# CommandSection

title: DESCRIPTION
content:
The term <b>ClamAV</b> refers to an open-source antivirus engine designed for detecting trojans, viruses, malware, and other malicious threats. While there isn't a single executable named "clamav" that encompasses all functions, the suite provides several commands to perform specific tasks.<br><br>The primary command for on-demand scanning is <b>clamscan</b>, which allows users to scan files or directories for known threats. It's widely used for email gateway scanning, file server protection, and as a standalone scanning tool on Linux/Unix systems.<br><br>Key components of the ClamAV suite include:<br><b>clamscan</b>: The command-line utility for scanning files and directories.<br><b>freshclam</b>: A tool for updating the virus definitions database, crucial for effective threat detection.<br><b>clamd</b>: A multi-threaded daemon that provides a high-performance scanning service, typically used for real-time scanning in conjunction with other applications like email servers or web proxies.<br><br>ClamAV relies on a continuously updated database of virus signatures, which is downloaded via <b>freshclam</b>. It's a versatile solution for adding an extra layer of security to Linux environments.


title: CAVEATS
content:
ClamAV, particularly <b>clamscan</b>, performs on-demand scanning and is <i>not</i> a real-time scanner on its own in the typical sense of a desktop antivirus program. For continuous real-time protection, it generally needs to be integrated with other system components or used with the <b>clamd</b> daemon.<br><br>The effectiveness of ClamAV relies heavily on its virus definitions being up-to-date. Neglecting to run <b>freshclam</b> regularly will significantly reduce its detection capabilities.<br><br>Using the <b>--remove</b> option can lead to data loss if legitimate files are incorrectly identified as threats (false positives). Always exercise extreme caution or use the <b>--move</b> or <b>--copy</b> options instead.


title: USAGE EXAMPLES
content:
Here are some common ways to use <b>clamscan</b>:<br>Scan a single file:<br><i><b>clamscan</b> /path/to/my_file.txt</i><br>Scan a directory recursively and only show infected files:<br><i><b>clamscan</b> -r -i /home/user/downloads</i><br>Scan a directory and move infected files to a quarantine folder:<br><i><b>clamscan</b> -r --move=/var/quarantine /var/www/html</i><br>Update virus definitions (using <b>freshclam</b>):<br><i><b>freshclam</b></i><br><br>It's common to schedule <b>freshclam</b> to run periodically via a cron job to ensure definition currency.


title: INTEGRATION WITH EMAIL SYSTEMS
content:
ClamAV is most famously integrated with email servers like Postfix or Exim to scan incoming and outgoing emails for malware. This is often achieved by passing email content through the <b>clamd</b> daemon, which offers faster scanning performance due to its persistent nature and pre-loaded definitions, avoiding the overhead of starting <b>clamscan</b> for each email.


title: DEFINITION UPDATES
content:
The effectiveness of ClamAV depends entirely on its virus definitions. The <b>freshclam</b> utility is used to download the latest virus definition database from ClamAV's servers. It is <i>highly recommended</i> to set up a cron job to run <b>freshclam</b> at least once a day, or even more frequently, to ensure you have the most current protection against new threats.


title: HISTORY
content:
ClamAV was originally developed by Tomasz Kojm in 2002 as an open-source project. Its aim was to provide a free and flexible antivirus solution, particularly for Unix-like operating systems. It quickly gained popularity for its use in mail servers and gateway scanning.<br><br>In 2007, ClamAV was acquired by Sourcefire, an American network security company. Subsequently, in 2013, Cisco Systems acquired Sourcefire, including the ClamAV project. Despite these acquisitions, ClamAV has remained an open-source project, with its development continuing to be community-driven and maintained by Cisco engineers. It has become a standard component in many Linux distributions and open-source security stacks.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print program version information and exit.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Be verbose during the scan process, showing more details.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan directories recursively. This is the default behavior when scanning directories.<br><br><b><b>--infected</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only print information about infected files.<br><br><b><b>--remove</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove infected files. <i>Use with extreme caution as this action is irreversible and can lead to data loss.</i><br><br><b><b>--move=</b><i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Move infected files to the specified <i>PATH</i>.<br><br><b><b>--copy=</b><i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copy infected files to the specified <i>PATH</i>.<br><br><b><b>--scan-archive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan files within archives (e.g., .zip, .tar, .rar). Enabled by default.<br><br><b><b>--scan-mail</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan mail files (e.g., .eml, .mbox).<br><br><b><b>--stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the scan report to standard output.<br><br><b><b>--socket=</b><i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the <i>clamd</i> daemon via a Unix socket at the specified <i>PATH</i>.<br><br><b><b>--host=</b><i>HOST</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the <i>clamd</i> daemon via TCP/IP on the specified <i>HOST</i>.<br><br><b><b>--port=</b><i>PORT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the <i>clamd</i> daemon via TCP/IP on the specified <i>PORT</i> (used with <b>--host</b>).<br><br><b><b>--timeout=</b><i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the connection timeout to <i>clamd</i> (in seconds).<br><br><b><b>--fdpass</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pass file descriptors to <i>clamd</i>. This is useful when <i>clamd</i> runs as a different user than <i>clamdscan</i>, allowing <i>clamd</i> to bypass permissions for scanning. Requires <i>clamd</i> to be configured with <i>AllowFDPass</i>.<br><br>


title: DESCRIPTION
content:
<i>clamdscan</i> is a command-line utility for scanning files and directories for viruses and other malware using the ClamAV daemon (<i>clamd</i>). Unlike its counterpart, <i>clamscan</i>, which loads virus definitions into memory for each scan, <i>clamdscan</i> offloads the scanning process to a persistent <i>clamd</i> daemon. This approach significantly improves performance, especially when performing multiple or frequent scans, as the daemon keeps the virus definitions loaded and ready, avoiding the overhead of reloading them repeatedly.<br><br>It communicates with the <i>clamd</i> daemon via a Unix socket or TCP/IP. This client-server architecture makes <i>clamdscan</i> ideal for environments requiring high-performance, continuous, or automated virus scanning, such as mail servers, file servers, or scheduled system scans.


title: CAVEATS
content:
<ul><li><b>Daemon Requirement</b>: <i>clamdscan</i> requires the <i>clamd</i> daemon to be running and accessible. If <i>clamd</i> is not running or misconfigured, <i>clamdscan</i> will fail.</li><li><b>Permissions</b>: Ensure that the user running <i>clamdscan</i> has sufficient read permissions to the files/directories being scanned, and that the <i>clamd</i> daemon (which typically runs under a dedicated user like 'clamav') also has the necessary permissions. The <b>--fdpass</b> option can help in certain permission scenarios.</li><li><b>Resource Usage</b>: While faster for repeated scans, <i>clamd</i> itself can consume significant memory as it keeps the virus definitions loaded.</li><li><b>Data Modification Options</b>: Options like <b>--remove</b>, <b>--move</b>, and <b>--copy</b> directly affect the scanned files. Use them with extreme caution and only after thorough testing, as incorrect usage can lead to data loss or unintended file relocation.</li></ul>


title: USAGE BEST PRACTICES
content:
<ul><li>Always ensure your <i>clamd</i> daemon is running and that its virus definitions are kept up-to-date using <i>freshclam</i>.</li><li>For automated or frequent scans (e.g., cron jobs), <i>clamdscan</i> is highly recommended over <i>clamscan</i> due to its performance benefits.</li><li>When using options like <b>--remove</b> or <b>--move</b>, it is advisable to test them in a controlled environment first to understand their behavior fully and prevent accidental data loss.</li><li>Monitor <i>clamd</i>'s logs for any issues or detected threats.</li></ul>


title: DAEMON INTERACTION
content:
<i>clamdscan</i> acts as a client to the <i>clamd</i> server. When you execute <i>clamdscan</i>, it establishes a connection to the <i>clamd</i> daemon (either via a Unix socket or TCP/IP), sends the paths of the files/directories to be scanned, and waits for the scanning results from the daemon. The actual virus scanning and detection logic reside within the <i>clamd</i> daemon, which maintains a loaded and updated database of virus signatures. This separation of concerns allows <i>clamd</i> to serve multiple <i>clamdscan</i> clients concurrently and efficiently.


title: HISTORY
content:
<i>clamdscan</i> is an integral part of the ClamAV open-source antivirus engine. It was developed to provide a more efficient and higher-performance scanning interface compared to the initial <i>clamscan</i> utility. As ClamAV's usage expanded beyond occasional, manual scans to server-side applications (like mail gateways and web servers) requiring continuous monitoring and faster response times, the need for a daemon-based scanning solution became apparent. <i>clamdscan</i> addresses this by leveraging the <i>clamd</i> daemon, which keeps virus definitions in memory, significantly reducing the overhead of reloading them for each scan request. This evolution made ClamAV a more viable and scalable solution for demanding production environments.


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>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version number of ClamAV and exits.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Be verbose during the scan process, providing more detailed output.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scans directories recursively, including all subdirectories and their contents.<br><br><b><b>-i</b>, <b>--infected</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only prints infected files. Suppresses output for clean files.<br><br><b><b>--remove[=yes/no]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes infected files. <i>WARNING: This option can be destructive and should be used with extreme caution.</i><br><br><b><b>--move=</b><i>DIRECTORY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Moves infected files to the specified <i>DIRECTORY</i> instead of removing them.<br><br><b><b>--copy=</b><i>DIRECTORY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies infected files to the specified <i>DIRECTORY</i>, leaving the originals in place.<br><br><b><b>--log=</b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Logs all scan results to the specified <i>FILE</i>.<br><br><b><b>--database=</b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads virus signatures from the specified <i>FILE</i> instead of the default location.<br><br><b><b>--exclude=</b><i>REGEX</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files matching the specified regular expression from the scan.<br><br><b><b>--include=</b><i>REGEX</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only scans files matching the specified regular expression.<br><br><b><b>--max-scansize=</b><i>SIZE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the maximum size of files to scan. Files larger than this will be skipped.<br><br><b><b>--no-summary</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the final summary message after the scan completes.<br><br><b><b>--bell</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rings the system bell when a virus is found.<br><br><b><b>--suppress-ok-results</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only output scan results for files that are not clean.<br><br>


title: DESCRIPTION
content:
<i>clamscan</i> is the command-line interface for the ClamAV antivirus engine, an open-source solution for detecting various types of malicious software, including viruses, trojans, malware, and other threats. <br><br>It allows users to scan individual files, specific directories, or entire file systems recursively for known signatures of malware. The effectiveness of <i>clamscan</i> heavily relies on an up-to-date virus definition database, which is typically maintained by the <i>freshclam</i> utility. <br><br>Beyond basic scanning, <i>clamscan</i> provides extensive options to control scan behavior, such as limiting file sizes, handling infected files (e.g., moving, copying, or removing them), logging results, and adjusting verbosity. It is widely used on Linux systems, particularly in email gateways and file servers, to ensure the integrity and security of data.


title: CAVEATS
content:
While <i>clamscan</i> is a powerful tool, it has certain limitations: <br><br><b>Database Dependency:</b> Its effectiveness is directly tied to the currency of its virus definition database, requiring regular updates via <i>freshclam</i>. <br><b>No Real-time Protection:</b> By itself, <i>clamscan</i> does not provide real-time, on-access scanning. For continuous monitoring, it's typically used in conjunction with the <i>clamd</i> daemon and <i>clamdscan</i> client. <br><b>False Positives:</b> Like any antivirus software, it can occasionally produce false positives. <br><b>Performance:</b> Scanning large numbers of files or deeply nested directories can be resource-intensive and time-consuming.


title: DATABASE UPDATES
content:
For <i>clamscan</i> to be effective, its virus definition database must be kept up-to-date. This is achieved by regularly running the <i>freshclam</i> utility, which downloads the latest signatures from ClamAV's servers. Outdated databases significantly reduce detection capabilities.


title: EXIT STATUS
content:
<i>clamscan</i> provides meaningful exit codes to indicate scan results, which are useful for scripting:<br><i><b>0</b></i>: No threats found.<br><i><b>1</b></i>: At least one threat found.<br><i><b>2</b></i>: An error occurred during scanning (e.g., file not found, permission issue).


title: HISTORY
content:
The ClamAV project, of which <i>clamscan</i> is a central component, began in 2001. It was conceived as an open-source antivirus engine, primarily designed for Unix-like systems and intended for integration with email gateways. <br><br>Over the years, it has grown to become a widely adopted solution for various anti-malware tasks, including desktop scanning, web content filtering, and file server protection. The project was acquired by Sourcefire in 2007 and subsequently by Cisco in 2013, but has maintained its open-source nature and community-driven development.


title: PARAMETERS
content:
<b><b>-o</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to <i>&lt;file&gt;</i>.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile or assemble the source files, but do not link.<br><br><b><b>-S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compile only; do not assemble or link.<br><br><b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preprocess only; do not compile, assemble or link.<br><br><b><b>-I</b> <i>&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add directory to include search path.<br><br><b><b>-L</b> <i>&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add directory to library search path.<br><br><b><b>-l</b><i>&lt;lib&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Link with library <i>&lt;lib&gt;</i>.<br><br><b><b>-D</b> <i>&lt;macro&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define a macro.<br><br><b><b>-U</b> <i>&lt;macro&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Undefine a macro.<br><br><b><b>-Wall</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable all standard warnings.<br><br><b><b>-Wextra</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable some extra warning flags not enabled by <b>-Wall</b>.<br><br><b><b>-Werror</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat all warnings as errors.<br><br><b><b>-O</b><i>&lt;level&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify optimization level. Common levels are <b>O0</b> (no opt), <b>O1</b>, <b>O2</b>, <b>O3</b> (aggressive), <b>Os</b> (size), <b>Oz</b> (smaller size).<br><br><b><b>-std=</b><i>&lt;standard&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify language standard (e.g., <b>c99</b>, <b>c++11</b>, <b>gnu17</b>).<br><br><b><b>-g</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate debug information.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show commands Clang runs.<br><br>


title: DESCRIPTION
content:
Clang is a compiler front end for the C, C++, Objective-C, and Objective-C++ programming languages, as well as a variety of other language standards like OpenMP and OpenCL. It is part of the <b>LLVM</b> project and uses LLVM as its back end.<br><br>Clang is known for its fast compilation times, excellent and human-readable diagnostic messages, and its modular architecture. It aims to be a complete drop-in replacement for <b>GCC</b> for many common use cases, offering superior error reporting and often faster compilation, especially during development. It's widely used in various software development environments, including macOS and iOS development, and increasingly in Linux and other Unix-like systems.


title: CAVEATS
content:
While Clang aims for GCC compatibility, there might be minor differences in behavior or warnings for certain non-standard or edge cases. Some older build systems might explicitly expect `gcc` or `g++` and require symlinking or environment variable adjustments (e.g., <b>CC</b>, <b>CXX</b>). Specific compiler extensions or intrinsic functions present in <b>GCC</b> might not have direct equivalents in Clang, or vice versa, though compatibility is generally high for standard C/C++.


title: STATIC ANALYZER
content:
Clang provides a powerful static analyzer (accessed via <b>scan-build</b>) which can detect logical errors, memory leaks, and other bugs in source code without executing the program.


title: SANITIZERS
content:
Clang includes various runtime sanitizers (enabled with <b>-fsanitize=</b>) such as <b>AddressSanitizer (ASan)</b>, <b>UndefinedBehaviorSanitizer (UBSan)</b>, and <b>ThreadSanitizer (TSan)</b>, which help detect common runtime errors like memory corruption, undefined behavior, and data races.


title: MODULE MAPS
content:
Clang introduced "Module Maps" as a way to improve build times and dependency management for C-family languages, similar to modules in other modern languages.


title: HISTORY
content:
Clang's development began in 2007 at Apple Inc. with the aim of replacing <b>GCC</b> as the compiler for their macOS and iOS development environments. The primary motivations were to provide a more modular and robust compiler infrastructure (<b>LLVM</b>), improve compilation speed, and generate superior diagnostics. It quickly gained traction due to its high quality, liberal licensing (Apache 2.0), and active open-source development. It has since become a major player in the compiler landscape, competing directly with <b>GCC</b> and being adopted by numerous projects and distributions.


title: PARAMETERS
content:
<b>-o <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the <i>output file</i> name. For example, <br><i>clang++ main.cpp -o myprogram</i> creates an <br>executable named 'myprogram'.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Compile only</i>, do not link. This produces <br>an object file (e.g., <i>.o</i> or <i>.obj</i>) <br>from a source file.<br><br><b>-S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Assemble only</i>, do not link. This generates <br>an assembly language file (e.g., <i>.s</i> or <br><i>.asm</i>) from a source file.<br><br><b>-E</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Preprocess only</i>. This runs the C++ <br>preprocessor and outputs the result to standard <br>output or a specified file, without compiling <br>or linking.<br><br><b>-I<dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <i><dir></i> to the list of directories <br>searched for header files during preprocessing <br>and compilation.<br><br><b>-L<dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <i><dir></i> to the list of directories <br>searched for libraries during the linking stage.<br><br><b>-l<lib></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Link with the specified library <i><lib></i>. <br>For instance, <i>-lpthread</i> links the POSIX <br>threads library.<br><br><b>-std=<standard></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the C++ language standard to use. <br>Examples include <i>-std=c++11</i>, <i>-std=c++17</i>, <br><i>-std=c++20</i>, or <i>-std=gnu++17</i> for GNU <br>extensions.<br><br><b>-Wall</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable <i>all common and recommended warnings</i>. <br>This is highly recommended for identifying <br>potential issues in code.<br><br><b>-Wextra</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable <i>additional warnings</i> not included <br>by <i>-Wall</i>. Often used alongside <i>-Wall</i> <br>for more exhaustive checks.<br><br><b>-g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate <i>debug information</i>, which is crucial <br>for effective debugging with tools like <i>GDB</i> <br>or <i>LLDB</i>.<br><br><b>-O<level></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the <i>optimization level</i>. Common levels <br>are <i>-O0</i> (no optimization), <i>-O1</i>, <i>-O2</i>, <br><i>-O3</i> (aggressive optimization), and <i>-Os</i> <br>(optimize for size).<br><br><b>-D<macro>[=<value>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define a preprocessor macro. For example, <br><i>-DNDEBUG</i> is often used to disable debug <br>assertions in release builds.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a summary of <i>command-line options</i> <br>and their descriptions.<br><br><b><input files...></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more <i>source files</i> (e.g., <i>.cpp</i>, <br><i>.cxx</i>), <i>object files</i> (e.g., <i>.o</i>), or <br><i>libraries</i> to be processed by <i>clang++</i>.<br><br>


title: DESCRIPTION
content:
<i>clang++</i> is the driver program for the <br><i>Clang C++ compiler</i>, which is a component <br>of the <br><i>LLVM project</i>. It serves as a modern, <br>fast, and highly standards-compliant <br>alternative to traditional C++ compilers <br>like <i>g++</i> (the GNU C++ compiler). <br>Its primary function is to translate C++ <br>source files into machine code, object files, <br>or complete executables.<br><br>A defining characteristic of <i>clang++</i> is <br>its exceptionally clear and helpful diagnostic <br>messages, which often provide precise details <br>and 'fix-it' suggestions for errors and <br>warnings. This significantly aids developers <br>in debugging. Built with a modular <br>architecture, <i>clang++</i> also facilitates <br>deep integration into development tools such <br>as Integrated Development Environments (IDEs), <br>static analyzers, and code formatters. It <br>strives for strict adherence to C++ language <br>standards, contributing to the portability and <br>correctness of compiled code across various <br>platforms and systems.


title: CAVEATS
content:
While <i>clang++</i> offers numerous advantages, <br>users should be aware of a few considerations:<br><br><i>clang++</i> typically relies on the <br>system-default linker (such as <i>ld</i> on Linux) <br>for the final linking stage. This means that <br>specific linker flags might still be required <br>or behave differently than with other compilers. <br>A full <i>LLVM toolchain</i> (including <br>assemblers, optimizers, and linkers) must be <br>properly installed and configured for <br><i>clang++</i> to function correctly. <br>Compatibility with very old or highly <br>non-standard C++ codebases may occasionally <br>require specific compiler flags or minor <br>code adjustments.


title: SUPERIOR DIAGNOSTICS
content:
<i>clang++</i> is widely acclaimed for its detailed <br>and user-friendly error and warning <br>messages. Unlike many compilers that provide <br>minimal information, <i>clang++</i> often includes <br>'fix-it' suggestions, highlights the exact <br>problematic code segments, and offers <br>contextual explanations. This significantly <br>streamlines the debugging process for developers.


title: MODULAR ARCHITECTURE AND TOOLING
content:
Built upon the extensible <i>LLVM infrastructure</i>, <br><i>clang++</i> features a highly modular design. <br>This architecture facilitates the creation of <br>a rich ecosystem of powerful development <br>tools, such as static analyzers (e.g., <br><i>Clang-Tidy</i>), code formatters (e.g., <br><i>Clang-Format</i>), refactoring tools, and <br>deep integration within Integrated Development <br>Environments (IDEs) for real-time error <br>checking, code completion, and navigation.


title: HISTORY
content:
The <i>Clang C++ compiler</i>, which <i>clang++</i> <br>drives, originated as part of the <br><i>LLVM project</i>, initiated by Apple Inc. in <br>2007. Its development aimed to create a <br>modern, modular compiler infrastructure with <br>a more developer-friendly BSD license, in <br>contrast to the GPL license of GCC. <br><i>clang++</i> rapidly gained prominence due to <br>its superior compilation speed, exceptionally <br>clear error diagnostics, and robust support <br>for evolving C++ language standards. It became <br>the default compiler on macOS and has been <br>widely adopted across various sectors, including <br>Android's NDK, academic research, open-source <br>projects, and commercial software development, <br>solidifying its position as a leading C++ <br>compiler.


title: SYNOPSIS
content:
<B>clang-cpp</B> [<I>options</I>] <I>input_file</I>...<br><B>clang-cpp</B> <B>-E</B> [<I>options</I>] <I>input_file</I>...


title: PARAMETERS
content:
<b><B>-E</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Stop after the preprocessing stage and print the output to standard output. This is the primary behavior when invoking <B>clang-cpp</B>.</i><br><br><b><B>-I</B> <I>&#60;dir&#62;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Add directory <I>dir</I> to the list of directories to be searched for header files.</i><br><br><b><B>-D</B> <I>&#60;macro&#62;[=<value>]</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Define a macro <I>macro</I> with an optional <I>value</I> (defaults to 1 if no value is given).</i><br><br><b><B>-U</B> <I>&#60;macro&#62;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Undefine the specified macro <I>macro</I>.</i><br><br><b><B>-P</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Inhibit the generation of <B>#line</B> directives (line markers) in the preprocessed output.</i><br><br><b><B>-M</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Generate a list of makefile dependencies for the source file.</i><br><br><b><B>-MM</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Generate a list of makefile dependencies, omitting system headers.</i><br><br><b><B>-MD</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Generate a dependency file suitable for <B>make</B> in addition to precompiling.</i><br><br><b><B>-MF</B> <I>&#60;file&#62;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>When used with <B>-M</B>, <B>-MM</B>, or <B>-MD</B>, specify the name of the dependency file.</i><br><br><b><B>-MT</B> <I>&#60;target&#62;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>When used with <B>-M</B>, <B>-MM</B>, or <B>-MD</B>, specify the target name for the dependency rule.</i><br><br><b><B>-x</B> <I>&#60;language&#62;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Treat subsequent input files as having type <I>language</I> (e.g., <B>c++</B>).</i><br><br><b><B>--help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display a summary of command-line options.</i><br><br><b><B>--version</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display the version of <B>Clang</B> used.</i><br><br>


title: DESCRIPTION
content:
<i><B>clang-cpp</B> is a specialized invocation of the <B>Clang</B> compiler front-end, designed to perform only the preprocessing stage for C++ source code. As part of the <B>LLVM</B> project, <B>Clang</B> provides a modern, fast, and highly conformant compiler infrastructure.<br><br>When invoked as <B>clang-cpp</B>, it behaves much like the traditional <B>cpp</B> (C preprocessor), but specifically for C++ language constructs. Its primary function is to expand macros, include header files, and handle conditional compilation directives (<B>#if</B>, <B>#ifdef</B>, etc.), producing a single translation unit ready for the next compilation stages. It is often used for debugging preprocessing issues, generating dependency files for build systems, or preparing code for static analysis tools by providing a fully expanded source file.</i>


title: CAVEATS
content:
<i><B>clang-cpp</B> is typically a symlink to the <B>clang</B> executable, configured to default to C++ preprocessing. While it focuses solely on preprocessing, it still leverages the full C++ parsing capabilities of <B>Clang</B>, offering more robust error checking and language understanding than simpler preprocessors.<br><br>It assumes a C++ context by default, but this can be overridden with <B>-x</B>. It does not perform compilation, assembly, or linking; its output is the preprocessed source code.</i>


title: <I>INTEGRATION WITH BUILD SYSTEMS</I>
content:
<i><B>clang-cpp</B>'s ability to generate dependency files via options like <B>-M</B>, <B>-MM</B>, and <B>-MD</B> makes it invaluable for build automation tools like <B>make</B> or <B>Ninja</B>. These dependency files ensure that source files are recompiled only when their direct or indirect dependencies (e.g., included headers) change, significantly optimizing build times.</i>


title: <I>STATIC ANALYSIS AND TOOLING</I>
content:
<i>Because <B>clang-cpp</B> produces a single translation unit that fully resolves all macros and includes, it is an essential component for static analysis tools, code formatters, and refactoring engines built upon the <B>Clang</B> infrastructure. These tools can operate on the fully preprocessed code, simplifying their parsing and analysis logic.</i>


title: HISTORY
content:
<i><B>Clang</B> development began in 2007 at Apple Inc. to provide a modern, modular, and BSD-licensed alternative to <B>GCC</B>. <B>clang-cpp</B> emerged as part of this effort, offering a dedicated C++ preprocessor that benefits from <B>Clang</B>'s advanced front-end architecture.<br><br>Its integration into the <B>LLVM</B> toolchain has made it a popular choice in various development environments, especially for C++ projects where precise preprocessing and strong adherence to C++ standards are crucial.</i>


title: SYNOPSIS
content:
<b>clang-format</b> [<i>options</i>] [<i>files</i>...]<br><br>Common usage examples:<br><b>clang-format</b> -i <i>file.cpp</i><br><b>clang-format</b> --style=<i>Google</i> <i>mycode.h</i><br>cat <i>input.js</i> | <b>clang-format</b> --assume-filename=<i>file.js</i> > <i>formatted.js</i>


title: PARAMETERS
content:
<b>--style=<<i>string</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the formatting style. Can be a predefined name (e.g., <I>LLVM</I>, <I>Google</I>, <I>Chromium</I>, <I>Microsoft</I>, <I>Mozilla</I>, <I>WebKit</I>), a path to a configuration file, a YAML configuration string, or <I>file</I> to discover the style from a <I>.clang-format</I> file.<br><br><b>-i, --in-place</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Format files in-place. This option overwrites the original input files with the formatted content.<br><br><b>--assume-filename=<<i>path</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When formatting standard input, assume the content comes from this file. This helps <I>clang-format</I> locate the correct style configuration file and apply language-specific rules.<br><br><b>--dump-config</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the current style configuration to standard output, typically derived from the closest <I>.clang-format</I> file or the default style.<br><br><b>--dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Don't apply changes; instead, print the names of files that would be reformatted. Useful for checking which files are out of compliance.<br><br><b>--sort-includes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts include blocks lexicographically, often organizing them into groups. This can be controlled further by style options.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version of <I>clang-format</I> and exit.<br><br>


title: DESCRIPTION
content:
<b>clang-format</b> is an integral part of the <I>LLVM</I> project, designed to automatically format source code in various languages, including C, C++, Objective-C, C#, Java, JavaScript, TypeScript, and Protocol Buffers.<br><br>Its primary goal is to ensure consistent coding styles across a project, enhancing code readability and maintainability. It achieves this by applying a set of predefined or custom rules, often specified in a <I>.clang-format</I> or <I>_clang-format</I> YAML configuration file located within the project directory or user's home. This allows for fine-grained control over indentation, line breaks, brace styles, and more.<br><br><b>clang-format</b> supports several popular built-in styles (e.g., LLVM, Google, Chromium, Microsoft) and can also infer a style from existing code. It can format files in-place, print changes to standard output, or generate diffs, making it suitable for integration into build systems, editor plugins, and version control pre-commit hooks. Its automation significantly reduces bikeshedding over code style, allowing developers to focus on functionality.


title: CAVEATS
content:
While highly effective, <b>clang-format</b> relies heavily on its configuration.<br>Inconsistent or poorly defined <I>.clang-format</I> files can lead to unexpected reformatting.<br>It focuses solely on code style, not semantic correctness or bug detection.<br>For large-scale legacy codebases, an initial formatting pass might result in significant changes, potentially complicating git history if not managed carefully.


title: CONFIGURATION FILE DISCOVERY
content:
When formatting a file, <b>clang-format</b> intelligently searches for its configuration file (<I>.clang-format</I> or <I>_clang-format</I>). It starts in the directory of the input file and traverses up the directory tree until it finds a configuration file or reaches the root of the file system. This mechanism ensures that project-specific or even sub-directory-specific styles can be applied automatically.


title: EDITOR AND IDE INTEGRATION
content:
One of <b>clang-format</b>'s strengths is its seamless integration with various text editors and Integrated Development Environments (IDEs). Plugins are available for popular tools like VS Code, Vim, Emacs, Sublime Text, and more, allowing developers to format code on-save, on-demand, or as part of a pre-commit hook. This immediate feedback helps maintain code style consistency throughout the development workflow.


title: HISTORY
content:
<b>clang-format</b> was developed as a sub-project of <I>Clang</I>, which is part of the broader <I>LLVM</I> compiler infrastructure project. It first appeared in the <I>LLVM</I> ecosystem around 2012-2013, with early versions integrated into <I>Clang</I> 3.3/3.4. Its creation aimed to provide an official, robust, and extensible code formatter tightly integrated with the <I>Clang</I> parser. This allowed it to understand the abstract syntax tree (AST) of the code, enabling more intelligent and accurate formatting than regex-based tools. Its YAML-based configuration system quickly led to widespread adoption in C++ and other language communities due to its flexibility and ease of sharing style rules.


title: SYNOPSIS
content:
<b>clang-tidy</b> [<i>options</i>] <i><source files></i> -- [<i>compiler options</i>]<br><br>Example: <i>clang-tidy -checks='clang-diagnostic-*' -p build/ src/main.cpp -- -std=c++17</i>


title: PARAMETERS
content:
<b><b>-checks=</b><i><string></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a comma-separated list of checks to enable or disable. Wildcards (<i>*</i>) are supported. For example, <i>-checks='clang-diagnostic-*,modernize-*'</i>.<br><br><b><b>-config=</b><i><string></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies configuration in YAML format directly or a path to a <i>.clang-tidy</i> config file. This allows global or per-directory configuration of checks and options.<br><br><b><b>-header-filter=</b><i><string></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Regular expression to match header files that should be analyzed. Useful for limiting analysis to project-specific headers, preventing analysis of system headers.<br><br><b><b>-fix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies suggested fixes for detected issues automatically. Use with caution, as it modifies source files. Consider using <i>-fix-errors</i> for only error-level fixes.<br><br><b><b>-p</b> <i><build-path></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the build directory containing the <i>compile_commands.json</i> file. This file is crucial for <i>clang-tidy</i> to accurately understand compilation flags for each source file.<br><br><b><b>-extra-arg=</b><i><string></i><br><b>-extra-arg-before=</b><i><string></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes additional arguments directly to the Clang compiler invocation for each analyzed file. Useful for adding include paths, preprocessor definitions, or other compiler-specific flags.<br><br><b><b>--</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A separator indicating that all subsequent arguments are compiler options and should be passed directly to the underlying Clang compiler. Essential when <i>compile_commands.json</i> is not used or needs augmentation.<br><br>


title: DESCRIPTION
content:
<b>clang-tidy</b> is a powerful, extensible static analysis and linter tool for C, C++, and Objective-C code. Built on the Clang compiler frontend, it identifies various programming errors, style violations, and potential bugs. It provides an extensible framework for diagnosing and fixing typical programming errors, style violations, and API misuses. <i>clang-tidy</i> integrates seamlessly with modern build systems (like CMake) by leveraging the <i>compile_commands.json</i> file, which provides compilation flags for each source file. It helps enforce coding standards, improve code quality, and detect issues early in the development cycle, making codebases more maintainable and robust. Many checks are available out-of-the-box, covering areas from performance to security, and custom checks can be easily implemented.<br>It also supports automatic application of suggested fixes.


title: CAVEATS
content:
Requires a <i>compile_commands.json</i> file for accurate analysis in most complex projects, which can be generated by build systems like CMake. <br>Can be computationally intensive and slow on large codebases, requiring careful configuration and selective check enabling. <br>Some checks might produce false positives, requiring manual review, careful configuration, or suppression directives in code.<br>Automatic fixes (with <i>-fix</i>) should always be reviewed and version-controlled before committing changes, as they might not always align perfectly with developer intent.


title: CONFIGURATION FILES
content:
<i>clang-tidy</i> can be configured using <i>.clang-tidy</i> files placed in the project directory hierarchy. These YAML-formatted files allow fine-grained control over which checks are enabled/disabled, their options, and how they behave. Configuration can be global (e.g., in your home directory) or specific to subdirectories, with configuration files closer to the source file overriding more distant ones.


title: INTEGRATION WITH BUILD SYSTEMS
content:
For effective use, <i>clang-tidy</i> relies on accurate compiler flags for correct parsing and semantic analysis. This is best achieved by generating a <i>compile_commands.json</i> file from your build system (e.g., using CMake with <i>-DCMAKE_EXPORT_COMPILE_COMMANDS=ON</i>). Tools like <i>run-clang-tidy.py</i> (often provided with Clang distributions) simplify running <i>clang-tidy</i> across an entire project based on this file, processing all relevant source files defined within it.


title: HISTORY
content:
<b>clang-tidy</b> originated as part of the LLVM project, leveraging the Clang compiler's robust parsing and semantic analysis capabilities. It was developed to provide a powerful, open-source alternative to commercial static analysis tools for C, C++, and Objective-C, enabling deeper code insights and seamless integration into CI/CD pipelines. Its development is ongoing, with new checks and features continually added by the community.


title: SYNOPSIS
content:
<br><b><code>clangd [<i>options</i>]</code></b><br><br>clangd is typically run as a background process by an editor, communicating over standard I/O using the <i>Language Server Protocol</i>. Its command-line options control its behavior and logging.


title: PARAMETERS
content:
<b>--compile-commands-dir=&lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the directory containing the <code>compile_commands.json</code> file, crucial for accurate project understanding.<br><br><b>--fallback-style=&lt;name&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the fallback code style for formatting when no <code>.clang-format</code> file is found in the project.<br><br><b>--log=&lt;value&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the verbosity of logging output (e.g., info, verbose, debug) to stderr.<br><br><b>--project-root=&lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly sets the project root directory, overriding `clangd`'s auto-detection.<br><br><b>--query-driver=&lt;paths&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of compiler paths to query for system include directories and default compilation flags.<br><br><b>--trace</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables logging of all <i>LSP</i> traffic (incoming and outgoing JSON-RPC messages) for debugging purposes.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <code>clangd</code> version information and then exits.<br><br><b>--background-index</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables background indexing of the project files to provide faster responses for queries like workspace symbols or find all references.<br><br>


title: DESCRIPTION
content:
clangd is a <i>Language Server Protocol (LSP)</i> server for C, C++, and Objective-C, part of the <i>LLVM project</i>. It provides advanced <i>IDE-like features</i> to any LSP-compatible editor (e.g., VS Code, Neovim, Emacs, Sublime Text). These features include intelligent code completion, on-the-fly diagnostics (errors and warnings), go-to-definition, find-all-references, symbol renaming, and code formatting.<br><br>clangd parses your code using <i>Clang's powerful parsing engine</i>, leveraging <code>compile_commands.json</code> files for accurate build configuration. This allows it to understand your project's compilation flags and include paths, providing highly accurate and context-aware language features. It significantly enhances developer productivity by bringing robust C-family language support to lightweight editors.


title: CAVEATS
content:
<br><b>Accuracy relies on <code>compile_commands.json</code>:</b> For optimal accuracy in diagnostics and navigation, <code>clangd</code> heavily relies on a correctly generated <code>compile_commands.json</code> file, which specifies compilation flags for each source file. Without it, <code>clangd</code> might guess flags or use a fallback, potentially leading to less accurate results.<br><br><b>Resource Usage:</b> For very large C++ codebases, <code>clangd</code> can consume significant memory and CPU resources, especially during initial indexing or extensive refactoring operations.<br><br><b>Editor Integration:</b> While it implements a standard protocol, the quality and feature set of <code>clangd</code> integration can vary between different editors due to how each editor's <i>LSP</i> client is implemented.


title: <BR>CONFIGURATION FILES:<BR>
content:
While command-line flags control <code>clangd</code>'s behavior, its core understanding of your project comes from configuration files:<br><ul><li><code>compile_commands.json</code>: Generated by build systems (like CMake or Ninja) or tools (like <code>bear</code>), this file tells <code>clangd</code> how each source file is compiled, including include paths and defines. It's crucial for accurate diagnostics and navigation.</li><li><code>.clangd</code>: A project-specific configuration file for <code>clangd</code> itself, allowing for settings like specific compilation flags, logging levels, or disabled features.</li><li><code>.clang-format</code>: Used by <code>clangd</code> for code formatting operations, defining coding style rules for the project.</li></ul>


title: <BR>LSP COMMUNICATION:<BR>
content:
<code>clangd</code> communicates with editors using <i>JSON-RPC</i> messages over standard input/output, adhering to the <i>Language Server Protocol</i> specification. This design allows it to be integrated into a wide range of editors and <i>IDEs</i> that support <i>LSP</i>, ensuring a consistent development experience across different environments.


title: HISTORY
content:
<br><code>clangd</code> emerged as part of the broader <i>LLVM project</i>, leveraging the highly robust and accurate parsing capabilities of <i>Clang</i>, the LLVM C/C++/Objective-C frontend. Its development gained momentum with the rise of the <i>Language Server Protocol (LSP)</i>, aiming to provide a modern, universal, and editor-agnostic solution for C-family language development.<br><br>Before <code>clangd</code> and <i>LSP</i>, editor integrations for C++ were often editor-specific or relied on less precise tag-based systems. <code>clangd</code> was designed to overcome these limitations by offering deep semantic understanding powered by a real compiler frontend, establishing itself as a leading language server for C++ development.


title: PARAMETERS
content:
<b>-f, --config &lt;file&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the YAML configuration file to use for <i>Clash</i>. This is typically required for operation.<br><br><b>-d, --dir &lt;dir&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the working directory for <i>Clash</i>, where it stores data like logs, cached geo-IP databases, and configuration backups.<br><br><b>-t, --test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Tests the syntax and validity of the specified configuration file without actually starting the <i>Clash</i> proxy.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current version information of the <i>Clash</i> client and exits.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a brief help message detailing available command-line options and usage.<br><br><b>-s, --strict</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables strict mode, which might alter how certain rules or network behaviors are handled, often related to DNS or connection handling.<br><br>


title: DESCRIPTION
content:
<i>Clash</i> is a cross-platform, rule-based proxy client that supports multiple proxy protocols, including Socks5, HTTP, Shadowsocks, VMess, Trojan, and more. It acts as a gateway for your network traffic, allowing you to define granular rules for how different connections are routed. This enables users to bypass geo-restrictions, enhance privacy, and manage network traffic effectively based on domains, IP ranges, process names, or geographical locations.<br><br>Utilizing a declarative YAML configuration file, <i>Clash</i> provides extensive customization options for proxy selection, load balancing, and complex traffic routing scenarios. It also features a built-in RESTful API and a web-based dashboard for real-time monitoring, management, and easy configuration changes. While not a native Linux command in the traditional sense, it's widely used as a powerful network utility for advanced proxying needs.


title: CAVEATS
content:
<i>Clash</i> is not a standard Linux utility shipped with most distributions; it needs to be installed separately. Its effective use requires a good understanding of network concepts and YAML configuration. Improper configuration can lead to network connectivity issues or expose your traffic to unintended proxies. Security is paramount; ensure your configuration files and proxy servers are trustworthy.


title: CONFIGURATION FILE FORMAT
content:
<i>Clash</i> relies entirely on a YAML-formatted configuration file. This file defines everything from proxy servers, proxy groups (for load balancing or failover), and DNS settings to a sophisticated set of rules governing how traffic is routed, e.g., 'DIRECT' for no proxy, 'PROXY' for a specific proxy, or 'REJECT' for blocking.


title: DASHBOARD AND API
content:
Beyond its command-line interface, <i>Clash</i> includes a powerful RESTful API and a web-based dashboard. The dashboard provides a graphical interface for monitoring network connections, viewing logs, switching proxy groups, and dynamically reloading the configuration without restarting the service, offering real-time control and visibility.


title: HISTORY
content:
Developed as an open-source project, <i>Clash</i> rapidly gained popularity, particularly among users seeking flexible and robust proxy solutions for bypassing internet censorship and managing complex network routing. Its adoption soared due to its support for a wide array of modern proxy protocols and its powerful rule-based engine, making it a go-to tool for advanced network proxying tasks across various operating systems.


title: PARAMETERS
content:
<b><b>-T type</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the terminal type to use instead of the value from the <I>TERM</I> environment variable. This is useful for testing or when <I>TERM</I> is set incorrectly.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of the <I>clear</I> command and exits.<br><br><b><b>-x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;This option, primarily effective for <I>xterm</I>-like terminals, clears the screen and also attempts to clear the terminal's scrollback buffer. This provides a completely blank slate, removing previous command output from view.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables quiet mode, suppressing any sound output that might occur on some terminals when clearing the screen.<br><br>


title: DESCRIPTION
content:
The <b>clear</b> command provides a portable and reliable way to clear your terminal screen. Instead of sending a hardcoded escape sequence, it consults the <I>TERM</I> environment variable to determine your current terminal type. It then looks up the appropriate "clear screen" (<I>cl</I>) capability in the <I>terminfo</I> database and sends that specific sequence to your terminal. This approach ensures that <I>clear</I> works correctly across a wide variety of terminal emulators and consoles, unlike simply typing <I>Ctrl+L</I> or using raw escape sequences which might not be universally effective. For modern <I>xterm</I>-compatible terminals, the <I>-x</I> option can also clear the scrollback buffer, providing a truly clean slate. Its primary purpose is to refresh the display, removing previous output and presenting a clean prompt.


title: CAVEATS
content:
The effectiveness of <I>clear</I> heavily depends on the correct <I>TERM</I> environment variable setting and the availability of a matching entry in the <I>terminfo</I> database. If these are misconfigured, <I>clear</I> may fail or produce unexpected results. The <I><b>-x</b></I> option for clearing the scrollback buffer is not universally supported by all terminal types; it is most effective on <I>xterm</I> and compatible emulators. For a more comprehensive terminal reset (including modes, tabs, etc.), the <I>reset</I> command is often more suitable.


title: HOW IT WORKS
content:
When <I>clear</I> is executed, it first reads the value of the <I>TERM</I> environment variable. It then uses this information to query the <I>terminfo</I> database for the specific escape sequence associated with the "clear screen" capability (often referred to as <I>cl</I> or <I>clear</I>). This sequence is then printed to standard output, which the terminal interprets as an instruction to clear its display.


title: ALTERNATIVE METHODS
content:
Users often use <I>Ctrl+L</I> as a keyboard shortcut to clear the screen, which typically sends a form feed character (<I>^L</I> or <I>\f</I>). While this works for many terminals, it's not as robust or portable as <I>clear</I>. Another programmatic alternative is <I>tput clear</I>, which leverages the same <I>terminfo</I> database but is part of the <I>tput</I> utility. For a full terminal reset, including scrollback and various settings, <I>reset</I> is the go-to command.


title: HISTORY
content:
The <I>clear</I> command is typically part of the <I>ncurses</I> (new curses) library utilities, which provide a programming interface for terminal control. Its functionality has existed for a long time within the Unix/Linux ecosystem, evolving from the older <I>termcap</I> (terminal capabilities) system to the more advanced <I>terminfo</I> system. Its purpose has consistently been to provide a robust and portable method for applications and users to clear the terminal display, abstracting away the complexities of different terminal escape sequences.


title: PARAMETERS
content:
<b>-T <I>type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides the value of the <B>TERM</B> environment variable, explicitly specifying the terminal type for which to retrieve screen-clearing capabilities. This is rarely needed as <B>clear</B> usually correctly infers the type.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of the <B>clear</B> utility to standard output.<br><br>


title: DESCRIPTION
content:
The concept of 'clear_console' in Linux typically refers to the action of erasing all visible text from the terminal screen and repositioning the cursor to the top-left corner. While 'clear_console' itself is <I>not</I> a standard standalone command in most Linux distributions, this functionality is robustly provided by the <B>clear</B> command. <B>clear</B> operates by consulting the <I>terminfo</I> database to retrieve the correct escape sequences specific to the current terminal type, ensuring broad compatibility across various terminal emulators. Its primary purpose is to offer a clean visual slate for subsequent command execution, improving readability without typically affecting the terminal's scrollback history.


title: CAVEATS
content:
The command <B>clear_console</B> is <I>not</I> a standard or pre-installed Linux command. The functionality of clearing the console is universally provided by the <B>clear</B> command. Users might encounter 'clear_console' in custom scripts or specific niche environments.<br>The <B>clear</B> command, while effective for the visible screen, generally does <I>not</I> erase the terminal's scrollback buffer; previous output can often still be viewed by scrolling up. Its effectiveness relies on the correct <B>TERM</B> environment variable and accurate <I>terminfo</I> database entries.


title: NOT A STANDARD COMMAND
content:
It is crucial to understand that <B>clear_console</B> is <I>not</I> a standard executable present in most Linux distributions. The typical command for clearing the terminal screen is <B>clear</B>. If you encounter 'clear_console', it is likely a custom script, an alias, or a misunderstanding of a similar command.


title: CLEARING SCROLLBACK BUFFER
content:
While <B>clear</B> effectively clears the currently visible portion of the terminal, it usually leaves the scrollback history intact. This means you can still scroll up to view previous commands and their output. To truly clear the entire buffer (including scrollback), terminal-specific escape sequences or functions might be necessary, such as `printf '\033[3J\033[H\033[2J'` for some Xterm-compatible terminals, or using your terminal emulator's built-in 'Clear Scrollback' feature.


title: EFFICIENCY CONSIDERATIONS
content:
For frequent use, some shell built-ins or direct escape sequences (e.g., `echo -e '\033c'`) can be marginally faster than invoking the external <B>clear</B> command, as built-ins are part of the shell and avoid process creation overhead. However, <B>clear</B> is generally preferred for its portability and reliance on the robust <I>terminfo</I> system.


title: HISTORY
content:
The ability to clear a terminal screen has been fundamental since the advent of video display terminals. The <B>clear</B> command, which facilitates this action, has been a standard utility in Unix-like operating systems for decades. Its implementation relies on the <I>terminfo</I> (or its predecessor, <I>termcap</I>) database, which was developed to abstract away the myriad of control sequences required by different terminal hardware. This abstraction allows applications like <B>clear</B> to function correctly across a wide array of terminal types, making it a robust and portable solution for screen management.


title: SYNOPSIS
content:
<b>clementine</b> [<i>OPTIONS...</i>] [<i>FILES/URLs...</i>]<br><b>clementine</b> <i>--remote-control-command</i>


title: PARAMETERS
content:
<b><i>FILES/URLs...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more audio files or URLs to open upon launch. If Clementine is already running, these are added to the playlist.<br><br><b><b>--play</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts playback if Clementine is running and paused or stopped.<br><br><b><b>--pause</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pauses playback if Clementine is running and playing.<br><br><b><b>--stop</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stops playback if Clementine is running.<br><br><b><b>--next</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Plays the next track in the current playlist.<br><br><b><b>--previous</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Plays the previous track in the current playlist.<br><br><b><b>--toggle-play</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Toggles between play and pause states for the current track.<br><br><b><b>--volume-up</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the playback volume.<br><br><b><b>--volume-down</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decreases the playback volume.<br><br><b><b>--set-volume</b> <<i>level</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the volume to a specific <i>level</i>, where <i>level</i> is an integer between 0 and 100.<br><br><b><b>--seek</b> <<i>seconds</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Seeks to a specific time (in <i>seconds</i> from the beginning) within the current track.<br><br><b><b>--random</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Toggles the random play mode (shuffles the playlist).<br><br><b><b>--repeat</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Toggles the repeat play mode for the current track or playlist.<br><br><b><b>--shuffle</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Toggles shuffle play mode (similar to <b>--random</b>).<br><br><b><b>--status</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the current playback status to standard output, including track title, artist, album, and position.<br><br><b><b>--activate</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Brings the Clementine main window to the foreground if it is running.<br><br><b><b>--quit</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends a command to the running Clementine instance to exit.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the Clementine application version and build information.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a summary of command-line options and their usage.<br><br>


title: DESCRIPTION
content:
<i>Clementine</i> is a free and open-source multiplatform music player that was initially created as a fork of Amarok 1.4. It is designed to provide a fast and user-friendly interface for managing and playing a wide variety of music files. Beyond local music collections, <i>Clementine</i> boasts extensive support for numerous internet radio services such as Spotify, SoundCloud, Icecast, and SomaFM, as well as podcasts. It can seamlessly integrate with cloud storage services like Google Drive, Dropbox, and OneDrive, allowing users to stream music directly from the cloud. Key features include smart and dynamic playlists, audio transcoding, CUE sheet support, and remote control capabilities via web interface or dedicated mobile apps (Android/iOS). Its objective is to offer a comprehensive, yet resource-efficient, music listening solution for desktop users.


title: CAVEATS
content:
<i>Clementine</i> is primarily a graphical user interface (GUI) application. Its command-line interface is mainly intended for launching the application, opening specific files, or controlling an already running instance. Most playback control options (e.g., <b>--play</b>, <b>--pause</b>, <b>--next</b>) require a Clementine instance to be active in the background for them to function correctly. If no instance is running, invoking these commands typically results in no action or simply launches the GUI without the intended control effect.


title: CROSS-PLATFORM AVAILABILITY
content:
One of <i>Clementine</i>'s significant strengths is its broad availability across multiple operating systems. It provides native builds for <b>Linux</b>, <b>Windows</b>, and <b>macOS</b>, ensuring a consistent and familiar user experience regardless of the user's preferred desktop environment.


title: HISTORY
content:
<i>Clementine</i> was created in 2010 as a fork of Amarok 1.4, a popular music player on Linux. The development team initiated this fork in response to the significant architectural changes and user interface redesign introduced in Amarok 2.0, which many long-time users found less intuitive and feature-rich than the previous version. <i>Clementine</i> aimed to restore the user experience and feature set of Amarok 1.4 while updating the underlying technologies to modern standards (initially Qt 4, later Qt 5) and adding new functionalities such as cloud service integration, advanced internet radio support, and improved library management. It quickly gained a dedicated user base across Linux, Windows, and macOS, becoming a popular choice for desktop music playback.


title: SYNOPSIS
content:
<i>[wrapper_script_name]</i> <b>[OPTIONS]</b> <i>[ARGUMENTS]</i><br><br><i>Description:</i> The `cli-wrapper` term refers to a custom script or program that acts as an intermediary for another command-line interface. Therefore, its actual invocation syntax (e.g., `my_custom_tool --flag value`) depends entirely on how the specific wrapper has been named and implemented by its creator. The `[wrapper_script_name]` would be the executable name given to the custom wrapper script or binary.


title: PARAMETERS
content:
<b><i>(Parameters depend on implementation)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Since `cli-wrapper` is a conceptual term and not a standard command, its parameters are entirely defined by the specific wrapper script or program a developer creates. Commonly, a wrapper might expose simplified versions of the underlying command's parameters or add its own specific options for control. Examples of such generic options might include:<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays usage information and available options for the specific wrapper script.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version of the wrapper script.<br><br><b><b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of output, often showing details about the underlying commands being executed.<br><br><b><b>--config</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a configuration file for the wrapper, if supported.<br><br>


title: DESCRIPTION
content:
The term <i>"cli-wrapper"</i> does <b>not</b> refer to a standard, universally available Linux command or utility found in typical distributions. Instead, it is a generic concept describing a custom script or program that provides a higher-level, more user-friendly interface to an existing, often more complex, command-line tool or set of tools.<br><br>A CLI wrapper's primary purpose is to simplify command-line interactions by: <br><ul><li>Abstracting away complex options or syntax.</li><li>Providing sensible default values for frequently used parameters.</li><li>Automating sequences of multiple underlying commands.</li><li>Adding input validation, error handling, or logging capabilities.</li><li>Integrating different tools into a unified workflow.</li></ul><br>The specific functionality, options, and even the name of a <i>"cli-wrapper"</i> are entirely determined by its developer. It can be implemented in various scripting languages like Bash, Python, Perl, Ruby, or compiled languages.


title: CAVEATS
content:
The term <i>"cli-wrapper"</i> does <b>not</b> refer to a standard, universally available Linux command or utility found in typical distributions. Its existence, name, syntax, and functionality are entirely dependent on a custom script or application created by a developer. Therefore, the information provided here is conceptual, describing what a <i>"CLI wrapper"</i> generally entails, rather than a specific command found on a system.


title: COMMON USE CASES FOR CLI WRAPPERS
content:
CLI wrappers are widely used across various domains to improve usability and efficiency:<br><ul><li><b>Simplification:</b> Reducing complex command-line arguments and options of powerful tools (e.g., `ffmpeg`, `aws cli`) to a few intuitive flags.</li><li><b>Automation:</b> Chaining multiple commands together into a single, easy-to-invoke action, automating repetitive tasks.</li><li><b>Abstraction:</b> Hiding the intricacies of underlying tools, APIs, or complex data structures from end-users.</li><li><b>Validation & Error Handling:</b> Adding input validation and robust error handling before executing the wrapped command, providing more user-friendly feedback.</li><li><b>Configuration Management:</b> Providing a consistent interface to configure underlying tools or services based on environment variables or configuration files.</li><li><b>Standardization:</b> Ensuring consistent usage of a tool across a team or organization by enforcing specific parameters or workflows.</li></ul>


title: HISTORY
content:
There is no specific history for a command named `cli-wrapper` as it is not a standard utility. However, the concept of creating 'wrapper' scripts or programs to simplify or automate complex command-line interactions has been a fundamental practice in Unix/Linux system administration and development since the early days of command-line interfaces. Developers and system administrators frequently create such wrappers to streamline workflows, ensure consistent usage of underlying tools, and abstract away low-level details, making complex operations more accessible.


title: SYNOPSIS
content:
<i>cli53</i> [global-options] <i>&lt;command&gt;</i> [command-options] [arguments]<br><br><b>Common Global Options:</b><br><i>  --access-key &lt;KEY_ID&gt;</i><br><i>  --secret-key &lt;ACCESS_KEY&gt;</i><br><i>  --profile &lt;PROFILE_NAME&gt;</i><br><i>  --region &lt;REGION&gt;</i><br><i>  --json</i><br><i>  --help</i><br><br><b>Examples of Commands:</b><br><i>  cli53 list</i><br><i>  cli53 create &lt;ZONE_NAME&gt;</i><br><i>  cli53 rrlist &lt;ZONE_NAME&gt;</i><br><i>  cli53 rrcreate &lt;ZONE_NAME&gt; &lt;NAME&gt; &lt;TYPE&gt; &lt;VALUE&gt; --ttl &lt;TTL&gt;</i><br><i>  cli53 import &lt;ZONE_NAME&gt; --file &lt;FILE&gt;</i><br><i>  cli53 export &lt;ZONE_NAME&gt; &gt; &lt;FILE&gt;</i>


title: PARAMETERS
content:
<b><i>&lt;command&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The subcommand to execute, e.g., <i>list</i> (zones), <i>create</i> (zone), <i>delete</i> (zone), <i>rrlist</i> (records), <i>rrcreate</i> (record), <i>rrdelete</i> (record), <i>import</i>, <i>export</i>. Each subcommand has its own specific set of options and arguments.<br><br><b><i>--access-key &lt;KEY_ID&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the AWS access key ID to use for authentication, overriding default credentials.<br><br><b><i>--secret-key &lt;ACCESS_KEY&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the AWS secret access key to use for authentication, overriding default credentials.<br><br><b><i>--profile &lt;PROFILE_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a specific profile from the AWS shared credentials file (~/.aws/credentials) or config file (~/.aws/config).<br><br><b><i>--region &lt;REGION&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the AWS region. While Route 53 is a global service, this may be used for credential resolution or other related AWS API calls.<br><br><b><i>--json</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs results in JSON format, making it suitable for programmatic parsing and scripting.<br><br><b><i>--help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the main command or a specific subcommand (e.g., <i>cli53 rrcreate --help</i>).<br><br><b><i>&lt;ZONE_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full domain name of the hosted zone, typically ending with a dot (e.g., <i>example.com.</i>). Used with zone management commands.<br><br><b><i>&lt;NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full DNS name of the record set (e.g., <i>www.example.com.</i>). Used with resource record commands.<br><br><b><i>&lt;TYPE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The DNS record type (e.g., <i>A</i>, <i>CNAME</i>, <i>MX</i>, <i>TXT</i>, <i>SRV</i>). Used with resource record commands.<br><br><b><i>&lt;VALUE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more values for the DNS record, depending on its type (e.g., IP address for A record, hostname for CNAME). Multiple values are space-separated.<br><br><b><i>--ttl &lt;SECONDS&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Time To Live (TTL) for the DNS record in seconds. Common for <i>rrcreate</i> and <i>rrupdate</i>.<br><br><b><i>--file &lt;PATH&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a standard BIND zone file for <i>import</i> or <i>export</i> operations.<br><br><b><i>--wait</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For certain commands (like <i>rrcreate</i>, <i>rrdelete</i>), this option makes <i>cli53</i> wait until the DNS changes have propagated before exiting.<br><br>


title: DESCRIPTION
content:
<i>cli53</i> is a command-line interface (CLI) tool designed for managing DNS records and hosted zones within Amazon Web Services (AWS) Route 53. It provides a convenient way to interact with Route 53 from the terminal, enabling users to create, update, delete, list, import, and export various types of DNS records (A, AAAA, CNAME, MX, TXT, SRV, NS, SOA, PTR, SPF, CAA) and hosted zones.<br><br>Built as a Python application, <i>cli53</i> simplifies routine DNS management tasks, making it ideal for scripting, automation, and DevOps workflows. It abstracts the complexities of the AWS Route 53 API, offering a straightforward command syntax. Users can manage public and private hosted zones, set DNS failover configurations, and control health checks, all from the command line. It's a valuable tool for anyone frequently interacting with AWS DNS services.


title: CAVEATS
content:
<ul><li><b>AWS Credentials Required:</b> <i>cli53</i> needs proper AWS authentication via environment variables, shared credentials files, or explicit command-line options.</li><li><b>IAM Permissions:</b> The AWS IAM user or role used must have sufficient permissions to interact with Route 53 (e.g., <i>route53:ChangeResourceRecordSets</i>, <i>route53:ListHostedZones</i>).</li><li><b>Pricing:</b> Using AWS Route 53 and its features incurs costs according to AWS's pricing model.</li><li><b>Third-Party Tool:</b> <i>cli53</i> is a community-maintained open-source tool, not an official AWS product. While widely used and reliable, support is community-driven.</li><li><b>Zone File Format:</b> When importing, the tool expects standard BIND zone file syntax. Deviations can lead to errors or incorrect record creation.</li></ul>


title: AUTHENTICATION
content:
<i>cli53</i> authenticates with AWS using standard methods. It prioritizes explicit command-line options (<i>--access-key</i>, <i>--secret-key</i>), followed by environment variables (<i>AWS_ACCESS_KEY_ID</i>, <i>AWS_SECRET_ACCESS_KEY</i>), and then AWS shared credential files (<i>~/.aws/credentials</i> or <i>~/.aws/config</i>, which can be selected using the <i>--profile</i> option or <i>AWS_PROFILE</i> environment variable).


title: INSTALLATION
content:
As a Python package, <i>cli53</i> is typically installed using <i>pip</i>, the Python package installer. Ensure you have Python and <i>pip</i> installed on your system:<br><br><i>pip install cli53</i>


title: HISTORY
content:
<i>cli53</i> was developed by Barnaby Gray and released as an open-source project, typically installed via Python's pip package manager. Its origins trace back to the early 2010s, providing a more focused and user-friendly command-line interface for Route 53 operations compared to the broader AWS CLI tools available at the time. It quickly gained popularity within the DevOps and system administration communities for its ease of use in scripting and automating DNS management tasks. The project has undergone continuous development and remains a widely adopted tool for managing AWS DNS.


title: DESCRIPTION
content:
The command '<I>clido</I>' is not a standard or commonly recognized Linux command. It does not appear in typical Linux distributions, nor is there a manual page entry for it. It is highly probable that '<I>clido</I>' is a typographical error for the widely used '<I>sudo</I>' command, which stands for 'superuser do' and allows a permitted user to execute a command as another user, typically the superuser (root).<br><br>While '<I>clido</I>' might conceptually imply 'command-line do,' this functionality is already robustly provided by '<I>sudo</I>' and other privilege escalation tools that are fundamental to Linux system administration. Users encountering '<I>clido</I>' are strongly advised to double-check their spelling or context, as its execution will invariably lead to a 'command not found' error. There is no known utility or package that provides this specific command name within common Linux ecosystems.


title: CAVEATS
content:
As '<I>clido</I>' is not a standard Linux command, attempting to execute it will result in a 'command not found' error.<br>Users should verify the spelling of commands, especially when dealing with critical system operations or privilege-escalation tools, to avoid confusion or potential security risks.


title: HISTORY
content:
There is no documented history or development for a standard Linux command named '<I>clido</I>'. Its apparent non-existence suggests it has not been part of any official Linux utility development or widely adopted open-source project. Its resemblance to '<I>sudo</I>' strongly implies it's a common typo rather than a deliberate command.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version information and exits.<br><br><b>-c <file>, --config <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file to use instead of the default.<br><br><b>-S <script>, --startup-script <script></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes a custom shell script upon <b>clifm</b> startup.<br><br><b>-t <dir>, --tabs <dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens <b>clifm</b> with new tabs for the specified directories. Multiple directories can be provided.<br><br><b>-s <file(s)>, --select <file(s)></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the given files or directories on startup in the current pane.<br><br><b>-l, --load-last</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads the last session, restoring previously open directories and tabs.<br><br><b>-p, --preview</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Toggles the file preview pane on or off at startup. Overrides configuration.<br><br>


title: DESCRIPTION
content:
<b>clifm</b> is a robust and highly configurable command-line interface file manager written in C. It provides a keyboard-driven, <i>vi</i>-like navigation experience within the terminal, focusing on speed and minimal resource usage. Users can efficiently browse directories, manipulate files, and execute custom commands. Its design emphasizes extensibility, allowing seamless integration with external programs for tasks like file viewing, editing, and archiving.<br><br><b>clifm</b> supports tabbed browsing, bookmarks, and a powerful command-line interface for complex operations, making it suitable for both casual users and power users who prefer a pure terminal environment. Its extensive configuration options allow tailoring nearly every aspect of its behavior and appearance, making it one of the most adaptable CLI file managers.


title: CAVEATS
content:
<b>clifm</b> relies heavily on external programs for advanced functionalities such as file previews, editing, and archiving. Users must ensure these external tools are installed and properly configured (e.g., <i>bat</i> for syntax highlighting, <i>fzf</i> for fuzzy search, appropriate image/video viewers) for a complete experience.<br><br>Customization, while powerful, requires manual editing of plain text configuration files, which might have a learning curve for new users not familiar with such a setup.


title: CONFIGURATION
content:
<b>clifm</b> is configured primarily via a plain text file, typically located at <i>~/.config/clifm/clifm.conf</i>. This file allows users to define a wide range of settings, including keybindings, color schemes, default applications for various file types, custom commands (aliases), and plugin paths. Its modular configuration allows for deep personalization.


title: KEYBINDINGS
content:
The default keybindings are heavily inspired by <i>vi</i>, using <i>h</i>, <i>j</i>, <i>k</i>, <i>l</i> for navigation. It also incorporates common shell keybindings for command-line editing and allows for user-defined shortcuts and macros, offering a highly efficient keyboard-driven workflow.


title: HISTORY
content:
<b>clifm</b> emerged in the late 2010s (around 2018-2019) as a modern, performance-oriented alternative to existing terminal file managers. Developed by <i>leo-arch</i> (Leonardo Taccari), it quickly gained traction within the Linux community for its minimal dependencies, C-based efficiency, and extensive customization options, particularly appealing to users seeking a highly personalized <i>vi</i>-like workflow in the terminal. Its development focuses on stability, speed, and a rich feature set while maintaining a small footprint, aiming to be a 'minimalist yet powerful' solution.


title: SYNOPSIS
content:
As <b>clip-view</b> is not a standard command, its syntax is custom-defined.<br>Typically, it would serve as a wrapper or alias for commands like <b>xclip</b>, with a common usage pattern: <br><b>clip-view</b> [<i>OPTIONS</i>]<br>Which internally might execute: <br><b>xclip</b> [<i>SELECTION_OPTIONS</i>] <b>-o</b> [<i>OTHER_OPTIONS</i>] | <i>DISPLAY_COMMAND</i>


title: PARAMETERS
content:
<b>-o</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When wrapping <b>xclip</b>, this option outputs the content of the X selection to standard output. This is the core functionality that a <b>clip-view</b> command would utilize.<br><br><b>-selection {primary|secondary|clipboard}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When wrapping <b>xclip</b>, this specifies which X selection to operate on. <b>primary</b> is the default (mouse selection), <b>clipboard</b> is for Ctrl+C/Ctrl+V content, and <b>secondary</b> is less common. A <b>clip-view</b> often targets <b>clipboard</b>.<br><br><b>-d {display_name}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When wrapping <b>xclip</b>, specifies the X display to use. Useful when working across multiple displays or in a complex X setup.<br><br><b>-noutf8</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When wrapping <b>xclip</b>, disables UTF-8 encoding for output, which can be useful for compatibility with legacy applications or specific character sets.<br><br>


title: DESCRIPTION
content:
The <b>clip-view</b> command is not a standard or widely distributed utility in common Linux distributions. It is most likely a custom alias, a shell script, or part of a niche application created by users to simplify the process of viewing the current content of the X selection (clipboard).<br><br>In the absence of a dedicated <b>clip-view</b> executable, users typically rely on tools like <b>xclip</b> or <b>xsel</b> to interact with the X clipboard from the command line. For instance, the command <i>xclip -o -selection clipboard</i> (for the conventional Ctrl+C/Ctrl+V clipboard) or <i>xclip -o</i> (for the primary mouse selection) is commonly used to output the clipboard's content to standard output. This output can then be piped to other commands for display (e.g., <i>less</i>, <i>cat</i>, <i>nvim -R -</i>).<br><br>Graphical desktop environments also provide built-in clipboard viewers or history managers (like Klipper in KDE or GNOME Clipboard Indicator), but <b>clip-view</b> implies a command-line approach.


title: CAVEATS
content:
The most significant caveat is that <b>clip-view</b> is <b>not a standard Linux command</b>. Its presence and behavior depend entirely on whether a user or system administrator has created it as a custom script or alias on a particular system. If you encounter this command, its exact functionality, available options, and underlying dependencies (e.g., on <b>xclip</b> or <b>xsel</b>) will vary.<br><br>It will only function correctly within an X Window System environment as it directly interacts with the X server's clipboard mechanisms. For headless servers or non-X environments, there is no direct equivalent of a system-wide graphical clipboard.


title: TYPICAL IMPLEMENTATIONS
content:
A common implementation of <b>clip-view</b> as a shell alias or function might look like:<br><code>alias clip-view='xclip -o -selection clipboard | less'</code><br>or as a slightly more complex script:<br><code>#!/bin/bash<br>xclip -o -selection clipboard "$@" | less</code><br>The specific choice of X selection (primary vs. clipboard) and the final display command (like <b>less</b>, <b>cat</b>, or a text editor) would depend entirely on the creator's preference and workflow.


title: CLIPBOARD TYPES IN X WINDOW SYSTEM
content:
On the X Window System, there are typically three types of selections (often referred to as clipboards):<br><ul><li><b>PRIMARY selection:</b> Content is automatically copied when text is highlighted/selected with the mouse. It is commonly pasted by middle-clicking. This is <b>xclip</b>'s default selection for output.</li><li><b>CLIPBOARD selection:</b> Content is copied explicitly using standard keybindings like Ctrl+C (or equivalent menu actions). It is pasted with Ctrl+V. This is the most common 'clipboard' for user-initiated copy/paste operations, and what a <b>clip-view</b> command would typically target.</li><li><b>SECONDARY selection:</b> This selection is less commonly used by general applications and often reserved for specific, application-defined purposes.</li></ul>Understanding these distinctions is crucial for correctly using underlying tools like <b>xclip</b>.


title: HISTORY
content:
The concept of a shared clipboard in the X Window System dates back to its early days, with mechanisms for selections (primary, secondary, and clipboard) being fundamental. Tools like <b>xclip</b> and <b>xsel</b> emerged as robust command-line interfaces to these X selections, enabling scripts and terminal users to interact with the clipboard.<br><br>While these underlying tools have been stable for a long time, the specific wrapper <b>clip-view</b> is a relatively modern, user-created convention. It reflects the desire for simpler, more memorable aliases for common clipboard inspection tasks in a command-line environment, abstracting away the specifics of <b>xclip</b> or <b>xsel</b> syntax.


title: SYNOPSIS
content:
<b>clj</b> [<i>options</i>] [<i>main-expression</i>] [<i>arguments</i>]<br>
<b>clj</b> -M:<I>alias</I> [<i>main-expression</i>] [<i>arguments</i>]<br>
<b>clj</b> -A:<I>alias</I> [<i>arguments</i>]<br>
<b>clj</b> -R:<I>alias</I> [<i>arguments</i>]<br>
<b>clj</b> -S:<I>subcommand</I> [<i>subcommand-arguments</i>]<br>
<b>clj</b> -P


title: PARAMETERS
content:
<b><b>-M</b> or <b>-M:&lt;I&gt;alias&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invokes a main entry point. Uses configuration from alias if provided.<br><br><b><b>-A</b> or <b>-A:&lt;I&gt;alias&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds paths or dependencies to the classpath. Includes configuration from alias if provided.<br><br><b><b>-R</b> or <b>-R:&lt;I&gt;alias&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures REPL behavior. Applies REPL-specific settings from alias if provided.<br><br><b><b>-S&lt;I&gt;subcommand&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes system-level operations. Common subcommands include <b>path</b> (prints classpath), <b>describe</b> (prints environment info), and <b>install</b> (installs the tool).<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resolves and downloads dependencies, then prints the resulting classpath.<br><br><b><b>-e &lt;I&gt;expression&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates the given Clojure expression directly.<br><br><b><b>-r</b>, <b>--repl</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts a standard Clojure REPL session.<br><br><b><b>-m &lt;I&gt;ns-name&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the namespace containing the 'main' function to be executed.<br><br><b><b>-i &lt;I&gt;file&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a Clojure source file before execution.<br><br><b><b>--config &lt;I&gt;file&lt;/I&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative 'deps.edn' configuration file.<br><br><b><b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints additional diagnostic information.<br><br><b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays usage information and available options.<br><br>


title: DESCRIPTION
content:
<b>clj</b> is the official command-line interface for Clojure, part of the <i>tools.deps.alpha</i> project. It simplifies the process of running Clojure programs, managing project dependencies, and launching a REPL (Read-Eval-Print Loop). It leverages <i>deps.edn</i> files to define project dependencies and source paths, allowing for easy execution of Clojure code without requiring a separate build tool like Leiningen or Boot. <b>clj</b> handles dependency resolution and classpath construction automatically, making it convenient for both development and scripting tasks in Clojure. It provides a lightweight and flexible alternative for project management.


title: CAVEATS
content:
Requires Java Development Kit (JDK) installed and configured in the system PATH. Relies heavily on <i>deps.edn</i> for configuration, which can have a learning curve. Not a standalone executable, but a wrapper script invoking Java. Network access is typically required for initial dependency resolution and downloads. Initial startup can be slow due to JVM startup and classpath construction.


title: <I>DEPS.EDN</I> INTEGRATION
content:
<b>clj</b> heavily utilizes <i>deps.edn</i> files, which are central to defining project dependencies, source paths, and aliases. These files are typically found in the project root and allow for declarative configuration of the Clojure environment.


title: ALIAS SYSTEM
content:
The <b>clj</b> tool employs a powerful alias system within <i>deps.edn</i>, allowing users to define specific configurations (e.g., different main functions, extra dependencies, JVM options) that can be invoked with options like <b>-M:&lt;I&gt;alias&lt;/I&gt;</b>, <b>-A:&lt;I&gt;alias&lt;/I&gt;</b>, or <b>-R:&lt;I&gt;alias&lt;/I&gt;</b>. This promotes reusable and flexible project setups.


title: HISTORY
content:
<b>clj</b> was introduced as part of Clojure's official <i>tools.deps.alpha</i> project, aiming to provide a simpler, dependency-driven way to manage Clojure projects without the overhead of existing build tools. It emerged in the late 2010s (around 2018-2019) to address community needs for a more lightweight and integrated project management solution, particularly for scripting and smaller applications. It gained significant traction as the preferred official method for starting Clojure projects and REPLs, moving away from relying solely on third-party tools.


title: PARAMETERS
content:
<b><b>--by-file</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reports results for each file scanned, in addition to the overall language summary. This provides a more granular view of the codebase breakdown.<br><br><b><b>--exclude-dir</b>=<i>DIR1,DIR2,...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes the specified comma-separated list of directories from the scan. This is useful for ignoring build artifacts, dependency folders (e.g., node_modules), or documentation.<br><br><b><b>--exclude-ext</b>=<i>EXT1,EXT2,...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files with the specified comma-separated list of extensions from the scan. Useful for ignoring non-source files or specific types of assets.<br><br><b><b>--force-lang</b>=<i>&lt;language&gt;,&lt;extension&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces files with the given <i>&lt;extension&gt;</i> to be counted as the specified <i>&lt;language&gt;</i>. This is helpful for non-standard file extensions or when <i>cloc</i> misidentifies a language.<br><br><b><b>--git</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Analyzes the files within a Git repository. By default, it processes the current working tree. Can be combined with other Git-related options like <b>--git-diff</b>.<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the results in JavaScript Object Notation (JSON) format. This is ideal for programmatic parsing and integration into other tools or scripts.<br><br><b><b>--out</b>=<i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the report output to the specified <i>&lt;file&gt;</i> instead of standard output (stdout).<br><br><b><b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all informational messages except the final report summary. Useful for cleaner output when <i>cloc</i> is used in scripts.<br><br><b><b>--read-lang-def</b>=<i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads language definitions from the specified file. This allows users to add custom language definitions or override existing ones.<br><br><b><b>--skip-vcs-ignores</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignores version control system ignore files (e.g., .gitignore, .hgignore). By default, <i>cloc</i> respects these files.<br><br>


title: DESCRIPTION
content:
<i>cloc</i> (Count Lines Of Code) is a free, open-source command-line utility designed to quickly count blank lines, comment lines, and physical lines of source code in many programming languages. It offers extensive language support, detecting over 150 different programming languages by default based on file extensions and heuristics. Users can analyze individual files, entire directories, or even content from standard input. <i>cloc</i> is highly versatile, capable of parsing various file types, including compressed archives and remote URLs. It provides detailed summary reports broken down by language, along with options to report results per file. Its ability to integrate with version control systems like Git allows for analysis of repositories, specific commits, or changes between revisions. The output can be customized to various formats, including plain text, CSV, XML, and JSON, making it an invaluable tool for software project analysis, tracking codebase size, and monitoring development progress.


title: CAVEATS
content:
<i>cloc</i> primarily counts lines and does not assess code quality or complexity. Its accuracy relies on file extensions and heuristics, which might occasionally misidentify languages or line types in highly unusual codebases. Mixed-language files can also pose challenges for precise categorization.


title: LANGUAGE DETECTION AND PARSING
content:
<i>cloc</i> employs a sophisticated system to identify and count lines of code. It categorizes lines into <b>blank</b> (empty or whitespace-only), <b>comment</b> (lines ignored by the compiler/interpreter), and <b>code</b> (executable or declarative lines). Its extensive internal database of language definitions enables accurate parsing across a vast range of programming, scripting, and markup languages.


title: VERSION CONTROL SYSTEM INTEGRATION
content:
A powerful feature of <i>cloc</i> is its direct integration with version control systems, notably Git. This allows developers to analyze not just the current codebase, but also historical states, changes between commits (e.g., <b>--git-diff</b> <i>&lt;commit1&gt;</i> <i>&lt;commit2&gt;</i>), or even patch files. This capability is invaluable for tracking project growth, refactoring efforts, and understanding development velocity over time.


title: FLEXIBLE OUTPUT FORMATS
content:
Beyond its default human-readable text report, <i>cloc</i> supports output in several machine-readable formats: <b>CSV</b>, <b>JSON</b>, and <b>XML</b>. These formats facilitate automation, data analysis, and integration with other tools or dashboards, making <i>cloc</i> a versatile component in CI/CD pipelines and reporting systems.


title: HISTORY
content:
<i>cloc</i> was created by Al Danford in 2006, written in Perl. It quickly gained popularity for its comprehensive language support, robust parsing capabilities, and cross-platform compatibility. Its continuous development and wide array of output formats have solidified its position as a go-to tool for source code analysis in various development environments.


title: SEE ALSO
content:
<b>wc(1)</b><br>Basic line, word, and byte counting utility., <b>sloccount(1)</b><br>Another tool for counting source lines of code, though often less maintained than <i>cloc</i>., <b>find(1)</b><br>Used to locate files that can then be piped to <i>cloc</i> for selective analysis., <b>xargs(1)</b><br>Often used with <i>find</i> to construct command lines for <i>cloc</i> from a list of files.


title: PARAMETERS
content:
<b>run <task_id></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Immediately executes a specific task by its ID, bypassing its regular schedule.<br><br><b>deploy</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deploys or synchronizes tasks defined in a local configuration file (e.g., <I>clockwork.json</I> or <I>clockwork.yaml</I>) with the Clockwork service.<br><br><b>trigger <event_id></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Triggers a custom event in Clockwork, which can be used to initiate event-driven tasks.<br><br><b>logs [<task_id>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays recent execution logs for all tasks or for a specific task if a task ID is provided.<br><br><b>status [<task_id>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the current status of all managed tasks or a specific task if a task ID is provided.<br><br><b>version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the installed version of the Clockwork CLI tool.<br><br><b>help [<command>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows general help information for the CLI or detailed help for a specific command.<br><br>


title: DESCRIPTION
content:
<b>clockwork-cli</b> is the official command-line interface for the Clockwork cloud-based task runner. It allows users to interact with their Clockwork account and managed tasks directly from the terminal. This tool simplifies the deployment, management, and monitoring of scheduled jobs and cron tasks without direct server access.<br><br>It integrates with various CI/CD pipelines and provides functionalities for running tasks on demand, triggering deployments, viewing logs, and checking task statuses. <b>clockwork-cli</b> is particularly useful for developers and system administrators working with web applications that rely on external scheduling services, abstracting away the complexities of server-side cron configurations.


title: CAVEATS
content:
Requires an active Clockwork account and a valid API key for most operations.<br>Primarily designed for managing cloud-based scheduled tasks, not local system cron jobs.<br>Requires internet connectivity to communicate with the Clockwork service.<br>Not a standard Linux distribution utility; it needs to be installed separately.


title: <B>CONFIGURATION-DRIVEN TASK MANAGEMENT</B>
content:
Tasks managed by <b>clockwork-cli</b> are typically defined in a declarative configuration file (e.g., <I>clockwork.json</I> or <I>clockwork.yaml</I>). The <I>deploy</I> command reads this file to synchronize task definitions with the Clockwork service, promoting an 'infrastructure-as-code' approach for task scheduling.


title: <B>REMOTE EXECUTION AND MONITORING</B>
content:
Unlike traditional cron, <b>clockwork-cli</b> facilitates remote task execution and centralized monitoring. Users can trigger tasks or view logs from any machine with the CLI installed and configured, without needing direct SSH access to the server where tasks are defined to run.


title: HISTORY
content:
<b>clockwork-cli</b> was developed by Clockwork.io as a crucial component of its cloud-based task scheduling platform. Its development has focused on providing a robust and convenient command-line interface for users to manage their scheduled jobs programmatically. It has evolved alongside the Clockwork service itself, aiming to simplify task deployment, monitoring, and integration into modern CI/CD workflows, reducing the reliance on direct server-side cron configurations.


title: SYNOPSIS
content:
<b>clojure</b> [<I>options</I>] [<I>main-fn</I>] [<I>args</I>...]<br><b>clojure</b> <I>-M</I> [<I>options</I>] [<I>main-fn</I>] [<I>args</I>...]<br><b>clojure</b> <I>-P</I> [<I>options</I>]<br><b>clojure</b> <I>-S</I><I>&lt;mode&gt;</I> [<I>options</I>]<br><b>clojure</b> <I>-T</I><I>&lt;tool&gt;</I> [<I>tool-args</I>...]


title: PARAMETERS
content:
<b><i>-Sdeps &lt;EDN&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies additional dependency information in EDN format, merged with existing <i>deps.edn</i> content.<br><br><b><i>-Spath</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the calculated effective classpath to standard output and exits.<br><br><b><i>-Sforce</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces recomputation of the classpath, bypassing cached versions.<br><br><b><i>-Scp &lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly sets the classpath instead of calculating it from <i>deps.edn</i>.<br><br><b><i>-J&lt;jvm-opt&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes a raw JVM option directly to the Java Virtual Machine (e.g., <i>-J-Xmx2g</i>).<br><br><b><i>-A&lt;alias&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies one or more aliases defined in <i>deps.edn</i> (comma-separated for multiple).<br><br><b><i>-M</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invokes the main execution mode, typically used to run an application's main function via its <i>:main-opts</i> or <i>:main-class</i>.<br><br><b><i>-m &lt;main-fn&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the main function to run from the current classpath (used with <i>-M</i> or implicitly for scripts).<br><br><b><i>-r</i> or <i>--repl</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts a Clojure REPL (Read-Eval-Print Loop) for interactive development.<br><br><b><i>-e &lt;form&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates a Clojure form string passed as an argument, then exits.<br><br><b><i>-T&lt;tool&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invokes a specific tool defined via a <i>:tool</i> alias in <i>deps.edn</i>.<br><br><b><i>-P</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints project information, including effective aliases, paths, and dependencies.<br><br><b><i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Clojure CLI version and exits.<br><br>


title: DESCRIPTION
content:
The <b>clojure</b> command (often invoked as <i>clj</i>) is the official command-line interface for running Clojure programs and interacting with the Clojure runtime. It leverages Clojure's <i>tools.deps.alpha</i> library for dependency management and project configuration, typically defined in <i>deps.edn</i> files.<br><br>Unlike traditional language runtimes that might only execute a single script, <b>clojure</b> is designed to orchestrate complex projects, managing classpaths, JVM options, and different execution modes (like running a main function, starting a REPL, or executing specific tools). It acts as a wrapper around the Java Virtual Machine (JVM), setting up the necessary environment for Clojure code execution. Its primary uses include starting a Read-Eval-Print Loop (REPL) for interactive development, executing a Clojure application's main entry point, or running custom build and development tools.


title: CAVEATS
content:
The <b>clojure</b> command requires a Java Development Kit (JDK) or Java Runtime Environment (JRE) to be installed and accessible on the system's PATH. It is not a standard Linux utility and must be installed separately, usually through a package manager or by downloading the official <b>clojure</b> CLI script. Its behavior heavily depends on the presence and content of <i>deps.edn</i> configuration files in the current directory or its parent directories, which define dependencies, source paths, and aliases. The command is primarily designed for Clojure projects and is not applicable for general system administration.


title: <I>DEPS.EDN</I> INTEGRATION
content:
The <b>clojure</b> command's core functionality is deeply intertwined with the <i>deps.edn</i> file. This file, typically located at the root of a Clojure project, is an EDN-formatted configuration that defines project dependencies, source code paths, test paths, and custom aliases. The CLI parses this file to construct the Java classpath, resolve dependencies, and apply specific configurations (like adding development tools or custom main functions) based on the supplied command-line options and aliases.


title: INTERACTIVE REPL USAGE
content:
One of the most common uses of the <b>clojure</b> command is to launch a Read-Eval-Print Loop (REPL). By running <I>clojure -A:dev -r</I> (where <i>:dev</i> is a common alias for development dependencies and REPL setup), developers gain an interactive environment to evaluate Clojure code, experiment with libraries, and connect to running applications for live debugging and development. The REPL is a cornerstone of Clojure's iterative and exploratory development workflow.


title: HISTORY
content:
The <b>clojure</b> command-line interface (CLI) is a relatively modern addition to the Clojure ecosystem, officially introduced around 2018. Before its advent, <i>Leiningen</i> and <i>Boot</i> were the predominant build and project management tools for Clojure. The <b>clojure</b> CLI, built around the <i>tools.deps.alpha</i> library, was developed to provide a simpler, more direct, and arguably more flexible approach to dependency management and project execution, leveraging plain EDN (Extensible Data Notation) for configuration instead of DSLs or build files. It aims to integrate more seamlessly with the underlying Java ecosystem and offers a powerful aliasing system for custom workflows. Its evolution reflects a desire for a 'native' CLI experience, optimized for Clojure's specific needs, and has become the de facto standard for new Clojure projects.


title: PARAMETERS
content:
<b><b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enable debug logging, showing more verbose output for troubleshooting.</i><br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show program's version number and exit.</i><br><br><b><b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Force an action that might otherwise be skipped (e.g., force a clean).</i><br><br><b><b>status</b> [<i>-w</i>|<i>--wait</i>] [<i>--format=json</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display the current status of cloud-init execution. The <b>-w</b> or <b>--wait</b> option waits for cloud-init to complete, while <b>--format=json</b> provides output in JSON format.</i><br><br><b><b>clean</b> [<i>--reboot</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Removes cloud-init's state, allowing it to run again on the next boot. Use with caution. The <b>--reboot</b> option can optionally reboot the system afterwards.</i><br><br><b><b>analyze</b> [<i>show</i>|<i>dump</i>|<i>blame</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Tools to analyze cloud-init's performance and execution details, showing what modules took time or dumping collected data.</i><br><br><b><b>collect-logs</b> [<i>-f</i>|<i>--stdout</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Collects all cloud-init related logs and system information into a single archive for debugging purposes. The <b>-f</b> or <b>--stdout</b> option prints to standard output instead of creating a file.</i><br><br>


title: DESCRIPTION
content:
<b>cloud-init</b> is a widely adopted open-source package that handles early initialization of cloud instances. It runs during the first boot of a virtual machine or container to configure various aspects, making the instance ready for use. Its primary function is to interpret "user data" provided by the cloud provider, which can include shell scripts, YAML files, or other formats to set up users, install packages, configure networking, inject SSH keys, and run arbitrary commands. It operates in distinct stages, ensuring services and configurations are applied in a correct order. By abstracting the underlying cloud platform, <b>cloud-init</b> provides a consistent way to initialize instances across different cloud environments like AWS, Azure, Google Cloud, and OpenStack, simplifying automation and infrastructure-as-code deployments.


title: CAVEATS
content:
<i>cloud-init</i> primarily executes only on the first boot of an instance. While its state can be reset using <b>cloud-init clean</b>, this is often used for testing and should be approached with caution in production environments as it can lead to unintended reconfigurations. Debugging issues can be challenging due to its early boot execution and complex module system. Proper 'user data' formatting and syntax are critical for successful configuration.


title: USER DATA
content:
<i>This is the primary input mechanism for</i> <b>cloud-init</b>. <i>Cloud providers allow users to pass arbitrary data (text) to instances during launch.</i> <b>cloud-init</b> <i>parses this data, which can be a shell script, YAML file for declarative configuration, or other formats, to perform tasks such as installing packages, creating users, injecting SSH keys, setting hostnames, and configuring network interfaces.</i>


title: CONFIGURATION FILES AND MODULES
content:
<i>cloud-init's core configuration is typically found in</i> <b>/etc/cloud/cloud.cfg</b> <i>and related directories. It operates using a modular system, where different "modules" handle specific tasks (e.g., `cloud_final_modules`, `cloud_config_modules`). These modules are executed in predefined stages (e.g., `init`, `config`, `final`) to ensure that dependencies are met and configurations are applied in the correct order during the boot process.</i>


title: HISTORY
content:
<i>cloud-init</i> was originally developed by Canonical (the creators of Ubuntu) in 2008 to provide a consistent way to provision instances within Amazon EC2. Over time, it evolved to support numerous other cloud platforms and virtualization technologies, including OpenStack, Microsoft Azure, Google Cloud Platform, VMware, and others. Its adoption across major cloud providers has made it a de facto standard for initial instance configuration, significantly simplifying cloud automation and enabling infrastructure-as-code practices for dynamic environments.


title: SEE ALSO
content:
<b>systemctl(1)</b>: <i>Used for controlling the cloud-init service (e.g., enable, start, stop).</i>, <b>journalctl(1)</b>: <i>For viewing cloud-init logs, often found under the 'cloud-init' unit.</i>, <b>ds-identify(8)</b>: <i>A utility that helps identify the cloud datasource, often used by cloud-init.</i>, <b>init(8)</b>: <i>The parent of all processes; cloud-init runs early in the boot sequence.</i>


title: SYNOPSIS
content:
<i>cloudflared</i> <command> [flags]<br><br>Common commands:<br><i>cloudflared</i> tunnel run <TUNNEL-NAME-OR-UUID> [--config <PATH>]<br><i>cloudflared</i> tunnel create <TUNNEL-NAME><br><i>cloudflared</i> proxy-dns [--address <ADDR>] [--port <PORT>]<br><i>cloudflared</i> login<br><i>cloudflared</i> update


title: PARAMETERS
content:
<b>--config <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to a configuration file for <i>cloudflared</i>.<br><br><b>--logfile <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes log output to a specified file instead of standard error.<br><br><b>--loglevel <level></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging verbosity (e.g., <i>debug</i>, <i>info</i>, <i>warn</i>, <i>error</i>).<br><br><b>--metrics <address></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exposes Prometheus metrics on the given address and port.<br><br><b>--no-autoupdate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables automatic updates of the <i>cloudflared</i> binary.<br><br><b>--proxy-dns-address <address></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <i>proxy-dns</i>) Specifies the address to listen on for DNS queries.<br><br><b>--proxy-dns-port <port></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <i>proxy-dns</i>) Specifies the port to listen on for DNS queries.<br><br><b>--proxy-dns-upstream <URL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <i>proxy-dns</i>) Defines an upstream DNS server URL for resolution.<br><br><b>--url <URL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(For <i>tunnel run</i>) Specifies the local service URL to expose via a quick tunnel.<br><br>


title: DESCRIPTION
content:
<i>cloudflared</i> is a command-line tool developed by Cloudflare that allows users to create secure, outbound-only tunnels (known as Cloudflare Tunnels or Argo Tunnels) from their infrastructure to Cloudflare's global network. This eliminates the need to open inbound firewall ports, significantly enhancing security. It's primarily used to expose local services like web servers, SSH, RDP, or databases to the internet through Cloudflare, leveraging Cloudflare's security, performance, and reliability features.<br><br><i>cloudflared</i> also functions as a DNS-over-HTTPS (DoH) proxy, allowing local applications to encrypt their DNS queries, improving privacy and security. It's a versatile tool for securing and connecting private networks to Cloudflare's edge.


title: CAVEATS
content:
<b>Requires Cloudflare Account:</b> To create tunnels and use most features, an active Cloudflare account and domain are necessary.<br><b>Security Implications:</b> While <i>cloudflared</i> enhances security by eliminating inbound firewall ports, exposing internal services still requires careful consideration of access controls and potential vulnerabilities.<br><b>Network Latency:</b> Performance can be affected by the distance and network latency to the nearest Cloudflare edge.<br><b>Complex Configurations:</b> Advanced setups involving multiple services, ingress rules, or specific access policies can require detailed YAML configuration.


title: KEY USE CASES
content:
<b>Exposing Internal Applications:</b> Securely make internal web applications (e.g., Jira, Confluence) accessible to specific users via Cloudflare Access without needing a VPN.<br><b>Secure Remote Access:</b> Provide secure SSH or RDP access to servers and workstations without opening firewall ports.<br><b>IoT and Edge Connectivity:</b> Connect IoT devices or services located at the network edge to a central dashboard or application.<br><b>DNS-over-HTTPS Proxy:</b> Function as a local DNS proxy to encrypt all DNS queries, enhancing privacy and security for local applications.


title: SECURITY MODEL
content:
<i>cloudflared</i> establishes an encrypted, outbound-only connection to Cloudflare's global network. This eliminates the need to open any inbound ports on your firewall, significantly reducing the attack surface. All traffic directed to your exposed service flows through Cloudflare's infrastructure, benefiting from their enterprise-grade security features like DDoS protection, Web Application Firewall (WAF), and bot management.


title: CONFIGURATION FILE
content:
While <i>cloudflared</i> can be operated with command-line flags, complex or persistent setups are typically managed using a YAML configuration file (e.g., located at <i>~/.cloudflared/config.yaml</i> or specified via the <i>--config</i> flag). This file allows for defining multiple tunnels, detailed service routing rules, advanced ingress policies, and logging preferences, offering greater flexibility and maintainability for production environments.


title: HISTORY
content:
<i>cloudflared</i> evolved from Cloudflare's 'Argo Tunnel' product, designed to provide a secure and efficient way to connect private resources to Cloudflare's network without public IP addresses or firewall rules. It aims to solve the problem of exposing internal services securely while leveraging Cloudflare's DDoS protection, WAF, and CDN capabilities. Its development focuses on ease of use, security, and integration with Cloudflare's broader ecosystem, becoming a cornerstone for connecting on-premises or private cloud infrastructure to Cloudflare Zero Trust.


title: SYNOPSIS
content:
<b><i>Configuration:</i></b><br><b>cmake</b> [options] &lt;source-dir&gt;<br><b>cmake</b> [options] <b>-S</b> &lt;source-dir&gt; <b>-B</b> &lt;build-dir&gt;<br><b><i>Building:</i></b><br><b>cmake</b> <b>--build</b> &lt;build-dir&gt; [options]<br><b><i>Scripting/Utilities:</i></b><br><b>cmake</b> <b>-P</b> &lt;script-file&gt; [args...]<br><b>cmake</b> <b>-E</b> &lt;command&gt; [args...]<br><b>cmake</b> <b>--help</b> [options]


title: PARAMETERS
content:
<b><b>-S &lt;source-dir&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the root directory of the source tree containing the <b><i>CMakeLists.txt</i></b> file.<br><br><b><b>-B &lt;build-dir&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the root directory for the build output. This enables <b><i>out-of-source builds</i></b>.<br><br><b><b>-G &lt;generator-name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the build system generator to use (e.g., <b><i>'Unix Makefiles'</i></b>, <b><i>'Ninja'</i></b>, <b><i>'Visual Studio 16 2019'</i></b>).<br><br><b><b>-D &lt;var&gt;[:&lt;type&gt;]=&lt;value&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines a <b><i>CMake</i></b> variable for the configuration phase. Useful for setting compiler flags, paths, or enabling/disabling features.<br><br><b><b>--build &lt;dir&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Builds a <b><i>CMake</i></b>-generated project within the specified build directory. This is the recommended way to build once configured.<br><br><b><b>-P &lt;script-file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Processes the given <b><i>CMake</i></b> language file in <b><i>script mode</i></b>, without generating a build system.<br><br><b><b>-E &lt;command&gt; [args...]</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes one of <b><i>CMake</i></b>'s bundled command-line utilities (e.g., <b><i>copy</i></b>, <b><i>rm</i></b>, <b><i>path</i></b>).<br><br><b><b>--install &lt;dir&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs the project built in <b><i>&lt;dir&gt;</i></b>, as defined by the <b><i>install()</i></b> commands in <b><i>CMakeLists.txt</i></b>.<br><br><b><b>--preset &lt;name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a named configure or build preset from a <b><i>CMakePresets.json</i></b> or <b><i>CMakeUserPresets.json</i></b> file.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for <b><i>cmake</i></b>, including a list of generators or specific options.<br><br>


title: DESCRIPTION
content:
<b><i>CMake</i></b> is a powerful, <b><i>cross-platform build system generator</i></b> designed to manage the compilation process of software using a compiler-independent method. Instead of building the code directly, <b><i>CMake</i></b> reads <b><i>CMakeLists.txt</i></b> files, which describe the project's source files, dependencies, and build instructions, and <b><i>generates native build tool files</i></b> specific to your chosen environment. This includes <b><i>Makefiles</i></b> for Unix/Linux, <b><i>Visual Studio projects</i></b> on Windows, <b><i>Xcode projects</i></b> on macOS, and others. This abstraction allows developers to define a single set of build instructions that work across diverse operating systems and compilers, simplifying complex multi-platform software development.<br>It supports <b><i>out-of-source builds</i></b>, ensuring that generated build files and intermediate objects do not clutter the source directory, promoting clean project structures and easy removal of build artifacts. <b><i>CMake</i></b> also offers advanced features like <b><i>testing frameworks</i></b> (<b><i>CTest</i></b>), <b><i>packaging tools</i></b> (<b><i>CPack</i></b>), and dependency management.


title: CAVEATS
content:
Understanding the <b><i>CMake</i></b> language (<b><i>CMakeLists.txt</i></b>) can have a steep learning curve, especially for complex projects or advanced features like custom commands and dependency management. While <b><i>CMake</i></b> aims for cross-platform compatibility, subtle differences in compiler behavior, library paths, and operating system specifics can still lead to platform-dependent issues. Debugging <b><i>CMakeLists.txt</i></b> issues often requires careful inspection of the generated build files and configuration output. Improper path handling in <b><i>CMake</i></b> scripts can lead to non-portable builds.


title: <B>OUT-OF-SOURCE BUILDS</B>
content:
A fundamental concept in <b><i>CMake</i></b> where the build artifacts (executables, libraries, object files, generated build system files) are created in a directory separate from the source code. This keeps the source tree clean, simplifies cleaning up build artifacts, and allows for multiple build configurations (e.g., debug and release) from the same source tree.


title: <B>GENERATORS</B>
content:
<b><i>CMake</i></b> doesn't build code directly; it generates files for a native build system. These are called <b><i>generators</i></b>. Examples include <b><i>'Unix Makefiles'</i></b> (for <b><i>make</i></b>), <b><i>'Ninja'</i></b> (for <b><i>Ninja</i></b>), and various <b><i>'Visual Studio'</i></b> generators for Windows. The choice of generator often depends on the target platform and developer preference.


title: <B>CMAKELISTS.TXT</B>
content:
The primary input file for <b><i>CMake</i></b>. This text file, written in the <b><i>CMake</i></b> language, defines the project's structure, source files, dependencies, build rules, and any custom commands or configurations. <b><i>CMake</i></b> processes this file to understand how to generate the native build system.


title: HISTORY
content:
<b><i>CMake</i></b> was initially developed by <b><i>Kitware Inc.</i></b> in the early 2000s, primarily to support the Insight Segmentation and Registration Toolkit (ITK) and the Visualization Toolkit (VTK). The need arose from the challenges of managing large, cross-platform software projects that required compilation on various operating systems (Windows, Linux, macOS) with different compilers. Its first public release was in 2001. Over the years, <b><i>CMake</i></b> has evolved significantly, adding features like modules, presets, and better dependency management, becoming a de-facto standard for build system generation in C++ and other language communities due to its flexibility and widespread adoption.


title: PARAMETERS
content:
<b><b>-t</b>, <b>--to</b> <i>FORMAT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the desired output format. Common formats include <I>html</I>, <I>xml</I>, <I>commonmark</I> (for re-rendering), <I>man</I>, <I>latex</I>, and <I>plaintext</I>.<br><br><b><b>-p</b>, <b>--safe</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable unsafe extensions, such as raw HTML blocks and autolinks, to enhance security when processing untrusted input.<br><br><b><b>-e</b>, <b>--extension</b> <i>EXT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable specific extensions (e.g., <I>table</I>, <I>strikethrough</I>, <I>autolink</I>, <I>tasklist</I>). This option can be specified multiple times.<br><br><b><b>-o</b>, <b>--output</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Direct the processed output to the specified <I>FILE</I> instead of standard output.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information of <i>cmark</i> and exit.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message and exit, detailing available options and usage.<br><br><b><b>--source-pos</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include source position attributes in the output (e.g., as data attributes in HTML), useful for debugging or linking back to original source.<br><br><b><b>--hardbreaks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Render newline characters within paragraphs as hard line breaks (<B>&lt;br&gt;</B> in HTML) instead of spaces.<br><br><b><b>--nobreaks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Render newline characters within paragraphs as spaces, even if they would otherwise be treated as hard breaks.<br><br><b><b>--validate-utf8</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Validate that the input text is valid UTF-8. If invalid bytes are encountered, an error will be reported.<br><br><b><b>--smart</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable smart punctuation, converting straight quotes to curly quotes, <I>---</I> to em-dashes, <I>--</I> to en-dashes, and <I>...</I> to ellipses.<br><br><b><b>--width</b> <i>WIDTH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the preferred line width for certain output formats like man pages or plaintext, aiding readability.<br><br><b><b>--warn-bare-urls</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Issue warnings about bare URLs. Note: this option is deprecated and may be removed in future versions.<br><br>


title: DESCRIPTION
content:
<i>cmark</i> is the reference C implementation of <B>CommonMark</B>, a highly specified and unambiguous dialect of Markdown. It serves to parse CommonMark-formatted text and render it into various output formats, including HTML, XML, man pages, LaTeX, and plaintext. Its primary goal is to provide a consistent and predictable Markdown parsing experience, addressing the ambiguities present in earlier, less defined Markdown implementations. It can process input from one or more files or standard input, writing the result to standard output or a specified file.


title: CAVEATS
content:
<i>cmark</i> strictly adheres to the CommonMark specification. This means it may not support all the non-standard extensions found in other Markdown flavors (like GitHub Flavored Markdown) unless explicitly enabled via the <b>--extension</b> option. Its primary focus is on correctness and consistency, not on supporting every possible Markdown syntax variation by default. The <b>--warn-bare-urls</b> option is deprecated.


title: LIBRARY USAGE
content:
In addition to being a command-line tool, <I>cmark</I> is also distributed as a C library (<i>libcmark</i>). This library can be integrated into other applications to provide robust CommonMark parsing and rendering capabilities, making it a foundational component for many Markdown-aware software projects.


title: COMMONMARK SPECIFICATION
content:
<i>cmark</i>'s behavior is precisely defined by the <B>CommonMark Specification</B>. This specification provides an unambiguous description of Markdown's syntax, including a comprehensive suite of thousands of test cases. This adherence ensures that <I>cmark</I>'s output for a given CommonMark input is consistent across different environments and versions.


title: HISTORY
content:
The <B>CommonMark</B> specification was created to address the long-standing problem of Markdown's ambiguities, which led to incompatible implementations. <I>cmark</I> is the reference C implementation of this specification, developed to provide a standard and predictable parsing and rendering engine. It was initially developed by John MacFarlane and others as part of the CommonMark initiative, aiming to bring consistency and a rigorous test suite to the Markdown ecosystem. Its development focuses on strict compliance with the spec and high performance.


title: PARAMETERS
content:
<b>-a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable asynchronous scroll. This often provides a smoother animation.<br><br><b>-b</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable bold characters for some of the falling drops, adding visual variation.<br><br><b>-B</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force all characters in the digital rain to be bold.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force Linux mode, which uses an older font and rendering style. Useful for older terminals or specific aesthetic preferences.<br><br><b>-o</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the old-style scrolling, which might appear slower or less fluid compared to the default.<br><br><b>-x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use X-style scrolling, which is typically faster and smoother. This is often the default behavior.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in screensaver mode. <i>cmatrix</i> will automatically exit upon any keypress, making it suitable for a temporary display.<br><br><b>-L</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force Linux charset, which may be necessary for proper character display on some Linux consoles if not automatically detected.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only lowercase letters in the digital rain, rather than the default mix of characters.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable UTF-8 support, allowing for a broader range of characters (e.g., various Katakana characters) to be displayed accurately.<br><br><b>-C <color></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the display color for the digital rain. Available colors include: <b>green</b> (default), <b>red</b>, <b>blue</b>, <b>white</b>, <b>yellow</b>, <b>cyan</b>, <b>magenta</b>, and <b>black</b> (though black on black would be invisible).<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message with command-line options and exit.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information for <i>cmatrix</i> and exit.<br><br>


title: DESCRIPTION
content:
<i>cmatrix</i> is a lightweight terminal utility that recreates the distinctive "digital rain" visual effect popularized by <b>The Matrix</b> film series. It displays a continuous flow of falling characters, primarily numbers and Katakana characters, across the terminal screen, mimicking the film's iconic green-on-black code.<br><br>This command is often used for aesthetic purposes, as a screensaver, or simply to add a visually striking element to a command-line interface. It's a fun and nostalgic tribute that runs directly in the text console, providing an immersive experience for fans of the franchise or anyone looking for a unique terminal background. Users can customize various aspects of the display, including the color, character set, and scrolling speed, to personalize their digital rain.


title: CAVEATS
content:
<i>cmatrix</i> is designed for terminal emulators and console environments. It will not run in a graphical window manager without a terminal application.<br>While generally lightweight, continuous animation can consume CPU cycles, especially on older systems or with certain terminal configurations.<br>The exact appearance of characters (e.g., Katakana) can depend on your terminal's font configuration and locale settings.<br>Exiting the command typically requires pressing <b>Ctrl+C</b>, unless the <b>-s</b> (screensaver) mode is enabled.


title: EXITING <I>CMATRIX</I>
content:
By default, you can terminate a running <i>cmatrix</i> instance by pressing <b>Ctrl+C</b>.<br>If the <b>-s</b> (screensaver) option is used, <i>cmatrix</i> will automatically exit upon any single keypress, making it convenient for temporary visual effects or actual screensaver use.


title: PERFORMANCE AND CUSTOMIZATION
content:
The smoothness of the animation can depend on your terminal emulator, system resources, and chosen options.<br>For a faster, X-style scroll, use the <b>-x</b> option (often default).<br>Experiment with different <b>-C <color></b> options and character sets (<b>-l</b>, <b>-u</b>) to personalize your digital rain experience.


title: HISTORY
content:
<i>cmatrix</i> was created by Aaron C. Seigo, inspired by the iconic "digital rain" sequence from the 1999 film <b>The Matrix</b>. Its primary goal was to bring this distinctive visual effect to the Linux terminal and console environment. Over time, it has become a popular utility among Linux users for its aesthetic appeal and as a nostalgic tribute to the film, gaining further maintenance and development from the open-source community.


title: SYNOPSIS
content:
<I>cmctl</I> <I>command</I> [<I>arguments</I>] [<I>options</I>]<br><br>Examples:<br><I>cmctl approve my-certificate-request</I><br><I>cmctl describe certificate my-app-certificate</I><br><I>cmctl status certificate my-app-cert --namespace production</I>


title: PARAMETERS
content:
<b><I>--help</I>, <I>-h</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for a command or subcommand.<br><br><b><I>--kubeconfig</I> <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the kubeconfig file to use for Kubernetes API requests.<br><br><b><I>--context</I> <I>name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the name of the kubeconfig context to use for the command.<br><br><b><I>--namespace</I>, <I>-n</I> <I>name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If present, specifies the namespace scope for the CLI request. Used for namespaced resources like <I>Certificates</I>.<br><br><b><I>--server</I> <I>address</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The address and port of the Kubernetes API server to connect to.<br><br><b><I>--log-level</I> <I>level</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging level for the command (e.g., 'info', 'debug').<br><br>


title: DESCRIPTION
content:
<b>cmctl</b> is the command-line interface (CLI) for <I>cert-manager</I>, a popular open-source X.509 certificate management solution for Kubernetes. It allows users to interact with and manage <I>cert-manager</I> resources such as <I>Issuers</I>, <I>ClusterIssuers</I>, <I>Certificates</I>, and <I>CertificateRequests</I> directly from their terminal. <br><br><b>cmctl</b> simplifies operations like viewing certificate statuses, checking pending certificate requests, describing issuer configurations, and even creating or deleting <I>cert-manager</I> objects. It is designed to work in conjunction with <I>kubectl</I>, leveraging <I>kubectl</I>'s context and authentication. This tool is essential for cluster administrators and developers who deploy applications requiring automatic certificate provisioning and renewal within their Kubernetes environments, providing a deeper insight into <I>cert-manager</I>'s operations than <I>kubectl</I> alone can offer for these specific resources.


title: CAVEATS
content:
<b>cmctl</b> is not a standard Linux system utility; it is a specialized tool for managing <I>cert-manager</I> within a Kubernetes environment.<br><br>It requires that <I>cert-manager</I> is installed and running in your Kubernetes cluster, and it relies on your existing <I>kubectl</I> configuration (kubeconfig, context, authentication) to communicate with the cluster's API server.<br><br>Commands and flags may evolve with new versions of <I>cert-manager</I> and its API, potentially leading to breaking changes.


title: INSTALLATION
content:
<b>cmctl</b> can be installed in several ways:<br>1. As a <I>kubectl</I> plugin: Many users install it via <I>kubectl krew install cert-manager</I> or by downloading the standalone binary and placing it in their PATH, often aliased as <I>kubectl cert-manager</I>.<br>2. As a standalone binary: Downloadable directly from the official <I>cert-manager</I> GitHub releases page for various operating systems.


title: KEY FUNCTIONALITY CATEGORIES
content:
<b>cmctl</b> commands are typically organized into categories:<br>1. <I>Lifecycle Management</I>: Commands like <I>approve</I> and <I>deny</I> for managing certificate request workflows.<br>2. <I>Resource Inspection</I>: Commands such as <I>describe</I>, <I>status</I>, and <I>get</I> (when used via <I>kubectl</I> plugin) to view detailed information about <I>cert-manager</I> resources.<br>3. <I>Utilities</I>: Commands like <I>convert</I> for migrating resource API versions or <I>verify</I> for validating configuration.


title: HISTORY
content:
<b>cmctl</b> emerged as an essential companion tool to the <I>cert-manager</I> project, which was initiated to automate X.509 certificate provisioning in Kubernetes environments. As <I>cert-manager</I> gained widespread adoption and its API surface expanded, a dedicated command-line utility became critical to simplify interactions with its custom resources.<br><br>Developed alongside <I>cert-manager</I> itself, <b>cmctl</b> provides specific verbs and tailored output formats that streamline common tasks, such as inspecting certificate statuses, approving certificate requests, or diagnosing issues. Its development is tightly coupled with the <I>cert-manager</I> release cycle, ensuring compatibility and introducing new functionalities as the core project evolves.


title: PARAMETERS
content:
<b>-s, --quiet, --silent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all normal output. <b>cmp</b> only returns an exit status.<br><br><b>-l, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the byte number (decimal) and the differing byte values (octal) for all differences.<br><br><b>-b, --print-bytes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the differing bytes themselves (in octal) in addition to the offset for the <i>-l</i> option. This option is often implied by <i>-l</i> or explicitly useful for clearer output alongside <i>-l</i>.<br><br><b>-i SKIP1:SKIP2, --ignore-initial=SKIP1:SKIP2</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip the first <i>SKIP1</i> bytes of <i>FILE1</i> and <i>SKIP2</i> bytes of <i>FILE2</i>. If <i>SKIP2</i> is omitted, it defaults to <i>SKIP1</i>.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br>


title: DESCRIPTION
content:
<b>cmp</b> is a command-line utility used to compare two files byte by byte. It is primarily designed to report if two files are identical or, if they differ, to indicate the location of the first differing byte and line number. Unlike <b>diff</b>, which is optimized for textual differences, <b>cmp</b> performs a raw, byte-level comparison, making it suitable for checking the integrity of binary files, comparing images, or verifying exact duplicates. Its primary utility lies in scripting, where its exit status (0 for identical, 1 for differences, 2 for errors) can be used to control program flow. By default, <b>cmp</b> produces no output if the files are identical; it only reports discrepancies.


title: CAVEATS
content:
<b>cmp</b> performs a strict byte-by-byte comparison. This means it will report differences even for minor changes like different newline characters (e.g., <i>LF</i> vs <i>CRLF</i>) that might be visually insignificant in text files. For sophisticated textual comparison and patch generation, <b>diff</b> is a more appropriate tool. <b>cmp</b>'s simplicity is its strength for binary files or quick checks of exact equality.


title: EXIT STATUS
content:
<b>cmp</b> uses specific exit status codes to indicate the result of the comparison, which is crucial for scripting:<br><i><b>0</b></i>: The files are identical.<br><i><b>1</b></i>: The files are different.<br><i><b>2</b></i>: An error occurred (e.g., inaccessible file, invalid option).


title: HISTORY
content:
The <b>cmp</b> command is a fundamental utility in the Unix operating system, dating back to its early versions. It has been a standard part of the GNU Core Utilities, demonstrating its enduring utility for basic file comparison tasks. Its design prioritizes simplicity and efficiency, focusing solely on byte-level equality, a characteristic that has remained consistent throughout its development.


title: SYNOPSIS
content:
<b>cms</b> <I>subcommand</I> [<I>options</I>] <I>file</I>...<br><br>Examples of common subcommands:<br>  <b>cms</b> create <I>file</I><br>  <b>cms</b> get [<I>-r revision</I>] <I>file</I><br>  <b>cms</b> put [<I>-m "comment"</I>] <I>file</I><br>  <b>cms</b> log <I>file</I>


title: PARAMETERS
content:
<b><I>subcommand</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the action to perform (e.g., <I>create</I>, <I>get</I>, <I>put</I>, <I>log</I>, <I>diff</I>).<br><br><b><I>file</I>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more files to operate on.<br><br><b>-r <I>revision</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a particular revision number to retrieve or operate on.<br><br><b>-m <I>"message"</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a comment or description for the new revision (typically used with <I>put</I>).<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Locks the file for exclusive editing when retrieving it (e.g., with <I>get</I>).<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unlocks a file that was previously locked.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the contents of the specified revision to standard output (e.g., with <I>get</I>).<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an operation, overriding potential warnings or restrictions.<br><br>


title: DESCRIPTION
content:
The <i>cms</i> (Configuration/Code Management System) command was a utility found on legacy Unix-like operating systems, such as Ultrix, designed for managing different versions of source code files and other text-based documents. Similar in concept to later and more widely known systems like SCCS (Source Code Control System) or RCS (Revision Control System), <i>cms</i> provided core functionalities for creating, retrieving, updating, and tracking changes to files over time.<br><br>Its primary purpose was to assist developers in maintaining a comprehensive history of revisions, allowing them to revert to previous versions if errors were introduced or to track changes made by different team members. It also included mechanisms to manage collaborative development, typically by controlling file access and preventing simultaneous, conflicting modifications. Although largely superseded by modern version control systems like Git or Subversion, <i>cms</i> represented an early approach to systematic software configuration management in the Unix environment.


title: CAVEATS
content:
The <i>cms</i> command is largely obsolete and not commonly found on modern Linux distributions. Its functionality has been entirely superseded by more advanced and widely adopted version control systems like Git, Mercurial, and Subversion. The specific usage, available subcommands, and options may vary significantly across different legacy Unix-like systems where it might have been available, as there was no universal standard for such a command.<br><br>This analysis is based on historical documentation and common practices for similar legacy configuration management systems.


title: HISTORY
content:
The <i>cms</i> command originates from earlier Unix-like operating systems, particularly those developed by Digital Equipment Corporation (DEC) such as Ultrix. It was part of a suite of tools for software development, serving as a precursor to more sophisticated version control systems. Its design principles likely influenced or ran in parallel with other early systems like SCCS (Source Code Control System) and RCS (Revision Control System), aiming to solve the fundamental problems of concurrent development and version tracking in a multi-user, multi-file software project environment. Its usage declined with the advent of more powerful and distributed version control systems in the late 20th and early 21st centuries.


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays a brief help message and exits.</i><br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Outputs the <i>cmus</i> version information and exits.</i><br><br><b>--listen [ADDR]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Starts <i>cmus</i> and listens for connections from <i>cmus-remote</i> clients. If ADDR is not specified, it listens on a default local socket. This is crucial for remote control or scripting.</i><br><br><b>--servername <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies a unique server name for this <i>cmus</i> instance. Useful when running multiple <i>cmus</i> instances concurrently to differentiate them for <i>cmus-remote</i>.</i><br><br><b>[file|directory|playlist]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>One or more paths to audio files, directories to scan for music, or M3U/PLS playlist files. These items will be added to the library or queue upon startup.</i><br><br>


title: DESCRIPTION
content:
<i>cmus</i> is a small, fast, and powerful <b>console music player</b> for Unix-like operating systems. Designed for efficiency and minimal resource usage, it offers a purely text-based user interface, making it an excellent choice for users who prefer working in the terminal or on systems with limited graphical capabilities.<br><br>Its core philosophy revolves around keyboard-driven navigation and control, providing a highly responsive and fluid user experience once familiarized with its keybindings. <i>cmus</i> supports a wide array of audio formats, including MP3, Ogg Vorbis, FLAC, WavPack, Musepack, WAV, and more, leveraging various audio output plugins like ALSA, PulseAudio, OSS, and Sun Audio. It features gapless playback, replaygain support, and a robust library management system that organizes music in a tree-like hierarchy.<br><br>Users can create and manage playlists, apply filters, and customize nearly every aspect of the player, from keybindings and colors to file display formats. Its lightweight nature and powerful features make it a favorite among power users and terminal enthusiasts.


title: CAVEATS
content:
<i>cmus</i> has a <b>text-based user interface (TUI)</b>, which means it lacks graphical elements common in modern music players. All interactions are performed via keyboard shortcuts, which can have a steep learning curve for new users. Configuration is primarily done through text files (`~/.config/cmus/rc` and `~/.config/cmus/autosave`), requiring manual editing for advanced customization. While highly efficient, it does not offer built-in visualizers or direct streaming capabilities like some graphical players; however, external tools can sometimes bridge these gaps.


title: INTERACTIVE KEYBINDINGS
content:
The primary method of interacting with <i>cmus</i> is through its extensive set of keyboard shortcuts. Users navigate different views (e.g., library, queue, playlists, settings) by pressing number keys (<i>1-7</i>), add files with `a`, play/pause with `p`, stop with `s`, and search with `/`. Mastering these bindings is essential for efficient use.


title: VIEWS AND MODES
content:
<i>cmus</i> organizes its functionality into several distinct views, accessible by pressing numbers <i>1</i> through <i>7</i>:<br><ul><li><i>1: Library (Artist/Album view)</i></li><li><i>2: Library (Flat view)</i></li><li><i>3: Play Queue</i></li><li><i>4: Playlists</i></li><li><i>5: File Browser</i></li><li><i>6: Filters and Settings</i></li><li><i>7: Help</i></li></ul>Each view offers specific commands and display options tailored to its purpose.


title: CONFIGURATION FILES
content:
<i>cmus</i> stores its main configuration in `~/.config/cmus/rc` and its auto-saved state (like current queue, library, and settings) in `~/.config/cmus/autosave`. These plain text files allow users to deeply customize keybindings, colors, column layouts, and various playback parameters.


title: HISTORY
content:
<i>cmus</i> was initially developed by <b>Timo Hirvonen</b>, with its first public release around 2008. It was conceived as a lightweight, fast, and highly customizable music player that embraced the Unix philosophy of doing one thing well and doing it efficiently. From its inception, the focus has been on providing a robust and responsive terminal-based experience, prioritizing speed and keyboard control over graphical interfaces. It has maintained an active development community, continually evolving with new features, bug fixes, and support for modern audio technologies while retaining its core principles of minimalism and performance.


title: SEE ALSO
content:
<b>cmus-remote(1)</b>: <i>The indispensable companion utility for controlling <i>cmus</i> instances from the command line or scripts.</i>, <b>mpd(1)</b>: <i>Music Player Daemon, another popular client-server architecture for console music playback.</i>, <b>ncmpcpp(1)</b>: <i>A popular feature-rich curses client for MPD.</i>, <b>alsamixer(1)</b>: <i>A terminal-based mixer often used to adjust system volume in conjunction with <i>cmus</i> when using ALSA output.</i>


title: DESCRIPTION
content:
<i>cmuwmtopbm</i> is a specialized utility included in the <b>Netpbm</b> suite of graphic conversion tools. Its primary function is to convert image files stored in the proprietary <b>CMU window manager bitmap format</b> into the standard <b>Portable BitMap (PBM)</b> format.<br><br>The CMU window manager bitmap format was specific to the <B>CMU Window Manager</B>, an early and now largely historical window manager developed at Carnegie Mellon University for the X Window System. The PBM format, on the other hand, is a very simple, 1-bit (black and white) image format, part of the Netpbm family, widely supported by various image processing applications.<br><br>This command is particularly useful for handling legacy image data originating from the CMU window manager environment, enabling users to view, manipulate, or integrate these historical bitmaps with modern image tools that support Netpbm formats. By default, <i>cmuwmtopbm</i> reads the CMU bitmap data from standard input; however, a specific input file can be provided as an argument. The converted PBM image is always written to standard output, allowing for easy piping with other Netpbm utilities or redirection to a file.


title: CAVEATS
content:
This tool is highly specialized for a legacy bitmap format. Its primary utility lies in converting historical data from the CMU Window Manager environment, which is largely obsolete. It is unlikely to be needed for contemporary image processing tasks unless dealing with specific legacy assets.


title: INPUT/OUTPUT BEHAVIOR
content:
By default, <i>cmuwmtopbm</i> reads the CMU bitmap from <b>standard input</b>. If a file path is provided as an argument, it reads from that specified file instead. The resulting PBM image is always written to <b>standard output</b>. This design allows for flexible use in shell pipelines, enabling seamless integration with other Netpbm tools or redirection of the output to a file.


title: HISTORY
content:
<i>cmuwmtopbm</i> is part of the <b>Netpbm</b> project, a collection of graphic conversion tools that originated from Jef Poskanzer's <I>Pbmplus</I> package in the late 1980s and early 1990s. The command was developed to address the need for interoperability between the specific bitmap format used by the early <b>CMU Window Manager</b> and the more universal Netpbm image processing ecosystem. Its existence highlights a period in computing when many bespoke graphic formats existed, and tools like Netpbm were crucial for format translation and interoperability.


title: PARAMETERS
content:
<b>-r<i>rev</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check out specified revision <i>rev</i>. If <i>rev</i> is a branch, the latest revision on that branch is retrieved.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lock the retrieved revision. This checks out a writable copy and locks the revision, preventing others from simultaneously checking out and locking the same revision for editing.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unlock the retrieved revision. If a revision is currently locked by the user, this option checks out an unlocked (read-only) copy and removes the lock.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwrite. Overwrites the working file even if it exists and is writable.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print to standard output. Instead of creating a working file, the retrieved revision is printed to <i>stdout</i>.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode. Suppresses diagnostic messages, useful in scripts.<br><br><b>-k<i>subst</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keyword expansion style. Controls how RCS keywords (e.g., <i>$Revision$</i>, <i>$Date$</i>) are expanded in the checked-out file. Common styles include <i>kv</i> (name and value, default), <i>kvl</i> (name, value, locker), <i>o</i> (old value), <i>b</i> (new value), <i>v</i> (value only), <i>l</i> (locker only), <i>n</i> (no expansion).<br><br><b>-M</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set modification time. Sets the modification time of the working file to the checkout time.<br><br>


title: DESCRIPTION
content:
<b>co</b> (check out) is a fundamental command within the <i>Revision Control System (RCS)</i>, a mature version control system designed primarily for managing revisions of individual files. Its core function is to retrieve a specific revision of a file from its RCS archive, which is typically a file ending with the `,v` suffix (e.g., `myfile.c,v`).<br><br>When <b>co</b> is executed, it creates a working copy of the chosen revision in the current directory, making it accessible for viewing, compilation, or editing. By default, <b>co</b> fetches the latest revision of the file. A key aspect of <b>co</b>'s operation is its ability to interact with the locking mechanism of RCS. Files can be checked out as read-only (unlocked), which is suitable for simply viewing or compiling a specific version, or they can be checked out with a lock (using the <i>-l</i> option), which signifies an intent to modify the file and prevents other users from concurrently locking and modifying the same revision. This locking mechanism is crucial for maintaining data integrity in a concurrent environment where multiple users might be working on the same files. After editing, the changes are typically committed back to the archive using the <b>ci</b> (check in) command.


title: CAVEATS
content:
<b>co</b> operates directly on RCS archive files (those ending in `,v`) and is designed for single-file version control, unlike modern systems that manage entire projects or repositories recursively.<br><br>RCS's locking mechanism is crucial for preventing conflicting changes. If a file is checked out for editing (with <i>-l</i>) and then the user forgets to check it back in or unlock it, others will be prevented from locking it. The <b>rcs -u</b> command can be used by an administrator to break locks.<br><br>While <b>co</b> and RCS are robust for their intended purpose, they have largely been superseded by distributed version control systems like Git for larger, collaborative software development due to RCS's lack of integrated branching, merging, and network capabilities, and its file-by-file operational model.


title: KEYWORD EXPANSION
content:
<b>co</b> supports keyword expansion, where specific strings embedded in the working file (e.g., <i>$Revision$</i>, <i>$Date$</i>, <i>$Author$</i>, <i>$Id$</i>) are automatically replaced with relevant metadata from the RCS archive during checkout. This feature is commonly used to embed version information directly into source code or documentation.


title: WORKING FILE PERMISSIONS
content:
When a file is checked out with a lock (<i>-l</i>), the resulting working file is typically made writable by the user who performed the checkout. If checked out without a lock (or with <i>-u</i>), the working file is usually created as read-only. This permission control is an integral part of RCS's locking mechanism.


title: HISTORY
content:
The <i>Revision Control System (RCS)</i>, including the <b>co</b> command, was developed by Walter F. Tichy at Purdue University in the early 1980s, with its initial release around 1982. It emerged as an influential tool for managing changes to files, particularly source code, in Unix-like environments. <b>co</b>'s design reflects the era's computing landscape, focusing on efficiency for individual file versioning and local disk-based operation. Its simplicity and effectiveness for managing single files or small collections of files ensured its widespread adoption and continued presence in standard Unix utilities, even as more complex and collaborative version control systems like CVS, Subversion, and Git gained prominence in the decades that followed. <b>co</b> remains valuable for simple revision tracking tasks.


title: SYNOPSIS
content:
This command is primarily an internal utility invoked by <I>Cockpit</I> components, not for direct user execution.<br>Its typical invocation is orchestrated by <B>cockpit-ws</B> or <I>systemd-logind</I>.<br><br> <B>cockpit-bridge</B> [<I>OPTIONS</I>]


title: PARAMETERS
content:
<b><B>--version</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version of the <B>cockpit-bridge</B> component and exits.<br><br><b><B>--help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message explaining available options.<br><br><b><B>--privileged</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts the bridge process with elevated privileges, typically invoked via <I>sudo</I> rules for specific tasks that require root access (e.g., managing storage or networking). This is a critical internal flag for privileged operations.<br><br><b><B>--log-level</B>=<I>LEVEL</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging verbosity. <I>LEVEL</I> can be <I>debug</I>, <I>info</I>, <I>warning</I>, <I>error</I>, or <I>critical</I>. Useful for troubleshooting.<br><br><b><B>--user</B>=<I>USERNAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the bridge process as a specific user. Primarily used internally when the web service needs to act on behalf of a particular user.<br><br><b><B>--shell</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts an interactive shell instead of the RPC protocol, primarily used for debugging.<br><br>


title: DESCRIPTION
content:
The <b>cockpit-bridge</b> command is an internal component of the <I>Cockpit</I> web console for managing Linux systems. It acts as a crucial bridge between the unprivileged <I>Cockpit</I> web service (<B>cockpit-ws</B>) and the underlying operating system services and commands. <br><br> Its primary role is to execute system commands and retrieve information on behalf of a logged-in user, often requiring elevated privileges. <B>cockpit-bridge</B> leverages mechanisms like <I>Polkit</I> or <I>sudo</I> to securely gain necessary permissions, ensuring that <I>Cockpit</I> can perform administrative tasks without the entire web service running as root. <br><br> It communicates with <B>cockpit-ws</B> over standard input/output using a simple RPC-like protocol. Users typically do not invoke <B>cockpit-bridge</B> directly from the command line; it is started automatically by <I>Cockpit</I> when a user logs in.


title: CAVEATS
content:
The <B>cockpit-bridge</B> command is an internal implementation detail of the <I>Cockpit</I> project. It is not intended for direct manual invocation by users from the command line, as doing so inappropriately could lead to security risks or unexpected system behavior. Its security model relies on careful integration with <I>Polkit</I> and <I>sudo</I> for privilege escalation and authorization checks. Misconfiguring <I>Cockpit</I>'s access controls, or manually invoking <B>cockpit-bridge</B> with incorrect privileges, could compromise system security.


title: SECURITY MODEL
content:
The security of <I>Cockpit</I> heavily relies on <B>cockpit-bridge</B>'s design. When a user authenticates to <I>Cockpit</I>, <B>cockpit-ws</B> starts a <B>cockpit-bridge</B> process for that user. This bridge process typically runs as the logged-in user. For tasks requiring elevated privileges (e.g., installing software, managing system services), <B>cockpit-bridge</B> uses <I>Polkit</I> policies or <I>sudo</I> rules to execute specific commands as root or with other necessary permissions. This ensures that only authorized operations are performed, and only for the duration required, limiting the attack surface compared to a monolithic privileged application.


title: COMMUNICATION PROTOCOL
content:
<B>cockpit-bridge</B> communicates with <B>cockpit-ws</B> (the web service) over standard input (<I>stdin</I>) and standard output (<I>stdout</I>) using a lightweight, JSON-based RPC (Remote Procedure Call) protocol. This allows <I>Cockpit</I>'s JavaScript frontend to make requests to the system, which are then relayed through <B>cockpit-ws</B> to the specific <B>cockpit-bridge</B> process, executed, and results are sent back through the same channels. This simple yet effective inter-process communication mechanism underpins <I>Cockpit</I>'s interactivity.


title: HISTORY
content:
<B>cockpit-bridge</B> is an integral part of the <I>Cockpit</I> project, which was initiated by <I>Red Hat</I> in 2014. From its inception, <I>Cockpit</I> was designed to be a secure, web-based interface for managing Linux systems, and the bridge component was crucial to achieving this. The development focused on creating a robust security model where the privileged operations are isolated and handled by a separate, minimal process (<B>cockpit-bridge</B>), rather than having the entire web server run with root privileges. This design principle has been a cornerstone of <I>Cockpit</I>'s security architecture since its early days, evolving with system technologies like <I>Polkit</I> for fine-grained authorization.


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


title: DESCRIPTION
content:
<i>cockpit-desktop</i> provides a user-friendly, web-based interface for managing a local Linux system. It's part of the broader Cockpit project, which aims to make Linux server administration accessible through a web browser. Unlike the general <i>cockpit</i> command which can manage remote systems via SSH, <i>cockpit-desktop</i> is specifically tailored for administering the machine it's running on. It allows users to perform common administrative tasks such as managing system services, reviewing logs, monitoring system resources, configuring networking, managing storage, and even running terminal commands directly from a web browser. The interface is designed to be intuitive and discoverable, making it suitable for both new Linux users and experienced administrators who prefer a graphical overview. It integrates seamlessly with the underlying Linux system, leveraging existing system tools and APIs like <i>systemd</i>, <i>firewalld</i>, and <i>Polkit</i> for secure operations.<br><br>When invoked, <i>cockpit-desktop</i> typically launches your default web browser and navigates to the local Cockpit instance (usually <i>https://localhost:9090</i>), providing immediate access to the system's administrative dashboard.


title: CAVEATS
content:
For <i>cockpit-desktop</i> to function, the Cockpit web service (typically provided by <i>cockpit.socket</i> or <i>cockpit.service</i>) must be running and accessible on the local system. It relies on a web browser being installed and configured as the default application for HTTPS URLs. All actions performed through Cockpit are executed with appropriate system privileges, often mediated by <i>Polkit</i>, requiring authentication for sensitive operations. While convenient, it's essential to secure access to the Cockpit web interface, even on a local system, especially if the port 9090 is exposed to the network.


title: DEFAULT PORT
content:
<i>cockpit-desktop</i> typically connects to the Cockpit web service running on port <b>9090</b> (<i>https://localhost:9090</i>).


title: SECURITY AND PERMISSIONS
content:
Cockpit integrates with <i>Polkit</i> (PolicyKit) to manage permissions. This means that users authenticated through Cockpit can only perform actions that their system privileges allow, and sensitive operations often prompt for a password.


title: MODULAR DESIGN
content:
Cockpit features a modular design, allowing for the installation of additional 'applications' or 'pages' (e.g., for managing Kubernetes, Podman, or specific vendor hardware) that extend its core functionality without cluttering the main interface.


title: HISTORY
content:
The Cockpit project was initiated by Red Hat engineers with the goal of creating a modern, user-friendly interface for Linux administration. It first appeared in Fedora distributions and quickly gained traction, becoming a standard component in enterprise Linux distributions like Red Hat Enterprise Linux and CentOS, as well as being available for Ubuntu, Debian, and others. The focus has always been on integration with standard Linux tools and technologies, rather than reimplementing them. <i>cockpit-desktop</i> emerged as a specific application of Cockpit's capabilities, allowing users to manage their local desktop or workstation directly from a web browser, providing a consistent administrative experience whether managing a server or a personal machine.


title: PARAMETERS
content:
<b>--self-signed</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Generates a new self-signed TLS certificate for the Cockpit web console. This option is useful for initial setup or testing environments where a trusted Certificate Authority (CA) certificate is not immediately required or available.</i><br><br><b>--host <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the hostname for which the self-signed certificate will be issued when used with <b>--self-signed</b>. If omitted, the system's current hostname is used by default.</i><br><br><b>--cert <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the full path to an existing TLS certificate file (e.g., <b>fullchain.pem</b>, <b>.crt</b>, <b>.pem</b>). This option must be used in conjunction with the <b>--key</b> option.</i><br><br><b>--key <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the full path to the private key file that corresponds to the certificate provided with the <b>--cert</b> option. This option is mandatory when <b>--cert</b> is used.</i><br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays a brief help message summarizing the command's usage and options, then exits.</i><br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Displays the version information of the <b>cockpit-tls</b> command and then exits.</i><br><br>


title: DESCRIPTION
content:
<b>cockpit-tls</b> is a specialized utility command designed to configure Transport Layer Security (TLS) certificates for the Cockpit web console. Cockpit serves as a web-based graphical interface for Linux servers, enabling administrators to manage system services, storage, networking, and more directly through a browser. Ensuring secure communication between the client's browser and the Cockpit server is paramount, and <b>cockpit-tls</b> facilitates this by managing the SSL/TLS certificates utilized by the <b>cockpit-ws</b> service.<br><br>This command simplifies certificate management tasks, allowing users to generate self-signed certificates for quick setup and testing, or to install and configure Cockpit to use pre-existing certificates and their corresponding private keys. It can also help integrate with system-wide certificate management solutions. By automating much of the TLS configuration process, <b>cockpit-tls</b> ensures that the Cockpit interface is securely accessible via HTTPS, placing certificates typically in the <i>/etc/cockpit/ws-certs.d/</i> directory for the <b>cockpit-ws</b> daemon to pick up.


title: CAVEATS
content:
<i>When generating certificates with <b>--self-signed</b>, these certificates will not be trusted by standard web browsers, which will result in security warnings. Self-signed certificates are suitable only for testing or internal, trusted networks.<br><br>It is crucial to ensure that the certificate and key files specified with <b>--cert</b> and <b>--key</b> have appropriate file permissions, allowing the <b>cockpit-ws</b> service (which typically runs under a dedicated user or group) to read them. Incorrect permissions will prevent Cockpit from establishing a secure connection.<br><br>After making any changes to the TLS configuration using <b>cockpit-tls</b> or by manually placing certificate files, it is necessary to restart or reload the <b>cockpit.socket</b> or <b>cockpit.service</b> systemd units for the new certificates to be loaded and take effect.</i>


title: CERTIFICATE STORAGE LOCATION
content:
<i>The <b>cockpit-ws</b> daemon, which serves the Cockpit web interface, primarily looks for TLS certificates in the <i>/etc/cockpit/ws-certs.d/</i> directory. Certificates within this directory are loaded in alphanumeric order based on their filenames. This means that a certificate named <b>00-custom.cert</b> will be preferred over <b>10-another.cert</b> or the default <b>99-self-signed.cert</b>. This design allows administrators to easily override default or automatically generated certificates by simply placing a higher-priority custom certificate file in this location.</i>


title: APPLYING CHANGES
content:
<i>After utilizing <b>cockpit-tls</b> to modify the TLS configuration or after manually placing new certificate files in the designated directory, it is essential to instruct the Cockpit service to reload its configuration. This is typically achieved by reloading or restarting the relevant systemd units. You can reload the socket unit with <b>sudo systemctl reload cockpit.socket</b>, or restart the main service with <b>sudo systemctl restart cockpit.service</b> to ensure the new certificates are loaded and used by the <b>cockpit-ws</b> daemon for secure connections.</i>


title: HISTORY
content:
Cockpit, the web-based server management tool, was initially released by Red Hat in 2014. From its inception, secure web access has been a core requirement, making the management of TLS certificates an integral part of its design. The <b>cockpit-tls</b> utility, or similar mechanisms for certificate configuration, has been consistently developed to simplify this process. While its exact implementation details might vary slightly across different Linux distributions or Cockpit versions (sometimes appearing as a direct script, a symbolic link, or its functionality being absorbed into other Cockpit components), its primary objective remains the same: to provide a straightforward method for setting up and updating TLS certificates for the Cockpit web service. Over time, it has evolved to support various certificate sources, from basic self-signed options to integrating with more advanced, automated certificate management practices.


title: PARAMETERS
content:
<b>--port=<I>PORT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the TCP port that <b>cockpit-ws</b> listens on (default 9090).<br><br><b>--listen-address=<I>ADDRESS</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the IP address <b>cockpit-ws</b> binds to. By default, it listens on all configured network interfaces.<br><br><b>--local-ssh</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces <b>cockpit-ws</b> to connect to <b>cockpit-bridge</b> via SSH on localhost instead of directly. Useful in certain proxy setups.<br><br><b>--no-tls</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables HTTPS (TLS) encryption. <I>Highly insecure</I> and should only be used for debugging on trusted networks.<br><br><b>--no-pam</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables PAM authentication. <I>Extremely insecure</I> and should never be used in production environments.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <b>cockpit-ws</b> version information and exits.<br><br>


title: DESCRIPTION
content:
<b>cockpit-ws</b> is the core web server component of the Cockpit project, an open-source, web-based graphical interface for managing Linux servers. It typically listens on TCP port 9090 (by default) for HTTPS connections, serving the necessary web assets (HTML, CSS, JavaScript) to the user's browser. Furthermore, it establishes WebSocket connections that facilitate real-time communication with the underlying system through the <b>cockpit-bridge</b> process.<br><br><b>cockpit-ws</b> handles user authentication, often via PAM, and manages web sessions, making it indispensable for providing a secure and interactive web-based administration experience. It allows users to monitor performance, manage services, view logs, configure networking, and perform various administrative tasks directly from a web browser without needing a separate client application.


title: CAVEATS
content:
Normally, <b>cockpit-ws</b> is started and managed by the <b>systemd</b> socket activation service (<b>cockpit.socket</b>), meaning it's rarely invoked directly by users. Disabling TLS (<b>--no-tls</b>) or PAM authentication (<b>--no-pam</b>) makes the server <I>highly insecure</I> and should only be done for debugging purposes in controlled environments. Ensure port 9090 (or custom port) is open in the firewall for external access.


title: DEFAULT PORT AND SECURITY
content:
<b>cockpit-ws</b> defaults to listening on TCP port 9090, exclusively using HTTPS (TLS) for secure communication. It integrates with the system's Pluggable Authentication Modules (PAM) for user authentication, ensuring that only authenticated users with sufficient privileges can access the server.


title: ARCHITECTURE OVERVIEW
content:
<b>cockpit-ws</b> serves the static web assets (HTML, CSS, JavaScript) to your browser and establishes WebSocket connections. These WebSockets communicate with the <b>cockpit-bridge</b> process, which in turn interacts with system services, D-Bus, and the shell to execute commands and retrieve system information, providing a real-time interactive experience.


title: HISTORY
content:
The Cockpit project, including <b>cockpit-ws</b>, was initiated by Red Hat and first publicly released around 2014. Its primary goal was to provide a modern, web-based interface for managing Linux servers without abstracting away underlying system tools and concepts. <b>cockpit-ws</b> has been a core component since its inception, responsible for the web interface and secure communication, evolving alongside web technologies and Linux distribution features like systemd and Podman.


title: PARAMETERS
content:
<b>-d, --diff <file1> <file2></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compare two files side-by-side in VS Code's diff editor.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display usage information and exit.<br><br><b>-n, --new-window</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force opening a new VS Code window.<br><br><b>-r, --reuse-window</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force opening in the last active VS Code window (this is the default behavior).<br><br><b>-w, --wait</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wait for the files to be closed in VS Code before returning control to the terminal.<br><br><b>--add <folder></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add folder(s) to the last active VS Code window.<br><br><b>--goto <file>:<line>[:<char>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open a file at the specified line and character position.<br><br><b>--install-extension <extension-id></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install a VS Code extension by its unique ID.<br><br><b>--list-extensions</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all installed VS Code extensions.<br><br><b>--profile <profile name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open VS Code with the specified profile.<br><br><b>--remote <table>:<path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Open a path in a remote context (e.g., SSH, Dev Containers).<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the VS Code version to the console.<br><br>


title: DESCRIPTION
content:
The <b>code</b> command is the command-line interface (CLI) for <i>Visual Studio Code</i>, a popular cross-platform source-code editor developed by Microsoft. It allows users to effortlessly open files, directories, or even remote workspaces directly from their terminal. This utility is instrumental in integrating VS Code into various development workflows, enabling quick file access, scripting, and version control operations. Whether you need to open a specific file for editing, start a new project in the current directory, or compare two files side-by-side, the <b>code</b> command provides a direct and efficient pathway to your editor. It's designed for seamless interaction, supporting numerous options to control how VS Code launches, such as opening in a new window, reusing an existing one, or waiting for files to be closed before returning control to the terminal.


title: CAVEATS
content:
The <b>code</b> command requires <i>Visual Studio Code</i> to be installed on your system. On most operating systems, the command is added to your system's PATH during VS Code installation or via an explicit option within the editor (e.g., 'Shell Command: Install 'code' command in PATH' on macOS/Linux). Its functionality is entirely dependent on the installed VS Code application and its configuration.


title: INSTALLATION AND PATH INTEGRATION
content:
While <i>Visual Studio Code</i> is installed like any other application, the <b>code</b> command typically requires an additional step to be accessible directly from the terminal. On macOS and Linux, VS Code prompts users to install the 'code' command into their system's PATH via the 'Shell Command: Install 'code' command in PATH' option available in the Command Palette (<i>Ctrl+Shift+P</i> or <i>Cmd+Shift+P</i>). This creates a symbolic link that makes the executable globally available.<br>On Windows, the installer usually offers an option to 'Add 'Open with Code' action to Windows Explorer file/directory context menu' and adds VS Code to the system PATH environment variable, making the <b>code</b> command available in PowerShell or Command Prompt automatically.


title: REMOTE DEVELOPMENT INTEGRATION
content:
The <b>code</b> command plays a pivotal role in <i>VS Code's Remote Development</i> capabilities. With extensions like 'Remote - SSH', 'WSL', or 'Dev Containers', users can open remote folders or repositories directly using the <b>code</b> command. For example, <b>code --remote ssh-remote+<hostname> /path/to/project</b> can open a project residing on a remote SSH server. This seamless integration allows developers to leverage the full power of VS Code while their development environment resides remotely, bridging the gap between local and cloud-based development seamlessly.


title: HISTORY
content:
The <b>code</b> command emerged with the initial public release of <i>Visual Studio Code</i> by Microsoft in April 2015. From its inception, the CLI was a core component, designed to offer a familiar and efficient way for developers to interact with the editor directly from their terminal, mirroring capabilities found in other popular editors like Sublime Text and Atom. Its evolution closely mirrors the development of VS Code itself, continuously gaining new features and options to support advancements like integrated terminal features, remote development capabilities, and profile management, solidifying its role as an indispensable tool in modern software development workflows.


title: SYNOPSIS
content:
<i>"codecrafters" is not a standard Linux command with a defined synopsis. It refers to an online educational platform where users build command-line tools. Any command usage under this name would be specific to a custom user script or alias.</i>


title: DESCRIPTION
content:
CodeCrafters is an online platform designed for developers to deepen their understanding of fundamental computer science concepts by rebuilding popular command-line tools and systems. Users engage in hands-on challenges, implementing applications inspired by real-world tools like Git, Docker, Redis, or HTTP servers from the ground up, using their preferred programming language. The platform provides detailed specifications, automated tests, and hints to guide the learning process. It emphasizes active learning and practical application of knowledge, moving beyond theoretical understanding to practical implementation.<br><br>It's crucial to note that "codecrafters" is not a standalone, universal Linux command that users would execute directly from their terminal in the same way as <b>ls</b> or <b>grep</b>. Instead, it refers to this educational service where participants <i>create</i> such tools, or might use their <i>own custom scripts/aliases</i> named "codecrafters" within their project directories.


title: CAVEATS
content:
<i>The term "codecrafters" does not correspond to a universally recognized or pre-installed Linux command. Users cannot expect to find <b>codecrafters</b> as an executable on a typical Linux distribution. If encountered, it likely refers to a user-defined alias, a custom script within a specific project context, or an informal reference to the CodeCrafters.io educational platform. Therefore, attempting to run <b>man codecrafters</b> or <b>codecrafters --help</b> will yield "command not found" errors unless explicitly configured by the user.</i>


title: LEARNING METHODOLOGY
content:
<i>CodeCrafters utilizes a unique "build-your-own" methodology. Instead of passive consumption of tutorials, participants actively write code for real-world tools, guided by automated tests and incremental challenges. This approach fosters a deeper comprehension of underlying principles and practical problem-solving skills, significantly enhancing a developer's understanding of system architecture and low-level programming concepts.</i>


title: HISTORY
content:
<i>CodeCrafters.io was founded to address the gap between theoretical knowledge and practical system-level understanding in software development. It emerged as a solution for developers seeking to understand how common tools like Git or Docker truly work under the hood. The platform aims to provide a structured, challenge-based learning environment that encourages deep dives into system programming and protocol implementation. Its development has focused on creating comprehensive learning paths and a robust testing infrastructure for user-submitted code.</i>


title: SYNOPSIS
content:
<I>N/A - The <B>codepage</B> command does not exist as a standard standalone utility in Linux.</I><br>Character encoding settings in Linux are primarily managed through environment variables and commands related to the system's locale configuration. For example, to view current locale settings, you would use <I>locale</I>. To convert text between encodings, you would use <I>iconv</I>.


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>As <B>codepage</B> is not a standalone command, it does not have specific command-line parameters.</I><br>Parameters for managing character encoding are found within commands like <I>locale</I> (e.g., <I>locale -a</I> to list all available locales) or <I>iconv</I> (e.g., <I>iconv -f &lt;from_encoding&gt; -t &lt;to_encoding&gt; &lt;input_file&gt;</I>).<br><br>


title: DESCRIPTION
content:
The term <B>codepage</B> is predominantly associated with DOS and Microsoft Windows operating systems, referring to a specific character set that defines how numeric values are mapped to visible characters. In the Linux and Unix-like world, the concept of character encoding is handled more broadly and flexibly through <B>locales</B> and specific encoding standards like UTF-8. There is <B>no standard, standalone Linux command named <I>codepage</I></B>. Instead, Linux systems manage character encoding as part of the locale settings (e.g., <I>en_US.UTF-8</I>), which dictate language, country, and character set preferences for user interfaces, data processing, and text display. Commands like <I>locale</I> are used to view and set these preferences, while <I>iconv</I> is used for converting text between different character encodings.


title: CAVEATS
content:
The most significant caveat is that <B>codepage</B> is <B>not a native Linux command</B>. Users migrating from Windows environments might search for such a command, but Linux handles character encoding through a different paradigm, primarily using locales and internationalization (i18n) standards. Directly manipulating "codepages" as distinct entities is uncommon; instead, focus is placed on the broader locale which includes character set definitions, typically UTF-8 for modern systems.


title: MANAGING CHARACTER ENCODING IN LINUX
content:
While <I>codepage</I> is not a command, here's how character encoding is typically managed:<br><br><I>1. Viewing Current Encoding:</I><br>To see your current character encoding, check your locale settings:<br><I>Command:</I> <B>locale charmap</B><br><I>Example output:</I> <B>UTF-8</B><br><br><I>2. Setting Locale and Encoding:</I><br>Locale settings, including the character encoding, are usually set in system-wide configuration files (e.g., <I>/etc/locale.conf</I>, <I>/etc/environment</I>) or user-specific files (e.g., <I>~/.bashrc</I>). Environment variables like <I>LANG</I> and <I>LC_ALL</I> control the locale.<br><I>Example:</I> <B>export LANG="en_US.UTF-8"</B><br><br><I>3. Converting File Encodings:</I><br>The <I>iconv</I> command is indispensable for converting text files from one encoding to another.<br><I>Syntax:</I> <B>iconv -f &lt;source_encoding&gt; -t &lt;destination_encoding&gt; &lt;input_file&gt; -o &lt;output_file&gt;</B><br><I>Example:</I> <B>iconv -f ISO-8859-1 -t UTF-8 old_file.txt -o new_file.txt</B>


title: HISTORY
content:
The concept of "codepages" emerged prominently in the DOS and early Windows era to manage character sets for different languages and regions. These were often single-byte encodings (e.g., CP437 for US/Europe, CP850 for multilingual). In contrast, the Unix/Linux world adopted a more unified and extensible approach with locales and standards like ISO 8859 and later UTF-8 (Unicode Transformation Format - 8-bit). UTF-8's variable-width encoding allowed for the representation of virtually all characters in all languages, largely rendering the need for separate, region-specific "codepages" obsolete for general text handling. Modern Linux systems heavily rely on UTF-8 as the default character encoding.


title: SYNOPSIS
content:
<b>codespell</b> [<i>OPTIONS</i>] [<i>files</i>...]<br><b>codespell</b> [<i>OPTIONS</i>] <i>-r</i> [<i>directories</i>...]


title: PARAMETERS
content:
<b>-w</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fixes misspelled words in place.<br><br><b>-D</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays only the errors found (default behavior).<br><br><b>-x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the difference (diff format) for potential fixes.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays context around the misspelled word.<br><br><b>-S SKIP_PATTERNS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips files or directories matching the given comma-separated patterns.<br><br><b>-I BUILTIN_DICTIONARY</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies additional built-in dictionaries to include (e.g., 'rare').<br><br><b>-L BUILTIN_DICTIONARY</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies built-in dictionaries to load (overrides default).<br><br><b>-d DICTIONARIES</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a comma-separated list of custom dictionary files to use.<br><br><b>-s SKIP_BUILTIN</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips specific built-in dictionaries (e.g., 'en_US').<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively checks files in the given directories.<br><br><b>--ignore-words-list IGNORE_WORDS_LIST</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a comma-separated list of words to ignore.<br><br><b>--check-filenames</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Also checks for misspelled words in filenames.<br><br><b>--check-hidden</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes hidden files/directories during recursive checks.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the program's version number and exit.<br><br>


title: DESCRIPTION
content:
<b>codespell</b> is a command-line utility designed to quickly scan source code, documentation, and comments for common spelling mistakes. Unlike general-purpose spell checkers, <b>codespell</b> focuses on a curated list of frequently misspelled words and common programming-related typos, making it highly effective for codebases without generating excessive noise from legitimate variable names or technical jargon. It can identify errors and, optionally, fix them in place. Its efficiency and targeted approach make it an ideal tool for integration into continuous integration (CI) pipelines, pre-commit hooks, or for regular local development checks to maintain code quality and readability.


title: CAVEATS
content:
<I>False Positives:</I> While optimized for code, <b>codespell</b> may still flag legitimate technical terms, variable names, or acronyms as errors, requiring manual review or adding to an ignore list.<br><I>Limited Scope:</I> It primarily focuses on common spelling errors and does not perform grammar checks or understand the linguistic context of the text.<br><I>In-place Modification:</I> Using the <b>-w</b> option modifies files directly. It is highly recommended to use <b>codespell</b> with version control (e.g., Git) to easily revert changes if unintended modifications occur.<br><I>Dictionary Dependent:</I> Its effectiveness relies on its built-in and user-defined dictionaries. Uncommon or domain-specific typos might be missed if not present in the dictionaries.


title: <I>INTEGRATION WITH CI/CD:</I>
content:
<b>codespell</b> is frequently integrated into Continuous Integration/Continuous Deployment (CI/CD) pipelines. This ensures that any new or modified code is automatically checked for spelling errors before it's merged, preventing common typos from entering the codebase. Tools like GitHub Actions, GitLab CI/CD, or Jenkins can easily run <b>codespell</b> as part of their build or test stages.


title: <I>CUSTOM DICTIONARIES:</I>
content:
Users can define custom dictionary files to include project-specific terminology, acronyms, or proper nouns that <b>codespell</b> should recognize as correctly spelled. This helps in reducing false positives and tailoring the tool to specific project needs, enhancing its utility.


title: <I>ERROR CODES:</I>
content:
<b>codespell</b> supports specific error codes for different types of issues, which can be enabled or disabled (e.g., <b>--enable-error-code</b>, <b>--disable-error-code</b>). This allows for fine-grained control over what kinds of spelling issues are reported.


title: HISTORY
content:
<b>codespell</b> was created by <I>Lucas C. Villa Real</I> with the first commit appearing in 2013. It originated from the need for a lightweight, code-centric spell checker that could efficiently identify common typos in source code without the overhead and false positives of traditional spell checkers when applied to programming contexts. Its development has been community-driven, expanding its dictionaries and features to better serve developers seeking to improve code readability and reduce technical debt associated with misspellings, especially in comments and documentation. It has gained popularity due to its focused approach and ease of integration into modern development workflows.


title: SYNOPSIS
content:
<code>coffee [options] &lt;file ...&gt;</code><br><code>coffee [options] -e &lt;command&gt;</code><br><code>coffee [options] -c &lt;file ...&gt;</code><br><code>coffee</code> (starts REPL if no arguments)


title: PARAMETERS
content:
<b><b>-c</b>, <b>--compile</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles .coffee files into .js.<br><br><b><b>-o</b> <i>&lt;dir&gt;</i>, <b>--output</b> <i>&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output directory for compiled JavaScript.<br><br><b><b>-w</b>, <b>--watch</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Watches source files for changes and recompiles.<br><br><b><b>-j</b> <i>&lt;file&gt;</i>, <b>--join</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Concatenates all compiled JavaScript into a single file.<br><br><b><b>-e</b> <i>&lt;command&gt;</i>, <b>--eval</b> <i>&lt;command&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Evaluates a string of CoffeeScript.<br><br><b><b>-p</b>, <b>--print</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the compiled JavaScript to stdout.<br><br><b><b>-l</b>, <b>--lint</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints potential errors and warnings (deprecated).<br><br><b><b>-s</b>, <b>--stdio</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads CoffeeScript from stdin, writes JavaScript to stdout.<br><br><b><b>-b</b>, <b>--bare</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compiles without the top-level function wrapper, preventing variable leakage.<br><br><b><b>-m</b>, <b>--map</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates source maps, aiding debugging of compiled JavaScript.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the CoffeeScript version.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information.<br><br>


title: DESCRIPTION
content:
The `coffee` command is the primary interface for CoffeeScript, a programming language that transpiles into JavaScript. Designed to enhance JavaScript's readability and conciseness, CoffeeScript introduces a more Ruby-like syntax, omitting many of JavaScript's often verbose elements like semicolons, parentheses for function calls, and curly braces for blocks. Its primary goal is to expose the good parts of JavaScript in a simpler, more approachable way.<br><br>The `coffee` command allows users to compile `.coffee` source files into `.js` files, execute CoffeeScript code directly, or even run a CoffeeScript REPL (Read-Eval-Print Loop) for interactive development. While it enjoyed significant popularity as a preferred language for web development before the widespread adoption of ECMAScript 2015 (ES6) and later standards, which introduced many of the features CoffeeScript pioneered, it remains a robust tool for those who appreciate its unique syntax and philosophy.


title: CAVEATS
content:
The `coffee` command requires Node.js and npm to be installed on the system, as CoffeeScript itself is written in JavaScript and distributed via npm. While CoffeeScript offers a concise syntax, its use has declined significantly since the advent of ECMAScript 2015 (ES6) and subsequent JavaScript standards, which have incorporated many features (e.g., arrow functions, classes, template literals) that CoffeeScript initially provided as syntactic sugar. This means less community support and fewer new projects adopting it compared to native JavaScript or TypeScript. Debugging compiled CoffeeScript can also be more challenging without proper source map setup, as error messages refer to the generated JavaScript.


title: <B>INSTALLATION</B>
content:
The `coffee` command is not typically pre-installed on Linux distributions. It can be installed globally using npm (Node Package Manager), which usually comes bundled with Node.js:<br><code>npm install -g coffeescript</code>


title: <B>USAGE EXAMPLES</B>
content:
<i>Compile a single file:</i><br><code>coffee -c my_script.coffee</code><br>(This will create `my_script.js` in the same directory)<br><br><i>Compile a directory and watch for changes:</i><br><code>coffee -o lib/ -cw src/</code><br>(Compiles `.coffee` files from `src/` into `lib/` and watches for modifications)<br><br><i>Execute a CoffeeScript file directly:</i><br><code>coffee my_script.coffee</code><br><br><i>Start an interactive REPL:</i><br><code>coffee</code><br>(Allows interactive CoffeeScript code execution)


title: HISTORY
content:
CoffeeScript was created by Jeremy Ashkenas and first publicly released in December 2009. It rapidly gained popularity within the web development community for its elegant syntax and the solutions it offered to JavaScript's perceived verbosity and quirks. It significantly influenced the design of future JavaScript standards, with many of its features (like arrow functions, classes, and destructuring assignment) eventually being adopted into ECMAScript 2015 (ES6) and later versions. Its peak usage was around 2013-2015. However, as native JavaScript evolved to include these features, and TypeScript emerged as a strong alternative for type-safe JavaScript development, CoffeeScript's widespread adoption began to decline. It remains a historical milestone in web development language evolution and is still maintained for existing projects.


title: SYNOPSIS
content:
<b>coinmon</b> [<i>options</i>]<br><br><b>Examples:</b><br><i>coinmon</i><br><i>coinmon -f BTC,ETH -C EUR</i><br><i>coinmon -s rank -l 20</i>


title: PARAMETERS
content:
<b><b>-c</b>, <b>--convert</b> <i>&lt;currency&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert prices to a specific fiat currency (e.g., <i>USD</i>, <i>EUR</i>, <i>GBP</i>, <i>JPY</i>). Default is <i>USD</i>.<br><br><b><b>-f</b>, <b>--find</b> <i>&lt;symbol&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter coins by symbol (e.g., <i>BTC</i>, <i>ETH</i>). Can be a comma-separated list.<br><br><b><b>-l</b>, <b>--limit</b> <i>&lt;number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Limit the number of coins displayed. Default is 10.<br><br><b><b>-s</b>, <b>--sort</b> <i>&lt;field&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort coins by a specific field. Possible fields: <i>rank</i>, <i>price</i>, <i>marketcap</i>, <i>volume</i>, <i>change1h</i>, <i>change24h</i>, <i>change7d</i>. Default is <i>marketcap</i>.<br><br><b><b>-t</b>, <b>--top</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show only the top <i>limit</i> coins (equivalent to using <b>-l</b>).<br><br><b><b>-u</b>, <b>--usd</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show prices converted to USD (equivalent to <b>-c USD</b>).<br><br><b><b>-e</b>, <b>--eur</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show prices converted to EUR (equivalent to <b>-c EUR</b>).<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help information for the command.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version number of coinmon.<br><br>


title: DESCRIPTION
content:
<i>coinmon</i> is an interactive command-line interface (CLI) tool designed for cryptocurrency enthusiasts to quickly check real-time market data directly from their Linux terminal.<br><br>It fetches data from reliable sources, presenting essential information such as current price, 24-hour percentage change, 24-hour volume, and market capitalization for a wide range of cryptocurrencies. Users can customize the display, sort results, and filter by currency, making it a convenient and efficient tool for quick market overviews without needing to open a web browser.


title: CAVEATS
content:
<i>coinmon</i> requires Node.js and npm for installation and execution.<br>It relies on external APIs (primarily CoinMarketCap) for data, meaning its functionality depends on the availability and stability of these APIs, and potential rate limits.<br>Data presented might have a slight delay compared to real-time exchange feeds, making it suitable for informational purposes rather than high-frequency trading decisions.


title: INSTALLATION
content:
<i>coinmon</i> is typically installed globally using <i>npm</i> (Node Package Manager). If you have Node.js and npm installed, you can install <i>coinmon</i> with the command:<br><code>npm install -g coinmon</code>


title: DATA SOURCE
content:
<i>coinmon</i> primarily fetches its cryptocurrency market data from the CoinMarketCap API, a widely recognized and comprehensive source for crypto prices, market caps, and trading volumes.


title: HISTORY
content:
<i>coinmon</i> emerged as a popular open-source command-line tool during the cryptocurrency boom, addressing the need for quick, terminal-based access to market data.<br>Developed in Node.js, it leverages the <i>npm</i> ecosystem for easy global installation and cross-platform compatibility, reflecting the growing demand for accessible crypto tools.


title: PARAMETERS
content:
<b>--api-key <key></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a CoinMarketCap API key for data fetching.<br><br><b>--api-keys-path <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a file containing API keys for multiple services.<br><br><b>--cache-dir <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the cache directory for storing fetched data.<br><br><b>--colors-config-path <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a custom colors configuration file.<br><br><b>--config <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the main configuration file.<br><br><b>--currency <currency></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the default fiat currency (e.g., USD, EUR, BTC) for display.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable debug mode for verbose output.<br><br><b>--export <filepath></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Export current market data to a specified file.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help information and exit.<br><br><b>--log-file <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the log file for recording application events.<br><br><b>--max-table-rows <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the maximum number of rows to display in the table view.<br><br><b>--no-color</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable color output in the terminal.<br><br><b>--open-link-strategy <strategy></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Strategy for opening external links (e.g., 'xdg-open', 'open', 'none').<br><br><b>--portfolio</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Start the application directly in the portfolio view.<br><br><b>--refresh-rate <seconds></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the data refresh rate in seconds.<br><br><b>--reset-config</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reset the application configuration to its default settings.<br><br><b>--reset-data</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clear all cached market data.<br><br><b>--secrets-path <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a file containing sensitive information like API keys.<br><br><b>--shortcut <keybinding></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define a custom keybinding for an application action.<br><br><b>--skip-checks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip checks for new version updates and configuration changes.<br><br><b>--time-format <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the time display format (e.g., '12h', '24h').<br><br><b>--token <token></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a CoinGecko API token.<br><br><b>--top <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only the top N cryptocurrencies by market capitalization.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the application version and exit.<br><br><b>--view-type <type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the initial view type (e.g., 'table', 'portfolio').<br><br>


title: DESCRIPTION
content:
<i>cointop</i> is a fast and lightweight terminal user interface (TUI) application designed for tracking cryptocurrency market data in real-time. Written in Go, it provides an interactive and customizable dashboard displaying live prices, market capitalization, 24-hour volume, supply, and price change percentages for thousands of cryptocurrencies.<br><br>Users can easily search, sort, and filter coins, switch between different fiat currencies, and customize the display columns. It leverages various cryptocurrency APIs to fetch up-to-date information, offering a convenient way for enthusiasts and traders to monitor market movements directly from their command line. Its intuitive keybindings and minimalist design make it efficient for quick market overviews.


title: CAVEATS
content:
<i>cointop</i> requires an active internet connection to fetch real-time market data. Users should be aware of potential API rate limits imposed by data providers like CoinMarketCap or CoinGecko, especially without a paid API key. The accuracy of data depends on the reliability of the underlying APIs. It functions purely as a monitoring tool and does not offer any direct trading or investment functionalities.


title: INTERACTIVE KEYBINDINGS
content:
<i>cointop</i> features a comprehensive set of interactive keybindings for efficient navigation and interaction within the TUI. Common keybindings include <b>q</b> to quit, <b>f</b> to toggle favorite coins, <b>s</b> to search, <b>p</b> to switch to portfolio view, and <b>?</b> to display a help menu. These shortcuts allow users to quickly perform actions without relying on mouse input, enhancing productivity directly from the terminal.


title: EXTENSIVE CUSTOMIZATION
content:
Users can extensively customize <i>cointop</i>'s behavior and appearance through its configuration files, typically located in <i>~/.cointop/config.yaml</i>. This includes setting the default fiat currency, configuring API keys, adjusting refresh rates, customizing color themes, and even defining personalized keybindings. This level of flexibility enables users to tailor the application precisely to their workflow and aesthetic preferences.


title: HISTORY
content:
<i>cointop</i> was initially developed by Ben La Monica (miguelmota) and emerged around late 2017 / early 2018, coinciding with a period of significant growth in cryptocurrency interest. Written in Go, its primary goal was to provide a fast, cross-platform, and user-friendly terminal interface for tracking crypto market data. It quickly gained traction within the open-source community, leading to continuous development, feature enhancements, and integrations with multiple data providers, solidifying its position as a popular command-line tool for cryptocurrency monitoring.


title: PARAMETERS
content:
<b>-b, --no-backspaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter out backspace characters. This option causes multiple characters at the same position to be overwritten, resulting in only the last character printed at that position being visible.<br><br><b>-f, --spaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Permit forward half-line motions (for superscripts and subscripts), which are otherwise discarded. This option makes <b>col</b> preserve multiple spaces, which can lead to wider output.<br><br><b>-h, --no-halfspaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Discard forward half-line motions and back-half line motions. This is the default behavior.<br><br><b>-l <N>, --lines=<N></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Buffer at most <i>N</i> lines. By default, no line limit is applied. If this limit is exceeded, <b>col</b> may truncate input or produce corrupted output.<br><br><b>-x, --expand-tabs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Expand tabs to multiple space characters. Without this option, <b>col</b> attempts to preserve tabs where possible.<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;Output version information and exit.<br><br><b>FILE...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more input files to process. If no files are specified, <b>col</b> reads from standard input.<br><br>


title: DESCRIPTION
content:
The <b>col</b> command acts as a filter, primarily designed to process text containing control sequences that manipulate cursor movement, such as reverse line feeds, half-line motions, and backspaces. These sequences are commonly generated by text formatting systems like <b>nroff</b> or <b>troff</b> (often used by <b>man</b> pages) to create effects like bolding or underlining on character-based terminals. <br><br><b>col</b> reads its standard input (or specified files) and outputs the processed text to standard output. It maintains a virtual screen buffer, simulating the behavior of a terminal, and resolves overlapping characters or cursor movements by determining the final character at each virtual position. For instance, it can resolve character overstrikes (e.g., '<i>_</i>' followed by a backspace and '<i>c</i>' to form an underlined '<i>c</i>') into a simpler, printable string. Its main purpose is to convert complex terminal-specific formatting into a linear stream of characters, suitable for programs like <b>lpr</b> (for printing) or <b>pr</b> (for pagination), ensuring that formatted text displays correctly on devices that do not interpret these control sequences.


title: CAVEATS
content:
The <b>col</b> command is primarily designed for processing text generated by traditional Unix text formatting tools like <b>nroff</b> or <b>troff</b>. While it handles common ASCII control sequences effectively, its behavior with complex Unicode characters, multi-byte sequences, or modern terminal escape codes (e.g., ANSI color codes) may be inconsistent or lead to unintended formatting. It processes input character by character, which can sometimes result in less-than-optimal output for highly structured or graphically oriented text.<br><br>It's generally not needed for modern pagers like <b>less</b> or <b>more</b> which can interpret <b>nroff</b> sequences directly. Its main utility is when piping to simpler tools or printers that do not handle such sequences natively.


title: TYPICAL USAGE
content:
The <b>col</b> command is often implicitly invoked by the <b>man</b> command to format manual pages for display. Users can also pipe output from other commands to <b>col</b> to clean up text before printing or further processing. For example, <i>nroff -man mydoc.n | col -b | lpr</i> would format '<i>mydoc.n</i>' as a man page, remove backspaces, and then print it.


title: HISTORY
content:
The <b>col</b> command has been a standard utility in Unix-like operating systems since their early days, originating from AT&T Bell Labs Unix and later becoming part of BSD and System V. Its development was directly tied to the need to render formatted text (especially from <b>nroff</b> and <b>troff</b>) correctly on line printers and character-based terminals. Over time, it was incorporated into various utility sets, including <i>util-linux</i> for Linux systems. While its core function remains consistent, modern terminal emulators and pagers often handle many of the same control sequences, reducing the direct need for <b>col</b> in interactive viewing, but it remains valuable for scripting and printing pipelines.


title: SEE ALSO
content:
<b>nroff</b>(1), <b>troff</b>(1), <b>man</b>(1), <b>pr</b>(1), <b>lpr</b>(1), <b>less</b>(1), <b>more</b>(1)


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;No standard parameters for a non-existent command. Any parameters would be custom to its specific definition on a given system.<br><br>


title: DESCRIPTION
content:
The command <b><i>cola</i></b> is not a standard or widely recognized utility found in typical Linux distributions like Ubuntu, Debian, CentOS, or Fedora.<br>It does not have a dedicated man page or inclusion in core utility packages. Therefore, its functionality, syntax, and options are not universally defined.<br><br>It is highly probable that <b><i>cola</i></b> refers to:<br>1. A custom alias or shell function defined by a user in their <b><i>.bashrc</i></b>, <b><i>.zshrc</i></b>, or similar shell configuration files.<br>2. A specific executable or script named <b><i>cola</i></b> installed as part of a particular application, project, or specialized development environment.<br>3. A typographical error for another common command.<br><br>Without a specific context, it is impossible to provide definitive information about its behavior.


title: CAVEATS
content:
Since <b><i>cola</i></b> is not a standard command, its presence and behavior are entirely dependent on its custom definition on a given system. It may execute arbitrary code, be malicious, or simply not exist. Users should exercise extreme caution when encountering non-standard commands and always verify their source and purpose before execution.


title: HOW TO CHECK FOR CUSTOM COMMANDS
content:
To determine if <b><i>cola</i></b> is an alias, function, or executable on your system, you can use the <b><i>type</i></b> command: <b><i>type cola</i></b>.<br>If it's an executable in your PATH, <b><i>which cola</i></b> might show its location. If it's a script or binary, you could then inspect its contents (if you have the necessary permissions and tools) to understand its functionality.


title: HISTORY
content:
There is no documented history for a standard 'cola' Linux command, as it does not exist in common utility sets or core utilities. Any 'history' would be specific to its custom creation and usage within a particular project, system, or organization.


title: SYNOPSIS
content:
<b>colima</b> [COMMAND] [OPTIONS]<br><br>Common commands:<br><b>colima start</b> [OPTIONS]<br><b>colima stop</b> [PROFILE]<br><b>colima delete</b> [PROFILE]<br><b>colima status</b> [PROFILE]<br><b>colima ssh</b> [PROFILE]<br><b>colima exec</b> [PROFILE] COMMAND [ARGS...]<br><b>colima list</b><br><b>colima logs</b> [PROFILE]


title: PARAMETERS
content:
<b>--cpu <n></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of CPUs for the VM (default: 2).<br><br><b>--memory <size></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Memory size for the VM (e.g., 2GB, 2048MB, default: 2GB).<br><br><b>--disk <size></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disk size for the VM (e.g., 60GB, 60000MB, default: 60GB).<br><br><b>--runtime <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Container runtime to use (<i>docker</i> or <i>containerd</i>, default: docker).<br><br><b>--vm-type <type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;VM type (<i>qemu</i>, <i>vz</i>, <i>hyperkit</i>, <i>wsl2</i>, default: auto-detected).<br><br><b>--profile <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Profile name for managing multiple Colima instances (default: <i>default</i>).<br><br><b>--mount <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mount host directory into the VM (e.g., <i>~/myproject:/mnt/myproject</i>). Can be specified multiple times.<br><br><b>--network-address</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable host network address for direct access to the VM (default: true).<br><br><b>--ssh-agent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable SSH agent forwarding to the VM (default: false).<br><br><b>--dns <ip></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a DNS server for the VM.<br><br><b>--kubernetes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install Kubernetes (K3s) inside the VM (default: false).<br><br>


title: DESCRIPTION
content:
Colima provides a Docker-compatible environment on macOS and Linux, leveraging <i>containerd</i> and optionally the <i>Docker CLI</i>. It acts as a lightweight, open-source alternative to Docker Desktop, running a minimal Linux virtual machine to host container runtimes. Colima supports various VM backends, including QEMU, HyperKit, Virtualization.framework (macOS), and WSL2 (Windows), offering flexibility across different operating systems.<br><br>It simplifies the setup process, allowing developers to run Docker containers, build images, and manage services locally using familiar Docker commands, but without the overhead of Docker Desktop. Colima is built on top of the <i>Lima</i> (Linux on Mac) project and extends its functionality specifically for container orchestration and development workloads, making it a popular choice for resource-efficient local development environments.


title: CAVEATS
content:
<i><br>Colima relies on underlying VM technologies (QEMU, HyperKit, Virtualization.framework, WSL2) to operate. Ensure the appropriate virtualization software is installed and configured on your system.<br>While it provides a robust Docker-compatible environment, it does not include the graphical user interface (GUI) components or advanced integrated Kubernetes cluster management features found in Docker Desktop. It is primarily designed for command-line driven development workflows.</i>


title: KEY FEATURES
content:
Supports both Docker and containerd runtimes.<br>Configurable VM resources (CPU, memory, disk).<br>Multiple VM profiles for different projects.<br>Integration with existing Docker CLI.<br>Mounting of host directories into the VM.<br>Optional Kubernetes (K3s) support for local development.<br>Seamless networking and port forwarding.


title: USAGE WORKFLOW
content:
1. <b>Install Colima:</b> Typically via Homebrew on macOS or Linux.<br>2. <b>Start Colima:</b> Run <i>colima start</i> (optional flags for resources, runtime).<br>3. <b>Use Docker/Nerdctl:</b> Once started, your existing <i>docker</i> or <i>nerdctl</i> commands will automatically connect to the Colima VM.<br>4. <b>Stop/Delete:</b> Use <i>colima stop</i> or <i>colima delete</i> when done to free up resources.


title: HISTORY
content:
<i><br>Colima emerged as a response to the increasing resource consumption and licensing changes of Docker Desktop. Built atop the open-source <a href="https://github.com/lima-vm/lima">Lima (Linux on Mac)</a> project, Colima simplifies the process of running container runtimes like Docker and containerd in a lightweight virtual machine. Its development aimed to provide a free, open-source, and resource-efficient alternative for local container development, gaining significant traction, especially among macOS users seeking a leaner solution. It abstracts away much of the manual configuration required for Lima, focusing specifically on container-related workflows.</i>


title: SYNOPSIS
content:
<b>collectd</b> [<I>-C <config-file></I>] [<I>-P <pid-file></I>] [<I>-f</I>] [<I>-s</I>] [<I>-h</I>] [<I>-v</I>]


title: PARAMETERS
content:
<b><I>-C <config-file></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate configuration file to use instead of the default (<I>/etc/collectd/collectd.conf</I>).<br><br><b><I>-P <pid-file></I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate PID file path to use. The default is typically <I>/var/run/collectd.pid</I>.<br><br><b><I>-f</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs <b>collectd</b> in the foreground, preventing it from daemonizing. Useful for debugging or when running under a process supervisor.<br><br><b><I>-s</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a summary of statistics (e.g., loaded plugins, number of values collected) and then exits.<br><br><b><I>-h</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message with command-line options and exits.<br><br><b><I>-v</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of <b>collectd</b> and exits.<br><br>


title: DESCRIPTION
content:
<b>collectd</b> is a powerful and efficient daemon that periodically collects system and application performance metrics.<br><br>It's designed to be highly extensible through a plugin architecture, allowing it to gather a vast array of data points, including CPU usage, memory consumption, network traffic, disk I/O, and much more, from various sources and applications.<br><br>The primary purpose of <b>collectd</b> is to enable long-term monitoring, performance analysis, and capacity planning. It operates with a focus on low resource consumption and high resolution, making it suitable for deployment on a wide range of systems, from small embedded devices to large server farms. Data collected by <b>collectd</b> can be stored in various backends like RRDtool, InfluxDB, Graphite, or simply written to CSV files, facilitating integration with visualization and alerting tools.


title: CAVEATS
content:
The functionality and behavior of <b>collectd</b> are almost entirely determined by its configuration file (<I>collectd.conf</I>) and the plugins enabled within it. Running <b>collectd</b> without a proper configuration or with no output plugins configured will result in data collection but no persistence.<br><br>While designed for low overhead, the resource consumption can increase with the number of enabled plugins and the frequency of data collection. Proper planning of data storage backend is crucial for long-term monitoring and performance.


title: CONFIGURATION FILE
content:
The <I>collectd.conf</I> file is the central point of control for <b>collectd</b>. It dictates which plugins are loaded, how often data is collected, where data is stored, and various other operational parameters. Understanding and customizing this file is essential for effective use of <b>collectd</b>.


title: PLUGIN ARCHITECTURE
content:
<b>collectd</b>'s core strength lies in its modular plugin architecture. Plugins are dynamically loaded components responsible for data collection (input plugins, e.g., <I>cpu</I>, <I>memory</I>, <I>network</I>), data processing (e.g., <I>threshold</I>, <I>match</I>), and data dispatching to various storage backends (output plugins, e.g., <I>rrdtool</I>, <I>influxdb</I>, <I>graphite</I>, <I>csv</I>). This design allows users to tailor <b>collectd</b> to their specific monitoring needs without modifying the core daemon.


title: HISTORY
content:
<b>collectd</b> was originally created by Florian Forster and first released in 2005. Its development was motivated by the need for a high-resolution, low-overhead monitoring solution that could run efficiently on various Unix-like systems. Over the years, it has evolved significantly, incorporating numerous plugins and output formats, and gaining widespread adoption in server environments and network monitoring due to its extensibility and efficiency. It remains actively maintained and developed by a community of contributors.


title: SYNOPSIS
content:
<b>:</b> [<i>arguments...</i>]<br><br>The colon command accepts any number of arguments, but it <i>ignores</i> them completely. Its behavior remains unchanged regardless of the arguments provided.


title: PARAMETERS
content:
<b>arguments...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Any arguments provided to the colon command are parsed but subsequently ignored. The command's behavior and exit status remain unaffected.<br><br>


title: DESCRIPTION
content:
The colon command, represented by the single character <b>:</b>, is a fundamental <i>shell builtin</i> rather than an external executable program. It performs no operation, effectively acting as a "no-op" or null command. Its primary characteristic is that it always exits with a <i>true</i> (zero) status code. This makes it incredibly versatile in shell scripting.<br><br>Common uses include creating infinite loops (e.g., <b>while :; do ... done</b>), serving as a placeholder when a command is syntactically required but no action is desired, and as a target for shell parameter expansion without assigning a value (e.g., <b>:${VAR:?error_msg}</b>). It's also frequently used as a separator character in environment variables like <i>PATH</i> or <i>IFS</i>, and can act as a simple "comment" if placed at the beginning of a line, though <b>#</b> is the preferred comment character. Its simplicity and consistent true return status make it an indispensable tool for shell scripters.


title: CAVEATS
content:
<ul><li>The colon command (<b>:</b>) is a <i>shell builtin</i>, meaning it's an integral part of the shell itself (e.g., Bash, Zsh) and not a separate executable file found in the system's PATH.</li><li>Although it accepts arguments, these arguments are merely parsed and then discarded, having no effect on the command's operation or exit status.</li><li>It should not be confused with the <b>true</b> command, which also returns a zero exit status but is typically an external executable (though some shells implement <b>true</b> as a builtin as well).</li><li>Using <b>:</b> at the beginning of a line can effectively "comment out" the rest of the line, similar to <b>#</b>, but <b>#</b> is the standard and more readable convention for comments.</li></ul>


title: USAGE IN LOOPS
content:
The colon command is commonly used to create infinite loops, often in <b>while</b> or <b>until</b> constructs, because it always returns a true exit status. For example: <b>while :; do echo 'Looping indefinitely...'; sleep 1; done</b>


title: PARAMETER EXPANSION
content:
It can be used in shell parameter expansion without affecting a variable's value or as a default target. For instance, <b>:${VAR:?ERROR: VAR not set}</b> will check if <b>VAR</b> is set and exit with an error if it isn't, without requiring an actual command to follow the colon.


title: PLACEHOLDER / NO-OP
content:
When a command is syntactically required but no action is desired, <b>:</b> serves as an excellent placeholder. For example, in a <b>case</b> statement where a specific pattern should do nothing: <b>case $VAR in pattern) :;; esac</b>


title: AS A SEPARATOR
content:
The colon character is widely used as a separator in various environment variables, most notably <b>PATH</b> (for directory lists) and <b>IFS</b> (Internal Field Separator). While this is a usage of the character, it's distinct from its command form, but highlights its special significance.


title: HISTORY
content:
The colon command (<b>:</b>) has been a fundamental part of Unix shells since the very early days, specifically present in the original <i>Bourne Shell</i> (<b>sh</b>) developed by Stephen Bourne. Its inclusion as a simple no-operation command with a guaranteed true exit status made it essential for various scripting paradigms from the outset. Its functionality has remained consistent across virtually all modern Unix-like shells, including <b>bash</b>, <b>zsh</b>, <b>ksh</b>, and <b>dash</b>, underscoring its foundational role in shell scripting.


title: SYNOPSIS
content:
<br><b>colord.conf</b> is a configuration file, not an executable command.<br>It is typically located at: <I>/etc/colord/colord.conf</I><br>The file uses an INI-like syntax, with sections enclosed in square brackets (e.g., <b>[Manager]</b>) and key-value pairs (e.g., <b>Logging=debug</b>). Comments usually start with a hash (<b>#</b>).


title: PARAMETERS
content:
<b>Logging</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging verbosity for the <b>colord</b> daemon. Possible values include <b>debug</b>, <b>info</b>, <b>warning</b>, <b>error</b>, <b>critical</b>. Default is usually <b>info</b> or <b>warning</b>.<br><br><b>Profiling</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A boolean (<b>true</b> or <b>false</b>) that, when set to <b>true</b>, may enable internal profiling for development or debugging purposes, potentially affecting performance.<br><br><b>EnableSane</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A boolean (<b>true</b> or <b>false</b>) to enable integration with the SANE (Scanner Access Now Easy) framework, allowing <b>colord</b> to manage color profiles for scanners.<br><br><b>EnableSensors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A boolean (<b>true</b> or <b>false</b>) to enable integration with sensor devices (like colorimeters) for display calibration. This typically requires the <b>colord-sensors</b> package.<br><br>


title: DESCRIPTION
content:
The <b>colord.conf</b> file serves as the primary static configuration file for the <b>colord</b> system daemon. <b>Colord</b> is a critical component of modern Linux desktop environments, responsible for managing color profiles for various devices such as displays, printers, scanners, and cameras. It ensures consistent color reproduction across the system by associating International Color Consortium (ICC) profiles with hardware. While much of <b>colord</b>'s operation is dynamic and managed via D-Bus, <b>colord.conf</b> provides an initial set of parameters and overrides for the daemon's behavior upon startup, such as logging verbosity or enabling specific hardware integration.


title: CAVEATS
content:
<b>colord.conf</b> is a static configuration file for the <b>colord</b> daemon, not a command-line utility. Direct manual editing by users is uncommon, as many <b>colord</b> settings are handled dynamically via D-Bus or through graphical user interfaces like GNOME Control Center's Color panel. Most installations rely on default settings, and the file may be sparsely populated or entirely commented out. Incorrect modifications can impact system color management.


title: TYPICAL FILE LOCATION
content:
The standard location for <b>colord.conf</b> is <b>/etc/colord/colord.conf</b>. System administrators may create or modify this file to override default daemon behavior, although often the default or D-Bus managed settings are sufficient.


title: RELATIONSHIP WITH D-BUS
content:
While <b>colord.conf</b> provides static configuration, much of <b>colord</b>'s runtime management, including device profile associations and active profiles, is handled dynamically via D-Bus, allowing graphical tools and applications to interact with the daemon in real-time.


title: HISTORY
content:
The <b>colord</b> project was initiated to provide a robust, consistent, and centralized color management solution for the Linux desktop, addressing the fragmentation of color profile handling. It integrates deeply with desktop environments like GNOME and KDE, providing a D-Bus API for applications to interact with color profiles and devices. The <b>colord.conf</b> file has been a part of its architecture since early development to define core daemon parameters before dynamic configuration became prevalent.


title: SYNOPSIS
content:
<I><B>colordiff</B> [<I>colordiff_options</I>] [<I>diff_options</I>] <I>file1</I> <I>file2</I></I><br>
<I><B>colordiff</B> [<I>colordiff_options</I>] -<B>R</B> <I>directory1</I> <I>directory2</I></I><br>
<I>or often used as a pager:</I><br>
<I><B>diff</B> <I>options</I> <I>files</I> | <B>colordiff</B></I>


title: PARAMETERS
content:
<b><I>All <B>diff</B> options</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<B>colordiff</B> passes all supplied command-line arguments directly to the underlying <B>diff</B> command.<br>Therefore, any option valid for <B>diff</B> is also valid for <B>colordiff</B>.<br><br><b>-<B>u</B>, --<B>unified</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in unified diff format (common and recommended for readability).<br><br><b>-<B>c</B>, --<B>context</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in context diff format (another common format).<br><br><b>-<B>r</B>, --<B>recursive</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively compare any subdirectories found in the specified paths.<br><br><b>-<B>y</B>, --<B>side-by-side</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in two columns, which can be combined with <B>-W</B> to set the output width.<br><br><b>--<B>help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the help message for the underlying <B>diff</B> command.<br><br><b>--<B>version</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display <B>colordiff</B>'s version information, and often the version of the underlying <B>diff</B> utility.<br><br>


title: DESCRIPTION
content:
<I>The <B>colordiff</B> command is a Perl script designed to colorize the output of the standard <B>diff</B> utility.</I><br>
<I>It acts as a wrapper around <B>diff</B>, automatically piping its output through an ANSI colorizer.</I><br>
<I>This significantly improves readability by visually distinguishing between added lines, deleted lines, and changed lines, as well as highlighting differences within lines (e.g., using different colors for characters that are unique to one version).</I><br>
<I>While <B>diff</B> itself provides line-by-line comparison, <B>colordiff</B> enhances this by applying pre-defined color schemes, making it easier to spot discrepancies at a glance.</I><br>
<I>Users can customize these color schemes via a configuration file, allowing for personalized visual feedback.</I><br>
<I>It's particularly useful when reviewing large code changes, configuration file differences, or any textual data where understanding modifications quickly is crucial.</I><br>
<I>Essentially, it's <B>diff</B>, but much easier on the eyes in a terminal environment.</I>


title: CAVEATS
content:
<I>As a wrapper script, <B>colordiff</B> relies on the standard <B>diff</B> utility being installed and accessible in the system's PATH.</I><br>
<I>The colored output is based on ANSI escape codes, which are primarily designed for terminal display.</I><br>
<I>If redirecting <B>colordiff</B>'s output to a file, these escape codes will be included, making the file unreadable unless viewed with a color-aware pager or stripped of codes.</I><br>
<I>While highly customizable, effective use often requires a good understanding of <B>diff</B>'s various output formats to optimize readability.</I>


title: <B>CONFIGURATION</B>
content:
<B>colordiff</B> allows extensive customization of its color schemes through a user-specific configuration file, typically located at <I>~/.colordiffrc</I>.<br>This file uses a simple key-value pair format to define colors for added lines, deleted lines, changed lines, and more, providing granular control over the visual output.


title: <B>INTEGRATION WITH PAGERS</B>
content:
For viewing large diffs, <B>colordiff</B> is often piped to a pager like <B>less</B> (e.g., <B>diff -u file1 file2 | colordiff | less -R</B>).<br>The <B>-R</B> or <B>--RAW-CONTROL-CHARS</B> option in <B>less</B> is crucial as it allows <B>less</B> to interpret the ANSI color escape sequences, preserving the colorized output.


title: HISTORY
content:
<I><B>colordiff</B> was created by Gavin Young in the early 2000s to provide colorized output for the standard <B>diff</B> command, addressing a common need for improved readability in terminal environments.</I><br>
<I>It's a standalone Perl script that gained popularity due to its simplicity and effectiveness, filling a gap left by the core <B>diff</B> utility which by default outputs plain text.</I><br>
<I>It's not part of the GNU diffutils but is widely available as a separate package in most Linux distributions and BSD systems, often installed via package managers like <B>apt</B>, <B>yum</B>, or <B>dnf</B>.</I><br>
<I>Its development has been steady, focusing on compatibility with various <B>diff</B> versions and improving color customization options via its configuration file.</I><br>
<I>Its continued usage highlights the enduring value of enhancing command-line tools for better user experience.</I>


title: SYNOPSIS
content:
<b>colorls</b> [OPTIONS] [PATH...]<br>Example: <b>colorls -l --sort-files ~/Documents</b><br>Example: <b>colorls --tree .</b>


title: PARAMETERS
content:
<b><b>--all</b>, <b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ignore entries starting with '<b>.</b>'.<br><br><b><b>--long</b>, <b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a long listing format, showing permissions, owner, size, and date.<br><br><b><b>--tree</b>, <b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display directory contents in a tree-like structure.<br><br><b><b>--sort-dirs</b>, <b>-sd</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort directories first, then files, preserving sub-sorting.<br><br><b><b>--git-status</b>, <b>-g</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show <i>Git</i> status indicators (modified, untracked, added files).<br><br><b><b>--report</b>, <b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a <i>Git</i> status report summary.<br><br><b><b>--exclude-dirs=PATTERNS</b>, <b>-D PATTERNS</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude directories matching specified patterns.<br><br><b><b>--exclude-files=PATTERNS</b>, <b>-F PATTERNS</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude files matching specified patterns.<br><br><b><b>--light-colors</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a lighter color scheme for improved readability on dark terminals.<br><br><b><b>--dark-colors</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a darker color scheme for improved readability on light terminals.<br><br><b><b>--ignore-case</b>, <b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore case when sorting entries.<br><br><b><b>--sort-date</b>, <b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort entries by modification date.<br><br><b><b>--sort-size</b>, <b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort entries by size, largest first.<br><br><b><b>--sort-reverse</b>, <b>-R</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reverse the order of the sort.<br><br><b><b>--files</b>, <b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List only files, excluding directories.<br><br><b><b>--dirs</b>, <b>-di</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List only directories, excluding files.<br><br><b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b><b>--version</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<b>colorls</b> is an open-source <i>Ruby</i> gem that serves as a highly visual and functional alternative to the traditional <b>ls</b> command in Unix-like operating systems. It aims to enhance the command-line experience by providing a rich, color-coded output that includes syntax highlighting for various file types, <i>Font Awesome</i> icons for files and directories, and integrated <i>Git</i> status indicators. Unlike <b>ls</b>, <b>colorls</b> offers immediate visual cues about file permissions, ownership, size, and modification dates, alongside a clear representation of <i>Git</i> repository changes (modified, untracked, added files). Its features extend to tree-view listings, intelligent sorting options, and customizable output. While offering significant aesthetic and informational improvements, <b>colorls</b> requires a <i>Ruby</i> environment and a compatible font (like <i>Nerd Fonts</i>) for full icon display, making it a popular choice for developers seeking a more informative and visually appealing directory listing tool.


title: CAVEATS
content:
Requires <i>Ruby</i> and <i>RubyGems</i> installed on the system.<br>Full icon display depends on a font with <i>Font Awesome</i> glyphs (e.g., <i>Nerd Fonts</i>) being configured in the terminal. Without it, icons may appear as broken characters.<br>For very large directories, <b>colorls</b> might be slightly slower than the native <b>ls</b> command due to additional processing for icons, colors, and <i>Git</i> status.<br>It is not a direct drop-in replacement for all <b>ls</b> aliases due to its distinct set of options.


title: INSTALLATION
content:
To install <b>colorls</b>, ensure <i>Ruby</i> and <i>RubyGems</i> are installed, then execute: <i>gem install colorls</i>. It is recommended to install it globally or manage with <i>rvm</i>/<i>rbenv</i>.


title: FONT REQUIREMENT
content:
For <b>colorls</b> to display icons correctly, your terminal font must support <i>Font Awesome</i> glyphs. Popular choices include <i>Nerd Fonts</i> which patch common programming fonts to include a wide range of icons, including those used by <b>colorls</b>. Without a compatible font, icons will likely render as generic replacement characters.


title: CONFIGURATION
content:
<b>colorls</b> allows extensive customization of its output, including icon mappings and color schemes, through <i>YAML</i> configuration files typically located in <i>~/.config/colorls/</i>. Users can define custom rules for file types, create personalized themes, and fine-tune its behavior.


title: HISTORY
content:
<b>colorls</b> emerged as an open-source project, primarily developed as a <i>Ruby</i> gem, in response to the growing demand for more visually appealing and informative command-line tools. It gained traction among developers and power users who sought to enhance their terminal workflow beyond the capabilities of the traditional <b>ls</b> command. Its development leveraged <i>Ruby</i>'s flexibility to parse file system information and integrate with external libraries like <i>Font Awesome</i> for icons and <i>Git</i> for status reporting. The project's evolution has been community-driven, with contributions continually refining its features, performance, and customization options, establishing it as a popular choice in the ecosystem of modern CLI utilities.


title: PARAMETERS
content:
<b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version of <i>colormgr</i> and exits.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows a summary of available commands and global options.<br><br><b>calibrate-device <I>device ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initiates a calibration process for the specified device. This command often launches a graphical application for user interaction.<br><br><b>create-profile-from-device <I>device ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new color profile based on readings or default settings from a connected device.<br><br><b>create-profile-from-target <I>device ID</I> <I>target type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a profile for a device based on a specified target type (e.g., sRGB, AdobeRGB for displays).<br><br><b>delete-device <I>device ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes a color device from the <i>colord</i> daemon's management and unassociates its profiles.<br><br><b>delete-profile <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes a color profile from the system and unassociates it from devices.<br><br><b>device-add-profile <I>device ID</I> <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Associates an existing profile with a specific device.<br><br><b>device-get-profiles <I>device ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all color profiles currently associated with a given device.<br><br><b>device-set-default-profile <I>device ID</I> <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a specific profile as the default for a device, which will be used unless overridden.<br><br><b>device-set-enabled <I>device ID</I> <I>true|false</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables a device's color management within <i>colord</i>.<br><br><b>device-set-mode <I>device ID</I> <I>mode</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color mode for a device (e.g., 'display', 'printer', 'scanner').<br><br><b>device-set-preferred-profile <I>device ID</I> <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a preferred profile for a device, which might be used when no default is explicitly specified.<br><br><b>device-set-profile-enabled <I>device ID</I> <I>profile ID</I> <I>true|false</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables the use of a specific profile for a device.<br><br><b>dump-all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps detailed information about all registered devices and profiles in XML format.<br><br><b>dump-device <I>device ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about a specific device in XML format.<br><br><b>dump-profile <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about a specific profile in XML format.<br><br><b>find-profiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Finds profiles based on various criteria (e.g., tags, manufacturer, creation date).<br><br><b>get-default-device</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the ID of the system's default color device.<br><br><b>get-default-profile</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the ID of the system's default color profile.<br><br><b>get-devices</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all color devices currently managed by <i>colord</i>.<br><br><b>get-icc-profiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all installed ICC profiles, showing their file paths and associated profile IDs.<br><br><b>get-preferred-profiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists preferred profiles for all devices, indicating which profile <i>colord</i> would recommend.<br><br><b>get-profiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all color profiles known to <i>colord</i>.<br><br><b>get-sensor-readings <I>sensor ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Gets current readings from a color sensor (e.g., ambient light sensor data).<br><br><b>import-profile <I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Imports an ICC profile file into the system. This command is often deprecated in favor of <i>profile-install</i>.<br><br><b>list-sensors</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available color sensors connected to the system.<br><br><b>monitor-all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitors D-Bus signals for any changes in devices or profiles, providing real-time updates.<br><br><b>monitor-devices</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitors D-Bus signals for changes specifically in color devices (e.g., added, removed, status changes).<br><br><b>monitor-profiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitors D-Bus signals for changes specifically in color profiles (e.g., added, removed, updated).<br><br><b>profile-get-icc-file <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the file path to the ICC profile associated with a given profile ID.<br><br><b>profile-install <I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs a new ICC profile from a specified file into the system.<br><br><b>profile-set-from-icc <I>profile ID</I> <I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Updates an existing profile's ICC data using a new ICC file, retaining its existing ID.<br><br><b>profile-uninstall <I>profile ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uninstalls a previously installed profile from the system.<br><br><b>sensor-calibrate <I>sensor ID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initiates a calibration routine for a specified color sensor.<br><br><b>sensor-set-mode <I>sensor ID</I> <I>mode</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the operational mode for a color sensor (e.g., 'ambient', 'spot').<br><br>


title: DESCRIPTION
content:
The <b>colormgr</b> command-line utility provides an interface to the <i>colord</i> system daemon, which manages color profiles for devices such as displays, printers, and scanners. It allows users and administrators to query, install, remove, and associate color profiles with hardware, ensuring accurate color reproduction across the system.<br><br><b>colormgr</b> interacts with <i>colord</i> via D-Bus, enabling programmatic control over color management features. It is commonly used in desktop environments like GNOME to configure display calibration and printer profiles, offering both diagnostic capabilities and the means to apply color corrections without relying on a graphical user interface.


title: CAVEATS
content:
<b>colormgr</b> relies entirely on the <i>colord</i> system daemon being installed and running. Without <i>colord</i>, <b>colormgr</b> will not function and typically report D-Bus errors.<br><br>Some commands, like <i>calibrate-device</i>, may require a graphical environment and launch a separate application for user interaction.<br><br>Permissions are crucial; typical users might only be able to query information, while administrative tasks (e.g., installing profiles, deleting devices) require elevated privileges (e.g., using <b>sudo</b>).


title: UNDERSTANDING IDS
content:
Many <b>colormgr</b> commands require <i>device ID</i>s or <i>profile ID</i>s. These are unique string identifiers managed by the <i>colord</i> daemon.<br><br>They can typically be found by using commands like <b>colormgr get-devices</b> to list device IDs and <b>colormgr get-profiles</b> to list profile IDs. These IDs are often UUIDs (Universally Unique Identifiers) or derived from hardware identifiers.


title: HISTORY
content:
The <b>colormgr</b> command and the underlying <i>colord</i> daemon were developed as part of the GNOME project to provide a standardized, system-wide color management solution for Linux. It emerged to centralize and simplify the handling of color profiles, replacing or augmenting older, more disparate methods.<br><br>Its development aimed to integrate seamlessly with desktop environments and allow hardware vendors to provide accurate color information for their devices. <b>colormgr</b> became a core component for color management in many Linux distributions, particularly those using GNOME, around the early 2010s, ensuring a consistent color experience.


title: DESCRIPTION
content:
The <b>grabc</b> command, often serving the role of a command-line <i>colorpicker</i> on Linux, provides a minimalistic way to identify colors from the X display using your mouse. When executed, it pauses and waits for a single mouse click anywhere on the screen. Upon clicking, <b>grabc</b> immediately identifies the color of the pixel directly under the mouse cursor and prints its hexadecimal RGB representation (e.g., `#RRGGBB` or `RRGGBB` depending on version/environment) to standard output. This utility is particularly efficient for tasks like web development, graphic design, or scripting where you need to quickly acquire a precise color value from an application or an image displayed on your screen without resorting to complex graphical tools. Its simplicity aligns with the <i>suckless</i> philosophy of doing one thing well.


title: CAVEATS
content:
<b>grabc</b> is typically part of the <i>suckless-tools</i> package and might not be installed by default on all Linux distributions. It requires an active X server environment to function, meaning it cannot be used in a purely command-line (TTY) session without X. Its output is generally limited to hexadecimal RGB format without options for other color spaces (e.g., HSL, CMYK) or decimal RGB values.


title: HISTORY
content:
<b>grabc</b> is a utility developed under the <i>suckless</i> philosophy, which advocates for software that is simple, small, and focuses on doing one thing well. Its development is rooted in the tradition of creating highly efficient and user-centric tools for the Unix-like environment, often resulting in a lean codebase and minimal features, ensuring stability and speed. It emerged as a solution for quick color grabbing without the overhead of larger graphical applications, consistent with other utilities in the <i>suckless-tools</i> collection.


title: PARAMETERS
content:
<b>start_column</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A 1-based integer specifying the first character position to remove.<br><br><b>end_column</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A 1-based integer specifying the last character position to remove (inclusive). If omitted, removes to end of line.<br><br>


title: DESCRIPTION
content:
<i>colrm</i> is a command-line utility that reads lines from standard input, removes characters within specified column ranges, and writes the modified lines to standard output. Unlike tools that operate on delimited fields, <i>colrm</i> works directly on 1-based character positions. It accepts one or two 1-based integer arguments.<br><br>If only a <i>start_column</i> is provided, all characters from that position to the end of the line are removed. If both <i>start_column</i> and <i>end_column</i> are given, characters within that inclusive range are removed. This command is particularly useful for extracting or tidying up fixed-width textual data by position.


title: CAVEATS
content:
<i>Caveats and limitations:</i><br><b>colrm</b> operates strictly on 1-based character positions (columns), not on semantic fields or delimiters. This can lead to unexpected results with variable-width data where you intend to remove logical "fields".<br>It processes standard input and writes to standard output, necessitating redirection or piping for file operations.<br>The command lacks options for delimiter specification, multi-byte character handling, or error suppression, making it a highly specialized and less flexible tool compared to <b>cut</b> or <b>awk</b> for diverse text processing.


title: HISTORY
content:
<b>colrm</b> is a standard Unix utility, part of the GNU Coreutils package on Linux systems. Its design reflects a simple, stream-based text processing paradigm, and its core functionality has remained consistent over time, serving as a specialized tool for fixed-width column manipulation.


title: PARAMETERS
content:
<b>-t, --table</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Determines the number of columns in the input and creates a table. This is often the most useful option for tabular data.<br><br><b>-s, --separator=CHARS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies custom input item separator(s). By default, <b>column</b> uses whitespace as a separator.<br><br><b>-o, --output-separator=CHARS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the string to use as a column separator in the output. Default is two spaces.<br><br><b>-c, --columns=NUM</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output is formatted to exactly <i>NUM</i> columns. This overrides automatic column determination.<br><br><b>-x, --fill-rows</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fill columns before filling rows. This means data will flow horizontally first, then wrap to the next row.<br><br><b>-n, --no-indent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Don't indent the first column. Useful when the first column doesn't need extra padding.<br><br><b>-R, --right-justify</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Right justifies text within all columns. By default, columns are left-justified.<br><br><b>-L, --logical</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use logical character counts rather than byte counts for column width, important for multi-byte characters.<br><br><b>-W, --width=WIDTH</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the maximum display width. If not set, it defaults to the terminal width.<br><br>


title: DESCRIPTION
content:
The <b>column</b> command is a versatile utility used to format its input into multiple columns, significantly enhancing the readability of tabular data in the terminal. It reads lines from standard input or specified files and intelligently arranges them into columns, automatically padding entries to ensure proper alignment.<br><br>Its primary function is to transform unstructured or line-oriented text into a more organized, grid-like format. For instance, the output of commands like <i>ls -l</i> or <i>ps aux</i> can be piped to <b>column -t</b> to automatically create a neat table.<br><br>Key features include the ability to automatically determine the optimal number of columns (table mode), specify custom input and output delimiters, control column width, and sort output. It is an invaluable tool for system administrators and developers who frequently work with command-line output and require clear, aligned data presentation.


title: CAVEATS
content:
While powerful for general tabular formatting, <b>column</b> is not designed for complex, highly customized text manipulation that requires advanced conditional formatting or numeric operations. For such tasks, tools like <i>awk</i> or <i>printf</i> are more suitable.<br><br>The automatic table mode (<i>-t</i>) relies on consistent delimiter usage in the input. If the input data has inconsistent delimiters or varying numbers of fields per line, the output might not be as expected.<br><br>Handling of non-printable characters or very long lines without breaks can sometimes lead to unexpected visual output.


title: COMMON USAGE EXAMPLE
content:
A very common use case for <b>column</b> is to make the output of commands like <i>ls -l</i> more readable:<br><i>ls -l | column -t</i><br>This command takes the long listing output of <i>ls</i> and automatically formats it into neatly aligned columns, making it much easier to scan and understand.


title: INPUT AND OUTPUT
content:
<b>column</b> reads data from standard input if no file is specified, or from the files listed as arguments. The formatted output is always written to standard output. This makes it ideal for piping the output of other commands directly into <b>column</b> for immediate formatting.


title: HISTORY
content:
The <b>column</b> command is part of the <i>util-linux</i> package, a collection of essential Linux utilities. It has been a standard feature of Unix-like operating systems for many years, evolving to include more sophisticated formatting options like the <i>-t</i> (table) mode, which significantly increased its utility for presenting structured data. Its development has focused on providing a fast and efficient way to make plain text output more readable, adapting to modern terminal capabilities and diverse data formats.


title: SYNOPSIS
content:
combine [<I>options</I>] <I>input_image</I>... <I>output_image</I><br><br><i>Note: This synopsis represents the common usage of the `combine` utility found in ImageMagick versions prior to v7, or as a symlink to the main `magick` command in newer versions for specific legacy operations. For more general image composition, refer to `magick composite` or `magick convert`.</i>


title: PARAMETERS
content:
<b><b>-channel</b> <I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which image channels (e.g., Red, Green, Blue, Alpha) are processed for the operation.<br><br><b><b>-compress</b> <I>type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the image compression type for the output file (e.g., <I>JPEG</I>, <I>Zip</I>, <I>LZW</I>).<br><br><b><b>-quality</b> <I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the image compression quality for formats like JPEG, MIFF, or PNG (0-100).<br><br><b><b>-strip</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes any profiles, comments, or metadata from the output image.<br><br><b><b>-verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about the image processing progress, including image attributes.<br><br><b><b>-monochrome</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Transforms the output image to black and white, effectively creating a bilevel image.<br><br>


title: DESCRIPTION
content:
The <b><I>combine</I></b> command is a utility from the ImageMagick suite, a powerful open-source software collection for image manipulation. Unlike general-purpose file utilities, <b><I>combine</I></b> is specifically designed for working with raster images. Its primary functions include joining multiple individual images into a single multi-image file (e.g., creating a GIF animation from a sequence of JPEGs, or a multi-page TIFF document).<br><br>Additionally, <b><I>combine</I></b> can be used to extract or combine specific color channels (like red, green, blue) from one or more images into a new image. This makes it valuable for specialized image processing tasks, such as creating grayscale images from a single channel, or merging channels from different sources. While it's part of a larger suite, <b><I>combine</I></b> offers a focused set of functionalities for complex image assembly and channel-level operations, particularly in scripting and automated workflows.


title: CAVEATS
content:
<ul><li><b><I>Domain Specific</I></b>: The <b><I>combine</I></b> command is part of the ImageMagick suite and is exclusively for image processing, not for general text or file manipulation.</li><li><b><I>Version Dependency</I></b>: Its specific behavior and availability as a standalone executable can vary between ImageMagick versions. In ImageMagick 7 and newer, many of its functionalities are integrated into the unified <b><I>magick</I></b> command.</li><li><b><I>Distinction from <I>composite</I></I></b>: Often confused with <b><I>composite</I></b>, which overlays images. <b><I>combine</I></b> typically merges images into a multi-frame file or performs channel-specific operations.</li></ul>


title: <I>MULTI-IMAGE FILE CREATION</I>
content:
One of <b><I>combine</I></b>'s key uses is to take a series of individual images and merge them into a single file format that supports multiple frames or pages, such as multi-page TIFFs, animated GIFs, or multi-layer MIFF files. This is crucial for applications requiring image sequences or grouped visual content.


title: <I>CHANNEL EXTRACTION AND MANIPULATION</I>
content:
Beyond simple merging, <b><I>combine</I></b> excels at working with individual color channels (Red, Green, Blue, Alpha). Users can extract a single channel from an image as a new grayscale image, or combine channels from different input images to create a new composite image. This is particularly useful for advanced image analysis or specialized visual effects.


title: HISTORY
content:
The <b><I>combine</I></b> command is one of the original utilities within the ImageMagick software suite, which was first released in 1987. Over decades, ImageMagick has evolved significantly. While <b><I>combine</I></b> has maintained its core purpose of merging images into multi-frame files or processing color channels, its role has somewhat shifted with the introduction of ImageMagick 7. In this newer version, a unified `magick` command largely encompasses the functionalities previously found in separate utilities like `combine`, `convert`, and `mogrify`, though `combine` might still exist as a backward-compatible symlink or for specific legacy scripts.


title: SYNOPSIS
content:
<b>combinediff</b> [<i>OPTIONS</i>] <i>DIFF1</i> <i>DIFF2</i> [<i>ORIGINAL_FILE1</i>] [<i>ORIGINAL_FILE2</i>]


title: PARAMETERS
content:
<b><i>DIFF1</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the first diff file (patch) to be combined.<br><br><b><i>DIFF2</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the second diff file (patch) to be combined.<br><br><b><i>ORIGINAL_FILE1</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) The path to the original file from which <i>DIFF1</i> was generated. Used to determine the exact base for comparison.<br><br><b><i>ORIGINAL_FILE2</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) The path to the original file from which <i>DIFF2</i> was generated. Used in conjunction with <i>ORIGINAL_FILE1</i> to produce a diff from <i>FILE1</i> (modified by <i>DIFF1</i>) to <i>FILE2</i> (modified by <i>DIFF2</i>).<br><br><b>-p <i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs the underlying <i>patch</i> command to strip <i>NUM</i> leading path components from file names in the diffs.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate in quiet mode, suppressing non-essential output.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, providing more details about the process.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable debug mode, showing internal commands and temporary files.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress errors from the underlying <i>diff</i> command.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore changes in amount of white space.<br><br><b>-w</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore all white space when comparing lines.<br><br><b>-b</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore changes in the amount of white space (but not actual white space characters).<br><br><b>-B</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore changes that consist solely of blank lines.<br><br><b>-I <i>REGEXP</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore changes whose lines match the specified regular expression.<br><br><b>-c <i>CONTEXT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the number of context lines to <i>CONTEXT</i> for the output diff (default is usually 3).<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force output to be in unified diff format (this is often the default).<br><br><b>-N</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat absent files as empty when comparing.<br><br><b>-o <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Direct the output of the combined diff to <i>FILE</i> instead of standard output.<br><br><b>--diff-options <i>...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pass additional options directly to the underlying <i>diff</i> command used by <b>combinediff</b>.<br><br><b>--strip-trailing-cr</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Strip trailing carriage returns (CR) from input lines, useful when dealing with Windows/Unix line ending differences.<br><br>


title: DESCRIPTION
content:
<b>combinediff</b> is a command-line utility designed to merge two patch files (diffs) that originated from the same base or original source file. It processes these two input diffs and produces a single, consolidated patch file as output.<br><br>This tool is particularly valuable in software development and version control contexts where changes from different branches or sets of modifications need to be integrated. Rather than applying two separate patches sequentially, <b>combinediff</b> enables the creation of a single patch that encapsulates all combined changes, streamlining the patching process.<br><br>It functions by analyzing the modifications described in both input diffs relative to their implied common ancestor. It then intelligently merges these changes, attempting to resolve overlaps and potential conflicts where possible. The resulting output is typically in the unified diff format, showing the aggregate transformation from the base file to a state reflecting both sets of modifications, or from one patched version to another, depending on the command's invocation.


title: CAVEATS
content:
<b>combinediff</b> works most reliably when both input diffs (<i>DIFF1</i> and <i>DIFF2</i>) are generated against a genuinely common original file. If the base files are significantly divergent or the diffs are not well-formed, the results may be unpredictable or incorrect. While it attempts to merge changes, it is not a full-fledged merge tool like <i>git merge</i> and may not handle complex overlapping conflicts gracefully, potentially producing a patch that requires manual intervention to apply cleanly.


title: CONCEPTUAL OPERATION
content:
At its core, <b>combinediff</b> conceptually performs a multi-step process: it reconstructs the original file(s) from the diffs if not provided, applies one diff to the original to get an intermediate state, and then generates a new diff between this intermediate state and the state resulting from applying the other diff. Alternatively, if two original files are provided, it generates a diff between the state of <i>ORIGINAL_FILE1</i> after <i>DIFF1</i> and the state of <i>ORIGINAL_FILE2</i> after <i>DIFF2</i>.


title: COMMON USE CASES
content:
<ul><li><i>Creating Delta Patches:</i> Generating a patch that transforms a file from a state where <i>DIFF1</i> was applied to a state where <i>DIFF2</i> was applied, assuming both originated from a common ancestor.</li><li><i>Consolidating Changes:</i> Merging two distinct sets of modifications (e.g., two bug fixes, or a bug fix and a feature) that both apply to the same base version of a file into a single, unified patch file. This simplifies distribution and application of changes.</li></ul>


title: HISTORY
content:
<b>combinediff</b> is typically distributed as part of the `patch` utilities, a suite of tools fundamental to Unix-like systems for managing and applying code changes. The original `patch` program was written by Larry Wall in 1985. <b>combinediff</b> serves as a higher-level script that leverages the core `diff` and `patch` functionalities to solve a specific problem of combining multiple sets of changes. Its development reflects a Unix philosophy of creating simple, composable tools to achieve complex tasks, preceding the widespread adoption of modern distributed version control systems which often incorporate similar merging capabilities directly.


title: SYNOPSIS
content:
<b>comby</b> [<i>OPTIONS</i>] <<i>MATCH_PATTERN</i>> <<i>REWRITE_PATTERN</i>> [<i>PATH...</i>]<br><b>comby</b> [<i>OPTIONS</i>] -f <<i>PATTERN_FILE</i>> [<i>PATH...</i>]<br><i>STDIN</i> | <b>comby</b> [<i>OPTIONS</i>] <<i>MATCH_PATTERN</i>> <<i>REWRITE_PATTERN</i>>


title: PARAMETERS
content:
<b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process files in directories recursively.<br><br><b><b>-f</b>, <b>--file</b> <<i>PATH</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a file containing the <i>MATCH_PATTERN</i> and <i>REWRITE_PATTERN</i>.<br><br><b><b>--in-place</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Modify files in place. Use with caution and version control.<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output results as JSON, providing structured data for programmatic use.<br><br><b><b>-d</b>, <b>--directories</b> <<i>LIST</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of directories to search within.<br><br><b><b>-e</b>, <b>--extensions</b> <<i>LIST</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A comma-separated list of file extensions to include (e.g., .js,.ts,.go).<br><br><b><b>-s</b>, <b>--stdin</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read input from standard input (stdin).<br><br><b><b>--match-only</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only show matched regions; do not perform rewriting.<br><br><b><b>--diff</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a diff of the proposed changes without applying them.<br><br><b><b>--review</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interactively review and approve each change before applying.<br><br><b><b>--count</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the number of matches found.<br><br>


title: DESCRIPTION
content:
<b>comby</b> is a powerful, syntax-aware code search and rewrite tool designed for large-scale refactoring and code transformations. Unlike traditional regular expression tools like <b>grep</b> or <b>sed</b>, <b>comby</b> understands code structure, allowing it to match and rewrite code based on its abstract syntax rather than just raw text. This makes it highly effective for performing complex, language-agnostic code modifications. It uses a flexible pattern-matching language that supports "holes" (e.g., <code>:[_]</code>, <code>:[x]</code>) to capture arbitrary code fragments, which can then be reused in the rewrite pattern. <b>comby</b> can process multiple files and directories, supports in-place modifications, and can output structured JSON results. Its primary use cases include refactoring codebases, applying codemods, migrating APIs, and enforcing coding standards across projects.


title: CAVEATS
content:
While <b>comby</b> offers powerful structural matching, its syntax-aware capabilities are heuristic and do not rely on full, formal AST parsers for every language. This means it might occasionally misinterpret highly complex or ambiguous code constructs. Learning the <b>comby</b> pattern syntax, especially the nuances of "holes," requires a slight learning curve compared to basic regex. For very large codebases or extremely intricate patterns, performance can be a consideration, although it is generally highly optimized. Always test changes on a version-controlled codebase and consider using the <b>--diff</b> or <b>--review</b> flags before applying <b>--in-place</b> modifications.


title: <I>HOLES SYNTAX</I>
content:
<b>comby</b> employs a specific syntax for "holes" in its patterns to capture arbitrary code fragments. Common hole types include <code>:&#91;_&#93;</code> (any single expression or statement), <code>:&#91;x&#93;</code> (a named hole that can be reused in the rewrite pattern), <code>:&#91;*&#93;</code> (zero or more expressions/statements), and <code>:&#91;*x&#93;</code> (zero or more named expressions/statements). This flexible mechanism allows for highly powerful and precise structural matching and rewriting.


title: HISTORY
content:
<b>comby</b> was developed by Rémy Goldschmidt and first released around 2018. It emerged as a response to the limitations of traditional regex-based tools when refactoring large codebases, where changes often need to respect code structure rather than just raw text. Its design prioritizes speed and the ability to operate across multiple programming languages without requiring specific language parsers, instead relying on robust heuristic parsing. Its development was driven by the need for a practical, fast tool for applying "codemods" and performing structural transformations efficiently.


title: PARAMETERS
content:
<b><b>-1</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress printing of column 1 (lines unique to FILE1).<br><br><b><b>-2</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress printing of column 2 (lines unique to FILE2).<br><br><b><b>-3</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress printing of column 3 (lines common to both files).<br><br><b><b>--output-delimiter=STR</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Separate columns with STR. Default is tab characters.<br><br><b><b>--nocheck-order</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not check that the input is sorted. This can lead to incorrect output if files are not sorted.<br><br><b><b>--zero-terminated</b>, <b>-z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Line delimiter is NUL, not newline. Input lines can contain newlines.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br>


title: DESCRIPTION
content:
The <b>comm</b> command compares two <I>already sorted</I> files, line by line. It outputs three columns by default: lines unique to the first file, lines unique to the second file, and lines common to both files.<br><br>This utility is particularly useful for identifying differences and commonalities between datasets when the order of lines is significant. For accurate results, both input files <I>must</I> be sorted in the same collating sequence; otherwise, <b>comm</b> may produce incorrect or incomplete output. Users can control which columns are displayed using options like <b>-1</b>, <b>-2</b>, and <b>-3</b> to suppress specific columns, allowing focus on unique or common lines. It can also accept standard input for one of the files by specifying a hyphen (<b>-</b>) as an argument.


title: CAVEATS
content:
The most crucial caveat is that <I>both input files must be sorted</I> for <b>comm</b> to function correctly and produce reliable output. If files are not sorted, the results will be unpredictable and likely incorrect.<br><br><b>comm</b> performs a character-by-character comparison. Leading/trailing whitespace or case differences will be treated as different lines unless normalized prior to comparison.<br><br>It is not designed for comparing unsorted files or for complex diffing scenarios (like showing line changes within a block), for which <b>diff</b> is more appropriate.


title: COLUMN STRUCTURE
content:
By default, <b>comm</b> outputs three columns, separated by tab characters (configurable with <b>--output-delimiter</b>): Column 1 contains lines found only in FILE1; Column 2 contains lines found only in FILE2; and Column 3 contains lines found in both FILE1 and FILE2.


title: STANDARD INPUT USAGE
content:
One of the input files can be specified as a hyphen (<b>-</b>), which indicates that <b>comm</b> should read from standard input for that file. For example, <b>comm file1 -</b> reads the content for the second file from standard input.


title: HISTORY
content:
<b>comm</b> is part of the GNU Core Utilities, a collection of fundamental tools commonly found on Unix-like operating systems. Its basic functionality has been a standard Unix utility for a long time, indicating its foundational role in text processing. The core logic of comparing sorted streams is efficient and well-established.


title: DESCRIPTION
content:
The command <I>comma</I> is <I>not</I> a standard Linux utility or widely recognized shell command found in common distributions such as Debian, Ubuntu, Fedora, or RHEL. It is also not part of fundamental command-line tool collections like the GNU Coreutils. The term likely arises from a misunderstanding, a typographical error (perhaps intending <I>comm</I>, a command that compares sorted files), or a reference to a highly specialized, non-standard script or a user-defined alias/function that is not part of the standard system environment.<br><br>Consequently, a functional analysis providing typical command-line syntax, options, and operational details for a standalone <I>comma</I> command cannot be accurately provided, as no such command exists as a public utility.


title: CAVEATS
content:
As <I>comma</I> is not a real command, any attempt to execute it will result in a 'command not found' error. Users often confuse it with the <I>comm</I>(1) command, which compares two sorted files line by line, or with the use of commas as delimiters within arguments of other commands (e.g., in CSV files, or for numeric formatting options).


title: COMMON MISCONCEPTIONS AND USAGE OF COMMAS
content:
The term 'comma' in Linux contexts is typically used as a character literal, often serving as a separator or delimiter within arguments for other commands (e.g., to separate fields in CSV files, as part of regular expressions, or for numeric formatting options). It is not the name of a command itself. For example, a comma might be used with `grep` to define patterns or with `awk` for field separation. The concept of a 'comma' command is a common source of confusion for new users expecting a utility related to the punctuation mark itself.


title: HISTORY
content:
<B>N/A</B> - Since <I>comma</I> is not a standard command, it has no development history or usage history in the context of official Linux utilities.


title: SYNOPSIS
content:
<code>command [-pVv] command_name [arg ...]</code><br><code>command -V command_name</code><br><code>command -v command_name</code><br><code>command -p command_name</code>


title: PARAMETERS
content:
<b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Searches the <code>PATH</code> using a default value</i> that is guaranteed to find all standard utilities. This is particularly useful in scripts to ensure that standard utilities are found even if the user has a modified or incomplete <code>PATH</code>.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a <i>description of <code>command_name</code></i>, indicating how it would be interpreted. For example, it might show if it's an alias, function, built-in, or executable, and its location. This is similar to the <code>type</code> command, but with a more concise output.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a <i>more verbose description of <code>command_name</code></i> than <code>-v</code>. This output often includes the exact path for executables, the definition for functions, or the alias expansion.<br><br><b>--</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicates the <i>end of options</i>. Any arguments following <code>--</code> are treated as <code>command_name</code> and its arguments, even if they start with a hyphen. This is useful when <code>command_name</code> itself might look like an option.<br><br>


title: DESCRIPTION
content:
<code>command</code> is a <i>shell built-in</i> that executes a command by searching for it only in the system's <code>PATH</code> for executables, or as a shell <i>built-in</i>, explicitly <b>ignoring shell aliases and functions</b> of the same name.<br><br>This is crucial for writing robust and predictable shell scripts, especially when the script needs to call the "true" or original version of a utility that might have been <i>aliased</i> or overridden by a <i>shell function</i> in the user's environment.<br><br>For instance, if <code>ls</code> is aliased to <code>ls --color=auto</code>, <code>command ls</code> will execute the original <code>ls</code> binary found in <code>PATH</code>. It also provides options to <i>query the type</i> and <i>location</i> of a command, similar to <code>type</code> or <code>which</code>. The primary goal is to ensure a command is executed in a predictable manner, free from potential user-defined overrides.


title: CAVEATS
content:
The <code>command</code> utility is a <i>shell built-in</i>, meaning its exact behavior and available options might have minor variations across different shells (e.g., Bash, Zsh, Ksh). However, its core functionality, especially for the <code>-p</code>, <code>-v</code>, and <code>-V</code> options, is consistent with the <i>POSIX standard</i>.<br><br>It <b>cannot be used to execute shell functions or aliases directly</b> by name; its purpose is specifically to bypass them and find the underlying executable or built-in.<br><br>Using <code>command</code> does <i>not</i> modify the shell's execution environment or <code>PATH</code> permanently. It only affects the command lookup for that single execution.


title: RETURN STATUS
content:
The <i>exit status</i> of <code>command</code> is that of the <code>command_name</code> if it is found and executed. If <code>command_name</code> is not found, or if an error occurs, <code>command</code> returns a non-zero status (typically 127 for command not found, or other non-zero values for syntax errors).


title: PURPOSE IN SCRIPTING
content:
<code>command</code> is an indispensable tool for <i>robust scripting</i>. It allows script writers to protect against unintended side effects from user configurations, ensuring that critical system utilities are called in their original form. This is vital for system maintenance scripts, installation scripts, or any script that needs to be self-contained and predictable regardless of the user's shell environment.


title: HISTORY
content:
The <code>command</code> utility was introduced as part of the <i>POSIX standard</i> for shell utilities. Its primary motivation was to address the challenge of <b>reliable command invocation</b> within shell scripts.<br><br>Before <code>command</code>, it was difficult for scripts to guarantee that they were executing a specific external utility rather than a user-defined alias or function, which could lead to unpredictable script behavior or security vulnerabilities.<br><br>It provides a standardized, portable mechanism for scripts to force the shell to perform a <code>PATH</code> search and execute the first match, ensuring predictable behavior across various Unix-like systems conforming to POSIX.


title: SYNOPSIS
content:
<br><code>git commit [-a | --interactive | --patch] [-s | --no-signoff] [-v | --verbose] [--amend] [-m &lt;msg&gt;] [-F &lt;file&gt;] [--author=&quot;&lt;author&gt;&quot;] [--no-verify] [&lt;file&gt;...]</code>


title: PARAMETERS
content:
<b>-m &lt;msg&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the given <I>msg</I> as the commit message.<br><br><b>-a | --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically stage files that have been modified and deleted, then commit.<br><br><b>--amend</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Combine the new changes with the previous commit, rather than creating a new one.<br><br><b>-F &lt;file&gt; | --file=&lt;file&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Take the commit message from the given <I>file</I>.<br><br><b>-s | --signoff</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a "Signed-off-by" line by the committer at the end of the commit message.<br><br><b>-v | --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show unified diff of all changes to be committed, above the message.<br><br><b>--no-verify</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Bypass the pre-commit and commit-msg Git hooks.<br><br><b>--author=&quot;&lt;author&gt;&quot;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Override the commit author for this commit.<br><br>


title: DESCRIPTION
content:
The `commit` command is not a standalone Linux utility but a fundamental subcommand of version control systems, most notably <I>Git</I>. This analysis focuses on <I>git commit</I>, which captures the current state of the project's <I>staged</I> changes (those added via `git add`) into a new commit object in the repository's history. Each commit represents a unique snapshot of the project at a specific point in time, identified by a SHA-1 hash, and includes the author, committer, timestamp, and a crucial commit message. The commit message provides essential context and documentation for the changes. This action permanently saves your work to the project's timeline, making it available for tracking, reverting, or sharing with others. Without committing, changes remain local, untracked, or only staged.


title: CAVEATS
content:
<I>The `commit` command is not a standalone Linux utility but a subcommand of version control systems (like Git or SVN). This analysis specifically details `git commit`, which is the prevalent use case in modern Linux development. Users must have Git installed and configured. Forgetting to stage files using `git add` before committing will result in those changes not being included in the commit.</I>


title: <I>COMMIT MESSAGE BEST PRACTICES</I>
content:
<I>A well-crafted commit message is vital for project maintainability. It typically has a concise subject line (under 50-72 characters) followed by an optional blank line and a more detailed body explaining "what" changes were made and "why," rather than just "how." This significantly aids in understanding project history, debugging, and collaboration.</I>


title: <I>THE STAGING AREA (INDEX)</I>
content:
<I>Before executing `git commit`, changes must typically be added to the Git "staging area" (or index) using `git add`. This intermediate step allows for granular control, letting developers select specific changes or even parts of changes to be included in the next commit, thereby crafting focused and logical commit units.</I>


title: HISTORY
content:
<I>The concept of "committing" changes is central to version control systems since their inception. When Linus Torvalds created Git in 2005, the `git commit` command was one of its core functionalities from the outset, enabling the atomic recording of changes to a repository. Its design reflects Git's distributed nature, where commits are local snapshots that can later be pushed to remote repositories. Over time, options like `--amend` and hooks were added to enhance its flexibility and integrate seamlessly with complex development workflows, making it a cornerstone of modern software development.</I>


title: PARAMETERS
content:
<b><b>-metric</b> <i>type</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the error metric to be used for comparison. Common types include <i>AE</i> (Absolute Error), <i>MSE</i> (Mean Squared Error), <i>PSNR</i> (Peak Signal-to-Noise Ratio), <i>SSIM</i> (Structural Similarity Index), <i>PAE</i> (Peak Absolute Error), <i>MAE</i> (Mean Absolute Error), <i>RMSE</i> (Root Mean Squared Error), <i>PerceptualHash</i>.<br><br><b><b>-fuzz</b> <i>percentage</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Colors that are similar within this percentage are considered the same. Useful for ignoring minor variations due to compression or noise.<br><br><b><b>-highlight-color</b> <i>color</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the color used to highlight differences in the output image. For example, <i>red</i>, <i>blue</i>, or <i>#FF0000</i>.<br><br><b><b>-lowlight-color</b> <i>color</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the color used for pixels that are identical in the output image.<br><br><b><b>-compose</b> <i>operator</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the composite operator to use when creating the difference image. Common operators include <i>difference</i>, <i>blend</i>, <i>xor</i>.<br><br><b><b>-verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints detailed information about the comparison, including the calculated metric value, to standard output.<br><br><b><b>-subimage-search</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares a smaller 'subimage' against a larger 'target image' to find the best match. The output image will highlight the matched area.<br><br><b><b>-dissimilarity-threshold</b> <i>value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a threshold for marking pixels as different. Pixels with difference below this value are considered identical.<br><br><b><b>-help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a comprehensive list of command-line options.<br><br>


title: DESCRIPTION
content:
The <i>compare</i> command from the ImageMagick suite is a powerful utility designed to compare two images and generate a visual representation of their differences. It calculates the difference metric between the two input images, often highlighting the pixels that vary between them. This is particularly useful for quality assurance, detecting unintended changes in image processing pipelines, or analyzing how image transformations affect visual fidelity.<br><br>The output can be an image showing the exact pixels that differ, often overlaid or blended to emphasize the changes, or a numerical metric indicating the degree of difference. It supports various comparison metrics like Absolute Error (AE), Mean Squared Error (MSE), Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and more, allowing for flexible analysis based on specific requirements.


title: CAVEATS
content:
<b>Requires ImageMagick:</b> The <i>compare</i> command is part of the ImageMagick suite; it's not a standalone core Linux utility. Users must install ImageMagick to use it.<br><br><b>Image Formats:</b> While ImageMagick supports a vast array of image formats, subtle differences in encoding or metadata between otherwise identical images can sometimes lead to unexpected comparison results.<br><br><b>Computational Cost:</b> Comparing very large images can be computationally intensive and memory-consuming, especially with certain metrics or detailed difference visualization.<br><br><b>Metric Interpretation:</b> Understanding the various comparison metrics (AE, MSE, PSNR, SSIM, etc.) is crucial for accurate interpretation of results. A low numerical difference doesn't always imply a visually identical image.


title: VISUAL OUTPUT
content:
<i>compare</i> typically produces a new image that visually highlights the differences between the two input images. This is distinct from tools like <i>cmp</i> or <i>diff</i> which output textual differences.


title: NUMERICAL OUTPUT
content:
Besides the visual difference image, <i>compare</i> can output a numerical difference metric (e.g., PSNR, AE) to standard output when used with the <b>-verbose</b> option and a <b>-metric</b> specified. This allows for automated scripting and quality control checks.


title: HISTORY
content:
ImageMagick itself dates back to 1990. The <i>compare</i> utility has been a core component of ImageMagick almost since its inception, designed to help users and developers assess visual fidelity and detect unintended changes in image processing. Its capabilities have evolved with ImageMagick, incorporating new comparison metrics, improved performance, and support for a wider range of image formats and color spaces. It's widely used in web development, quality control, and scientific imaging for automated image verification.


title: SYNOPSIS
content:
<b>compare.im6</b> [options] <i>&lt;reference_image&gt;</i> <i>&lt;target_image&gt;</i> [<i>&lt;output_image&gt;</i>]


title: PARAMETERS
content:
<b><b>-metric</b> <i>&lt;type&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the method for measuring image differences (e.g., <b>AE</b> for Absolute Error count, <b>MSE</b> for Mean Squared Error, <b>PSNR</b> for Peak Signal-to-Noise Ratio).<br><br><b><b>-fuzz</b> <i>&lt;percentage&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a percentage of color difference to be considered identical, allowing for minor variations without marking them as differences (e.g., <b>5%</b>).<br><br><b><b>-highlight-color</b> <i>&lt;color&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color used to visually highlight differing pixels in the output image (e.g., <b>red</b>, <b>#FF0000</b>).<br><br><b><b>-lowlight-color</b> <i>&lt;color&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color used for identical pixels in the output image, often a transparent or subtle color (e.g., <b>grey</b>, <b>none</b>).<br><br><b><b>-compose</b> <i>&lt;method&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Determines how the difference image is composed (e.g., <b>Difference</b> to show the absolute difference, <b>Over</b> to overlay differences).<br><br><b><b>-verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs detailed information about the comparison, including the computed metric, to standard error.<br><br><b><b>-file</b> <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the comparison metric result (e.g., the numerical error value) to the specified file instead of standard error.<br><br><b><b>-dissimilarity-threshold</b> <i>&lt;value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only highlights pixels whose measured difference exceeds this numerical threshold, providing finer control over what constitutes a 'significant' difference.<br><br><b><b>-subimage-search</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables searching for a smaller reference image within a larger target image, reporting its location and similarity.<br><br>


title: DESCRIPTION
content:
The <b>compare.im6</b> command is a utility from the ImageMagick 6 suite, specifically designed to analyze the differences between two image files. It takes a reference image and a target image, then visually highlights any discrepancies between them. The primary output is typically a third image that visually represents these differences, often by coloring or overlaying the pixels that do not match. This tool is invaluable for tasks such as automated regression testing of image processing pipelines, quality assurance, or simply tracking changes in image assets. It provides various options to control the comparison process, including different metrics for measuring dissimilarity and ways to customize the visual output.


title: CAVEATS
content:
The <b>compare.im6</b> command is specifically part of the ImageMagick 6 distribution. Users should be aware that the syntax, available options, and default behaviors might differ significantly from ImageMagick 7 (where the equivalent command is typically just <b>magick compare</b>). Compatibility issues can arise if scripts designed for IM6 are run with IM7, or vice-versa. Performance on very large images can be resource-intensive, requiring substantial memory and CPU.


title: UNDERSTANDING COMPARISON METRICS
content:
<b>compare.im6</b> offers various <b>-metric</b> types to quantify image differences. For instance, <b>AE</b> (Absolute Error) counts the number of differing pixels, while <b>MSE</b> (Mean Squared Error) and <b>RMSE</b> (Root Mean Squared Error) provide statistical measures of the average squared difference between pixel values. <b>PSNR</b> (Peak Signal-to-Noise Ratio) is commonly used to measure image quality in terms of noise. Choosing the appropriate metric depends on the specific analysis objective. These metrics are particularly useful for automated testing, where a numerical value is preferred over visual inspection.


title: HISTORY
content:
ImageMagick, the software suite to which <b>compare.im6</b> belongs, was first released in 1990. Version 6, indicated by the <b>.im6</b> suffix, was a long-standing and widely adopted stable release. The explicit <b>.im6</b> naming convention is often used in environments where both ImageMagick 6 and the newer ImageMagick 7 (released in 2016) might be installed concurrently. This allows system administrators or developers to precisely specify which version's utilities to invoke, ensuring backward compatibility for legacy scripts that rely on IM6's specific behaviors or default settings.


title: PARAMETERS
content:
<b>-a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>alias</b> names.<br><br><b>-b</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>built-in</b> commands.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>command</b> names (includes aliases, functions, built-ins).<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>directory</b> names.<br><br><b>-e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>exported shell variable</b> names.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>file</b> names.<br><br><b>-g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>command group</b> names.<br><br><b>-j</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>job</b> names.<br><br><b>-k</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>shell keyword</b> names.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>login</b> names.<br><br><b>-m</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>mount point</b> names.<br><br><b>-o <i>option</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a named completion <i>option</i> (e.g., <i>default</i>, <i>filenames</i>, <i>nospace</i>).<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>command pathnames</b> found in <i>$PATH</i>.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>readonly shell variable</b> names.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>service</b> names (requires <i>/etc/services</i>).<br><br><b>-t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>tags</b> (requires <i>ctags</i> support).<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for <b>user</b> names.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion for all <b>shell variable</b> names (includes exported and readonly).<br><br><b>-A <i>action</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a completion <i>action</i> (e.g., <i>command</i>, <i>file</i>, <i>variable</i>, <i>user</i>) to the generated list.<br><br><b>-G <i>globpat</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter the generated list using a <b>glob pattern</b>.<br><br><b>-P <i>prefix</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a <i>prefix</i> to each generated completion word.<br><br><b>-S <i>suffix</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a <i>suffix</i> to each generated completion word.<br><br><b>-W <i>wordlist</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion from a space-separated <i>wordlist</i>.<br><br><b>-F <i>function</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute <i>function</i> to generate completions, typically for complex logic.<br><br><b>-C <i>command</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Execute <i>command</i> to generate completions, similar to <i>-F</i> but uses an external command.<br><br><b>-X <i>filterpat</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter the generated list using an <b>extended pattern</b> (shell pattern matching).<br><br><b>-V <i>varname</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate completion using the contents of shell variable <i>varname</i> as a wordlist.<br><br><b><i>word</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The optional <i>word</i> to complete; <i>compgen</i> only outputs matches beginning with this <i>word</i>. If omitted, all possible completions are generated.<br><br>


title: DESCRIPTION
content:
<i><code>compgen</code></i> is a <b>Bash built-in command</b> designed to generate possible completion words based on specified criteria. It serves as the core engine for <b>programmable completion</b>, primarily utilized by the <i><code>complete</code></i> built-in. Unlike actual completion, <i><code>compgen</code></i> outputs a list of matching words to <i>standard output</i>, which can then be processed or filtered before being presented to the user by Bash's completion system. This allows for highly customized and intelligent tab-completion behaviors. It supports a wide array of options to define the type of completions, such as commands, keywords, aliases, built-ins, functions, variables, files, and directories. Furthermore, it can apply patterns for matching, specify word lists, and handle prefixes. This flexibility makes <i><code>compgen</code></i> an indispensable tool for scripting sophisticated completion rules, enhancing user productivity by streamlining command-line interactions. It effectively transforms complex completion logic into a manageable and extensible system within the shell environment.


title: CAVEATS
content:
<i><code>compgen</code></i> is a <b>Bash built-in command</b>, meaning it is not a standalone executable. Its primary purpose is to generate raw completion lists for the <i><code>complete</code></i> built-in, and its output is typically not formatted for direct user consumption. The effectiveness of certain options (e.g., <i>-s</i> for services, <i>-t</i> for tags) depends on the underlying system configuration and presence of specific files or tools (like <i>/etc/services</i> or <i>ctags</i>).


title: TYPICAL USAGE WITH <I><CODE>COMPLETE</CODE></I>
content:
<i><code>compgen</code></i> is most frequently used within a <b>completion function</b> that is registered with the <i><code>complete</code></i> built-in, to populate the <i><code>COMPREPLY</code></i> array.<br><br>For example, to provide specific words for a command '<i>mycommand</i>':<br><pre><code>_my_command_completion() {<br>&nbsp;&nbsp;COMPREPLY=( $(compgen -W "alpha beta gamma" -- "$1") )<br>}<br>complete -F _my_command_completion mycommand</code></pre><br>This setup makes 'alpha', 'beta', and 'gamma' available for tab completion after typing '<i>mycommand</i> '.


title: HISTORY
content:
Programmable completion capabilities, including the <i><code>compgen</code></i> built-in, were introduced in <b>Bash 2.0</b>, released in 1996. This marked a significant enhancement, allowing users to define highly customized tab-completion rules beyond simple filename expansion. <i><code>compgen</code></i> provided the core logic for generating completion candidates, separating this functionality from the rule definition handled by <i><code>complete</code></i>. It has since remained a fundamental and stable component of Bash's advanced completion system, evolving alongside the shell to support new features and completion types.


title: SYNOPSIS
content:
<B>complete</B> [-abcdefgjksuv] [-pr] [-DE] [-o <I>comp-option</I>] [-A <I>action</I>] [-G <I>globpat</I>] [-P <I>prefix</I>] [-S <I>suffix</I>] [-W <I>wordlist</I>] [-F <I>function</I>] [-C <I>command</I>] [-X <I>filterpat</I>] [-V <I>varname</I>] [<I>name</I> ...]


title: PARAMETERS
content:
<b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display completion specifications for the specified <I>name</I>(s) or all if no <I>name</I> is given.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove completion specifications for the specified <I>name</I>(s) or all if no <I>name</I> is given.<br><br><b>-o <I>comp-option</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a completion option. Common options include <I>default</I> (use default Bash completion), <I>dirnames</I> (complete directory names), <I>filenames</I> (complete filenames), <I>nospace</I> (do not append a space after completion).<br><br><b>-A <I>action</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an action to generate completions. For example, <I>command</I> (command names), <I>file</I> (filenames), <I>variable</I> (variable names).<br><br><b>-G <I>globpat</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply <I>globpat</I> (a glob pattern) to the list of possible completions generated by other options.<br><br><b>-P <I>prefix</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <I>prefix</I> to each completion generated.<br><br><b>-S <I>suffix</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add <I>suffix</I> to each completion generated.<br><br><b>-W <I>wordlist</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a static, space-separated list of words from which to complete.<br><br><b>-F <I>function</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a shell <I>function</I> to be executed to generate completions dynamically. This is the most powerful method.<br><br><b>-C <I>command</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an external <I>command</I> to be executed to generate completions. The output of the command is used as the completion list.<br><br><b>-X <I>filterpat</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply <I>filterpat</I> to the list of possible completions. Any completion matching the pattern will be removed.<br><br><b>[<I>name</I> ...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name(s) of the command(s) for which completion is being defined, modified, or removed.<br><br>


title: DESCRIPTION
content:
The <I>complete</I> builtin command in <B>Bash</B> is used to specify how arguments to a particular command should be completed when the Tab key is pressed. It allows users and shell scripts to define custom <B>programmable completion rules</B>, greatly enhancing productivity by reducing typing and errors. These rules can range from simple word lists to complex functions that dynamically generate possible completions based on context. This mechanism is fundamental to the user-friendly experience of modern command-line interfaces.


title: CAVEATS
content:
This is a <I>shell builtin</I> command, specifically for <B>GNU Bash</B>. It is not an external executable program found in standard system paths like <I>/usr/bin</I>. Its syntax and behavior may differ significantly in other shells like <B>Zsh</B> (which uses <I>compdef</I>) or <B>Fish</B>. Defining complex completion rules, especially using <I>-F</I> (function) or <I>-C</I> (command), requires good knowledge of shell scripting and the <I>compgen</I> command.


title: HOW COMPLETION WORKS
content:
When a user types a command and presses the <B>Tab</B> key, <B>Bash</B> looks up if a completion rule has been defined for that command using <I>complete</I>. If a rule exists, Bash executes the specified action (e.g., calls a function, runs an external command, or uses a static wordlist) to generate a list of possible completions. These are then filtered and presented to the user, either directly or after pressing <B>Tab</B> again to cycle through options.


title: EXAMPLE USAGE
content:
<B>1. Simple word list completion:</B><br><I>To complete arguments for 'mycommand' from a static list:</I><br><B>complete</B> <B>-W</B> <I>"start stop restart status"</I> <I>mycommand</I><br><br><B>2. Filename completion:</B><br><I>To complete filenames for 'editfile' (default for many commands, but explicit):</I><br><B>complete</B> <B>-f</B> <I>editfile</I><br><br><B>3. Displaying existing rules:</B><br><I>To display all currently defined completion rules:</I><br><B>complete</B> <B>-p</B>


title: HISTORY
content:
The concept of programmable command-line completion evolved to greatly enhance the usability of Unix-like shells. Early shells offered basic filename completion. As shell functionality grew, the need for context-aware completion for command arguments became apparent. Bash's <I>complete</I> builtin, introduced in later versions of Bash, provided a powerful and flexible mechanism for users and developers to define highly customized completion behaviors. This marked a significant productivity improvement for shell users, moving beyond simple filename completion to sophisticated argument completion for complex commands and their options.


title: PARAMETERS
content:
<b>-o <I>option</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds the specified completion <I>option</I> for the given command(s). Common options include 'nospace', 'nosort', 'plusdirs', 'filenames', 'dirnames', 'default', 'bashdefault', 'noquote', 'unfiltered', and 'extdebug'.<br><br><b>+o <I>option</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the specified completion <I>option</I> for the given command(s).<br><br><b>-D</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clears all previously set completion options for the specified command(s).<br><br><b><I>name</I> ...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more command names for which completion options are to be modified. If no <I>name</I> is provided, options for the command currently being completed are modified.<br><br>


title: DESCRIPTION
content:
compopt is a <B>bash built-in command</B> used to fine-tune the behavior of <I>programmable completion</I> for specific commands. It allows you to add, remove, or clear completion options previously set using the `complete` command, or to modify options for the command currently being completed. This command is crucial for advanced customization of shell completion, enabling precise control over how Bash suggests completions for command arguments, options, and filenames.<br><br>For instance, one can specify that a command's arguments should not have a trailing space added after completion (`nospace`), or that directory names should always be included in the suggestions (`plusdirs`). Unlike `complete -o`, which sets options for an entire completion specification, `compopt` provides the flexibility to adjust these options dynamically, often within a completion function itself, based on the context of the completion. This makes `compopt` an invaluable tool for developers writing sophisticated completion scripts, ensuring a smoother and more intuitive command-line experience for users. It is an integral part of Bash's powerful completion system.


title: CAVEATS
content:
compopt is a <B>bash built-in</B> command; it is not a standalone executable found in `$PATH`. This means its availability and behavior are tied directly to the Bash shell. It is primarily used within <I>programmable completion functions</I> to dynamically adjust completion behavior based on the current context. Its effects are local to the current shell session unless the completion settings are loaded from a shell startup file (e.g., `.bashrc`, `.bash_completion`).<br><br>Using `compopt` outside of a completion function or without an active completion attempt may not yield the expected results, as it often operates on the state of the current completion word.


title: INTERACTION WITH 'COMPLETE -O'
content:
While `complete -o <I>option</I>` sets global options for a completion specification, `compopt -o <I>option</I>` can be used <B>within a completion function</B> to override or modify these options dynamically for the current completion attempt. For example, a completion function might initially suggest filenames but then use `compopt -o nospace` if a particular argument is recognized as the last argument in a command. This dynamic control is a key strength of `compopt`.


title: DEFAULT BEHAVIOR
content:
When no <I>name</I> is provided to `compopt`, it modifies the options for the <B>current command being completed</B>. This is its most common usage within completion functions, allowing the function to influence the completion behavior specific to the exact context of the completion call.


title: HISTORY
content:
The `compopt` command was introduced as part of the <B>Bash Programmable Completion</B> system. This system significantly enhanced Bash's ability to provide sophisticated command-line completion beyond simple filename or command name expansion. Programmable completion, including commands like `complete`, `compgen`, and `compopt`, was a major feature addition that aimed to provide powerful, customizable completion capabilities, similar to those found in other shells like `zsh`. Its development was driven by the need for more intelligent and context-aware completion scripts, allowing users to complete not just commands and files, but also arguments, options, and even values specific to certain commands. It has been a standard part of Bash for many years, evolving with the shell itself.


title: SYNOPSIS
content:
<b>docker compose</b> [<i>OPTIONS</i>] [<i>COMMAND</i>] [<i>ARGS...</i>]<br><br><i>Common Commands:</i><br><b>docker compose up</b> <i>[OPTIONS]</i>: Creates and starts containers, networks, and volumes.<br><b>docker compose down</b> <i>[OPTIONS]</i>: Stops and removes containers, networks, and volumes.<br><b>docker compose ps</b>: Lists containers and their status.<br><b>docker compose build</b>: Builds or rebuilds service images.<br><b>docker compose logs</b> <i>[OPTIONS]</i>: Displays log output from services.<br><b>docker compose exec</b> <i>[OPTIONS] SERVICE COMMAND [ARGS...]</i>: Executes a command in a running container.


title: PARAMETERS
content:
<b><b>--file &lt;file&gt;</b>, <b>-f &lt;file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternate compose file (default: <i>docker-compose.yml</i>).<br><br><b><b>--project-name &lt;name&gt;</b>, <b>-p &lt;name&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternate project name (default: directory name).<br><br><b><b>--env-file &lt;file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternate environment file to load.<br><br><b><b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show more output, including debugging information.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the Compose version number and exit.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a help message and exit.<br><br>


title: DESCRIPTION
content:
<i>compose</i> (more commonly known as <i>docker compose</i>) is a powerful tool for defining and running multi-container Docker applications. It allows you to configure your application's services using a YAML file, typically named <i>docker-compose.yml</i>. With a single command, you can then spin up, scale, or tear down all the services defined in your configuration.<br><br>It simplifies the orchestration of complex applications by abstracting away the underlying Docker commands for each service. This makes development, testing, and staging environments much easier to manage, ensuring that your application's dependencies (databases, web servers, queues, etc.) are consistently configured and interconnected.<br><br>Originally a separate Python-based utility (<i>docker-compose</i>), its functionality has been integrated directly into the Docker CLI as of Docker Engine v1.13 and later, accessible via <i>docker compose</i>. This integration streamlines the workflow and leverages the native Go implementation of Docker, offering improved performance and maintainability.


title: CAVEATS
content:
Requires a working Docker Engine installation. <br>Configuration is done via YAML files, which are highly sensitive to indentation and syntax. <br>Networking between services is handled automatically by Compose, but understanding Docker networking can be beneficial for advanced configurations. <br>While <i>docker compose</i> is the modern integrated version, older systems might still use the standalone <i>docker-compose</i> binary. Be aware of which version you are using.


title: <B>KEY CONCEPTS: DOCKER-COMPOSE.YML</B>
content:
The heart of any Compose application is the <i>docker-compose.yml</i> file. This YAML file declaratively defines your application's services, networks, and volumes. Each service typically corresponds to a container and can specify its Docker image, build context, ports, environment variables, dependencies, and more. This declarative approach ensures consistent environment setup and simplifies application deployment across different machines.


title: HISTORY
content:
The concept of defining multi-container applications originated with Fig, a Python-based tool acquired by Docker. This tool was then rebranded and evolved into <i>docker-compose</i>, initially released as a standalone utility written in Python. It quickly became an essential part of the Docker ecosystem for local development and testing.<br><br>Over time, Docker Inc. decided to integrate core Compose functionality directly into the main Docker CLI. This led to the development of <i>docker compose</i> (note the space, indicating a subcommand of <i>docker</i>), which is a Go-based implementation. This integrated version began appearing in Docker Engine 1.13 and has since become the recommended way to use Compose, offering better performance, stability, and a unified command-line experience with other Docker commands. The standalone <i>docker-compose</i> binary is still available for backward compatibility but is largely considered legacy.


title: SEE ALSO
content:
docker(1): The core Docker CLI command for managing containers, images, volumes, etc., dockerfile(5): Manual page describing the syntax for Dockerfiles, used for building Docker images., docker-compose(1): The manual page for the standalone, legacy docker-compose command.


title: PARAMETERS
content:
<b><b>--help</b> (<I>-h</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help for the given command. When no command is specified, it shows the list of available commands.<br><br><b><b>--version</b> (<I>-V</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays this application version.<br><br><b><b>--quiet</b> (<I>-q</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not output any message.<br><br><b><b>--verbose</b> (<I>-v</I>, <I>-vv</I>, <I>-vvv</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of messages: 1 for normal output, 2 for more verbose output and 3 for debug.<br><br><b><b>--no-interaction</b> (<I>-n</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ask any interactive question.<br><br><b><b>--profile</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display timing and memory usage information.<br><br><b><b>--working-dir</b> (<I>-d</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If specified, use the given directory as working directory.<br><br><b><b>--no-dev</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables installation of require-dev packages. Commonly used with <b>install</b> or <b>update</b>.<br><br><b><b>--optimize-autoloader</b> (<I>-o</I>)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Convert PSR-0/4 autoloading to classmap to get a faster autoloader. Commonly used with <b>install</b> or <b>update</b>.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulates a command without actually performing any changes. Used to see what would happen.<br><br>


title: DESCRIPTION
content:
<i>Composer</i> is an application-level package manager for the <i>PHP</i> programming language. It provides a standard format for managing dependencies of <i>PHP</i> software and required libraries. Unlike system package managers (like <i>apt</i> or <i>yum</i>), <i>Composer</i> focuses on a project's dependencies and installs them locally within the project directory (typically <b>vendor/</b>).<br><br>It works by reading a <b>composer.json</b> file, which declares the libraries your project depends on. <i>Composer</i> then finds the correct versions of these libraries, downloads them, and installs them into your project. It also generates an autoloader script, making it easy to use the installed libraries without manual `require` statements. <i>Composer</i> is widely adopted in the <i>PHP</i> ecosystem, facilitating collaborative development, maintaining consistent environments, and streamlining the inclusion of third-party packages from its primary repository, <i>Packagist</i>.


title: CAVEATS
content:
<i>Composer</i> requires <i>PHP</i> to be installed on your system. It relies heavily on network connectivity to download packages from <i>Packagist</i> or other repositories. For large projects with many dependencies, operations like `composer install` or `composer update` can consume significant time and memory. It's crucial to be mindful of the source of your packages to avoid security vulnerabilities, as malicious packages could compromise your system.


title: <B>COMPOSER.JSON</B>
content:
The primary configuration file for <i>Composer</i>. It's a <i>JSON</i> object that defines project metadata, required packages, autoloading rules, scripts, and other configurations. It's typically located in the root of your project directory.


title: <B>COMPOSER.LOCK</B>
content:
This file is automatically generated after a successful `composer install` or `composer update`. It records the exact versions of all installed packages, including their transitive dependencies. This ensures that everyone working on the project, and production environments, uses the identical set of dependencies, promoting consistency and reproducibility.


title: <B>PACKAGIST</B>
content:
The main package repository for <i>Composer</i>. It's where <i>Composer</i> looks for packages by default. Developers publish their <i>PHP</i> libraries to <i>Packagist</i>, making them discoverable and installable via <i>Composer</i>.


title: <B>VENDOR/</B> DIRECTORY
content:
By default, <i>Composer</i> installs all project dependencies into this directory. It's recommended to add this directory to your version control's ignore list (e.g., <b>.gitignore</b>) and regenerate it using `composer install` when cloning a project.


title: AUTOLOADING
content:
<i>Composer</i> generates a <b>vendor/autoload.php</b> file. Including this single file in your project automatically makes all classes from your installed dependencies, as well as your own project's classes (if configured in <b>composer.json</b>), available without requiring manual `require` or `include` statements for each file.


title: HISTORY
content:
<i>Composer</i> was created by Nils Adermann and Jordi Boggiano and first released in March 2012. Its development was largely inspired by similar tools in other language ecosystems, notably Node.js's <i>npm</i> and Ruby's <i>Bundler</i>. Before <i>Composer</i>, <i>PHP</i> lacked a widely accepted standard for dependency management, leading to fragmented approaches and challenges in integrating third-party libraries. <i>Composer</i> quickly filled this void, becoming the de-facto standard for managing <i>PHP</i> project dependencies and revolutionizing how modern <i>PHP</i> applications are built and maintained.


title: SYNOPSIS
content:
<b>composer-require-checker</b> <i>check</i> [<i>options</i>] [<i>&lt;path&gt;</i>]<br><b>composer-require-checker</b> <i>&lt;command&gt;</i> [<i>options</i>]


title: PARAMETERS
content:
<b>check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs the dependency analysis. This is the default subcommand if no command is specified.<br><br><b>&lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the project directory to analyze. Defaults to the current working directory.<br><br><b>--strict</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fails if any package is declared but not used, <b>or</b> if any package is used but not declared. This enforces stricter dependency hygiene.<br><br><b>--dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs the check but always exits with status code 0, regardless of whether issues are found. Useful for CI logs without failing builds.<br><br><b>--ignore-dev</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not check <b>require-dev</b> dependencies for usage in the production code. This prevents reporting unused dev dependencies as issues.<br><br><b>--ignore-linter</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude specific paths that might be generated by linters or code formatters (e.g., <b>.php-cs-fixer/.php-cs-fixer.cache</b>).<br><br><b>--ignore-php</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not report issues related to the 'php' platform requirement in <b>composer.json</b>.<br><br><b>--path-to-composer-json &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the exact path to the <b>composer.json</b> file to be analyzed.<br><br><b>--composer-vendor-dir &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the path to the Composer vendor directory, if it's not the default <b>./vendor</b>.<br><br><b>--exclude &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude specific files or directories from analysis. This option can be used multiple times to exclude several paths.<br><br><b>--config &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a custom configuration file (e.g., <b>composer-require-checker.json</b>) for advanced settings.<br><br><b>--dump-configuration</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the default configuration to standard output. Useful for creating a custom config file.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increase the verbosity of messages. Can be used multiple times for more detailed output (e.g., -vv, -vvv).<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the application version information.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help for the command or a specific subcommand.<br><br>


title: DESCRIPTION
content:
<i>composer-require-checker</i> is a command-line tool designed for PHP projects managed with Composer. Its primary function is to analyze your project's source code and compare the packages it actually uses against the <b>require</b> section of your <b>composer.json</b> file. It identifies two main issues: packages declared in <b>composer.json</b> but never used in the code, and packages used in the code but not declared in <b>composer.json</b>. This helps maintain a clean <b>composer.json</b>, reduce project size by removing unnecessary dependencies, and prevent runtime errors due to missing packages. By enforcing dependency hygiene, it contributes to better project maintainability and performance.


title: CAVEATS
content:
<ul><li>Relies primarily on static analysis of PHP code; dynamic usage (e.g., via <b>eval()</b>, variable functions, or complex class loading mechanisms) might not be fully detected, potentially leading to false negatives (packages used but not reported as such).</li><li>It checks direct usages. If a package is pulled in as a transitive dependency and then used without being explicitly in your <b>composer.json</b>'s <b>require</b> section, it might be reported as "used but not declared".</li><li>For optimal results and to manage exceptions, it is highly recommended to use a dedicated configuration file (e.g., <b>composer-require-checker.json</b>) in complex projects.</li></ul>


title: INSTALLATION
content:
<b>composer-require-checker</b> is typically installed via Composer. <br>To install it globally and make it available system-wide: <br><i>composer global require maglnet/composer-require-checker</i><br>Alternatively, to install it as a development dependency for a specific project: <br><i>composer require --dev maglnet/composer-require-checker</i><br>When installed as a project dependency, the executable is found within your project's <b>vendor/bin/</b> directory (e.g., <i>./vendor/bin/composer-require-checker</i>).


title: CONFIGURATION FILE
content:
For advanced usage and to customize its behavior, <b>composer-require-checker</b> supports a configuration file, typically named <b>composer-require-checker.json</b>, placed in the project root. This JSON file allows you to specify:<ul><li>Paths to exclude from analysis (e.g., test files, generated code).</li><li>Packages to explicitly ignore (e.g., specific polyfills).</li><li>Custom 'symbol providers' for very specific use cases.</li></ul>Using a configuration file is crucial for complex projects to avoid false positives and tailor the checks to your project's unique structure.


title: HISTORY
content:
<b>composer-require-checker</b> was developed to address the common problem of "dependency creep" in PHP projects. As projects evolve, features are added and removed, often leaving behind unused packages in <b>composer.json</b>, which leads to larger project sizes, slower Composer operations, and potential security vulnerabilities from outdated dependencies. The tool provides an automated, static analysis-based approach to identify these discrepancies. Its development has focused on robust analysis capabilities and flexible configuration options to integrate seamlessly into various project structures and CI/CD pipelines, promoting better dependency hygiene in PHP development.


title: SYNOPSIS
content:
<b>composite.im6</b> [<i>options</i>] <I>overlay_image</I> <I>background_image</I> <I>output_image</I>


title: PARAMETERS
content:
<b>-compose <i>operator</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the composition algorithm to use. This is the most crucial option, determining how pixels from the overlay image are blended with those of the background image. Examples include <i>Over</i> (default), <i>Src</i>, <i>Dst</i>, <i>Plus</i>, <i>Minus</i>, <i>Multiply</i>, <i>Screen</i>, <i>Overlay</i>, <i>Hardlight</i>, <i>Softlight</i>, <i>Difference</i>, and many more for various blending effects.<br><br><b>-geometry <i>WxH+X+Y</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the size and position of the overlay image relative to the background image. <i>W</i> and <i>H</i> are width and height, and <i>X</i> and <i>Y</i> are horizontal and vertical offsets (positive or negative) from the origin defined by <i>-gravity</i> or the default top-left.<br><br><b>-gravity <i>direction</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the initial placement of the overlay image within the background image before any <i>-geometry</i> offsets are applied. Common values include <i>NorthWest</i>, <i>North</i>, <i>NorthEast</i>, <i>West</i>, <i>Center</i>, <i>East</i>, <i>SouthWest</i>, <i>South</i>, <i>SouthEast</i>.<br><br><b>-blend <i>value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Blends the overlay image with the background image by a specified percentage. A value of 100 uses only the overlay image, 0 uses only the background, and 50 is an even blend.<br><br><b>-dissolve <i>value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dissolves the overlay image into the background image by a specified percentage based on its opacity channel.<br><br><b>-tile</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Tiles the overlay image across the background image, useful for creating patterned backgrounds or textures.<br><br><b>-alpha <i>channel</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls how the alpha channel is handled during composition. Common values include <i>On</i>, <i>Off</i>, <i>Set</i>, <i>Remove</i>, <i>Extract</i>, <i>Copy</i>, <i>Opaque</i>, <i>Transparent</i>, <i>Activate</i>, <i>Deactivate</i>.<br><br><b>-channel <i>type</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies the operation only to specific color channels (e.g., <i>Red</i>, <i>Green</i>, <i>Blue</i>, <i>Alpha</i>, <i>RGB</i>, <i>All</i>).<br><br><b>-quality <i>value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the JPEG/MIFF/PNG compression level for the output image (0-100).<br><br><b>-verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, displaying detailed information about the image processing progress and file attributes.<br><br>


title: DESCRIPTION
content:
The <b>composite.im6</b> command is a specialized utility from the ImageMagick 6 suite, designed for combining multiple images into a single output image. It primarily performs pixel-level image blending, allowing one image (the 'overlay' or 'source') to be placed onto another (the 'background' or 'destination') using a variety of composition operators. These operators define how the pixel values of the source and destination images are combined, enabling effects like blending, superimposing, transparency, and advanced mathematical operations on pixel data. <br><br>While `composite` (without the `.im6` suffix) is a general ImageMagick command, the `.im6` explicitly signifies its origin from the ImageMagick 6 series. It's particularly useful for tasks such as watermarking, creating image collages, layering graphics, or applying texture maps, offering fine-grained control over the composition process through options like geometry, gravity, and, most importantly, the composition operator.


title: CAVEATS
content:
The <b>composite.im6</b> command is specifically from the ImageMagick 6 suite. While still functional, ImageMagick 7 (IM7) introduced a unified command-line tool, <b>magick</b>, which consolidates the functionality of many individual commands like `composite`. <br><br>In IM7, the equivalent operation is typically performed using <b>magick composite</b> or by incorporating the <b>-composite</b> operator within the <b>magick convert</b> command. Users should be aware that the exact behavior or available options might slightly differ between IM6 and IM7. For new projects, it's generally recommended to use IM7's `magick` command for better compatibility, performance, and access to the latest features.


title: HISTORY
content:
ImageMagick, a free and open-source software suite for displaying, converting, and editing raster images, has a long history dating back to 1987. The <b>composite</b> command was a core utility within this suite, designed from early versions to specifically handle the task of overlaying images. <br><br>The suffix `.im6` signifies a particular build or installation of ImageMagick that belongs to the version 6 series. For many years, ImageMagick provided separate executables for each major function (e.g., `convert` for format conversion, `mogrify` for in-place modifications, `composite` for layering). <br><br>With the release of ImageMagick 7, a significant architectural change occurred: most of these individual commands were unified under a single `magick` executable, accessible via subcommands (e.g., `magick composite`). While `composite.im6` directly invokes the IM6 version, modern systems usually have symbolic links or alias the simpler `composite` command to the appropriate version, or encourage direct use of `magick`.


title: PARAMETERS
content:
<b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Force</b></i> compression. Overwrite existing `.Z` files without prompting. Also forces compression of symbolic links and allows compressing files that don't actually shrink.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Verbose</b></i> mode. Displays the percentage of reduction for each file compressed.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Compress to standard output</b></i>. The original file is not changed. Useful for piping.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Decompress</b></i>. This is equivalent to calling `uncompress`.<br><br><b>-r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Recursive</b></i>. If any of the file names are directories, <b><i>compress</i></b> attempts to compress all files inside them (and their subdirectories).<br><br><b>-b bits</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Maximum bits</b></i>. Specifies the maximum number of bits (from 9 to 16) to use for LZW codes. The default is 16.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>Quiet</b></i> mode. Suppress all diagnostic messages, warnings, and prompts.<br><br>


title: DESCRIPTION
content:
The <b><i>compress</i></b> command reduces the size of named files using adaptive Lempel-Ziv coding (LZW). When `compress` is successful, the original file is replaced by a compressed version with a `.Z` extension. For example, `file.txt` would become `file.txt.Z`. If no files are specified, <b><i>compress</i></b> reads from standard input and writes to standard output.<br><br>By default, <b><i>compress</i></b> removes the original file after successful compression, but this behavior can be altered using options like `-c` to write to standard output without deleting the original. The companion command `uncompress` (often a hard link to `compress -d`) restores files to their original state. Similarly, `zcat` (another hard link) displays the uncompressed content of a `.Z` file to standard output without decompressing it on disk. While historically important, <b><i>compress</i></b> has largely been superseded by more efficient compression tools like `gzip`, `bzip2`, and `xz` which offer better compression ratios.


title: CAVEATS
content:
<b><i>compress</i></b> uses the LZW algorithm, which, while historically significant, generally achieves lower compression ratios compared to modern alternatives like `gzip`, `bzip2`, or `xz`. Its primary use today is often for compatibility with older systems or archives. The LZW algorithm was subject to patent issues (Unisys patent) which contributed to its decline in popularity, although these patents have since expired.


title: EXIT STATUS
content:
<b><i>compress</i></b> exits with status 0 if all operations completed successfully, 1 if an error occurred, and 2 if a warning was issued but the operation completed.


title: <B><I>HARD LINKS</I></B>
content:
The `uncompress` and `zcat` commands are typically hard links to the <b><i>compress</i></b> executable, providing convenient shortcuts for decompression and viewing compressed file contents, respectively.


title: HISTORY
content:
The <b><i>compress</i></b> utility emerged in the early days of Unix, becoming a standard tool for file compression. Its core mechanism is the Lempel-Ziv-Welch (LZW) algorithm, developed in 1984. This algorithm was notable for its efficiency at the time, making <b><i>compress</i></b> widely adopted across various Unix-like operating systems. However, the commercial licensing of the LZW patent by Unisys in the 1990s led to widespread concerns and the development of royalty-free alternatives, most notably `gzip` (which uses the deflate algorithm). Despite the patent expiration, `gzip` and later `bzip2` and `xz` offered superior compression, leading to <b><i>compress</i></b>'s diminished usage in new projects, though it remains important for interacting with legacy data.


title: SYNOPSIS
content:
<b>compseq</b> <b>-sequence</b> <i>&lt;input_file&gt;</i> [<b>-samelength</b> <i>&lt;N&gt;</i>] [<b>-lessthan</b> <i>&lt;N&gt;</i>] [<b>-greaterthan</b> <i>&lt;N&gt;</i>] [<b>-output</b> <i>&lt;output_file&gt;</i>] [<b>-summary</b>] [<b>-auto</b>] [<b>-stdout</b>]


title: PARAMETERS
content:
<b><b>-sequence</b> <i>&lt;input_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Required.</i> Specifies the input sequence file (e.g., FASTA, GenBank) to be analyzed.<br><br><b><b>-samelength</b> <i>&lt;N&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs sequences whose length is <b>exactly</b> <i>&lt;N&gt;</i> bases/amino acids.<br><br><b><b>-lessthan</b> <i>&lt;N&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs sequences whose length is <b>less than</b> <i>&lt;N&gt;</i> bases/amino acids.<br><br><b><b>-greaterthan</b> <i>&lt;N&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs sequences whose length is <b>greater than</b> <i>&lt;N&gt;</i> bases/amino acids.<br><br><b><b>-output</b> <i>&lt;output_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output file for filtered sequences or the summary report. If not specified, output typically goes to stdout unless <i>-auto</i> is used.<br><br><b><b>-summary</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs a summary report instead of the actual sequences. The report includes counts for sequences matching each length criterion.<br><br><b><b>-auto</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the program automatically without interactive prompts, often used in scripts. Directs output to a generated file name based on input unless <i>-output</i> or <i>-stdout</i> is used.<br><br><b><b>-stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directs all output to the standard output, overriding the default output file behavior for <i>-auto</i> or <i>-output</i>.<br><br>


title: DESCRIPTION
content:
<i>compseq</i> is a command-line utility from the EMBOSS (European Molecular Biology Open Software Suite) package, widely used in bioinformatics. Its primary function is to analyze biological sequence files (e.g., DNA, RNA, protein) and filter sequences based on their lengths. Users can specify criteria to output sequences that are either exactly equal to, shorter than, or longer than a given numeric length. <br><br>This tool is invaluable for quality control in genomics and proteomics workflows, enabling researchers to quickly identify and extract sequences of a specific size range, or to discard sequences that do not meet length requirements for downstream analysis. Beyond filtering sequences, <i>compseq</i> can also generate a concise summary report detailing the counts of sequences that satisfy each specified length criterion, providing a quick statistical overview of the dataset without writing out the actual sequences.


title: CAVEATS
content:
<i>compseq</i> is part of the EMBOSS suite, which may not be pre-installed on all Linux distributions; it typically needs to be installed separately via a package manager. <br><br>The command is primarily designed for biological sequences (DNA, RNA, protein); its utility outside this domain for general text file length comparisons is limited compared to general-purpose text processing tools like <i>awk</i> or <i>grep</i>. <br><br>When multiple length criteria flags (e.g., <i>-lessthan</i> and <i>-greaterthan</i>) are used, the program will output sequences that satisfy <b>any</b> of the specified criteria, effectively performing a logical OR operation.


title: COMBINING LENGTH CRITERIA
content:
When using multiple length specification flags (e.g., <i>-lessthan</i>, <i>-greaterthan</i>, and <i>-samelength</i>) in a single command, <i>compseq</i> will output sequences that meet <b>any</b> of the specified conditions. It performs a logical OR operation between the criteria, rather than an AND. For example, <code>compseq -sequence file.fasta -lessthan 100 -greaterthan 500</code> would output sequences shorter than 100 <b>OR</b> longer than 500.


title: OUTPUT FILE NAMING WITH -AUTO
content:
When the <i>-auto</i> option is used without explicitly specifying an output file via <i>-output</i> or directing to standard output with <i>-stdout</i>, <i>compseq</i> will automatically generate an output filename. This name typically combines the input filename with a program-specific suffix, such as <i>&lt;input_name&gt;.compseq</i> for sequence output or <i>&lt;input_name&gt;.compseq_summary</i> for summary reports.


title: HISTORY
content:
<i>compseq</i> is a key component of the EMBOSS (European Molecular Biology Open Software Suite), a comprehensive collection of bioinformatics applications first released in 2000. Developed by the EMBOSS project, the suite provides a robust and freely available set of tools for molecular biology research. <i>compseq</i> has been a consistent utility within this framework, evolving alongside the broader EMBOSS project to support diverse sequence formats and analytical demands in genomics, proteomics, and general molecular biology.


title: PARAMETERS
content:
<b><i>-b</i>, <i>--bytes</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show sizes in bytes rather than human-readable format (e.g., KB, MB, GB).<br><br><br><b><i>-x</i>, <i>--exclude <pattern></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude files matching the specified glob <i><pattern></i>.<br><br><br><b><i>-v</i>, <i>--verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print more detailed information during processing, often showing each file being processed.<br><br><br><b><i>-h</i>, <i>--help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><br><b><i>-V</i>, <i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><br><b><i>-r</i>, <i>--recursive</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process directories recursively, descending into subdirectories.<br><br><br><b><i>-L</i>, <i>--dereference</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dereference symbolic links. If a symbolic link points to a file or directory, the target of the link is processed instead of the link itself.<br><br><br><b><i>-p</i>, <i>--progress</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a progress bar during processing, useful for large operations.<br><br><br><b><i>-s</i>, <i>--summarize</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For directories, only show the total summary for logical, compressed sizes, and ratio, without listing individual files within.<br><br><br><b><i>-o</i>, <i>--output <file></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to the specified <i><file></i> instead of standard output.<br><br><br><b><i>-i</i>, <i>--include <pattern></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include files matching the specified glob <i><pattern></i>. This option can be used multiple times.<br><br><br><b><i>-n</i>, <i>--nthreads <num></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the number of parallel threads to use for scanning.<br><br><br><b><i>-M</i>, <i>--min-size <size></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only process files larger than the specified <i><size></i>. Size can be suffixed with K, M, G, T, P, E.<br><br><br><b><i>-X</i>, <i>--max-size <size></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only process files smaller than the specified <i><size></i>. Size can be suffixed with K, M, G, T, P, E.<br><br><br>


title: DESCRIPTION
content:
<i><b>compsize</b></i> is a specialized utility for the Btrfs filesystem, designed to analyze and report on the compression effectiveness of files and directories. It provides insights into the 'logical' size (the uncompressed data size) versus the 'compressed' size (the actual disk space consumed after Btrfs compression). By comparing these two values, <i><b>compsize</b></i> calculates and displays the compression ratio, which is crucial for understanding how much storage space is being saved by Btrfs's transparent compression features. This tool is invaluable for administrators and users who want to optimize storage usage, identify files that compress well or poorly, and fine-tune their Btrfs compression policies.<br><br>It can operate on individual files or recursively traverse directories, providing detailed statistics for each item and often a summary for directories. Unlike general-purpose disk usage tools like <i><b>du</b></i>, <i><b>compsize</b></i> specifically understands and reports on Btrfs's compression mechanisms.


title: CAVEATS
content:
<i><b>compsize</b></i> is a Btrfs-specific utility and will only provide meaningful output for files located on a Btrfs filesystem. It requires appropriate permissions to read the files and their metadata, typically needing root privileges or <i>CAP_SYS_ADMIN</i> capabilities if accessing underlying block devices directly, though standard file permissions suffice for mounted filesystems. It does not modify files; it only reports on their compression status.


title: OUTPUT FORMAT
content:
The default output of <i><b>compsize</b></i> typically presents information in columns:<br>1. <i>Logical Size</i>: The uncompressed size of the data.<br>2. <i>Compressed Size</i>: The actual size the data occupies on disk after Btrfs compression.<br>3. <i>Ratio</i>: The compression ratio (Logical Size / Compressed Size). A ratio greater than 1.0 indicates effective compression.<br>4. <i>Path</i>: The full path to the file or directory being analyzed.


title: TYPICAL USAGE
content:
To check compression for a single file: <br><i><b>compsize</b></i> /path/to/your/file.txt<br><br>To recursively check an entire directory and get a summarized total for it: <br><i><b>compsize</b></i> -r -s /path/to/your/directory/<br><br>To see verbose output while processing files in a directory: <br><i><b>compsize</b></i> -rv /path/to/another/directory/


title: HISTORY
content:
<i><b>compsize</b></i> is part of the <i>btrfs-progs</i> package, the official userspace utilities for managing the Btrfs filesystem. It was developed alongside the Btrfs filesystem itself to provide administrators with tools to understand and optimize its unique features, such as transparent compression. Its functionality has evolved to include various filtering and reporting options, reflecting the growing adoption and need for deeper insights into Btrfs's performance and storage characteristics.


title: PARAMETERS
content:
<b><b>-b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Daemonize <i>compton</i>, running it in the background.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable client-side shadows on windows.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable fading effects for windows (e.g., on open/close, focus changes).<br><br><b><b>-D</b> <i>DELAY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the fading steps or duration for fade effects.<br><br><b><b>--config</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternative configuration file to use. Default is often <i>~/.config/compton.conf</i> or <i>~/.config/picom.conf</i>.<br><br><b><b>--backend</b> <i>BACKEND</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Choose the compositing backend: <b>glx</b> (hardware accelerated) or <b>xrender</b> (software rendering).<br><br><b><b>--vsync</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable VSync to prevent screen tearing, with various modes available (e.g., <i>drm</i>, <i>opengl</i>, <i>none</i>).<br><br><b><b>--shadow-exclude</b> '<i>EXPRESSION</i>'</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define rules to exclude specific windows from having shadows based on their properties.<br><br><b><b>--opacity-rule</b> '<i>EXPRESSION</i>'</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply custom opacity rules to windows based on their properties (e.g., make certain windows transparent).<br><br><b><b>--inactive-dim</b> <i>FACTOR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dim inactive windows by a specified factor.<br><br><b><b>--log-level</b> <i>LEVEL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the logging verbosity (e.g., <i>error</i>, <i>warn</i>, <i>info</i>, <i>debug</i>).<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the <i>compton</i> version information.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a summary of command-line options.<br><br>


title: DESCRIPTION
content:
<i>compton</i> is a standalone composite manager for the X Window System, designed to provide various visual effects such as <b>shadows</b>, <b>transparency</b>, <b>fading</b>, and <b>blur</b> for windows and the desktop.<br><br>It is commonly used with lightweight window managers (like Openbox, i3, Awesome) that do not include built-in compositing capabilities, allowing users to achieve a modern and aesthetically pleasing desktop appearance without the overhead of a full desktop environment. While <i>compton</i> itself is relatively lightweight and efficient, it's important to note that its development has largely ceased, with <b>picom</b> being its actively maintained successor. <i>compton</i> aimed to provide smooth animations and visual enhancements, significantly improving the aesthetic appeal and user experience of X-based desktops.


title: CAVEATS
content:
<b>compton</b> is largely considered a <b>deprecated</b> project. Its development has ceased, and it has been effectively succeeded by <b>picom</b>.<br><br>Many Linux distributions now either ship <b>picom</b> under the <i>compton</i> name or have replaced <i>compton</i> with <i>picom</i> entirely in their repositories. Users are strongly encouraged to use <b>picom</b> for better performance, more features, and ongoing maintenance.


title: CONFIGURATION FILES
content:
While <i>compton</i> accepts command-line arguments, its full power and flexibility are unleashed through a configuration file, typically located at <i>~/.config/compton.conf</i> (or <i>~/.config/picom.conf</i> for its successor). These files allow for intricate customization of shadow properties, fading behavior, opacity rules for specific windows, and more. Command-line options can override settings defined in the configuration file.


title: BACKEND SUPPORT
content:
<i>compton</i> supports different compositing backends. The primary ones are <b>xrender</b> (software rendering, widely compatible but can be slower) and <b>glx</b> (hardware-accelerated rendering using OpenGL, generally preferred for smoother performance and lower CPU usage if your graphics driver supports it). Users can choose the backend based on their system's capabilities and performance needs.


title: HISTORY
content:
<b>compton</b> originated as a fork of <i>xcompmgr-dana</i>, which itself was an improved version of the original <i>xcompmgr</i>. It was created to provide more features, better performance, and enhanced stability for X composite management.<br><br>For several years, <i>compton</i> was a popular choice for users of lightweight window managers seeking modern visual effects. However, its development eventually slowed down and stopped. This led to the creation of <b>picom</b>, a direct and actively maintained successor that continues <i>compton</i>'s lineage, incorporating new features, bug fixes, and performance improvements, effectively rendering <i>compton</i> obsolete in terms of active development and community support.


title: PARAMETERS
content:
<b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show program's version number and exit.<br><br><b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show this help message and exit, or show help for a specific subcommand (e.g., <b>conan install --help</b>).<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the command's result in JSON format (where applicable).<br><br><b><i>Subcommand specific options</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Most options are specific to the subcommand being executed (e.g., <b>conan install</b> has options like <b>--build</b>, <b>--require-override</b>; <b>conan create</b> has <b>--test-folder</b>, <b>--build-policy</b>).<br><br>


title: DESCRIPTION
content:
<b>Conan</b> is a decentralized, open-source package manager designed specifically for C/C++ projects. It automates the complex process of managing dependencies across various platforms, compilers, and build systems. Unlike traditional system package managers, Conan focuses on developer-centric workflows, allowing the creation, packaging, and consumption of binaries and source code. <br><br> Its core purpose is to solve the historical challenges of C/C++ dependency management, including binary compatibility issues, cross-platform development, and integration with diverse build environments like CMake, Meson, and Visual Studio. Developers define 'recipes' (Python scripts) to dictate how libraries are built and packaged, promoting reproducibility and facilitating collaboration in large-scale C/C++ software development by providing a consistent way to share and consume components.


title: CAVEATS
content:
Conan, while powerful, has a notable learning curve, especially for complex C/C++ projects with intricate build configurations. Ensuring binary compatibility across different compilers, versions, and settings can be challenging and requires careful recipe management. It is not a build system itself, but rather integrates with existing ones, which means understanding both Conan and your chosen build system is crucial. Proper maintenance of package recipes is essential for long-term project stability.


title: DECENTRALIZED ARCHITECTURE
content:
Conan operates with a decentralized model, leveraging a local cache for downloaded packages. It can connect to various remote repositories (e.g., JFrog Artifactory, Bintray, or custom servers), allowing organizations to host their own packages and distribute them globally without a central point of failure, enabling highly flexible and scalable package management.


title: RECIPES AND PROFILES
content:
Packages in Conan are defined by 'recipes,' which are Python scripts specifying how a library is built, packaged, and integrated. 'Profiles' are another key concept, used to define environment settings like compiler, architecture, build type, and C++ standard, ensuring consistent and reproducible builds across different development environments and facilitating binary compatibility.


title: INTEGRATION WITH BUILD SYSTEMS
content:
Conan integrates seamlessly with popular C/C++ build systems such as CMake, Meson, MSBuild, and Autotools. It achieves this by generating configuration files (e.g., CMake toolchains, Visual Studio property sheets) that guide the build system in finding and linking with declared dependencies, simplifying the build process significantly for complex projects.


title: HISTORY
content:
<b>Conan</b> was initially developed by JFrog and first released around 2016. Its inception aimed to bring modern, developer-friendly package management practices, prevalent in languages like Python (pip) and Node.js (npm), to the historically challenging C/C++ ecosystem. It sought to address issues like binary management, cross-platform compilation, and the complexities of decentralized repositories. Since its initial release, Conan has undergone continuous development, gaining significant adoption within the C/C++ community and evolving to support a wide range of platforms, compilers, and build systems.


title: DESCRIPTION
content:
The command <b>conan-frogarian</b> does not appear to be a standard, recognized, or publicly documented Linux utility. A comprehensive search across common command repositories, man pages, and online documentation databases yields no relevant results for this specific name. It is highly probable that <b>conan-frogarian</b> is either a fictitious command, a typo, or a highly specialized, internal script used within a private or very niche environment that is not publicly documented.<br><br>Without access to its source code or specific usage context, it is impossible to provide a definitive analysis of its functionality, syntax, or purpose. Therefore, the information provided below reflects the *absence* of this command in standard Linux ecosystems rather than a detailed breakdown of its operation.


title: CAVEATS
content:
This analysis is based on the premise that <b>conan-frogarian</b> is not a publicly documented or standard Linux command. Its existence is not verifiable within common Linux environments or documentation.<br>If this command exists in a specific, private, or custom environment, its actual functionality, syntax, and parameters would differ significantly from this analysis.


title: NOTE ON FICTIONAL OR PRIVATE COMMANDS
content:
When encountering command names that do not yield results in standard documentation, it is important to consider that they might be fictional, custom scripts, or internal tools specific to a particular organization or user. Without context or access to such tools, analysis beyond noting their non-existence is speculative.


title: HISTORY
content:
As the command <b>conan-frogarian</b> is not recognized as a standard or documented Linux utility, there is no public record of its development history, origins, or evolution of usage within the Linux ecosystem.


title: SYNOPSIS
content:
<b>conda</b> <I>command</I> [<I>options</I>] [<I>arguments</I>]<br><br>Examples:<br><b>conda</b> <I>install</I> <I>numpy</I><br><b>conda</b> <I>create</I> <I>--name</I> <I>myenv</I> <I>python=3.9</I><br><b>conda</b> <I>activate</I> <I>myenv</I>


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show help message and exit.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the <i>conda</i> version number and exit.<br><br><b><b>-y</b>, <b>--yes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ask for confirmation for actions.<br><br><b><b>--json</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report all output as JSON, useful for scripting.<br><br><b><b>-c</b> <I>channel</I>, <b>--channel</b> <I>channel</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify additional channels to search for packages.<br><br><b><b>-n</b> <I>env</I>, <b>--name</b> <I>env</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the name of the environment to operate on.<br><br><b><b>-p</b> <I>path</I>, <b>--prefix</b> <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the path to the environment prefix.<br><br><b><b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run; only display what would have been done.<br><br>


title: DESCRIPTION
content:
<i>conda</i> is an open-source, cross-platform package, dependency, and environment management system. It's language-agnostic, supporting Python, R, Java, C/C++, and more. Developed by Anaconda, Inc., <i>conda</i> solves the challenge of <I>dependency hell</I> by allowing users to create isolated environments, each with its own set of packages and their specific versions. This prevents conflicts between different projects requiring conflicting package versions.<br><br>Unlike <I>pip</I>, which primarily manages Python packages, <i>conda</i> manages non-Python dependencies as well, making it ideal for scientific computing and data science workflows where many tools are written in various languages. It automatically handles package installation, updates, and removal, ensuring all necessary dependencies are met.<br><br><i>conda</i> facilitates reproducible research and development by enabling users to easily share and recreate specific environments. It's the default package manager for Anaconda and Miniconda distributions, widely adopted for its robust capabilities in managing complex software stacks.


title: CAVEATS
content:
<i>conda</i> environments and caches can consume significant disk space, especially with many environments or large packages. Dependency resolution can sometimes be slow or lead to complex conflicts if channel priorities are not managed carefully or if mixing packages from various sources. While powerful, <i>conda</i> requires users to understand environment activation/deactivation and channel management for optimal use. It is not a system-level package manager like <I>apt</I> or <I>yum</I>.


title: CHANNEL MANAGEMENT
content:
<i>conda</i> uses 'channels' to find packages. By default, it uses the 'defaults' channel. However, many packages are available on 'conda-forge', a community-driven channel. Users can add channels using <b>conda config --add channels <I>channel_name</I></b>. The order of channels in the configuration determines priority for dependency resolution, which is crucial for managing complex environments.


title: HISTORY
content:
<i>conda</i> was first released in 2012 by Continuum Analytics (now Anaconda, Inc.). It was initially developed to manage Python packages and dependencies for scientific computing, particularly to address the challenges of <I>dependency hell</I> and provide isolated, reproducible environments. Over time, its capabilities expanded to include packages from other programming languages (R, C/C++, Java, etc.), making it a versatile cross-platform package manager. It has since become the cornerstone of the Anaconda and Miniconda distributions, widely adopted in data science and machine learning communities.


title: SYNOPSIS
content:
<b>conda create</b> [<i>options</i>] [<i>package_spec</i> ...] <br><b>conda create</b> <b>-n</b> <i>environment_name</i> [<i>package_spec</i> ...] <br><b>conda create</b> <b>--prefix</b> <i>/path/to/env</i> [<i>package_spec</i> ...] <br><b>conda create</b> <b>--file</b> <i>environment.yml</i> <br><b>conda create</b> <b>--clone</b> <i>existing_env</i> <b>-n</b> <i>new_env_name</i>


title: PARAMETERS
content:
<b><b>-n</b>, <b>--name</b> <i>&lt;ENVIRONMENT_NAME&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the name of the new environment. Environments created with a name are typically stored in your Conda installation's 'envs' directory.</i><br><br><b><b>-p</b>, <b>--prefix</b> <i>&lt;PATH&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the exact path to the new environment. This allows creating environments in custom locations.</i><br><br><b><i>package_spec</i> [<i>package_spec</i> ...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>One or more package specifications to install in the new environment (e.g., 'python=3.9', 'numpy', 'pandas').</i><br><br><b><b>-c</b>, <b>--channel</b> <i>&lt;CHANNEL&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies an additional channel to search for packages. Can be used multiple times.</i><br><br><b><b>-y</b>, <b>--yes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Do not ask for confirmation before proceeding with the creation process.</i><br><br><b><b>--clone</b> <i>&lt;EXISTING_ENV&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Clones an existing environment (specified by name or path) to create a new one with the same packages.</i><br><br><b><b>--file</b> <i>&lt;PATH_TO_YAML&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Reads package specifications and environment configurations from a YAML file (e.g., 'environment.yml').</i><br><br><b><b>--dry-run</b>, <b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Perform a dry run; only display what would have been done, without making any changes.</i><br><br><b><b>--override-channels</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Ignores the channels defined in the user's .condarc file and only uses the channels specified with <b>--channel</b>.</i><br><br>


title: DESCRIPTION
content:
The <b>conda create</b> command is a fundamental component of the Conda package, dependency, and environment management system. It enables users to set up new, isolated environments, each with its own independent set of installed Python versions, packages, and dependencies. This isolation is crucial for managing different projects that might require conflicting package versions or specific software configurations, preventing compatibility issues across your development work.<br><br>By using <b>conda create</b>, developers and researchers can ensure reproducible workflows, share specific environment configurations, and switch between different project contexts seamlessly. The command allows for high flexibility, from specifying exact Python versions to including a wide range of packages, including those beyond Python, such as R, Node.js, or system libraries.


title: CAVEATS
content:
Environments created with <b>conda create</b> are isolated, meaning you must <b>activate</b> them using <b>conda activate</b> before you can use the packages installed within them. Creating many environments can consume significant disk space. While Conda manages dependencies, complex package specifications might sometimes lead to dependency conflicts, requiring manual intervention or adjustment of specified package versions. If no packages are explicitly specified, Conda typically installs a default set of packages, including Python and pip.


title: ENVIRONMENT LOCATION
content:
Environments created using the <b>-n</b> or <b>--name</b> option are typically stored in the 'envs' directory within your main Conda installation path (e.g., '~/anaconda3/envs/' or '/opt/conda/envs/'). Environments created with the <b>-p</b> or <b>--prefix</b> option are placed exactly at the specified path.


title: BEST PRACTICES FOR REPRODUCIBILITY
content:
For reproducible environments, it is highly recommended to use <b>--file</b> with an <i>environment.yml</i> file. This YAML file lists all desired packages and their versions, ensuring that anyone can recreate the exact same environment. Always pin package versions (e.g., 'python=3.9.7', 'numpy=1.23.0') to avoid unexpected breaking changes from future package updates.


title: HISTORY
content:
Conda was first released in 2012 by Continuum Analytics (now Anaconda Inc.), primarily to address the challenges of managing scientific computing packages and their complex dependencies. The <b>conda create</b> command has been a cornerstone of Conda since its early days, facilitating the crucial isolation of environments. Its ability to manage non-Python packages, unlike Python-specific tools like <b>pip</b> and <b>virtualenv</b>, marked a significant advancement in package and environment management within the scientific and data science communities.


title: SEE ALSO
content:
conda activate(1), conda env list(1), conda install(1), conda remove(1), conda update(1), pip(1), virtualenv(1)


title: PARAMETERS
content:
<b><i>package_spec</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more package specifications to install. This can include version constraints (e.g., <i>numpy=1.20</i>, <i>'python>=3.8,<3.9'</i>).<br><br><b><b>-n</b> <i>ENVIRONMENT</i>, <b>--name</b> <i>ENVIRONMENT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install packages into a specific environment by its name. If not specified, packages are installed into the current active environment.<br><br><b><b>-p</b> <i>PATH</i>, <b>--prefix</b> <i>PATH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install packages into a specific environment by its absolute path.<br><br><b><b>-c</b> <i>CHANNEL</i>, <b>--channel</b> <i>CHANNEL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an additional channel to search for packages. Can be used multiple times. E.g., <i>conda-forge</i>.<br><br><b><b>--override-channels</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore the channels specified in your <i>.condarc</i> file and only use those provided with <b>-c</b>.<br><br><b><b>-y</b>, <b>--yes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not ask for confirmation before executing the installation.<br><br><b><b>--no-deps</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not install dependencies. Useful for very specific cases, but generally not recommended.<br><br><b><b>--force-reinstall</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force reinstall of all packages, even if they are already installed and up-to-date.<br><br><b><b>--file</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read package specifications from a file, one per line. Useful for reproducible environments.<br><br>


title: DESCRIPTION
content:
The <b>conda install</b> command is a fundamental utility within the Conda package management system, used to install new packages into a specified or currently active Conda environment. Unlike traditional system-level package managers, Conda is language-agnostic, capable of managing packages for Python, R, Ruby, Java, and more, along with their non-language-specific dependencies.<br><br><b>conda install</b> excels at resolving complex dependency trees, ensuring that all necessary libraries and their compatible versions are installed without conflicts. It leverages "channels" (repositories where packages are stored) to find and download packages. This command is crucial for creating isolated development environments, allowing users to manage different sets of software versions for various projects without interfering with each other.


title: CAVEATS
content:
When using <b>conda install</b>, be mindful of channel priority and potential dependency conflicts. Using <b>--override-channels</b> or specifying multiple channels can sometimes lead to unexpected package versions if not managed carefully. Always ensure your desired environment is activated before installing packages to avoid installing into the base environment unintentionally.


title: CONDA CHANNELS
content:
Conda packages are distributed via "channels," which are URLs to package repositories. The default channel is <i>repo.anaconda.com/pkgs/main</i>. Popular community channels like <i>conda-forge</i> offer a vast array of additional packages. The order of channels matters for dependency resolution unless <b>--strict-channel-priority</b> is used.


title: ENVIRONMENT MANAGEMENT
content:
While <b>conda install</b> adds packages, it's typically used in conjunction with <b>conda create</b> to first establish an isolated environment. Activating the environment (e.g., <i>conda activate myenv</i>) before installing ensures packages are confined to that specific environment, preventing global system pollution and enabling project-specific dependency sets.


title: HISTORY
content:
Conda was developed by Continuum Analytics (now Anaconda Inc.) starting around 2012, primarily to address the challenges of package and environment management in scientific computing, especially for Python and R. It was designed to be platform-agnostic and handle complex binary dependencies that traditional language-specific package managers often struggled with. The <b>conda install</b> command has been a core component since its inception, continually evolving to improve dependency resolution and channel management capabilities.


title: SYNOPSIS
content:
Due to its non-standard nature, a generic synopsis is illustrative. <br><br>Typically, such a command might follow patterns like:<br> <B>config_data</B> [<I>options</I>] <I>&lt;action&gt;</I> [<I>parameters</I>]<br>or<br> <B>config_data</B> <I>&lt;category&gt;</I> <I>&lt;action&gt;</I> [<I>options</I>] [<I>value</I>]<br><br>Examples of actions could include <I>show</I>, <I>get</I>, <I>set</I>, <I>add</I>, <I>delete</I>, <I>save</I>, <I>load</I>, or <I>validate</I>, applied to various configuration parameters.


title: PARAMETERS
content:
<b>show</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display current configuration settings relevant to the command's scope.<br><br><b>get <I>param</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieve the value of a specific configuration parameter.<br><br><b>set <I>param</I> <I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set or modify a configuration parameter to a new value.<br><br><b>add <I>item</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a new configuration item, entry, or object.<br><br><b>delete <I>item</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove an existing configuration item or entry.<br><br><b>save [<I>file</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Persist the current configuration to a non-volatile storage or a specified file.<br><br><b>load [<I>file</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Load configuration settings from a specified file, replacing or merging current settings.<br><br><b>validate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check the current or proposed configuration for syntax or semantic errors and inconsistencies.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display usage information and available options (common for many commands).<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the command's version information.<br><br>


title: DESCRIPTION
content:
The <I>config_data</I> command is <B>not a standard, universally available Linux utility</B> found in most general-purpose distributions (like <I>ls</I> or <I>grep</I>). Instead, it typically exists as a specialized command within specific software packages, embedded systems, network devices (e.g., Cisco IOS XR, HP OpenView NNM), or custom application environments.<br><br>Its primary purpose is to <I>manipulate, query, or manage configuration settings</I> for the particular application or system it belongs to. The exact functionality, syntax, and available options of <I>config_data</I> are <B>highly dependent on its specific implementation</B>. Users encountering this command should consult the documentation for the software or system it is part of, as there is no single, canonical definition. It often serves to persist settings, apply changes, validate configurations, or retrieve current operational parameters.


title: CAVEATS
content:
The <I>config_data</I> command is <B>highly specialized</B> and its behavior, options, and availability are <B>entirely dependent on the specific software application or system</B> it is bundled with. It is not part of the standard Linux utility set. Therefore, any analysis of this command must be interpreted in the context of the particular product it belongs to. Attempting to use a <I>config_data</I> command from one system on another will likely result in an 'command not found' error or unexpected behavior.


title: CONTEXT IS KEY
content:
When encountering <I>config_data</I>, the absolute first step is to determine which software package or system it belongs to. This context is crucial for understanding its capabilities, limitations, and correct usage. Without this, detailed analysis is impossible.


title: DOCUMENTATION SOURCE
content:
The authoritative source for information about any specific <I>config_data</I> implementation will be the official documentation, user guides, or command reference manuals for the software or hardware product it is part of.


title: HISTORY
content:
As <I>config_data</I> is not a standard, standalone Linux command, it does not have a general, unified history. Instead, its development and usage history are tied directly to the specific applications, network operating systems, or embedded platforms where it is implemented. Each instance of <I>config_data</I> would have its own independent development lifecycle as part of its parent product.


title: SEE ALSO
content:
sysctl(8), dconf(1), gconftool-2(1), General: Application-specific CLI tools for configuration management, General: Configuration management systems like Ansible, Puppet, Chef (though not direct commands)


title: PARAMETERS
content:
<b><I>MSL_script_file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the <b>Magick Scripting Language</b> (MSL) XML file to be executed. This is the primary input for the <b>conjure.im6</b> command.<br><br><b>[<I>script_arguments</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional arguments that are passed directly to the MSL script for its internal processing. The script can then access and use these arguments, often via XML tags within the MSL file.<br><br><b>-<I>option</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generic <i>ImageMagick</i> options, such as <b>-debug</b>, <b>-verbose</b>, <b>-version</b>, or <b>-help</b>, which control the behavior of the <b>conjure.im6</b> command itself. These are distinct from arguments passed to the MSL script.<br><br>


title: DESCRIPTION
content:
The <b>conjure.im6</b> command is a specialized utility within the <i>ImageMagick</i> 6 suite, designed to interpret and execute scripts written in the <b>Magick Scripting Language</b> (MSL).<br><br>MSL is an XML-based language that allows users to define complex image processing workflows, combining various <i>ImageMagick</i> operations into a single, reusable script. This command provides a structured way to automate intricate image manipulation tasks, making it particularly useful for batch processing where a sequence of operations needs to be applied consistently to multiple images.<br><br>While <b>conjure.im6</b> processes the script, the actual image manipulation is performed by the underlying <i>ImageMagick</i> libraries, allowing the script to leverage the full power of <i>ImageMagick</i>'s extensive capabilities for image creation, editing, and conversion.


title: CAVEATS
content:
<b>Version Specificity:</b> The <b>.im6</b> suffix indicates this command is tied to <i>ImageMagick</i> version 6. Its behavior or even existence may vary with other <i>ImageMagick</i> versions.<br><br><b>MSL Usage:</b> The <b>Magick Scripting Language</b> (MSL) is an older feature of <i>ImageMagick</i> and is less commonly used in modern workflows, which often prefer direct command-line utilities (like <b>convert</b> or <b>mogrify</b>) or programming APIs (like MagickWand).<br><br><b>Security Risks:</b> Executing MSL files from untrusted sources can pose security risks, as MSL scripts can perform various file operations and interact with the system.


title: MAGICK SCRIPTING LANGUAGE (MSL)
content:
MSL is an XML-based language used by <b>conjure.im6</b> to define image processing workflows. It consists of various tags like <I>magickscript</I> (the root element), <I>read</I> (for input images), <I>operation</I> (for applying specific <i>ImageMagick</i> operations like resize, blur, composite), and <I>write</I> (for saving output images). This allows for intricate sequences of <i>ImageMagick</i> operations to be scripted and executed efficiently.


title: IMAGEMAGICK VERSIONING
content:
The <b>.im6</b> suffix is crucial, indicating that this specific executable is linked to <i>ImageMagick</i> version 6. On systems where multiple versions of <i>ImageMagick</i> are installed (e.g., v6 and v7), such suffixes help distinguish between the command versions. A generic <b>conjure</b> command might exist and point to the default version, or a <b>conjure.im7</b> might be present for <i>ImageMagick</i> 7, reflecting different installed versions of the suite.


title: HISTORY
content:
The <b>conjure</b> command, and by extension <b>conjure.im6</b>, has been a part of the <i>ImageMagick</i> suite for a significant period, particularly prominent in version 6. It was developed to provide a structured, XML-based approach (<b>Magick Scripting Language</b> or MSL) for defining and automating complex image processing tasks. This allowed for greater reusability and portability of workflows, serving as an early form of advanced batch processing within <i>ImageMagick</i>.


title: PARAMETERS
content:
<b><b>--config=</b><i>FILE</i>, <b>-c </b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the specified configuration <i>FILE</i> instead of the default <i>~/.config/conky/conky.conf</i> or <i>~/.conkyrc</i>.<br><br><b><b>--daemonize</b>, <b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Daemonizes Conky, running it in the background as a detached process.<br><br><b><b>--display=</b><i>DISPLAY</i>, <b>-D </b><i>DISPLAY</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the X <i>DISPLAY</i> Conky should attach to.<br><br><b><b>--double-buffer</b>, <b>-b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables double buffering to reduce or eliminate flickering during updates on some systems.<br><br><b><b>--force-rgba</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces RGBA (Red Green Blue Alpha) visual mode for transparency, even if not automatically detected.<br><br><b><b>--lua-load=</b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads an external Lua script <i>FILE</i>, allowing for advanced custom functions and data processing.<br><br><b><b>--quiet</b>, <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses most output to standard output, making Conky run silently in the terminal.<br><br><b><b>--version</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints Conky's version information and exits.<br><br><b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message detailing command-line options and exits.<br><br>


title: DESCRIPTION
content:
<i>conky</i> is a free, lightweight system monitor for the X Window System. It displays a vast array of information directly on your desktop, including CPU usage, memory and swap usage, disk space, network activity, temperatures, processes, and much more. Unlike many system monitors, Conky is designed to be highly configurable via a simple text-based configuration file, allowing users to precisely control what information is displayed, its layout, colors, and update frequency.<br><br>Known for its low resource consumption, Conky runs efficiently in the background, providing real-time system statistics without significantly impacting performance. Its extensibility through built-in variables and Lua scripting enables users to create highly customized and visually appealing desktop widgets, making it a popular choice for Linux desktop enthusiasts seeking both functionality and aesthetic control.


title: CAVEATS
content:
Conky is primarily designed for the X Window System; while it can run under Wayland via Xwayland, some features or transparency settings might not behave identically.<br>Achieving perfect visual integration (e.g., transparent background without artifacts) can sometimes require careful fine-tuning of configuration parameters like <i>own_window_type</i>, <i>own_window_transparent</i>, and <i>own_window_argb_visual</i> specific to your desktop environment.<br>The configuration file's flexibility, especially with Lua scripting, can present a learning curve for new users.


title: CONFIGURATION FILE
content:
Conky's entire behavior and display are controlled by a single configuration file, typically named <i>conky.conf</i> and located in <i>~/.config/conky/</i> or as <i>~/.conkyrc</i>. This file is a plain-text document defining global settings (like update interval, window position, colors) and a 'text' section that uses Conky's special variables and objects to display dynamic system information. Modern Conky configurations often leverage Lua syntax within this file for enhanced control and flexibility.


title: VARIABLES AND OBJECTS
content:
Conky utilizes a rich set of built-in variables and objects to fetch and display system information. These are placeholders (e.g., <b>${cpu cpu0}</b> for first CPU core usage, <b>${memperc}</b> for memory percentage, <b>${downspeed eth0}</b> for download speed on 'eth0') that expand to real-time data. Users embed these variables directly into the 'text' section of their configuration file, combining them with static text, colors, and formatting options to create their desired output.


title: HISTORY
content:
Conky originated as a fork of <i>torsmo</i>, another popular lightweight system monitor, in 2004. The primary motivation for the fork was to continue development and add new features while maintaining torsmo's core principles of being small, fast, and highly configurable. Over the years, Conky has undergone significant development, adding extensive support for various system metrics, Lua scripting, improved rendering capabilities, and a vast ecosystem of user-contributed configurations, solidifying its position as a go-to tool for desktop system monitoring and customization.


title: SYNOPSIS
content:
<pre><b>conntrack</b> { <i>list</i> | <i>dump</i> | <i>delete</i> | <i>flush</i> | <i>event</i> | <i>expect</i> | <i>count</i> | <i>stats</i> | <i>help</i> | <i>version</i> } [<i>options</i>] [<i>arguments</i>]</pre><br>Common usage patterns include:<pre><b>conntrack</b> <i>list</i> [<b>-s</b> <i>src_ip</i>] [<b>-d</b> <i>dst_ip</i>] [<b>-p</b> <i>proto</i>] [<b>-o</b> <i>output_opts</i>]<br><b>conntrack</b> <i>delete</i> <b>-s</b> <i>src_ip</i> <b>-d</b> <i>dst_ip</i> <b>-p</b> <i>proto</i> [<b>--sport</b> <i>src_port</i>] [<b>--dport</b> <i>dst_port</i>]<br><b>conntrack</b> <i>flush</i><br><b>conntrack</b> <i>event</i> [<b>-o</b> <i>output_opts</i>]</pre>


title: PARAMETERS
content:
<b>"list"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays all currently tracked connections. Also available as "dump" or shorthand "-L".<br><br><b>"delete"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes connection tracking entries matching specified criteria. Shorthand "-D".<br><br><b>"flush"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes all connection tracking entries from the table. Shorthand "-F". <b>Use with caution!</b><br><br><b>"event"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitors and displays real-time connection tracking events as they occur (e.g., new connections, state changes, destruction). Shorthand "-E".<br><br><b>"expect"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages connection expectation entries, which are used by Netfilter helpers (ALGs) for complex protocols like FTP or SIP. Shorthand "-X".<br><br><b>"count"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current number of tracked connections. Shorthand "-C".<br><br><b>"stats"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows statistics about connection tracking operations (e.g., inserts, deletes, searches). Shorthand "-S".<br><br><b>"-s <IP>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters connections by source IP address. Also `--src <IP>`.<br><br><b>"-d <IP>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters connections by destination IP address. Also `--dst <IP>`.<br><br><b>"-p <protocol>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters connections by protocol (e.g., <i>tcp</i>, <i>udp</i>, <i>icmp</i>, <i>sctp</i>). Also `--proto <protocol>`.<br><br><b>"--sport <port>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters connections by source port number.<br><br><b>"--dport <port>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters connections by destination port number.<br><br><b>"-o <option>"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies output format options (e.g., <i>xml</i>, <i>timestamp</i>, <i>id</i>, <i>mark</i>). Also `--output <option>`.<br><br><b>"-n"</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays numerical IP addresses and port numbers instead of resolving names. Also `--numeric`.<br><br>


title: DESCRIPTION
content:
The <b>conntrack</b> command-line utility is a user-space tool that interacts with the Netfilter connection tracking system, a core component of the Linux kernel's networking stack. This system tracks the state of all network connections (TCP, UDP, ICMP, etc.) passing through the firewall. <br><br>Connection tracking is fundamental for stateful packet inspection, enabling firewalls (like those configured via <b>iptables</b> or <b>nftables</b>) to make intelligent decisions based on the context of a connection rather than just individual packets. It's also vital for Network Address Translation (NAT) operations, allowing the kernel to correctly route return traffic for masqueraded or port-forwarded connections. <br><br>With <b>conntrack</b>, administrators can view detailed information about active connections, including source and destination IP addresses and ports, protocol, state (e.g., ESTABLISHED, TIME_WAIT), timeouts, and NAT specifics. Beyond mere inspection, it provides capabilities to add, delete, or flush connection tracking entries, offering granular control over the firewall's state table. It's an invaluable tool for network diagnostics, troubleshooting connectivity issues, and managing firewall performance.


title: CAVEATS
content:
<ul><li><b>Root Privileges</b>: Most operations, especially modifying or flushing entries, require root privileges. Listing connections generally also requires root or CAP_NET_ADMIN capabilities.</li><li><b>Kernel Module</b>: The <i>nf_conntrack</i> kernel module (and potentially protocol-specific modules like <i>nf_conntrack_tcp</i>) must be loaded for <b>conntrack</b> to function.</li><li><b>Performance Impact</b>: On systems with extremely high connection rates, running <b>conntrack list</b> can be resource-intensive and might impact system performance due to the large amount of data being processed.</li><li><b>Data Volatility</b>: Connection tracking entries are dynamic. Deleting entries carelessly can disrupt active network sessions (e.g., dropping SSH connections or file transfers).</li><li><b>Verbose Output</b>: The default output for listing connections can be very verbose. It's often necessary to pipe the output to tools like <b>grep</b> or <b>less</b> for easier analysis.</li></ul>


title: UNDERSTANDING CONNECTION STATES
content:
Connection tracking assigns states to network connections. For TCP, common states include:<br><i>NEW</i>: The first packet of a connection.<br><i>ESTABLISHED</i>: Normal data transfer state.<br><i>RELATED</i>: A new connection related to an existing one (e.g., FTP data channel).<br><i>INVALID</i>: Packet does not belong to any known connection.<br><i>UNTRACKED</i>: Packet explicitly configured not to be tracked.<br><i>TIME_WAIT</i> / <i>CLOSE_WAIT</i>: States after connection termination, indicating resources are being held before full closure.<br>These states are crucial for understanding firewall behavior and troubleshooting.


title: CONNTRACK SYSCTL TUNABLES
content:
Several kernel parameters can be tuned via <b>sysctl</b> to control connection tracking behavior and resource usage:<br><i>net.netfilter.nf_conntrack_max</i>: The maximum number of connections that can be tracked concurrently. Increasing this is often necessary for high-load servers.<br><i>net.netfilter.nf_conntrack_tcp_timeout_established</i>: Timeout for established TCP connections (default is often 5 days).<br><i>net.netfilter.nf_conntrack_generic_timeout</i>: Default timeout for protocols without specific handlers.<br>Adjusting these can significantly impact network performance and stability, especially under DDoS attacks or high legitimate traffic.


title: HISTORY
content:
The <b>conntrack</b> utility is an integral part of the Netfilter project, a framework within the Linux kernel that provides various network packet manipulation functions, including connection tracking. It was developed alongside the <i>iptables</i> firewall utility, providing a user-space interface to the kernel's <i>nf_conntrack</i> module which was introduced to enable stateful firewalling and advanced NAT capabilities. <br><br>Its initial development aimed to give administrators visibility and control over the kernel's connection state table, a critical component for firewalls to understand the context of network traffic (e.g., whether a packet belongs to an existing connection or is part of a new one). Over time, as Netfilter evolved and the <i>nftables</i> framework emerged as the modern successor to <i>iptables</i>, the fundamental role of connection tracking remained unchanged, solidifying <b>conntrack</b>'s importance as a diagnostic and management tool in Linux networking. Its design focuses on direct interaction with the kernel's conntrack table, providing a low-level but powerful interface.


title: PARAMETERS
content:
<b><I>agent</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs a Consul agent. This is the core process that either serves as a cluster server or a client forwarding requests.<br><br><b><I>kv</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interacts with Consul's distributed Key-Value (KV) store, allowing data to be put, retrieved, and deleted.<br><br><b><I>catalog</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows interaction with the service catalog, such as listing registered services or nodes.<br><br><b><I>services</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists the services registered against the local agent.<br><br><b><I>acl</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages Access Control Lists (ACLs) to secure communication and access within Consul.<br><br><b><I>operator</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides commands for cluster-level operations, such as managing Raft peers or autopilot configurations.<br><br><b><I>join</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs a Consul agent to join an existing cluster by connecting to one or more known agents.<br><br><b><I>leave</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Gracefully causes a Consul agent to leave the cluster. Useful for planned maintenance or shutdowns.<br><br><b><I>members</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists the members (agents) currently known to the Consul cluster.<br><br><b><I>reload</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Triggers a graceful reload of the agent's configuration without restarting the process.<br><br><b><I>status</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reports the status of the Consul cluster, including server leader and Raft peer information.<br><br><b><I>validate</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Validates configuration files and policies for syntax and semantic correctness.<br><br><b><I>version</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Consul version and build information.<br><br><b>[flags]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Most subcommands accept specific flags to modify behavior. Common flags include:<br>  <I>-dev</I> (for <I>agent</I>): Runs a single-node development agent.<br>  <I>-server</I> (for <I>agent</I>): Specifies the agent should run in server mode.<br>  <I>-bootstrap-expect</I> (for <I>agent</I>): Sets the number of expected server nodes for initial cluster bootstrap.<br>  <I>-data-dir</I> (for <I>agent</I>): Specifies the directory for agent state.<br>  <I>-config-dir</I> (for <I>agent</I>): Specifies a directory to load configuration files from.<br>  <I>-h</I> or <I>--help</I>: Displays help for the specific subcommand.<br><br>


title: DESCRIPTION
content:
The <b>consul</b> command is the primary command-line interface (CLI) for HashiCorp Consul, a distributed service mesh that provides service discovery, configuration, and segmentation functionality. It serves two main purposes:<br><br>1. <B>Running the Consul Agent:</B> When used with the <I>agent</I> subcommand, it starts and operates a Consul agent process, which can run as either a server (participating in raft consensus, storing cluster state) or a client (forwarding requests to servers, running health checks).<br>2. <B>Interacting with the Consul Cluster:</B> The CLI allows users and automated scripts to interact with a running Consul cluster. This includes registering services, querying the service catalog, managing the Key-Value (KV) store, configuring Access Control Lists (ACLs), checking health statuses, and performing cluster operations.<br><br>Consul is widely used in modern cloud and datacenter environments to manage dynamic infrastructure, enabling applications to discover and communicate with each other reliably and securely, even as their network locations change.


title: CAVEATS
content:
The <b>consul</b> command is not a standard Linux utility but part of the HashiCorp Consul application. Its effective use requires an understanding of distributed systems, networking, and the Consul architecture. Running a production Consul cluster involves careful planning for high availability, disaster recovery, and security, often leveraging external tools like cloud provider services or configuration management. Misconfiguration can lead to cluster instability or data loss. It typically runs as a long-lived service, often managed by init systems like Systemd.


title: AGENT MODES: SERVER VS. CLIENT
content:
A Consul agent can run in two modes:<br><br><b>Server:</b> Participates in the Raft consensus algorithm, stores the cluster's state (service catalog, KV data, ACLs), and acts as the backbone of the cluster. A Consul cluster requires at least one server, and typically 3 or 5 for high availability.<br><b>Client:</b> Forwards all RPC requests to a server. Clients run health checks, register services, and handle DNS queries locally, but they do not store persistent cluster state. Most application nodes run as Consul clients.


title: CONFIGURATION
content:
Consul agents are typically configured via configuration files (JSON or HCL format) specified with the <I>-config-dir</I> or <I>-config-file</I> flags when starting the agent. These files define network bindings, data directories, security settings, and integration points.


title: WEB UI
content:
Consul includes an optional built-in web user interface accessible via a browser. This UI provides a visual representation of the service catalog, nodes, KV store, and ACLs, and can be enabled by passing the <I>-ui</I> flag to the <I>agent</I> subcommand.


title: HISTORY
content:
HashiCorp Consul was initially released in 2014 by HashiCorp, known for other infrastructure tools like Vagrant, Terraform, and Vault. It quickly gained traction as a robust solution for service discovery and configuration in microservices architectures and dynamic cloud environments. Over the years, it has evolved to include advanced features like a service mesh with Connect, expanded ACL capabilities, and improved multi-datacenter support, becoming a foundational component in many modern infrastructure stacks.


title: SYNOPSIS
content:
<b><I>iconv</I></b> [<I>OPTIONS</I>] <b>-f</b> <I>FROM_ENCODING</I> <b>-t</b> <I>TO_ENCODING</I> [<I>INPUT_FILE</I>...]


title: PARAMETERS
content:
<b><b>-f</b> <I>FROM_ENCODING</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the original character encoding of the input text. This must be an encoding recognized by <b><I>iconv</I></b>.<br><br><b><b>-t</b> <I>TO_ENCODING</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the target character encoding for the output text. This must also be an encoding recognized by <b><I>iconv</I></b>.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Discards characters that cannot be converted from the source encoding to the target encoding without causing an error. Without this option, conversion failure for a character might result in an error and termination.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses warnings about illegal or unconvertible characters encountered during the conversion process.<br><br><b><b>-o</b> <I>OUTPUT_FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Redirects the converted output to the specified <I>OUTPUT_FILE</I> instead of standard output.<br><br><b><b>-l</b>, <b>--list</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all character encodings supported by the current <b><I>iconv</I></b> implementation.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays version information for the <b><I>iconv</I></b> utility.<br><br><b><b>-?</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with usage information and options.<br><br>


title: DESCRIPTION
content:
While "conv" is not a standard Linux command, it is highly probable that the intended command was <b><I>iconv</I></b>. This utility is fundamental for converting text from one character encoding to another. <br>It is essential in environments where files originate from different systems or use diverse language settings, for instance, converting between UTF-8, Latin-1, UTF-16, or various ISO encodings.<br> <b><I>iconv</I></b> reads input from standard input or specified files and writes the converted output to standard output or a designated output file. It plays a crucial role in internationalization (I18N) and ensuring data integrity across different character sets.


title: CAVEATS
content:
Not all characters from the <I>FROM_ENCODING</I> might have an equivalent representation in the <I>TO_ENCODING</I>. Without the <b>-c</b> option, encountering such characters can lead to conversion errors and command termination. The set of supported encodings can vary slightly depending on the specific <b><I>iconv</I></b> implementation and the underlying C library (e.g., glibc) on a given system.


title: CLARIFICATION ON 'CONV' COMMAND
content:
The command 'conv' is not a standard, widely recognized Linux utility. This analysis is provided for <b><I>iconv</I></b>, which is the most common and core utility related to character set conversion and is often what users might implicitly refer to when thinking of 'conversion' commands. Another possible command the user might have intended, especially for image format conversions, is <b><I>convert</I></b> from the ImageMagick suite. This document specifically focuses on <b><I>iconv</I></b> due to its nature as a fundamental text processing utility.


title: HISTORY
content:
<b><I>iconv</I></b> is an integral part of the GNU C Library (glibc) and has been a standard utility on Unix-like operating systems for decades. Its importance grew significantly with the advent of Unicode and the increasing need for robust internationalization support in software and data handling, enabling seamless text exchange across diverse language and platform environments.


title: SYNOPSIS
content:
The <i>convert</i> command follows a flexible syntax, generally structured as:<br><br><i>convert</i> [<i>input_options</i>] <i>input_file</i> [<i>output_options</i>] <i>output_file</i><br><br>Or for operations involving multiple images:<br><br><i>convert</i> <i>image1</i> <i>image2</i> ... [<i>operation</i>] <i>output_file</i><br><br>Options can be placed before the input file to apply globally, or between input and output files to apply specific effects or transformations to the processing pipeline.


title: PARAMETERS
content:
<b>-resize <i>WxH</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resizes the image to the specified width (W) and height (H). Modifiers like '<i>WxH</i><b>!</b>' (exact size), '<i>WxH</i><b>&gt;</b>' (if larger), or '<i>WxH</i><b>&lt;</b>' (if smaller) can be appended.<br><br><b>-rotate <i>degrees</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rotates the image by the given number of <i>degrees</i> clockwise.<br><br><b>-crop <i>WxH</i>+<i>X</i>+<i>Y</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts a rectangular region from the image, starting at offset (X,Y) with dimensions Width (W) and Height (H).<br><br><b>-quality <i>value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the compression quality for formats like JPEG (0-100) or PNG (0-9), where higher values mean better quality/larger file size.<br><br><b>-format <i>format</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly specifies the output image format (e.g., 'png', 'jpeg', 'gif', 'webp'). This often overrides the format inferred from the output filename's extension.<br><br><b>-strip</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes all profiles (e.g., EXIF, IPTC, XMP) and comments from the image, typically reducing file size.<br><br><b>-auto-orient</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically rotates the image based on its EXIF orientation tag, if present, ensuring it appears correctly oriented.<br><br><b>-fill <i>color</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color for drawing operations (e.g., text, shapes) or used as a background color.<br><br><b>-annotate <i>geometry</i> <i>text</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds <i>text</i> to the image at a specified <i>geometry</i> (position and optional rotation).<br><br><b>-monochrome</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Transforms the image into a grayscale image using only black and white pixels, effectively binarizing it.<br><br><b>-background <i>color</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the background color used when an image is cropped, resized with expansion, or composited on a canvas.<br><br><b>-alpha <i>option</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the alpha channel of the image, with options like 'on', 'off', 'set', 'remove', 'extract', to manage transparency.<br><br>


