing command arguments). If a rule finds a valid correction, it presents it to the user, who can then accept or reject it.


title: HISTORY
content:
<I>The Fuck</I> was created by Vladimir Iakovlev and gained significant popularity on GitHub. Its development aimed to alleviate the frustration of common command-line typos and syntax errors. Since its inception, it has evolved with community contributions, adding support for more commands, shells, and customizable rules. Its utility quickly resonated with CLI users, making it one of the most starred projects for command-line productivity. The project's continuous development focuses on expanding its rule set and improving its intelligence for suggesting relevant corrections based on various error messages and contexts.


title: SYNOPSIS
content:
<b>func</b> [<i>options</i>] &lt;<i>target</i>&gt; &lt;<i>module</i>&gt;.&lt;<i>function</i>&gt; [<i>arguments...</i>]


title: PARAMETERS
content:
<b><b>--host</b>=<i>HOST_NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a single host (by hostname or FQDN) to target for the command execution.<br><br><b><b>--group</b>=<i>GROUP_NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Targets all hosts belonging to a specific group defined on the Spacewalk/Satellite server.<br><br><b><b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the command on all systems managed by the connected Spacewalk/Satellite server.<br><br><b><b>--server</b>=<i>SERVER_URL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides the default Spacewalk/Satellite server URL to connect to a different one.<br><br><b><b>--config</b>=<i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file instead of the default <i>/etc/spacewalk/func.conf</i> or <i>/etc/rhn/func.conf</i>.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more detailed information about the command execution.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses output messages, showing only critical errors or results.<br><br><b><b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the command execution, often bypassing checks or confirmations.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulates the command execution without making any actual changes on the target systems.<br><br><b><b>--no-wait</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the command and immediately returns without waiting for the results from the target systems.<br><br>


title: DESCRIPTION
content:
The <b>func</b> command, short for <i>Fedora Unified Network Controller</i>, is a powerful client-side utility primarily used in environments leveraging Red Hat Satellite or Spacewalk servers. Its core purpose is to facilitate centralized remote management of registered Linux systems.<br><br>It enables administrators to execute commands, retrieve system information, manage packages (install, update, remove), and perform various administrative tasks across a fleet of servers from a central point. <b>func</b> achieves this by communicating with the <i>rhnmd</i> (RHN Management Daemon) running on the target clients, leveraging a secure and robust infrastructure.<br><br>While not a general-purpose Linux command found on all distributions, <b>func</b> is indispensable in enterprise settings for automating tasks, ensuring compliance, and maintaining consistency across a large number of managed systems, significantly streamlining operational workflows.


title: CAVEATS
content:
The <b>func</b> command requires that the target Linux systems are registered with a Spacewalk or Red Hat Satellite server and have the <i>rhnmd</i> daemon running and configured correctly. It is not a standalone utility for general Linux administration but rather an integral part of a larger, centralized system management infrastructure. Improper use, especially with the <b>--all</b> or <b>--force</b> options, can have widespread and unintended consequences across an entire managed fleet.


title: MODULE AND FUNCTION SYNTAX
content:
The &lt;<i>module</i>&gt;.&lt;<i>function</i>&gt; syntax is crucial for <b>func</b>. Examples include <i>package.install</i> (to install packages), <i>system.uptime</i> (to get system uptime), <i>file.read</i> (to read file contents), or <i>service.start</i> (to start a service). The available modules and functions depend on the capabilities exposed by the <i>rhnmd</i> daemon and the Spacewalk/Satellite server.


title: CONFIGURATION FILES
content:
<b>func</b> typically reads its configuration from <i>/etc/spacewalk/func.conf</i> or <i>/etc/rhn/func.conf</i>. These files define server URLs, proxy settings, and other communication parameters necessary for <b>func</b> to connect to the management server.


title: HISTORY
content:
The <b>func</b> command emerged as part of Red Hat's efforts to provide centralized system management capabilities, initially within the <i>Red Hat Network (RHN)</i> tools. As RHN evolved into Spacewalk (the open-source upstream project) and subsequently Red Hat Satellite, <b>func</b> continued to be a core client-side utility for interacting with these management servers. Its development has focused on robust and scalable remote execution, adapting to new features and capabilities introduced in the server-side management platforms, making it a cornerstone for enterprise Linux administration.


title: SYNOPSIS
content:
<b>function</b> <I>name</I> [<b>()</b>] <b>{</b> <I>commands</I> <b>;</b> <b>}</b><br>or<br><b>function</b> <I>name</I> [<b>()</b>] <I>compound-command</I>


title: PARAMETERS
content:
<b>name</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The identifier chosen for the function. This name will be used to invoke the function later.<br><br><b>commands</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The body of the function, consisting of one or more shell commands. These commands are typically enclosed within curly braces <b><I>{ }</I></b>, forming a compound command.<br><br>


title: DESCRIPTION
content:
The <b><I>function</I></b> keyword is a shell builtin primarily found in Bash and KornShell (ksh) for defining shell functions. Unlike the POSIX-compliant <b><I>name() { commands; }</I></b> syntax, the <b><I>function</I></b> keyword provides an alternative, often considered more readable, way to declare a function. When used, the parentheses <b><I>()</I></b> after the function name become optional, though they can still be included.<br><br>Functions allow you to encapsulate a sequence of commands into a reusable block, which can be executed simply by typing the function's name. This improves script modularity, readability, and reduces redundancy. Variables can be made local to a function using the <b><I>local</I></b> keyword, preventing interference with global variables. Functions also accept positional parameters, similar to scripts, enabling dynamic behavior based on input. They execute within the current shell environment, meaning they can modify the shell's state (e.g., change directories, set environment variables) without launching a subshell.


title: CAVEATS
content:
The <b><I>function</I></b> keyword is a Bash and KornShell extension and is not part of the POSIX shell standard. Scripts using it may not be portable to shells like Dash or pure POSIX shells. Always use the <b><I>local</I></b> keyword for variables intended to be scoped only within the function, to prevent unintended side effects on global variables. The return status of a function is determined by the exit status of the last command executed within its body, or explicitly set using the <b><I>return</I></b> command.


title: FUNCTION ARGUMENTS
content:
Inside a function, arguments passed to it are accessible via positional parameters, just like in a script: <b><I>$1</I></b> for the first argument, <b><I>$2</I></b> for the second, <b><I>$@</I></b> for all arguments, and <b><I>$#</I></b> for the number of arguments. These are distinct from any positional parameters of the script itself.


title: RETURN STATUS
content:
A function's exit status is crucial for error handling and flow control. By default, it's the exit status of the last command executed within its body. You can explicitly set the return status using the <b><I>return</I></b> command, followed by an integer value (0 for success, non-zero for failure). For example: <b><I>return 1</I></b>.


title: HISTORY
content:
The <b><I>function</I></b> keyword syntax originated in the KornShell (ksh) to provide a more explicit way to declare functions, distinct from the traditional Bourne shell (and later POSIX) <b><I>name() { commands; }</I></b> syntax. Bash adopted this syntax to offer compatibility and an alternative style. While the POSIX-compliant syntax remains widely used and is more portable, the <b><I>function</I></b> keyword is popular in Bash scripts for its clarity.


title: SYNOPSIS
content:
<i>funzip</i> <i>[unzip_options]</i> <i>file.zip</i> <i>[files_to_view...]</i><br><i>Note: funzip typically passes its arguments directly to the underlying unzip command.</i>


title: PARAMETERS
content:
<b><i>unzip_options</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Options that are passed directly to the underlying <i>unzip</i> command. Common options used with <i>funzip</i> include:<br><ul><li><b>-l</b>: List contents of the .zip archive (often the default behavior for <i>funzip</i> when no specific files are given).</li><li><b>-v</b>: Verbose listing of the .zip archive contents, showing details like sizes, compression methods, and dates.</li><li><b>-p</b>: Extract files to standard output (stdout). When used with a specific file within the archive, <i>funzip</i> often pipes this output to a pager for viewing.</li><li><b>-t</b>: Test the integrity of the .zip archive contents.</li></ul><br><br><b><i>file.zip</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the .zip archive file to be inspected or viewed.<br><br><b><i>files_to_view...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional. Specifies one or more specific files within the archive whose content should be viewed. If omitted, <i>funzip</i> typically lists the archive's overall contents rather than displaying a specific file's content.<br><br>


title: DESCRIPTION
content:
<i>funzip</i> is a non-standard Linux command, typically implemented as a shell script or alias, designed to provide a convenient way to view the contents of a .zip archive. Instead of extracting files to disk, <i>funzip</i> usually lists the archive's contents (similar to <i>unzip -l</i> or <i>unzip -v</i>) or pipes the content of a specified file from within the archive directly to a pager program like <i>less</i> or <i>more</i>.<br>This allows for quick inspection of archive metadata or file content without modifying the filesystem. Its primary purpose is to "funnel" the output of <i>unzip</i> through a viewer program, making it easy to browse ZIP files without full extraction.


title: CAVEATS
content:
<i>funzip</i> is not a standard executable in the <i>unzip</i> package or core Linux utilities; it's commonly a user-defined alias or a shell script. Its exact behavior (e.g., which pager it uses, default options) can vary significantly depending on its implementation on a given system. It relies on the <i>unzip</i> utility being installed and accessible in the system's PATH.


title: TYPICAL IMPLEMENTATION
content:
A common shell script implementation of <i>funzip</i> might look like this:<br><br><i>#!/bin/sh</i><br><i>if [ "$#" -eq 1 ]; then</i><br><i>  unzip -l "$1" | less</i><br><i>else</i><br><i>  unzip -p "$@" | less</i><br><i>fi</i><br><br>This example first tries to list the archive's contents if only an archive path is provided. Otherwise, if additional arguments are present (assumed to be filenames within the archive), it attempts to extract those specific files to standard output and pipes them to <i>less</i> for viewing. Actual implementations may vary widely depending on the creator's preferences and system configuration.


title: HISTORY
content:
<i>funzip</i> does not have a formal development history like standard Linux commands. It emerged as a common convenience script or alias within the Unix/Linux community to streamline the process of viewing ZIP archive contents without extraction. Its creation was driven by the desire for a quick "peek" functionality, often leveraging the piping capabilities of the shell with <i>unzip</i> and a pager, making a non-interactive process interactive for quick inspections.


title: PARAMETERS
content:
<b><i>-a</i>, <i>--all</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show all files specified on the command line, even if not used by any process. By default, only files in use are shown.<br><br><b><i>-c</i>, <i>--mounts</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate on the mount point. All processes using any file on the specified mount point (filesystem) are listed.<br><br><b><i>-k</i>, <i>--kill</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Kill the processes identified by <b>fuser</b>. A specific signal can be sent with <i>-SIGNAL</i> (e.g., <i>-9</i> for SIGKILL).<br><br><b><i>-i</i>, <i>--interactive</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with <i>-k</i>, it prompts for confirmation before killing each process.<br><br><b><i>-m</i>, <i>--mount</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Same as <i>-c</i>, operates on the mount point. This is particularly useful for identifying processes preventing a filesystem from being unmounted.<br><br><b><i>-n</i>, <i>--no-fork</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When using <i>-k</i>, <b>fuser</b> does not fork for each process killed. This can be faster for many processes but may have implications for signal handling.<br><br><b><i>-s</i>, <i>--silent</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Silent operation. No output is printed to standard output. Only the exit code indicates success or failure.<br><br><b><i>-u</i>, <i>--user</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Append the username of the process owner to the PID in the output.<br><br><b><i>-v</i>, <i>--verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verbose output. Provides more detailed information about processes and files.<br><br><b><i>-4</i>, <i>--ipv4</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only match IPv4 sockets. Useful when querying network connections.<br><br><b><i>-6</i>, <i>--ipv6</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only match IPv6 sockets. Useful when querying network connections.<br><br><b><i>-l</i>, <i>--list-signals</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all known signal names that can be sent with the <i>-k</i> option.<br><br><b><i>-V</i>, <i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<b>fuser</b> is a command-line utility used to identify processes that are currently using specific files, directories, or network sockets. It displays the Process IDs (PIDs) of these processes. This tool is invaluable for system administrators and users alike, especially when attempting to unmount a filesystem that is reported as "busy" or when diagnosing why a file cannot be deleted.<br><br>Beyond just listing PIDs, <b>fuser</b> can also provide additional information such as the user owning the process (with <i>-u</i>) and even send a signal to (or kill) the identified processes (with <i>-k</i>), making it a powerful utility for managing system resources and troubleshooting. It supports various file types, including regular files, block devices, mount points, and network sockets (IPv4/IPv6).


title: CAVEATS
content:
<b>fuser</b>'s ability to identify processes can be limited by insufficient user permissions. To see all processes, it often needs to be run as <i>root</i> or with <i>sudo</i>.<br>Not all types of filesystems or kernel objects are fully supported, though common ones are.<br>The exact output format can sometimes vary slightly between versions or Linux distributions, which might affect shell scripting that parses <b>fuser</b>'s output. For robust scripting, <b>lsof</b> is often preferred for its more consistent output, though it can be slower.


title: UNMOUNTING BUSY FILESYSTEMS
content:
One of the most common uses of <b>fuser</b> is to identify and terminate processes preventing a filesystem from being unmounted. For example, <i>fuser -m /mnt/mydata</i> will list all processes using files on <i>/mnt/mydata</i>. To kill these processes, you can use <i>fuser -km /mnt/mydata</i>.


title: NETWORK SOCKET USAGE
content:
<b>fuser</b> can also identify processes using network sockets. For instance, <i>fuser -n tcp 80</i> will show processes listening on or connected to TCP port 80. You can specify a protocol (<i>tcp</i>, <i>udp</i>) and a port number, or even specific local/remote IP/port combinations like <i>tcp:8080</i> or <i>udp:53@192.168.1.1</i>.


title: HISTORY
content:
The <b>fuser</b> command has been a part of Unix-like operating systems for many years, serving as a fundamental utility for system administration. It was originally developed to address the common problem of identifying processes that hold open files or resources, particularly when trying to unmount a filesystem.<br><br>On Linux, it's typically part of the <i>psmisc</i> package, which provides various utilities for process management. Its design emphasizes speed and simplicity for its primary function, often making it a quicker alternative to more comprehensive tools like <b>lsof</b> when the goal is simply to find PIDs associated with a file or device.


title: SYNOPSIS
content:
<b>fusermount</b> [<i>options</i>] <i>mountpoint</i><br><b>fusermount</b> -u [<i>options</i>] <i>mountpoint</i><br><b>fusermount</b> -z [<i>options</i>] <i>mountpoint</i><br><b>fusermount</b> -V<br><b>fusermount</b> -h


title: PARAMETERS
content:
<b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unmount the specified FUSE filesystem. This is the default action if no other action-specifying options are provided.<br><br><b>-z</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a lazy unmount. The filesystem is immediately detached from the file hierarchy, and all references to the filesystem are cleaned up as soon as they are no longer busy.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable quiet mode. Suppress error messages if the unmount operation fails.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information about <i><b>fusermount</b></i> and exit.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help information and exit.<br><br>


title: DESCRIPTION
content:
<i><b>fusermount</b></i> is a crucial helper program for managing filesystems created using the Filesystem in Userspace (FUSE) framework. Its primary purpose is to enable unprivileged users to unmount FUSE filesystems that they have mounted, a task that would typically require root privileges if performed directly with the standard <i><b>umount</b></i> command.<br><br>When a FUSE filesystem is to be unmounted, <i><b>fusermount</b></i> handles the communication with the kernel's FUSE module and the FUSE daemon process (the user-space program implementing the filesystem). It ensures that all resources are properly released, the mount point is cleaned up, and the FUSE daemon is gracefully terminated. This dedicated approach prevents issues like stale mount points or lingering processes that can occur with improper unmounting.<br><br>It is commonly installed as a setuid-root executable, allowing it to temporarily gain the necessary permissions to interact with the kernel's mounting infrastructure, while still operating in a secure manner under the user's context.


title: CAVEATS
content:
<i><b>fusermount</b></i> typically requires being installed setuid root to allow unprivileged users to perform unmount operations. If the permissions are configured incorrectly, users may be unable to unmount their FUSE filesystems. While <i><b>fusermount</b></i> strives for safe unmounting, it may still fail if the filesystem is excessively busy, requiring a lazy unmount (<i><b>-z</b></i>) or manual intervention.


title: SETUID ROOT REQUIREMENT
content:
For ordinary users to be able to unmount FUSE filesystems, the <i><b>fusermount</b></i> executable is usually installed with the setuid bit set. This grants it temporary root privileges to perform the necessary kernel system calls for unmounting, while the rest of its execution remains under the calling user's permissions, ensuring security.


title: MODERN VERSIONS (FUSERMOUNT3)
content:
With the advent of FUSE 3, a new version of the unmounting utility, <i><b>fusermount3</b></i>, was introduced. While serving the same core purpose, <i><b>fusermount3</b></i> is designed to work with the updated FUSE 3 API and kernel module. Users should be aware of which version their system and FUSE applications are using to ensure compatibility.


title: HISTORY
content:
<i><b>fusermount</b></i> has been an essential component of the FUSE (Filesystem in Userspace) project since its early development by Miklos Szeredi. It was created to solve the fundamental problem of allowing unprivileged users to manage their own FUSE mounts, bridging the gap between user-space applications and privileged kernel operations. Its evolution has been intertwined with the FUSE library and kernel module, consistently providing a robust and secure mechanism for FUSE filesystem lifecycle management.


title: PARAMETERS
content:
<b><b>--font</b> &lt;font&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the font and size to be used for displaying text in the menu, e.g., 'sans-serif 10'.<br><br><b><b>--width</b> &lt;width&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the width of the <i>fuzzel</i> window, either in pixels or as a percentage of the screen width.<br><br><b><b>--lines</b> &lt;lines&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Determines the maximum number of visible lines displayed in the menu before scrolling is required.<br><br><b><b>--prompt</b> &lt;prompt&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the text string displayed as a prompt at the beginning of the input field.<br><br><b><b>--background</b> &lt;color&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the background color of the <i>fuzzel</i> window. Colors can be specified in hexadecimal (e.g., #RRGGBB).<br><br><b><b>--text-color</b> &lt;color&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default color for the text displayed in the menu entries.<br><br><b><b>--selection-color</b> &lt;color&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the background color of the currently highlighted or selected entry.<br><br><b><b>--selection-text-color</b> &lt;color&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the text color for the currently highlighted or selected entry.<br><br><b><b>--border-color</b> &lt;color&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the color of the border surrounding the <i>fuzzel</i> window.<br><br><b><b>--border-width</b> &lt;width&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the width of the window border in pixels.<br><br><b><b>--dmenu</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <i>dmenu</i> compatibility mode, adjusting behavior for scripts expecting <i>dmenu</i>-like interaction.<br><br>


title: DESCRIPTION
content:
<i>fuzzel</i> is a lightweight and highly efficient application launcher specifically designed for Wayland compositors. It functions similarly to traditional X11 utilities like <i>dmenu</i>, by reading lines from standard input, presenting them in a searchable list, and outputting the user's selected line to standard output.<br><br>It is renowned for its speed, minimal resource usage, and seamless integration with Wayland environments. <i>fuzzel</i> focuses on core functionality, offering fuzzy matching for quick filtering of entries and a simple, command-line driven configuration approach. This design philosophy makes it an ideal choice for users seeking a straightforward, responsive, and native Wayland application menu without extensive feature bloat.


title: CAVEATS
content:
<i>fuzzel</i> is primarily designed for Wayland compositors and might not function optimally or at all in X11 environments without a Wayland compatibility layer. Its configuration is heavily reliant on command-line arguments, offering less flexibility through dedicated configuration files compared to some other launchers.


title: INPUT AND OUTPUT
content:
<i>fuzzel</i> typically receives its list of selectable entries via standard input (stdin). For example, a list of applications can be piped to it using commands like `ls /usr/bin/ | fuzzel`. Upon selection, the chosen entry is printed to standard output (stdout), allowing for seamless integration into shell scripts or other command chains.


title: HISTORY
content:
<i>fuzzel</i> emerged to address the need for a fast, minimal, and native application launcher for the burgeoning Wayland ecosystem. While <i>dmenu</i> served as an inspiration for its core functionality, <i>fuzzel</i> was developed from the ground up to integrate seamlessly with Wayland compositors, aiming for low latency and a dependency footprint suitable for modern Linux desktop environments. Its development focuses on performance and Wayland-specific features, making it a popular choice for users of <i>sway</i> and other <i>wlroots</i>-based compositors.


title: SYNOPSIS
content:
<b>fvm</b> <i>&lt;command&gt;</i> [<i>&lt;options&gt;</i>]<br><b>fvm</b> [<i>&lt;global-options&gt;</i>] <i>&lt;command&gt;</i> [<i>&lt;command-options&gt;</i>]


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for FVM or a specific subcommand.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about FVM's operations.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the current version of FVM.<br><br><b>--global</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with subcommands like 'use' to apply the action globally, affecting all projects.<br><br><b>--force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an action, such as overwriting existing files or proceeding despite warnings.<br><br><b>--skip-setup</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with 'install' to skip the initial Flutter SDK setup process after download.<br><br><b>--config [path]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom FVM config file path (default: .fvm/fvm_config.json).<br><br>


title: DESCRIPTION
content:
The <b>fvm</b> command, short for <i>Flutter Version Manager</i>, is a powerful tool designed for developers working with the Flutter SDK. It enables the installation, management, and switching between multiple Flutter SDK versions on a single machine. This capability is crucial for projects requiring specific Flutter versions, ensuring consistency and preventing conflicts. FVM simplifies the process of testing applications against different SDK releases, managing global or project-specific SDK paths, and handling stable, beta, dev, or master channels. It abstracts away the complexity of manual SDK downloads and path configurations, making development workflows smoother and more reliable.


title: CAVEATS
content:
<b>fvm</b> is not a standard Linux command that comes pre-installed with most distributions. It is a third-party tool primarily used by Flutter developers to manage Flutter SDK versions. Its functionality is specific to Flutter development environments and requires Flutter SDK to be installed or managed by FVM itself. It must be installed separately, typically via Dart's global pub activation or by downloading from its repository. Environment variables (like PATH) might need to be configured correctly for <b>fvm</b> and the Flutter SDKs it manages to be accessible.


title: COMMON SUBCOMMANDS
content:
<b>fvm</b> operates primarily through subcommands, each performing a specific task:<br><ul><li><b>fvm install</b> <i>&lt;version&gt;</i>: Downloads and installs a specified Flutter SDK version (e.g., '3.0.0' or 'stable').</li><li><b>fvm use</b> <i>&lt;version&gt;</i>: Sets the specified Flutter SDK version for the current project, or globally if '--global' is used.</li><li><b>fvm list</b>: Displays all Flutter SDK versions currently installed by FVM.</li><li><b>fvm remove</b> <i>&lt;version&gt;</i>: Deletes a specific Flutter SDK version from the FVM managed directory.</li><li><b>fvm releases</b>: Lists all available Flutter SDK release versions for installation.</li><li><b>fvm doctor</b>: Checks the FVM setup and reports any issues.</li><li><b>fvm exec</b> <i>&lt;command&gt;</i>: Executes a Flutter-related command using the FVM-managed Flutter SDK for the current project or global setup.</li></ul>


title: INSTALLATION
content:
<b>fvm</b> is typically installed via the Dart Pub package manager:<br><code>dart pub global activate fvm</code><br>Alternatively, it can be installed directly from its GitHub repository for specific versions or development branches.


title: HISTORY
content:
The <b>fvm</b> (Flutter Version Manager) project emerged from the growing need within the Flutter development community to manage multiple Flutter SDK versions seamlessly. As Flutter applications became more complex and projects often relied on different SDK releases (e.g., stable for production, beta for testing new features), manual switching and environment variable management became cumbersome. FVM was created to automate this process, allowing developers to switch SDK versions per project or globally with simple commands. It gained significant traction as a vital tool for ensuring project consistency and simplifying developer workflows, evolving rapidly to support new Flutter features and installation methods.


title: SYNOPSIS
content:
<i>fwconsole</i> [<i>global-options</i>] <<i>command</i>> [<i>arguments</i>]<br><i>fwconsole</i> [<i>global-options</i>] <i>--help</i>|<<i>command</i>> <i>--help</i>


title: PARAMETERS
content:
<b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help for the command or a specific subcommand, showing available options and arguments.<br><br><b><b>--version</b>, <b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <i>fwconsole</i> application version.<br><br><b><b>--quiet</b>, <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not output any message, suppressing all console output.<br><br><b><b>--verbose</b>, <b>-v</b>|<b>vv</b>|<b>vvv</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increase the verbosity of messages. <i>-v</i> for normal output, <i>-vv</i> for more verbose, <i>-vvv</i> for debug.<br><br><b><b>--ansi</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces ANSI output, enabling colored and formatted text even if not detected automatically.<br><br><b><b>--no-ansi</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables ANSI output, removing colored and formatted text.<br><br><b><b>--no-interaction</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ask any interactive questions, useful for scripting or automation.<br><br>


title: DESCRIPTION
content:
<i>fwconsole</i> is the primary command-line interface (CLI) tool for managing and interacting with FreePBX systems. FreePBX is a popular open-source web-based graphical user interface (GUI) that controls and manages Asterisk, an open-source framework for building communications applications.<br><br>While FreePBX offers extensive web-based administration, <i>fwconsole</i> provides a powerful alternative for administrators who prefer command-line operations, require automation, or need to perform tasks that are difficult or impossible through the web interface. It allows for advanced configuration, troubleshooting, module management, system service control (like Asterisk restarts), database operations, and file permissions adjustments. The command’s modular design means that its functionality is extended through various subcommands, often corresponding to FreePBX modules, offering granular control over the entire communications system.


title: CAVEATS
content:
Using <i>fwconsole</i> requires an installed FreePBX system; it is not a general Linux command. Many operations require root privileges or execution via <i>sudo</i>. Incorrect usage can lead to system instability, data loss, or disruption of FreePBX/Asterisk services. The available subcommands and their specific options can vary significantly based on the FreePBX version and the modules currently installed and enabled on the system.


title: COMMON SUBCOMMANDS & USAGE
content:
While <i>fwconsole</i> has global options, its power lies in its vast array of subcommands, each designed for specific management tasks. These are typically executed as <i>fwconsole &lt;command&gt; [options]</i>. Some frequently used subcommands include:<br><ul><li><b><i>chown</i></b>: Fixes file permissions for Asterisk and FreePBX directories. Essential after manual file changes or upgrades.</li><li><b><i>reload</i></b>: Reloads Asterisk configuration, applying changes made via the FreePBX GUI or CLI.</li><li><b><i>restart</i></b>: Restarts Asterisk services entirely.</li><li><b><i>ma</i></b>: Module Admin commands, e.g., <i>fwconsole ma downloadinstall &lt;module&gt;</i>, <i>fwconsole ma upgradeall</i>.</li><li><b><i>db</i></b>: Database interaction commands, e.g., <i>fwconsole db query &quot;SELECT * FROM users&quot;</i>.</li><li><b><i>userman</i></b>: User Management commands, e.g., <i>fwconsole userman sync</i>.</li></ul>This modularity allows for precise control over different aspects of the FreePBX system.


title: HISTORY
content:
<i>fwconsole</i> emerged as the modern successor to the legacy <i>amportal</i> command-line utility in FreePBX. Developed to leverage the robust Symfony Console component, it provided a more structured, extensible, and user-friendly command-line interface. This shift aimed to standardize CLI interactions, improve maintainability, and offer richer functionality for administrators managing FreePBX systems. Its adoption marked a significant step in FreePBX's evolution towards a more professional and developer-friendly administration environment.


title: SEE ALSO
content:
<b>asterisk(8)</b>: The underlying open-source PBX application managed by FreePBX., <b>php(1)</b>: The scripting language that FreePBX is built upon., <b>amportal(deprecated)</b>: The legacy CLI tool that <i>fwconsole</i> effectively replaced.


title: SYNOPSIS
content:
<b>fwupdmgr</b> [<i>OPTIONS...</i>] [<i>COMMAND</i>]<br><br><i>Common Usage Examples:</i><br>&nbsp;&nbsp;&nbsp;<b>fwupdmgr</b> <i>refresh</i><br>&nbsp;&nbsp;&nbsp;<b>fwupdmgr</b> <i>get-updates</i><br>&nbsp;&nbsp;&nbsp;<b>fwupdmgr</b> <i>update</i><br>&nbsp;&nbsp;&nbsp;<b>fwupdmgr</b> <i>get-devices</i>


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help information for the command.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the version of <b>fwupdmgr</b>.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show extra information and debug data for operations.<br><br><b>--force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Override some warnings or errors during an operation.<br><br><b>--offline</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform operations without an internet connection, using cached data or local files.<br><br><b>get-devices</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all devices currently supported by <i>fwupd</i>.<br><br><b>refresh</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Download the latest metadata from the LVFS, including available firmware updates.<br><br><b>get-updates</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check for and display available firmware updates for detected devices.<br><br><b>update</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install all available firmware updates. A system reboot may be required.<br><br><b>downgrade</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downgrade firmware to an older version if available and supported.<br><br><b>verify</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check the integrity and authenticity of installed firmware.<br><br><b>install [FILE]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install a specific firmware file (e.g., a .cab file) from a local path.<br><br><b>get-history</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the update history for devices.<br><br><b>clear-history</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clear the local firmware update history.<br><br><b>get-remotes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all configured LVFS remotes (sources for firmware metadata).<br><br><b>enable-remote [ID]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable a specific remote for firmware retrieval.<br><br><b>disable-remote [ID]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable a specific remote.<br><br><b>set-remote-url [ID] [URL]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Change the URL for a specified remote.<br><br><b>get-details [DEVICE_ID]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show detailed information about a specific device or firmware.<br><br><b>unlock</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unlock a device for firmware flashing, often for self-healing or specific updates.<br><br><b>factory-reset</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to reset a device's firmware to factory defaults.<br><br><b>monitor</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitor for device changes or firmware update notifications.<br><br><b>security-attr</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List security attributes for devices, such as enabled protections.<br><br><b>dump-blob [ID]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dump a firmware blob to a file (for debugging or analysis).<br><br><b>service-config</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the configuration of the <i>fwupd</i> daemon.<br><br><b>clear-results</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clear cached results for a specific device or all devices.<br><br>


title: DESCRIPTION
content:
<b>fwupdmgr</b> is a command-line client for the <i>fwupd</i> daemon, which provides a safe and secure way to update device firmware on Linux. It integrates with the Linux Vendor Firmware Service (LVFS), a web service where hardware vendors can upload firmware binaries. <b>fwupdmgr</b> allows users to refresh metadata, check for, download, and install firmware updates for various devices (e.g., system BIOS, Thunderbolt controllers, input devices, NVMe drives). It supports both online updates (from LVFS) and offline updates using local <i>.cab</i> files. The tool aims to standardize firmware updates across Linux distributions, enhancing security and stability by ensuring devices run the latest stable firmware versions.


title: CAVEATS
content:
Internet connectivity is required for online firmware updates from LVFS. Firmware updates carry inherent risks; it's advisable to back up important data before proceeding. Not all hardware is supported by LVFS; vendor participation is crucial. The <i>fwupd</i> daemon must be running, typically managed by <i>systemd</i>. Some updates require a system reboot to complete.


title: SECURITY
content:
Firmware updates delivered via <b>fwupdmgr</b> are cryptographically signed by hardware vendors, ensuring authenticity and preventing tampering. LVFS acts as a trusted distribution point, enhancing the security of the firmware update process by providing a central, verified source.


title: GUI INTEGRATION
content:
While <b>fwupdmgr</b> is a powerful command-line tool, its functionality is often exposed through user-friendly graphical software centers like GNOME Software and KDE Discover, providing a convenient interface for users to check for and apply firmware updates without needing to use the terminal.


title: UNATTENDED UPDATES
content:
The <i>fwupd</i> daemon can be configured to perform unattended firmware updates, which can be particularly useful in server environments or for large deployments. This feature allows for automated updates, although it requires careful configuration and consideration of potential risks.


title: HISTORY
content:
<i>fwupd</i> (and thus <b>fwupdmgr</b>) was primarily developed by Richard Hughes at Red Hat, starting around 2015. It aimed to solve the fragmented and often insecure firmware update landscape on Linux by providing a unified, secure, and vendor-agnostic mechanism through the Linux Vendor Firmware Service (LVFS). Its adoption grew rapidly, becoming a standard component in major Linux distributions for managing firmware updates, often integrated into graphical software centers.


title: SYNOPSIS
content:
<b>fx</b> [<i>options</i>] [<i>script</i>] [<i>files...</i>]<br><b>cat</b> <i>input.json</i> | <b>fx</b> [<i>script</i>]


title: PARAMETERS
content:
<b><b>-j</b>, <b>--json-path</b> <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies a JSON Path expression to filter or select specific elements from the input JSON. For example, <b>fx -j '$.store.books'</b>.<br><br><b><b>-m</b>, <b>--multiple</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Processes multiple JSON inputs, treating each file or line from stdin as a separate JSON document. Useful when you have a stream of JSON objects.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current version of the <i>fx</i> command.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the help message and available options for <i>fx</i>.<br><br><b>[<i>script</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional JavaScript expression or file path. If an expression, it's applied to the input JSON (e.g., <b>fx 'd => d.items.map(i => i.name)'</b>). If a file, the script within the file is executed.<br><br><b>[<i>files...</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional input JSON files. If no files are specified, <i>fx</i> reads JSON data from standard input (stdin).<br><br>


title: DESCRIPTION
content:
<i>fx</i> is a command-line tool for interactive JSON processing and manipulation. Unlike traditional text processing utilities, <i>fx</i> is designed specifically for working with JSON data, offering powerful features for pretty-printing, filtering, and transforming JSON payloads.<br><br>Its key strength lies in its interactive REPL (Read-Eval-Print Loop) mode, which allows users to explore JSON data in real-time by typing JavaScript expressions. It also supports non-interactive usage, where you can pipe JSON data to <i>fx</i> and apply a JavaScript script or a JSON Path expression directly, making it highly flexible for scripting and automation.<br><br>Built on Node.js, <i>fx</i> leverages the familiarity and power of JavaScript, enabling complex data transformations that might be more cumbersome with other tools. It's particularly useful for developers and system administrators who frequently deal with API responses, configuration files, or logs in JSON format.


title: CAVEATS
content:
Since <i>fx</i> is built on Node.js, it requires Node.js to be installed on the system. This can make it heavier in terms of dependencies and memory footprint compared to native binaries like <b>jq</b>, especially for very large JSON files. Performance might vary depending on the complexity of the JavaScript script and the size of the input data.


title: INTERACTIVE MODE
content:
When <i>fx</i> is invoked without a <i>script</i> argument and receives JSON from stdin or a file, it enters an interactive REPL mode. In this mode, the input JSON is assigned to the variable <b>d</b>. Users can then type JavaScript expressions directly (e.g., <b>d.data[0].name</b>) to explore, filter, or transform the data, seeing immediate results. This provides a highly dynamic and exploratory way to work with JSON.


title: JAVASCRIPT SCRIPTING
content:
One of <i>fx</i>'s most powerful features is its ability to use arbitrary JavaScript for transformations. The input JSON is accessible as the variable <b>d</b> within the script. This allows for complex operations, custom filtering, data aggregation, and integration with standard JavaScript functions, offering a level of flexibility not commonly found in simpler JSON processing tools.


title: HISTORY
content:
<i>fx</i> is a relatively modern tool that emerged with the widespread adoption of JSON as a primary data interchange format and the popularity of Node.js. Developed by Andrej Bauer, it gained traction as a user-friendly alternative to more complex JSON processing tools, primarily due to its intuitive interactive mode and the power of JavaScript for data manipulation.


title: SYNOPSIS
content:
<I><b>fzputtygen</b> [ -t <I>keytype</I> ] [ -b <I>bits</I> ] [ -q ] [ -o <I>output-file</I> ] [ -O <I>output-type</I> ] [ -C <I>comment</I> ] [ -P ] [ -p <I>passphrase</I> ] [ -L ] [ -l ] [ -h ] [ -V ] [ -E <I>fingerprint-type</I> ] [ -i <I>input-file</I> ] [ -W <I>old-passphrase</I> ] [ -w <I>new-passphrase</I> ] [ -z <I>random-seed-file</I> ]</I>


title: PARAMETERS
content:
<b><I>-t <I>keytype</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the type of key to generate. Supported types include <b>rsa</b>, <b>dsa</b>, <b>ecdsa</b>, and <b>ed25519</b>.</I><br><br><b><I>-b <I>bits</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Sets the number of bits in the key. For RSA, common values are 2048 or 4096.</I><br><br><b><I>-q</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Enables quiet mode, suppressing verbose output during key generation or other operations.</I><br><br><b><I>-o <I>output-file</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the file path where the generated or converted key (private or public) will be saved.</I><br><br><b><I>-O <I>output-type</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Determines the format for the output. Common types are <b>private</b> (PuTTY's .ppk or OpenSSH private key), <b>public</b> (OpenSSH public key format), or <b>fingerprint</b>.</I><br><br><b><I>-C <I>comment</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Assigns a comment to the generated or imported key, which is often visible in the public key.</I><br><br><b><I>-P</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Instructs <b>fzputtygen</b> to prompt for changing the passphrase of an existing key. Requires <b>-i</b>.</I><br><br><b><I>-p <I>passphrase</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the new passphrase to be used when generating a key or changing an existing key's passphrase.</I><br><br><b><I>-L</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Loads a private key specified by <b>-i</b> and prints its fingerprint.</I><br><br><b><I>-l</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Loads a public key specified by <b>-i</b> and prints its fingerprint.</I><br><br><b><I>-h</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Displays a help message with available command-line options.</I><br><br><b><I>-V</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Displays the version information of <b>fzputtygen</b>.</I><br><br><b><I>-E <I>fingerprint-type</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the algorithm to use for calculating the key fingerprint (e.g., <b>md5</b>, <b>sha256</b>).</I><br><br><b><I>-i <I>input-file</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the file path of an existing private or public key to be loaded, converted, or have its passphrase changed.</I><br><br><b><I>-W <I>old-passphrase</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Provides the current passphrase for an encrypted input key when performing operations like conversion or passphrase change.</I><br><br><b><I>new-passphrase</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Provides the new passphrase when generating a key or changing an existing key's passphrase, bypassing the prompt.</I><br><br><b><I>-z <I>random-seed-file</I></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies a file containing random data to seed the key generation process, enhancing randomness.</I><br><br>


title: DESCRIPTION
content:
<I><b>fzputtygen</b> is a utility primarily associated with the FileZilla client, typically found on Windows, but functionally analogous to <b>puttygen</b> available on Linux. Its core purpose is to generate SSH (Secure Shell) key pairs, comprising a public and a private key. These keys are fundamental for secure authentication, especially in scenarios involving SSH, SFTP, and SCP connections.<br><br>The utility supports various key algorithms, including RSA, DSA, ECDSA, and Ed25519, allowing users to choose the appropriate security level and compatibility. A crucial feature is its ability to convert keys between different formats, notably PuTTY's proprietary PPK format and the widely used OpenSSH format. This interoperability is vital for users who need to use keys generated by PuTTY in OpenSSH environments (like Linux servers) or vice-versa. Users can add a passphrase to their private keys for an additional layer of security, protecting them even if the private key file is compromised. The public key can then be easily extracted for placement on remote servers, enabling password-less, secure authentication.</I>


title: CAVEATS
content:
<I><b>fzputtygen</b> is typically bundled with the FileZilla client for Windows, and while its core functionality mirrors <b>puttygen</b>, it is not a standard, standalone command found in most Linux distributions. On Linux, users generally rely on the <b>puttygen</b> utility (if PuTTY tools are installed) or more commonly, the built-in <b>ssh-keygen</b> for SSH key management.<br><br>When dealing with keys, always ensure a strong, unique passphrase for private keys. Securely store private keys and restrict access to them. Be mindful of the differences between PuTTY's proprietary PPK format and the widely used OpenSSH format; proper conversion is necessary for interoperability across different SSH clients and servers.</I>


title: <I>KEY FORMATS AND INTEROPERABILITY</I>
content:
<I><b>fzputtygen</b> excels at generating and converting keys between PuTTY's PPK format and the standard OpenSSH format. This is crucial for users who might generate keys on a Windows machine (using PuTTYgen/fzputtygen) and need to deploy them on a Linux server (which uses OpenSSH). The command facilitates seamless key exchange, bridging the gap between different SSH client ecosystems.</I>


title: <I>SECURITY BEST PRACTICES</I>
content:
<I>When generating keys, it's highly recommended to use a strong passphrase to encrypt the private key. This provides an additional layer of security, protecting the private key even if the file itself is compromised. <b>fzputtygen</b> allows setting and changing passphrases for this purpose, enhancing the overall security posture of SSH connections.</I>


title: HISTORY
content:
<I><b>fzputtygen</b> is a variant of <b>puttygen</b>, which is part of the PuTTY suite of network utilities. PuTTY was initially developed for Windows by Simon Tatham in 1998 as a free and open-source SSH, Telnet, Rlogin, and raw TCP client. <b>puttygen</b> was developed alongside it to facilitate the creation and management of SSH keys specifically for use with PuTTY.<br><br>The <b>fzputtygen</b> executable itself is a specific repackaging or rebranding of <b>puttygen</b> included within the FileZilla client distribution, particularly on Windows, to provide integrated key generation capabilities for SFTP connections. Its development history is thus intertwined with both the PuTTY project's evolution and FileZilla's need for an embedded key management tool, ensuring compatibility with PuTTY's key format and widespread SSH standards.</I>


title: PARAMETERS
content:
<b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of the <i>fzsftp</i> component and then exits. This is one of the few command-line options typically accessible to users directly for diagnostic purposes.<br><br>


title: DESCRIPTION
content:
<i>fzsftp</i> is an essential component of the FileZilla cross-platform graphical FTP, FTPS, and SFTP client. It is <b>not</b> a standalone command-line SFTP client intended for direct user interaction. Instead, <i>fzsftp</i> functions as a backend process, responsible for handling all Secure File Transfer Protocol (SFTP) communications initiated by the FileZilla GUI. When a user configures an SFTP connection within FileZilla, the GUI client spawns <i>fzsftp</i> to establish and manage the secure SSH-based file transfer session.<br><br>It communicates with the remote SFTP server, performing operations like listing directories, uploading, downloading, and managing permissions, all while relaying information back to the FileZilla graphical interface. Its design focuses on robust, secure, and efficient SFTP operations tailored for seamless integration with the FileZilla application.


title: CAVEATS
content:
<i>fzsftp</i> is primarily an <b>internal</b> helper application for the FileZilla client and is <b>not</b> designed for direct interactive use by end-users as a standalone command-line SFTP client. Users typically interact with FileZilla's graphical interface, which then utilizes <i>fzsftp</i> behind the scenes. Attempting to run <i>fzsftp</i> directly from the terminal without the FileZilla GUI may result in unexpected behavior or limited functionality, as it relies on specific communication protocols with its parent FileZilla process.


title: INTERNAL COMMUNICATION
content:
<i>fzsftp</i> typically communicates with the FileZilla GUI process via standard input/output (stdin/stdout) and possibly through specific pipes or IPC mechanisms, exchanging commands, status updates, and file transfer data. This allows the GUI to control and display the progress of SFTP operations.


title: SECURITY
content:
By leveraging the underlying Secure Shell (SSH) protocol, <i>fzsftp</i> provides strong encryption and authentication for all file transfers. This protects sensitive data in transit from eavesdropping, tampering, and unauthorized access, ensuring a secure channel for transferring files over untrusted networks.


title: HISTORY
content:
<i>fzsftp</i> was developed as an integral part of the FileZilla project, an open-source, cross-platform graphical FTP, FTPS, and SFTP client. As FileZilla evolved to support SFTP, a dedicated component was needed to handle the SSH File Transfer Protocol securely and efficiently. <i>fzsftp</i> was created for this purpose, allowing FileZilla to leverage SSH's secure channels for file transfers without directly bundling a full <i>ssh</i> or <i>sftp</i> client, instead providing a tailored backend. Its development paralleled the growth and feature expansion of the FileZilla client itself, ensuring robust SFTP capabilities.


title: PARAMETERS
content:
<b>-o <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the name of the output file (executable or library).<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile or assemble the source files, but do not link them. Generates object files (.o).<br><br><b>-S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile only; do not assemble or link. Generates assembly code files (.s).<br><br><b>-E</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preprocess only; do not compile, assemble, or link. Prints the preprocessed source code to standard output.<br><br><b>-Wall</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable all commonly used warning options, encouraging robust code.<br><br><b>-Wextra</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable extra warning flags, in addition to those enabled by -Wall.<br><br><b>-g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produce debugging information in the output file, essential for use with debuggers like GDB.<br><br><b>-O[0-3]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the optimization level. -O0 (no optimization), -O1 (moderate), -O2 (more), -O3 (most aggressive).<br><br><b>-std=<standard></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the C++ language standard to compile against (e.g., c++11, c++17, gnu++20).<br><br><b>-I<dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <I>dir</I> to the list of directories to be searched for header files.<br><br><b>-L<dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <I>dir</I> to the list of directories to be searched for libraries.<br><br><b>-l<lib></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Link with the library named <I>lib</I>. For example, -lm links with libm.a or libm.so.<br><br><b>-D<macro></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define a preprocessor macro. Equivalent to #define in source code.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print verbose information about the compilation stages and the commands executed.<br><br><b>-shared</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a shared library (e.g., .so file) instead of an executable.<br><br>


title: DESCRIPTION
content:
<b>g++</b> is the GNU C++ compiler, a crucial component of the <I>GNU Compiler Collection</I> (GCC). It serves as the primary tool for compiling C++ source code into executable programs, shared libraries, or object files on Linux and other Unix-like operating systems. <br>It handles the entire compilation process, from preprocessing source files and compiling them into assembly, to assembling the assembly into machine code, and finally linking object files with necessary libraries to produce the final output. <br><b>g++</b> supports various C++ language standards (e.g., C++11, C++17, C++20), allowing developers to write modern C++ applications. It provides extensive options for optimization, debugging, warning control, and managing include and library paths, making it a flexible and powerful development tool. It automatically links standard C++ runtime libraries, simplifying the build process for most C++ projects.


title: CAVEATS
content:
Compiling very large projects can be resource-intensive in terms of CPU and memory.<br>Linker errors (e.g., 'undefined reference') can be particularly cryptic, often requiring careful examination of library dependencies and symbol visibility. <br>Binaries compiled with specific <b>g++</b> versions or flags might not be fully compatible or portable across different Linux distributions or older systems without proper dependency management.


title: COMPILATION PHASES
content:
When you invoke <b>g++</b>, it typically orchestrates a series of distinct compilation phases:<br><I>1. Preprocessing</I>: Handles preprocessor directives (e.g., <I>#include</I>, <I>#define</I>) to expand macros and include header files.<br><I>2. Compiling</I>: Translates the preprocessed C++ source code into assembly language specific to the target architecture.<br><I>3. Assembling</I>: Converts the assembly code into machine-executable object files (.o), which are binary representations of individual source files.<br><I>4. Linking</I>: Combines all generated object files with necessary external libraries (both static and shared) to create the final executable program or shared library.


title: ERROR AND WARNING MESSAGES
content:
<b>g++</b> provides detailed feedback during compilation. <I>Warnings</I> (e.g., 'warning: unused variable') indicate potential issues that might not prevent compilation but suggest suboptimal or risky code. <I>Errors</I> (e.g., 'error: expected declaration before ‘}’ token') signify critical problems that halt the compilation process. Messages usually include the file name, line number, and column number, making debugging easier.


title: HISTORY
content:
<b>g++</b> is the C++ front-end for the <I>GNU Compiler Collection</I> (GCC), which was originally initiated by Richard Stallman as part of the GNU Project in the mid-1980s. While GCC's initial focus was on the C language, C++ support was quickly integrated, with <b>g++</b> emerging as the dedicated command for C++ compilation. Its development has consistently kept pace with the evolution of the C++ language standard, rapidly adopting features from new standards like C++11, C++17, and C++20. <b>g++</b> has become the de facto standard compiler for C++ development on Linux and other Unix-like systems, widely adopted for its open-source nature, robustness, and comprehensive support for the language.


title: SYNOPSIS
content:
<b>gacutil</b> <i>[options]</i> <i>[assembly_path | assembly_name]</i><br><br>Common forms:<br><b>gacutil</b> <b>/i</b> <i>&lt;assembly_path&gt;</i><br><b>gacutil</b> <b>/u</b> <i>&lt;assembly_name&gt;[,version[,culture[,publickeytoken]]]</i><br><b>gacutil</b> <b>/l</b> <i>[assembly_name]</i>


title: PARAMETERS
content:
<b><b>/i</b> <i>&lt;assembly_path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs an assembly into the GAC.<br><br><b><b>/u</b> <i>&lt;assembly_name&gt;[,version[,culture[,publickeytoken]]]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uninstalls an assembly from the GAC.<br><br><b><b>/l</b> <i>[&lt;assembly_name&gt;]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists assemblies in the GAC, optionally filtered by name.<br><br><b><b>/lr</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all assemblies in the GAC and their references.<br><br><b><b>/ul</b> <i>&lt;assembly_list_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uninstalls assemblies listed in a specified file.<br><br><b><b>/ulr</b> <i>&lt;assembly_list_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uninstalls assemblies listed in a file, respecting references.<br><br><b><b>/ldl</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays information about the GAC location.<br><br><b><b>/cdl</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clears the download cache.<br><br><b><b>/gacdir</b> <i>&lt;directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the GAC directory (primarily for Mono environments).<br><br><b><b>/nologo</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the startup banner and copyright message.<br><br><b><b>/silent</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all output messages.<br><br><b><b>/validate</b> <i>[&lt;assembly_path&gt;]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Validates GAC consistency or a specific assembly.<br><br><b><b>/check</b> <i>&lt;assembly_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks if a specific assembly is present in the GAC.<br><br><b><b>/verify</b> <i>[&lt;assembly_name&gt;]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verifies the strong name of assemblies in the GAC or a specific assembly.<br><br><b><b>/r</b> <i>&lt;assembly_name&gt; &lt;reference_data&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a reference count to an assembly in the GAC.<br><br><b><b>/il</b> <i>&lt;assembly_list_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs assemblies listed in a specified file.<br><br><b><b>/ir</b> <i>&lt;assembly_list_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs assemblies listed in a file, respecting references.<br><br><b><b>/h</b> | <b>/?</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message.<br><br>


title: DESCRIPTION
content:
<i>gacutil</i> is a command-line utility provided by the Mono runtime, the open-source implementation of the .NET Framework. Its primary function is to manage the Global Assembly Cache (GAC), a machine-wide code cache for .NET assemblies. The GAC stores strongly named assemblies that are shared by multiple applications. <i>gacutil</i> allows developers and administrators to install, uninstall, list, and verify the integrity of assemblies within the GAC. It's crucial for deploying shared .NET components on Linux systems running Mono applications, ensuring different applications can safely reference the same versions of libraries without conflicts. While modern .NET (.NET Core/.NET 5+) has largely moved away from the GAC model, <i>gacutil</i> remains relevant for legacy .NET Framework applications ported to Mono on Linux environments.


title: CAVEATS
content:
<ul><li>Primarily used with <i>Mono</i> on Linux, not native .NET Core/.NET 5+ environments.</li><li>Requires <i>Mono runtime</i> to be installed.</li><li>Permissions: Often requires <i>root privileges</i> to modify the GAC.</li><li>Strong Naming: Only <i>strongly named assemblies</i> can be installed into the GAC.</li><li>Not typically used in modern containerized .NET Core deployments.</li></ul>


title: GLOBAL ASSEMBLY CACHE (GAC) ON LINUX
content:
The GAC on Linux (Mono) typically resides in <i>/usr/lib/mono/gac/</i> or similar paths. It's a structured directory where assemblies are placed based on their strong name, version, culture, and public key token. This structure allows for side-by-side execution of different versions of the same assembly.


title: STRONG NAMING
content:
Assemblies installed in the GAC <i>must</i> be strongly named. This involves signing the assembly with a cryptographic key pair, which ensures unique identification, protects against tampering, and helps prevent version conflicts (DLL Hell) by allowing multiple versions of an assembly to coexist.


title: HISTORY
content:
<i>gacutil</i> originated with the Microsoft .NET Framework on Windows. It was later implemented as part of the <i>Mono Project</i> to provide compatibility for .NET applications on Linux and other platforms. Its usage on Linux is almost exclusively tied to Mono, which aims to provide an open-source, cross-platform implementation of the .NET Framework. While .NET Core and subsequent .NET versions have largely deprecated the GAC concept, <i>gacutil</i> remains a legacy tool for managing shared assemblies in Mono environments.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits, listing all available options.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the program's version number and exits.<br><br><b><b>-d</b>, <b>--directory</b> <i><PATH></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the directory where downloaded files will be saved. Defaults to the current working directory.<br><br><b><b>-f</b>, <b>--format</b> <i><FORMAT></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output filename format using a template string, allowing for highly customizable file naming based on item metadata.<br><br><b><b>-u</b>, <b>--username</b> <i><USERNAME></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the username for site authentication on platforms requiring login.<br><br><b><b>-p</b>, <b>--password</b> <i><PASSWORD></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the password for site authentication. For better security, consider using a config file or cookie file instead.<br><br><b><b>--cookies</b> <i><FILE></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads cookies from a Netscape-style cookies file for authentication, often preferred over direct username/password.<br><br><b><b>--range</b> <i><RANGE></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads only a specific range of items from a gallery, e.g., <i>'1-5'</i> for the first five, <i>'10-'</i> for from the tenth onwards, or <i>'7'</i> for just the seventh item.<br><br><b><b>--filter</b> <i><EXPRESSION></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters items to download based on a Python-like expression involving item metadata (e.g., <i>'width > 1280 and height > 720'</i>).<br><br><b><b>--no-mtime</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents setting the file's modification time to the original upload date, using the download time instead.<br><br><b><b>--write-metadata</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes a JSON file containing all available metadata for each downloaded item alongside the media file.<br><br><b><b>--config</b> <i><PATH></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file to use instead of the default locations.<br><br>


title: DESCRIPTION
content:
<b>gallery-dl</b> is a powerful and versatile command-line utility for downloading image galleries, albums, and collections from a wide array of websites.<br>Written in Python, it supports an extensive list of sites, ranging from popular image hosting services and social media platforms to niche art communities. Its primary purpose is to automate the process of saving large quantities of images, GIFs, and sometimes videos, organized as galleries or collections.<br><br>Users can specify URLs pointing to individual galleries, user profiles, or even search results, and <b>gallery-dl</b> intelligently identifies and downloads all associated media. It handles common challenges like <i>pagination</i>, dynamically loaded content, and various site structures. Key features include robust site support, flexible file naming conventions, filtering options (e.g., by date, resolution), authentication support for restricted content, and the ability to resume interrupted downloads. This makes <b>gallery-dl</b> an indispensable tool for archiving personal collections, backing up online content, or simply curating images from the web efficiently.


title: CAVEATS
content:
<b>gallery-dl</b> relies on specific <i>extractors</i> for each website. Frequent website design changes can sometimes break these extractors, requiring users to update <b>gallery-dl</b> regularly for continued compatibility.<br>Some sites implement strict <i>rate limiting</i> or sophisticated anti-bot measures, which may lead to slower downloads, temporary IP blocks, or require more complex authentication strategies (e.g., manual CAPTCHA solving, which is not directly supported).<br>Downloading very large collections can consume significant bandwidth and disk space, and users should be mindful of storage capacity.


title: CONFIGURATION FILES
content:
<b>gallery-dl</b> supports configuration files (typically <i>~/.config/gallery-dl/config.json</i> or <i>~/.gallery-dl.conf</i>) where default options, login credentials, and extractor-specific settings can be persistently stored. This avoids the need to type them repeatedly on the command line, greatly enhancing usability for frequent users and automating routine tasks.


title: EXTRACTOR SYSTEM
content:
The core of <b>gallery-dl</b>'s versatility lies in its extensible <i>extractor</i> system. Each supported website has a dedicated module (an <i>extractor</i>) responsible for parsing that site's specific structure and identifying media files. This modular design allows for rapid addition of support for new sites and quick adaptation to changes on existing ones. Advanced users can even write their own custom extractors for unsupported sites.


title: HISTORY
content:
<b>gallery-dl</b> emerged as a dedicated solution for image gallery downloads, building upon the success and methodology of general-purpose media downloaders like <b>youtube-dl</b>. Its development was driven by the need for a robust, extensible tool specifically tailored to handle the nuances of image galleries from diverse websites, which often differ significantly from video hosting platforms in their structure and presentation.<br>It is written in Python, allowing for easy extensibility and cross-platform compatibility. The project is actively maintained, with frequent updates to ensure compatibility with ever-changing website layouts and to add support for new sites. Its design emphasizes modularity through <i>extractors</i>, which are specific scripts for each supported website, making it highly adaptable to new content sources.


title: SYNOPSIS
content:
galleta <I>command</I> [<I>options</I>] [<I>arguments</I>]<br> galleta set <I>name</I> <I>value</I> [<I>options</I>]<br> galleta get <I>name</I> [<I>options</I>]<br> galleta list [<I>options</I>]<br> galleta delete <I>name</I> [<I>options</I>]


title: PARAMETERS
content:
<b>-e, --expiry <time></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets an expiration time for the cookie (e.g., '1h', '30m', '2024-12-31'), after which it would be automatically purged.<br><br><b>-p, --path <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a storage path or namespace for the cookie, typically related to a specific application or context. This helps categorize and isolate cookies.<br><br><b>-s, --secure</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Marks the cookie as 'secure', indicating it should be stored or transmitted encrypted, or restrict its readability/access to the creating user or privileged processes only.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an operation, such as overwriting an existing cookie without prompt, deleting a protected cookie, or ignoring warnings.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity of output, providing more detailed information about the operation, cookie properties, or debugging messages.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the `galleta` command itself or for a specified subcommand.<br><br>


title: DESCRIPTION
content:
Please note: <b>'galleta' is not a standard Linux command found in typical distributions.</b> This analysis describes a <i>hypothetical</i> command designed to manage small, application-specific data tokens, conceptually similar to web browser cookies or X Window System 'magic cookies'. Its primary purpose would be to provide a simple, yet versatile, command-line interface for various applications and scripts to store, retrieve, and manage ephemeral or persistent key-value pairs. Such a utility would be immensely useful for maintaining session state across script executions, handling temporary configuration settings, or securely managing authentication tokens for API interactions. By offering a standardized way for command-line tools and shell scripts to interact with these 'cookies', `galleta` could reduce the need for individual applications to implement their own complex and often inconsistent data storage mechanisms for small pieces of information.


title: CAVEATS
content:
As a hypothetical command, 'galleta' lacks a real-world implementation. A robust version would require careful consideration of critical aspects such as security (e.g., encryption for sensitive values, strict access control), storage mechanisms (e.g., reliable file system interaction, a local database), and synchronization for multi-user or concurrent application access. Its design would need to prevent naming collisions and ensure data integrity across various operations.


title: STORAGE MECHANISM (HYPOTHETICAL)
content:
A hypothetical 'galleta' command might store cookies in a structured directory under a user's home directory (e.g., <I>~/.galleta/</I>) for user-specific data, or in a system-wide location like <I>/var/lib/galleta/</I> for global or system-wide cookies. Each cookie could be implemented as a small, uniquely named file containing the value and metadata, or entries within a local database (like SQLite), ensuring atomic operations and proper permissions.


title: SECURITY CONSIDERATIONS (HYPOTHETICAL)
content:
Given its nature as a potential store for sensitive tokens or session identifiers, 'galleta' would need robust security features. This could include mandatory encryption for cookie values when the '--secure' flag is used, strict file permissions to restrict unauthorized access, and potential integration with system security modules (e.g., AppArmor, SELinux) to control which applications can access specific cookie namespaces or operations. Proper handling of cookie expiry and secure deletion would also be crucial to prevent data leakage.


title: HISTORY
content:
The conceptual foundation for a 'galleta' command stems from the pervasive use of 'cookies' in computing. Early examples include 'magic cookies' used in systems like MIT's Project Athena for authentication and access control in distributed environments (e.g., X Window System). The most widely recognized 'cookies' are HTTP cookies, essential for session management and stateful interactions on the web. A hypothetical 'galleta' command would encapsulate these diverse 'cookie' paradigms into a generalized command-line utility, aiming to provide a standardized, consistent, and easy-to-use interface for managing small, application-specific data chunks. Its conceptual development would likely arise from a recurring need for simpler, more consistent inter-process or inter-script communication of ephemeral data or lightweight application state.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Likely displays a help message or usage information for the command. This is a common option for most Linux utilities.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Potentially prints the version information of the <i>gamma4scanimage</i> utility or the associated software package.<br><br><b><b>-d</b>, <b>--device</b> <i><device_name></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If the command interacts with hardware, this option would specify the gamma-ray detection device or scanner to be used (e.g., a specific port or device ID).<br><br><b><b>-o</b>, <b>--output</b> <i><filename></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output file path where the acquired or processed image data will be saved. The format might be specific to gamma-ray data (e.g., raw binary, FITS, or a custom format).<br><br><b><b>-r</b>, <b>--resolution</b> <i><value></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If applicable, sets the resolution of the acquired image, possibly in pixels per unit or bins per spectrum.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the command's output, providing more detailed progress or debugging information.<br><br><b><b>--gain</b> <i><value></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If interacting with detector hardware, this option might control the electronic gain setting of the gamma detector, affecting signal amplification.<br><br><b><b>--duration</b> <i><seconds></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For acquisition, this could specify the integration or scanning time for data collection.<br><br>


title: DESCRIPTION
content:
<i>gamma4scanimage</i> is not a standard Linux command found in common distributions or widely adopted software suites like SANE (Scanner Access Now Easy) or ImageMagick. Its name strongly suggests it is a specialized utility used for acquiring, processing, or analyzing images, likely in the context of gamma-ray spectroscopy, medical imaging (e.g., PET scans), or industrial inspection. It would typically be part of a larger, proprietary, or highly niche software package designed for specific scientific or engineering applications that involve gamma radiation detection and imaging. <br><br>As such, its exact functionality, available options, and system requirements are entirely dependent on the specific software environment it was developed for. Without access to that particular software suite's documentation, a detailed functional description is not publicly available. It likely interacts with specialized hardware for gamma detection and produces image data relevant to gamma-ray analysis.


title: CAVEATS
content:
<i>gamma4scanimage</i> is not a standard, publicly documented Linux command. Information provided here is based on logical inference from its name and common command-line utility patterns. Its actual behavior, parameters, and availability depend entirely on the specific proprietary or specialized software suite it belongs to. Users should refer to the documentation of the software package that includes <i>gamma4scanimage</i> for accurate and complete information.


title: USAGE CONTEXT
content:
This command requires a specific software environment to function. It is not part of standard Linux distributions or common imaging software. Its presence on a system implies the installation of a specialized gamma-ray spectroscopy or imaging application, and its proper use necessitates understanding that application's framework and hardware interfaces.


title: LIKELY APPLICATIONS
content:
Given its name, <i>gamma4scanimage</i> would be used in fields such as nuclear physics, astrophysics (gamma-ray astronomy), medical imaging (e.g., SPECT, PET), radiation safety, and industrial non-destructive testing (NDT) where gamma radiation is used for imaging or analysis.


title: HISTORY
content:
Information on the specific development history and evolution of <i>gamma4scanimage</i> is not publicly available. As a highly specialized or proprietary utility, its development is likely tied to a particular scientific research project, academic institution, or commercial entity involved in gamma-ray detection and imaging technology. Its usage is confined to environments where the specific parent software package is installed and operational.


title: PARAMETERS
content:
<b>-l, --location <LAT>:<LON></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify your geographic location (latitude and longitude in decimal degrees). Overrides automatic location detection.<br><br><b>-O, --temperature <TEMP></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a specific color temperature (e.g., 6500K for daylight, 3500K for warmer light). This prevents automatic adjustments.<br><br><b>-o, --one-shot</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply the color temperature adjustment once and then exit, rather than running continuously.<br><br><b>-x, --exit</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exit a running <I>gammastep</I> instance. This will restore the original screen gamma settings.<br><br><b>-p, --print</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the current color temperature and brightness settings and then exit.<br><br><b>-r, --restore</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restore the original gamma ramps (color settings) to their default system values and exit.<br><br><b>-b, --brightness <VALUE></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the screen brightness. Value must be between 0.1 and 1.0. Note: This is a gamma adjustment, not true backlight control.<br><br><b>-g, --gamma <R>:<G>:<B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set specific gamma values for red, green, and blue channels (e.g., 1.0:1.0:1.0 for no change).<br><br><b>-P, --pidfile <PATH></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a file to write the process ID (PID) of the running <I>gammastep</I> instance.<br><br><b>-t, --transition <SECONDS></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the duration of the color temperature transition between daytime and nighttime in seconds (default is 600 seconds).<br><br><b>-m, --method <METHOD></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the screen adjustment method (e.g., <I>randr</I>, <I>wayland</I>, <I>drm</I>). Defaults to auto-detection.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, showing more details about operations.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message and exit.<br><br>


title: DESCRIPTION
content:
<I>gammastep</I> is a command-line utility designed to adjust the color temperature of your display according to the time of day and your geographical location. The primary goal is to reduce eye strain, especially during evening and night hours, by shifting the screen's color spectrum towards warmer tones (redder light) as the sun sets, and back to cooler tones (bluer light) during daylight hours.<br><br>It functions by determining the sunrise and sunset times for your specified location and then smoothly transitions the display's color temperature between a daytime and a nighttime value. This automatic adjustment helps your eyes adapt to the ambient light conditions, making screen viewing more comfortable and potentially aiding in better sleep by reducing exposure to blue light in the evening. <I>gammastep</I> can run continuously in the background or apply a one-shot adjustment.


title: CAVEATS
content:
The effectiveness of brightness control (`-b`) depends on the display driver; it adjusts gamma ramps, which might not be true backlight control. Location detection might rely on external services or GeoClue, which may require network access. If multiple instances are run without the `--one-shot` or `--exit` flags, they can conflict.


title: CONFIGURATION FILE
content:
<I>gammastep</I> can be configured using a configuration file, typically located at <I>$HOME/.config/gammastep/config</I> or <I>$HOME/.gammastep.conf</I>. This file allows users to set default options, including day and night temperatures, location, and transition times, without needing to specify them on the command line every time.


title: DAEMON MODE
content:
When run without the <I>--one-shot</I> option, <I>gammastep</I> runs as a daemon, continuously monitoring the time and smoothly adjusting the screen's color temperature throughout the day and night. This is the typical way to use <I>gammastep</I> for automatic, persistent adjustments.


title: HISTORY
content:
<I>gammastep</I> emerged as an alternative to other popular screen color temperature adjustment tools like <I>Redshift</I> and <I>f.lux</I>. Its development aims to provide a robust solution, particularly for Wayland display servers, where <I>Redshift</I> historically faced challenges due to Wayland's design principles. While <I>Redshift</I> primarily targeted X11, <I>gammastep</I> often offers better native Wayland support, leveraging protocols like <I>wlr-output-management</I> to achieve its effects. It maintains similar functionality to its predecessors, focusing on circadian rhythm-based color temperature adjustments for user comfort.


title: PARAMETERS
content:
<b><b>-p</b>, <b>--port</b> <i>&lt;port&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>port</i> to listen on (default: 8545).<br><br><b><b>-h</b>, <b>--host</b> <i>&lt;host&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>host</i> to listen on (default: 0.0.0.0).<br><br><b><b>-d</b>, <b>--deterministic</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates <i>deterministic</i> addresses and mnemonic.<br><br><b><b>-a</b>, <b>--accounts</b> <i>&lt;num&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of accounts to generate (default: 10).<br><br><b><b>-e</b>, <b>--defaultBalanceEther</b> <i>&lt;ether&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Default <i>Ether balance</i> for accounts (default: 100).<br><br><b><b>-m</b>, <b>--mnemonic</b> <i>&lt;phrase&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mnemonic <i>phrase</i> to generate accounts from.<br><br><b><b>-i</b>, <b>--networkId</b> <i>&lt;id&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>network ID</i> to use (default: current time or deterministic).<br><br><b><b>-l</b>, <b>--gasLimit</b> <i>&lt;limit&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>gas limit</i> for transactions (default: 6721975).<br><br><b><b>-g</b>, <b>--gasPrice</b> <i>&lt;price&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>gas price</i> for transactions (default: 20000000000).<br><br><b><b>-s</b>, <b>--seed</b> <i>&lt;seed&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <i>seed</i> to use to generate accounts.<br><br><b><b>-b</b>, <b>--blockTime</b> <i>&lt;seconds&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures Ganache to create a <i>block every</i> specified <i>seconds</i> (default: 0, immediate mining).<br><br><b><b>-f</b>, <b>--fork</b> <i>&lt;url/path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Fork</i> a remote chain. Allows interaction with existing contracts on a live network.<br><br><b><b>-k</b>, <b>--hardfork</b> <i>&lt;name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The Ethereum <i>hardfork</i> to use (e.g., <i>istanbul</i>, <i>london</i>).<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the <i>version</i> number.<br><br>


title: DESCRIPTION
content:
<i>ganache-cli</i> is a command-line tool that provides a personal, in-memory Ethereum blockchain for rapid decentralized application (DApp) development and testing. It simulates an Ethereum client, allowing developers to deploy contracts, run tests, and execute transactions without connecting to a public Ethereum network like Mainnet or a testnet. It's designed to offer immediate feedback and a highly configurable environment, making the development workflow significantly faster. <i>Ganache-CLI</i> automatically generates a set of pre-funded accounts, instantly mines blocks as transactions occur, and supports the standard JSON-RPC methods, enabling seamless integration with development tools like Truffle, Hardhat, and Web3.js.


title: CAVEATS
content:
<b>Not for Production:</b> <i>ganache-cli</i> is an in-memory, local development tool and is not suitable for production deployments or use on public networks.<br><b>Ephemeral State:</b> All blockchain state is lost when the process is terminated, unless a snapshot (using the <i>--db</i> option) is explicitly saved.<br><b>Limited JSON-RPC Support:</b> While it supports most common <i>eth_</i> and <i>net_</i> methods, some advanced or rarely used RPC calls might not be implemented.<br><b>Resource Usage:</b> Forking a large mainnet chain can consume significant memory and disk space.


title: INTEGRATION WITH TRUFFLE
content:
<i>ganache-cli</i> is often used in conjunction with the Truffle framework. Truffle projects automatically connect to <i>Ganache-CLI</i> (or a similar local blockchain) on port 8545 by default for deployment and testing.


title: DEBUGGING SUPPORT
content:
It provides verbose logging and transaction tracing capabilities, aiding in debugging smart contracts during development.


title: HISTORY
content:
<i>ganache-cli</i> originated as <i>testrpc</i>, a simple local Ethereum development server. It was later rebranded and integrated into the Truffle Suite by ConsenSys, becoming <i>ganache-cli</i>. This rebranding aimed to align it with the broader Ganache product line, which also includes a desktop application (Ganache UI). Its development has focused on providing a fast, reliable, and feature-rich local blockchain simulation environment, continually adapting to new Ethereum protocol upgrades (hardforks) and developer needs.


title: PARAMETERS
content:
<b>-b, --blacklist &lt;extensions&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Comma-separated list of extensions to blacklist (e.g., <i>jpg,png,css</i>).<br><br><b>-d, --dir &lt;directory&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output results to the specified directory.<br><br><b>-o, --output &lt;file&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write results to the specified file instead of standard output.<br><br><b>-p, --providers &lt;names&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Comma-separated list of providers to use (e.g., <i>wayback,commoncrawl,otx</i>). Default: all.<br><br><b>-s, --subs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include subdomains in the results.<br><br><b>-t, --threads &lt;number&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of concurrent threads to use (default: 10).<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the current version of <i>gau</i>.<br><br><b>--blacklist-domain &lt;domains&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Comma-separated list of domains to blacklist (e.g., <i>cdn.example.com</i>).<br><br><b>--delay &lt;milliseconds&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Delay between requests in milliseconds to prevent rate limiting.<br><br><b>--json</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output results in JSON format.<br><br><b>--many</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Accept multiple domains via standard input, one domain per line.<br><br><b>--no-subs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude subdomains from the results. Useful when only one domain is provided.<br><br><b>--retries &lt;number&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of retries for failed HTTP requests (default: 10).<br><br><b>--timeout &lt;seconds&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;HTTP client timeout in seconds (default: 10).<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, showing more details during execution.<br><br>


title: DESCRIPTION
content:
<i>gau</i> (Get All URLs) is a <b>Go-based command-line tool</b> designed to fetch known URLs for a specified domain. It aggregates URLs from various open-source intelligence (OSINT) services, including the <b>Wayback Machine</b>, <b>Common Crawl</b>, and <b>Open Threat Exchange (OTX)</b>. This tool is particularly valuable for <b>security researchers, penetration testers, and bug bounty hunters</b> to quickly enumerate potential attack surfaces by discovering historical and archived URLs associated with a target domain.<br><br>It offers various options to refine the URL gathering process, such as filtering by extensions, including or excluding subdomains, specifying which providers to query, and controlling concurrency for performance. The output can be directed to a file, displayed on the console, or even formatted as JSON, making it flexible for integration into automated workflows. <i>gau</i> streamlines the initial reconnaissance phase by providing a comprehensive list of known URLs, significantly expanding the scope for further analysis or vulnerability discovery.


title: CAVEATS
content:
<i>gau</i> is <b>not a standard Linux distribution command</b>; it's a third-party tool typically installed via Go. Its functionality relies heavily on external services (Wayback Machine, Common Crawl, OTX), meaning its performance and accuracy are dependent on the availability and rate limits of these services.<br><br>It can generate a large volume of URLs, requiring careful handling of output, and some returned URLs might be outdated or non-existent.


title: INSTALLATION
content:
<i>gau</i> is typically installed using Go's package manager. Ensure Go is installed on your system, then run:<br><b>go install github.com/lc/gau@latest</b><br>This command will compile and place the <i>gau</i> executable in your <i>$GOPATH/bin</i> directory, which should be in your system's PATH.


title: USAGE EXAMPLES
content:
<b>Get URLs for a single domain:</b><br><i>gau example.com</i><br><br><b>Include subdomains in the results:</b><br><i>gau example.com --subs</i><br><br><b>Use specific providers and save output to a file:</b><br><i>gau example.com -p wayback,commoncrawl -o urls.txt</i><br><br><b>Process multiple domains from a file via stdin:</b><br><i>cat domains.txt | gau --many</i><br><br><b>Output in JSON format:</b><br><i>gau example.com --json</i>


title: HISTORY
content:
<i>gau</i> was developed by <i>lc</i> (Luke Cyca) as a Go-based tool to simplify and automate the process of gathering URLs from various archival and intelligence sources. It quickly gained popularity within the security community, particularly among penetration testers and bug bounty hunters, for its efficiency and ease of use in the initial reconnaissance phases. Its development reflects the community's need for aggregated intelligence on target domains.


title: SYNOPSIS
content:
<b>gawk</b> [<i>options</i>] [<i>-f program-file</i> | <i>--source program-text</i>] [<i>file ...</i>]<br><b>gawk</b> [<i>options</i>] <i>program-text</i> [<i>file ...</i>]


title: PARAMETERS
content:
<b><b>-F</b> <i>fs</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the field separator for input records to <i>fs</i>. This can be a single character or a regular expression.<br><br><b><b>-v</b> <i>var=value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a <i>value</i> to a variable <i>var</i> before program execution begins. Useful for passing external data into the <b>gawk</b> script.<br><br><b><b>-f</b> <i>program-file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the <b>gawk</b> program source from the specified <i>program-file</i>, allowing for larger, more complex scripts.<br><br><b><b>-W lint</b>, <b>--lint</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Issues warnings about constructs that are not portable to other <i>awk</i> implementations or might indicate a mistake in the script logic.<br><br><b><b>-W posix</b>, <b>--posix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables GNU extensions and uses POSIX <i>awk</i> features exclusively, ensuring strict compatibility with the POSIX standard.<br><br><b><b>-W traditional</b>, <b>--traditional</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Behaves like original <i>awk</i>, disabling most GNU extensions for backward compatibility.<br><br><b><b>-E</b> <i>encoding</i>, <b>--encoding=</b><i>encoding</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the character encoding for input and output, supporting various character sets.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a summary of the <b>gawk</b> command-line options and usage information.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints <b>gawk</b>'s version number and configuration information to standard output.<br><br>


title: DESCRIPTION
content:
<b>gawk</b> (GNU Awk) is a powerful pattern scanning and processing language. It reads input files line by line, attempting to match each line against a set of user-defined patterns. For each line that matches a pattern, <b>gawk</b> executes a corresponding action. This makes it exceptionally useful for data extraction, text transformation, and report generation from structured or semi-structured text files like logs, CSVs, or configuration files.<br><br>At its core, <b>gawk</b> operates on "fields" within a line, which are by default separated by whitespace. It provides built-in variables for the current record (<i>$0</i>), the number of fields (<i>NF</i>), the current record number (<i>NR</i>), and individual fields (<i>$1</i>, <i>$2</i>, etc.). It supports regular expressions for sophisticated pattern matching, offers conditional statements, loops, associative arrays, and user-defined functions, making it a complete programming language for text manipulation. <b>gawk</b> is the GNU Project's implementation of the <i>awk</i> programming language, designed to be compatible with the original <i>awk</i> while adding many GNU-specific extensions and features.


title: CAVEATS
content:
While powerful, <b>gawk</b> can become memory-intensive for extremely large files or when using large associative arrays, potentially impacting performance. Its expressive syntax, while concise, can sometimes lead to less readable scripts for complex logic, especially for those new to <i>awk</i>. Locale settings can significantly affect string and regular expression behavior; using <b>--posix</b> often helps ensure consistent behavior across different environments.


title: PATTERNS AND ACTIONS
content:
An <i>awk</i> program consists of a series of rules, each defined as <i>pattern { action }</i>. <b>gawk</b> reads each input line, and if the line matches the specified <i>pattern</i>, the <i>action</i> block is executed. If no pattern is given, the action is performed for every line. If no action is given, the line matching the pattern is simply printed. Patterns can be regular expressions, arithmetic relational expressions, or combinations thereof. Actions can include variables, loops, conditionals, and built-in or user-defined functions.


title: BEGIN AND END BLOCKS
content:
<b>gawk</b> provides special patterns: <i>BEGIN</i> and <i>END</i>. The <i>BEGIN</i> block's action is executed once before any input lines are read and processed. It's typically used for initializing variables or printing headers. The <i>END</i> block's action is executed once after all input lines have been read. It's often used for final calculations, summaries, or printing footers. These blocks do not operate on input lines directly.


title: BUILT-IN VARIABLES
content:
<b>gawk</b> provides several useful built-in variables that provide information about the input or control program behavior. Key ones include:<br><i><b>NR</b></i> (Number of Record): The current input record number.<br><i><b>NF</b></i> (Number of Fields): The total number of fields in the current input record.<br><i><b>FS</b></i> (Field Separator): The input field separator (default is whitespace).<br><i><b>OFS</b></i> (Output Field Separator): The output field separator (default is a space).<br><i><b>RS</b></i> (Record Separator): The input record separator (default is newline).<br><i><b>ORS</b></i> (Output Record Separator): The output record separator (default is newline).<br><i><b>$0</b></i>: The entire current input record.<br><i><b>$1, $2, ...</b></i>: Individual fields of the current input record.


title: HISTORY
content:
The <i>awk</i> programming language was originally developed at Bell Labs in the 1970s by Alfred Aho, Peter Weinberger, and Brian Kernighan (hence <i>A.W.K.</i>). It was designed for text processing and report generation. <b>gawk</b>, the GNU Project's implementation, was written to be a free software alternative, offering compatibility with the original <i>awk</i> while introducing numerous extensions and enhancements. First released in the mid-1980s, <b>gawk</b> has since become the standard <i>awk</i> implementation on most Linux and Unix-like systems due to its robust feature set, adherence to standards (like POSIX), and continuous development.


title: SYNOPSIS
content:
<b>gbp</b> <I>command</I> [<I>options</I>] [<I>arguments</I>]<br><br>The most common command is <b>gbp buildpackage</b>:<br><b>gbp buildpackage</b> [<I>options</I>]


title: PARAMETERS
content:
<b>--git-debian-branch=<I>branch</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Git branch that contains the Debian packaging files (e.g., 'debian/sid').<br><br><b>--git-upstream-branch=<I>branch</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Git branch that contains the original upstream source code.<br><br><b>--git-tag</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a Git tag for the new package version after a successful build.<br><br><b>--no-sign</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <b>dpkg-buildpackage</b> not to sign the generated <i>.dsc</i> and <i>.changes</i> files.<br><br><b>--git-ignore-branch</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows building even if the current Git branch does not match the expected Debian branch name.<br><br><b>--git-builder=<I>builder</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the command to invoke <b>dpkg-buildpackage</b> with, typically 'debuild' or 'fakeroot debian/rules build'.<br><br><b>--git-export-dir=<I>directory</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exports the source tree to the specified temporary directory before building the package.<br><br>


title: DESCRIPTION
content:
The <b>gbp</b> command, primarily known as <i>git-buildpackage</i>, is a powerful suite of tools designed to streamline and automate the process of maintaining Debian packages within a Git repository. It integrates Git's version control capabilities with Debian's established packaging workflow.<br><br><i>git-buildpackage</i> helps developers manage various aspects of a Debian package, including importing new upstream versions, generating upstream tarballs (often using <i>pristine-tar</i>), applying packaging-specific changes, updating changelogs, and ultimately building source and binary Debian packages. It enforces a specific Git branching model (e.g., a 'debian' branch for packaging, an 'upstream' branch for original sources) to ensure consistency and reproducibility.<br><br>By automating common tasks like generating <i>.dsc</i>, <i>.deb</i>, and <i>.changes</i> files, <b>gbp</b> significantly reduces manual effort and potential errors, making it a cornerstone tool for many Debian developers and maintainers who leverage Git for their packaging efforts.


title: CAVEATS
content:
<b>gbp</b> requires a specific and consistent Git repository layout to function correctly, typically involving 'debian', 'upstream', and 'pristine-tar' branches. Initial setup can be complex for newcomers. It heavily relies on other Debian packaging tools being correctly installed and configured.


title: CONFIGURATION FILES
content:
<b>gbp</b> is highly configurable. Settings can be defined in a hierarchy of configuration files: project-specific settings in <i>.git/gbp.conf</i>, user-specific settings in <i>~/.gbp.conf</i>, and system-wide defaults in <i>/etc/git-buildpackage/gbp.conf</i>. This allows for flexible customization of its behavior.


title: BRANCHING MODEL
content:
A core concept of <b>gbp</b> is its reliance on a specific Git branching model. Common branches include:<br><i>upstream</i>: The original (often untouched) upstream source.<br><i>debian/<suite></i>: (e.g., <i>debian/sid</i>) Contains the Debian packaging files and changes.<br><i>pristine-tar</i>: Used by <i>pristine-tar</i> to store a delta of the upstream tarball, allowing for verifiable and reproducible tarball generation.


title: HISTORY
content:
<i>git-buildpackage</i> emerged from the Debian community's ongoing efforts to enhance and streamline package maintenance through better integration with Git. It consolidated various scripts and best practices, evolving into a robust, widely adopted tool that provides a structured and reproducible workflow for Debian package development using Git repositories. Its development has been driven by the need for more efficient and collaborative packaging processes.


title: SYNOPSIS
content:
<b>gcal</b> [<i>options</i>] [<i>month</i> [<i>year</i>]]<br><b>gcal</b> [<i>options</i>] [[-]<i>day</i>.<i>month</i>.<i>year</i>]


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with command options.<br><br><b><b>-s</b> <i>NUMBER</i>, <b>--starting-weekday</b>=<i>NUMBER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the starting day of the week (1=Monday, 7=Sunday).<br><br><b><b>-m</b> <i>NUMBER</i>, <b>--month</b>=<i>NUMBER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the month to display.<br><br><b><b>-y</b> <i>NUMBER</i>, <b>--year</b>=<i>NUMBER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the year to display.<br><br><b><b>-C</b> <i>STRING</i>, <b>--culture</b>=<i>STRING</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies specific culture/region rules for calendar display.<br><br><b><b>-A</b>, <b>--astro-calendar</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a calendar including astronomical events (e.g., solstices, equinoxes).<br><br><b><b>-L</b>, <b>--lunar-calendar</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a calendar displaying lunar phases.<br><br><b><b>-f</b> <i>FILE</i>, <b>--file</b>=<i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads personal appointments or events from the specified file.<br><br><b><b>-P</b>, <b>--print-holidays</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a list of holidays for the current or specified culture.<br><br>


title: DESCRIPTION
content:
<b>gcal</b> is the highly versatile GNU calendar program, offering a rich set of features beyond simple month displays. It can generate calendars for any specified month or year, calculate astronomical events like solstices and equinoxes, and display lunar phases. Users can also integrate personal appointment files, making <b>gcal</b> a powerful tool for scheduling and reminders.<br><br>It supports numerous output formats, including standard text, PostScript, and HTML, allowing for diverse presentation needs. Its extensive customization options enable users to define specific holidays, display rules, and output layouts, making it adaptable to various regional and personal requirements. <b>gcal</b> stands out for its flexibility and ability to handle complex date calculations, making it a comprehensive solution for command-line calendar management.


title: CAVEATS
content:
<b>gcal</b> is a very feature-rich but also quite old command. Its extensive documentation (man page) can be overwhelming for new users. Configuration files for custom holidays or events require a specific syntax that might have a learning curve.<br><br>While powerful, its default ASCII output may appear less modern compared to graphical calendar applications. Some advanced output features, like PostScript, may depend on additional system tools.


title: CUSTOMIZATION FILES
content:
<b>gcal</b> heavily relies on configuration files (e.g., <i>~/.gcalrc</i>, <i>/etc/gcalrc</i>) for defining global and user-specific holidays, special events, and display rules. These files use a specific syntax to allow for highly personalized calendar generation.


title: INTERNATIONALIZATION
content:
<b>gcal</b> offers extensive support for different cultures and languages. Users can specify a culture via the <b>-C</b> option, which affects the names of days and months, the first day of the week, and holiday definitions, making it suitable for a global user base.


title: OUTPUT FORMATS
content:
Beyond basic terminal output, <b>gcal</b> can generate calendars in formats like PostScript (with <b>-X</b>), HTML (with <b>-H</b>), and XML, enabling integration into documents or web pages. This flexibility is a significant advantage over simpler calendar tools.


title: HISTORY
content:
<b>gcal</b> is a foundational utility of the GNU Project, developed as a highly advanced and flexible alternative to the traditional Unix <b>cal</b> command. Its inception reflects the GNU philosophy of providing powerful, free software tools.<br><br>Over the years, <b>gcal</b> has evolved to support complex calendar calculations, including astronomical events, lunar phases, and culturally specific date representations. Its continuous development has focused on extensive customization, diverse output formats, and strong internationalization, making it a robust and comprehensive command-line calendar solution widely used in GNU/Linux environments.


title: PARAMETERS
content:
<b><b>-e</b>, <b>--expression</b>=<i>EXPRESSION</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates the given mathematical <i>EXPRESSION</i> and prints the result to standard output. This is the primary way to specify the calculation.<br><br><b><b>-s</b>, <b>--set-mode</b>=<i>MODE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the calculator's operational <i>MODE</i>. Common modes include <i>basic</i>, <i>scientific</i>, <i>financial</i>, and <i>programming</i>. This influences how expressions are interpreted and what functions are available.<br><br><b><b>-u</b>, <b>--show-units</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a list of all supported unit conversions and their corresponding symbols.<br><br><b><b>-p</b>, <b>--show-plugins</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available calculator plugins, which extend functionality, such as currency conversion or specific financial tools.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information for <i>gcalccmd</i> and exits.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and command usage, then exits.<br><br>


title: DESCRIPTION
content:
<i>gcalccmd</i> is a command-line utility that provides direct access to the powerful calculation engine of the GNOME Calculator.<br><br>It enables users to perform a wide range of mathematical, scientific, financial, and programming calculations directly from the terminal, bypassing the need to launch the full graphical application. This makes it ideal for quick evaluations, shell scripting, and integration into automated workflows. Users simply input a mathematical expression as an argument, and <i>gcalccmd</i> processes it, returning the calculated result to standard output. It supports a vast array of functions, constants, and unit conversions, adapting its capabilities based on the selected mode. Its efficiency and versatility make it a valuable tool for diverse computational needs on a Linux system.


title: CAVEATS
content:
<i>gcalccmd</i> relies on the underlying <i>gnome-calculator</i> libraries. If <i>gnome-calculator</i> is not installed or its libraries are not accessible, <i>gcalccmd</i> may not function correctly or might not be available on the system. The exact set of supported functions, units, and calculation modes is dependent on the version of <i>gnome-calculator</i> and its loaded plugins. Error messages for invalid expressions can sometimes be generic, requiring familiarity with GNOME Calculator's expression syntax.


title: USAGE EXAMPLES
content:
Here are some common ways to use <i>gcalccmd</i>:<br><br><b>Basic arithmetic:</b><br><i>gcalccmd "2 + 2"</i><br><i>gcalccmd "(5 * 8) / 4"</i><br><br><b>Scientific calculations:</b><br><i>gcalccmd --set-mode=scientific "sqrt(16)"</i><br><i>gcalccmd --set-mode=scientific "sin(pi/2)"</i><br><br><b>Programming mode (base conversions, bitwise ops):</b><br><i>gcalccmd --set-mode=programming "0xFF + 0o77"</i><br><i>gcalccmd --set-mode=programming "10 << 2"</i><br><br><b>Unit conversions:</b><br><i>gcalccmd "10 USD to EUR"</i><br><i>gcalccmd "100 km to miles"</i>


title: SUPPORTED MODES
content:
<i>gcalccmd</i> supports various operational modes, similar to its graphical counterpart, configurable via the <b>--set-mode</b> option:<br><b>basic</b>: For simple arithmetic operations.<br><b>scientific</b>: Enables advanced mathematical functions like trigonometry, logarithms, exponentials, and constants like pi.<br><b>financial</b>: Provides functions for financial calculations such as loan payments, compound interest, and depreciation.<br><b>programming</b>: Allows calculations in different number bases (binary, octal, decimal, hexadecimal) and supports bitwise operations.<br>The availability of modes and functions depends on the installed plugins and version of <i>gnome-calculator</i>.


title: HISTORY
content:
<i>gcalccmd</i> is an integral component of the GNOME desktop environment, specifically designed to offer a non-graphical, command-line interface to the robust <i>gnome-calculator</i> backend. Its development has evolved alongside <i>GNOME Calculator</i> itself, providing a consistent and programmatic way to access its extensive features for shell scripting, quick calculations, and integration into larger automation tasks without the overhead of launching a graphical window. It serves as a bridge for command-line users to leverage the powerful capabilities of the GNOME Calculator.


title: SYNOPSIS
content:
<b>gcalcli</b> [<i>GLOBAL_OPTIONS</i>] <<i>COMMAND</i>> [<i>COMMAND_OPTIONS</i>] [<i>ARGUMENTS</i>]<br><br><b>Common Commands:</b><br>&nbsp;&nbsp;<b>gcalcli</b> <i>agenda</i> [<i>--days N</i>] [<i>--details</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>calw</i> [<i>--weekstart day</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>calm</i> [<i>--calendar cal</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>add</i> <I>"Event Title"</I> [<i>--when "date time"</i>] [<i>--duration N</i>] [<i>--where "location"</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>quickadd</i> <I>"Event description..."</I><br>&nbsp;&nbsp;<b>gcalcli</b> <i>delete</i> <I>"Event Title"</I> [<i>--interactive</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>edit</i> <I>"Event Title"</I> [<i>--new_title "New Title"</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>search</i> <I>"keyword"</I><br>&nbsp;&nbsp;<b>gcalcli</b> <i>sync</i> <I>sync_directory</I> [<i>--calendar cal</i>]<br>&nbsp;&nbsp;<b>gcalcli</b> <i>remind</i> [<i>--earlier N</i>] [<i>--calendar cal</i>]


title: PARAMETERS
content:
<b><i>--calendar</i> <I>CALENDAR</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the calendar to use by ID or alias. Default is 'default'.<br><br><b><i>--default-calendar</i> <I>CALENDAR</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Override the default calendar specified in the config file.<br><br><b><i>--config</i> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternative configuration file path.<br><br><b><i>--noauth_local_webserver</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable the local webserver for OAuth2 authentication. Useful for SSH.<br><br><b><i>--tsv</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in Tab Separated Values format for scripting.<br><br><b><i>--client-id</i> <I>ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;OAuth2 client ID. Overrides the config file setting.<br><br><b><i>--client-secret</i> <I>SECRET</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;OAuth2 client secret. Overrides the config file setting.<br><br><b><i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show program's version number and exit.<br><br><b><i>--help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show help message and exit.<br><br><b><i>agenda --days</i> <I>N</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show events for the next N days. Default is 7.<br><br><b><i>agenda --details</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display more event details in the agenda view.<br><br><b><i>calw --weekstart</i> <I>DAY</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the day the week starts (e.g., 'Sunday', 'Monday').<br><br><b><i>add --title</i> <I>TITLE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the title of the new event.<br><br><b><i>add --when</i> <I>DATE_TIME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the start date and time for the event.<br><br><b><i>add --duration</i> <I>MINUTES</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the duration of the event in minutes (e.g., '60', '1h 30m').<br><br><b><i>add --where</i> <I>LOCATION</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the location of the event.<br><br><b><i>add --description</i> <I>TEXT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a detailed description to the event.<br><br><b><i>delete --interactive</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt for confirmation before deleting each matching event.<br><br><b><i>edit --new_title</i> <I>TITLE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a new title when editing an event.<br><br><b><i>remind --earlier</i> <I>MINUTES</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check for events starting within the next N minutes.<br><br>


title: DESCRIPTION
content:
<b>gcalcli</b> is a powerful command-line interface for Google Calendar, enabling users to interact with their calendar events directly from the terminal. It provides functionalities to <I>view agendas</I>, <I>browse monthly or weekly calendars</I>, <I>add new events</I>, <I>delete existing ones</I>, <I>edit event details</I>, and <I>search</I> for specific entries. Designed for efficiency and automation, gcalcli is an invaluable tool for users who prefer a text-based workflow or need to script calendar operations. It supports multiple calendars, color-coding, and integrates seamlessly with other command-line utilities. Its initial setup involves an OAuth2 authentication process to connect with your Google account, after which you can effortlessly manage your schedule without leaving the terminal.


title: CAVEATS
content:
Setting up <b>gcalcli</b> requires initial OAuth2 authentication with Google, which can be challenging in environments without a web browser (e.g., SSH sessions). The command relies on the Google Calendar API, and users might encounter <I>API rate limits</I> with excessive use. It primarily manages events; advanced calendar settings or shared calendar permissions are typically handled through the Google Calendar web interface.


title: AUTHENTICATION
content:
The first time you run <b>gcalcli</b>, it will prompt you to authenticate with your Google account via an OAuth2 flow. This typically involves opening a browser window to grant permissions. If you are in a headless environment, use the <I>--noauth_local_webserver</I> option, which will provide a URL to open manually and paste a verification code back into the terminal.


title: CONFIGURATION FILE
content:
<b>gcalcli</b> uses a configuration file, typically located at <I>~/.gcalcli_oauth.py</I> or <I>~/.gcalcli_oauth.json</I> (depending on version/setup). This file stores your API credentials, default calendar settings, calendar aliases, color preferences, and other customizations. It can be manually edited to fine-tune its behavior.


title: QUICK ADD FEATURE
content:
The <I>quickadd</I> command allows you to add events using natural language, similar to Google Calendar's web interface. For example: <I>gcalcli quickadd 'Lunch with John tomorrow at 1 PM at The Cafe'</I>. This intelligently parses the event details from your descriptive text.


title: HISTORY
content:
<b>gcalcli</b> emerged as an open-source project to bridge the gap between Google Calendar's web interface and the power of the command line. It has been actively developed by a community of contributors, focusing on providing a robust and flexible tool for system administrators, developers, and power users who need to automate or quickly access their calendar information without graphical overhead. Its development has consistently adapted to changes in the Google Calendar API and user needs for CLI-based productivity, making it a staple for text-based scheduling.


title: PARAMETERS
content:
<b>-o <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output executable or object file.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles or assembles the source files but does not link them. Creates object files (<I>.o</I>).<br><br><b>-S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles only; does not assemble or link. Produces assembly code (<I>.s</I>).<br><br><b>-E</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preprocesses only; does not compile, assemble, or link. Outputs preprocessed code to standard output.<br><br><b>-Wall</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables a large set of common and useful warnings.<br><br><b>-Wextra</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables additional warnings not included in <I>-Wall</I>.<br><br><b>-g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produces debugging information for use with debuggers like GDB.<br><br><b>-O<level></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optimizes the code for speed and size. Levels range from <I>-O0</I> (no optimization) to <I>-O3</I>, <I>-Os</I> (optimize for size), and <I>-Ofast</I>.<br><br><b>-I <dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds <I>dir</I> to the list of directories to be searched for header files.<br><br><b>-L <dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds <I>dir</I> to the list of directories to be searched for libraries.<br><br><b>-l <lib></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Links with the specified library <I>lib</I>. For example, <I>-lm</I> links with <I>libm.a</I>.<br><br><b>-std=<c/c++version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the C or C++ standard to use (e.g., <I>-std=c99</I>, <I>-std=c++11</I>).<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the commands executed by the compiler driver and the compiler's version.<br><br>


title: DESCRIPTION
content:
<I><b>gcc</b></I> (GNU Compiler Collection) is a highly optimized and widely used compiler system developed by the GNU Project. It serves as the standard compiler for most Unix-like operating systems, including Linux. <I><b>gcc</b></I> is not just a C compiler; it's a collection supporting multiple programming languages such as C, C++, Objective-C, Fortran, Ada, Go, and D. Its primary function is to translate human-readable source code into machine-executable binaries. This involves several stages: preprocessing, compilation, assembly, and linking. <I><b>gcc</b></I> is renowned for its portability, supporting a vast array of processor architectures and operating systems, making it a cornerstone of open-source software development and a critical tool for developers building applications, libraries, and operating systems.


title: CAVEATS
content:
While powerful, <I><b>gcc</b></I> can have a steep learning curve for complex projects, especially concerning intricate build systems and cross-compilation. Different versions of <I><b>gcc</b></I> may have varying default behaviors or support for language features and optimizations, which can lead to portability issues if not managed carefully. Compiler flags can significantly impact performance, binary size, and debugging capabilities; selecting appropriate flags requires understanding. <br> Large projects can result in long compilation times, necessitating tools like <I><b>make</b></I> or <I><b>ninja</b></I> for efficient incremental builds.


title: COMPILATION STAGES
content:
Understanding the stages <I><b>gcc</b></I> performs is crucial for effective use and debugging:<br>1.  <I>Preprocessing</I>: Handles directives like <I>#include</I> and <I>#define</I>, expanding macros and including header files. Output is <I>.i</I> (for C) or <I>.ii</I> (for C++) files.<br>2.  <I>Compilation</I>: Translates preprocessed source code into assembly code specific to the target architecture. Output is <I>.s</I> files.<br>3.  <I>Assembly</I>: Converts the assembly code into machine code (binary instructions) in object files. Output is <I>.o</I> files.<br>4.  <I>Linking</I>: Combines the object files with necessary libraries and runtime components to produce a single executable program or a shared library.


title: HISTORY
content:
<I><b>gcc</b></I> was originally written by Richard Stallman in 1987 for the GNU Project as the GNU C Compiler. Its initial purpose was to be a free software compiler for the GNU operating system. It quickly expanded its support to C++, and by 1999, it officially became the GNU Compiler Collection, reflecting its broader language support. <I><b>gcc</b></I> has been instrumental in the growth of the free software movement and the development of Linux and other open-source operating systems, evolving continuously with new language standards, optimizations, and target architectures.


title: SYNOPSIS
content:
<b>gcc-ar-4.8</b> [<i>command_key</i>] [<i>modifier_options</i>] <i>archive_file</i> [<i>member_files</i>...]


title: PARAMETERS
content:
<b><i>command_key</i>: <b>d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Delete specified members from the archive.<br><br><b><i>command_key</i>: <b>m</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Move members within the archive.<br><br><b><i>command_key</i>: <b>p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the contents of specified members to standard output.<br><br><b><i>command_key</i>: <b>q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quickly append files to the end of the archive (does not check for duplicates).<br><br><b><i>command_key</i>: <b>r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replace or add new files to the archive. If a file exists, it's updated; otherwise, it's added.<br><br><b><i>command_key</i>: <b>t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a table of contents of the archive, listing its members.<br><br><b><i>command_key</i>: <b>x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extract members from the archive to the current directory.<br><br><b><i>modifier_option</i>: <b>a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Place new files after an existing member specified by <i>position_member</i> (used with <b>r</b> or <b>m</b>).<br><br><b><i>modifier_option</i>: <b>b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Place new files before an existing member specified by <i>position_member</i> (used with <b>r</b> or <b>m</b>).<br><br><b><i>modifier_option</i>: <b>c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create the archive if it does not already exist (suppresses warning message).<br><br><b><i>modifier_option</i>: <b>i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Synonym for <b>b</b> (insert before).<br><br><b><i>modifier_option</i>: <b>s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add or update the archive's object file symbol table. Essential for linking static libraries.<br><br><b><i>modifier_option</i>: <b>S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not generate an archive symbol table. Useful for non-object file archives.<br><br><b><i>modifier_option</i>: <b>u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only replace files in the archive if they are newer than the existing members (used with <b>r</b>).<br><br><b><i>modifier_option</i>: <b>v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verbose mode; display a description of each operation performed.<br><br>


title: DESCRIPTION
content:
<b>gcc-ar-4.8</b> is a wrapper script or symbolic link provided as part of the GCC 4.8 compiler suite. Its primary function is to invoke the underlying <b>ar</b> (archiver) utility, ensuring that the correct version or configuration of <b>ar</b> is used within the GCC 4.8 toolchain environment.<br><br>The <b>ar</b> command itself is a standard Unix utility used to create, modify, and extract from archives, most notably static libraries (typically <i>.a</i> files). These static libraries bundle multiple object files (<i>.o</i> files) into a single file, which can then be linked with programs during compilation. <b>gcc-ar-4.8</b> effectively provides the full functionality of <b>ar</b> but is specifically tied to the GCC 4.8 installation, helping manage dependencies and paths within that particular compiler ecosystem.


title: CAVEATS
content:
This specific executable, <b>gcc-ar-4.8</b>, is a wrapper that simply executes the underlying <b>ar</b> utility. Its behavior is entirely dependent on the <b>ar</b> version it invokes, which is typically the one bundled with GCC 4.8.<br>It is primarily used for managing static libraries (<i>.a</i> files) in C/C++ compilation. It is <b>not</b> a general-purpose archive utility like <b>tar</b> or <b>zip</b>.


title: STATIC LIBRARIES
content:
<b>gcc-ar-4.8</b> is instrumental in the creation of static libraries, which are collections of object files combined into a single archive file. When a program is linked against a static library, the necessary code from the library is copied directly into the executable, resulting in a self-contained binary. This contrasts with dynamic libraries (shared libraries), where code is linked at runtime.


title: INTEGRATION WITH GCC
content:
While <b>ar</b> can be invoked directly, <b>gcc-ar-4.8</b> is provided to ensure that the archiving tool specifically configured or bundled with GCC 4.8 is used. This prevents potential issues arising from using an incompatible <b>ar</b> version found elsewhere on the system's PATH, ensuring toolchain consistency.


title: HISTORY
content:
The <b>ar</b> command has been a fundamental part of Unix-like operating systems since their early days, primarily used for managing collections of files, especially object files to form static libraries. With the advent of complex toolchains like GCC, specific wrappers or versions of tools were introduced to ensure compatibility and consistency within a particular compiler ecosystem. <b>gcc-ar-4.8</b> exemplifies this, providing a version-specific invocation of <b>ar</b> tailored for the GCC 4.8 release, simplifying the compiler's interaction with the archiving process and ensuring the correct <b>ar</b> binary from the GCC toolchain is utilized.


title: PARAMETERS
content:
<b>-a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display all symbols, including debugger-only symbols and those with no address.<br><br><b>-C, --demangle</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Demangle low-level symbol names (e.g., C++ mangled names) into user-level readable names.<br><br><b>-D, --dynamic</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display dynamic symbols only (from the dynamic symbol table for shared objects).<br><br><b>-g, --extern-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only external (global) symbols.<br><br><b>-l, --line-numbers</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use source file and line number information for each symbol, if available in debugging info.<br><br><b>-n, --numeric-sort</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort symbols by their address (numeric value) instead of alphabetically by name.<br><br><b>-P, --portability</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the POSIX.2 standard format for output, ensuring consistent parsing across systems.<br><br><b>-r, --reverse-sort</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reverse the order of the sort (e.g., descending for numeric sort, Z-A for alphabetical).<br><br><b>-S, --print-size</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the size of defined symbols in addition to their value.<br><br><b>-s, --print-sections</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the section name for each symbol (e.g., .text, .data, .bss).<br><br><b>-t <<i>radix</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the radix for printing symbol values: <b>d</b> (decimal), <b>o</b> (octal), or <b>x</b> (hexadecimal).<br><br><b>-u, --undefined-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only undefined symbols, which are referenced by the file but not defined within it.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print `nm`'s version number and exit.<br><br>


title: DESCRIPTION
content:
The `nm` utility is a diagnostic tool that inspects object files, archives, or shared libraries and lists the symbols (e.g., functions, global variables, static variables) defined or referenced within them.<br><br>It displays crucial information such as the symbol's name, its value (typically an address), its type (e.g., 'T' for text, 'D' for data, 'U' for undefined), and the section it resides in. This is fundamental for debugging, understanding program structure, analyzing compilation and linking issues, and low-level system programming.<br><br>`gcc-nm-4.8` refers to the `nm` utility bundled with the GNU Compiler Collection (GCC) 4.8 toolchain, providing consistent functionality for analyzing binaries compiled by that specific GCC version or other compatible toolchains.


title: CAVEATS
content:
The exact output format and available options for `nm` can vary slightly between different versions of GNU Binutils or other `nm` implementations, as well as across operating systems. `gcc-nm-4.8` specifically refers to the version bundled with the GCC 4.8 release; while generally compatible, using it with binaries compiled by significantly different toolchains might sometimes yield unexpected symbol information due to underlying ABI or object file format differences.<br><br>`nm` is primarily designed for object files and archives; some features might not be fully supported or relevant when analyzing raw executables or shared libraries without embedded debugging symbols.


title: SYMBOL TYPE CHARACTERS
content:
`nm` uses single characters to denote a symbol's type, which is key to interpreting its output. Uppercase letters typically denote global symbols, while lowercase denotes local symbols.<br><br>Common types include:<br><b>T</b> (or <b>t</b>): Symbol in the .text (code) section.<br><b>D</b> (or <b>d</b>): Symbol in the .data (initialized data) section.<br><b>B</b> (or <b>b</b>): Symbol in the .bss (uninitialized data) section.<br><b>U</b>: Undefined symbol (referenced, but defined elsewhere, usually in a library).<br><b>W</b> (or <b>w</b>): Weak symbol (can be overridden by a strong symbol).<br><b>A</b>: Absolute symbol (value is fixed, not relative to any section).<br><b>V</b>: Weak object symbol.<br><b>C</b>: Common symbol.


title: DEFAULT OUTPUT FORMAT
content:
By default, `nm`'s output for each symbol typically consists of three columns:<br>1.  The symbol's value (address), usually in hexadecimal. This column is empty for undefined symbols.<br>2.  A single character representing the symbol's type (as described above).<br>3.  The symbol's name.<br><br>Example output:<br><code>0000000000400520 T main</code><br><code>                 U puts@@GLIBC_2.2.5</code><br><code>0000000000601030 D my_global_var</code><br><br>Options like `--portability` (`-P`) can alter this structure for easier programmatic parsing, while `--demangle` (`-C`) helps interpret C++ symbol names.


title: HISTORY
content:
`nm` has been a fundamental utility in Unix-like operating systems since their early development, providing a crucial mechanism for inspecting the internal structure of compiled binaries. It originated as part of the Programmer's Workbench (PWB) and subsequently became a standard component of Unix toolchains.<br><br>Its core purpose—to list and categorize symbols—remains essential for debugging, understanding program linkages, and low-level software analysis. `gcc-nm-4.8` specifically denotes the version of `nm` that shipped as part of the GNU Binutils package distributed alongside GCC version 4.8, ensuring compatibility and consistency within that particular compiler environment.


title: PARAMETERS
content:
<b><i>&lt;archive_file&gt;</i>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more archive library files (e.g., <i>.a</i> files) for which the symbol table needs to be generated or updated.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version number of the <b>ranlib</b> utility.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a summary of command-line options and usage.<br><br><b><b>-D</b>, <b>--preserve-dates</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When creating the symbol table in the archive, do not use the current time for its modification date. This helps in creating reproducible builds.<br><br><b><b>-U</b>, <b>--enable-deterministic-archives</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate deterministically. The symbol table in the archive will be created with 0 for the UID, GID, and modification time. This is also useful for reproducible builds.<br><br><b><b>--plugin</b> <i>&lt;name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a BFD plugin. This option is generally used for specialized scenarios involving object file formats.<br><br>


title: DESCRIPTION
content:
The <b>gcc-ranlib-4.8</b> command is a specific version of the <b>ranlib</b> utility, which is a crucial component of the GNU Binutils package. Its primary function is to generate or update an index (or table of contents) within an archive library file, typically those created by the <b>ar</b> archiver (e.g., <i>.a</i> files).<br><br>This index lists the symbols (functions and variables) defined by the object files contained within the archive. When a linker, such as <b>ld</b>, searches for undefined symbols during the linking process, it can use this index to quickly locate the relevant object file within the library, significantly speeding up the linking time. Without such an index, the linker would have to scan the entire archive sequentially.<br><br>The <i>-4.8</i> suffix indicates that this particular <b>ranlib</b> executable was likely distributed or compiled as part of, or specifically for use with, the GNU Compiler Collection (GCC) version 4.8 toolchain. While modern versions of <b>ar</b> often automatically create and update this symbol table, <b>ranlib</b> ensures its presence and correctness, especially in older build environments or for specific library management tasks.


title: CAVEATS
content:
While <b>gcc-ranlib-4.8</b> explicitly refers to a specific version, its core functionality is identical to the standard <b>ranlib</b> utility found in GNU Binutils. Modern versions of the <b>ar</b> archiver often automatically maintain the symbol table within archives, reducing the explicit need to run <b>ranlib</b> separately. However, it can still be important for ensuring compatibility with older linkers or for specific build system requirements.


title: ROLE IN STATIC LINKING
content:
<b>gcc-ranlib-4.8</b> is primarily used in the context of static linking. When creating a static library (an <i>.a</i> file), <b>ranlib</b> ensures that the linker can efficiently find the necessary object files by providing an internal index. This contrasts with dynamic linking, where shared libraries (<i>.so</i> files) are resolved at runtime or load time.


title: PART OF GNU BINUTILS
content:
The <b>ranlib</b> utility, including its versioned variants like <b>gcc-ranlib-4.8</b>, is typically part of the GNU Binutils package. Binutils provides a collection of binary tools, including assemblers, linkers, and utilities for manipulating object files and archives, essential for software development on Linux and other Unix-like systems.


title: HISTORY
content:
The <b>ranlib</b> utility has been a fundamental part of the Unix toolchain for managing static libraries since early versions of AT&T System V Unix. It was designed to address the performance issues of linkers that had to sequentially scan large archive files to resolve symbols. Over time, its functionality was often integrated into the <b>ar</b> utility itself, making explicit invocation less common for routine tasks. The naming convention <b>gcc-ranlib-4.8</b> suggests its distribution as part of a specific GNU toolchain version, likely ensuring compatibility and consistency with <b>GCC 4.8</b> and its associated build processes.


title: SYNOPSIS
content:
<br><b>gcloud</b> <i>[GLOBAL_FLAGS]</i> <i><GROUP | COMMAND></i> <i>[SUBGROUP | SUBCOMMAND]</i> <i>[ARGS...]</i><br><br>Example: <b>gcloud compute instances create</b> <i>my-vm</i> <b>--zone=</b><i>us-central1-a</i>


title: PARAMETERS
content:
<b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help for a specific command or group.<br><br><b><b>--project=</b><i>PROJECT_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Google Cloud project to operate on. This flag overrides the active configuration's project setting.<br><br><b><b>--format=</b><i>FORMAT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output format for command results (e.g., <i>json</i>, <i>yaml</i>, <i>text</i>, <i>table</i>, <i>csv</i>). Useful for scripting.<br><br><b><b>--account=</b><i>ACCOUNT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the user account to use for authorization. This is useful when managing multiple Google Cloud accounts.<br><br><b><b>--quiet</b> or <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses interactive prompts and confirmations, making commands non-interactive and suitable for scripts.<br><br><b><b>--verbosity=</b><i>LEVEL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the verbosity level for logging output (e.g., <i>debug</i>, <i>info</i>, <i>warning</i>, <i>error</i>, <i>critical</i>, <i>none</i>).<br><br><b><b>--log-http</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Logs all HTTP traffic to stderr, which is invaluable for debugging API interactions.<br><br><b><b>--configuration=</b><i>NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activates a named <b>gcloud</b> configuration, allowing easy switching between different project/account setups.<br><br>


title: DESCRIPTION
content:
The <b>gcloud</b> command is a powerful, unified command-line tool that is part of the Google Cloud SDK. It allows developers and administrators to manage their Google Cloud resources and services directly from the terminal. <b>gcloud</b> supports a wide range of Google Cloud products, including Compute Engine, Cloud Storage, Cloud SQL, Kubernetes Engine, and many more. It provides a consistent interface for managing projects, authentication, deployments, and various cloud operations.<br><br>The tool offers features like automatic updates, easy configuration, and integration with shell scripting for automation. It simplifies complex tasks by abstracting away underlying API calls, making it an essential tool for anyone working with Google Cloud. <b>gcloud</b> commands are structured hierarchically, allowing users to navigate through various service groups and execute specific actions, such as creating virtual machines, listing storage buckets, or deploying applications. It also supports different output formats (JSON, YAML, text, table) for easy parsing and analysis.


title: CAVEATS
content:
Requires prior installation of the Google Cloud SDK. Continuous internet connectivity and proper authentication (e.g., via <b>gcloud auth login</b>) are essential for operation. Commands within <b>gcloud</b> are highly specific to the Google Cloud service they manage, requiring users to learn sub-command structures for each product. Be mindful that commands under <b>gcloud alpha</b> and <b>gcloud beta</b> are experimental and subject to breaking changes.


title: OUTPUT FORMATTING
content:
The <b>gcloud</b> command offers extensive options for formatting its output, making it highly suitable for scripting and automation. By using the <b>--format</b> flag, users can specify formats such as <i>json</i>, <i>yaml</i>, <i>text</i>, or <i>table</i>. For example, <b>gcloud compute instances list --format=json</b> provides machine-readable JSON output, while <b>--format="table(name, status, zone)"</b> allows for custom table views. This flexibility greatly enhances the command's utility for parsing data and integrating with other tools.


title: INTERACTIVE PROMPTS AND AUTOMATION
content:
Many <b>gcloud</b> commands require user confirmation for destructive actions or to fill in missing information. The <b>--quiet</b> (or <b>-q</b>) flag can be used to suppress all interactive prompts, making commands non-interactive and suitable for scripts. Conversely, if detailed operation logs are needed for debugging, the <b>--verbosity=debug</b> flag can be used to provide extensive output, including full HTTP requests and responses. This combination of flags is crucial for both silent automation and in-depth troubleshooting.


title: HISTORY
content:
The <b>gcloud</b> command is part of the Google Cloud SDK, which evolved to unify command-line access to Google Cloud services. Prior to its introduction, users relied on standalone tools like <b>gsutil</b> (for Cloud Storage) and <b>bq</b> (for BigQuery). Google launched the Google Cloud SDK to centralize CLI access, establishing <b>gcloud</b> as the primary interface. Its development focuses on providing a consistent and user-friendly experience across all Google Cloud products, featuring automatic updates and comprehensive API coverage. It is continuously updated to support new services and features, reflecting Google Cloud's rapid expansion.


title: SYNOPSIS
content:
<b>gcloud app</b> <i><SUBCOMMAND></i> [<i>ARGUMENTS</i>] [<i>--OPTION_NAME</i>=<i>VALUE</i>]...<br><br><b>Common Subcommands:</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>deploy</b> [<i>SERVICE_YAML_PATH</i>...] [<i>--version</i>=<i>VERSION</i>] [<i>--project</i>=<i>PROJECT_ID</i>]<br>&nbsp;&nbsp;&nbsp;&nbsp;<b>browse</b> [<i>--service</i>=<i>SERVICE_NAME</i>] [<i>--version</i>=<i>VERSION</i>]<br>&nbsp;&nbsp;&nbsp;&nbsp;<b>logs read</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>versions list</b>


title: PARAMETERS
content:
<b><i><SUBCOMMAND></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The specific operation to perform within the `gcloud app` command group. Examples include <b>deploy</b> (to upload and run application code), <b>browse</b> (to open the application in a web browser), <b>versions</b> (to manage deployed versions), <b>services</b> (to manage application services), <b>instances</b> (to manage VM instances), <b>logs</b> (to read application logs), <b>regions</b> (to list available regions), and <b>create</b> (to create an App Engine application).<br><br><b><i><ARGUMENTS></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Arguments specific to the chosen subcommand, such as file paths for deployment (e.g., `app.yaml`) or names of services/versions to operate on.<br><br><b><b>--project</b>=<i>PROJECT_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The Google Cloud project ID to operate on. If not specified, the currently configured project is used.<br><br><b><b>--version</b>=<i>VERSION</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the application version to target for operations like deployment, browsing, or traffic management. If not specified during deploy, a unique version ID is generated.<br><br><b><b>--service</b>=<i>SERVICE_NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the application service to target, particularly relevant when managing multi-service applications. Defaults to 'default' if not specified.<br><br><b><b>--verbosity</b>={<i>debug</i>|<i>info</i>|<i>warning</i>|<i>error</i>|<i>critical</i>|<i>none</i>}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the output verbosity level. Defaults to `info`. Useful for troubleshooting.<br><br><b><b>--format</b>=<i>FORMAT_TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format for command results (e.g., `json`, `yaml`, `text`, `list`, `table`). Useful for scripting.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed help for the command or subcommand, including all available options and examples.<br><br><b><b>--no-promote</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Specific to `deploy`) Prevents the deployed version from receiving all traffic immediately upon successful deployment. Traffic must be manually split later.<br><br><b><b>--stop-previous-version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Specific to `deploy`) Stops the previously deployed version when a new version is successfully deployed and promoted. Useful for resource management.<br><br><b><b>--bucket</b>=<i>BUCKET_NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Specific to `deploy`) Specifies a Google Cloud Storage bucket to use for staging application files. Defaults to a bucket automatically created by gcloud.<br><br>


title: DESCRIPTION
content:
The `gcloud app` command group is an essential part of the Google Cloud SDK, specifically designed for interacting with and managing Google App Engine applications. App Engine is a fully managed, serverless platform for developing and hosting web applications at scale. This command group provides a comprehensive set of functionalities, enabling developers to deploy new versions of their applications, manage existing services and versions, view logs, scale instances, and configure various aspects of their App Engine projects. It streamlines the development workflow by offering command-line control over the entire application lifecycle on Google Cloud Platform, from initial deployment to ongoing maintenance and monitoring. Key operations include deploying application code, browsing deployed applications, managing traffic splitting between versions, and inspecting service health. Note that `gcloud-app` is commonly understood as referring to this `gcloud app` command group.


title: CAVEATS
content:
The `gcloud app` command group requires the Google Cloud SDK to be installed and properly configured, including authentication with a Google Cloud account. Operations like `deploy` can incur costs, so it's important to understand App Engine pricing and resource usage. Deployments can take several minutes depending on application size, dependencies, and network conditions. Users must have appropriate IAM permissions within the target Google Cloud project to perform `gcloud app` operations, typically 'App Engine Admin' or similar roles.


title: APP ENGINE ENVIRONMENTS
content:
App Engine offers two main environments: the Standard environment (ideal for rapid scaling and low cost with language-specific runtimes) and the Flexible environment (providing more customization, custom runtimes, and Docker support). The `gcloud app deploy` command can deploy applications to either environment, typically determined by the `runtime` specified in the `app.yaml` configuration file.


title: CONFIGURATION FILES
content:
App Engine applications are configured using a set of YAML files deployed alongside your code. Key files include `app.yaml` (main application configuration), `dispatch.yaml` (for routing requests to specific services), `index.yaml` (for Datastore indexes), and `cron.yaml` (for scheduled tasks). These files are typically deployed together with your application code using `gcloud app deploy`.


title: HISTORY
content:
The `gcloud` command-line tool, which encompasses `gcloud app`, was first introduced as part of the Google Cloud SDK, aiming to provide a unified interface for managing all Google Cloud resources. The `gcloud app` command group specifically evolved to manage Google App Engine applications, largely replacing or complementing earlier standalone tools like `appcfg.py` for application deployment and management. Its development has focused on enhancing developer productivity, supporting new App Engine features (such as services and the flexible environment), and integrating seamlessly with other Google Cloud services, offering a consistent command-line experience across the platform.


title: PARAMETERS
content:
<b>login</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Authenticates the <b>gcloud</b> CLI with user credentials via a web browser flow.<br><br><b>activate-service-account</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Authenticates using a service account key file, typically for automated environments.<br><br><b>list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all authenticated accounts and indicates the currently active one.<br><br><b>print-access-token</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the access token for the currently active account to standard output.<br><br><b>application-default login</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Authenticates for Application Default Credentials (ADC) using user credentials.<br><br><b>revoke</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Revokes access credentials for specified authenticated accounts, logging them out.<br><br><b>configure-docker</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures Docker to use <b>gcloud</b> credentials for authenticating to Google Container Registry (GCR) or Artifact Registry.<br><br><b>--project=[PROJECT_ID]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A global option specifying the Google Cloud project for the command to operate within.<br><br><b>--account=[ACCOUNT]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A global option specifying which authenticated account to use for the command.<br><br><b>--quiet | -q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A global option that disables interactive prompts for non-destructive commands.<br><br><b>--format=[FORMAT]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A global option setting the output format of the command (e.g., json, text, yaml).<br><br>


title: DESCRIPTION
content:
The <b>gcloud auth</b> command is a crucial component of the Google Cloud SDK, designed to manage authentication to Google Cloud APIs and resources. It provides a comprehensive set of subcommands to handle various authentication methods, including user accounts, service accounts, and Application Default Credentials (ADC). Users commonly employ <b>gcloud auth login</b> for interactive browser-based authentication, while <b>gcloud auth activate-service-account</b> is utilized for non-interactive scenarios, such as in CI/CD pipelines or virtual machines, by leveraging service account key files. The command also facilitates listing active accounts, revoking credentials, and printing access tokens for direct API interactions. Proper use of <b>gcloud auth</b> ensures secure and authorized access to Google Cloud services like Compute Engine, Cloud Storage, and BigQuery. It serves as the primary interface for configuring the SDK's credentials, enabling the <b>gcloud</b> CLI to interact with your cloud projects effectively.


title: CAVEATS
content:
<b>Credential Security</b>: Service account key files grant powerful access and must be handled with extreme care. Avoid committing them to version control systems.<br><b>Token Expiration</b>: Access tokens obtained are temporary but are automatically refreshed by the SDK. However, long-lived service account keys should be rotated periodically for security.<br><b>Application Default Credentials (ADC)</b>: Be aware of the ADC lookup order. Using <b>gcloud auth application-default login</b> can set user credentials as ADC, potentially overriding other service account credentials in an environment.<br><b>Permissions</b>: The authenticated account or service account requires appropriate IAM roles and permissions to perform actions on Google Cloud resources. Insufficient permissions will result in 'Permission Denied' errors.<br><b>Multiple Accounts</b>: While <b>gcloud auth list</b> shows multiple accounts, only one can be active at a time for general <b>gcloud</b> commands unless explicitly specified with the <b>--account</b> flag per command.


title: RECOMMENDED AUTHENTICATION FLOWS
content:
For interactive user access, <b>gcloud auth login</b> is the standard method, providing a seamless browser-based authentication experience. For automated processes, such as CI/CD pipelines or scripts running outside Google Cloud infrastructure, using <b>gcloud auth activate-service-account</b> with a service account key file is a common practice. However, when running applications or services directly on Google Cloud infrastructure (e.g., Compute Engine, Cloud Run, GKE), leveraging the instance's built-in service account via the metadata service is the most secure and recommended approach, as it eliminates the need to manage sensitive key files.


title: UNDERSTANDING SCOPES
content:
When authenticating, especially with <b>gcloud auth login</b>, the permissions granted are often tied to OAuth 2.0 scopes. For instance, a broad scope like <i>https://www.googleapis.com/auth/cloud-platform</i> grants extensive access. While <b>gcloud</b> typically handles the necessary scopes automatically for its commands, understanding scopes is critical for developing custom applications and for fine-tuning security permissions, as they define the specific set of resources and actions an authenticated principal is allowed to perform.


title: HISTORY
content:
The <b>gcloud auth</b> command is a fundamental part of the Google Cloud SDK, which has undergone continuous evolution since its initial release. Its development has paralleled the rapid expansion of Google Cloud services, leading to a unified and flexible authentication interface that consolidates various underlying methods. Historically, authentication to Google Cloud APIs involved disparate approaches. <b>gcloud auth</b> streamlined this process, providing robust support for user accounts, service accounts, and more recently, advanced features like Workload Identity federation. The command's evolution also reflects Google's emphasis on Application Default Credentials (ADC) as a preferred authentication strategy for applications, making <b>gcloud auth application-default login</b> a key entry point for developers. Its ongoing refinement ensures secure, efficient, and user-friendly access to Google Cloud resources.


title: PARAMETERS
content:
<b><I>COMPONENT_ID</I>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The unique identifier(s) of the Google Cloud SDK component(s) to install. Multiple IDs can be provided, separated by spaces. Use `gcloud components list` to see available components.<br><br><b><b>--quiet</b>, <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress interactive prompts and assume 'yes' to all questions during installation. This is particularly useful for scripting and automation.<br><br>


title: DESCRIPTION
content:
The `gcloud components install` command is a core utility within the Google Cloud SDK, designed for managing its modular components. Although sometimes referred to informally as `gcloud-components-install` due to its function, the standard and documented command-line invocation is `gcloud components install`. This command enables users to extend the functionality of their Google Cloud SDK by installing optional software components, such as <i>kubectl</i> for Kubernetes management, App Engine SDKs for specific programming languages, or various tool sets for Google Cloud services like BigQuery and Dataflow.<br><br>It automates the download, verification, and integration of these components, ensuring they are compatible with the installed SDK version and providing a streamlined experience for tailoring the SDK to specific development and operational needs. It is crucial for accessing tools not included in the default SDK installation.


title: CAVEATS
content:
<ul><li>Requires an active internet connection to download components from Google Cloud servers.</li><li>Requires sufficient free disk space to accommodate the new components.</li><li>Depending on the SDK installation path and user permissions, elevated privileges (e.g., `sudo`) might be required to perform the installation.</li><li>Components are installed for and must be compatible with the currently active Google Cloud SDK version.</li><li>Some components may have their own system dependencies that need to be met.</li></ul>


title: COMMON COMPONENTS
content:
Some frequently installed Google Cloud SDK components include:<br><ul><li><b>kubectl</b>: The command-line tool for controlling Kubernetes clusters.</li><li><b>app-engine-java</b>, <b>app-engine-python</b>, <b>app-engine-go</b>, <b>app-engine-php</b>, <b>app-engine-standard</b>: SDKs for developing Google App Engine applications in various programming languages and environments.</li><li><b>beta</b>: Provides access to beta-level commands and features within the `gcloud` CLI.</li><li><b>alpha</b>: Provides access to alpha-level commands and features within the `gcloud` CLI.</li><li><b>cloud-datastore-emulator</b>: An emulator for testing Google Cloud Datastore applications locally.</li><li><b>gsutil</b>: A Python-based command-line tool for interacting with Cloud Storage. (Often included by default but can be reinstalled).</li><li><b>bq</b>: The command-line tool for BigQuery. (Often included by default).</li></ul>


title: USAGE EXAMPLE
content:
To install the <i>kubectl</i> and <i>beta</i> components, you would run:<br><br>`gcloud components install kubectl beta`<br><br>To install <i>kubectl</i> without any interactive prompts:<br><br>`gcloud components install kubectl --quiet`


title: HISTORY
content:
The Google Cloud SDK and its component management system evolved alongside the rapid growth of Google Cloud Platform. Initially, installing additional tools might have involved separate downloads or manual setup processes. The `gcloud components` command family was introduced to streamline the management of these tools, providing a centralized and consistent interface for installing, updating, and removing SDK components.<br><br>This modular approach allows users to customize their SDK installation, only downloading and maintaining the tools they actively use, making the SDK more efficient and user-friendly by reducing unnecessary disk space usage and potential software conflicts. The `install` subcommand is a core part of this modularity, ensuring developers can easily extend their CLI capabilities to match their specific development and operational requirements.


title: SYNOPSIS
content:
<b>gcloud components update</b> [<I>COMPONENT_ID</I>...] [--allow-no-backup] [--dry-run] [--ignore-errors] [--quiet] [--skip-security-check] [--version=<I>VERSION</I>]


title: PARAMETERS
content:
<b><I>COMPONENT_ID</I>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional. The IDs of specific components to update. If not provided, all currently installed components will be updated to their latest versions.<br><br><b>--allow-no-backup</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows the Cloud SDK to update without first creating a backup of the current installation. Using this flag is not recommended as a failed update without a backup may leave the SDK in an unusable state.<br><br><b>--dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a dry run of the update command, showing what changes would be made without actually modifying your local installation. No changes will be made to your local installation, making it useful for verifying the update plan.<br><br><b>--ignore-errors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continues the update process for other components even if one or more components fail to update. Errors will be logged, but the command will not stop.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables all interactive prompts during the update process. If a prompt is encountered, the command will return a non-zero exit code, indicating failure.<br><br><b>--skip-security-check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Bypasses the security check (checksum validation) before updating components. This is generally not recommended as it reduces the integrity verification of downloaded files.<br><br><b>--version=<I>VERSION</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a particular Cloud SDK version to update to, instead of the latest available. This option will also reinstall any components that are already up to date for that specified version.<br><br>


title: DESCRIPTION
content:
The <b>gcloud components update</b> command is an essential tool for maintaining your Google Cloud CLI (Command Line Interface) installation. It allows you to update all installed components of the SDK to their latest available versions. Keeping your Cloud SDK up-to-date is crucial for several reasons: it ensures you have access to the newest features, bug fixes, and security patches, and maintains compatibility with the latest Google Cloud services.<br><br>By default, <b>gcloud components update</b> scans your current SDK installation, identifies components that have newer versions available, and proceeds to download and install those updates. This process typically includes a backup of your current installation, allowing for a rollback if an update fails. You can also specify particular components to update, or even revert to a specific historical version of the SDK, offering flexibility in managing your development environment.<br><br>This command is part of the modular design of the gcloud CLI, where functionalities are broken down into manageable components, allowing users to install and update only what they need, rather than requiring a full SDK reinstallation for every update.


title: CAVEATS
content:
Requires an active internet connection to download updates.<br>Depending on your system's permissions and how the SDK was installed, you might need elevated privileges (e.g., <I>sudo</I>) to perform the update.<br>Major updates can sometimes introduce breaking changes. Regularly checking release notes is advisable.<br>Using the <I>--allow-no-backup</I> or <I>--skip-security-check</I> flags can compromise the integrity and stability of your SDK installation, and should be used with caution.


title: MODULAR DESIGN
content:
The Google Cloud SDK is designed with a modular architecture. Instead of a single monolithic package, it consists of core components and optional components. <b>gcloud components update</b> leverages this design by allowing targeted updates of individual components or the entire SDK, making the update process more efficient and user-friendly. This means you only download and install the parts you need, saving bandwidth and disk space.


title: BACKUP AND ROLLBACK
content:
By default, <b>gcloud components update</b> creates a backup of your current SDK installation before applying updates. This crucial feature provides a safety net, allowing you to revert to the previous working version if an update fails or introduces unforeseen issues. The <I>gcloud components revert</I> command can be used to restore from these backups, ensuring continuity of your development workflow.


title: HISTORY
content:
The <b>gcloud</b> CLI has evolved significantly since its inception, mirroring the rapid growth of Google Cloud Platform. Initially, managing the SDK might have involved more manual downloads or re-installations. The introduction of the <I>gcloud components</I> sub-command structure marked a significant improvement in SDK management, allowing for a modular approach where users could install, update, and remove specific parts of the SDK. <b>gcloud components update</b> became a cornerstone of this modularity, providing a streamlined way to keep the SDK current without requiring a full reinstallation, thus enhancing developer experience and efficiency in maintaining their Google Cloud development environments.


title: SEE ALSO
content:
gcloud components install, gcloud components list, gcloud components remove, gcloud components revert, gcloud version


title: SYNOPSIS
content:
<b>gcloud compute</b> <i><subcommand></i> [<i>arguments...</i>] [<i>--flags...</i>]<br><br><i>Example:</i><br><b>gcloud compute instances create</b> my-vm <b>--zone</b>=us-central1-a <b>--machine-type</b>=e2-medium<br><b>gcloud compute firewall-rules list --project</b>=my-gcp-project


title: PARAMETERS
content:
<b>--project=PROJECT_ID</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Google Cloud project to operate on. Crucial for multi-project environments.<br><br><b>--zone=ZONE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the Compute Engine zone for zonal resources like VM instances or disks. Overrides default zone.<br><br><b>--region=REGION</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the Compute Engine region for regional resources such as addresses or subnets. Overrides default region.<br><br><b>--format=FORMAT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the output format of the command (e.g., <i>json</i>, <i>yaml</i>, <i>text</i>, <i>list</i>, <i>csv</i>, <i>none</i>). Useful for scripting.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed help for the command or subcommand, including examples and flag descriptions.<br><br><b>--verbosity=LEVEL</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the command's logging level (e.g., <i>debug</i>, <i>info</i>, <i>warning</i>, <i>error</i>, <i>critical</i>).<br><br><b>instances</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Subcommand Group) Manages virtual machine instances (e.g., <i>create</i>, <i>start</i>, <i>stop</i>, <i>delete</i>).<br><br><b>disks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Subcommand Group) Manages persistent disks and snapshots (e.g., <i>create</i>, <i>list</i>, <i>delete</i>).<br><br><b>firewall-rules</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Subcommand Group) Manages network firewall rules (e.g., <i>create</i>, <i>update</i>, <i>list</i>).<br><br><b>networks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Subcommand Group) Manages Virtual Private Cloud (VPC) networks and subnets (e.g., <i>create</i>, <i>list</i>).<br><br><b>ssh</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Subcommand) Connects to a virtual machine instance using SSH, handling authentication automatically.<br><br>


title: DESCRIPTION
content:
The <b>gcloud compute</b> command group provides a comprehensive command-line interface for interacting with and managing Google Compute Engine (GCE) resources. As a core part of the Google Cloud SDK, it allows users to perform various operations on virtual machine instances, persistent disks, networks, firewalls, load balancers, and more, directly from their terminal.<br><br>It streamlines infrastructure management tasks, enabling efficient automation and scripting of cloud resource provisioning, configuration, and monitoring, making it an essential tool for developers and administrators working with Google Cloud's virtual infrastructure.


title: CAVEATS
content:
<ul><li><b>Dependency on Google Cloud SDK:</b> Requires the <b>gcloud</b> command-line tool, which is part of the Google Cloud SDK, to be installed and configured.</li><li><b>Authentication:</b> Requires proper authentication to a Google Cloud account with sufficient IAM permissions for the operations being performed.</li><li><b>Regional/Zonal Specificity:</b> Many Compute Engine resources are zonal or regional. Incorrectly specifying or omitting <b>--zone</b> or <b>--region</b> can lead to errors or operations on unintended resources.</li><li><b>Resource Limitations:</b> Operations are subject to project quotas and available resources in a given region/zone.</li></ul>


title: COMMAND GROUP STRUCTURE
content:
<b>gcloud compute</b> is a command <i>group</i>, meaning it serves as a namespace for numerous subcommands (e.g., <b>gcloud compute instances</b>, <b>gcloud compute disks</b>). To see available subcommands, run <b>gcloud compute --help</b>.


title: INTERACTIVE HELP
content:
Most <b>gcloud</b> commands and subcommands offer extensive help accessed via <b>--help</b>, which includes examples and descriptions of all available flags specific to that command. For example, <b>gcloud compute instances create --help</b>.


title: ALPHA/BETA FEATURES
content:
<b>gcloud compute</b> also provides access to alpha and beta versions of features through <b>gcloud alpha compute</b> and <b>gcloud beta compute</b> respectively, allowing users to test upcoming functionalities and API changes.


title: HISTORY
content:
Google Compute Engine (GCE) was first launched in public beta in 2012. The <b>gcloud compute</b> commands evolved alongside it as the primary command-line interface for managing GCE resources. The <b>gcloud</b> CLI, introduced as a successor to older tools like <i>gcutil</i>, aimed to provide a unified and consistent interface across all Google Cloud services. Since its inception, <b>gcloud compute</b> has seen continuous development, adding support for new GCE features, instance types, networking capabilities, and management paradigms, becoming an essential tool for developers and administrators working with Google Cloud's virtual infrastructure.


title: SYNOPSIS
content:
<b>gcloud config</b> <i>&lt;subcommand&gt;</i> [<i>&lt;arguments&gt;</i>...] [<i>&lt;flags&gt;</i>...]


title: PARAMETERS
content:
<b><b>set</b> <i>&lt;PROPERTY_NAME&gt;</i> <i>&lt;VALUE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a specified SDK property to a given value. Common properties include <i>project</i>, <i>account</i>, <i>compute/zone</i>, and <i>compute/region</i>.<br><br><b><b>get</b> <i>&lt;PROPERTY_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the value of a specified SDK property from the active configuration or global settings.<br><br><b><b>list</b> [--all]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all active SDK properties. The <i>--all</i> flag shows properties from all possible levels (user, active configuration, environment variables, etc.).<br><br><b><b>unset</b> <i>&lt;PROPERTY_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes a specified SDK property from the active configuration.<br><br><b><b>configurations activate</b> <i>&lt;CONFIG_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activates a named configuration, making its properties the current active settings for the SDK.<br><br><b><b>configurations create</b> <i>&lt;CONFIG_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new, empty named configuration. This configuration can then be populated with properties using <b>gcloud config set</b>.<br><br><b><b>configurations delete</b> <i>&lt;CONFIG_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes a specified named configuration. The currently active configuration cannot be deleted directly.<br><br><b><b>configurations describe</b> <i>&lt;CONFIG_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the properties associated with a specific named configuration.<br><br><b><b>configurations list</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available named configurations configured with the SDK.<br><br>


title: DESCRIPTION
content:
The <b>gcloud config</b> command group is central to managing the Google Cloud SDK's behavior. It allows users to control various SDK <b>properties</b>, such as the active Google Cloud project, default compute zone, and user account. These properties dictate how subsequent <b>gcloud</b> commands interact with Google Cloud services.<br><br>Beyond individual properties, <b>gcloud config</b> also facilitates the creation and management of named <b>configurations</b>. A configuration is a distinct set of properties that can be activated to quickly switch contexts, for instance, between development and production environments, or between different Google Cloud projects. This feature is crucial for users working with multiple projects or needing different settings for various tasks, streamlining workflow and reducing errors.<br><br>Properties can be set at different levels, including globally for the SDK, specific to an active configuration, or overridden by environment variables and command-line flags, providing a flexible hierarchy for managing SDK settings.


title: CAVEATS
content:
Properties set via <b>gcloud config</b> apply to the current active configuration or global settings. Environment variables (e.g., <i>CLOUDSDK_CORE_PROJECT</i>) and command-line flags (e.g., <i>--project</i>) generally take precedence over properties set through <b>gcloud config</b>.<br><br>Ensure that the Google Cloud SDK is properly initialized (using <b>gcloud init</b>) for optimal functionality.


title: PROPERTY PRECEDENCE
content:
The Google Cloud SDK resolves property values based on a specific order of precedence, from highest to lowest: <br>1. <b>Command-line flags</b> (e.g., <i>--project</i>)<br>2. <b>Environment variables</b> (e.g., <i>CLOUDSDK_CORE_PROJECT</i>)<br>3. <b>Properties in the active configuration</b><br>4. <b>Properties in the global configuration</b><br>Understanding this hierarchy is crucial for debugging unexpected behavior.


title: USE CASES FOR MULTIPLE CONFIGURATIONS
content:
Multiple configurations are invaluable for managing different operational contexts:<br><b>Switching Projects:</b> Easily switch between development, staging, and production projects without re-authenticating or re-setting project IDs.<br><b>Managing Multiple Accounts:</b> Use different Google accounts for distinct tasks or projects.<br><b>Regional Deployments:</b> Define configurations for different default compute regions or zones.


title: HISTORY
content:
The <b>gcloud config</b> command group is an integral part of the Google Cloud SDK, which has evolved significantly since its inception. It provides a consistent interface for managing SDK settings, adapting to the growing complexity and features of Google Cloud Platform. Its development has focused on simplifying multi-project and multi-environment workflows for developers and administrators.


title: SYNOPSIS
content:
gcloud config set <I>PROPERTY_NAME</I> <I>VALUE</I> [<b>--configuration</b>=<I>CONFIGURATION_NAME</I>] [<b>--unset</b>] [<b>--installation</b>]


title: PARAMETERS
content:
<b><I>PROPERTY_NAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The identifier for the configuration setting to be modified (e.g., `core/project`, `compute/zone`).<br><br><b><I>VALUE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired value to assign to the specified property.<br><br><b><b>--configuration</b>=<I>CONFIGURATION_NAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies the property change to a specific named gcloud configuration rather than the currently active one. For example, use `default`, `dev`, `prod`.<br><br><b><b>--unset</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the specified property from the configuration instead of setting a new value.<br><br><b><b>--installation</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the property globally for the entire gcloud installation, affecting all configurations, unless overridden by a configuration-specific setting.<br><br>


title: DESCRIPTION
content:
The `gcloud config set` command is a fundamental utility within the Google Cloud CLI (Command Line Interface) for managing and modifying its configuration properties. These properties dictate the default behavior of subsequent `gcloud` commands, streamlining workflows by eliminating the need to repeatedly specify common parameters like the Google Cloud project ID, compute zone, or user account.<br><br>When executed, `gcloud config set` updates the specified property within the currently active gcloud configuration. Users typically maintain multiple configurations (e.g., 'default', 'development', 'production') to easily switch between different Google Cloud environments or projects without altering their global settings.<br><br>Common properties that can be set include `core/project` (the default Google Cloud project), `core/account` (the default user account for authentication), `compute/zone` (the default compute engine zone), and `compute/region` (the default compute engine region). By setting these, `gcloud` commands automatically apply these values unless overridden by command-line flags or environment variables.<br><br>This command is crucial for establishing and maintaining a consistent development or operational environment, improving efficiency, and reducing the potential for errors associated with manual parameter entry. It plays a central role in customizing the `gcloud` CLI to fit specific user or project requirements.


title: CAVEATS
content:
The command `gcloud config set` is the actual official Google Cloud CLI command for managing configuration properties. The name 'gcloud-config-set' as a standalone command is not standard within the gcloud CLI.<br><br>Changes made with `gcloud config set` persist and affect all subsequent gcloud commands run under the modified configuration. It's important to understand the property precedence: command-line flags override environment variables, which override properties in the active configuration, which in turn override installation-level properties.


title: CLARIFICATION ON COMMAND NAME
content:
The command specified as 'gcloud-config-set' is not a standard `gcloud` CLI command. The correct and official command for setting Google Cloud SDK properties is `gcloud config set`. It is possible that 'gcloud-config-set' refers to a custom script, an alias, or a slight misremembering of the standard command.


title: PROPERTY PRECEDENCE
content:
Understanding how gcloud resolves configuration properties is critical. Properties are resolved in a specific order: command-line flags (highest precedence) override environment variables (e.g., `CLOUDSDK_CORE_PROJECT`), which override properties set in the active gcloud configuration, which finally override properties set globally for the gcloud installation. This hierarchy determines the effective value of any given property at runtime.


title: HISTORY
content:
The Google Cloud CLI, including its robust configuration system, was designed to provide a flexible and powerful interface for interacting with Google Cloud services. The `gcloud config` command group has been a core component since the early stages of the CLI's development, allowing users to manage distinct operational contexts (projects, accounts, regions) and streamline their command-line interactions. Its evolution has focused on providing granular control and easy switching between different environments, adapting to the complex needs of cloud developers and operators.


title: SEE ALSO
content:
gcloud config list(1), gcloud config get(1), gcloud config configurations activate(1), gcloud auth login(1)


title: PARAMETERS
content:
<b><b>clusters</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Commands for managing Google Kubernetes Engine (GKE) clusters. This includes operations like creating, deleting, resizing, and configuring GKE clusters.<br><br><b><b>node-pools</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Commands for managing node pools within GKE clusters. Node pools allow you to define groups of nodes with specific configurations, such as machine types or disk sizes.<br><br><b><b>images</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Historically)</i> Commands for managing container images stored in Google Container Registry (GCR). While still functional for GCR, for new projects and advanced features, `gcloud artifacts` is recommended for Google Artifact Registry (GAR).<br><br><b><b>binauthz</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Commands for interacting with Binary Authorization, a service that helps ensure only trusted images are deployed on GKE or Cloud Run.<br><br><b><b>registries</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Deprecated)</i> Provides information about container registries linked to your Google Cloud project. Largely superseded by `gcloud artifacts` for managing Artifact Registry.<br><br><b><b>get-server-config</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the GKE server configuration, which includes information about supported Kubernetes versions and node pool configurations.<br><br>


title: DESCRIPTION
content:
The `gcloud container` command group provides a comprehensive interface for interacting with Google Cloud's container services. Its primary focus is on managing Google Kubernetes Engine (GKE) clusters, including operations such as creating, deleting, updating, and scaling clusters and their node pools. It also historically managed Google Container Registry (GCR) images, though `gcloud artifacts` is now the preferred command for Google Artifact Registry (GAR) images.<br><br>This command group serves as the central point for cloud developers and administrators to automate and script container-related tasks, integrate with CI/CD pipelines, and perform ad-hoc management of containerized workloads running on Google Cloud.


title: CAVEATS
content:
The `gcloud container` is a <i>command group</i>, not a standalone executable command. It must be followed by a sub-command (e.g., `clusters`, `node-pools`, `images`).<br>While `gcloud container images` still works for Google Container Registry (GCR), for managing images in Google Artifact Registry (GAR), the dedicated `gcloud artifacts` command group offers more comprehensive and future-proof functionality.


title: HISTORY
content:
The `gcloud container` command group evolved alongside Google Kubernetes Engine (GKE), which was launched in 2014 as Google Container Engine. As Kubernetes gained prominence, the `gcloud` CLI expanded its `container` group to provide robust management capabilities. Initially, it was the primary interface for Google Container Registry (GCR) images. More recently, with the introduction of Google Artifact Registry (GAR) as a unified package manager, the `gcloud artifacts` command group was introduced, leading to a partial shift in image management functionality, though `gcloud container images` remains functional for GCR. Its development tracks closely with the continuous evolution of containerization and orchestration services on Google Cloud.


title: PARAMETERS
content:
<b><i>GCLOUD_WIDE_FLAG ...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <b>gcloud feedback</b> command does not have its own specific flags. However, like all gcloud commands, it supports <I>gcloud wide flags</I> that control global behaviors such as authentication, project selection, logging, and verbosity. These flags are applied to the overarching <b>gcloud</b> command invocation and affect its execution environment.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed help for the <b>gcloud feedback</b> command itself, including its synopsis and description.<br><br><b>--verbosity=<LEVEL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the log verbosity level for the <b>gcloud</b> command's execution. Common levels include <i>debug</i>, <i>info</i>, <i>warning</i>, <i>error</i>, and <i>critical</i>. This can affect any console output generated before the browser opens.<br><br><b>--quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all interactive prompts. If any value is required, it must be provided via a flag or configuration. While <b>gcloud feedback</b> is typically non-interactive, this flag ensures no unexpected prompts during its execution.<br><br>


title: DESCRIPTION
content:
The <b>gcloud feedback</b> command provides a convenient and direct channel for users to share their experiences and insights regarding the Google Cloud Command-Line Interface (CLI). When invoked, this command automatically launches your default web browser and navigates to a specific, dedicated feedback form hosted by Google Cloud. This mechanism is designed to simplify the process of communicating directly with the Google Cloud development team.<br><br>Users can leverage this command to report encountered bugs, suggest new features or enhancements they would like to see, or provide general comments and observations about the CLI's usability, performance, or documentation. It serves as a critical bridge for user-driven improvements, ensuring that the feedback from the global user base can be collected efficiently and considered for future updates and refinements to the <b>gcloud</b> toolset. It eliminates the need to manually search for a feedback portal, streamlining the process of contributing to the evolution of the Google Cloud CLI.


title: CAVEATS
content:
Requires an active internet connection to access the feedback form hosted by Google.<br>A functional web browser must be installed and configured as the default browser on your operating system for the command to successfully open the feedback form.<br>The exact feedback URL may change over time, but the command should always point to the current form.


title: BROWSER INTERACTION
content:
The command's primary function is to launch your default web browser and navigate to the Google Cloud CLI feedback form. It does not perform any direct data submission from the command line itself; instead, it relies entirely on the user to complete and submit the form within the opened browser window. This ensures that user privacy and data submission are handled securely through standard web protocols.


title: HISTORY
content:
The <b>gcloud feedback</b> command has been an integral part of the Google Cloud CLI since its early development. It was introduced to provide a direct and accessible channel for user feedback, emphasizing Google's commitment to user-driven improvements and responsiveness in the continuous development of its cloud tools. This command reflects a design philosophy focused on empowering users to contribute to the CLI's evolution.


title: SYNOPSIS
content:
<b>gcloud help</b> [<I>COMMAND_GROUP</I> | <I>COMMAND</I>]<br>(Also commonly used: <b>gcloud</b> [<I>COMMAND_GROUP</I> | <I>COMMAND</I>] <b>--help</b>)


title: PARAMETERS
content:
<b><I>COMMAND_GROUP</I> | <I>COMMAND</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the `gcloud` command group (e.g., <I>compute</I>) or specific command (e.g., <I>compute instances create</I>) for which to display detailed help. If omitted, `<b>gcloud help</b>` displays general help for the `gcloud` tool itself.<br><br>


title: DESCRIPTION
content:
The `gcloud-help` command, conceptually represented by the `<b>gcloud help</b>` subcommand, provides comprehensive, integrated documentation for the Google Cloud Command Line Interface (CLI). It allows users to quickly understand the purpose, syntax, and available options for any `gcloud` command or command group. When invoked with `<b>gcloud help</b>` without additional arguments, it displays a high-level overview of available command groups and their primary functions. When a specific command or command group is provided as an argument (e.g., `<b>gcloud help compute instances</b>`), it presents detailed information. This detailed help typically includes a synopsis, a description of its functionality, a list of its flags and positional arguments, and practical examples illustrating common use cases.<br><br>This integrated help system is crucial for navigating the extensive capabilities of the `gcloud` CLI, enabling users to efficiently discover and utilize commands without needing to consult external documentation. It ensures that up-to-date command information is readily available directly from the terminal, reflecting the currently installed `gcloud` SDK version.


title: CAVEATS
content:
Requires the Google Cloud SDK (including the `gcloud` CLI) to be installed and properly configured on the system.<br>The displayed help content reflects the version of `gcloud` currently installed, which may vary from online documentation if your SDK is not up-to-date.<br>Network connectivity might be required for `gcloud` to check for updates or fetch certain component-specific help information.


title: GLOBAL FLAGS
content:
While `<b>gcloud help</b>` itself does not have specific flags, the `gcloud` CLI supports a set of <I>global flags</I> that can be used with any `gcloud` command, including `help`. These flags control general behavior such as output formatting (`--format`), logging verbosity (`--verbosity`), or quiet execution (`--quiet`). For example, `<b>gcloud --quiet help compute</b>` would suppress interactive prompts during help output.


title: HELP CONTENT STRUCTURE
content:
The help output for `gcloud` commands typically follows a consistent structure, including:<br>- `NAME`: A brief identifier for the command.<br>- `SYNOPSIS`: The command's syntax, showing arguments and flags.<br>- `DESCRIPTION`: A detailed explanation of the command's purpose and functionality.<br>- `POSITIONAL ARGUMENTS`: Description of arguments that specify values (e.g., resource names).<br>- `FLAGS`: A list of available command-specific and global flags, with their descriptions.<br>- `EXAMPLES`: Practical usage examples demonstrating common scenarios.


title: HISTORY
content:
The `gcloud` CLI and its integrated help system were developed by Google as part of the Google Cloud SDK. Introduced to provide a unified command-line interface for managing Google Cloud resources, the `<b>gcloud help</b>` functionality has been a core component since its early versions. It has evolved alongside the `gcloud` CLI itself, continuously adapting to new services, commands, and user feedback to provide a comprehensive, intuitive, and readily accessible source of command-line documentation. Its design emphasizes discoverability and consistency across the myriad of Google Cloud services.


title: SYNOPSIS
content:
<b>gcloud iam</b> <i><SUBCOMMAND></i> [<i>arguments</i>] [<i>options</i>]<br><br>Examples of common <i><SUBCOMMAND></i>s and their typical usage:<br><b>roles</b> <i><OPERATION></i>: Manage custom IAM roles.<br><b>service-accounts</b> <i><OPERATION></i>: Manage service accounts and their keys.<br><b>policies</b> <i><OPERATION></i>: Manage IAM policies on resources.<br><b>workload-identity-pools</b> <i><OPERATION></i>: Manage Workload Identity Federation pools.


title: PARAMETERS
content:
<b>--format=FORMAT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output format, e.g., 'json', 'yaml', 'table', 'text'. Crucial for scripting.<br><br><b>--project=PROJECT_ID</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The Google Cloud project ID or number to operate on. Essential for scoping IAM changes.<br><br><b>--impersonate-service-account=SERVICE_ACCOUNT_EMAIL</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The service account email to use for authentication, useful for automated tasks.<br><br><b>--log-http</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the HTTP requests and responses made by the command for debugging.<br><br><b>--quiet | -q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses user prompts, making commands suitable for non-interactive scripts.<br><br><b>--account=ACCOUNT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The user account or service account to use for authentication instead of the default.<br><br>


title: DESCRIPTION
content:
The <b>gcloud iam</b> is not a single executable but a powerful <i>command group</i> within the <b>gcloud</b> CLI, dedicated to managing Google Cloud Identity and Access Management (IAM) resources directly from the command line. IAM is a cornerstone Google Cloud service that defines who (identity) has what access (role) to which resource, ensuring granular control over cloud assets.<br><br>This command group provides an extensive interface for interacting with various IAM components, including custom roles, service accounts, service account keys, and IAM policies. Users can seamlessly create, update, delete, and list these resources, as well as manage the binding of members to roles on different Google Cloud resources like projects, folders, or organizations. It is indispensable for automating IAM configurations, scripting access control changes, and integrating security practices into CI/CD pipelines. The <b>gcloud iam</b> commands significantly simplify complex IAM operations, enabling administrators and developers to maintain precise control over resource access across their Google Cloud environments.


title: CAVEATS
content:
Using <b>gcloud iam</b> requires proper authentication and sufficient IAM permissions for the operations being performed (e.g., <i>iam.roles.create</i>, <i>iam.serviceAccounts.delete</i>, <i>resourcemanager.projects.setIamPolicy</i>).<br><br>Changes to IAM policies, especially complex ones, might experience a short propagation delay across Google Cloud services before becoming fully effective. When updating policies, be cautious with commands like <b>set-iam-policy</b> as they replace the entire policy; prefer <b>add-iam-policy-binding</b> or <b>remove-iam-policy-binding</b> for incremental changes to avoid unintended overwrites.


title: COMMON USE CASES
content:
<ul><li>Creating and managing custom IAM roles for specific organizational needs.</li><li>Automating the creation, deletion, and management of service accounts for applications and services.</li><li>Granting or revoking granular permissions at the project, folder, or organization level.</li><li>Scripting policy updates and auditing IAM configurations across resources.</li><li>Managing Workload Identity Federation for external identities.</li></ul>


title: REQUIRED PERMISSIONS
content:
Operations within <b>gcloud iam</b> generally require specific IAM permissions:<br><ul><li>For roles: <i>iam.roles.create</i>, <i>iam.roles.delete</i>, <i>iam.roles.update</i>.</li><li>For service accounts: <i>iam.serviceAccounts.create</i>, <i>iam.serviceAccounts.delete</i>, <i>iam.serviceAccountKeys.create</i>.</li><li>For policies on projects: <i>resourcemanager.projects.getIamPolicy</i>, <i>resourcemanager.projects.setIamPolicy</i>. Similar permissions exist for folders and organizations.</li></ul>


title: HISTORY
content:
The <b>gcloud iam</b> command group evolved as Google Cloud's Identity and Access Management capabilities matured, moving from simpler access control lists to a highly granular and flexible permission system. Its initial release provided core functionalities for managing policies and service accounts. Over time, it expanded significantly with new subcommands to support advanced features like custom roles, Workload Identity Federation, and robust service account key management. Its development mirrors the increasing demand for detailed cloud resource access control, continuously receiving updates and improvements as part of the broader <b>gcloud</b> CLI lifecycle, ensuring a consistent and powerful interface for identity management.


title: PARAMETERS
content:
<b><I>GLOBAL_FLAGS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <b>gcloud info</b> command primarily uses <I>global flags</I> that apply to all <b>gcloud</b> commands. These flags control aspects like output formatting, verbosity, and interactive behavior. Common examples include:<br><br><b>--format=<I>FORMAT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output format for the command result (e.g., <b>json</b>, <b>yaml</b>, <b>table</b>, <b>text</b>). Useful for parsing information programmatically.<br><br><b>--log-http</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints all HTTP traffic to stderr, which can be useful for debugging network issues.<br><br><b>--verbosity=<I>LEVEL</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output verbosity (e.g., <b>debug</b>, <b>info</b>, <b>warning</b>, <b>error</b>, <b>critical</b>, <b>none</b>). Higher verbosity levels provide more detailed diagnostic output.<br><br><b>--quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses interactive prompts and messages, useful for scripting.<br><br>


title: DESCRIPTION
content:
The <b>gcloud info</b> command is a utility within the Google Cloud SDK that provides a comprehensive overview of your current <b>gcloud</b> environment and SDK installation. It's an invaluable tool for troubleshooting, verifying configurations, and understanding the state of your development setup.<br><br>It displays crucial details such as the active <b>gcloud</b> configuration, the currently authenticated account, the default project, zone, and region. Furthermore, it lists installed SDK components, their versions, and paths to important directories (like the SDK root, configuration directory, and logs). This command helps users quickly diagnose issues related to incorrect configurations, missing components, or outdated SDK versions, making it a first stop for debugging <b>gcloud</b> command failures.


title: CAVEATS
content:
Requires the Google Cloud SDK to be installed and accessible in the system's PATH. The information displayed is reflective of the currently active <b>gcloud</b> configuration and components, which might not be global if multiple configurations exist or if the SDK is installed in different locations.<br><br>Some information, like component update status, requires an internet connection to check against Google Cloud repositories.


title: USAGE FOR TROUBLESHOOTING
content:
<b>gcloud info</b> is often the first command to run when experiencing issues with other <b>gcloud</b> commands. It helps identify:<br>Incorrectly set default project, zone, or region.<br>Outdated or missing SDK components.<br>Issues with the active user account or permissions (though <b>gcloud auth list</b> provides more detail).<br>Problems with SDK installation paths or environment variables.


title: HISTORY
content:
The <b>gcloud info</b> command has been a fundamental part of the Google Cloud SDK since its early days. As the SDK evolved, its purpose remained consistent: to provide a centralized diagnostic output for the user's local <b>gcloud</b> environment. It has been continuously maintained and updated to reflect changes in SDK structure, component management, and configuration mechanisms, ensuring it remains relevant for troubleshooting the ever-expanding set of <b>gcloud</b> commands and services.


title: SEE ALSO
content:
gcloud components update(1), gcloud config list(1), gcloud auth list(1), gcloud topics configurations(1)


title: SYNOPSIS
content:
<b><code>gcloud init</code></b> [<i>--console-only</i>] [<i>--no-launch-browser</i>] [<i>--skip-diagnostics</i>] [<i>--project=PROJECT_ID</i>] [<i>--account=ACCOUNT_ID</i>] [<i>--json</i>] [<i>--quiet</i>]


title: PARAMETERS
content:
<b><i>--console-only</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the authorization flow to occur entirely within the console without launching a web browser.<br><br><b><i>--no-launch-browser</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents <b><code>gcloud init</code></b> from automatically opening a web browser for authentication. The authorization URL will be printed to the console.<br><br><b><i>--skip-diagnostics</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the environment diagnostic checks that <b><code>gcloud init</code></b> performs, such as Python and network connectivity tests.<br><br><b><i>--project=PROJECT_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default Google Cloud project for the SDK to the specified <i>PROJECT_ID</i> directly, skipping the interactive project selection.<br><br><b><i>--account=ACCOUNT_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default user account for authentication to the specified <i>ACCOUNT_ID</i> (e.g., an email address).<br><br><b><i>--json</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs authorization URLs and other relevant information in JSON format, useful for scripting or automated environments.<br><br><b><i>--quiet</i> or <i>-q</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all interactive prompts, using default values or values provided by other flags. Useful for non-interactive scripts.<br><br>


title: DESCRIPTION
content:
<b><code>gcloud-init</code></b> is <b>not a standard, standalone command</b> in the Google Cloud SDK. It is highly probable that the command intended was <br><b><code>gcloud init</code></b>, which is the official command used to initialize your Google Cloud SDK environment. <br><br>This process involves authenticating with Google Cloud, selecting a default project, and configuring various SDK properties such as default compute zone and region. It helps users set up their development environment for interacting with Google Cloud services.<br><br>This analysis will focus on <b><code>gcloud init</code></b> as it is the user-facing command fulfilling the concept of "gcloud initialization" on Linux.


title: CAVEATS
content:
The literal command <b><code>gcloud-init</code></b> (with a hyphen) does not exist as a user-executable command in the Google Cloud SDK. This analysis pertains to <b><code>gcloud init</code></b>. <br><br>Requires an active internet connection to authenticate and retrieve project/configuration data from Google Cloud. <br><br>Modifies user-specific configuration files (e.g., <i><code>~/.config/gcloud/</code></i>) and can update SDK components.


title: PURPOSE OF INITIALIZATION
content:
<b><code>gcloud init</code></b> serves as the primary gateway for new users or new environments to connect their local machine to Google Cloud. It ensures that the SDK has the necessary credentials and default settings to execute commands against Google Cloud resources effectively.


title: CONFIGURATION STORAGE
content:
The settings configured by <b><code>gcloud init</code></b> are stored in configuration files within the user's home directory (e.g., <i><code>~/.config/gcloud/</code></i>). Multiple configurations can be created and managed using <b><code>gcloud config configurations</code></b>.


title: HISTORY
content:
The <b><code>gcloud init</code></b> command has been a fundamental part of the Google Cloud SDK since its inception, evolving with new authentication methods and configuration options to streamline the setup process for developers and administrators. It replaced earlier, more manual setup procedures.


title: SYNOPSIS
content:
gcloud-kms-decrypt <b --location</b>=<I>LOCATION</I>> <b --keyring</b>=<I>KEY_RING</I>> <b --key</b>=<I>KEY_NAME</I>> <b --ciphertext-file</b>=<I>INPUT_FILE</I>> <b --plaintext-file</b>=<I>OUTPUT_FILE</I>> [<b --version</b>=<I>VERSION</I>] [<b --additional-authenticated-data</b>=<I>DATA</I>] [<b --project</b>=<I>PROJECT_ID</I>]


title: PARAMETERS
content:
<b>--location</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The Google Cloud region or global endpoint where the KMS key is located.<br><br><b>--keyring</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the key ring that contains the cryptographic key.<br><br><b>--key</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the cryptographic key to use for decryption.<br><br><b>--ciphertext-file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the input file containing the data to be decrypted.<br><br><b>--plaintext-file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the output file where the decrypted data will be written.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(optional) The specific version of the cryptographic key to use. If not specified, the primary (latest) version is used.<br><br><b>--additional-authenticated-data</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(optional) Additional authenticated data (AAD) that was provided during encryption. This data is not encrypted but must be provided during decryption to ensure integrity.<br><br><b>--project</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(optional) The Google Cloud project ID to which the key belongs, if different from the currently configured project.<br><br>


title: DESCRIPTION
content:
gcloud-kms-decrypt is a command-line tool designed to decrypt data using the Google Cloud Key Management Service (KMS). It leverages the robust cryptographic capabilities of Google Cloud to securely unlock previously encrypted sensitive information. <br><br>This command typically takes a file containing ciphertext, a reference to a specific KMS cryptographic key, and outputs the decrypted plaintext to another specified file. It abstracts away the underlying API calls, providing a convenient interface for developers and operations teams to manage encrypted data within their workflows. <br><br>KMS provides a centralized, cloud-hosted key management service for creating, storing, and managing cryptographic keys. Using gcloud-kms-decrypt ensures that decryption operations are performed in a controlled environment, often requiring appropriate Identity and Access Management (IAM) permissions, thus enhancing data security and compliance. It's an essential tool for applications that encrypt data at rest or in transit and need a secure method for retrieval.


title: CAVEATS
content:
Requires the gcloud CLI to be installed and properly configured with authenticated access to Google Cloud. <br>The user or service account executing the command must possess the necessary IAM permissions on the KMS key (e.g., <I>cloudkms.cryptoKeyDecrypter</I>). <br>Network connectivity to Google Cloud services is essential for the command to function. <br>Decryption will fail if the provided key is incorrect, if the <I>additional-authenticated-data</I> (if used during encryption) does not match, or if the ciphertext has been tampered with. <br>The exact behavior and available options might vary slightly if gcloud-kms-decrypt is a custom wrapper script rather than a direct alias to <I>gcloud kms decrypt</I>.


title: KEY RESOURCE PATH SPECIFICATION
content:
Instead of <I>--location</I>, <I>--keyring</I>, and <I>--key</I>, some <I>gcloud</I> commands or wrapper scripts might accept a full KMS key resource path directly, in the format <I>projects/&lt;project_id&gt;/locations/&lt;location&gt;/keyRings/&lt;key_ring_name&gt;/cryptoKeys/&lt;key_name&gt;</I>. This provides a concise way to specify the key.


title: IAM PERMISSIONS FOR DECRYPTION
content:
For successful decryption, the principal (user account, service account, or group) executing gcloud-kms-decrypt must have the <I>cloudkms.cryptoKeyDecrypter</I> role granted on the specific KMS key or its parent resources (key ring, project). This role allows the principal to use the key for decryption operations.


title: INPUT/OUTPUT DATA HANDLING
content:
The command is designed to work with file-based input and output. For small pieces of data, base64 encoding/decoding might be necessary if the ciphertext is provided directly on the command line or via standard input, as <I>gcloud kms encrypt</I> typically outputs base64-encoded ciphertext.


title: HISTORY
content:
Google Cloud Key Management Service (KMS) was officially launched in 2017, providing a managed service for cryptographic keys. The <I>gcloud</I> CLI has since evolved to include comprehensive support for KMS operations, allowing users to manage keys and perform encryption/decryption operations directly from the command line. The <I>gcloud kms decrypt</I> functionality, which gcloud-kms-decrypt likely wraps or mirrors, has been a core component of this offering, enabling secure data handling in cloud environments.


title: SYNOPSIS
content:
<b>gcloud logging logs list</b> [<i>LOG_NAMES ...</i>] [<b>--log-filter</b>=<i>EXPRESSION</i>] [<b>--limit</b>=<i>LIMIT</i>] [<b>--page-size</b>=<i>PAGE_SIZE</i>] [<b>--sort-by</b>=<i>FIELD,...</i>] [<b>--uri</b>] [<i>GLOBAL_FLAGS</i>]


title: PARAMETERS
content:
<b><i>LOG_NAMES ...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more log names to list. If unspecified, all logs within the project are listed. Log names often include service prefixes, like <i>cloudfunctions.googleapis.com%2Fcloud-functions</i>.<br><br><b><b>--log-filter</b>=<i>EXPRESSION</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A filter expression that filters the logs listed by name. This allows for advanced filtering based on log properties, such as resource type or service. For example: 'resource.type="gce_instance"'.<br><br><b><b>--limit</b>=<i>LIMIT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The maximum number of logs to list. This is useful for restricting the output size for very large projects or for quick checks.<br><br><b><b>--page-size</b>=<i>PAGE_SIZE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The maximum number of logs to retrieve per API call. This can affect performance and memory usage for commands that return a large number of results.<br><br><b><b>--sort-by</b>=<i>FIELD,...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of fields to sort the results by. The default sort order is typically alphanumeric by log name.<br><br><b><b>--uri</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If specified, only the URIs of the logs are displayed, providing a concise output suitable for scripting.<br><br>


title: DESCRIPTION
content:
<i>gcloud logging logs list</i> is a command within the Google Cloud SDK that allows users to enumerate the logs present in a specified Google Cloud project. This command is part of the <i>gcloud logging</i> component, which provides comprehensive tools for interacting with Google Cloud Logging. By default, if no specific log names are provided, it fetches and displays a list of all distinct log names that have recorded entries within the project. Users can also specify one or more log names as positional arguments to filter the output and list only those specific logs. This functionality is crucial for administrators and developers to understand the logging landscape of their projects, identify active log streams, and prepare for more granular operations like reading specific log entries or managing log sinks.


title: CAVEATS
content:
This command requires the Google Cloud SDK to be installed and configured with appropriate authentication. The user's Google Cloud IAM role must include permissions to list logs (e.g., <i>logging.logs.list</i> or the broader <i>roles/logging.viewer</i>). The command operates on the currently configured project, which can be overridden using the global <i>--project</i> flag. Listing a very large number of logs might take time, and pagination options (<i>--limit</i>, <i>--page-size</i>) can be helpful for performance management.


title: PERMISSIONS REQUIRED
content:
To successfully execute <i>gcloud logging logs list</i>, your Google Cloud account must have an IAM role that grants the <i>logging.logs.list</i> permission. Common roles that include this permission are <i>roles/logging.viewer</i> (Logs Viewer) or <i>roles/owner</i> (Project Owner).


title: DEFAULT PROJECT
content:
The command operates on the Google Cloud project that is currently configured in your <i>gcloud</i> CLI environment. You can set or change the default project using <i>gcloud config set project [PROJECT_ID]</i> or by providing the global <i>--project=[PROJECT_ID]</i> flag with the command.


title: HISTORY
content:
The <i>gcloud</i> command-line tool is a core component of the Google Cloud SDK, first released in 2013, and continuously updated. The <i>logging</i> component, which interfaces with Google Cloud Logging (formerly Stackdriver Logging), has evolved significantly to support the growing capabilities of cloud logging. The <i>logs list</i> subcommand has been a fundamental part of the logging management toolset since early versions, providing a basic but essential inventory capability for cloud log data.


title: SEE ALSO
content:
gcloud logging logs describe(1), gcloud logging logs delete(1), gcloud logging read(1), gcloud logging sinks list(1)


title: SYNOPSIS
content:
<code>gcloud projects <I>SUBCOMMAND</I> [<I>GLOBAL_OPTIONS</I>]</code><br><br>Common <code><I>SUBCOMMANDS</I></code> include:<br><ul><li><code>list</code>: List all active projects.</li><li><code>create</code>: Create a new project.</li><li><code>delete</code>: Mark a project for deletion.</li><li><code>describe</code>: Display details about a project.</li><li><code>get-iam-policy</code>: Get the IAM policy for a project.</li><li><code>set-iam-policy</code>: Set the IAM policy for a project.</li><li><code>add-iam-policy-binding</code>: Add an IAM policy binding to a project.</li><li><code>remove-iam-policy-binding</code>: Remove an IAM policy binding from a project.</li><li><code>update</code>: Update a project's attributes.</li></ul>


title: PARAMETERS
content:
<b><code><I>SUBCOMMAND</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The specific operation to perform on a project. Each subcommand has its own set of arguments and options.<br><br><b><code>--filter=<I>EXPRESSION</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a resource filter to limit the output of <code>list</code> operations based on property values.<br><br><b><code>--format=<I>FORMAT</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output format (e.g., <code>json</code>, <code>yaml</code>, <code>text</code>, <code>table</code>) for command results.<br><br><b><code>--limit=<I>INTEGER</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Maximum number of resources to list (e.g., with <code>list</code> subcommand).<br><br><b><code>--sort-by=<I>FIELD</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort list output by the specified field (e.g., <code>list</code> subcommand).<br><br><b><code>--project=<I>PROJECT_ID_OR_NUMBER</I></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The ID or number of the project to operate on. Often required for specific operations like <code>describe</code> or <code>delete</code>.<br><br><b><code>--quiet</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable interactivity and prompt for input. Automatically assume 'yes' to prompts.<br><br><b><code>--help</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help for the command group or a specific subcommand.<br><br>


title: DESCRIPTION
content:
<code>gcloud projects</code> is a <b>command group</b> within the <b>Google Cloud CLI (gcloud CLI)</b>, specifically designed for managing Google Cloud projects.<br><br>It provides comprehensive functionalities to:<br><ul><li>List existing projects.</li><li>Create new projects.</li><li>Delete projects.</li><li>Describe project details.</li><li>Manage Identity and Access Management (IAM) policies, including getting, setting, adding, and removing bindings for project-level permissions.</li><li>Update project attributes.</li></ul>This command group is essential for administrators and developers working with Google Cloud, enabling programmatic control over project lifecycles and access permissions. It allows users to interact directly with the Cloud Resource Manager API from the command line, facilitating automation and scripting of project-related tasks.


title: CAVEATS
content:
<ul><li><b>Permissions:</b> Operations like <code>create</code>, <code>delete</code>, and <code>set-iam-policy</code> require specific <I>IAM permissions</I> (e.g., <code>resourcemanager.projects.create</code>, <code>resourcemanager.projects.delete</code>) on the organization or billing account.</li><li><b>Project Deletion:</b> Project deletion is <I>irreversible</I> after a 30-day grace period during which the project is quarantined. During this period, the project can be undeleted.</li><li><b>Billing:</b> Creating projects does not inherently incur costs, but provisioning resources within them will typically require an active <I>billing account</I> and may generate charges.</li><li><b>API Enablement:</b> Certain actions or managing specific resources within a project might require the corresponding Google Cloud APIs to be enabled within that project first.</li></ul>


title: RESOURCE HIERARCHY AND PROJECTS
content:
Google Cloud projects are a fundamental building block of the Google Cloud resource hierarchy. They serve as distinct organizational containers for all Google Cloud resources (e.g., Compute Engine instances, Cloud Storage buckets, BigQuery datasets), billing, and Identity and Access Management (IAM) policies. Understanding and effectively managing projects is crucial for robust resource organization, cost management, and access control within Google Cloud environments.


title: DEFAULT PROJECT CONFIGURATION
content:
Many <code>gcloud</code> commands operate on a default project, which can be conveniently set using <code>gcloud config set project <I>PROJECT_ID</I></code>. This configuration simplifies command invocation by eliminating the need to explicitly specify the <code>--project</code> flag for every command that targets a specific project, unless an override is required for a particular operation.


title: HISTORY
content:
The <code>gcloud CLI</code> is the primary command-line interface for Google Cloud, evolving from earlier specialized tools. The <code>gcloud projects</code> command group has been a core component since the early days of the <code>gcloud CLI</code>, reflecting the foundational role of projects in the Google Cloud resource hierarchy.<br><br>Its functionality has consistently expanded over time to cover more aspects of project management, including comprehensive IAM policy control, integration with the Cloud Resource Manager API, and alignment with Google Cloud's evolving best practices for resource organization.


title: PARAMETERS
content:
<b><i>BACKUP_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The integer ID of the backup to describe. This ID can be obtained from the output of <b>gcloud sql backups list</b> or found in the Google Cloud Console.<br><br><b><b>--instance=</b><i>INSTANCE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the Cloud SQL instance for which the backup details are being requested. This is a required flag to specify the target instance.<br><br>


title: DESCRIPTION
content:
The <b>gcloud sql backups describe</b> command retrieves comprehensive and detailed information about a specific backup associated with a Google Cloud SQL instance. This command is essential for administrators and developers who need to thoroughly inspect various attributes of a backup, such as its unique ID, the instance it belongs to, its exact start and end times, total size, current status (e.g., SUCCESSFUL, FAILED), the type of backup (automatic or on-demand), and the specific database version covered. It provides a complete overview, enabling users to monitor backup progress, verify successful completions, or retrieve critical details for advanced auditing, troubleshooting, and compliance purposes within their Cloud SQL environment.


title: CAVEATS
content:
Requires the <i>cloudsql.backups.get</i> IAM permission for the specified Cloud SQL instance.<br>The specified <i>BACKUP_ID</i> must exist and belong to the provided <i>INSTANCE</i>, otherwise the command will return a 'not found' error.<br>Network connectivity to Google Cloud APIs is necessary for the command to execute successfully.


title: OUTPUT FORMAT
content:
By default, the command outputs the backup details in a human-readable table format. For programmatic use, it is highly recommended to combine it with global flags such as <b>--format=json</b> or <b>--format=yaml</b> to retrieve machine-readable output, which is invaluable for scripting, automation, and integration with other tools.


title: REQUIRED PERMISSIONS
content:
To successfully execute this command, the calling principal (user account or service account) must possess IAM roles that grant the <i>cloudsql.backups.get</i> permission on the specific Cloud SQL instance. Common roles that include this permission are <i>Cloud SQL Client</i> and <i>Cloud SQL Viewer</i>.


title: HISTORY
content:
The <b>gcloud</b> CLI, including the Cloud SQL command group, has evolved significantly since its inception to provide robust management capabilities for Google Cloud resources. The <b>gcloud sql backups describe</b> command, as part of this evolution, has been a core utility for inspecting backup resources, reflecting Google Cloud's commitment to providing detailed visibility into database operations and data protection strategies across various Cloud SQL versions and configurations.


title: SEE ALSO
content:
gcloud sql backups list(1), gcloud sql backups create(1), gcloud sql operations describe(1), gcloud sql instances describe(1)


title: PARAMETERS
content:
<b><I>TOPIC</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the conceptual topic for which to display help. Examples include <I>conventions</I>, <I>configurations</I>, <I>filters</I>, <I>formatting</I>, <I>project-id</I>, <I>authentication</I>.<br><br><b>list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available conceptual topics that can be queried with <b>gcloud topic</b>.<br><br>


title: DESCRIPTION
content:
gcloud topic is a subcommand of the Google Cloud CLI <b>gcloud</b> tool, designed to provide conceptual and high-level help on various aspects of Google Cloud. Unlike <b>gcloud COMMAND --help</b>, which offers specific usage details for a particular command, <b>gcloud topic</b> delves into broader, foundational areas such as authentication, project management, working with filters and projections, data formatting, and common conventions used across the <b>gcloud</b> CLI.<br><br>It serves as a valuable resource for understanding the underlying principles and configurations of the <b>gcloud</b> environment, rather than just command-line syntax. Users can list all available topics or request detailed information on a specific one.


title: CAVEATS
content:
<b>gcloud topic</b> is a subcommand of the <b>gcloud</b> command-line tool, which is part of the Google Cloud SDK. It is not a standalone Linux utility.<br><br>It provides conceptual help and overviews, not detailed command-line syntax or operational examples for specific <b>gcloud</b> commands. For command-specific help, use <b>gcloud <I>COMMAND</I> --help</b>.


title: FINDING AVAILABLE TOPICS
content:
To discover all the conceptual topics you can explore, use <b>gcloud topic list</b>. This command will output a list of all available topics, which you can then use with <b>gcloud topic <I>TOPIC_NAME</I></b>.


title: GLOBAL FLAGS
content:
Like most <b>gcloud</b> commands, <b>gcloud topic</b> also supports various global <b>gcloud</b> flags (e.g., <b>--help</b>, <b>--verbosity</b>, <b>--format</b>). These flags control aspects like output formatting, logging levels, or displaying help information for the <b>gcloud topic</b> command itself.


title: HISTORY
content:
The <b>gcloud</b> command-line tool, along with its <b>topic</b> subcommand, has been an integral part of the Google Cloud SDK since its inception. It was developed by Google to provide a consistent and programmatic interface for interacting with Google Cloud services. The <b>topic</b> feature was designed to complement operational command help by offering conceptual guidance, which became increasingly important as the <b>gcloud</b> CLI grew in complexity and scope. Its structure has evolved to reflect the ongoing development and expansion of Google Cloud services and the SDK itself.


title: SEE ALSO
content:
gcloud(1) (The main Google Cloud CLI command), gcloud --help (Provides general help for the gcloud command and lists top-level command groups.), gcloud <I>COMMAND</I> --help (Displays detailed help for a specific gcloud command, including its arguments, flags, and examples.)


title: PARAMETERS
content:
<b>--only-cli</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays only the core <i>gcloud</i> CLI version, omitting the detailed list of installed components (like <i>gsutil</i>, <i>bq</i>, etc.) and system information.<br><br>


title: DESCRIPTION
content:
The <b>gcloud version</b> command is an essential utility within the Google Cloud SDK, designed to provide a comprehensive overview of the installed <i>gcloud</i> CLI and its associated components. When executed, it typically displays the version of the <i>gcloud</i> command-line tool itself, along with the versions of various <i>gcloud</i> components like <i>gsutil</i>, <i>bq</i>, and others that are part of your SDK installation. Beyond just component versions, it often includes valuable system information such as the Python version being used by the SDK and details about the operating system.<br><br>This command is invaluable for troubleshooting, verifying successful SDK installations, and confirming that specific components are up-to-date. While a quick <i>gcloud --version</i> might provide just the main CLI version, <b>gcloud version</b> offers a more detailed breakdown, making it the preferred choice for a thorough version check. It helps users quickly ascertain the exact environment they are working with, which is crucial for debugging compatibility issues or ensuring that the correct tool versions are present for specific tasks.


title: CAVEATS
content:
The command requires the Google Cloud SDK to be installed and properly configured on the system. The exact output format and listed components may vary slightly depending on the SDK version, installed components, and the operating system.


title: TYPICAL OUTPUT EXAMPLE
content:
A common output from <b>gcloud version</b> might look like this:<br><br><pre>Google Cloud SDK 465.0.0<br>bq 2.0.100<br>core 2024.03.15<br>gsutil 5.28<br><br>Python 3.10.12 (64-bit)<br>Runtime: Python<br>Locale: en_US<br>Platform: Linux-6.5.0-26-generic-x86_64-with-glibc2.35<br>Modules: Pylint, numpy, requests, google-auth, OpenSSL, setuptools<br>gcloud: [location]<br>bq: [location]<br>gsutil: [location]</pre><br>Note that the <i>[location]</i> placeholders will be actual file paths on your system.


title: HISTORY
content:
The <b>gcloud version</b> command has been a fundamental part of the Google Cloud SDK since its early iterations. Its primary function, to report the versions of the CLI and its components, has remained consistent. As the Google Cloud ecosystem and the SDK evolved, the command's output expanded to include more granular component details and system information, reflecting the growing complexity and modularity of the SDK. It has consistently served as a quick diagnostic tool for developers and administrators.


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version information and exits.<br><br>


title: DESCRIPTION
content:
<i>gconf-schemas</i> is a utility from the GConf configuration system, primarily used in older GNOME 2 environments. Its core function is to compile GConf XML schema definition files (typically with a <i>.schemas</i> extension) into a more efficient binary format (<i>.compiled</i>). These compiled schemas are then used by the GConf daemon (<i>gconfd-2</i>) to understand and validate application preferences. This command is typically invoked automatically during the installation of software packages that provide GConf schemas, ensuring that the system's GConf database is updated with new or modified schema definitions. While essential for GConf-based systems, GConf itself has been largely replaced by DConf in modern GNOME versions, making <i>gconf-schemas</i> less relevant today for new development or typical user interaction.


title: CAVEATS
content:
GConf, and consequently <i>gconf-schemas</i>, is largely deprecated. Modern GNOME environments have transitioned to DConf for configuration management. This command is primarily relevant for maintaining or interacting with legacy systems running older GNOME versions or applications still relying on GConf.


title: SCHEMA LOCATION
content:
GConf schemas are typically installed in system-wide directories such as <i>/etc/gconf/schemas/</i> or <i>/usr/share/gconf/schemas/</i>. The <i>gconf-schemas</i> command scans these predefined locations to find and compile schema definitions.


title: COMPILATION PROCESS
content:
The command transforms human-readable XML schema files (e.g., <i>my-application.schemas</i>) into binary <i>.compiled</i> files. These compiled files are then loaded by the GConf daemon (<i>gconfd-2</i>) to validate and manage configuration keys for applications.


title: HISTORY
content:
GConf was the standard configuration system for the GNOME 2 desktop environment, designed to provide a centralized, XML-based storage for application preferences. <i>gconf-schemas</i> played a crucial role in compiling these schemas for efficient use by the GConf daemon. With the advent of GNOME 3 and later desktop environments, GConf began to be phased out in favor of DConf, a more performant and simpler configuration system. As such, <i>gconf-schemas</i>'s relevance has diminished over time.


title: SYNOPSIS
content:
<b>gcore</b> [<I>OPTION</I>]... <I>PID</I><br>Where <I>PID</I> is the process ID of the target running process.


title: PARAMETERS
content:
<b><b>-o</b> <I>FILE</I>, <b>--output=</b><I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output core dump file. If this option is omitted, `gcore` defaults to creating a file named `core.<I>PID</I>` in the current working directory, where `<I>PID</I>` is the process ID of the dumped process.<br><br>


title: DESCRIPTION
content:
`gcore` is a utility that generates a core dump file from a currently running process. This is particularly useful for post-mortem debugging, allowing developers and system administrators to inspect the memory state of a program at a specific point in time without terminating it. Unlike terminating a process with `SIGSEGV` or similar signals which might generate a core dump, `gcore` allows you to non-invasively capture the process's memory snapshot. The generated core file can then be loaded into a debugger like `gdb` to analyze the program's state, variables, and call stack, helping to diagnose issues like crashes, hangs, or unexpected behavior. It effectively freezes the process briefly to take the snapshot, minimizing disruption to a live system.


title: CAVEATS
content:
<b>Permissions:</b> To generate a core dump, `gcore` typically requires the same user ID as the target process or root privileges.<br><b>Process State:</b> While `gcore` aims to be non-invasive, it briefly pauses the target process to capture the memory state. This pause, though usually very short, might impact real-time applications or sensitive systems.<br><b>Disk Space:</b> Core dump files can be very large, consuming significant disk space, especially for processes with large memory footprints. Ensure sufficient free space before generating a dump.<br><b>`ptrace` limitations:</b> `gcore` relies on the `ptrace` system call. If `ptrace` is restricted (e.g., via `YAMA` security module, `sysctl kernel.ptrace_scope`), `gcore` might fail.


title: ANALYZING THE CORE DUMP
content:
Once a core dump file (`core.<I>PID</I>` or a custom file name) is generated, it can be loaded into `gdb` for analysis. The typical command for this is:<br><b>gdb</b> <I>executable_path</I> <I>core_file_path</I><br>For example: <b>gdb</b> /usr/bin/myprogram core.12345<br>Inside `gdb`, you can then use commands like <b>bt</b> (backtrace), <b>info locals</b>, <b>print variable</b>, etc., to inspect the program's state at the time the core dump was taken.


title: HISTORY
content:
The `gcore` utility is typically distributed as part of the `gdb` (GNU Debugger) package or the `binutils` project. Its development is intertwined with `gdb`'s capabilities, providing a standalone method to achieve what `gdb` can do interactively: capture a process's memory image for later inspection. It emerged as a convenient tool for system administrators and developers needing to quickly diagnose issues on live systems without having to attach `gdb` and then manually detach.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the <i>gcov</i> version number and exits.<br><br><b><b>-a</b>, <b>--all-blocks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show information for every basic block, not just lines.<br><br><b><b>-b</b>, <b>--branches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display branch probability information, showing how often each branch was taken or not taken.<br><br><b><b>-f</b>, <b>--function-summaries</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a summary of how many times each function in the source file was called.<br><br><b><b>-o</b> <<i>directory</i>|<i>file</i>>, <b>--object-directory</b> <<i>directory</i>>, <b>--object-file</b> <<i>file</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the directory where the <b>.gcno</b> and <b>.gcda</b> files are located, or the specific object file.<br><br><b><b>-i</b>, <b>--json-format</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the coverage results in JSON format (available in newer GCC/<i>gcov</i> versions).<br><br><b><b>-l</b>, <b>--long-file-names</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use long, full path filenames in the output, useful when multiple files with the same name exist.<br><br><b><b>-p</b>, <b>--preserve-paths</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preserve the full path information from the object file when generating output, rather than just the filename.<br><br>


title: DESCRIPTION
content:
<i>gcov</i> is a command-line utility that provides code coverage analysis for programs compiled with GCC. It works by processing profile data generated during program execution, which is created when the code is compiled with specific GCC flags (typically <b>-fprofile-arcs -ftest-coverage</b>).<br><br>After an instrumented program runs, <i>gcov</i> analyzes the generated <b>.gcda</b> (data) and <b>.gcno</b> (notes) files to produce human-readable <b>.gcov</b> reports. These reports indicate how many times each line of code was executed, identify lines that were never reached, and provide detailed branch coverage information.<br><br>It is an invaluable tool for software testing, helping developers measure the effectiveness of their test suites, pinpoint untested code paths, and ensure comprehensive code coverage, thereby improving software quality and reliability.


title: CAVEATS
content:
<i>gcov</i> requires the program to be compiled with specific GCC flags (<b>-fprofile-arcs -ftest-coverage</b>) to generate the necessary profiling data.<br><br>It must be run in an environment where the original source files and the generated <b>.gcda</b> and <b>.gcno</b> files are accessible, usually in the same directory as the object file or specified via <b>-o</b>.<br><br>It's a low-level tool; for generating graphical or aggregate reports, it's often used in conjunction with other tools like <i>lcov</i>.


title: WORKFLOW
content:
The typical workflow for using <i>gcov</i> involves three main steps:<br>1. <b>Compilation:</b> Compile your source code with GCC using the <b>-fprofile-arcs -ftest-coverage</b> flags.<br>2. <b>Execution:</b> Run the compiled executable. This generates <b>.gcda</b> files containing execution counts.<br>3. <b>Analysis:</b> Run <i>gcov</i> on the original source files. <i>gcov</i> processes the <b>.gcda</b> and <b>.gcno</b> files to generate <b>.gcov</b> output files, showing line-by-line coverage.


title: OUTPUT FILES
content:
<i>gcov</i> relies on and produces specific file types:<br><b>.gcno</b> (<i>graph notes</i>): Generated during compilation with <b>-ftest-coverage</b>, contains control flow graph and source line information.<br><b>.gcda</b> (<i>graph data</i>): Generated during program execution, contains execution counts for basic blocks and arcs.<br><b>.gcov</b> (<i>coverage output</i>): Generated by <i>gcov</i>, a human-readable text file showing coverage statistics for each line of the source file.


title: HISTORY
content:
<i>gcov</i> has been an integral part of the GNU Compiler Collection (GCC) since its early versions, evolving alongside the compiler itself. Initially, it provided basic line coverage. Over time, its capabilities expanded to include branch coverage, function summaries, and more sophisticated output formats, including the recent addition of JSON output, reflecting the growing demand for automated and parseable coverage data in modern CI/CD pipelines. It has consistently served as the foundational tool for code coverage analysis within the GNU/Linux ecosystem.


title: SYNOPSIS
content:
<i>gcov-4.8</i> [<i>OPTIONS</i>] <i>SOURCE_FILE</i><br><i>gcov-4.8</i> [<i>OPTIONS</i>] <i>OBJECT_FILE</i>


title: PARAMETERS
content:
<b>-a, --all-blocks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show information for all basic blocks, even empty ones.<br><br><b>-b, --branches</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display branch probabilities and execution counts.<br><br><b>-c, --checksum</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verify data files against source file checksum for consistency.<br><br><b>-f, --function-summaries</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a summary for each function within the source file.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a summary of command-line options.<br><br><b>-l, --long-file-names</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use long, unique file names for output, including full paths.<br><br><b>-m, --demangled-names</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Demangle C++ symbol names in the output.<br><br><b>-n, --no-output</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not create any .gcov files; useful for checksum validation.<br><br><b>-o <<i>DIR</i>>, --object-directory=<<i>DIR</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the directory containing object files and profile data.<br><br><b>-p, --preserve-paths</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preserve the full path to source files when creating output.<br><br><b>-r, --relative-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show only relative paths in the output, stripping absolute prefixes.<br><br><b>-s, --stop-on-errors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stop processing if an error is encountered during analysis.<br><br><b>-t, --stdout</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the coverage report to standard output instead of a file.<br><br><b>-u, --unconditional-branches</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display execution counts for unconditional branches.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the gcov version information.<br><br>


title: DESCRIPTION
content:
<i>gcov-4.8</i> is a command-line utility, part of the GNU Compiler Collection (GCC) 4.8, designed for analyzing code coverage of programs compiled with GCC. It helps developers understand which parts of their source code are executed when a program runs, aiding in identifying untested code paths and improving test suite effectiveness.<br><br>To use <i>gcov-4.8</i>, source files must first be compiled with GCC using the <b>-fprofile-arcs</b> and <b>-ftest-coverage</b> flags. This instrumentation generates two types of files: <b>.gcno</b> files (notes) during compilation, and <b>.gcda</b> files (data) during program execution. After the instrumented program runs, <i>gcov-4.8</i> processes these <b>.gcno</b> and <b>.gcda</b> files, along with the original source files, to produce detailed coverage reports. These reports typically show execution counts for each line of code, branch probabilities, and function call counts, outputting to files with a <b>.gcov</b> extension.


title: CAVEATS
content:
<b>1. Requires Specific Compilation Flags:</b> Programs must be compiled with <b>-fprofile-arcs</b> and <b>-ftest-coverage</b>.<br><b>2. Runtime Overhead:</b> The instrumentation adds runtime overhead to the instrumented program, which can affect performance.<br><b>3. Verbose Output:</b> Outputs text-based reports directly, which can be lengthy; external tools like <b>lcov</b> are commonly used for aggregation and generating HTML reports.<br><b>4. Language Support:</b> Primarily designed for C, C++, and Fortran source files.<br><b>5. Version Compatibility:</b> Compatibility is generally tied to the GCC version that generated the profile data (e.g., <i>gcov-4.8</i> is best used with data from GCC 4.8).


title: WORKING PRINCIPLE
content:
The typical workflow for using <i>gcov-4.8</i> involves three main steps:<br><br>1.  <b>Compilation:</b> Compile your source code with GCC using the <b>-fprofile-arcs</b> and <b>-ftest-coverage</b> flags. This instruments the code and generates <b>.gcno</b> (graph notes) files.<br>2.  <b>Execution:</b> Run the compiled program. As it executes, it records profiling data into <b>.gcda</b> (graph data) files.<br>3.  <b>Analysis:</b> Execute <i>gcov-4.8</i> on the original source files (or object files). <i>gcov-4.8</i> then reads the <b>.gcno</b> and <b>.gcda</b> files to produce human-readable coverage reports, usually named with a <b>.gcov</b> extension, in the same directory as the source file or specified output directory.


title: OUTPUT FILES
content:
<i>gcov-4.8</i> relies on and generates specific file types:<br><br><b>.gcno files:</b> Generated during compilation with <b>-ftest-coverage</b>. These contain a graph of the program's control flow.<br><b>.gcda files:</b> Generated during program execution with <b>-fprofile-arcs</b>. These contain dynamic execution counts for edges and blocks.<br><b>.gcov files:</b> The human-readable output files generated by <i>gcov-4.8</i>. They annotate the original source code with execution counts for each line and often include branch and function summaries.


title: HISTORY
content:
<i>gcov</i> has been an integral part of the GNU Compiler Collection (GCC) since its early versions, evolving alongside the compiler itself to provide robust code coverage analysis. Its development focused on offering a reliable method for developers to assess the effectiveness of their test suites.<br><br>The <i>gcov-4.8</i> variant signifies its distribution with GCC version 4.8, a widely adopted and stable release family during the 2010s. This version, like its predecessors and successors, plays a crucial role in software quality assurance by helping to identify untested code paths, thereby guiding developers to improve test coverage and overall code reliability. Its core functionality has remained consistent, though minor enhancements and bug fixes have been introduced across GCC versions.


title: SYNOPSIS
content:
<b>gcpdiag</b> [<i>global-options</i>] &lt;<i>command</i>&gt; [<i>command-options</i>] [<i>arguments</i>]<br>Example: <b>gcpdiag projects</b> &lt;<i>project-id</i>&gt; [--json]<br>Example: <b>gcpdiag rules list</b>


title: PARAMETERS
content:
<b>--project &lt;project-id&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Google Cloud project ID to diagnose.<br><br><b>--billing-project &lt;project-id&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the project ID to use for billing purposes, useful when diagnosing a project without active billing.<br><br><b>--log-level &lt;level&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adjusts the verbosity of log output. Possible levels include <i>debug</i>, <i>info</i>, <i>warning</i>, <i>error</i>.<br><br><b>--output &lt;format&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Determines the output format of the diagnostic results. Options include <i>text</i> (default), <i>json</i>, and <i>json-pretty</i>.<br><br><b>--rule &lt;rule-id&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes only the specified diagnostic rule(s). Multiple rules can be provided as a comma-separated list.<br><br><b>--resource-type &lt;type&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Limits the diagnostic scan to specific types of resources (e.g., <i>gce_instance</i>, <i>gke_cluster</i>).<br><br><b>--run-in-gce</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs <i>gcpdiag</i> within a Google Compute Engine instance to diagnose issues related to the host VM.<br><br><b>--auth-url &lt;url&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom URL for the authentication server, for advanced authentication configurations.<br><br><b>--api-url &lt;url&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a custom URL for the Google Cloud API endpoint, useful for private API access or testing.<br><br><b>--enable-gce-serial-port-access</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables access to the Google Compute Engine serial port, required for certain deep VM diagnostics. Requires appropriate IAM permissions.<br><br><b>projects &lt;project-id&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A subcommand used to initiate a diagnostic scan of a specific Google Cloud project.<br><br><b>rules list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A subcommand to list all available diagnostic rules with their descriptions.<br><br>


title: DESCRIPTION
content:
<i>gcpdiag</i> is a powerful open-source command-line tool designed to help users diagnose common issues and misconfigurations within their Google Cloud Platform projects. It automatically scans for unhealthy resources, security vulnerabilities, performance bottlenecks, and operational best practices violations by applying a comprehensive set of diagnostic rules. The tool provides actionable insights and recommended solutions, making it invaluable for SREs, developers, and cloud administrators to maintain the health, security, and efficiency of their GCP environments. It supports scanning entire projects or specific assets, and its output can be customized for various formats, including JSON and console-friendly text.


title: CAVEATS
content:
Running <i>gcpdiag</i> requires appropriate <B>IAM permissions</B> to access various Google Cloud resources and APIs. Depending on the project's size and the rules executed, it might generate a significant number of API calls, potentially affecting <B>API rate limits</B> or incurring <B>operational costs</B>. Not all diagnostic rules apply to all services or regions, and some may require specific Google Cloud APIs to be enabled.


title: INSTALLATION
content:
<i>gcpdiag</i> can be installed using Python's package installer with <b>pip install gcpdiag</b>. Alternatively, it is available as a component of the <b>gcloud CLI</b>, installable via <b>gcloud components install gcpdiag</b>.


title: REQUIRED PERMISSIONS
content:
To effectively diagnose a project, the executing principal (user or service account) needs sufficient IAM roles. Commonly required roles include <i>Project Viewer</i>, <i>Security Reviewer</i>, and specific <i>Viewer</i> roles for services like Compute Engine, Kubernetes Engine, Cloud SQL, etc. Access to Cloud Logging and Monitoring data is also crucial for comprehensive analysis.


title: EXTENSIBILITY
content:
One of <i>gcpdiag</i>'s strengths is its extensibility. Users and contributors can develop and submit new diagnostic rules, allowing the tool to adapt and provide insights into new services, emerging issues, or specific organizational best practices.


title: HISTORY
content:
<i>gcpdiag</i> is an open-source tool developed by Google Cloud to empower users and support teams with self-service diagnostic capabilities. Its development emerged from the growing complexity of cloud environments and the need for automated troubleshooting. Actively maintained on GitHub, it continuously evolves with new diagnostic rules and features, reflecting the latest Google Cloud services and best practices.


title: SYNOPSIS
content:
<b>gcrane</b> <I>command</I> [ <I>options</I>... ] <br><br>Where <I>command</I> refers to a subcommand of the underlying `crane` tool, such as `pull`, `push`, `copy`, or `delete`. `gcrane` handles the necessary authentication to Google Cloud registries automatically.


title: PARAMETERS
content:
<b><I>pull</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pulls an image from a Google Cloud registry to local storage or stdout.<br><br><b><I>push</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pushes an image or OCI layout to a Google Cloud registry.<br><br><b><I>copy</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies an image from one Google Cloud registry or any other registry to another.<br><br><b><I>delete</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes an image or tag from a Google Cloud registry.<br><br><b><I>ls</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all tags for a given repository in a Google Cloud registry.<br><br><b><I>digest</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the manifest digest for a specific image in a Google Cloud registry.<br><br><b><I>config</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fetches the image configuration (OCI config) for an image from a Google Cloud registry.<br><br><b><I>tag</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds or removes tags on an image in a Google Cloud registry.<br><br><b><I>mutate</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies modifications to an image's manifest (e.g., adding layers, changing config).<br><br>


title: DESCRIPTION
content:
`gcrane` is a specialized command-line tool designed to simplify interactions with <I>Google Container Registry (GCR)</I> and <I>Artifact Registry</I>. It acts as a convenient wrapper around the powerful <I>crane</I> utility from the <I>go-containerregistry</I> project.<br><br>Its primary benefit lies in automating authentication to Google Cloud's various container image services, leveraging your existing `gcloud` credentials. While `crane` itself provides extensive functionality for manipulating container images, `gcrane` removes the complexity of manual authentication setup, allowing users to seamlessly perform operations like pulling, pushing, copying, and deleting images and tags within the Google Cloud ecosystem. It's particularly useful for CI/CD pipelines and scripting where seamless interaction with Google Cloud's container registries is required without manual credential management.


title: CAVEATS
content:
Not a standard Linux distribution command; it must be installed separately. It relies heavily on `gcloud` for authentication, so `gcloud` must be configured and authenticated to your Google Cloud project. <br>While it simplifies GCR/Artifact Registry interactions, understanding the underlying `crane` commands and image registry concepts is still beneficial.


title: AUTHENTICATION
content:
The primary benefit of `gcrane` is its automatic authentication. It uses your default `gcloud` credentials to authenticate requests to Google Container Registry and Artifact Registry. This means you do not need to manually configure Docker credential helpers or pass explicit authentication tokens, making it ideal for scripts and CI/CD environments where `gcloud` is already configured.


title: INSTALLATION
content:
`gcrane` is typically installed as a Go binary. You can usually find pre-built binaries on its GitHub releases page, or compile it from source if Go is installed: <br><b>go install github.com/google/go-containerregistry/cmd/gcrane@latest</b>


title: HISTORY
content:
`gcrane` is part of the broader `go-containerregistry` project, which is a collection of Go libraries and tools for working with OCI (Open Container Initiative) image formats and registries. Developed by Google, `gcrane` specifically emerged to streamline the authentication challenges faced when using `crane` directly with Google Container Registry and Artifact Registry, thereby enhancing usability for Google Cloud users. Its development reflects the increasing need for programmatic and scripting-friendly interactions with container registries in modern cloud-native workflows.


title: PARAMETERS
content:
<b><i>SHELL_NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the shell for which to generate the completion script. Common valid values include <b>bash</b>, <b>zsh</b>, <b>fish</b>, or <b>powershell</b>. The generated script is printed to standard output.<br><br>


title: DESCRIPTION
content:
The <b>gcrane-completion</b> command, typically a wrapper script or a conceptual reference to the <b>gcrane completion</b> subcommand, is designed to generate shell auto-completion scripts for the <i>gcrane</i> utility.<br><br>The <i>gcrane</i> tool itself is used for interacting with Google Container Registry (GCR) and Artifact Registry. By executing this command with a specified shell name (e.g., <i>bash</i>, <i>zsh</i>), users can obtain a script that, when sourced into their shell configuration (like <i>.bashrc</i> or <i>.zshrc</i>), provides intelligent auto-completion for <i>gcrane</i> commands, subcommands, and flags.<br><br>This feature significantly enhances command-line productivity by reducing typing and preventing common syntax errors, making <i>gcrane</i> more user-friendly for routine operations.


title: CAVEATS
content:
To activate the completion functionality, the generated script must be <i>sourced</i> into your shell's configuration (e.g., <i>~/.bashrc</i>, <i>~/.zshrc</i>, <i>~/.config/fish/completions/gcrane.fish</i>).<br><br>The <b>gcrane</b> executable must be installed and accessible in your system's <i>PATH</i> for the completion to work correctly.<br><br>PowerShell completion might require specific PowerShell module installations or versions depending on your environment.


title: ACTIVATION EXAMPLES
content:
To permanently enable shell completion, you typically add a line to your shell's configuration file:<br><br><i>For Bash:</i><br><i>echo 'source <(gcrane-completion bash)' >> ~/.bashrc</i><br><i>source ~/.bashrc</i><br><br><i>For Zsh:</i><br><i>echo 'autoload -Uz compinit; compinit'</i><br><i>echo 'source <(gcrane-completion zsh)' >> ~/.zshrc</i><br><i>source ~/.zshrc</i><br><br>Note: If <b>gcrane-completion</b> is not a direct executable but rather <b>gcrane completion</b>, replace <b>gcrane-completion</b> with <b>gcrane completion</b> in the above commands.


title: OUTPUT
content:
The command prints the full shell completion script to standard output. Users often redirect this output to a file (e.g., <i>gcrane-completion bash > /etc/bash_completion.d/gcrane</i>) or source it directly using process substitution (e.g., <i>source <(gcrane-completion bash)</i>).


title: HISTORY
content:
The ability to generate shell completion scripts is a standard feature in many modern command-line tools, particularly those built with the Go language using libraries like Cobra.<br><br>While <b>gcrane-completion</b> as a standalone command might be a specific wrapper, the underlying <b>gcrane completion</b> subcommand was integrated relatively early in the <i>gcrane</i> tool's development. <i>gcrane</i> itself is part of the <i>go-containerregistry</i> project and extends the base <i>crane</i> tool with Google Cloud-specific authentication and registry interactions.


title: PARAMETERS
content:
<b><I>&lt;repository&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full path to the container repository to clean up. Example: <I>gcr.io/my-project/my-app</I>.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively delete untagged images from all repositories underneath the specified <I>&lt;repository&gt;</I>.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not delete any images; instead, print a list of what <b>would be deleted</b> if the command were run without this flag. <br><i>Highly recommended for safe operation.</i><br><br><b><b>--grace</b> <I>string</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The minimum age of untagged images to consider for deletion. Images newer than this period will be kept. <br>Examples: <I>'1h'</I> (1 hour), <I>'24h'</I> (24 hours), <I>'7d'</I> (7 days). <br><i>Default: '7d'</i><br><br><b><b>--keep-last</b> <I>int</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of most recent untagged images to keep, even if they are older than the grace period.<br><br><b><b>--allow-tags</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows the deletion of images that *do* have tags. <br><i><b>WARNING:</b> Use with extreme caution as this can lead to unintended deletion of active images.</i><br><br><b><b>--keep-tags</b> <I>strings</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of tags to explicitly keep, even if they would otherwise be deleted (e.g., <I>'latest,stable'</I>). <br>Useful when combined with <i>--allow-tags</i>.<br><br><b><b>--insecure</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allow connecting to registries over HTTP. <br><i>Not recommended for production environments.</i><br><br><b><b>--platform</b> <I>string</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter images by their platform (e.g., <I>'linux/amd64'</I>). Only images matching this platform will be considered for deletion.<br><br><b><b>--platform-os</b> <I>string</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter images by operating system (e.g., <I>'linux'</I>).<br><br><b><b>--platform-arch</b> <I>string</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter images by architecture (e.g., <I>'amd64'</I>).<br><br><b><b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print more detailed output during execution, showing each image considered.<br><br>


title: DESCRIPTION
content:
The <b>gcrane-gc</b> command, part of the <i>gcrane</i> utility (from the <I>go-containerregistry</I> project), is designed to help manage storage costs and optimize repository cleanliness within container registries like Google Container Registry (GCR) or Artifact Registry.<br><br>It identifies and deletes untagged image manifests and their associated layers that are older than a specified grace period. This is crucial for environments where many temporary or older images accumulate without being explicitly tagged, leading to unnecessary storage consumption and potential cost increases.<br><br>While primarily focused on untagged images, it offers options for more aggressive cleanup, including the deletion of tagged images, though this should be used with extreme caution. The command emphasizes safety through its <i>--dry-run</i> option, allowing users to preview deletions before executing them permanently.


title: CAVEATS
content:
<b>gcrane-gc</b> performs destructive operations. Once images are deleted, they cannot be recovered.<br><br>The <b>--allow-tags</b> flag is particularly dangerous as it enables the deletion of actively tagged images, which can break deployments or lead to data loss. Always use <b>--dry-run</b> first to understand the impact of your command before actual execution, especially when using aggressive options.<br><br>Ensure the authenticated user or service account has the necessary permissions (e.g., <I>storage.objects.delete</I> for GCR/Artifact Registry) to perform deletions in the specified repository.


title: PERMISSIONS REQUIRED
content:
To successfully run <b>gcrane gc</b>, the identity executing the command must have permissions to list and delete objects within the target container repository. For Google Container Registry or Artifact Registry, this typically means having roles like <I>Storage Object Admin</I> or custom roles with permissions such as <I>storage.objects.list</I> and <I>storage.objects.delete</I>.


title: RECOMMENDED WORKFLOW
content:
A safe and recommended workflow for using <b>gcrane gc</b> is:<br>1. Run with <b>--dry-run</b> to see what will be deleted: <br> <I>gcrane gc --dry-run gcr.io/my-project/my-app</I><br>2. Review the output carefully to ensure only desired images are targeted.<br>3. If satisfied, run the command without <b>--dry-run</b> to perform the actual deletions: <br> <I>gcrane gc gcr.io/my-project/my-app</I>


title: HISTORY
content:
The <b>gcrane</b> utility is part of the <I>go-containerregistry</I> project, an open-source Go library and set of command-line tools developed by Google. It provides a lightweight, robust, and programmatic way to interact with OCI-compliant container registries. The <b>gc</b> (garbage collection) subcommand was introduced to address the common operational need for managing untagged and old image layers, helping users maintain clean and cost-effective container image repositories without relying solely on cloud provider-specific garbage collection policies or complex scripting.


title: PARAMETERS
content:
<b><b>--verbose</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose logging output. When used with <b>gcrane-help</b>, it might display additional diagnostic information about the help system itself, or if <b>gcrane-help</b> is a wrapper, it might pass this flag to the underlying <b>gcrane</b> command.<br><br>


title: DESCRIPTION
content:
The <b>gcrane-help</b> command serves as the primary entry point for obtaining assistance and documentation regarding the <b>gcrane</b> command-line tool. It provides an overview of <b>gcrane</b>'s capabilities, lists its available subcommands (such as <b>auth</b>, <b>cp</b>, <b>pull</b>, <b>push</b>, and <b>delete</b>), and explains their basic usage. Users can consult <b>gcrane-help</b> to understand the overall structure of <b>gcrane</b> and to navigate to specific subcommand help, which is typically accessed by appending <i>--help</i> to the subcommand (e.g., <b>gcrane pull --help</b>). This command is essential for new users to grasp <b>gcrane</b>'s functionality and for experienced users to quickly reference available operations and global flags.


title: CAVEATS
content:
While <b>gcrane-help</b> provides general information for the <b>gcrane</b> suite, for detailed usage and specific options of individual subcommands (e.g., <b>gcrane pull</b> or <b>gcrane push</b>), you must use the subcommand's dedicated help, typically by running <b>gcrane</b> <i>&lt;subcommand&gt;</i> <b>--help</b>. <b>gcrane-help</b> itself usually doesn't take specific subcommand arguments.


title: HISTORY
content:
<b>gcrane</b> is a specialized command-line tool designed for efficient interaction with Google Container Registry (GCR) and Google Artifact Registry. Developed as a more lightweight and focused alternative to broader tools like <b>gcloud</b> or raw <b>docker</b> commands for registry operations, its development prioritizes direct image management tasks like copying, pushing, pulling, and deleting. The integrated <b>help</b> functionality (accessed via <b>gcrane-help</b> or <b>gcrane help</b>) has been a core component from its early stages, ensuring users can quickly ascertain command usage and available options without needing to consult external documentation, thereby enhancing usability and adoption for managing container images in GCP's ecosystem.


title: SYNOPSIS
content:
<b>gcrane ls</b> [<i>options</i>] <i>&lt;registry/path&gt;</i><br>The <i>&lt;registry/path&gt;</i> specifies the registry endpoint or a specific repository within it (e.g., <I>gcr.io/my-project</I> or <I>us-east1-docker.pkg.dev/my-project/my-repo</I>).


title: PARAMETERS
content:
<b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the list of images and tags in JSON format.<br><br><b><b>--recursive</b>, <b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List images and repositories recursively within the specified registry path.<br><br><b><b>--tags-only</b>, <b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When used, this flag limits the output to only image tags. It implies and behaves like <b>--recursive</b>, listing all tags found under the specified path.<br><br>


title: DESCRIPTION
content:
gcrane-ls is a subcommand of the <b>gcrane</b> tool, designed for efficient interaction with container registries, particularly Google Container Registry (GCR) and Artifact Registry. Its primary function is to list container images and their tags within a specified repository or across an entire registry path. It provides a more streamlined way to browse registry contents compared to <b>gcloud</b> or <b>docker</b> commands for similar purposes, offering flexible output formats and filtering capabilities. It's often used for inventorying images, checking image existence, or understanding the structure of a registry for automation and scripting purposes.


title: CAVEATS
content:
<I>Authentication:</I> Requires proper authentication (e.g., <B>gcloud auth configure-docker</B> or service account credentials) to access private registries.<br><br><I>Permissions:</I> User or service account needs appropriate permissions (e.g., <I>storage.objects.list</I> for GCR) to list images.<br><br><I>Rate Limiting:</I> Excessive requests might hit registry rate limits, leading to temporary service disruption.<br><br><I>Large Registries:</I> Listing recursively on very large registries can take considerable time and consume more resources.


title: AUTHENTICATION
content:
Before using <I>gcrane-ls</I>, ensure you are authenticated to your container registry. For Google Container Registry or Artifact Registry, this typically involves running <B>gcloud auth configure-docker</B> or setting up appropriate service account credentials. Missing authentication will result in permission denied errors.


title: USAGE EXAMPLES
content:
<B>gcrane ls gcr.io/my-project</B><br><i>Lists all top-level image repositories within 'my-project'.</i><br><br><B>gcrane ls -r gcr.io/my-project/my-app</B><br><i>Recursively lists all image tags under the 'my-app' repository.</i><br><br><B>gcrane ls --json -r gcr.io/my-project | jq .</B><br><i>Lists all images and tags recursively for 'my-project' in JSON format and pipes it to <B>jq</B> for pretty-printing.</i>


title: HISTORY
content:
<b>gcrane</b> is a tool developed by Google. It emerged as a more performant and programmatic alternative to <B>gcloud</B> commands for interacting with Google's container registries (GCR and Artifact Registry). <I>gcrane-ls</I> specifically addresses the need for quick and flexible listing of registry contents, providing features like recursive listing and JSON output that are highly beneficial for scripting and automation. It's often used in CI/CD pipelines or for inventory management of container assets.


title: PARAMETERS
content:
<b><i>&lt;input_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input raster dataset (e.g., a GeoTIFF).<br><br><b><i>&lt;output_directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The directory where the generated tile pyramid will be stored. If not specified, a directory named after the input file (without extension) will be created.<br><br><b><b>-p</b> <i>PROFILE</i>, <b>--profile=</b><i>PROFILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the tile cutting profile. Common options include <b>mercator</b> (for Web Mercator/EPSG:3857, default), <b>geodetic</b> (for EPSG:4326/WGS84), and <b>raster</b> (for pixel-based tiles without reprojection).<br><br><b><b>-s</b> <i>SRS</i>, <b>--s_srs=</b><i>SRS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>Source Spatial Reference System</b> for the input dataset, if it's not correctly defined in the file metadata (e.g., <i>EPSG:4326</i>, <i>PROJ.4 string</i>).<br><br><b><b>-t</b> <i>SRS</i>, <b>--t_srs=</b><i>SRS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the <b>Target Spatial Reference System</b> for the output tiles. Defaults to <i>EPSG:3857 (Web Mercator)</i> if the profile is 'mercator'.<br><br><b><b>-z</b> <i>ZOOM</i>, <b>--zoom=</b><i>ZOOM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the zoom levels to generate. Can be a single level (e.g., '10'), a range (e.g., '2-12'), or 'all' to generate all relevant zoom levels from the base imagery.<br><br><b><b>-r</b> <i>METHOD</i>, <b>--resampling=</b><i>METHOD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <b>resampling method</b> used for generating tiles at different zoom levels. Options include <b>average</b> (default), <b>near</b> (nearest neighbor), <b>bilinear</b>, <b>cubic</b>, <b>cubicspline</b>, <b>lanczos</b>, and <b>mode</b>.<br><br><b><b>-e</b>, <b>--resume</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <b>resume mode</b>, skipping previously generated and existing tiles in the output directory. Useful for continuing interrupted jobs or updating specific parts of a tile set.<br><br><b><b>-a</b> <i>VALUE</i>, <b>--alpha=</b><i>VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a <b>custom alpha band value</b> for transparent areas. Useful for handling nodata values or adding transparency.<br><br><b><b>--processes=</b><i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>number of parallel processes</b> (CPU cores) to use for tile generation. Can significantly speed up processing on multi-core systems.<br><br><b><b>--webviewer=</b><i>VIEWER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a simple HTML web viewer for the tiles. Options are <b>openlayers</b>, <b>leaflet</b>, <b>all</b> (both), or <b>none</b> (default).<br><br><b><b>--xyz</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the output tile structure to be <b>XYZ</b> (Google Maps compatible) instead of TMS, even if another profile might imply TMS.<br><br><b><b>--tms</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the output tile structure to be <b>TMS</b> (Tile Map Service) instead of XYZ.<br><br><b><b>--title=</b><i>TITLE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a <b>title</b> for the generated web viewer page.<br><br><b><b>--copyright=</b><i>TEXT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds <b>copyright information</b> to the web viewer page.<br><br><b><b>--url=</b><i>URL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a <b>base URL</b> for the tiles, useful when serving them from a different location.<br><br><b><b>--tile-size=</b><i>PIXELS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <b>size of the output tiles</b> in pixels (e.g., 256 for standard web maps). Default is 256.<br><br><b><b>--src-nodata=</b><i>VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the <b>nodata value</b> for the input dataset. Pixels with this value will be treated as transparent.<br><br><b><b>--force-alpha</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ensures an <b>alpha band</b> is added to the output tiles, even if the source image doesn't have one.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <b>verbose output</b>, showing more detailed progress messages during tile generation.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses most output messages, showing only critical errors.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br>


title: DESCRIPTION
content:
gdal2tiles.py is a versatile <b>Python script</b> included with the <b>GDAL</b> (Geospatial Data Abstraction Library) project.<br><br>Its primary purpose is to convert large geospatial raster datasets, such as GeoTIFFs, satellite imagery, or aerial photographs, into a pyramid of efficiently organized image tiles. These tiles are typically arranged in an <b>XYZ (Google Maps compatible)</b> or <b>TMS (Tile Map Service)</b> structure, optimized for display in web mapping applications like OpenLayers, Leaflet, or the Google Maps API.<br><br>The tool handles complex operations including <b>re-projection</b> (e.g., to Web Mercator, EPSG:3857), <b>resampling</b> of imagery at different zoom levels, and precise <b>tile cutting</b>. By pre-generating these tiles, web applications can display vast amounts of geospatial data quickly and smoothly, loading only the necessary tiles for the current viewport and zoom level, significantly enhancing user experience for interactive web maps.


title: CAVEATS
content:
When processing <b>very large input files</b> or generating <b>many zoom levels</b>, <b>gdal2tiles.py</b> can be <b>memory-intensive</b>. Using the <b>--processes</b> option is recommended for multi-core systems, but too many processes with large tile sizes can exhaust RAM. Ensure the input dataset's <b>Spatial Reference System (SRS)</b> is correctly defined or explicitly set with <b>-s SRS</b> to avoid projection errors. Interrupting a process without <b>--resume</b> can lead to incomplete tile sets.


title: OUTPUT TILE STRUCTURE
content:
The generated tiles are organized hierarchically in the <i>&lt;output_directory&gt;</i> following a <b>z/x/y.(png|jpg)</b> convention (for XYZ profiles) or <b>z/x/y.(png|jpg)</b> with Y inverted (for TMS profiles). <i>z</i> represents the zoom level, <i>x</i> the column index, and <i>y</i> the row index of the tile. This structure allows web mapping clients to easily request and display tiles based on their current view.


title: PERFORMANCE CONSIDERATIONS
content:
For optimal performance with large datasets, consider:<br><i>- Using the <b>--processes</b> option to utilize multiple CPU cores.</i><br><i>- Specifying a limited <b>--zoom</b> range if not all levels are needed.</i><br><i>- Using <b>--resume</b> to pick up interrupted jobs or update existing tile sets.</i><br><i>- Ensuring sufficient disk space for the output, as tile sets can be very large.</i><br><i>- Using efficient input formats (e.g., Cloud Optimized GeoTIFF) for faster reads.</i>


title: WEB VIEWER GENERATION
content:
When <b>--webviewer</b> is used, <b>gdal2tiles.py</b> creates a simple HTML file (e.g., <i>openlayers.html</i> or <i>leaflet.html</i>) in the <i>&lt;output_directory&gt;</i>. This HTML file serves as a basic, ready-to-use map viewer that displays the generated tiles. It's an excellent way to quickly preview the output and verify the tiling process without needing to set up a full web mapping application.


title: HISTORY
content:
<b>gdal2tiles.py</b> emerged as a critical utility within the <b>GDAL</b> (Geospatial Data Abstraction Library) ecosystem, driven by the proliferation of <b>web mapping applications</b> (e.g., Google Maps, OpenStreetMap) in the mid-2000s. As web mapping platforms adopted the <b>tiled map service</b> paradigm, a robust tool was needed to prepare vast raster datasets for efficient online delivery.<br><br>Originally developed as a Python script leveraging GDAL's powerful C/C++ backend, it became a de facto standard for converting geospatial imagery into web-ready tile pyramids. Its continuous development reflects ongoing improvements in GDAL, offering support for new formats, projections, and performance optimizations, making it an indispensable tool for geospatial web developers and data providers.


title: SYNOPSIS
content:
<b>gdal_contour</b> <br> [-b <i>&lt;band&gt;</i>] <br> [-a <i>&lt;attribute_name&gt;</i>] <br> [-3d] <br> [-i <i>&lt;interval&gt;</i>] <br> [-f <i>&lt;format_name&gt;</i>] <br> [-nln <i>&lt;layer_name&gt;</i>] <br> [-s <i>&lt;smooth_points&gt;</i>] <br> [-snodata <i>&lt;value&gt;</i>] <br> [-v] <br> [-q] <br> [-<i>&lt;output_format_option&gt;</i> <i>&lt;value&gt;</i>] <br> <i>&lt;src_filename&gt;</i> <i>&lt;dst_filename&gt;</i>


title: PARAMETERS
content:
<b>-b <i>&lt;band&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the input raster band to read. Defaults to band 1.<br><br><b>-a <i>&lt;attribute_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of an attribute field to be added to the contour lines, storing the elevation value for each contour.<br><br><b>-3d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the output contour lines to be 3D, including the Z coordinate derived from the elevation.<br><br><b>-i <i>&lt;interval&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the contour interval in ground units (e.g., meters or feet). This is a mandatory parameter for contour generation.<br><br><b>-f <i>&lt;format_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output vector format name (e.g., <i>ESRI Shapefile</i>, <i>GPKG</i>, <i>GeoJSON</i>). If not specified, GDAL attempts to guess the format from the destination filename extension.<br><br><b>-nln <i>&lt;layer_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a specific name to the output layer within the destination vector dataset.<br><br><b>-s <i>&lt;smooth_points&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a specified number of intermediate points to smooth the generated contour lines. Higher values result in smoother lines but may increase processing time and file size.<br><br><b>-snodata <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an input pixel value to treat as no data. Pixels with this value will be ignored during contour generation.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, displaying progress messages and additional information during processing.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses progress messages and other non-essential output, useful for scripting.<br><br><b>-<i>&lt;output_format_option&gt;</i> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows passing format-specific creation options for the output dataset. These options vary by vector format.<br><br><b><i>&lt;src_filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input raster file (Digital Elevation Model) from which contours will be generated.<br><br><b><i>&lt;dst_filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the output vector file where the generated contour lines will be saved.<br><br>


title: DESCRIPTION
content:
<i>gdal_contour</i> is a GDAL utility that generates vector contour lines from a raster Digital Elevation Model (DEM). It reads a single-band raster image and outputs a vector dataset (e.g., Shapefile, GeoPackage, GeoJSON) containing contour lines as polygons or lines. The contours represent points of equal elevation, making it a fundamental tool in GIS for terrain analysis. Users can specify the contour interval, a base contour level, and optionally an attribute field to store the elevation value. The command is widely used for hydrological analysis, terrain visualization, and engineering applications to delineate elevation breaks. It leverages GDAL's robust I/O capabilities, supporting numerous raster and vector formats for input and output respectively.


title: CAVEATS
content:
The accuracy of generated contours depends on the resolution and quality of the input DEM. Smoothing with the <i>-s</i> option can visually improve contours but might slightly deviate them from exact elevation values or introduce artifacts. Processing very large raster datasets can be computationally intensive and require significant memory.


title: EXAMPLES
content:
To generate contours at 10-unit intervals from <i>input.tif</i> to <i>output.shp</i>, with elevation values stored in an attribute field named <i>ELEV</i>:<br><code>gdal_contour -i 10 -a ELEV input.tif output.shp</code><br><br>To create smoothed contours at 5-unit intervals and save them in GeoPackage format:<br><code>gdal_contour -i 5 -s 3 -f GPKG input.tif output.gpkg</code>


title: HISTORY
content:
<i>gdal_contour</i> is a core utility within the GDAL (Geospatial Data Abstraction Library) suite, which was initially developed by Frank Warmerdam and first released in 1998. It has evolved alongside GDAL, continually benefiting from improved performance, extended format support, and bug fixes, establishing itself as a standard tool for creating vector contours from raster elevation data in GIS workflows.


title: SYNOPSIS
content:
<i><b>gdal_translate</b></i> [<i>options</i>] <i><src_filename> <dst_filename></i><br><br><i>src_filename</i>: The path to the source raster dataset.<br><i>dst_filename</i>: The path for the output raster dataset.


title: PARAMETERS
content:
<b><b>-of</b> <i><format></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select the output format. Common formats include GeoTIFF (GTiff), ERDAS Imagine (HFA), PNG, JPEG, NetCDF, etc.<br><br><b><b>-ot</b> <i><type></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output data type. Examples: Byte, UInt16, Int16, UInt32, Int32, Float32, Float64.<br><br><b><b>-sds</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copy all subdatasets from the input to the output. Each subdataset becomes a new file.<br><br><b><b>-b</b> <i><band></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select specific input band(s) to process. Can be used multiple times.<br><br><b><b>-mask</b> <i><band></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an input band to use as a mask band for the output dataset.<br><br><b><b>-srcwin</b> <i><xoff> <yoff> <xsize> <ysize></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select a rectangular region from the source image using pixel/line coordinates.<br><br><b><b>-projwin</b> <i><ulx> <uly> <lrx> <lry></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select a rectangular region from the source image using georeferenced coordinates (e.g., longitude/latitude).<br><br><b><b>-outsize</b> <i><xsize> <ysize></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the output file size in pixels and lines, or as a percentage of the input (e.g., 50%).<br><br><b><b>-tr</b> <i><xres> <yres></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the output file resolution in georeferenced units.<br><br><b><b>-r</b> <i><resampling_method></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select a resampling algorithm. Options: near, bilinear, cubic, cubicspline, lanczos, average, mode.<br><br><b><b>-a_srs</b> <i><srs_def></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assign a coordinate system to the output. Can be a WKT string, EPSG code, Proj.4 string, etc.<br><br><b><b>-a_ullr</b> <i><ulx> <uly> <lrx> <lry></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assign georeferenced coordinates for the upper-left and lower-right corners of the output image.<br><br><b><b>-a_nodata</b> <i><value></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assign a NoData value to the output bands.<br><br><b><b>-scale</b> [<i><src_min> <src_max></i> [<i><dst_min> <dst_max></i>]]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a linear scaling to pixel values. Can specify input/output ranges.<br><br><b><b>-co</b> <i><NAME=VALUE></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify creation options for the output format. These are format-specific (e.g., TFW=YES for GeoTIFF).<br><br><b><b>-mo</b> <i><METADATA_ITEM=VALUE></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add metadata to the output dataset.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress progress messages and other non-error output (quiet mode).<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report more details about the process (verbose mode).<br><br>


title: DESCRIPTION
content:
<i><b>gdal_translate</b></i> is a fundamental utility within the GDAL (Geospatial Data Abstraction Library) suite. It serves as a versatile tool for converting raster images between various formats, performing fundamental image manipulations, and handling georeferencing information.<br><br>Its primary function is to transform a source dataset into a new destination dataset, allowing users to:<br><br><ul><li>Change the file format (e.g., GeoTIFF to PNG, NetCDF to JPEG).</li><li>Adjust the spatial resolution or dimensions of the image.</li><li>Subset or clip regions of interest from a larger image.</li><li>Change the data type of the pixel values (e.g., float to byte).</li><li>Assign or modify georeferencing information, such as coordinate systems or ground control points (GCPs).</li><li>Apply scaling, offset, or NoData value transformations.</li><li>Copy metadata and color interpretation information.</li></ul><br><i><b>gdal_translate</b></i> is widely used in GIS, remote sensing, and mapping workflows for preparing data for analysis, visualization, or integration into different systems. It leverages the extensive driver support of the GDAL library, enabling compatibility with a vast array of raster formats.


title: CAVEATS
content:
<i><b>gdal_translate</b></i> is a powerful tool, but users should be aware of a few considerations:<br><br>1.  <I>Memory Usage:</I> For very large datasets, processing can consume significant memory, especially when resampling or changing data types.<br>2.  <I>Driver Dependencies:</I> The availability of input and output formats depends on how the GDAL library was compiled. Some formats might require specific external libraries.<br>3.  <I>Georeferencing Nuances:</I> While <i><b>-a_srs</b></i> and <i><b>-a_ullr</b></i> assign georeferencing, they do not reproject data. For reprojection, <i><b>gdalwarp</b></i> is the appropriate command.<br>4.  <I>Creation Options:</I> Understanding format-specific creation options (<i><b>-co</b></i>) is crucial for optimizing output size, compression, and internal structure. Refer to GDAL's format-specific documentation for details.


title: GDAL DRIVERS
content:
<i><b>gdal_translate</b></i> leverages GDAL drivers to read and write numerous raster formats. To see a list of supported formats and their capabilities, use the command <i><b>gdalinfo --formats</b></i>.<br><br>Each driver may support specific creation options (<i><b>-co</b></i>) which can be found in the GDAL online documentation for that particular format.


title: COORDINATE SYSTEMS
content:
When dealing with coordinate systems, GDAL supports various definitions including EPSG codes (e.g., EPSG:4326 for WGS84), WKT (Well-Known Text) strings, or Proj.4 strings. Correctly specifying the SRS is critical for geospatial data integrity.


title: HISTORY
content:
<i><b>gdal_translate</b></i> is a core component of the GDAL (Geospatial Data Abstraction Library) project, which was initiated by Frank Warmerdam in 1998. GDAL quickly became the de facto standard for reading and writing raster and vector geospatial data formats.<br><br>As one of the earliest and most fundamental utilities provided by the library, <i><b>gdal_translate</b></i> has evolved alongside GDAL itself. Its design reflects GDAL's philosophy of providing a consistent API and command-line interface for diverse geospatial data, abstracting away the complexities of different file formats. Over the years, it has seen continuous development, with new options added to support advanced transformations, broader format compatibility, and improved performance, cementing its role as an indispensable tool in the geospatial community.


title: SYNOPSIS
content:
<b>gdaladdo</b> [<i>-r {resampling_method}</i>] [<i>-ro</i>] [<i>-clean</i>] [<i>-b {band}</i>] [<i>-co {NAME=VALUE}</i>] [<i>-oo {NAME=VALUE}</i>] [<i>-q</i>] <i>&lt;filename&gt;</i> [<i>{LEVELS}...</i>]


title: PARAMETERS
content:
<b>filename</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the input raster dataset for which overviews will be built or updated.<br><br><b>LEVELS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A space-separated list of overview levels. These are integers representing the downsampling factor (e.g., '2 4 8 16' for 1:2, 1:4, 1:8, 1:16 resolution reduction).<br><br><b>-r {resampling_method}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the resampling method to use when building overviews. Common methods include: <br><i>nearest</i> (nearest neighbour), <br><i>average</i> (average of all contributing pixels), <br><i>cubic</i> (cubic convolution), <br><i>gauss</i> (gaussian kernel), etc. Choosing a method affects visual quality and processing speed.<br><br><b>-ro</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read-only mode. Overviews will be written to a separate external <i>.ovr</i> file instead of being embedded in the input dataset. This is useful for formats that don't support internal overviews or to avoid modifying the original file.<br><br><b>-clean</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes all existing overviews from the dataset. This can be used before generating new overviews to ensure a fresh set.<br><br><b>-b {band}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects a specific band (or bands, comma-separated) for which to build overviews. By default, overviews are built for all bands.<br><br><b>-co {NAME=VALUE}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creation options for the overview dataset (or <i>.ovr</i> file). These are format-specific; for example, for GeoTIFF, you might use 'TILED=YES' or 'COMPRESS=LZW'.<br><br><b>-oo {NAME=VALUE}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open options for the input dataset. These are format-specific parameters passed to the GDAL driver when opening the source file.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode. Suppresses progress messages and other non-error output.<br><br>


title: DESCRIPTION
content:
<i>gdaladdo</i> is a powerful <B>GDAL</B> utility designed to build or update overview images (pyramids) for raster datasets. These overviews are downsampled, lower-resolution versions of the original data, crucial for efficiently displaying large geospatial images at various zoom levels. Instead of loading the entire high-resolution dataset, mapping applications can quickly access the appropriate overview level, significantly improving display performance and responsiveness.<br><br><i>gdaladdo</i> supports various resampling algorithms (e.g., <i>nearest</i>, <i>average</i>, <i>cubic</i>) to control how the overviews are generated, impacting visual quality and file size. Overviews can be stored internally within certain file formats (like GeoTIFF) or as external auxiliary <i>.ovr</i> files. This command is an essential tool for preparing large raster datasets for web mapping services, desktop GIS applications, and other data visualization tools where performance is critical.


title: CAVEATS
content:
Building overviews can be computationally intensive and may consume significant disk space, especially for large datasets or many overview levels. While <i>gdaladdo</i> usually modifies files in-place for formats like GeoTIFF, always ensure you have backups of critical data before running operations that modify files. Some file formats do not support internal overviews, requiring the use of the <i>-ro</i> option to create external <i>.ovr</i> files. Overviews should ideally be generated after any reprojection or significant data manipulation to ensure consistency with the base dataset.


title: OVERVIEW STORAGE AND ACCESS
content:
Overviews can be stored in two primary ways: <br>1. <B>Internal</B>: Embedded directly within the main raster file (e.g., GeoTIFF). This is the default and often preferred for simplicity. <br>2. <B>External</B>: Written to a separate auxiliary file with a '.ovr' extension (e.g., 'image.tif.ovr'). This is necessary for formats that don't support internal overviews or when the original file should remain unmodified (using the <i>-ro</i> option). When a GIS application opens a GDAL dataset, it automatically detects and utilizes these overviews for faster display at lower resolutions.


title: PERFORMANCE BENEFITS
content:
The primary benefit of using <i>gdaladdo</i> is a dramatic improvement in performance when viewing large raster datasets. Without overviews, GIS software would need to resample the full-resolution data on-the-fly for every zoom level, which is slow and resource-intensive. With overviews, the software can simply load and display a pre-computed, appropriately scaled version of the data, leading to smoother navigation and quicker rendering, especially in web mapping services or desktop applications handling terabytes of imagery.


title: HISTORY
content:
<i>gdaladdo</i> is an integral utility within the <B>GDAL</B> (Geospatial Data Abstraction Library) project, which commenced development in 1998 under the leadership of Frank Warmerdam. GDAL has since become the de facto standard library for reading and writing raster and vector geospatial data formats. <i>gdaladdo</i> was developed early on as a core utility to address the common challenge of efficiently visualizing large raster datasets, providing a foundational capability for performant GIS and mapping applications that handle extensive imagery.


title: SYNOPSIS
content:
<b>gdalbuildvrt</b> [<i>options</i>] <i>&lt;output_vrt_file&gt;</i> [<i>&lt;src_dataset&gt;</i> ...]|<i>-input_file_list &lt;filename&gt;</i>


title: PARAMETERS
content:
<b><i>&lt;output_vrt_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the output VRT file to be created. This is a mandatory argument.<br><br><b><i>&lt;src_dataset&gt;</i> ...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more input GDAL-supported raster datasets. These are the source files from which the VRT will be built.<br><br><b><b>-input_file_list</b> <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads a list of input datasets from a text file, one path per line. This is an alternative to listing all input datasets on the command line.<br><br><b><b>-r</b> <i>&lt;resampling_method&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the resampling algorithm to use when a pixel needs to be resampled (e.g., when inputs have different resolutions or extents). Options include <b>nearest</b>, <b>bilinear</b>, <b>cubic</b>, <b>cubicspline</b>, <b>lanczos</b>, <b>average</b>, <b>mode</b>. Default is <b>nearest</b>.<br><br><b><b>-te</b> <i>&lt;xmin&gt; &lt;ymin&gt; &lt;xmax&gt; &lt;ymax&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the target extent of the output VRT in georeferenced coordinates. The coordinates should be in the target SRS of the VRT.<br><br><b><b>-tr</b> <i>&lt;xres&gt; &lt;yres&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the target resolution of the output VRT in georeferenced units (e.g., meters or degrees per pixel). Requires <b>-te</b> to be specified.<br><br><b><b>-ts</b> <i>&lt;xsize&gt; &lt;ysize&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the target size of the output VRT in pixels and lines. This is an alternative to <b>-tr</b> for defining output dimensions.<br><br><b><b>-a_srs</b> <i>&lt;srs_def&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a target Spatial Reference System (SRS) to the VRT. Can be an EPSG code (e.g., 'EPSG:4326'), WKT, PROJ.4 string, or a file path to an SRS definition.<br><br><b><b>-a_ullr</b> <i>&lt;ulx&gt; &lt;uly&gt; &lt;lrx&gt; &lt;lry&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns georeferenced coordinates to the VRT from its upper-left and lower-right corners. This implies the VRT's extent and resolution.<br><br><b><b>-vrtnodata</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a nodata value to the VRT bands. Pixels matching this value are considered transparent. Can be a single value or a comma-separated list for multiple bands.<br><br><b><b>-srcnodata</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides the nodata value of the source datasets before they are used in the VRT. Can be a single value or 'none' to ignore source nodata.<br><br><b><b>-b</b> <i>&lt;band_number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects a specific band from the source datasets to be included in the VRT. This option can be specified multiple times for multiple bands.<br><br><b><b>-sd</b> <i>&lt;subdataset_number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects a specific subdataset from hierarchical source datasets (e.g., HDF5, NetCDF) to be processed.<br><br><b><b>-separate</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Places each input file into a separate band in the VRT. Requires all input files to have the same dimensions. Useful for combining different spectral bands from different files.<br><br><b><b>-allow_projection_difference</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows input datasets with different projections. When enabled, all input datasets will be reprojected on-the-fly to the VRT's SRS (determined by the first input or <b>-a_srs</b>).<br><br><b><b>-overwrite</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrites an existing VRT file if it already exists.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses progress messages and other non-error output during execution.<br><br><b><b>-stats</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces computation of statistics (min/max, mean, stddev) on the VRT during its creation. This can be time-consuming for large datasets.<br><br>


title: DESCRIPTION
content:
<b>gdalbuildvrt</b> is a powerful command-line utility provided by the GDAL (Geospatial Data Abstraction Library) project. Its primary purpose is to create a Virtual Raster Dataset (VRT) file from one or more GDAL-supported raster datasets. A VRT file is essentially an XML text file that describes how to access and display data from other raster files without actually duplicating the pixel data. This allows users to mosaic, reproject, or transform multiple datasets into a single logical view without consuming significant disk space. <b>gdalbuildvrt</b> is particularly useful for creating large seamless mosaics from numerous smaller image tiles, or for defining complex data views that combine different bands or datasets, all while preserving the original data integrity and minimizing processing time until the data is actually accessed. It supports various options to control the output VRT's spatial extent, resolution, coordinate system, and resampling methods.


title: CAVEATS
content:
VRT files are XML definitions, not actual raster data. While they provide a unified view, performance can depend on the underlying data and the complexity of the VRT. Large VRTs combining many small files might have performance overhead due to numerous file accesses. Using <b>-allow_projection_difference</b> can lead to on-the-fly reprojection, which is computationally intensive when the VRT is accessed. Changes to source datasets are reflected in the VRT, but the VRT itself doesn't automatically update if source files are deleted or moved without recreating the VRT. It's crucial to ensure source datasets remain accessible at their original paths.


title: VRT XML STRUCTURE
content:
A VRT file is a human-readable XML document. It contains references to source datasets, their georeferencing information, band properties, and how they contribute to the virtual dataset. This transparency allows advanced users to manually edit VRTs for fine-grained control or specific edge cases not directly covered by command-line options.


title: ON-THE-FLY PROCESSING
content:
VRTs enable on-the-fly processing, often referred to as 'lazy evaluation'. Operations like mosaicking, reprojection, or band selection are not performed until the VRT is opened by a GDAL-aware application (e.g., QGIS, ArcMap, or another GDAL utility) and pixels are actually requested. This approach saves disk space and processing time by only processing the necessary data when it's accessed, rather than pre-computing entire new files.


title: COMMON USE CASES
content:
<ul><li><b>Mosaicking</b>: Combining numerous adjacent satellite images or aerial photos into a single seamless image view without duplicating data.</li><li><b>Clipping/Subsetting</b>: Defining a smaller area of interest from a larger dataset virtually, without creating a new clipped file.</li><li><b>Reprojection</b>: Creating a virtual dataset in a different coordinate system without re-saving the entire dataset.</li><li><b>Band Manipulation</b>: Creating virtual datasets with specific band combinations or operations (e.g., using specific bands from different files as a single virtual multi-band image).</li></ul>


title: HISTORY
content:
<b>gdalbuildvrt</b> is an integral part of the GDAL library, which was first released in 1998 by Frank Warmerdam. The Virtual Raster Dataset (VRT) format and <b>gdalbuildvrt</b> utility were introduced early in GDAL's development, providing a flexible and efficient way to manage and combine geospatial raster data without data duplication. Its development has mirrored GDAL's evolution, with continuous improvements in capabilities, performance, and support for new data formats and projection systems. It has become a fundamental tool in geospatial data processing workflows, especially for handling large volumes of imagery and creating seamless mosaics.


title: PARAMETERS
content:
<b><i>&lt;mode&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The operation to perform. Common modes include <b>hillshade</b>, <b>slope</b>, <b>aspect</b>, <b>color-relief</b>, <b>tpi</b>, <b>tri</b>, <b>roughness</b>.<br><br><b><i>&lt;input_dem&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input Digital Elevation Model raster file.<br><br><b><i>&lt;output_raster&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the output raster file that will be generated.<br><br><b><b>-of</b> <i>&lt;format&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the output format driver. E.g., <b>-of</b> <i>GTiff</i>.<br><br><b><b>-b</b> <i>&lt;band&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the input band to use from the DEM (default is 1).<br><br><b><b>-s</b> <i>&lt;scale&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scale factor for vertical units relative to horizontal units. Default is 1.0. Useful for units conversion (e.g., feet to meters).<br><br><b><b>-z</b> <i>&lt;zfactor&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Vertical exaggeration factor. Useful for making terrain relief more prominent in hillshades.<br><br><b><b>-alg</b> <i>&lt;algorithm&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the algorithm for slope/aspect computation. E.g., <b>-alg</b> <i>ZevenbergenThorne</i>.<br><br><b><b>-compute_edges</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Computes values for edge pixels which might be <i>nodata</i> by default due to filter size.<br><br><b><b>-co</b> <i>&lt;NAME=VALUE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes creation options to the output format driver. E.g., <b>-co</b> <i>COMPRESS=LZW</i>.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode; suppresses progress messages.<br><br><b><b>-md</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Nodata value for the output raster.<br><br><b><b>-az</b> <i>&lt;azimuth&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>hillshade</b>) Azimuth of the sun in degrees (0-360, 0 is North). Default is 315.<br><br><b><b>-alt</b> <i>&lt;altitude&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>hillshade</b>) Altitude of the sun in degrees (0-90, 90 is directly overhead). Default is 45.<br><br><b><b>-combined</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>hillshade</b>) Produces a combined hillshade and slope output (grayscale).<br><br><b><b>-multidirectional</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>hillshade</b>) Generates a multidirectional hillshade (more natural appearance).<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>slope</b>) Output slope in percent instead of degrees.<br><br><b><b>-zero_for_flat</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>aspect</b>) Sets aspect of flat areas (slope 0) to 0 instead of <i>nodata</i>.<br><br><b><b>-color-text-file</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>color-relief</b>) Path to a text file defining color ramps.<br><br><b><b>-alpha</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>color-relief</b>) Adds an alpha band to the output, allowing transparency.<br><br><b><b>-clip</b> <i>&lt;min_val&gt; &lt;max_val&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>color-relief</b>) Clips the elevation range used for color-relief.<br><br><b><b>-nearest_color_entry</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>color-relief</b>) Uses the nearest color entry from the color file instead of interpolation.<br><br><b><b>-denom</b> <i>&lt;factor&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <b>tpi</b>, <b>tri</b>, <b>roughness</b>) Denominator for output values (e.g., <b>-denom</b> <i>100</i> to output values in meters/feet instead of cm/inches).<br><br>


title: DESCRIPTION
content:
<b>gdaldem</b> is a versatile command-line utility from the GDAL (Geospatial Data Abstraction Library) suite designed for processing Digital Elevation Models (DEMs). It can generate various derived products from a DEM, such as <i>hillshade</i> images, <i>slope</i> maps (in degrees or percent), <i>aspect</i> maps (direction of slope), <i>color relief</i> visualizations, and terrain analysis products like <i>Topographic Position Index (TPI)</i>, <i>Terrain Ruggedness Index (TRI)</i>, and <i>Roughness</i>.<br><br>It supports a wide range of raster formats for both input and output, leveraging GDAL's extensive format drivers. Users can customize the output using numerous options, including scaling factors, vertical exaggeration, illumination parameters for hillshades, and specific algorithms for slope and aspect calculations. This tool is fundamental for geospatial analysis, cartography, and environmental modeling, allowing users to transform raw elevation data into more interpretable and analytically useful representations.


title: CAVEATS
content:
<ul><li><b>gdaldem</b> assumes input DEM is projected correctly. Issues can arise if geographic (lat/long) coordinates are used without appropriate scaling (<b>-s</b>).</li><li>The <b>-compute_edges</b> option can be computationally intensive, especially for large datasets or large filter windows (for <b>tpi</b>, <b>tri</b>, <b>roughness</b>).</li><li>Output resolutions and extents are typically derived directly from the input DEM. For custom outputs, <b>gdal_translate</b> or <b>gdalwarp</b> might be needed post-processing.</li></ul>


title: DEM PROCESSING MODES
content:
<b>gdaldem</b> supports several distinct processing modes, each designed for a specific terrain analysis task. These include: <br><ul><li><b>hillshade</b>: Generates a shaded relief map based on illumination parameters.</li><li><b>slope</b>: Calculates the steepness of the terrain.</li><li><b>aspect</b>: Determines the directional orientation of the slope.</li><li><b>color-relief</b>: Creates a color-coded representation of elevation, often using a specified color ramp file.</li><li><b>tpi</b> (Topographic Position Index): Compares the elevation of a central pixel to the mean elevation of its neighborhood.</li><li><b>tri</b> (Terrain Ruggedness Index): Quantifies terrain ruggedness by summarizing elevation differences between a central pixel and its neighbors.</li><li><b>roughness</b>: Similar to TRI, measures the local variation in elevation.</li></ul>These modes make <b>gdaldem</b> a comprehensive tool for various DEM-derived products.


title: HISTORY
content:
<b>gdaldem</b> has been an integral part of the GDAL utility suite since its inception, evolving with the library itself. It leverages GDAL's robust raster I/O capabilities and has seen continuous improvements in algorithms, performance, and supported options. Its development reflects the growing need for specialized terrain analysis tools directly accessible from the command line, making it a staple for automated geospatial workflows and scripting.


title: SYNOPSIS
content:
<b>gdalwarp</b> [<i>&lt;options&gt;</i>] <i>&lt;source_dataset&gt;</i> [<i>&lt;source_dataset&gt;</i> ...] <i>&lt;destination_dataset&gt;</i>


title: PARAMETERS
content:
<b><b>-s_srs</b> <i>&lt;srs_def&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the spatial reference system of the source dataset. Can be an EPSG code (e.g., EPSG:4326), a PROJ.4 string, or a WKT string.<br><br><b><b>-t_srs</b> <i>&lt;srs_def&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the spatial reference system for the output dataset.<br><br><b><b>-r</b> <i>&lt;resample_method&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the resampling method to use (e.g., <i>nearest</i>, <i>bilinear</i>, <i>cubic</i>, <i>average</i>).<br>See 'Resampling Methods' in 'Additional' section for more details.<br><br><b><b>-of</b> <i>&lt;format&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format (e.g., GTiff, PNG, JPEG). Defaults to the format of the source if not specified.<br><br><b><b>-ot</b> <i>&lt;type&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the output band data type (e.g., Byte, UInt16, Float32). Useful for memory and storage optimization.<br><br><b><b>-ts</b> <i>&lt;width&gt;</i> <i>&lt;height&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the target output file size in pixels and lines. One of these can be 0 to maintain aspect ratio.<br><br><b><b>-tr</b> <i>&lt;xres&gt;</i> <i>&lt;yres&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output file resolution in target georeferenced units.<br><br><b><b>-te</b> <i>&lt;xmin&gt;</i> <i>&lt;ymin&gt;</i> <i>&lt;xmax&gt;</i> <i>&lt;ymax&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output georeferenced extents of the output file. Coordinates are in target SRS units.<br><br><b><b>-cutline</b> <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables clipping the output raster to the extent of a vector cutline specified by a file (e.g., a shapefile).<br><br><b><b>-crop_to_cutline</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Crops the output raster to the extent of the cutline's bounding box, potentially reducing the output file size.<br><br><b><b>-srcnodata</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the source nodata value(s) to be ignored or treated as transparent.<br><br><b><b>-dstnodata</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a specific nodata value to the output raster where input data is missing or out of bounds.<br><br><b><b>-overwrite</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows overwriting the existing destination dataset without prompting.<br><br><b><b>-multi</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a multi-threaded warping algorithm, potentially speeding up processing on multi-core systems.<br><br><b><b>-co</b> <i>&lt;NAME=VALUE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes creation options to the output format driver (e.g., <i>COMPRESS=LZW</i> for GeoTIFF).<br><br>


title: DESCRIPTION
content:
<i>gdalwarp</i> is a powerful command-line utility from the GDAL (Geospatial Data Abstraction Library) suite. Its primary function is to transform raster images from one coordinate system to another, a process commonly known as reprojection or warping. This tool is indispensable for geospatial data harmonization, allowing users to align datasets originating from different projections, resolutions, or geographic extents. Beyond simple reprojection, <i>gdalwarp</i> can mosaic multiple input rasters into a single output, clip data using a vector cutline, change output resolution, and apply various resampling algorithms. It supports a vast array of input and output raster formats and handles complex georeferencing information automatically, making it a fundamental component in GIS and remote sensing workflows.


title: CAVEATS
content:
For large datasets or complex transformations, <i>gdalwarp</i> can be resource-intensive, requiring significant CPU and RAM. Incorrectly defined source or target spatial reference systems can lead to misaligned or erroneous output. While <i>-multi</i> can improve performance, it's not always a panacea for extremely large files, and I/O can still be a bottleneck.


title: RESAMPLING METHODS
content:
The choice of resampling method (controlled by <i>-r</i>) significantly impacts the output raster's appearance and data integrity.<br><b>nearest</b> (Nearest Neighbor): Fastest, preserves original pixel values, best for categorical data.<br><b>bilinear</b> (Bilinear Interpolation): Smooths data, suitable for continuous data, calculates new pixel value from weighted average of 4 nearest pixels.<br><b>cubic</b> (Cubic Convolution): Smoother than bilinear, uses 16 nearest pixels, good for continuous data but computationally more intensive.<br><b>average</b>: Computes the average of all contributing pixels.


title: SPATIAL REFERENCE SYSTEMS (SRS)
content:
Defining the SRS is crucial for accurate reprojection. SRS can be specified using various formats:<br><b>EPSG Codes</b>: A widely recognized code for a coordinate system (e.g., EPSG:4326 for WGS84 Lat/Lon).<br><b>PROJ.4 Strings</b>: A text string defining projection parameters (e.g., '+proj=utm +zone=10 +ellps=WGS84').<br><b>WKT</b> (Well-Known Text): A more verbose, standard text representation of coordinate systems.<br><i>gdalwarp</i> relies on the PROJ library for performing the actual coordinate transformations.


title: HISTORY
content:
<i>gdalwarp</i> is a core utility within the GDAL (Geospatial Data Abstraction Library) project, which was initially released in 1998. As GDAL evolved into the de-facto standard for reading and writing raster and vector geospatial data, <i>gdalwarp</i> steadily gained features and optimizations. Its development has been driven by the needs of the geospatial community, incorporating advanced resampling algorithms, improved projection support (leveraging the PROJ library), and performance enhancements like multi-threading, making it a robust and indispensable tool for geospatial data processing.


title: PARAMETERS
content:
<b>-q, --quiet, --silent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not print the introductory and copyright messages.<br><br><b>-ex COMMAND, --command=COMMAND</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute the specified GDB command upon startup.<br><br><b>-s FILE, --symbols=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read symbol table from FILE.<br><br><b>-c FILE, --core=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use FILE as a core dump to analyze.<br><br><b>-p PID, --pid=PID</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attach GDB to the running process with the given PID.<br><br><b>-b BAUDRATE, --baud=BAUDRATE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the serial device baud rate for remote debugging.<br><br><b>-tui</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Start GDB with the Text User Interface enabled, showing source code, assembly, and registers.<br><br><b>executable_file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The program to be debugged. GDB loads its symbols and prepares to run it.<br><br><b>core_file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A core dump file generated by a crashed program. GDB analyzes its state.<br><br><b>process_id</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The ID of a running process to attach to for live debugging.<br><br>


title: DESCRIPTION
content:
The <B>gdb</B> command, short for <I>GNU Debugger</I>, is a powerful, open-source debugger for various programming languages, most notably C and C++. It allows you to examine what is going on inside a program while it executes or what a program was doing at the moment it crashed. <br><br>Key capabilities include:<br><ul><li>Setting breakpoints to pause execution at specific points.</li><li>Stepping through code line by line.</li><li>Inspecting and modifying variables and memory.</li><li>Analyzing call stacks to understand program flow.</li><li>Debugging core dumps to investigate crashes post-mortem.</li><li>Attaching to running processes.</li><li>Debugging remote targets over a network.</li></ul><br>GDB is an essential tool for software development, helping developers find and fix bugs efficiently across many Unix-like operating systems.


title: CAVEATS
content:
Debugging with <B>gdb</B> is most effective when the target program is compiled with debug symbols (e.g., using <I>-g</I> flag with GCC). Without symbols, debugging is limited to assembly level. The learning curve can be steep for beginners, as it primarily operates via a command-line interface. Debugging a running process introduces overhead and can slightly alter its real-time behavior. Complex multi-threaded or multi-process applications can be challenging to debug effectively with GDB alone.


title: COMMON USE CASES
content:
<ul><li><B>Post-mortem Debugging:</B> Analyzing core dump files to determine the cause of a program crash.</li><li><B>Live Process Debugging:</B> Attaching to a running process to inspect its state or debug issues in real-time without restarting.</li><li><B>Step-by-Step Execution:</B> Understanding program flow by executing code line by line and observing changes in variables and memory.</li><li><B>Remote Debugging:</B> Debugging programs running on embedded systems or different machines via a network connection (often using <I>gdbserver</I>).</li></ul>


title: INTERACTION MODES
content:
<ul><li><B>Command-Line Interface (CLI):</B> The default interactive mode, where users type GDB commands.</li><li><B>Text User Interface (TUI):</B> Activated with <I>-tui</I>, it provides a curses-based interface showing source code, registers, and assembly alongside the command line.</li><li><B>Batch Mode:</B> Executing GDB commands from a script or file for automated debugging tasks.</li><li><B>Integration with IDEs:</B> Many Integrated Development Environments (IDEs) like VS Code, Eclipse, and CLion use GDB as their backend debugger, providing a graphical frontend.</li></ul>


title: HISTORY
content:
Developed by Richard Stallman in 1986 as part of the GNU Project, <B>gdb</B> was initially designed to debug programs written in C. Over the years, its capabilities have expanded to support C++, Fortran, Ada, Go, Rust, and other languages. It quickly became and remains a cornerstone tool for open-source software development and system-level debugging on Unix-like operating systems. Its active development continues, ensuring its relevance in modern programming environments.


title: SYNOPSIS
content:
<b>gdbus</b> [<i>--system</i> | <i>--session</i> | <i>--address=ADDRESS</i>] [<i>--verbose</i>] <i>COMMAND</i> [<i>COMMAND_OPTIONS</i>]<br><br>Common Commands:<br><b>gdbus</b> <i>call</i> [<i>OPTIONS</i>] <i>BUS_NAME OBJECT_PATH INTERFACE_NAME METHOD_NAME</i> [<i>ARGUMENTS...</i>]<br><b>gdbus</b> <i>monitor</i> [<i>OPTIONS</i>] <i>BUS_NAME</i><br><b>gdbus</b> <i>emit</i> [<i>OPTIONS</i>] <i>OBJECT_PATH INTERFACE_NAME SIGNAL_NAME</i> [<i>ARGUMENTS...</i>]<br><b>gdbus</b> <i>introspect</i> [<i>OPTIONS</i>] <i>BUS_NAME OBJECT_PATH</i>


title: PARAMETERS
content:
<b><i>--system</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the system D-Bus bus.<br><br><b><i>--session</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the session D-Bus bus (this is the default behavior).<br><br><b><i>--address=ADDRESS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to a D-Bus daemon at a specific address instead of the default system or session bus.<br><br><b><i>--verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, printing more details about D-Bus interactions, especially useful for debugging.<br><br><b><i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the program's version information and exit.<br><br><b><i>--help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a help message and exit.<br><br><b><i>COMMAND</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The specific operation to perform (e.g., <i>call</i>, <i>monitor</i>, <i>emit</i>, <i>introspect</i>, <i>status</i>, <i>list-names</i>, etc.). Each command has its own specific set of arguments and options.<br><br><b><i>[COMMAND_OPTIONS]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Options and arguments specific to the chosen <i>COMMAND</i>. These vary widely depending on the operation.<br><br>


title: DESCRIPTION
content:
<b>gdbus</b> is a powerful command-line utility provided by the GLib library for interacting with the D-Bus message bus. It offers a convenient interface to perform various D-Bus operations, such as calling methods on remote D-Bus objects, sending and receiving signals, and monitoring D-Bus traffic. It serves as an essential tool for debugging D-Bus services, scripting interactions with D-Bus applications, and exploring the D-Bus system. <b>gdbus</b> supports both the system bus and the session bus, and it can handle complex D-Bus data types using the GVariant text format. It simplifies D-Bus interactions, making them accessible without requiring direct programming in C or using lower-level D-Bus tools like <b>dbus-send</b>.


title: CAVEATS
content:
D-Bus services and permissions: Interactions with D-Bus services are subject to D-Bus policies and permissions, which may restrict certain operations or access. <br> Complex arguments: When calling methods or emitting signals with structured data types, arguments must be correctly formatted according to the GVariant text format, which can be verbose and require careful escaping. <br> GLib dependency: <b>gdbus</b> is part of the GLib library; therefore, it requires GLib to be installed on the system to function.


title: COMMON COMMANDS
content:
<b>gdbus</b> supports a variety of commands for different D-Bus operations:<br><ul><li><i>call</i>: Call a method on a remote D-Bus object.</li><li><i>monitor</i>: Monitor all messages (method calls, signals, replies) flowing through the D-Bus bus.</li><li><i>emit</i>: Emit a D-Bus signal from the command line.</li><li><i>introspect</i>: Introspect an object on the bus to discover its interfaces, methods, signals, and properties.</li><li><i>status</i>: Show the status of the D-Bus daemon.</li><li><i>list-names</i>: List all unique bus names currently on the bus.</li><li><i>name-owner</i>: Find the unique connection name that owns a specific bus name.</li></ul>


title: ARGUMENT FORMATTING (GVARIANT)
content:
Arguments for commands like <i>call</i> and <i>emit</i>, as well as complex data types returned by methods, are specified using the GVariant text format. This flexible format allows for representing various data types, including basic types (integers, strings, booleans), arrays, tuples, and dictionaries. For example:<br><ul><li>String: <i>'hello world'</i></li><li>Unsigned 32-bit integer: <i>uint32 42</i></li><li>Boolean: <i>true</i> or <i>false</i></li><li>Array of strings: <i>['item1', 'item2', 'item3']</i></li><li>Tuple: <i>(int32 123, 'a string')</i></li></ul>


title: HISTORY
content:
<b>gdbus</b> is part of the GLib library, a fundamental component of the GNOME desktop environment and many other Linux applications. It was introduced to provide a more consistent, higher-level, and programmatically friendly way to interact with D-Bus, especially for developers working within the GLib/GObject ecosystem. Its development aimed to simplify D-Bus integration compared to earlier, lower-level tools like <b>dbus-send</b>, making D-Bus interactions more robust and easier to script.


title: SYNOPSIS
content:
<b>gdc</b> [<i>options</i>] <i>files</i>... [<i>-o output_file</i>]<br><b>gdc</b> [<i>-std=version</i>] [<i>-I import_path</i>] [<i>-L library_path</i>] [<i>-l library</i>] [<i>-Olevel</i>] [<i>-g</i>] [<i>-c</i>] <i>source_file.d</i> [<i>-o executable</i>]


title: PARAMETERS
content:
<b><i>-o &lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output file name.<br><br><b><i>-c</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile or assemble the source files, but do not link.<br><br><b><i>-S</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile only; do not assemble or link.<br><br><b><i>-E</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preprocess only; do not compile, assemble, or link.<br><br><b><i>-Wall</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable all common warnings.<br><br><b><i>-O&lt;level&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set optimization level (e.g., -O2, -O3, -Os).<br><br><b><i>-g</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate debugging information for debuggers like GDB.<br><br><b><i>-std=&lt;version&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the D language standard to use (e.g., d2).<br><br><b><i>-I&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add directory to the D import search path.<br><br><b><i>-L&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add directory to the library search path for linking.<br><br><b><i>-l&lt;lib&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Link with the specified library.<br><br><b><i>-fPIC</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate position-independent code for shared libraries.<br><br><b><i>-shared</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a shared library.<br><br><b><i>-fcheck-contract</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable all D language contract checks (asserts, in/out, invariants).<br><br><b><i>-fdoc</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate Ddoc documentation files.<br><br>


title: DESCRIPTION
content:
<i>gdc</i> is the GNU D compiler, a frontend for the D programming language integrated into the GNU Compiler Collection (GCC). It allows developers to compile D source code into executables, shared libraries, or static libraries. <i>gdc</i> leverages GCC's robust backend, providing optimized code generation, support for multiple architectures, and integration with the wider GCC toolchain.<br><br>It supports various D language features and standards, enabling the creation of high-performance and reliable applications. Like other GCC frontends, <i>gdc</i> accepts a wide array of standard GCC options for optimization, debugging, linking, and warning control, alongside D-specific options for language versioning, contract checking, and module management. Its presence within GCC makes it a strong contender for D development on Linux and other GCC-supported platforms.


title: CAVEATS
content:
<i>gdc</i>'s behavior is heavily dependent on the GCC version it's built against. Newer GCC versions might offer better D language feature support or optimizations. Not all D language features, especially very recent ones from the D Language Specification, might be fully implemented or optimized in older <i>gdc</i> versions. Compatibility with specific D runtime libraries might also vary.


title: D LANGUAGE INTEGRATION
content:
<i>gdc</i> provides seamless integration for compiling D source files (<i>.d</i> or <i>.di</i>) within a mixed-C/C++ project environment. It can compile D code and link it with object files or libraries generated by other GCC frontends.


title: RUNTIME LIBRARY
content:
<i>gdc</i> typically uses <i>libphobos</i>, the D standard library implementation for <i>gdc</i>, along with <i>libdruntime</i>, the D runtime library. These are crucial for D applications to function correctly, providing garbage collection, concurrency primitives, and other core functionalities.


title: HISTORY
content:
The D language compiler frontend for GCC, <i>gdc</i>, began development in the early 2000s by David Friedman and others, aiming to integrate D into the robust GNU Compiler Collection ecosystem. This integration allowed D to benefit from GCC's established optimization passes, multi-platform support, and extensive tooling. While not the first D compiler (DMD by Walter Bright predates it), <i>gdc</i> offered an open-source, GCC-native alternative, appealing to developers already reliant on the GNU toolchain. Its development has progressed alongside GCC's releases, often adding support for new D language features and improving performance, ensuring D's presence within the broader open-source compiler landscape.


title: PARAMETERS
content:
<b>-n, --no-install</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not actually install the package; only resolve dependencies.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress progress indicators and most output during operation.<br><br><b>--apt-line</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulate the installation and output a line suitable for <b>apt-get</b> to install the package and its dependencies.<br><br><b>--non-interactive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ask questions during installation; useful for scripting and automated environments.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information for <b>gdebi</b> and exit.<br><br>


title: DESCRIPTION
content:
The <b>gdebi</b> command is a lightweight tool designed to install local Debian (<code>.deb</code>) package files. Its primary advantage over <b>dpkg</b> is its ability to automatically resolve and install package dependencies from configured APT repositories. While <b>dpkg</b> can install <code>.deb</code> files, it will fail if dependencies are not met, leaving the user to manually find and install them. <b>gdebi</b> bridges this gap by performing a dependency check and then using APT's mechanisms to fetch and install any required packages, much like <b>apt install</b> would for repository packages. It provides a more user-friendly and complete experience for installing downloaded <code>.deb</code> files.


title: CAVEATS
content:
<b>gdebi</b> relies on your system's configured APT repositories to find and install dependencies. If a dependency is not available in these repositories (e.g., a custom library), <b>gdebi</b> will not be able to resolve it. It is primarily designed for installing single local <code>.deb</code> files, not for managing large sets of packages or complex repository interactions.


title: GUI FRONT-END
content:
<b>gdebi</b> also has a graphical user interface (GUI) counterpart, typically named <b>gdebi-gtk</b> or simply 'GDebi Package Installer'. This GUI application provides a visual way to inspect a <code>.deb</code> package, view its dependencies, and then proceed with installation, offering an even more user-friendly experience for desktop users.


title: TYPICAL USAGE
content:
The most common use case for <b>gdebi</b> is when you download a <code>.deb</code> package directly from a software vendor's website (e.g., Google Chrome, VS Code). Instead of manually checking and installing dependencies, you can simply run <b>gdebi</b> on the downloaded file, and it will handle the rest, ensuring all necessary components are present before the main package is installed.


title: HISTORY
content:
<b>gdebi</b> was developed to address a common pain point for Linux users: installing locally downloaded <code>.deb</code> packages while automatically handling their dependencies. Before its widespread use, users often had to resort to complex <b>dpkg</b> commands followed by <b>apt-get -f install</b> to fix dependency issues. <b>gdebi</b> streamlined this process, particularly benefiting users who frequently install software not available directly in official repositories. Its development provided a simpler, more intuitive way to integrate external applications into the system, often becoming the default application for opening <code>.deb</code> files in desktop environments.


title: PARAMETERS
content:
<b><i>package.deb</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the local Debian package file (<b>.deb</b>) to be installed. If this argument is omitted, <i>gdebi-gtk</i> will launch with a file selection dialog, allowing the user to browse and select a <b>.deb</b> file from their system.<br><br>


title: DESCRIPTION
content:
<i>gdebi-gtk</i> is a graphical application designed for easy installation of local Debian (<b>.deb</b>) package files. Unlike the lower-level <b>dpkg</b> command, which only installs the specified package and requires all dependencies to be met manually, <i>gdebi-gtk</i> automatically checks for and attempts to resolve all necessary package dependencies. It presents a clear interface showing package details, required dependencies (indicating which are already installed and which need to be fetched), and any potential conflicts.<br><br>This utility streamlines the process of installing software distributed as standalone <b>.deb</b> files, especially when they are not available in standard APT repositories. By automating dependency resolution, <i>gdebi-gtk</i> provides a user-friendly experience, abstracting away the complexity of managing software prerequisites. It typically offers a straightforward "Install Package" button once the dependencies are validated.


title: CAVEATS
content:
<b>Caveats and Limitations:</b><br><i>gdebi-gtk</i> requires a graphical desktop environment to operate.<br>Internet access is typically needed if the required package dependencies are not already present on the system or locally cached.<br>It relies on the APT package management system for dependency resolution, meaning your <b>/etc/apt/sources.list</b> and related configurations must be correctly set up.<br>While it is excellent for installing new local packages, it is not designed as a comprehensive package manager for upgrades or removals, though it might offer basic removal for the opened package.


title: GUI INTERACTION
content:
When a <b>.deb</b> package is opened with <i>gdebi-gtk</i>, its graphical interface prominently displays crucial information such as the package name, version, architecture, installed size, and a detailed description. Crucially, it lists all package dependencies, clearly indicating which are already satisfied and which need to be installed. This visual feedback helps users understand the impact of the installation. The interface typically features an "Install Package" button to initiate the installation process and may also offer a "Reinstall Package" or "Remove Package" option depending on the package's current state on the system.


title: DEPENDENCY RESOLUTION MECHANISM
content:
The primary advantage of <i>gdebi-gtk</i> over simpler tools like <b>dpkg -i</b> is its intelligent dependency resolution. Upon loading a <b>.deb</b> file, <i>gdebi-gtk</i> leverages the APT system to identify all prerequisite packages. It then checks the system's configured APT repositories and local package caches to locate and offer to install these missing dependencies automatically. This prevents common installation failures caused by missing libraries or other required software, ensuring a smoother and more reliable installation experience for the user.


title: HISTORY
content:
<i>gdebi</i> and its graphical counterpart, <i>gdebi-gtk</i>, emerged to address a significant usability gap in Debian-based package management. While <b>dpkg</b> provided fundamental package installation, its lack of automatic dependency resolution often led to frustration for users attempting to install standalone <b>.deb</b> files. <i>gdebi-gtk</i> filled this void by providing a straightforward, graphical solution that integrated with the APT system to automatically fetch and install missing dependencies.<br><br>Its development has been intertwined with the evolution of the GTK+ toolkit, providing a consistent user experience over time. It has become a standard utility in distributions like Ubuntu, offering a simple double-click installation method for local Debian packages, thereby enhancing the overall user experience for software installation outside of official repositories.


title: DESCRIPTION
content:
The command <b>gdiffmk</b> is not a standard utility found in typical Linux distributions or their core packages. It is highly probable that this command name is either a typo, a custom script created by a user or administrator, or part of a very niche, non-standard software installation. Users looking for file comparison utilities or tools to mark differences might be thinking of <i>diffmk</i> (part of the Texinfo documentation system), <i>diff</i> (the standard GNU utility for comparing files), or a graphical diff tool. Without context, specific functionality cannot be attributed to <b>gdiffmk</b> as a universally recognized command.


title: CAVEATS
content:
As <b>gdiffmk</b> is not a standard Linux command, attempting to execute it will likely result in a 'command not found' error unless a custom script with this name exists in your system's PATH. Its behavior and availability are entirely dependent on non-standard configurations, if it exists at all on a given system.


title: VERIFICATION
content:
Users should verify the exact spelling of the command they intend to use. If the goal is to compare files, <b>diff</b> is the primary tool. If marking differences specifically in Texinfo files, <b>diffmk</b> is the relevant utility.


title: HISTORY
content:
There is no known history or development timeline for <b>gdiffmk</b> as a standard, distributed Linux command. Its appearance likely stems from local script creation or a misunderstanding of existing command names, rather than being part of a public project or package.


title: SYNOPSIS
content:
<b>gdisk</b> [<b>-l</b>|<b>--list-partitions</b>] [<b>-h</b>|<b>--help</b>] [<b>-v</b>|<b>--version</b>] <i>device</i>


title: PARAMETERS
content:
<b><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>The disk device (e.g., /dev/sda, /dev/nvme0n1) on which to operate. This is usually the primary argument.</I><br><br><b><b>-l</b>, <b>--list-partitions</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Lists the partition table for the specified device and then exits, without entering the interactive mode.</I><br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Displays a brief help message showing command-line options and then exits.</I><br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Prints the program's version number and exits.</I><br><br>


title: DESCRIPTION
content:
<b>gdisk</b> is a powerful, interactive utility designed for creating, manipulating, and managing <i>GUID Partition Table (GPT)</i> disk partition tables. It serves as a modern alternative to the traditional <b>fdisk</b> command, which primarily focuses on <i>Master Boot Record (MBR)</i> partitioning schemes. With its intuitive, menu-driven text interface, <b>gdisk</b> allows users to perform various partitioning tasks such as creating new partitions, deleting existing ones, changing partition types, resizing partitions, and setting partition attributes.<br><br>Beyond basic partitioning, <b>gdisk</b> offers advanced features like converting MBR or Apple Partition Map (APM) disks to GPT, backing up and restoring partition tables, and verifying partition integrity. It is part of the <i>gptfdisk</i> utility suite, which also includes <b>sgdisk</b> for scripting and non-interactive operations. <b>gdisk</b> is essential for managing modern storage devices that typically use GPT, supporting larger disk sizes and more partitions than MBR.


title: CAVEATS
content:
<I><b>Root Privileges:</b> <b>gdisk</b> requires root (sudo) privileges to operate on disk devices.</I><br><I><b>Data Loss Risk:</b> Incorrect use of <b>gdisk</b>, especially when writing changes to disk, can lead to severe data loss. Always back up important data before making partitioning changes.</I><br><I><b>Interactive Only:</b> Most operations are performed within the interactive menu. Command-line options are limited to listing, help, and version information.</I><br><I><b>GPT Focus:</b> While it can convert MBR to GPT, its primary design and best use case are for disks already using or intended for GPT. For MBR disks, <b>fdisk</b> might be more appropriate.</I>


title: INTERACTIVE MODE
content:
<I>Upon launching <b>gdisk</b> with a device (e.g., <b>gdisk /dev/sda</b>), it enters an interactive, menu-driven interface. Users type single-character commands followed by Enter to perform actions. Some common interactive commands include:</I><br><I><b>p</b>: Print the partition table.</I><br><I><b>n</b>: Create a new partition.</I><br><I><b>d</b>: Delete a partition.</I><br><I><b>w</b>: Write partition table to disk and exit (<b>CAUTION: permanent changes!</b>).</I><br><I><b>q</b>: Quit without saving changes.</I><br><I><b>r</b>: Recovery and transformation options (e.g., backup, restore, convert MBR to GPT).</I>


title: GPT ADVANTAGES
content:
<I>GPT offers several advantages over MBR, including support for disk sizes larger than 2TB, virtually unlimited partitions (limited by OS to typically 128), CRC checksums for partition table integrity, and redundant primary/backup partition tables.</I>


title: HISTORY
content:
<b>gdisk</b> was developed by <i>Roderick W. Smith</i> as part of the <i>gptfdisk</i> project, with its initial public release around 2009. The primary motivation for its creation was the increasing adoption of <i>GUID Partition Table (GPT)</i> as a successor to the older <i>Master Boot Record (MBR)</i> partitioning scheme, especially with the proliferation of larger hard drives (beyond 2TB) and the advent of UEFI firmware. <b>gdisk</b> aimed to provide a familiar, <b>fdisk</b>-like interactive text interface specifically tailored for GPT management, addressing a gap in existing Linux partitioning tools at the time. Its development ensured robust and user-friendly support for GPT on Linux systems.


title: SYNOPSIS
content:
<b>gdown</b> [<i>OPTIONS</i>] <i>URL</i> | <b>--id</b> <i>FILE_ID</i> | <b>--folder</b> <i>FOLDER_URL</i>


title: PARAMETERS
content:
<b>-O, --output <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Specifies the output file path or directory.</b> <i>gdown</i> will save the downloaded file to this location.<br><br><b>--id <file_id></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Downloads a file by its Google Drive ID.</b> Useful when you only have the ID and not a full URL.<br><br><b>--folder <folder_url></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Downloads an entire Google Drive folder.</b> Requires the <i>--recursive</i> option for nested content.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Suppresses output.</b> Only errors will be displayed, making it suitable for scripting.<br><br><b>--no-check-certificate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Disables SSL certificate verification.</b> Use with caution, primarily for self-signed certificates in controlled environments.<br><br><b>--fuzzy</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Enables fuzzy matching for file names.</b> Useful when the exact filename isn't known for a folder download.<br><br><b>--recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Downloads contents of a folder recursively.</b> Required when using <i>--folder</i> to get all sub-files and folders.<br><br><b>--convert</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Converts Google Docs, Sheets, or Slides to standard formats.</b> E.g., a Google Doc will be converted to PDF.<br><br><b>--unzip</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Unzips a downloaded zip file automatically.</b> Saves the contents to the output directory.<br><br><b>--remaining-attempts <N></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Sets the maximum number of download attempts.</b> Useful for unreliable networks or temporary Google Drive issues.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Displays help message and exits.</b><br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Shows the program's version and exits.</b><br><br>


title: DESCRIPTION
content:
<i>gdown</i> is a command-line utility designed to simplify downloading files and folders from Google Drive. It acts as a convenient wrapper around the Google Drive API, specifically handling common scenarios that make direct downloads via tools like <i>wget</i> or <i>curl</i> difficult, such as Google's "too many downloads" warning pages or the need to bypass browser-based prompts.<br><br>It's particularly useful for downloading large public files, datasets, or shared content directly from the terminal without requiring manual interaction with a web browser. Beyond simple file downloads, <i>gdown</i> can also download entire shared Google Drive folders recursively and supports conversion of Google-specific document formats (like Docs, Sheets, Slides) into standard formats such as PDF, XLSX, or PPTX. It's built on Python and typically installed via <i>pip</i>, making it cross-platform and easy to integrate into scripts.


title: CAVEATS
content:
<i>gdown</i> primarily relies on public or shared Google Drive links. Downloading private files requires additional authentication steps, which are beyond the typical command-line usage and often involve configuring Google API credentials.<br><br>While it handles Google's download limits better than direct methods, extreme usage might still trigger temporary blocks. For very large folder structures or extremely slow networks, <i>gdown</i>'s performance might not match dedicated sync tools like <i>rclone</i>, which are optimized for persistent connections and resumable transfers.


title: INSTALLATION
content:
<i>gdown</i> is a Python package and can be easily installed using <i>pip</i>, the Python package installer.<br><br>To install: <b>pip install gdown</b><br><br>Ensure you have Python and <i>pip</i> installed on your system.


title: USAGE EXAMPLES
content:
<b>Basic File Download:</b><br><i>gdown</i> https://drive.google.com/uc?id=YOUR_FILE_ID<br><br><b>Download to Specific File:</b><br><i>gdown</i> --output my_downloaded_file.zip https://drive.google.com/uc?id=YOUR_FILE_ID<br><br><b>Download a Folder Recursively:</b><br><i>gdown</i> --folder --recursive https://drive.google.com/drive/folders/YOUR_FOLDER_ID<br><br><b>Download by File ID:</b><br><i>gdown</i> --id YOUR_FILE_ID


title: HISTORY
content:
The <i>gdown</i> utility originated as a convenient Python package to address the common challenges of downloading files from Google Drive, particularly large files that trigger browser warnings or require bypassing manual prompts. It was developed by W. Kato (wkentaro) and quickly gained popularity within the machine learning and data science communities for easily downloading pre-trained models and datasets often hosted on Google Drive. Its development has focused on providing a simple, robust command-line interface for Google Drive downloads, abstracting away the complexities of Google's API and web interface interactions.


title: PARAMETERS
content:
<b>-c <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file path for <b>gdrive</b>.<br><br><b>-m <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative MIME type mapping file path.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about operations.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the <b>gdrive</b> command or a specific subcommand.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the <b>gdrive</b> tool version.<br><br><b>about</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays information about your Google Drive account, including storage usage.<br><br><b>download (<I>dl</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads files or directories from Google Drive. Options include:<br>  <I>-r, --recursive</I>: Downloads folders recursively.<br>  <I>--skip-existing</I>: Skips downloading files that already exist locally.<br>  <I>--path <path></I>: Specifies the local directory to download files to.<br>  <I>--no-clobber</I>: Prevents overwriting existing local files.<br><br><b>upload (<I>up</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uploads files or directories to Google Drive. Options include:<br>  <I>--parent <id></I>: Specifies the parent folder ID on Drive for the upload.<br>  <I>-r, --recursive</I>: Uploads folders recursively.<br>  <I>--convert</I>: Converts uploaded files to Google Docs formats.<br>  <I>--name <name></I>: Specifies the name of the file on Drive.<br><br><b>list (<I>ls</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists files and folders in your Google Drive. Options include:<br>  <I>-q, --query <query></I>: Filters results using a Google Drive API query string.<br>  <I>-m, --max <num></I>: Sets the maximum number of items to list.<br>  <I>-o, --order <field></I>: Orders the results by a specified field (e.g., <I>modifiedTime</I>).<br><br><b>sync</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Synchronizes a local directory with a Google Drive folder. Options include:<br>  <I>--id <id></I>: Specifies the Google Drive folder ID for synchronization.<br>  <I>--delete-extraneous</I>: Deletes files on Drive that don't exist locally.<br>  <I>--dry-run</I>: Performs a simulated sync without actual changes.<br><br><b>info</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about a specific file or folder on Google Drive using its ID or path.<br><br><b>mkdir</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new folder on Google Drive.<br><br><b>delete (<I>rm</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes files or folders from Google Drive. Options include:<br>  <I>-r, --recursive</I>: Deletes folders recursively.<br>  <I>--trash</I>: Moves items to trash instead of permanent deletion.<br><br><b>share</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages sharing permissions for files or folders on Google Drive.<br><br><b>unshare</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes sharing permissions for files or folders.<br><br><b>cat</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the content of a file directly to standard output.<br><br>


title: DESCRIPTION
content:
<b>gdrive</b> is a powerful and versatile command-line utility designed to interact with Google Drive directly from your Linux terminal. It provides a comprehensive set of features for managing your cloud storage, including uploading and downloading files, listing directory contents, creating and deleting folders, and synchronizing local directories with Google Drive.<br><br>Its non-interactive nature makes it ideal for scripting automated backup and synchronization tasks. <b>gdrive</b> leverages Google's OAuth2 authentication for secure access, guiding the user through a browser-based authentication flow upon its first use. It's an essential tool for users who prefer terminal-based workflows or need to integrate Google Drive operations into shell scripts and cron jobs.


title: CAVEATS
content:
Initial authentication requires browser interaction to generate a token, which might be challenging in headless environments without a browser.<br><br>Google Drive API rate limits can be encountered with frequent or large operations, potentially leading to temporary errors.<br><br>Synchronization logic, especially for complex scenarios or large datasets, requires careful configuration to avoid unintended data loss or duplication.<br><br>Handling Google Docs/Sheets/Slides formats: <b>gdrive</b> can convert uploaded files to native Google formats, but downloading them typically results in exported versions (e.g., PDF, DOCX), not the editable native format.


title: AUTHENTICATION PROCESS
content:
Upon first execution, <b>gdrive</b> typically provides a URL. You must open this URL in a web browser, log in with your Google account, grant <b>gdrive</b> permissions, and then copy the authorization code displayed back into your terminal. This process generates a configuration token that <b>gdrive</b> stores for future use, allowing subsequent operations without re-authentication.


title: FILE IDS
content:
<b>gdrive</b> often refers to files and folders using their unique Google Drive IDs rather than their names, especially for operations like <I>download</I> or <I>info</I>. These IDs can be obtained using the <I>list</I> command. Using IDs ensures precision, as multiple files can share the same name within Google Drive.


title: HISTORY
content:
<b>gdrive</b> was initially developed by Burman as an open-source project. It provides a simple yet effective way to manage Google Drive files from the command line, gaining popularity for its ease of use compared to more complex cloud storage tools. Its development has focused on providing essential functionalities for typical Drive interactions, making it a go-to tool for scripting and automation of cloud storage tasks on Linux systems.


title: PARAMETERS
content:
<b>-s, --summarize</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display only the total size of the current directory, similar to 'du -sh'.</i><br><br><b>-H, --human-readable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Use human-readable sizes (e.g., 1K, 234M, 2G) in non-interactive output.</i><br><br><b>-L, --dereference</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Follow symbolic links during scanning.</i><br><br><b>-a, --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display all files and directories, not just directories or large files.</i><br><br><b>-m, --no-mouse</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disable mouse support in the interactive user interface.</i><br><br><b>-c, --no-color</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disable colorized output in the terminal.</i><br><br><b>-r, --remote-host <host></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Analyze disk usage on a remote host via SSH. Requires SSH access and 'gdu' on the remote.</i><br><br><b>-x, --one-file-system</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Skip directories residing on different filesystems.</i><br><br><b>-i, --ignore-dirs <pattern></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Comma-separated list of directory names to ignore during scanning.</i><br><br><b>-f, --file <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Read directory contents from a 'du'-compatible file instead of scanning the disk.</i><br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display the help message and exit.</i><br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Print the version information and exit.</i><br><br>


title: DESCRIPTION
content:
<b>gdu</b> (Go Disk Usage) is a modern, blazing-fast, and interactive disk usage analyzer written in <i>Go</i>. It offers an <i>ncurses</i>-like graphical interface for quickly inspecting disk space consumption on Linux/Unix systems. <br><br>Designed for efficiency, especially on solid-state drives (SSDs) and filesystems with numerous large directories, <b>gdu</b> leverages parallel processing to scan and report disk usage much quicker than traditional tools like <i>du</i> or even <i>ncdu</i>. Its intuitive interface allows users to easily navigate directory structures, view file and folder sizes, sort entries by various criteria, and even perform direct file or directory deletion operations from within the application, providing a comprehensive and efficient disk management experience.


title: CAVEATS
content:
Scanning certain system directories (e.g., <i>/root</i>, <i>/proc</i>, <i>/sys</i>) may require <b>sudo</b> or root privileges. The interactive UI requires a compatible terminal emulator. Analyzing remote hosts mandates <b>gdu</b>'s presence on the remote system for execution.


title: INTERACTIVE FEATURES
content:
The <b>gdu</b> interactive UI is highly intuitive. Press <I>h</I> within the application to view a list of keyboard shortcuts for navigation (e.g., <I>j</I>/<I>k</I> for up/down), sorting, showing/hiding percentages (<I>g</I>), and performing actions like deleting files (<I>d</I>) or quitting (<I>q</I>). It provides a real-time, dynamic overview of disk space usage.


title: PERFORMANCE OPTIMIZATION
content:
<b>gdu</b> is engineered for speed. It utilizes parallel processing to traverse and analyze directories concurrently, significantly reducing scan times compared to single-threaded alternatives. This makes it particularly efficient for large filesystems, network shares, and modern storage devices like SSDs, providing rapid insights into disk consumption.


title: HISTORY
content:
Developed by Ondřej Dušek (dundee) and written in <i>Go</i>, <b>gdu</b> emerged as a high-performance alternative to existing disk usage analyzers. Its primary motivation was to address the speed limitations of tools like <i>ncdu</i>, especially when dealing with very large filesystems and modern SSDs, by leveraging <i>Go</i>'s concurrency features for parallel scanning. It gained popularity for its speed and interactive interface since its initial stable releases around 2019-2020.


title: PARAMETERS
content:
<b>--new-window</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens a new, empty window for editing.<br><br><b>--new-document</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new, untitled document within an existing or new window.<br><br><b>--encoding=ENCODING</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the character encoding for the specified files. Use <b>--list-encodings</b> for options.<br><br><b>--list-encodings</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a list of all supported character encodings.<br><br><b>--standalone</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs <i>gedit</i> as a separate, independent process, not attaching to an existing instance.<br><br><b>--fullscreen</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts <i>gedit</i> in full-screen mode, hiding window decorations.<br><br><b>--print</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the specified files using the default printer.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the <i>gedit</i> version information and exits.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays available command-line options and exits.<br><br>


title: DESCRIPTION
content:
<i>gedit</i> is the official text editor of the <b>GNOME</b> desktop environment, designed to be simple and easy-to-use. It provides a clean, minimalistic interface while offering essential features for general-purpose text editing and basic programming. Key capabilities include syntax highlighting for various programming languages, customizable fonts and colors, a tabbed interface for managing multiple documents, undo/redo functionality, and a powerful search and replace feature. <br><br>Unlike command-line editors such as <i>Vim</i> or <i>Nano</i>, <i>gedit</i> is a graphical application, making it accessible and intuitive for users accustomed to GUI environments. It's often used for editing configuration files, writing simple scripts, taking notes, or developing small programs. While not an IDE, its plugin system allows extending functionality for specific tasks, making it a versatile tool for both everyday users and developers looking for a lightweight editor.


title: CAVEATS
content:
<i>gedit</i> is a lightweight editor and may not be suitable for very large files (hundreds of MBs) as performance can degrade significantly. It also lacks advanced features found in full-fledged Integrated Development Environments (IDEs) or more powerful text editors like <i>VS Code</i> or <i>Emacs</i>, such as integrated debugging, sophisticated code completion, or complex project management. It strictly requires a graphical user interface and cannot be used directly from a terminal without a display server.


title: PLUGIN EXTENSIBILITY
content:
<i>gedit</i> supports a rich set of official and third-party plugins that can significantly extend its functionality. These plugins can add features like a file browser pane, snippet management, external tool execution, document statistics, and more, allowing users to tailor the editor to their specific needs without cluttering the core interface.


title: SYNTAX HIGHLIGHTING
content:
A core feature of <i>gedit</i> is its extensive support for syntax highlighting, which automatically color-codes text based on the language's syntax. This makes code and configuration files significantly more readable and helps in identifying syntax errors, supporting dozens of programming languages and markup formats out-of-the-box.


title: HISTORY
content:
<i>gedit</i> was first released in 1999 as part of the <b>GNOME 2</b> desktop environment. It was developed to provide a simple, easy-to-use default text editor that seamlessly integrates with the GNOME user experience, adhering to its Human Interface Guidelines. Written in C and built upon the GTK+ toolkit, it aimed to offer an intuitive alternative to the more complex command-line editors prevalent at the time, like <i>Vim</i> and <i>Emacs</i>. Its development has consistently focused on user-friendliness, accessibility, and robust basic text editing capabilities, evolving with the GNOME project itself.


title: SYNOPSIS
content:
<b>gem</b> [<I>options</I>] [<I>command</I>] [<I>arguments</I>]<br><br>Examples:<br><b>gem install rails</b><br><b>gem update</b><br><b>gem list --local</b>


title: PARAMETERS
content:
<b><b>gem install <I>gemname</I> [<I>options</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs one or more specified gems. Often requires root privileges for system-wide installation.<br>Example: <b>gem install bundler</b><br><br><b><b>gem update [<I>gemname</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Updates all installed gems or a specific gem to the latest version. This command refreshes your gem versions based on remote sources.<br>Example: <b>gem update --system</b> (updates RubyGems itself)<br><br><b><b>gem uninstall <I>gemname</I> [<I>options</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes one or more specified gems from your system. Careful use is advised to avoid breaking dependencies.<br>Example: <b>gem uninstall rails</b><br><br><b><b>gem list [<I>options</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all installed gems. Can be filtered or display remote gems using various options.<br>Example: <b>gem list --local</b><br><br><b><b>gem search <I>query</I> [<I>options</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Searches for gems on remote sources (like rubygems.org) matching the given query.<br>Example: <b>gem search rails --remote</b><br><br><b><b>gem build <I>gemspec_file</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds a gem package (.gem file) from a gemspec file, which defines the gem's contents and metadata.<br>Example: <b>gem build my_gem.gemspec</b><br><br><b><b>gem push <I>gem_file</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Publishes a built gem (.gem file) to a remote gem host, typically rubygems.org. Requires authentication.<br>Example: <b>gem push my_gem-1.0.0.gem</b><br><br><b><b>gem env</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about your RubyGems environment, including paths, versions, and configurations.<br>Example: <b>gem env</b><br><br><b><b>gem help [<I>command</I>]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides help information for the general <b>gem</b> command or a specific subcommand.<br>Example: <b>gem help install</b><br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current version of RubyGems itself.<br>Example: <b>gem --version</b><br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help documentation for the <b>gem</b> command.<br>Example: <b>gem --help</b><br><br>


title: DESCRIPTION
content:
The <b>gem</b> command is the primary command-line interface for RubyGems, Ruby's standard package manager. It provides essential functionalities for managing Ruby libraries, known as 'gems'. Developers use <b>gem</b> to install, update, uninstall, and list gems, fetching them from remote repositories like rubygems.org. It intelligently handles gem dependencies, ensuring all necessary libraries are installed. Beyond just consumption, <b>gem</b> also empowers gem authors to create, build, and publish their own gems to the community. It is analogous to package managers like <i>pip</i> for Python or <i>npm</i> for Node.js, forming the backbone of the Ruby ecosystem's dependency management.


title: CAVEATS
content:
When installing gems globally (system-wide), the <b>gem</b> command often requires root privileges (e.g., using <b>sudo</b>), which can be a security concern or lead to permission issues.<br>While RubyGems handles dependencies, complex projects often benefit from version managers like <i>RVM</i> or <i>rbenv</i> and project-specific dependency tools like <i>Bundler</i> to avoid conflicts and maintain isolated gem environments.<br>Older versions of RubyGems might have less robust dependency resolution, which could lead to 'gem hell' where incompatible versions clash.


title: <B>GEMFILE AND BUNDLER INTEGRATION</B>
content:
While <b>gem</b> manages globally installed libraries, projects often use a <b>Gemfile</b> and the <b>bundle</b> command (from the <i>Bundler</i> gem) for managing project-specific dependencies. <b>Bundler</b> ensures that each project uses a consistent set of gem versions, which is crucial for reproducible builds and deployment. <b>gem install bundler</b> is typically the first step to enable this workflow.


title: <B>GEM SOURCES</B>
content:
By default, <b>gem</b> fetches libraries from <i>rubygems.org</i>, the central repository for Ruby gems. However, it can also install gems from local files, Git repositories, or other custom gem servers configured in the RubyGems environment. This flexibility allows for private gem hosting and development workflows.


title: HISTORY
content:
RubyGems was created to address the need for a robust package management system in the Ruby ecosystem, similar to Perl's CPAN. Its development began in 2003, with the first official release in 2004. It quickly gained traction and became the de facto standard for distributing Ruby libraries. Over time, RubyGems has improved significantly in dependency resolution and integration with the Ruby interpreter, often shipping as part of the Ruby distribution itself.


title: SYNOPSIS
content:
<b>gemtopnm</b> [<I>options</I>] [<I>gemfile</I>]<br>Options: [<I>-b</I>] [<I>-t</I>] [<I>-x XPOS</I>] [<I>-y YPOS</I>] [<I>-w WIDTH</I>] [<I>-h HEIGHT</I>]


title: PARAMETERS
content:
<b><I>gemfile</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input GEM <i>.img</i> file. If omitted, <b>gemtopnm</b> reads from standard input.<br><br><b>-b</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When processing monochrome images, interpret the pixel color index 0 as the background color. This can invert the appearance of some monochrome images.<br><br><b>-t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When processing monochrome images, interpret the pixel color index 0 as the target (foreground) color. This is typically the default behavior.<br><br><b>-x <I>XPOS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the X-coordinate of the top-left corner for cropping the output image. The default is 0.<br><br><b>-y <I>YPOS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the Y-coordinate of the top-left corner for cropping the output image. The default is 0.<br><br><b>-w <I>WIDTH</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the width for cropping the output image. If not specified, the full width of the input image from <I>XPOS</I> is used.<br><br><b>-h <I>HEIGHT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the height for cropping the output image. If not specified, the full height of the input image from <I>YPOS</I> is used.<br><br>


title: DESCRIPTION
content:
<b>gemtopnm</b> is a utility that reads a Graphics Environment Manager (GEM) <i>.img</i> raster image file and converts it into a Portable Anymap (PNM) format image, which is then written to standard output.<br><br>It supports various GEM image types, including monochrome, 2-color, and 16-color files. Monochrome and 2-color images are converted to Portable Bitmaps (PBM), while 16-color images are converted to Portable Pixmaps (PPM). The tool can handle both screen dump files and printer-specific GEM <i>.img</i> files.<br><br>It is particularly useful for users needing to process legacy GEM graphics on modern Unix-like systems, enabling integration with other image manipulation tools within the Netpbm suite.


