# CommandSection

title: COMMAND NAMING CONVENTION
content:
Although commonly referred to as 'cryptsetup-luksformat' or 'cryptsetup luksformat command' in informal discussions, the precise command syntax is '<b>cryptsetup luksFormat</b>' (note the capital 'F' for the 'luksFormat' subcommand). The hyphenated or all-lowercase forms are common shorthand references to this specific function within the <b>cryptsetup</b> command-line tool suite.


title: POST-FORMATTING STEPS
content:
After successfully formatting a device with <b>cryptsetup luksFormat</b>, the device is initialized for encryption but not yet ready for data storage. The subsequent steps typically involve:<br>1. 'Opening' the LUKS volume using <b>cryptsetup open</b> to create a decrypted mapping device (e.g., <i>/dev/mapper/my_encrypted_volume</i>).<br>2. Formatting this newly mapped device with a desired filesystem (e.g., <b>mkfs.ext4 /dev/mapper/my_encrypted_volume</b>).<br>3. Mounting the filesystem to a mount point (e.g., <b>mount /dev/mapper/my_encrypted_volume /mnt/mydata</b>) to make it accessible for reading and writing data.


title: HISTORY
content:
The LUKS (Linux Unified Key Setup) standard was initially developed by Clemens Fruhwirth, with its first version (LUKS1) being released in 2004. It quickly became the de facto standard for full disk encryption on Linux, primarily managed by the <b>cryptsetup</b> utility.<br><br>A significant advancement came with the introduction of LUKS2, which debuted with <b>cryptsetup</b> version 2.0 in 2018. LUKS2 introduced numerous improvements, including: a more robust and extensible JSON-based header format, enhanced metadata redundancy, support for modern and stronger PBKDFs like Argon2i/Argon2id, and better integration with volume management. When using recent versions of <b>cryptsetup</b>, <b>cryptsetup luksFormat</b> defaults to creating LUKS2 volumes, providing superior security and flexibility for new encrypted devices.


title: SEE ALSO
content:
cryptsetup(8), cryptsetup-open(8), cryptsetup-close(8), cryptsetup-luksAddKey(8), cryptsetup-luksRemoveKey(8), cryptsetup-luksDump(8), cryptsetup-luksHeaderBackup(8), lsblk(8), fdisk(8), parted(8), mkfs(8), mount(8)


title: SYNOPSIS
content:
<b>cryptsetup</b> <i>open</i> &lt;device&gt; &lt;name&gt; [<i>options</i>]<br>or (for LUKS devices)<br><b>cryptsetup</b> <i>luksOpen</i> &lt;device&gt; &lt;name&gt; [<i>options</i>]


title: PARAMETERS
content:
<b><b>&lt;device&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the encrypted block device (e.g., <I>/dev/sda1</I> or <I>/dev/disk/by-uuid/...</I>).<br><br><b><b>&lt;name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired name for the decrypted device-mapper mapping (e.g., <I>myvolume</I> would create <I>/dev/mapper/myvolume</I>).<br><br><b><b>--type &lt;TYPE&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the device type. Common types include <I>luks</I> (default for <I>luksOpen</I>), <I>plain</I>, or <I>loopaes</I>.<br><br><b><b>--key-file &lt;FILE&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a specified key file for decryption instead of prompting for a passphrase. The key file's permissions must be secure.<br><br><b><b>--key-slot &lt;NUM&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which key slot (0-7 for LUKS1, 0-31 for LUKS2) to use for decryption. If not specified, all active key slots are tried.<br><br><b><b>--header &lt;FILE&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses an external header file for LUKS metadata instead of the one on the device. Useful for damaged devices or backups.<br><br><b><b>--read-only</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens the device in read-only mode, preventing any writes to the decrypted volume.<br><br><b><b>--allow-discards</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables TRIM/discard support for SSDs or virtual machines, allowing the underlying device to reclaim unused blocks. This can have security implications if not understood.<br><br><b><b>--uuid &lt;UUID&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the UUID of the LUKS device to open, useful when device paths are not stable.<br><br><b><b>--persistent</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a persistent device-mapper mapping that can be handled by <I>systemd-cryptsetup-generator</I> for automatic opening during boot.<br><br>


title: DESCRIPTION
content:
The command <I><b>cryptsetup open</b></I> is used to decrypt an encrypted block device (typically formatted with <I>LUKS - Linux Unified Key Setup</I>) and make its contents accessible to the operating system. When successful, it creates a new virtual block device under <I>/dev/mapper/</I> (e.g., <I>/dev/mapper/myencryptedvolume</I>) which represents the decrypted data. This decrypted device can then be mounted like any regular block device (e.g., using <I>mount</I> command) to access the underlying filesystem.<br><br>The <I>open</I> action requires a passphrase or a key file to decrypt the device. It utilizes the Linux kernel's device-mapper subsystem to perform the encryption/decryption on-the-fly, providing a transparent layer for data access. It's a fundamental command for managing encrypted storage in Linux environments.


title: CAVEATS
content:
<b><I>Important Caveats:</I></b><br><b>&bull;</b> Requires root privileges to execute.<br><b>&bull;</b> An incorrect passphrase or key file will result in a failure to open the device.<br><b>&bull;</b> If the target device name (<I>&lt;name&gt;</I>) is already in use under <I>/dev/mapper/</I>, the command will fail.<br><b>&bull;</b> Improperly closing (not running <I>cryptsetup close</I>) or forcefully unmounting the underlying filesystem can lead to data corruption. Always unmount the filesystem before closing the device.<br><b>&bull;</b> Using <I>--key-file</I> requires careful attention to the security of the key file itself, as its compromise directly leads to data exposure.<br><b>&bull;</b> Enabling <I>--allow-discards</I> can potentially leak information about file deletions or free space, as it exposes block usage patterns to the underlying storage.


title: USAGE WORKFLOW
content:
The typical workflow for accessing an encrypted LUKS volume involves three steps:<br>1. Open the encrypted device: <I><b>cryptsetup open</b> &lt;device&gt; &lt;name&gt;</I><br>2. Mount the decrypted filesystem: <I><b>mount</b> /dev/mapper/&lt;name&gt; /mnt/mountpoint</I><br>3. When finished, unmount the filesystem: <I><b>umount</b> /mnt/mountpoint</I><br>4. Close the encrypted device: <I><b>cryptsetup close</b> &lt;name&gt;</I><br>It is crucial to unmount the filesystem before closing the device to prevent data loss or corruption.


title: DEVICE MAPPER INTEGRATION
content:
<I>cryptsetup open</I> does not directly access the filesystem on the encrypted device. Instead, it interacts with the Linux kernel's <I>device-mapper</I> subsystem. This subsystem creates a new virtual block device (<I>/dev/mapper/&lt;name&gt;</I>) that acts as a transparent layer. All I/O operations to this virtual device are intercepted by <I>dm-crypt</I>, decrypted or encrypted on-the-fly, and then passed to the underlying physical device. This design ensures that applications and the kernel's filesystem drivers interact only with unencrypted data, simplifying the encryption process from their perspective.


title: HISTORY
content:
The <I>cryptsetup</I> utility and its <I>open</I> action are integral parts of the Linux disk encryption landscape, primarily driven by the <I>dm-crypt</I> kernel module and the <I>LUKS (Linux Unified Key Setup)</I> on-disk format.<br><br>The <I>dm-crypt</I> module, which provides transparent device encryption, was merged into the Linux kernel around 2004. <I>cryptsetup</I> emerged as the user-space tool to manage <I>dm-crypt</I> devices, significantly simplifying its usage compared to direct <I>dmsetup</I> commands. The <I>LUKS</I> specification, developed by Clemens Fruhwirth, standardized the on-disk format for <I>dm-crypt</I>, allowing for multi-passphrase support and easier portability of encrypted volumes across different Linux systems. <I>cryptsetup</I> became the primary tool for creating and managing <I>LUKS</I> volumes.<br><br>Over the years, <I>cryptsetup</I> has seen continuous development, incorporating features like LUKS2 (with support for more key slots, different PBKDFs, and JSON metadata), TRIM/discard support, and tighter integration with system boot processes (e.g., via <I>initramfs</I> and <I>systemd-cryptsetup</I>) to facilitate seamless unlocking of root filesystems or other critical encrypted partitions during startup.


title: SYNOPSIS
content:
<b>cryptsetup-reencrypt</b> <i>[OPTIONS]</i> <i>&lt;device&gt;</i><br><b>cryptsetup-reencrypt</b> <i>&lt;device&gt;</i> <b>--resume</b><br><b>cryptsetup-reencrypt</b> <i>&lt;device&gt;</i> <b>--cancel</b><br><b>cryptsetup-reencrypt</b> <i>&lt;device&gt;</i> <b>--status</b>


title: PARAMETERS
content:
<b>--new-key-slot <i>&lt;NUM&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a temporary key slot to use for the new key, typically an empty one.<br><br><b>--new-cipher <i>&lt;CIPHER[:MODE]&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the new cipher and optional mode to use for encryption (e.g., <i>aes-xts-plain64</i>).<br><br><b>--new-key-size <i>&lt;BITS&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the new key size in bits (e.g., <i>256</i>).<br><br><b>--new-pbkdf <i>&lt;PBKDF&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the new PBKDF (e.g., <i>argon2i</i>, <i>pbkdf2</i>) for key derivation.<br><br><b>--new-pbkdf-force-iterations <i>&lt;ITER&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the PBKDF iterations, bypassing internal benchmarks.<br><br><b>--header-only</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Re-encrypts only the LUKS header, not the data area.<br><br><b>--allow-discards</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables TRIM/DISCARD support for the re-encrypted blocks, potentially improving performance on SSDs.<br><br><b>--data-alignment <i>&lt;ALIGNMENT&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the sector alignment for the re-encryption process.<br><br><b>--reduce-device-size <i>&lt;SIZE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reduces the effective size of the device during re-encryption.<br><br><b>--resume</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continues a previously interrupted re-encryption operation.<br><br><b>--cancel</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stops and rolls back a suspended re-encryption operation, restoring the original state.<br><br><b>--offline</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs re-encryption while the device is not opened by <b>cryptsetup</b>, requiring the volume to be unmounted.<br><br><b>--online</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to perform re-encryption while the device is opened and in use (for data only). Use with caution.<br><br><b>--progress-display <i>&lt;TYPE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls how progress is displayed (e.g., <i>progressbar</i>, <i>percentage</i>).<br><br><b>--use-random-key</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a new random master key for the volume, discarding existing master key material.<br><br>


title: DESCRIPTION
content:
The <b>cryptsetup-reencrypt</b> command provides a powerful and unique capability to re-encrypt an existing LUKS (Linux Unified Key Setup) encrypted volume without requiring the entire data to be decrypted and re-encrypted, or necessitating additional storage space for a new encrypted volume. This utility is invaluable for upgrading cryptographic parameters such as the encryption <i>cipher</i>, <i>key size</i>, or the <i>PBKDF</i> (Password-Based Key Derivation Function) used for key derivation, or for migrating a LUKS1 volume to the newer LUKS2 format. It works by streaming data in blocks, re-encrypting them on the fly and writing them back to the original location. <br><br>While not a truly "online" operation in the sense that the device can remain actively mounted and in use for all changes (especially header modifications), <b>cryptsetup-reencrypt</b> allows for a semi-online re-encryption process for data blocks, which can be paused and resumed. This minimizes downtime and simplifies the process compared to traditional methods involving data migration. It manages this complex task by utilizing a temporary key slot in the LUKS header to store the new encryption key and parameters during the re-encryption process. This ensures data integrity and allows for recovery in case of an interruption. <br><br>It's an essential tool for maintaining the security of encrypted storage over time, adapting to new cryptographic standards or improving security without a complete reformat and data restoration.


title: CAVEATS
content:
While designed for safety, <b>cryptsetup-reencrypt</b> is an inherently critical operation. It is strongly recommended to <b>backup all critical data</b> before proceeding.<br><br>A free LUKS key slot is required to store the temporary new header during the process. If all 8 key slots are in use, you must remove one first.<br><br>Interrupting the operation, especially during the header re-encryption phase, can potentially render the volume inaccessible. Although it has recovery mechanisms, unexpected power loss or system crashes are a risk.<br><br>The process can be time-consuming for large volumes and will impact system performance while running. For 'online' data re-encryption, the underlying filesystem and applications might experience reduced responsiveness.


title: USAGE WORKFLOW
content:
Before starting, ensure the LUKS volume is <b>unmounted</b> if using <i>--offline</i> mode, or carefully consider the implications of <i>--online</i> mode. Provide the necessary password(s) when prompted. <br>1. <b>Preparation:</b> Ensure a free key slot is available. If not, remove an unused key slot first with <i>cryptsetup luksKillSlot</i>.<br>2. <b>Execution:</b> Run the command with desired parameters, e.g., <i>cryptsetup-reencrypt --new-cipher aes-xts-plain64 --new-key-size 512 /dev/sdXN</i>.<br>3. <b>Monitoring:</b> Monitor the progress using the <i>--progress-display</i> option.<br>4. <b>Interruption/Resumption:</b> If interrupted, the operation can usually be resumed using <i>cryptsetup-reencrypt /dev/sdXN --resume</i>. To revert to the original state, use <i>cryptsetup-reencrypt /dev/sdXN --cancel</i>.<br>5. <b>Completion:</b> Once complete, the temporary key slot is removed, and the volume operates with its new cryptographic parameters.


title: LUKS FORMAT MIGRATION
content:
One of the most common and powerful uses of <b>cryptsetup-reencrypt</b> is to migrate an existing LUKS1 volume to the newer LUKS2 format. This is typically done by running the command with the <i>--new-pbkdf argon2i</i> option (as Argon2 is a LUKS2-specific KDF) or by explicitly setting other LUKS2-specific parameters. This process updates the on-disk format of the LUKS header, allowing access to LUKS2's advanced features like multiple key slots, JSON metadata, and more robust PBKDFs, without needing to re-encrypt the entire data area if no cipher/key-size change is desired.


title: HISTORY
content:
The <b>cryptsetup-reencrypt</b> utility was introduced as part of the <b>cryptsetup</b> project starting with version 2.0.0. Its development was driven by the increasing need for in-place re-encryption capabilities, particularly with the introduction of the more flexible LUKS2 format and the desire to update cryptographic parameters without the laborious process of decrypting and then re-encrypting an entire disk. It significantly simplified the maintenance and security upgrades of LUKS-encrypted volumes, addressing a long-standing demand from users and administrators.


title: SYNOPSIS
content:
<b>crystal</b> [<i>global options</i>] <i>&lt;command&gt;</i> [<i>command options</i>] [<i>arguments</i>]<br><br>Common commands:<br><b>crystal</b> <i>build &lt;source_file&gt;</i> [<i>options</i>]<br><b>crystal</b> <i>run &lt;source_file&gt;</i> [<i>options</i>]<br><b>crystal</b> <i>init &lt;project_type&gt; &lt;project_name&gt;</i><br><b>crystal</b> <i>deps</i><br><b>crystal</b> <i>spec</i> [<i>options</i>]<br><b>crystal</b> <i>tool &lt;tool_command&gt;</i><br><b>crystal</b> <i>eval &lt;code_snippet&gt;</i><br><b>crystal</b> <i>help</i> [<i>command</i>]<br><b>crystal</b> <i>version</i>


title: PARAMETERS
content:
<b><i>build &lt;source_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles the specified Crystal source file(s) into an executable binary. This command is used to create standalone applications.<br><br><b><i>run &lt;source_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles and immediately executes the specified Crystal source file(s). This is convenient for rapid development and scripting.<br><br><b><i>init &lt;project_type&gt; &lt;project_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initializes a new Crystal project with a specified type (e.g., <i>app</i> for an application, <i>lib</i> for a library) and structure.<br><br><b><i>deps</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs project dependencies defined in the <i>shard.yml</i> file, leveraging the Shards package manager to resolve and fetch libraries.<br><br><b><i>spec</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the project's test suite (known as 'specs') using Crystal's built-in testing framework.<br><br><b><i>tool &lt;tool_command&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides access to various development tools, such as <i>format</i> for automatic code formatting, <i>env</i> for environment information, or <i>docs</i> for generating API documentation.<br><br><b><i>eval &lt;code_snippet&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates a given Crystal code snippet directly from the command line, similar to a REPL but for single expressions.<br><br><b><i>help</i> [<i>command</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help information for the <b>crystal</b> command or detailed help for a specific subcommand.<br><br><b><i>version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the installed Crystal compiler version and related build information.<br><br><b><i>--release</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A common option (e.g., for <i>build</i> or <i>run</i>) that compiles with aggressive optimizations, producing faster and often smaller executables suitable for production.<br><br><b><i>--debug</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A common option (e.g., for <i>build</i> or <i>run</i>) that compiles with debug information included, which is invaluable for debugging with tools like GDB.<br><br><b><i>-o &lt;path&gt;</i>, <i>--output &lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output path and filename for the compiled executable when using the <i>build</i> command.<br><br><b><i>-v</i>, <i>--verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, displaying more detailed information about the compilation and execution process.<br><br>


title: DESCRIPTION
content:
The <b>crystal</b> command invokes the Crystal language compiler and its associated toolchain. Crystal is a general-purpose, object-oriented programming language that aims to combine the developer productivity and elegant syntax of scripting languages like Ruby with the raw performance and type safety of compiled languages like C or Go. It features a powerful type inference system that typically eliminates the need for explicit type annotations, while still being statically typed. Crystal compiles directly to efficient native code, ensuring high execution speed. Key features include built-in concurrency primitives (fibers and channels), powerful compile-time macros for advanced metaprogramming, and automatic garbage collection. It is commonly used for web applications, command-line tools, and various other general-purpose software development tasks where a balance of speed, safety, and developer experience is desired.


title: CAVEATS
content:
While the Crystal ecosystem is growing rapidly, it is still smaller and less mature than those of older, more established languages like Ruby or Python. Compilation times for large projects can be noticeable, especially in debug mode. Although stable, the language and its tooling are subject to continuous development and improvements.


title: SHARDS
content:
Shards is Crystal's official dependency manager, analogous to RubyGems for Ruby or npm for Node.js. It manages project dependencies defined in a <i>shard.yml</i> file, allowing developers to easily fetch, install, and manage libraries (also called 'shards') from various sources, typically GitHub.


title: MACROS
content:
Crystal supports powerful compile-time macros, which enable advanced metaprogramming capabilities. These macros allow developers to generate code dynamically at compile time, reducing boilerplate, extending the language's expressiveness, and improving performance without incurring runtime overhead.


title: CONCURRENCY
content:
Crystal includes built-in primitives for highly efficient concurrent programming. It utilizes lightweight fibers (similar to goroutines in Go) for concurrent execution and channels for safe communication and synchronization between these fibers, simplifying the development of parallel and concurrent applications.


title: HISTORY
content:
Crystal development began around 2011 at Manas Technology Solutions (later spun off as Crystal Language team), driven by the desire to merge the developer-friendliness and elegant syntax of Ruby with the performance characteristics of compiled languages. The project rapidly gained community interest and evolved over the years, with a strong focus on type inference and native compilation. A significant milestone was the release of Crystal 1.0.0 in March 2021, signifying its stability and readiness for widespread adoption in production environments.


title: SYNOPSIS
content:
N/A: 'cs' is not a standard Linux command with a defined, general syntax. Its behavior depends entirely on how it's defined on a specific system.


title: DESCRIPTION
content:
The command 'cs' is <b>not a universally recognized or standard utility</b> shipped with most Linux distributions. Unlike commands such as `ls`, `grep`, or `cat`, there is no predefined system binary or official manual page associated with 'cs' by default across typical Linux environments. <br><br>Therefore, if 'cs' is executable on your system, it is highly probable that it functions in one of the following ways:<br><i><b>1. An alias:</b></i> A short command defined by a user or system administrator (e.g., `alias cs='clear; ls -l'` or `alias cs='cscope'`) within shell configuration files like `.bashrc`, `.zshrc`, or system-wide profiles.<br><i><b>2. A custom script or program:</b></i> An executable file named 'cs' that has been created and placed in a directory included in your system's `PATH` environment variable.<br><i><b>3. Part of a specific software package:</b></i> A command provided by a niche or specialized application that has been installed on the system, which is not common across all Linux setups (e.g., specific build tools, framework utilities).<br><br>Without specific context from your system, a general analysis of 'cs' as a standard, predefined Linux command is not possible.


title: CAVEATS
content:
Due to its non-standard nature, the behavior and even the existence of 'cs' can vary drastically from one Linux environment to another. There is no guarantee of its presence, functionality, or even safety across different systems. Relying on 'cs' without understanding its specific definition on a given system can lead to unexpected results, errors, or unintended actions. Users should always verify what 'cs' executes before using it, especially in scripts or critical operations.


title: IDENTIFYING 'CS' ON YOUR SYSTEM
content:
If the command 'cs' works on your terminal, you can investigate its origin and definition using these shell commands:<br><i><b>1. `type cs`</b></i>: This command will tell you if 'cs' is an alias, a function, a built-in command, or an external program.<br><i><b>2. `which cs`</b></i>: If 'cs' is an external program (a script or binary), this will show its full path on the filesystem.<br><i><b>3. `man cs`</b></i>: Attempt to open a manual page for 'cs'. If one exists, it indicates that 'cs' is likely part of an installed package with documentation.<br>These steps are crucial for understanding what 'cs' does on your specific Linux environment and are the only way to analyze its specific functionality.


title: SYNOPSIS
content:
The <b>cs-complete-dep</b> command is typically invoked as a Common Lisp function within a Lisp environment, rather than directly from the shell as an executable. Its conceptual invocation resembles:<br><i>(cs-complete-dep "PARTIAL-SYSTEM-NAME")</i><br>Where <i>"PARTIAL-SYSTEM-NAME"</i> is a string representing the initial characters of an ASDF system name for which completion candidates are sought. In most interactive settings (e.g., Emacs SLIME), this function is called automatically by completion frameworks.


title: PARAMETERS
content:
<b>PARTIAL-SYSTEM-NAME</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A <I>string</I> containing the initial characters of the ASDF system name for which to generate completion suggestions. The function returns a list of ASDF system names that start with or contain this partial string.<br><br>


title: DESCRIPTION
content:
The <b>cs-complete-dep</b> utility is a specialized component within the Common Lisp ecosystem, primarily designed to facilitate interactive dependency resolution for <I>ASDF</I> (Another System Definition Facility) systems. ASDF is Common Lisp's de-facto standard system definition tool, similar in concept to Makefiles or project files in other languages, used to define how Common Lisp code is organized, compiled, and loaded.<br><br><b>cs-complete-dep</b> works by providing a list of possible ASDF system names that match a given partial input string. Its main use case is within interactive development environments, particularly in <I>Emacs</I> with <I>SLIME</I> (Superior Lisp Interaction Mode for Emacs), where it powers completion functionality for commands that require an ASDF system name (e.g., loading a system, finding its definition). It's not a standalone general-purpose shell command but rather a Lisp function that is invoked programmatically to enhance developer workflow by reducing typing and errors when dealing with numerous Lisp systems and their dependencies.


title: CAVEATS
content:
<b>cs-complete-dep</b> is a Common Lisp function and <B>not</B> a standard Linux shell command found in typical system paths. Its direct execution from a shell prompt is not common or straightforward. It requires a Common Lisp implementation (e.g., <I>SBCL</I>, <I>CCL</I>), <I>ASDF</I>, and the `cs-tools` library (or similar completion-providing library) to be loaded and available within the Lisp environment. Its primary utility is within interactive Lisp development tools like Emacs with SLIME for dynamic completion.


title: INTERACTIVE USAGE
content:
In practical use, <b>cs-complete-dep</b> is seldom called directly by a user. Instead, it serves as a backend function for interactive completion utilities. For example, when using <I>Emacs</I> with <I>SLIME</I> and typing a partial ASDF system name at the REPL or when loading a system, <I>SLIME</I>'s completion machinery internally calls <b>cs-complete-dep</b> to fetch relevant suggestions, which are then presented to the user for selection. This makes system loading and interaction much more efficient and less error-prone.


title: HISTORY
content:
<b>cs-complete-dep</b> is part of the `cs-tools` collection, a set of Common Lisp utilities aimed at enhancing the developer experience. Its development is intertwined with the evolution of interactive Common Lisp programming environments, particularly the growing adoption of <I>SLIME</I> and the need for robust, dynamic completion mechanisms for <I>ASDF</I> system names and other Lisp entities. It emerged as a solution to streamline dependency management and system loading workflows within the Lisp REPL and editor integration.


title: SEE ALSO
content:
asdf (Common Lisp system definition tool), quicklisp (Common Lisp library manager), slime (Emacs mode for Common Lisp development), emacs (Text editor, often used for Lisp development), sbcl (Steel Bank Common Lisp implementation)


title: SYNOPSIS
content:
<i>cs-fetch</i> <b>[version]</b> <b>[architecture]</b> <b>[platform]</b> <b>[destination]</b><br><br>This representation reflects the common arguments handled by the internal script function. If <i>cs-fetch</i> is exposed as a standalone command, it may use named flags (e.g., <b>--version</b>, <b>--arch</b>) or positional arguments.


title: PARAMETERS
content:
<b>version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The specific <i>code-server</i> release version to fetch (e.g., <b>4.10.0</b>, <b>latest</b>). Defaults to <b>latest</b> if omitted.<br><br><b>architecture</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The target CPU architecture (e.g., <b>amd64</b>, <b>arm64</b>, <b>armhf</b>). Automatically detected if not specified.<br><br><b>platform</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The target operating system platform (e.g., <b>linux</b>). Automatically detected if not specified.<br><br><b>destination</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The directory where the downloaded binary should be placed (e.g., <b>/usr/bin</b>). Defaults to a common system path if not specified.<br><br>


title: DESCRIPTION
content:
<i>cs-fetch</i> is a specialized utility, often distributed as a shell script or an internal function within <i>code-server</i>'s installation and management tools. Its primary role is to download pre-compiled <i>code-server</i> binaries from official releases. It streamlines acquiring the correct executable for specified versions, architectures, and operating systems. This utility simplifies setup and updates, ensuring the proper <i>code-server</i> instance is retrieved. It's not a general-purpose file transfer tool like <i>curl</i> or <i>wget</i>, but rather a domain-specific helper for the <i>code-server</i> ecosystem.


title: CAVEATS
content:
Not a standard Linux command; primarily associated with <i>code-server</i>.<br>Often an internal shell script or function rather than a standalone user-facing executable.<br>Requires an active internet connection to download binaries.<br>Its exact CLI interface and availability can vary depending on how <i>code-server</i> is installed or packaged.


title: CORE PURPOSE
content:
<i>cs-fetch</i> specifically targets <i>code-server</i> binaries and associated assets, often incorporating compatibility and integrity checks. It is designed to abstract away the complexity of finding the right download URL for a given version and system.


title: AVAILABILITY
content:
This utility is typically found within the <i>code-server</i> installation directory or is part of the <i>code-server</i> installation script (e.g., <i>install.sh</i>). It is generally not a globally available command on most Linux systems by default; users often interact with it indirectly via <i>code-server</i>'s broader installation or update mechanisms.


title: HISTORY
content:
<i>cs-fetch</i> emerged as a crucial component within the <i>code-server</i> project (initially developed by <i>cdr/code-server</i>, now <i>coder/code-server</i>). Its development aimed to simplify the acquisition of correct pre-built <i>code-server</i> binaries. This was essential given <i>code-server</i>'s cross-platform nature and frequent updates, streamlining installation and updates for users and reducing manual dependency management efforts.


title: SYNOPSIS
content:
<b>cs-install</b> [<i>&lt;options&gt;</i>] <i>&lt;software_or_environment_name&gt;</i> [<i>&lt;software_or_environment_name&gt;</i>...]


title: PARAMETERS
content:
<b><i>&lt;software_or_environment_name&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The primary argument specifies the name of the software, tool, or development environment to be installed. This name is institution-specific and corresponds to a predefined package or setup. Common examples include:<br><b><i>java</i></b>: For Java Development Kit (JDK) and related tools.<br><b><i>python</i></b> (or <b><i>python3</i></b>): For Python interpreter, pip, and common libraries.<br><b><i>c/c++</i></b>: For GCC compilers, Make, and debugging tools.<br><b><i>ide</i></b>: For Integrated Development Environments like VS Code, Eclipse, or IntelliJ.<br><b><i>git</i></b>: For Git version control.<br><b><i>web</i></b>: For web development frameworks or servers.<br><b><i>config</i></b>: To apply specific course or department-related configurations or aliases.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(<i>Optional</i>) Displays a help message, including usage instructions and a list of available software names supported by the specific <i>cs-install</i> implementation. Availability varies by institution.<br><br>


title: DESCRIPTION
content:
<i>cs-install</i> is a non-standard Linux command-line utility primarily found in educational or institutional Computer Science environments, such as universities or colleges. Its main purpose is to simplify and automate the installation and configuration of software, tools, and development environments specifically required for various Computer Science courses and projects.<br><br>Instead of students manually installing compilers, IDEs, libraries, or specific versions of programming languages, <i>cs-install</i> acts as a wrapper script. It handles the underlying complexities of package management (e.g., using <i>apt</i>, <i>yum</i>, <i>pip</i>, or custom scripts), dependency resolution, and setting up environment variables or configuration files. This ensures that all students have a consistent and correctly configured development setup, reducing setup headaches and support issues.<br><br>The specific software packages available through <i>cs-install</i> are entirely defined by the institution providing the utility, making it a highly customized tool for a particular academic ecosystem.


title: CAVEATS
content:
<b>Non-Standard Command</b>: <i>cs-install</i> is not a part of standard Linux distributions. It is an institution-specific utility.<br><b>Institution-Dependent Functionality</b>: Its capabilities, the list of available software, and internal workings are entirely defined by the university or department providing it.<br><b>Internet Connection Required</b>: Typically, <i>cs-install</i> requires an active internet connection to download software packages.<br><b>Permissions</b>: Depending on the setup, it might require <i>sudo</i> privileges for system-wide installations or modifications.<br><b>System Modification</b>: It can modify system-wide or user-specific configuration files and install packages.


title: USAGE EXAMPLES
content:
Here are common ways <i>cs-install</i> might be used, though actual usage depends on the specific institution's implementation:<br><br><b><i>cs-install java</i></b><br>Installs the Java Development Kit and configures the environment for Java programming.<br><br><b><i>cs-install python3 ide</i></b><br>Installs Python 3, pip, and a recommended Integrated Development Environment (IDE) like VS Code.<br><br><b><i>cs-install c/c++ git</i></b><br>Sets up C/C++ development tools (compiler, debugger) and installs Git for version control.<br><br><b><i>cs-install config</i></b><br>Applies specific course or department-wide configurations to the user's environment, such as shell aliases or environment variables.


title: HISTORY
content:
The concept behind <i>cs-install</i> emerged from the need to standardize and streamline software setup for students in Computer Science departments. Historically, students often struggled with manual installations, version conflicts, and missing dependencies, leading to significant support overhead. <i>cs-install</i>, or similar tools, were developed as custom scripts by departmental IT staff to automate this process, ensuring a consistent and functional development environment across a large student body. Its "history" is largely anecdotal, evolving from simple shell scripts into more robust, institution-specific solutions over time, adapting to changing course requirements and operating system updates.


title: PARAMETERS
content:
<b>--compile</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles Java source files in the current project.<br><br><b>--run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the main class of the compiled Java application. May require a main class argument.<br><br><b>--test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs predefined unit or integration tests (e.g., JUnit tests).<br><br><b>--clean</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes compiled <B>.class</B> files and other build artifacts.<br><br><b>--jar <I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Packages the compiled application into a JAR file with the specified name.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays usage information and available options for <B>cs-java</B>.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version of the <B>cs-java</B> script or the underlying Java version.<br><br>


title: DESCRIPTION
content:
<I>The command <B>cs-java</B> is not a standard Linux utility found in typical distributions. It is highly probable that <B>cs-java</B> is a custom script or an alias specifically created within a Computer Science (CS) or academic environment, such as a university or college department.</I><br><br><I>Its purpose would be to simplify common Java development workflows for students or researchers. Instead of typing lengthy <B>javac</B>, <B>java</B>, or <B>jar</B> commands with specific class paths or options, <B>cs-java</B> acts as a convenient wrapper. It might automate tasks like:</I><br><I>&nbsp;&nbsp;&nbsp;&bull; Compiling Java source code (e.g., all <B>.java</B> files in a directory).<br>&nbsp;&nbsp;&nbsp;&bull; Running compiled Java applications.<br>&nbsp;&nbsp;&nbsp;&bull; Executing automated tests (e.g., JUnit).<br>&nbsp;&nbsp;&nbsp;&bull; Cleaning build artifacts (e.g., <B>.class</B> files).<br>&nbsp;&nbsp;&nbsp;&bull; Packaging applications into JAR files.<br>&nbsp;&nbsp;&nbsp;&bull; Managing project dependencies (though less likely to be a full-fledged build system like Maven or Gradle).</I><br><br><I>The exact functionality of <B>cs-java</B> would be entirely dependent on its implementation within the specific environment where it is found.</I>


title: CAVEATS
content:
<I>The primary caveat is that <B>cs-java</B> is not a standard, universally available command. Its presence, behavior, and options are entirely specific to the environment in which it was created.</I><br><br><I>&nbsp;&nbsp;&nbsp;&bull; <B>Portability:</B> Code relying on <B>cs-java</B> will not be portable to other Linux systems without replicating the script.<br>&nbsp;&nbsp;&nbsp;&bull; <B>Undocumented behavior:</B> Its functionality might not be officially documented outside the specific institution. Users may need to inspect the script's source code or ask local administrators.<br>&nbsp;&nbsp;&nbsp;&bull; <B>Security implications:</B> As it's a custom script, its source should be trusted if it executes with elevated permissions or handles sensitive data.</I>


title: UNDERSTANDING A CUSTOM COMMAND
content:
<I>To understand the exact functionality of <B>cs-java</B> on a specific system, you can use the following methods:</I><br><I>&nbsp;&nbsp;&nbsp;&bull; <B>Check its type:</B> Use <B><I>type cs-java</I></B> to see if it's an alias, function, or an executable.<br>&nbsp;&nbsp;&nbsp;&bull; <B>Locate the script:</B> If it's an executable, use <B><I>which cs-java</I></B> to find its path, then inspect the script file (e.g., <B><I>cat $(which cs-java)</I></B> or <B><I>less $(which cs-java)</I></B>).<br>&nbsp;&nbsp;&nbsp;&bull; <B>Look for documentation:</B> Check local course materials, system documentation, or ask system administrators or instructors.</I>


title: HISTORY
content:
<I>Given that <B>cs-java</B> is a custom command, it does not have a public, documented history like standard Linux utilities. It likely emerged from a need within academic computer science departments to provide a simplified and consistent interface for students to compile, run, and manage Java projects, especially in environments where full-fledged build systems like Maven or Gradle might be considered too complex for introductory courses.</I><br><br><I>Its development would typically be internal to the institution, evolving as teaching methodologies or underlying Java versions change.</I>


title: SYNOPSIS
content:
<b>cs-launch</b> <i>[OPTIONS] [ARGUMENTS...]</i><br><br><i>Note: This synopsis is illustrative as <b>cs-launch</b> is not a standard command. Its actual syntax and options vary based on its specific implementation.</i>


title: PARAMETERS
content:
<b><i>(No standard parameters)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;This command is not standard, so a universal list of parameters does not exist. Any parameters or options would be specific to its custom implementation. Hypothetically, such a command might accept options for configuration files (e.g., <i>--config &lt;file&gt;</i>), server addresses (e.g., <i>--server &lt;host&gt;</i>), or specific modes of operation (e.g., <i>--mode &lt;type&gt;</i>).<br><br>


title: DESCRIPTION
content:
The <b>cs-launch</b> command is not a standard utility found in most mainstream Linux distributions. Its functionality is highly dependent on the specific system or software package where it is implemented. Typically, commands prefixed with 'cs-' or containing 'launch' suggest its role in 'client-server' operations or as a custom script designed to initiate or start an application or service. It likely acts as a wrapper script to set up environment variables, configure paths, or orchestrate the launch of more complex underlying programs, potentially specific to a 'Computer Science' department's tools, a 'Customer Support' application, or a 'CodeReady Studio' environment. Due to its custom nature, a universal manual page or common set of options does not exist for <b>cs-launch</b>.


title: CAVEATS
content:
The <b>cs-launch</b> command is not a standard, universally distributed Linux utility. It is almost certainly a custom script, an alias, or part of a specific software package (e.g., development environments like Red Hat CodeReady Studio, or internal corporate tools). Therefore, its behavior, available options, and arguments are entirely dependent on its particular implementation on a given system. Users encountering this command should consult local documentation, the script itself, or the administrators of the system where it is present to understand its precise functionality.


title: PURPOSE IN CUSTOM ENVIRONMENTS
content:
<b>cs-launch</b> often serves as a simplified interface for complex underlying operations. It abstracts away the intricacies of setting up environment variables, configuring dependencies, or calling multiple sub-commands, allowing users to start a specific application or service with a single, memorable command tailored to their environment.


title: HISTORY
content:
As <b>cs-launch</b> is not a standard Linux command, it does not have a documented public history of development or usage. Its history would be tied to the specific project, organization, or software package for which it was created.


title: SEE ALSO
content:
<i>Given the 'launch' suffix, related concepts could include general process management or service activation commands. However, direct functional equivalents are impossible to name without knowing <b>cs-launch</b>'s specific purpose.</i><br><br><b>ps</b>(1)<br><b>kill</b>(1)<br><b>nohup</b>(1)<br><b>systemctl</b>(1) (for managing systemd services)<br><b>exec</b>(3) (shell built-in for process replacement)


title: PARAMETERS
content:
<b><code><i>&lt;service_or_host_name&gt;</i></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The logical name of the service or host to be resolved within the specific development environment's context.<br><br><b><code>-h</code>, <code>--help</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message and exits, showing available options and usage.<br><br><b><code>-v</code>, <code>--verbose</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more detailed information about the resolution process or errors.<br><br><b><code>-f</code>, <code>--format</code> <i>&lt;format_type&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format, such as <code>json</code>, <code>plain</code>, or <code>yaml</code>, if supported by the implementation.<br><br>


title: DESCRIPTION
content:
The <b><code>cs-resolve</code></b> command is <i>not a standard utility</i> found in most Linux distributions. <br>It typically appears within specific development environments, such as Red Hat CodeReady Workspaces (formerly Eclipse Che) or OpenShift Dev Spaces. <br>Its primary purpose is to facilitate internal service discovery, allowing applications or components within a complex, containerized, or cloud-native environment to locate and connect to other services by their logical names rather than hardcoded IP addresses or ports. <br>For instance, an application might need to connect to a 'database' service, and <b><code>cs-resolve</code></b> would provide the necessary network details (e.g., hostname, port) for that service, often by querying an internal service registry or Kubernetes API. <br>This abstraction is crucial in microservices architectures where service instances can be dynamic, scaling up or down, and moving between different network locations.


title: CAVEATS
content:
The <b><code>cs-resolve</code></b> command is <i>not a general-purpose network utility</i>. Its functionality and availability are entirely dependent on the specific software product or script that includes it (e.g., Red Hat CodeReady Workspaces, OpenShift Dev Spaces, or custom development setups). <br>It should not be confused with standard DNS resolution tools like <code>dig</code> or <code>nslookup</code>. Its behavior and output can vary significantly between different versions or implementations within those specific environments.


title: ROLE IN CLOUD-NATIVE DEVELOPMENT
content:
In cloud-native and Kubernetes-based environments, <b><code>cs-resolve</code></b> acts as an abstraction over complex service discovery mechanisms. It enables developers to reference services by simple, logical names, while the underlying system handles the dynamic mapping to network endpoints, greatly simplifying application configuration and deployment.


title: CONTEXT-SPECIFIC USAGE
content:
Users should be aware that <b><code>cs-resolve</code></b> is designed to operate within the specific context of the environment it's provided with. Attempting to use it outside of this environment, or without the necessary configuration, will likely result in errors or incorrect resolution.


title: HISTORY
content:
The concept behind <b><code>cs-resolve</code></b> emerged with the rise of containerization and microservices architectures, particularly in cloud-native development platforms. As applications became distributed across multiple containers and services, direct IP-based communication became impractical due to the dynamic nature of container lifecycles and scaling. <br>Utilities like <b><code>cs-resolve</code></b> were developed as part of larger platforms (such as Eclipse Che, which evolved into CodeReady Workspaces and OpenShift Dev Spaces) to provide an abstraction layer for service discovery. Its development is tied to the evolution of these IDE-as-a-Service and development environment platforms, aiming to simplify dependency management and inter-service communication for developers.


title: SEE ALSO
content:
<code>dig(1)</code>, <code>nslookup(1)</code>, <code>host(1)</code>, <code>getent(1)</code>, <code>kubectl(1)</code>


title: SYNOPSIS
content:
<b>csc</b> <i>[options] &lt;source files&gt;</i><br><b>csc</b> <i>[options] @&lt;response file&gt;</i>


title: PARAMETERS
content:
<b><b>/out:&lt;file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output assembly file.<br><br><b><b>/target:&lt;target&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the format of the output file (e.g., <i>exe</i>, <i>library</i>, <i>module</i>, <i>winexe</i>).<br><br><b><b>/reference:&lt;assembly list&gt;</b> or <b>/r:&lt;assembly list&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;References metadata from the specified assembly files.<br><br><b><b>/debug</b> or <b>/debug+</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Emits debugging information into the output.<br><br><b><b>/optimize</b> or <b>/optimize+</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables optimizations performed by the compiler.<br><br><b><b>/warnaserror</b> or <b>/warnaserror+</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats all warnings as errors, stopping compilation if any warning occurs.<br><br><b><b>/recurse:&lt;wildcard&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles source files in the current directory and all subdirectories matching the wildcard.<br><br><b><b>/define:&lt;symbol list&gt;</b> or <b>/d:&lt;symbol list&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines conditional compilation symbols.<br><br><b><b>@&lt;response file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads compiler options from a specified response file.<br><br>


title: DESCRIPTION
content:
The <b>csc</b> command, primarily known as the C# compiler, is used to compile C# source code files into executable applications (<i>.exe</i>) or libraries (<i>.dll</i>). It is a crucial component of the <i>.NET framework</i> and <i>Mono project</i>, enabling developers to build applications that run on Linux, Windows, and macOS.<br><br>While originally a Windows-centric tool (<b>csc.exe</b>), its availability on Linux via Mono and later <i>.NET Core/.NET 5+</i> has made it a truly cross-platform compilation utility. It processes <i>.cs</i> files, resolves references, and produces Common Intermediate Language (CIL) code, which is then executed by the Common Language Runtime (CLR). This command is essential for developing C# applications in a Linux environment.


title: CAVEATS
content:
The <b>csc</b> command directly refers to the Mono/Microsoft C# compiler; it is not a general-purpose Linux utility. It requires a <i>.NET SDK</i> or <i>Mono runtime environment</i> to be installed and configured. In modern .NET development, <b>csc</b> is often invoked indirectly via higher-level commands like <b>dotnet build</b>, which handle project-level settings. The exact set of options may vary slightly between different versions or implementations.


title: USAGE WITH <B>DOTNET CLI</B>
content:
While <b>csc</b> can be invoked directly, in modern .NET development, it's more common to use the <b>dotnet build</b> or <b>dotnet publish</b> commands. These commands automatically invoke <b>csc</b> with the correct project settings, dependencies, and build configurations defined in <i>.csproj</i> files. Direct <b>csc</b> invocation is often reserved for compiling single files or for specialized scenarios outside of a project context.


title: MONO VS. <B>.NET CSC</B>
content:
Historically, Mono provided its own C# compiler, often invoked as <b>mcs</b> or via its own <b>csc</b> wrapper. With Microsoft's open-sourcing of .NET and the adoption of <i>Roslyn</i> (Microsoft's C# compiler written in C#), the <b>csc</b> command in modern Linux environments typically refers to the compiler from the official <i>.NET SDK</i>, providing consistent behavior and feature sets across platforms.


title: HISTORY
content:
The <b>csc</b> command originated with Microsoft's <i>.NET Framework</i> for Windows. Its availability on Linux began with the <i>Mono project</i>, an open-source implementation of .NET. With Microsoft's open-sourcing of <i>.NET Core</i> (later simply <i>.NET</i>), the official <b>csc</b> compiler became a first-class citizen on Linux as part of the <i>.NET SDK</i>. This evolution has focused on modernizing C# language features and ensuring broad cross-platform compatibility.


title: PARAMETERS
content:
<b><b>-b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces a 'break' from option processing, treating the first argument as a command rather than an option.<br><br><b><b>-c</b> <I>command_string</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands from the following <I>command_string</I> argument.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exits if a command terminates abnormally or with a non-zero exit status.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fast startup; bypasses reading the <I>.cshrc</I> file.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the shell to be interactive, even if it appears not to be.<br><br><b><b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Parses commands but does not execute them (useful for syntax checking).<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands from standard input.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads a single command line and exits.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>verbose</I> shell variable, causing command input to be echoed after history substitution.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>verbose</I> shell variable before <I>.cshrc</I> is executed.<br><br><b><b>-x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>echo</I> shell variable, causing commands to be echoed after variable expansion.<br><br><b><b>-X</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>echo</I> shell variable before <I>.cshrc</I> is executed.<br><br>


title: DESCRIPTION
content:
`csh`, or the <I>C Shell</I>, is a command language interpreter (shell) for Unix-like operating systems. It was developed by Bill Joy at the University of California, Berkeley, in the late 1970s as part of the Berkeley Software Distribution (BSD) project. <br><br>Distinctive for its syntax, which closely resembles the C programming language, `csh` introduced several innovative features that are now commonplace in modern shells, such as command history, aliasing, and job control. It was designed to provide a more <I>programmer-friendly</I> interactive environment than the original Bourne shell (`sh`).<br><br>While `csh` proved popular for interactive use, its adoption for general-purpose shell scripting is often discouraged due to various <I>quirks</I> and inconsistencies in its parsing, quoting, and error handling mechanisms, especially when compared to Bourne-like shells such as `bash`. Most modern systems that include `csh` often provide `tcsh` (TENEX C Shell), an enhanced and more robust version, which is typically invoked when `csh` is called. Its historical significance is undeniable, but `tcsh` or `bash` are generally preferred for new work.


title: CAVEATS
content:
`csh` is widely known for its <I>scripting limitations</I>. Its parsing rules, particularly regarding quoting and redirection, can be complex and error-prone, making it less suitable for robust shell scripting compared to POSIX-compliant shells like <I>sh</I> or <I>bash</I>. <br>Furthermore, `csh` does not handle functions in the same way as Bourne-like shells, and its error handling is often considered less sophisticated. On many modern systems, the `csh` executable is actually a symbolic link or a hard link to `tcsh`, an enhanced version that addresses some of the original `csh`'s shortcomings, but retains its C-like syntax and fundamental scripting characteristics. <br>It is generally <I>not recommended</I> for new shell script development.


title: <B>INTERACTIVE VS. SCRIPTING USE</B>
content:
While `csh` pioneered features vital for interactive use (like history and aliasing), it's largely discouraged for complex scripting due to its non-standard behavior and subtle parsing issues, making scripts less portable and robust.


title: <B>C-LIKE SYNTAX</B>
content:
The shell's command syntax mimics C, evident in control structures such as `if (expression) then ... endif` and variable assignment using `=` and `set` commands, contrasting with the Bourne shell's `if [ expression ] then ... fi`.


title: <B>VARIABLE HANDLING</B>
content:
`csh` distinguishes between shell variables (set with `set`) and environment variables (set with `setenv`). This is different from Bourne-like shells where `VAR=value` and `export VAR` handle both.


title: HISTORY
content:
The <I>C Shell</I> was developed by <I>Bill Joy</I> at the University of California, Berkeley, and first released in <I>1978</I> as part of the 2BSD (Second Berkeley Software Distribution) Unix system. Its primary goal was to provide a more <I>user-friendly interactive shell</I> that incorporated features like command history and job control, which were lacking in the contemporary Bourne shell (`sh`). It introduced a syntax highly influenced by the C programming language, which was the dominant language for Unix system programming at the time. While `csh` revolutionized interactive shell usage, its design decisions for scripting led to various complexities. Over time, an enhanced version, `tcsh` (TENEX C Shell), superseded it in common usage, largely addressing many of `csh`'s interactive deficiencies and some scripting quirks, though maintaining the core C-like syntax.


title: SYNOPSIS
content:
<b>csslint</b> [<i>options</i>] &lt;<i>file</i>&gt; [&lt;<i>file</i>&gt;...]<br><b>cat</b> &lt;<i>file</i>&gt; | <b>csslint</b> [<i>options</i>] -


title: PARAMETERS
content:
<b><b>--format</b>=&lt;<i>format</i>&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format for the linting results. Common formats include <i>text</i> (default), <i>compact</i>, <i>csslint-xml</i>, <i>checkstyle-xml</i>, and <i>json</i>.<br><br><b><b>--warnings</b>=&lt;<i>rules</i>&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of rules that should be treated as warnings. This overrides the default severity of specified rules.<br><br><b><b>--errors</b>=&lt;<i>rules</i>&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of rules that should be treated as errors. This overrides the default severity of specified rules.<br><br><b><b>--rules</b>=&lt;<i>rules</i>&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of rules to explicitly enable or disable. Rules can be disabled by prefixing their name with a hyphen (e.g., <i>-box-model</i>).<br><br><b><b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all output if no errors or warnings are found. Useful for scripting in CI/CD pipelines.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and usage examples.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version number of <i>csslint</i>.<br><br><b><b>-</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads CSS input from standard input (stdin) instead of a file.<br><br>


title: DESCRIPTION
content:
<i>csslint</i> is a command-line tool that performs static analysis on Cascading Style Sheets (CSS) code.<br><br>It helps developers identify potential errors, inconsistencies, inefficiencies, and deviations from coding conventions. By providing configurable rules, it allows teams to enforce coding standards and improve the maintainability, browser compatibility, and performance of their stylesheets. <i>csslint</i> can be integrated into build processes, used as a pre-commit hook, or run standalone to validate CSS files.


title: CAVEATS
content:
<i>csslint</i> has not been actively maintained for several years, which means it may not fully support newer CSS features (like advanced Flexbox/Grid properties, custom properties, or newer at-rules). For modern CSS development, more actively maintained linters like <i>Stylelint</i> are generally recommended due to their comprehensive rule sets, plugin ecosystem, and community support.


title: CONFIGURING RULES INLINE
content:
Specific <i>csslint</i> rules can be enabled or disabled directly within CSS files using special comments. For example, to disable the 'box-model' rule for a section of code, you can use <i>/* csslint box-model:false */</i>.


title: EXIT CODES
content:
<i>csslint</i> returns a non-zero exit code if any errors are detected during the linting process. This behavior is crucial for integrating <i>csslint</i> into automated build systems and Continuous Integration (CI/CD) pipelines, allowing builds to fail when code quality issues are found.


title: HISTORY
content:
<i>csslint</i> was created by Nicholas C. Zakas and Nicole Sullivan in 2011. It emerged as an early tool to provide programmatic enforcement of CSS coding standards and to identify common pitfalls and best practice violations. While it gained significant popularity in the early 2010s, its development has slowed considerably in recent years, leading to the rise of more modern and actively developed alternatives in the CSS linting ecosystem.


title: PARAMETERS
content:
<b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays usage information for the command.</i><br><br><b><b>--version</b>, <b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Outputs the version of the <b>csv2tsv</b> utility.</i><br><br>


title: DESCRIPTION
content:
<i>The <b>csv2tsv</b> command is a utility designed to transform data from a Comma Separated Values (CSV) format to a Tab Separated Values (TSV) format. CSV is a common plaintext format where data fields are delimited by commas, while TSV uses tab characters as delimiters. This conversion is crucial for interoperability between different applications and systems that may prefer one format over the other.</i><br><br><i><b>csv2tsv</b> typically reads CSV data from standard input or specified files and writes the corresponding TSV data to standard output. A key feature is its robust handling of quoted fields in CSV. This means if a data field contains a comma or newline character, it is usually enclosed in double quotes (e.g., <b>"field, with, comma"</b>). The command correctly parses these quoted fields, ensuring that the embedded commas are not treated as delimiters and that the quotes themselves are removed in the output. Similarly, if a double quote appears within a quoted field (e.g., <b>"field with ""quote"" here"</b>), it is often represented by two consecutive double quotes, which <b>csv2tsv</b> should also correctly interpret and convert to a single quote in the TSV output.</i><br><br><i>This utility is particularly useful in data processing pipelines, shell scripting, and scenarios where data needs to be reshaped for database imports, spreadsheet programs, or analytical tools that have specific delimiter requirements.</i>


title: CAVEATS
content:
<i>The functionality of <b>csv2tsv</b> can vary significantly depending on its implementation. Basic versions might not handle malformed CSV (e.g., unbalanced quotes, missing delimiters) gracefully, potentially leading to incorrect output or errors. Complex CSV variations, such as different quoting styles, custom escape characters, or multi-line records not properly quoted, might also pose challenges. Encoding issues (e.g., UTF-8 vs. Latin-1) are also not typically handled by simple <b>csv2tsv</b> scripts and can lead to character corruption unless input is properly encoded. For advanced CSV manipulation or robust error handling, more sophisticated tools like <b>miller</b> or dedicated CSV parsing libraries in scripting languages are often preferred.</i>


title: COMMON IMPLEMENTATIONS
content:
<i>Many versions of <b>csv2tsv</b> are custom scripts. A common approach for implementing <b>csv2tsv</b> is using <b>awk</b> for parsing (e.g., handling quoted fields and delimiters), or Python with its built-in <b>csv</b> module for robust parsing. These scripts provide a lightweight solution for data transformation without requiring larger, more complex data processing frameworks.</i>


title: HISTORY
content:
<i>The command <b>csv2tsv</b> does not typically refer to a single, universally distributed program but rather a common task and often a specific script or small utility developed within various Linux environments or data processing toolkits. Its emergence stems from the widespread use of both CSV and TSV as simple, human-readable data interchange formats. As data processing grew, the need for quick, reliable conversion between these formats led to the creation of numerous ad-hoc scripts (often using <b>awk</b>, <b>sed</b>, or Python) and dedicated utilities to bridge the gap. While not part of the core GNU utilities, its functionality is frequently implemented and distributed within larger data analysis suites or as standalone scripts to facilitate common data wrangling tasks.</i>


title: PARAMETERS
content:
<b>-n, --no-header-row</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume no header row exists in the input file.<br><br><b>-p, --process-all-columns</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process rows with too many or too few columns by truncating or padding.<br><br><b>-e, --skip-errors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip rows that cause parsing errors without reporting them to stderr.<br><br><b>-I, --no-inference</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable type inference for faster processing, treating all data as strings.<br><br><b>-r, --max-rows <N></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stop processing after reading N rows from the input.<br><br><b>-c, --columns <COLUMNS></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of column names or indices to keep in the output.<br><br><b>-C, --exclude-columns <COLUMNS></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of column names or indices to exclude from the output.<br><br><b>--fill-missing-columns</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add missing columns to rows to match the header, filling with --fill-value.<br><br><b>--fill-value <VALUE></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The value to use when filling missing columns (default is empty string).<br><br><b>--truncate-excess-columns</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove excess columns from rows that have more columns than the header.<br><br><b>-H, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message and exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the version number and exit.<br><br>


title: DESCRIPTION
content:
<i>csvclean</i> is a powerful utility from the <b>csvkit</b> suite designed to identify and fix common structural issues in CSV (Comma Separated Values) files. It plays a crucial role in data preprocessing by ensuring that CSV data adheres to a consistent format, making it suitable for further analysis or database ingestion. The command's primary function is to parse input CSV files, identify problematic rows—such as those with an incorrect number of columns (either too many or too few), completely blank rows, or rows that fail to parse due to malformed data. By default, <i>csvclean</i> outputs the corrected, valid rows to standard output (<i>stdout</i>) and writes any problematic, malformed rows to standard error (<i>stderr</i>), optionally with line numbers, allowing users to inspect and address the errors separately. This separation of valid and invalid data streams makes <i>csvclean</i> an invaluable tool for robust data pipeline automation and manual data quality control. It can also handle various CSV dialects and character encodings, making it versatile for diverse datasets.


title: CAVEATS
content:
<i>csvclean</i> primarily focuses on structural integrity (e.g., column count consistency) rather than validating data content or semantic correctness. By default, problematic rows are sent to <i>stderr</i>, which might require redirection to capture for analysis. Processing very large files without options like <i>--max-rows</i> can be memory-intensive. It relies on <i>csvkit</i>'s parsing engine, which, while robust, may struggle with extremely malformed or non-standard CSV dialects.


title: <B>STANDARD INPUT/OUTPUT</B>
content:
<i>csvclean</i> can read from standard input if <i>FILE</i> is omitted or specified as '-', and writes cleaned data to standard output. This allows it to be easily integrated into shell pipelines with other Unix commands for chained processing.


title: <B>ERROR REPORTING</B>
content:
For rows that <i>csvclean</i> deems problematic, it outputs them to <i>stderr</i> along with line numbers and a descriptive error message (e.g., 'Expected 3 columns, found 4'). This detailed error reporting is crucial for debugging and understanding data quality issues.


title: <B>COLUMN NORMALIZATION</B>
content:
When using <i>--process-all-columns</i> in conjunction with <i>--fill-missing-columns</i> or <i>--truncate-excess-columns</i>, <i>csvclean</i> can enforce a consistent column count across all rows. This feature is often a prerequisite for loading data into databases, structured data frames, or for consistent machine learning input.


title: HISTORY
content:
<i>csvclean</i> is an integral part of the <b>csvkit</b> suite, an open-source collection of command-line tools for converting to and working with CSV. <b>csvkit</b> was initially developed by Christopher Groskopf and released around 2012, gaining popularity for its powerful, yet simple, approach to CSV manipulation using standard Unix pipes. <i>csvclean</i> was conceived as a necessary utility within this suite to address the common problem of inconsistent or malformed CSV data, enabling seamless integration of diverse datasets into analytical workflows. Its development has focused on robustness and adherence to the CSV standard, making it a reliable tool for data quality in various data science and engineering tasks.


title: SYNOPSIS
content:
<b>csvformat</b> [<i>options</i>] [<i>FILE ...</i>]<br><br><i>Common options:</i><br><b>csvformat</b> [<b>-H</b> | <b>--no-header-row</b>] [<b>-T</b> | <b>--tabs</b>] [<b>-U</b> [<i>0</i>|<i>1</i>|<i>2</i>] | <b>--quoting</b> [<i>0</i>|<i>1</i>|<i>2</i>]] [<b>-D</b> <i>DELIMITER</i> | <b>--delimiter</b> <i>DELIMITER</i>] [<b>-Q</b> <i>QUOTECHAR</i> | <b>--quotechar</b> <i>QUOTECHAR</i>] [<b>-e</b> <i>ENCODING</i> | <b>--encoding</b> <i>ENCODING</i>] [<b>-t</b> | <b>--skip-initial-space</b>] [<b>-p</b> | <b>--doublequote</b>] [<b>-x</b> <i>ESCAPECHAR</i> | <b>--escapechar</b> <i>ESCAPECHAR</i>] [<b>-m</b> <i>LINETERMINATOR</i> | <b>--lineterminator</b> <i>LINETERMINATOR</i>] [<b>-S</b> | <b>--skip-header-row</b>] [<i>FILE ...</i>]


title: PARAMETERS
content:
<b>FILE ...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more CSV files to process. If omitted, <b>csvformat</b> reads from standard input (stdin).<br><br><b>-H, --no-header-row</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not output the header row in the reformatted CSV.<br><br><b>-T, --tabs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use tabs as the field delimiter for the output CSV. This is a shortcut for <b>-D '\t'</b>.<br><br><b>-U [0|1|2], --quoting [0|1|2]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control the quoting behavior for output fields.<br><b>0</b>: Quote all fields.<br><b>1</b>: Quote non-numeric fields (default for <b>csvformat</b>).<br><b>2</b>: Quote minimally, only when necessary (e.g., fields containing delimiters or quote characters).<br><br><b>-D DELIMITER, --delimiter DELIMITER</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a custom output field delimiter. Can be a single character or a multi-character string.<br><br><b>-Q QUOTECHAR, --quotechar QUOTECHAR</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a custom output quote character, default is double-quote (<b>"</b>).<br><br><b>-e ENCODING, --encoding ENCODING</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the character encoding of the input CSV file, e.g., 'iso-8859-1'.<br><br><b>-t, --skip-initial-space</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When reading input, skip initial whitespace immediately following the delimiter.<br><br><b>-p, --doublequote</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force double-quoting of embedded quotes within a field. This is the default CSV behavior and generally recommended.<br><br><b>-x ESCAPECHAR, --escapechar ESCAPECHAR</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an escape character for output, used to escape the delimiter or quote character if they appear in a field and quoting is not applied.<br><br><b>-m LINETRMINATOR, --lineterminator LINETRMINATOR</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a custom line terminator for output. Default is system-dependent (e.g., '\n' for Unix, '\r\n' for Windows).<br><br><b>-S, --skip-header-row</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip the first row when reading input. Useful if the input file has a header but you don't want to process it.<br><br>


title: DESCRIPTION
content:
The <b>csvformat</b> command is a utility from the <i>csvkit</i> suite designed to reformat Comma Separated Values (CSV) files. It allows users to control various aspects of the CSV dialect, such as the delimiter, quote character, quoting style, and line terminator. This is particularly useful when converting CSV files between different formats, standardizing disparate CSV inputs, or preparing data for systems that expect a specific CSV dialect.<br><br>For example, it can convert a tab-separated file to a comma-separated one, change how fields are quoted (e.g., quoting all fields, only non-numeric, or minimally), or adjust the character used for escaping. It reads data from standard input or specified files and writes the reformatted CSV to standard output.


title: CAVEATS
content:
<b>csvformat</b> is part of the <i>csvkit</i> suite, written in Python, and thus requires a Python environment to be installed. While highly versatile, it expects reasonably well-formed CSV input. Extremely malformed files might still require pre-processing with other tools or manual cleaning. The default quoting behavior (<b>-U 1</b>, quote non-numeric) might differ from other tools that default to minimal quoting, which is important to consider for consistent output.


title: HISTORY
content:
<b>csvformat</b> is a core component of the <i>csvkit</i> project, an open-source suite of command-line tools for working with CSV data. <i>csvkit</i> was originally created by Christopher Groskopf and first released around 2012-2013. It rapidly gained traction within the data science, journalism, and analysis communities due to its simplicity, Unix-like philosophy (do one thing well), and Python-based extensibility. <b>csvformat</b> has been fundamental to the suite since its early development, addressing the common need for transforming CSV files between different dialects.


title: SYNOPSIS
content:
<b>csvgrep</b> [<i>CSV_OPTIONS</i>] <b>-c</b> <i>COLUMNS</i> (<b>-r</b> <i>REGEX</i> | <b>-f</b> <i>REGEX_FILE</i>) [<b>--not-match</b>] [<i>FILE</i>]


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b><b>-d</b> <i>DELIMITER</i>, <b>--delimiter</b> <i>DELIMITER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the single-character field delimiter of the input CSV file. Default is comma.<br><br><b><b>-t</b>, <b>--tabs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats the input CSV file as tab-delimited. Overrides <b>-d</b>.<br><br><b><b>-q</b> <i>QUOTECHAR</i>, <b>--quotechar</b> <i>QUOTECHAR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the single-character quoting character of the input CSV file. Default is double quote.<br><br><b><b>-u</b> <i>{0,1,2,3}</i>, <b>--quoting</b> <i>{0,1,2,3}</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls when quotes are added to output fields. 0 = QUOTE_MINIMAL, 1 = QUOTE_ALL, 2 = QUOTE_NONNUMERIC, 3 = QUOTE_NONE.<br><br><b><b>--skip-lines</b> <i>SKIP_LINES</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of initial non-CSV lines to skip before processing the CSV data.<br><br><b><b>--blanks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not convert quoted empty strings to NULL values. By default, empty strings are treated as NULL.<br><br><b><b>--no-inference</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables type inference when parsing the input. All values will be treated as strings.<br><br><b><b>--zero</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables 0-based indexing for columns. By default, 1-based indexing is used.<br><br><b><b>-c</b> <i>COLUMNS</i>, <b>--columns</b> <i>COLUMNS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of column names or 1-based (or 0-based with <b>--zero</b>) indices to operate on. This option is mandatory for filtering.<br><br><b><b>-r</b> <i>REGEX</i>, <b>--regex</b> <i>REGEX</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A regular expression to match against the specified columns. Mutually exclusive with <b>-f</b>.<br><br><b><b>-f</b> <i>REGEX_FILE</i>, <b>--file</b> <i>REGEX_FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A file containing regular expressions (one per line) to match. Mutually exclusive with <b>-r</b>.<br><br><b><b>-i</b>, <b>--ignore-case</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform case-insensitive matching for regular expressions.<br><br><b><b>-m</b>, <b>--match</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When multiple columns or expressions are used, match if <b>all</b> of them are true (AND logic). By default, it's OR logic.<br><br><b><b>--not-match</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instead of matching rows, exclude them (inverse matching).<br><br><b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the CSV file to operate on. If omitted, <i>csvgrep</i> reads from standard input (stdin).<br><br>


title: DESCRIPTION
content:
<i>csvgrep</i> is a powerful command-line utility from the <i>csvkit</i> suite, designed specifically for filtering rows in CSV files based on values within specified columns. It operates akin to the traditional <i>grep</i> command but is optimized for structured CSV data, understanding headers, columns, and various CSV dialects. Users can target columns by name or numerical index and apply regular expressions to match or exclude rows. With options for case-insensitive matching (<b>-i</b>), logical AND/OR combinations (<b>-m</b>), and inverse matching (<b>--not-match</b>), <i>csvgrep</i> is invaluable for data cleaning, extracting specific subsets, or preparing data for further analysis. It seamlessly integrates with other <i>csvkit</i> tools and standard UNIX pipes.


title: CAVEATS
content:
Due to its Python-based implementation, <i>csvgrep</i> might exhibit slower performance compared to native C-based tools for very large datasets, especially when not streaming data efficiently. Regular expressions are processed using Python's <b>re</b> module, so users should be familiar with its specific syntax. For extremely large files, memory usage can be a concern if the entire file is loaded into memory, though <i>csvkit</i> generally aims for streaming where possible.


title: REGULAR EXPRESSION SYNTAX
content:
<i>csvgrep</i> leverages Python's powerful <b>re</b> module for regular expression processing. This provides a rich and flexible pattern matching capability. Users should consult Python's official regular expression documentation for detailed syntax and features.


title: INPUT AND OUTPUT
content:
By default, <i>csvgrep</i> reads CSV data from standard input (stdin) if no <i>FILE</i> is specified, and writes the filtered output to standard output (stdout). This design promotes seamless integration into UNIX pipelines, allowing it to be chained with other <i>csvkit</i> commands or traditional UNIX utilities like <b>head</b>, <b>tail</b>, or <b>less</b>.


title: COLUMN SELECTION FLEXIBILITY
content:
Columns can be selected either by their header name (e.g., <b>-c "City,State"</b>) or by their numerical index (e.g., <b>-c 1,2</b>). By default, column indices are 1-based, but the <b>--zero</b> option can be used to switch to 0-based indexing for convenience.


title: HISTORY
content:
<i>csvgrep</i> is an integral part of <i>csvkit</i>, an open-source suite of command-line tools for working with CSV files. Conceived by Christopher Groskopf and initially released around 2012, <i>csvkit</i> was developed to bridge the gap between traditional UNIX text processing utilities and the structured nature of CSV data. It provides familiar functionality like <i>grep</i>, <i>cut</i>, and <i>sort</i> but with full awareness of CSV's columnar structure and various dialects, making it a robust and user-friendly solution for data professionals.


title: SYNOPSIS
content:
<b>csvkit</b> <I>[GLOBAL_OPTIONS]</I> <I>COMMAND</I> <I>[COMMAND_OPTIONS]</I> <I>[ARGUMENTS]</I><br><b>csvkit --version</b><br><b>csvkit --help</b>


title: PARAMETERS
content:
<b>csvcut</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select, reorder, or remove columns from CSV files.<br><br><b>csvgrep</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter rows from CSV files based on pattern matching.<br><br><b>csvsort</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort rows in a CSV file by one or more columns.<br><br><b>csvstack</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stack multiple CSV files vertically, concatenating rows.<br><br><b>csvjoin</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Join two or more CSV files horizontally based on common columns.<br><br><b>csvstat</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compute descriptive statistics for columns in a CSV file.<br><br><b>csvlook</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Render CSV data in a fixed-width format suitable for terminal viewing.<br><br><b>csvclean</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fix common errors in CSV files, such as inconsistent line endings.<br><br><b>csvformat</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert CSV to a custom delimiter or fixed-width format.<br><br><b>in2csv</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert various formats (e.g., JSON, Excel, HTML tables) to CSV.<br><br><b>csvsql</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute SQL queries against CSV files, or import/export to/from SQL databases.<br><br><b>csvjson</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert CSV to JSON format (either an array of objects or arrays).<br><br><b>csvpy</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load CSV data into a Python environment for scripting or interactive analysis.<br><br><b>csvdiff</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compare two CSV files and highlight differences.<br><br>


title: DESCRIPTION
content:
<b>csvkit</b> is a suite of command-line tools for converting to and working with CSV (Comma Separated Values) data. It simplifies common data manipulation tasks, offering utilities for viewing, cleaning, transforming, and analyzing CSV files directly from the terminal. Built on Python, <b>csvkit</b> bridges the gap between simple text processing tools and more complex database operations, allowing users to leverage familiar Unix pipes for data workflows. Its subcommands provide functionalities like converting JSON or Excel to CSV, filtering rows, selecting columns, joining files, sorting, statistical analysis, and importing/exporting to/from SQL databases. It's an invaluable tool for data professionals, analysts, and anyone routinely handling tabular data.


title: CAVEATS
content:
<b>csvkit</b> is written in Python, requiring a Python installation on your system. While powerful for many tasks, for extremely large datasets (e.g., terabytes), it might be less performant than specialized big data tools, as it often loads data into memory. It generally assumes well-formed CSV; malformed files might require prior cleaning or specific options.


title: INSTALLATION
content:
<b>csvkit</b> is a Python package and can be easily installed using Python's package installer, <b>pip</b>: <I><code>pip install csvkit</code></I>


title: PIPING
content:
One of <b>csvkit</b>'s greatest strengths is its design to work seamlessly with Unix pipes, allowing users to chain multiple commands together for complex data workflows (e.g., <I><code>cat data.csv | csvgrep -c "City" -m "New York" | csvcut -c "Name", "Age"</code></I>).


title: ENCODING
content:
<b>csvkit</b> provides robust support for various character encodings, which can often be specified using a global <I><code>--encoding</code></I> option or subcommand-specific options to handle diverse datasets.


title: HISTORY
content:
<b>csvkit</b> was created by Christopher Groskopf and first released in 2012. It emerged from the need for robust, programmatic tools to handle CSV files efficiently on the command line, leveraging Python's strong data handling capabilities. It quickly gained popularity among journalists, data analysts, and developers due to its ease of use and ability to integrate into Unix-like command-line workflows, filling a niche between basic shell utilities and full-fledged statistical software or database systems. Its development continues as an open-source project, actively maintained and improved by its community.


title: PARAMETERS
content:
<b><b>-H</b>, <b>--no-header-row</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Suppresses the output of the header row, displaying only data rows.</i><br><br><b><b>-y</b>, <b>--linenumbers</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Adds a column displaying row numbers as the first column of the output table.</i><br><br><b><b>-p</b>, <b>--pretty-output</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enables or disables enhanced output formatting, including colors and Unicode box characters for borders. This is typically enabled by default.</i><br><br><b><b>--width <I>N</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Sets the maximum column width for displayed data to <b>N</b> characters, truncating content if necessary.</i><br><br><b><b>-d <I>DELIMITER</I></b>, <b>--delimiter <I>DELIMITER</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the single-character string used to separate fields in the input CSV file. Defaults to comma.</i><br><br><b><b>-t</b>, <b>--tabs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>A shorthand for setting the input delimiter to a tab character, assuming the input is tab-separated.</i><br><br><b><b>-q <I>QUOTECHAR</I></b>, <b>--quotechar <I>QUOTECHAR</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the character used to quote fields in the input CSV file. Defaults to a double quote.</i><br><br><b><b>-u <I>{0,1,2,3}</I></b>, <b>--quoting <I>{0,1,2,3}</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Controls the quoting behavior for output, corresponding to different CSV module constants (e.g., 0 for QUOTE_MINIMAL, 1 for QUOTE_ALL).</i><br><br><b><b>-b</b>, <b>--doublequote</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Forces double quoting of all fields when writing, even if not necessary.</i><br><br><b><b>-e <I>ENCODING</I></b>, <b>--encoding <I>ENCODING</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the character encoding of the input CSV file (e.g., 'utf-8', 'latin-1').</i><br><br><b><b>-L</b>, <b>--skipinitialspace</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Ignores whitespace immediately following the delimiter in the input.</i><br><br><b><b>-z <I>SNIFFLIMIT</I></b>, <b>--snifflimit <I>SNIFFLIMIT</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Limits the number of rows to sniff when inferring CSV dialect and column types from the input.</i><br><br><b><b>-I</b>, <b>--no-inference</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disables automatic type inference for columns, treating all data as strings for display.</i><br><br><b><b>-c <I>COLUMNS</I></b>, <b>--columns <I>COLUMNS</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies a comma-separated list of column names or 0-based indices to include in the output.</i><br><br><b><b>-C <I>COLUMNS</I></b>, <b>--not-columns <I>COLUMNS</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies a comma-separated list of column names or 0-based indices to exclude from the output.</i><br><br><b><b>-r</b>, <b>--reverse</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Reverses the order of the data rows in the output table.</i><br><br>


title: DESCRIPTION
content:
<i><b>csvlook</b> is a utility from the <b>csvkit</b> suite of command-line tools, designed to make CSV (Comma Separated Values) files human-readable directly in your terminal. <br><br>It transforms raw CSV data into a well-formatted, aligned, and often colorful table, complete with borders and header rows. This command is invaluable for quickly inspecting data, debugging scripts, or exploring datasets without needing a spreadsheet application. It can read CSV data from standard input or a specified file. <b>csvlook</b> leverages <b>csvkit</b>'s robust parsing capabilities, which can handle various CSV dialects, delimiters, and encodings, making it a flexible tool for diverse data sources.</i>


title: CAVEATS
content:
<i>While highly convenient, <b>csvlook</b> has some limitations.</i> <br><br><i>For extremely wide CSVs, the output may still exceed typical terminal width, requiring horizontal scrolling or manual truncation with <b>--width</b>, which can hide valuable data.</i> <br><br><i>Processing and rendering extremely large datasets can be slower compared to simply viewing the raw text.</i> <br><br><i>The correct display of Unicode characters and colors in the output depends on the capabilities and proper configuration of the terminal emulator and its fonts.</i>


title: <B>PIPING CAPABILITIES</B>
content:
<i><b>csvlook</b> is designed to integrate seamlessly into Unix-like pipelines. Data can be piped directly into <b>csvlook</b> from other commands (e.g., <B>curl example.com/data.csv | csvlook</B>), or its formatted output can be piped to other tools like <b>less</b> for paginated viewing of large tables.</i>


title: <B>DEFAULT FORMATTING</B>
content:
<i>By default, <b>csvlook</b> attempts to provide the most aesthetically pleasing output. This includes intelligent column width adjustments, automatic type inference for numeric and date values (which can influence display), and colored output for improved readability, provided the terminal supports it. This default behavior usually offers a good balance between readability and information density.</i>


title: HISTORY
content:
<i><b>csvlook</b> is an integral part of the <b>csvkit</b> library, an open-source suite of command-line tools designed for processing CSV data.</i> <br><br><i>It was initially developed by Christopher Groskopf and publicly released around 2012. The project's goal was to provide a more robust, Python-based alternative to traditional shell utilities (like <b>cut</b>, <b>awk</b>, <b>grep</b>) for common CSV tasks, particularly aimed at data journalists and analysts.</i> <br><br><i>Since its inception, <b>csvkit</b>, and by extension <b>csvlook</b>, has become a popular choice for quick and reliable CSV manipulation in command-line environments due to its ease of use, powerful parsing capabilities, and user-friendly output.</i>


title: SEE ALSO
content:
<b>csvcut</b>(1), <b>csvstat</b>(1), <b>csvgrep</b>(1), <b>csvsort</b>(1), <b>cat</b>(1), <b>less</b>(1), <b>column</b>(1), <b>awk</b>(1)


title: SYNOPSIS
content:
<b>csvpy</b> [<i>OPTIONS</i>] [<i>FILE</i>]<br><b>csvpy</b> [<i>OPTIONS</i>] -<br><i>FILE</i> can be a path to a CSV file or '-' for standard input.


title: PARAMETERS
content:
<b><b>-H</b>, <b>--no-header-row</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude the header row from the output.<br><br><b><b>-n</b>, <b>--no-data-rows</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude data rows from the output, printing only the header and structure.<br><br><b><b>-l</b>, <b>--list-column-names</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output a list of column names only. This is equivalent to using <b>-n -H</b>.<br><br><b><b>-d</b> <i>CHAR</i>, <b>--delimiter</b> <i>CHAR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the character used to separate fields in the input CSV.<br><br><b><b>-t</b>, <b>--tabs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use tabs as the delimiter. This option overrides any character set by <b>-d</b>.<br><br><b><b>-q</b> <i>CHAR</i>, <b>--quotechar</b> <i>CHAR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the character used to quote fields containing special characters.<br><br><b><b>-u</b> <i>NUM</i>, <b>--quoting</b> <i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control how fields are quoted (0: QUOTE_MINIMAL, 1: QUOTE_ALL, 2: QUOTE_NONNUMERIC, 3: QUOTE_NONE).<br><br><b><b>-b</b>, <b>--no-doublequote</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable the escaping of quote characters by doubling them within a quoted field.<br><br><b><b>-p</b> <i>CHAR</i>, <b>--escapechar</b> <i>CHAR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a character to escape special characters not covered by quoting.<br><br><b><b>-z</b> <i>INT</i>, <b>--maxfieldsize</b> <i>INT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the maximum allowed size of a single field in bytes to prevent runaway memory usage.<br><br><b><b>-e</b> <i>ENCODING</i>, <b>--encoding</b> <i>ENCODING</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the character encoding of the input file (e.g., 'utf-8', 'latin-1').<br><br><b><b>-S</b>, <b>--skipinitialspace</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip whitespace immediately following the delimiter.<br><br><b><b>-I</b>, <b>--ignore-aliases</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not attempt to convert column names to valid Python identifiers (e.g., spaces to underscores).<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the program's version number and exit.<br><br><b><b>--locale</b> <i>LOCALE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the locale to use for number formatting, especially for numerical columns.<br><br>


title: DESCRIPTION
content:
<i>csvpy</i> is a command-line utility from the <br><i>csvkit</i> suite that converts a CSV file into <br>Python data structures (typically a list of lists or <br>a list of dictionaries).<br>It's particularly useful for quickly generating <br>Python code that represents your CSV data, <br>which can then be directly incorporated into Python <br>scripts, used in interactive Python sessions, or <br>for debugging purposes.<br>Instead of processing the data for display or <br>transformation, it outputs Python literal representations, <br>demonstrating how <i>csvkit</i> internally parses CSVs.<br>It provides a convenient way to get a Python-friendly <br>view of your tabular data without writing <br>parsing logic from scratch, making data accessible <br>for immediate programmatic use.


title: CAVEATS
content:
<i>csvpy</i> is designed to output Python code, not raw data for further piping <br>to other command-line tools in the traditional Unix sense. <br>For very large CSV files, the generated Python output can be <br>extremely verbose and may consume significant memory <br>if directly loaded into a Python interpreter without care. <br>It's an integral part of the <br><i>csvkit</i> suite, so it requires <br><i>csvkit</i> to be installed to function.


title: <B>USE CASES</B>
content:
<i>csvpy</i> is commonly used for:<br>1.  Generating boilerplate Python code to represent CSV data for testing or quick prototyping.<br>2.  Quickly inspecting the structure of a CSV file in a Pythonic way, showing how <i>csvkit</i> interprets columns and rows.<br>3.  Debugging CSV parsing issues by seeing exactly how <i>csvkit</i> translates the file's contents into Python objects.


title: <B>PIPING AND INPUT</B>
content:
<i>csvpy</i> can read from standard input (pipe) by specifying '-' as the file argument, allowing it to be integrated into shell pipelines:<br><i>cat my_data.csv | csvpy</i><br><i>some_command_generating_csv | csvpy -</i><br>However, it's important to remember that its output is Python code, not raw tabular data, which limits its utility for piping into other text-processing command-line tools like <i>grep</i> or <i>awk</i>.


title: HISTORY
content:
<i>csvpy</i> is a component of the <br><i>csvkit</i> project, an open-source suite of command-line tools for <br>working with CSV files. <br><i>csvkit</i> was initially developed by Christopher Groskopf <br>around 2011 to provide robust, text-based tools for common <br>CSV data processing tasks, drawing inspiration from Unix <br>utilities. <br><i>csvpy</i>'s specific role was to bridge the gap <br>between raw CSV data and its direct use within <br>Python environments, making it easier for developers <br>and data analysts to integrate CSV content into <br>scripts or explore data interactively in Python. <br>It reflects <i>csvkit</i>'s underlying Pythonic approach to CSV parsing.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show help message and exit.<br><br><b>-d DELIMITER, --delimiter DELIMITER</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the delimiter of the input CSV file.<br><br><b>-t, --tabs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicate that the input CSV file is delimited with tabs. Overrides -d.<br><br><b>-q QUOTECHAR, --quotechar QUOTECHAR</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the quote character of the input CSV file.<br><br><b>-u {0,1,2,3}, --quoting {0,1,2,3}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control the inclusion of quotes around output fields (e.g., 0=QUOTE_NONE, 1=QUOTE_MINIMAL).<br><br><b>-b, --no-double-quote</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevent writing an extra quote each time a quote is encountered in a field.<br><br><b>-p PARSER_CLASS, --parser-class PARSER_CLASS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a custom class to use for parsing CSV files.<br><br><b>-z, --gzip</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the output file with gzip.<br><br><b>--no-header-row</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip the header row when parsing input files.<br><br><b>-c COLUMNS, --columns COLUMNS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of column names or 1-based indices to sort by.<br><br><b>-r, --reverse</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the data in descending order.<br><br><b>-l LOCALE, --locale LOCALE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the locale for sorting, affecting string comparison.<br><br><b>-k, --key</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat sort keys as column identifiers (default behavior).<br><br><b>-i, --ignore-case</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a case-insensitive sort.<br><br><b>--zero</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When parsing, treat the 0th column as the first column (0-indexed).<br><br>


title: DESCRIPTION
content:
<i>csvsort</i> is a powerful command-line utility from the <i>csvkit</i> suite designed for sorting CSV (Comma Separated Values) files. It allows users to arrange data based on one or more specified columns, handling various CSV dialects, including tab-separated values. Unlike generic text sorting tools, <i>csvsort</i> understands the structure of CSV data, correctly parsing fields and respecting quoting rules. It supports both ascending and descending order, case-insensitive sorting, and locale-aware sorting. It can process files from standard input or a specified file path, outputting the sorted data to standard output, making it highly suitable for data pipelines.


title: CAVEATS
content:
<i>csvsort</i> requires the <i>csvkit</i> Python package to be installed on the system. For extremely large files, memory consumption can be significant as the data is loaded into memory for sorting. Its performance is dependent on Python's CSV parsing and sorting capabilities.


title: COLUMN SPECIFICATION
content:
Columns for sorting are precisely defined using the <i>-c</i> option. Users can specify columns by their header name (e.g., <i>-c 'City,Population'</i>) or by their 1-based numerical index (e.g., <i>-c '1,3'</i>). The <i>--zero</i> option allows for 0-based indexing. When multiple columns are provided, <i>csvsort</i> performs a multi-level sort, sorting by the first specified column, then by the second for rows with identical values in the first, and so on.


title: STANDARD I/O SUPPORT
content:
Adhering to the Unix philosophy, <i>csvsort</i> is designed to work seamlessly with standard input (stdin) and standard output (stdout). This enables powerful data processing pipelines, where the output of one command can be directly fed as input to <i>csvsort</i> using pipes (<i>|</i>), and its sorted output can then be directed to another command or redirected to a file.


title: HISTORY
content:
The <i>csvsort</i> command is a component of the open-source <i>csvkit</i> suite, a collection of Python-based command-line tools for working with CSV files. Initiated by Christopher Groskopf around 2012, <i>csvkit</i> aims to bridge the gap between simple shell tools and complex scripting for data analysis, offering CSV-aware equivalents to common Unix utilities like <i>sort</i>, <i>cut</i>, and <i>grep</i>. It has evolved through community contributions to become a widely used tool for data professionals.


title: SYNOPSIS
content:
csvsql [OPTIONS] <I>FILES...</I><br><br><b>Examples:</b><br><i>csvsql --query "SELECT column_a, column_b FROM data.csv WHERE column_a > 10"</i><br><i>csvsql --db sqlite:///my_data.db --insert file1.csv file2.csv</i>


title: PARAMETERS
content:
<b>--query <SQL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <b>SQL query</b> to execute against the input CSV files.<br><br><b>--tables</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>List table names</b> derived from the input CSV filenames without executing a query.<br><br><b>--dialect <DIALECT></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the <b>SQL dialect</b> for the query (e.g., <i>sqlite</i>, <i>postgresql</i>, <i>mysql</i>). Defaults to <i>sqlite</i>.<br><br><b>--db <CONNECTION_STRING></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provide a <b>SQLAlchemy connection string</b> to connect to an external database (e.g., <i>postgresql://user:pass@host/db</i>).<br><br><b>--insert</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Insert data</b> from the CSV files into the database specified by <b>--db</b>. CSV filenames become table names.<br><br><b>--no-create</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with <b>--insert</b>, it prevents <i>csvsql</i> from creating tables if they already exist in the database.<br><br><b>--table <TABLE_NAME></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a <b>single table name</b> to use for the input CSV file, overriding the default filename-based name.<br><br><b>--sniff-limit <BYTES></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Limit the number of <b>bytes to sniff</b> from the start of the file for column type inference (default: 102400).<br><br><b>--no-inference</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Disable column type inference</b>; all columns will be treated as text.<br><br><b>--encoding <ENCODING></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the <b>input file encoding</b> (default: <i>utf-8</i>).<br><br><b>--unique-constraint <COLUMN></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a <b>unique constraint</b> to the specified column(s) when creating a table via <b>--insert</b>.<br><br><b>--no-header-row</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat the <b>first row as data</b> rather than column headers.<br><br><b>--blanks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Do not convert empty strings to NULLs</b> when inserting data into the database.<br><br><b>--skip-errors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Skip problematic rows</b> that cause errors during data processing or insertion.<br><br>


title: DESCRIPTION
content:
<br><i>csvsql</i> is a powerful command-line tool from the <b>csvkit</b> suite that enables users to execute <b>SQL queries directly against one or more CSV files</b>. It treats each CSV file as a database table, intelligently inferring column data types by default. This capability allows for complex data manipulation, filtering, aggregation, and joining operations on tabular data without the overhead of loading it into a traditional relational database management system. It leverages <I>SQLAlchemy</I> for database abstraction, meaning it can query CSVs in-memory (using SQLite) or connect to external databases to create tables and insert data. Ideal for quick data analysis and transformations.


title: CAVEATS
content:
While highly convenient, <i>csvsql</i>'s performance for extremely large files (gigabytes) might be slower than a dedicated database import and query. Its column type inference, though intelligent, is not always flawless and may require manual override with <b>--no-inference</b> or type casting within SQL. Memory usage can also be a factor for very large datasets if the entire file needs to be loaded into memory for processing.


title: IN-MEMORY SQL VS. EXTERNAL DATABASE
content:
By default, <i>csvsql</i> uses an <I>in-memory SQLite database</I> to process queries against CSV files. This is fast and requires no external setup. However, with the <b>--db</b> option, it can connect to and query any database supported by <I>SQLAlchemy</I> (e.g., PostgreSQL, MySQL, Oracle), allowing for data insertion or more persistent query operations.


title: COLUMN TYPE INFERENCE
content:
<i>csvsql</i> attempts to <I>automatically detect column data types</I> (e.g., text, integer, float, date) by inspecting the first few rows of each CSV. This simplifies querying as you don't need to manually define schemas. For specific cases, <b>--sniff-limit</b> controls the amount of data sniffed, and <b>--no-inference</b> disables this feature entirely, treating all columns as text.


title: HISTORY
content:
<i>csvsql</i> is an integral part of <I>csvkit</I>, an open-source suite of utilities created by <B>Christopher Groskopf</B>. Initiated around 2011, <I>csvkit</I> was developed to address the common need for robust, Unix-pipe-friendly tools to process CSV data, often mimicking the capabilities found in traditional databases or spreadsheet software. <I>csvsql</I> specifically aimed to bring the power and flexibility of SQL queries directly to flat CSV files, becoming a cornerstone for data analysts and developers working with structured text data.


title: PARAMETERS
content:
<b>-t <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify input field separator (default ',').<br><br><b>--separator <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for specifying input field separator.<br><br><b>-T <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify output field separator (default ',').<br><br><b>--output-separator <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for specifying output field separator.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not quote output fields.<br><br><b>--unquoted</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for not quoting output fields.<br><br><b>-q <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify output quote character (default '"').<br><br><b>--quote <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for specifying output quote character.<br><br><b>-U <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Separate unquoted fields with specified character.<br><br><b>--unquoted-separator <I>char</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for separating unquoted fields with specified character.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not treat the first line as a header.<br><br><b>--no-header</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for not treating the first line as a header.<br><br><b>-H</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly treat the first line as a header (default for some commands).<br><br><b>--header</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for explicitly treating the first line as a header.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show version information and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for showing version information.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form for displaying help message.<br><br><b><I>subcommand-specific-options</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Many subcommands accept additional options tailored to their specific functionality. Use `csvtool <I>subcommand</I> --help` for details (e.g., `-f`, `-r`, `-n`).<br><br>


title: DESCRIPTION
content:
<i>csvtool</i> is a powerful and versatile command-line utility designed specifically for processing Comma Separated Values (CSV) files. Unlike general-purpose text processing tools like <i>awk</i> or <i>sed</i>, <i>csvtool</i> understands the structured nature of CSV, correctly handling quoted fields, various delimiters, and embedded newlines. It provides a wide array of operations, including selecting specific columns, reordering fields, merging multiple CSV files, splitting large files, sorting data, identifying unique records, and counting rows. Its intuitive syntax makes complex CSV manipulations straightforward, making it an indispensable tool for data analysts, system administrators, and anyone working with tabular data in the command line environment. It streamlines tasks that would be cumbersome with less specialized tools, ensuring data integrity by respecting CSV formatting rules.


title: CAVEATS
content:
<i>csvtool</i> is a powerful tool but might not be installed by default on all Linux distributions, requiring manual installation. While generally efficient, for extremely large datasets or highly complex transformations, specialized scripting (e.g., Python with Pandas) or database solutions might offer superior performance or flexibility. The 'select' subcommand uses a custom expression language that requires familiarity with its syntax.


title: KEY FEATURES
content:
<i>csvtool</i> is distinguished by its direct handling of CSV intricacies, including quoted fields and varied delimiters, ensuring data integrity. It offers a rich set of subcommands for common data tasks, such as column extraction, row filtering, sorting, merging, and more. Its performance is optimized for typical command-line usage, providing a fast and reliable alternative to general-purpose text utilities for structured data.


title: BASIC USAGE EXAMPLES
content:
Below are some common usage examples for <i>csvtool</i>:<br><b>Extract columns 1 and 3 from a file:</b><br><i>csvtool col 1,3 input.csv</i><br><b>Sort a CSV file by the second column numerically:</b><br><i>csvtool sort -n 2 input.csv</i><br><b>Filter rows where the first column equals 'active':</b><br><i>csvtool select '{1} == "active"' input.csv</i><br><b>Concatenate multiple CSV files:</b><br><i>csvtool cat file1.csv file2.csv > output.csv</i>


title: HISTORY
content:
<i>csvtool</i> was developed by Chris Double as a lightweight, efficient, and user-friendly command-line alternative for common CSV manipulation tasks. Its design prioritizes correct handling of CSV specifics like quoted fields and delimiters, adhering to the Unix philosophy. It has become a valuable utility for quick and reliable CSV processing in command-line environments, avoiding reliance on more complex scripting language setups.


title: PARAMETERS
content:
<b>-a, --append</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Append tags to an existing tags file instead of overwriting it.<br><br><b>-f file, --output-file=file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write tags to the specified <i>file</i> instead of the default 'tags'.<br><br><b>-R, --recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively process files in subdirectories.<br><br><b>-x, --cxref</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print a verbose cross-reference (cxref) file to standard output, rather than a tag file.<br><br><b>--exclude=pattern</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude files or directories matching the specified shell <i>pattern</i> from tag generation.<br><br><b>--languages=list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restrict the languages for which tags are generated to those specified in the comma-separated <i>list</i>.<br><br><b>--list-languages</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List the programming languages supported by ctags.<br><br><b>--sort={yes|no}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Determines whether the tag file entries are sorted. `yes` is the default; `no` can speed up generation for very large projects.<br><br><b>-u, --update</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Update tags for the specified files. Existing tags for those files are updated, and new tags are added.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information for ctags and exit.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief usage summary and exit.<br><br>


title: DESCRIPTION
content:
<i>The <b>ctags</b> command is a powerful programming tool used to generate an index (or "tag") file of identifiers found in source code files. This index file contains a list of language objects such as functions, variables, classes, macros, and structures, along with their locations within the source files. Programmers commonly use these tag files with text editors and integrated development environments (IDEs) like Vim, Emacs, or VS Code to enable rapid navigation through large codebases. Features such as "jump to definition," symbol browsing, and intelligent auto-completion are powered by the information within the tags file.</i><br><br><i><b>ctags</b> supports a wide array of programming languages, including C, C++, Java, Python, JavaScript, Ruby, and many others, making it an indispensable utility for software development. By providing a structured overview of the code's components, it significantly enhances productivity and code comprehension for developers.</i>


title: CAVEATS
content:
<i>It's important to note that there are different implementations of <b>ctags</b>, primarily <i>Exuberant Ctags</i> (the most widely distributed historical version) and <i>Universal Ctags</i> (an actively developed successor). While their core functionality is similar, Universal Ctags offers significantly enhanced language support and parsing capabilities. Users should be aware of which version they are using, as options and feature sets can differ.<br><br>Generating tags for extremely large codebases can be time-consuming and result in large tag files. While <b>ctags</b> is highly effective, it's typically a lexical scanner rather than a full-fledged parser, meaning it might occasionally misinterpret complex code constructs, although Universal Ctags has made significant strides in this area.</i>


title: COMMON USAGE PATTERN
content:
<i>A very common way to generate tags for an entire project is to navigate to the project's root directory and run: <code><b>ctags -R .</b></code> This command recursively scans all files in the current directory and its subdirectories, creating a 'tags' file.</i>


title: EDITOR INTEGRATION
content:
<i>Text editors like Vim and Emacs leverage the 'tags' file for powerful navigation. For instance, in Vim, placing the cursor over a symbol (e.g., function name) and pressing <code><b>Ctrl-]</b></code> will jump directly to its definition, while <code><b>Ctrl-t</b></code> will return to the previous location. This dramatically speeds up code exploration.</i>


title: CONFIGURATION FILES
content:
<i><b>ctags</b> can be configured using a file named <code><b>.ctags</b></code> in your home directory or in the project root. This file can contain default options, language-specific settings, and regular expressions for custom tag patterns, allowing users to tailor tag generation to their specific needs.</i>


title: HISTORY
content:
<i>The concept of <b>ctags</b> originated in the early days of Unix at AT&T Bell Labs and was a standard utility in the Berkeley Software Distribution (BSD). The original <b>ctags</b> primarily supported C and Pascal. Later, <i>Exuberant Ctags</i> emerged, significantly expanding language support to include many other programming languages, and became the de-facto standard implementation used across various Unix-like systems. More recently, <i>Universal Ctags</i> was forked from Exuberant Ctags to provide continued development, enhanced language parsing, and support for an even broader range of modern programming languages and features.</i>


title: PARAMETERS
content:
<b><b>--docker-host</b> <i><host></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Docker daemon host to connect to.<br><br><b><b>--filter</b> <i><expression></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters containers by name, status, or ID using a regular expression.<br><br><b><b>--refresh</b> <i><seconds></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the refresh rate of the display in seconds (default: 1).<br><br><b><b>--sort</b> <i><column></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the initial sort column (e.g., 'cpu', 'mem', 'name').<br><br><b><b>--follow</b> <i><container_id></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Follows a specific container, showing only its details.<br><br><b><b>--hide-exited</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Hides exited containers from the main view.<br><br><b><b>--hide-exited-duration</b> <i><duration></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Hides exited containers older than the specified duration (e.g., '1h', '30m').<br><br><b><b>--disable-host-info</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the display of host-level information in the header.<br><br><b><b>--disable-update-check</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the automatic check for new <i>ctop</i> updates.<br><br>


title: DESCRIPTION
content:
<i>ctop</i> is an <b>interactive command-line utility</b> designed for real-time monitoring of Docker and Podman containers. It provides a familiar <i>top</i>-like interface, displaying essential metrics such as <b>CPU usage, memory consumption, network I/O, block I/O, and process IDs</b> (PIDs) for all running containers.<br><br>Users can <b>sort containers</b> by various metrics (e.g., CPU, memory), <b>filter the displayed list</b> by name or status, and view detailed information for individual containers. Its ncurses-based interface allows for intuitive navigation and interaction directly within the terminal, making it an indispensable tool for developers and system administrators to quickly identify resource bottlenecks, troubleshoot issues, or simply keep an eye on their containerized applications.


title: CAVEATS
content:
<i>ctop</i> requires either the <b>Docker or Podman daemon</b> to be running and accessible on the host where it is executed.<br>Depending on your system's configuration and security policies, you might need <b>elevated privileges</b> (e.g., being part of the 'docker' group or using <i>sudo</i>) to access container statistics via the daemon's API.<br>It is not typically pre-installed on most Linux distributions and usually requires a <b>manual installation</b> process.


title: <B>INTERACTIVE KEYBINDINGS</B>
content:
<i>ctop</i> offers a rich set of keybindings for interactive management and navigation within the terminal interface:<br><b>s</b>: Sort containers by the currently selected column (e.g., CPU, Memory, Name)<br><b>f</b>: Apply or clear filters to narrow down the displayed containers<br><b>d</b>: Display detailed information for the currently selected container<br><b>l</b>: View real-time logs for the selected container<br><b>k</b>: Kill the selected container<br><b>p</b>: Pause or unpause the selected container<br><b>r</b>: Restart the selected container<br><b>e</b>: Execute a command within the selected container (drops you into its shell)<br><b>q</b> or <b>Ctrl+C</b>: Quit <i>ctop</i> and exit the application


title: HISTORY
content:
<i>ctop</i> was developed by <b>Brandon Cicen</b> (<i>bcicen</i>) and first released around <b>2017</b>. It quickly gained traction as a more user-friendly and interactive alternative to traditional container monitoring commands like <i>docker stats</i>, providing a comprehensive real-time overview of container performance in a familiar <i>top</i>-like interface. It continues to be an <b>actively maintained open-source project</b> on GitHub, with ongoing development and community contributions.


title: SYNOPSIS
content:
<br>The "ctrlaltdel" action is initiated by simultaneously pressing the <I>Control</I>, <I>Alt</I>, and <I>Delete</I> keys.<br><br>There is no direct command-line executable named "ctrlaltdel" that accepts options or arguments in the conventional sense. Its behavior is instead defined and configured by the system's initialization process and related services.<br><br>For configuring the action in <I>systemd</I>-based systems, relevant commands and configuration files include:<br><B>systemctl</B> <I>mask ctrl-alt-del.target</I><br><B>systemctl</B> <I>unmask ctrl-alt-del.target</I><br>And modifying <I>/etc/systemd/logind.conf</I>.<br><br>For configuration in <I>SysVinit</I>-based systems, the relevant configuration file is:<br><I>/etc/inittab</I> (specifically the 'ca' action entry)


title: PARAMETERS
content:
<b>None directly for the key sequence itself.</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The Ctrl+Alt+Del key combination does not accept command-line parameters directly.<br><br><b>HandleCtrlAltDel (systemd logind.conf)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;In systemd, this option within the `/etc/systemd/logind.conf` file (or its overrides in `/etc/systemd/logind.conf.d/`) determines the action taken when Ctrl+Alt+Del is pressed. Possible values include `reboot` (default), `poweroff`, or `ignore`. Example: <B>HandleCtrlAltDel=ignore</B>.<br><br><b>Target overriding (systemd)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <I>ctrl-alt-del.target</I> is a systemd target unit. Its behavior can be altered by masking it (e.g., <B>systemctl mask ctrl-alt-del.target</B>) to prevent the default action, or by linking it to a different target (though less common for this specific target).<br><br><b>SysVinit 'ca' entry parameters</b><br>&nbsp;&nbsp;&nbsp;&nbsp;In SysVinit, the 'ca' entry in `/etc/inittab` specifies a command to execute (e.g., <B>/sbin/shutdown -t1 -a -r now</B>). Parameters like `-r` (reboot), `-h` (halt), or `now` are arguments passed to the executed command (e.g., `shutdown`), not to 'ctrlaltdel' itself.<br><br>


title: DESCRIPTION
content:
The Ctrl+Alt+Del key combination is a special input sequence widely recognized in computing, used in Linux systems to initiate a system reboot or shutdown. Unlike typical shell commands, "ctrlaltdel" is not an executable program itself but rather a specific keyboard event interpreted by the operating system's initialization process.<br><br>In modern Linux distributions that utilize <I>systemd</I>, the Ctrl+Alt+Del sequence is intercepted and handled by the <I>systemd-logind</I> service. By default, it triggers a system reboot by activating the <I>ctrl-alt-del.target</I> which ultimately calls `systemctl reboot`. This behavior is configurable and can be modified to power off the system, ignore the key sequence entirely, or perform a custom action.<br><br>In older Linux systems using <I>SysVinit</I>, the `init` process would monitor for this key sequence and execute a predefined action specified in the `/etc/inittab` file, typically involving the `shutdown` command to perform a graceful system restart. It serves as a vital mechanism for administrators to perform a controlled system restart, especially in situations where the system may become unresponsive or for routine maintenance.


title: CAVEATS
content:
Modifying the default behavior of Ctrl+Alt+Del typically requires root or sudo privileges. Disabling this key combination can potentially make it harder to gracefully reboot an unresponsive system, forcing a hard reset instead. In graphical desktop environments (like GNOME, KDE), the key combination might be intercepted by the desktop environment itself to display a logout/shutdown dialog before the kernel or systemd handles it.


title: DISABLING/ENABLING CTRL+ALT+DEL IN SYSTEMD
content:
To disable the immediate reboot action (leaving it to the graphical environment or ignoring it):<br><B>sudo systemctl mask ctrl-alt-del.target</B><br>To re-enable the default reboot action:<br><B>sudo systemctl unmask ctrl-alt-del.target</B><br><br>Alternatively, you can edit <I>/etc/systemd/logind.conf</I> and set `HandleCtrlAltDel=ignore`, then restart the service: <B>sudo systemctl restart systemd-logind</B>.


title: DISABLING/ENABLING CTRL+ALT+DEL IN SYSVINIT
content:
To disable the action in older SysVinit systems, comment out or remove the 'ca' line in <I>/etc/inittab</I> (e.g., <I>#ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now</I>). After modifying the file, inform `init` to reload its configuration: <B>sudo init q</B> or <B>sudo telinit q</B>.


title: HISTORY
content:
The Ctrl+Alt+Del key combination originated with IBM PC systems, reportedly designed by David Bradley to provide a quick way to soft-reboot the original PC. It was widely adopted by MS-DOS and subsequently Windows as a 'warm boot' mechanism.<br><br>Linux adopted this concept early on. In systems using <I>SysVinit</I>, the `init` process was configured via `/etc/inittab` to listen for this key sequence and execute a defined command (usually `shutdown`). This allowed for a graceful shutdown or reboot, helping to prevent data loss.<br><br>With the advent of <I>systemd</I>, the handling of Ctrl+Alt+Del transitioned to the <I>systemd-logind</I> service. This provides a more integrated and flexible approach to power management events within the modern Linux ecosystem, while preserving the original intent of offering a failsafe or convenient way to restart the system.


title: SEE ALSO
content:
init(8), systemd(1), systemctl(1), shutdown(8), reboot(8), logind.conf(5), inittab(5), systemd-logind(8)


title: SYNOPSIS
content:
<b>cu</b> [<I>options</I>] [<I>system-name</I> | <I>phone-number</I>] <br><b>cu</b> <B>-l</B> <I>line</I> [<B>-s</B> <I>speed</I>] [<I>options</I>]


title: PARAMETERS
content:
<b>-l <I>line</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the communication line or device to use, e.g., <I>/dev/ttyS0</I> for a serial port or <I>network!host</I> for network connections.<br><br><b>-s <I>speed</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the transmission speed (baud rate) for the connection, such as <I>9600</I> or <I>115200</I>.<br><br><b>-e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables even parity for the data transmission.<br><br><b>-o</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables odd parity for the data transmission.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompts the user for a phone number to dial instead of taking it from the command line.<br><br><b>-t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicates a 'direct' connection (hardwired), typically used for null-modem cables or direct serial console access without modem dialing.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets half-duplex mode, meaning characters are not echoed locally and must be echoed by the remote system.<br><br><b>-x <I>debug_level</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the debugging level for output, useful for troubleshooting connection issues.<br><br>


title: DESCRIPTION
content:
The <b>cu</b> (call up) command is a utility for connecting to other systems, typically via a serial port (like a modem or a direct null-modem cable) or, less commonly today, a network connection. It's a foundational part of the older <I>UUCP</I> (Unix-to-Unix Copy Program) suite, though it can operate independently. <br><br>While largely superseded by more modern terminal emulators like <I>minicom</I> or <I>screen</I> for general serial console access, <b>cu</b> remains valuable for its simplicity and directness. It allows users to establish a terminal connection, send and receive data, and even transfer files (using internal escape sequences or external programs like <I>kermit</I> or <I>xmodem</I> via shell escapes). Its primary use cases include interacting with network equipment via console ports, configuring modems, or establishing point-to-point data links between two Unix-like systems.


title: CAVEATS
content:
The <b>cu</b> command, while simple, has several considerations:<br><ul><li><I>Device Permissions:</I> The user running <b>cu</b> must have appropriate read and write permissions to the serial device (e.g., <I>/dev/ttyS0</I>). This often means being a member of the <I>dialout</I> or <I>uucp</I> group.</li><li><I>Configuration Files:</I> When connecting by system name or phone number, <b>cu</b> relies on <I>UUCP</I> configuration files like <I>/etc/uucp/Systems</I> and <I>/etc/uucp/Devices</I>. These files might not be present or correctly configured on modern Linux distributions, making the <B>-l</B> (line) option more common for direct serial access.</li><li><I>Escape Sequences:</I> To perform actions like disconnecting, executing local commands, or transferring files, <b>cu</b> uses special escape sequences (e.g., <B>~.</B> to quit). Forgetting these can make it seem like the session is hung.</li><li><I>Feature Set:</I> It offers a much more basic feature set compared to modern terminal emulators like <I>minicom</I> or <I>screen</I>, lacking robust scripting, log file capabilities, or extensive file transfer protocols built-in (though external programs can be invoked).</li></ul>


title: COMMON ESCAPE SEQUENCES
content:
While connected, <b>cu</b> interprets lines beginning with a tilde (<B>~</B>) as escape sequences, allowing control over the session:<br><ul><li><B>~.</B><br> Terminates the connection and exits <b>cu</b>. (The most important one!)</li><li><B>~!</B><br> Escapes to a local shell. Type <I>exit</I> to return to the <b>cu</b> session.</li><li><B>~$</B><br> Executes a local command and sends its output to the remote system. For example, <B>~$ ls</B> would send a directory listing to the remote system.</li><li><B>~%take <I>from</I> [<I>to</I>]</B><br> Receives a file from the remote system.</li><li><B>~%put <I>from</I> [<I>to</I>]</B><br> Sends a file to the remote system.</li></ul>


title: TYPICAL USAGE EXAMPLE
content:
To connect to a device on a serial port (e.g., <I>/dev/ttyUSB0</I>) at a specific baud rate (e.g., 115200):<br><br><B>cu -l /dev/ttyUSB0 -s 115200</B><br><br>This is the most common modern use case for directly interacting with serial consoles.


title: HISTORY
content:
The <b>cu</b> command originated as a core component of the <I>UUCP</I> (Unix-to-Unix Copy Program) suite, which was developed at AT&T Bell Labs in the late 1970s and early 1980s. <I>UUCP</I> provided a means for Unix systems to communicate and transfer files over telephone lines and later, early networks. <b>cu</b>'s role was specifically to establish interactive terminal sessions. While <I>UUCP</I>'s prominence waned with the widespread adoption of TCP/IP and the internet, <b>cu</b> has persisted in various Unix and Linux distributions. Its continued relevance is primarily in niche areas such as interacting with embedded systems, network devices, and industrial control systems via their serial console ports, where its simplicity and directness are often preferred.


title: SYNOPSIS
content:
The 'cups' system is managed and interacted with through a suite of command-line utilities. While there isn't a single 'cups' executable for general user tasks, key commands for user interaction and administration include:<br><br><b>lp</b> [<i>options</i>] <i>file(s)</i><br><b>lpstat</b> [<i>options</i>]<br><b>lpadmin</b> [<i>options</i>]<br><b>cancel</b> [<i>options</i>] <i>job-id(s)</i>


title: PARAMETERS
content:
<b><b>-d</b> <i>destination</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the printer or class for printing (e.g., with <b>lp</b>) or querying (e.g., with <b>lpstat</b>).<br><br><b><b>-o</b> <i>option=value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a print job option, such as paper size or duplex printing (used with <b>lp</b>).<br><br><b><b>-p</b> <i>printer</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Designates a specific printer for status query or configuration (used with <b>lpstat</b>, <b>lpadmin</b>).<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a comprehensive summary of all CUPS server status information (used with <b>lpstat</b>).<br><br><b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables a printer to accept jobs or enables a printer queue (used with <b>lpadmin</b>).<br><br><b><b>-x</b> <i>printer</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes the specified printer from the CUPS configuration (used with <b>lpadmin</b>).<br><br><b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Cancels all jobs (on <b>cancel</b>) or shows all destinations (on <b>lpstat</b>).<br><br>


title: DESCRIPTION
content:
The <b>Common Unix Printing System (CUPS)</b> is a modular, open-source printing system developed by Apple Inc. for Unix-like operating systems. It provides a standardized layer between applications and printers, allowing programs to print to network or local printers without needing to know printer-specific details. CUPS uses the <I>Internet Printing Protocol (IPP)</I> as its foundation, offering advanced features like network printer auto-discovery, driver-less printing, and robust print job management. It superseded the traditional LPD (Line Printer Daemon) system, bringing a more modern, flexible, and extensible printing architecture to Linux and other Unix environments. CUPS includes a daemon (<I>cupsd</I>), various command-line utilities, and a web-based administration interface.


title: CAVEATS
content:
The term 'cups' itself typically refers to the entire printing <I>system</I>, not a single direct command-line executable for common user interaction. Users interact with CUPS primarily through a set of related commands like <b>lp</b>, <b>lpstat</b>, <b>lpadmin</b>, or via the web-based administration interface at <I>http://localhost:631</I>. The underlying CUPS daemon, <I>cupsd</I>, must be running for the printing system to function.


title: WEB INTERFACE
content:
CUPS provides a powerful web-based administration interface, accessible by default at <I>http://localhost:631</I>. This interface allows users and administrators to manage printers, view print jobs, configure server settings, and troubleshoot printing issues without needing command-line knowledge.


title: PPD FILES AND DRIVERS
content:
CUPS extensively uses <I>PostScript Printer Description (PPD)</I> files to understand printer capabilities. While modern CUPS versions increasingly support driver-less printing via IPP Everywhere, PPD files remain crucial for older or specialized printers, defining supported paper sizes, resolutions, and other device-specific features.


title: HISTORY
content:
CUPS was originally developed by Michael Sweet at Easy Software Products, with its first public release in 1999. It rapidly gained adoption as a modern replacement for the traditional LPD system, becoming the default printing system for macOS (starting with Mac OS X 10.2 Jaguar in 2002) and most Linux distributions. Apple open-sourced CUPS after acquiring Easy Software Products, and its development is now maintained by the OpenPrinting project, ensuring its continued relevance and evolution in the open-source community.


title: PARAMETERS
content:
<b>-c <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate configuration file for <b>cups-browsed</b>.<br><br><b>-D</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug mode, logging extensive information to standard error.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Daemonizes the process, running it in the background (default behavior).<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs in the foreground, preventing daemonization.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-L <i>level</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging level (e.g., <i>debug</i>, <i>info</i>, <i>warn</i>, <i>error</i>).<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of <b>cups-browsed</b> and exits.<br><br>


title: DESCRIPTION
content:
<b>cups-browsed</b> is a daemon that discovers and manages network printers for the Common Unix Printing System (CUPS). Its primary function is to browse for shared CUPS printers and IPP (Internet Printing Protocol) printers advertised on the local network, primarily using Bonjour/DNS-SD (mDNS) or the legacy CUPS browsing protocol. <br><br>Upon discovering new printers, <b>cups-browsed</b> can automatically create local print queues for them, making them immediately available to users on the system without manual configuration. It also monitors the availability of these printers, updating or removing queues as printers appear or disappear from the network. This automation simplifies printer setup significantly in network environments, especially for desktop users who might not have administrative privileges to configure printers manually. It typically runs in the background and is an essential component for seamless network printing discovery.


title: CAVEATS
content:
<b>cups-browsed</b> relies heavily on network services like Bonjour/DNS-SD (mDNS) for discovery. Proper firewall configuration is crucial to allow UDP ports 5353 (mDNS) and 631 (IPP/CUPS) for browsing and printing. <br><br>Its effectiveness can be limited by network topology, especially across different subnets without a configured mDNS reflector or other discovery mechanisms. While it automates queue creation, it may not always select the optimal driver or configuration for complex printers, sometimes requiring manual adjustment via <b>lpadmin</b>.


title: CONFIGURATION FILE
content:
<i>/etc/cups/cups-browsed.conf</i><br>This file controls <b>cups-browsed</b>'s behavior, including which browsing protocols to use, which network interfaces to monitor, and whether to auto-create local queues. It's crucial for fine-tuning its operation in specific network environments.


title: INTEGRATION WITH CUPS
content:
<b>cups-browsed</b> works in conjunction with the main <b>cupsd</b> daemon. While <b>cupsd</b> handles print jobs and core printer management, <b>cups-browsed</b> focuses solely on the discovery and dynamic creation/removal of printer queues in <b>cupsd</b>'s configuration, ensuring that available network printers are always reflected locally.


title: HISTORY
content:
<b>cups-browsed</b> was developed as part of the CUPS (Common Unix Printing System) project, which was originally created by Easy Software Products. CUPS became the standard printing system for most Linux distributions and macOS. <br><br>After Apple acquired CUPS development in 2007, the project continued to evolve. With Apple's shift in focus, the OpenPrinting organization took over stewardship of CUPS development for Linux and other Unix-like systems. <b>cups-browsed</b> emerged to address the need for automatic printer discovery and queue management, especially with the increasing prevalence of network-advertised printers using IPP and Bonjour, simplifying printer setup for end-users.


title: SYNOPSIS
content:
Due to its non-standard and largely non-existent status in modern CUPS installations, a definitive and universally applicable synopsis for <B>cups-calibrate</B> is not available. If it were part of a specific project, its usage might have resembled:<BR><BR><I>cups-calibrate [options] &lt;printer_name&gt;</I><BR><BR>However, users will generally find no manual page or executable for this command on their systems.


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;As <B>cups-calibrate</B> is not a standard command in modern CUPS installations, there are no universally defined or documented parameters. Any parameters would have been specific to the particular, likely experimental, version or project it belonged to.<br><br>


title: DESCRIPTION
content:
cups-calibrate is a command that was historically or experimentally associated with the <B>CUPS</B> (Common Unix Printing System) for printer color calibration. Its primary intent was to help generate or apply color correction data, such as <I>ICC profiles</I>, to ensure more accurate color reproduction from a printer. This would typically involve printing specific test patterns and then measuring or visually adjusting the output to match a reference.<BR><BR>However, it is crucial to note that <B>cups-calibrate is NOT a standard command</B> found in most modern Linux distributions or mainstream CUPS installations. It appears to have been part of specific development efforts, experimental branches, or third-party add-ons related to color management rather than a core, widely distributed CUPS utility. For color calibration in contemporary CUPS environments, users typically rely on printer manufacturer-provided <I>ICC profiles</I>, or utilize external professional color management software and hardware (e.g., spectrophotometers, colorimeters) with tools like <I>ArgyllCMS</I> or <I>dispcalGUI</I> to create custom profiles that CUPS can then use.


title: CAVEATS
content:
This command is <B>not typically found</B> on modern Linux systems or as part of standard CUPS installations. Attempting to run it will usually result in a "command not found" error.<BR>Its functionality has either been absorbed into other tools, superseded by more robust color management solutions, or was part of an abandoned experimental project.<BR>Color calibration for CUPS printers is now primarily achieved using <I>ICC profiles</I> supplied by manufacturers or generated by third-party color management software.


title: MODERN CUPS COLOR MANAGEMENT
content:
Instead of <B>cups-calibrate</B>, modern CUPS relies heavily on <I>ICC (International Color Consortium) profiles</I> for color management. These profiles describe the color characteristics of a device (like a printer). Printers often come with pre-calibrated profiles. For advanced users or specific needs, custom <I>ICC profiles</I> can be created using external tools (e.g., spectrophotometers and software like <B>ArgyllCMS</B> or <B>displayCAL</B>) and then associated with a printer queue in CUPS, typically via the <I>PPD (PostScript Printer Description) file</I> or through CUPS configuration options. This allows CUPS to perform color conversions to ensure the printed output closely matches the intended colors.


title: HISTORY
content:
The command <B>cups-calibrate</B> does not have a well-documented public history as a standard CUPS utility. It appears to have been either an experimental utility, part of a specialized CUPS color management project (e.g., <I>cups-color-calibration</I> from early 2000s), or a component in specific commercial CUPS derivatives. It was never widely adopted into the core CUPS distribution for general user calibration purposes, leading to its current status as a largely non-existent or forgotten command in mainstream Linux environments.


title: PARAMETERS
content:
<b><b>--api-version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS API version.<br><br><b><b>--build</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the build platform and architecture.<br><br><b><b>--cflags</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the C compiler flags needed to compile CUPS applications.<br><br><b><b>--datadir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS data directory path.<br><br><b><b>--docdir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS documentation directory path.<br><br><b><b>--exec-prefix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS executable prefix path.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><b>--install-prefix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the base CUPS installation prefix path.<br><br><b><b>--ldflags</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the linker flags needed to link CUPS applications.<br><br><b><b>--libs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the libraries required to link against CUPS.<br><br><b><b>--mandir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS manual page directory path.<br><br><b><b>--serverbin</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS server binary directory path.<br><br><b><b>--serverroot</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS server root directory path (where configuration files reside).<br><br><b><b>--sitedir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS site data directory path.<br><br><b><b>--statedir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS state directory path.<br><br><b><b>--sysconfdir</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS system configuration directory path.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CUPS version number.<br><br>


title: DESCRIPTION
content:
The <b>cups-config</b> command is a utility provided by the <b>CUPS</b> (Common Unix Printing System) project. Its primary purpose is to allow build systems and scripts to query the build configuration, installation paths, and linking information for CUPS libraries and components. <br><br>Instead of hardcoding paths, developers use <b>cups-config</b> to dynamically retrieve values such as the installation prefix, server binary directory, data directory, and necessary compiler flags or libraries. This ensures that software depending on CUPS can compile and link correctly, regardless of where CUPS is installed on a particular system. It serves a similar role to <b>pkg-config</b> for other libraries, making software development more robust and portable by automating the discovery of system-specific CUPS details.


title: CAVEATS
content:
<b>cups-config</b> is primarily intended for developers and build systems, not typical end-users. Its output reflects how CUPS was configured and installed on the specific system, and it will fail if CUPS is not installed or the command is not in the system's <i>PATH</i>.


title: USAGE IN BUILD SYSTEMS
content:
<b>cups-config</b> is frequently invoked by <i>configure</i> scripts, <i>Makefiles</i>, or modern build tools like <i>CMake</i>. It automates the process of determining necessary header paths (for compilation) and library flags (for linking) for applications that interact with the CUPS printing system. This automation significantly simplifies the compilation and portability of software, eliminating the need for developers to hardcode installation-specific paths.


title: HISTORY
content:
<b>CUPS</b> (Common Unix Printing System) was originally developed by Easy Software Products, with its first stable release in 1999. It rapidly became the standard printing system for most Linux distributions and macOS. <b>cups-config</b> was introduced as an integral part of the CUPS toolkit. Its purpose was to provide a standardized, portable method for other software (such as printer drivers or CUPS-aware applications) to automatically discover CUPS installation details and compile/link against its libraries, adapting to various system configurations without requiring manual path adjustments. This functionality is analogous to what <b>gtk-config</b> or later <b>pkg-config</b> provided for other development libraries.


title: PARAMETERS
content:
<b><i>(None)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><B>Note:</B> <b>cups-driverd</b> is an internal CUPS daemon and does not expose user-facing command-line options. Any parameters are typically for internal debugging or specific operational modes managed by <b>cupsd</b> itself.</i><br><br>


title: DESCRIPTION
content:
The <b>cups-driverd</b> command is an internal daemon component of the Common Unix Printing System (CUPS). Its primary role is to manage and provide information about installed printer drivers and PostScript Printer Description (PPD) files to the main CUPS scheduler, <b>cupsd</b>. It scans predefined locations for PPD files and other driver components, processes them, and makes this driver information available for printer setup and configuration. Essentially, <b>cups-driverd</b> acts as a backend service for driver discovery and enumeration, allowing users and applications to find and select appropriate drivers when adding new printers or modifying existing ones. <br><br>Users typically do not interact with <b>cups-driverd</b> directly; it is automatically started, stopped, and managed by the <b>cupsd</b> daemon or the system's init system (e.g., <b>systemd</b>). Its correct operation is crucial for the CUPS system to identify and utilize the vast array of available printer drivers, ensuring seamless printing functionality. Issues with <b>cups-driverd</b> can manifest as problems with printer discovery or the inability to select specific printer features.


title: CAVEATS
content:
Because <b>cups-driverd</b> is an internal CUPS daemon, it is not intended for direct user execution. Attempting to run it manually may lead to unexpected behavior or conflicts with the running CUPS service. Troubleshooting issues related to driver discovery often involves checking the logs of the main <b>cupsd</b> daemon (e.g., <i>/var/log/cups/error_log</i>) and ensuring that PPD files and driver binaries are correctly installed and have appropriate permissions.<br><br>Malfunctions of <b>cups-driverd</b> can prevent new printers from being added or correctly configured, as the system relies on it to enumerate available drivers.


title: PPD FILES AND DRIVER INFORMATION
content:
<b>cups-driverd</b> largely deals with PostScript Printer Description (PPD) files. PPD files are text files that describe the capabilities and features of a PostScript printer, including supported resolutions, paper sizes, and options for things like duplexing or collating. <b>cups-driverd</b> parses these files and presents the information in a structured way to CUPS, allowing the system to correctly configure and interact with a wide range of printers.


title: INTERACTION WITH CUPSD
content:
<b>cups-driverd</b> functions as a helper daemon for <b>cupsd</b>, the main CUPS scheduler. When a request comes in to add or configure a printer, or to list available drivers, <b>cupsd</b> queries <b>cups-driverd</b> to retrieve the necessary driver information. This architectural separation allows for modularity and efficient management of driver data without burdening the main scheduler with parsing and managing all driver files directly.


title: HISTORY
content:
The Common Unix Printing System (CUPS) was initially developed by Michael Sweet and released by Easy Software Products in 1999. It quickly became the de facto standard printing system for Unix-like operating systems. Apple Inc. acquired CUPS in 2007, continuing its development. <b>cups-driverd</b> has been a fundamental component of the CUPS architecture since its early days, tasked with managing printer drivers and PPD files. While CUPS has evolved to support driverless printing technologies like AirPrint and IPP Everywhere, the role of <b>cups-driverd</b> remains vital for supporting traditional PPD-based drivers and providing comprehensive driver information within the CUPS ecosystem.


title: PARAMETERS
content:
<b><b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Enables debug mode.</I><br>Provides more detailed output to standard error, useful for troubleshooting the update process.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Forces the update.</I><br>Instructs the command to force the PPD update even if no changes are detected between the existing PPD and the new driver information.<br><br><b><b>-m</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Updates from model/driver PPD.</I><br>Causes the utility to update PPDs using information found in a `driver.ppd` or `model.ppd` file, rather than relying on dynamic information from the `cups-driverd` daemon.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Enables verbose output.</I><br>Prints more information about the update process to standard output, including actions taken and files processed.<br><br><b><b><I>ppd-file</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Specifies a particular PPD file to update.</I><br>If provided, the command will attempt to update only this specific PPD file. If omitted, the command typically processes all relevant PPD files managed by CUPS.<br><br>


title: DESCRIPTION
content:
The `cups-genppdupdate` command is a utility provided by the Common Unix Printing System (CUPS). Its primary function is to update PostScript Printer Description (PPD) files, which define the capabilities and features of printers. These PPD files are crucial for CUPS to correctly interact with and configure printing devices.<br><br>`cups-genppdupdate` is typically used to synchronize existing PPD files with updated information, often derived from a `driver.ppd` file, a `model.ppd` file, or directly from the `cups-driverd` daemon. This ensures that printer configurations remain current and accurate, reflecting any changes in driver capabilities or printer specifications.<br><br>It's often invoked internally by CUPS when printer drivers are updated or when new printer models are detected, helping to maintain a consistent and functional printing environment. While it can be run manually, its main purpose is to automate the PPD update process within the CUPS ecosystem, ensuring that printer options and features are correctly reported and utilized.


title: CAVEATS
content:
This command is primarily an internal CUPS utility, designed to be invoked by system processes or other CUPS components. It is generally not intended for direct manual execution by end-users.<br><br>Direct manual execution might require root privileges or specific CUPS user permissions, depending on the system's configuration. Incorrect usage or manual manipulation of PPD files without proper understanding can disrupt printing functionality and lead to unexpected behavior. The exact behavior and available options may vary slightly between different CUPS versions and Linux distributions.


title: PURPOSE OF PPD FILES
content:
PostScript Printer Description (PPD) files are fundamental to CUPS. They act as declarative configuration files that describe the capabilities of a PostScript printer, including supported paper sizes, resolutions, duplexing options, available input trays, and other device-specific features. `cups-genppdupdate` helps keep these definitions accurate and current, allowing CUPS to fully utilize printer capabilities.


title: INTEGRATION WITH CUPS ECOSYSTEM
content:
This command is often called automatically by CUPS system scripts, service managers, or by the `cups-driverd` daemon when a printer driver is updated, new printer models are detected, or CUPS needs to re-evaluate the capabilities of an installed printer. This automation is key to maintaining a functional, flexible, and dynamic printing environment, minimizing manual configuration efforts.


title: HISTORY
content:
`cups-genppdupdate` is part of the `cups-filters` project, which originated from the Common Unix Printing System (CUPS). Initially developed by Apple Inc., CUPS and its associated utilities, including this PPD updater, evolved as the printing landscape changed. When CUPS's development transitioned to OpenPrinting/Linux Foundation, `cups-filters` became a separate project to provide essential printing filters, drivers, and utilities, including this crucial PPD maintenance script. Its role has adapted to changes in CUPS's driver management, ensuring printer configurations remain up-to-date and compatible with evolving standards and hardware, facilitating dynamic printer configuration.


title: PARAMETERS
content:
<b>-o <I>option=value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies CUPS options to be passed to the underlying <i>lp(1)</i> command when submitting a print job. Multiple options can be comma-separated. These options must precede any other command-line arguments. For example, <i>job-sheets=none,none</i> can be used to suppress banner pages.<br><br>


title: DESCRIPTION
content:
<i>cups-lpd</i> is a mini-daemon provided by the CUPS (Common Unix Printing System) project. Its primary function is to enable CUPS to receive print jobs and respond to printer status requests from clients using the legacy LPD (Line Printer Daemon) protocol, as defined in RFC 1179. This allows older or non-CUPS-aware systems to print to CUPS-managed printers.<br><br><i>cups-lpd</i> is typically not run directly by users but is invoked by an <i>inetd(8)</i> or <i>xinetd(8)</i> super-server when a connection is made to the standard LPD port (port 515). When a client sends a print job, <i>cups-lpd</i> translates the LPD request into a CUPS job, passing any specified LPD options as CUPS options to the underlying <i>lp(1)</i> command. Similarly, it retrieves printer status information from CUPS and formats it for LPD clients. It integrates with CUPS configuration files like <i>cupsd.conf(5)</i> and <i>printers.conf</i> and logs activity via <i>syslog</i>.


title: CAVEATS
content:
<i>cups-lpd</i> implements a subset of the RFC 1179 LPD protocol. It is inherently insecure as the LPD protocol itself does not support authentication or encryption, making it unsuitable for untrusted networks without additional security measures (e.g., VPNs or firewalls). Proper configuration of <i>Allow</i> and <i>Deny</i> rules in <i>cupsd.conf(5)</i> is crucial to restrict access to the LPD service. Because of its security limitations and the availability of more modern and secure printing protocols like IPP, <i>cups-lpd</i> is often used for backward compatibility with legacy systems.


title: CONFIGURATION WITH SUPER-SERVERS
content:
<i>cups-lpd</i> is typically not run as a standalone daemon but rather launched by a super-server like <i>inetd(8)</i> or <i>xinetd(8)</i>. These super-servers listen on the LPD port (515) and invoke <i>cups-lpd</i> for each incoming connection. A typical <i>xinetd</i> service entry for LPD might look like this:<br><code>service lpd<br>{<br>&nbsp;&nbsp;socket_type = stream<br>&nbsp;&nbsp;protocol = tcp<br>&nbsp;&nbsp;wait = no<br>&nbsp;&nbsp;user = lp<br>&nbsp;&nbsp;server = /usr/lib/cups/cups-lpd<br>&nbsp;&nbsp;server_args = -o job-sheets=none,none<br>&nbsp;&nbsp;disable = no<br>}</code><br>The <i>server_args</i> line demonstrates how to pass options like suppressing banner pages to <i>cups-lpd</i> via the super-server.


title: HISTORY
content:
The Line Printer Daemon (LPD) protocol, defined in RFC 1179, was a foundational network printing protocol widely used in Unix-like systems. When CUPS (Common Unix Printing System) was developed as a modern, modular printing system, it aimed to replace and enhance the traditional LPD-based printing. To ensure compatibility with existing LPD clients and infrastructure, CUPS included <i>cups-lpd</i> as a bridge. This daemon allows CUPS to accept jobs from systems still relying on the LPD protocol, effectively translating the LPD requests into the internal CUPS job format. Over time, while IPP (Internet Printing Protocol) became the preferred and more secure protocol for CUPS, <i>cups-lpd</i> has remained a vital component for backward compatibility and integration in heterogeneous network environments.


title: SYNOPSIS
content:
<b>cupsaccept</b> [ <i>-E</i> ] [ <i>-U username</i> ] [ <i>-h hostname[:port]</i> ] <i>printer(s)</i>


title: PARAMETERS
content:
<b><i>-E</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces encryption when communicating with the CUPS server.<br><br><b><i>-U username</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for authentication with the CUPS server. This is often required for administrative tasks.<br><br><b><i>-h hostname[:port]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate CUPS server to connect to. If a port is not specified, the default CUPS port (631) is used.<br><br><b><i>printer(s)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more names of printers or printer classes for which to accept jobs. Multiple names should be separated by spaces.<br><br>


title: DESCRIPTION
content:
The <b>cupsaccept</b> command is a vital component of the Common Unix Printing System (CUPS), designed to manage the status of print queues. Its primary function is to instruct the CUPS scheduler to begin accepting new print jobs for one or more specified printers or classes. When a printer queue is "accepted," any subsequent print requests directed to it will be successfully added to its queue for processing. This command effectively reverses the state set by <b>cupsreject</b>, which prevents a queue from taking in new jobs.<br><br>Administrators commonly use <b>cupsaccept</b> to bring a printer online after maintenance, initial setup, or after it has been temporarily stopped from accepting jobs. It is crucial to understand that <b>cupsaccept</b> only influences the acceptance of <i>new</i> jobs; it does not affect the processing or printing of jobs already present in the queue. For managing the processing of existing jobs, <b>cupsenable</b> and <b>cupsdisable</b> are used. This clear distinction is fundamental for effective CUPS administration.


title: CAVEATS
content:
The <b>cupsaccept</b> command requires administrative privileges to modify printer queue states. This typically means running as <i>root</i> or as a user who is a member of the <i>lpadmin</i> group, depending on the system's CUPS configuration.<br><br>It only affects the acceptance of <i>new</i> jobs; it does not start or stop the processing of jobs already in the queue. To control job processing, use <b>cupsenable</b> and <b>cupsdisable</b>.


title: DISTINCTION FROM CUPSENABLE
content:
It's important to differentiate <b>cupsaccept</b> from <b>cupsenable</b>. While both commands are used to manage printer status, they serve distinct purposes.<br><br><b>cupsaccept</b> controls whether a printer <i>accepts new jobs</i> into its queue. If a printer is not 'accepted', new print requests will be rejected.<br><br><b>cupsenable</b> controls whether a printer is <i>processing jobs already in its queue</i>. A printer can be 'accepted' (receiving new jobs) but 'disabled' (not processing them yet).<br><br>For a printer to be fully operational and processing jobs, it typically needs to be both 'accepted' and 'enabled'.


title: USAGE CONTEXT
content:
Administrators often use <b>cupsaccept</b> in conjunction with <b>cupsenable</b> when bringing a printer online after maintenance or troubleshooting. For example, after fixing a paper jam or replacing toner, an administrator might first use <b>cupsaccept</b> to allow new jobs to be spooled, and then <b>cupsenable</b> to resume printing of both new and existing jobs.


title: HISTORY
content:
<b>cupsaccept</b> is an integral part of the Common Unix Printing System (CUPS), which was originally developed by Easy Software Products and later acquired by Apple Inc. CUPS was first released in 1999 and quickly became the standard printing system for most Linux distributions and macOS. The <b>cupsaccept</b> utility has been a core command since early versions of CUPS, providing essential administrative control over printer queue status and job flow.


title: SYNOPSIS
content:
<b>cupsaddsmb</b> [ <i>-H server</i> ] [ <i>-U username</i> ] [ <i>-v</i> ] <b>-a</b><br><b>cupsaddsmb</b> [ <i>-H server</i> ] [ <i>-U username</i> ] [ <i>-v</i> ] <i>printer ...</i>


title: PARAMETERS
content:
<b><i>-H server</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the CUPS server hostname or IP address to connect to. If not specified, the default is the local host.<br><br><b><i>-U username</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for authentication with the CUPS server. If not specified, the command may prompt for credentials.<br><br><b><i>-v</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, providing more detailed information about the operation and any errors encountered during the process.<br><br><b><i>-a</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exports all currently configured CUPS printers to the Samba server. This option is mutually exclusive with specifying individual printer names.<br><br><b><i>printer ...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more specific CUPS printer names to export to Samba. Multiple printer names should be separated by spaces. This option is mutually exclusive with the <i>-a</i> option.<br><br>


title: DESCRIPTION
content:
<i>cupsaddsmb</i> is a command-line utility provided by the Common Unix Printing System (CUPS) that automates the process of exporting CUPS-configured printers to a Samba server. This allows Windows clients on the network to easily discover, connect to, and print through these shared printers.<br><br>It typically configures the Samba <i>[printers]</i> share and manages the necessary printer definitions and settings within Samba's internal database (like <i>printers.tdb</i>). The command simplifies the integration of CUPS-managed print services into a Microsoft Windows network environment, enabling seamless access for Windows users without extensive manual Samba configuration for each printer. It requires appropriate permissions to interact with both the CUPS daemon and the Samba server, often necessitating root or administrative privileges.


title: CAVEATS
content:
<b>Permissions:</b> Running <i>cupsaddsmb</i> typically requires root privileges or a user with sufficient permissions to modify CUPS configuration and Samba's printer database.<br><b>Samba Configuration:</b> The Samba <i>[printers]</i> share must be correctly configured in <i>smb.conf</i> (e.g., with <i>browsable = yes</i>, <i>printable = yes</i>, and an appropriate <i>path</i>).<br><b>Samba RPC Client:</b> The command often relies on the <i>rpcclient</i> utility (part of the Samba package) to interact with the Samba server's RPC interface. Ensure <i>rpcclient</i> is installed and accessible in the system's PATH.<br><b>Driver Management:</b> While <i>cupsaddsmb</i> configures printers in Samba, the actual Windows printer drivers might still need to be manually uploaded to the Samba server's driver store (e.g., <i>[print$]</i> share) for automatic client installation.<br><b>Security:</b> Care should be taken regarding the security implications of exposing printers via Samba, especially concerning guest access and driver installation policies.


title: DRIVER STORE FOR WINDOWS CLIENTS
content:
For Windows clients to automatically download printer drivers when connecting to a shared printer, the Samba server usually needs a designated 'driver store' (often shared as <i>[print$]</i>). While <i>cupsaddsmb</i> handles the printer definition, the actual driver files may need to be uploaded to this store separately using other Samba tools or manual methods.


title: AUTHENTICATION TO CUPS
content:
When <i>cupsaddsmb</i> connects to the CUPS server, if the <i>-U username</i> option is not provided, it may attempt to authenticate as the current user or prompt for a username and password, depending on the CUPS server's authentication settings (e.g., <i>AuthType Basic</i>, <i>AuthType Digest</i>).


title: TESTING AND VERIFICATION
content:
After running <i>cupsaddsmb</i>, it is highly recommended to test the printer sharing from a Windows client. Verify that the printer is discoverable in the network, drivers can be installed, and print jobs are successfully processed.


title: HISTORY
content:
<i>cupsaddsmb</i> was developed as an integral part of the CUPS project, specifically to address the need for seamless interoperability between Unix-based printing environments and Microsoft Windows networks. Its introduction significantly simplified the previously complex and manual task of configuring shared printers within Samba for Windows clients. This command has been crucial in establishing CUPS as a robust and widely adopted printing solution in mixed OS environments, facilitating the sharing of printers without deep manual intervention in Samba's configuration files for each printer.


title: SYNOPSIS
content:
<b>cupsctl</b> [ <i>OPTIONS</i> ] [ <i>SETTING=VALUE</i> ... ] <br><b>cupsctl</b> [ <b>--help</b> | <b>--version</b> ]


title: PARAMETERS
content:
<b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces encryption (HTTPS) when connecting to the CUPS server.<br><br><b><b>-U</b> <i>username</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for authentication with the server.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompts the user for a password when connecting to the server.<br><br><b><b>-h</b> <i>hostname[:port]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate CUPS server to connect to. The default is <i>localhost:631</i>.<br><br><b><b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debugging output during command execution, providing more verbose information about the process.<br><br><b><b>--no-daemon</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents <i>cupsctl</i> from automatically restarting the <i>cupsd</i> daemon after configuration changes are applied. Changes will not take effect until the daemon is manually restarted.<br><br><b><b>--[no-]remote-admin</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (<b>--remote-admin</b>) or disables (<b>--no-remote-admin</b>) remote administration of the CUPS server via its web interface. Enabling this allows other machines to access the administration pages.<br><br><b><b>--[no-]remote-printers</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (<b>--remote-printers</b>) or disables (<b>--no-remote-printers</b>) remote printer browsing/sharing for printers served by this CUPS instance. This affects whether printers on this server are advertised to other CUPS servers.<br><br><b><b>--[no-]share-printers</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (<b>--share-printers</b>) or disables (<b>--no-share-printers</b>) sharing of local printers via IPP, LPD, and SMB protocols. This makes local printers available to other computers on the network.<br><br><b><b>--[no-]web-interface</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (<b>--web-interface</b>) or disables (<b>--no-web-interface</b>) the CUPS web-based administration interface, typically accessed at <i>http://localhost:631</i>.<br><br><b><b>--[no-]user-interface</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deprecated in newer CUPS versions, this option previously controlled the user interface (often synonymous with <b>--web-interface</b>). It should generally be avoided in favor of <b>--web-interface</b>.<br><br><b><b>--[no-]private-browsing</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (<b>--private-browsing</b>) or disables (<b>--no-private-browsing</b>) private browsing mode for CUPS, which can affect the visibility of network printers and job history for users.<br><br><b><i>SETTING=VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a specific configuration directive in the <i>cupsd.conf</i> file to the provided value. For example, <i>LogLevel=debug</i> to increase logging detail, or <i>Port=80</i> to change the listening port. Multiple settings can be specified.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message with command usage and available options, then exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the CUPS version information that <i>cupsctl</i> is part of, then exits.<br><br>


title: DESCRIPTION
content:
<i>cupsctl</i> is a command-line utility used to query, display, and change the operational settings of the Common Unix Printing System (CUPS) scheduler daemon, <i>cupsd</i>. It provides a convenient way for administrators to manage the global configuration of the CUPS server, which is typically stored in the <i>cupsd.conf</i> file. Changes made with <i>cupsctl</i> are persistent, meaning they are written directly to the configuration file, and the CUPS daemon is usually restarted to apply them immediately. This command is essential for tasks like enabling or disabling the CUPS web interface, managing remote administration access, setting log levels, and configuring printer sharing options without directly editing the configuration file.


title: CAVEATS
content:
Most operations with <i>cupsctl</i> that modify settings require administrative privileges (typically <i>root</i> or a user in the 'lpadmin' group, depending on your system's CUPS configuration). Incorrectly configuring CUPS settings can lead to service disruptions, printing failures, or security vulnerabilities. Enabling remote administration or sharing options should be done with extreme caution, especially in insecure or untrusted network environments, as it can expose your printing system to unauthorized access.


title: PERSISTENT CONFIGURATION
content:
A key feature of <i>cupsctl</i> is that changes made using this command are permanently written to the main CUPS configuration file, <i>cupsd.conf</i>. This ensures that your server settings persist across daemon restarts and system reboots, unlike some other utilities that might apply temporary configurations.


title: DAEMON RESTART BEHAVIOR
content:
By default, after successfully applying configuration changes, <i>cupsctl</i> attempts to gracefully restart the <i>cupsd</i> daemon. This action ensures that the new settings take effect immediately without requiring manual intervention. If this automatic restart behavior is not desired (e.g., when scripting multiple changes), the <b>--no-daemon</b> option can be used to suppress it.


title: HISTORY
content:
<i>cupsctl</i> is an integral component of the Common Unix Printing System (CUPS), which was originally developed by Easy Software Products and later acquired by Apple Inc. in 2007. Since its inception, CUPS has aimed to provide a modular, standardized, and extensible printing system for Unix-like operating systems. <i>cupsctl</i> has been a core utility for managing the runtime configuration of the <i>cupsd</i> daemon, abstracting the direct editing of <i>cupsd.conf</i> and ensuring proper interaction with the running service. Its functionality has remained largely consistent throughout CUPS's development, serving as the primary command-line interface for global server settings.


title: SYNOPSIS
content:
<b>cupsd</b> [ <b>-c</b> <i>config-file</i> ] [ <b>-f</b> ] [ <b>-h</b> ] [ <b>-l</b> <i>log-level</i> ] [ <b>-D</b> ] [ <b>-o</b> <i>option=value</i> ] [ <b>-R</b> <i>root-certificate</i> ] [ <b>-S</b> <i>server-certificate</i> ] [ <b>-v</b> ]


title: PARAMETERS
content:
<b><b>-c</b> <i>config-file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies an alternate configuration file to use instead of the default <b>cupsd.conf</b>.</i><br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Runs the CUPS scheduler in the foreground. This is useful for debugging as it keeps the process attached to the terminal.</i><br><br><b><b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Shows a brief command usage help message.</i><br><br><b><b>-l</b> <i>log-level</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Sets the logging level for the daemon. Common levels include <b>info</b>, <b>warn</b>, <b>error</b>, and <b>debug</b>.</i><br><br><b><b>-D</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enables debug logging. This often implies the <b>debug</b> log level and provides more verbose output.</i><br><br><b><b>-o</b> <i>option=value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Sets a server option directly on the command line. This can override settings from <b>cupsd.conf</b>.</i><br><br><b><b>-R</b> <i>root-certificate</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the path to a root certificate file for SSL/TLS connections.</i><br><br><b><b>-S</b> <i>server-certificate</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the path to a server certificate file for SSL/TLS connections.</i><br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays the CUPS version information.</i><br><br>


title: DESCRIPTION
content:
<i>cupsd</i> is the central component of the Common Unix Printing System (CUPS). It acts as the print spooler and scheduler, managing print jobs, queues, and printers across a network or locally. Its primary function is to accept print requests from clients, process them, route them to the appropriate printer, and manage the printer's status. <i>cupsd</i> supports various printing protocols, including IPP (Internet Printing Protocol), LPD, and SMB, making it versatile for diverse environments.<br><br>It handles tasks like job scheduling, filter processing (to convert document formats to printer-readable formats), and provides printer sharing services. Typically, <i>cupsd</i> runs as a background service, started automatically at boot by the system's init system (e.g., systemd), and is rarely invoked directly by an end-user. It is fundamental for any Linux or Unix-like system that requires robust and flexible printing capabilities.


title: CAVEATS
content:
<i>cupsd</i> is a system daemon and is typically managed by the system's init system (e.g., systemd). Users should generally not attempt to start or stop it directly from the command line unless for specific debugging purposes. Configuration changes are primarily made through the <b>cupsd.conf</b> file or the CUPS web interface, rather than command-line arguments to <i>cupsd</i> itself. Misconfiguration can lead to printing failures or security vulnerabilities. Troubleshooting often involves examining the log files located in <b>/var/log/cups/</b>.


title: CONFIGURATION FILES
content:
<i>cupsd</i> heavily relies on configuration files for its operation. The primary configuration file is <b>/etc/cups/cupsd.conf</b>, which controls server-wide settings like listening addresses, logging, and security policies. Printer definitions are stored in <b>/etc/cups/printers.conf</b>, and printer capabilities are often described by PPD (PostScript Printer Description) files.


title: WEB INTERFACE
content:
CUPS provides a convenient web-based administration interface, typically accessible via a web browser at <b>http://localhost:631</b>. This interface allows administrators and users to add/remove printers, manage print jobs, view printer status, and configure various server settings without direct command-line interaction with <i>cupsd</i>.


title: LOG FILES
content:
<i>cupsd</i> generates several critical log files in the <b>/var/log/cups/</b> directory. Key logs include <b>error_log</b> (for daemon errors and warnings), <b>access_log</b> (for client connection and print job requests), and <b>page_log</b> (for details on each printed page). These logs are essential for diagnosing issues and monitoring the printing system's activity.


title: HISTORY
content:
CUPS was originally developed by Easy Software Products and first released in 1999. It was designed to replace older Unix printing systems like LPD and LPng, offering a more modular, robust, and Internet Printing Protocol (IPP) compliant solution. Apple Inc. acquired Easy Software Products in 2007, making CUPS an integral part of macOS. Development continued under Apple, solidifying its position as the de facto standard printing system across most Linux distributions and macOS. The <i>cupsd</i> daemon has remained the core of the CUPS architecture since its inception, continually evolving to support new printing technologies and protocols.


title: SYNOPSIS
content:
cupsdisable [ -E ] [ -U <i>username</i> ] [ -c ] [ -h <i>hostname</i>[:<i>port</i>] ] [ -r <i>reason</i> ] <i>destination(s)</i>


title: PARAMETERS
content:
<b>-E</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces encryption when connecting to the CUPS server.<br><br><b>-U <i>username</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for authentication with the CUPS server.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables a printer class instead of a printer.<br><br><b>-h <i>hostname</i>[:<i>port</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate CUPS server to connect to. The default is the local host.<br><br><b>-r <i>reason</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a human-readable reason for disabling the printer or class. This reason is often displayed by queue status commands like <b>lpstat</b>.<br><br><b><i>destination(s)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more printer names or class names (if <I>-c</I> is used) to be disabled. At least one destination is required.<br><br>


title: DESCRIPTION
content:
The <b>cupsdisable</b> command is a utility provided by the Common Unix Printing System (CUPS) that allows administrators to disable specific printers, printer classes, or individual print jobs. When a printer or class is disabled, it will no longer accept new print jobs, and any jobs currently queued for that destination will remain pending until the printer is re-enabled using <b>cupsenable</b>. This command is crucial for managing print queues, especially when a printer requires maintenance, is out of order, or needs to be taken offline temporarily without disrupting the print server.<br><br>You can specify one or more printer or class names as arguments. Optionally, a reason for disabling can be provided using the <I>-r</I> option, which is visible in print queue status. Disabling a printer effectively pauses its operation from the CUPS server's perspective, ensuring that users cannot send new print tasks to it. This mechanism is vital for maintaining system stability and preventing print job failures when hardware issues or administrative tasks are underway.


title: CAVEATS
content:
<b><I>Permissions</I></b>: Disabling printers typically requires administrative privileges (e.g., root or a member of the <I>lpadmin</I> group) on the CUPS server. Without proper permissions, the command will fail with an authorization error.<br><b><I>Job State</I></b>: Jobs already sent to a printer before it was disabled will remain in the queue (pending) and will not print until the printer is re-enabled. No new jobs will be accepted while disabled.


title: <I>IMPACT ON PRINT JOBS</I>
content:
When a printer is disabled using <b>cupsdisable</b>, it stops accepting new print jobs. Any jobs already in the queue for that printer will remain 'held' or 'pending' and will only be processed once the printer is re-enabled using the <b>cupsenable</b> command. This ensures that no jobs are lost during maintenance or troubleshooting.


title: <I>CHECKING PRINTER STATUS</I>
content:
After using <b>cupsdisable</b>, you can verify the status of the printer or class using the <b>lpstat -p</b> command. This command will typically show the printer as 'disabled' and often display the reason provided with the <I>-r</I> option, if one was specified.


title: HISTORY
content:
The <b>cupsdisable</b> command is an integral part of the Common Unix Printing System (CUPS), which was originally developed by Easy Software Products. CUPS replaced older printing systems like LPR/LPD on many Unix-like operating systems, providing a modern and standardized approach to printing. <b>cupsdisable</b>, along with <b>cupsenable</b>, was designed as a fundamental administrative tool to manage printer states, reflecting CUPS's focus on robust network printing capabilities and simplified administration. Its core functionality has remained consistent since early CUPS versions.


title: SYNOPSIS
content:
cupsenable [ -E ] [ -U <I>username</I> ] [ -P <I>password</I> ] [ -h <I>hostname[:port]</I> ] <I>destination(s)</I>


title: PARAMETERS
content:
<b>-E</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces encryption when connecting to the CUPS server.<br><br><b>-U <I>username</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for authentication with the CUPS server.<br><br><b>-P <I>password</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the password to use for authentication with the CUPS server. If not provided, the user may be prompted.<br><br><b>-h <I>hostname[:port]</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate CUPS server to connect to. The port defaults to 631 if not specified.<br><br><b><I>destination(s)</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more printer or class names to enable. These are required arguments.<br><br>


title: DESCRIPTION
content:
The <b>cupsenable</b> command is a utility from the <I>CUPS</I> (Common Unix Printing System) suite. Its primary function is to reactivate a printer or a printer class that has been previously disabled, typically using the <b>cupsdisable</b> command.<br><br>When a printer or class is disabled, it will not accept new print jobs. Running <b>cupsenable</b> changes its state to "enabled," allowing the spooler to accept and process new print requests for that destination. This command is essential for managing print services on a Linux or Unix-like system, ensuring that printers are available when needed. It sends a request to the CUPS daemon (<I>cupsd</I>) to update the printer's operational state. Successful execution means the specified printer(s) or class(es) are ready to receive jobs again.


title: CAVEATS
content:
<b>Permissions</b>: Requires administrative privileges (e.g., root or a member of the <I>lpadmin</I> group) to enable printers, especially if they are system-wide.<br><br><b>CUPS Daemon</b>: The CUPS daemon (<I>cupsd</I>) must be running for this command to function correctly.<br><br><b>Impact</b>: Enabling a busy printer might immediately resume printing a backlog of jobs if any were pending.


title: USE CASES
content:
Commonly used after maintenance, paper jams, or out-of-paper conditions to resume normal printing operations. It can also be scripted for automated printer management.


title: DEFAULT BEHAVIOR
content:
By default, <b>cupsenable</b> enables the specified printer indefinitely. There is no option to enable for a specific duration or until a certain event occurs.


title: HISTORY
content:
The <b>cupsenable</b> command is an integral part of the <I>CUPS</I> (Common Unix Printing System) project. <I>CUPS</I> was originally developed by Easy Software Products and later acquired by Apple Inc. in 2007. It became the standard printing system for macOS and many Linux distributions. In 2020, development of <I>CUPS</I> transitioned to OpenPrinting, an organization focused on improving printing on Linux and Unix systems. <b>cupsenable</b> has been a fundamental utility since the early versions of <I>CUPS</I>, maintaining consistent functionality for managing printer availability.


title: SYNOPSIS
content:
<b>cupsfilter</b> [ <b>-E</b> ] [ <b>-U</b> <i>username</i> ] [ <b>-c</b> <i>config-file</i> ] [ <b>-d</b> <i>printer</i> ] [ <b>-e</b> ] [ <b>-f</b> <i>filter</i> ] [ <b>-i</b> <i>mimetype</i> ] [ <b>-m</b> <i>mimetype</i> ] [ <b>-o</b> <i>option=value</i> ] [ <b>-p</b> <i>filename</i> ] [ <b>-t</b> <i>title</i> ] [ <b>-u</b> ] <i>file</i>


title: PARAMETERS
content:
<b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables encryption (SSL/TLS) for connections to the CUPS scheduler.<br><br><b><b>-U</b> <i>username</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use when connecting to the scheduler.<br><br><b><b>-c</b> <i>config-file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the specified <i>cupsd.conf</i> file for configuration, overriding the default.<br><br><b><b>-d</b> <i>printer</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the destination <i>printer</i> for filtering. This is crucial for selecting the correct PPD and filter chain.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies that the output should be a raw print file, bypassing the final backend filter. Useful for direct printer data.<br><br><b><b>-f</b> <i>filter</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an explicit <i>filter</i> program to use, bypassing the automatic filter chain determination.<br><br><b><b>-i</b> <i>mimetype</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the input file's MIME type. This helps in accurate filter chain selection, especially for ambiguous files.<br><br><b><b>-m</b> <i>mimetype</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the desired output MIME type for the filtered data.<br><br><b><b>-o</b> <i>option=value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies job options (e.g., <i>media=A4</i>, <i>print-quality=draft</i>) that influence the filtering process.<br><br><b><b>-p</b> <i>filename</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the PPD (PostScript Printer Description) <i>file</i> to use for filtering, simulating a specific printer's capabilities.<br><br><b><b>-t</b> <i>title</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the job <i>title</i> for the filtering operation.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies that the output should be uncompressed, which is useful for debugging.<br><br><b><i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The input file to be processed. Use a hyphen (<b>-</b>) to read from standard input.<br><br>


title: DESCRIPTION
content:
<b>cupsfilter</b> is a command-line utility that is an integral part of the Common Unix Printing System (CUPS). Its primary function is to simulate the CUPS printing pipeline by processing an input file through the appropriate CUPS filters and outputting the resulting print-ready data to standard output.<br><br>This tool is invaluable for developers, administrators, and users who need to test CUPS filters, debug printing issues, or simply convert a document into a format suitable for a printer without actually sending it to a physical device. It determines the correct filter chain based on the input file's MIME type, the specified printer, and any provided options, just as the CUPS scheduler would.<br><br>The output can range from PostScript to PCL or even raw printer data, depending on the chosen printer's PPD file and the desired output MIME type. By allowing explicit specification of input/output MIME types, filters, and printer PPDs, <b>cupsfilter</b> offers granular control over the conversion process, making it a powerful utility for pre-press preparation or system diagnostics.


title: CAVEATS
content:
<ul><li><b>cupsfilter</b> mimics the CUPS filtering process but does not interact with actual printer backends or network queues. The output is always directed to standard output.</li><li>Accurate filter chain resolution relies on a properly installed and configured CUPS environment (e.g., correct <i>cupsd.conf</i>, PPD files, and MIME type definitions).</li><li>MIME type detection can sometimes be ambiguous; explicitly specifying the input MIME type with <b>-i</b> is recommended for consistent results.</li></ul>


title: STANDARD OUTPUT USAGE
content:
The filtered data is always sent to standard output (<i>stdout</i>). This design choice allows users to easily pipe the output to other commands, save it to a file for later use, or inspect it directly in the terminal. This makes <b>cupsfilter</b> highly versatile for integration into scripts or for detailed debugging purposes.


title: MIME TYPE RESOLUTION LOGIC
content:
<b>cupsfilter</b> leverages the sophisticated MIME type rules defined within the CUPS system to determine the appropriate filter chain. If the input file's type cannot be confidently determined or is ambiguous, explicitly specifying it with the <b>-i</b> option ensures the correct filtering process is applied, preventing unexpected results.


title: HISTORY
content:
<b>cupsfilter</b> has been a core utility within the CUPS project since its early versions. Its stable functionality, providing a direct interface to the CUPS filtering pipeline, underscores its significance for testing, debugging, and pre-processing print jobs. It has evolved alongside the CUPS daemon, adapting to new features and standards while maintaining its primary role as a powerful diagnostic and conversion tool for administrators and developers.


title: PARAMETERS
content:
<b>printer</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the CUPS printer or class for which to reject new jobs.<br><br>


title: DESCRIPTION
content:
<b>cupsreject</b> is a command-line utility used in the Common Unix Printing System (CUPS) to prevent a specified printer or class from accepting new print jobs. When a printer is rejected, any new jobs sent to it will be held in the queue but will not be processed or printed until the printer is accepted again using the <b>cupsaccept</b> command. It is important to note that <b>cupsreject</b> <i>does not stop</i> jobs that are already in the queue from printing; it only affects the acceptance of subsequent new jobs. This command is typically used by administrators for maintenance, troubleshooting, or when a printer is temporarily unavailable for new work, but existing jobs should complete.


title: CAVEATS
content:
To use <b>cupsreject</b>, you must be a member of the 'lpadmin' group or have root privileges. <br>Rejecting a printer only prevents new jobs from being accepted; it does not stop jobs already in the queue from processing.


title: PERMISSIONS
content:
Administrative privileges are required to run <b>cupsreject</b>. Users must typically be part of the 'lpadmin' group or execute the command as the 'root' user to modify printer states.


title: DIFFERENCE FROM CUPSDISABLE
content:
It's crucial to understand the distinction between <b>cupsreject</b> and <b>cupsdisable</b>. <br><b>cupsreject</b>: Prevents new jobs from being added to the queue, but existing jobs continue to print. <br><b>cupsdisable</b>: Stops the printer from processing any jobs at all, effectively pausing all printing activity on that device, including jobs already in the queue. <br>Use <b>cupsreject</b> when you want to clear the incoming queue for new jobs but allow current jobs to finish. Use <b>cupsdisable</b> when you need to immediately halt all printing operations.


title: HISTORY
content:
<b>cupsreject</b> is a core component of the Common Unix Printing System (CUPS), which was originally developed by Easy Software Products and first released in 1999. CUPS became the standard printing system for many Unix-like operating systems, including most Linux distributions and macOS. The <b>cupsreject</b> command, alongside its counterparts like <b>cupsaccept</b>, <b>cupsenable</b>, and <b>cupsdisable</b>, has been fundamental to CUPS's robust print queue management capabilities since its early versions, providing administrators with fine-grained control over printer states.


title: PARAMETERS
content:
<b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows resource limits for each page in the PostScript file.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows verbose PostScript comment, font, and resource information detected within the file.<br><br>


title: DESCRIPTION
content:
<i>cupstestdsc</i> is a utility included with the <I>Common Unix Printing System (CUPS)</I>.<br><br>Its primary purpose is to validate the conformance of PostScript files to the <I>Adobe Document Structuring Conventions (DSC)</I>. DSC is a set of rules and comments embedded within PostScript files that provide structural information, making it easier for applications and print systems to process, parse, and manipulate the document.<br><br>This command is invaluable for identifying issues in PostScript files that might lead to printing errors, incorrect page ordering, or improper resource handling by CUPS. It reports errors, warnings, and informational messages regarding the DSC structure, including header errors, comment errors, and resource conflicts.<br><br>Administrators and developers often use <i>cupstestdsc</i> to diagnose why a particular PostScript file fails to print correctly or behaves unexpectedly when processed by CUPS, helping to ensure print job reliability and compatibility.


title: CAVEATS
content:
This command only checks for <I>DSC compliance</I>, not general PostScript language validity. A DSC-compliant file may still contain PostScript errors that prevent it from printing correctly. Its focus is primarily on the structural comments and headers.<br><br>It is generally a developer or debugging tool, not typically used by end-users for everyday printing tasks.


title: INPUT SOURCE
content:
If no filenames are specified on the command line, <I>cupstestdsc</I> reads PostScript data from standard input (stdin). This allows piping PostScript output from other commands directly into <I>cupstestdsc</I> for validation.


title: HISTORY
content:
The <i>cupstestdsc</i> utility is an integral part of the <I>CUPS (Common Unix Printing System)</I> project, which was originally developed by Easy Software Products and later acquired by Apple Inc. CUPS itself was designed to provide a modular, standards-based printing system for Unix-like operating systems. <I>cupstestdsc</I> was developed alongside CUPS to ensure the robust handling of PostScript files, particularly those adhering to Adobe's Document Structuring Conventions. Its existence underscores CUPS's commitment to processing print jobs reliably by validating the structural integrity of PostScript documents, which is crucial for features like page management, font handling, and resource inclusion.


title: PARAMETERS
content:
<b><i>filename.ppd</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more PPD files that <i>cupstestppd</i> should analyze and validate. You can list multiple files, separated by spaces.<br><br><b><i>-r</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <i>relaxed mode</i>. In this mode, <i>cupstestppd</i> will ignore certain non-critical errors or warnings that might otherwise be reported. This can be useful for PPDs that are slightly non-standard but known to function correctly.<br><br><b><i>-v</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <i>verbose mode</i>. When this option is used, <i>cupstestppd</i> provides more detailed output, including additional warnings that might be ignored in standard operation. This is helpful for in-depth debugging and understanding all potential issues.<br><br>


title: DESCRIPTION
content:
<i>cupstestppd</i> is a crucial utility provided with CUPS (Common Unix Printing System) that thoroughly checks the syntax and semantics of PostScript Printer Description (PPD) files. PPD files are essential as they describe the capabilities, features, and options of a PostScript printer. This command ensures that PPD files adhere to the Adobe PostScript Printer Description File Format Specification and CUPS-specific requirements.<br><br>It identifies and reports various warnings and errors that could lead to printing failures, incorrect option handling, or even security vulnerabilities. As such, <i>cupstestppd</i> is an indispensable tool for printer driver developers and system administrators seeking to diagnose or prevent printing issues related to malformed or non-compliant PPD files.


title: CAVEATS
content:
While <i>cupstestppd</i> performs extensive checks on PPD syntax and common semantic issues, it cannot guarantee a PPD file will work perfectly with all applications or printer firmware. Some reported warnings might be benign depending on the specific printer model or driver implementation.<br><br>The utility is primarily designed for PostScript printers, as PPDs inherently describe PostScript features. While PPDs can be used for configuration with non-PostScript devices via CUPS filters, the core validation focuses on PostScript compliance.


title: EXIT CODES
content:
The return (exit) code of <i>cupstestppd</i> is significant for scripting and automated environments:<br><ul><li><b>0</b>: Indicates that no errors or warnings were found, meaning the PPD file is considered valid and compliant.</li><li><b>1</b>: Indicates that errors were found in the PPD file, suggesting a problem that needs to be addressed.</li><li>Greater than <b>1</b>: Signifies other operational issues, such as the specified PPD file not being found or an internal error during processing.</li></ul>


title: IMPORTANCE FOR DEVELOPMENT AND TROUBLESHOOTING
content:
This utility is absolutely crucial for developers of printer drivers to ensure their PPD files are valid and will integrate seamlessly with CUPS. For system administrators, it's an invaluable first step when troubleshooting printing problems suspected to be related to PPD files. It helps in diagnosing common issues like missing options, incorrect value ranges, invalid constraints, or non-compliance with specifications, which can lead to unexpected print output or complete job failures.


title: HISTORY
content:
<i>cupstestppd</i> is an integral component of the CUPS project, which was originally developed by Easy Software Products and later acquired and maintained by Apple Inc. It has consistently served as a vital tool for ensuring the quality and compliance of PPD files within the CUPS printing ecosystem, adapting as PPD specifications and CUPS's own requirements have evolved over time. Its inclusion highlights CUPS's commitment to robust and standards-compliant printing solutions.


title: SYNOPSIS
content:
<b>curl</b> <i>[options]</i> <i>[URL...]</i><br><br><u>Examples:</u><br><i>curl https://example.com</i><br><i>curl -O https://example.com/file.zip</i><br><i>curl -X POST -d "key=value" https://api.example.com/data</i>


title: PARAMETERS
content:
<b><b>-o</b> <i>&lt;file&gt;</i>, <b>--output</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes output to <i>&lt;file&gt;</i> instead of standard output.<br><br><b><b>-O</b>, <b>--remote-name</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes output to a file named as the remote file (e.g., if downloading from <i>http://example.com/doc.pdf</i>, saves as <i>doc.pdf</i>).<br><br><b><b>-L</b>, <b>--location</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Follows <i>HTTP</i> 3xx redirects.<br><br><b><b>-I</b>, <b>--head</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fetches only the <i>HTTP</i> header information of a document.<br><br><b><b>-X</b> <i>&lt;command&gt;</i>, <b>--request</b> <i>&lt;command&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom request method to use when communicating with the <i>HTTP</i> server (e.g., <i>GET</i>, <i>POST</i>, <i>PUT</i>, <i>DELETE</i>).<br><br><b><b>-d</b> <i>&lt;data&gt;</i>, <b>--data</b> <i>&lt;data&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends the specified data in a <i>POST</i> request to the <i>HTTP</i> server. Often used for form submissions or sending <i>JSON</i> payloads.<br><br><b><b>-H</b> <i>&lt;header&gt;</i>, <b>--header</b> <i>&lt;header&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes a custom header to the server (e.g., <i>'Content-Type: application/json'</i>, <i>'Authorization: Bearer token'</i>).<br><br><b><b>-u</b> <i>&lt;user:password&gt;</i>, <b>--user</b> <i>&lt;user:password&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies user and password for server authentication.<br><br><b><b>-k</b>, <b>--insecure</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows <i>curl</i> to proceed and operate even if the server's <i>SSL</i> certificate is invalid or cannot be verified. Use with caution.<br><br><b><b>-s</b>, <b>--silent</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in silent or quiet mode, suppressing the progress meter and error messages.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes the operation more talkative, displaying a lot of debugging information.<br><br>


title: DESCRIPTION
content:
<b>curl</b> is a robust and widely-used command-line tool for transferring data to or from a server. It supports an extensive array of protocols, including <i>HTTP</i>, <i>HTTPS</i>, <i>FTP</i>, <i>FTPS</i>, <i>SCP</i>, <i>SFTP</i>, <i>TFTP</i>, <i>DICT</i>, <i>TELNET</i>, <i>LDAP</i>, <i>LDAPS</i>, <i>FILE</i>, <i>IMAP</i>, <i>POP3</i>, <i>SMTP</i>, and many more.<br><br>Developed to work without user interaction, curl is ideal for automated tasks, scripts, and applications. Its capabilities include support for proxies, user authentication, <i>HTTP POST</i>, <i>SSL certificates</i>, <i>cookies</i>, file transfer resume, and <i>Metalink</i>. It's an indispensable tool for developers for testing <i>REST APIs</i>, system administrators for downloading files and managing remote resources, and anyone needing to interact with web services or transfer data over a network.


title: CAVEATS
content:
When using <b>-k</b> or <b>--insecure</b>, <i>curl</i> will bypass <i>SSL</i> certificate verification, which can expose your connection to security risks like Man-in-the-Middle attacks. It should be used only in development or controlled environments.<br><br>Be mindful of shell escaping when providing complex <i>URLs</i> or <i>data payloads</i>, especially with special characters or spaces, as the shell might interpret them before <i>curl</i> receives them.<br><br>For very large file transfers, consider using <b>-o</b> to stream directly to a file to avoid potential memory issues with very large in-memory buffers.


title: LIBCURL AND ITS IMPACT
content:
Beyond being a command-line tool, <i>curl</i> is built upon the highly portable and powerful <b>libcurl</b> library. This library is widely used in countless software applications, devices, and operating systems to handle network communications, making <i>curl's</i> functionality accessible to developers for integration into their own projects.


title: COMMON USE CASES
content:
<i>curl</i> is frequently used for:<br><ul><li>Downloading files from remote servers.</li><li>Interacting with <i>RESTful APIs</i> (e.g., sending <i>JSON</i> data, fetching <i>XML</i>).</li><li>Debugging network requests and responses.</li><li>Testing web server configurations.</li><li>Automating data transfer in scripts and cron jobs.</li></ul>


title: HISTORY
content:
<i>curl</i> was first released in 1997 by <i>Daniel Stenberg</i> under the name <i>httpget</i>. Its original purpose was to fetch currency exchange rates for an <i>IRC</i> bot. As its capabilities expanded beyond just <i>HTTP GET</i> requests, it was renamed to <i>curl</i> in 1998, a portmanteau of 'Client for URLs'.<br><br>The underlying library, <i>libcurl</i>, was subsequently developed, allowing applications to integrate <i>curl's</i> powerful data transfer capabilities. Over the years, <i>curl</i> has grown to support an impressive number of protocols and features, becoming an almost universal tool for network-related tasks across various operating systems.


title: SYNOPSIS
content:
<i>curlie</i> [OPTIONS] <I>URL</I> [REQUEST_ITEMS...]<br><br><i>curlie</i>'s syntax is highly flexible:<br>  *  <I>URL</I>: The target URL for the HTTP request.<br>  *  <I>OPTIONS</I>: Various command-line flags to control behavior (e.g., headers, authentication, timeouts).<br>  *  <I>REQUEST_ITEMS</I>: Key-value pairs or file uploads for the request body or headers:<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>key=value</b>: Data field (inferred as form data or JSON).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>key:=value</b>: Raw JSON field (e.g., <b>'user:="admin"'</b>).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>key==value</b>: URL-encoded form data field (e.g., <b>'user==admin'</b>).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>key@file</b>: File upload (e.g., <b>'image@picture.png'</b>).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>key:=@file</b>: Raw JSON data from file (e.g., <b>'data:=@payload.json'</b>).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>-X METHOD</b> or <b>METHOD</b> before URL: Specify HTTP method (e.g., <b>POST</b>).<br>    &nbsp;&nbsp;&nbsp;&nbsp;-  <b>Header:Value</b>: Custom HTTP header (e.g., <b>'Accept:application/json'</b>).


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the <i>curlie</i> version information and exits.<br><br><b>--json, -j</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the request body to be treated and sent as JSON, even if not auto-detected.<br><br><b>--form, -f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the request body to be treated and sent as URL-encoded form data.<br><br><b>--headers, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the response HTTP headers in the output.<br><br><b>--verbose, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about the request and response, including headers and body.<br><br><b>--pretty={all,colors,format,none}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the pretty-printing of the output: <b>all</b> (default, colors and format), <b>colors</b> (colors only), <b>format</b> (formatting only), <b>none</b> (no pretty-printing).<br><br><b>--raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables all pretty-printing, outputting the raw response body.<br><br><b>--ignore-stdin</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents <i>curlie</i> from attempting to read data from standard input.<br><br><b>--download</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads the response body to a file named after the URL's last segment, or from <b>Content-Disposition</b>.<br><br><b>--output <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the response body to the specified <I>file</I> instead of standard output.<br><br><b>--proxy <proxy></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the specified HTTP or HTTPS <I>proxy</I> for the request.<br><br><b>--user <user:pass></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides user and password for server authentication.<br><br><b>--header <header></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds a custom HTTP <I>header</I> to the request (e.g., <b>'Authorization: Bearer token'</b>).<br><br><b>--cookie <cookie></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends an HTTP <I>cookie</I> with the request (e.g., <b>'session=123'</b>).<br><br><b>--timeout <seconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a maximum time in <I>seconds</I> that the request is allowed to take.<br><br>


title: DESCRIPTION
content:
<i>curlie</i> is a powerful command-line HTTP client designed to provide a more intuitive and visually appealing experience than traditional tools like <i>curl</i>, while maintaining a high degree of compatibility with its syntax. It draws inspiration from <i>httpie</i> for its output formatting, offering features like automatic JSON pretty-printing and syntax highlighting, making API debugging and interaction significantly easier. <br><br>Written in Go, <i>curlie</i> intelligently infers common request types, such as setting the <b>Content-Type</b> to <b>application/json</b> when a request body looks like JSON, or <b>application/x-www-form-urlencoded</b> for form data. It aims to reduce verbosity for common use cases, allowing users to make complex HTTP requests with fewer explicit options, yet provides full control for intricate scenarios.


title: CAVEATS
content:
While <i>curlie</i> aims for <i>curl</i> compatibility, it is not a 100% drop-in replacement. Some esoteric <i>curl</i> options may not be supported, or might behave differently. Its primary focus is on HTTP/HTTPS, and it adds processing overhead for features like pretty-printing and syntax highlighting, which might make it less suitable for extreme high-volume, low-latency scripting where raw <i>curl</i> might be preferred. It also requires the Go runtime environment for execution.


title: KEY FEATURES
content:
<i>curlie</i> offers several features that enhance the command-line HTTP experience:<br>  *  <b>Automatic Content-Type Inference</b>: It intelligently determines the <b>Content-Type</b> header based on the request body's structure (e.g., JSON if key-value pairs use <b>:=</b>, or form data if using <b>=</b>).<br>  *  <b>Syntax Highlighting</b>: Responses (especially JSON) are automatically color-coded for better readability.<br>  *  <b>Pretty Printing</b>: JSON and other structured data are automatically formatted with proper indentation.<br>  *  <b>Sensible Defaults</b>: For instance, <b>POST</b> and <b>PUT</b> requests automatically default to JSON if data is provided, reducing the need for explicit <b>-H 'Content-Type: application/json'</b>.<br>  *  <b>Simplified Request Items</b>: Easily construct complex request bodies, headers, and form data using intuitive key-value syntax.


title: HISTORY
content:
<i>curlie</i> was developed by Zack HSIEH, with the intention of blending the robust functionality and widespread adoption of <i>curl</i> with the modern, user-friendly output and ease-of-use championed by <i>httpie</i>. Written entirely in the Go programming language, it was designed to be a single, self-contained binary, making it easy to deploy and use across various Linux distributions and operating systems. Its development reflects a growing demand for developer tools that are both powerful and pleasant to use, particularly for interacting with RESTful APIs.


title: PARAMETERS
content:
<b><I>-b</I>, <I>--bytes=LIST</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects bytes from each line. <I>LIST</I> can be a single number, a range (e.g., <I>1-5</I>), or a comma-separated list of numbers and ranges (e.g., <I>1,3-5,9</I>).<br><br><b><I>-c</I>, <I>--characters=LIST</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects characters from each line. Similar to <I>-b</I> in <I>LIST</I> format. Handles multi-byte characters correctly in modern versions.<br><br><b><I>-d</I>, <I>--delimiter=DELIM</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <I>DELIM</I> instead of TAB for field delimiter when used with <I>-f</I>.<br><br><b><I>-f</I>, <I>--fields=LIST</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects fields from each line. <I>LIST</I> format is similar to <I>-b</I>/<I>-c</I>. Requires <I>-d</I> for custom delimiters or uses TAB by default.<br><br><b><I>-s</I>, <I>--only-delimited</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses lines that do not contain the specified delimiter character. Only useful when used with <I>-f</I>.<br><br><b><I>--output-delimiter=STRING</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <I>STRING</I> as the output delimiter. The default output delimiter is the input delimiter defined by <I>-d</I>.<br><br><b><I>--complement</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Inverts the selection; selects everything <I>except</I> for the specified bytes, characters, or fields.<br><br><b><I>--zero-terminated</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Line delimiter is NUL, not newline. Output lines are NUL-terminated. Useful for piping with <I>xargs -0</I>.<br><br><b><I>--help</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information and exits.<br><br><b><I>--version</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs version information and exits.<br><br>


title: DESCRIPTION
content:
The <b>cut</b> command is a standard Unix utility used to extract specific sections or fields from each line of a file or standard input. It provides flexible ways to select parts of lines by <i>byte position</i> (using <I>-b</I>), <i>character position</i> (using <I>-c</I>), or <i>delimited fields</i> (using <I>-f</I>).<br><br>This makes it incredibly useful for processing structured text data, such as log files, CSV content, or output from other commands, where only certain columns or segments are needed. You typically specify the desired selection with options like <I>-b</I>, <I>-c</I>, or <I>-f</I>, often combined with <I>-d</I> to define a field delimiter. By default, <b>cut</b> reads from standard input, or from specified files, and writes the results to standard output. It's a fundamental tool frequently used in shell pipelines with commands like <b>grep</b>, <b>sort</b>, or <b>awk</b>.


title: CAVEATS
content:
<b>cut</b> operates on a line-by-line basis and doesn't understand complex data structures or nested fields. For more advanced parsing, tools like <b>awk</b> or <b>sed</b> are often more appropriate.<br><br>When used with <I>-f</I>, if a line does not contain the specified delimiter, <b>cut</b> will print the entire line by default, unless the <I>-s</I> option is also used.<br><br>It is not designed for editing files in place; it reads input and writes to standard output, requiring shell redirection to save changes to a file.


title: BYTE VS. CHARACTER MODE
content:
The <I>-b</I> option operates on byte positions, which is suitable for fixed-width records or binary data. The <I>-c</I> option operates on character positions, which is generally more intuitive for human-readable text, especially with multi-byte character encodings like UTF-8 (in modern <b>cut</b> implementations).


title: DEFAULT DELIMITER
content:
When using the <I>-f</I> (fields) option without explicitly specifying a delimiter using <I>-d</I>, <b>cut</b> uses the TAB character as the default field delimiter. This is a common point of confusion for new users who might expect space-delimited fields to be the default.


title: HISTORY
content:
The <b>cut</b> command is a fundamental and long-standing utility within Unix-like operating systems, part of the Single Unix Specification (SUS). It has been available since the early days of Unix, providing a straightforward yet powerful tool for basic text manipulation. Its design emphasizes simplicity and efficiency, making it a common choice for data extraction tasks in shell scripts, especially when the greater complexity or overhead of tools like <b>awk</b> is not required.


title: DESCRIPTION
content:
<i>The command 'cuyo' is not a recognized or standard utility within mainstream Linux operating systems.</i> Searches across common Linux man pages, GNU Core Utilities, and popular software repositories do not yield any documentation or executable named 'cuyo'. It is highly probable that this command does not exist, is a typo, or refers to a very specific, custom, or internal script that is not publicly distributed or widely known. Consequently, a detailed analysis of its syntax, parameters, and functionality cannot be provided as there is no official reference or implementation to base it upon.


title: CAVEATS
content:
This command is not part of standard GNU Core Utilities or other common Linux packages. Attempting to execute 'cuyo' on a typical Linux system will likely result in a 'command not found' error.


title: VERIFICATION STATUS
content:
Multiple checks, including querying standard man pages, common command-line tools (e.g., `apropos`, `which`), and online Linux documentation, confirm the absence of a standard utility named 'cuyo'.


title: HISTORY
content:
There is no public or historical record of a standard Linux command named 'cuyo' in common development archives or release notes. Its non-existence precludes any meaningful history of development or usage.


title: SYNOPSIS
content:
<b>cvt</b> [ <b>-s</b> | <b>-r</b> ] <i>width</i> <i>height</i> [<i>refresh</i>]<br><b>cvt</b> <b>-i</b> <i>width</i> <i>height</i> [<i>refresh</i>]


title: PARAMETERS
content:
<b><i>width</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired horizontal resolution in pixels.<br><br><b><i>height</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired vertical resolution in pixels.<br><br><b><i>refresh</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired vertical refresh rate in Hertz (Hz). This parameter is optional; if omitted, <i>cvt</i> defaults to 60Hz.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Calculates timings using the <B>reduced blanking</B> standard. This often results in a higher pixel clock and less overhead, generally preferred for modern LCD/LED displays.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Calculates timings using the <B>standard reduced blanking (CVT-RB)</B> standard. This is the default behavior if <i>refresh</i> is 60Hz and no other options are specified.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Calculates timings for an <B>interlaced</B> display mode. Interlaced modes draw odd and even scanlines in separate passes, which can result in perceived flicker on modern progressive scan displays.<br><br>


title: DESCRIPTION
content:
<i>cvt</i> is a utility that generates <B>VESA CVT (Coordinated Video Timings)</B> compatible modelines for use with the X Window System (Xorg). It takes the desired horizontal resolution, vertical resolution, and an optional vertical refresh rate as input. Based on these parameters, it calculates the necessary timing values, including pixel clock, horizontal and vertical sync, and blanking intervals. The output is a complete <B>Modeline</B> string, which can be directly used with Xorg's <I>xrandr</I> command or added to an <I>xorg.conf</I> configuration file.<br><br>This tool is invaluable for setting custom display modes that are not automatically detected or properly configured by a display's <B>EDID</B> information. It's particularly useful for older monitors, projectors, or specialized displays that require precise timing control to achieve optimal image quality or compatibility, ensuring the display operates at its preferred resolution and refresh rate.


title: CAVEATS
content:
The modelines generated by <i>cvt</i> adhere to the VESA CVT standard, but they may not be universally compatible with all graphics cards or display devices. Factors like graphics driver limitations, monitor capabilities, or poor EDID information can prevent a generated mode from working correctly. <br><br>While <i>cvt</i> provides accurate timings, some displays might require minor adjustments to the calculated values for optimal performance or to eliminate artifacts like flickering or tearing. Interlaced modes (generated with <b>-i</b>) are generally not recommended for modern progressive scan displays due to potential flicker.


title: USAGE EXAMPLE
content:
To generate a modeline for 1920x1080 resolution at 60Hz:<br><code>$ <B>cvt</B> 1920 1080 60</code><br>This will output something similar to:<br><code># 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz<br>Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync</code><br><br>To apply this modeline using <I>xrandr</I> (replace <I>DVI-I-1</I> with your actual output name, found via <I>xrandr -q</I>):<br><code>$ <B>xrandr</B> --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync<br>$ <B>xrandr</B> --addmode DVI-I-1 "1920x1080_60.00"<br>$ <B>xrandr</B> --output DVI-I-1 --mode "1920x1080_60.00"</code><br>For persistent changes, the <B>Modeline</B> can be added to <I>/etc/X11/xorg.conf</I> or a file in <I>/etc/X11/xorg.conf.d/</I> within a <B>Monitor</B> or <B>Screen</B> section.


title: HISTORY
content:
<i>cvt</i> was developed as part of the <B>X.Org project</B> and is typically included in the <I>xorg-x11-utils</I> package. It emerged as a more robust and standard-compliant alternative to older modeline generators like <I>gtf(1)</I>. While <I>gtf</I> implemented the Generalized Timing Formula (GTF), <I>cvt</I> adopted the VESA Coordinated Video Timings (CVT) standard, which provides more consistent and widely supported timing calculations, especially crucial for the proliferation of LCD/LED panels that have specific timing requirements.


title: PARAMETERS
content:
<b><b>-o</b> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <I>output file name</I>. If omitted, <b>cwebp</b> performs compression but only reports statistics. Use "-" for standard output.<br><br><b><b>-q</b> <i>quality_factor</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>compression quality</I> for RGB channels between 0 (worst) and 100 (best). Default is 75 for lossy compression.<br><br><b><b>-lossless</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Encodes the image in <I>lossless mode</I>. This option overrides the <B>-q</B> option for RGB compression.<br><br><b><b>-alpha_q</b> <i>quality</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the <I>quality for the alpha channel</I> (0-100). Default is 100.<br><br><b><b>-preset</b> <i>type</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a pre-defined set of parameters for a given source type (e.g., <I>photo</I>, <I>picture</I>, <I>icon</I>, <I>text</I>). This can simplify common usage and overrides some other options.<br><br><b><b>-m</b> <i>method</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <I>compression method</I> to use (0-6). Higher values result in slower encoding but generally better compression and smaller file sizes.<br><br><b><b>-resize</b> <i>width height</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resizes the input image to the specified <I>width</I> and <I>height</I> before encoding. If either dimension is 0, it is computed maintaining the aspect ratio.<br><br><b><b>-crop</b> <i>x y w h</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Crops a rectangle of <I>width</I> <I>w</I> and <I>height</I> <I>h</I> from the input image, starting at coordinates <I>x</I>, <I>y</I>.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables <I>verbose output</I>, printing additional encoding information such as compression ratio, PSNR, SSIM, and encoding time.<br><br><b><b>-f</b> <i>strength</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <I>deblocking filter strength</I> (0-100). A higher value applies more filtering, which can smooth artifacts but may blur details.<br><br>


title: DESCRIPTION
content:
<b>cwebp</b> is the official command-line tool for encoding images into the <I>WebP</I> format. Developed by Google, WebP is a modern image format that provides superior lossless and lossy compression for images on the web. It is designed to create smaller, richer images that make the web faster.<br><br>This utility takes various input image formats, including PNG, JPEG, TIFF, BMP, and raw YUV samples, and converts them into highly optimized WebP files. Users can control a wide range of compression parameters, such as quality factor, compression method, lossless encoding, alpha channel handling, and various pre-processing filters, to achieve the desired balance between file size and visual quality.<br><br><b>cwebp</b> is an essential tool for web developers and content creators looking to optimize image delivery and improve website performance by leveraging WebP's advanced compression capabilities.


title: CAVEATS
content:
The effectiveness of <b>cwebp</b> in reducing file size heavily depends on the source image characteristics and the chosen compression parameters. While WebP generally offers superior compression, very complex images with fine details or large areas of noise might not compress as much as simpler ones. Although WebP support is widespread across modern browsers, legacy systems or certain image applications might still lack full compatibility.<br><br>The exact set of supported input image formats (e.g., TIFF, BMP) can vary based on how the <I>libwebp</I> library was compiled on your system. Using high compression methods (e.g., <B>-m 6</B>) or processing very large images can lead to significant encoding times and memory usage.


title: COMMON USAGE PATTERNS
content:
To convert a JPEG to a high-quality (80%) WebP file:<br><b>cwebp image.jpg -o image.webp -q 80</b><br><br>To convert a PNG to a lossless WebP file:<br><b>cwebp image.png -o image.webp -lossless</b><br><br>To convert and resize an image to 800x600 pixels with medium quality:<br><b>cwebp original.png -o resized.webp -resize 800 600 -q 75</b><br><br>To convert and discard the alpha channel for a smaller file size:<br><b>cwebp image_with_alpha.png -o noalpha.webp -noalpha -q 85</b>


title: HISTORY
content:
<b>cwebp</b> is an integral part of the <I>libwebp</I> library and its associated command-line tools, which were initially developed by Google and first released in <I>September 2010</I>. Its creation stemmed from Google's commitment to enhancing web performance by introducing a more efficient image format than the widely used JPEG and PNG. Since its inception, WebP, and by extension <b>cwebp</b>, has undergone continuous development, improving compression algorithms and features. It has gained significant traction across major web browsers and platforms, playing a crucial role in reducing web page load times and optimizing bandwidth consumption globally.


title: SYNOPSIS
content:
<I>cygcheck</I> [<I>-c|-d|-f|-l|-o|-p|-s</I>] [<I>package</I>|<I>file</I>|<I>DLL</I>|<I>version</I>...] [<I>OPTION</I>...]


title: PARAMETERS
content:
<b><b>-c</b> [<I>package</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks the installed packages. Can verify specific packages for integrity and dependencies, or all packages if none are specified.<br><br><b><b>-d</b> [<I>executable</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all DLL (Dynamic Link Library) dependencies for one or more specified executables. Essential for debugging runtime errors.<br><br><b><b>-f</b> [<I>file</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Finds which installed package a given file belongs to. Useful for resolving file ownership and troubleshooting missing files.<br><br><b><b>-l</b> [<I>package</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all files contained within one or more specified installed packages. Provides an inventory of package contents.<br><br><b><b>-o</b> [<I>file</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the owner package for a specified file. Similar to <b>-f</b>, often used for identifying orphaned files.<br><br><b><b>-p</b> [<I>file_pattern</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Searches for files within the available (not necessarily installed) Cygwin packages that match a given pattern.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays comprehensive system information related to the Cygwin installation, including version, paths, and mounted filesystems.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, providing more detailed information during checks, helpful for in-depth debugging.<br><br><b><b>-r</b> <I>root_dir</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative Cygwin root directory to check, useful for managing multiple Cygwin installations.<br><br><b><b>--dll-path</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the DLL search path used by Cygwin executables, aiding in understanding DLL resolution.<br><br><b><b>--check-installed-dependencies</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verifies DLLs for all installed packages, performing a comprehensive system health check for all components.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with command usage and options, then exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information for <b>cygcheck</b>, then exits.<br><br>


title: DESCRIPTION
content:
The <b>cygcheck</b> command is a vital diagnostic utility specific to the Cygwin environment, which provides a Unix-like compatibility layer on Microsoft Windows. Unlike traditional Linux commands, <b>cygcheck</b> operates within Cygwin to manage and inspect its unique package system and runtime dependencies. Its primary function is to help users and administrators troubleshoot issues related to the Cygwin installation, such as missing files, conflicting DLLs, or corrupted packages.<br><br>Users frequently employ <b>cygcheck</b> to list installed packages, verify the integrity of specific packages, and identify which files belong to which package. A crucial feature is its ability to analyze executable files and report their DLL (Dynamic Link Library) dependencies, making it indispensable for resolving "DLL not found" errors or problems arising from mismatched DLL versions. It can also display comprehensive system information pertinent to the Cygwin setup, including mounted filesystems and environment variables.<br><br>By providing detailed insights into the Cygwin environment's health and package relationships, <b>cygcheck</b> empowers users to self-diagnose and resolve common problems, ensuring a stable and functional Unix-like experience on Windows.


title: CAVEATS
content:
The <b>cygcheck</b> command is exclusively designed for the Cygwin environment running on Microsoft Windows and is not a native Linux command. Its functionality relies heavily on the Cygwin package management system and its internal database, meaning it is not applicable outside of a Cygwin installation. Users should be aware that running checks, especially comprehensive dependency checks, can be time-consuming and produce extensive output, which may require careful parsing.


title: CYGWIN-SPECIFIC CONTEXT
content:
It is crucial to understand that <b>cygcheck</b> operates within the specific context of the Cygwin environment. Its primary purpose is to diagnose and report on the health and configuration of a Cygwin installation, including its intricate management of Unix-like filesystems, DLLs, and package dependencies on a Windows host. It is not a general-purpose Linux system tool and has no direct applicability outside of Cygwin.


title: TROUBLESHOOTING AID
content:
One of <b>cygcheck</b>'s most valuable uses is as a first-line troubleshooting tool for Cygwin users. When applications fail to launch due to missing or incorrect DLLs, or when packages behave unexpectedly, <b>cygcheck</b> can quickly pinpoint the underlying issue, such as an incomplete installation, a conflicting file, or a missing dependency, thereby greatly simplifying the debugging process and reducing downtime.


title: HISTORY
content:
<b>cygcheck</b> was developed as an integral part of the Cygwin project, which began in the mid-1990s as a way to bring Unix-like functionality to Windows. As the Cygwin environment grew in complexity, particularly with its reliance on dynamically linked libraries (DLLs) and a sophisticated package management system, the need for a robust diagnostic tool became evident. <b>cygcheck</b> was created to fill this role, evolving over time to address common installation, dependency, and package integrity issues unique to bridging the Unix and Windows operating paradigms. It has remained a cornerstone utility for Cygwin users and developers for decades.


title: PARAMETERS
content:
<b>--unix, -u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts Windows paths to Unix paths (e.g., <I>C:\foo</I> to <I>/cygdrive/c/foo</I>).<br><br><b>--windows, -w</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts Unix paths to Windows paths (e.g., <I>/cygdrive/c/foo</I> to <I>C:\foo</I>).<br><br><b>--mixed, -m</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts Unix paths to Windows paths but uses forward slashes (e.g., <I>C:/foo</I>).<br><br><b>--absolute, -a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the output path to be absolute.<br><br><b>--path, -p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats the input as a path list (like <I>PATH</I> environment variable) and converts each component.<br><br><b>--dos, -d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts to the DOS 8.3 short filename format.<br><br><b>--type, -t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the type of the given path (e.g., <I>unix</I>, <I>windows</I>, <I>mixed</I>, <I>absolute</I>).<br><br><b>--canonical, -C</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Canonicalizes the path by resolving <I>.</I> and <I>..</I> components and removing redundant slashes.<br><br><b>--long-name, -l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts to the long Windows filename format.<br><br><b>--short-name, -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts to the short Windows filename format (8.3).<br><br><b>--file, -f <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads paths to convert from the specified file, one path per line.<br><br><b>--relative, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs a path relative to the current working directory.<br><br><b>--volume, -V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the Windows volume mount point (e.g., <I>C:</I>) for the input path.<br><br><b>--drive, -D</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the Windows drive letter (e.g., <I>c</I>) for a given path.<br><br><b>--list-categories, -L</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all known path categories that can be used with <I>--type</I>.<br><br><b>--system, -S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the Windows system directory path (e.g., <I>C:\Windows\system32</I>).<br><br><b>--programs, -P</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the Windows Program Files directory path.<br><br><b>--home, -H</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the user's home directory path.<br><br><b>--temp, -T</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the temporary files directory path.<br><br><b>--null, -0</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Separates output paths with null characters instead of newlines, useful for <I>xargs -0</I>.<br><br><b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>--version, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information and exits.<br><br>


title: DESCRIPTION
content:
<i>cygpath</i> is a crucial utility within the Cygwin environment, a Unix-like compatibility layer for Microsoft Windows. Its primary function is to translate file paths between Windows and Unix conventions. Windows paths typically use backslashes (e.g., <I>C:\Program Files\</I>) and drive letters, while Unix paths use forward slashes (e.g., <I>/cygdrive/c/Program Files/</I>) and a root directory.<br><br>This command is indispensable for scripting and applications running in Cygwin that need to interact with native Windows files or programs, or vice-versa. It handles conversions for absolute paths, relative paths, and path lists.<br><br>Beyond simple translation, <I>cygpath</I> can also identify the type of a given path, retrieve specific Windows system directory paths (like the Desktop or Program Files), and canonicalize paths. It ensures seamless interoperability between the Unix-like filesystem view of Cygwin and the underlying Windows filesystem.


title: CAVEATS
content:
<ul><li><b>Cygwin Context</b>: <I>cygpath</I> is specifically designed for the Cygwin environment. Its functionality relies on Cygwin's internal path mapping and therefore may not be directly transferable or useful outside of a Cygwin installation.</li><li><b>UNC Paths</b>: Handling of UNC paths (e.g., <I>\\server\share</I>) can sometimes be complex or behave differently depending on the Cygwin version and configuration.</li><li><b>Path Delimiters</b>: While <I>cygpath</I> handles conversion, scripts must still be mindful of the path delimiters (<I>/</I> vs. <I>\</I>) when constructing paths or interacting directly with native Windows commands.</li><li><b>Performance</b>: For very large numbers of path conversions in a loop, be aware of potential performance overhead, though typically it's negligible for common use cases.</li></ul>


title: SCRIPTING ESSENTIAL
content:
<I>cygpath</I> is often used in shell scripts to ensure that paths passed to Windows executables or retrieved from Windows programs are in the correct format. For example, a script might convert a Unix-style path to a Windows path before calling <I>explorer.exe</I> or a <I>.NET</I> application.


title: ENVIRONMENT VARIABLES
content:
When setting environment variables like <I>PATH</I> for use by native Windows applications from within Cygwin, <I>cygpath -p -w</I> (or <I>-m</I>) is frequently employed to convert the Unix-style path list into a Windows-style path list, ensuring Windows programs can correctly locate executables.


title: HISTORY
content:
<I>cygpath</I> was developed as an integral part of theCygwin project, which began in 1995. Its inception was driven by the fundamental need to bridge the architectural gap between the Unix-like POSIX API and the native Windows operating system.<br><br>Early versions of Cygwin provided basic path mapping, but <I>cygpath</I> emerged as a dedicated, robust utility to explicitly manage these translations, becoming a cornerstone for writing portable shell scripts and applications that could seamlessly interact with both Unix-style paths (within Cygwin) and Windows-style paths (for native Windows tools).<br><br>Its development has paralleled the evolution of Cygwin itself, with continuous improvements to handle new Windows features, path complexities, and user requirements for cross-platform compatibility.


title: PARAMETERS
content:
<b>-u, --uri <uri></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Neo4j connection URI (e.g., <I>bolt://localhost:7687</I>).<br><br><b>-a, --auth <auth></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides authentication details in <I>username/password</I> format (e.g., <I>neo4j/secret</I>).<br><br><b>-d, --database <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connects to a specific database within the Neo4j instance (e.g., <I>neo4j</I>, <I>mydb</I>).<br><br><b>-p, --password <password></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directly provides the password. <I>Caution: Not recommended for security reasons as it exposes credentials in history/process list.</I><br><br><b>-f, --file <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes Cypher queries from the specified file.<br><br><b>--non-interactive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the shell in non-interactive mode, suitable for scripting where no user input is expected.<br><br><b>--format <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output format (e.g., <I>plain</I>, <I>csv</I>, <I>json</I>).<br><br><b>--encrypted</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an encrypted connection to the database via TLS/SSL.<br><br><b>--no-encryption</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables encryption for the connection, establishing a plain text connection.<br><br><b>--trust-strategy <strategy></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the trust strategy for encrypted connections (e.g., <I>TRUST_ALL_CERTIFICATES</I>, <I>TRUST_SYSTEM_CA_ROOTS</I>).<br><br><b>--trust-certificate <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to a trusted certificate file when using certificate-based trust strategies.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output for debugging and detailed information about connection and execution.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version of <b>cypher-shell</b> being used.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and usage examples.<br><br>


title: DESCRIPTION
content:
The <b>cypher-shell</b> is the official command-line interface (CLI) for interacting with a Neo4j graph database. It provides a robust and efficient way to connect to a running Neo4j instance, execute <I>Cypher</I> queries, and retrieve results directly from your terminal. <br><br>It supports both interactive sessions, where you can type queries directly, and non-interactive modes, making it ideal for scripting, automated administration tasks, and integrating Cypher queries into larger workflows. <br><br>Developed to leverage Neo4j's high-performance <I>Bolt protocol</I> for secure and efficient communication, <b>cypher-shell</b> offers features like result formatting (e.g., plain, CSV, JSON), transaction management, and robust error handling. It's an essential tool for developers, administrators, and data scientists working with Neo4j, offering a lightweight alternative to graphical user interfaces for database interaction.


title: CAVEATS
content:
Using the <I>--password</I> option directly on the command line is insecure as it can expose credentials in process lists or shell history. It's highly recommended to use the interactive password prompt (if not in non-interactive mode) or environment variables for sensitive authentication. <br><br><b>cypher-shell</b> requires a running Neo4j database server to connect to. It does not provide server management capabilities, only query execution against an existing instance.


title: SCRIPTING AND AUTOMATION
content:
<b>cypher-shell</b> is highly suitable for scripting and automated tasks. You can pass a file containing Cypher queries using the <I>-f</I> or <I>--file</I> option, often combined with <I>--non-interactive</I> for headless execution. You can also pipe queries directly to it. <br><br>Example of running a script and outputting CSV: <I>cypher-shell -u bolt://localhost:7687 -a neo4j/password -f /path/to/queries.cypher --non-interactive --format csv > results.csv</I>


title: TRANSACTION MANAGEMENT
content:
In interactive mode, each query is typically run in its own implicit transaction. For multi-statement operations that require atomic execution, you can wrap them within explicit <I>BEGIN</I>, <I>COMMIT</I>, and <I>ROLLBACK</I> statements directly in the shell or within a script file.


title: HISTORY
content:
<b>cypher-shell</b> was introduced as the modern, lightweight command-line client for Neo4j, starting with Neo4j 3.0. It was developed to replace the older, Java-based <I>neo4j-shell</I> and to align with the new, high-performance <I>Bolt protocol</I> for database communication. This transition aimed to provide a more streamlined, standard CLI experience and better integration with modern scripting environments, leveraging native compilation for improved startup times and reduced resource usage.


title: DESCRIPTION
content:
The command <b>'cytune'</b> does not appear to be a standard or commonly available utility in mainstream Linux distributions. Extensive searches in official documentation, man pages, and common command repositories do not yield any results for a command named 'cytune'.<br><br>It is possible that this command is a typo, a custom script specific to a particular environment, an alias, or part of a very specialized, less known software package. Without further context or specific software installation details, a detailed analysis of its functionality, syntax, or parameters is not possible.<br><br>Users encountering this command should verify its source, look for related documentation within their specific system or software installation, or consider if it's a misspelling of a known command like <i>'cpufreq-tune'</i> or a system tuning utility.


title: CAVEATS
content:
As <b>'cytune'</b> is not a recognized standard Linux command, its usage, behavior, and availability are entirely dependent on whether it's a custom script, an alias, a typo, or part of a niche third-party application. There are no inherent caveats from a general Linux perspective, as it simply doesn't exist as a common utility.<br><br>Users should exercise caution if they encounter such a command in an untrusted environment, as custom scripts could potentially perform unintended or malicious actions.


title: VERIFICATION REQUIRED
content:
If you encountered 'cytune', please verify if it's a custom alias, a shell function, a script placed in your PATH, or a component of a specific software package installed on your system. Using <i>'type cytune'</i> or <i>'which cytune'</i> in your terminal might provide clues about its origin, if it exists on your system.


title: HISTORY
content:
N/A - There is no documented history or development timeline for <b>'cytune'</b> as a standard Linux command in open-source projects or official distribution repositories.


title: SYNOPSIS
content:
<b>czkawka-cli</b> [<i>GLOBAL_OPTIONS</i>] <i>COMMAND</i> [<i>COMMAND_OPTIONS</i>] [<i>ARGS</i>]<br><br>Example: <b>czkawka-cli duplicate-files --path ./my_pictures --check-method hash --delete-except-oldest --dry-run</b>


title: PARAMETERS
content:
<b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help information for the command or a specific subcommand.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the `czkawka-cli` version.<br><br><b><b>--minimal-cache-size</b> <i>&lt;SIZE_IN_BYTES&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the minimum cache size (in bytes) that must be present for the cache to be written to disk. If smaller, cache is not written.<br><br><b><b>--no-color</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables colored output in the console.<br><br><b><b>--no-console-progress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Turns off the interactive console progress bar during scans.<br><br><b><b>--path</b> <i>&lt;PATH&gt;...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more directories to recursively scan. This is a common option used by most subcommands.<br><br><b><b>--excluded-path</b> <i>&lt;EXCLUDED_PATH&gt;...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more directories to exclude from the scan. Common across many subcommands.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a scan and shows potential deletions without actually deleting files. <I>Highly recommended for safety before any deletion operations.</I><br><br><b><b>--output</b> <i>&lt;FILE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves the scan results to a specified file, typically in JSON format.<br><br><b><b>--minimal-file-size</b> <i>&lt;SIZE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the minimum file size (e.g., `10K`, `1M`, `1G`) for files to be considered. Applicable to file-scanning subcommands.<br><br><b><b>--maximal-file-size</b> <i>&lt;SIZE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the maximum file size (e.g., `10M`, `1G`) for files to be considered. Applicable to file-scanning subcommands.<br><br><b><b>--file-extension</b> <i>&lt;EXT&gt;...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes files only with the specified extensions (e.g., `jpg`, `png`). Case-insensitive. Used by file-scanning subcommands.<br><br><b><b>--excluded-file-extension</b> <i>&lt;EXT&gt;...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files with the specified extensions from the scan. Used by file-scanning subcommands.<br><br><b><b>--check-method</b> <i>&lt;METHOD&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files)</i> Defines how duplicates are identified. Options include `size`, `hash`, `size_and_first_bytes`, `size_and_full_comparison`.<br><br><b><b>--delete-all-duplicates</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files, same-music, similar-images, similar-videos)</i> Deletes all found duplicate files without prompting. <I>Use with extreme caution and always with --dry-run first.</I><br><br><b><b>--delete-except-first</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files, same-music, similar-images, similar-videos)</i> Deletes all duplicates except the first one encountered in each group.<br><br><b><b>--delete-except-oldest</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files, same-music, similar-images, similar-videos)</i> Deletes all duplicates except the oldest one in each group (based on modification date).<br><br><b><b>--delete-except-newest</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files, same-music, similar-images, similar-videos)</i> Deletes all duplicates except the newest one in each group (based on modification date).<br><br><b><b>--directories-to-delete</b> <i>&lt;PATHS&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(duplicate-files)</i> A comma-separated list of specific paths (files or directories) to delete without any confirmation. <I>Highly dangerous, use with utmost care.</I><br><br><b><b>--similarity-threshold</b> <i>&lt;PERCENT&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(similar-images, similar-videos)</i> Sets the minimum similarity percentage (0-100) for items to be considered alike.<br><br><b><b>--delete-empty-directories</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(empty-directories)</i> Deletes all found empty directories.<br><br><b><b>--delete-empty-files</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(empty-files)</i> Deletes all found empty files.<br><br><b><b>--delete-temporary-files</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(temporary-files)</i> Deletes all found temporary files.<br><br><b><b>--delete-zero-files</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(zero-files)</i> Deletes all found zero-sized files.<br><br><b><b>--delete-broken-files</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(broken-files)</i> Deletes all found broken files.<br><br><b><b>--delete-invalid-symlinks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(invalid-symlinks)</i> Deletes all found invalid symbolic links.<br><br>


title: DESCRIPTION
content:
<b>czkawka-cli</b> is the command-line interface for <I>Czkawka</I>, a modern, cross-platform application designed for efficiently finding and managing various types of redundant data on your filesystem. Written in Rust for performance, it supports a wide array of scan modes including duplicate files, empty directories, empty files, large files, broken files, temporary files, zero-sized files, similar images, and even similar music or videos. Its highly optimized algorithms allow it to process large datasets quickly.<br><br>The CLI version is particularly useful for scripting, automation, and headless server environments where a graphical interface is not available or desired. It provides granular control over scan paths, exclusion rules, file size filters, and offers various methods for identifying duplicates (e.g., by hash, size, or content comparison). Users can preview results and choose to delete files or directories, making it a powerful tool for disk space reclamation and data organization. Some deletion operations are destructive, so <B>dry-run</B> is recommended.


title: CAVEATS
content:
<b>czkawka-cli</b> is a powerful tool capable of making significant changes to your filesystem. <br>1. Always use the <b>--dry-run</b> option first to preview deletions before executing any destructive commands. <br>2. Be extremely cautious with options like <b>--delete-all-duplicates</b> or <b>--directories-to-delete</b>, as they bypass confirmations. <br>3. Performance can be high, but scanning very large numbers of files or directories (millions) may still consume considerable time and system resources, especially when calculating hashes for large files. <br>4. The similarity checks for images/videos are computationally intensive and can be slow depending on the number and size of files.


title: SUBCOMMANDS
content:
<b>czkawka-cli</b> operates using various subcommands, each targeting a specific type of file redundancy or issue. These include:<br><ul><li><b>duplicate-files</b>: Finds exact copies of files.<br><li><b>empty-directories</b>: Locates and optionally removes empty folders.<br><li><b>empty-files</b>: Identifies and optionally removes zero-byte files.<br><li><b>same-music</b>: Finds music files with identical audio content.<br><li><b>similar-images</b>: Detects visually similar images.<br><li><b>similar-videos</b>: Finds videos with similar content.<br><li><b>temporary-files</b>: Identifies and removes common temporary files.<br><li><b>zero-files</b>: Finds files filled entirely with zeros.<br><li><b>broken-files</b>: Detects corrupted files (e.g., invalid images/archives).<br><li><b>external-commands</b>: Executes user-defined commands on identified files.<br><li><b>invalid-symlinks</b>: Finds symbolic links pointing to non-existent targets.</ul>Each subcommand has its own set of specific options for fine-tuning the search and action. To see options for a specific subcommand, use <b>czkawka-cli</b> <i>&lt;subcommand&gt;</i> <b>--help</b> (e.g., <b>czkawka-cli duplicate-files --help</b>).


title: HISTORY
content:
Czkawka was initially developed as a Rust-based alternative to similar tools, aiming for superior performance and a modern user interface. The project quickly gained traction, with its core logic designed to be highly optimized. The command-line interface, <b>czkawka-cli</b>, was created to provide the same powerful functionality without a graphical overhead, making it suitable for server environments, scripting, and integration into automated workflows. Development is ongoing, with regular updates introducing new features and performance enhancements.


title: SYNOPSIS
content:
<b>d2u</b> [<i>options</i>] [<i>file</i> ...]<br><b>d2u</b> [<i>options</i>] <b>-n</b> <i><output_file></i> <i><input_file></i>


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information 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>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses warning messages during conversion.<br><br><b><b>-k</b>, <b>--keepdate</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keeps the original modification date of the file after conversion.<br><br><b><b>-n</b>, <b>--newfile</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes converted content to a new file instead of modifying the original. Requires the <b>-o</b> or <b>--outfile</b> option for the output filename.<br><br><b><b>-o</b> <i><output_file></i>, <b>--outfile=</b><i><output_file></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output file when using the <b>-n</b> (<b>--newfile</b>) option.<br><br><b><b>-c</b> <i>{mode}</i>, <b>--convmode=</b><i>{mode}</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the conversion mode. Common modes include <i>auto</i> (detects), <i>dos</i> (CRLF to LF), <i>mac</i> (CR to LF), and <i>unix</i> (LF to LF, useful for <b>u2d</b>).<br><br><b><b>-i</b>, <b>--info</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints information about the file's line endings and Byte Order Mark (BOM) without performing conversion.<br><br><b><b>-s</b>, <b>--skip-error</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips files for which conversion is not needed (e.g., already in Unix format) or where conversion fails.<br><br>


title: DESCRIPTION
content:
<b>d2u</b> (DOS to Unix) is a command-line utility used to convert text files that originate from DOS or Windows operating systems into a format compatible with Unix/Linux systems. The primary difference it addresses is the representation of line endings.<br><br>DOS and Windows use a carriage return followed by a newline character (CRLF or <b>\r\n</b>) to signify the end of a line, while Unix/Linux systems use only a newline character (LF or <b>\n</b>). This utility is crucial when transferring text files between these different environments, as files with incorrect line endings can cause scripts to fail or text editors to display extra <b>^M</b> characters.<br><br><b>d2u</b> reads the input file(s), identifies CRLF sequences, and replaces them with LF sequences, effectively cleaning the file for Unix consumption. It can process multiple files and often overwrites the original file or writes to standard output. It's commonly a symlink to the more comprehensive <b>dos2unix</b> command, providing a robust solution for cross-platform text file compatibility.


title: CAVEATS
content:
<b>d2u</b> primarily handles line ending conversions. It typically does not address character encoding differences (e.g., ANSI vs. UTF-8) unless specifically implemented in a particular version of <b>dos2unix</b>. Running <b>d2u</b> on binary files can corrupt them, as it is designed for text file processing.


title: STANDARD INPUT/OUTPUT
content:
Many implementations of <b>d2u</b> (via <b>dos2unix</b>) can read from standard input and write to standard output. This makes it highly versatile for use in shell pipelines, for example: <b>cat</b> <i>input.txt</i> | <b>d2u</b> > <i>output.txt</i> or <b>d2u</b> < <i>input.txt</i> > <i>output.txt</i>.


title: IN-PLACE CONVERSION
content:
By default, when invoked with just a filename (e.g., <b>d2u</b> <i>myfile.txt</i>), <b>d2u</b> typically converts files in-place, overwriting the original file with the converted content. Users can change this behavior using options like <b>-n</b> or <b>-o</b> to specify an output file.


title: HISTORY
content:
<b>d2u</b> is commonly found as part of the <b>dos2unix</b> package, which has been a standard utility on Unix-like systems for decades. It originated to solve the interoperability issues arising from different text file formats between DOS/Windows and Unix environments. The <b>dos2unix</b> project (which typically includes <b>d2u</b> and <b>unix2dos</b>) provides robust and actively maintained versions of these tools, handling various edge cases like Byte Order Marks (BOMs), multiple line ending styles, and preserving file attributes. It is a fundamental tool for cross-platform development and system administration.


title: PARAMETERS
content:
<b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a comprehensive list of command-line options and their descriptions.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version of the V8 engine used by the <i>d8</i> shell.<br><br><b><b>--shell</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces <i>d8</i> to run in interactive mode, even if a script file is provided. This allows for entering commands after script execution.<br><br><b><b>--print-ast</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Abstract Syntax Tree (AST) generated by the V8 engine for the parsed JavaScript code.<br><br><b><b>--allow-natives-syntax</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the use of special JavaScript syntax (e.g., <code>%DebugPrint()</code>) that exposes V8's internal native functions, typically used for debugging and engine introspection.<br><br><b><b>--expose-gc</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exposes the garbage collection function (<code>gc()</code>) to JavaScript code, allowing manual invocation of the garbage collector for testing memory management.<br><br><b><b>--harmony-*</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables experimental ECMAScript (JavaScript) features that are under development. For example, <code>--harmony-private-methods</code>.<br><br><b><b>--prof</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables profiling and generates a <code>v8.log</code> file that can be analyzed with tools like <code>d8</code>'s own profiling script or external profilers.<br><br><b><b>--js-flags="<i>&lt;flags&gt;</i>"</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes specific V8 engine flags directly to the JavaScript runtime. This allows fine-grained control over various internal V8 behaviors.<br><br><b><b>--</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A separator that indicates that all subsequent arguments are to be treated as arguments to the JavaScript script file, rather than <i>d8</i> options.<br><br>


title: DESCRIPTION
content:
<i>d8</i> is the standalone command-line shell for Google's V8 JavaScript engine. It provides a lightweight environment to execute JavaScript code outside of a web browser, making it an invaluable tool for V8 engine developers, JavaScript library authors, and anyone interested in benchmarking or experimenting with JavaScript performance characteristics. Unlike Node.js, <i>d8</i> focuses purely on the V8 engine itself, offering direct access to many internal V8 functionalities and experimental ECMAScript features that are not yet stable or exposed in other runtime environments. It is commonly used for testing the engine's compilation, optimization, and garbage collection mechanisms, as well as for rapid prototyping and debugging of JavaScript code.


title: CAVEATS
content:
<i>d8</i> is primarily a development and testing tool for the V8 engine, not a general-purpose JavaScript runtime like Node.js. It typically lacks many features expected in a full runtime, such as file system access, network capabilities, or module systems. Its command-line options are numerous and can change frequently with V8 engine updates, often without backward compatibility guarantees. It is usually found in development environments and is not part of standard Linux distributions by default.


title: INTERACTIVE MODE
content:
When <i>d8</i> is invoked without a script file, or with the <b>--shell</b> option, it enters an interactive read-eval-print loop (REPL). In this mode, users can type JavaScript code directly, which is immediately executed, making it useful for quick tests and explorations of JavaScript syntax and V8 features.


title: SCRIPT EXECUTION
content:
To execute a JavaScript file, simply provide its path as an argument to <i>d8</i>: <code>d8 my_script.js</code>. Arguments can be passed to the script using the <b>--</b> separator: <code>d8 my_script.js -- arg1 arg2</code>. Inside <code>my_script.js</code>, these arguments can be accessed via the global <code>arguments</code> object, which is an array of strings.


title: HISTORY
content:
The <i>d8</i> shell emerged as a crucial component of Google's V8 JavaScript engine project, which was first released in 2008 as the JavaScript engine for the Google Chrome web browser. From its inception, V8 was designed for high performance, compiling JavaScript to native machine code. <i>d8</i> was developed as an essential accompanying tool, providing a direct interface to test, benchmark, and debug the V8 engine's functionalities independently of a browser environment. It has continuously evolved alongside the V8 engine and the ECMAScript standard, incorporating new features and optimizations as they are developed.


title: SYNOPSIS
content:
<i>dab</i><br><br><b>Note:</b> This command is <b>not standard</b>. Running it in a typical Linux environment will result in 'command not found' or similar errors.


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;No standard parameters are defined for 'dab' as it is not a recognized Linux command.<br><br>


title: DESCRIPTION
content:
The command <i>dab</i> is <b>not a standard Linux utility</b> found in common distributions like Debian, Ubuntu, Fedora, or Arch Linux. It does not appear in core Linux man pages or typical package repositories. If you encounter a reference to 'dab', it is highly probable that it refers to:<br><br>1. A <b>typo</b> or misspelling of another common command.<br>2. A <b>custom alias or shell script</b> specific to a user's or system administrator's environment.<br>3. A very <b>niche or internal tool</b> within a specific, closed-source, or highly specialized system, not intended for general public use.<br><br>Therefore, general information regarding its functionality, options, and usage cannot be provided as it is not a universally recognized command.


title: CAVEATS
content:
Attempting to execute <i>dab</i> in a typical Linux terminal will almost certainly result in an error message such as 'command not found'. Users should verify the spelling of commands or inquire about specific custom scripts if they believe 'dab' should exist on their system. Creating a custom script or alias named <i>dab</i> is possible, but its functionality would be entirely dependent on its definition by the user.


title: CHECKING FOR CUSTOM COMMANDS
content:
To determine if 'dab' is a custom alias or function on your system, you can use the commands: <i>type dab</i> or <i>which dab</i>. These commands will indicate if 'dab' is an alias, a function, or if it's not found.


title: HISTORY
content:
As <i>dab</i> is not a standard Linux command, there is <b>no documented history</b> of its development, usage, or evolution within the mainstream Linux ecosystem. Any 'history' would pertain only to custom scripts or aliases users might have created for their personal use, which is beyond general documentation.


title: PARAMETERS
content:
<b><b>-a</b>, <b>--chdir</b> <i>&lt;directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Change the current working directory of the daemon to <i>&lt;directory&gt;</i>.<br><br><b><b>-c</b>, <b>--close_fd</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Close all open file descriptors. By default, <i>stdin</i>, <i>stdout</i>, and <i>stderr</i> are handled.<br><br><b><b>-e</b>, <b>--err</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Redirect the standard error (<i>stderr</i>) of the daemon to <i>&lt;file&gt;</i>.<br><br><b><b>-l</b>, <b>--logfile</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Redirect both standard output (<i>stdout</i>) and standard error (<i>stderr</i>) to <i>&lt;file&gt;</i>.<br><br><b><b>-o</b>, <b>--out</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Redirect the standard output (<i>stdout</i>) of the daemon to <i>&lt;file&gt;</i>.<br><br><b><b>-p</b>, <b>--pidfile</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write the Process ID (PID) of the daemon to the specified <i>&lt;file&gt;</i>, useful for process management.<br><br><b><b>-u</b>, <b>--user</b> <i>&lt;user&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Change the effective user ID to <i>&lt;user&gt;</i> after daemonizing for security purposes.<br><br><b><b>-g</b>, <b>--group</b> <i>&lt;group&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Change the effective group ID to <i>&lt;group&gt;</i> after daemonizing for security purposes.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, printing information about the daemonization process to <i>stderr</i>.<br><br><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;Display version information and exit.<br><br><b><b>--</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicate the end of options; all subsequent arguments are treated as the command to run.<br><br>


title: DESCRIPTION
content:
<i>daemonize</i> is a lightweight yet powerful utility designed to transform any standard command or script into a proper Unix daemon process. Unlike simply backgrounding a process with `&`, <i>daemonize</i> handles the intricate steps required for robust daemonization: it forks the process into the background, detaches it from the controlling terminal, thereby making it immune to hangup signals (SIGHUP) when the launching shell exits. Additionally, it redirects standard input, output, and error streams, typically to <i>/dev/null</i> or specified log files, preventing unintended terminal output or input dependencies. It also changes the current working directory to <i>/</i> by default (or a user-specified path) to avoid issues with unmounting filesystems. This command is invaluable for developers and system administrators who need to run applications or scripts continuously in the background as services without them being tied to an interactive session, ensuring stability and independence.


title: CAVEATS
content:
Not a universally standard Linux command; it often requires explicit installation (e.g., <i>apt install daemonize</i> on Debian/Ubuntu, <i>yum install daemonize</i> on CentOS/RHEL). Its availability may vary across distributions.<br><i>daemonize</i> itself does not provide service management capabilities like automatic restarts on failure, dependency management, or integration with system-wide service hierarchies. For these features, it should be used in conjunction with a service manager like <i>systemd</i> (e.g., by calling <i>daemonize</i> from within a <i>.service</i> unit file) or <i>SysVinit</i> scripts.<br>While <i>daemonize</i> handles the initial setup, the launched program must still be designed to run indefinitely and handle its own lifecycle (e.g., graceful shutdown on signals) if required.<br>If the program being daemonized itself performs daemonization steps (e.g., by calling <i>daemon(3)</i> or doing its own <i>fork()</i>/<i>setsid()</i>), using <i>daemonize</i> on it might lead to unexpected behavior or redundant operations.


title: CORE DAEMONIZATION STEPS
content:
A well-behaved Unix daemon typically performs a series of critical steps upon startup to properly detach from its environment: 1) <b>Forking</b>: The parent process forks, and the child continues. 2) <b>Parent Exit</b>: The original parent process exits, detaching the child from the controlling terminal. 3) <b>Session Leader</b>: The child calls <i>setsid()</i> to create a new session and become the session leader, ensuring it doesn't acquire a controlling terminal. 4) <b>Second Fork</b> (optional but common): The session leader forks again, and the grandchild exits. This prevents the session leader from reacquiring a controlling terminal. 5) <b>Change Directory</b>: The working directory is changed to <i>/</i> or a suitable location to prevent issues with unmounting filesystems. 6) <b>Close File Descriptors</b>: All open file descriptors (especially <i>stdin</i>, <i>stdout</i>, <i>stderr</i>) are closed to prevent resource leaks and terminal interaction. 7) <b>Redirect Standard I/O</b>: <i>stdin</i>, <i>stdout</i>, and <i>stderr</i> are redirected to <i>/dev/null</i> or log files to prevent unexpected output or input requests. The <i><b>daemonize</b></i> command automates most of these crucial steps.


title: USAGE WITH SERVICE MANAGERS
content:
While <i><b>daemonize</b></i> effectively launches a process as a daemon, it does not offer full lifecycle management (e.g., start, stop, restart, status, dependencies). For robust service management, it is typically integrated with system-wide service managers like <i><b>systemd</b></i> or traditional <i><b>SysVinit</b></i>. For <i><b>systemd</b></i>, you would define a `<i>.service</i>` unit file where the `<i>ExecStart</i>` directive invokes <i><b>daemonize</b></i> with your command. This allows <i><b>systemd</b></i> to supervise the daemon, handle its logging, manage its dependencies, and ensure it restarts automatically if it crashes, providing a complete and resilient service solution.


title: HISTORY
content:
The concept of a "daemon" process has existed since the earliest days of Unix, referring to background processes that run continuously without direct user interaction. Early daemonization involved complex manual steps within program code or shell scripts. The <i>daemonize</i> utility emerged in the early 2000s as a simpler, standardized way to wrap arbitrary executables into proper daemons, abstracting away the error-prone boilerplate like double-forking, detaching from the controlling terminal, and managing file descriptors. It filled a gap for users who needed to run simple scripts or programs as background services without writing full daemon-aware applications or complex <i>init.d</i> scripts. Its development focused on providing a robust, standalone tool for a common system administration task.


title: SEE ALSO
content:
<b>nohup</b>(1), <b>disown</b>(1), <b>systemd.service</b>(5), <b>start-stop-daemon</b>(8), <b>init</b>(8)


title: PARAMETERS
content:
<b><i>FORMATS...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more desired output formats to generate. Common formats include <b>html</b>, <b>html-single</b>, <b>pdf</b>, <b>epub</b>, <b>man</b>, and <b>txt</b>.<br><br><b><b>-i</b> <i>FILE</i>, <b>--input</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the main DocBook XML input file (e.g., <i>book.xml</i> or <i>set.xml</i>). If omitted, <b>daps</b> typically searches for a default file in the current directory.<br><br><b><b>-o</b> <i>DIR</i>, <b>--output</b> <i>DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the directory where the generated output files will be placed. Defaults to a 'build' directory within the project.<br><br><b><b>-B</b> <i>DIR</i>, <b>--build-dir</b> <i>DIR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the temporary build directory where intermediate files are stored during the transformation process.<br><br><b><b>-c</b>, <b>--clean</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Cleans (removes) the build and output directories for the specified formats, or all if no formats are specified.<br><br><b><b>-k</b>, <b>--keep-tmp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keeps temporary files generated during the build process, which can be useful for debugging.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, displaying more details about the build steps as they are executed.<br><br><b><b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug output, providing even more granular information for troubleshooting build issues.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <b>daps</b> version information and exits.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message detailing available options and usage, then exits.<br><br>


title: DESCRIPTION
content:
The <b>daps</b> command (DocBook Authoring and Publishing Suite) is a specialized command-line utility primarily used in openSUSE and SUSE Linux distributions to automate the process of building DocBook XML documentation. It acts as a high-level wrapper, orchestrating underlying tools like <i>xsltproc</i>, <i>Apache FOP</i>, and <i>dblatex</i> to transform DocBook XML source files into a wide array of output formats, including HTML, PDF, EPUB, and man pages.<br><br>Its main purpose is to simplify complex DocBook build workflows, allowing authors to generate documentation without needing to manually execute multiple low-level transformation commands. It handles stylesheet application, dependency management, and output directory structuring based on the project's configuration, making the documentation generation process efficient and repeatable.


title: CAVEATS
content:
The <b>daps</b> command is not a universally available standard Linux command. It is primarily developed and integrated within the openSUSE/SUSE ecosystem for their DocBook documentation toolchain. Its successful operation relies on a correctly structured DocBook XML project and the prior installation and configuration of underlying DocBook processing tools and stylesheets (e.g., <i>xsltproc</i>, <i>Apache FOP</i>, <i>dblatex</i>). Command-line options and behaviors might show minor variations across different versions or specific distribution implementations.


title: CONFIGURATION
content:
<b>daps</b> allows for project-specific customization through a configuration file, typically named <i>daps.conf</i> or <i>_daps_config</i>. This file, usually located in the DocBook project's root directory, enables users to define output paths, specify custom stylesheet parameters, and fine-tune the invocation of underlying processing tools.


title: TYPICAL USAGE
content:
Typically, <b>daps</b> is executed from the root directory of a DocBook project, where the main <i>book.xml</i> or <i>set.xml</i> file resides. For example, to generate HTML output for the entire project, one might simply run: <br><br><i>daps html</i><br><br>To clean previously built PDF artifacts: <br><br><i>daps --clean pdf</i>


title: HISTORY
content:
The <b>daps</b> command emerged as a core component of the DocBook Authoring and Publishing Suite, developed primarily within the SUSE Linux environment, and later becoming integral to openSUSE's documentation efforts. Its inception addressed the challenges and complexities of manually managing DocBook XML transformations, offering a more automated and user-friendly approach to generate diverse output formats from a single DocBook source. Over time, it has evolved to support a wider array of formats and configuration options, solidifying its role as an essential tool for DocBook-based documentation projects within the SUSE ecosystem.


title: SYNOPSIS
content:
<b>darling</b> <i>[subcommand] [arguments...]</i> <br><i>or</i><br> <b>darling</b> <i>&lt;path_to_macOS_application_bundle&gt;</i> <br><i>or</i><br> <b>darling</b> <i>&lt;path_to_macOS_executable_file&gt;</i>


title: PARAMETERS
content:
<b><i>&lt;path_to_macOS_application_bundle&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directly launches a macOS application bundle (e.g., MyApp.app).<br><br><b><i>&lt;path_to_macOS_executable_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directly launches a standalone macOS executable.<br><br><b><b>shell</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enters a macOS-like shell environment within <b>Darling</b>, useful for interacting with the emulated macOS filesystem.<br><br><b><b>launch</b> <i>[options] &lt;executable&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly launches a specific macOS executable with additional options.<br><br><b><b>mount</b> <i>&lt;path_to_dmg&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mounts a macOS Disk Image (DMG) file, making its contents accessible within the <b>Darling</b> environment.<br><br><b><b>unmount</b> <i>&lt;mount_point&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unmounts a previously mounted DMG file.<br><br><b><b>install-xcode-toolchain</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs the Xcode command-line tools within the <b>Darling</b> environment for development purposes.<br><br><b><b>xcode-select</b> <i>[--install] [--switch &lt;path&gt;]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages the active Xcode developer directory within <b>Darling</b>, similar to its macOS counterpart.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <b>Darling</b> version information.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays usage information and available subcommands.<br><br>


title: DESCRIPTION
content:
<b>Darling</b> is a free and open-source compatibility layer that enables macOS applications and their frameworks to run natively on Linux. Inspired by <b>Wine</b> (which facilitates Windows applications on Linux), <b>Darling</b> aims to provide a similar environment for Apple's operating system. It achieves this by implementing a user-space translation layer for macOS frameworks and APIs, coupled with a kernel module that intercepts and translates macOS system calls into their Linux equivalents.<br><br>The project's goal is to allow users to execute proprietary macOS software directly on a Linux system without requiring full virtualization, which typically consumes more resources. While still under active development and not yet fully compatible with all macOS applications, <b>Darling</b> represents a significant effort to bridge the gap between macOS's Mach-O binary format and Linux's ELF, offering a unique solution for cross-platform application compatibility.


title: CAVEATS
content:
<b>Darling</b> is an ambitious and complex project, and as such, it comes with several caveats and limitations:<br><ul><li><b>Experimental and Incomplete:</b> Many macOS frameworks and APIs are still under development or not yet implemented, meaning not all macOS applications will run correctly or at all.</li><li><b>Kernel Module Requirement:</b> It relies on a custom kernel module to handle system call translation, which necessitates root privileges for installation and might require specific kernel versions or configurations.</li><li><b>Performance Overhead:</b> While not full virtualization, the translation layer introduces a performance impact, especially for graphics-intensive applications. Full graphics acceleration support is an ongoing challenge.</li><li><b>Compatibility:</b> Primarily designed for x86_64 architecture, supporting older 32-bit macOS applications is dependent on the underlying Linux system's capabilities.</li><li><b>Security:</b> Running macOS applications in a compatibility layer may introduce unforeseen security implications, though <b>Darling</b> aims to be as secure as possible.</li></ul>


title: ARCHITECTURE
content:
<b>Darling</b>'s architecture involves two primary components: a <i>user-space environment</i> and a <i>kernel module</i>. The user-space component provides implementations of macOS libraries (like `libc++`, `libdispatch`, etc.) and frameworks (like `CoreFoundation`, `AppKit`). When a macOS application makes a system call, the <b>Darling</b> kernel module intercepts it, translates it into an equivalent Linux system call, and then passes it to the Linux kernel. This approach allows macOS binaries (Mach-O format) to run directly on a Linux kernel (ELF format) by transparently handling the differences in system call interfaces and library expectations.


title: INSTALLATION
content:
As <b>Darling</b> is not a standard package in most mainstream Linux distributions, installation typically involves either adding a custom package repository (e.g., via `apt` or `dnf`) or building the project from source. Building from source requires specific development tools, kernel headers, and dependencies. Due to its nature as a kernel module, installation and setup often require administrative privileges and careful attention to kernel versions to ensure compatibility and stability.


title: HISTORY
content:
Development on <b>Darling</b> began around 2013, initiated by Luboš Doležel. Its inception was driven by the desire to create a compatibility layer for macOS, mirroring the success of <b>Wine</b> for Windows applications. The project has steadily evolved, relying on reverse-engineering macOS APIs and open-source implementations of its core frameworks. Due to the closed-source and complex nature of macOS, progress has been challenging but persistent. Over the years, <b>Darling</b> has attracted a community of contributors and continues to be an active project, striving to offer a unique solution for macOS application compatibility on Linux, filling a niche that traditional virtualization doesn't fully address for native-like performance.


title: SYNOPSIS
content:
<b>dart</b> [<i>VM_OPTIONS</i>] <i>&lt;script_path&gt;</i> [<i>SCRIPT_ARGUMENTS</i>]<br><b>dart</b> [<i>GLOBAL_OPTIONS</i>] <i>&lt;command&gt;</i> [<i>COMMAND_OPTIONS</i>] [<i>COMMAND_ARGUMENTS</i>]


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help information or help for a specific subcommand.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Dart SDK version information.<br><br><b><b>--enable-asserts</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the execution of assert statements in Dart code when running scripts.<br><br><b><b>--observe[=&lt;port&gt;/&lt;host&gt;:&lt;port&gt;]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the Dart VM service and opens the Observatory debugger/profiler, often with an optional port or host:port.<br><br><b><b>--disable-service-auth-codes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the use of authentication codes for the Dart VM service, primarily for development or trusted environments.<br><br><b><b>--packages=&lt;path&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the <b>.packages</b> file, which maps package names to URIs for package resolution.<br><br><b><b>--enable-debugging</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debugging for the Dart VM, allowing debuggers to attach.<br><br><b><b>--profile</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables CPU profiling during execution, collecting performance data.<br><br><b><b>--current-directory=&lt;path&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the current working directory for the Dart process, affecting relative path resolution.<br><br><b><b>--verbosity=&lt;level&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the verbosity level for logs (e.g., <b>all</b>, <b>warning</b>, <b>error</b>) from the Dart VM.<br><br><b><b>--enable-experiment=&lt;name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables a specific experimental Dart language feature, often requiring an SDK restart.<br><br>


title: DESCRIPTION
content:
The <b>dart</b> command is the primary command-line interface for interacting with the Dart SDK. It serves as a versatile tool for Dart developers, enabling them to <br><br><i>run</i> Dart scripts directly, <br><i>compile</i> Dart source code into native executables for various platforms (Windows, macOS, Linux, ARM) or JavaScript for web deployment, <br><i>test</i> Dart applications, <br><i>manage packages</i> using the integrated <b>pub</b> subcommand, <br>and perform many other development tasks such as <i>code analysis</i>, <i>formatting</i>, <i>documentation generation</i>, and <i>debugging</i>. <br><br>It leverages the Dart Virtual Machine (VM) for fast, JIT-compiled execution during development and can also create optimized, AOT-compiled executables for production deployment, offering flexibility for different development and deployment needs across mobile (Flutter), web, desktop, and server environments.


title: CAVEATS
content:
The <b>dart</b> command is not a standard core Linux utility; it requires the Dart SDK to be installed and correctly configured in the system's PATH.<br><br>Its functionality is highly dependent on the subcommand invoked (e.g., <b>run</b>, <b>compile</b>, <b>pub</b>), and the options available often vary significantly between these subcommands.<br><br>Direct execution of Dart scripts (<b>dart script.dart</b>) defaults to JIT compilation, which is optimized for fast development cycles but may have a larger memory footprint and slower startup than AOT-compiled native executables produced by <b>dart compile</b>.


title: COMMON SUBCOMMANDS
content:
The <b>dart</b> command acts as a dispatcher for various essential subcommands, each providing distinct functionality: <br><br><i><b>run</b></i>: Executes a Dart application or script.<br><i><b>compile</b></i>: Compiles Dart source code into native executables or JavaScript.<br><i><b>test</b></i>: Runs tests defined for a Dart project.<br><i><b>pub</b></i>: Manages packages (e.g., <b>pub get</b>, <b>pub upgrade</b>, <b>pub publish</b>).<br><i><b>create</b></i>: Generates new Dart project templates (e.g., console app, web app).<br><i><b>fix</b></i>: Applies automated fixes to Dart source code.<br><i><b>format</b></i>: Formats Dart source code according to style guidelines.<br><i><b>analyze</b></i>: Analyzes Dart code for errors, warnings, and style issues.<br><br>Each subcommand has its own set of specific options and arguments, which can be viewed using <b>dart help &lt;subcommand_name&gt;</b>.


title: HISTORY
content:
The Dart programming language and its SDK, including the <b>dart</b> command, were developed by Google. <br><br>Initially unveiled in 2011, Dart was conceived as an alternative to JavaScript for web development. While its direct adoption in browsers didn't materialize as broadly intended, Dart found significant success and renewed focus with the advent of the <i>Flutter</i> UI toolkit in 2017. Flutter's rise, especially for cross-platform mobile development, propelled Dart into widespread use across mobile, web, desktop, and backend environments. <br><br>The <b>dart</b> command has evolved alongside the language and SDK, growing from a simple script runner to a comprehensive development hub for the entire Dart ecosystem, integrating build, test, and package management functionalities.


title: SYNOPSIS
content:
<b>dasel</b> <i>&lt;selector&gt;</i> [<i>options</i>] [<i>&lt;file&gt;</i>]<br><b>dasel</b> <i>&lt;subcommand&gt;</i> <i>&lt;selector&gt;</i> [<i>options</i>] [<i>&lt;file&gt;</i>]<br><br><i>Common subcommands:</i><br><b>dasel select</b> <i>&lt;selector&gt;</i> [<i>options</i>] [<i>&lt;file&gt;</i>]<br><b>dasel put</b> <i>&lt;selector&gt;</i> [<i>options</i>] [<i>&lt;file&gt;</i>]<br><b>dasel delete</b> <i>&lt;selector&gt;</i> [<i>options</i>] [<i>&lt;file&gt;</i>]<br><b>dasel convert</b> [<i>options</i>] [<i>&lt;file&gt;</i>]


title: PARAMETERS
content:
<b><b>-f</b>, <b>--file</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the input file path. If omitted, <i>dasel</i> reads from standard input (stdin).<br><br><b><b>-p</b>, <b>--parser</b> <i>&lt;format&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the parser to use for the input data (e.g., <i>json</i>, <i>yaml</i>, <i>toml</i>, <i>xml</i>, <i>csv</i>, <i>properties</i>). Auto-detected by file extension if possible.<br><br><b><b>-t</b>, <b>--type</b> <i>&lt;format&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the output format (e.g., <i>json</i>, <i>yaml</i>, <i>toml</i>, <i>xml</i>, <i>csv</i>, <i>properties</i>). Defaults to the input parser type.<br><br><b><b>-s</b>, <b>--selector</b> <i>&lt;expression&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The selector expression used to target specific data elements. Often provided as a positional argument.<br><br><b><b>-w</b>, <b>--write</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes changes back to the input file. Requires <b>--file</b> to be specified.<br><br><b><b>-v</b>, <b>--value</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The value to set when using the <i>put</i> subcommand.<br><br><b><b>-a</b>, <b>--append</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Used with <i>put</i> to append a value to an array at the selected path.<br><br><b><b>--pretty</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pretty-prints the output JSON or YAML data for readability.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <i>dasel</i> version information.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the help message for the command or subcommand.<br><br>


title: DESCRIPTION
content:
<i>Dasel</i> is a powerful command-line tool designed for querying and modifying data structures, serving as a universal alternative to specialized tools like <b>jq</b> for JSON or <b>yq</b> for YAML. It supports a wide array of data formats including JSON, YAML, TOML, XML, CSV, and Properties files, allowing users to interact with structured data using a unified selector syntax.<br><br>The tool excels in scenarios requiring automation, scripting, or quick data manipulation without the need for complex programming. Users can select specific values, update existing data, delete entries, or even convert data between different formats. Its intuitive selector language, reminiscent of CSS selectors or object pathing, makes it accessible for navigating nested data. <i>Dasel</i> streamlines data processing tasks, making it an indispensable utility for developers and system administrators working with diverse configuration files and data payloads.


title: CAVEATS
content:
While powerful, <i>dasel</i>'s universal nature means its selector syntax can be less specialized than format-specific tools (e.g., <b>jq</b>'s extensive function library). Mastering its selector syntax requires a learning curve, especially for complex queries or transformations. Performance on extremely large datasets might not match highly optimized, native format parsers.


title: SUPPORTED DATA FORMATS
content:
<i>Dasel</i> natively supports a wide range of structured data formats for both input and output:<br><ul><li><b>JSON</b> (JavaScript Object Notation)</li><li><b>YAML</b> (YAML Ain't Markup Language)</li><li><b>TOML</b> (Tom's Obvious, Minimal Language)</li><li><b>XML</b> (eXtensible Markup Language)</li><li><b>CSV</b> (Comma Separated Values)</li><li><b>Properties</b> (Java Properties files)</li></ul>


title: SELECTOR SYNTAX OVERVIEW
content:
<i>Dasel</i> employs a flexible selector syntax to pinpoint data elements. Key components include:<br><ul><li><b>Dot Notation:</b> Access object fields (e.g., <i>user.profile.name</i>)</li><li><b>Array Indexing:</b> Access array elements (e.g., <i>items[0]</i>, <i>items[:]</i> for all)</li><li><b>Filters:</b> Select elements based on conditions (e.g., <i>users[name=John]</i>)</li><li><b>Wildcards:</b> Match any key or index (e.g., <i>*.id</i>)</li><li><b>Root Selector:</b> <i>.</i> refers to the root of the document.</li></ul>This allows for powerful and precise data navigation.


title: HISTORY
content:
<i>Dasel</i> was created by Tom Wright (also known as TomKennedy on GitHub) and first released in 2020. Developed in Go, it was designed to address the need for a single, versatile command-line tool capable of processing various structured data formats, drawing inspiration from the success of <b>jq</b> for JSON data. Its open-source development and active community have contributed to its growing popularity as a go-to utility for data manipulation on the command line.


title: SYNOPSIS
content:
<code>dash [<i>options</i>] [<i>script-file</i> [<i>arguments</i>]]</code><br><code>dash -c <i>command_string</i> [<i>command_name</i> [<i>arguments</i>]]</code><br><code>dash -s [<i>arguments</i>]</code>


title: PARAMETERS
content:
<b>-c <i>command_string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands from the provided <i>command_string</i> instead of a file or standard input.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands from standard input. This is the default if no file is specified and standard input is a terminal.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the shell to run in interactive mode, even if standard input/output are not terminals.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes <code>dash</code> act as a login shell. This usually involves reading specific startup files.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads commands but does not execute them. This option is useful for checking the syntax of shell scripts.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints shell input lines as they are read. Useful for debugging scripts.<br><br><b>-x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints commands and their arguments as they are executed. This is a common debugging aid.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats unset variables as an error. An attempt to expand an unset variable will cause the shell to exit with an error.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays usage information for the <code>dash</code> command.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the <code>dash</code> shell version information.<br><br>


title: DESCRIPTION
content:
<b>dash</b> (<b>D</b>ebian <b>A</b>lmquist <b>SH</b>ell) is a modern, lightweight, POSIX-compliant command interpreter. It is a derivative of the original Almquist shell (ASH), designed specifically for speed and minimal resource consumption. This makes it an ideal choice for executing system scripts efficiently.<br><br><code>dash</code> is often the default <code>/bin/sh</code> on Debian and Ubuntu systems, replacing <code>bash</code> for this critical role. Its primary advantages include significantly faster startup times and a lower memory footprint compared to <code>bash</code>, which contributes to quicker system boots and more efficient execution of numerous small scripts.<br><br>While highly optimized for non-interactive script execution, <code>dash</code> lacks many user-friendly interactive features (like advanced command history, tab completion, or extensive globbing) found in <code>bash</code>. Its strict adherence to the POSIX standard ensures high portability for scripts written against it, but also means scripts relying on <i>bash</i>-specific extensions (<i>bashisms</i>) will likely fail.


title: CAVEATS
content:
<ul><li><b><i>Bashisms</i> Incompatibility:</b> <code>dash</code> strictly adheres to POSIX standards. Scripts written specifically for <code>bash</code> that utilize <i>bash</i>-specific features (e.g., <code>[[ ... ]]</code> for conditional expressions, process substitution <code><()</code>, certain array manipulations, non-standard globbing) will likely fail or behave unexpectedly when executed by <code>dash</code>.<br></li><li><b>Limited Interactive Features:</b> Unlike feature-rich shells like <code>bash</code> or <code>zsh</code>, <code>dash</code> offers minimal interactive capabilities. It lacks advanced command history, tab completion, prompt customization, and other conveniences expected by interactive users. It is primarily designed for script execution.<br></li><li><b>Debugging Complexity:</b> Due to its minimalistic nature, debugging complex scripts can sometimes be more challenging in <code>dash</code> compared to <code>bash</code>, which offers more sophisticated introspection tools.</li></ul>


title: PERFORMANCE AND RESOURCE EFFICIENCY
content:
<code>dash</code> is engineered for speed and minimal memory footprint. Its lean design means it starts up significantly faster and consumes fewer resources than <code>bash</code>, making it highly efficient for running numerous small system scripts, especially those executed during system boot or in resource-constrained environments. This contributes to quicker system startup times and overall lower system load.


title: POSIX COMPLIANCE AND SCRIPT PORTABILITY
content:
A core tenet of <code>dash</code> is its strict adherence to the POSIX.1-2001 and POSIX.1-2008 standards. This strong compliance ensures that scripts written using only POSIX-specified features will execute predictably and portably across different Unix-like systems. However, this also means that scripts containing <code>bash</code>-specific syntax or extensions (often called "<i>bashisms</i>") will fail or behave incorrectly when executed by <code>dash</code>, highlighting the importance of writing POSIX-compliant shell scripts for maximum compatibility.


title: PRIMARY USE CASE: SYSTEM SCRIPTING VS. INTERACTIVE USE
content:
While <code>dash</code> can be used interactively, its primary design goal and optimal use case is non-interactive execution of system scripts. For daily interactive shell usage, most users prefer feature-rich shells like <code>bash</code> or <code>zsh</code> due to their extensive capabilities such as advanced command history, tab completion, sophisticated prompt customization, and interactive debugging features. <code>dash</code> focuses on providing a robust, fast, and reliable interpreter for automated tasks.


title: HISTORY
content:
<code>dash</code> is a direct descendant of the <i>Almquist shell</i> (ASH), originally developed by Kenneth Almquist in the late 1980s. ASH was known for its small size and speed. It was adopted by NetBSD and later FreeBSD as their <code>/bin/sh</code> due to its efficiency and POSIX compliance.<br><br>The <i>Debian Almquist SHell</i> (<code>dash</code>) was developed specifically for Debian, stemming from the NetBSD version of ASH. In 2006, Debian made a significant change, switching the default <code>/bin/sh</code> symlink from <code>bash</code> to <code>dash</code>. This decision was primarily driven by the desire for faster boot times and reduced memory usage for system scripts, which are frequently executed during startup and throughout system operation. Ubuntu followed suit shortly thereafter. This transition sometimes revealed "<i>bashisms</i>" in scripts that were implicitly relying on <code>bash</code> features.


title: SYNOPSIS
content:
<b>datamash</b> [<i>OPTIONS</i>] <i>OPERATION</i> [<i>FIELD...</i>]<br><br>Examples of <i>OPERATION</i>:<br>&nbsp;&nbsp;<b>sum</b>, <b>mean</b>, <b>median</b>, <b>min</b>, <b>max</b>, <b>count</b>, <b>distinct</b>, <b>range</b>, <b>stddev</b>, <b>var</b>, <b>concat</b>, <b>unique</b>.<br><br>Examples of <i>FIELD</i>:<br>&nbsp;&nbsp;<i>1</i>, <i>2</i>, <i>3</i>, <i>1-3</i>, <i>ALL</i>, <i>FIELD_NAME</i> (with <i>-H</i>).


title: PARAMETERS
content:
<b><b>-H</b>, <b>--header-row</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat the first line of input as a header row. <i>datamash</i> will output the header row before the results.<br><br><b><b>-W</b>, <b>--whitespace</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use whitespace (one or more spaces or tabs) as the field delimiter instead of the default single tab character.<br><br><b><b>-t</b> <i>CHAR</i>, <b>--field-delimiter=</b><i>CHAR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use <i>CHAR</i> as the field delimiter for input and output. For example, <b>-t,</b> for CSV files.<br><br><b><b>-g</b> <i>N[,M...]</i>, <b>--group=</b><i>N[,M...]</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Group input lines by the values in fields <i>N</i>, <i>M</i>, etc. All operations will be performed per group. Input must be sorted by the group fields unless <b>-s</b> is used.<br><br><b><b>-f</b>, <b>--full</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print all input lines along with the calculated results. Results are appended as new columns to the end of each input line.<br><br><b><b>-s</b>, <b>--sort</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the input internally by the group fields before processing. Useful when input is not pre-sorted; can be memory-intensive for large files.<br><br><b><b>--no-strict-header</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not strictly check for header compatibility when using aggregate operations with <b>--header-row</b>.<br><br><b><b>--skip-header-row</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip the header row from input, but do not print it to output unless <b>--full</b> is specified.<br><br><b><b>--filler=</b><i>STR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replace empty fields with <i>STR</i>. Default is empty string.<br><br>


title: DESCRIPTION
content:
<i>datamash</i> is a powerful and efficient command-line utility designed for performing basic numeric, textual, and statistical operations on tabular text data. It reads input from standard input or files, processes data by grouping or by column, and outputs the results. It's particularly useful for data aggregation, transformation, and statistical analysis on CSV-like or tab-separated data. Common use cases include calculating sums, averages, medians, minimums, maximums, and counts of fields, as well as concatenating or finding distinct values within groups. <i>datamash</i> simplifies tasks that would otherwise require more complex scripting with tools like <i>awk</i>, making it a go-to for quick data summaries and reports in shell pipelines. It supports various delimiters and can handle header rows.


title: CAVEATS
content:
When using the <b>-g</b> (group by) option, input data <b>must</b> be sorted by the group fields. If the input is not sorted, <i>datamash</i> will produce incorrect results. You can use the <b>-s</b> option to internally sort the data, but for very large files, it might be more efficient to pre-sort the data using <i>sort(1)</i> before piping it to <i>datamash</i>. Numeric operations require valid numerical data; non-numeric values in numeric fields will typically be skipped or cause errors.


title: COMMON OPERATIONS
content:
<i>datamash</i> supports a wide array of operations. Some of the most frequently used include:<br><b>sum</b>: Calculates the sum of values in the specified fields.<br><b>mean</b>: Computes the arithmetic mean (average) of values.<br><b>median</b>: Finds the median value.<br><b>min</b>: Determines the minimum value.<br><b>max</b>: Determines the maximum value.<br><b>count</b>: Counts the number of non-empty values.<br><b>distinct</b>: Counts the number of unique non-empty values.<br><b>concat</b>: Concatenates values in the specified fields with a comma (or custom) separator.<br><b>unique</b>: Prints unique values in the specified fields, one per line.


title: USAGE WITH PIPELINES
content:
<i>datamash</i> is typically used as part of a shell pipeline. It reads data from standard input (or files) and writes results to standard output, making it highly composable with other Unix commands like <i>cat</i>, <i>grep</i>, <i>sort</i>, <i>cut</i>, and <i>awk</i>. This allows for complex data processing workflows by chaining simple, focused commands.


title: HISTORY
content:
<i>datamash</i> is a relatively modern utility within the GNU Project, specifically designed to address common data aggregation and transformation tasks that often become cumbersome with traditional Unix tools like <i>awk</i> or a combination of <i>cut</i>, <i>sort</i>, and <i>uniq</i>. Its development aimed to provide a dedicated, efficient, and user-friendly command-line tool for statistical calculations on tabular data, simplifying complex data manipulation pipelines for system administrators and data analysts.


title: SYNOPSIS
content:
<b>datashader_cli</b> <i>&lt;command&gt; &lt;input_path&gt; &lt;output_path&gt;</i> [<i>options</i>]<br><br><b>Commands:</b><br>&nbsp;&nbsp;<b>points</b>: Rasterize point data.<br>&nbsp;&nbsp;<b>raster</b>: Rasterize pre-aggregated raster data.<br>&nbsp;&nbsp;<b>polygons</b>: Rasterize polygon data.<br>&nbsp;&nbsp;<b>lines</b>: Rasterize line data.<br>&nbsp;&nbsp;<b>mesh</b>: Rasterize mesh data.


title: PARAMETERS
content:
<b><b>--width</b> <i>&lt;int&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output image width in pixels. (Default: 800)<br><br><b><b>--height</b> <i>&lt;int&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output image height in pixels. (Default: 600)<br><br><b><b>--x</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Name of the column containing x-coordinates (longitude).<br><br><b><b>--y</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Name of the column containing y-coordinates (latitude).<br><br><b><b>--xmin</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Minimum x-coordinate for the spatial extent.<br><br><b><b>--ymin</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Minimum y-coordinate for the spatial extent.<br><br><b><b>--xmax</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Maximum x-coordinate for the spatial extent.<br><br><b><b>--ymax</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Maximum y-coordinate for the spatial extent.<br><br><b><b>--agg</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Aggregation method (e.g., 'count', 'mean', 'sum', 'min', 'max').<br><br><b><b>--column</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Column to aggregate for 'mean', 'sum', 'min', 'max' aggregations.<br><br><b><b>--cmap</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Colormap to apply (e.g., 'fire', 'viridis', 'blues').<br><br><b><b>--format</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output format ('png' for image, 'netcdf' for aggregated data). (Default: 'png')<br><br><b><b>--by</b> <i>&lt;str&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Column to group data by before aggregation.<br><br><b><b>--logx</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply logarithmic scaling to the x-axis.<br><br><b><b>--logy</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply logarithmic scaling to the y-axis.<br><br><b><b>--pre-agg</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicates that input data is already pre-aggregated (for 'raster' command).<br><br><b><b>--resample-width</b> <i>&lt;int&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resample width for finer control over rasterization.<br><br><b><b>--resample-height</b> <i>&lt;int&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resample height for finer control over rasterization.<br><br><b><b>--line-width</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Width of lines in pixels (for 'lines' command). (Default: 1.0)<br><br><b><b>--buffer</b> <i>&lt;float&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Buffer distance around geometries (for 'polygons', 'lines' commands).<br><br><b><b>--antialias</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply antialiasing to the output image for smoother edges.<br><br>


title: DESCRIPTION
content:
The <b>datashader_cli</b> command-line interface provides a convenient way to apply Datashader's powerful rasterization capabilities to large datasets without writing Python code. It is designed to visualize millions or billions of data points, lines, or polygons by aggregating them into a fixed-size raster image. This process makes it possible to render complex datasets that would otherwise overwhelm traditional plotting tools.<br><br>It supports various input formats, including CSV and Parquet, and can output visualizations as PNG images or aggregated data in NetCDF format. The CLI offers subcommands for different data types (e.g., points, rasters, polygons, lines), allowing users to specify aggregation methods, colormaps, output dimensions, and spatial extents directly from the terminal.


title: CAVEATS
content:
<b>datashader_cli</b> is optimized for large datasets, but performance and memory usage can still be significant for extremely large files or complex operations without sufficient system resources. For optimal performance, especially with distributed data, it's recommended to use Parquet files and potentially leverage Dask for out-of-core processing. The CLI currently has a limited set of options compared to the full Python Datashader API, and some advanced customization requires scripting in Python.


title: INPUT DATA FORMATS
content:
Supports CSV, Parquet, and in some cases, NetCDF files. Ensure your input files are structured appropriately with identifiable columns for X and Y coordinates, and any columns used for aggregation.


title: OUTPUT IMAGE QUALITY
content:
The quality of the output image (PNG) is determined by the <b>--width</b> and <b>--height</b> parameters. Higher resolutions will result in larger files but may reveal finer details in the data.


title: HISTORY
content:
The <b>datashader_cli</b> was developed as part of the Datashader project, initiated by Anaconda Inc. to address the growing challenge of visualizing very large datasets. While Datashader primarily offers a Python API for programmatic use, the CLI was introduced to provide a more accessible entry point for users who need to quickly generate visualizations without writing Python code. It emerged to streamline common rasterization workflows, making it easier to integrate Datashader into shell scripts or data pipelines where a direct command-line interface is preferred.


title: SYNOPSIS
content:
<b>date</b> [<i>OPTION</i>]... [+<i>FORMAT</i>]<br><b>date</b> [-u|--utc|--universal] [<i>MMDDhhmm</i>[[<i>CC</i>]<i>YY</i>][.<i>ss</i>]]<br><b>date</b> [<i>-s</i>|<i>--set</i>=<i>STRING</i>]<br><b>date</b> [<i>-r</i>|<i>--reference</i>=<i>FILE</i>]<br><b>date</b> [<i>--date</i>=<i>STRING</i>]


title: PARAMETERS
content:
<b>--date=<i>STRING</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display time described by <i>STRING</i>, not 'now'.<br><br><b>--set=<i>STRING</i>, -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the date and time described by <i>STRING</i>. Requires root privileges.<br><br><b>--utc, --universal, -u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print or set Coordinated Universal Time (UTC).<br><br><b>--iso-8601[=<i>TIMESPEC</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output date/time in ISO 8601 format. <i>TIMESPEC</i> can be 'date', 'hours', 'minutes', 'seconds', 'ns'.<br><br><b>--rfc-3339[=<i>TIMESPEC</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output date/time in RFC 3339 format. <i>TIMESPEC</i> similar to --iso-8601.<br><br><b>--reference=<i>FILE</i>, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the last modification time of <i>FILE</i>.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br><b>+<i>FORMAT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control the output format. <i>FORMAT</i> is a string with special characters like %Y for year, %m for month, etc.<br><br>


title: DESCRIPTION
content:
The <b>date</b> command in Linux is a versatile utility used to display or set the system date and time. When invoked without arguments, it prints the current date and time in a default format. It's widely used in shell scripts for generating timestamps, logging, and naming files uniquely based on the current time.<br><br>Users can customize the output format extensively using format control sequences. Additionally, <b>date</b> allows system administrators to adjust the system clock, either to a specific time or by parsing a human-readable date string. It interacts with the system's time zone settings and can display time in UTC. While <b>date</b> manages the system clock, <b>hwclock</b> is typically used to manage the hardware clock (RTC). Proper synchronization between the two is important for persistent time settings across reboots.


title: CAVEATS
content:
<b>date</b> command operations on the system clock often require root privileges (e.g., using --set or supplying a new date/time string). Changes made by <b>date</b> are to the system clock, which is distinct from the hardware clock (RTC). To ensure time persistence across reboots, the hardware clock might need to be synchronized with the system clock using <b>hwclock</b>. Time zone handling relies on the <b>TZ</b> environment variable and /etc/localtime configuration; incorrect settings can lead to unexpected output.


title: COMMON FORMAT SPECIFIERS
content:
The <b>+<i>FORMAT</i></b> option uses various specifiers to control output:<br><b>%Y</b>: 4-digit year (e.g., 2023)<br><b>%m</b>: Month as a decimal number (01-12)<br><b>%d</b>: Day of the month (01-31)<br><b>%H</b>: Hour (00-23)<br><b>%M</b>: Minute (00-59)<br><b>%S</b>: Second (00-60)<br><b>%s</b>: Seconds since 1970-01-01 00:00:00 UTC<br><b>%Z</b>: Alphabetic time zone abbreviation (e.g., EST)<br><b>%A</b>: Full weekday name (e.g., Monday)<br><b>%B</b>: Full month name (e.g., January)<br><b>%c</b>: Locale's appropriate date and time representation


title: HISTORY
content:
The <b>date</b> command has been a fundamental part of Unix-like operating systems since their inception, making it one of the oldest and most consistently used utilities. It is part of the GNU Core Utilities (<i>coreutils</i>) package in Linux distributions, ensuring its widespread availability and standardization. Over time, it has evolved to support a richer set of formatting options, various input date string parsing capabilities, and features like ISO 8601 and RFC 3339 output, reflecting modern needs for precise and standardized time representation. Its core functionality for displaying and setting time remains vital for system administration, scripting, and general user queries.


title: PARAMETERS
content:
<b><b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b><b>-p</b> <I>port</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the specified port on the remote host. Defaults to 22.<br><br><b><b>-i</b> <I>identity_file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the path to the private key file for authentication.<br><br><b><b>-l</b> <I>username</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the username to log in as on the remote host.<br><br><b><b>-y</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Always accept new host keys without prompting. <b>Use with extreme caution</b> as it bypasses host key verification, making it vulnerable to man-in-the-middle attacks.<br><br><b><b>-N</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not execute a remote command or allocate a pseudo-terminal. Useful for port forwarding only.<br><br><b><b>-T</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable pseudo-terminal allocation. Useful for executing commands non-interactively.<br><br><b><b>-C</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable compression for the connection, which can be useful over slow links.<br><br><b><b>-L</b> <I>local_port</I>:<I>remote_host</I>:<I>remote_port</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Local port forwarding. Forward local port to a remote host and port via the SSH tunnel.<br><br><b><b>-R</b> <I>remote_port</I>:<I>local_host</I>:<I>local_port</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remote port forwarding. Forward a remote port to a local host and port via the SSH tunnel.<br><br><b><b>-W</b> <I>host</I>:<I>port</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Proxy forwarding. Forward stdio to a remote host and port.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Request subsystem (e.g., used for sftp). If this option is used, <I>command</I> specifies the subsystem name.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Go to background after successful authentication. Requires <b>-N</b> (no command).<br><br><b><I>user@host</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The remote user and hostname or IP address to connect to.<br><br><b>[<I>command</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional command to execute on the remote host. If not provided, an interactive shell will be opened.<br><br>


title: DESCRIPTION
content:
<i>dbclient</i> is the client program for <i>Dropbear</i>, a small and efficient SSH 2 server and client. It's designed to be lightweight and resource-friendly, making it suitable for embedded systems, routers, and environments where <i>OpenSSH</i> might be considered too large.<br><br>It allows users to securely connect to remote servers, execute commands, and transfer files over an encrypted channel. While offering a subset of <i>OpenSSH</i>'s features, it provides essential SSH protocol version 2 functionality, focusing on minimal overhead and efficient operation for systems with constrained resources.


title: CAVEATS
content:
<b>Feature Limitations:</b> Compared to <I>OpenSSH</I>, <I>dbclient</I> has fewer features, notably lacking support for X11 forwarding, SSH agent forwarding (though private key files can be specified), and a wider range of authentication methods.<br><br><b>Security Warning (-y):</b> Using the <b>-y</b> option is highly discouraged in production environments as it disables critical host key verification, making connections susceptible to active man-in-the-middle attacks. Always verify host keys manually or via known_hosts.<br><br><b>Community Support:</b> While stable, <I>Dropbear</I> and its client generally have a smaller community and less extensive public documentation than <I>OpenSSH</I>.


title: PORTABILITY AND RESOURCE USAGE
content:
<I>dbclient</I> is known for its exceptional portability and minimal resource requirements. Its small binary size and low memory footprint make it an ideal choice for resource-constrained environments like IoT devices, network appliances, and older hardware where a full-fledged <I>OpenSSH</I> installation might be too heavy.


title: HISTORY
content:
<I>Dropbear</I>, including its client <I>dbclient</I>, was developed by Matt Johnston with its initial release around 2003. It emerged as a lightweight, small-footprint alternative to the more feature-rich <I>OpenSSH</I> suite, specifically targeting embedded Linux systems, routers, and devices with limited memory and storage. Its design prioritizes efficiency and low resource consumption, which has cemented its place in the embedded systems world.


title: PARAMETERS
content:
<b><b>-nosplash</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the display of the splash screen during application startup.<br><br><b><b>-run</b> <i>&lt;script_path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes a specified <i>DBeaver</i> script (e.g., SQL script) upon application launch. Useful for automation or specific tasks.<br><br><b><b>-consoleLog</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directs application log output to the console (standard output/error), useful for debugging and troubleshooting.<br><br><b><b>-data</b> <i>&lt;workspace_path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom workspace directory for <i>DBeaver</i> instead of the default location.<br><br><b><b>--launcher.suppressErrors</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the display of launcher error dialogs, often used in automated environments where user interaction is not desired.<br><br>


title: DESCRIPTION
content:
<i>DBeaver</i> is a powerful and versatile open-source cross-platform database tool. It supports a wide range of databases including <b>MySQL</b>, <b>PostgreSQL</b>, <b>Oracle</b>, <b>SQL Server</b>, <b>SQLite</b>, <b>DB2</b>, <b>MariaDB</b>, <b>Sybase</b>, <b>Teradata</b>, <b>Netezza</b>, and many more, through JDBC drivers. It provides a rich set of features for database management, development, and administration.<br><br>Key functionalities include a <b>SQL editor</b> with syntax highlighting and auto-completion, visual query builder, data manipulation tools (view, edit, delete), schema navigation, ER diagrams, data export/import, backup/restore capabilities, and a robust plugin architecture. <i>DBeaver</i> allows users to connect to multiple databases simultaneously, manage connections, execute SQL queries, browse data, create and alter database objects, and perform various administrative tasks efficiently. Its intuitive graphical user interface makes it accessible for both beginners and experienced database professionals, enhancing productivity across diverse database environments. The <b>dbeaver</b> command typically launches the GUI application, often from a DEB/RPM package installation or a standalone tarball.


title: CAVEATS
content:
<i>DBeaver</i> is primarily a Graphical User Interface (GUI) application; thus, its command-line options are limited compared to traditional CLI tools. Many underlying options are related to the <i>Eclipse</i> platform or Java Virtual Machine (JVM) settings. It requires a functioning Java Runtime Environment (JRE/JDK) to operate. Its behavior and availability of the <b>dbeaver</b> command may vary slightly depending on the installation method (e.g., DEB/RPM package, Snap, Flatpak, or direct tarball extraction). Script execution via <b>-run</b> expects specific <i>DBeaver</i> script formats or standard SQL files.


title: INSTALLATION
content:
<i>DBeaver</i> can be installed on Linux via official <b>DEB</b>/<b>RPM</b> packages, <b>Snap</b>, <b>Flatpak</b>, or by extracting a tarball. The <b>dbeaver</b> command typically becomes available in the system's <b>PATH</b> after a proper installation, allowing it to be invoked directly from the terminal.


title: CONFIGURATION
content:
User-specific configurations, including database connections, preferences, and workspaces, are typically stored in the user's home directory (e.g., <i>~/.dbeaver</i> on Linux systems, or within the specified workspace if <b>-data</b> is used). This allows for personalized setup and data management.


title: JDBC DRIVERS
content:
<i>DBeaver</i> relies on <b>JDBC</b> (Java Database Connectivity) drivers to establish connections with various databases. These drivers are often downloaded automatically by <i>DBeaver</i> itself when a new connection type is configured, or they can be configured manually if required for specific database versions or custom setups.


title: HISTORY
content:
<i>DBeaver</i> was initially released in 2011 by Serge Rider. It quickly gained popularity as an open-source alternative to commercial database tools, leveraging the <i>Eclipse</i> platform for its core. Over the years, it has continuously evolved, adding support for an ever-growing list of database types, enhancing its feature set (e.g., visual query builder, ER diagrams), and improving performance. Its strong community support and active development have solidified its position as a leading universal database management tool. The <b>dbeaver</b> command itself represents the executable wrapper for this Java-based application, evolving with new versions to integrate better with various Linux distributions and desktop environments.


title: PARAMETERS
content:
<b><i>(None)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;This script typically does not accept any command-line options or arguments. It performs its function without needing user input beyond its invocation.<br><br>


title: DESCRIPTION
content:
This utility script is an integral part of the D-Bus message bus system.<br>Its primary function is to <b>locate and remove</b> D-Bus <i>session socket files</i> that have become <i>stale</i> or <i>orphaned</i>. These files are typically found in transient directories like `<i>/tmp</i>` or `<i>XDG_RUNTIME_DIR</i>` (e.g., `<i>/run/user/<UID></i>`).<br>A socket is considered stale if the D-Bus session daemon that created it is no longer running, leaving behind an unusable file.<br>Removing these defunct sockets is crucial to prevent potential issues with new D-Bus sessions, such as `<b>dbus-daemon</b>` failing to bind to an address, or applications attempting to connect to a non-existent bus. It helps maintain a clean and functional D-Bus environment.<br>It is commonly invoked by system services or desktop environment startup scripts as a routine maintenance task.


title: CAVEATS
content:
<i>Permissions:</i> The script requires appropriate file system permissions to delete files in the directories where D-Bus session sockets are typically created (e.g., `<i>/tmp</i>`, `<i>/run/user/<UID></i>`).<br><i>Scope:</i> It primarily targets <b>session bus sockets</b>, which are created per user session. The system bus socket (e.g., `<i>/var/run/dbus/system_bus_socket</i>`) is managed differently and is not cleaned by this utility.<br><i>System Integration:</i> While helpful for system hygiene, its direct invocation by end-users is rare. It's usually part of system-level cleanup or startup routines managed by the operating system or desktop environment.


title: <B>PURPOSE AND RATIONALE</B>
content:
The script's main purpose is to prevent resource exhaustion (e.g., too many open files, address binding conflicts) that can arise from leftover D-Bus socket files. These files are crucial for inter-process communication within D-Bus, but if they persist after their associated `<b>dbus-daemon</b>` process has died, they become defunct and can hinder new session startups.


title: <B>TYPICAL INVOCATION</B>
content:
This utility is rarely invoked manually by an end-user. Instead, it is commonly executed by system-wide cleanup scripts (e.g., `<i>/etc/cron.daily/dbus-cleanup</i>`), during desktop environment startup (e.g., GNOME, KDE), or as part of a system's initialization sequence to ensure a clean D-Bus state for new sessions.


title: HISTORY
content:
<b>dbus-cleanup-sockets</b> is a supporting utility script that has been part of the D-Bus package since its early development. It was introduced to address the practical challenge of managing temporary socket files that could accumulate and cause issues, especially in environments where D-Bus sessions might not always terminate gracefully. Its evolution is tied to the D-Bus messaging system itself, serving a consistent role in maintaining system cleanliness and reliability rather than undergoing significant standalone development or feature additions.


title: PARAMETERS
content:
<b>--auto-syntax</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output shell syntax appropriate for the current shell (sh or csh).<br><br><b>--sh-syntax</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output shell syntax compatible with Bourne shell (sh, bash, zsh, etc.).<br><br><b>--csh-syntax</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output shell syntax compatible with C shell (csh, tcsh).<br><br><b>--config-file=<I>FILENAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the specified configuration file instead of the default session.conf.<br><br><b>--close-stderr</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Close standard error when forking the bus daemon. Useful for clean script execution.<br><br><b>--disable-unix-fd</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not allow passing of Unix file descriptors over the D-Bus connection.<br><br><b>--fork</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fork into the background after starting the D-Bus daemon. <b>dbus-launch</b> will not wait for the launched program.<br><br><b>--exit-with-session</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Kill the bus daemon when the <b>dbus-launch</b> process exits. Ensures proper cleanup.<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><b><I>PROGRAM</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The program to launch after starting or connecting to the D-Bus session bus. All subsequent arguments are passed to this program.<br><br>


title: DESCRIPTION
content:
<b>dbus-launch</b> is a utility primarily used to start a <i>D-Bus message bus</i> from a shell script, and optionally launch a program within the context of that bus session. Its main purpose is to ensure that a program has the necessary environment variables set (specifically <i>DBUS_SESSION_BUS_ADDRESS</i>) to connect to and communicate over the D-Bus session bus. This is particularly useful for applications not launched by a desktop environment or session manager that would normally handle D-Bus setup.<br><br>By using <b>dbus-launch</b>, a program can easily find and connect to the session bus, enabling inter-process communication with other D-Bus-aware applications. It can either start a new bus daemon or connect to an existing one if the environment variables are already defined, offering flexibility for various use cases. It acts as a bridge, ensuring that the application can participate in the D-Bus communication ecosystem.


title: CAVEATS
content:
<ul><li>Using <b>dbus-launch</b> without a program or without <i>--exit-with-session</i> can lead to lingering D-Bus daemon processes if not properly managed.</li><li>When launching a program, it's often crucial to use <i>--exit-with-session</i> if you want the bus daemon to terminate when the launched program exits, preventing orphaned processes.</li><li>It's generally not required for applications launched via a desktop environment (like GNOME or KDE) as the session manager typically handles D-Bus setup automatically.</li><li>Care should be taken when using <i>--fork</i> as <b>dbus-launch</b> will not wait for the launched program to finish, which might require additional process management in shell scripts.</li></ul>


title: ENVIRONMENT VARIABLES
content:
<b>dbus-launch</b> is primarily responsible for setting the <i>DBUS_SESSION_BUS_ADDRESS</i> environment variable. This variable contains the network address of the D-Bus session bus, allowing D-Bus-aware applications to connect to it. Without this variable, applications would not know how to find and communicate with the bus daemon.


title: SESSION MANAGEMENT VS. PROGRAM LAUNCH
content:
While <b>dbus-launch</b> can start a bus, for complete session management and a more robust D-Bus setup, especially for graphical sessions, <b>dbus-run-session</b>(1) is often preferred. <b>dbus-launch</b> is more suited for launching a single program in a D-Bus context or for simple script-based session initiation rather than managing a full desktop environment.


title: HISTORY
content:
The <i>D-Bus</i> inter-process communication system, of which <b>dbus-launch</b> is a core component, was initiated by the FreeDesktop.org project in the early 2000s (around 2002-2003). It was designed to provide a standardized way for applications to communicate on Unix-like operating systems. <b>dbus-launch</b> emerged as an essential utility alongside the main <b>dbus-daemon</b> to facilitate easy integration of applications with the D-Bus session bus, particularly in environments where a full-fledged session manager might not be present or where an application needs to explicitly control its D-Bus session. Its role has remained consistent over the years, serving as a reliable method to ensure D-Bus connectivity for standalone programs or custom shell scripts.


title: SYNOPSIS
content:
<i>dbus-monitor</i> [--system | --session] [--dest=NAME] [--address=ADDRESS] [--profile] [--monitor] [--version] [--help] [MATCHES]


title: PARAMETERS
content:
<b>--system</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Monitor the system bus.</i><br><br><b>--session</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Monitor the session bus (default if neither --system nor --session is specified, or if DBUS_SESSION_BUS_ADDRESS is set).</i><br><br><b>--dest=NAME</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Only show messages sent to the specified D-Bus unique or well-known name.</i><br><br><b>--address=ADDRESS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Connect to a specific D-Bus address instead of the default session or system bus.</i><br><br><b>--profile</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show a breakdown of time spent on D-Bus messages, typically used for performance profiling.</i><br><br><b>--monitor</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Become a 'monitor' on the bus. This often requires elevated privileges to see all messages.</i><br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Print the version of dbus-monitor and exit.</i><br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Print a help message and exit.</i><br><br><b>[MATCHES]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Optional D-Bus match rules to filter messages. For example: "type='signal',interface='org.freedesktop.DBus.Properties'". Multiple rules can be specified.</i><br><br>


title: DESCRIPTION
content:
<i>dbus-monitor</i> is a powerful command-line utility used to observe and debug D-Bus messages in real-time.<br><br>D-Bus is a crucial inter-process communication (IPC) mechanism widely adopted in Linux and other Unix-like operating systems, allowing applications and system components to communicate efficiently. <i>dbus-monitor</i> can display all messages sent on either the system bus (for system-wide services and privileged communication) or the session bus (for user-specific applications), making it an indispensable tool for debugging inter-process communication issues, understanding application behavior, or monitoring system events like hardware changes or network status updates.<br><br>It provides a raw, unfiltered view of the messages, including method calls (requests), signals (notifications), and errors (responses indicating failure), detailing critical information such as the sender, destination, object path, interface, member (method/signal name), and arguments. This deep insight helps developers and system administrators trace the flow of D-Bus communication, diagnose connectivity problems, or verify proper message exchanges.


title: CAVEATS
content:
<i><br><b>Permissions:</b> To monitor the system bus or all messages on the session bus, you typically need root privileges or to be part of a group that allows D-Bus monitoring. Without appropriate permissions, you might only see messages originating from your own user session.<br><br><b>Volume of Output:</b> On a busy system, <i>dbus-monitor</i> can produce a very large volume of output, making it difficult to find specific messages. Using match rules (`MATCHES`) is crucial for effective filtering.<br><br><b>Raw Output:</b> The output is raw and can be verbose. Understanding D-Bus message structure (type, sender, destination, path, interface, member, arguments) is necessary to interpret the results effectively.</i>


title: FILTERING MESSAGES
content:
<i>Using match rules is fundamental for effective monitoring. For example, to only see signals related to NetworkManager, you might use <b>dbus-monitor --system "type='signal',interface='org.freedesktop.NetworkManager'"</b>. You can specify multiple match rules to narrow down the output even further.</i>


title: INTERPRETING OUTPUT
content:
<i>Messages are typically displayed with their type (e.g., "signal", "method call", "error"), sender, destination, object path, interface, member, and arguments. Pay attention to the `serial` numbers to trace requests and responses, and `sender` and `destination` to understand communication flow.</i>


title: HISTORY
content:
<i>D-Bus was developed by the freedesktop.org project to standardize inter-process communication on Linux and other Unix-like systems. It emerged as a solution for desktop environments (like GNOME and KDE) to communicate with system services and each other, replacing older, disparate IPC mechanisms. <i>dbus-monitor</i> was created as a fundamental tool within the D-Bus ecosystem to provide visibility into this communication, essential for debugging and development from the early days of D-Bus's adoption (around 2003-2004). Its core functionality has remained consistent, reflecting its foundational role.</i>


title: SYNOPSIS
content:
<b>dbus-send</b> [<i>OPTIONS</i>] <i>OBJECT_PATH INTERFACE.MEMBER</i> [<i>ARGUMENTS...</i>]<br><br><i>Common Usage Examples:</i><br><b>dbus-send</b> --session --print-reply --dest=<i>org.freedesktop.DBus</i> /org/freedesktop/DBus <i>org.freedesktop.DBus.ListNames</i><br><b>dbus-send</b> --system --type=signal --dest=<i>com.example.Service</i> /com/example/Object <i>com.example.Interface.Event</i> string:"Hello"


title: PARAMETERS
content:
<b>--session</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <b>dbus-send</b> to connect to the D-Bus session bus. This is the default if no bus type is specified.<br><br><b>--system</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <b>dbus-send</b> to connect to the D-Bus system bus. This bus is typically used for system-wide services.<br><br><b>--address=<i>ADDRESS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a custom D-Bus address to connect to, overriding <i>--session</i> or <i>--system</i>. Useful for connecting to non-standard or private D-Bus instances.<br><br><b>--print-reply</b><br>&nbsp;&nbsp;&nbsp;&nbsp;For method calls, this option makes <b>dbus-send</b> block and wait for a reply message from the service, then print its contents to standard output. If omitted, method calls are fire-and-forget.<br><br><b>--dest=<i>NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The well-known bus name of the D-Bus service that should receive the message (e.g., <i>org.freedesktop.DBus</i>). This is a mandatory component for method calls and signals.<br><br><b>--type=<i>MESSAGE_TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the type of D-Bus message to send. Defaults to <i>method_call</i>. Other common types include <i>signal</i>, <i>method_return</i>, and <i>error</i>.<br><br><b><i>OBJECT_PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The D-Bus object path on the destination service to which the message is directed (e.g., <i>/org/freedesktop/DBus</i>).<br><br><b><i>INTERFACE.MEMBER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The D-Bus interface and member (method or signal) name to be invoked or emitted (e.g., <i>org.freedesktop.DBus.ListNames</i>). The format is <i>InterfaceName.MemberName</i>.<br><br><b><i>TYPE:VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Arguments to the method call or signal. Each argument must be specified as a <i>type:value</i> pair, where <i>type</i> is a D-Bus type code (e.g., <i>string</i>, <i>int32</i>, <i>boolean</i>, <i>double</i>) and <i>value</i> is the corresponding data. Multiple arguments are space-separated.<br>Examples: <i>string:"hello"</i>, <i>int32:123</i>, <i>boolean:true</i>.<br><br>


title: DESCRIPTION
content:
<b>dbus-send</b> is a command-line utility used to send messages to a D-Bus message bus. D-Bus is a robust system for inter-process communication (IPC), enabling applications to communicate by exposing objects and methods, or by emitting and listening for signals. <b>dbus-send</b> provides a direct interface for interacting with D-Bus services from the shell, making it invaluable for scripting, debugging, and testing D-Bus functionality. Users can specify the target bus (session or system), the destination service name, the object path, the interface, the method to call or signal to emit, and arguments with their specific D-Bus types. Its simplicity makes it a quick tool for one-off interactions or integration into shell scripts.


title: CAVEATS
content:
<ul><li><i>Complex Type Handling:</i> Specifying complex D-Bus type signatures (e.g., arrays, structs, dictionaries) can be cumbersome and error-prone on the command line due to verbose syntax.</li><li><i>Limited Introspection:</i> While useful for basic interaction, <b>dbus-send</b> does not provide built-in introspection capabilities to discover available methods or signals. Tools like <b>busctl</b> or <b>gdbus</b> are better suited for this.</li><li><i>Permission Requirements:</i> Correct D-Bus security policies must be in place for <b>dbus-send</b> to successfully communicate with services. Permission denied errors are common if policies are not configured correctly.</li><li><i>Synchronous vs. Asynchronous:</i> Method calls are asynchronous by default; use <i>--print-reply</i> to make them synchronous. Signals are always asynchronous.</li></ul>


title: COMMON USE CASES
content:
<b>dbus-send</b> is frequently used for:<br><ul><li><i>Debugging and Testing:</i> Directly invoking methods on a D-Bus service during development or troubleshooting.</li><li><i>System Administration:</i> Scripting interactions with system services exposed via D-Bus, such as NetworkManager, UDisks, systemd, or PolicyKit.</li><li><i>Custom Signaling:</i> Emitting custom signals for other applications to receive, useful in event-driven scripting.</li><li><i>Connectivity Checks:</i> Verifying D-Bus service availability and basic functionality.</li></ul>


title: D-BUS TYPE SYSTEM
content:
Successful use of <b>dbus-send</b> relies on understanding the D-Bus type system. Arguments must be prefixed with their D-Bus type (e.g., <i>string:"hello"</i>, <i>int32:123</i>, <i>boolean:true</i>, <i>double:3.14</i>). For aggregates like arrays, structs, and dictionaries, specific syntax is required (e.g., <i>array:string:"item1","item2"</i>, <i>struct:int32:1,string:"name"</i>). Incorrect type specification is a common source of errors and will lead to D-Bus errors.


title: HISTORY
content:
D-Bus was conceived as part of the freedesktop.org project, with its initial release around 2002-2003, aiming to standardize inter-process communication for Linux desktop environments (GNOME, KDE) and later for system services. <b>dbus-send</b> was included as one of the fundamental command-line utilities within the <b>dbus</b> package. It was designed to provide a straightforward, scriptable interface for interacting with D-Bus services, proving invaluable for system administrators, developers, and power users for debugging, testing, and automating D-Bus interactions from the command line from the early days of D-Bus adoption.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show help message and exit.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show version number and exit.<br><br><b>--ensure[=FILENAME]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If <i>FILENAME</i> exists, its contents are printed to standard output. Otherwise, a new UUID is generated, stored in <i>FILENAME</i>, and then printed. If <i>FILENAME</i> is omitted, it defaults to <i>/var/lib/dbus/machine-id</i>.<br><br><b>--get[=FILENAME]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If <i>FILENAME</i> exists, its contents are printed to standard output. Otherwise, the command exits with an error. If <i>FILENAME</i> is omitted, it defaults to <i>/var/lib/dbus/machine-id</i>.<br><br><b>--create-machine-id</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Deprecated.</i> This option is equivalent to `dbus-uuidgen --ensure`. It was used to create or ensure the existence of the machine ID file.<br><br><b>--template</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Deprecated.</i> This option previously output a template for the machine ID file, which was just a newly generated UUID. Its functionality is now covered by simply running `dbus-uuidgen` without any options to generate a new UUID and print it to standard output.<br><br>


title: DESCRIPTION
content:
dbus-uuidgen is a fundamental utility within the D-Bus message bus system, primarily used to generate or retrieve a unique machine identifier. This identifier is a Universally Unique Identifier (UUID), specifically a version 4 UUID, which is randomly generated. The generated UUID is typically stored in the file <i>/var/lib/dbus/machine-id</i>.<br><br>The D-Bus daemon and various D-Bus applications rely on this stable machine ID to identify the local system uniquely, especially in scenarios involving network-transparent communication or when maintaining consistent state across reboots. It plays a vital role in ensuring that D-Bus instances can correctly identify their host and interact properly.<br><br>If the <i>/var/lib/dbus/machine-id</i> file does not exist, `dbus-uuidgen` can be used to create it with a new UUID. If the file already exists, the command can retrieve and print its existing content. This tool is often run automatically during system installation or when setting up the D-Bus environment to ensure a unique identifier is present.


title: CAVEATS
content:
The `--create-machine-id` and `--template` options are deprecated; users should prefer `--ensure` or simply running `dbus-uuidgen` for generating a new UUID.<br><br>The machine ID (typically in <i>/var/lib/dbus/machine-id</i>) should remain constant for a given system. Changing it frequently can lead to issues with D-Bus applications and services that rely on a stable machine identity.<br><br>The <i>/var/lib/dbus/machine-id</i> file must have appropriate permissions (typically readable by the `dbus` user/group, such as 0444 or 0644) to ensure proper D-Bus functionality and security.


title: <B>UUID FORMAT</B>
content:
The UUID generated by `dbus-uuidgen` is a standard version 4 UUID (randomly generated) as specified in RFC 4122. It consists of 32 hexadecimal digits, displayed in 5 groups separated by hyphens (e.g., `xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx`), where the '4' indicates the UUID version and the 'y' indicates the variant.


title: HISTORY
content:
`dbus-uuidgen` has been an integral part of the D-Bus package since its early days, facilitating the setup and management of unique machine identifiers essential for inter-process communication within the D-Bus architecture. Its core functionality of generating and retrieving UUIDs has remained consistent over time, though specific options have been deprecated in favor of more consistent naming conventions or simplified usage.


title: SYNOPSIS
content:
<b>dbwrap_tool</b> [<i>global-options</i>] <i>subcommand</i> [<i>subcommand-options</i>] [<i>arguments</i>]


title: PARAMETERS
content:
<b><b>--dbpath</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the absolute path to the NSS database directory. This option is crucial for most operations.<br><br><b><b>--pwdfile</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to a file containing the database password.<br><br><b><b>--password</b> <i>&lt;password&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the database password directly on the command line. Use with caution as it's less secure than a password file.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message for the command or the specified subcommand.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, providing more detailed information about the operation.<br><br>


title: DESCRIPTION
content:
The <b>dbwrap_tool</b> is a specialized command-line utility used within the Dogtag Certificate System (PKI) to interact with its internal database. This database, often referred to as the 'dbwrap' database, is an abstraction layer built on top of an <I>NSS (Network Security Services)</I> database. <br><br>It is primarily used by administrators of PKI instances (like those found in <I>FreeIPA</I> deployments) to manage cryptographic objects such as certificates, private keys, and trust anchors directly within the PKI's security module database. Common operations include listing, importing, exporting, and deleting certificates or keys, as well as managing their trust settings. Unlike generic database tools, <b>dbwrap_tool</b> is tailored specifically for the structure and requirements of the Dogtag PKI's cryptographic store, making it a critical tool for PKI maintenance and troubleshooting.


title: CAVEATS
content:
<b>dbwrap_tool</b> is not a general-purpose database management tool. It is specifically designed for the Dogtag Certificate System's internal NSS database. <br><br>Direct manipulation of the PKI database using this tool should only be performed by experienced administrators, as incorrect operations can compromise the integrity and security of the PKI instance. Ensure proper backups are in place before making significant changes.


title: KEY SUBCOMMANDS
content:
While general options exist, <b>dbwrap_tool</b> primarily operates through subcommands, each with its own specific options and arguments. Common subcommands include: <br><i>status</i> (check database status), <br><i>list</i> (enumerate certificates, keys, or objects), <br><i>import</i> (add new cryptographic material), <br><i>export</i> (retrieve existing material), <br><i>delete</i> (remove entries), and <br><i>modify</i> (change properties like trust flags). <br><br>To get help on a specific subcommand, use <code><b>dbwrap_tool</b> <i>subcommand</i> <b>--help</b></code>.


title: HISTORY
content:
The <b>dbwrap_tool</b> is an integral part of the Dogtag Certificate System, an open-source PKI solution that has been under development for many years, evolving from the Mozilla NSS libraries. Its usage is tightly coupled with deployments of Dogtag PKI, notably as the underlying PKI component in <I>FreeIPA</I>, where it manages the cryptographic material for certificates, keys, and trust policies.


title: PARAMETERS
content:
<b>-c <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes dbx commands from the specified <i>file</i> before accepting user input.<br><br><b>-I <i>directory</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds <i>directory</i> to the list of directories dbx searches for source files.<br><br><b>-P <i>process_id</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attaches dbx to a running program identified by <i>process_id</i>.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the initial dbx banner and copyright message.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the dbx version information and exits.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the <i>executable</i> immediately upon dbx startup.<br><br><b><i>executable</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the program to be debugged. This program must be compiled with debugging information (e.g., using `gcc -g`).<br><br><b><i>corefile</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of a core dump file to analyze post-mortem.<br><br><b><i>process_id</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The process ID of a running program to attach to.<br><br>


title: DESCRIPTION
content:
dbx is a command-line symbolic debugger used primarily for C, C++, and Fortran programs. Originating from UC Berkeley, it became a prominent debugging tool, especially on Unix-like operating systems, most notably Sun Microsystems' Solaris. It allows developers to control program execution, inspect variables, set breakpoints, and trace program flow to identify and fix bugs.<br><br>While dbx provides a comprehensive set of debugging features, its prevalence on modern Linux distributions is limited. The open-source GNU Debugger (gdb) has largely superseded it as the standard debugger for most Linux development environments due to its wide availability, active development, and integration with the GNU toolchain. However, dbx might still be encountered in legacy systems, environments using specific commercial compilers (like Oracle/Sun Studio), or specialized embedded systems. Its command set is generally similar to gdb, making the transition for experienced users relatively straightforward, though specific syntax and capabilities may differ.


title: CAVEATS
content:
dbx is not a standard utility on most modern Linux distributions. Its primary use is often tied to specific commercial Unix compilers (like Sun Studio/Oracle Developer Studio) or legacy systems. For general Linux development, gdb is the widely adopted and recommended debugger. Compatibility and feature sets can vary significantly between dbx versions.


title: COMMON <B>DBX</B> COMMANDS
content:
<ul><li><b>run</b>: Starts the execution of the program.</li><li><b>cont</b>: Continues execution from the current point.</li><li><b>next</b>: Executes the next source line, stepping over function calls.</li><li><b>step</b>: Executes the next source line, stepping into function calls.</li><li><b>stop at <i>line_number</i></b>: Sets a breakpoint at the specified line number.</li><li><b>stop in <i>function_name</i></b>: Sets a breakpoint at the entry point of a function.</li><li><b>print <i>variable</i></b>: Displays the value of a variable.</li><li><b>where</b> or <b>trace</b>: Displays the current stack trace.</li><li><b>list</b>: Displays source code around the current execution point.</li><li><b>quit</b>: Exits dbx.</li></ul>


title: DEBUGGING WORKFLOW
content:
<ol><li>Compile your program with debugging information (e.g., `gcc -g myprogram.c -o myprogram`).</li><li>Start dbx: `dbx myprogram`.</li><li>Set breakpoints (e.g., `stop at main.c:25`).</li><li>Run the program (`run`).</li><li>When a breakpoint is hit, inspect variables (`print myvar`), step through code (`next`, `step`), or view the call stack (`where`).</li><li>Continue execution (`cont`) or quit (`quit`).</li></ol>


title: HISTORY
content:
dbx originated at the University of California, Berkeley, in the late 1970s and early 1980s as part of the BSD Unix development. It quickly gained popularity as a robust symbolic debugger. Sun Microsystems adopted and further developed dbx as a core component of its SunOS and later Solaris operating systems and their associated developer toolchains (SunPro, later Sun Studio, now Oracle Developer Studio). While it remained prominent in the Solaris ecosystem, its adoption on Linux has been limited, largely due to the rise and widespread adoption of the open-source gdb by the GNU project, which offered similar capabilities and was freely available alongside the GCC compiler.


title: DESCRIPTION
content:
<b>dc</b> (Desk Calculator) is a powerful and versatile reverse-polish notation (RPN) calculator included in Unix-like operating systems. Unlike traditional infix calculators, <b>dc</b> requires operands to be entered before the operator, pushing numbers onto a stack and then applying operations to the top elements. This stack-based approach allows for complex computations without the need for parentheses.<br><br>A key feature of <b>dc</b> is its support for arbitrary precision arithmetic, meaning it can handle numbers of any size, limited only by available memory. This makes it suitable for scientific calculations and financial modeling where high precision is crucial.<br><br>Beyond basic arithmetic (+, -, *, /), <b>dc</b> offers extensive capabilities including stack manipulation (duplication, swapping), register storage for variables, input/output operations, and macro definition for scripting complex sequences of commands. It operates by reading commands from standard input or specified files, making it highly scriptable and often used as a backend for the <b>bc</b> command, which provides a more familiar infix interface.


title: CAVEATS
content:
The use of Reverse Polish Notation (RPN) can be counter-intuitive for users accustomed to infix notation, requiring a different way of thinking about calculations.<br><br>Debugging complex <b>dc</b> scripts or macros can be challenging due to its non-interactive nature (unless explicitly managed) and the stack-based operations, which can be hard to trace without careful logging.


title: KEY FEATURES AND OPERATIONS
content:
<b>dc</b>'s power comes from its extensive set of single-character commands. These include:<br><b>Arithmetic:</b> <i>+</i>, <i>-</i>, <i>*</i>, <i>/</i>, <i>%</i> (modulo), <i>^</i> (exponentiation), <i>~</i> (division with remainder).<br><b>Stack Manipulation:</b> <i>p</i> (print top), <i>n</i> (print and pop), <i>f</i> (print stack), <i>d</i> (duplicate), <i>r</i> (reverse top two).<br><b>Registers:</b> <i>s<i>x</i></i> (store top of stack into register <i>x</i>), <i>l<i>x</i></i> (load register <i>x</i> onto stack). Registers are single lowercase letters.<br><b>Input/Output:</b> <i>?</i> (read line from stdin), <i>k</i> (set input base), <i>o</i> (set output base), <i>P</i> (print top as ASCII string).<br><b>Macros and Control Flow:</b> <i>[string]</i> (define macro), <i>x</i> (execute macro), <i>=<i>x</i></i> (conditional execution if equal), <i>&lt;<i>x</i></i> (conditional if less than).


title: HISTORY
content:
<b>dc</b> is one of the oldest Unix utilities, dating back to the first versions of Unix developed at Bell Labs in the early 1970s. It was created by Robert Morris and Lorinda Cherry. Its arbitrary precision arithmetic capabilities were revolutionary for its time, providing a powerful tool for complex mathematical computations within the Unix environment. It was also designed to serve as the backend for <b>bc</b>, allowing <b>bc</b> to inherit its precision and stack-based power while offering a more conventional infix syntax to users. Its core design has remained remarkably consistent over decades.


title: SEE ALSO
content:
<b>bc(1)</b> - An arbitrary precision calculator language (often uses <b>dc</b> as a backend)., <b>calc(1)</b> - A more user-friendly interactive calculator., <b>expr(1)</b> - Evaluate expressions in the shell.


title: PARAMETERS
content:
<b>if=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the input file (or device) to read from.<br><br><b>of=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output file (or device) to write to.<br><br><b>bs=BYTES</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the block size in bytes for both input and output. Reads and writes BYTES bytes at a time.<br><br><b>count=BLOCKS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies only BLOCKS input blocks.<br><br><b>skip=BLOCKS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips BLOCKS input blocks before starting to copy.<br><br><b>seek=BLOCKS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips BLOCKS output blocks before starting to write.<br><br><b>hash=ALGORITHM</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the hash algorithm(s) to compute on the fly (e.g., <i>md5</i>, <i>sha1</i>, <i>sha256</i>, <i>sha512</i>). Multiple algorithms can be specified separated by commas.<br><br><b>hashlog=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Logs the computed hash results to the specified FILE.<br><br><b>hashwindow=BYTES</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the block size for hash calculation, allowing hashes of portions of the input.<br><br><b>hashformat=FORMAT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the output format of hash logs (e.g., <i>md5sum</i>, <i>sha1sum</i>, <i>raw</i>).<br><br><b>statusinterval=SECONDS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides status updates (bytes copied, elapsed time, transfer rate) every SECONDS.<br><br><b>errlog=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Logs read errors and their locations (bad blocks) to the specified FILE.<br><br><b>abortonerror=on/off</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls whether <b>dcfldd</b> aborts upon encountering read errors. Default is <i>off</i> (continue on error).<br><br><b>mtef=on/off</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables/disables Multi-Target Error Flagging, indicating if an error occurred for a specific output file when writing to multiple destinations.<br><br><b>map=on/off</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a 'map' file that indicates successful and failed reads, useful for damaged media.<br><br><b>wipesig=SIGNATURE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wipes the output with a repeating byte sequence defined by SIGNATURE.<br><br><b>wipebyte=BYTE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wipes the output with a single specified BYTE.<br><br><b>noerror</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continues after read errors (similar to <i>conv=noerror</i>).<br><br><b>sync</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pads every input block with NULs to the specified <i>bs</i> size (similar to <i>conv=sync</i>).<br><br><b>conv=notrunc</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not truncate the output file; preserve existing data outside the written area.<br><br><b>conv=nocreat</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not create the output file; it must already exist.<br><br>


title: DESCRIPTION
content:
<b>dcfldd</b> is a modified version of the standard Unix/Linux <b>dd</b> command, specifically designed for digital forensics and data acquisition. While <b>dd</b> is a powerful tool for low-level copying, <b>dcfldd</b> extends its capabilities to address crucial requirements in forensic investigations. Its primary enhancements include on-the-fly hashing (supporting MD5, SHA1, SHA256, SHA512), which ensures data integrity by allowing verification of the acquired image against the source without a separate hashing pass.<br><br>It also provides detailed progress reporting, estimates of completion time, and improved error handling, such as logging bad blocks and continuing acquisition despite read errors. Furthermore, <b>dcfldd</b> can wipe disks securely and verify the wiping process. These features make <b>dcfldd</b> an indispensable tool for forensic examiners, enabling them to create forensically sound images of storage media while maintaining an auditable chain of custody.


title: CAVEATS
content:
While highly effective, <b>dcfldd</b> can be slower than plain <b>dd</b> due to the overhead of on-the-fly hashing and enhanced error handling. Users must exercise extreme caution when specifying input (<i>if</i>) and output (<i>of</i>) files, as incorrect usage can lead to irreversible data loss on the target device. Although still widely used in digital forensics, its development has not been as active as the core <b>dd</b> utility in recent years.


title: <I>FORENSIC SOUNDNESS AND DATA INTEGRITY</I>
content:
One of the most significant advantages of <i>dcfldd</i> is its ability to calculate cryptographic hashes (like MD5 or SHA-1) of the source data simultaneously during the copying process. This 'on-the-fly' hashing ensures that the acquired image is an exact, unaltered replica of the original source, a fundamental requirement for maintaining the integrity and admissibility of digital evidence in legal proceedings. The hash values can be logged to a separate file, providing an auditable record of the acquisition.


title: <I>ENHANCED ERROR HANDLING AND REPORTING</I>
content:
Unlike standard <i>dd</i>, which might halt upon encountering read errors, <i>dcfldd</i> offers more robust error handling capabilities. It can be configured to continue copying even when bad blocks are encountered, logging the locations of these errors to a specified file. This feature is crucial when dealing with damaged or failing storage media, allowing forensic examiners to maximize data recovery while documenting any unreadable sectors.


title: HISTORY
content:
<i>dcfldd</i> was developed by the Digital Forensics Lab at the DoD Cyber Crime Center (DC3) to provide enhanced capabilities for digital evidence acquisition beyond what the standard <i>dd</i> command offered. Its primary goal was to ensure data integrity during imaging processes by integrating features like on-the-fly hashing and improved error handling, which are critical in forensic investigations. Since its initial release, it has become a staple tool in the digital forensics community, widely adopted for creating forensically sound copies of storage media.


title: SYNOPSIS
content:
<i><b>dcode</b></i> [<i>OPTIONS</i>] [<i>INPUT_STRING</i>]<br><i><b>dcode</b></i> [<i>OPTIONS</i>] <i>-f FILE</i>


title: PARAMETERS
content:
<b><i><b>-t</b> TYPE</i>, <i><b>--type</b> TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the encoding type to decode from. Common types might include <i>base64</i>, <i>url</i>, <i>hex</i>, <i>rot13</i>, <i>ascii</i>, <i>utf8</i>, <i>json_escape</i>.<br><br><b><i><b>-i</b> STRING</i>, <i><b>--input</b> STRING</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the input string directly on the command line for decoding.<br><br><b><i><b>-f</b> FILE</i>, <i><b>--file</b> FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an input file containing the data to be decoded. If not provided and <i>INPUT_STRING</i> is also absent, <i><b>dcode</b></i> might read from standard input (<i>stdin</i>).<br><br><b><i><b>-o</b> FILE</i>, <i><b>--output</b> FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an output file to write the decoded data to, instead of standard output (<i>stdout</i>).<br><br><b><i><b>-h</b></i>, <i><b>--help</b></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and their usage.<br><br><b><i><b>-v</b></i>, <i><b>--version</b></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version information for the <i><b>dcode</b></i> utility.<br><br>


title: DESCRIPTION
content:
<i><b>dcode</b></i> (a hypothetical or custom command) is a utility designed to convert encoded data back into its original, readable format. It aims to support a multitude of common encoding schemes, including but not limited to Base64, URL encoding, hexadecimal, ROT13, and various character set encodings. Its primary use case is for forensic analysis, debugging, and general data manipulation where information has been deliberately or incidentally encoded. Users can typically provide input directly as a string, or specify an input file for decoding. The decoded output can then be displayed on standard output or redirected to a specified file. The versatility of such a tool lies in its ability to quickly reverse common transformations applied to data in diverse contexts, from web requests to binary data streams.


title: CAVEATS
content:
<i><b>dcode</b></i> is <i>not</i> a standard Linux command found in most default distributions. Its existence and functionality depend entirely on custom scripts, specific third-party tool installations, or specialized environments. Therefore, its exact behavior, supported encoding types, and command-line options can vary significantly. Users should verify its presence and manual for their specific system. Relying on <i><b>dcode</b></i> for critical operations without understanding its source and implementation is not advisable. Improper input or unsupported encoding types may lead to errors or unexpected output.


title: <I>COMMON USAGE SCENARIOS</I>
content:
<i><b>dcode</b></i> would be highly valuable in scenarios such as:<br>- <i>Web Development</i>: Decoding URL-encoded query parameters or POST data.<br>- <i>Security Analysis</i>: Unpacking Base64-encoded strings from logs, network captures, or malware samples.<br>- <i>Data Forensics</i>: Reversing obfuscated text or binary data from disk images.<br>- <i>Scripting</i>: Integrating into automated workflows for data transformation.


title: <I>EXTENSIBILITY</I>
content:
A robust implementation of <i><b>dcode</b></i> would ideally be extensible, allowing users or developers to add support for new or custom encoding types through plugins or configuration files, enhancing its utility in diverse technical environments.


title: HISTORY
content:
As <i><b>dcode</b></i> is not a standard, universally distributed command, it does not have a formal, well-documented history like core Linux utilities. Instances of <i><b>dcode</b></i> are typically custom-written shell scripts or small programs developed by individuals or specific projects to fulfill particular decoding needs. Its "history" is therefore fragmented, consisting of countless independent implementations tailored for specific tasks or environments. It often serves as a quick utility for developers, security analysts, or data engineers who need to frequently decode specific data formats without resorting to more complex programming solutions or online tools.


title: SEE ALSO
content:
<i><b>base64</b></i>(1), <i><b>uuencode</b></i>(1), <i><b>uudecode</b></i>(1), <i><b>xxd</b></i>(1), <i><b>hexdump</b></i>(1), <i><b>python</b></i>(1)


title: SYNOPSIS
content:
<b>dconf</b> read <i>KEY</i><br><b>dconf</b> [--profile <i>PROFILE</i>] [--database <i>DATABASE</i>] read <i>KEY</i>


title: PARAMETERS
content:
<b><i>KEY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full path to the configuration key to be read (e.g., <i>/org/gnome/desktop/interface/text-scaling-factor/</i>). This is a required argument.<br><br><b>--profile <i>PROFILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative dconf profile to use, overriding the default.<br><br><b>--database <i>DATABASE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a particular database within the active profile to read from. Used in conjunction with --profile or implicitly with the default profile.<br><br><b>--noprofile</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the use of any dconf profile, typically causing operations to default to the user database. Useful for specific debugging or isolated operations.<br><br>


title: DESCRIPTION
content:
The <b>dconf-read</b> command is a utility for interacting with the dconf configuration system. It allows users and scripts to retrieve the value associated with a specific key from the dconf database. Dconf serves as a low-level configuration system for GNOME and other applications, storing settings in a binary format. <b>dconf-read</b> is typically used to inspect current settings, often as part of troubleshooting or scripting configuration backups. It complements <b>dconf-write</b> for setting values and <b>dconf-list</b> for enumerating keys within a path. The dconf system is designed for speed and persistence, and <b>dconf-read</b> provides direct access to these stored preferences. Its output is the raw GVariant representation of the key's value.


title: CAVEATS
content:
<b>Permissions:</b> Reading certain system-wide or protected keys might require elevated privileges or the correct user context.<br><b>Non-existent Keys:</b> If the specified <i>KEY</i> does not exist, <b>dconf-read</b> will typically return an empty string or an error, depending on the dconf version and context.<br><b>Key Path Format:</b> Keys must always be absolute paths, beginning with a forward slash (<i>/</i>).<br><b>Output Format:</b> The output is the raw GVariant string representation, which might require further parsing in scripts, especially for complex types like arrays or dictionaries.


title: KEY PATH STRUCTURE
content:
Dconf keys adhere to a hierarchical path structure, analogous to a file system. Each key represents a unique setting and starts with a leading slash (e.g., <i>/org/gnome/desktop/interface/color-scheme</i>). Understanding this structure is fundamental for accurately specifying keys to read.


title: VALUE TYPES AND REPRESENTATION
content:
The values returned by <b>dconf-read</b> are presented in a GVariant string representation. This means boolean values appear as <i>true</i> or <i>false</i>, strings are enclosed in single quotes (e.g., <i>'hello'</i>), numbers are unquoted, and arrays are represented with square brackets (e.g., <i>['item1', 'item2']</i>). This format ensures consistent and machine-readable output.


title: HISTORY
content:
Dconf was introduced as the default configuration system for GNOME 3, replacing the older GConf. Its development focused on performance, atomic updates, and a simpler data model, making it more efficient for desktop environments. <b>dconf-read</b> is an integral part of the core <b>dconf</b> utility, providing direct command-line access to the underlying binary database. Its utility became prominent with the widespread adoption of GNOME 3, offering a straightforward way to inspect configuration settings.


title: SYNOPSIS
content:
<br><b>dconf reset</b> <i>PATH</i><br><b>dconf reset</b> <i>--force</i><br><b>dconf reset</b> <i>--gsettings-of SCHEMA</i>


title: PARAMETERS
content:
<b><i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Mandatory for targeted reset</I>.<br>Specifies the DConf path (e.g., <I>/org/gnome/desktop/interface/</I> or <I>/org/gnome/desktop/interface/font-name</I>) to reset. If a directory path is given, all keys under it are reset. If a key path, only that specific key is reset.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Resets entire user database</I>.<br>Resets the entire user DConf database to its default values. This is an extremely destructive operation, removing all personalized settings stored in DConf, and should be used with extreme caution.<br><br><b><b>--gsettings-of</b> <i>SCHEMA</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Resets settings for a specific GSettings schema</I>.<br>Resets all keys associated with the specified GSettings schema (e.g., <I>org.gnome.desktop.interface</I>). This offers a more granular way to reset than <I>--force</I> but broader than a single <I>PATH</I>, affecting all settings defined by that schema.<br><br>


title: DESCRIPTION
content:
The <b>dconf-reset</b> command is a powerful utility within the DConf configuration system, primarily used in GNOME and other GTK+-based desktop environments. DConf acts as a low-level configuration system, storing settings for various applications in a binary database, often found at <I>~/.config/dconf/user</I>.<br><br>This command's core function is to revert specific DConf keys, sub-paths, or even the entire user DConf database back to their default values. This is particularly useful for troubleshooting when application behavior becomes erratic due to corrupted or misconfigured settings. It can also serve to quickly undo extensive customizations, restoring a clean slate.<br><br>While highly effective, <b>dconf-reset</b> should be used with caution, as it can lead to the loss of personalized settings. Users should understand the scope of the reset operation—whether it targets a single key, a directory of keys, a specific GSettings schema, or the entire database—to avoid unintended data loss.


title: CAVEATS
content:
<b>dconf-reset</b> is a powerful command that performs irreversible actions, especially when using the <I>--force</I> option. This can lead to the loss of all personalized settings for applications utilizing DConf, requiring manual re-configuration.<br><br>It's important to note that <b>dconf-reset</b> only affects configuration settings stored within the DConf database. It does not alter traditional configuration files located elsewhere (e.g., in <I>~/.config/</I> or <I>/etc/</I> that are not DConf-managed).<br><br>Running applications might not immediately reflect changes after a reset; a restart of the affected application or even a desktop session logout/login might be necessary for the new default settings to take effect.


title: TARGET OF OPERATION
content:
<b>dconf-reset</b> operates exclusively on the user's DConf database, which is typically stored as a binary file at <I>~/.config/dconf/user</I>. It does not affect system-wide default settings (which are typically defined by system administrators or packages) or other users' configurations, unless executed with elevated privileges or on behalf of another user.


title: IMPACT ON RUNNING APPLICATIONS
content:
When settings are reset using <b>dconf-reset</b>, applications currently running and utilizing those DConf settings may not immediately pick up the changes. This is because applications often load their configurations at startup or periodically. For the changes to take full effect, it might be necessary to restart the specific application whose settings were reset, or in some cases, even log out and back in to your desktop session for system-wide DConf changes.


title: HISTORY
content:
DConf was developed as a successor to GConf, primarily for the GNOME 3 desktop environment, aiming for a simpler, more performant, and more robust configuration system. The <I>dconf-reset</I> command is an integral part of the <I>dconf</I> utility suite, designed to provide a standardized way to manage and revert configurations within this new system. Its development mirrors the evolution of GNOME's configuration philosophy towards a more unified and centralized approach.


title: DESCRIPTION
content:
<i><b>dconf-service</b></i> is the D-Bus service that provides the backend for the <I>dconf</I> configuration system.<br>It enables applications to efficiently read and write configuration settings stored in the <I>dconf</I> database. The service manages concurrent access to the database, provides change notifications to applications when settings are modified, and handles user-specific configuration data.<br>It is a fundamental component of the GNOME desktop environment's configuration management, acting as the low-level storage for settings that are typically accessed through the higher-level <I>GSettings</I> API.<br>Unlike most commands, <i><b>dconf-service</b></i> is not intended for direct manual invocation by users; instead, it is automatically started via D-Bus activation whenever an application requests a <I>dconf</I> setting.


title: CAVEATS
content:
<i><b>dconf-service</b></i> is a system-level D-Bus service and is not meant for direct user interaction or manual startup. It is typically managed by D-Bus activation and <I>systemd --user</I>.<br>Improper termination or interference with this service can disrupt application configuration and lead to unexpected behavior for applications relying on <I>dconf</I> and <I>GSettings</I>.


title: D-BUS ACTIVATION
content:
<i><b>dconf-service</b></i> is typically started on demand through D-Bus activation. When an application attempts to interact with <I>dconf</I> (e.g., read or write a setting), D-Bus automatically launches <i><b>dconf-service</b></i> if it's not already running. This 'lazy' activation saves system resources.


title: GSETTINGS BACKEND
content:
The <I>GSettings</I> API, part of the <I>GLib</I> library, is the high-level interface that applications use to access and manage their settings. <i><b>dconf-service</b></i> serves as the primary backend for <I>GSettings</I>, translating <I>GSettings</I> requests into operations on the <I>dconf</I> database. This abstraction simplifies configuration management for developers.


title: DATABASE LOCATION
content:
User-specific <I>dconf</I> settings are commonly stored in a binary database file, typically located at <I>~/.config/dconf/user</I>. The <i><b>dconf-service</b></i> manages access to this file, ensuring data integrity and consistency.


title: HISTORY
content:
The <I>dconf</I> configuration system, along with its service <i><b>dconf-service</b></i>, emerged as a modern replacement for the older <I>GConf</I> system, primarily within the GNOME project.<br>Developed to offer improved performance, simplicity, and a more robust design, <I>dconf</I> utilizes a binary database format unlike <I>GConf</I>'s XML-based storage.<br>Its development focused on tighter integration with the <I>GSettings</I> API, providing a fast and efficient backend for application configuration in contemporary Linux desktop environments, especially GNOME.


title: PARAMETERS
content:
<b><i>KEY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full, absolute path to the dconf key to be modified (e.g., <I>/org/gnome/desktop/interface/text-scaling-factor</I>). Keys are organized hierarchically, similar to a file system path.<br><br><b><i>VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The value to set for the specified key. This must be a string formatted according to the GVariant specification (e.g., <I>'true'</I> for a boolean, <I>1.25</I> for a double, <I>"'some string'"</I> for a string, or <I>"[1, 2, 3]"</I> for an array). Note the nested quoting for strings within arrays.<br><br><b><b>--database=</b><i>DATABASE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative dconf database file to operate on instead of the default user or system databases.<br><br><b><b>--profile=</b><i>PROFILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative dconf profile to load for the operation. Profiles define the database hierarchy used by dconf.<br><br><b><b>--sync</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Immediately synchronizes pending changes to disk after the write operation. This ensures persistence and can be useful in scripts where immediate effect is desired, but might slightly impact performance.<br><br><b><b>--noprofile</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables loading of the dconf profile for this operation, using only the default database paths.<br><br><b><b>--gsettings-backend=</b><i>BACKEND</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a particular GSettings backend to use for the operation (e.g., <I>memory</I> or <I>dconf</I>). This is typically for debugging or advanced use cases.<br><br>


title: DESCRIPTION
content:
The <b>dconf-write</b> command, typically invoked as a subcommand of the <b>dconf</b> utility (i.e., <b>dconf write</b>), is used to set a specific value for a given key within the <I>dconf</I> configuration system.<br><br><b>dconf</b> is a low-level key-value database primarily used by desktop environments like GNOME to store application settings, user preferences, and system configurations. Unlike its predecessor <I>GConf</I> which used XML files, <I>dconf</I> uses a binary database for improved performance and simpler management.<br><br>This command provides a direct way to modify these settings programmatically. It requires a full path to the configuration key (e.g., <I>/org/gnome/desktop/interface/text-scaling-factor</I>) and the value to be set. The value must be provided in GVariant format, which supports various data types including strings, integers, booleans, arrays, and more. While powerful for scripting and automation, direct manipulation requires careful attention to key paths and value formats to avoid unintended side effects on applications or the desktop environment.


title: CAVEATS
content:
Incorrect key paths or improperly formatted GVariant values can lead to unexpected behavior, data corruption, or instability in applications and the desktop environment. Users should exercise caution and ideally back up configurations or use <I>dconf-editor</I> or <I>dconf read</I> to inspect current values before making changes.<br>The command requires appropriate user permissions to write to the dconf database. Changes might not take effect immediately in running applications; a restart of the application or session might be necessary for them to apply.


title: COMMAND NAMING CONVENTION
content:
While the prompt refers to <I>dconf-write</I>, the functionality is typically accessed via the <I>dconf</I> command's <I>write</I> subcommand (e.g., <B>dconf write KEY VALUE</B>). On many systems, <I>dconf-write</I> might exist as a symbolic link to the main <I>dconf</I> executable or is simply an informal way to refer to this specific operation, reflecting its historical usage or a common mental model of its function.


title: GVARIANT FORMAT SPECIFICS
content:
Understanding GVariant serialization is crucial for using <I>dconf write</I> effectively. Common types include:<br>- <b>Booleans:</b> <I>'true'</I> or <I>'false'</I><br>- <b>Integers/Doubles:</b> Raw numbers (e.g., <I>123</I>, <I>3.14</I>)<br>- <b>Strings:</b> Must be enclosed in single quotes, then the whole GVariant string typically in shell-level single or double quotes to prevent shell interpretation (e.g., <I>"'Hello World'"</I>).<br>- <b>Arrays:</b> Represented as <I>"[value1, value2, ...]"</I>, where each value adheres to GVariant syntax and is comma-separated.<br>- <b>Tuples:</b> Similar to arrays but defined with parentheses, <I>"(value1, value2)"</I>.


title: HISTORY
content:
The <I>dconf</I> system was introduced as the successor to <I>GConf</I> in GNOME 3, aiming for a more performant and simpler configuration management solution. <I>dconf-write</I> (or more commonly <I>dconf write</I>) emerged as the primary command-line interface for direct programmatic manipulation of these new binary-based configurations. Its development is tied closely to the evolution of the GNOME desktop environment and its underlying infrastructure, providing a robust backbone for desktop settings.


title: SYNOPSIS
content:
<b>dd</b> [<I>OPERAND</I>]...<br><br>Common operands include:<br><b>if=</b><I>FILE</I> <b>of=</b><I>FILE</I> <b>bs=</b><I>BYTES</I> <b>count=</b><I>BLOCKS</I> <b>skip=</b><I>BLOCKS</I> <b>seek=</b><I>BLOCKS</I> <b>conv=</b><I>CONV</I> <b>status=</b><I>STATUS</I>


title: PARAMETERS
content:
<b>if=<I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads from <I>FILE</I> instead of standard input. If <I>FILE</I> is a device, reads raw data from it.<br><br><b>of=<I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes to <I>FILE</I> instead of standard output. If <I>FILE</I> is a device, writes raw data to it. Be cautious, this can overwrite data.<br><br><b>bs=<I>BYTES</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets both input and output block size to <I>BYTES</I>. This can significantly optimize transfer speed.<br><br><b>count=<I>BLOCKS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies only <I>BLOCKS</I> input blocks. Useful for partial copies or creating files of specific sizes.<br><br><b>skip=<I>BLOCKS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips <I>BLOCKS</I> input blocks before starting the copy. This is useful for ignoring headers or initial data.<br><br><b>seek=<I>BLOCKS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips <I>BLOCKS</I> output blocks before starting the copy. This allows writing to a specific offset within the output file or device.<br><br><b>conv=<I>CONV</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts the file according to a comma-separated list of symbols (e.g., <i>notrunc</i> to prevent truncation of output file, <i>noerror</i> to continue on read errors, <i>sync</i> to pad input blocks to <b>bs</b> size, <i>lcase</i> to convert uppercase to lowercase, <i>ucase</i> for lowercase to uppercase).<br><br><b>status=<I>STATUS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls information displayed to stderr. Common values are <i>progress</i> (shows transfer progress), <i>noxfer</i> (suppresses final transfer statistics), and <i>none</i> (suppresses all messages).<br><br>


title: DESCRIPTION
content:
<b>dd</b> is a powerful, low-level command-line utility used for copying and converting data. It operates on a byte-by-byte basis, allowing precise control over input and output operations. Its primary strength lies in handling raw data streams, making it invaluable for tasks such as creating disk images, restoring backups, zeroing out storage devices, and performing data conversions (e.g., ASCII to EBCDIC). Unlike general-purpose copy commands like <b>cp</b>, <b>dd</b> provides granular control over block sizes, offsets, and data transformations. While extremely versatile, its raw access capabilities also make it notoriously dangerous; a simple typo in parameters can lead to irreversible data loss by overwriting critical system partitions or disks. Users often affectionately refer to it as the "disk duplicator" or, due to its destructive potential, the "data destroyer." It's frequently employed by system administrators and power users for disk forensics, bootable USB creation, and testing I/O performance.


title: CAVEATS
content:
<b>dd</b> is extremely powerful and potentially destructive. A minor mistake in specifying input or output files (e.g., using a raw disk device like <b>/dev/sda</b>) can lead to irreversible data loss by overwriting critical system files or entire partitions. Always double-check your parameters before execution, especially when working with raw devices. It is not designed for general-purpose file copying like <b>cp</b>; use <b>cp</b> for regular file operations.


title: COMMON USE CASES
content:
<b>dd</b> is widely used for:<br><i>Disk Imaging:</i> Creating a bit-for-bit copy of a partition or entire disk (e.g., <b>dd if=/dev/sda of=/mnt/backup/sda.img bs=4M status=progress</b>).<br><i>Creating Bootable USB Drives:</i> Writing an ISO image directly to a USB stick (e.g., <b>dd if=debian.iso of=/dev/sdb bs=4M status=progress</b>).<br><i>Zeroing/Wiping Disks:</i> Filling a disk with zeros for security or preparing it for a new filesystem (e.g., <b>dd if=/dev/zero of=/dev/sda bs=4M status=progress</b>).<br><i>Creating Files of Specific Size:</i> Generating a large dummy file for testing (e.g., <b>dd if=/dev/zero of=largefile.bin bs=1G count=10</b>).


title: PERFORMANCE CONSIDERATIONS
content:
The <b>bs</b> (block size) parameter significantly impacts <b>dd</b>'s performance. Choosing an appropriate block size (e.g., 4M, 16M, or 64K) can dramatically speed up transfers, especially when dealing with large files or raw disk devices. A too-small block size leads to excessive system calls, while a too-large one might not be handled efficiently by the underlying hardware.


title: SHOWING PROGRESS
content:
For long-running <b>dd</b> operations, the <b>status=progress</b> operand (available in GNU coreutils versions) is invaluable for monitoring progress. Alternatively, on many systems, you can send a <b>SIGUSR1</b> signal to a running <b>dd</b> process (e.g., <b>kill -USR1 &lt;pid_of_dd&gt;</b>) to make it print its current transfer statistics to stderr without interrupting the operation.


title: HISTORY
content:
The <b>dd</b> command originated in the early versions of Unix, developed at Bell Labs. Its name is often said to be an acronym for "disk duplicator" or "data definition" (from IBM's JCL <b>DD</b> statement), though jokingly also referred to as "data destroyer" due to its powerful and potentially dangerous capabilities. It was designed to provide low-level I/O operations and data conversion functionalities, fulfilling a niche where higher-level tools were insufficient. Its core functionality has remained largely consistent over decades, making it a staple in Unix-like operating systems.


title: PARAMETERS
content:
<b>-o, --ordinal</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the day of the year as an ordinal number (e.g., 1st, 2nd) rather than the standard Discordian suffix (e.g., Sweetmorn, Pungenday).<br><br><b>-R, --rfc-2822</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Formats the Discordian date output to be RFC 2822 compliant. This can be useful for integration with systems expecting standard date formats while still showing the Discordian context.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information and exits.<br><br><b>[DATE]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional argument to specify a Gregorian date (in a format recognized by the <I>date</I>(1) command) for which to print the Discordian equivalent, instead of the current system date.<br><br>


title: DESCRIPTION
content:
The <b>ddate</b> command is a delightful and whimsical utility that prints the current date according to the <I>Discordian calendar</I>. Unlike conventional date commands, <b>ddate</b> embraces the chaotic and humorous philosophy of Discordianism, a parody religion centered around the worship of Eris, the Greek goddess of strife and discord. Its primary purpose is not practicality but rather to provide a moment of amusement and a nod to counter-culture computing traditions. It's often found in Linux and Unix-like systems as a nod to the developers' sense of humor.<br><br>The Discordian calendar, as described in <I>Principia Discordia</I>, features five 73-day seasons: Chaos, Discord, Confusion, Bureaucracy, and The Aftermath, along with special holy days and Apostle weeks. <b>ddate</b> translates the Gregorian date into this unique format, often including references to the Discordian year (YOLD - Year of Our Lord Discordia) and specific calendar elements like St. Tib's Day or the Apostle weeks. It serves as a charming relic of early hacker culture and a testament to the playful side of software development.


title: CAVEATS
content:
The primary caveat of <b>ddate</b> is its purely <I>novelty</I> nature. It should not be used for any serious time-keeping or scheduling purposes as the Discordian calendar is not universally recognized or practical for everyday use.<br><br>Its output format is non-standard and varies significantly from the Gregorian calendar. Furthermore, the availability and specific options of <b>ddate</b> can vary slightly between different Linux distributions, as it is often part of a 'fun' or 'misc' utilities package rather than a core system component.


title: CULTURAL SIGNIFICANCE & EXAMPLE OUTPUT
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The <b>ddate</b> command is more than just a utility; it's a small piece of hacker and internet culture, symbolizing rebellion against convention and a celebration of the absurd. It connects users to a shared history of playful defiance within the tech community.<br><br>A typical output of <b>ddate</b> on a random day might look like: <br><I>Today is Setting Orange, the 24th day of Chaos in the YOLD 3190</I><br>The specific format includes the Discordian day of the week, day of the season, season name, and the Discordian Year of Our Lord Discordia (YOLD).


title: HISTORY
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The <b>ddate</b> command emerged from the culture of early Unix and Linux development, particularly within the hacker and open-source communities who appreciated its blend of humor and technical ingenuity. Its existence is deeply rooted in the <I>Discordianism</I> parody religion, which gained popularity in the mid-20th century, particularly through works like <I>Principia Discordia</I> and <I>The Illuminatus! Trilogy</I>.<br><br>While an exact first release date is hard to pinpoint, <b>ddate</b> has been a long-standing component of many Unix-like systems, often included as a non-essential but beloved utility. It serves as an inside joke and a symbol of the playful side of programming, contrasting with the often serious nature of system administration. It highlights the tradition of developers embedding quirky features or 'Easter eggs' into their software, enriching the user experience beyond mere functionality.


title: SYNOPSIS
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<i>ddcutil</i> <i>[global-options]</i> <i>command</i> <i>[command-options]</i> <i>[arguments]</i><br>Example: <i>ddcutil</i> <b>detect</b><br>Example: <i>ddcutil</i> <b>setvcp</b> <i>brightness</i> <i>50</i><br>Example: <i>ddcutil</i> <b>--display</b> <i>1</i> <b>getvcp</b> <i>0x10</i>


title: PARAMETERS
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<b><b>--display</b> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects which monitor to operate on (by its detected sequence number, starting from 1).<br><br><b><b>--bus</b> <i>ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the I2C bus ID to communicate with a monitor directly.<br><br><b><b>--enable-capabilities</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Augments the <b>capabilities</b> command output by showing associated VCP codes.<br><br><b><b>--sleep-multiplier</b> <i>FACTOR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adjusts inter-command delays for DDC/CI messages, useful for monitors with unreliable implementations.<br><br><b><b>detect</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scans for and lists all DDC/CI capable monitors currently connected to the system.<br><br><b><b>getvcp</b> <i>CODE|NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads and displays the current value of a specified VCP feature (e.g., <b>getvcp brightness</b> or <b>getvcp 0x10</b>).<br><br><b><b>setvcp</b> <i>CODE|NAME</i> <i>VALUE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a VCP feature to a specific <i>VALUE</i> (e.g., <b>setvcp brightness 50</b>).<br><br><b><b>capabilities</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the full list of DDC/CI capabilities and supported VCP features of the selected monitor.<br><br><b><b>vcpinfo</b> <i>CODE|NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides detailed information about a specific VCP feature, including its name, type, and possible values.<br><br><b><b>scs</b> <i>COMMAND</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends a Screen Control Standard command to the monitor (e.g., <b>scs reset</b> for a factory reset).<br><br><b><b>read-edid</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads and displays the monitor's Extended Display Identification Data (EDID).<br><br><b><b>save-state</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves the current VCP settings of the selected monitor to a specified <i>FILE</i>.<br><br><b><b>load-state</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads VCP settings from a specified <i>FILE</i> and applies them to the selected monitor.<br><br>


title: DESCRIPTION
content:
<i>ddcutil</i> is a powerful Linux command-line utility for querying and controlling monitor settings, such as brightness, contrast, input source, and color temperature, directly from the command line. It communicates with monitors using the DDC/CI (Display Data Channel Command Interface) protocol, which is an industry standard for communication between a computer and a display device over the video cable (VGA, DVI, HDMI, DisplayPort). This allows users to automate monitor configurations, integrate display management into scripts, or simply adjust settings without relying on physical monitor buttons or often limited GUI tools.<br><br><i>ddcutil</i> supports a wide range of VCP (Virtual Control Panel) features, enabling fine-grained control over various display parameters. It can detect connected monitors, identify their capabilities, and apply specific settings by writing values to VCP features. Its robust error handling and diagnostic capabilities make it an invaluable tool for system administrators, power users, and anyone needing programmatic control over their display devices.


title: CAVEATS
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<b>DDC/CI Support:</b> Not all monitors fully implement the DDC/CI standard or may have buggy implementations, leading to unexpected behavior or limited control over certain features.<br><b>Kernel Modules & Permissions:</b> Requires the <i>i2c-dev</i> kernel module to be loaded. Access to <i>/dev/i2c-*</i> devices typically requires root privileges or properly configured udev rules.<br><b>Video Driver Issues:</b> Certain proprietary video drivers or specific kernel versions may interfere with DDC/CI communication, potentially causing issues or preventing functionality.<br><b>Multiple Displays/GPUs:</b> Identifying the correct I2C bus can be complex in systems with multiple monitors, integrated graphics, or multiple discrete GPUs.


title: GUI INTEGRATION
content:
<i>ddcutil</i> serves as the foundational backend for several graphical user interfaces (GUIs), such as <i>ddcui</i> (a Qt-based GUI), which offer a more intuitive way to adjust monitor settings without direct command-line interaction.


title: AUTOMATION POTENTIAL
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Its command-line nature makes <i>ddcutil</i> exceptionally well-suited for scripting. Users can automate tasks such as dynamically adjusting brightness based on ambient light, switching input sources, or synchronizing settings across multiple monitors as part of their daily workflow or system events.


title: HISTORY
content:
<i>ddcutil</i> was developed to fill a critical gap in Linux display management, providing a robust and reliable command-line interface for DDC/CI communication that was often missing or poorly implemented in existing tools. Its creation aimed to enable programmatic control over monitor settings, addressing the need for automation and advanced configuration. The project has continuously focused on broad monitor compatibility, comprehensive VCP feature support, and robust error handling, establishing itself as the de facto utility for DDC/CI control on Linux.


