# CommandSection

title: PROXMOX BACKUP SERVER (PBS) INTEGRATION
content:
<i>qmrestore</i> can directly restore backups <br> stored on a Proxmox Backup Server. When specifying <br> the <i>backup_file</i>, you can use the format <br> <i>&lt;pbs_storage_id&gt;:&lt;backup_id&gt;</i> (e.g., <br> <i>pbstest:backup/ct/100/2023-10-26T12:00:00Z</i>) <br> to pull the backup from the PBS repository.


title: SUPPORTED BACKUP FORMATS
content:
Primarily, <i>qmrestore</i> works with backups <br> created by <i>vzdump</i>, which by default uses <br> the highly efficient <b>VMA (Virtual Machine Archive)</b> format. <br> It can also handle older <i>vzdump</i> formats <br> (e.g., plain raw disk images) and compressed archives <br> (gzip, zstd) that wrap these formats.


title: STORAGE SYSTEM COMPATIBILITY
content:
Restored virtual machine disks can be placed <br> on a wide range of storage types configured in <br> Proxmox VE, including: <br> <b>Local Directory</b>, <b>LVM-Thin</b>, <b>ZFS</b> <br> (on local pools or ZFS over iSCSI), <b>Ceph RBD</b>, <br> <b>NFS</b>, and <b>SMB/CIFS</b> shares. <br> The choice of storage affects performance and features <br> available to the VM.


title: HISTORY
content:
The <i>qmrestore</i> command has been a core component <br> of the Proxmox Virtual Environment since its early versions. <br> Proxmox VE, first released in 2007, was built upon <br> Debian Linux and KVM/LXC technologies. <br> As Proxmox VE matured, <i>qmrestore</i> evolved alongside, <br> gaining support for new features like various storage types <br> (ZFS, Ceph, etc.), improved backup formats (e.g., VMA), <br> and a wider array of configuration options to match <br> the growing capabilities of the platform. <br> A significant development was its integration with <br> the dedicated Proxmox Backup Server (PBS) in later versions <br> of Proxmox VE (PVE 6.x onwards), allowing seamless <br> restores directly from PBS repositories.


title: PARAMETERS
content:
<b>-e <I>editor</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the text editor to use instead of the one defined by the <i>$EDITOR</i> environment variable.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force operations: overwrite existing destination files without prompting.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt for confirmation before performing each rename or move operation.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run: show what changes would be made without actually executing them.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output: print each rename/move operation as it is performed.<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:
The <b><i>qmv</b></i> command, part of the <i>moreutils</i> package, provides an intuitive way to rename or move multiple files interactively. Unlike traditional methods that require scripting or complex regular expressions, <b><i>qmv</b></i> generates a temporary file containing a two-column list: original filenames on the left, and corresponding target filenames on the right. <br><br>Users then edit this temporary file using their preferred text editor (specified by the <i>$EDITOR</i> environment variable). After saving and exiting the editor, <b><i>qmv</b></i> reads the modified list and performs the necessary `mv` operations, ensuring that files are moved or renamed as specified. This interactive approach is particularly useful for complex renaming tasks such as correcting capitalization, adding prefixes/suffixes, reordering file name components, or swapping names between multiple files. It also offers safeguards like dry-run mode and confirmation prompts to prevent unintended changes.


title: CAVEATS
content:
1. Requires an external text editor: The <i>$EDITOR</i> environment variable must be set, or the <b>-e</b> option must be used to specify an editor.<br>2. Careful editing: Errors in the temporary file (e.g., invalid characters, non-existent paths, or incorrect formatting) can lead to failed operations or unintended results.<br>3. Overwriting files: If a target filename already exists, <b><i>qmv</b></i> will prompt for confirmation unless the <b>-f</b> (force) option is used, in which case it will overwrite without warning.<br>4. Filesystem boundaries: Moving files across different filesystems might involve copying and then deleting, which can be slower than simple renames within the same filesystem.


title: ENVIRONMENT VARIABLE: $EDITOR
content:
<b><i>qmv</b></i> relies heavily on the <i>$EDITOR</i> environment variable to determine which text editor to launch. If this variable is not set, <b><i>qmv</b></i> will typically fall back to a default editor like <i>vi</i> or <i>nano</i>, or prompt the user, or exit with an error. Setting <i>$EDITOR</i> (e.g., <b>export EDITOR=nano</b>) ensures a consistent editing experience.


title: INTERACTIVE EDITING FORMAT
content:
When <b><i>qmv</b></i> launches the editor, it presents a file with two tab-separated columns. The left column lists the original filenames, and the right column is where you specify the new filenames. Any changes made to the right column will be applied. It is crucial to maintain the tab-separated format and ensure that no newlines are inadvertently introduced within a filename entry. Lines starting with <b>#</b> are treated as comments and ignored.


title: HISTORY
content:
<b><i>qmv</b></i> is part of the <i>moreutils</i> collection of utilities, created by Joey Hess. The <i>moreutils</i> package began development in the early 2000s, aiming to provide a set of small, simple, and powerful tools that extend the functionality of standard Unix commands. <b><i>qmv</b></i> stands out for its unique approach to bulk renaming, leveraging the user's familiarity with text editors to solve complex renaming tasks that are cumbersome with simple scripting or regex-based tools. Its design emphasizes interactivity and user control, filling a niche between the basic `mv` command and more advanced, programmatic renaming utilities.


title: DESCRIPTION
content:
The command <b>qoitopam</b> does not appear to be a standard or commonly known Linux command or utility. It is not found in typical Linux distributions' core packages, man pages, or common command-line toolsets. <br><br>It is possible that <b>qoitopam</b> is a typo, a highly specialized custom script unique to a specific environment, or a fictional name. Without further context or verification, it cannot be analyzed as a standard Linux command.


title: CAVEATS
content:
As <b>qoitopam</b> is not a recognized command, any assumed usage or expected behavior is undefined. Users encountering this name should verify its spelling or the source from which it was obtained, as it is unlikely to be a universally available or functional command on most Linux systems.


title: VERIFICATION
content:
If you intended to inquire about a specific command, please double-check the spelling. If <b>qoitopam</b> refers to a custom script or a very niche tool, specific details about its origin and purpose would be required for any meaningful analysis.


title: HISTORY
content:
There is no documented history available for <b>qoitopam</b> as it is not a recognized Linux command in standard distributions or common software repositories.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information about the command-line options and exits.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the application's version information and exits.<br><br><b><b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the application in debug mode, providing more verbose output in the console for troubleshooting.<br><br><b><b>--portable</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs <i>qownnotes</i> in portable mode, causing it to store all settings and data files in the same directory as the executable, rather than system-wide locations.<br><br><b><b>--note</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens the specified note file (e.g., <i>/home/user/notes/MyNote.md</i>) directly in the application's editor.<br><br><b><b>--folder</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the main note folder of the application to the specified path and opens it.<br><br><b><b>--show-on-startup</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ensures that the main application window is shown immediately upon startup, even if the application is already running in the background or configured to hide initially.<br><br><b><b>--new-note</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new, empty note within the application. If the application is already running, it will open a new note tab.<br><br><b><b>--search</b> <i>&lt;query&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a search for the specified <i>&lt;query&gt;</i> string across all notes upon application startup, highlighting matching notes.<br><br><b><b>--current-note-path</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the absolute path of the currently active note to standard output and then exits. This is particularly useful for scripting purposes.<br><br><b><b>--select-note</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the specified note file in the note list sidebar of the application's user interface, without necessarily opening it in the editor.<br><br>


title: DESCRIPTION
content:
<i>qownnotes</i> is a free, open-source, and cross-platform plain-text file note-taking application with Markdown support. It allows users to store notes as plain-text files, which can be synchronized with cloud services like Nextcloud or OwnCloud using WebDAV. This ensures full ownership and control over your data, making it accessible even outside of the application. The application provides a rich set of features including Markdown formatting, syntax highlighting, note search, linking between notes, and a customizable interface. It's designed to be a powerful yet simple tool for managing personal knowledge bases, to-do lists, and general notes, offering both a graphical desktop interface and a command-line interface for specific actions like opening notes or folders.


title: CAVEATS
content:
While <i>qownnotes</i> stores notes as plain-text Markdown files, its full feature set (e.g., tags, linking, versioning) relies on internal indexing and the application's UI. Direct manipulation of note files outside the application may not immediately reflect in its internal state, requiring a refresh or restart. Features like note encryption rely on the application itself and are not inherent to the plain-text files.<br>Command-line options are primarily for launching the application with specific contexts; full programmatic control via CLI for editing or extensive management is limited.


title: INTEGRATION WITH NEXTCLOUD/OWNCLOUD
content:
<i>qownnotes</i> is specifically designed for seamless integration with Nextcloud and OwnCloud instances. Users can configure the application to store their Markdown notes within a synchronized WebDAV folder, ensuring that their notes are always accessible across devices and are under their control, leveraging the privacy and security features of their self-hosted cloud.


title: MARKDOWN FEATURES AND LIVE PREVIEW
content:
The application fully embraces Markdown, allowing users to format their notes with standard syntax for headings, lists, links, code blocks, tables, and more. A key feature is the live preview, which renders the Markdown content in real-time alongside the editor, providing an immediate visual representation of the final formatted note.


title: HISTORY
content:
<i>qownnotes</i> was first released in 2015 by Patrik K. and has since undergone continuous development, quickly becoming a popular open-source Markdown note-taking solution. Its development has focused on robust integration with Nextcloud/OwnCloud for secure, synchronized note storage, alongside a rich feature set for local note management. It gained traction for its emphasis on data ownership (plain-text files) and cross-platform compatibility (Linux, Windows, macOS), providing a powerful yet simple alternative to proprietary note-taking tools. The project maintains an active community, ensuring ongoing improvements and new features.


title: SYNOPSIS
content:
<b>qpdf</b> [<i>options</i>] <i>input.pdf</i> [<i>output.pdf</i>]<br><b>qpdf</b> --empty --pages <i>input.pdf</i> [<i>pagespec</i>] [<i>output.pdf</i>]<br><b>qpdf</b> --json <i>input.pdf</i><br><b>qpdf</b> {<i>--help</i>|<i>--version</i>}


title: PARAMETERS
content:
<b><b>--encrypt</b> <i>key_bits user_password owner_password</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encrypts the output PDF with specified key bits (40, 128, or 256) and passwords.<br><br><b><b>--decrypt</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decrypts an encrypted input PDF file. May require <b>--password</b>.<br><br><b><b>--linearize</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optimizes the output PDF for web viewing (fast web view) by linearizing its internal structure.<br><br><b><b>--qdf</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the PDF in 'QDF' mode, which makes its internal structure more readable by uncompressing streams and making objects direct.<br><br><b><b>--empty --pages</b> <i>input.pdf [pagespec]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new PDF using pages specified from input files, enabling merging or splitting operations.<br><br><b><b>--password</b> <i>password</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the password for accessing an encrypted input PDF file.<br><br><b><b>--flatten-annotations</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts interactive annotations (e.g., form fields, pop-ups) into static content.<br><br><b><b>--remove-unreferenced-objects</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes objects that are not directly referenced from the PDF's logical structure, potentially reducing file size.<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs a JSON representation of the PDF's structural information, useful for programmatic analysis.<br><br><b><b>--coalesce-contents</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to combine multiple content streams on a single page into one, simplifying the page description.<br><br><b><b>--compression</b>=<i>level</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the compression level for output streams, where 0 means no compression and higher levels mean more compression.<br><br><b><b>--replace-input</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replaces the original input file with the generated output file. Use with caution.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with detailed command-line options and usage.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of the <b>qpdf</b> utility.<br><br>


title: DESCRIPTION
content:
<b>qpdf</b> is a powerful command-line tool for structural, content-preserving transformations of PDF files. It can encrypt and decrypt documents, linearize them for web optimization, merge or split PDFs, and uncompress streams for detailed analysis. <b>qpdf</b> is invaluable for inspecting the internal object structure of PDF files, making it a favorite among developers and power users for debugging, security analysis, and advanced PDF manipulations that go beyond simple content editing. It is known for its reliability in handling various PDF complexities and preserving the integrity of the document's content while modifying its underlying structure.


title: CAVEATS
content:
<b>qpdf</b> focuses on structural transformations, not direct content editing like changing text or images. Incorrect use, especially with options like <b>--replace-input</b>, can lead to data loss. While powerful, <b>qpdf</b> may not fully preserve all highly complex or proprietary PDF features, or they might behave unexpectedly if not explicitly handled. Output in QDF mode is for inspection and debugging; modifications to QDF output might not result in a valid PDF if not syntactically correct.


title: INSPECTING PDF STRUCTURE
content:
<b>qpdf</b> excels at providing deep insights into a PDF's internal structure. Options like <b>--json</b>, <b>--show-pages</b>, <b>--show-object-streams</b>, and <b>--qdf</b> are invaluable for debugging malformed PDFs, understanding PDF vulnerabilities, or analyzing how specific features are implemented within a document.


title: SECURITY APPLICATIONS
content:
Beyond encryption and decryption, <b>qpdf</b> can be used in security contexts to sanitize PDF files. For instance, removing unreferenced objects (<b>--remove-unreferenced-objects</b>) can eliminate potentially malicious hidden data, and it can be used to modify permission bits or add/remove passwords to control access to sensitive documents.


title: HISTORY
content:
<b>qpdf</b> was originally developed by Jay Berkenbilt, with its first public release appearing around 2004-2005. Written in C++, it was designed to be a robust and reliable tool for manipulating PDF files at a structural level. It gained popularity as a versatile command-line utility for its ability to handle complex PDF features, including various encryption schemes and object streams, while providing a clear and efficient interface. Its development has continued steadily, adapting to evolving PDF specifications and addressing a wide range of use cases from simple merges to intricate structural analysis.


title: PARAMETERS
content:
<b>file...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more input files to decode. If no files are specified, <b>qpdldecode</b> reads the quoted-printable encoded data from standard input.<br><br>


title: DESCRIPTION
content:
The <b>qpdldecode</b> command is a utility designed to decode data that has been encoded using the quoted-printable transfer encoding. Quoted-printable is primarily used in the context of email and MIME (Multipurpose Internet Mail Extensions) to represent non-ASCII characters (bytes with values from 128 to 255) and certain ASCII characters (like '=', '?', '_') in a way that is safe for various mail transport agents and older systems that might not handle 8-bit data correctly. <br><br>It works by replacing such characters with an equals sign ('=') followed by a two-digit hexadecimal representation of the character's byte value. For example, the character 'é' (0xE9 in Latin-1) would be encoded as '=E9'. Newline characters are typically handled by explicit carriage return and line feed, or by 'soft' line breaks indicated by '=<' followed by a line ending.<br><br><b>qpdldecode</b> reads the quoted-printable encoded data either from specified input files or, if no files are provided, from standard input. It then converts this encoded data back into its original binary or plain text form and writes the decoded output to standard output. This makes it a crucial tool for parsing and displaying email messages or other MIME parts that utilize quoted-printable encoding.


title: CAVEATS
content:
<i>Character Set Interpretation</i>: <b>qpdldecode</b> decodes byte sequences. The actual character interpretation (e.g., UTF-8, Latin-1) depends on the MIME `charset` parameter, which <b>qpdldecode</b> itself does not interpret. It simply outputs the raw decoded bytes.<br><i>Error Handling</i>: Malformed quoted-printable sequences might lead to decoding errors or unexpected output, depending on the specific implementation.<br><i>Availability</i>: <b>qpdldecode</b> is typically part of the <i>mmencode</i> or <i>mpack</i> package and may not be universally installed on all Linux distributions by default.


title: USAGE EXAMPLE
content:
To decode a file named <i>encoded.txt</i> containing quoted-printable data:<br><i>qpdldecode encoded.txt > decoded.txt</i><br><br>To decode data piped from another command:<br><i>cat encoded.txt | qpdldecode > decoded.txt</i><br><br>Or directly using <i>echo</i> for a simple string:<br><i>echo 'Hello=2C world=21' | qpdldecode</i>


title: HISTORY
content:
The quoted-printable encoding, and consequently tools like <b>qpdldecode</b>, emerged as part of the MIME (Multipurpose Internet Mail Extensions) standard, primarily defined in RFCs like RFC 2045, RFC 2046, and RFC 2047, published in the mid-1990s. MIME was developed to allow email to contain rich content beyond plain ASCII text, including non-ASCII characters, binary data, and multimedia.<br><br><b>qpdldecode</b> is typically bundled with <i>mmencode</i> (often part of the <i>mpack</i> suite of utilities), which provides a comprehensive set of tools for handling MIME encodings. Its development closely mirrors the adoption of MIME in email and web technologies, making it an essential, though often behind-the-scenes, component for parsing and rendering complex message formats.


title: PARAMETERS
content:
<b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Displays usage information</I> for the command.<br><br><b>--port <port>, -p <port></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the port number</I> for the web server (default is a random free port).<br><br><b>--address <address>, -a <address></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Binds the server to a specific IP address</I> (e.g., 192.168.1.100).<br><br><b>--interface <interface>, -i <interface></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Selects a network interface</I> to use (e.g., eth0, wlan0).<br><br><b>--recursive, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Serves directories recursively</I>. When used, a directory's contents are accessible.<br><br><b>--secure, -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Uses HTTPS</I> for the server (this is the default behavior).<br><br><b>--no-secure, -P</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Disables HTTPS</I> and uses plain HTTP.<br><br><b>--keep-alive, -k</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Keeps the server running</I> after the first transfer is complete, allowing multiple downloads.<br><br><b>--output <dir>, -o <dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies the output directory</I> when in <I>receive</I> mode.<br><br><b>--tls-key <path>, -t <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Path to a custom TLS private key</I> for HTTPS.<br><br><b>--tls-cert <path>, -c <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Path to a custom TLS certificate</I> for HTTPS.<br><br><b>--url-only, -e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Prints only the URL</I> to the console, without generating and displaying the QR code.<br><br><b>--zip</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Compresses directories into a zip archive</I> before serving, allowing easier download of multiple files.<br><br><b>--fqdn</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Uses the Fully Qualified Domain Name</I> (FQDN) instead of the local IP address in the generated URL.<br><br><b>--version, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Displays the qrcp version information</I> and exits.<br><br>


title: DESCRIPTION
content:
qrcp is a command-line utility designed for <I>effortless and secure file transfers</I> between devices on the same local network. It simplifies the process by launching a temporary web server to host the specified files or directories. Upon activation, qrcp generates a <I>QR code</I> that encapsulates the direct download URL. Users can then scan this QR code with a smartphone or any QR-enabled device, allowing them to instantly access and download the shared content via their web browser.<br><br>This eliminates the need for USB cables, cloud services, or complex network configurations. By default, qrcp prioritizes security by using <I>HTTPS</I> with a self-signed certificate, ensuring that data is encrypted during transit within the local network. It's an ideal tool for quick, ad-hoc sharing of documents, photos, or any files between a computer and a mobile device, or even between two computers connected to the same Wi-Fi network. It also supports a <I>receive</I> mode, allowing the host to create an upload endpoint for others to send files.


title: CAVEATS
content:
<B>Local Network Dependency</B>: <I>qrcp</I> relies on devices being on the same local network. It is not designed for transfers over the internet without additional networking setup (e.g., port forwarding).<br><B>Firewall Considerations</B>: Local firewalls may block incoming connections to the <I>qrcp</I> server's port, requiring manual configuration.<br><B>HTTPS Browser Warnings</B>: By default, <I>qrcp</I> uses a self-signed SSL/TLS certificate. Browsers will typically display security warnings (e.g., "Privacy error", "Not secure") when accessing the generated URL. Users must bypass these warnings to proceed with the download.<br><B>Ephemeral Nature</B>: Unless <I>--keep-alive</I> is specified, the server shuts down after the first successful transfer, meaning subsequent attempts to download will fail.<br><B>QR Code Readability</B>: For very long URLs (e.g., due to complex IP addresses or directories), the generated QR code might become dense and difficult for some scanners to read.


title: RECEIVE MODE
content:
The <B>qrcp receive</B> command allows your computer to act as an upload endpoint. Instead of serving files, it creates a temporary web page where other devices can upload files to your machine. This is particularly useful for getting photos or documents from a mobile device onto a desktop.


title: SECURITY ON LOCAL NETWORKS
content:
While <I>qrcp</I> defaults to HTTPS for encryption, it's important to remember that it operates on your local network. Any device connected to that network could potentially try to access the server if they know the IP address and port (even without the QR code). However, the ephemeral nature (server typically closes after one transfer) and random port selection enhance security for quick, ad-hoc transfers. Always be mindful of what network you are using for transfers.


title: HISTORY
content:
<I>qrcp</I> emerged as a modern solution for a common problem: quickly sharing files between devices on a local network without relying on cloud services or complex configurations. Written in Go, it benefits from being a single static binary, making it easy to deploy and use across various Linux distributions and operating systems. Its development was driven by the desire for a simple, secure (defaulting to HTTPS), and convenient command-line tool. Since its initial release, <I>qrcp</I> has gained popularity among developers and general users alike for its straightforward approach, leveraging the ubiquity of smartphone QR code scanners to streamline local file transfers.


title: SYNOPSIS
content:
<b>qrencode</b> [<i>OPTIONS</i>] [<i>STRING</i>]<br><br>If <i>STRING</i> is provided, it is encoded into a QR Code. If <i>STRING</i> is omitted, <code>qrencode</code> reads the input data from <i>standard input (stdin)</i>. The generated QR Code can be output to a file or displayed directly in the terminal, depending on the chosen options.


title: PARAMETERS
content:
<b><b>-o</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output file path. If not provided, output goes to stdout (for image formats) or stderr (for ANSI/ASCII).<br><br><b><b>-s</b> <i>SIZE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the pixel size of each module (dark or light square) in the QR Code. Default is 3.<br><br><b><b>-l</b> <i>LEVEL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the error correction level: <i>L</i> (low, 7%), <i>M</i> (medium, 15%), <i>Q</i> (quartile, 25%), or <i>H</i> (high, 30%). Default is L.<br><br><b><b>-v</b> <i>VERSION</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the QR Code version (size). Versions range from 1 (21x21 modules) to 40 (177x177 modules). Auto-detection is used if not specified.<br><br><b><b>-m</b> <i>MARGIN</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the quiet zone margin width around the QR Code in modules. Default is 4.<br><br><b><b>-t</b> <i>TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format: <i>PNG</i>, <i>SVG</i>, <i>EPS</i>, <i>ANSI</i> (color terminal), <i>ASCII</i> (monochrome terminal), or <i>UTF8</i> (UTF-8 characters for terminal). Default is PNG.<br><br><b><b>-8</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes input <i>STRING</i> as UTF-8. Useful for non-ASCII characters.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats the input data as raw binary, preventing internal character encoding conversions.<br><br><b><b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information and exits.<br><br>


title: DESCRIPTION
content:
<code>qrencode</code> is a powerful <i>command-line utility</i> for generating <i>QR Code images</i> from given input data. It is built upon the <i>libqrencode</i> library, making it a reliable tool for quickly creating QR codes directly from the terminal. The command offers extensive <i>customization options</i>, allowing users to control parameters such as the <i>error correction level</i>, QR Code <i>version</i>, <i>module size</i>, and <i>quiet zone margin</i>.<br><br>It supports various output formats, including common image types like <i>PNG</i>, <i>SVG</i>, and <i>EPS</i>, as well as <i>text-based representations</i> like <i>ANSI</i> and <i>ASCII art</i> for terminal display. This flexibility makes <code>qrencode</code> suitable for a wide range of applications, from embedding URLs and contact information into images to generating codes for automated scripts or documentation. Data can be supplied as a command-line argument or read from standard input, enhancing its integration with other Linux tools and shell scripting.


title: CAVEATS
content:
<i>Data Capacity Limits</i>: The amount of data that can be encoded in a QR Code is limited by its <i>version</i> and <i>error correction level</i>. Higher error correction levels reduce data capacity.<br><br><i>Scanning Reliability</i>: Extremely large or complex QR codes, or those with very small module sizes, might be difficult for some scanners to read, especially on lower-resolution displays or prints.<br><br><i>Terminal Output</i>: ANSI/ASCII output formats are dependent on the terminal's capabilities and font settings for proper display and scannability. Color ANSI output might not be supported everywhere.


title: USAGE EXAMPLES
content:
<b>1. Encode a simple URL to PNG:</b><br><i>qrencode -o myurl.png "https://www.example.com"</i><br><br><b>2. Display QR code in terminal (ANSI):</b><br><i>qrencode -t ANSI "Hello, World!"</i><br><br><b>3. Encode data from a file with high error correction:</b><br><i>cat input.txt | qrencode -l H -o from_file.png</i><br><br><b>4. Generate a large QR code for contact info:</b><br><i>qrencode -s 5 -v 10 -o contact.svg "MECARD:N:John Doe;TEL:1234567890;EMAIL:john.doe@example.com;;"</i>


title: HISTORY
content:
The <code>qrencode</code> command is part of the <i>libqrencode</i> library, which was developed by <i>Kentaro Fukuchi</i> starting around <i>2008</i>. The library aimed to provide an <i>open-source</i> and <i>portable C library</i> for encoding data into QR Codes, adhering to the <i>ISO/IEC 18004 standard</i>. <code>qrencode</code> serves as the primary command-line interface to this robust library, making QR code generation widely accessible on <i>Linux</i> and <i>Unix-like systems</i> for scripting, automation, and general use. Its continuous development has ensured compliance with QR Code standards and support for various output formats.


title: SEE ALSO
content:
zbarimg(1): A command-line tool for scanning and decoding bar codes and QR codes from image files or video streams., convert(1): (ImageMagick) A versatile command-line tool for converting images between different formats and performing various image manipulations., printf(1): Formats and prints data, often used to pipe string data to <code>qrencode</code>'s standard input.


title: PARAMETERS
content:
<b><i>-verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Causes <i>qrttoppm</i> to print informative messages about its processing to standard error. This can be useful for debugging or understanding the conversion process.<br><br><b><i>qrtfile</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the input QRT image file. If omitted, <i>qrttoppm</i> reads the QRT image data from standard input (<i>stdin</i>).<br><br>


title: DESCRIPTION
content:
<i>qrttoppm</i> is a utility from the Netpbm package designed to convert image files created by the QRT (QRT Ray Tracer) software into the Portable Pixmap (PPM) format. The QRT Ray Tracer is an older ray tracing program for generating images. PPM is a widely supported uncompressed image format, making <i>qrttoppm</i> useful for importing QRT-generated images into modern image processing workflows.<br><br>It reads the QRT image data from standard input by default, or from a specified file, and writes the resulting PPM image to standard output. This allows for easy piping with other Netpbm tools or redirection to a file. The command primarily serves as a bridge for accessing legacy QRT image data within the Netpbm ecosystem.


title: CAVEATS
content:
The QRT Ray Tracer format is a legacy format, and <i>qrttoppm</i> might not support all possible variations or features of the QRT format, especially if new versions or extensions were developed for QRT after <i>qrttoppm</i>'s last update.<br><br>As with many Netpbm tools, output is to standard output, which needs to be redirected to a file or piped to another command to save the resulting PPM image.


title: INPUT AND OUTPUT
content:
By default, <i>qrttoppm</i> expects the QRT image data to be provided via standard input (<i>stdin</i>). This allows for flexible piping of data from other commands.<br><br>The converted PPM image is always written to standard output (<i>stdout</i>). To save the output to a file, users typically redirect <i>stdout</i> using the shell's `>` operator, for example: <br><b>qrttoppm</b> <i>image.qrt</i> > <i>image.ppm</i>


title: HISTORY
content:
The <i>qrttoppm</i> command was introduced into the Netpbm collection by Bryan Henderson in 2000. Its creation facilitated the conversion of images generated by the older QRT Ray Tracer, allowing users to integrate these legacy images into more modern image processing pipelines via the versatile Netpbm toolkit. The command has remained relatively stable since its inception, reflecting its specialized role in handling a specific, older image format.


title: PARAMETERS
content:
<b><b>-a</b> <i>date_time</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a future time for the job to be eligible for execution. Format typically <i>[[[[CC]YY]MM]DD]hhmm[.SS]</i>.<br><br><b><b>-b</b> <i>option</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies that the job is not a script. For example, <b>-b n</b> treats the command line arguments as the executable and its arguments.<br><br><b><b>-e</b> <i>path</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the path for the job's standard error output. By default, it's typically <i>job_name.eJOBID</i> in the submission directory.<br><br><b><b>-I</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Submits an interactive job. This requests resources and then provides a shell prompt on the allocated compute node(s).<br><br><b><b>-k</b> <i>type</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which files (output/error) to keep on the execution host after the job completes (e.g., <b>k oe</b> for both).<br><br><b><b>-l</b> <i>resource_list</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A crucial option to request specific resources for the job. Common requests include <i>nodes=X:ppn=Y</i> (X nodes, Y processors per node), <i>walltime=HH:MM:SS</i>, and <i>mem=Xgb</i>.<br><br><b><b>-M</b> <i>email_address</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an email address to send job notifications to.<br><br><b><b>-m</b> <i>type</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls when email notifications are sent (e.g., <b>a</b> for abort, <b>b</b> for begin, <b>e</b> for end of job; <b>abe</b> for all).<br><br><b><b>-N</b> <i>job_name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assigns a descriptive name to the job, which appears in <b>qstat</b> output and filenames.<br><br><b><b>-o</b> <i>path</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the path for the job's standard output. By default, it's typically <i>job_name.oJOBID</i> in the submission directory.<br><br><b><b>-P</b> <i>project_name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the project name associated with the job, often used for accounting or resource allocation.<br><br><b><b>-q</b> <i>queue</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Submits the job to a specific queue (e.g., <i>debug</i>, <i>batch</i>, <i>long</i>). Different queues may have different resource limits or priorities.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exports all current environment variables from the submission environment to the job's execution environment.<br><br><b><b>-v</b> <i>variable_list</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exports specific environment variables (comma-separated) from the submission environment to the job.<br><br><b><b>-W</b> <i>attribute_list</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows specifying advanced job attributes, such as dependencies (e.g., <i>depend=afterok:JOBID</i>) or group lists (<i>group_list=group_name</i>).<br><br><b><b>-X</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables X11 forwarding for interactive jobs, allowing GUI applications to run on compute nodes and display on the user's local machine.<br><br>


title: DESCRIPTION
content:
The <b>qsub</b> command is a fundamental utility in <b>High-Performance Computing (HPC)</b> environments that utilize the <b>Portable Batch System (PBS)</b>, including its open-source derivatives like <b>Torque Resource Manager</b> and commercial versions such as <b>Altair PBS Pro</b>.<br><br>It serves as the primary interface for users to submit batch scripts (typically shell scripts) to a central job scheduler. Instead of executing computationally intensive tasks directly on login nodes, <b>qsub</b> allows users to queue these jobs, offloading computation and managing resources effectively.<br><br>The scheduler then intelligently manages resource allocation (such as <i>CPUs, memory, wall time, and GPUs</i>) across available compute nodes, ensuring efficient utilization and fair access for all users. Once a job is successfully submitted, <b>qsub</b> returns a unique <i>job ID</i>, which can be used with other <b>q</b> commands (like <b>qstat</b> or <b>qdel</b>) to monitor or manage the job's lifecycle.<br><br>A typical workflow involves creating a script containing both executable commands and <b>PBS directives</b> (e.g., <i>#PBS -l nodes=1:ppn=2,walltime=01:00:00</i>), then executing <b>qsub script_name.sh</b>. This process enables complex scientific simulations, data processing, and parallel computations to run unattended in a managed, optimized environment.


title: CAVEATS
content:
The exact syntax and available options for <b>qsub</b> can vary slightly depending on the specific <b>PBS/Torque/PBS Pro</b> version and the system's configuration. It is always recommended to consult the system's specific <i>man page</i> or documentation.<br><br>Incorrect or insufficient resource requests (e.g., via <b>-l</b>) can lead to long wait times, job failure, or resource contention. Users must be aware of their cluster's resource policies.<br><br><b>qsub</b> is specific to PBS-compatible systems. Other popular schedulers like <b>SLURM</b> (which uses <b>sbatch</b>) or <b>LSF</b> (which uses <b>bsub</b>) have different command sets, even though they fulfill a similar purpose.


title: JOB SCRIPTS AND DIRECTIVES
content:
While <b>qsub</b> can submit a single executable, it most commonly takes a shell script as its argument. This script often contains special <b>PBS directives</b> (lines starting with <i>#PBS</i>), which are interpreted by <b>qsub</b> and the scheduler <i>before</i> the script itself is executed. These directives define job parameters like resource requests (e.g., <i>#PBS -l nodes=1:ppn=2</i>), output file paths (<i>#PBS -o</i>), and job names (<i>#PBS -N</i>). They provide a convenient way to encapsulate all job requirements within a single file.


title: STANDARD I/O REDIRECTION
content:
By default, the standard output (<i>stdout</i>) and standard error (<i>stderr</i>) streams generated by a job are redirected to files in the directory from which <b>qsub</b> was invoked. The default filenames are typically in the format <i>job_name.oJOBID</i> for standard output and <i>job_name.eJOBID</i> for standard error. Users can override these default paths and filenames using the <b>-o</b> and <b>-e</b> options, respectively, either on the command line or within the job script as <b>#PBS</b> directives.


title: HISTORY
content:
<b>qsub</b> is an integral part of the <b>Portable Batch System (PBS)</b>, which was originally developed by <i>NASA Ames Research Center</i> in the early 1990s to manage computationally intensive tasks on supercomputers and clusters. PBS quickly became a de facto standard for batch job management in <b>High-Performance Computing (HPC)</b> environments.<br><br>Over time, the rights to PBS were acquired by <i>Altair Engineering</i>, leading to the development of the commercial product <b>PBS Professional (PBS Pro)</b>. Concurrently, an open-source version, <b>OpenPBS</b>, continued to evolve, giving rise to projects like the <b>Torque Resource Manager</b> (now often referred to as OpenPBS or PBS Open Source).<br><br>The core functionality and command-line interface of <b>qsub</b> have remained remarkably consistent across these various implementations, providing a stable and familiar method for users to submit jobs to PBS-compatible batch systems, underscoring its enduring utility in research and industrial computing.


title: PARAMETERS
content:
<b><i>input_file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the source MP4 or MOV file that needs to be optimized.<br><br><b><i>output_file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path where the optimized output file will be saved. A new file is created.<br><br>


title: DESCRIPTION
content:
<i>qt-faststart</i> is a command-line utility designed to optimize MP4 and MOV video files for progressive downloading and streaming.<br><br>By default, many video encoding tools place the 'moov' atom (metadata containing essential information like duration, tracks, and timestamps) at the end of the file. This means a player must download the entire file before it can begin playback. <i>qt-faststart</i> re-writes the file, relocating this 'moov' atom from the end to the beginning.<br><br>This allows web browsers and media players to start playback almost immediately, as soon as the initial metadata and a small portion of the video data are downloaded, significantly improving the user experience for web-hosted video content. It does not re-encode the video or audio streams, only rearranges the file structure.


title: CAVEATS
content:
<i>qt-faststart</i> requires sufficient disk space to create the output file, as it will be roughly the same size as the input file.<br><br>It only works for MP4 and MOV file formats and does not perform video or audio re-encoding, focusing solely on metadata rearrangement.


title: HOW <I>QT-FASTSTART</I> WORKS
content:
<i>qt-faststart</i> scans the input file to locate the 'moov' atom. If found at the end of the file, it reads all media data, then writes the 'moov' atom to the beginning of the new output file, followed by the media data. This ensures the media player has all necessary structural information upfront to begin progressive playback.


title: HISTORY
content:
<i>qt-faststart</i> emerged as a crucial utility to address the common problem of non-progressive MP4/MOV files served over HTTP. Before popular video tools like <i>ffmpeg</i> integrated direct 'faststart' options, this standalone program provided a simple solution, becoming a widely used method for optimizing web videos. While <i>ffmpeg</i>'s own <i>-movflags faststart</i> option is now more commonly used for this purpose, <i>qt-faststart</i> remains a simple, effective, and often included utility in FFmpeg distributions.


title: PARAMETERS
content:
<b>-qt=<I>QtVersion</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which Qt version to use. Common values include version numbers (e.g., '5', '6'), specific aliases (e.g., 'qt515', 'qt62'), or 'default' to use the system default configuration.<br><br><b>-run-script</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If the <i>COMMAND</i> is a script, this option ensures it is executed properly after setting up the environment, rather than being treated as a binary executable.<br><br><b>-list-versions</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available Qt versions that <i>qtchooser</i> can detect based on its configuration files.<br><br><b>-print-env</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the environment variables (e.g., <i>PATH</i>, <i>QT_INSTALL_LIBS</i>) that would be set for the chosen Qt version, without executing any command. Useful for debugging.<br><br><b>-help, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-version, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information about <i>qtchooser</i> and exits.<br><br>


title: DESCRIPTION
content:
<i>qtchooser</i> is a utility designed to help developers manage multiple Qt installations on a single system. It acts as a wrapper around Qt command-line tools (such as <i>qmake</i>, <i>moc</i>, <i>uic</i>, <i>rcc</i>, etc.) by setting the necessary environment variables (like <i>PATH</i>, <i>QT_INSTALL_LIBS</i>, <i>QT_INSTALL_HEADERS</i>) to point to a specific Qt version. This allows users to easily switch between different Qt major or minor versions (e.g., Qt5, Qt6, or specific patch versions) without manually modifying system paths or rebuilding projects. It achieves this by reading configuration files, typically located in <i>/etc/xdg/qtchooser</i> and <i>~/.config/qtchooser</i>, which map user-friendly version names to actual installation paths. When a command is invoked via <i>qtchooser</i>, it ensures that the correct Qt binaries and libraries are found, streamlining cross-version development and testing.


title: CAVEATS
content:
<i>qtchooser</i> relies on configuration files (e.g., <i>.conf</i> files in <i>/etc/xdg/qtchooser</i> and <i>~/.config/qtchooser</i>) to define Qt version paths. If these files are incorrect, missing, or do not point to valid Qt installations, <i>qtchooser</i> may not function as expected or might fail to find the desired Qt version. The <i>QT_SELECT</i> environment variable takes precedence over command-line arguments, potentially overriding the selected Qt version. While it manages the environment for command-line tools, it doesn't directly influence how already compiled applications link against Qt libraries unless specifically designed to do so.


title: ENVIRONMENT VARIABLE <I>QT_SELECT</I>
content:
If the <i>QT_SELECT</i> environment variable is set, it overrides any <i>-qt</i> option passed to <i>qtchooser</i>. This variable specifies the desired Qt version (e.g., <code>export QT_SELECT=qt6</code>). It is particularly useful for persistent selection within a shell session, build scripts, or CI environments, ensuring that all subsequent Qt command-line tool invocations use the specified version without needing to explicitly pass the <i>-qt</i> flag.


title: CONFIGURATION FILES
content:
<i>qtchooser</i> discovers available Qt versions by reading <i>.conf</i> files. These files are typically located in <i>/etc/xdg/qtchooser/</i> for system-wide configurations and <i>~/.config/qtchooser/</i> for user-specific overrides. Each <i>.conf</i> file defines a Qt version alias and its corresponding binary path. For example, a file named <i>qt6.conf</i> might contain the path <code>/opt/Qt/6.x.x/gcc_64/bin</code>, allowing users to select this version simply by using <code>-qt=qt6</code>.


title: HISTORY
content:
<i>qtchooser</i> was introduced to address the growing need for developers to manage multiple Qt installations side-by-side on a single development machine. Prior to its existence, switching between different Qt major or minor versions for command-line build tools (like <i>qmake</i>) often involved cumbersome manual adjustments to the system's <i>PATH</i> environment variable or the use of custom wrapper scripts. This process was prone to errors and inefficiencies. <i>qtchooser</i> streamlined this workflow by providing a standardized and easy-to-use mechanism to select the desired Qt environment for development and build tasks, significantly improving the developer experience for cross-version Qt development and testing.


title: PARAMETERS
content:
<b>--project <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens the specified <i>Qt Creator</i> project file (e.g., .pro, .qbs, CMakeLists.txt).<br><br><b>--file <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens the specified source file in the editor.<br><br><b>--line <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Navigates to the specified line number within the file opened by <i>--file</i>. Requires <i>--file</i>.<br><br><b>--column <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Navigates to the specified column number within the file opened by <i>--file</i> and <i>--line</i>.<br><br><b>--settings <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads settings from the specified file instead of the default <i>Qt Creator</i> settings.<br><br><b>--clean-settings</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resets all <i>Qt Creator</i> settings to their factory defaults.<br><br><b>--profile <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts <i>Qt Creator</i> with a specific profiler configuration.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose debug output to the console, useful for troubleshooting.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <i>Qt Creator</i> version information and exits.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a summary of command-line options and exits.<br><br>


title: DESCRIPTION
content:
<b>Qt Creator</b> is a powerful, cross-platform integrated development environment (IDE) specifically designed for the development of applications using the <i>Qt</i> framework. It supports C++, QML, and JavaScript programming.<br><br>As a comprehensive IDE, it provides a rich set of tools to streamline the entire software development lifecycle, from project creation and code editing to debugging, building, and deployment. Key features include an intelligent code editor with syntax highlighting, code completion, and refactoring tools; integrated debugging capabilities; a visual UI designer for both <i>Qt Widgets</i> and <i>QML</i>; project and build management for systems like <i>QMake</i>, <i>CMake</i>, <i>Qbs</i>, and <i>Conan</i>; and integrated version control support for Git, Mercurial, and Subversion. <i>Qt Creator</i> aims to provide a first-class development experience for <i>Qt</i> developers, offering deep integration with the <i>Qt</i> libraries and tools, making it an indispensable tool for building robust and scalable cross-platform applications.


title: CAVEATS
content:
<i>Qt Creator</i> is primarily a graphical application; its command-line interface is mainly for opening files or projects and setting initial configurations, not for performing complex IDE operations via scripts. As a full-fledged IDE, it can be resource-intensive, particularly with large projects or complex build systems. Its functionality is heavily reliant on a properly configured <i>Qt</i> development environment and associated toolchains (compilers, debuggers).


title: TARGET AUDIENCE
content:
<i>Qt Creator</i> is primarily aimed at developers building cross-platform applications using the <i>Qt</i> framework, ranging from desktop applications to embedded systems and mobile development.


title: EXTENSIBILITY
content:
The IDE supports a rich plugin architecture, allowing users to extend its functionality with custom tools, language support, and integrations, catering to specific development needs.


title: HISTORY
content:
<i>Qt Creator</i> was first released in 2008 by <i>Trolltech</i> (later acquired by <i>Nokia</i>, then sold to <i>Digia</i>, and now maintained by <i>The Qt Company</i>). It was developed to provide a lightweight yet powerful IDE tightly integrated with the <i>Qt</i> framework, addressing the need for a dedicated development environment for <i>Qt</i> applications. Since its inception, it has seen continuous development, aligning with new <i>Qt</i> versions and expanding its feature set to support modern C++ standards, advanced debugging, and diverse build systems, solidifying its position as the de facto IDE for <i>Qt</i> development.


title: SYNOPSIS
content:
<B>qtile</B> <I>subcommand</I> [<I>options</I>] [<I>arguments</I>]<br><B>qtile start</B> [<I>options</I>]<br><B>qtile cmd</B> [<I>options</I>] [<I>command</I>]<br><B>qtile check</B> [<I>options</I>]


title: PARAMETERS
content:
<b><B>start</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the Qtile window manager session. This is the most common use of the command.<br><br><b><B>start</B> <I>--config &lt;file&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file to use instead of the default <B>config.py</B>.<br><br><b><B>start</B> <I>--no-spawn</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents Qtile from spawning any X applications on startup.<br><br><b><B>start</B> <I>--display &lt;display&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connects Qtile to a specified X display.<br><br><b><B>cmd</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connects to a running Qtile instance via its IPC socket to send commands or query its state.<br><br><b><B>cmd</B> <I>-c &lt;command&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes a specified IPC command directly, e.g., 'qtile cmd -c shutdown'.<br><br><b><B>cmd</B> <I>--list-commands</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available commands that can be sent to the running Qtile instance.<br><br><b><B>cmd</B> <I>--json</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Formats the output of commands as JSON, useful for scripting.<br><br><b><B>shell</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens an interactive Python shell connected to the running Qtile instance, allowing direct manipulation.<br><br><b><B>check</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks the default Qtile configuration file for syntax errors without starting Qtile.<br><br><b><B>check</B> <I>--file &lt;file&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks a specified configuration file for syntax errors.<br><br><b><B>run-cmd</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes an arbitrary Python command string within the running Qtile process.<br><br><b><B>top</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a list of currently managed windows and their properties, similar to 'xwininfo -tree'.<br><br><b><B>migrate</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assists in migrating older Qtile configuration files to be compatible with newer versions.<br><br>


title: DESCRIPTION
content:
Qtile is a dynamic, <I>full-featured tiling window manager</I> written and configured in <B>Python</B>. It aims to be simple, flexible, and extensible, allowing users to tailor their desktop environment precisely to their needs through straightforward Python code.<br><br>Unlike many other window managers, Qtile's configuration is not a declarative file but rather <B>executable Python code</B>, enabling complex logic, custom widgets, and dynamic behaviors. It supports both <I>X11</I> and <I>Wayland</I> (through its Wayland compositor functionality). The <B>qtile</B> command itself is the primary interface for managing and interacting with the Qtile session, used for starting the window manager, sending commands to a running instance, checking configuration files, and more. It provides a robust and powerful environment for developers and power users who prefer a highly customizable and scriptable desktop.


title: CAVEATS
content:
Qtile requires a working Python installation and a graphical environment (X11 or Wayland). Its configuration file, <B>config.py</B>, is a Python script; therefore, syntax errors or runtime exceptions in this file will prevent Qtile from starting correctly. Debugging these issues often requires checking the log files. Users unfamiliar with Python or the concepts of tiling window managers may face a steeper learning curve initially.


title: CONFIGURATION FILE
content:
Qtile's configuration is managed through a Python script, typically located at <B>~/.config/qtile/config.py</B>. This file is loaded and executed by Qtile at startup, allowing users to define keybindings, layouts, widgets, screens, and custom behaviors using standard Python syntax and libraries.


title: INTER-PROCESS COMMUNICATION (IPC)
content:
The <B>qtile cmd</B> and <B>qtile shell</B> subcommands communicate with a running Qtile instance via a Unix domain socket. This IPC mechanism allows external scripts or user commands to interact with the window manager, send commands, query its state, or trigger actions without needing to restart the session.


title: LOGGING AND DEBUGGING
content:
Qtile generates log files (usually in <B>~/.local/share/qtile/qtile.log</B> or a path specified by <I>--log-path</I>) that are crucial for debugging startup issues or runtime errors. The <B>qtile check</B> command can also be used to pre-validate the configuration file for basic syntax errors before attempting to start Qtile.


title: HISTORY
content:
Qtile was originally developed by <I>Aldric Giacomoni</I> and released in <B>2009</B>. Its core design principle was to provide a highly flexible and programmable window manager by leveraging the power of <B>Python</B> for its configuration and extensibility. Over the years, it has evolved significantly, gaining features like a built-in status bar with a wide range of widgets, support for multiple screens, and more recently, experimental but functional <I>Wayland compositor</I> capabilities, broadening its applicability beyond just X11 environments. Its development continues to be community-driven, focusing on stability, performance, and user-friendliness for Python enthusiasts.


title: PARAMETERS
content:
<b><b>create</b> [options]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initializes a new Quarkus project. Options include specifying <i>groupId</i>, <i>artifactId</i>, <i>version</i>, build tool (Maven/Gradle), and initial extensions.<br><br><b><b>dev</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the Quarkus application in development mode. This enables live coding, automatically recompiling and reloading changes without requiring a manual restart.<br><br><b><b>build</b> [options]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds the Quarkus application into a deployable artifact, typically a JAR. The <i>--native</i> option can be used to compile a native executable using GraalVM.<br><br><b><b>add extension</b> &lt;extension-name...&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds one or more specified Quarkus extensions to an existing project, updating its build configuration (e.g., <i>pom.xml</i> or <i>build.gradle</i>).<br><br><b><b>test</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the unit and integration tests defined within the Quarkus project.<br><br><b><b>help</b> [command]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help information for the <b>quarkus</b> CLI or detailed help for a specific subcommand.<br><br>


title: DESCRIPTION
content:
The <b>quarkus</b> command-line interface (CLI) is a developer tool designed to streamline the creation, development, and building of applications using the Quarkus framework.<br><br>Quarkus is a Kubernetes-native Java framework tailored for GraalVM and OpenJDK, focusing on high performance, fast boot times, and low memory consumption. The <b>quarkus</b> CLI provides a convenient way to interact with the framework, allowing users to initialize new projects, run applications in development mode with live coding capabilities, add various extensions for different functionalities (like REST, database integration, messaging), and build deployable artifacts for cloud and serverless environments. It significantly enhances developer productivity by providing an efficient and responsive development loop, making Java a first-class citizen in the modern microservices and serverless landscape.


title: CAVEATS
content:
The <b>quarkus</b> command is not a standard Linux utility and requires a Java Development Kit (JDK 11+) and Apache Maven or Gradle installed. While it can be installed as a standalone CLI (e.g., via SDKMAN! or Homebrew), it's also commonly invoked through Maven or Gradle wrappers (e.g., <i>./mvnw quarkus:dev</i>). Many commands must be executed from within the root directory of a Quarkus project.


title: INSTALLATION
content:
The <b>quarkus</b> CLI can be installed via several methods:<br><ul><li>Using <i>SDKMAN!</i>: <i>sdk install quarkus</i></li><li>Using <i>Homebrew</i> (macOS/Linux): <i>brew install quarkus</i></li><li>By downloading a distribution archive from the official Quarkus website and adding its <i>bin</i> directory to your system's PATH.</li></ul>


title: PROJECT STRUCTURE
content:
A typical Quarkus project created with the CLI follows a standard Maven or Gradle layout, including:<br><ul><li><i>src/main/java</i>: For Java source code.</li><li><i>src/main/resources</i>: For application configuration (e.g., <i>application.properties</i>) and static assets.</li><li><i>src/test/java</i>: For test source code.</li><li><i>pom.xml</i> (Maven) or <i>build.gradle</i> (Gradle): Project build file.</li></ul>


title: HISTORY
content:
Quarkus was first unveiled by Red Hat in March 2019, emerging as a response to the challenges of traditional Java frameworks in cloud-native and serverless environments, specifically high memory consumption and slow startup times. It quickly gained traction due to its 'Supersonic Subatomic Java' promise, leveraging modern technologies like GraalVM, Eclipse Vert.x, Hibernate ORM with Panache, and RESTEasy Reactive to deliver unparalleled performance and efficiency for cloud-native Java applications.


title: SYNOPSIS
content:
<B>quickemu</B> [--create-vm &lt;OS_NAME&gt; | --start &lt;VM_NAME&gt; | --download-disk &lt;VM_NAME&gt; | --list-vms | --delete-vm &lt;VM_NAME&gt;] [OPTIONS]


title: PARAMETERS
content:
<b><B>--help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b><B>--version</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the <I>quickemu</I> version information.<br><br><b><B>--create-vm &lt;OS&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new virtual machine configuration. <I>OS</I> can be <I>linux</I>, <I>windows</I>, <I>macos</I>, <I>android</I>.<br><br><b><B>--start &lt;VM_NAME&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the specified virtual machine. The <I>VM_NAME</I> corresponds to the VM's configuration directory.<br><br><b><B>--download-disk &lt;VM_NAME&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads a pre-configured or default disk image for the specified virtual machine.<br><br><b><B>--list-vms</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all currently configured virtual machines and their statuses.<br><br><b><B>--delete-vm &lt;VM_NAME&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes the specified virtual machine's configuration and associated disk images.<br><br><b><B>--disk &lt;SIZE&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the virtual disk size (e.g., <I>32G</I>, <I>200G</I>) for new VMs.<br><br><b><B>--ram &lt;SIZE&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allocates a specified amount of <I>RAM</I> to the VM (e.g., <I>4G</I>, <I>8192M</I>).<br><br><b><B>--cpu &lt;COUNT&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of virtual <I>CPU</I> cores for the VM (e.g., <I>4</I>, <I>8</I>).<br><br><b><B>--full-screen</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Launches the virtual machine directly into full-screen display mode.<br><br><b><B>--display &lt;TYPE&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the display backend to use: <I>sdl</I> for local display or <I>spice</I> for remote access and advanced features.<br><br><b><B>--spice-port &lt;PORT&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>SPICE</I> port for remote connections when using <B>--display spice</B>.<br><br><b><B>--net-user</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures user-mode networking, which is simpler but has limitations (e.g., no incoming connections).<br><br><b><B>--net-tap</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures <I>TAP</I> networking for more advanced network configurations, often requiring <I>sudo</I> privileges.<br><br><b><B>--ssh-port &lt;PORT&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <I>SSH</I> port forwarding from the host to the guest on the specified port.<br><br><b><B>--uefi</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <I>UEFI</I> firmware for the virtual machine boot process, compatible with modern operating systems.<br><br><b><B>--bios</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses traditional <I>BIOS</I> firmware for the virtual machine, for older operating systems or specific needs.<br><br><b><B>--vm-dir &lt;PATH&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative directory where VM configuration files and disk images will be stored.<br><br><b><B>--usb-passthrough &lt;VENDOR_ID:PRODUCT_ID&gt;</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes through a physical <I>USB</I> device to the virtual machine using its <I>Vendor ID</I> and <I>Product ID</I>.<br><br>


title: DESCRIPTION
content:
<I>quickemu</I> is a powerful yet easy-to-use command-line wrapper designed to streamline the process of creating, configuring, and running <I>QEMU</I> virtual machines. It significantly reduces the complexity associated with raw <I>QEMU</I> commands, making advanced virtualization accessible to users of all skill levels. <br><br> Leveraging <I>KVM</I> for hardware-accelerated virtualization on <I>Linux</I>, <I>quickemu</I> provides near-native performance for guest operating systems. It supports a wide range of guests including <I>Windows</I>, <I>macOS</I>, various <I>Linux</I> distributions, and <I>Android</I>. Its features include automatic disk image management, flexible network configuration (user-mode, TAP), display options (<I>SDL</I>, <I>SPICE</I>), <I>USB</I> passthrough, and choice of <I>UEFI</I> or <I>BIOS</I> firmware. <br><br> Configurations are stored in simple <I>YAML</I> files, making them easy to inspect and modify. <I>quickemu</I> aims to provide a hassle-free virtualization experience.


title: CAVEATS
content:
Optimal performance requires <I>KVM</I> (Kernel-based Virtual Machine) to be enabled and configured on the <I>Linux</I> host. <br><br> Certain features, particularly advanced networking (<B>--net-tap</B>) and <I>USB</I> passthrough, may require additional host system configuration or <I>sudo</I> privileges. <br><br> Virtualizing <I>macOS</I> can be resource-intensive and might require specific bootloader setup (like <I>OpenCore</I>) and a compatible <I>QEMU</I> version.


title: <I>YAML</I> CONFIGURATION
content:
Each virtual machine's configuration is stored in a simple, human-readable <I>.conf</I> file (using <I>YAML</I> syntax) within its dedicated directory. This allows for easy manual inspection and modification of settings beyond command-line options.


title: <I>AUTOMATIC DOWNLOADS</I>
content:
For certain guest operating systems, <I>quickemu</I> can automatically download necessary disk images, <I>UEFI</I> firmwares, and bootloaders, simplifying the setup process significantly.


title: <I>GUEST OS SUPPORT</I>
content:
<I>quickemu</I> offers robust support for a wide array of guest operating systems including <I>Windows</I> (from 7 to 11), various <I>Linux</I> distributions (e.g., <I>Ubuntu</I>, <I>Fedora</I>, <I>Arch</I>), <I>macOS</I> (Intel and ARM, where applicable), and <I>Android</I> (x86_64 images).


title: HISTORY
content:
<I>quickemu</I> was developed by <I>Martin O'Halloran</I> (<I>martinohalloran</I>) with the primary goal of abstracting away the often complex command-line arguments required to launch <I>QEMU</I> virtual machines. It emerged as a solution to provide an easy and intuitive way to run various guest operating systems, especially notoriously difficult ones like <I>macOS</I> and <I>Windows</I>, on <I>Linux</I> hosts. <br><br> Since its inception, it has evolved into a popular open-source project, known for its user-friendliness and active development, continuously adding support for new features and operating systems while maintaining its focus on simplicity.


title: SEE ALSO
content:
<I>qemu-system-x86_64</I>(1), <I>virt-manager</I>(1), <I>virsh</I>(1), <I>kvm</I>(1), <I>VBoxManage</I>(1)


title: PARAMETERS
content:
<b>-o, --output <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the filename to save the downloaded content as. If not provided, <i><b>quickget</b></i> typically infers the filename from the URL.<br><br><b>-P, --directory <i>DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the directory where the downloaded file should be saved. The directory must exist.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all output during the download process, showing only errors if they occur.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, displaying detailed information about the download progress, HTTP headers, and potential issues.<br><br><b>-c, --continue</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to resume an interrupted or incomplete download. This is useful for large files or unstable connections.<br><br><b>--no-clobber</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevent overwriting an existing file at the destination path. If the file already exists, the download will typically be skipped.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message and exit.<br><br>


title: DESCRIPTION
content:
<i><b>quickget</b></i> is not a standard, universally distributed Linux command, but rather a hypothetical or custom script often created as a convenience wrapper around more powerful utilities like <i><b>wget</b></i> or <i><b>curl</b></i>.<br><br>Its primary purpose is to simplify common file download operations, providing a user-friendly interface that abstracts away the often complex syntax of its underlying tools. Users would typically employ <i><b>quickget</b></i> for quick, ad-hoc downloads of files from specified URLs, such as configuration files, small scripts, or documents, without needing to remember numerous options or lengthy command structures.<br><br>It aims to streamline the process, making it faster and less error-prone for everyday use by providing sensible defaults and only exposing the most commonly used options. While its exact features can vary depending on its implementation, the core idea is to make web content retrieval 'quick' and 'get' straight to the point.


title: CAVEATS
content:
<i><b>quickget</b></i> is not a standard utility found in most Linux distributions' core packages. It is typically a custom script or part of specialized environments (e.g., Puppy Linux, EasyOS, or personal utility collections).<br><br>As such, its specific behavior, available options, and underlying implementation (e.g., whether it uses <i><b>wget</b></i> or <i><b>curl</b></i>) can vary significantly. Users should be aware that a <i><b>quickget</b></i> command might not exist on all systems, or its functionality may differ from this general description. Always exercise caution when downloading files from untrusted sources, regardless of the command used.


title: IMPLEMENTATION DETAILS
content:
The typical implementation of <i><b>quickget</b></i> is a simple shell script (e.g., Bash) that parses its own command-line arguments and then constructs and executes commands using powerful external tools like <i><b>wget</b></i> or <i><b>curl</b></i>. This design choice makes it highly flexible and adaptable, but also means its precise behavior and any limitations are entirely dependent on the specific script's author and its underlying dependencies.


title: TYPICAL USE CASES
content:
While general file downloading is its core, <i><b>quickget</b></i> scripts are often tailored for specific, repetitive tasks. This could include fetching system updates from a dedicated server, downloading specific application configurations, retrieving small utility scripts from a version control system, or quickly grabbing multimedia files. Its simplicity makes it ideal for inclusion in automated scripts or for users who prefer minimal typing for common tasks.


title: HISTORY
content:
Given its non-standard nature, <i><b>quickget</b></i> has no formal, documented history as a universal command. Instead, it likely originated as a practical shell script born out of the need for simplified web content retrieval within various Linux communities or by individual users seeking to create personal shortcuts.<br><br>Its development focus has always been on user convenience, abstracting the often verbose options of <i><b>wget</b></i> or <i><b>curl</b></i> for common download scenarios. It represents a user-centric approach to scripting, prioritizing ease of use over comprehensive functionality, and thus its 'history' is more a collection of similar, independently developed utility scripts than a single evolving project.


title: PARAMETERS
content:
<b>new &lt;patch&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new, empty patch file in the series and makes it the topmost patch.<br><br><b>add &lt;file&gt;...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds one or more files to the topmost patch, so changes to them will be recorded.<br><br><b>edit &lt;file&gt;...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens files for editing, marking them for inclusion in the current patch. Changes are recorded when 'refresh' is run.<br><br><b>diff [-p &lt;num&gt;]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the differences currently recorded in the topmost patch, or between the current state and a specific patch.<br><br><b>refresh</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Updates the topmost patch with changes made to the source tree since the patch was applied or last refreshed.<br><br><b>push [-f|-a|-q]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies the next patch(es) in the series onto the source tree. '-a' applies all remaining patches, '-f' forces application even with conflicts.<br><br><b>pop [-a|-q]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unapplies the current patch(es) from the source tree, moving them off the applied stack. '-a' unapplies all currently applied patches.<br><br><b>top</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the name of the patch currently at the top of the applied stack.<br><br><b>patches</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all patches in the series, indicating which ones are currently applied.<br><br><b>series</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the full ordered list of all patches in the series, whether applied or not.<br><br><b>grep &lt;pattern&gt; &lt;patch&gt;...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Searches for a specified pattern within the contents of patches.<br><br><b>delete [-r] &lt;patch&gt;...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes one or more patches from the series. '-r' also unapplies them if they are currently applied.<br><br><b>rename &lt;old_patch&gt; &lt;new_patch&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Renames a patch in the series.<br><br><b>fold [-a]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Combines the current topmost patch with the next patch in the series into a single patch file.<br><br>


title: DESCRIPTION
content:
<i>quilt</i> is a powerful command-line tool designed to manage a stack of patches applied to source code. It allows developers to keep track of a series of changes independent of the main codebase, enabling them to easily apply, unapply, add, remove, and reorder patches. This is particularly useful in development workflows where multiple modifications need to be maintained on top of a stable or upstream version, such as in Linux kernel development or embedded systems.<br><br><i>quilt</i> maintains a directory of patches and a patch control (PC) directory to track which patches are currently applied. Developers can create new patches, refresh existing ones with new changes, or inspect the differences introduced by individual patches. Its design facilitates iterative development and easy sharing of patch sets, making it a flexible alternative or complement to version control systems like Git for managing specific patch layers.


title: CAVEATS
content:
<i>quilt</i> can have a steeper learning curve compared to simple patch utilities. It requires a specific directory structure for its operation (the `patches` directory and the hidden `.pc` directory) which must be managed correctly. While powerful for managing linear patch stacks, it is not a full-fledged version control system and lacks capabilities like branching or merging found in tools like Git. Mismanagement of its state can lead to difficulties in applying or unapplying patches, especially with merge conflicts.


title: PATCH MANAGEMENT DIRECTORIES
content:
<i>quilt</i> relies on two main directories: `patches/` (by default), which stores all the individual patch files, and `.pc/` (patch control), a hidden directory where `<i>quilt</i>` stores its internal state, including the original files before patches were applied, allowing for easy unapplication and refresh operations.


title: ENVIRONMENT VARIABLES
content:
<i>quilt</i> behavior can be influenced by environment variables like `QUILT_PATCHES` (to specify an alternative patch directory) and `QUILT_PC` (to specify an alternative patch control directory), allowing for flexible configuration and isolation of patch sets for different projects.


title: HISTORY
content:
<i>quilt</i> was originally developed by Andrew Morton for managing the extensive patch set of the Linux kernel's development tree (the "mm" tree) before the kernel's full migration to Git. It provided a flexible way to organize and test numerous independent patches on top of the stable kernel. Although much of kernel development has since moved to Git's integrated patch management, <i>quilt</i> remains valuable for maintaining local patch sets on existing codebases, especially in environments where a full Git repository might be overkill or impractical, or for specific layering tasks.


title: PARAMETERS
content:
<b>-u, --user</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays user quotas. This is the default if no option is given and a user is specified.</i><br><br><b>-g, --group</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays group quotas.</i><br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Suppresses verbose messages and only prints filesystems where usage is over quota.</i><br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays quotas on all mounted filesystems, even those with no disk usage or limits.</i><br><br><b>-s, --softonly</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Prints only entries where a soft limit is exceeded and the grace period is active.</i><br><br><b>-h, --human-readable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Shows sizes in human-readable units (e.g., K, M, G).</i><br><br><b>-l, --local-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Skips querying remote filesystems (like NFS or CIFS shares).</i><br><br><b>-F <<i>format-name</i>>, --filesystem-format=<<i>format-name</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the quota format to use (e.g., 'vfsold', 'vfsv0', 'vfsv1'). Useful for specific filesystem types.</i><br><br><b>-f <<i>filesystem</i>>, --file=<<i>filesystem</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies a particular filesystem to query. If omitted, all quota-enabled filesystems are checked.</i><br><br>


title: DESCRIPTION
content:
The <B>quota</B> command is a Linux utility used to display disk usage and limits for users and groups on filesystems where quotas are enabled. Disk quotas are a system feature that allows administrators to set limits on the amount of disk space and/or the number of files (inodes) that a user or group can consume on a particular filesystem.<br><br>When executed, <B>quota</B> shows the current disk block usage, inode usage, and the configured soft and hard limits for the calling user or specified user/group. It also indicates if a grace period is active, meaning a soft limit has been exceeded but the hard limit has not yet been enforced. This command is crucial for users to monitor their disk consumption and avoid hitting their allocated limits, and for administrators to quickly check compliance.<br><br>It provides a snapshot of current quota status but does not allow modification of quota settings; that functionality is handled by commands like <B>edquota</B> or <B>setquota</B>.


title: CAVEATS
content:
<ul><li><B>quota</B> only displays information; it cannot be used to modify quota settings. Use <B>edquota</B> or <B>setquota</B> for modifications.</li><li>Quotas must be enabled and properly configured on a filesystem for <B>quota</B> to display any relevant information.</li><li>Viewing another user's or group's quotas often requires root privileges.</li><li>The output can be confusing without understanding the concepts of soft limits, hard limits, and grace periods.</li></ul>


title: SOFT VS. HARD LIMITS
content:
<i><B>Soft limits</B> are warnings; users are allowed to temporarily exceed them. If the soft limit is exceeded, a grace period begins. If usage remains above the soft limit after the grace period expires, the soft limit effectively becomes a hard limit.<br><br><B>Hard limits</B> are absolute; users cannot write any more data or create more files once this limit is reached, even if the grace period has not expired.</i>


title: GRACE PERIOD
content:
<i>When a user or group exceeds their soft limit, a 'grace period' (typically 7 days) starts. During this period, they can still write data. If usage drops below the soft limit within the grace period, the timer resets. If not, the soft limit becomes a hard limit until usage is reduced. The <B>quota</B> command displays the remaining time for active grace periods.</i>


title: INODES
content:
<i>In addition to disk block usage (storage space), quotas can also be applied to the number of <B>inodes</B> a user or group can consume. An inode is a data structure on a Unix-like filesystem that stores information about a file or directory, such as its permissions, ownership, and physical location on disk. Even if a user has free disk space, they might hit an inode limit if they create many small files.</i>


title: HISTORY
content:
Disk quota systems have been a fundamental feature of Unix-like operating systems since their early development to manage shared disk resources. The <B>quota</B> command, as part of the broader quota utilities suite, has been a standard component of Linux distributions for decades, providing users and administrators with a simple way to monitor disk usage against predefined limits. Its functionality has remained largely consistent, focusing on robust reporting.


title: PARAMETERS
content:
<b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check all mounted filesystems that support quotas, as listed in <i>/etc/mtab</i>.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create new quota files. This option instructs <i>quotacheck</i> to skip existing quota files and create new ones based on the current disk usage.<br><br><b><b>-g</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check group quotas only. By default, both user and group quotas are checked if neither <b>-u</b> nor <b>-g</b> is specified.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check user quotas only. By default, both user and group quotas are checked if neither <b>-u</b> nor <b>-g</b> is specified.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Be verbose, showing scan progress and information about quota file updates.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force check even if the filesystem is mounted and active. Use this option with caution, as it can lead to inaccurate results or data corruption if the filesystem is heavily used.<br><br><b><b>-i</b> / <b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not repair inconsistencies; report them only. This makes <i>quotacheck</i> run in a 'read-only' mode without modifying quota files.<br><br><b><b>-R</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When used with <b>-a</b>, also check the root filesystem. The root filesystem is often skipped by default for safety reasons.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable verbose logging. This can be useful in scripts where progress output is not desired.<br><br><b><b>-M</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not remount filesystems read-only when scanning with <b>-a</b>. This can be useful on systems where remounting is problematic, but it increases the risk of inconsistencies.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a progress bar during the scan, which can be helpful for very large filesystems.<br><br><b><b>-T</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not truncate existing quota files. This can be useful in specific recovery scenarios.<br><br><b><b>-x</b> <i>filesystem</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude the specified filesystem from the check, typically used with <b>-a</b>.<br><br>


title: DESCRIPTION
content:
<i>quotacheck</i> is a Linux command-line utility used to verify and repair the consistency of disk quota files on filesystems. It scans the specified filesystems, builds a fresh table of current disk usage (blocks and inodes) for all users and groups, and then compares this information with the data stored in the existing quota files (e.g., <i>aquota.user</i>, <i>aquota.group</i>, or older <i>quota.user</i>, <i>quota.group</i>). If any discrepancies are found, <i>quotacheck</i> updates the quota files to reflect the actual disk usage, ensuring the integrity of the quota system.<br><br>It is commonly run after system crashes or unexpected shutdowns to correct potential inconsistencies. While it can be run on mounted filesystems using the <b>-f</b> (force) option, it is generally recommended to unmount the filesystem first to prevent data corruption or inaccurate results during the scan. This command is crucial for maintaining accurate disk usage tracking and enforcement in a multi-user environment.


title: CAVEATS
content:
Running <i>quotacheck</i> on a mounted filesystem with the <b>-f</b> option is generally <b>not recommended</b> as it can lead to data corruption or inaccurate results if the filesystem is actively being written to. For best results and safety, the filesystem should ideally be unmounted before running <i>quotacheck</i>. If unmounting is not feasible, consider remounting it read-only. The scan can be time-consuming, especially for large filesystems with a high number of files and directories.


title: QUOTA FILE LOCATIONS
content:
Quota files are typically named <i>aquota.user</i> and <i>aquota.group</i> (or <i>quota.user</i> and <i>quota.group</i> for older systems) and usually reside in the root directory of the filesystem being checked. Their correct placement is critical for the quota system to function properly.


title: INTEGRATION WITH SYSTEM STARTUP
content:
<i>quotacheck</i> is often run automatically during system startup by init scripts if quotas are enabled for a filesystem. This usually occurs after <i>fsck</i> has completed its checks, ensuring quota consistency before users log in and start modifying files on the filesystem.


title: HISTORY
content:
Disk quotas have been a fundamental feature of Unix-like operating systems for decades. The <i>quotacheck</i> utility has been an integral part of the quota system since its early implementations, designed to ensure the integrity of quota files. Its core functionality has remained consistent, adapting over time to new quota file formats (such as the <i>aquota</i> format) and evolving kernel quota modules to maintain compatibility and efficiency across different Linux distributions and kernel versions.


title: SYNOPSIS
content:
<code>qutebrowser [<i>OPTIONS</i>] [<i>URL</i>...]</code><br><br>Invokes the qutebrowser application. <i>OPTIONS</i> are command-line flags that modify its behavior. <i>URL</i>s are optional addresses to open upon startup; if omitted, the configured start pages are loaded.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows qutebrowser version information and exits.<br><br><b>--private-window</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens a new window in private browsing mode (incognito), not saving history or cookies.<br><br><b>--temp-basedir</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts qutebrowser with a temporary base directory, ensuring no configuration or history is saved.<br><br><b>--basedir <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative base directory for configuration, data, and cache files.<br><br><b>--config-py <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the specified Python file as the configuration file instead of the default.<br><br><b>--set <setting>=<value></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides a specific configuration setting on startup. Useful for temporary changes.<br><br><b>--backend <backend></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the web backend to use (e.g., <i>webengine</i> or <i>webkit</i>).<br><br><b>--target <window></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens URLs in an existing window identified by its ID or 'last-focused'.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug logging, providing more verbose output for troubleshooting.<br><br>


title: DESCRIPTION
content:
qutebrowser is a free, open-source web browser that sets itself apart with its <i>keyboard-driven</i> workflow and minimal graphical user interface. Inspired by command-line interfaces and text editors like Vim, it offers powerful navigation and interaction entirely through keyboard shortcuts, making it highly efficient for users who prefer not to use a mouse.<br><br>Built using Python and Qt, qutebrowser supports modern web standards and is highly customizable, allowing users to tailor its appearance, keybindings, and behavior through a Python configuration file. It aims to provide a fast, efficient, and distraction-free browsing experience.


title: CAVEATS
content:
While powerful for keyboard-centric users, qutebrowser has a learning curve due to its unique keybindings. It may occasionally struggle with rendering complex or heavily JavaScript-dependent websites compared to mainstream browsers, as its rendering engine (QtWebEngine/QtWebKit) might lag behind the very latest features of engines like Blink or Gecko. It is also less suited for users heavily reliant on mouse interactions or extensive browser extensions.


title: CONFIGURATION
content:
qutebrowser uses a Python-based configuration file (<code>config.py</code>), allowing for highly flexible and programmatic customization of key bindings, colors, fonts, and behavior. This makes it exceptionally powerful for users who want fine-grained control over their browsing environment.


title: EXTENSIBILITY
content:
Although it doesn't support traditional browser extensions like Chrome or Firefox, its Python backend and extensive command system allow for significant customization and integration with external tools through custom commands and userscripts.


title: HISTORY
content:
qutebrowser was initially conceived and developed by Florian Bruhin, with the first public release in 2014. Its development was driven by the desire for a browser that integrated the efficient, modal editing paradigm found in Vim with a modern web rendering engine (initially QtWebKit, later primarily QtWebEngine). It gained popularity among developers and power users seeking a fast, keyboard-only browsing experience, differentiating itself from other minimalist browsers by its deep configurability via Python.


title: SYNOPSIS
content:
<b>r</b> <i>[no options/arguments typically for a simple alias]</i><br><i>(commonly aliased to `fc -s` or `!!`)</i>


title: PARAMETERS
content:
<b>No direct parameters for the alias 'r'</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When 'r' is used as a simple alias, it typically doesn't accept direct parameters. Its functionality is pre-defined by the alias itself.<br><br><b><event-number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the command corresponding to the specified history event number. This is a common pattern for what 'r' might be aliased to (e.g., <code>alias r='fc -s'</code> or <code>alias r='!!'</code>, but also custom aliases like <code>alias r10='!10'</code>).<br><br><b>-<offset></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the command found by counting <offset> commands back from the current line. For example, <code>!-1</code> is equivalent to <code>!!</code>.<br><br><b>!<string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the most recent command in history that begins with <string>. This is often used for quick re-execution (e.g., <code>!ls</code> to re-run the last <code>ls</code> command).<br><br><b>!!</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the immediately preceding command. This is one of the most common actions 'r' is aliased to (e.g., <code>alias r='!!'</code>).<br><br>


title: DESCRIPTION
content:
The letter <b>"r"</b> is <i>not</i> a standard, standalone Linux command or executable. Instead, it is very commonly used as a custom <br>shell alias or function by users to quickly repeat previous commands from their command history.<br><br>Typically, when a user types <b>"r"</b>, it's configured to execute one of the following underlying shell features:<br><ul><li><b><I><code>fc -s</code></I></b>: A shell built-in (from Korn shell, adopted by Bash) that re-executes the last command from the history list.</li><li><b><I><code>!!</code></I></b>: A shell history expansion (from C shell, adopted by Bash, Zsh) that re-executes the immediately preceding command.</li><li><b><I><code>!<event-number></code></I></b>: Re-executes the command corresponding to a specific history event number.</li><li><b><I><code>!<string></code></I></b>: Re-executes the most recent command starting with the specified string.</li></ul><br>The exact behavior of <b>"r"</b> is entirely dependent on the user's shell configuration files (e.g., <code>.bashrc</code>, <code>.zshrc</code>), where the alias or function is defined.


title: CAVEATS
content:
<ul><li><b>Not a Standard Executable:</b> <b>"r"</b> is not a standard Linux command found in <code>/bin</code>, <code>/usr/bin</code>, or other common executable paths by default. It's almost always a user-defined shortcut.</li><li><b>Shell-Dependent:</b> Its existence and behavior are entirely dependent on the user's shell configuration (e.g., Bash, Zsh, Fish) and whether they have explicitly defined it.</li><li><b>Potential Conflicts:</b> On systems where the R statistical programming language is installed, the executable for R is often named <code>R</code> (capitalized), but a user alias of <code>r</code> (lowercase) could potentially conflict or cause confusion if not carefully managed.</li><li><b>No Manual Page:</b> Because it's not a standard command, there is no dedicated <code>man r</code> page.</li></ul>


title: R STATISTICAL LANGUAGE
content:
The letter <b>"R"</b> (capitalized) can also refer to the <a href="https://www.r-project.org/" target="_blank">R programming language</a>, a free software environment for statistical computing and graphics. When installed on Linux, its executable is typically named <code>R</code>. This is distinct from any shell alias <b>"r"</b> used for command history recall.


title: HISTORY
content:
The ability to recall and re-execute commands from shell history is a fundamental feature of modern Unix-like shells, dating back to early shells like the C shell (<code>csh</code>) in the late 1970s, which introduced the '!' history expansion mechanism. The <code>fc</code> (fix command) built-in originated in the Korn shell (<code>ksh</code>) in the early 1980s and was later adopted by Bash. The use of <b>"r"</b> as a simple alias for these powerful history features is a widespread user convenience, demonstrating the flexibility and customizability of Unix shells rather than being a specific historical development of an 'r' command itself.


title: SYNOPSIS
content:
<b>r2</b> <I>[options]</I> <I>[file]</I><br>The <I>[file]</I> argument specifies the binary, device, or remote target to open. If omitted, <I>r2</I> typically starts in an empty project or a default environment, ready to receive commands.


title: PARAMETERS
content:
<b>-A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically analyze all referenced functions, code blocks, and data structures upon loading the file.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Start in <I>debug mode</I>, allowing attachment to a running process, opening a core dump, or launching a new process for debugging.<br><br><b>-w</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open the specified file in <I>write mode</I>, enabling modifications to the binary directly.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in <I>quiet mode</I>, suppressing startup banners, introductory messages, and non-essential output.<br><br><b>-i <I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute <I>radare2</I> commands from the specified script <I>file</I> immediately after loading the target.<br><br><b>-e <I>k=v</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a configuration variable <I>k</I> to value <I>v</I> before the main prompt is displayed or analysis begins.<br><br><b>-c <I>cmd</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run a specific <I>radare2</I> command <I>cmd</I> right after loading the file, before entering the interactive shell.<br><br><b>-p <I>plugin</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load an external <I>plugin</I> by its name, enhancing functionality or adding support for specific formats/architectures.<br><br><b>-l <I>lib</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load a shared <I>library</I> or a plugin file directly by its path.<br><br><b>-a <I>arch</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force analysis and disassembly for a specific CPU <I>architecture</I>, overriding auto-detection if necessary.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the <I>version</I> information of <I>radare2</I> and exit.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the <I>help</I> message, listing common options and basic usage, and exit.<br><br>


title: DESCRIPTION
content:
<b>r2</b>, also known as <I>radare2</I>, is a comprehensive open-source framework designed for reverse engineering and binary analysis. It provides a powerful suite of tools that facilitate deep inspection, disassembly, debugging, and exploitation of executable files.<br><br>Highly modular and extensible, <I>radare2</I> supports a vast array of CPU architectures (e.g., x86, ARM, MIPS, PowerPC) and file formats (e.g., ELF, PE, Mach-O). It's widely used for tasks such as malware analysis, vulnerability research, exploit development, and software auditing. Its unique command-line interface enables powerful scripting and automation, making it a preferred tool among security professionals and researchers. Despite its command-line nature, <I>r2</I> offers robust data visualization, graph analysis, and interactive debugging capabilities, proving to be a versatile solution for understanding complex binaries.


title: CAVEATS
content:
<b>r2</b> has a <I>steep learning curve</I> due to its extensive command set and a design philosophy that prioritizes command-line interaction, which can be daunting for newcomers. While powerful, it can be <I>resource-intensive</I> for very large binaries, especially during deep analysis. Its active development cycle means that syntax and features may occasionally change between versions.


title: INTERACTIVE SHELL
content:
<b>r2</b> provides a powerful and flexible interactive shell where users can execute commands to analyze, debug, and manipulate binaries. This shell features advanced capabilities such as autocompletion, command history, and a highly customizable prompt.


title: SCRIPTING CAPABILITIES
content:
The framework is highly scriptable, supporting various programming languages (e.g., Python, Go, Node.js) through official bindings. This allows users to automate complex analysis tasks, integrate <I>r2</I> into custom workflows, and extend its functionality programmatically.


title: PLUGINS AND EXTENSIBILITY
content:
<b>radare2</b> boasts a robust plugin architecture, enabling developers to create custom tools, file format loaders, disassemblers, analyzers, and debuggers. This design ensures that the framework can be adapted to new architectures, file types, and analysis methodologies.


title: VISUAL MODES
content:
Beyond its command-line interface, <I>r2</I> includes several visual modes, accessible via the `V` command. These modes offer a more interactive and graphical experience for tasks like viewing disassembly, hex dumps, call graphs, and debugging registers.


title: HISTORY
content:
<b>radare2</b> was initially conceived by Sergi 'pancake' Alvarez in 2006 as a simple command-line hexadecimal editor named 'radare'. Over the years, it gradually evolved into a sophisticated, multi-purpose reverse engineering framework, incorporating features like disassembly, debugging, and advanced analysis. Its development has been largely community-driven, emphasizing extensibility, cross-platform compatibility, and a Unix-like philosophy where every function is accessible via a simple command, promoting scripting and automation. It gained significant traction for being a powerful open-source alternative to commercial tools.


title: SEE ALSO
content:
gdb(1): <I>GNU Debugger</I>, objdump(1): <I>Display information from object files</I>, readelf(1): <I>Display information about ELF files</I>, strings(1): <I>Find printable strings in files</I>, ida(1): <I>IDA Pro disassembler and debugger (commercial)</I>


title: DESCRIPTION
content:
The command <b>r2e</b> does not appear to be a standard, widely recognized, or pre-installed utility in common Linux distributions (e.g., Debian, Ubuntu, Fedora, CentOS, Arch Linux). It is not found in typical core utility packages or common software repositories. Therefore, there is no universally defined functionality, set of options, or usage patterns for <b>r2e</b>. It might be a custom script developed for a specific environment, an internal tool unique to a particular organization, a typo in the command name, or part of a highly specialized or niche software package not broadly documented or distributed. Without further context, it is impossible to provide detailed information about its purpose or behavior. Users encountering this command should verify its source and intended use within their specific system or environment.


title: CAVEATS
content:
As <b>r2e</b> is not a standard command, its functionality, syntax, and options are unknown. Attempting to execute it on a typical Linux system will likely result in a 'command not found' error unless it has been custom installed or aliased by the user or system administrator. Users should exercise caution if they encounter this command in an unknown context, as custom scripts can have arbitrary effects.


title: HISTORY
content:
There is no widely documented history or development timeline for a standard Linux command named <b>r2e</b> within open-source projects or major Linux distributions.


title: PARAMETERS
content:
<b><b>-A</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all relevant binary information (a combination of common options like entry, imports, exports, sections, symbols, strings).<br><br><b><b>-B</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display binary architecture information (e.g., architecture, bits, OS, endianness, file type, machine).<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display call-graphs (requires pre-analysis or specific flags).<br><br><b><b>-C</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display C++ classes found in the binary.<br><br><b><b>-D</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display debug information (e.g., DWARF, PDB).<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display entry points of the binary.<br><br><b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display exported symbols.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display functions detected in the binary.<br><br><b><b>-F</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display flags associated with binary elements.<br><br><b><b>-g</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the binary's signature (e.g., hash, fuzzy hash).<br><br><b><b>-H</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display header information (raw or interpreted).<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display imported symbols and their libraries.<br><br><b><b>-I</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display general information about the binary (similar to -B but more comprehensive).<br><br><b><b>-j</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in JSON format, ideal for scripting and programmatic parsing.<br><br><b><b>-K</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display ELF sections (specific to ELF binaries).<br><br><b><b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List linked libraries.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all supported binary formats by <b>rabin2</b>.<br><br><b><b>-M</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the address of the <i>main</i> function (if detected).<br><br><b><b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display sections by name.<br><br><b><b>-N</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display symbols by name.<br><br><b><b>-O</b> <i>offset</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open a binary at a specific offset (useful for fat binaries or embedded files).<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show section permissions (read, write, execute).<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode, suppress column names and headers.<br><br><b><b>-qq</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Even quieter mode, output only raw data without any formatting.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show output in raw format (no pretty printing).<br><br><b><b>-R</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display relocations.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display symbols (all types: local, global, etc.).<br><br><b><b>-S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display sections.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display printable strings from the binary.<br><br><b><b>-T</b> <i>table</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display fields of a given table (e.g., <b>-T strings</b> for detailed string properties).<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display undefined symbols.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show version information of <b>rabin2</b>.<br><br><b><b>-x</b> <i>section_name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display content of a specific section in hexadecimal format.<br><br><b><b>-Z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display sections with Zignatures (code signatures).<br><br>


title: DESCRIPTION
content:
<b>rabin2</b> is a powerful command-line utility from the <i>radare2</i> reverse engineering framework. It specializes in rapidly extracting critical metadata from various binary file formats (e.g., ELF, PE, Mach-O, MZ, COFF, etc.) without requiring a full loading of the binary into an interactive environment.<br><br>It provides detailed insights into a binary's structure, including header information, sections, segments, symbols (imports, exports, local), entry points, relocations, and strings. <b>rabin2</b> is commonly used for initial reconnaissance, triage, and scripting tasks involving executables, shared libraries, and object files, offering a quick overview before deeper analysis with <i>radare2</i> itself.


title: CAVEATS
content:
<b>rabin2</b> relies on the underlying <i>r_bin</i> library within the <i>radare2</i> framework, which may have limitations in perfectly parsing extremely malformed or obscure binary formats. While fast, it performs static analysis and cannot provide runtime insights like a debugger. For in-depth analysis, dynamic inspection, or interactive reverse engineering, the full <i>radare2</i> environment (<b>r2</b>) is required.


title: JSON OUTPUT FOR SCRIPTING
content:
The <b>-j</b> option is one of <b>rabin2's</b> most powerful features for automation. It outputs all requested information in a structured JSON format, making it trivial to parse with scripting languages like Python or Node.js. This enables seamless integration into automated analysis pipelines and custom tooling.


title: INTEGRATION WITH RADARE2
content:
Although a standalone tool, <b>rabin2</b> shares its binary parsing engine with <i>radare2</i> itself. Many of the commands executed within an <b>r2</b> session (e.g., <i>i</i> for info, <i>is</i> for symbols, <i>ie</i> for exports) are internally powered by the same logic used by <b>rabin2</b>, ensuring consistency and accuracy across the framework.


title: HISTORY
content:
<b>rabin2</b> is an integral part of the <i>radare2</i> open-source reverse engineering framework, which originated around 2006. It was developed to provide a quick, standalone utility for extracting binary metadata, leveraging the robust binary parsing capabilities of <i>radare2's</i> core <i>r_bin</i> library. Its evolution is closely tied to the continuous development and expansion of the <i>radare2</i> project, aiming for comprehensive format support and performance.


title: SYNOPSIS
content:
<b>racket</b> [<i>options</i>] [<i>file</i> [<i>arg ...</i>]]<br><b>racket</b> [<i>options</i>] <b>-e</b> <i>expression</i><br><b>racket</b> [<i>options</i>] <b>-f</b>


title: PARAMETERS
content:
<b><b>-e</b> <i>&lt;expression&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates the given <i>expression</i> directly and prints the result. This is useful for one-off calculations or script snippets.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts an interactive REPL (Read-Eval-Print Loop), allowing users to type and evaluate Racket code interactively.<br><br><b><b>-l</b> <i>&lt;language&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads the specified <i>language</i> module as the top-level environment for evaluation or script execution. For example, <b>-l racket/base</b>.<br><br><b><b>-t</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the module at <i>path</i> as the main module for execution. This is a common way to run Racket scripts.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restricts the executed program to a sandbox environment, limiting file system and network access for security.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs Racket without a graphical user interface, preventing the launch of GUI-dependent components.<br><br><b><b>--collect</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces compilation of source files into <i>.zo</i> (compiled Racket object) files for faster future loading. By default, compilation is often on-demand.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the Racket version information and exits.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available command-line options and exits.<br><br><b><b>--</b> <i>&lt;program-arguments&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicates that all subsequent arguments are to be treated as arguments for the Racket program being executed, rather than options for the <b>racket</b> command itself.<br><br>


title: DESCRIPTION
content:
The <b>racket</b> command is the primary executable for the Racket programming language. It serves as an interpreter, JIT compiler, and interactive Read-Eval-Print Loop (REPL). It can execute Racket source files, compile them into bytecode (<i>.zo</i> files) for faster loading, or launch various Racket-based tools. Racket is a multi-paradigm language, supporting functional, object-oriented, logic, and imperative programming styles, and is particularly strong in language-oriented programming, allowing users to create and integrate new languages.<br><br>Beyond running scripts, <b>racket</b> can be used for interactive development sessions, evaluating expressions on the fly, or building standalone applications. Its extensibility and rich macro system make it a powerful tool for academic research, education, and general-purpose software development, providing a robust platform for sophisticated program construction.


title: CAVEATS
content:
The command-line interface for <b>racket</b> can be quite intricate due to its multiple execution modes (script, REPL, compilation, tool invocation). Users should be aware of the interaction between options, especially when mixing <b>-e</b>, <b>-f</b>, and specifying a file. Performance can vary between directly interpreted code and JIT-compiled bytecode, with the latter generally being faster. Sandbox restrictions imposed by <b>-r</b> can significantly limit program capabilities, requiring careful consideration for privileged operations.


title: EXECUTION MODES
content:
The <b>racket</b> command supports several primary execution modes: running a Racket source file as a script; launching an interactive REPL for immediate code evaluation; compiling Racket code into bytecode for improved performance; and executing various Racket-based command-line tools or utilities. The specific mode is typically determined by the presence or absence of a filename and specific command-line options like <b>-e</b> or <b>-f</b>.


title: COMPILATION AND BYTECODE
content:
When executing Racket code, <b>racket</b> often employs a Just-In-Time (JIT) compiler to translate source code into optimized bytecode, which is then executed by the Racket virtual machine. This bytecode is frequently cached in <i>.zo</i> (compiled Racket object) files, improving subsequent load times. The <b>--collect</b> option can be used to force compilation for specific directories, ensuring that compiled versions are readily available.


title: LANGUAGE-ORIENTED PROGRAMMING
content:
A core philosophy behind Racket is language-oriented programming. The <b>racket</b> command facilitates this by allowing users to load and switch between different programming languages (e.g., using <b>-l</b>) that are implemented within the Racket framework. This enables developers to create highly specialized domain-specific languages (DSLs) tailored to particular problems, leveraging Racket's powerful macro system and module system.


title: HISTORY
content:
The Racket language and its associated tools, including the <b>racket</b> command, evolved from PLT Scheme, a variant of the Scheme programming language. PLT Scheme was created in 1995 with an initial focus on educational software. In 2010, PLT Scheme was officially renamed Racket to reflect its broader ambitions beyond being just a Scheme variant, emphasizing its unique features for language-oriented programming and the creation of domain-specific languages. The <b>racket</b> executable represents the culmination of years of development aimed at providing a powerful, extensible, and high-performance programming environment.


title: PARAMETERS
content:
<b>pkg</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages Racket packages, including installation, updates, and removal.<br><br><b>exe</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds standalone executables from Racket source files.<br><br><b>cs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles Racket source code into .zo (bytecode) files.<br><br><b>test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs tests defined within Racket projects or specific files.<br><br><b>doc</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates documentation for Racket libraries and projects.<br><br><b>setup</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs various setup tasks for a Racket installation, such as compiling core files.<br><br><b>config</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages Racket's system and user configuration settings.<br><br><b>help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides detailed help for <i>raco</i> itself or specific subcommands.<br><br><b>version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the installed Racket version information.<br><br>


title: DESCRIPTION
content:
<i>raco</i> is the indispensable command-line utility for the <br>Racket programming language ecosystem. It serves as the central <br>hub for a wide array of development, deployment, and system <br>management tasks. Developers utilize <i>raco</i> for essential <br>operations such as managing Racket packages (installing, <br>updating, and removing libraries), compiling Racket source code <br>into standalone executables or bytecode, running automated tests <br>for Racket projects, and generating project documentation. Beyond <br>these, it offers tools for system setup, debugging, introspection, <br>and configuration management specific to Racket installations. <br>Its modular design means that much of <i>raco</i>'s functionality <br>is provided through a diverse set of subcommands, each focused <br>on a specific aspect of Racket development, making it a powerful <br>and versatile tool for anyone working with Racket.


title: CAVEATS
content:
The functionality and availability of specific <i>raco</i> subcommands <br>can vary between different versions of the Racket programming <br>language. Some older subcommands might be deprecated or replaced <br>by newer alternatives (e.g., <i>planet</i> replaced by <i>pkg</i>). <br>It requires a proper Racket installation to be present in the <br>system's PATH.


title: EXTENSIBILITY
content:
<i>raco</i> is designed to be highly extensible. <br>Developers can create their own custom <i>raco</i> subcommands <br>by writing Racket modules, making it possible to integrate <br>project-specific tooling directly into the <i>raco</i> workflow. <br>This allows for tailored automation and simplifies complex <br>development tasks within the Racket environment.


title: SUBCOMMAND HELP
content:
Each <i>raco</i> subcommand typically <br>offers its own detailed help documentation. Users can get <br>specific usage information, options, and arguments for a <br>particular subcommand by running <br><code><b>raco</b> <I>subcommand</I> <b>--help</b></code> <br>or <br><code><b>raco help</b> <I>subcommand</I></code>.


title: HISTORY
content:
<i>raco</i> evolved as the central command-line utility for <br>what was originally PLT Scheme and later became Racket. Its <br>development paralleled Racket's growth into a full-fledged <br>programming ecosystem. Initially, simpler, specialized scripts <br>handled tasks like package management. However, as the system <br>matured, the need for a unified, extensible command-line <br>interface led to the creation of <i>raco</i>. Notable historical <br>changes include the transition from older package managers like <br><i>planet</i> to the more robust and modern <i>raco pkg</i> <br>subcommand, reflecting ongoing improvements in Racket's tooling <br>and infrastructure.


title: PARAMETERS
content:
<b><i>-a</i> <arch></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify architecture (e.g., x86, arm, mips). Use '<i>r2 -a ?</i>' for a list of supported architectures.<br><br><b><i>-b</i> <bits></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify register size / bitness (e.g., 16, 32, 64). Overrides auto-detection.<br><br><b><i>-D</i> <debugger></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the given debugger profile (e.g., '<i>rap</i>' for r_a_p, '<i>gdb</i>' for gdbserver). Use '<i>r2 -D ?</i>' for a list of supported debuggers.<br><br><b><i>-d</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open in debug mode. If a file is specified, it opens for debugging; otherwise, it attaches to a process ID (PID).<br><br><b><i>-e</i> <key=value></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set an r2 configuration variable (e.g., '<i>scr.color=true</i>', '<i>asm.bits=32</i>').<br><br><b><i>-i</i> <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute commands from a script file before the r2 prompt is shown. Can be specified multiple times.<br><br><b><i>-q</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode: suppress radare2 startup messages and only show the prompt.<br><br><b><i>-p</i> <project></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load or create a project file. Projects save analysis information, flags, comments, and other metadata.<br><br><b><i>-c</i> '<cmd>'</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute a single radare2 command before the r2 prompt. Can be specified multiple times.<br><br><b><i>-s</i> <addr></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Seek to a specified address or offset in the binary upon loading. Accepts numeric addresses or flag names.<br><br><b><i>-w</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open the file in write mode, allowing modifications to the binary.<br><br><b><i>-A</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform automatic analysis passes when the file is loaded. This can take time for large binaries.<br><br><b><i>-R</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open the file in read-only mode, preventing accidental modifications.<br><br><b><i>-N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not load any r2plugins, useful for debugging or specific scenarios.<br><br><b><i>-V</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the radare2 version information and exit.<br><br><b><i>-h</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message and exit.<br><br>


title: DESCRIPTION
content:
<i>radare2</i> (r2) is an open-source, cross-platform command-line framework for reverse engineering, binary analysis, and debugging. It provides a comprehensive suite of tools for disassembling, analyzing, patching, and debugging binary executables, malware, and firmware. <br><br>It supports a wide range of architectures (x86, ARM, MIPS, PowerPC, etc.) and file formats (ELF, PE, Mach-O, Java, WebAssembly, etc.). <i>r2</i> is known for its powerful, scriptable command-line interface, which allows for deep programmatic interaction with binary data. It can be used for tasks ranging from simple file viewing and hex editing to complex malware analysis, vulnerability research, and exploit development. <br><br>While it has a steep learning curve due to its extensive feature set and unique command syntax, its modular design and extensibility via plugins make it an invaluable tool for security researchers, malware analysts, and developers working with low-level code.


title: CAVEATS
content:
<i>radare2</i> has a notoriously steep learning curve due to its extensive command-line interface and highly modular structure. Users often need to be familiar with assembly language, binary formats, and reverse engineering concepts. While powerful, its text-based UI can be less intuitive than graphical tools like IDA Pro or Ghidra, especially for beginners. The project is under active development, so commands and features might evolve, and documentation can sometimes lag behind the latest changes. Performance can also be an issue with very large or complex binaries, especially during initial analysis passes.


title: CORE FUNCTIONALITY
content:
<i>radare2</i> operates primarily through its command-line interface. Users interact with the binary by typing commands, which are often mnemonic (e.g., '<i>s</i>' for seek, '<i>pd</i>' for print disassembly, '<i>px</i>' for print hexdump). It supports various 'modes' like visual mode ('<i>V</i>') for interactive analysis and graphical representations, and debug mode ('<i>d</i>') for live debugging. The framework's power comes from chaining these commands and leveraging its deep understanding of binary structures.


title: EXTENSIBILITY AND SCRIPTING
content:
One of <i>radare2</i>'s key strengths is its extensibility. It features a rich plugin architecture allowing users to add support for new architectures, file formats, analysis algorithms, and visualization tools. Furthermore, nearly all of its functionality can be accessed and automated via scripting through its powerful JSON output and bindings for various programming languages, including Python, Go, Rust, and JavaScript, making it highly adaptable for custom analysis workflows.


title: HISTORY
content:
<i>radare2</i> was initially conceived by Sergi Álvarez (pancake) in 2006 as a simple command-line hexadecimal editor. Over time, it grew organically into a full-fledged reverse engineering framework, incorporating features for disassembly, analysis, debugging, and exploitation. Its development has been driven by a strong open-source community, making it a powerful and free alternative to commercial reverse engineering solutions like IDA Pro. Its modular architecture and extensive API have fostered a vibrant ecosystem of plugins and integrations, cementing its role as a leading tool in the security research and malware analysis domains.


title: SYNOPSIS
content:
radeontool [ -h ] [ -b [on|off|<level>] ] [ -d [on|off] ] [ -f [on|off|<level>] ] [ -g [red|green|blue] [<gamma>] ] [ -i ] [ -l ] [ -S ] [ -q ] [ -r <reg> [<value>] ] [ -t [on|off|pal|ntsc] ] [ -v ] [ -X ] [ -x ] [ -M <mclk> ] [ -C <cclk> ] [ -O ]


title: PARAMETERS
content:
<b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-b [on|off|<level>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls laptop panel backlight. 'on' for full brightness, 'off' for disabled, or a specific brightness '<level>' (0-255).<br><br><b>-d [on|off]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables digital outputs (DVI/HDMI).<br><br><b>-f [on|off|<level>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the fan speed. 'on' for full speed, 'off' for lowest, or '<level>' (0-255 or 0-100%) for specific speed. Note: some cards have limited support.<br><br><b>-g [red|green|blue] [<gamma>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets or reads the gamma value for a specified color channel (red, green, blue). If <gamma> is omitted, it reads the current value. Defaults to all channels.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints various card information, including PCI ID, chip ID, and memory size.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all supported features and their current status.<br><br><b>-S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves the current card state to a configuration file.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Queries and displays the current status of various features like backlight, DVI output, and fan.<br><br><b>-r <reg> [<value>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads from or writes to a specific Radeon register. <reg> and <value> should be hexadecimal. Use with extreme caution as this can damage hardware.<br><br><b>-t [on|off|pal|ntsc]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the TV output, allowing to turn it on/off or set PAL/NTSC mode.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output for more detailed information.<br><br><b>-X</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables XFree86 DGA (Direct Graphics Access) functionality (experimental).<br><br><b>-x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables XFree86 DGA functionality.<br><br><b>-M <mclk></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Experimental)</i> Sets the memory clock speed in MHz. Use with extreme caution; can damage hardware.<br><br><b>-C <cclk></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Experimental)</i> Sets the core clock speed in MHz. Use with extreme caution; can damage hardware.<br><br><b>-O</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Experimental)</i> Resets clock speeds to their default values. Use with caution.<br><br>


title: DESCRIPTION
content:
<i>radeontool</i> is a command-line utility designed to control various features of ATI Radeon graphics cards under Linux. It provides direct access to hardware-specific settings, allowing users to manage aspects such as laptop panel backlight, digital output (DVI/HDMI) enable/disable, and fan speed control. It can also be used to adjust gamma settings, access the DDC bus (I2C), and dump or write to Radeon registers (with extreme caution).<br><br>Additionally, <i>radeontool</i> offers experimental features like controlling TV output, enabling/disabling XFree86 DGA access, and highly experimental overclocking capabilities for memory and core clocks. Due to its direct hardware interaction, particularly with overclocking and register manipulation, users are advised to exercise caution as improper use may lead to hardware damage or instability. It is a powerful tool for low-level Radeon management.


title: CAVEATS
content:
<i>radeontool</i> is explicitly labeled as a <b>highly experimental</b> utility. Its functionality may not work on all ATI Radeon cards, and many features, particularly overclocking and direct register manipulation (using <B>-r</B>), carry a significant risk of causing <b>permanent hardware damage</b> or system instability if used improperly. Users should proceed with extreme caution. It typically requires root privileges or appropriate permissions to access device files like <B>/dev/mem</B> and <B>/dev/pci</B>.


title: PERMISSIONS
content:
For most operations, <i>radeontool</i> requires direct access to system memory and PCI devices, typically necessitating <b>root privileges</b> or specific user permissions granted to access files like <B>/dev/mem</B> and <B>/dev/pci</B>.


title: EXIT STATUS
content:
The command returns an exit status of <b>0</b> upon successful execution, and a non-zero value (greater than 0) if an error occurred during operation.


title: KNOWN ISSUES (BUGS)
content:
As noted in its documentation, <i>radeontool</i> is experimental, and certain features may not function correctly on all Radeon card models. Overclocking functionality is particularly prone to issues and can lead to hardware damage.


title: HISTORY
content:
<i>radeontool</i> was authored by David Airlie and is based on work by others. Its development is rooted in providing a low-level command-line interface for managing ATI Radeon graphics card features, often interacting directly with the hardware through kernel interfaces. Its existence reflects the need for fine-grained control over graphics card settings, particularly for older or specific Radeon chipsets under Linux.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show version information and exit.<br><br><b><b>-d</b> <i>&lt;delay&gt;</i>, <b>--delay=</b><i>&lt;delay&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the delay between updates in seconds (default: 1). Use 0 for continuous updates.<br><br><b><b>-b</b>, <b>--batch</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in batch mode; print once and exit (non-interactive).<br><br><b><b>-p</b>, <b>--pretty</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable pretty-print mode for simpler, less verbose output, often used with batch mode.<br><br><b><b>-c</b>, <b>--color</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force color output, even if not on a tty.<br><br><b><b>-n</b> <i>&lt;iterations&gt;</i>, <b>--iterations=</b><i>&lt;iterations&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the number of iterations (updates) before exiting.<br><br><b><b>-a</b>, <b>--all-blocks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display all available rings and blocks, including less commonly used ones.<br><br><b><b>-i</b>, <b>--irq</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show IRQ (Interrupt Request) counters for various GPU components.<br><br><b><b>-g</b> <i>&lt;gpu_id&gt;</i>, <b>--gpu=</b><i>&lt;gpu_id&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the GPU to monitor (0-indexed, default: 0 for the first detected GPU).<br><br><b><b>-U</b>, <b>--human-readable</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use human-readable units for memory sizes (e.g., KB, MB, GB) instead of bytes.<br><br><b><b>-P</b>, <b>--percentages</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show percentages for each block's utilization when applicable.<br><br><b><b>-f</b>, <b>--framebuffer</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display framebuffer memory usage statistics.<br><br><b><b>-s</b>, <b>--sclk-mclk</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display SCLK (Shader Clock) and MCLK (Memory Clock) frequencies.<br><br><b><b>-S</b>, <b>--sensors</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display GPU sensor data, including temperature and power consumption.<br><br><b><b>-F</b>, <b>--fps</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display current frame rate (requires specific driver/application setup for accurate reporting).<br><br><b><b>-j</b>, <b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output data in JSON format, suitable for scripting and parsing by other tools.<br><br>


title: DESCRIPTION
content:
<b>radeontop</b> is a command-line utility designed for real-time monitoring of AMD Radeon GPU utilization. It provides a comprehensive overview of various GPU components, including shader engine usage, memory controller activity, video decode/encode engines, and power consumption. Similar to <b>htop</b> or <b>top</b> for CPU and memory, <b>radeontop</b> offers a dynamic, interactive display of GPU metrics, making it an invaluable tool for developers, system administrators, and enthusiasts to diagnose performance issues, monitor resource allocation, and understand the behavior of demanding applications. It leverages the <b>amdgpu</b> kernel driver and <b>DRM</b> (Direct Rendering Manager) interfaces to retrieve detailed statistics, presenting them in a human-readable format. The tool supports multiple GPUs and can output data in various formats, including an interactive ncurses-based display or a JSON stream for scripting and further analysis.


title: CAVEATS
content:
<b>radeontop</b> relies heavily on the <b>amdgpu</b> kernel driver and the <b>DRM</b> (Direct Rendering Manager) subsystem. It will not work with older <b>radeon</b> drivers or non-AMD GPUs.<br><br>The availability and accuracy of certain metrics (like FPS) depend on the specific driver version, kernel configuration, and how applications interact with the GPU.<br><br>For optimal functionality, ensure you are running a recent Linux kernel with the <b>amdgpu</b> driver enabled.<br><br>Some metrics might require root privileges or specific udev rules for non-root users to access GPU performance counters.


title: INSTALLATION
content:
<b>radeontop</b> is often available in the official repositories of major Linux distributions. For Debian/Ubuntu, it can be installed via <i>sudo apt install radeontop</i>. For Fedora, <i>sudo dnf install radeontop</i>. On other distributions, it might be part of a larger <b>amdgpu_top</b> or <b>radeontop</b> package, or may require building from source from its GitHub repository.


title: INTERACTIVE MODE
content:
By default, <b>radeontop</b> runs in an interactive, ncurses-based display mode, updating metrics in real-time. This mode provides a dynamic overview of GPU activity, similar to <b>htop</b>, allowing users to quickly assess GPU workload and identify potential bottlenecks. The interactive interface updates statistics every second (by default) and can be customized with various display options. Pressing 'q' exits this mode.


title: HISTORY
content:
<b>radeontop</b> emerged as a community-driven open-source project to fill a gap in monitoring tools for AMD Radeon GPUs on Linux, paralleling <b>nvidia-smi</b> for NVIDIA cards. It leverages the growing capabilities of the <b>amdgpu</b> open-source driver, which has become the primary driver for modern AMD GPUs on Linux. Its development has focused on providing a comprehensive, real-time overview of GPU statistics, moving from basic utilization figures to more detailed insights into various engine blocks, memory usage, and sensor data. It aims to provide similar functionality to what <b>top</b> does for CPU and memory, but tailored specifically for the GPU.


title: SYNOPSIS
content:
<b>rage</b> <i>[OPTIONS]</i> <i>[FILE...]</i><br><b>rage</b> <i>-d</i> <i>[OPTIONS]</i> <i>[FILE...]</i>


title: PARAMETERS
content:
<b><b>-e</b>, <b>--encrypt</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Encrypts</i> the input (this is the default behavior).<br><br><b><b>-d</b>, <b>--decrypt</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Decrypts</i> the input.<br><br><b><b>-o</b> <i>FILE</i>, <b>--output</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the output to the specified <i>FILE</i> instead of standard output.<br><br><b><b>-a</b>, <b>--armor</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes the encrypted output in a <i>PEM-encoded armored format</i>, making it suitable for text-based transmission.<br><br><b><b>-r</b> <i>RECIPIENT</i>, <b>--recipient</b> <i>RECIPIENT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a recipient for encryption. This can be an <i>age public key</i> (e.g., <code>age1...</code>) or an <i>SSH public key</i>.<br><br><b><b>-i</b> <i>FILE</i>, <b>--identity</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an <i>identity file</i> (private key) for decryption. This can be an <i>age identity file</i> or an <i>SSH private key</i>.<br><br><b><b>-p</b>, <b>--passphrase</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a <i>passphrase</i> for encryption or decryption, prompting interactively for the passphrase.<br><br><b><b>--pinentry</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <i>pinentry</i> for passphrase or identity input, providing a secure graphical prompt for credentials.<br><br><b><b>--ssh-key-path</b> <i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a directory or file to search for <i>SSH private keys</i> for decryption, useful for custom key locations.<br><br>


title: DESCRIPTION
content:
<i>rage</i> is a modern command-line tool for encrypting and decrypting files and streams, fully compatible with the <i>age</i> file format. Written in Rust, it aims to provide a simple, secure, and robust encryption solution. It supports multiple recipient types, including X25519 public keys for secure key exchange, SSH public keys for convenient integration with existing infrastructure, and passphrase-based encryption for simple use cases. <i>rage</i> prioritizes secure defaults and forward secrecy, making it a reliable choice for protecting sensitive data. It can be used for securely sharing files, backing up data, or encrypting arbitrary streams of bytes. Its design focuses on ease of use while adhering to strong cryptographic principles.


title: CAVEATS
content:
<i>rage</i> uses the <i>age</i> file format, which is intentionally distinct from <i>PGP/GPG</i>. Consequently, files encrypted with <i>age</i> cannot be decrypted by <i>GPG</i>, and vice-versa. Users should be aware of this ecosystem difference. The overall security of encrypted data depends heavily on the secure management of <i>private keys</i> or <i>passphrases</i>; their loss or compromise will lead to data loss or unauthorized access. Unlike <i>GPG</i>, there is no inherent "web of trust"; recipients must be explicitly specified.


title: KEY DERIVATION
content:
For <i>passphrase-based encryption</i>, <i>rage</i> utilizes <i>scrypt</i>, a computationally intensive <i>key derivation function</i>, to protect against <i>brute-force attacks</i> on the passphrase. This significantly increases the effort required for an attacker to guess the passphrase, enhancing security.


title: FORWARD SECRECY
content:
When encrypting with <i>X25519 recipients</i>, <i>rage</i> incorporates <i>forward secrecy</i>. This cryptographic property ensures that even if a recipient's long-term private key is compromised in the future, past communications encrypted with that key remain secure because a unique, ephemeral key is generated for each encryption operation.


title: HISTORY
content:
The <i>age</i> encryption format was developed by Filippo Valsorda with the goal of creating a simple, modern, and secure alternative to older, more complex formats like <i>PGP</i>. <i>rage</i> is a popular and actively maintained Rust implementation of the <i>age</i> specification. It emerged as a performant and reliable command-line tool, quickly gaining traction for its ease of use, robust design, and adherence to strong cryptographic principles, becoming a preferred choice for <i>age</i> encryption in the Linux ecosystem and beyond.


title: SYNOPSIS
content:
<b>rails</b> <I>subcommand</I> [<I>options</I>] [<I>arguments</I>] <br><br>Recommended invocation: <b>bundle exec rails</b> <I>subcommand</I> [<I>options</I>] [<I>arguments</I>]


title: PARAMETERS
content:
<b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the Ruby on Rails version being used.<br><br><b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the help message for the <b>rails</b> command or a specific subcommand (e.g., <b>rails help new</b>).<br><br><b>--verbose, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of output for certain operations.<br><br><b>--no-color</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables colored output from the <b>rails</b> command.<br><br>


title: DESCRIPTION
content:
The <b>rails</b> command is the primary command-line interface (CLI) for interacting with the Ruby on Rails web application framework. While not a native Linux utility, it's a crucial tool for developers building applications with Rails on Linux environments. <br><br>It provides functionalities ranging from creating new Rails projects (<i>rails new</i>), generating code (<i>rails generate</i> for models, controllers, etc.), managing the database (<i>rails db</i> for migrations, seeding), starting the development server (<i>rails server</i>), running tests (<i>rails test</i>), and entering the application console (<i>rails console</i>). <br><br>The <b>rails</b> command acts as a dispatcher for various subcommands, each with its own set of options and arguments, streamlining common development tasks and adhering to Rails' 'convention over configuration' philosophy.


title: CAVEATS
content:
The <b>rails</b> command is part of the Ruby on Rails framework, not a core Linux utility. It requires a functional Ruby installation, RubyGems, and Bundler to be present on the system. <br><br>Most <b>rails</b> commands are context-dependent and must be run within a Rails application directory (except for <b>rails new</b>). <br><br>Its full functionality often depends on application-specific gems (managed by Bundler) and proper database configuration.


title: COMMON SUBCOMMANDS
content:
The power of the <b>rails</b> command lies in its extensive subcommands, each designed for specific tasks. Some of the most frequently used include:<br><i><b>new</b></i>: Creates a new Rails application.<br><i><b>server (s)</b></i>: Starts the development web server.<br><i><b>generate (g)</b></i>: Generates code for models, controllers, migrations, etc.<br><i><b>db</b></i>: Manages database operations like migrations, seeding, and console access.<br><i><b>console (c)</b></i>: Opens an IRB session with your Rails application loaded.<br><i><b>test (t)</b></i>: Runs the application's test suite.<br><i><b>routes</b></i>: Lists all defined application routes.<br><br>Each subcommand has its own specific options, which can be viewed using <b>rails help &lt;subcommand&gt;</b> (e.g., <b>rails help new</b>).


title: BUNDLE EXEC
content:
It is best practice to prefix <b>rails</b> commands with <b>bundle exec</b> (e.g., <b>bundle exec rails server</b>). This ensures that the command runs using the specific gem versions defined in your application's <i>Gemfile</i>, preventing conflicts with other gem versions installed on your system.


title: HISTORY
content:
Ruby on Rails was created by David Heinemeier Hansson (DHH) and open-sourced in July 2004. It quickly gained popularity for its developer-friendly approach, emphasizing 'Convention over Configuration' (CoC) and 'Don't Repeat Yourself' (DRY) principles. <br><br>The <b>rails</b> command-line interface has evolved alongside the framework, consolidating many tasks previously handled by Rake or custom scripts, becoming the central point for managing Rails applications.


title: PARAMETERS
content:
<b>--environment, -e <I>environment</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Rails environment to load. Defaults to <I>development</I>. Example: <B>rails console -e production</B>.<br><br><b>--sandbox</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the console in sandbox mode. All database changes made during the session are rolled back upon exiting. Useful for experimentation without affecting persistent data.<br><br><b>--binding <I>binding</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Binds the console to a specific object or expression. Less commonly used for typical interactive sessions.<br><br><b>--debugger</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads the debugger within the console session. Its usage varies with Ruby versions and debugger gems (e.g., <I>binding.pry</I> or the <I>debugger</I> gem are more common now).<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with all available options for the command.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the Rails framework version currently being used by the application.<br><br><b>--</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes any subsequent arguments directly to the underlying IRB (Interactive Ruby) shell. Example: <B>rails console -- --no-rc</B> (prevents IRB from loading its initialization file).<br><br>


title: DESCRIPTION
content:
The <I>rails console</I> command provides an interactive Ruby shell (IRB or Pry) environment preloaded with the current Rails application. It's an indispensable tool for debugging, experimenting with application code, inspecting database records, and performing administrative tasks directly within the context of your Rails project. You can access models, controllers, helpers, and any other application component as if your application were running. It allows direct interaction with the database, running ActiveRecord queries, and manipulating data. Typically invoked from the root directory of a Rails application as <B>bin/rails console</B>, or simply <B>rails console</B> if the <I>rails</I> executable is in your PATH and you are inside a Rails application directory. It operates in the development environment by default.


title: CAVEATS
content:
<ul><li>Requires a valid Rails application directory to execute successfully.</li><li>By default, changes made to the database are persistent (unless <I>--sandbox</I> is used), so exercise caution, especially in production environments.</li><li>Running the console in a production environment should be done with extreme care due to potential data modification, performance impact, and security implications.</li><li>Long-running or memory-intensive operations in the console can impact system performance and consume significant resources.</li></ul>


title: EXITING THE CONSOLE
content:
To gracefully exit the <I>rails console</I> session, type <I>exit</I>, <I>quit</I>, or press <I>Ctrl+D</I>.


title: COMMON USES
content:
The console is commonly used for testing new ActiveRecord queries, creating/updating/deleting records, testing methods on models, prototyping new features, and quickly fixing data inconsistencies or performing administrative tasks.


title: ENVIRONMENT LOADING
content:
The console loads the full Rails environment, including all application code, initializers, configuration, and the database connection, making it identical to the running application's context for that specific environment.


title: HISTORY
content:
The <I>rails console</I> has been a fundamental and indispensable part of the Ruby on Rails framework since its early versions. It provides a direct, interactive gateway into the application's runtime, significantly aiding rapid development, debugging, and data manipulation. Its design reflects Rails' philosophy of developer productivity, offering immediate feedback and powerful introspection capabilities, evolving alongside the framework's core features to maintain its utility as a primary development tool.


title: SEE ALSO
content:
<B>rails server</B>, <B>rails dbconsole</B>, <B>rails generate</B>, <B>rails routes</B>, <B>irb(1)</B>, <B>pry(1)</B>


title: SYNOPSIS
content:
<b>rails-db</b> [<i>OPTIONS</i>]<br>or, more commonly:<br><b>bundle exec rails-db</b> [<i>OPTIONS</i>]


title: PARAMETERS
content:
<b><b>--host &lt;address&gt;</b>, <b>-h &lt;address&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the IP address or hostname the web server should bind to. Defaults to <i>localhost</i> (127.0.0.1).<br><br><b><b>--port &lt;number&gt;</b>, <b>-p &lt;number&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the port number on which the web server will listen. Defaults to <i>3000</i>.<br><br><b><b>--environment &lt;name&gt;</b>, <b>-e &lt;name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the Rails environment (e.g., <i>development</i>, <i>production</i>) in which the application should load. This affects database connections and configurations.<br><br><b><b>--no-assets</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the command from serving static assets (JavaScript, CSS). Useful in environments where assets are served by a separate web server.<br><br><b><b>--version</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the installed version of the <b>rails-db</b> gem.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a help message with available command-line options and usage information.<br><br>


title: DESCRIPTION
content:
The <b>rails-db</b> command is not a native Linux utility, but rather an executable provided by the <b>rails-db</b> Ruby gem. Its primary function is to launch a local web-based graphical user interface (GUI) for interacting with the database of a Ruby on Rails application. <br><br> Once started, this GUI allows developers and data analysts to conveniently browse database tables, view and edit individual records, execute custom SQL queries, inspect schema details, and perform basic data manipulation operations directly within their browser. It acts as an in-application database management tool, simplifying tasks that would otherwise require external database clients or complex command-line interactions. It aims to provide a user-friendly way to explore and manage application data during development and debugging.


title: CAVEATS
content:
The <b>rails-db</b> command requires a Ruby on Rails application and the <b>rails-db</b> gem to be installed within that application's Gemfile. It is primarily designed for development and debugging purposes. <br><br>Due to its direct database access capabilities, exposing the <b>rails-db</b> interface publicly in production environments without robust authentication and authorization mechanisms is highly discouraged and poses significant security risks. It's recommended to run it only in a trusted local or private network context.


title: INSTALLATION AND USAGE CONTEXT
content:
To use <b>rails-db</b>, you must add <code>gem 'rails-db'</code> to your Rails application's <code>Gemfile</code> and then run <code>bundle install</code>. The command is typically executed from the root directory of your Rails project. After launching, it will provide a URL (e.g., <i>http://localhost:3000/rails/db</i>) which you can open in your web browser to access the GUI.


title: SECURITY CONSIDERATIONS
content:
While highly convenient for development, exercising caution is paramount when using <b>rails-db</b>. It bypasses ActiveRecord's security layers and directly accesses the database. Always ensure it's not accessible from untrusted networks, and consider adding authentication if it must be used outside of a strictly private environment.


title: HISTORY
content:
The <b>rails-db</b> gem, specifically the popular version by Sebastian Grebe, emerged around 2016-2017. It was created to address a common developer need for a straightforward, in-app web interface to manage Rails application databases without resorting to external, often generic, database clients (like phpMyAdmin or Adminer). Its development aimed to streamline the process of browsing and manipulating application data directly from a browser, integrating seamlessly with the Rails environment and its database configurations.


title: PARAMETERS
content:
<b>GENERATOR</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the generator whose actions you wish to reverse (e.g., <i>controller</i>, <i>model</i>, <i>scaffold</i>, <i>migration</i>). This must correspond to a generator previously used.<br><br><b>args</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Arguments specific to the <i>GENERATOR</i>, used to identify the exact files to be destroyed. For instance, for a model, this would be the model name and its attributes (e.g., <i>User name:string</i>).<br><br><b>--force, --no-force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Less common for destroy) <b>--force</b> forces overwriting of files, while <b>--no-force</b> prevents overwriting. Typically, <b>destroy</b> deletes, but these options relate to file system interaction.<br><br><b>--skip-namespace</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips namespacing the generated files, used to destroy non-namespaced components if they were generated without namespace.<br><br><b>--skip-routes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents <b>destroy</b> from attempting to remove entries from <i>config/routes.rb</i>. Useful if routes were manually edited or are no longer directly tied to the destroyed component.<br><br><b>--skip-assets</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the destruction of asset files (CSS, JavaScript) that might have been generated alongside a view or controller.<br><br><b>--skip-test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the destruction of test files associated with the destroyed component. Also accessible via <b>--no-test-framework</b> or <b>--no-test</b>.<br><br>


title: DESCRIPTION
content:
The <b>rails destroy</b> command is the inverse operation of <b>rails generate</b>. It is a fundamental command in the Ruby on Rails framework, used to remove files and configurations previously created by Rails generators. When you use <b>rails generate</b> to create models, controllers, scaffolds, or other application components, <b>rails destroy</b> can be used to reverse those actions, cleaning up your project directory and associated configuration files.<br><br>This command intelligently targets and deletes files based on the conventions followed by the corresponding generator. For instance, <b>rails destroy model User</b> will attempt to remove the <i>app/models/user.rb</i> file, its associated test files, and the relevant migration file. It also endeavors to undo modifications made to <i>config/routes.rb</i> (e.g., resource declarations) and other configuration files.<br><br>It's an invaluable tool for maintaining a clean codebase during development, allowing developers to easily undo experiments or refactorings. While it attempts to revert changes thoroughly, it's always recommended to use version control (like Git) to manage your project, as <b>rails destroy</b> might not catch every custom modification or perfectly clean up complex scenarios.


title: CAVEATS
content:
<b>rails destroy</b> is a powerful tool, but it's not foolproof. It primarily relies on file naming conventions and the records kept by the <b>generate</b> command.<br><br>1. <i>Manual Modifications</i>: If you've manually edited the files created by a generator, or the <i>config/routes.rb</i> file, <b>destroy</b> might not perfectly revert all changes. It will attempt to remove specific lines or files but might leave orphaned code or not touch lines it doesn't recognize.<br><br>2. <i>Database Impact</i>: <b>rails destroy model</b> will remove the migration file, but it <b>will not revert the database changes themselves</b> (i.e., it won't drop the table). You need to run <b>bin/rails db:rollback</b> (or <b>db:migrate:down VERSION=...</b>) separately to undo the database schema changes after destroying a migration file.<br><br>3. <i>Version Control</i>: Always use <b>rails destroy</b> within a version-controlled project (e.g., Git). This allows you to easily review and revert any unintended deletions or modifications.<br><br>4. <i>Incomplete Destruction</i>: In complex scenarios or with heavily customized generators, <b>destroy</b> might not remove all related files or configurations. Manual cleanup may be necessary.


title: INTERACTIVE CONFIRMATION
content:
<b>rails destroy</b> does not typically ask for confirmation before deleting files. It assumes you know what you're doing. Always be sure of the command before executing it.


title: TARGETING SPECIFIC GENERATORS
content:
To see what a specific generator would do, you can often run it with a <b>--pretend</b> or <b>--help</b> option, though <b>destroy</b> itself doesn't have a <b>--pretend</b> mode like <b>generate</b>. However, running <b>rails destroy model User</b> and then observing the output before committing to Git (if applicable) is a common practice.


title: ROUTE CLEANUP
content:
When destroying controllers or scaffolds, <b>rails destroy</b> attempts to remove corresponding entries from <i>config/routes.rb</i>. For instance, destroying a resource like <b>resources :users</b> will often remove that line. If routes are nested or heavily customized, manual adjustment might still be required.


title: HISTORY
content:
The concept of <b>generate</b> and <b>destroy</b> commands has been integral to the Ruby on Rails framework since its early days, streamlining development by automating repetitive file creation and removal. Initially, some generation tasks were handled by Rake tasks, but with the evolution of the Rails command-line interface (<b>rails</b> executable), <b>generate</b> and <b>destroy</b> became core <b>bin/rails</b> commands. Their functionality has largely remained consistent, adapting to new Rails features (e.g., asset pipeline, Turbolinks, Stimulus) by correctly handling associated file types and configurations. The <b>destroy</b> command specifically was designed as the symmetrical reverse of <b>generate</b>, reflecting Rails' convention-over-configuration philosophy by providing a clean way to undo common development actions.


title: SYNOPSIS
content:
<B>rails generate</B> &lt;GENERATOR&gt; [arguments] [options]<br><br>Examples:<br><i>rails generate model User name:string email:string</i><br><i>rails generate controller Products index show</i><br><i>rails generate scaffold Post title:string body:text --skip-stylesheets</i><br><i>rails generate migration AddDetailsToProducts description:text part_number:string</i>


title: PARAMETERS
content:
<b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help for the specified generator, or list all available generators if no generator is given.<br><br><b>--pretend, -p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in dry-run mode. Shows the files that would be generated without actually creating them.<br><br><b>--force, -f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrite files that already exist during generation.<br><br><b>--skip, -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip files that already exist, preventing them from being overwritten.<br><br><b>--quiet, -q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress status messages during the generation process.<br><br><b>--no-color</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable colorized output for generator status messages.<br><br><b>--skip-routes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not add an entry to the application's <B>config/routes.rb</B> file.<br><br><b>--skip-test, --no-test-framework</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not generate any test files for the component.<br><br><b>--skip-assets</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not generate asset files (e.g., JavaScript or CSS) for the component.<br><br>


title: DESCRIPTION
content:
The <B>rails generate</B> command is a fundamental tool in the Ruby on Rails framework, used to automate the creation of various application components. It leverages pre-defined templates and Rails' "convention over configuration" philosophy to generate boilerplate code for models, controllers, views, migrations, scaffolds, mailers, jobs, and more.<br><br>By providing the generator name and specific arguments (e.g., model name, controller actions, database fields), <B>rails generate</B> quickly sets up the necessary files and directories, often including associated test files, routes, and database migration files. This drastically reduces the amount of manual setup, ensures consistency, and helps developers adhere to Rails best practices. It's an indispensable command for rapidly building and expanding Rails applications, working in conjunction with <B>rails destroy</B> which serves as its counterpart for removing generated code.


title: CAVEATS
content:
While <B>rails generate</B> is powerful, care must be taken when using the <B>--force</B> option, as it will overwrite existing files without confirmation. Generated code provides a solid starting point but rarely fits all needs perfectly; manual review and customization are always required. Over-reliance without understanding the generated code can sometimes lead to unnecessary boilerplate.


title: LISTING AVAILABLE GENERATORS
content:
Running <B>rails generate</B> without any arguments will display a comprehensive list of all built-in and custom generators available within the current Rails application, categorized by their type (e.g., Rails, Active Record, Test Unit).


title: CUSTOM GENERATORS
content:
Developers can extend Rails' code generation capabilities by creating their own custom generators. This allows for automation of domain-specific boilerplate code or adherence to unique project standards, further enhancing development workflow efficiency.


title: HISTORY
content:
The concept of code generation has been integral to Ruby on Rails since its early versions. Initially, generators were invoked via <B>script/generate</B> (pre-Rails 3). With the release of Rails 3, the command was unified under the main <B>rails</B> executable, becoming <B>rails generate</B>. This evolution solidified its role as a core tool for adhering to Rails' "Convention over Configuration" principle, significantly boosting developer productivity by automating repetitive setup tasks and ensuring consistent project structure across applications.


title: PARAMETERS
content:
<b>-d, --database=<I>DATABASE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the database for the application. Common choices include <b><I>postgresql</I></b>, <b><I>mysql</I></b>, <b><I>sqlite3</I></b>. Also supports JDBC and other enterprise databases.<br><br><b>--skip-bundle</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the <I>bundle install</I> step after generating the application, useful for manual gem installation later.<br><br><b>--skip-test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the generation of Test Unit files and the <I>test</I> directory, often used when employing alternative testing frameworks like RSpec.<br><br><b>--skip-system-test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the generation of system test files.<br><br><b>--api</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a bare-bones API-only application, excluding components like Action View, Action Controller's browser-specific functionality, and browser-related middleware.<br><br><b>--webpack=<I>WEBPACK</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Chooses a JavaScript bundling tool for the frontend. Options typically include <b><I>esbuild</I></b>, <b><I>rollup</I></b>, or <b><I>webpack</I></b>.<br><br><b>--css=<I>CSS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Chooses a CSS framework or preprocessor. Examples include <b><I>tailwind</I></b>, <b><I>bootstrap</I></b>, <b><I>bulma</I></b>, <b><I>sass</I></b>.<br><br><b>--minimal</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a minimalistic Rails application, skipping many non-essential components and default gems for a leaner setup.<br><br><b>--skip-git</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Git repository initialization. By default, <I>rails new</I> initializes a new Git repository.<br><br><b>--skip-active-record</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes Active Record, Rails' ORM, useful if planning to use a different persistence layer or no database.<br><br><b>--skip-action-cable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Action Cable, the framework for WebSocket integration.<br><br><b>--skip-action-mailer</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Action Mailer, the email sending framework.<br><br><b>--skip-action-text</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Action Text, for rich text content.<br><br><b>--skip-action-view</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Action View, the templating layer.<br><br><b>--skip-javascript</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips the generation of JavaScript files and dependencies.<br><br><b>--skip-sprockets</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Sprockets, the asset pipeline.<br><br><b>-T, --skip-turbolinks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips Turbolinks, which speeds up page navigation.<br><br><b>-m, --template=<I>PATH</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom application template file to be applied after the application is generated, allowing for highly customized setups.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrites existing files if the target directory already exists. Use with caution.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the Rails version.<br><br>


title: DESCRIPTION
content:
The <b><I>rails new</I></b> command is the foundational tool for initiating a new Ruby on Rails web application. It automates the setup of a complete Rails project directory, including essential subdirectories like <I>app/</I>, <I>config/</I>, <I>db/</I>, <I>lib/</I>, <I>public/</I>, and <I>test/</I>. The command generates a boilerplate structure with all necessary configuration files, default database settings (typically SQLite), and initial application code, adhering to Rails' convention over configuration philosophy. This command saves significant time by providing a ready-to-run skeleton, allowing developers to immediately begin building features without manual setup. It also installs default gem dependencies, ensuring the application is functional out-of-the-box. Developers can customize the generated application using various options to tailor it to specific needs, such as choosing a different database, skipping certain components, or integrating specific front-end tools.


title: CAVEATS
content:
Creating a new Rails application with <b><I>rails new</I></b> requires a pre-existing Ruby environment with RubyGems installed. The command can take several minutes to complete, especially if <I>bundle install</I> is run, as it downloads and installs all necessary gem dependencies. If the specified <I>APP_PATH</I> directory already exists and is not empty, the command will typically fail unless the <I>--force</I> option is used, which will overwrite existing files. It's crucial to be aware of the Rails version being used, as available options and default behaviors can change between major releases.


title: DEFAULT APPLICATION STRUCTURE
content:
When <b><I>rails new</I></b> creates an application, it establishes a well-defined directory structure:<br><b><I>app/</I></b>: Contains the core application code (models, views, controllers, helpers, assets).<br><b><I>bin/</I></b>: Executable scripts like <I>rails</I> itself and <I>bundle</I>.<br><b><I>config/</I></b>: Application configuration files (e.g., database, routes, environments).<br><b><I>db/</I></b>: Database schema and migrations.<br><b><I>lib/</I></b>: Custom libraries and modules.<br><b><I>log/</I></b>: Application log files.<br><b><I>public/</I></b>: Static assets accessible directly by the web server.<br><b><I>test/</I></b>: Unit, integration, and functional tests.<br><b><I>tmp/</I></b>: Temporary files.<br>This structure enforces conventions that promote organization and understandability.


title: CUSTOMIZATION WITH TEMPLATES
content:
One powerful feature of <b><I>rails new</I></b> is its support for application templates via the <b><I>--template</I></b> (or <b><I>-m</I></b>) option. A template is a Ruby script that can automate additional setup steps after the basic application is generated. This can include adding specific gems, configuring test frameworks, setting up initial data, or even generating custom code. Templates are invaluable for standardizing application setups across an organization or for quickly bootstrapping projects with specific tech stacks.


title: HISTORY
content:
The <b><I>rails new</I></b> command has been a cornerstone of the Ruby on Rails framework since its early days, shortly after David Heinemeier Hansson open-sourced it in 2004. Initially, it was a simple script to scaffold a basic MVC structure. Over time, as Rails evolved and incorporated new features like Action Cable, Action Text, and integrated JavaScript tooling, the <b><I>rails new</I></b> command itself was updated to include options for these features and to manage the default setup. Its continuous evolution reflects the framework's commitment to providing a productive and modern development environment, always aiming to provide a solid, opinionated starting point while offering flexibility through numerous customization flags.


title: PARAMETERS
content:
<b><B>--help</B>, <B>-h</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message outlining available options and usage.<br><br><b><B>--grep</B>=<I>PATTERN</I>, <B>-g</B>=<I>PATTERN</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters the displayed routes by a given <I>PATTERN</I>. The pattern can match the route's prefix, verb, URI pattern, or controller#action.<br><br><b><B>-E</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When used with <B>--grep</B>, treats the provided <I>PATTERN</I> as a regular expression, allowing for more powerful filtering.<br><br><b><B>--expanded</B>, <B>-x</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs each route's information on separate lines, providing a more detailed and readable view for complex routes.<br><br><b><B>--json</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the routes in JSON format, useful for programmatic parsing or integration with other tools.<br><br><b><B>--controller</B>=<I>CONTROLLER</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters routes to only show those handled by a specific <I>CONTROLLER</I> (e.g., <I>UsersController</I>).<br><br>


title: DESCRIPTION
content:
The <I>rails routes</I> command displays a comprehensive list of all defined routes within a Ruby on Rails application. This includes the HTTP verb (GET, POST, PUT, DELETE, PATCH), the URI pattern, the corresponding controller action, and the route's helper name (prefix). It is an indispensable tool for debugging routing issues, understanding the application's URL structure, and verifying that routes are correctly defined and mapped.<br><br>The command is typically executed from the root directory of a Rails application, leveraging its configuration to present the current routing table. It helps developers quickly ascertain how incoming requests are dispatched to specific parts of their application.


title: CAVEATS
content:
The <I>rails routes</I> command must be executed within the root directory of a valid Ruby on Rails application. It requires Ruby and the Rails framework to be installed in the environment. The output reflects only the routes defined in the application's <I>config/routes.rb</I> file and does not validate their accessibility or the existence of corresponding controller actions (unless <B>--unused</B> is specifically requested).


title: OUTPUT COLUMNS
content:
The default output of <I>rails routes</I> typically presents routes in four columns:<br>1. <B>Prefix</B>: The helper method name used to generate URLs for the route.<br>2. <B>Verb</B>: The HTTP method(s) (e.g., GET, POST) that the route responds to.<br>3. <B>URI Pattern</B>: The path that matches the route, potentially including dynamic segments.<br>4. <B>Controller#Action</B>: The controller and action method that handles requests matching this route.


title: ROUTE ORDER
content:
In Rails, the order in which routes are defined in <I>config/routes.rb</I> is significant. Rails matches incoming requests against routes in the order they appear. More specific routes should generally be defined before more generic ones to ensure they are matched correctly.


title: HISTORY
content:
The ability to inspect application routes has been a core feature of Ruby on Rails since its early days. Initially available as a Rake task called <I>rake routes</I>, it was later integrated directly into the <I>rails</I> command-line interface (CLI) as <I>rails routes</I> around Rails 4.0. This unification streamlined the developer workflow by consolidating many common tasks under the primary <I>rails</I> executable.


title: SYNOPSIS
content:
<b>rails server</b> [<i>options</i>]<br><b>rails s</b> [<i>options</i>]<br><i>Starts the Rails application server.</i>


title: PARAMETERS
content:
<b><b>-p</b>, <b>--port=PORT</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the port the server will listen on. Default is 3000.<br><br><b><b>-b</b>, <b>--binding=IP</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the IP address the server will bind to. Default is 0.0.0.0 (all interfaces).<br><br><b><b>-e</b>, <b>--environment=ENVIRONMENT</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the Rails environment (e.g., development, test, production). Default is 'development'.<br><br><b><b>-d</b>, <b>--daemon</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the server as a daemon in the background.<br><br><b><b>-P</b>, <b>--pid=PIDFILE</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the PID file path. Useful with <b>--daemon</b>. Default is <i>tmp/pids/server.pid</i>.<br><br><b><b>-C</b>, <b>--config=FILE</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the server configuration file (e.g., for Puma, <i>config/puma.rb</i>).<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a list of available options and their descriptions.<br><br>


title: DESCRIPTION
content:
The <b>rails server</b> command is a fundamental tool for Ruby on Rails developers, used to launch a local web server that serves the Rails application over HTTP. It allows developers to view and interact with their application in a web browser during development. By default, it typically uses the Puma web server (though older Rails versions used WEBrick or Thin). When executed within a Rails project directory, it reads the application's configuration and code, making it accessible usually at <i>http://localhost:3000</i>. This command monitors changes to application files (in development mode), often reloading parts of the application automatically, streamlining the development feedback loop. While essential for development, <b>rails server</b> is generally not recommended for production environments, which typically require more robust, performance-oriented, and scalable server setups like Nginx/Puma or Passenger deployments.


title: CAVEATS
content:
Not suitable for production deployments directly; dedicated web servers like Nginx/Apache combined with application servers (Puma, Passenger, Unicorn) are preferred for performance and stability.<br>Requires being executed within the root directory of a Ruby on Rails application.<br>In development mode, server restarts or reloads may be necessary for some code changes (e.g., initializer changes), though many changes are picked up automatically by tools like <i>spring</i> or <i>zeitwerk</i>.


title: STOPPING THE SERVER
content:
To stop a server running in the foreground, press <code>Ctrl+C</code> in the terminal. If the server is running as a daemon (using <b>-d</b>), you'll need to kill the process using the PID found in the specified PID file (e.g., <code>kill $(cat tmp/pids/server.pid)</code>).


title: DEFAULT ACCESS
content:
By default, the application will be accessible via a web browser at <i>http://localhost:3000</i>. You can change the port and binding address using the respective command-line options.


title: LOG OUTPUT
content:
The server outputs logs directly to the terminal, including HTTP requests, database queries, and application-specific messages. These logs are also written to files within the <i>log/</i> directory (e.g., <i>log/development.log</i>).


title: HISTORY
content:
The <b>rails server</b> command has evolved from its origins as <i>script/server</i> in early versions of Ruby on Rails (pre-Rails 3.0). This change unified many common development tasks under the single <b>rails</b> executable, improving consistency and ease of use. Initially, WEBrick was the default server. Over time, as Rails applications grew in complexity and performance demands, more robust and performant servers like Thin, Unicorn, and eventually Puma gained popularity. Puma became the default web server for new Rails applications starting with Rails 5. The command's core function has remained consistent: providing a convenient way to run the Rails application locally for development and testing purposes.


title: SEE ALSO
content:
rails(1): The main Ruby on Rails command-line interface., rails console(1): Starts the Rails interactive console., rails generate(1): Generates new Rails application components., puma(1): The default web server often used by <b>rails server</b>.


title: SYNOPSIS
content:
Not applicable as a standard Linux command. <br>Syntax would depend entirely on its specific implementation if it is a custom script or part of a particular software.


title: DESCRIPTION
content:
The <i>'railway'</i> command does not appear to be a standard or widely recognized utility available in most Linux distributions. <br>Typically, Linux commands have associated manual pages (e.g., <b>man ls</b>) that detail their function, syntax, and options. No such entry exists for <i>'railway'</i> in common system directories. <br>It is possible that <i>'railway'</i> refers to a custom-made script, an alias configured by a user, or a component of a specific, less common software package or cloud platform (like Railway.app). <br>Without further context or clarification, a detailed analysis of its functionalities, parameters, and historical development as a Linux command-line utility cannot be provided.


title: CAVEATS
content:
This analysis is based on the premise that <i>'railway'</i> is a standard Linux command-line utility. As it is not universally recognized, the information provided reflects this lack of standardization rather than describing a specific command's features. <br>Any functionality associated with <i>'railway'</i> would be specific to its custom implementation or the software package it belongs to.


title: VERIFICATION REQUIRED
content:
Please verify the exact command name and its source. If <i>'railway'</i> is part of a specific software installation (e.g., a specific framework's CLI or a cloud platform's client), its documentation should be consulted for accurate details.


title: POSSIBLE MISINTERPRETATION
content:
It might be a typographical error, or confusion with other tools or concepts that share a similar name (e.g., 'rails' for Ruby on Rails, or the Railway.app cloud deployment platform).


title: HISTORY
content:
There is no documented history for <i>'railway'</i> as a standard or core Linux command. <br>Its usage and development would be entirely confined to any custom or niche applications where this name might be adopted.


title: SYNOPSIS
content:
<b>rain</b> [OPTIONS]<br><br>While <b>rain</b> is not a standard command, its common implementations often follow a similar invocation pattern, allowing for customization through various options.


title: PARAMETERS
content:
<b>-s, --speed <milliseconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the animation speed, typically in milliseconds per frame. A lower value means faster rain.<br><br><b>-c, --color <color_code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <I>color</I> of the raindrops, often using ANSI color codes or named colors like 'green', 'blue', etc.<br><br><b>-C, --char <character></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>character</I> used to represent individual raindrops, e.g., '|', ':', '.', etc.<br><br><b>--no-clear</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the screen from being cleared at startup, allowing rain to appear over existing terminal content.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief <I>help message</I> and usage information for the command.<br><br>


title: DESCRIPTION
content:
The <b>rain</b> command typically provides a captivating visual effect, simulating <I>falling rain</I> directly within the terminal.<br>Unlike standard utility commands, <b>rain</b> is usually a non-standard script or a small program, often written in <I>Bash</I> or <I>C</I>, leveraging <B>ANSI escape codes</B> to manipulate cursor position and character output. Its primary purpose is aesthetic, offering a relaxing or entertaining backdrop to a command-line interface. It's a popular choice among users looking to personalize their terminal environment or simply for a bit of visual flair.<br>The effect usually involves vertical lines or characters that appear to fall from the top of the terminal to the bottom, continuously clearing and redrawing to create the illusion of movement.


title: CAVEATS
content:
The <b>rain</b> command is <B>not a standard Linux utility</B> and its availability depends on specific installations or custom scripts. <br>Performance can vary; intensive animations might consume CPU resources, especially on older systems or with very high speeds.<br>Compatibility with all terminal emulators and configurations (e.g., font settings) is not guaranteed, and visual artifacts might occur.<br>Ensure you know how to terminate the command (usually <B>Ctrl+C</B>), as it often runs in an infinite loop.


title: USAGE NOTES
content:
Since <b>rain</b> is often a script, you might need to make it executable (e.g., <B>chmod +x rain.sh</B>) and place it in your <B>PATH</B> (e.g., <B>/usr/local/bin</B>) to run it simply as <b>rain</b>.<br>To stop the animation, press <B>Ctrl+C</B>.


title: CUSTOMIZATION
content:
Many <b>rain</b> scripts are easily modifiable by editing the source code directly, allowing users to fine-tune colors, characters, and animation logic beyond command-line options.


title: HISTORY
content:
The <b>rain</b> command does not have a formal standardized history like core Linux utilities. Instead, it represents a popular genre of <B>terminal entertainment programs</B> and scripts that emerged with the widespread use of Unix-like systems.<br>Typically, these implementations are hobby projects or examples demonstrating the power of <B>ANSI escape sequences</B> for terminal manipulation. They showcase how simple character output and cursor positioning can create complex visual effects.<br>Many variations exist across different programming languages and shell scripting environments, reflecting the creative freedom and community contributions prevalent in the open-source world.


title: SYNOPSIS
content:
<b>rainbowstream</b> [<i>options</i>]<br>To start the real-time stream: <b>rainbowstream</b><br>For help: <b>rainbowstream</b> --help


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b>-c CONFIG_FILE, --config=CONFIG_FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens a specified configuration file instead of the default one.<br><br><b>-i, --image</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables image rendering directly within the terminal. Requires external tools like <i>w3mimgdisplay</i> or <i>libcaca</i> to be installed.<br><br><b>-s, --stream-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the application in stream-only mode, meaning it will display the real-time stream without an interactive input prompt.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activates debug mode, showing verbose debug messages that can be useful for troubleshooting.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the program's version number and exits.<br><br>


title: DESCRIPTION
content:
<i>rainbowstream</i> is a powerful and colorful command-line interface (CLI) client for Twitter. Written in Python, it enables users to interact with Twitter directly from their terminal. Key features include a real-time tweet stream, allowing users to see tweets as they happen. It supports fundamental Twitter actions such as tweeting, replying, retweeting, and liking tweets. Users can also perform searches for tweets or look up specific user profiles. A distinctive aspect is its vibrant, customizable color output, enhancing readability and user experience in the terminal. It offers optional integration with external tools like <i>w3mimgdisplay</i> or <i>libcaca</i> for displaying images directly within the terminal, making it one of the most feature-rich CLI Twitter clients. <i>rainbowstream</i> is ideal for users who prefer working in a terminal environment and need quick, efficient access to their Twitter feed.


title: CAVEATS
content:
<b>API Changes:</b> Due to significant changes and restrictions in the Twitter (now X) API, <i>rainbowstream</i> may no longer function as expected or at all without updates to accommodate the new API access policies.<br><b>Dependencies:</b> Requires Python and <i>pip</i> for installation. Image rendering requires additional tools like <i>w3mimgdisplay</i> or <i>libcaca</i>.<br><b>Authentication:</b> Requires OAuth authentication with Twitter API keys, which is typically handled interactively on the first run.


title: INTERNAL COMMANDS
content:
Once <i>rainbowstream</i> is launched, it provides its own interactive prompt where users can execute various commands for Twitter interaction. Examples include: <b>t</b> (tweet), <b>r</b> (reply), <b>rt</b> (retweet), <b>s</b> (search), <b>li</b> (like), <b>unli</b> (unlike), <b>f</b> (follow), <b>u</b> (unfollow), <b>dm</b> (direct message), and <b>q</b> (quit/exit).


title: CONFIGURATION
content:
<i>rainbowstream</i> allows extensive customization through a configuration file (typically in <i>~/.rainbowstream</i>). Users can modify themes, key bindings, auto-completion, and other display settings to personalize their experience.


title: HISTORY
content:
Developed by Ora Karunakaran and first released around 2014-2015, <i>rainbowstream</i> quickly gained popularity as a feature-rich and visually appealing command-line Twitter client. Its development aimed to provide a comprehensive Twitter experience directly within the terminal, offering real-time streams and full interaction capabilities. Its continued functionality is heavily reliant on the evolving Twitter (X) API, which has undergone significant changes since its initial development.


title: PARAMETERS
content:
<b><I>-T</I>, <I>--tasks</I> [PATTERN]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the tasks (matching PATTERN if provided) with their descriptions.<br><br><b><I>-D</I>, <I>--describe</I> [PATTERN]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the tasks (matching PATTERN if provided) and their descriptions, even if they don't have descriptions.<br><br><b><I>-P</I>, <I>--prereqs</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the tasks and their prerequisites.<br><br><b><I>-t</I>, <I>--trace</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable full backtrace on errors and verbose output for debugging.<br><br><b><I>-f</I>, <I>--rakefile</I> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the specified <I>Rakefile</I> instead of the default <I>Rakefile</I> or <I>rakefile</I>.<br><br><b><I>-C</I>, <I>--rakelib</I> <I>DIR</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <I>DIR</I> to the Rake library search path. Can be specified multiple times.<br><br><b><I>-r</I>, <I>--require</I> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Require a Ruby file before executing the <I>Rakefile</I>.<br><br><b><I>-s</I>, <I>--silent</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all Rake messages (e.g., 'executing task...').<br><br><b><I>-v</I>, <I>--verbose</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Log message to standard output (verbose mode).<br><br><b><I>-V</I>, <I>--version</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the Rake version and exit.<br><br><b><I>-h</I>, <I>--help</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br>


title: DESCRIPTION
content:
<B>Rake</B> (Ruby Make) is a software task management and build automation tool written in Ruby. It's conceptually similar to the classic Unix <I>make</I> utility but leverages the full power and flexibility of the Ruby programming language. <br><br> <B>Rake</B> allows developers to define a set of tasks and their dependencies within a file typically named <I>Rakefile</I>. These tasks can be anything from compiling code, running tests, deploying applications, or cleaning up build artifacts. Because <I>Rakefiles</I> are pure Ruby code, they can execute any Ruby method or shell command, making them incredibly versatile for automating complex workflows. <br><br> It is widely used in the Ruby ecosystem, especially within Ruby on Rails projects, where it handles database migrations, asset precompilation, and many other common development and deployment tasks. <B>Rake</B> provides a clean, programmatic way to manage project-specific operations, offering a more expressive alternative to shell scripts for many build and automation needs.


title: CAVEATS
content:
Rake is written in Ruby and requires a Ruby environment to be installed and configured on your system. Its tasks are defined in <I>Rakefiles</I> which are Ruby scripts, meaning knowledge of Ruby is beneficial for defining or modifying tasks. While it runs on Linux, it's not a core system utility but rather an application commonly used in Ruby development.


title: RAKEFILES
content:
Rake tasks are defined in a file named <I>Rakefile</I> (or <I>rakefile</I>), located in the project's root directory. This file is essentially a Ruby script that uses Rake's DSL (Domain Specific Language) to define tasks, their dependencies, and the actions to be performed. Each task typically has a name and a block of Ruby code that gets executed when the task is invoked. For example, a task might run tests or compile assets.


title: TASKS
content:
A <B>Rake</B> task is a named operation that can be executed. Tasks can have prerequisites, meaning other tasks that must be completed before the current task can run. This dependency mechanism allows for complex workflows to be defined and managed. Tasks can also accept arguments, providing flexibility in their execution. To run a task, you simply type <I>rake [task_name]</I> in your terminal from the project's root directory.


title: HISTORY
content:
Rake was created by <B>Jim Weirich</B>, a prominent figure in the Ruby community, in 2003. It quickly became the standard build tool for Ruby projects, largely replacing shell scripts for complex build and automation tasks. Its integration with the Ruby on Rails framework solidified its widespread adoption, making it an indispensable tool for managing development and deployment workflows in the Ruby ecosystem.


title: PARAMETERS
content:
<b>None</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<code>rancid-cvs</code> is generally executed without specific command-line parameters by the <code>rancid-run</code> script or a cron job. It operates based on the RANCID environment and configuration files.<br><br>


title: DESCRIPTION
content:
<code>rancid-cvs</code> is an integral script within the <I>RANCID (Really Awesome New Cisco Idiosyncratic Deleter)</I> suite, designed for network device configuration management. Its primary function is to provide version control for collected network device configurations by committing them to a <I>Concurrent Versions System (CVS)</I> repository.<br><br>Typically invoked by `rancid-run` or directly via a cron job, <code>rancid-cvs</code> compares the newly collected device configurations with their previously stored versions. If changes are detected, new configurations are added or updated in the CVS repository. This process ensures that a historical record of all configuration changes is maintained, facilitating auditing, troubleshooting, and the ability to roll back to previous configurations if necessary. It processes all RANCID-managed groups, detecting new devices, removed devices, and changes in existing configurations, making it a critical component for tracking network infrastructure evolution.


title: CAVEATS
content:
["<b>CVS Dependency:<\/b> Requires a functional <I>CVS<\/I> server and client setup. If RANCID is configured for <I>Git<\/I>, <code>rancid-cvs<\/code> is not used; instead, <code>rancid-git<\/code> is utilized.","<b>Permissions:<\/b> Must be run with appropriate user permissions (typically the <code>rancid<\/code> user) to access configuration directories and the <I>CVS<\/I> repository.","<b>Repository Size:<\/b> Over time, the <I>CVS<\/I> repository can grow significantly, especially with frequent configuration changes across many devices, potentially impacting performance and storage.","<b>Legacy System:<\/b> <I>CVS<\/I> is considered a legacy version control system; modern RANCID deployments often prefer <I>Git<\/I> for its advanced features and wider adoption."]


title: DAILY OPERATION
content:
<code>rancid-cvs</code> is typically executed as part of a daily automated process, usually via a cron job, which first calls <code>rancid-run</code>. After <code>rancid-run</code> collects and processes device configurations, <code>rancid-cvs</code> handles the commit to the <I>CVS</I> repository, ensuring that all detected changes are versioned without manual intervention.


title: BENEFITS OF VERSION CONTROL
content:
By integrating with <I>CVS</I>, <code>rancid-cvs</code> enables several critical network operations capabilities. This includes the ability to easily audit who made what changes and when, compare current configurations with previous versions, and quickly revert a device's configuration to a known good state, significantly reducing downtime from erroneous changes.


title: HISTORY
content:
The <code>rancid-cvs</code> script is an original component of the <I>RANCID</I> (Really Awesome New Cisco Idiosyncratic Deleter) suite, which was first publicly released around 1999. In its early development, <I>CVS (Concurrent Versions System)</I> was the dominant version control system, making <code>rancid-cvs</code> a natural choice for managing configuration changes. While the RANCID project has evolved significantly over the years, introducing support for other version control systems like <I>Git</I> (via <code>rancid-git</code>), <code>rancid-cvs</code> has maintained its role for deployments specifically utilizing <I>CVS</I>. Its consistent functionality reflects the core purpose of RANCID: to provide robust version control and change tracking for network device configurations.


title: PARAMETERS
content:
<b><i>num</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the number of pseudo-random bytes to generate. If not provided, <b>openssl rand</b> will typically generate 1024 bytes by default or as configured.<br><br><b><b>-out</b> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the generated bytes to the specified <i>file</i> instead of standard output.<br><br><b><b>-base64</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes the generated bytes using Base64 before printing.<br><br><b><b>-hex</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes the generated bytes using hexadecimal format before printing. This is often used for human-readable output of short random strings.<br><br><b><b>-rand</b> <i>file(s)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more files to use for seeding the PRNG. Multiple files can be separated by <b>:</b> (colon). This is typically used to supplement the system's entropy sources.<br><br><b><b>-writerand</b> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes an updated random seed file to the specified <i>file</i>. This can be used to maintain a consistent state for the PRNG across invocations, though it's generally advised to rely on system entropy.<br><br><b><b>-engine</b> <i>id</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a particular OpenSSL engine to utilize for cryptographic operations, potentially including random number generation.<br><br>


title: DESCRIPTION
content:
The <b>openssl rand</b> command is a utility provided by the OpenSSL cryptographic toolkit. It is used to generate pseudo-random bytes suitable for cryptographic purposes. Unlike directly reading from <i>/dev/random</i> or <i>/dev/urandom</i>, <b>openssl rand</b> utilizes OpenSSL's internal cryptographically secure pseudo-random number generator (CSPRNG).<br><br>By default, the CSPRNG is seeded automatically from the operating system's entropy sources (like <i>/dev/urandom</i>). The generated bytes are printed to standard output unless an output file is specified. This command is crucial for applications requiring high-quality random data, such as generating cryptographic keys, nonces, salts, or any data where unpredictability is paramount for security.<br><br>The generated output can be formatted in various ways, including raw binary, hexadecimal, or Base64 encoding, making it versatile for different integration needs. Users should be aware that while cryptographically secure, the output is still pseudo-random and relies on a well-seeded and robust entropy source.


title: CAVEATS
content:
The command name <i>rand.1s</i> is non-standard. This analysis assumes the user refers to the common <b>openssl rand</b> utility, which is typically documented as <i>rand(1)</i> or <i>openssl-rand(1)</i>. The randomness quality is dependent on the underlying operating system's entropy sources and the proper seeding of OpenSSL's PRNG. Relying solely on user-provided seed files (via <b>-rand</b>) without sufficient entropy can compromise security.


title: CLARIFICATION ON 'RAND.1S'
content:
The suffix <i>.1s</i> is not a standard manual page section designator in Linux. Standard sections are <i>.1</i> for user commands, <i>.2</i> for system calls, etc. While <i>.s</i> might imply a shell script, a specific <i>rand.1s</i> entry is not universally found. This analysis proceeds under the assumption that the request refers to the widely used <b>openssl rand</b> command, which is typically documented under <i>rand(1)</i> or <i>openssl-rand(1)</i>.


title: DIFFERENCE FROM /DEV/RANDOM AND /DEV/URANDOM
content:
While <b>openssl rand</b> often uses <i>/dev/urandom</i> (or other OS-provided sources) as its initial seed, it then employs OpenSSL's own cryptographically secure pseudo-random number generator (CSPRNG) to produce subsequent random data. This contrasts with directly reading from <i>/dev/random</i> (which blocks if entropy is low) or <i>/dev/urandom</i> (which doesn't block but is theoretically less secure if the initial seed is compromised, though this is rarely an issue in practice for most use cases). OpenSSL's CSPRNG aims to provide a consistent, high-quality stream of pseudo-random data independent of direct, continuous entropy consumption.


title: HISTORY
content:
The <b>openssl rand</b> command is an integral part of the OpenSSL project, a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. OpenSSL has been under continuous development since the late 1990s, evolving to meet modern cryptographic standards and security requirements. The <b>rand</b> utility has been a core component, consistently providing a reliable way to generate cryptographically secure random data within the OpenSSL ecosystem, reflecting the project's long-standing commitment to secure communication and data handling.


title: SYNOPSIS
content:
The 'random' functionality is not a command in itself but rather a special device file accessed by other utilities. To read from the random devices:<br><br><b>cat /dev/random</b><br><b>head -c <i>N</i> /dev/urandom</b><br><b>dd if=/dev/urandom of=<i>output_file</i> bs=1 count=<i>N</i></b><br><br>The data read is raw binary random bytes.


title: DESCRIPTION
content:
The term 'random' in Linux typically refers to the special character device files, <b>/dev/random</b> and <b>/dev/urandom</b>. These devices serve as the operating system's primary source for high-quality, cryptographically secure pseudo-random numbers (CSPRNGs). They achieve this by collecting 'entropy' from various unpredictable hardware events, such as keyboard timings, mouse movements, disk I/O, and interrupt timings. The kernel maintains an entropy pool from these sources.<br><br><b>/dev/random</b> is designed to provide true randomness. It blocks (pauses) when its internal entropy pool is depleted, ensuring that all numbers generated are derived from sufficient entropy. This makes it ideal for highly sensitive cryptographic keys or one-time pads where true unpredictability is paramount.<br><br>In contrast, <b>/dev/urandom</b> (unlimited random) does not block. If the entropy pool is low, it reuses the existing pool, generating numbers from a cryptographically secure pseudo-random number generator that is continuously reseeded from the entropy pool. While theoretically less 'random' if the initial seed is compromised, for almost all practical applications, including SSL/TLS, GPG, and UUID generation, <b>/dev/urandom</b> provides sufficient cryptographic strength and is generally preferred due to its non-blocking nature and higher throughput.


title: CAVEATS
content:
<b>/dev/random</b> can block indefinitely if entropy is low, potentially causing applications to hang. This is common in headless servers, virtual machines, or during early boot.<br>While <b>/dev/urandom</b> does not block, its security relies on a sufficiently seeded entropy pool. Though extremely rare, a compromised initial seed or a flawed PRNG could theoretically weaken its output (though in practice, for Linux, it's considered cryptographically robust for nearly all uses).<br>Insufficient entropy can lead to delays in cryptographic operations, key generation, and system startup.


title: ENTROPY POOL AND MANAGEMENT
content:
The kernel maintains an 'entropy pool' filled by unpredictable hardware events. The quality and quantity of this entropy are crucial for the security of generated numbers. The available entropy can be monitored via <b>/proc/sys/kernel/random/entropy_avail</b>. Daemons like <b>rngd</b> or <b>haveged</b> can be used to feed additional entropy from dedicated hardware random number generators (TRNGs) or other sources into the kernel's pool, especially useful for systems with low natural entropy.


title: THE RANDOM SHELL VARIABLE
content:
In some shell environments, such as Bash, there is a special shell variable named <b>$RANDOM</b>. When referenced, it expands to a pseudo-random integer between 0 and 32767. This variable's randomness is generally suitable for shell scripting tasks where cryptographic security is not required, as its generator is typically less robust than the kernel's <b>/dev/urandom</b>.


title: HISTORY
content:
The Linux kernel's random number generator was developed by Theodore Ts'o and introduced in Linux 1.3.30 in 1995, aiming to provide a high-quality, cryptographically secure source of randomness within the kernel. Before this, systems often relied on less secure or ad-hoc methods for generating random numbers. The distinction between <b>/dev/random</b> (blocking, true randomness) and <b>/dev/urandom</b> (non-blocking, pseudo-random) was established early on to balance security needs with performance. In later kernels (Linux 3.17, 2014), the <b>getrandom(2)</b> system call was introduced as a modern, unified interface to access random data, combining the best aspects of both devices and providing flags for blocking behavior.


title: PARAMETERS
content:
<b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show program's version number and exit.<br><br><b>--select-file=<filename></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select the specified file at startup.<br><br><b>--choosefile=<filename></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write the path of the chosen file to <i>filename</i> and exit.<br><br><b>--choosedir=<dirname></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write the path of the chosen directory to <i>dirname</i> and exit.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable debug mode, showing additional information.<br><br><b>--disable-config</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not load any configuration files.<br><br><b>--copy-config={all|rc|rifle|scope|commands|mimetypes}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copy default configuration files to the config directory.<br><br><b>--list-tagged-files</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List files that have been tagged by <i>ranger</i>.<br><br>


title: DESCRIPTION
content:
<i>ranger</i> is a free and open-source console file manager with a curses-based interface. It features a multi-pane layout, similar to a column browser, providing an overview of the directory hierarchy. Its design emphasizes speed and efficiency, making it a popular choice for users who prefer working in the terminal.<br><br>A key characteristic of <i>ranger</i> is its intuitive, VI-inspired key bindings for navigation and file operations. It offers a powerful file preview system that can display images, videos, archives, and text files directly within the terminal (requires external tools). It also supports various file operations like copying, moving, deleting, and creating files and directories, as well as file tagging and custom commands through its Python-based extensibility.


title: CAVEATS
content:
Performance may degrade in directories containing an extremely large number of files or when previewing very large media files without optimized external previewers. Terminal emulator capabilities and font support can affect the visual rendering of file previews and icons. Extensive customization requires familiarity with Python.


title: KEY BINDINGS AND EXTENSIBILITY
content:
<i>ranger</i> leverages a <b>VI-like command mode</b> for efficient navigation and manipulation of files, allowing users to perform complex actions with minimal keystrokes. Its functionality is highly extensible through <b>Python plugins and scripts</b>, enabling users to add custom commands, define new file previewers, and integrate with other tools. Configuration files (e.g., <i>rc.conf</i>, <i>rifle.conf</i>, <i>scope.sh</i>) are also written in Python or shell script, offering powerful customization options.


title: HISTORY
content:
<i>ranger</i> was created by <b>Roman Zimbelmann</b> and first released around 2009. Its development was driven by the desire for a fast, powerful, and keyboard-centric file manager for the command line, inspired by the efficiency of Vim and the visual layout of column browsers. It quickly gained popularity among terminal enthusiasts for its innovative features and customizable nature.


title: PARAMETERS
content:
<b>-n &lt;number&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Output the top <i>&lt;number&gt;</i> of mirrors after ranking.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Enable verbose output, displaying detailed progress of mirror tests.<br><br><b>-p &lt;protocols&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Only test mirrors using the specified comma-separated <i>&lt;protocols&gt;</i> (e.g., http,https).<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Reverse the sort order, listing the slowest mirrors first.<br><br><b>-t &lt;seconds&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Set the connection timeout for each mirror test to <i>&lt;seconds&gt;</i>.<br><br><b>-o &lt;file&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Write the ranked mirrorlist to <i>&lt;file&gt;</i> instead of standard output.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Display help message and exit.<br><br>


title: DESCRIPTION
content:
<br>The <i>rankmirrors</i> command is a crucial utility primarily used within the <br>Arch Linux ecosystem, specifically alongside its Pacman package manager. <br>Its core function is to intelligently evaluate and sort the mirrors listed <br>in a system's mirrorlist file based on their current connection speed and <br>responsiveness. By performing network tests to each specified mirror, <br><i>rankmirrors</i> can determine which servers offer the fastest download <br>speeds at a given time. The output is a new, reordered mirrorlist, <br>typically written to standard output, which can then be used to update <br>the system's active mirror configuration. This process is vital for <br>Arch Linux users as it ensures that package downloads, system updates, <br>and software installations are sourced from the most efficient servers, <br>thereby significantly reducing download times and improving the overall <br>efficiency and reliability of package management operations. <br>It helps maintain an optimized and responsive Arch Linux installation.


title: CAVEATS
content:
<br><i>rankmirrors</i> relies on active network connectivity and mirror availability during its execution. <br>Temporary network issues or mirror outages can significantly affect the ranking results. <br>It is specifically designed for the Arch Linux mirrorlist format and may not be compatible <br>with mirror configurations used by other Linux distributions. <br>The actual download speed experienced by the user may still vary due to factors <br>beyond the command's testing scope, such as local network conditions or server load.


title: <BR>COMMON USAGE EXAMPLE
content:
<br>To rank the default mirrorlist, output the top 5 fastest HTTPS mirrors, <br>and save them to a new file named <i>/etc/pacman.d/mirrorlist.new</i>:<br><code>rankmirrors -n 5 -p https /etc/pacman.d/mirrorlist > /etc/pacman.d/mirrorlist.new</code><br><br>After reviewing the content of the <i>.new</i> file, <br>it can be moved to replace the active mirrorlist:<br><code>mv /etc/pacman.d/mirrorlist.new /etc/pacman.d/mirrorlist</code>


title: HISTORY
content:
<br><i>rankmirrors</i> is an integral component of the <br><i>pacman-contrib</i> package, <br>a collection of supplementary utilities for Arch Linux's Pacman package manager. <br>Its development has consistently been driven by the Arch Linux community's need <br>to efficiently manage and optimize package download sources. <br>It emerged as an automation tool to streamline the process of identifying the fastest mirrors, <br>a task that was historically performed manually or via basic scripts.


title: DESCRIPTION
content:
<i>ranlib</i> is a utility used to create or update an index in an archive (static library) file. Static libraries, typically with a <i>.a</i> extension, are collections of object files (<i>.o</i>) that the linker can use to resolve external symbol references. The index generated by <i>ranlib</i> is a table of contents within the archive that lists the global symbols defined by the object files it contains. When the linker (<i>ld</i>) needs to find a symbol, it can consult this index to quickly locate the relevant object file within the library, significantly speeding up the linking process for large libraries. Without an index, the linker would have to scan every object file in the archive sequentially, which can be inefficient. On most Linux systems, <i>ranlib</i> is commonly a hard link to the <i>ar</i> (archiver) command, specifically executing the equivalent of <i>ar -s</i> (create a symbol table) or <i>ar -ts</i> (list and create symbol table). Therefore, its primary function is to ensure that a static library is properly indexed for efficient linking.


title: CAVEATS
content:
<i>ranlib</i>'s behavior is highly dependent on the underlying <i>ar</i> implementation. On GNU/Linux systems, it's typically a hard link to <i>ar</i> and behaves as <i>ar -s</i>. This means it accepts archive files as arguments but no specific <i>ranlib</i> options.<br><br>The <i>ranlib</i> command does not modify the object files themselves; it only adds or updates a symbol table within the archive file.<br><br>For archives that contain object files compiled for different architectures (e.g., in cross-compilation environments), it's crucial to use the <i>ranlib</i> (or <i>ar</i>) from the correct toolchain to ensure the index is generated correctly for the target architecture.


title: IMPACT ON LINKING
content:
An indexed static library significantly speeds up the linking process. Without an index, the linker would need to perform a linear scan of all object files within the archive to resolve symbol dependencies. For large libraries, this can be extremely time-consuming. <i>ranlib</i> creates a lookup table, allowing the linker to directly jump to the relevant object file.


title: IDEMPOTENCY
content:
Running <i>ranlib</i> multiple times on the same archive is generally safe and idempotent. If an index already exists, <i>ranlib</i> will update it; if it doesn't, it will create it. It does not corrupt existing data or unnecessarily bloat the archive.


title: HISTORY
content:
The concept of indexing archive files for faster linking has existed since the early days of Unix. <i>ranlib</i> emerged as a dedicated utility to perform this indexing operation, simplifying the command for users. While its core function remains consistent, its implementation has evolved. On many modern systems, particularly those using GNU binutils, <i>ranlib</i> is no longer a separate executable but rather a symbolic or hard link to the <i>ar</i> command, which then executes its internal <i>s</i> (symbol table) function when invoked as <i>ranlib</i>. This consolidation streamlines maintenance and ensures consistency between <i>ar</i> and <i>ranlib</i>'s indexing capabilities.


title: SYNOPSIS
content:
<b>rapper</b> [<i>OPTIONS</i>] <i>FILE</i> [<i>BASE_URI</i>]<br><i>FILE</i> can be '-' to read from standard input.


title: PARAMETERS
content:
<b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a summary of command-line options.<br><br><b>--version, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the <b>rapper</b> program version.<br><br><b>--input <I>FORMAT</I>, -i <I>FORMAT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the input RDF syntax format (e.g., <i>rdfxml</i>, <i>turtle</i>, <i>n3</i>, <i>ntriples</i>, <i>json</i>, <i>guess</i>).<br><br><b>--output <I>FORMAT</I>, -o <I>FORMAT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output RDF syntax format (e.g., <i>rdfxml</i>, <i>turtle</i>, <i>n3</i>, <i>ntriples</i>, <i>json</i>, <i>dot</i>, <i>html</i>).<br><br><b>--count, -c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Count and print the number of triples parsed.<br><br><b>--generate-bnode-ids, -g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate new blank node IDs during parsing.<br><br><b>--debug, -d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print debugging information for diagnostics.<br><br><b>--quiet, -q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress informational messages.<br><br><b>--warn, -w</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print warning messages if issues are encountered.<br><br><b>--rdfs-rules, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply RDFS inference rules to the parsed graph.<br><br><b>--model <I>MODEL</I>, -m <I>MODEL</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load RDF into a specific model type (e.g., <i>memory</i>, <i>file</i>, <i>sqlite</i>).<br><br><b>--namespaces, -N</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the namespaces defined in the input.<br><br><b>--lax, -L</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Relax parsing rules, attempting to recover from errors.<br><br><b>--input-uri <I>URI</I>, -I <I>URI</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the base URI for resolving relative URIs in the input.<br><br><b>--output-uri <I>URI</I>, -O <I>URI</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the base URI for resolving relative URIs in the output.<br><br><b>--canonical, -C</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate canonical output, typically N-Triples for unambiguous representation.<br><br><b>--allow-no-file, -a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allow <b>rapper</b> to operate without a specified input file, reading from stdin.<br><br><b>--error-messages-to-stderr, -e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Direct error messages to standard error (default).<br><br><b>--sink-to-stdout, -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Direct parsed triples output to standard output (default).<br><br><b>--parser-feature <I>FEATURE=VALUE</I>, -P <I>FEATURE=VALUE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a specific parser feature with a value.<br><br><b>--serializer-feature <I>FEATURE=VALUE</I>, -S <I>FEATURE=VALUE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a specific serializer feature with a value.<br><br><b>--xml-declaration, -x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include an XML declaration in XML-based output formats.<br><br>


title: DESCRIPTION
content:
<b>rapper</b> is a versatile command-line utility used for parsing and serializing RDF (Resource Description Framework) data. It's a key component of the Redland RDF library, providing functionality to convert RDF data between various formats. Users can specify both input and output formats, making it invaluable for data interoperability and transformation tasks.<br><br>Beyond simple conversion, <b>rapper</b> offers features for syntax checking, counting triples, applying RDFS inference rules, and debugging. It supports a wide array of RDF syntaxes, including RDF/XML, Turtle, N-Triples, N3, JSON-LD, and more, enabling seamless integration with diverse RDF datasets. This tool is essential for developers and data architects working with semantic web technologies and linked data principles.


title: CAVEATS
content:
Support for all possible RDF format variations and extensions may not be exhaustive, and malformed input can lead to parsing errors. Inference capabilities with <i>--rdfs-rules</i> are limited to RDFS and not full OWL.


title: INPUT/OUTPUT HANDLING
content:
By default, <b>rapper</b> reads RDF from the specified <i>FILE</i> argument. If <i>FILE</i> is set to '-', it reads from standard input (<i>stdin</i>). Parsed and serialized output is sent to standard output (<i>stdout</i>), which can be redirected to a file or piped to another command. This allows for flexible integration into shell scripts and data processing pipelines.


title: SUPPORTED FORMATS
content:
<b>rapper</b> supports a wide array of RDF serialization formats for both input and output. Common input formats include <i>rdfxml</i>, <i>n3</i>, <i>turtle</i>, <i>ntriples</i>, <i>json</i> (for JSON-LD), <i>atom</i>, and <i>rss-1.0</i>. Output formats similarly cover <i>rdfxml</i>, <i>n3</i>, <i>turtle</i>, <i>ntriples</i>, <i>json</i>, <i>dot</i> (for Graphviz), and <i>html</i>. The <i>guess</i> format can be used for input to automatically detect the format based on content and file extension.


title: HISTORY
content:
<b>rapper</b> is part of the <i>Redland RDF Application Framework</i>, developed primarily by <i>Dave Beckett</i> since 2000. It serves as a foundational command-line utility for interacting with RDF data, leveraging the underlying <i>Raptor RDF Parser Library</i> and <i>Rasqal RDF Query Library</i> (both also part of Redland). Its development has tracked the evolution of RDF standards, offering a robust and flexible tool for RDF data manipulation and transformation within the Semantic Web ecosystem.


title: SYNOPSIS
content:
<br><b>rar</b> <I>&lt;command&gt;</I> <I>[-switch1] [-switch2] ...</I> <I>&lt;archive_name&gt;</I> <I>[&lt;files...&gt; | &lt;@listfiles...&gt;]</I> <I>[&lt;destination_path&gt;]</I><br><br>Common commands:<br><b>rar a</b> <I>&lt;archive_name&gt;</I> <I>&lt;files...&gt;</I> <I>(add files to archive)</I><br><b>rar x</b> <I>&lt;archive_name&gt;</I> <I>[&lt;destination_path&gt;]</I> <I>(extract files with full paths)</I><br><b>rar e</b> <I>&lt;archive_name&gt;</I> <I>[&lt;destination_path&gt;]</I> <I>(extract files to current directory)</I><br><b>rar l</b> <I>&lt;archive_name&gt;</I> <I>(list contents of archive)</I><br><b>rar t</b> <I>&lt;archive_name&gt;</I> <I>(test archive integrity)</I>


title: PARAMETERS
content:
<b>a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds files to an archive. If the archive does not exist, it will be created.<br><br><b>x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts files from an archive, recreating their full directory paths.<br><br><b>e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts files from an archive to the current directory, ignoring original paths.<br><br><b>l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists the contents of an archive without extracting them.<br><br><b>t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Tests the integrity of the archive files.<br><br><b>-ad</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Appends the archive name to the destination path during extraction.<br><br><b>-ap<path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a path prefix inside the archive for files being added or extracted.<br><br><b>-ep1</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes the base directory from file names when archiving or extracting.<br><br><b>-hp<password></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encrypts both file data and file headers using the specified <I>password</I>.<br><br><b>-idp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the percentage indicator during operations.<br><br><b>-m<0-5></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the compression method, where 0 is 'store' (no compression) and 5 is 'best' compression.<br><br><b>-o+</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the overwrite mode to 'overwrite all existing files' during extraction.<br><br><b>-o-</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the overwrite mode to 'do not overwrite existing files' during extraction.<br><br><b>-p<password></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encrypts file data using the specified <I>password</I>.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recurses subdirectories when archiving files.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a solid archive, which can improve compression for many small files.<br><br><b>-sfx</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a self-extracting archive (SFX) that can be run directly to extract its contents.<br><br><b>-v<size></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates multi-volume archives, splitting them into parts of the specified <I>size</I> (e.g., '100m', '4g').<br><br><b>-x<file|@list></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes specified files or files listed in a file from the operation.<br><br><b>-y</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assumes 'Yes' to all queries, useful for non-interactive operations.<br><br>


title: DESCRIPTION
content:
The <I>rar</I> command-line utility is the official tool for managing files in the proprietary RAR archive format. While it can create, modify, and list RAR archives, its primary use on Linux systems is often for extracting content from existing RAR files, which are frequently encountered due to their popularity on Windows platforms and for data distribution. Unlike many standard Linux archiving tools like <I>tar</I> or <I>zip</I>, <I>rar</I> is not open-source; the full version for creating archives is commercial trialware. For simple extraction, the <I>unrar</I> utility (often distributed separately or as a free component) is commonly used and often preferred as it's freely redistributable for extraction purposes.<br><br>RAR archives are known for their strong compression, especially with solid archiving, and support features like encryption, recovery records, and multi-volume archives.


title: CAVEATS
content:
The <I>rar</I> archive format and the <I>rar</I> utility are proprietary software developed by RARLAB. While <I>rar</I> itself is often available for download on Linux, its full functionality for creating archives typically requires a commercial license after a trial period. For simple extraction of RAR archives, the open-source <I>unrar</I> utility is often preferred on Linux as it is freely redistributable and widely available in package repositories, though it generally cannot create new RAR archives. The proprietary nature means that the format specifications are not openly published, potentially limiting interoperability and long-term archival stability compared to open formats.


title: COMMON USE CASES
content:
While <I>rar</I> can be used for creation, its most frequent use on Linux is to extract files from RAR archives downloaded from other sources, often created on Windows. The commands `<b>rar x <I>archive.rar</I></b>` or `<b>rar e <I>archive.rar</I></b>` are the most common operations for users.


title: LICENSING AND AVAILABILITY
content:
The <I>rar</I> executable is not typically included in standard Linux distributions' repositories due to its proprietary license. Users usually need to download it directly from the RARLAB website or through third-party repositories. The <I>unrar</I> utility, however, is almost universally available in distribution repositories.


title: HISTORY
content:
The RAR format and its associated tools were created by <I>Eugene Roshal</I> in 1993, with the name RAR standing for "Roshal ARchive". It quickly gained popularity on Windows platforms due to its strong compression ratios and features like multi-volume archives and recovery records, often outperforming ZIP in certain scenarios. While Windows users commonly interact with WinRAR, the command-line <I>rar</I> utility has been available for various platforms, including Linux, since its early days. Its proprietary nature and commercial licensing model for creation have led to the development and widespread adoption of the freely redistributable <I>unrar</I> utility for extraction purposes on open-source operating systems like Linux, where open formats and tools are generally preferred.


title: SYNOPSIS
content:
<i>rarcrack</i> <i>&lt;archive.rar&gt;</i> [<i>options</i>]<br><br>Examples:<br><i>rarcrack</i> <i>archive.rar</i> <i>--letters</i> <i>--numbers</i> <i>--symbols</i> <i>--minlen=4</i> <i>--maxlen=8</i><br><i>rarcrack</i> <i>archive.rar</i> <i>--dictionary=wordlist.txt</i>


title: PARAMETERS
content:
<b><i>&lt;archive.rar&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the encrypted RAR archive file to be cracked.<br><br><b><b>-L</b>, <b>--letters</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes all lowercase and uppercase letters (a-z, A-Z) in the character set for brute-force attacks.<br><br><b><b>-N</b>, <b>--numbers</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes all numeric digits (0-9) in the character set for brute-force attacks.<br><br><b><b>-S</b>, <b>--symbols</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes common symbols (!@#$%^&amp;*()-_+=~`[]{}\|;:'",.&lt;&gt;/? ) in the character set for brute-force attacks.<br><br><b><b>-l</b> <i>&lt;length&gt;</i>, <b>--len=</b><i>&lt;length&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets both the minimum and maximum password length to a specific value.<br><br><b><b>-m</b> <i>&lt;length&gt;</i>, <b>--minlen=</b><i>&lt;length&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the minimum password length for brute-force attacks.<br><br><b><b>-M</b> <i>&lt;length&gt;</i>, <b>--maxlen=</b><i>&lt;length&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the maximum password length for brute-force attacks.<br><br><b><b>-f</b> <i>&lt;file&gt;</i>, <b>--charset-file=</b><i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a custom character set defined in the specified file for brute-force attacks. Each character on a new line.<br><br><b><b>-c</b> <i>&lt;name&gt;</i>, <b>--charset=</b><i>&lt;name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a predefined character set. Common names include <i>all</i>, <i>alpha</i>, <i>num</i>, <i>alnum</i>.<br><br><b><b>-d</b> <i>&lt;file&gt;</i>, <b>--dictionary=</b><i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a dictionary attack using the specified wordlist file. Each word on a new line.<br><br><b><b>-s</b> <i>&lt;password&gt;</i>, <b>--start-pass=</b><i>&lt;password&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the brute-force attack from a specific password, useful for resuming an interrupted attack.<br><br><b><b>-t</b> <i>&lt;num&gt;</i>, <b>--threads=</b><i>&lt;num&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the number of CPU threads to use for the cracking process, accelerating performance.<br><br><b><b>-H</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information and exits.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about the cracking progress.<br><br><b><b>-e</b> <i>&lt;delay&gt;</i>, <b>--delay=</b><i>&lt;delay&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a delay (in seconds) between password attempts, primarily useful in specific network or rate-limited scenarios.<br><br>


title: DESCRIPTION
content:
<i>rarcrack</i> is a command-line utility designed to recover lost or forgotten passwords for RAR archives. It primarily employs two common password cracking techniques: brute-force attacks and dictionary attacks.<br><br>In a <b>brute-force attack</b>, <i>rarcrack</i> systematically tries every possible combination of characters within a specified charset and length range until the correct password is found. This method is exhaustive but can be extremely time-consuming for complex or long passwords. For <b>dictionary attacks</b>, it attempts passwords from a provided list of common words or phrases, which is much faster if the password is included in the dictionary.<br><br>The tool supports multi-threading to speed up the cracking process and can often resume an attack from a previous state, making it suitable for long-running password recovery operations. Its simplicity and effectiveness make it a popular choice for recovering access to password-protected RAR files.


title: CAVEATS
content:
Cracking complex or long passwords can be an extremely time-consuming and CPU-intensive process, potentially taking days, weeks, or even years depending on available hardware and password strength. Success is not guaranteed, especially for strong, truly random passwords. Users should only employ <i>rarcrack</i> on files for which they have explicit permission or ownership, as unauthorized password cracking can have legal implications.


title: ATTACK MODES
content:
<i>rarcrack</i> supports two primary attack modes: <b>Brute-Force</b> and <b>Dictionary Attack</b>. Brute-force is exhaustive but slow, requiring character set and length definitions. Dictionary attack is faster but only works if the password is in the provided wordlist. Only one attack mode should be specified at a time.


title: RESUMING ATTACKS
content:
<i>rarcrack</i> can automatically save its progress to a status file (e.g., <i>&lt;archive_name&gt;.xml</i>) in the same directory as the archive. If an attack is interrupted, simply restarting the command with the same parameters will allow it to resume from where it left off, significantly saving time and resources.


title: PERFORMANCE CONSIDERATIONS
content:
The performance of <i>rarcrack</i> is heavily dependent on CPU power and the number of threads utilized. Using the <b>-t</b> or <b>--threads</b> option can significantly accelerate the cracking speed by leveraging multiple CPU cores. For optimal performance, ensure your system has sufficient processing capabilities.


title: HISTORY
content:
<i>rarcrack</i> emerged as a focused tool to address the common problem of forgotten passwords for RAR archives. Unlike general-purpose password cracking frameworks, it specializes in direct RAR file analysis and attack. Its development has typically been community-driven, often found in penetration testing distributions, providing a simple yet effective solution for this specific use case without requiring complex hash extraction or conversion steps.


title: SYNOPSIS
content:
rarp [-v] [-H <I>type</I>] [-a] [-d <I>hostname</I>] [-s <I>hostname</I> <I>hw_addr</I>] [-f <I>filename</I>]


title: PARAMETERS
content:
<b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about the actions performed.<br><br><b>-H <I>type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the hardware address type. Common types include 'ether' (Ethernet), 'ax25', 'netrom', 'arcnet', 'fddi'.<br><br><b>-a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays all current RARP table entries.<br><br><b>-d <I>hostname</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes the RARP entry associated with the specified <I>hostname</I>.<br><br><b>-s <I>hostname</I> <I>hw_addr</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a static RARP entry. <I>hostname</I> is the IP address or name, and <I>hw_addr</I> is the hardware (MAC) address.<br><br><b>-f <I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads RARP entries from the specified <I>filename</I>. Each line in the file should contain a hostname and a hardware address.<br><br>


title: DESCRIPTION
content:
The <i>rarp</i> command manipulates the kernel's Reverse Address Resolution Protocol (RARP) cache. RARP is a deprecated network protocol used by a host to discover its own IP address when it only knows its MAC (hardware) address. This was typically used by diskless workstations during boot-up to obtain their IP configuration. The <i>rarp</i> utility allows system administrators to view existing static RARP entries or add/delete them from the kernel's RARP table. Unlike ARP, which resolves IP to MAC, RARP resolves MAC to IP. Modern networks rarely use RARP, having largely replaced it with BOOTP and subsequently DHCP, which offer more robust and dynamic address assignment capabilities. As such, the <i>rarp</i> command is often not installed by default on contemporary Linux distributions, or its functionality is integrated into more general-purpose tools like <i>ip</i>.


title: CAVEATS
content:
<i>Obsolete Protocol</i>: RARP is largely deprecated and replaced by DHCP and BOOTP, making the command rarely necessary in modern networks.<br><i>Kernel Support</i>: The Linux kernel must be compiled with RARP support for this command to function.<br><i>Static Entries Only</i>: This command primarily manages static RARP cache entries; it does not typically send RARP requests to dynamically resolve addresses itself (that's the job of an RARP daemon like <i>rarpd</i>).<br><i>Availability</i>: The <i>rarp</i> utility is often part of the <i>net-tools</i> package, which is being superseded by the <i>iproute2</i> suite on many contemporary Linux distributions. It might not be installed by default.


title: RARP VS. ARP
content:
While both RARP and ARP are address resolution protocols, they serve inverse functions. <B>ARP</B> (Address Resolution Protocol) maps an <I>IP address to a hardware (MAC) address</I>. <B>RARP</B> (Reverse Address Resolution Protocol) maps a <I>hardware (MAC) address to an IP address</I>.


title: ROLE OF RARPD
content:
The <I>rarp</I> command line utility manipulates static entries in the kernel's RARP cache. Actual RARP requests from clients are typically handled by a daemon, such as <I>rarpd</I>, which listens for RARP requests and replies with the appropriate IP address configured for the requesting MAC.


title: HISTORY
content:
RARP was standardized in <I>RFC 903</I> in <I>1984</I> as a simple mechanism for diskless workstations to determine their own IP address based on their known MAC address. It quickly gained adoption for bootstrapping such systems. However, its limitations, such as requiring a RARP server on each network segment and its one-to-one mapping, led to its gradual replacement. <I>BOOTP</I> (<I>RFC 951</I>, <I>1985</I>) and, more prominently, <I>DHCP</I> (<I>RFC 2131</I>, <I>1997</I>) emerged as more versatile and dynamic alternatives, providing not just IP addresses but also other network configuration details (netmask, gateway, DNS servers). The <I>rarp</I> command itself is part of the <I>net-tools</I> collection, a set of command-line utilities for network configuration that has seen declining usage in favor of the more modern and powerful <I>iproute2</I> utilities.


title: PARAMETERS
content:
<b>nonint</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs <b>raspi-config</b> in a non-interactive mode, primarily used for scripting and automated setup. This mode bypasses the interactive menu and executes a specific sub-command directly. Examples of sub-commands include: <i>do_expand_rootfs</i> (expands the filesystem), <i>do_camera [0|1]</i> (enables/disables camera), <i>do_ssh [0|1]</i> (enables/disables SSH), <i>get_hostname</i> (retrieves hostname), <i>set_hostname &lt;name&gt;</i> (sets hostname), <i>do_i2c [0|1]</i> (enables/disables I2C), <i>do_spi [0|1]</i> (enables/disables SPI), and many others. It allows programmatic control over the same settings available in the interactive menu.<br><br>


title: DESCRIPTION
content:
The <b>raspi-config</b> command is a powerful, interactive utility designed specifically for Raspberry Pi OS (formerly Raspbian) to simplify system configuration. It provides a user-friendly, ncurses-based text interface (TUI) that allows users to manage various essential settings without needing to directly edit configuration files or use complex command-line arguments. Key functionalities include changing the user password, configuring network options (like Wi-Fi), enabling or disabling interfaces such as SSH, I2C, SPI, and Camera, setting locale and timezone, expanding the root filesystem to utilize the full SD card, and updating the tool itself. It plays a crucial role in the initial setup and ongoing maintenance of a Raspberry Pi, making it accessible for users of all technical levels to customize their device's behavior and hardware interactions.


title: CAVEATS
content:
Requires <b>sudo</b> to execute most functions.<br>Primarily designed for Raspberry Pi OS; functionality and availability may vary on other Linux distributions.<br>Many configuration changes require a system reboot to take full effect.<br>Directly modifies critical system files and settings; caution is advised.


title: INTERACTIVE MENU INTERFACE
content:
When run without the <i>nonint</i> parameter, <b>raspi-config</b> presents a menu-driven interface, allowing users to navigate through various configuration options using keyboard arrows and the Enter key. This intuitive TUI makes it accessible for users who may not be familiar with Linux command-line intricacies.


title: CONFIGURATION PERSISTENCE
content:
Changes made via <b>raspi-config</b> are typically persistent across reboots, as the utility modifies underlying system configuration files and settings directly. This ensures that your chosen settings (e.g., enabled interfaces, password changes) remain active until explicitly changed again.


title: HISTORY
content:
<b>raspi-config</b> was developed by the Raspberry Pi Foundation as an essential tool to simplify the initial setup and ongoing management of Raspberry Pi devices running Raspberry Pi OS. It emerged as a user-friendly alternative to manually editing various system configuration files (e.g., <i>/boot/config.txt</i>, <i>/etc/default/locale</i>) and command-line interactions for common tasks. Its evolution has mirrored the development of the Raspberry Pi hardware and operating system, continually adding support for new features, interfaces, and models, solidifying its role as a fundamental utility for all Raspberry Pi users.


title: SYNOPSIS
content:
<b>rasttopnm</b> [<i>-alphaout=alpha-filename</i>] [<i>-alphainvert</i>] [<i>-force</i>] [<i>-assume24bit</i>] [<i>-cmapout=cmap-filename</i>] [<i>-verbose</i>] [<i>rasterfile</i>]


title: PARAMETERS
content:
<b><b>-alphaout=</b><i>alpha-filename</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts the alpha (transparency) channel into a separate PGM file named <i>alpha-filename</i>. If omitted, the alpha channel is discarded.<br><br><b><b>-alphainvert</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Inverts the values of the alpha channel before outputting it via <b>-alphaout</b>. Useful if the input alpha is conventionally inverted.<br><br><b><b>-force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to convert the file even if its header appears suspicious or malformed. Use with caution as it might result in corrupted output.<br><br><b><b>-assume24bit</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats input files that <b>rasttopnm</b> cannot otherwise classify as 24-bit color rasterfiles. This option is a workaround for certain non-standard or malformed raster files.<br><br><b><b>-cmapout=</b><i>cmap-filename</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts the colormap of colormapped rasterfiles into a separate PPM file named <i>cmap-filename</i>.<br><br><b><b>-verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output during the conversion process, printing diagnostic messages to standard error.<br><br><b><i>rasterfile</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input Sun rasterfile. If not specified, <b>rasttopnm</b> reads from standard input.<br><br>


title: DESCRIPTION
content:
<b>rasttopnm</b> is a utility from the Netpbm project that converts a Sun rasterfile (also known as SunOS rasterfile or Sun icon format) into a portable anymap (PBM, PGM, or PPM) image. It supports various Sun rasterfile formats, including both old and new versions, those with colormaps, and run-length encoded data.<br><br>The output format (PBM for black & white, PGM for grayscale, PPM for color) is automatically determined by the input rasterfile's characteristics. This tool is essential for interoperability between legacy Sun image formats and modern image processing tools that support the Netpbm formats.


title: CAVEATS
content:
<b>rasttopnm</b> is specifically designed for Sun raster files and will not work for other image formats. While the <b>-force</b> option can assist with slightly malformed headers, severely corrupted files might still fail or produce unusable output. Alpha channel information is discarded by default unless explicitly extracted using the <b>-alphaout</b> option.


title: INPUT/OUTPUT
content:
<b>rasttopnm</b> reads the Sun rasterfile from standard input if no <i>rasterfile</i> argument is provided. The converted portable anymap image is written to standard output. This behavior makes it highly suitable for use in pipelines with other Netpbm tools.


title: NETPBM PHILOSOPHY
content:
True to the Netpbm philosophy, <b>rasttopnm</b> is a simple, single-purpose tool. It focuses solely on the conversion from Sun raster to PBM/PGM/PPM, allowing subsequent tools in a pipeline to handle further image processing tasks like scaling, filtering, or conversion to other image formats.


title: HISTORY
content:
<b>rasttopnm</b> is a component of the Netpbm package, a suite of graphics utilities that evolved from Jef Poskanzer's Pbmplus toolkit in the late 1980s. Pbmplus was developed to be a versatile toolset for image manipulation, emphasizing simple, pipe-able tools and portable image formats (PBM, PGM, PPM). <b>rasttopnm</b> was included to specifically handle the Sun rasterfile format, which was common on Sun Microsystems workstations. Its presence reflects the Netpbm project's aim to provide comprehensive format conversion capabilities. The Netpbm project continues to be actively maintained by Bryan Henderson.


title: SEE ALSO
content:
<b>pnm(5)</b> (overview of Netpbm formats), <b>anytopnm(1)</b> (convert arbitrary graphics format to portable anymap), <b>pnmtojpeg(1)</b> (convert portable anymap to JPEG), <b>pnmtops(1)</b> (convert portable anymap to PostScript)


title: SYNOPSIS
content:
<b>ls</b> [<i>OPTION</i>]... [<i>FILE</i>]...<br><br><i>OPTION</i>: Represents one or more command-line options that modify the behavior of <b>ls</b>. Options typically start with a single hyphen (-) followed by a letter (e.g., -l) or two hyphens for long options (e.g., --all).<br><i>FILE</i>: Specifies the path to a directory or file whose contents or information should be listed. If no <i>FILE</i> is specified, <b>ls</b> operates on the current directory. If a <i>FILE</i> is a directory, its contents are listed. If a <i>FILE</i> is a regular file, its information is listed.


title: PARAMETERS
content:
<b><b>-a</b>, <b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ignore entries starting with '.' (dot files), which are normally hidden.<br><br><b><b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a long listing format, showing detailed information including permissions, number of hard links, owner, group, size, and modification time.<br><br><b><b>-h</b>, <b>--human-readable</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;With <b>-l</b>, print sizes in human-readable format (e.g., 1K, 234M, 2G) instead of bytes.<br><br><b><b>-R</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List the contents of subdirectories recursively.<br><br><b><b>-d</b>, <b>--directory</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List directory entries themselves, rather than their contents. Useful when you want to see details about the directory itself, not what's inside it.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the output by modification time, with the newest files appearing first.<br><br><b><b>-r</b>, <b>--reverse</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reverse the order of the sort. Can be combined with <b>-t</b> for oldest first, or <b>-S</b> for smallest first.<br><br><b><b>-F</b>, <b>--classify</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Append an indicator character to entries: '/' for directories, '*' for executables, '@' for symbolic links, '|' for FIFOs, and '=' for sockets.<br><br><b><b>-S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the output by file size, with the largest files appearing first.<br><br><b><b>-1</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List one file per line. This is the default output format when output is piped to another command.<br><br>


title: DESCRIPTION
content:
The <b>ls</b> command is a fundamental utility in Unix-like operating systems, used to list the contents of directories. When invoked without arguments, it displays the files and subdirectories in the current working directory.<br><br>It can be used to view detailed information about files, such as permissions, ownership, size, and modification time, using various options. <b>ls</b> is indispensable for navigating the file system, identifying files, and inspecting their properties, making it one of the most frequently used commands by system administrators and everyday users alike. Its output can be customized extensively to display information in different formats, sort criteria, and filter based on file types.


title: CAVEATS
content:
For directories containing a very large number of files, the <b>ls</b> output can be extensive and difficult to parse directly without piping to tools like <b>less</b> or <b>grep</b>.<br><br>The exact output format and available options for <b>ls</b> can vary slightly between different implementations (e.g., GNU <b>ls</b> on Linux vs. BSD <b>ls</b> on macOS/FreeBSD), though core functionality remains consistent.<br><br>User permissions affect what <b>ls</b> can display. If a user lacks read permission for a directory, <b>ls</b> will not be able to list its contents, and if they lack execute permission for a directory, they won't be able to 'cd' into it or access its files by path, even if the files themselves are readable.


title: EXIT STATUS
content:
The <b>ls</b> command exits with status 0 if all <i>FILE</i> operands were processed successfully, and a non-zero value (>0) if an error occurred. This behavior is crucial for scripting, allowing automated checks on whether the command executed without issues.


title: COLOR OUTPUT
content:
Many modern <b>ls</b> implementations, especially GNU <b>ls</b>, support colored output to visually distinguish between different file types (e.g., directories in blue, executables in green, symbolic links in cyan). This feature is often controlled by the <i>LS_COLORS</i> environment variable and typically enabled by default via shell aliases (e.g., <code>alias ls='ls --color=auto'</code>).


title: HISTORY
content:
The <b>ls</b> command is one of the oldest and most fundamental utilities in the Unix operating system, dating back to its earliest versions developed at Bell Labs in the early 1970s. It was created as a simpler alternative to 'dir', a command on Multics. Over decades, <b>ls</b> has evolved, with significant enhancements added by various Unix distributions and later by the GNU Project.<br><br>GNU <b>ls</b>, part of the GNU Coreutils, became the standard on Linux systems, introducing many new features like colored output, human-readable sizes (<b>-h</b>), and more robust sorting options, making it more user-friendly and powerful than its original AT&T Unix counterpart.


title: SYNOPSIS
content:
<code>rawtopgm</code> <br> [ <i>-width</i> <I>cols</I> ] <br> [ <i>-height</i> <I>rows</I> ] <br> [ <i>-maxval</i> <I>maxval</I> ] <br> [ <i>-bytes</i> <I>bytes_per_sample</I> ] <br> [ <i>-msbfirst</i> | <i>-lsbfirst</i> ] <br> [ <i>-rowstride</i> <I>bytes_per_row</I> ] <br> [ <i>-headerbytes</i> <I>bytes</I> ] <br> [ <i>rawfile</i> ]


title: PARAMETERS
content:
<b>-width <I>cols</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>width</b> of the image in pixels. This is a mandatory parameter as <code>rawtopgm</code> cannot guess the image width from raw data.<br><br><b>-height <I>rows</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>height</b> of the image in pixels. This is a mandatory parameter as <code>rawtopgm</code> cannot guess the image height from raw data.<br><br><b>-maxval <I>maxval</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <b>maximum grayscale value</b> for pixels. This determines the dynamic range of the image. Common values are 255 for 8-bit images or 65535 for 16-bit images. Defaults to 255 if not specified.<br><br><b>-bytes <I>bytes_per_sample</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>number of bytes per pixel sample</b>. Use 1 for 8-bit images, 2 for 16-bit images, etc. Defaults to 1 if not specified.<br><br><b>-msbfirst</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies that multi-byte samples (e.g., 16-bit pixels) are stored with the <b>most significant byte first</b> (big-endian). This is the default if neither <code>-msbfirst</code> nor <code>-lsbfirst</code> is given.<br><br><b>-lsbfirst</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies that multi-byte samples are stored with the <b>least significant byte first</b> (little-endian).<br><br><b>-rowstride <I>bytes_per_row</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>number of bytes between the start of one row and the start of the next</b>. Useful when rows are padded. If not specified, it defaults to <code>width * bytes_per_sample</code>.<br><br><b>-headerbytes <I>bytes</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <b>number of bytes to skip</b> at the beginning of the input file before reading image data. Useful for files with a small header.<br><br>


title: DESCRIPTION
content:
<code>rawtopgm</code> is a utility from the Netpbm project designed to convert raw, unformatted grayscale pixel data into the Portable Graymap (PGM) image format. It is particularly useful for processing data directly from imaging sensors, scanners, or scientific instruments that output raw pixel streams without any embedded header or structural information.<br><br>The command requires the user to specify crucial image parameters such as <i>width</i>, <i>height</i>, <i>maximum pixel value</i>, and the <i>number of bytes per sample</i>, as this information is not present in the raw data itself. It also handles byte order (MSB first or LSB first) for multi-byte samples. <code>rawtopgm</code> typically reads raw data from standard input or a specified file and writes the resulting PGM image to standard output, making it easy to pipe its output to other Netpbm tools for further manipulation, such as scaling, cropping, or conversion to other image formats.


title: CAVEATS
content:
<code>rawtopgm</code> relies entirely on user-provided metadata (width, height, maxval, bytes per sample) as raw data contains no self-describing information. Incorrect parameters will lead to a garbled or corrupted image. It only generates PGM (grayscale) images; for color raw data, other tools or custom scripts are needed. It does not handle any form of image compression.


title: STANDARD INPUT/OUTPUT
content:
<code>rawtopgm</code> typically reads raw image data from standard input if no <i>rawfile</i> argument is provided, and writes the resulting PGM image to standard output. This behavior makes it ideal for use in shell pipelines, allowing it to easily integrate with other commands. For example, <code>cat raw_data.bin | rawtopgm -width 640 -height 480 -maxval 255 > image.pgm</code> is a common usage pattern. This flexibility is a core design principle of Netpbm tools.


title: HISTORY
content:
<code>rawtopgm</code> is part of the Netpbm package, a comprehensive set of graphics utilities that evolved from the Pbmplus project in the early 1990s. The Netpbm tools are known for their simplicity, flexibility, and ability to be chained together in shell pipelines. <code>rawtopgm</code> was developed to handle the common task of converting raw sensor output directly into a standard image format, making it accessible for further processing within the Netpbm ecosystem.


title: SYNOPSIS
content:
<b>rawtoppm</b> [-force] [-rows] [-r | -g | -b | -rgb] [-interleave | -nodynamicrange] [-output <I>output_file</I>] <I>width</I> <I>height</I>


title: PARAMETERS
content:
<b><I>width</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The width of the image in pixels. This is a mandatory argument that defines the horizontal dimension of the output image.<br><br><b><I>height</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The height of the image in pixels. This is a mandatory argument that defines the vertical dimension of the output image.<br><br><b><b>-force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not check for end-of-file after reading all expected data. This can be useful when dealing with potentially truncated or continuously streaming inputs.<br><br><b><b>-rows</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process the input data in row-major order. This option is often implicitly understood or may align with the default data output format of many raw sources.<br><br><b><b>-r</b> | <b>-g</b> | <b>-b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts and converts only the specified color channel (red, green, or blue) into a grayscale PPM image. The data from the other channels is ignored.<br><br><b><b>-rgb</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Processes all three color channels (Red, Green, Blue) in the default RGB order. This is the default behavior if no specific channel extraction option is provided.<br><br><b><b>-interleave</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assumes that the color components for each pixel are interleaved (e.g., R-G-B-R-G-B...). This is a common arrangement for many raw data outputs from hardware devices.<br><br><b><b>-nodynamicrange</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the default dynamic range adjustment that <b>rawtoppm</b> might perform to optimize output. Use this to preserve exact original pixel values without scaling.<br><br><b><b>-output</b> <I>output_file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output file for the PPM image. If this option is not provided, <b>rawtoppm</b> writes the image to standard output (stdout).<br><br>


title: DESCRIPTION
content:
The <b>rawtoppm</b> command is a specialized utility within the <I>Netpbm</I> suite, designed to convert raw RGB (Red, Green, Blue) byte streams into a standard <I>Portable Pixmap</I> (PPM) image format.<br><br>It's particularly useful for processing data directly from hardware sources such as frame grabbers, scanners, or embedded systems that output unprocessed pixel data. Unlike image processing tools that handle complex file formats with headers or compression, <b>rawtoppm</b> expects a continuous stream of raw pixel data, where each byte or group of bytes represents a color component for a specific pixel.<br><br>Users must specify the image's <I>width</I> and <I>height</I>, as this information is not present in the raw data stream. The command reads the raw bytes from standard input by default, or from a specified file, and then outputs the resulting PPM image to standard output, which can be redirected to a file or piped to another <I>Netpbm</I> tool for further manipulation.<br><br>It's a foundational tool for integrating raw hardware output into a standard image processing workflow, leveraging the simplicity and interoperability of the Netpbm formats.


title: CAVEATS
content:
<b>rawtoppm</b> is strictly for truly raw, uncompressed byte streams. It does not handle any form of image headers, metadata, or complex raw camera formats (like those from DSLRs, e.g., CR2, NEF). For such files, a pre-processor like <b>dcraw</b> or specialized conversion tools are required before using <b>rawtoppm</b>.<br><br>The command assumes 8-bit samples per color component, producing a PPM with a maximum pixel value of 255. The exact order of input bytes (e.g., RGB vs. BGR) is crucial and must match the implicit or explicit assumptions of the command, or the output image colors will be incorrect.


title: STANDARD INPUT/OUTPUT
content:
By default, <b>rawtoppm</b> reads raw byte data from standard input (stdin) and writes the resulting PPM image to standard output (stdout). This allows for easy piping with other commands, such as `cat raw_data.bin | rawtoppm 640 480 > image.ppm` for converting a file, or processing a live stream.


title: MAXVAL AND DEPTH
content:
The output PPM image will always have a `MAXVAL` of 255, meaning it's an 8-bit per channel image. This characteristic aligns with common raw hardware outputs. If higher bit depths are needed, the output PPM can be further processed by other Netpbm tools, such as `pnmdepth`, to adjust the depth.


title: HISTORY
content:
<b>rawtoppm</b> is an integral part of the <I>Netpbm</I> project, which originated from the <I>PBMPlus</I> package created by Jef Poskanzer in the late 1980s. <I>PBMPlus</I> was designed to provide a set of simple, composable tools for manipulating bitmap images on Unix-like systems. The utility <b>rawtoppm</b> was developed early in this lineage to fulfill the fundamental need of converting raw, unformatted pixel data from hardware devices (like early video digitizers or scanners) into a universally readable image format. Its design reflects the Unix philosophy of small, single-purpose utilities that can be chained together, making it a robust and enduring component for basic image stream processing.


title: SYNOPSIS
content:
<b>rbac-lookup</b> [<i>OPTIONS</i>]<br>Example: <b>rbac-lookup</b> <i>--user=jsmith</i><br>Example: <b>rbac-lookup</b> <i>--host=webserver.example.com</i> <i>--extop=DNSSEC</i>


title: PARAMETERS
content:
<b>--user=USER</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <i>user principal</i> for whom to look up permissions.<br><br><b>--host=HOST</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <i>host principal</i> for which to look up permissions.<br><br><b>--service=SERVICE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <i>service principal</i> (e.g., HTTP/server.example.com) for which to look up permissions.<br><br><b>--extop=EXTOP</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters the lookup to show permissions related to a specific <i>extended operation</i> (e.g., DNSSEC).<br><br><b>--rule=RULE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays permissions granted by a specific <i>RBAC rule</i>, by its name.<br><br><b>--all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays all matching rules, not just the effective permissions.<br><br><b>--permissions</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists only the effective permissions, without additional rule details.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides more detailed output, including the rules granting the permissions.<br><br>


title: DESCRIPTION
content:
The <b>rbac-lookup</b> command is a crucial utility within the FreeIPA identity and access management system. It allows administrators to query and understand the effective Role-Based Access Control (RBAC) permissions for a given user, host, or service principal. Instead of just listing assigned roles, <b>rbac-lookup</b> resolves the <i>actual</i> permissions that are granted by those roles and associated rules. This is particularly useful for auditing, troubleshooting access issues, and verifying that security policies are correctly applied. It can show which rules grant specific permissions to principals, helping to trace the source of an access grant or denial.


title: CAVEATS
content:
Requires an active Kerberos ticket or FreeIPA authentication to run effectively.<br>Only works against a FreeIPA server.<br>The output can be extensive depending on the number of rules and principals involved.<br>Understanding the output often requires familiarity with FreeIPA's RBAC concepts (permissions, privileges, roles, rules).


title: PURPOSE OF RBAC LOOKUP
content:
Unlike simply listing roles a user belongs to, <b>rbac-lookup</b> performs a full evaluation of all rules, roles, and privileges to show the exact permissions that are <i>effective</i> for a principal in a given context. This is crucial for security auditing and troubleshooting "access denied" scenarios.


title: HISTORY
content:
The <b>rbac-lookup</b> command was introduced as part of the FreeIPA project, which aims to provide an integrated identity and authentication solution for Linux/UNIX environments. As FreeIPA's RBAC capabilities matured, a dedicated tool was needed to effectively debug and verify complex permission assignments. <b>rbac-lookup</b> filled this need, becoming an essential utility for administrators to gain insight into the runtime application of RBAC policies, especially in larger, more intricate FreeIPA deployments.


title: PARAMETERS
content:
<b><i>-r</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the restricted shell mode. When <b>bash</b> is started with this option, or invoked as <b>rbash</b>, it enters restricted mode.<br><br><b><i>--login</i> or <i>-l</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes this shell a login shell, reading appropriate startup files like <i>.bash_profile</i>.<br><br><b><i>-c string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads and executes commands from <i>string</i> instead of positional parameters.<br><br><b><i>-s</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands from standard input. If this option is used, positional parameters are set to the remaining arguments.<br><br><b><i>-i</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes this shell interactive.<br><br>


title: DESCRIPTION
content:
<i>rbash</i>, or <i>Restricted Bash</i>, is a version of the Bash shell that operates in a restricted mode. Its primary purpose is to provide a controlled environment for users, limiting their capabilities and preventing certain actions that could compromise system security or stability. When running in restricted mode, users are typically unable to change directories with `cd` beyond certain paths, set `PATH` or `SHELL` variables, execute commands with `/` in their names, redirect output, or call `exec`. This makes it suitable for scenarios like FTP servers, kiosks, or specific application interfaces where users should only perform predefined actions. However, <i>rbash</i> is not a security sandbox and should not be relied upon as a standalone security measure. It is relatively easy to bypass its restrictions if not combined with other Linux security mechanisms.


title: CAVEATS
content:
<i>rbash</i> is often insufficient as a standalone security measure. Experienced users can frequently bypass its restrictions through various methods, such as using `ssh` escape sequences, exploiting poorly configured system utilities (`vi`, `less`, `awk`, `find`, `nmap`), or through environment variable manipulation. It is strongly recommended to combine <i>rbash</i> with other Linux security mechanisms like `chroot` jails, `SELinux`/`AppArmor`, cgroups, and strict file system permissions (`sudo` for specific commands) to create a truly secure restricted environment.


title: RESTRICTIONS IN <I>RBASH</I>
content:
When <i>rbash</i> is active, the following actions are typically restricted:<br><ul><li>Changing directories with the <i>cd</i> builtin command.</li><li>Setting or unsetting the values of the <i>SHELL</i>, <i>PATH</i>, <i>ENV</i>, or <i>BASH_ENV</i> variables.</li><li>Specifying command names containing a slash (`/`).</li><li>Specifying a filename containing a slash as an argument to the <i>.</i> builtin command.</li><li>Using the <i>hash</i> builtin command to specify command names containing a slash.</li><li>Importing function definitions from the shell environment at startup.</li><li>Parsing the <i>SHELLOPTS</i> environment variable from the shell environment at startup.</li><li>Redirecting output using `>`, `>>`, `>|`, `&>`, `&>>`.</li><li>Using <i>exec</i> to replace the shell with another command.</li><li>Adding or deleting builtins with the <i>enable</i> builtin command.</li><li>Turning off restricted mode with `set +r` or `set +o restricted`.</li></ul>


title: SETTING UP <I>RBASH</I>
content:
To set up <i>rbash</i> for a user, you typically need to:<br><ul><li>Create a symlink from <i>rbash</i> to <b>bash</b> (if <i>rbash</i> doesn't already exist as an executable linked to <b>bash</b>).</li><li>Change the user's default shell in <i>/etc/passwd</i> to <i>/bin/rbash</i> (or wherever <i>rbash</i> is located).</li><li>Configure the user's <i>PATH</i> variable in their <i>~/.bash_profile</i> or equivalent to include only safe executables within specific, controlled directories.</li><li>Ensure that the user's environment and startup files (<i>.bashrc</i>, <i>.bash_profile</i>) do not contain commands that could allow a bypass.</li><li>Combine with a `chroot` jail for stronger isolation.</li></ul>


title: HISTORY
content:
The concept of a restricted shell has existed in Unix-like systems for a long time, often implemented by `sh` (Bourne shell) or other shells. <i>rbash</i> is not a separate executable but rather <b>bash</b> itself invoked with the <i>-r</i> option or through a symlink named <i>rbash</i>. This functionality has been an integral part of the Bash shell for many years, providing administrators with a built-in method to create restricted user environments without needing external tools. Its development has mirrored the evolution of Bash, with ongoing efforts to address potential bypasses, though it remains primarily a deterrent against accidental misuse rather than a robust security sandbox.


title: SYNOPSIS
content:
<b>rbenv</b> <I>command</I> [<I>args</I>...]<br><br>Common commands include:<br><b>rbenv</b> <I>install</I> <I>version</I><br><b>rbenv</b> <I>global</I> <I>version</I><br><b>rbenv</b> <I>local</I> <I>version</I><br><b>rbenv</b> <I>versions</I><br><b>rbenv</b> <I>rehash</I><br><b>rbenv</b> <I>exec</I> <I>command</I> [<I>args</I>...]


title: PARAMETERS
content:
<b>install <version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs a specific Ruby version. Requires the <I>ruby-build</I> plugin.<br><br><b>global <version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the global Ruby version to be used for all shells and projects.<br><br><b>local <version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a project-specific Ruby version by creating a <I>.ruby-version</I> file in the current directory.<br><br><b>shell <version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a shell-specific Ruby version, overriding global and local versions. This setting is temporary.<br><br><b>versions</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all installed Ruby versions and indicates the currently active one.<br><br><b>rehash</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rebuilds the rbenv shim executables. Must be run after installing new Ruby versions or gems with executables.<br><br><b>exec <command></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes a command with the currently selected Ruby version. Useful for scripts.<br><br><b>which <command></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the full path to the executable that rbenv will run for a given command.<br><br><b>version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the currently active Ruby version and its origin (global, local, shell).<br><br><b>version-name</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays only the name of the currently active Ruby version.<br><br>


title: DESCRIPTION
content:
rbenv is a lightweight Ruby version management tool that allows you to install and switch between multiple versions of Ruby on the same machine. Unlike other managers like RVM, rbenv operates by modifying your <B>PATH</B> environment variable and using "shims"—small executable scripts that intercept commands like <I>ruby</I>, <I>gem</I>, <I>bundle</I>, etc.<br><br>When you run a Ruby command, rbenv determines which Ruby version should be used based on a hierarchy of settings (local, global, shell) and executes the command with the correct Ruby interpreter. This approach makes rbenv less intrusive and more transparent, as it doesn't "hijack" your shell. It's particularly useful for development environments where different projects might require different Ruby versions, ensuring dependency isolation and consistency.


title: CAVEATS
content:
rbenv itself does <B>not</B> install Ruby versions; it relies on the <I>ruby-build</I> plugin for this functionality. Users must ensure <I>rbenv rehash</I> is run after installing new Ruby versions or gems that include executable scripts, otherwise the executables might not be found. It does not manage gemsets by default, though plugins are available for this purpose. Unlike RVM, rbenv does not modify your shell environment with 'hooks' or 'cd' command overrides.


title: <I>SHIMS EXPLAINED</I>
content:
rbenv works by inserting its own directory of <B>shims</B> at the front of your <B>PATH</B>. When you run a command like <I>ruby</I> or <I>bundle</I>, your operating system searches <B>PATH</B> from left to right. It finds the rbenv shim first, which then determines the correct Ruby version based on your settings (global, local, shell) and executes the actual Ruby executable from that version's installation directory. This allows for seamless switching without shell "hooks".


title: <I>INSTALLATION SETUP</I>
content:
After installing rbenv, you typically need to add <B>eval "$(rbenv init -)"</B> to your shell's initialization file (e.g., <I>~/.bashrc</I>, <I>~/.zshrc</I>) to enable its functionality, including auto-completion and shims.


title: HISTORY
content:
rbenv was created by Sam Stephenson, aiming to be a simpler and less invasive alternative to existing Ruby version managers like RVM. Its design philosophy focuses on being unobtrusive, primarily working by manipulating the <B>PATH</B> environment variable and using a system of <I>shims</I> rather than modifying core shell functions. This design choice has made it popular among developers who prefer a more transparent and explicit control over their Ruby environment.


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help information or help for a specific command.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the <i>rbt</i> tool version and exits.<br><br><b>--server <URL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the URL of the Review Board server to connect to. This overrides any configured server URL.<br><br><b>--username <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the username for authentication to the Review Board server. Can be used with --password.<br><br><b>--password <pass></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the password for authentication. Not recommended for interactive use due to security concerns; consider using a password file or environment variable.<br><br><b>post --revision-range <range></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with the 'post' command to specify the range of revisions to include in the diff (e.g., 'tip:parent' or 'commit1:commit2').<br><br><b>post --summary <text></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a concise, one-line summary for the review request being posted or updated.<br><br><b>post --description <text></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a detailed description for the review request, explaining the changes and their purpose.<br><br><b>post --target-people <users></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of usernames to designate as reviewers for the request.<br><br><b>post --target-groups <groups></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of group names whose members should be reviewers for the request.<br><br><b>post --publish</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically publishes the review request immediately after it's created or updated, making it visible to reviewers.<br><br><b>post --private</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Marks the review request as private, so it's only visible to specified target people/groups and administrators.<br><br><b>post --diff-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates the diff output to standard output or a file, but does not post it to the Review Board server.<br><br>


title: DESCRIPTION
content:
<i>rbt</i> is the command-line client for <I>Review Board</I>, a widely used web-based code review tool. It empowers developers to interact with a Review Board server directly from their terminal, streamlining the process of creating, updating, and managing code review requests. The tool integrates seamlessly with various version control systems such as Git, Mercurial, SVN, Perforce, and CVS, allowing users to generate diffs and submit them for peer review with ease. <i>rbt</i> simplifies the workflow by handling common tasks like posting new review requests, updating existing ones with new changes, displaying review request statuses, and applying patches. It is a crucial component of the Review Board ecosystem, designed to improve the efficiency and visibility of the code review process within development teams.


title: CAVEATS
content:
<i>rbt</i> is not a standard Linux command-line utility bundled with operating systems. It is a third-party tool that must be installed separately (commonly via <i>pip</i>, the Python package installer). It requires a running Review Board server instance to connect to and perform operations. Its behavior is highly dependent on the configured version control system and the specific Review Board server version. Configuration often involves creating a <i>.reviewboardrc</i> file in the repository or user's home directory.


title: INSTALLATION
content:
<i>rbt</i> is typically installed as a Python package using <I>pip</I>:<br><b>pip install rbtools</b><br>It is recommended to use a Python virtual environment to manage dependencies.


title: CONFIGURATION
content:
Most configurations for <i>rbt</i> are stored in a <I>.reviewboardrc</I> file. This file can be placed in your home directory or the root of your version control repository. It specifies details like the Review Board server URL, repository name, and default reviewers. Example content:<br><b>REVIEWBOARD_URL = 'http://your-reviewboard-server/'</b><br><b>REPOSITORY = 'your-repo-name'</b>


title: HISTORY
content:
The <i>rbt</i> command-line client is an integral part of the Review Board project, which was initially released in 2007. Developed in Python, <i>rbt</i> was created to provide developers with programmatic access to the Review Board server's functionalities, complementing its web interface. Over the years, it has evolved significantly, adding support for new version control systems, improving authentication methods, and introducing new commands to cover a broader range of code review workflows. It remains an actively maintained open-source tool, serving as the primary command-line interface for the Review Board ecosystem.


title: PARAMETERS
content:
<b><I>0</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the system runlevel to 0, typically initiating a system halt or shutdown.<br><br><b><I>1</I> or <I>S</I> or <I>s</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the system runlevel to 1 (single-user mode), providing a minimal environment for system maintenance.<br><br><b><I>2</I>, <I>3</I>, <I>4</I>, <I>5</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the system runlevel to a multi-user mode. The specific services started or stopped in these runlevels depend on the system's configuration (e.g., <I>/etc/inittab</I> and <I>/etc/rcX.d</I> scripts).<br><br><b><I>6</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the system runlevel to 6, typically initiating a system reboot.<br><br>


title: DESCRIPTION
content:
The <i>rc</i> command, commonly found as an applet within <B>BusyBox</B>, functions as a simplified System V init compatible runlevel change utility. It is primarily used in embedded systems or minimal Linux environments where a full-featured <i>init</i> system like <i>systemd</i> or traditional <i>SysVinit</i> might be too resource-intensive. When invoked, <i>rc</i> typically triggers a change to a specified system runlevel, causing the execution of corresponding initialization or shutdown scripts, often found in directories like <I>/etc/init.d</I> or <I>/etc/rcX.d</I>. Its behavior is often a subset of what a full <i>init</i> process would provide, focusing specifically on managing the system's operational state by transitioning between runlevels.


title: CAVEATS
content:
The <i>rc</i> command is specific to <B>BusyBox</B> and is not a standard standalone utility found in all GNU/Linux distributions. Its presence and exact behavior depend on how <B>BusyBox</B> was compiled and installed. In many <B>BusyBox</B> setups, <i>rc</i> might be a symbolic link to the <B>init</B> applet, inheriting its functionalities. It offers limited features compared to full-fledged <i>init</i> systems like <B>systemd</B> or traditional <B>SysVinit</B>.


title: CONFIGURATION FILES
content:
The behavior of <i>rc</i> relies on system configuration files such as <I>/etc/inittab</I> (which defines runlevels and processes) and scripts located in directories like <I>/etc/init.d/</I> and <I>/etc/rc<I>X</I>.d/</I> (which contain scripts executed during runlevel transitions).


title: USAGE CONTEXT
content:
Predominantly found in environments utilizing <B>BusyBox</B>, such as embedded Linux devices (e.g., routers, IoT devices), minimal server installations, or custom-built Linux distributions where resource efficiency is paramount.


title: HISTORY
content:
<B>BusyBox</B> itself was created by Bruce Perens in 1996 to provide a compact set of Unix utilities for embedded systems. The <i>rc</i> applet (often part of or linked to the <B>init</B> applet) was included from early versions to offer essential system startup and runlevel management capabilities in environments with limited resources, adhering to a simplified <B>System V init</B> style. Its development has focused on efficiency and minimal footprint.


title: SYNOPSIS
content:
<b>rc-service</b> <i>&lt;service_name&gt;</i> [<i>&lt;command&gt;</i>]<br><b>rc-service</b> [<i>options</i>]


title: PARAMETERS
content:
<b><i>&lt;service_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the service to manage (e.g., <i>sshd</i>, <i>net.eth0</i>, <i>cronie</i>).<br><br><b><i>&lt;command&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The action to perform on the service. Common commands include: <i>start</i>, <i>stop</i>, <i>restart</i>, <i>reload</i>, <i>status</i>, <i>condrestart</i>, <i>zap</i> (remove PID file), <i>crashed</i> (check if service crashed).<br><br><b><b>-l</b>, <b>--list</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available services located in <i>/etc/init.d/</i>.<br><br><b><b>-s</b>, <b>--status-all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the status of all services currently known to OpenRC.<br><br><b><b>-i</b>, <b>--info</b> <i>&lt;service_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows detailed information about a specific service, including its description, dependencies, and runlevels it belongs to.<br><br><b><b>--if-exists</b> <i>&lt;service_name&gt;</i> [<i>&lt;command&gt;</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the specified command only if the service exists. Useful in scripts where a service might not always be present.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses output for status commands. Useful for scripting.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version of OpenRC being used.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a help message with usage information.<br><br>


title: DESCRIPTION
content:
<i><b>rc-service</b></i> is a fundamental command-line utility within the OpenRC init system, primarily used for managing services on Linux distributions that utilize OpenRC (such as Gentoo, Alpine Linux, or Artix Linux). It provides a user-friendly interface to interact with service scripts located in <i>/etc/init.d/</i>.<br><br>Unlike traditional SysVinit scripts where users might directly execute <i>/etc/init.d/service_name start</i>, <i><b>rc-service</b></i> offers a consistent and abstracted way to perform common actions like starting, stopping, restarting, reloading, or checking the status of a service. It acts as a wrapper around the core <i><b>rc</b></i> command and leverages OpenRC's dependency-based service management.<br><br>The command simplifies service interaction by handling the underlying complexities, making it easier for administrators to control system daemons and processes. It is essential for daily system administration tasks on OpenRC-based systems.


title: CAVEATS
content:
<i><b>rc-service</b></i> is specific to systems using <i>OpenRC</i> as their init system. It is not available or functional on systems primarily using other init systems like <i>systemd</i>, <i>SysVinit</i> (standalone), or <i>runit</i>. Most service management actions (e.g., <i>start</i>, <i>stop</i>, <i>restart</i>) typically require superuser (root) privileges.


title: COMMON USAGE EXAMPLES
content:
To start a service: <i><b>rc-service sshd start</b></i><br>To stop a service: <i><b>rc-service cronie stop</b></i><br>To restart a network interface: <i><b>rc-service net.eth0 restart</b></i><br>To check the status of a service: <i><b>rc-service nginx status</b></i><br>To list all available services: <i><b>rc-service -l</b></i><br>To get information about a service: <i><b>rc-service -i dnsmasq</b></i>


title: SERVICE STATES
content:
<i>OpenRC</i> services can be in various states: <b>started</b> (running), <b>stopped</b> (not running), <b>inactive</b> (not configured to start), or report a <b>crashed</b> status if a process associated with it unexpectedly terminated. <i><b>rc-service status</b></i> provides the current state.


title: INTEGRATION WITH RUNLEVELS
content:
While <i><b>rc-service</b></i> manages immediate service actions, <i>OpenRC</i> uses <i>runlevels</i> to define which services start automatically at boot. The <i><b>rc-update</b></i> command is used to add or remove services from specific runlevels (e.g., <i>default</i>, <i>boot</i>, <i>shutdown</i>).


title: HISTORY
content:
<i>OpenRC</i>, and by extension <i><b>rc-service</b></i>, originated within the <i>Gentoo Linux</i> project in the mid-2000s. It was developed as a more modular, dependency-aware, and flexible alternative to traditional <i>SysVinit</i>. Its design emphasizes simplicity, parallelization of service startup, and clear separation of concerns. Over time, it has been adopted by other Linux distributions like <i>Alpine Linux</i>, <i>Artix Linux</i>, and <i>Debian's Devuan</i> fork, offering a non-<i>systemd</i> init system option.


title: SYNOPSIS
content:
<b>rc-update</b> <I>command</I> [<I>options</I>] [<I>arguments</I>]<br><b>rc-update</b> {add | del} <I>service</I> [<I>runlevel</I> ...]<br><b>rc-update</b> show [-v | --verbose]


title: PARAMETERS
content:
<b>add <I>service</I> [<I>runlevel</I> ...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds the specified <i>service</i> to one or more <i>runlevels</i>. If no <i>runlevel</i> is specified, the service is typically added to the 'default' runlevel.<br><br><b>del <I>service</I> [<I>runlevel</I> ...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the specified <i>service</i> from one or more <i>runlevels</i>. If no <i>runlevel</i> is specified, the service is removed from all runlevels it is currently in.<br><br><b>show</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current status of all services, indicating which runlevels they are enabled in. This is useful for auditing the system's startup configuration.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used exclusively with the 'show' command, this option provides a more detailed output, showing all services and their respective runlevel statuses in a more expanded format.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message with command usage information and then exits.<br><br><b><I>service</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the service script (e.g., 'sshd', 'cron', 'netmount') located in the <I>/etc/init.d/</I> directory.<br><br><b><I>runlevel</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of an OpenRC runlevel (e.g., 'default', 'boot', 'sysinit', 'shutdown', 'nonetwork'). Services are enabled or disabled within these specific system states.<br><br>


title: DESCRIPTION
content:
<i>rc-update</i> is a crucial command within the <I>OpenRC</I> init system, primarily used on Gentoo Linux and other distributions that utilize OpenRC instead of systemd or SysVinit. Its main purpose is to manage which services are started or stopped automatically when the system enters specific runlevels. <br><br>The command allows system administrators to add or remove service scripts from various runlevels by creating or deleting symbolic links in the <I>/etc/runlevels/</I> directory structure. This ensures that services are properly initialized or terminated according to the system's operational state. For instance, services added to the 'default' runlevel will start automatically when the system boots into its normal operating mode, while 'boot' runlevel services are fundamental for the initial system setup. <br><br>Essentially, <i>rc-update</i> provides a streamlined interface for configuring system-wide service startup behavior without manually manipulating symbolic links, making system maintenance more efficient and less error-prone. It serves as OpenRC's equivalent to <I>update-rc.d</I> in SysVinit or <I>systemctl enable/disable</I> in systemd for managing service boot-time behavior.


title: CAVEATS
content:
The <i>rc-update</i> command is specific to systems using the <I>OpenRC</I> init system. It will not be present or functional on systems running <I>systemd</I> (e.g., most modern Fedora, Ubuntu, Debian) or traditional <I>SysVinit</I> (e.g., older Debian, CentOS 6). Changes made by <i>rc-update</i> are persistent across reboots but may not take immediate effect. For changes to apply without a reboot, the affected service must be manually started or stopped using the <I>rc-service</I> command.


title: OPENRC RUNLEVELS
content:
In OpenRC, runlevels define distinct system states, each associated with a specific set of services that should be running. Common runlevels include: <br><ul><li><b>boot</b>: Contains services essential for the initial system bring-up, such as mounting the root filesystem.</li><li><b>sysinit</b>: Services required after 'boot' but before 'default', often including filesystem checks and basic network configuration.</li><li><b>default</b>: The standard operating state, containing services for normal system operation (e.g., SSH, web server, database). This is the typical target for normal boots.</li><li><b>shutdown</b>: Services designed to be stopped gracefully during system shutdown.</li><li><b>nonetwork</b>: A variation of 'default' where network services are explicitly disabled, useful for troubleshooting.</li></ul><br><i>rc-update</i> manages the symbolic links within <I>/etc/runlevels/</I> directories, where each subdirectory corresponds to a runlevel and contains links to the service scripts in <I>/etc/init.d/</I> that should be active in that runlevel.


title: HISTORY
content:
<i>rc-update</i> is an integral component of the <I>OpenRC</I> init system, which originated from <I>Gentoo Linux</I> in the early 2000s as a more flexible and dependency-aware alternative to the traditional <I>SysVinit</I>. Its development aimed to simplify the process of managing service startup and shutdown across different runlevels, moving away from the manual manipulation of symbolic links that was common with SysVinit. The command provides a higher-level abstraction for configuring service integration into runlevels, reflecting OpenRC's focus on modularity, robust dependency tracking, and faster boot times through parallel service startup.


title: SYNOPSIS
content:
Given that <b>rcat</b> is a non-standard command, a definitive synopsis is impossible. If it implies 'reverse cat', it would likely follow the syntax of the standard <b>tac</b> command:<br><br><b>tac</b> [<i>OPTION</i>]... [<i>FILE</i>]...


title: PARAMETERS
content:
<b>-b, --before</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attach the separator before instead of after the record. (Refers to <b>tac</b>'s functionality)<br><br><b>-r, --regex</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret the separator as a regular expression. (Refers to <b>tac</b>'s functionality)<br><br><b>-s, --separator=STRING</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use STRING as the record separator instead of newline. (Refers to <b>tac</b>'s functionality)<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit. (Common for GNU utilities like <b>tac</b>)<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit. (Common for GNU utilities like <b>tac</b>)<br><br>


title: DESCRIPTION
content:
The command <b>rcat</b> is <i>not a standard Linux command</i> found in typical Linux distributions. Unlike ubiquitous utilities such as <b>cat</b> (which concatenates files and prints them to standard output) or <b>tac</b> (which prints files in reverse line order), <b>rcat</b> does not exist as a default system binary. Its appearance typically indicates either a common typographical error for <b>cat</b>, or it refers to a custom alias, shell function, or script configured on a specific system. Such a custom command might be designed to perform a 'reverse cat' operation (similar to <b>tac</b>), or perhaps a specialized remote file concatenation, although the latter is less common. This analysis, therefore, focuses on the most probable interpretations of 'rcat' while consistently highlighting its non-standard nature, providing information based on the functionalities it <i>might</i> imply, particularly the 'reverse cat' concept.


title: CAVEATS
content:
<b>rcat</b> is <i>not a standard Linux command</i> included in typical distributions or GNU Core Utilities. Its existence or functionality, if encountered on a specific system, is entirely dependent on a custom installation, user-defined script, or shell alias. Users attempting to use 'rcat' should first verify if it's an alias or a custom binary configured on their system. The behavior described in this analysis is speculative, primarily drawing parallels with the standard <b>tac</b> command, which performs a 'reverse cat' operation.


title: NON-STANDARD COMMAND CLARIFICATION
content:
It is crucial to understand that <b>rcat</b> is <i>not a part of standard GNU Core Utilities</i> or common Linux distributions. If you encounter 'rcat' in a script, documentation, or on a specific system, it almost certainly refers to:<br>1. A simple typo for the ubiquitous <b>cat</b> command.<br>2. A custom alias, shell function, or script on that specific system designed to perform a particular task (e.g., internally using <b>tac</b>, or a specialized remote file operation).


title: COMMON INTERPRETATIONS OF 'RCAT'
content:
When <b>rcat</b> appears, it commonly leads to two main interpretations due to the 'r' prefix:<br>1. 'Reverse Cat': This is the most common conceptual interpretation, referring to the functionality of the standard <b>tac</b> command, which prints file content line by line starting from the last line.<br>2. 'Remote Cat': Less frequently, the 'r' prefix in Unix commands often denotes 'remote' (e.g., <b>rcp</b> for remote copy, <b>rsh</b> for remote shell). In this context, 'rcat' might imply a custom command to 'cat' a file from a remote machine, though this is purely speculative and depends entirely on a bespoke implementation.


title: HISTORY
content:
Since <b>rcat</b> is not a standard command, it has no official development history. However, the concept of reading files in reverse (which 'rcat' might imply) is embodied by the standard <b>tac</b> command. <b>tac</b> (short for 'cat' backwards) was developed as part of the GNU Core Utilities, a collection of essential tools for Unix-like operating systems. It provides a 'reverse' counterpart to the well-known <b>cat</b> command, which concatenates and displays files from beginning to end. <b>tac</b>'s primary use case involves processing log files or other sequential data in reverse chronological order, often used in conjunction with other text processing utilities.


title: PARAMETERS
content:
<b>--config <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the `rclone` configuration file.<br><br><b>--dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a trial run without making any changes, showing what would happen.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity to info level logging.<br><br><b>-vv</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity to debug level logging.<br><br><b>--progress</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows progress during transfer operations.<br><br><b>--checksum</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks the checksum of files after transfer for verification.<br><br><b>--bwlimit <rate></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Limits bandwidth usage during transfers (e.g., 1M, 1G).<br><br><b>--include <filter></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes files matching the specified filter pattern.<br><br><b>--exclude <filter></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files matching the specified filter pattern.<br><br><b>--filter-from <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads filter patterns from a specified file.<br><br><b>--transfers <num></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of file transfers to run in parallel.<br><br><b>--checkers <num></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of checksum checkers to run in parallel.<br><br><b>--ignore-existing</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips files that already exist at the destination.<br><br><b>--immutable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents modification of files at the destination, useful for append-only backups.<br><br><b>--log-file <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes log messages to the specified file.<br><br><b>--timeout <duration></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the IO idle timeout.<br><br><b>--retries <num></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of times to retry a failed operation.<br><br>


title: DESCRIPTION
content:
<code>rclone</code> is a powerful command-line program to manage files on cloud storage. It is often described as "<i>rsync</i> for cloud storage" because of its robust synchronization capabilities, but it offers much more. <code>rclone</code> supports over 50 cloud storage providers, including popular services like Amazon S3, Google Drive, Microsoft OneDrive, Dropbox, and many others, as well as local file systems and SSH/SFTP.<br><br>Its core functionalities include copying, syncing, moving, deleting, and listing files and directories. <code>rclone</code> can perform one-way and two-way synchronization, ensuring that data is kept consistent across different locations. It features client-side encryption, allowing users to encrypt files before uploading them to the cloud, enhancing privacy and security.<br><br>A significant feature of <code>rclone</code> is its ability to mount cloud storage as a local file system using FUSE, making cloud data accessible to any application as if it were on a local disk. This makes it incredibly versatile for tasks such as backing up data, migrating files between cloud providers, streaming media directly from cloud storage, or even serving files via HTTP/WebDAV. Its reliability, speed, and comprehensive feature set make <code>rclone</code> an indispensable tool for managing vast amounts of data across diverse cloud environments.


title: CAVEATS
content:
<ul><li><b>Data Loss Risk</b>: The `<b>sync</b>` command is powerful and can cause irreversible data loss if used incorrectly, as it makes the destination an exact copy of the source, potentially deleting files on the destination. Always use `<b>--dry-run</b>` first.</li><li><b>Performance with Small Files</b>: Transferring a very large number of small files can be slower than expected due to overheads from API calls.</li><li><b>API Rate Limits</b>: Cloud providers often impose API rate limits. While <code>rclone</code> attempts to handle these, excessive operations can still lead to throttling or temporary bans.</li><li><b>Complexity</b>: Due to its extensive feature set and numerous options, <code>rclone</code> can have a steep learning curve for new users.</li></ul>


title: <B>SUPPORTED CLOUD PROVIDERS</B>
content:
<code>rclone</code> boasts support for over 50 cloud storage providers, including but not limited to: Amazon S3, Google Drive, Google Cloud Storage, Microsoft OneDrive, Dropbox, Backblaze B2, SFTP, FTP, WebDAV, Azure Blob Storage, Box, pCloud, Yandex Disk, and local file systems. This extensive compatibility makes it a universal tool for cloud data management.


title: <B>CLIENT-SIDE ENCRYPTION</B>
content:
<code>rclone</code> provides robust client-side encryption, allowing users to encrypt file names and contents before they leave the local machine. This ensures that data stored on cloud providers remains private and secure, as the cloud provider only receives encrypted data, unable to read or access the original content.


title: <B>FUSE MOUNT CAPABILITIES</B>
content:
One of <code>rclone</code>'s standout features is its ability to mount remote cloud storage as a local filesystem using FUSE (Filesystem in Userspace). This allows any application on the system to interact with cloud files and folders as if they were stored locally, enabling seamless integration with other tools, streaming media, or editing files directly from the cloud.


title: <B>CONFIGURATION AND REMOTES</B>
content:
<code>rclone</code> manages connections to cloud storage providers through "remotes," which are configured interactively or via a configuration file (`~/.config/rclone/rclone.conf`). Each remote stores the necessary credentials and settings for a specific cloud service, simplifying subsequent operations by referencing the remote's name (e.g., `mygoogledrive:`).


title: HISTORY
content:
<code>rclone</code> was created by Nick Craig-Wood and first released in 2014. Written in Go, it quickly gained popularity due to its cross-platform compatibility, robust feature set, and support for a growing number of cloud storage providers. It originated from the need for a reliable `<i>rsync</i>`-like tool for cloud storage, evolving into a comprehensive file management utility. The project is open-source and actively developed, with a strong community contributing to its continuous improvement and expansion of supported services.


title: SYNOPSIS
content:
<b>rcp</b> [<i>OPTION</i>]... <i>SOURCE</i>... <i>DESTINATION</i><br><br><i>Common Usage Patterns:</i><br><b>rcp</b> [<b>-p</b>] [<b>-r</b>] <i>local_file</i> <i>remote_host</i>:<i>remote_path</i><br><b>rcp</b> [<b>-p</b>] [<b>-r</b>] <i>remote_host</i>:<i>remote_path</i> <i>local_file</i><br><b>rcp</b> [<b>-p</b>] [<b>-r</b>] <i>user</i>@<i>remote_host</i>:<i>source_path</i> <i>destination_path</i><br><b>rcp</b> [<b>-p</b>] [<b>-r</b>] <i>source_path</i> <i>user</i>@<i>remote_host</i>:<i>destination_path</i><br><b>rcp</b> [<b>-p</b>] [<b>-r</b>] <i>user1</i>@<i>host1</i>:<i>path1</i> <i>user2</i>@<i>host2</i>:<i>path2</i>


title: PARAMETERS
content:
<b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preserves the modification times, access times, and modes (permissions) of the source files in the destination.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively copies directories and their contents. If a source file is a directory, <code>rcp</code> copies the directory and all its files, including subdirectories and their files, to the destination.<br><br>


title: DESCRIPTION
content:
<code>rcp</code> (remote copy) is a command-line utility used to transfer files or directories between different machines on a network. It is part of the traditional "r-commands" suite, which includes <code>rsh</code> and <code>rlogin</code>. <code>rcp</code> operates by utilizing <code>rsh</code> as its underlying transport, relying on its authentication mechanisms, such as <code>.rhosts</code> files or host-based authentication. While functional for simple file transfers, <code>rcp</code> is widely considered <I>insecure</I> for modern usage over untrusted networks. This is because it transmits all data, including potential credentials and the file content itself, in <I>plain text</I>, making it highly vulnerable to eavesdropping and man-in-the-middle attacks. For secure and encrypted file transfers, modern alternatives like <code>scp</code> (SSH-based copy) or <code>rsync</code> over SSH are strongly recommended and widely preferred. <code>rcp</code> is primarily found on older systems or within very secure, trusted local networks where its simplicity might still be acceptable for specific legacy tasks. It supports both single file transfers and recursive directory copying.


title: CAVEATS
content:
<code>rcp</code> is considered a highly <I>insecure</I> command for file transfer over untrusted networks. It transmits all data, including usernames, passwords, and file contents, in <I>plain text</I>, making it vulnerable to eavesdropping, man-in-the-middle attacks, and unauthorized access. Its authentication mechanism, often relying on <code>.rhosts</code> files or <code>/etc/hosts.equiv</code>, is also weak and prone to security breaches. Due to these significant security flaws, its use is strongly discouraged in favor of modern, encrypted alternatives like <code>scp</code> or <code>rsync</code> over SSH.


title: SECURITY IMPLICATIONS
content:
The most critical aspect of <code>rcp</code> is its <I>lack of encryption</I>. It transmits all data in plain text, making it highly susceptible to interception. It should <I>never</I> be used to transfer sensitive information or over public/untrusted networks.<br>


title: AUTHENTICATION METHODS
content:
<code>rcp</code> primarily relies on <code>rsh</code>'s authentication, which typically uses <code>.rhosts</code> files in user home directories or the <code>/etc/hosts.equiv</code> file. These methods allow passwordless access but are inherently insecure as they trust remote hosts based solely on their IP address or hostname, which can be spoofed.


title: HISTORY
content:
<code>rcp</code> is one of the original remote commands developed for Berkeley Unix (BSD) in the early 1980s. It was designed to facilitate file transfers between networked Unix systems in a relatively trusted environment. Along with <code>rsh</code> (remote shell) and <code>rlogin</code> (remote login), it formed a core suite of tools for distributed system administration. Its primary advantage was simplicity and ease of use, leveraging host-based authentication. However, with the exponential growth of the internet and increasing awareness of network security in the late 1990s and early 2000s, <code>rcp</code>'s fundamental lack of encryption became a critical vulnerability. This led to its gradual deprecation in favor of more secure protocols and commands, particularly <code>scp</code> and <code>rsync</code> which build upon the robust and encrypted SSH protocol. While still available on many legacy systems, its historical context highlights a different era of network security considerations.


title: SYNOPSIS
content:
<b>rcrack</b> [<i>OPTIONS</i>] <b>-t</b> <i>&lt;tables_directory&gt;</i> { <i>&lt;hash_file&gt;</i> [<i>&lt;hash_file&gt;</i>...] | <b>-l</b> <i>&lt;hash_value(s)&gt;</i> }


title: PARAMETERS
content:
<b><b>-h</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an input <i>file</i> containing password hashes to be cracked. Multiple files can be provided.<br><br><b><b>-t</b> <i>&lt;directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Mandatory.</i> Points to the <i>directory</i> where <b>rcrack</b> can find the pre-generated <i>rainbow tables</i>.<br><br><b><b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <i>live cracking</i> mode, allowing hashes to be provided directly on the command line instead of from a file.<br><br><b><b>-o</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the cracked username and password pairs to the specified output <i>file</i>.<br><br><b><b>-p</b> <i>&lt;number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of <i>threads</i> or CPU cores <b>rcrack</b> should use for the cracking process.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays cracking <i>statistics</i> during and after the process, such as hashes cracked and speed.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <b>rcrack</b> to display the <i>username</i> alongside the cracked password if available in the input hash format.<br><br>


title: DESCRIPTION
content:
<b>rcrack</b> is a command-line utility from the <i>Ophcrack</i> project, designed for efficient offline recovery of Windows user passwords. It leverages pre-computed <i>rainbow tables</i> to quickly find plaintext passwords corresponding to LM and NTLM hash values.<br><br>Users typically provide <b>rcrack</b> with a directory containing the rainbow tables and a file (or direct input) of hashes extracted from Windows systems (e.g., SAM files). Its primary strength lies in its speed for cracking hashes that are vulnerable to rainbow table attacks, making it a valuable tool for password auditing and recovery in environments using older Windows hashing schemes.


title: CAVEATS
content:
<b>rcrack</b> is primarily effective against <i>LM</i> and <i>NTLM</i> hashes, commonly found in older Windows environments. It is less effective or ineffective against modern, salted hash algorithms (e.g., <i>NTLMv2</i> with strong entropy) or hashes from other operating systems.<br><br>Requires substantial, pre-generated <i>rainbow tables</i>, which can be very large (gigabytes to terabytes) and time-consuming to create. The cracking success depends heavily on the quality and completeness of these tables.


title: RAINBOW TABLES
content:
<i>Rainbow tables</i> are pre-computed tables used in cryptanalysis to reverse cryptographic hash functions, usually for cracking password hashes. They store pre-calculated chains of hash values and their corresponding plaintext, significantly speeding up the cracking process compared to brute-force or dictionary attacks, especially for unsalted hashes.


title: SUPPORTED HASH TYPES
content:
<b>rcrack</b> specifically targets <i>LM</i> (LAN Manager) and <i>NTLM</i> (NT LAN Manager) hash algorithms. These are traditional hash formats used by Microsoft Windows for storing user passwords, particularly in Windows NT, 2000, XP, and older versions of Vista/7, though NTLM continues to be used in various authentication contexts.


title: HISTORY
content:
<b>rcrack</b> was developed as a core command-line component of the <i>Ophcrack</i> project. <i>Ophcrack</i>, first released around 2006, quickly became a popular open-source tool for Windows password auditing and recovery, primarily due to its efficient implementation of <i>rainbow table</i> attacks. <b>rcrack</b> provides the raw cracking engine accessible from the terminal.


title: PARAMETERS
content:
<b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initializes an <i>RCS file</i> for a given working file, creating the <i>,v</i> file if it doesn't exist. This is the first step to place a file under RCS control.<br><br><b><b>-l</b>[<i>rev</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Locks the specified <i>revision</i> (or the default, usually the latest) in the <i>RCS file</i>, preventing others from checking in changes until unlocked. Typically used in conjunction with <b>co</b>.<br><br><b><b>-u</b>[<i>rev</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unlocks the specified <i>revision</i> (or the default) in the <i>RCS file</i>, allowing others to check in changes. Often used to release a forgotten lock or after a check-in.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in quiet mode, suppressing non-error diagnostic messages during execution.<br><br><b><b>-r</b>[<i>rev</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default <i>revision</i> for subsequent operations (e.g., <b>co</b> without a <b>-r</b> option will check out this revision).<br><br><b><b>-b</b>[<i>rev</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default branch to which new revisions will be added when checking in via <b>ci</b>.<br><br><b><b>-t</b>[<i>file</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a <i>file</i> (or standard input if <i>file</i> is omitted) containing the descriptive text for the <i>RCS file</i>. This text summarizes the project or file's purpose.<br><br><b><b>-n</b><i>name</i>[:[<i>rev</i>]]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Associates a symbolic <i>name</i> (tag) with a specific <i>revision</i>. If <i>rev</i> is omitted, the current head revision is used. Useful for marking releases or important versions.<br><br><b><b>-o</b><i>range</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes revisions within the specified <i>range</i> from the <i>RCS file</i>. The range can be a single revision, a branch, or a pair of revisions (e.g., <i>1.1:1.3</i>). Use with caution as this is irreversible.<br><br><b><b>-a</b><i>login</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a user's <i>login</i> name to the access list of the <i>RCS file</i>, granting them permission to make changes.<br><br><b><b>-e</b>[<i>login</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes a user's <i>login</i> name from the access list of the <i>RCS file</i>. If <i>login</i> is omitted, all entries are removed, restricting changes to the file's owner.<br><br><b><b>-k</b><i>subst</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls keyword expansion when revisions are checked out. Common values include <i>kv</i> (keyword and value), <i>o</i> (old value), or <i>b</i> (binary file, suppressing all expansion).<br><br>


title: DESCRIPTION
content:
The <b>rcs</b> command, part of the Revision Control System (RCS) suite, is used to administer <i>RCS files</i>, which store revisions of text files. It allows users to create, modify attributes of, and perform various administrative tasks on these version-controlled files. <br><br>Unlike modern distributed version control systems like Git, <b>rcs</b> operates on a per-file basis, managing a single file's revision history in a corresponding <i>RCS file</i> (typically named with a <i>,v</i> suffix, e.g., <i>myfile.c,v</i>). <br><br>While not commonly used for large-scale team development today, <b>rcs</b> remains valuable for versioning individual scripts, configuration files, or small personal projects where a full-fledged version control system might be overkill. Its primary functions include initializing <i>RCS files</i>, locking/unlocking revisions to prevent simultaneous edits, setting default branches/revisions, and managing access lists.


title: CAVEATS
content:
<b>rcs</b> is a file-based version control system and lacks many features of modern systems. It does not provide atomic commits across multiple files, making multi-file changes difficult to manage consistently. Concurrent modifications by multiple users require careful manual locking (using <b>rcs -l</b>) to prevent conflicts. It is generally not suitable for large, collaborative projects or distributed development workflows.


title: RCS FILES (<I>,V</I> FILES)
content:
For every source file (e.g., <i>example.c</i>) managed by <b>rcs</b>, there is a corresponding <i>RCS file</i> (e.g., <i>example.c,v</i>). These <i>RCS files</i> store all revisions, logs, and administrative information for that specific source file. <b>rcs</b> commands directly manipulate these <i>,v</i> files, while <b>ci</b> and <b>co</b> commands interact with them to manage the working copies. It's crucial to always interact with the <i>,v</i> file via <b>rcs</b>, <b>ci</b>, or <b>co</b>, and never directly modify it.


title: BASIC WORKFLOW
content:
A typical workflow for managing a file with RCS involves: <br>1. <b>rcs -i <i>file</i></b>: Initialize the <i>RCS file</i> for <i>file</i>. This creates <i>file,v</i>. <br>2. <b>ci -l <i>file</i></b>: Check in the first revision (if starting fresh) or subsequent changes, and lock the working file for exclusive editing. <br>3. Edit <i>file</i> in your preferred editor. <br>4. <b>ci -u <i>file</i></b>: Check in your changes and unlock the file. This creates a new revision in <i>file,v</i>. <br>5. <b>co -l <i>file</i></b>: Check out a revision and lock it for further editing. <br>6. <b>rcs -u <i>file</i></b>: Manually unlock a file if it was locked inadvertently or a previous operation failed, releasing the lock without checking in changes.


title: HISTORY
content:
The Revision Control System (RCS) was initially developed by <i>Walter F. Tichy</i> at Purdue University in 1982. It quickly became a standard tool for managing source code and documentation on Unix-like systems throughout the 1980s and 1990s. Its primary design focused on efficient storage and retrieval of individual file revisions. <br><br><b>RCS</b> served as the foundation for the Concurrent Versions System (CVS), which extended its capabilities to support concurrent access by multiple users and operate on entire projects, paving the way for more modern version control systems like Subversion (SVN) and Git.


title: PARAMETERS
content:
<b><I>script_path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the run control script (e.g., an <b>init.d</b> script) to be tested. This is often a mandatory argument for `rctest` implementations designed to test specific scripts.<br><br><b><I>action</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The action to be passed to the target script, such as <b>start</b>, <b>stop</b>, <b>status</b>, <b>restart</b>, <b>reload</b>, or <b>force-reload</b>. This argument simulates how an <i>init</i> system would invoke the script.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the command's output, showing more details about the execution process or the output of the tested script. This is a common option for debugging.<br><br><b><b>-d</b>, <b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug mode, often printing internal operations, environment variables, or detailed error information helpful for troubleshooting the <b>rctest</b> utility itself or the script being tested.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulates the execution of the script without actually performing any system changes. This is useful for previewing actions and dependencies without risk.<br><br>


title: DESCRIPTION
content:
The <b>rctest</b> command is not a standard utility found in most modern Linux distributions. Its name suggests it is designed for testing <I>run control</I> (RC) scripts, typically those found in the <b>/etc/init.d</b> directory or the <b>/etc/rc.local</b> script. When it exists, <b>rctest</b> usually provides a way to execute these system startup/shutdown scripts outside of the normal boot sequence, allowing administrators or developers to verify their functionality, check for errors, and ensure they behave as expected before deployment or during troubleshooting.<br><br>Due to its non-standard nature, the exact implementation, available options, and behavior of <b>rctest</b> can vary significantly depending on the specific Linux distribution, embedded system, or custom environment where it is found. It might simulate the execution environment of an <I>init</I> system, passing arguments like <b>start</b>, <b>stop</b>, <b>status</b>, or <b>restart</b> to the target script. Users should consult the documentation specific to their system if <b>rctest</b> is present.


title: CAVEATS
content:
<b>rctest</b> is not a standard Linux command and is rarely found on modern general-purpose distributions (which typically use systemd). Its functionality, if present, is highly specific to its implementation and the environment it serves (e.g., custom embedded systems or older SysVinit-based distributions). <br><br>When testing system startup/shutdown scripts, especially with root privileges, always exercise caution as improper execution can lead to system instability or unintended side effects.


title: USAGE CONTEXT
content:
If encountered, <b>rctest</b> is most likely to be found on specialized Linux systems, such as embedded devices, legacy servers still running SysVinit, or custom-built distributions. It is generally not part of the core utilities provided by major desktop or server Linux distributions today.


title: SECURITY CONSIDERATIONS
content:
As <b>rctest</b> would typically involve executing system scripts that might modify system state or privileged resources, it often requires root privileges. Care should be taken when using such a command, as executing untrusted or improperly configured scripts can lead to security vulnerabilities or system malfunctions.


title: HISTORY
content:
The concept of testing run control scripts predates modern init systems like systemd. In the era of SysVinit, where scripts in <b>/etc/init.d</b> were central to system startup and shutdown, utilities like <b>rctest</b> (or custom shell scripts with similar functionality) might have been used to manually test the behavior of these scripts. However, there is no widely documented or standardized history for a specific command named <b>rctest</b>. Its appearance is likely limited to specific embedded Linux projects, legacy systems, or custom build environments where a simple testing utility for run control scripts was deemed necessary.


title: PARAMETERS
content:
<b><i>host</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The hostname or IP address of the remote machine from which to retrieve the date and time.<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the date and time obtained from the remote host to standard output, but <i>do not</i> set the local system's clock. This option is useful for testing connectivity or viewing the remote time without modifying the system.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the date and time on the local system using the time retrieved from the remote host. This is typically the default behavior if no other action-modifying options like <b>-p</b> are specified and a host is provided. Setting the system clock usually requires root privileges.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a local TCP port number of 1023 or less when connecting to the remote host. This option is sometimes necessary when communicating with older Time Protocol servers that enforce connections originating from privileged ports. Using this option requires root privileges to bind to a low-numbered port.<br><br>


title: DESCRIPTION
content:
The <b>rdate</b> command is a utility used to retrieve the current date and time from a specified remote network host and set the local system's clock accordingly. It primarily utilizes the <i>Time Protocol</i> (RFC 868) over TCP port 37. While historically useful for basic time synchronization, it is now largely considered a legacy tool. Modern systems prefer <i>NTP</i> (Network Time Protocol) based solutions (like <b>ntpdate</b>, <b>ntpd</b>, or <b>chrony</b>) for their superior accuracy, robustness, and advanced features such as handling leap seconds, stratum information, and cryptographic authentication. <b>rdate</b>'s simplicity means it lacks these sophisticated capabilities, making it less suitable for critical time synchronization in contemporary networked environments.


title: CAVEATS
content:
<b>Security:</b> <b>rdate</b> uses the insecure RFC 868 Time Protocol, which offers no authentication or encryption. This makes it vulnerable to man-in-the-middle attacks, where a malicious actor could provide an incorrect time.<br><b>Accuracy:</b> It is less accurate than NTP. It does not account for network latency in a sophisticated manner, nor does it handle leap seconds or provide stratum information, which are crucial for precise timekeeping.<br><b>Privileges:</b> Setting the system time and using the <b>-L</b> option typically require root privileges.<br><b>Deprecation:</b> It has been largely superseded by NTP clients (<b>ntpdate</b>, <b>ntpd</b>, <b>chrony</b>) for robust, secure, and accurate time synchronization.<br><b>Firewall:</b> Requires TCP port 37 to be open on both the client and the server for communication.


title: TIME PROTOCOL (RFC 868)
content:
The <i>Time Protocol</i>, defined in RFC 868, is a very simple network protocol that <b>rdate</b> relies upon. A server implementing this protocol listens on TCP port 37 and, upon receiving a connection, sends a 32-bit unsigned integer representing the number of seconds since January 1, 1900, 00:00 UT. It then closes the connection. This protocol's simplicity means it does not account for network latency, leap seconds, or provide any authentication or error correction, which are significant limitations compared to modern time synchronization protocols like NTP.


title: HISTORY
content:
<b>rdate</b> has been a part of Unix-like systems for many decades, implementing the simple <i>RFC 868 Time Protocol</i> which was published in May 1983. Its early existence predates the widespread adoption and sophistication of <i>NTP</i> (Network Time Protocol), whose initial RFCs (RFC 958 in 1985, RFC 1305 in 1992) introduced much more advanced time synchronization capabilities. Due to its straightforward nature, <b>rdate</b> served as a basic utility for time synchronization in early network environments. However, as network security and the demand for highly accurate timekeeping grew, <i>NTP</i>-based solutions became the industry standard, effectively rendering <b>rdate</b> obsolete for most production use cases today.


title: PARAMETERS
content:
<b><B>-dryrun</B>, <B>-D</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a dry run, showing what actions <I>rdfind</I> would take without actually modifying any files. Highly recommended before any destructive operations.<br><br><b><B>-deleteduplicates</B>, <B>-N</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes all but one instance of each set of duplicate files found. This action permanently removes files and should be used with extreme care after a <B>-dryrun</B>.<br><br><b><B>-makelinks</B>, <B>-L</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replaces all but one instance of each set of duplicate files with hard links to the remaining original file. This saves disk space without deleting content.<br><br><b><B>-output</B> <I>file</I>, <B>-o</B> <I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the list of identified duplicate files and proposed actions to the specified output <I>file</I> instead of standard output.<br><br><b><B>-checksum</B> <I>algorithm</I>, <B>-C</B> <I>algorithm</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the checksum <I>algorithm</I> to use for content comparison. Common options include <I>md5</I> (default), <I>sha1</I>, and <I>crc32</I>.<br><br><b><B>-ignoreempty</B>, <B>-E</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignores zero-byte (empty) files during the duplicate finding process. Empty files are often not considered 'true' duplicates.<br><br><b><B>-recurse</B>, <B>-R</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recurses into subdirectories (this is the default behavior).<br><br><b><B>-sizesort</B>, <B>-Z</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the output by file size, which can be useful for identifying the largest potential space savings.<br><br><b><B>-verbose</B>, <B>-V</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more information about the scanning process.<br><br><b><B>-help</B>, <B>-H</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and usage information.<br><br>


title: DESCRIPTION
content:
The <I>rdfind</I> command is a powerful utility designed to locate and manage duplicate files across one or more specified directory trees. Unlike <I>find</I>, which primarily operates on file metadata, <I>rdfind</I> identifies identical files based on their actual content. It typically employs a two-phase approach: first, it groups files by size, and then it computes checksums (like MD5 or SHA1) for files within those size-identical groups to confirm byte-for-byte equality. Once duplicates are identified, <I>rdfind</I> offers various actions, including listing the duplicates, replacing redundant copies with hard links to a single original file, or safely deleting all but one instance of each duplicate set. Its efficiency makes it suitable for large filesystems, helping to reclaim disk space or ensure data consistency.<br><br>It's crucial to use <I>rdfind</I>'s destructive options with caution, always employing the <B>-dryrun</B> flag first to preview changes.


title: CAVEATS
content:
Using <I>rdfind</I> with options like <B>-deleteduplicates</B> or <B>-makelinks</B> can lead to irreversible data loss or unexpected filesystem changes if not used carefully. Always perform a <B>-dryrun</B> first and review its output thoroughly. The process can be I/O intensive, especially on large datasets, and may impact system performance during execution. While checksum algorithms like MD5 or SHA1 are highly reliable, theoretical (though extremely rare) collision risks exist, where two different files could produce the same checksum.


title: SAFE USAGE PRACTICES
content:
Before executing any command that modifies files (e.g., <B>-deleteduplicates</B> or <B>-makelinks</B>), always run <I>rdfind</I> with the <B>-dryrun</B> flag. This allows you to inspect the list of identified duplicates and the proposed actions without making any changes. Review the output carefully to ensure that the files <I>rdfind</I> targets are indeed duplicates you wish to manage. Only after you are confident in the proposed actions should you remove the <B>-dryrun</B> flag and execute the command.


title: HOW IT IDENTIFIES DUPLICATES
content:
<I>rdfind</I> primarily uses a two-stage process to identify duplicate files:<br><br>1. <B>Size Comparison:</B> It first groups files by their exact size. Files of different sizes cannot be duplicates, so this significantly reduces the number of files that need deeper analysis.<br>2. <B>Checksum Verification:</B> For files within the same size group, <I>rdfind</I> then calculates a checksum (e.g., MD5 or SHA1) for their content. Only if the checksums match are the files considered true byte-for-byte duplicates. This ensures accuracy even if files have identical names or timestamps but different content.


title: HISTORY
content:
<I>rdfind</I> is a specialized utility developed for the specific task of efficiently finding and managing duplicate files. While its exact initial development history is not widely documented in general Linux utility timelines, it emerged as a practical solution to address the common problem of disk space waste and data redundancy on filesystems, often used by system administrators and power users for maintenance tasks. Its focus on content-based comparison (checksums) distinguishes it from general-purpose file searching tools.


title: PARAMETERS
content:
<b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing progress and details during the diff creation process.<br><br><b><b>-z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compresses the output diff file, reducing its size at the cost of increased CPU usage during diff creation and patching.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the creation of the diff file, overwriting any existing file with the same name without prompting.<br><br><b><b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables 'lame' mode, which avoids using random files for temporary diff operations. Useful for NFS shares but not recommended for optimal performance or security.<br><br><b><b>-t</b> <i>TMP_DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative directory (<i>TMP_DIR</i>) for storing temporary files during the diff generation. Defaults to /tmp.<br><br><b><b>-x</b> <i>EXCLUDE_LIST</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files and directories matching any of the regular expressions provided in <i>EXCLUDE_LIST</i> from the diff operation.<br><br><b><i>OLD_DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the original or older version of the directory tree.<br><br><b><i>NEW_DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the newer or updated version of the directory tree.<br><br><b><i>DIFF_FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the output binary diff file. If omitted, defaults to <i>rdiffdir.diff</i> in the current directory.<br><br>


title: DESCRIPTION
content:
<i>rdiffdir</i> is a utility designed to compute and generate a binary difference (diff) between two specified directory trees: an <i>OLD_DIR</i> and a <i>NEW_DIR</i>. It operates by recursively traversing both directories, identifying changed, added, or removed files. For files that have been modified, it internally uses the <i>rdiff</i> utility to create a binary diff at the file level. The output is a single, compact binary diff file (by default <i>rdiffdir.diff</i>) that encapsulates all the changes necessary to transform <i>OLD_DIR</i> into <i>NEW_DIR</i>. This mechanism is particularly useful for efficient storage, backup, and transmission of directory updates, as only the changes, rather than the entire new version, need to be stored or sent. The binary nature of the diff makes it applicable to any file type, not just plain text. It is typically part of the <i>rdiff</i> package, distinct from <i>rdiff-backup</i>.


title: CAVEATS
content:
<i>rdiffdir</i> is distinct from <i>rdiff-backup</i>; they serve different purposes. This utility is part of the older <i>rdiff</i> package and might not be actively maintained or widely available in modern Linux distributions. While it creates binary diffs, these can still be large for directories with many or heavily modified files. Its usage of regular expressions for exclusion can also be complex to manage correctly.


title: USAGE PATTERN
content:
<i>rdiffdir</i> generates a binary diff file between two directories. To reconstruct the newer directory from the old one using this diff, the separate <i>rdiffpatchdir</i> utility is typically used.<br><br><b>Example:</b><br>1. Create a diff: <b>rdiffdir</b> <i>/path/to/old_dir</i> <i>/path/to/new_dir</i> <i>changes.rdiff</i><br>2. Apply the diff: <b>rdiffpatchdir</b> <i>/path/to/old_dir</i> <i>/path/to/reconstructed_new_dir</i> <i>changes.rdiff</i>


title: HISTORY
content:
<i>rdiffdir</i> belongs to the <i>rdiff</i> suite, a set of tools focused on generating binary diffs of files and directories. Developed primarily in the early 2000s, it aimed to provide a compact way to represent changes between directory snapshots. Its direct utility has somewhat waned with the advent of more versatile tools like <i>rsync</i> for synchronization and other dedicated backup solutions, but it remains a classic example of a direct binary differencing approach for directory trees.


title: SYNOPSIS
content:
<b>react-native</b> <i>&lt;command&gt;</i> [<i>options</i>] [<i>arguments</i>]<br><br>Examples:<br><b>react-native</b> <i>init</i> <i>MyProjectName</i><br><b>react-native</b> <i>run-android</i><br><b>react-native</b> <i>start</i>


title: PARAMETERS
content:
<b>init <i>&lt;ProjectName&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initializes a new React Native project in a directory named <i>&lt;ProjectName&gt;</i>, setting up the basic file structure and dependencies.<br><br><b>run-android</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds and launches the React Native application on an attached Android device or a running Android emulator.<br><br><b>run-ios</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds and launches the React Native application on an attached iOS device or a running iOS simulator (requires macOS and Xcode).<br><br><b>start</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the Metro JavaScript bundler and development server, which serves your JavaScript bundle to the device during development.<br><br><b>bundle</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Bundles the JavaScript code and assets into a single file for release builds, typically used for production deployment.<br><br><b>log-android</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints logs from the Android device or emulator, useful for debugging.<br><br><b>log-ios</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints logs from the iOS simulator or device (requires macOS), useful for debugging.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the installed version of the React Native CLI.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides help information for the main CLI command or a specific subcommand when used as <b>react-native</b> <i>&lt;command&gt;</i> <b>--help</b>.<br><br>


title: DESCRIPTION
content:
React Native is an open-source UI software framework created by Meta Platforms, Inc. It enables developers to build robust, high-performance mobile applications for Android and iOS platforms using JavaScript and the React library. Unlike traditional hybrid frameworks, React Native compiles JavaScript components into native UI components, offering a truly native look, feel, and performance. The <b>react-native</b> command-line interface (CLI) serves as the indispensable toolkit for developers working with React Native projects. It streamlines the entire development lifecycle, from initializing new project structures with necessary configurations and dependencies to running applications on various emulators, simulators, or physical devices. Furthermore, the CLI handles crucial tasks like bundling JavaScript code and static assets into production-ready packages and managing development servers for real-time code changes. It significantly simplifies the process of creating cross-platform mobile applications by abstracting away many platform-specific build complexities, allowing developers to write and maintain a single, efficient codebase that achieves native capabilities on both major mobile operating systems.


title: CAVEATS
content:
The <b>react-native</b> command is not a core Linux utility but a JavaScript application CLI. It requires Node.js and a package manager like npm or yarn to be installed. Building for Android necessitates a Java Development Kit (JDK) and Android SDK, usually managed via Android Studio. For iOS development, a macOS environment with Xcode and its command-line tools is mandatory. Setting up the complete development environment can be complex and platform-specific.


title: METRO BUNDLER INTEGRATION
content:
The <b>react-native</b> CLI tightly integrates with Metro Bundler, a JavaScript bundler optimized for React Native. Metro's primary role is to compile, optimize, and serve your application's JavaScript code and assets to the devices, enabling features like Fast Refresh and Hot Module Replacement during development, and generating production bundles.


title: NATIVE MODULES AND BRIDGING
content:
A key strength of React Native, facilitated by its CLI, is its ability to interact with native platform features through 'native modules'. These modules allow JavaScript code to call platform-specific APIs (e.g., camera, GPS) and vice-versa, leveraging the native bridging mechanism. The CLI helps in linking and managing these native dependencies, although newer versions automate much of this process.


title: HISTORY
content:
React Native was open-sourced by Facebook (now Meta) in March 2015, stemming from an internal hackathon project focused on enabling developers to build native UIs using JavaScript. Initially, it provided support exclusively for iOS, with Android support being integrated and released in September 2015. Over the years, the CLI has undergone significant enhancements, including improvements in dependency management (e.g., auto-linking native modules), performance, and developer experience. It has become a cornerstone for cross-platform mobile development, continuously evolving through substantial contributions from Meta and a vibrant open-source community.


title: PARAMETERS
content:
<b>--port &lt;number&gt;, -p &lt;number&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the port on which the Metro bundler will run. Default is 8081.<br><br><b>--host &lt;string&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the host address the bundler should listen on. Defaults to 'localhost'.<br><br><b>--reset-cache, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clears the Metro bundler's cache before starting. Useful for resolving bundling issues.<br><br><b>--no-interactive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables interactive mode, preventing the display of the development menu in the terminal.<br><br><b>--max-workers &lt;number&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the maximum number of worker processes Metro can use for bundling.<br><br><b>--config &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative path to a Metro configuration file (e.g., <I>metro.config.js</I>).<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose logging output from the bundler, showing more detailed information.<br><br><b>--https</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the development server with HTTPS instead of HTTP.<br><br><b>--cert &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the SSL certificate file when using HTTPS.<br><br><b>--key &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the SSL private key file when using HTTPS.<br><br>


title: DESCRIPTION
content:
The <B>react-native-start</B> command is the primary method to launch the Metro bundler, which serves as the essential development server for React Native applications. It compiles JavaScript code (including JSX and TypeScript), bundles static assets (like images and fonts), and efficiently delivers them to your React Native device or simulator.<br><br>By default, the bundler listens on port 8081, making the bundled application accessible to the client app running on a device or emulator. It continuously monitors your project files for changes, recompiling and pushing updates. This command enables crucial developer features such as Fast Refresh and Hot Module Replacement (HMR), providing instantaneous feedback on code modifications without requiring a full app restart. It is an integral part of the <I>react-native-cli</I> and is fundamental for any local React Native development workflow, streamlining the process by managing dependencies and serving the JavaScript bundle efficiently.


title: CAVEATS
content:
Requires Node.js and npm/yarn to be installed and properly configured.<br><br>Can be resource-intensive (CPU and memory) for large projects or when the <I>--reset-cache</I> option is frequently used.<br><br>Common issues include port conflicts (if the default port 8081 is already in use) and network firewall restrictions that might prevent connections.<br><br>Relies heavily on the <I>metro-bundler</I> package; issues with its installation or version can affect <I>react-native-start</I>'s functionality.


title: INTERACTIVE MODE
content:
When run without the <I>--no-interactive</I> flag, <I>react-native-start</I> presents an interactive menu in the terminal. This menu allows developers to perform common actions such as reloading the app, opening the debugger, or toggling Fast Refresh, significantly enhancing the development workflow and providing quick access to essential tools.


title: METRO BUNDLER INTEGRATION
content:
The <I>react-native-start</I> command is essentially a convenient wrapper that initializes and manages the Metro bundler. Metro is a highly optimized JavaScript bundler designed specifically for React Native, focusing on speed and efficiency for large codebases. It is crucial for transforming your source code into a format runnable on mobile devices.


title: FAST REFRESH
content:
A key development feature enabled by <I>react-native-start</I> is Fast Refresh. This allows you to see changes to your React components instantly on your device or simulator without losing component state. It dramatically speeds up the iteration cycle during development by providing near real-time feedback on code modifications.


title: HISTORY
content:
<I>react-native-start</I> has been a core command since the early days of React Native, serving as the gateway to local application development. It initially integrated tightly with a component called 'Packager,' which later evolved into the standalone and highly optimized <I>Metro</I> bundler. While the underlying technology has seen significant improvements in performance, caching mechanisms, and the introduction of features like Fast Refresh, the command's primary function—to serve the JavaScript bundle and assets to devices—has remained consistent, solidifying its role as the central piece for React Native development.


title: PARAMETERS
content:
<b>-a <i>ARRAY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assign words read to sequential indices of <i>ARRAY</i>, starting at zero.<br><br><b>-d <i>DELIM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continue reading until the first character of <i>DELIM</i> is encountered, rather than newline.<br><br><b>-e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use <i>Readline</i> to obtain the line, providing editing features when reading from a terminal.<br><br><b>-n <i>NCHARS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Return after reading at most <i>NCHARS</i> characters rather than waiting for a newline or <i>DELIM</i>.<br><br><b>-p <i>PROMPT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display <i>PROMPT</i> on standard error without a trailing newline before attempting to read.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Backslash does not act as an escape character. The backslash is considered part of the line.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Silent mode. Do not echo input coming from a terminal.<br><br><b>-t <i>TIMEOUT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Cause <i><b>read</b></i> to terminate after <i>TIMEOUT</i> seconds if a complete line is not read.<br><br><b>-u <i>FD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read from file descriptor <i>FD</i> instead of standard input (0).<br><br><b><i>VARIABLE...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more shell variables to which the words of the input line will be assigned. If fewer <i>VARIABLES</i> are provided than words, the remaining words are assigned to the last <i>VARIABLE</i>. If no <i>VARIABLES</i> are provided, the entire line is stored in the <i><b>REPLY</b></i> variable.<br><br>


title: DESCRIPTION
content:
The <i><b>read</b></i> command is a shell built-in that reads a single line from standard input (or a specified file descriptor) and splits it into fields. These fields are then assigned sequentially to shell variables. By default, words are separated by whitespace (spaces, tabs, newlines), but this behavior can be altered using the <i><b>IFS</b></i> (Internal Field Separator) environment variable. It's an indispensable tool for interactive shell scripting, allowing scripts to prompt users for input or to process data line by line from files or pipes. The command can handle various scenarios, such as reading sensitive information without echoing it, setting a timeout for input, or reading only a specific number of characters. Its flexibility makes it a cornerstone for creating dynamic and interactive shell automation.


title: CAVEATS
content:
The behavior of <i><b>read</b></i> is heavily influenced by the <i><b>IFS</b></i> (Internal Field Separator) environment variable, which determines how input lines are split into words. Care must be taken when setting or unsetting <i><b>IFS</b></i> to achieve desired parsing results. The command's return status indicates success (0) if a line was read, or failure (non-zero) if EOF was reached, a timeout occurred, or an error occurred. This status is crucial for loop control when processing files line by line. Be aware that the <i><b>-s</b></i> option only works when reading from a terminal; it has no effect when input is redirected from a pipe or file. Similarly, <i><b>-p</b></i> and <i><b>-e</b></i> are primarily useful for interactive terminal input.


title: RETURN STATUS
content:
The <i><b>read</b></i> command returns a status of 0 upon successful completion (i.e., a line was read). It returns a non-zero status if an end-of-file is encountered, a timeout occurs (with <i><b>-t</b></i>), or an error occurs. This is critical for controlling loops and error handling in scripts.


title: IFS AND WORD SPLITTING
content:
By default, <i><b>read</b></i> splits the input line into words based on the characters in the <i><b>IFS</b></i> (Internal Field Separator) environment variable. If <i><b>IFS</b></i> is unset or contains only whitespace, words are delimited by whitespace (spaces, tabs, newlines). Leading and trailing <i><b>IFS</b></i> whitespace is trimmed, and consecutive <i><b>IFS</b></i> characters are treated as a single delimiter. Understanding and manipulating <i><b>IFS</b></i> is key for precise parsing.


title: READING FROM FILES AND PIPES
content:
While <i><b>read</b></i> defaults to standard input, it can read from files using input redirection (e.g., <i>while read line; do ... done < file.txt</i>) or from pipes (e.g., <i>cat file.txt | while read line; do ... done</i>). The <i><b>-u</b></i> option also allows reading from a specific file descriptor opened with <i><b>exec</b></i>.


title: HISTORY
content:
The <i><b>read</b></i> command is a fundamental shell built-in, present in virtually all modern Unix-like shells, including <i><b>bash</b></i>, <i><b>ksh</b></i>, and <i><b>zsh</b></i>. Its core functionality of reading a line and assigning to variables has been a staple of shell scripting since early versions of the Bourne shell. Over time, various options like <i><b>-p</b></i> for prompts, <i><b>-s</b></i> for silent input, and <i><b>-t</b></i> for timeouts have been added to enhance its capabilities for interactive scripts and robust data processing. Its ubiquitous nature makes it one of the most frequently used commands in shell automation and user interaction.


title: PARAMETERS
content:
<b><b>-f</b>, <b>--canonicalize-existing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Canonicalize by following every component of the path, checking that each component exists and is a directory (except for the last one). All symbolic links are resolved, and the resulting path is absolute.<br><br><b><b>-e</b>, <b>--canonicalize-existing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;This option is equivalent to <b>-f</b>. It canonicalizes the path by following all symbolic links and requiring all components to exist.<br><br><b><b>-m</b>, <b>--canonicalize-missing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Canonicalize by following every component of the path, but do not require them to exist. This can be useful for constructing paths that may not yet exist but need to be resolved against existing components.<br><br><b><b>-n</b>, <b>--no-newline</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not output the trailing newline character. Useful for assigning the output directly to a shell variable without extra whitespace.<br><br><b><b>-q</b>, <b>--quiet</b>, <b>--silent</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress most (or all) error messages. When used, <b>readlink</b> will still return a non-zero exit status on errors, but will not print diagnostic messages to standard error.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report messages about non-existent source or errors. This is usually the default behavior without <b>-q</b>.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br>


title: DESCRIPTION
content:
The <b>readlink</b> command is used to display the value of a symbolic link or to canonicalize a path by resolving all its components. <br><br>When given a symbolic link, <b>readlink</b> by default simply prints the string that the symbolic link points to, without checking if the target actually exists. For example, if 'mylink' points to '../targetfile', <b>readlink mylink</b> will output '../targetfile'. <br><br>Its more powerful modes, enabled by options like <b>-f</b>, <b>-e</b>, or <b>-m</b>, allow it to follow all symbolic links in a path and resolve it to its canonical, absolute form. This means it will traverse directories and links until it reaches a path with no symbolic link components left, typically an absolute path. This is useful for scripts that need to work with real file paths, regardless of how they were referenced.<br><br><b>readlink</b> is a lightweight tool, part of the GNU core utilities, often used in shell scripts for robust path handling.


title: CAVEATS
content:
Differences exist between GNU <b>readlink</b> (common on Linux) and BSD <b>readlink</b> (common on macOS/FreeBSD). GNU versions typically offer more robust options like <b>-f</b>, <b>-e</b>, and <b>-m</b> for path canonicalization, which may not be present in BSD variants. <br><br>When using <b>-m</b>, be aware that the resulting path might contain components that do not exist, and its meaning can be ambiguous if used without careful consideration.


title: EXIT STATUS
content:
<b>readlink</b> exits with a status of 0 upon successful operation. A non-zero exit status indicates an error, such as a file not found, permission denied, or an invalid option. Scripts should always check the exit status for reliable error handling.


title: SYMLINK VALUE VS. CANONICAL PATH
content:
It's crucial to distinguish between merely reading the <i>value</i> of a symbolic link (the path string it contains, e.g., using <b>readlink mylink</b>) and resolving a <i>canonical path</i> (following all links and removing `.` or `..` components to get an absolute, true path, e.g., using <b>readlink -f mylink</b>). The former gives you the link's raw content, the latter gives you the ultimate, absolute destination.


title: HISTORY
content:
The concept of resolving symbolic links is fundamental to Unix-like operating systems, implemented via the <b>readlink(2)</b> system call. The <b>readlink</b> utility itself is a standard tool provided by the GNU Core Utilities on Linux systems, translating the system call's functionality into a convenient command-line interface. Its development has focused on providing robust path canonicalization features, making it an indispensable tool for shell scripting and system administration.


title: PARAMETERS
content:
<b>dev=<I>target</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the SCSI device or target for the optical drive (e.g., <I>dev=/dev/sr0</I> or <I>dev=0,0,0</I>). This is a mandatory and fundamental option.<br><br><b>speed=<I>speed</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the read speed for the optical drive (e.g., <I>speed=8</I>).<br><br><b>output=<I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the file path where the read data will be written. If omitted, data is written to standard output.<br><br><b>sector=<I>start_sector</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts reading from the specified sector number.<br><br><b>sectors=<I>count</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the specified number of sectors from the <I>start_sector</I>.<br><br><b>noerror</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables reading with error correction, making the command attempt to read even problematic sectors.<br><br><b>raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads data in raw mode, including sync bytes and error correction codes. Useful for exact disc copies or forensic analysis.<br><br><b>raw96r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads raw 96-byte sectors including R-W subchannel data.<br><br><b>raw96p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads raw 96-byte sectors including P-Q subchannel data.<br><br><b>cdda</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads audio data from an audio CD.<br><br><b>audioscan</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scans the disc for audio tracks and prints their start and length.<br><br><b>dummy</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a test run without actually reading or writing data, useful for verifying options.<br><br><b>debug=<I>level</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the debug level for more verbose output.<br><br>


title: DESCRIPTION
content:
<i>readom</i> is a command-line utility used for reading data from various optical media, such as CD-ROMs, DVDs, and sometimes Blu-ray discs. It's part of the <i>cdrecord</i> or <i>wodim</i> suite of tools, primarily designed for low-level interaction with optical drives.<br><br>The command enables users to extract raw data, audio tracks, or complete disc images (ISOs) from optical media. It's particularly useful for creating backups of discs, extracting specific tracks, or performing forensic analysis on disc content. <i>readom</i> can handle different reading modes, including raw reading with or without error correction, and supports various data formats. It interfaces with optical drives typically through SCSI or ATAPI emulation layers, allowing precise control over the reading process. While <i>readom</i> provides powerful capabilities for disc manipulation, its usage often requires understanding of optical media structures and device addressing.


title: CAVEATS
content:
<i>readom</i> typically requires root privileges or appropriate device permissions to access optical drives. It relies on the SCSI subsystem or ATAPI emulation. Its functionality can sometimes be replicated or surpassed by <i>dd</i> for block devices, or by <i>cdrdao</i> for specific CD audio extraction needs. <i>readom</i> is part of the <i>cdrecord</i> / <i>wodim</i> suite, which has seen less development compared to other tools, and its specific behavior can vary slightly across different distributions or package versions. It's designed for low-level access, meaning incorrect usage can potentially damage media or lead to incomplete reads.


title: PERMISSIONS
content:
<i>readom</i> often requires root privileges or proper <I>sg</I> group permissions to access optical devices directly.


title: DEVICE NAMING
content:
Optical drives are typically accessed via paths like <I>/dev/sr0</I>, <I>/dev/cdrom</I>, or SCSI addresses like <I>0,0,0</I>. The <I>dev=</I> option must correctly identify the target drive.


title: ERROR HANDLING
content:
Without <I>noerror</I>, <i>readom</i> attempts robust error correction. With <I>noerror</I>, it will read whatever it can, potentially including corrupted data, which is useful for data recovery.


title: HISTORY
content:
<i>readom</i> emerged as part of the <i>cdrecord</i> project, initially developed by Jörg Schilling. <i>cdrecord</i> was one of the earliest and most comprehensive open-source tools for burning CDs and DVDs on Unix-like systems. <i>readom</i> provided the complementary functionality of robustly reading data from these optical media, particularly useful for creating exact copies or extracting raw streams. Over time, due to licensing disagreements and development directions, <i>cdrecord</i> was forked, leading to <i>wodim</i> (Write Optical Disc Media). <i>readom</i> has largely maintained its original purpose and syntax across these forks, serving as a low-level utility for direct interaction with optical drives. Its importance has somewhat diminished with the rise of GUI-based burning software and the increasing prevalence of USB drives over optical media for data transfer, but it remains valuable for specific niche tasks like disc archival, data recovery, or audio extraction where low-level control is paramount.


title: PARAMETERS
content:
<b><i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the variable(s) or function(s) to be declared read-only. If <i>value</i> is provided, the variable is assigned that value before being marked read-only.<br><br><b><i>-a</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with <i>name</i> to declare or mark an indexed array variable as read-only. If <i>name</i> is not an array, it is created as an indexed array first.<br><br><b><i>-A</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with <i>name</i> to declare or mark an associative array variable as read-only. If <i>name</i> is not an array, it is created as an associative array first.<br><br><b><i>-f</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mark shell functions as read-only. When used without <i>name</i> arguments, it doesn't list functions; it's typically used with one or more function names to make them read-only.<br><br><b><i>-p</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a list of all currently read-only variables and functions in a reusable format. When this option is used, no <i>name</i> arguments are accepted.<br><br>


title: DESCRIPTION
content:
The <b>readonly</b> command is a shell built-in that declares or marks shell variables and functions as read-only. Once a variable or function is made read-only, its value cannot be changed, nor can it be unset. Attempting to modify or unset a read-only entity will result in an error message. This command is particularly useful for ensuring that critical configuration parameters, environment variables, or core functions remain constant throughout a script's execution, thereby preventing accidental or malicious alteration. It can also be used to list all currently read-only variables and functions in the current shell session.


title: CAVEATS
content:
Once a variable or function is declared read-only, there is no shell command to revert this state within the current shell session. It cannot be unset or assigned a new value. This immutability applies to the current shell and its subshells (if exported). A read-only variable cannot be "un-readonly" and then modified; its state is permanent for the shell session.


title: SCOPE AND INHERITANCE
content:
Read-only variables are local to the current shell by default. If a read-only variable is also <i>exported</i> (e.g., using `<b>export readonly VAR=value</b>` or `<b>readonly -x VAR=value</b>`), it will be inherited by subshells as read-only. However, its read-only status in a subshell is independent of the parent shell; a subshell cannot make a read-only variable from its parent writable, nor can it unset it. Redefining a read-only function in a subshell is also not possible.


title: USAGE WITH ASSIGNMENTS
content:
You can assign a value to a variable and make it read-only in one step: `<b>readonly MY_VAR="my_value"</b>`. If the variable `MY_VAR` already exists, it must not be read-only to be successfully marked, otherwise an error occurs. This allows for atomic declaration and protection.


title: HISTORY
content:
The <b>readonly</b> command has been a fundamental built-in feature of POSIX-compliant shells like Bash, Zsh, and Ksh for a very long time, providing a robust mechanism for variable and function immutability. Its design aligns with the principle of ensuring script stability and preventing unintended modifications to critical state.


title: PARAMETERS
content:
<b>-m <mapfile></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative kernel map file (e.g., <b>System.map</b>) for symbol resolution instead of <b>/proc/kallsyms</b>.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the profile counts as percentages of the total.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints counts as intervals, showing the frequency of hits within ranges.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses symbol lookup, printing raw addresses instead of symbolic names.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, displaying additional information like the profile buffer size and symbols used.<br><br><b>-a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows all entries, including those with zero profile counts.<br><br><b>-b</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows basic block counts (if enabled in kernel profiling).<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the output based on profile counts (descending by default).<br><br><b>-z</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Zeros the profile counters after reading them. Requires write access to <b>/proc/profile</b>.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resets the entire profile buffer (equivalent to <b>echo -1 > /proc/profile</b>). Requires write access.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the output in a format suitable for external plotting tools.<br><br><b>-M</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints addresses as module name + offset, making it easier to identify module-specific hot spots.<br><br><b>profile_file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional: Specifies an alternative profile data file to read from instead of the default <b>/proc/profile</b>.<br><br>


title: DESCRIPTION
content:
<code>readprofile</code> is a utility used to extract and interpret raw kernel profiling information. It reads data from the <i>/proc/profile</i> pseudo-filesystem entry, which is populated by the Linux kernel's built-in profiler. This profiler, when enabled (via <i>CONFIG_PROFILING</i> during kernel compilation), tracks execution counts at various kernel addresses. <br><br>The command translates these raw memory addresses into human-readable symbolic names (like function names or module offsets) by consulting the kernel's symbol table, typically found in <i>/proc/kallsyms</i> or an external <i>System.map</i> file. By analyzing the frequency of execution at different kernel locations, system administrators and developers can identify performance bottlenecks and understand where the kernel spends most of its processing time. While more sophisticated tools like <i>perf</i> and <i>oprofile</i> are now widely used, <code>readprofile</code> provides a direct and simple way to access the kernel's own profiling data for quick insights.


title: CAVEATS
content:
<code>readprofile</code> relies on the kernel's profiling feature being enabled (<b>CONFIG_PROFILING</b> compiled into the kernel). Without this, <b>/proc/profile</b> will not exist or contain useful data. <br><br>Symbol resolution requires access to <b>/proc/kallsyms</b> or a specified <b>System.map</b> file, which may require root privileges. For persistent and advanced profiling, modern tools like <i>perf</i> or <i>oprofile</i> are generally preferred over the basic <i>/proc/profile</i> interface.


title: ENABLING KERNEL PROFILING
content:
For <b>readprofile</b> to function, the Linux kernel must be compiled with profiling support (<b>CONFIG_PROFILING=y</b>). Additionally, the profiling mechanism can often be controlled via <b>sysctl</b> parameters, such as <b>kernel.perf_event_paranoid</b>, although <b>readprofile</b> specifically interacts with the older <b>/proc/profile</b> interface.


title: THE SYSTEM.MAP FILE
content:
The <i>System.map</i> file is a crucial component for <b>readprofile</b> to translate raw memory addresses into meaningful function names. It contains a list of kernel symbols and their corresponding memory addresses. If <b>/proc/kallsyms</b> is not available or incomplete, specifying the correct <i>System.map</i> file (often located in <b>/boot/</b>) with the <b>-m</b> option is essential for accurate symbol resolution.


title: HISTORY
content:
<code>readprofile</code> has been a long-standing utility within the Linux ecosystem, typically distributed as part of the <i>util-linux</i> package. It emerged as a fundamental tool for basic kernel performance analysis, directly interacting with the kernel's internal profiling buffer via the <i>/proc</i> filesystem. Its usage predates the widespread adoption of more comprehensive and feature-rich profiling frameworks like <i>perf</i>, serving as an accessible initial point for understanding kernel execution patterns.


title: SYNOPSIS
content:
<i>Not applicable</i>: The command 'readshortcut' is not a standard Linux command and therefore has no defined syntax or usage.


title: DESCRIPTION
content:
The command 'readshortcut' is <b>not a standard Linux command</b> found in common distributions or core utilities. It is not part of GNU Coreutils, busybox, or other widely used packages like util-linux. If you encounter this command, it likely refers to one of the following:<br><br>1. A <i>custom script or application</i> specifically named 'readshortcut' installed on a particular system.<br>2. A <i>misconception</i>, where the user might be looking for ways to manage or inspect keyboard shortcuts within a desktop environment (like KDE, GNOME, XFCE, LXQt).<br>3. An internal mechanism or utility related to a <i>specific desktop environment's</i> shortcut management system, rather than a general-purpose command-line tool.<br><br>Standard Linux shells and utilities do not include a command explicitly named 'readshortcut' for general use. Users typically interact with system-wide or application-specific shortcuts through graphical system settings, configuration files, or specialized tools like those used for X11 property inspection.


title: CAVEATS
content:
This command is <b>not part of standard Linux installations</b>. Attempting to execute 'readshortcut' on a typical Linux system will result in a 'command not found' error unless a custom script or application with this name has been specifically installed by the user or system administrator. Its behavior, if it exists as a custom tool, would be entirely dependent on its implementation.


title: DESKTOP ENVIRONMENT SHORTCUT MANAGEMENT
content:
Desktop environments such as GNOME, KDE Plasma, XFCE, and LXQt provide graphical interfaces within their system settings to manage keyboard shortcuts. These settings allow users to define custom keybindings for launching applications, performing actions, or window management. The underlying mechanisms often involve D-Bus, GSettings schemas (for GNOME), or specific configuration files managed by the desktop environment.


title: X11 PROPERTY INSPECTION
content:
For inspecting properties of X Window System elements (like windows or the root window), the <i>xprop</i> command can be used. While not directly 'reading a shortcut' in the sense of a user-defined keybinding, it can reveal properties related to keyboard mappings, atom names, and other X11-specific data that might be relevant to how applications interpret input events.


title: HISTORY
content:
As 'readshortcut' is not a standard Linux command, it does not have a documented history of development or usage within mainstream Linux distributions or open-source projects. Any tool with this name would be a custom or highly specialized utility without widespread adoption or a historical footprint.


title: PARAMETERS
content:
<b><b>-e</b>, <b>--canonicalize-existing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;All components of the path must exist. This is the default behavior.<br><br><b><b>-m</b>, <b>--canonicalize-missing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path may not exist. Do not require that components exist.<br><br><b><b>-L</b>, <b>--logical</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resolve symlinks logically. All but the last component of the path are resolved logically (like <i>pwd -L</i>).<br><br><b><b>-P</b>, <b>--physical</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resolve symlinks physically. All components of the path are resolved physically (like <i>pwd -P</i>). This is the default behavior.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress most error messages.<br><br><b><b>-s</b>, <b>--strip</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Don't resolve the last path component if it's a symbolic link.<br><br><b><b>-z</b>, <b>--zero</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;End each output line with NUL, not newline. Useful for processing with <i>xargs -0</i>.<br><br><b><b>--relative-to=DIR</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output paths relative to DIR. If FILE is not under DIR, the absolute path is returned.<br><br><b><b>--relative-base=DIR</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compute path relative to base directory DIR. Similar to <i>--relative-to</i> but with different behavior if FILE is not under DIR.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help and exit.<br><br>


title: DESCRIPTION
content:
<i>realpath</i> is a Linux command-line utility used to return the canonicalized absolute pathname of a file or directory. This means it resolves all symbolic links, processes any <b>.</b> (current directory) and <b>..</b> (parent directory) components, and returns the absolute path from the root directory.<br><br>It's particularly useful in scripts and automation where you need to ensure you're referencing the <i>actual</i> location of a file, rather than a symlink or a path containing relative components. For example, if you have a symlink <i>~/mylink</i> pointing to <i>/usr/local/bin/myapp</i>, <i>realpath ~/mylink</i> would output <i>/usr/local/bin/myapp</i>. By default, <i>realpath</i> requires that all components of the path exist, ensuring the returned path refers to an existing entity. It's crucial for robustness in file system operations and for simplifying paths to their true, unambiguous form.


title: CAVEATS
content:
By default, <i>realpath</i> requires all path components to exist to return a canonical path. If any part of the path (except the final component when using <b>--canonicalize-missing</b>) does not exist, an error will be reported.<br><br>When using <b>--relative-to</b>, if the target path is not located within the specified base directory, <i>realpath</i> will return the absolute path instead of a relative one.


title: ERROR HANDLING
content:
<i>realpath</i> exits with a non-zero status if any specified path cannot be resolved or does not exist (unless <b>-m</b> is used and the non-existence is only for the final component). This makes it suitable for use in shell scripts where robust error checking is important.


title: SECURITY IMPLICATIONS
content:
While primarily a utility for path resolution, its function of revealing the true path by resolving all symlinks actually helps mitigate certain types of path traversal vulnerabilities by showing the actual target location, rather than a manipulated symbolic link.


title: HISTORY
content:
The <i>realpath</i> command is part of the GNU Core Utilities (<i>coreutils</i>) package, which provides essential tools for file, text, and shell manipulation on Unix-like operating systems. It was developed to provide a robust and standardized way to resolve paths, leveraging underlying system calls like <i>realpath(3)</i> (the C library function). Its widespread inclusion in <i>coreutils</i> ensures its availability and consistent behavior across most Linux distributions, making it a fundamental utility for scripting and system administration tasks.


title: PARAMETERS
content:
<b><i>-i, --interface &lt;interface&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the wireless interface to use, which must be in monitor mode (e.g., wlan0mon).<br><br><b><i>-b, --bssid &lt;BSSID&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The BSSID (MAC address) of the target Access Point (AP) with WPS enabled.<br><br><b><i>-c, --channel &lt;channel&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the channel of the target AP. If not specified, Reaver attempts to auto-detect.<br><br><b><i>-p, --pin &lt;PIN&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a known WPS PIN to test. Useful for verifying suspected or default PINs.<br><br><b><i>-vv, --verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity, showing more detailed information about the attack progress.<br><br><b><i>-L, --lock-delay &lt;seconds&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Time to wait after detecting an AP lockout or rate-limiting (default is 60 seconds).<br><br><b><i>-x, --fail-retry &lt;number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of failed attempts before Reaver waits for a 'lock-delay' period.<br><br><b><i>--no-nacks</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables sending NACK (Negative Acknowledgement) messages. Can sometimes help with certain APs.<br><br><b><i>--win7</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Imitates the behavior of a Windows 7 client during the WPS handshake, which might bypass some AP lockouts.<br><br><b><i>--pixie-dust</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs the WPS Pixie Dust attack, attempting to recover the PIN offline from a single WPS exchange.<br><br><b><i>--start-at &lt;pin&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the brute-force attack from a specific WPS PIN.<br><br><b><i>--end-at &lt;pin&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ends the brute-force attack at a specific WPS PIN.<br><br><b><i>--output-file &lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the output of the attack to the specified file.<br><br><b><i>--session &lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads and saves the session to a specified file, allowing the attack to be resumed later.<br><br>


title: DESCRIPTION
content:
The <b>reaver</b> command is an open-source tool designed to exploit a critical vulnerability in the Wi-Fi Protected Setup (WPS) protocol. Its primary function is to perform an online brute-force attack against the WPS PIN, which is an 8-digit numerical code used for easy device connectivity. Reaver leverages a design flaw where the WPS PIN is verified in two independent halves (the first 4 digits and the next 3, with the last digit being a checksum), effectively reducing the complexity of brute-forcing from billions of possibilities to a few thousand for each half.<br><br>While initially developed for brute-forcing, Reaver has evolved to incorporate other WPS attack methods, most notably the 'Pixie Dust' attack, which can sometimes recover the WPS PIN offline from a single WPS transaction, bypassing the need for extensive online brute-forcing. Reaver is widely used in network security auditing to test the robustness of WPS implementations and is a significant tool in penetration testing.


title: CAVEATS
content:
Using <b>reaver</b> for unauthorized access to wireless networks is illegal and unethical. It can cause network instability, AP lockouts, and may alert network administrators. It requires a wireless adapter capable of monitor mode and packet injection. Success is not guaranteed, as many modern APs have implemented stronger countermeasures against WPS attacks (e.g., faster lockouts, disabling WPS). The Pixie Dust attack's success depends on the AP's vulnerable WPS implementation.


title: PREREQUISITES
content:
A specialized wireless network adapter capable of both <i>monitor mode</i> and <i>packet injection</i> is essential for <b>reaver</b> to function. Tools from the <b>aircrack-ng</b> suite, such as <b>airmon-ng</b>, are often used to put the wireless interface into the required monitor mode before running <b>reaver</b>.


title: ATTACK PRINCIPLES
content:
The classic <b>reaver</b> brute-force attack exploits the WPS PIN verification process. The 8-digit PIN is split, and the AP confirms the validity of the first four digits separately from the next three (the last digit is a checksum). This allows <b>reaver</b> to test approximately 11,000 combinations for the first half and 1,100 for the second, significantly reducing the overall brute-force time compared to a full 8-digit PIN. The <i>Pixie Dust</i> attack, on the other hand, targets weaknesses in the WPS 'E-S1' and 'E-S2' nonces, allowing for an offline calculation of the PIN in some cases.


title: TYPICAL WORKFLOW
content:
A common workflow involves:<br>1. Putting the wireless adapter into monitor mode using <b>airmon-ng</b>.<br>2. Scanning for WPS-enabled Access Points using <b>wash -i &lt;interface&gt;</b>.<br>3. Launching <b>reaver</b> against a target AP identified by <b>wash</b> using its BSSID and channel.


title: HISTORY
content:
<b>Reaver</b> emerged as a groundbreaking tool in 2011, quickly gaining notoriety for demonstrating a severe vulnerability in the Wi-Fi Protected Setup (WPS) protocol. Its release brought widespread attention to the fundamental design flaw that allowed the 8-digit WPS PIN to be brute-forced relatively quickly. This exposure prompted many manufacturers to issue firmware updates to mitigate the vulnerability, often by disabling WPS by default or implementing aggressive lockout mechanisms. However, many older or unpatched devices remain vulnerable. The tool's development continued, integrating new attack vectors like the 'Pixie Dust' attack, which offered an often faster, offline method to retrieve the WPS PIN, further highlighting the protocol's weaknesses.


title: PARAMETERS
content:
<b><b>--force</b>, <b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an immediate reboot without gracefully shutting down processes or syncing disk data. This option should be used with extreme caution as it can lead to data loss or file system corruption.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information and exits.<br><br>


title: DESCRIPTION
content:
The <b>reboot</b> command is used to restart the Linux system. It's a critical administrative utility that safely shuts down the operating system and then reboots it. When executed, <b>reboot</b> initiates a graceful shutdown process: it sends termination signals to all running processes, unmounts all mounted file systems, and syncs data to disk to prevent data corruption. Only after these operations are completed does it instruct the hardware to perform a restart.<br><br>Historically, <b>reboot</b> was part of traditional init systems like SysVinit. In modern Linux distributions, especially those using <i>systemd</i>, <b>reboot</b> is typically a symbolic link to the <b>systemctl</b> command (i.e., equivalent to <b>systemctl reboot</b>). This ensures consistency and leverages <i>systemd</i>'s robust service management capabilities for a controlled shutdown and restart.<br><br>The primary uses for <b>reboot</b> include applying kernel updates, system patches, resolving system instability, or general maintenance. Due to its system-wide impact and the need to preserve data integrity, <b>reboot</b> typically requires root privileges to execute.


title: CAVEATS
content:
<i>Root Privileges</i>:<br>The <b>reboot</b> command requires superuser (root) privileges to execute. Users without root access will typically receive a 'permission denied' error.<br><br><i>Data Integrity</i>:<br>Unless <b>--force</b> is used, <b>reboot</b> attempts to shut down all processes and sync disk caches to prevent data loss. Always allow the system to complete this process naturally.<br><br><i>Modern Implementations</i>:<br>On <i>systemd</i>-based systems, <b>reboot</b> often acts as a front-end to <b>systemctl reboot</b>. While convenient, for advanced control or specific systemd features, directly using <b>systemctl</b> might be more explicit.<br><br><i>Active Sessions</i>:<br>Be aware that a reboot will terminate all active user sessions and unsaved work. Notify users before performing a system-wide reboot.


title: HISTORY
content:
The <b>reboot</b> command has been a fundamental part of Unix-like operating systems since their early days, originally serving as a direct interface to the kernel's restart functionality. In traditional Unix and Linux systems (e.g., using SysVinit), <b>reboot</b> was often a standalone utility or part of a suite like <i>sysvinit-tools</i>.<br><br>With the advent of modern init systems like <i>systemd</i>, the role of <b>reboot</b> has largely shifted. On most contemporary Linux distributions, <b>reboot</b> is now implemented as a symbolic link to <b>systemctl</b>. This change reflects the move towards a unified control interface for system states and services, centralizing system shutdown and restart operations under <i>systemd</i>'s comprehensive management framework. While the command name remains consistent, its underlying implementation has evolved significantly to adapt to modern Linux architecture.


title: SYNOPSIS
content:
<B>rec</B> [<i>global options</i>] [<i>format options</i>] [<i>input options</i>] <I>&lt;output_file&gt;</I> [<i>output options</i>] [<i>effect options</i>] [<i>effect arguments</i>]<br><br><I>Example:</I> <B>rec</B> <I>-r 44100 -c 2 output.wav trim 0 10s</I>


title: PARAMETERS
content:
<b><B>-q</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables quiet mode, suppressing progress messages.<br><br><b><B>-V</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity, showing detailed information and warnings.<br><br><b><B>-v</B> <I>&lt;volume&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adjusts the input volume multiplicatively. A value of 1.0 means no change.<br><br><b><B>-t</B> <I>&lt;type&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output audio file type (e.g., <B>wav</B>, <B>flac</B>, <B>mp3</B>).<br><br><b><B>-r</B> <I>&lt;rate&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the sample rate (in Hz) for the recording (e.g., <B>44100</B> for CD quality).<br><br><b><B>-c</B> <I>&lt;channels&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the number of audio channels (e.g., <B>1</B> for mono, <B>2</B> for stereo).<br><br><b><B>--input-device</B> <I>&lt;device&gt;</I> or <B>-d</B> <I>&lt;device&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the specific audio input device (e.g., <B>default</B>, <B>alsa</B>, <B>pulseaudio</B>).<br><br><b><B>trim</B> <I>&lt;start&gt;</I> [<I>&lt;length&gt;</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Records for a specific duration. <I>start</I> is usually <B>0</B> for recording from the beginning. <I>length</I> specifies the duration (e.g., <B>10s</B> for 10 seconds).<br><br><b><B>silence</B> <I>&lt;threshold_percent&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stops recording automatically when silence is detected. Requires additional parameters for duration and threshold.<br><br><b><B>gain</B> <I>&lt;level&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies a gain effect to the recorded audio.<br><br><b><B>norm</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Normalizes the recorded audio to a standard peak level.<br><br>


title: DESCRIPTION
content:
The <B>rec</B> command is a powerful utility derived from the <I>SoX</I> (Sound e<B>X</B>change) audio processing suite. It serves as a convenient wrapper for the <B>sox</B> command, specifically designed for recording audio from an input device, such as a microphone or line-in, to an output file. <B>rec</B> supports a wide array of audio formats (e.g., WAV, MP3, FLAC) and allows for real-time application of various audio effects and transformations during the recording process. It offers precise control over recording parameters like sample rate, channels, and duration, making it a versatile tool for capturing high-quality audio directly from the command line. Its capabilities extend beyond simple recording, enabling users to monitor input levels, apply noise reduction, or automatically stop recording based on silence.


title: CAVEATS
content:
<B>rec</B> relies heavily on the underlying audio system (e.g., ALSA, PulseAudio, OSS) and its proper configuration. Issues with device access, permissions, or system mixer settings can prevent successful recording. When recording to compressed formats like MP3, external encoders (e.g., LAME) might be required and need to be present on the system.


title: COMMON USAGE EXAMPLES
content:
<B>rec</B> <I>my_recording.wav</I><br><i>Records audio to <B>my_recording.wav</B> until manually stopped.</i><br><br><B>rec</B> <I>-r 48000 -c 1 speech.flac trim 0 30s</I><br><i>Records 30 seconds of mono audio at 48kHz to <B>speech.flac</B>.</i><br><br><B>rec</B> <I>presentation.mp3 silence 1 0.1 3% 1 2.0 3%</I><br><i>Records to <B>presentation.mp3</B>, stopping after 2 seconds of silence below 3% volume.</i>


title: HISTORY
content:
The <B>rec</B> command is an integral part of the <B>SoX</B> (Sound e<B>X</B>change) project, which originated in the early 1990s. <B>SoX</B> was developed as a command-line utility for converting and processing various audio file formats. As a convenience, <B>rec</B> was introduced as a specific alias or wrapper for <B>sox</B> itself, simplifying the syntax for audio recording tasks by implicitly setting the input to an audio device. Its long history reflects the continuous evolution of digital audio processing on Unix-like systems.


title: PARAMETERS
content:
<b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force conversion even if the target encoding might result in information loss or an uncertain result.<br><br><b>-i, --info</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display detailed information about the internal graph of character sets and recoding steps, aiding in understanding conversion paths.<br><br><b>-l, --list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all known character sets, their aliases, and available recoding steps that <b>recode</b> can handle.<br><br><b>-o <<i>file</i>>, --output=<<i>file</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Direct the converted output to the specified <i>file</i> instead of standard output.<br><br><b>-s, --sequence</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat subsequent arguments as distinct recoding chains, allowing multiple conversion operations in a single invocation.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produce verbose output, showing details of the conversion process, which can be useful for debugging.<br><br><b>-w, --warn</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Issue warnings for characters that cannot be accurately represented in the target encoding, indicating potential data loss.<br><br><b>-d, --debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produce extensive debugging output, primarily for developers to understand the internal operations of <b>recode</b>.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message that summarizes command usage and options, then exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information for the <b>recode</b> utility and exit.<br><br>


title: DESCRIPTION
content:
The <b>recode</b> command is a powerful and versatile utility designed for converting character sets and other text properties between different encodings and formats. It acts as a universal filter, reading from standard input or specified files, and writing the converted output to standard output or a designated output file.<br><br>Unlike simpler conversion tools, <b>recode</b> supports a wide array of character encodings, including various ISO-8859-x, KOI8-x, EBCDIC, UTF-8, and many legacy systems. Its strength lies in its ability to not only change character sets but also perform complex transformations such as line ending conversions (e.g., between CRLF, LF, and CR), character normalization (NFC, NFD, NFKC, NFKD), and encoding/decoding of various text formats like Quoted-Printable (QP), Base64, HTML entities, XML entities, and URL encoding.<br><br>Users define conversion rules through specific "recoding chains," which dictate the sequence of transformations. This allows <b>recode</b> to handle intricate conversion paths, making it an indispensable tool for ensuring text interoperability across diverse operating systems, applications, and network protocols. Whether preparing files for different platforms or cleaning up text data, <b>recode</b> offers comprehensive control over character and format conversions.


title: CAVEATS
content:
While powerful, <b>recode</b> can have a steep learning curve due to its extensive recoding chain syntax. Its comprehensive nature means understanding character encodings and internal steps is often necessary for complex conversions. For simple, standard character set conversions, <b>iconv(1)</b> is often preferred due to its simpler interface and widespread availability on Linux systems.


title: RECODING CHAIN SYNTAX
content:
The core functionality of <b>recode</b> is defined by its 'recoding chain' arguments. These chains specify the source and target encodings, along with optional intermediate steps or format transformations. A typical chain looks like <i>source_encoding</i>..<i>target_encoding</i>.<br><br>Common elements within a recoding chain include:<br><ul><li><b>Encoding Names:</b> e.g., <i>LATIN-1</i>, <i>UTF-8</i>, <i>KOI8-R</i>, <i>EBCDIC-US</i>.<br><li><b>Line Ending Conversions:</b> e.g., <i>CR-LF</i> (Windows/DOS), <i>LF</i> (Unix/Linux), <i>CR</i> (Macintosh).<br><li><b>Text Formats:</b> <i>QP</i> (Quoted-Printable), <i>BASE64</i>, <i>HTML</i> (HTML entities), <i>XML</i> (XML entities), <i>URL</i> (URL encoding/decoding).<br><li><b>Normalization Forms:</b> <i>NFC</i>, <i>NFD</i>, <i>NFKC</i>, <i>NFKD</i> (Unicode normalization forms).<br><li><b>Transliteration:</b> Steps to approximate characters not representable in the target encoding.</ul><b>recode</b> intelligently finds the best path through its internal 'graph' of character sets and steps to perform the requested conversion.


title: HISTORY
content:
The <b>recode</b> utility was developed by François Pinard and is part of the GNU project. It was designed to be a highly flexible and universal character set and format converter, predating widespread UTF-8 adoption but continually updated to support modern encodings and text processing needs. It has been a long-standing tool for handling diverse text data across different computing environments.


title: PARAMETERS
content:
<b>FILE...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Input file(s) to convert. If no files are specified, <b>recode-sr-latin</b> reads from standard input and writes to standard output.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explain the conversion steps and provide detailed information about the process.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force conversion even if some characters cannot be perfectly represented in the target script or if auto-detection encounters ambiguities.<br><br><b>-d, --dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run; show what would be done without actually writing any output files or modifying content.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message and exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information about the <b>recode</b> utility (which <b>recode-sr-latin</b> is based on) and exit.<br><br>


title: DESCRIPTION
content:
<i>recode-sr-latin</i> is a specialized wrapper or alias for the <i>recode</i> utility, specifically designed to handle transliteration between Serbian Cyrillic and Serbian Latin scripts. It aims to simplify the process of converting text files encoded in one Serbian script into the other, often attempting to auto-detect the input script. This command is particularly useful for users working with Serbian language content who need to switch between the two official scripts used for the language. It leverages the robust character set conversion capabilities of the underlying <i>recode</i> library to perform context-aware transliteration, ensuring accurate conversion of Serbian specific characters and digraphs (like 'nj', 'lj', 'dž').


title: CAVEATS
content:
<i>recode-sr-latin</i> relies on the underlying <i>recode</i> library's transliteration rules, which are generally accurate but fixed. It might struggle with highly ambiguous inputs or non-standard encodings if auto-detection fails. Its exact behavior can depend on its implementation (e.g., a shell script versus a symbolic link to <i>recode</i>). For complex scenarios, specifying exact encodings might be necessary with the main <i>recode</i> command.


title: AUTOMATIC SCRIPT DETECTION
content:
One of the key features of <i>recode-sr-latin</i> is its ability to often automatically detect whether the input text is in Serbian Cyrillic or Serbian Latin, and then perform the appropriate conversion (Cyrillic to Latin, or Latin to Cyrillic) without explicit direction from the user.


title: BIDIRECTIONAL CONVERSION
content:
Unlike many simple character encoding tools, <i>recode-sr-latin</i> is designed for bidirectional conversion. It can accurately convert text from Serbian Cyrillic to Latin script, and conversely, from Serbian Latin to Cyrillic script, handling special digraphs (e.g., 'nj', 'lj', 'dž') and single characters correctly.


title: HISTORY
content:
The <i>recode</i> project, upon which <i>recode-sr-latin</i> is built, dates back to the 1990s, developed by François Pinard. It was conceived as a robust and extensible character set and script converter. The specific inclusion of <i>recode-sr-latin</i> emerged from the need to accurately handle the unique bidirectional transliteration rules between Serbian Cyrillic and Latin scripts, a task more complex than simple character encoding conversions, thereby making <i>recode</i> a comprehensive tool for Slavic language text processing.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show program's version number and exit.<br><br><b>--no-color</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable colored output from the framework.<br><br><b>--no-meta</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable the startup metadata (version, author, etc.).<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable debug mode for more verbose output and error details.<br><br><b>--headless</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run the framework in headless mode, without an interactive prompt. Useful for scripting.<br><br><b>--command <<i>command</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute a single framework command and exit. Used with --headless for automated tasks.<br><br><b>--script <<i>file</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute commands from a script file and exit. Used with --headless for automated workflows.<br><br><b>--workspace <<i>workspace_name</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load or create a specific workspace upon startup.<br><br>


title: DESCRIPTION
content:
recon-ng is an open-source web reconnaissance framework written in Python. It is designed to automate the painful process of information gathering during penetration tests, providing a powerful and extensible platform for Open Source Intelligence (OSINT). Much like Metasploit, recon-ng is an interactive shell where users can load modules, set options, run commands, and organize data using workspaces.<br><br>Its modular architecture allows users to perform various reconnaissance tasks, including passive information gathering (e.g., discovering subdomains, identifying email addresses, finding related hosts) using publicly available data. It integrates with numerous third-party APIs (e.g., Google, Shodan, VirusTotal), requiring users to obtain and configure API keys for full functionality. It's a critical tool for ethical hackers and security researchers to build a comprehensive picture of their target's online presence before launching more intrusive attacks.


title: CAVEATS
content:
recon-ng's full potential is realized through an interactive shell, not solely via command-line arguments. Many modules require API keys from third-party services, which need to be obtained and configured within the framework. Users should be mindful of ethical considerations and legal boundaries when performing reconnaissance, ensuring activities are authorized and within scope.


title: INTERACTIVE MODE
content:
While recon-ng has startup command-line options, its primary mode of operation is an interactive shell. Users enter the framework by simply typing <b>recon-ng</b>, then use internal commands (e.g., <i>show modules</i>, <i>use</i>, <i>set</i>, <i>run</i>) to navigate its features.


title: WORKSPACES
content:
recon-ng utilizes 'workspaces' to organize reconnaissance data. Each workspace acts as a separate database, allowing users to keep findings from different targets or projects isolated and clean. Commands like <i>workspaces add</i>, <i>workspaces select</i>, and <i>workspaces list</i> are used to manage them.


title: MODULES
content:
The framework's functionality is extended through a wide array of modules, categorized by their purpose (e.g., <i>recon</i>, <i>reporting</i>). Users can load specific modules using the <i>use</i> command and then configure module-specific options before execution. New modules can be easily developed and integrated.


title: API KEYS
content:
Many powerful modules in recon-ng rely on third-party services that require API keys for access (e.g., Shodan, Censys, Hunter.io). These keys must be obtained by the user from the respective service providers and then configured within recon-ng using the <i>keys add</i> command to unlock the full capabilities of the framework.


title: HISTORY
content:
recon-ng was created by Justin Seitz, also known as 'LaNMaSteR53', and first publicly released around 2012. It quickly gained traction in the cybersecurity community due to its powerful capabilities and modular design, which mirrored the success of other interactive frameworks like Metasploit. It has undergone continuous development, adapting to new OSINT techniques and integrating with an expanding list of data sources, solidifying its position as a go-to tool for penetration testers and security analysts.


title: SYNOPSIS
content:
<b>recordmydesktop</b> [<i>OPTIONS</i>...] [<i>OUTPUT_FILE</i>]<br><br>Examples:<br><i>recordmydesktop --on-the-fly-encoding output.ogv</i><br><i>recordmydesktop --windowid 12345678 --no-sound my_window_recording.ogv</i>


title: PARAMETERS
content:
<b><b>--output</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output filename. If not provided, it defaults to 'out.ogv'.<br><br><b><b>--no-sound</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables audio recording.<br><br><b><b>--windowid</b> <i>&lt;id&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Records a specific window identified by its X window ID.<br><br><b><b>--on-the-fly-encoding</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes the video during recording, which might consume more CPU but provides the final file immediately upon stopping.<br><br><b><b>--fps</b> <i>&lt;n&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the frames per second for video capture. Default is often 15.<br><br><b><b>--no-cursor</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the mouse cursor from being recorded in the video.<br><br><b><b>--pause</b> <i>&lt;signal&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a signal (e.g., SIGUSR1) to pause recording. Sending the same signal again resumes it.<br><br><b><b>--stop</b> <i>&lt;signal&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a signal (e.g., SIGUSR2) to stop recording.<br><br>


title: DESCRIPTION
content:
<i>recordmydesktop</i> is a lightweight command-line tool designed for recording audio and video from a Linux desktop session. It captures screen activity and optionally audio inputs, saving the output to an <br><b>Ogg Theora</b> video file (.ogv). Known for its efficiency and ease of use, it allows users to record the entire screen, specific windows, or defined regions. It supports on-the-fly encoding to reduce finalization time, or encoding upon exit. <br>It's a popular choice for creating tutorials, demonstrations, or capturing system behavior without significant system overhead.


