# CommandSection

title: CAVEATS
content:
The primary output format is <b>Ogg Theora</b> (.ogv), which may require specific players or conversion for broader compatibility. While efficient, 'on-the-fly-encoding' can be CPU-intensive. Files can become very large if recorded at high frame rates or resolutions for extended periods.


title: CONTROLLING RECORDING WITH SIGNALS
content:
<i>recordmydesktop</i> can be controlled externally using standard Unix signals. For example, to pause/resume recording, you can send <br><b>SIGUSR1</b> (User-defined signal 1) to its process ID (PID). To stop, you can send <br><b>SIGUSR2</b> (User-defined signal 2) or <br><b>SIGTERM</b>. This allows for scriptable control of the recording process.


title: HISTORY
content:
Developed by <i>John J. Cabello</i>, <i>recordmydesktop</i> emerged as a lightweight, open-source solution for screen recording on Linux. It gained popularity for its simplicity and efficiency, especially in environments where more resource-intensive applications were not feasible. While newer, more feature-rich tools have appeared, it remains a reliable choice for basic screen capture.


title: PARAMETERS
content:
<b><i>&lt;OLD_RECOUNT_FILE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the <i>recount</i> output file representing the older version of the codebase for comparison.<br><br><b><i>&lt;NEW_RECOUNT_FILE&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the <i>recount</i> output file representing the newer version of the codebase for comparison.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message and exits, detailing command usage and available options.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information for the <b>recount-diff</b> utility and exits.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses non-error output, showing only significant differences or error messages.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, providing more detailed information about the comparison process and results.<br><br><b>-b, --blanks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the number of blank lines between the two input files.<br><br><b>-c, --comments</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the number of comment lines.<br><br><b>-e, --empty</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the number of empty files found.<br><br><b>-f, --files</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the total number of files.<br><br><b>-l, --lines</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the number of actual code lines (non-blank, non-comment).<br><br><b>-L, --total-lines</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compares and reports only the differences in the total number of all lines (code + comments + blanks).<br><br><b>-m, --match-paths</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to match file paths across the two input files even if their internal order differs.<br><br><b>-s, --sort</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the output by file paths or other relevant criteria for consistent and readable comparison results.<br><br><b>-D, --display-diffs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays granular differences for individual files within the comparison, not just overall summaries.<br><br><b>-x <i>&lt;PATTERN&gt;</i>, --exclude-files=<i>&lt;PATTERN&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files whose paths match the specified <i>&lt;PATTERN&gt;</i> from the comparison. Pattern typically supports wildcards.<br><br><b>-i <i>&lt;PATTERN&gt;</i>, --include-files=<i>&lt;PATTERN&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes only files whose paths match the specified <i>&lt;PATTERN&gt;</i> in the comparison. This option usually takes precedence over <i>--exclude-files</i>.<br><br>


title: DESCRIPTION
content:
The <b>recount-diff</b> command, typically found as part of the <i>recount</i> suite, is a specialized utility designed to compare and report differences in various code metrics between two <i>recount</i> output files. These input files (often with a <i>.recount</i> extension) contain aggregated statistics such as lines of code (LOC), comment lines, blank lines, and total file counts for a given codebase at a specific point in time.<br><br><b>recount-diff</b> is invaluable for software development teams to track project evolution, quantify the impact of refactoring efforts, or monitor overall codebase growth or shrinkage. Unlike traditional line-by-line textual diffs, this tool focuses on the quantitative changes in source code characteristics, providing a high-level overview. It enables developers and project managers to quickly ascertain how metrics like the total number of files, lines of code, or specific line types have changed between different snapshots or versions of a project, thereby facilitating better project management and code quality assessment.


title: CAVEATS
content:
The <b>recount-diff</b> command is designed to operate on output files generated by the <i>recount</i> utility itself. It cannot directly compare raw source code directories or files. Therefore, prior execution of <i>recount</i> on both versions of the codebase is a prerequisite.<br><br>The accuracy of the reported differences is directly dependent on the consistency and correctness of the input <i>.recount</i> files. Inconsistent options used during the initial <i>recount</i> runs (e.g., different exclusion patterns) can lead to misleading comparison results. <br><br>As this utility is part of a specific package (<i>recount</i>), its availability and the exact set of options may vary across different Linux distributions or versions of the <i>recount</i> package. Always consult the specific man page or <i>--help</i> output for your installed version.


title: INPUT FILE FORMAT
content:
Each input file for <b>recount-diff</b> is typically a structured text file (e.g., JSON or a custom format) produced by the <b>recount</b> command. These files contain aggregated data per language and per file, providing a detailed breakdown of line types and counts.


title: TYPICAL USAGE SCENARIO
content:
A common use case involves running <b>recount</b> on your project at the beginning of a sprint (generating <i>old_project.recount</i>) and again at the end (generating <i>new_project.recount</i>). You can then use <b>recount-diff old_project.recount new_project.recount</b> to get an immediate summary of code added, removed, or modified, helping to assess sprint productivity or codebase changes.


title: HISTORY
content:
The <b>recount-diff</b> utility emerged as an integral component of the open-source <i>recount</i> project, which was developed to provide a lightweight and efficient way to count lines of code, comments, and blank lines across various programming languages. Recognizing the need to track changes over time, <b>recount-diff</b> was created to complement the core <i>recount</i> tool by enabling quantitative comparisons between different codebase snapshots. Its development reflects the broader trend in software engineering towards metric-driven development and the automation of codebase analysis, allowing for better visibility into project growth and architectural evolution.


title: SYNOPSIS
content:
<i>recover</i> [<b>-vNLaf</b>] [<b>-o</b> <i>output_dir</i>] [<b>-i</b> <i>inode_num</i>] <i>device</i> [<i>target_path</i>]


title: PARAMETERS
content:
<b><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the filesystem device (e.g., <i>/dev/sda1</i>) from which to recover files. This must be an unmounted partition.<br><br><b><i>target_path</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional. A specific path or filename within the filesystem being recovered to target for recovery. Can be a directory for recursive recovery or a specific file name.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, displaying detailed information about the scanning and recovery process.<br><br><b><b>-N</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run. The command will simulate the recovery process and report what could be recovered without actually writing any data to the output directory.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all identifiable recoverable inodes or files found on the device without attempting to recover them. Useful for previewing.<br><br><b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to recover all identifiable deleted files and place them into the specified output directory, organizing them by inode or file type.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force recovery, even if some filesystem checks indicate potential issues or the filesystem is not cleanly unmounted (use with caution).<br><br><b><b>-o</b> <i>output_dir</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the directory where recovered files will be placed. This directory <b>must not</b> be on the filesystem currently being recovered to prevent further data corruption.<br><br><b><b>-i</b> <i>inode_num</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a particular inode number to recover. This is most effective when you know the exact inode of the deleted file, typically obtained from filesystem logs or specific analysis tools.<br><br>


title: DESCRIPTION
content:
The <i>recover</i> command, typically found in older or specialized Linux environments, is a utility designed to undelete files from ext2 and ext3 filesystems. It operates by scanning the filesystem for orphaned inodes or unlinked directory entries that still contain file data. To minimize further data corruption, it is crucial to run <i>recover</i> on an <b>unmounted</b> filesystem. Success is highly dependent on whether the disk blocks occupied by the deleted file have been overwritten by new data. Due to the dynamic nature of disk usage, complete and perfect recovery is rarely guaranteed, especially for fragmented files. This tool is largely considered a legacy utility, having been superseded by more advanced forensic tools and filesystem-specific recovery utilities.


title: CAVEATS
content:
The <i>recover</i> command is <b>not</b> a standard, universally available utility on most modern Linux distributions. Its effectiveness is severely limited by several critical factors: <br>1. <b>Data Overwriting</b>: Any new data written to the disk after deletion can overwrite the blocks of the deleted file, making recovery impossible. <br>2. <b>Filesystem State</b>: For safe and effective recovery, the target filesystem <b>must be unmounted</b> and ideally accessed in read-only mode. Running on a mounted filesystem risks further data loss or corruption. <br>3. <b>Fragmentation</b>: Highly fragmented files are significantly more challenging to recover perfectly, as their data blocks may be scattered across the disk. <br>4. <b>Filesystem Type</b>: This utility is primarily designed for older ext2 and ext3 filesystems and is generally not suitable for modern filesystems like ext4, XFS, Btrfs, or ZFS. <br>5. <b>Legacy Tool</b>: For critical data recovery, consider more robust, actively maintained, and feature-rich tools such as <i>extundelete</i>, <i>TestDisk</i>, or forensic suites.


title: HISTORY
content:
The <i>recover</i> utility, as described, emerged in the context of early Linux filesystems, primarily ext2 and later ext3, as a basic undeletion tool. It was often distributed as part of specific filesystem utilities or packages, sometimes associated with efforts like <i>e2undel</i> (though <i>e2undel</i> itself is a distinct tool). Its initial development aimed to provide a direct, albeit rudimentary, way to salvage accidentally deleted files by examining raw filesystem structures. However, with the evolution of Linux filesystems (e.g., journaling in ext3/ext4, advanced features in XFS/Btrfs) and the advent of more sophisticated data recovery and forensic analysis tools, the original <i>recover</i> command has largely become obsolete or niche. Modern data recovery often relies on filesystem-specific utilities, snapshotting capabilities, or byte-level disk imaging combined with specialized forensic software.


title: PARAMETERS
content:
<b><b>-q</b>, <b>--query</b>=<i>EXPR</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the query expression to filter records. Records matching the expression are selected.<br><br><b><b>-P</b>, <b>--print</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the selected records. This is often implied but can be used to explicitly show output.<br><br><b><b>-e</b>, <b>--exact</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform exact string matches for queries, rather than using regular expressions.<br><br><b><b>-s</b>, <b>--sort</b>=<i>FIELD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the selected records by the specified field(s). Can be specified multiple times for multi-level sorting.<br><br><b><b>-C</b>, <b>--cut</b>=<i>FIELD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove the specified field(s) from the output records.<br><br><b><b>-S</b>, <b>--select</b>=<i>FIELD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select and display only the specified field(s) from the output records. Fields are printed in the order specified.<br><br><b><b>-F</b>, <b>--format</b>=<i>FORMAT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output format. Supported formats include <i>rec</i>, <i>csv</i>, <i>plain</i>, and <i>custom</i>.<br><br><b><b>-i</b>, <b>--index</b>=<i>FIELD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume that the specified field is indexed, potentially speeding up queries on large files.<br><br><b><b>-n</b>, <b>--no-headers</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not print field headers when using <i>plain</i> or <i>csv</i> output formats.<br><br><b><b>-c</b>, <b>--count</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instead of printing records, print only the count of selected records.<br><br><b><b>-t</b>, <b>--record-type</b>=<i>TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process only records of the specified type. Useful when a <I>rec</I> file contains multiple record definitions.<br><br><b><b>-o</b>, <b>--output</b>=<i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to the specified file instead of standard output.<br><br><b><b>-v</b>, <b>--invert</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invert the match; select records that do NOT match the query expression.<br><br><b><b>-O</b>, <b>--output-fields</b>=<i>FIELDS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When using <b>--format=custom</b>, specify the fields and their format for the output. Example: <i>Name:%n,Age:%a</i>.<br><br>


title: DESCRIPTION
content:
<i>recsel</i> is a powerful command-line utility from the GNU Recutils package, designed for querying, filtering, and manipulating data stored in <I>rec</I> files. <I>rec</I> files are a plain text, human-readable format for simple flat-file databases, structured as a sequence of records, each composed of fields.<br><br>The command allows users to select records based on complex query expressions (supporting boolean logic, comparisons, and regular expressions), sort them by specific fields, and select which fields to display. It can output the results in various formats, including the original <I>rec</I> format, CSV, plain text tables, or a custom format defined by the user. <I>recsel</I> is essential for automating data extraction and transformation from <I>rec</I> databases, making it a versatile tool for shell scripting and data processing.


title: CAVEATS
content:
<i>recsel</i> is specifically designed for GNU Recutils' <I>rec</I> file format, making it less applicable to other database or data interchange formats. Its query language, while powerful, is unique to Recutils and not directly compatible with standard SQL.


title: QUERY LANGUAGE
content:
The query expression used with <b>-q</b> supports a rich set of operators and functions. It allows boolean logic (AND, OR, NOT), comparisons (==, !=, &lt;, &lt;=, &gt;, &gt;=), regular expression matching (~), and field existence checks (<i>FIELD?</i>). Expressions can be nested using parentheses, enabling highly specific data filtering.


title: OUTPUT FORMATS
content:
Beyond the default <I>rec</I> format, <i>recsel</i> offers flexibility in output. <b><I>csv</I></b> generates comma-separated values, ideal for spreadsheets. <b><I>plain</I></b> produces a human-readable table with aligned columns. The <b><I>custom</I></b> format, used with <b>--output-fields</b>, provides granular control over how each field is presented, allowing for highly specific report generation.


title: HISTORY
content:
<i>recsel</i> is a core component of GNU Recutils, a project initiated and primarily developed by Jose E. Marchesi. The Recutils package aims to provide a simple yet robust set of tools for managing flat-file databases in a human-readable format. Its development reflects a focus on simplicity, portability, and text-based data management, aligning with traditional Unix philosophies.


title: DESCRIPTION
content:
The <b>rector</b> command is not a standard or commonly recognized utility within typical Linux distributions. Extensive searches of official documentation, man pages, and common system utilities across various distributions (e.g., Debian, Ubuntu, Fedora, CentOS) do not yield a command with this specific name in their default or common repositories. <br><br>It is possible that <b>rector</b> refers to a highly specialized, custom-built, or internal command specific to a particular environment or organization, perhaps deployed for a very niche system administration task or development workflow. Alternatively, it might be a typo for another existing command with similar-sounding functionality. Therefore, a detailed analysis of its specific functionality, parameters, and usage cannot be provided, as it does not form part of the widely recognized or distributed standard Linux command set.


title: CAVEATS
content:
This command is not part of the standard Linux utility set and is not generally available or documented. Attempting to execute <i>rector</i> on a typical Linux system will almost certainly result in a 'command not found' error.


title: HISTORY
content:
There is no documented history for a standard Linux command named <i>rector</i> in common usage or distribution. The name 'rector' is more commonly associated with PHP Rector, a refactoring tool for PHP, which operates within a PHP development environment rather than as a general-purpose Linux system utility. This PHP tool is not invoked directly as 'rector' from the system shell in the same way as a standard Linux command.


title: PARAMETERS
content:
<b><b>-L <i>LABEL</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <i>LABEL</i> instead of the actual file name in the output header for <i>OLDFILE</i> or <i>NEWFILE</i>.<br><br><b><b>--label=<i>LABEL</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form of <b>-L</b>.<br><br><b><b>-N</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treats any missing input files (<i>OLDFILE</i> or <i>NEWFILE</i>) as empty during the comparison.<br><br><b><b>--new-file</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form of <b>-N</b>.<br><br><b><b>-S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Strips trailing carriage returns (CR) from all input lines before processing. Useful for cross-platform diffs.<br><br><b><b>--strip-trailing-cr</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form of <b>-S</b>.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the <i>rediff</i> version information and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Long form of <b>-V</b>.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with command usage and exits.<br><br><b><b><i>OLDFILE</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the original, base file that the diff was created from.<br><br><b><b><i>NEWFILE</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the target, modified file that the diff describes.<br><br><b><b><i>PATCHFILE</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the potentially hand-edited diff file. If omitted, <i>rediff</i> reads the diff content from standard input (<i>stdin</i>).<br><br>


title: DESCRIPTION
content:
<i>rediff</i> is a command-line utility from the <i>GNU Diffutils</i> package designed to make an edited diff output file usable again as input for the <i>patch(1)</i> command. <br><br>When a diff file, typically generated by <i>diff -u</i> or <i>diff -c</i>, is manually altered—for instance, by changing or removing context lines, or by introducing formatting errors—the <i>patch</i> command may fail to apply it correctly. <br><br><i>rediff</i> addresses this issue by comparing the original source and target files (or their versions) with the potentially corrupted diff. It then attempts to recreate a valid unified or context diff that accurately represents the changes between the original files while incorporating the modifications specified in the edited diff. This process essentially re-generates the necessary context surrounding the changes, ensuring that the patch can be applied cleanly. It's particularly useful in scenarios where a patch needs minor adjustments but its apply-ability must be maintained.


title: CAVEATS
content:
<i>rediff</i> is designed to fix common issues in hand-edited diffs, but it may not be able to perfectly reconstruct all diffs, especially if the original changes were ambiguous or the hand-editing significantly altered the diff's fundamental structure beyond minor context or formatting issues. <br><br>It primarily works with unified or context diff formats. For complex patch management or version control, dedicated systems like <i>Git</i> or <i>SVN</i> offer more robust solutions.


title: <B>USAGE EXAMPLE</B>
content:
To fix a hand-edited unified diff file named <i>edited.diff</i>, which was originally generated between <i>original_file_a.txt</i> and <i>original_file_b.txt</i>, and save the corrected diff to <i>fixed.diff</i>:<br><br><b>rediff original_file_a.txt original_file_b.txt edited.diff > fixed.diff</b><br><br>This command will attempt to regenerate the diff, restoring correct context and formatting, making <i>fixed.diff</i> suitable for input to <i>patch(1)</i>.


title: HISTORY
content:
<i>rediff</i> is a component of the <i>GNU Diffutils</i> package, a suite of essential tools for comparing and merging files on Unix-like operating systems. The lineage of these tools, including <i>diff</i> and <i>patch</i>, traces back to the earliest versions of AT&T Unix. <br><br>While <i>diff</i> generates differences and <i>patch</i> applies them, <i>rediff</i> emerged to address a practical problem: the occasional need to manually adjust a diff script (e.g., to remove a specific change or correct a typo) without rendering it unusable by <i>patch</i>. Its development underscores the importance of maintaining patch integrity within software development and sharing workflows, particularly in environments where patches were frequently exchanged as email attachments or simple text files.


title: SYNOPSIS
content:
<b>redis-benchmark</b> [-h <i>host</i>] [-p <i>port</i>] [-s <i>socket</i>] [-a <i>password</i>] [-c <i>clients</i>] [-n <i>requests</i>] [-d <i>size</i>] [-P <i>numreq</i>] [-t <i>tests</i>] [<i>OPTIONS</i>]


title: PARAMETERS
content:
<b>-h <host></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Server hostname to connect to (default: 127.0.0.1).<br><br><b>-p <port></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Server port to connect to (default: 6379).<br><br><b>-s <socket></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Server socket path for Unix domain sockets (overrides host and port).<br><br><b>-a <password></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Password for Redis authentication.<br><br><b>-u <uri></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to Redis using a URI string (e.g., redis://user:pass@host:port/db).<br><br><b>-c <clients></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Number of parallel connections (clients) to open during the benchmark (default: 50).<br><br><b>-n <requests></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Total number of requests to execute across all clients (default: 100000).<br><br><b>-d <size></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Data size of SET/GET values in bytes (default: 3).<br><br><b>-P <numreq></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pipeline <i>numreq</i> requests. If 0, don't pipeline (default: 1).<br><br><b>-t <tests></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Comma-separated list of specific tests/commands to run (e.g., ping,set,get,lpush).<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode; only show requests per second (RPS) values.<br><br><b>-N <requests></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip N requests to pre-populate the dataset before starting the actual benchmark.<br><br><b>-csv</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output results in CSV format.<br><br><b>--json</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output results in JSON format (available in newer Redis versions).<br><br><b>--show-latency-dist</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a detailed latency distribution graph at the end of the benchmark.<br><br><b>--cluster</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable cluster mode for testing Redis Cluster instances.<br><br>


title: DESCRIPTION
content:
<i>redis-benchmark</i> is a command-line utility included with Redis that simulates client connections to a Redis server to measure its performance. It can test various Redis commands like <b>PING</b>, <b>SET</b>, <b>GET</b>, <b>LPUSH</b>, <b>LPOP</b>, etc., under different load conditions. Users can configure the number of concurrent clients, total requests, data size, and pipelining.<br><br>The tool outputs critical metrics such as requests per second (throughput), latency (minimum, maximum, average, and percentiles), and error rates. It is an invaluable tool for understanding how a Redis instance behaves under specific workloads and for identifying potential bottlenecks or validating optimizations.


title: CAVEATS
content:
<i>redis-benchmark</i> runs on the client machine, so network latency and the client machine's resources (CPU, memory, network I/O) can significantly influence results. It is best to run it from a machine with good network proximity to the Redis server and sufficient available resources to avoid skewing the measurements.<br><br>The benchmark simulates synthetic workloads. Real-world application patterns might involve more complex command sequences, specific data structures, or transaction logic that <i>redis-benchmark</i> does not fully replicate. Options like <b>--show-latency-dist</b> or <b>--latency-history</b> can consume significant memory and CPU on the client, potentially impacting high-throughput benchmarks.


title: BENCHMARKING STRATEGY
content:
It's recommended to run benchmarks multiple times and average the results to account for transient system variations. Vary parameters such as client connections (<b>-c</b>), total requests (<b>-n</b>), and data size (<b>-d</b>) to understand performance characteristics across different scales and identify potential bottlenecks under specific load profiles.


title: IMPACT OF PIPELINING
content:
Using the <b>-P</b> option for pipelining significantly impacts observed throughput. Pipelining allows sending multiple commands to the server without waiting for individual replies, which dramatically reduces the impact of network round-trip time (RTT). This showcases Redis's ability to process commands efficiently in high-latency network environments or when dealing with a large number of concurrent operations.


title: HISTORY
content:
<i>redis-benchmark</i> has been a standard utility distributed with Redis since its early versions. It has continuously evolved alongside the Redis server, adding support for new features such as pipelining, authentication, TLS encryption, and Redis Cluster. Its primary design goal remains to provide a simple, quick, and effective way to assess Redis performance under various synthetic loads.


title: PARAMETERS
content:
<b><b>-h</b> <i><hostname></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the specified Redis server hostname (default: 127.0.0.1).<br><br><b><b>-p</b> <i><port></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the specified Redis server port (default: 6379).<br><br><b><b>-a</b> <i><password></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Authenticate to the Redis server using the provided password.<br><br><b><b>-s</b> <i><socket></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Connect to the Redis server using the specified Unix domain socket path.<br><br><b><b>-n</b> <i><dbnum></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select the specified Redis database number (default: 0).<br><br><b><b>--raw</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output raw Redis replies, useful for scripting as it avoids pretty-printing.<br><br><b><b>--no-raw</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output formatted and pretty-printed replies (default behavior).<br><br><b><b>-r</b> <i><count></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Repeat the specified command <i><count></i> times.<br><br><b><b>-i</b> <i><interval></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;When repeating commands, wait <i><interval></i> seconds between executions. Useful with <b>-r</b>.<br><br><b><b>--latency</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run a latency test, continuously pinging the server and showing statistics.<br><br><b><b>--stat</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print Redis server statistics continuously in an ASCII art style.<br><br><b><b>--bigkeys</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan the database for keys that are very large (in terms of elements or bytes).<br><br><b><b>--hotkeys</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Discover keys that are frequently accessed by the server.<br><br><b><b>--memkeys</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Analyze memory usage per key pattern (requires Redis 4.0+).<br><br><b><b>--pipe</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read Redis commands from standard input and send them to the server in a pipelined fashion for efficiency.<br><br><b><b>--scan</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan the database for keys matching a given pattern, similar to the <i>SCAN</i> command.<br><br>


title: DESCRIPTION
content:
The `redis-cli` command is a powerful and versatile command-line utility for Redis, the open-source, in-memory data structure store. It allows users to interact directly with a Redis server by sending Redis commands and receiving replies. This tool is essential for administering Redis instances, debugging applications, monitoring performance, and executing ad-hoc data operations. It supports various connection methods, including TCP/IP and Unix domain sockets, and offers a range of specialized modes like latency monitoring, statistical reporting, and key analysis (`--bigkeys`, `--hotkeys`, `--memkeys`). `redis-cli` can operate in interactive mode, where users type commands one by one, or non-interactive mode, where commands are passed as arguments or piped from standard input, making it suitable for scripting and automation.


title: CAVEATS
content:
Connecting to a remote Redis server without TLS encryption can expose sensitive data and credentials to network eavesdropping. Always use strong passwords and consider IP whitelisting or TLS for production environments. Some `redis-cli` features, like `--hotkeys` or `--memkeys`, require specific Redis server versions (e.g., 4.0+). Extensive use of `--bigkeys` or `--scan` on large databases can be resource-intensive on both the client and server.


title: INTERACTIVE VS. NON-INTERACTIVE MODE
content:
When `redis-cli` is invoked without a command argument, it enters an interactive mode, prompting the user to type Redis commands. This is ideal for exploratory work or debugging. When a command and its arguments are provided directly on the command line (e.g., `redis-cli GET mykey`), it operates in a non-interactive mode, executing the command and exiting. This mode is suitable for scripting.


title: SPECIAL MODES AND TOOLS
content:
Beyond basic command execution, `redis-cli` offers several specialized modes. The <i>latency</i> mode helps diagnose network or server processing delays. <i>Stat</i> mode provides a live dashboard of server metrics. Tools like <i>bigkeys</i>, <i>hotkeys</i>, and <i>memkeys</i> are invaluable for database analysis and optimization, helping administrators identify and address performance bottlenecks related to data structure size or access patterns.


title: TLS/SSL SUPPORT
content:
For secure connections, `redis-cli` supports TLS/SSL. Options like <b>--tls</b>, <b>--cacert</b>, <b>--cert</b>, and <b>--key</b> allow it to connect to Redis servers configured with TLS encryption, ensuring data privacy and integrity over the network.


title: HISTORY
content:
`redis-cli` has been an integral part of the Redis distribution since its early days. It evolved alongside Redis itself, gaining new features to support Redis's growing capabilities, such as Redis Cluster commands, TLS support, and various analytical tools (`--bigkeys`, `--hotkeys`, `--memkeys`). Its development reflects the pragmatic and performance-oriented philosophy of the Redis project, providing a robust and efficient way to interact with the database.


title: PARAMETERS
content:
<b><i>&lt;config_file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the Redis configuration file. Options provided on the command line will override settings in this file.<br><br><b><b>--port</b> <i>&lt;port_number&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the TCP port on which Redis will listen for connections. Default is 6379.<br><br><b><b>--daemonize</b> <i>&lt;yes|no&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If set to 'yes', Redis will run as a background process (daemon). Default is 'no'.<br><br><b><b>--loglevel</b> <i>&lt;debug|verbose|notice|warning&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls the verbosity of Redis logs. 'notice' is the default and recommended for production.<br><br><b><b>--bind</b> <i>&lt;address&gt;</i> [<i>&lt;address&gt;</i>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Binds Redis to specific IP addresses. By default, it binds to all available network interfaces if `protected-mode` is disabled, or to 127.0.0.1 if enabled.<br><br><b><b>--protected-mode</b> <i>&lt;yes|no&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables protected mode. When enabled, Redis only accepts connections from localhost or via the `bind` directive unless a password is set.<br><br><b><b>--dir</b> <i>&lt;directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the working directory where Redis will save RDB snapshot files and AOF log files.<br><br><b><b>--dbfilename</b> <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the RDB snapshot file. Default is dump.rdb.<br><br><b><b>--requirepass</b> <i>&lt;password&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a password for client authentication. Clients must use the AUTH command to connect.<br><br><b><b>--maxmemory</b> <i>&lt;bytes&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures the maximum amount of memory Redis should use. When the limit is reached, Redis will start evicting keys based on the `maxmemory-policy`.<br><br><b><b>--slaveof</b> <i>&lt;masterip&gt;</i> <i>&lt;masterport&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures this Redis instance to be a replica (slave) of another Redis server (master).<br><br><b><b>--sentinel</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs Redis in Sentinel mode, used for high availability to monitor master and replica instances.<br><br><b><b>--cluster-enabled</b> <i>&lt;yes|no&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables or disables Redis Cluster support for sharding data across multiple instances.<br><br>


title: DESCRIPTION
content:
The `redis-server` command initiates the Redis server, an open-source, in-memory data structure store used as a database, cache, and message broker. Redis supports various data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, and geospatial indexes with radius queries. <br><br>When executed, `redis-server` listens for incoming client connections, typically on port 6379, enabling applications to store, retrieve, and manipulate data. It can run in the foreground, displaying logs to the console, or daemonized in the background. While primarily an in-memory database for high performance, Redis offers persistence options (RDB snapshots and AOF logs) to ensure data durability across server restarts. <br><br>The server's behavior is highly configurable via command-line arguments or, more commonly, through a `redis.conf` configuration file.


title: CAVEATS
content:
<b>Security:</b><br>By default, Redis 6+ runs with `protected-mode` enabled, binding only to localhost (127.0.0.1) unless specified otherwise. If `protected-mode` is disabled or Redis is bound to all interfaces (0.0.0.0) without a strong password, it can be vulnerable to unauthorized access.<br><br><b>Persistence:</b><br>While Redis is an in-memory store, it offers persistence. If persistence (RDB or AOF) is not properly configured, data stored in Redis may be lost upon server restart or crash.<br><br><b>Memory Usage:</b><br>Redis stores data primarily in RAM. Large datasets can consume significant memory, potentially impacting system stability if not managed via `maxmemory` settings.


title: CONFIGURATION FILE
content:
The most common way to configure `redis-server` is by providing a `redis.conf` file as an argument. This file contains detailed settings for persistence, memory limits, logging, security, and more. Command-line options override settings in the configuration file, allowing for quick adjustments or specific instance configurations.


title: PERSISTENCE
content:
Redis offers two primary methods for data persistence: <b>RDB</b> (Redis Database) snapshots, which are point-in-time compressed binary files of the dataset, and <b>AOF</b> (Append Only File), which logs every write operation received by the server. Users can configure Redis to use one or both, balancing performance with data durability requirements.


title: SERVICE MANAGEMENT
content:
In production environments, `redis-server` is typically run as a background daemon and managed via a system service manager like <i>systemd</i> (`systemctl`). This ensures Redis starts automatically on boot, can be easily started/stopped, and its processes are monitored for stability.


title: HISTORY
content:
Redis was created by <i>Salvatore Sanfilippo</i> (also known as antirez) in 2009. Initially developed to improve the scalability of his startup's real-time web analytics service, Redis quickly gained popularity as a standalone open-source project. Its unique combination of performance, versatility, and rich data structures led to its widespread adoption across various industries. Over the years, it has evolved significantly, adding features like replication, persistence, clustering, and high availability (Sentinel), becoming one of the most widely used NoSQL databases and caching solutions. While Salvatore stepped down as the lead developer in 2020, development continues under the stewardship of Redis Inc. and the broader community.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><b>-V</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about operations.<br><br><b><b>-O</b> <i>TEMP</i>, <b>--one-shot</b> <i>TEMP</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color temperature to <i>TEMP</i> (in Kelvin) once and then exits. Useful for quick manual adjustments.<br><br><b><b>-x</b>, <b>--print</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the current color temperature to standard output and exits.<br><br><b><b>-l</b> <i>LAT:LON</i>, <b>--location</b> <i>LAT:LON</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manually sets the geographical location using latitude and longitude (e.g., 59.9:10.8). This overrides location providers.<br><br><b><b>-l</b> <i>PROVIDER</i>, <b>--location-provider</b> <i>PROVIDER</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the location provider to use (e.g., <i>geoclue2</i>, <i>manual</i>). Default is usually <i>geoclue2</i> if available.<br><br><b><b>-t</b> <i>DAY:NIGHT</i>, <b>--temperature</b> <i>DAY:NIGHT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the color temperatures for day and night in Kelvin (e.g., 6500:3700). 6500K is standard daylight, lower values are warmer.<br><br><b><b>-b</b> <i>DAY:NIGHT</i>, <b>--brightness</b> <i>DAY:NIGHT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the brightness for day and night (e.g., 1.0:0.8). Value 1.0 means no change. Note: this applies a gamma adjustment, not true backlight control.<br><br><b><b>-g</b> <i>R:G:B</i>, <b>--gamma</b> <i>R:G:B</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets gamma correction for red, green, and blue channels (e.g., 0.8:0.9:1.0). Can be used to fine-tune colors.<br><br><b><b>-m</b> <i>METHOD</i>, <b>--method</b> <i>METHOD</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the method for setting color temperature. Common methods include <i>randr</i> (X11), <i>vidmode</i> (older X11), or <i>wayland</i>.<br><br>


title: DESCRIPTION
content:
<b>redshift</b> is a program that adjusts the color temperature of your screen according to your surroundings. This helps to reduce eye strain and improve sleep quality by reducing the amount of blue light emitted by your display during evening and night hours.<br><br>The program takes your geographical location into account to determine the time of day and automatically transitions the screen's color temperature from a daylight setting to a warmer, redder tone as sunset approaches and through the night. It can run continuously in the background, applying smooth transitions. Users have extensive control over configuration, including specifying manual color temperatures, location coordinates, and various brightness/gamma settings, making it a highly customizable tool for eye comfort.


title: CAVEATS
content:
<b>redshift</b>'s ability to adjust brightness and gamma might be limited by your display driver or desktop environment. On some Wayland compositors, direct color temperature adjustment might not be fully supported or require specific configuration. Users might experience flickering or unexpected behavior if the display method or driver interactions are not harmonious. Ensure location services like Geoclue are properly set up if using automatic location detection.


title: CONFIGURATION FILE
content:
For persistent settings and more advanced options, <b>redshift</b> reads from a configuration file, typically located at <i>~/.config/redshift/redshift.conf</i>. This file allows users to define default temperatures, brightness levels, location providers, and even specific settings per screen or monitor, without needing to pass numerous command-line arguments each time <b>redshift</b> is launched.


title: DAEMON MODE AND AUTOSTART
content:
By default, when run without the <b>--one-shot</b> option, <b>redshift</b> operates as a daemon, continuously monitoring the time of day and smoothly transitioning the screen's color temperature. For automatic operation upon system startup, it is common practice to add <b>redshift</b> to a desktop environment's autostart applications or run it as a systemd user service.


title: HISTORY
content:
Inspired by proprietary applications like <i>f.lux</i>, <b>redshift</b> was developed by Jon Lund Steffensen, with initial public releases appearing around 2009-2010. Its aim was to provide a free and open-source solution for adjusting screen color temperature on Linux and BSD systems. Over the years, it has evolved to support various display environments, including X11 (via RandR and Vidmode) and more recently Wayland, adapting to the changing Linux graphics stack and striving for wider compatibility.


title: SYNOPSIS
content:
<i>refer</i> [ <b>-a</b> ] [ <b>-b</b> ] [ <b>-c</b> <i>fields</i> ] [ <b>-e</b> ] [ <b>-i</b> <i>file</i> ] [ <b>-k</b> <i>keys</i> ] [ <b>-l</b> <i>num</i> ] [ <b>-n</b> ] [ <b>-o</b> ] [ <b>-p</b> <i>file</i> ] [ <b>-s</b> <i>keys</i> ] [ <b>-t</b> ] [ <b>-x</b> ] [ <b>-L</b> ] [ <b>-m</b> <i>macro</i> ] [ <i>file ...</i> ]


title: PARAMETERS
content:
<b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reverses the order of citations in the output.<br><br><b><b>-b</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not include references cited only by <i>.</i>[, <i>.</i>] if the input document does not contain explicit <i>.</i>[, <i>.</i>] lines.<br><br><b><b>-c</b> <i>fields</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Capitalizes the specified <i>fields</i> (e.g., <i>T</i> for title) in the references.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets global numbering for references across all files.<br><br><b><b>-i</b> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an additional <i>file</i> to be searched for references. Can be used multiple times.<br><br><b><b>-k</b> <i>keys</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the output references based on the specified <i>keys</i> (e.g., <i>AD</i> for author-date).<br><br><b><b>-l</b> <i>num</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses <i>et al.</i> after <i>num</i> authors in the formatted reference.<br><br><b><b>-n</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Does not number the references in the bibliography.<br><br><b><b>-o</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs a list of undefined references at the end of the run.<br><br><b><b>-p</b> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a primary reference <i>file</i> to search. This file is searched before the default libraries.<br><br><b><b>-s</b> <i>keys</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the bibliography list by the specified <i>keys</i>.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses warning messages for unresolved references.<br><br><b><b>-x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses warning messages for unknown items in reference files.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Searches standard system reference libraries for matching entries.<br><br><b><b>-m</b> <i>macro</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a <i>macro</i> package (e.g., <i>ms</i>, <i>me</i>) to be used for formatting.<br><br>


title: DESCRIPTION
content:
The <i>refer</i> command is a preprocessor for <i>roff</i> document formatting systems like <i>groff</i>, <i>troff</i>, and <i>nroff</i>. It automates the inclusion and formatting of bibliographic citations and reference lists within a document. Users embed citations within their text using special macros (typically <i>.</i>[ and <i>.</i>]). <i>refer</i> reads these documents, searches designated bibliography files for the corresponding references, and then formats them according to specified styles or defaults. The output is a new document stream with formatted citations and a generated bibliography, which can then be piped to a <i>roff</i> formatter for final presentation. It's an essential tool for generating academic and technical papers in the <i>roff</i> ecosystem, handling tasks like numbering, sorting, and author-date formatting.


title: CAVEATS
content:
<i>refer</i> is tightly integrated with the <i>roff</i> suite and requires understanding of <i>roff</i> document structure and macro packages. Bibliography files must adhere to a specific flat-file database format with tagged fields (e.g., %A for author, %T for title). Its capabilities are less flexible than modern bibliographic management systems (like BibTeX or Zotero) and it is primarily used in environments where <i>roff</i> is the preferred text processing tool.


title: BIBLIOGRAPHY FILE FORMAT
content:
<i>refer</i> expects bibliography files to be plain text, with each reference entry separated by a blank line. Within each entry, fields are tagged with a percent sign (<i>%</i>) followed by a single uppercase letter, indicating the field type (e.g., <i>%A</i> for Author, <i>%T</i> for Title, <i>%D</i> for Date, <i>%J</i> for Journal, <i>%K</i> for Keywords).<br><br><b>Example entry:</b><br><i>%A John Doe</i><br><i>%T A Study on Linux Commands</i><br><i>%J Journal of Unix Studies</i><br><i>%V 10</i><br><i>%N 2</i><br><i>%D 2023</i><br><i>%K Linux, Command, Refer</i>


title: CITATION SYNTAX IN DOCUMENT
content:
Citations within the main document are typically enclosed by the <i>roff</i> macros <i>.</i>[ and <i>.</i>]. The content between these macros can be keywords or authors used to match entries in the bibliography files.<br><br><b>Example citation in document:</b><br>This concept was explored by Doe (<i>.</i>[John Doe, 2023]).<br>Another important work discusses this topic (<i>.</i>[A Study on Linux Commands]).<br><br><i>refer</i> processes these to insert appropriate citations and build the bibliography list.


title: HISTORY
content:
<i>refer</i> originated as part of the powerful <i>troff</i> text processing system developed at Bell Labs, alongside `nroff`, `eqn`, `tbl`, and `pic`. It was designed to manage and format bibliographic citations for academic and technical publications, a critical need in early Unix computing environments. Its development reflects the strong emphasis on document preparation in the Unix philosophy, providing robust tools for complex tasks before the advent of modern word processors. It remains a core component of the GNU <i>roff</i> (<i>groff</i>) suite, maintaining compatibility with its legacy.


title: DESCRIPTION
content:
The command '<b>reflac</b>' does not appear to be a standard or commonly recognized Linux command within typical distributions or core utility packages. It is not found in common manual pages or command-line tool documentation. It is highly probable that '<b>reflac</b>' is either a typographical error for another command, a highly specialized tool specific to a particular system or project, a custom script, or a non-existent command. Without further context or specific package information, it is not possible to provide detailed functionality or usage instructions for a standard '<b>reflac</b>' command.


title: CAVEATS
content:
As '<b>reflac</b>' is not a standard Linux command, attempting to execute it on most systems will result in a 'command not found' error. Any information regarding its hypothetical functionality would be speculative. Users encountering this command in a specific environment should consult local documentation, system administrators, or the source of the software package that might include it.


title: VERIFICATION STATUS
content:
Extensive searches across common Linux manual page repositories, package databases (e.g., Debian, Red Hat, Arch Linux), and open-source project documentation consistently yield no results for a standard utility named '<b>reflac</b>'. This confirms its non-standard status.


title: HISTORY
content:
There is no documented history or development timeline for a standard '<b>reflac</b>' command within the Linux ecosystem or common open-source projects. This further supports the conclusion that it is not a widely distributed or recognized utility.


title: PARAMETERS
content:
<b>-c, --country <country></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters mirrors by specified country. Can be used multiple times for multiple countries. Use <b>--list-countries</b> for a full list.<br><br><b>-f, --fastest <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs only the specified number of fastest mirrors. Requires a speed test.<br><br><b>-l, --latest <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs only the specified number of most recently synchronized mirrors.<br><br><b>-p, --protocol <protocol></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters mirrors by protocol (e.g., http, https, ftp). Can be used multiple times.<br><br><b>-s, --sort <method></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the mirror list by the specified method. Common methods include <i>rate</i> (speed), <i>age</i> (last sync time), <i>score</i>, or <i>country</i>.<br><br><b>--save <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves the generated mirrorlist to the specified file. Typically used with <b>/etc/pacman.d/mirrorlist</b>.<br><br><b>--age <minutes></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters mirrors synchronized within the last specified number of minutes.<br><br><b>--list-countries</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all supported countries from the Arch Linux Mirror Status page.<br><br><b>--threads <number></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the number of parallel connections to use for mirror speed testing.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays more detailed output during execution, including mirror selection and sorting progress.<br><br>


title: DESCRIPTION
content:
<i>reflector</i> is a command-line utility for Arch Linux that retrieves the latest Pacman mirror list from the Arch Linux Mirror Status page, filters the results based on user-specified criteria, and then sorts them according to various metrics such as synchronization time, download speed, or country.<br><br>Its primary goal is to help users select fast and up-to-date mirrors, thereby significantly improving the download speeds for package updates and installations. Users can specify parameters like desired countries, preferred protocols (e.g., HTTPS), and the age of the last synchronization. After filtering, <i>reflector</i> can optionally test the speed of the remaining mirrors and output the results, often saved directly to the system's <b>/etc/pacman.d/mirrorlist</b> file, replacing the default or current list.


title: CAVEATS
content:
<i>reflector</i> requires an active internet connection to query the mirror status page and test mirror speeds. Over-reliance on sorting purely by 'fastest' might occasionally pick a mirror that is fast but unstable or temporarily overloaded. It's recommended to combine speed sorting with other criteria like 'latest' or 'country' for more reliable results.


title: TYPICAL USAGE
content:
A common way to use <i>reflector</i> is to update the <b>/etc/pacman.d/mirrorlist</b> file, often combined with a service or cron job for regular updates. For example: <br><code>sudo reflector --country 'United States' --protocol https --sort rate --save /etc/pacman.d/mirrorlist</code><br>This command fetches HTTPS mirrors from the United States, sorts them by speed, and saves the list.


title: MIRROR SCORE VS. SPEED
content:
The 'score' method sorts mirrors based on a metric provided by the Arch Linux Mirror Status page, which considers factors beyond just raw speed, potentially offering a more balanced selection. 'Rate' (speed) directly measures download speed during the execution of <i>reflector</i>.


title: HISTORY
content:
<i>reflector</i> was developed specifically for Arch Linux to address the challenge of maintaining an optimal <b>pacman</b> mirror list. Given Arch's rolling release nature and global user base, having a reliable and fast mirror is crucial for efficient system updates. It emerged as a practical solution to automate the process of finding and sorting mirrors, replacing manual editing or less sophisticated scripts.


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 version information and exits.<br><br><b>-i, --iso</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the currently active ISO 3166-1 alpha2 country code configured in the kernel.<br><br><b>-s, --source</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Indicates the source of the regulatory database being used (e.g., built-in kernel data, loaded from a userspace file).<br><br><b>-r, --raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the regulatory database in a raw, machine-readable format. This format is typically intended for parsing by other tools or scripts.<br><br><b>-p, --pretty</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the database in a human-readable, pretty-printed format. This is often the default output format for easier readability.<br><br><b>-a, --active</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps only the active regulatory rules that apply to the currently configured country, providing a concise view of current restrictions.<br><br><b>-c <country>, --country <country></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps regulatory rules for a specific 2-letter ISO 3166-1 alpha2 country code (e.g., 'US' for United States, 'DE' for Germany).<br><br><b>-f <file>, --file <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the contents of a specified regulatory database file instead of the kernel's currently active regulatory database.<br><br>


title: DESCRIPTION
content:
regdbdump is a utility designed to inspect the contents of the Linux kernel's wireless regulatory database. This crucial database holds rules governing the operation of wireless devices, such as Wi-Fi adapters, based on the current geographical location or country code.<br><br>It defines permitted frequency ranges, maximum transmission power levels, and allowed operational modes to ensure compliance with local and international regulations. The command allows users to view the entire database, rules for specific countries, or the currently active regulatory settings. This makes it an invaluable tool for debugging wireless connectivity issues related to regulatory restrictions, verifying proper regional configurations, or understanding wireless spectrum usage. It's commonly used by developers, system administrators, and advanced users involved in wireless networking.


title: CAVEATS
content:
The output of `regdbdump` can be very extensive, especially when dumping the entire database without specifying a country. Users should be aware that `regdbdump` is a diagnostic tool; it only reads and displays the regulatory database state and does not modify it. Changes to the regulatory domain are typically managed by tools like `iw` or `crda`. Interpreting the raw output (`-r` option) requires an understanding of the regulatory database file format.


title: REGULATORY DOMAIN
content:
Wireless devices must operate within specific frequency ranges and power limits as mandated by regulatory bodies in different countries. The Linux kernel maintains a regulatory database to enforce these rules, preventing interference and ensuring legal operation.


title: KERNEL INTEGRATION
content:
The wireless subsystem within the Linux kernel (primarily `mac80211` and `cfg80211`) relies on information provided by `crda` (which itself utilizes the `regdb` database) to ensure that Wi-Fi adapters and other wireless devices adhere to the local regulatory requirements of the active domain.


title: DATABASE FORMAT
content:
The regulatory database files, typically located in `/lib/crda/`, are stored in a binary format. `regdbdump` possesses the capability to parse this binary format and present its contents in either a raw or a more human-readable, pretty-printed form.


title: HISTORY
content:
`regdbdump` is an integral part of the `crda` (Central Regulatory Domain Agent) project. This project was developed to standardize and manage the Linux kernel's wireless regulatory domain settings. Before `crda`, wireless drivers often contained hardcoded regulatory information, which led to inconsistencies and challenges in complying with diverse international regulations. The introduction of `crda` and its accompanying utilities, including `regdbdump`, established a unified and flexible mechanism for dynamically applying regulatory rules based on the system's geographical location, thereby ensuring legal and compliant wireless operation across various regions.


title: SYNOPSIS
content:
<b>reiserfsck</b> [<i>options</i>] <i>device</i><br><b>reiserfsck</b> [--check | --fix-fixable | --rebuild-tree | --rebuild-sb | --journal-reset] [<i>options</i>] <i>device</i>


title: PARAMETERS
content:
<b>-a, --auto-check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically fix fixable problems without asking for user confirmation.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force checking even if the file system is marked clean or mounted. Use with extreme caution.<br><br><b>-r, --rebuild-tree</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rebuild the entire file system tree from scratch. This is a drastic, potentially data-losing operation used for severely corrupted file systems.<br><br><b>-y</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume 'yes' to all questions asked by <i><b>reiserfsck</b></i>.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume 'no' to all questions asked by <i><b>reiserfsck</b></i>.<br><br><b>--check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a consistency check only; do not attempt to fix any errors found.<br><br><b>--fix-fixable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Fix problems that are not structural and are considered safe to correct automatically.<br><br><b>--journal-reset</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reset the file system journal. Use with caution as it can lead to data loss if the file system was not cleanly unmounted.<br><br><b>--rebuild-sb</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rebuild the superblock of the file system. Use when the superblock is corrupted.<br><br><b>--scan-devices</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scan all block devices for ReiserFS partitions. Requires root privileges.<br><br><b>--check-lost-found</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Check and clean up entries in the <i>lost+found</i> directory.<br><br><b>--clean-attributes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Cleans unknown or corrupted file system attributes.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a progress bar during the operation.<br><br><b>-j JOURNAL_DEVICE, --journal-dev JOURNAL_DEVICE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an external journal device if the ReiserFS file system uses one.<br><br><b>-o SB_OFFSET, --offset SB_OFFSET</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the offset to the superblock in cases where it's not at the default location.<br><br>


title: DESCRIPTION
content:
<i><b>reiserfsck</b></i> is a utility designed to check and repair ReiserFS file systems. It is an essential tool for maintaining the integrity of ReiserFS volumes, especially after an improper shutdown, power failure, or system crash. The command works by analyzing the file system's metadata, tree structure, and journal to detect and correct inconsistencies, lost blocks, and other errors that could lead to data corruption. It can be used in different modes, ranging from a simple check to an interactive repair process. While ReiserFS is less common in modern Linux distributions compared to ext4 or XFS, <i><b>reiserfsck</b></i> remains crucial for systems still utilizing this file system. It's generally recommended to unmount the file system before running <i><b>reiserfsck</b></i> to ensure data consistency and prevent further damage during the repair process.


title: CAVEATS
content:
<i><b>Always unmount the ReiserFS file system before running reiserfsck</b></i>, especially for repair operations. Running on a mounted file system can lead to severe data corruption and loss.<br>The <i><b>--rebuild-tree</b></i> option is a very destructive operation and should only be used as a last resort when the file system is heavily corrupted. It can result in significant data loss.<br>It's highly recommended to back up critical data before attempting any repair operation with <i><b>reiserfsck</b></i>.<br>ReiserFS is an older file system; consider migrating to a more modern and actively maintained file system like ext4 or XFS if possible, as development on ReiserFS has largely ceased.


title: EXIT CODES
content:
<i><b>reiserfsck</b></i> typically returns an exit code indicating the result of its operation:<br><i>0</i>: No errors found.<br><i>1</i>: File system errors corrected.<br><i>2</i>: File system errors, but system should be rebooted to fully apply corrections.<br><i>4</i>: File system errors uncorrected, requiring manual intervention.<br><i>8</i>: Operational error during <i><b>reiserfsck</b></i> execution.


title: USAGE CONTEXT
content:
<i><b>reiserfsck</b></i> is often run automatically by the generic <i><b>fsck</b></i> utility at boot time if a ReiserFS partition is detected and marked as 'dirty' (e.g., after an unclean shutdown). It can also be invoked manually for proactive checks or emergency repairs on unmounted ReiserFS volumes.


title: HISTORY
content:
ReiserFS was developed by Hans Reiser and his company Namesys, first released in 2001. It was notable for being the first journaling file system to be included in the Linux kernel mainline. <i><b>reiserfsck</b></i> is the accompanying utility for checking and repairing ReiserFS file systems.<br>While initially gaining some popularity, its adoption waned, particularly after the development of ext3/ext4 and XFS, and due to the legal issues involving Hans Reiser. Development on ReiserFS largely ceased, making <i><b>reiserfsck</b></i> an older tool for a legacy file system, though still essential for those systems that continue to use ReiserFS.


title: PARAMETERS
content:
<b><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The special file (e.g., /dev/sdb1) corresponding to the ReiserFS filesystem to be tuned.<br><br><b>-j <i>journal_size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the journal size in blocks. Larger journals can improve performance and recovery but consume more space. Must be within the allowed range (e.g., 512-32768 blocks).<br><br><b>-o [<b>+</b>|<b>-</b>]<i>option</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Modifies default mount options stored in the superblock. For example, <b>+notail</b> enables tail packing, while <b>-notail</b> disables it. Other options may include <b>no_unhashed_relocation</b> or <b>unhashed_relocation</b>.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current tunable parameters of the specified ReiserFS filesystem without making any changes.<br><br><b>-t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a test run. It will show what would be done without actually committing any changes to the filesystem.<br><br><b>-b <i>block_size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Rarely used after mkfs) Attempts to change the filesystem block size. This is a highly dangerous operation and can lead to data loss if not handled correctly. Block size is usually set during filesystem creation with <i>mkfs.reiserfs</i>.<br><br><b>-f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the operation, overriding some safety checks. Use with extreme caution as it can increase the risk of data loss.<br><br><b>-q</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs quietly, suppressing most output.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of <i>reiserfstune</i>.<br><br>


title: DESCRIPTION
content:
<i>reiserfstune</i> is a utility from the <i>reiserfsprogs</i> package designed to modify various tunable parameters of an <b>unmounted</b> ReiserFS filesystem. It allows administrators to adjust characteristics like the journal size, block allocation policies, and default mount options stored within the filesystem's superblock. This tool is primarily used for performance optimization or to alter default behaviors, such as enabling or disabling the 'notail' feature, which affects how small files are stored. It is crucial that the filesystem targeted by <i>reiserfstune</i> be <b>unmounted</b> before any operations are performed, as modifying an active filesystem can lead to data corruption. The changes made by <i>reiserfstune</i> are persistent and stored in the filesystem's metadata, affecting future mounts.


title: CAVEATS
content:
<b>Filesystem Must Be Unmounted:</b> It is absolutely critical that the ReiserFS filesystem targeted by <i>reiserfstune</i> is unmounted before executing the command. Operating on a mounted filesystem can lead to severe data corruption and loss.<br><br><b>Risk of Data Loss:</b> Incorrect usage, especially with options like <i>-b</i> (block size change) or <i>-f</i> (force), can result in irreversible data loss. Always back up critical data before making significant changes.<br><br><b>Deprecated Status:</b> ReiserFS itself is largely considered a legacy filesystem and is not actively developed or widely recommended for new deployments. Its tooling, including <i>reiserfstune</i>, reflects this status.


title: DISPLAYING CURRENT SETTINGS
content:
To view the current tunable parameters of a ReiserFS filesystem without making any changes, use the <i>-s</i> option (e.g., <i>reiserfstune -s /dev/sdb1</i>). This is a safe way to inspect the filesystem's configuration before attempting any modifications.


title: PERFORMANCE IMPLICATIONS
content:
Adjusting parameters like journal size (<i>-j</i>) can significantly impact filesystem performance. A larger journal can reduce the frequency of metadata writes to disk and improve recovery times after crashes, but it consumes more disk space. Similarly, the <i>notail</i> option affects how small files are stored; enabling it can improve performance for workloads with many small files, while disabling it might be better for systems with large files and fewer small ones, potentially at the cost of disk space efficiency for tiny files.


title: HISTORY
content:
The <i>reiserfstune</i> utility is an integral part of the <i>reiserfsprogs</i> suite, which was developed by Hans Reiser and his company Namesys. ReiserFS was a prominent journaling filesystem in the early 2000s, offering features like tail packing and efficient handling of small files that were innovative for its time. <i>reiserfstune</i> was created as a companion tool to allow administrators to fine-tune these features post-creation. Its development paralleled the evolution of the ReiserFS filesystem itself. While ReiserFS saw significant adoption in its heyday, its usage has declined considerably over the years, largely due to the rise of more modern and actively maintained filesystems like ext4, XFS, and Btrfs, as well as the legal issues surrounding its creator. Consequently, <i>reiserfstune</i> is now primarily encountered in environments managing older ReiserFS installations.


title: SYNOPSIS
content:
<I>rekor-cli</I> [<b>global options</b>] &lt;<b>command</b>&gt; [<b>command options</b>] [arguments]<br><br>Common usage examples:<br> &nbsp; <b>rekor-cli</b> <b>search</b> <b>--artifact-hash</b> &lt;I>sha256-hash</I>&gt;<br> &nbsp; <b>rekor-cli</b> <b>upload</b> <b>--artifact</b> &lt;I>path/to/artifact</I>&gt; <b>--signature</b> &lt;I>path/to/signature</I>&gt; <b>--public-key</b> &lt;I>path/to/publickey</I>&gt;<br> &nbsp; <b>rekor-cli</b> <b>get</b> <b>--uuid</b> &lt;I>entry-uuid</I>&gt;


title: PARAMETERS
content:
<b><b>--rekor-server</b> <I>URL</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Rekor server URL to interact with. If omitted, the default public Rekor instance is used.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the command or any subcommand.<br><br><b><b>--log-level</b> <I>level</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging verbosity level (e.g., <I>debug</I>, <I>info</I>, <I>warn</I>, <I>error</I>).<br><br><b><b>--artifact</b> <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>upload</I>, <I>verify</I>) Path to the software artifact (e.g., binary, container image) to be processed.<br><br><b><b>--signature</b> <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>upload</I>, <I>verify</I>) Path to the digital signature associated with the artifact.<br><br><b><b>--public-key</b> <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>upload</I>, <I>verify</I>, <I>search</I>) Path to the public key used for signing or to search for entries signed by a specific key.<br><br><b><b>--hash</b> <I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>search</I>) Specifies the cryptographic hash of the artifact to search for in the log.<br><br><b><b>--email</b> <I>address</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>search</I>) Searches for log entries associated with a specific signer's email address.<br><br><b><b>--uuid</b> <I>UUID</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>get</I>, <I>search</I>) Specifies the unique identifier of a Rekor entry to retrieve or search for.<br><br><b><b>--type</b> <I>artifact-type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Used with <I>upload</I>, <I>verify</I>) Defines the type of artifact being uploaded or verified (e.g., <I>dsse</I>, <I>oci</I>, <I>rpm</I>, <I>alpine</I>, <I>go.mod</I>, <I>jar</I>, <I>helm.prov</I>).<br><br>


title: DESCRIPTION
content:
rekor-cli is the command-line interface for <I>Rekor</I>, a critical component of the <I>Sigstore</I> project. Rekor provides an immutable, tamper-proof transparency log for software supply chain metadata. This tool enables users to record software artifacts (such as signed container images, binaries, and build materials) into the public Rekor log, making them verifiable and auditable by anyone. It supports various operations including uploading diverse artifact types, searching for entries using criteria like artifact hash, public key, or email, retrieving specific log entries by UUID, and verifying an artifact's presence and integrity in the log. rekor-cli significantly enhances software supply chain security by offering a transparent and verifiable record of artifact signing events.


title: CAVEATS
content:
rekor-cli requires network connectivity to interact with a Rekor server. The Rekor log is an append-only transparency log; entries, once added, cannot be modified or removed, ensuring immutability and auditability. Users should be aware of the specific artifact types and their associated signing mechanisms to ensure correct upload and verification workflows. Compatibility between the rekor-cli client and the Rekor server API is important for seamless operation.


title: REKOR TRANSPARENCY LOG
content:
The Rekor log is built on a cryptographically verifiable <I>Merkle tree</I> structure. This design ensures that every entry added to the log is linked to its predecessors in a way that any tampering with past entries would invalidate the entire log, making it instantly detectable. This provides strong guarantees of integrity and immutability.


title: INTEGRATION WITH SIGSTORE TOOLS
content:
rekor-cli works in concert with other Sigstore tools, most notably <I>cosign</I>. When <I>cosign</I> signs a container image or another artifact, it often automatically uploads the signature metadata and related information to Rekor. This seamless integration ensures that signing events are publicly recorded and easily auditable, fostering greater trust and transparency in software supply chains.


title: HISTORY
content:
rekor-cli is an integral part of the open-source Sigstore project, which was launched in late 2020 by the Linux Foundation, Google, Red Hat, and other key industry players. Sigstore was created to enhance software supply chain security through cryptographic signing and verifiable transparency logs. Rekor was introduced as the project's transparency log component, providing a public, verifiable record of signing events. rekor-cli was developed concurrently as the primary command-line interface to interact with this log, evolving to support an expanding array of artifact types and verification processes within the growing Sigstore ecosystem. Its development is community-driven and continues to be actively maintained.


title: SYNOPSIS
content:
<i>remove-default-ispell [dictionary_name]</i><br><br><b>Note:</b> This command is typically invoked automatically by package management scripts and rarely directly by users.


title: PARAMETERS
content:
<b><i>dictionary_name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) Specifies the name of the dictionary (e.g., 'en', 'fr') for which the default setting should be removed. When invoked by package scripts, this is often implicitly known or derived from the package.<br><br>


title: DESCRIPTION
content:
The <i>remove-default-ispell</i> command is a specialized utility primarily used within Debian-based Linux distributions to manage the default dictionary configuration for the <i>ispell</i> spell checker.<br><br>It is not typically invoked directly by end-users but rather as part of a package's maintenance scripts, specifically during the uninstallation or purging of <i>ispell</i> dictionary packages (e.g., <i>ispell-en</i>, <i>ispell-fr</i>). Its core function is to reverse the action of its counterpart, <i>make-default-ispell</i>, by removing the symbolic links or configuration entries that designate a particular iSpell dictionary as the system-wide default.<br><br>This process often involves interacting with the <i>update-alternatives</i> system, which manages multiple versions of commands or files by creating and updating symbolic links in standard directories. When <i>remove-default-ispell</i> is executed, it ensures that if the dictionary associated with the package being removed was set as the default, that default is properly unlinked or unset. This helps maintain system integrity and prevents <i>ispell</i> from attempting to use a dictionary that no longer exists.<br><br>After its execution, <i>ispell</i> might revert to an internal fallback or require explicit dictionary selection if no other dictionary has been set as the default.


title: CAVEATS
content:
This command is an internal script designed for package management, not a general-purpose user utility. Direct manual invocation is usually unnecessary and could lead to unexpected behavior if not understood in the context of <i>update-alternatives</i> and <i>ispell</i> package dependencies.<br><br>Its functionality is highly dependent on the <i>update-alternatives</i> system, primarily found on Debian and its derivatives (like Ubuntu).


title: INVOCATION CONTEXT
content:
The <i>remove-default-ispell</i> script is most frequently executed as part of a package's <i>prerm</i> (pre-removal) or <i>postrm</i> (post-removal) script during the <i>dpkg</i> or <i>apt</i> package uninstallation process. This ensures that the system's <i>ispell</i> default dictionary configuration is correctly adjusted when a dictionary package is removed.


title: HISTORY
content:
The <i>remove-default-ispell</i> script emerged as part of the Debian packaging efforts for <i>ispell</i> dictionaries. As different <i>ispell</i> dictionaries became available as separate packages (e.g., <i>ispell-english</i>, <i>ispell-french</i>), a mechanism was needed to allow users and system administrators to choose a default dictionary and to correctly handle its removal.<br><br>Its development is closely tied to the <i>update-alternatives</i> framework, which was introduced to manage symbolic links for commands and files that might have multiple implementations or versions installed on a system. The script's primary role has been to ensure proper cleanup and default configuration management during package uninstallation, preventing broken links or residual configurations.


title: DESCRIPTION
content:
The <b>remove-default-wordlist</b> command is a utility script primarily found in Kali Linux environments. Its main function is to permanently remove the large <b>rockyou.txt.gz</b> wordlist file, which is often pre-installed in <b>/usr/share/wordlists/</b>.<br><br>This command is particularly useful for users who need to conserve disk space, especially when running Kali Linux in a virtual machine with limited storage, or during live boot sessions where persistent storage is scarce. By executing this simple command, users can quickly free up several gigabytes of space occupied by this extensive wordlist.<br><br>It's part of a suite of wordlist management tools in Kali, designed to help security professionals manage their resources efficiently. While removing this wordlist saves space, users can re-download it using <b>install-wordlists</b> if needed for specific penetration testing or auditing tasks.


title: CAVEATS
content:
This command is specific to Kali Linux and may not be present or function identically on other distributions. It requires root privileges (or <b>sudo</b>) to execute successfully, as it modifies system-level files. Removing the <b>rockyou.txt.gz</b> wordlist means it will no longer be available locally for tools that rely on it, requiring re-download if needed later.


title: IMPACT
content:
Successfully running this command will delete the <b>/usr/share/wordlists/rockyou.txt.gz</b> file, freeing up several gigabytes of disk space.


title: HISTORY
content:
The <b>remove-default-wordlist</b> script emerged as a practical solution within the Kali Linux distribution to address disk space constraints, particularly relevant for live USB boots, minimal installations, and virtual machines. As the default <b>rockyou.txt.gz</b> wordlist grew in size, this utility became essential for users needing to optimize their storage. It reflects Kali Linux's ongoing efforts to provide flexible and resource-efficient tools for security professionals.


title: PARAMETERS
content:
<b><I>version</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Node.js version to be removed. This could be a full version string (e.g., <i>14.17.0</i>, <i>16.x</i>) or a major version (e.g., <i>14</i>, <i>16</i>), depending on the script's parsing logic. If the specified version is currently in use, the script might warn the user or fail unless a force option is provided.<br><br><b><B>--all</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional flag that, if implemented, would remove <B>all</B> Node.js versions currently installed and managed by the system or script. This is typically used for a complete cleanup.<br><br><b><B>-f</B>, <B>--force</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional flag to force the removal without prompting for confirmation, or to bypass checks that might prevent removal (e.g., if the version is currently active). Use with caution as it can lead to unintended data loss.<br><br><b><B>-h</B>, <B>--help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional flag to display a help message or usage information for the command.<br><br>


title: DESCRIPTION
content:
The command <i>remove-nodeversion</i> is <B>not a standard Linux utility</B> or a command provided by widely adopted Node.js version managers like nvm or n.<br><br>Instead, it is a <B>descriptive name for a hypothetical script or a custom alias</B> that would be designed to uninstall one or more specific versions of Node.js previously installed on a system. Its primary purpose, if it were to exist, would be to clean up disk space, manage Node.js environments, or remove deprecated/unwanted versions.<br><br>Typically, such a script would function by locating the installation directory of the specified Node.js version (e.g., within a user's home directory under a version manager's structure) and recursively deleting it. It might also attempt to clean up related symlinks or environment variables, depending on its sophistication.<br><br>Developers often use such removal mechanisms to maintain a tidy development environment, resolve version conflicts, or free up system resources after completing projects that required specific Node.js versions.


title: CAVEATS
content:
This command name (<i>remove-nodeversion</i>) is <B>not a standard, pre-installed Linux command</B> or part of any major Node.js version manager by this exact name. Its existence implies a <B>custom script, alias, or internal function</B> within a specific, less common Node.js management setup.<br><br>Therefore, its <B>exact syntax, options, and behavior are entirely dependent on its implementation</B> by the system administrator or developer who created it.<br><br>Users seeking to remove Node.js versions should typically consult the documentation for their specific Node.js version manager (e.g., nvm, n, Volta, fnm) as they provide their own, standardized uninstall commands.


title: TYPICAL IMPLEMENTATION CONTEXT
content:
If you encounter a `remove-nodeversion` command, it's most likely to be:<br><br>1.  A <B>shell script</B> (e.g., Bash, Zsh) written by a system administrator or developer to automate Node.js version cleanup in a specific environment.<br>2.  An <B>alias</B> defined in a shell configuration file (e.g., `.bashrc`, `.zshrc`) that points to a more complex command from a version manager (e.g., `alias remove-nodeversion='nvm uninstall'`).<br>3.  Part of a <B>less common or internal Node.js version management tool</B> not widely distributed.


title: ALTERNATIVE COMMANDS
content:
For standard Node.js version management, always refer to the specific tool you are using:<br><ul><li>For <B>nvm</B>: `nvm uninstall <I>version</I>`</li><li>For <B>n</B>: `n rm <I>version</I>`</li><li>For <B>Volta</B>: `volta uninstall node@<I>version</I>`</li><li>For <B>fnm</B>: `fnm uninstall <I>version</I>`</li></ul>


title: HISTORY
content:
The command name <i>remove-nodeversion</i> does <B>not have a documented history</B> as a standalone or widely adopted Linux utility. Instead, the concept of removing Node.js versions is integral to modern JavaScript/Node.js development workflows that often involve managing multiple Node.js versions concurrently.<br><br>Tools like <I>nvm</I> (Node Version Manager), <I>n</I>, <I>Volta</I>, and <I>fnm</I> emerged to address the need for easy switching and removal of Node.js versions. While these tools provide their own specific commands for uninstallation (e.g., `nvm uninstall <version>`, `n rm <version>`), the descriptive name `remove-nodeversion` might be adopted in custom scripts or aliases to simplify these operations for specific environments or users, reflecting a common desire for a straightforward removal mechanism.


title: PARAMETERS
content:
<b><I>username</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The login name of the user whose shell is to be disabled.<br><br>


title: DESCRIPTION
content:
The command "remove-shell" is <I>not a standard, universally available Linux command</I> found in most distributions. Instead, the operation of "removing" or disabling a user's login shell is typically performed by changing their assigned shell to a non-interactive one, such as <B>/sbin/nologin</B> or <B>/bin/false</B>.<br><br>A hypothetical "remove-shell" command would serve to prevent a specified user from logging in interactively via a shell. This is a common security practice for system accounts, service accounts, or temporarily locking out a user without deleting their account. By setting a user's shell to a program that immediately exits (like nologin), it ensures that direct shell access is denied while other services (e.g., mail, FTP if configured) associated with the user account might still function.<br><br>The primary method for achieving this in standard Linux environments is using the <B>chsh</B> (change shell) command or by directly editing the <B>/etc/passwd</B> file (though direct editing is discouraged for safety). Therefore, any "remove-shell" command encountered would likely be a custom script or utility specific to a particular system's administration practices.


title: CAVEATS
content:
This command is <I>not part of standard Linux utilities</I>. The functionality it describes is typically achieved via <B>chsh</B>.<br>Disabling a user's shell prevents <I>all</I> interactive logins for that user. Ensure this is the intended action, as it will affect SSH, console logins, etc.<br>It does not delete the user account or their home directory. It only restricts shell access.<br>Improper use, especially with administrative accounts, can lead to system lockout if not carefully managed.


title: ALTERNATIVE METHOD (STANDARD)
content:
The most common and recommended way to achieve the effect of 'removing' a user's shell is using the <B>chsh</B> command. For example:<br><code>chsh -s /sbin/nologin <I>username</I></code><br>This sets the user's shell to <B>/sbin/nologin</B>, which immediately exits upon login attempt, effectively disabling interactive access.


title: VERIFYING SHELL STATUS
content:
You can check a user's assigned shell using <B>getent passwd</B>:<br><code>getent passwd <I>username</I></code><br>The last field of the output will show the user's current shell.


title: HISTORY
content:
The concept of disabling a user's interactive shell access dates back to early Unix systems for managing service accounts or restricting login capabilities. While a specific "<B>remove-shell</B>" command is not historically standard, the underlying methods (modifying <B>/etc/passwd</B> or using utilities like <B>chsh</B>) have been integral to user management in Unix-like operating systems since their inception. The introduction of specific non-login shells like <B>/sbin/nologin</B> provided a standardized and robust way to achieve this security objective, evolving alongside user management tools.


title: SYNOPSIS
content:
<b>rename.ul</b> [<i>options</i>] <i>expression file</i>...<br>The <i>expression</i> is typically a Perl-compatible substitution expression like <b>s/<i>pattern</i>/<i>replacement</i>/[<i>flags</i>]</b>.


title: PARAMETERS
content:
<b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the names of files successfully renamed.<br><br><b><b>-n</b>, <b>--no-act</b>, <b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not make any changes; just print what would be renamed. This is highly recommended for testing expressions before actual execution.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrite existing destination files without prompting.<br><br><b><b>-i</b>, <b>--interactive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt before overwriting an existing destination file.<br><br><b><b>-k</b>, <b>--keep-basename</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not replace the directory path if it is part of the filename. Only the basename is subject to renaming.<br><br><b><b>-o</b>, <b>--no-overwrite</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not overwrite existing destination files. This is the default behavior if neither <b>-f</b> nor <b>-i</b> is specified.<br><br><b><b>-d</b>, <b>--dirs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate on directories, not just files. By default, 'rename.ul' only renames non-directory files.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br>


title: DESCRIPTION
content:
<i>rename.ul</i> is a powerful command-line utility for renaming multiple files or directories based on a regular expression. Unlike <b>mv</b> (which renames one file at a time or moves files), <i>rename.ul</i> allows you to apply a substitution rule across many files simultaneously, making it ideal for bulk renaming tasks. It uses Perl-compatible regular expressions (PCRE) for its renaming logic, typically in the format <b>s/<i>old</i>/<i>new</i>/</b>. This means you can define complex patterns to match parts of filenames and replace them with new content, including capturing groups and various regex modifiers. While incredibly versatile, its power also means it can cause significant, irreversible changes if used incorrectly. It's an essential tool for system administrators and power users needing advanced file manipulation capabilities. It is part of the <i>util-linux</i> project and often symlinked from the more generic <b>rename</b> command.


title: CAVEATS
content:
<br><b>1. Power and Risk:</b> <i>rename.ul</i> is extremely powerful due to its use of Perl regular expressions. Incorrectly formed expressions can lead to unintended renames, accidental overwrites, or even data loss. Always use the <b>-n</b> (<i>--no-act</i>) option to test your renaming expression before executing it.<br><br><b>2. <i>rename</i> Command Variations:</b> Be aware that there are multiple <b>rename</b> commands in Linux. The <i>rename.ul</i> command typically refers to the version included with the <i>util-linux</i> package, which is designed to be compatible with the Perl <i>rename</i> script syntax (<b>s/old/new/</b>). Other distributions or installations might have a different <b>rename</b> command (e.g., from Perl). Always consult the specific <b>man</b> page for the <b>rename</b> command you are using.<br><br><b>3. No Directory Creation:</b> <i>rename.ul</i> only renames existing files or directories; it does not create new directory structures as part of the rename process. For example, renaming <b>file.txt</b> to <b>newdir/file.txt</b> will fail if <b>newdir</b> does not exist.


title: THE <I>EXPRESSION</I> ARGUMENT
content:
The core of <i>rename.ul</i>'s power lies in the <i>expression</i> argument, which is typically a Perl-compatible substitution regular expression. This takes the form <b>s/<i>pattern</i>/<i>replacement</i>/[<i>flags</i>]</b>.<br><br><b><i>pattern</i></b>: This is a regular expression that defines what to search for within the filenames. It can include special characters, character classes, and capturing groups (e.g., <b>(<i>.*</i>)</b>).<br><b><i>replacement</i></b>: This is the string that will replace the matched <i>pattern</i>. It can include backreferences (e.g., <b><i>\1</i></b>, <b><i>\2</i></b>) to refer to the content captured by groups in the <i>pattern</i>.<br><b><i>flags</i></b> (<i>optional</i>): These are single-letter modifiers that change the behavior of the substitution. Common flags include:<br>  - <b>g</b>: Global replacement (replace all occurrences of the pattern, not just the first).<br>  - <b>i</b>: Case-insensitive matching.<br>  - <b>s</b>: Treat string as a single line (dot `.` matches newline).<br>  - <b>x</b>: Extended regex format (ignore whitespace in pattern, allow comments).<br><br><b>Example:</b> To rename all files ending with <b>.jpeg</b> to <b>.jpg</b>, you would use: <b>rename.ul</b> '<b>s/\.jpeg$/\.jpg/</b>' <i>*.jpeg</i>


title: SAFETY FIRST: ALWAYS USE <I>--NO-ACT</I>!
content:
Given the destructive potential of <i>rename.ul</i>, it is paramount to always test your commands using the <b>-n</b> or <b>--no-act</b> option first. This option performs a dry run, printing exactly what renames would occur without actually modifying any files. Only after verifying the output of the dry run matches your intent should you remove the <b>-n</b> option and execute the command for real. This simple step can prevent irreversible data loss or chaotic file organization.


title: HISTORY
content:
<b>rename</b> utility has a long and somewhat fragmented history in the Linux ecosystem. The most prominent version, whose syntax <i>rename.ul</i> largely replicates, originated as a Perl script written by Larry Wall (the creator of Perl) often referred to as <i>prename</i> or Perl <i>rename</i>. This script gained popularity for its powerful regular expression capabilities, far surpassing the simple renaming of <b>mv(1)</b>. The <i>util-linux</i> project, a collection of essential system utilities, later adopted its own implementation of <b>rename</b> that aims to be compatible with the Perl script's <b>s/old/new/</b> syntax. <i>rename.ul</i> is specifically the name given to this <i>util-linux</i> version, differentiating it from potentially other <b>rename</b> implementations on a system. Its development has focused on providing a robust, standard utility for bulk file renaming using advanced pattern matching.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message explaining command usage and options.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of the <b>rendercheck</b> utility.<br><br>


title: DESCRIPTION
content:
The <b>rendercheck</b> command is a diagnostic utility for the X Window System. Its primary purpose is to test and report on the capabilities of the X server's <i>RENDER extension</i>. This extension, introduced in X11, provides advanced graphics operations such as alpha blending, anti-aliasing, and compositing, which are crucial for modern desktop environments and applications. <br><br>When executed, <b>rendercheck</b> connects to the active X server and queries its RENDER extension version. It then systematically checks for support of various RENDER operations, including different pixel formats, picture formats, and geometric primitive rendering capabilities (e.g., trapezoids, triangles). The output typically lists each checked feature, indicating whether it is <i>SUPPORTED</i> or <i>UNSUPPORTED</i> by the server. <br><br>This tool is invaluable for debugging graphics issues, verifying that display drivers are correctly exposing RENDER functionality, or simply understanding the graphic capabilities of a specific X server setup. It helps ensure that applications requiring advanced rendering features can operate optimally.


title: CAVEATS
content:
<b>Diagnostic Only:</b> <b>rendercheck</b> merely reports capabilities; it does not resolve or fix underlying issues.<br><br><b>X Window System Specific:</b> This command is exclusively relevant to the X Window System and has no utility in environments using other display servers like Wayland.<br><br><b>RENDER Extension Required:</b> For meaningful results, the X server must have the RENDER extension enabled. If not, the output might indicate a complete lack of RENDER support.


title: OUTPUT INTERPRETATION
content:
The output of <b>rendercheck</b> provides a detailed list of RENDER features. Each entry typically shows a feature name followed by a status, such as 'SUPPORTED' or 'UNSUPPORTED'. 'SUPPORTED' indicates the X server and its drivers correctly implement that specific RENDER operation or pixel format. 'UNSUPPORTED' suggests a lack of implementation, a disabled feature, or a driver issue. Pay attention to features marked 'UNSUPPORTED' if an application or desktop environment is experiencing rendering artifacts or performance problems, as it might point to missing required capabilities.


title: IMPORTANCE OF RENDER EXTENSION
content:
The RENDER extension is fundamental for modern graphical interfaces on X. It enables transparency effects (alpha blending), smooth edges on fonts and graphics (anti-aliasing), and efficient off-screen rendering and compositing (used by desktop compositors like Compiz, KWin, or Mutter). Without proper RENDER support, user interfaces may appear blocky, lack transparency, or suffer from poor performance, impacting the overall user experience.


title: HISTORY
content:
The RENDER extension was a significant addition to the X Window System, first introduced in <i>X11R6.6</i> (part of X.Org 6.6) around 2000-2001. It was designed to address the growing need for sophisticated 2D graphics operations like alpha blending, anti-aliasing, and compositing, which were becoming standard in modern user interfaces. <b>rendercheck</b> was developed concurrently as a crucial diagnostic tool within the X.Org project. It became part of the standard <i>xorg-x11-apps</i> or <i>xorg-x11-server-utils</i> distribution, serving as a reliable way to verify the correct implementation and capabilities of the RENDER extension across different X server and graphics driver configurations. Its core functionality has remained largely unchanged since its inception.


title: SYNOPSIS
content:
<b>renice</b> <i>new_priority [[-p] pid ...] [[-g] pgroup ...] [[-u] user ...]</i><br><b>renice</b> <i>[-n increment] [-p | -g | -u] ID...</i>


title: PARAMETERS
content:
<b>new_priority</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired new nice value. Valid range is from <i>-20</i> (highest priority) to <i>19</i> (lowest priority).<br><br><b>-p pid...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more Process IDs (PIDs) whose nice value will be adjusted. This is the default if no type flag is provided.<br><br><b>-g pgroup...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more Process Group IDs (PGIDs) whose nice value will be adjusted. All processes within the specified group(s) will be affected.<br><br><b>-u user...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more User IDs (UIDs) or usernames. All processes owned by the specified user(s) will have their nice value adjusted.<br><br><b>-n increment</b><br>&nbsp;&nbsp;&nbsp;&nbsp;An alternative syntax to specify an increment to the current nice value. For example, <i>-n 5</i> adds 5 to the current nice value. This option is typically used in conjunction with <i>-p</i>, <i>-g</i>, or <i>-u</i>.<br><br>


title: DESCRIPTION
content:
<i>renice</i> alters the scheduling priority of one or more running processes. This priority is known as the "nice value", which ranges from <i>-20</i> (highest priority) to <i>19</i> (lowest priority). A lower nice value means the process gets more CPU time. The command allows users to change the nice value of processes, process groups, or processes owned by specific users. Regular users can only "renice" their own processes to a higher (less favorable) nice value (i.e., increase the nice value or decrease the priority). Root users, however, can change the nice value to any allowed value, including making processes run at a higher priority by decreasing their nice value. This is particularly useful for managing system resources, for instance, by reducing the priority of a CPU-intensive background task to ensure interactive applications remain responsive.


title: CAVEATS
content:
Only the <i>root</i> user can decrease a process's nice value (i.e., increase its priority). Regular users can only increase a process's nice value (i.e., decrease its priority) for processes they own. Renicing a process only affects its scheduling priority until the system reboots or the process exits. It does not provide persistent priority changes across reboots.


title: UNDERSTANDING NICE VALUES
content:
The "nice value" is a numerical representation of a process's scheduling priority. In Linux, it ranges from <i>-20</i> (least "nice," highest priority) to <i>19</i> (most "nice," lowest priority). A lower nice value means the process is more likely to receive CPU time from the kernel's scheduler. The term "nice" implies being "nice" to other processes by yielding CPU time; thus, a higher nice value means the process is more willing to share CPU resources.


title: IMPACT ON SYSTEM PERFORMANCE
content:
Adjusting nice values can significantly impact system responsiveness. By increasing the nice value (decreasing priority) of CPU-intensive background tasks (e.g., video encoding, large compilations), interactive applications like web browsers or text editors can remain smooth and responsive. Conversely, decreasing the nice value (increasing priority) of critical real-time or low-latency applications (e.g., audio processing, scientific simulations) can ensure they receive adequate CPU time, potentially at the expense of other less critical processes.


title: HISTORY
content:
The <i>renice</i> command has been a standard utility in Unix-like operating systems since early versions of BSD (e.g., 4.0BSD). It provides a simple command-line interface to interact with the kernel's process scheduler, allowing users to fine-tune resource allocation behavior. Its core functionality has remained largely consistent over decades.


title: PARAMETERS
content:
<b><i>&lt;database-file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the repository database file to create or update (e.g., <i>custom.db.tar.zst</i>).<br><br><b><i>&lt;package-file&gt;...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more paths to Pacman package files (e.g., <i>package-1.0-1-x86_64.pkg.tar.zst</i>) to add to the database.<br><br><b><i>-d</i>, <i>--delta</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generate delta files for packages. This creates small files representing differences between package versions, useful for efficient updates.<br><br><b><i>-f</i>, <i>--force</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force package recreation; overwrite existing package entries in the database even if the package version is not newer.<br><br><b><i>-q</i>, <i>--quiet</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress output messages, showing only errors.<br><br><b><i>-n</i>, <i>--new</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only add new packages to the database. Do not update existing package entries, even if the provided package is a newer version.<br><br><b><i>-s</i>, <i>--sign</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sign the repository database using GnuPG. This provides integrity and authenticity verification for users.<br><br><b><i>-k &lt;keyid&gt;</i>, <i>--key &lt;keyid&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the GnuPG key ID to use for signing the database. Only valid when <i>--sign</i> is also used.<br><br><b><i>-p</i>, <i>--prevent-update</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not update the timestamp of existing packages in the database if their version hasn't changed.<br><br><b><i>--skip-pgp-check</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip PGP signature checks on package files being added. Use with caution, as it bypasses a security measure.<br><br><b><i>--zstd</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the database using Zstandard (zstd) compression. This is often the default for recent <i>pacman-utils</i> versions.<br><br><b><i>--gz</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the database using gzip compression.<br><br><b><i>--xz</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the database using xz compression.<br><br><b><i>--bz2</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the database using bzip2 compression.<br><br><b><i>-v</i>, <i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information for <i><b>repo-add</b></i>.<br><br><b><i>-h</i>, <i>--help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br>


title: DESCRIPTION
content:
<i><b>repo-add</b></i> is a utility from the <i>pacman-utils</i> package designed to create or update a Pacman package repository database. This database, typically ending with <i>.db.tar.gz</i> or <i>.db.tar.zst</i>, contains metadata about packages (such as name, version, architecture, dependencies, and file listings) that Pacman uses to manage software. When invoked, <i><b>repo-add</b></i> takes the path to a database file and one or more Pacman package files (e.g., <i>.pkg.tar.zst</i>).<br><br>If the specified database file does not exist, <i><b>repo-add</b></i> creates it. If it already exists, it updates existing package entries with newer versions or adds new package entries. It extracts the necessary metadata directly from the package files, ensuring the repository database accurately reflects the available packages. This command is indispensable for maintaining local or remote custom package repositories, allowing users to distribute their own packages or mirror official repositories effectively.


title: CAVEATS
content:
<i><b>repo-add</b></i> is part of the <i>pacman-utils</i> package and is primarily used on Arch Linux and its derivatives.<br><br>The database file must typically end with a compression suffix (e.g., <i>.db.tar.zst</i>, <i>.db.tar.gz</i>). If the suffix doesn't match the desired compression, you might need to specify the compression type explicitly with options like <i>--zstd</i> or <i>--gz</i>.<br><br>For signing the repository database with <i>--sign</i>, GnuPG must be installed and properly configured with the signing key available in your keyring.


title: REPOSITORY STRUCTURE
content:
A typical Pacman repository consists of a directory containing the package files themselves (<i>.pkg.tar.zst</i>) and the corresponding repository database file (e.g., <i>custom.db.tar.zst</i> and its signature <i>custom.db.tar.zst.sig</i> if signed). When adding packages, ensure they are placed in the same directory as, or a directory accessible by, the <i>repo-add</i> command, and that the <i>&lt;database-file&gt;</i> path points to the desired location within that repository structure.


title: DATABASE SIGNING AND TRUST
content:
Signing the repository database with GnuPG (using the <i>--sign</i> option) is a critical security practice. When users add a repository to their <i>pacman.conf</i> and import the repository maintainer's public key, Pacman can verify the integrity and authenticity of the database before trusting the package information. This prevents malicious actors from tampering with the repository database and serving compromised packages.


title: HISTORY
content:
<i><b>repo-add</b></i> has been an integral part of the Arch Linux packaging ecosystem since the early days of <i>pacman</i>. It has evolved alongside <i>pacman</i> itself, adapting to new package formats, compression methods (such as the shift from <i>gzip</i> to <i>xz</i> and later to <i>zstd</i> for package and database compression), and security features like GnuPG signing for repository integrity. Its development reflects the ongoing efforts to make package management robust, secure, and efficient for Arch Linux users and developers.


title: SYNOPSIS
content:
repo-remove [OPTIONS] <repository_path> [--rpm <package.rpm> | --path <path_to_rpm> | --old-packages]


title: PARAMETERS
content:
<b>--rpm <package.rpm></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an RPM file by its name to be removed from the repository's metadata. The file must exist in the repository path.<br><br><b>--path <path_to_rpm></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a relative path to an RPM file within the repository directory to be removed from the metadata.<br><br><b>--old-packages</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes entries for RPMs that no longer exist on the filesystem within the specified repository path. This cleans up stale metadata.<br><br><b>-d, --database <db_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate database path for the repository metadata (e.g., when using createrepo_c).<br><br><b>--skip-symlinks</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs the command to skip processing symbolic links when scanning for RPMs or paths.<br><br><b>--temp-path <temp_dir></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a temporary directory to be used for internal operations during metadata regeneration.<br><br><b>--workers <num></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of parallel workers to use for processing, speeding up operations on large repositories.<br><br><b>--checksum <algo></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the checksum algorithm to use for metadata entries (e.g., sha256, sha512).<br><br><b>--quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses most output from the command, showing only critical errors.<br><br>


title: DESCRIPTION
content:
The <i>repo-remove</i> command, often part of broader repository management tools like <b>createrepo_c</b> (where its functionality is typically accessed via subcommands like <b>modify</b>), is used to remove package entries from a local RPM repository's metadata. This process <i>does not delete the actual package files</i> from the filesystem but updates the <b>repodata</b> to reflect that certain packages are no longer available in the repository. This is crucial for maintaining accurate package lists, especially after removing old or deprecated RPM files. Without updating the <b>repodata</b>, package managers like DNF or YUM might still list packages that no longer exist, potentially leading to installation or update errors.


title: CAVEATS
content:
The command <i>repo-remove</i> is not a standalone, universally available utility in most standard Linux distributions like <b>Ubuntu</b> or <b>Fedora</b>. Its functionality is typically provided by subcommands or options within broader repository management tools, such as the <b>createrepo_c modify</b> subcommand. Directly invoking <i>repo-remove</i> might only work if it's a custom script, an alias, or part of a less common utility set. The primary method to achieve this is usually by regenerating the repository metadata or using specific <b>modify</b> operations offered by tools like <b>createrepo_c</b>. Removing entries from the repository metadata <i>does not delete the actual RPM files</i> from the filesystem; it only updates the repository's index.


title: IMPACT ON REPOSITORY INTEGRITY
content:
Removing packages from repository metadata using <i>repo-remove</i> (or its equivalent functionality) without deleting the corresponding RPM files can lead to inconsistencies if not managed properly. While package managers will no longer see the removed packages as available, the actual files will still consume disk space. Conversely, deleting RPM files from the repository directory without updating the metadata can lead to errors when a package manager attempts to retrieve a non-existent file, indicating a broken repository.


title: INCREMENTAL VS. FULL REBUILDS
content:
Tools that provide <i>repo-remove</i> functionality, like <b>createrepo_c</b>, often offer both incremental updates and full rebuilds of repository metadata. Incremental updates are faster for minor changes like removing a few packages. However, for significant changes, to resolve complex inconsistencies, or to ensure complete accuracy, a full rebuild of the repository metadata might sometimes be preferred. A full rebuild effectively achieves a 'remove' by simply not including the unwanted packages in the newly generated metadata, ensuring a clean slate.


title: HISTORY
content:
The concept of managing RPM repository metadata has evolved significantly with tools like <b>createrepo</b> and its modern successor <b>createrepo_c</b>. While a direct, standalone <i>repo-remove</i> command might not have been a consistent or widely adopted utility across all Linux distributions, the functionality to remove packages from a repository's index has always been essential for maintaining clean and accurate software repositories. Early methods often involved manually recreating repository metadata or using bespoke scripts to filter out unwanted RPMs. Modern tools like <b>createrepo_c</b> now provide more robust and efficient ways to incrementally modify existing repositories, including the removal of specific package entries or the cleanup of stale entries, often through dedicated <b>modify</b> subcommands, streamlining what might conceptually be called 'repo-remove' operations.


title: SYNOPSIS
content:
<I>reportbug</I> [<I>OPTIONS</I>] [<I>package</I> ...]<br><I>reportbug</I> [<I>OPTIONS</I>] <I>--file</I> <I>FILENAME</I><br><I>reportbug</I> [<I>OPTIONS</I>] <I>--version</I><br><I>reportbug</I> [<I>OPTIONS</I>] <I>--help</I>


title: PARAMETERS
content:
<b><b>-f</b>, <b>--file</b> <I>FILENAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the bug report content from the specified file instead of interactive input.<br><br><b><b>-n</b>, <b>--no-interact</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs `reportbug` in a non-interactive mode, using configuration and default values where possible.<br><br><b><b>-N</b>, <b>--no-action</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prepares the bug report but does not send it. Useful for reviewing or saving the report locally.<br><br><b><b>-m</b>, <b>--mail</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explicitly specifies to send the bug report via email (this is the default submission method).<br><br><b><b>-u</b>, <b>--usenet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies to send the bug report via Usenet (NNTP) instead of email.<br><br><b><b>-q</b>, <b>--query-bts</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Queries the Debian Bug Tracking System (BTS) for information about a specific bug number.<br><br><b><b>-p</b> <I>PACKAGE</I>, <b>--package</b> <I>PACKAGE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the package the bug applies to, bypassing the interactive prompt for package selection.<br><br><b><b>-s</b> <I>SEVERITY</I>, <b>--severity</b> <I>SEVERITY</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the bug's severity level (e.g., 'critical', 'grave', 'serious', 'important', 'normal', 'wishlist').<br><br><b><b>--no-system-info</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents `reportbug` from automatically attaching general system information to the bug report.<br><br><b><b>--no-dpkg-info</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents `reportbug` from automatically attaching the output of `dpkg -l` to the bug report.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a concise help message with command options and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information of `reportbug` and exits.<br><br>


title: DESCRIPTION
content:
The `reportbug` command is a crucial utility within Debian and its derivatives, designed to facilitate the interactive reporting of bugs to the Debian Bug Tracking System (BTS). It guides users through a series of questions to gather all necessary information for a comprehensive bug report, including the affected package, its version, the severity of the bug, and a detailed description of the problem. `reportbug` automatically adds essential headers and can attach relevant system information, such as `dpkg -l` output, to the report. Users can choose to submit the report via email (the default) or save it to a file. By standardizing the bug reporting process and ensuring reports contain vital data, `reportbug` significantly aids maintainers in understanding and resolving software issues, contributing to the stability and quality of the Debian ecosystem.


title: CAVEATS
content:
`reportbug` is primarily designed for and most effective within Debian and Debian-derived operating systems. While it can be manually configured on other systems, its core functionality is tied to the Debian Bug Tracking System (BTS).<br><br>Submitting bug reports via email or Usenet requires appropriate mail client (MTA) or NNTP client configuration on the system. Incorrectly filled or formatted reports may be difficult for maintainers to process, so careful attention to the interactive prompts is advised.


title: INTERACTIVE WORKFLOW
content:
`reportbug` is designed to be highly interactive. When executed without specific parameters, it prompts the user through a series of questions, guiding them to select the package, describe the bug, specify its severity, and decide whether to attach system information. This step-by-step process helps users provide well-formed and complete bug reports even if they are unfamiliar with the precise requirements of the Debian Bug Tracking System.


title: CONFIGURATION FILE
content:
Many aspects of `reportbug`'s behavior, such as default email address, real name, preferred submission method, and whether to include system information, can be customized via a personal configuration file, typically located at <I>~/.reportbugrc</I>. This allows advanced users to set defaults and bypass repetitive questions for a more streamlined workflow.


title: BUG SEVERITY LEVELS
content:
The tool prompts for a bug's severity, which helps maintainers prioritize fixes. Common severity levels include: <I>critical</I> (makes the package or system as a whole unusable), <I>grave</I> (makes the package unusable or causes data loss), <I>serious</I> (violates Debian policy, causes a major functionality loss), <I>important</I> (a bug that affects the usability of a package without making it unusable), <I>normal</I> (the default, a typical bug), and <I>wishlist</I> (a feature request).


title: HISTORY
content:
The `reportbug` utility has been an integral part of the Debian project's bug reporting infrastructure for many years, evolving to streamline and standardize the process of submitting issues to the Debian Bug Tracking System (BTS). Initially simpler, it has grown into a sophisticated interactive Python script designed to gather comprehensive information from users, ensuring that bug reports are well-structured and contain all necessary details for maintainers. Its continuous development reflects Debian's commitment to community-driven maintenance and quality assurance, making bug reporting accessible and efficient for its vast user base.


title: PARAMETERS
content:
<b><b>-a</b>, <b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report quotas on all currently mounted file systems that have quota support enabled in <i>/etc/fstab</i> and are mounted with quota options.<br><br><b><b>-u</b>, <b>--user</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report user quotas. This is the default behavior if no quota type is specified.<br><br><b><b>-g</b>, <b>--group</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report group quotas.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display additional information about the quota-enabled file systems being processed, including their mounted status.<br><br><b><b>-s</b>, <b>--human-readable</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display sizes (blocks and inodes) in human-readable units (e.g., K for kilobyte, M for megabyte, G for gigabyte, T for terabyte).<br><br><b><b>-t</b>, <b>--time-statistics</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report statistics for time limits (grace periods), showing remaining time until a soft limit becomes a hard limit.<br><br><b><b>-i</b>, <b>--no-details</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only summary lines for each file system, omitting the detailed per-user or per-group information.<br><br><b><b>-n</b>, <b>--no-names</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not attempt to resolve numeric UIDs/GIDs to user/group names; display the numeric IDs instead.<br><br><b><b>-p</b>, <b>--punishment</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not honor grace periods. Report all users/groups who are over their soft limit as if they are already over their hard limit, showing them as 'OVER'.<br><br><b><b>-F</b>, <b>--format=<i>&lt;format&gt;</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the quota file format to use. Common formats include <i>vfsold</i> (for old style quotas), <i>vfsv0</i>, <i>vfsv1</i>, and <i>xfs</i>.<br><br>


title: DESCRIPTION
content:
The <b>repquota</b> command provides a summary of disk usage and quota limits for users or groups on a given file system, or across all quota-enabled file systems. It is primarily used by system administrators to monitor compliance with configured disk space limits and identify users or groups exceeding their allocated resources.<br><br>Unlike the <b>quota</b> command, which shows individual user/group quotas for the current user, <b>repquota</b> generates a comprehensive, aggregated report for all users or groups with entries in the quota files on the specified file system. The output typically includes user or group ID, current block usage, soft and hard block limits, inode usage, and soft and hard inode limits. It also indicates the status of grace periods if soft limits have been exceeded, showing time remaining or if the limit is exceeded.<br><br><b>repquota</b> gathers its information by reading the quota files (e.g., <i>aquota.user</i>, <i>aquota.group</i> for ext4/xfs) or by interacting directly with the kernel's quota subsystem. Running <b>repquota</b> usually requires root privileges to access and display quota data for all users and groups across the system.


title: CAVEATS
content:
To use <b>repquota</b>, the filesystem must be mounted with the appropriate quota options (e.g., <i>usrquota</i>, <i>grpquota</i> in <i>/etc/fstab</i>) and the quota system must be active via <b>quotaon</b>. For a complete system-wide report, <b>repquota</b> typically requires root privileges. While <b>repquota</b> can report on XFS filesystems using the <i>-F xfs</i> option, the <b>xfs_quota</b> command is often preferred for more granular and native XFS quota management features.


title: UNDERSTANDING OUTPUT COLUMNS
content:
The typical output of <b>repquota</b> provides a tabular report with several key columns:<br><i>Filesystem</i>: The mounted filesystem being reported on.<br><i>User/Group Name</i>: The identifier (name or UID/GID) for the user or group.<br><i>Blocks</i>: The current disk space used by the user/group, usually in kilobytes.<br><i>Quota</i>: The <i>soft block limit</i>. Exceeding this triggers a grace period.<br><i>Limit</i>: The <i>hard block limit</i>. Exceeding this prevents further writes.<br><i>Grace</i>: Indicates the status of the grace period for blocks. Shows remaining time, or 'none' if within limits, or 'OVER'/'--' if grace period expired or hard limit exceeded.<br><i>Files</i> (Inodes): The current number of inodes (files and directories) used.<br><i>Quota</i> (Inodes): The <i>soft inode limit</i>.<br><i>Limit</i> (Inodes): The <i>hard inode limit</i>.<br><i>Grace</i> (Inodes): Indicates the status of the grace period for inodes.


title: GRACE PERIODS EXPLAINED
content:
A <i>grace period</i> is a temporary allowance granted when a user or group exceeds their <i>soft limit</i> for blocks or inodes. During this period, they can continue to use disk space or create files. If the usage remains above the soft limit after the grace period expires, the soft limit effectively becomes a <i>hard limit</i>. This means that no further writes or file creations will be permitted until the usage drops below the soft limit. <b>repquota</b> is crucial for administrators to monitor the status and remaining time of these grace periods, enabling proactive management before hard limits are enforced.


title: HISTORY
content:
The <b>repquota</b> command has been a fundamental part of the Linux quota tools suite for many years, evolving alongside the kernel's increasing support for disk quotas and various filesystem types. It is part of the standard <i>quota</i> package, which provides a comprehensive set of utilities for managing disk space limits. Its development has seen adaptations to new quota file formats (such as <i>vfsv0</i> and <i>vfsv1</i>) to support modern filesystems. Although specialized tools like <b>xfs_quota</b> emerged for specific filesystem features, <b>repquota</b> remains a widely used general-purpose reporting tool.


title: SYNOPSIS
content:
The `repren` command does not have a standard synopsis.<br><br><b>Common `rename` (Perl version) synopsis:</b><br><code>rename [options] expression replacement file...</code><br><br><b>Common `rename` (util-linux version) synopsis:</b><br><code>rename [options] from to file...</code>


title: PARAMETERS
content:
<b><b>Perl-based `rename` options:</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br><br><b><code>-v</code>, <code>--verbose</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show files successfully renamed and provide verbose output of actions.<br><br><b><code>-n</code>, <code>--no-act</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run; print what would be done without actually renaming any files.<br><br><b><code>-f</code>, <code>--force</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwrite of existing files without prompting for confirmation.<br><br><b><code>-s</code>, <code>--symlink</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate on the target of symbolic links, rather than the links themselves.<br><br><b><code>-k</code>, <code>--keep-going</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continue processing other files even if an error occurs during renaming.<br><br><b><b>Util-linux `rename` options:</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br><br><b><code>-v</code>, <code>--verbose</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display verbose information about each successful or failed renaming operation.<br><br><b><code>-n</code>, <code>--no-act</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run; print what would be done without actually renaming any files.<br><br><b><code>-f</code>, <code>--force</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwrite of existing files without prompting for confirmation.<br><br><b><code>-i</code>, <code>--interactive</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt before overwriting an existing file to prevent accidental data loss.<br><br>


title: DESCRIPTION
content:
The `repren` command is <I>not a standard utility</I> found in most Linux distributions. Its name, however, strongly suggests a function of 'REPlace' and 'RENaming' files. This task is commonly handled by the `rename` command, which comes in <I>two primary versions</I> on Linux systems: the Perl-based `rename` (often `prename` or `perl-rename`) and the simpler `util-linux` `rename` (sometimes `rename.ul`). Both allow for batch renaming of files based on pattern matching and substitution, often using regular expressions.<br><br>If `repren` were to exist, it would likely combine or enhance capabilities similar to these existing, widely used file renaming tools.


title: CAVEATS
content:
The command name `rename` exists in <I>two distinct forms</I> on Linux, leading to frequent confusion and syntax errors. The <B>Perl-based version</B> (often preferred for complex tasks) offers powerful regular expression capabilities, while the <B>`util-linux` version</B> provides simpler string replacement. Users must verify which `rename` version is installed on their system (e.g., by checking `man rename` or `which rename`) to apply the correct syntax. `repren` itself is not a recognized command.


title: USAGE EXAMPLES (FOR `RENAME`)
content:
<B>Perl-based `rename` (e.g., using `s/old/new/` regex syntax):</B><br><code>rename 's/jpg/jpeg/' *.jpg</code><br><i>Renames all files ending with <code>.jpg</code> to <code>.jpeg</code>.</i><br><br><code>rename 's/foo/bar/gi' *</code><br><i>Replaces all occurrences of 'foo' (case-insensitive) with 'bar' in all filenames in the current directory.</i><br><br><B>Util-linux `rename` (e.g., using `old new` string replacement syntax):</B><br><code>rename jpg jpeg *.jpg</code><br><i>Renames all files with 'jpg' in their name to 'jpeg'.</i><br><br><code>rename ' ' '_' *.txt</code><br><i>Replaces the first occurrence of a space with an underscore in filenames ending with <code>.txt</code>.</i>


title: HISTORY
content:
While `repren` has <I>no known history</I> or official development, the `rename` command has evolved significantly. The original `rename` utility, part of the `util-linux` project, offered basic string replacement functionality. Later, a more powerful <B>Perl-based `rename` script</B> (often named `prename` or `perl-rename` in some distributions) gained widespread adoption due to its full regular expression support. This made complex batch renaming operations significantly easier and more flexible than simple string substitution, allowing for sophisticated pattern matching. Many modern Linux systems often symlink `rename` to this Perl version to provide advanced capabilities by default.


title: PARAMETERS
content:
<b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress <b>reptyr</b>'s output, only printing errors.<br><br><b>-L <i>FILENAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Log <b>reptyr</b>'s debug output to the specified <i>FILENAME</i>.<br><br><b>-P</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not attempt to change the process's controlling terminal. This can be useful if the process doesn't need a new TTY or if changing it causes issues.<br><br><b>-T</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not try to reattach the process's controlling terminal. This is typically done automatically to ensure full terminal control.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not detach the process from its current TTY. Use with extreme caution as this can lead to unpredictable behavior or conflicts.<br><br><b>-o</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to close all other open file descriptors in the target process besides stdin/stdout/stderr. This can be aggressive and potentially risky.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not close the process's old stdin/stdout/stderr file descriptors. Use with caution as this may lead to resource leaks or unexpected interactions.<br><br><b>-A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Acquire a TTY for the process by acquiring the new TTY that <b>reptyr</b> itself is running in, rather than trying to get the target process's original TTY. Useful in advanced scenarios.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continue the target process even if it is currently stopped.<br><br><b>-e <i>VAR=VAL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set an environment variable <i>VAR</i> to <i>VAL</i> in the target process's environment. Can be specified multiple times.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <b>reptyr</b>'s version number and exit.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the <b>ptrace</b> version number and exit.<br><br><b>-h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br>


title: DESCRIPTION
content:
<b>reptyr</b> is a powerful utility that allows you to attach a running program to a new terminal. This is particularly useful in scenarios where a long-running process was started in a terminal session that is about to be closed, or if you simply want to move the process to a different terminal without interrupting its execution. It achieves this by using the <b>ptrace</b> system call to seize control of the target process, redirecting its standard input, output, and error streams to the new terminal. It effectively "reparents" the process, making it behave as if it was launched from the new terminal.<br><br>While <b>nohup</b> and shell job control (like <b>disown</b>) can prevent processes from terminating when a shell exits, they don't allow for re-establishing interactive control. <b>reptyr</b> fills this gap, providing a way to take over a process's console I/O even if it wasn't initially started in a persistent session like <b>screen</b> or <b>tmux</b>. This capability makes <b>reptyr</b> an invaluable tool for system administrators and developers who need flexibility in managing background processes.


title: CAVEATS
content:
<ul><li><b>Root Privileges:</b> <b>reptyr</b> typically requires root privileges or the <i>CAP_SYS_PTRACE</i> capability to attach to processes owned by other users or if the system's <i>ptrace_scope</i> is restricted.</li><li><b>Security Context:</b> Reparenting a process changes its controlling terminal, which might have security implications or affect programs that rely on specific terminal properties.</li><li><b>Unstable State:</b> While generally robust, <b>reptyr</b> can sometimes leave the target process in an unstable state, especially if the process was designed to interact directly with its original terminal in complex or unusual ways.</li><li><b>File Descriptors:</b> <b>reptyr</b> focuses on standard I/O. Other open file descriptors in the process (e.g., pipes, sockets, device files) that are tied to the old terminal or session remain untouched, which might cause issues. The <b>-o</b> option attempts to mitigate this but can be risky.</li><li><b>PID Stability:</b> The attachment applies only to the specified <i>PID</i>. If the process forks or executes new binaries, child processes might not be affected as expected or might still be tied to the original terminal.</li></ul>


title: <I>HOW IT WORKS (ADVANCED)</I>
content:
<b>reptyr</b> operates by utilizing the Linux <b>ptrace</b> system call. It attaches to the target process, then manipulates its file descriptors for standard input (<i>0</i>), output (<i>1</i>), and error (<i>2</i>), redirecting them to the new controlling terminal where <b>reptyr</b> itself is running. It also attempts to change the process's controlling terminal group. This manipulation often involves injecting code into the target process's memory space to perform necessary system calls (like <b>fcntl</b>) to close old descriptors and open new ones, effectively giving the process a new 'home' terminal.


title: <I>PERMISSIONS AND PTRACE SCOPE</I>
content:
For <b>reptyr</b> to successfully attach to a process, the user running <b>reptyr</b> must have sufficient permissions to debug the target process. This typically means:<br><ul><li>Running <b>reptyr</b> as the root user.</li><li>The invoking user owns the target process.</li><li>The system's <i>ptrace_scope</i> setting (found at <i>/proc/sys/kernel/yama/ptrace_scope</i>) is configured to allow `ptrace` operations between processes. A value of <i>0</i> usually allows tracing any process by any user, while a value of <i>1</i> (the default on many modern systems) restricts tracing to children of the tracer, or processes that are owned by the same user.</li></ul>


title: HISTORY
content:
<b>reptyr</b> was originally developed by Nelson Elhage and publicly released around 2011. Its primary motivation was to provide a flexible solution for a common user dilemma: forgetting to launch a long-running command within a persistent terminal multiplexer like <b>screen</b> or <b>tmux</b>. Prior to <b>reptyr</b>, users would often have to kill and restart such processes if their original terminal session was closed. By leveraging the low-level <b>ptrace</b> system call, <b>reptyr</b> filled a crucial gap, offering an on-demand mechanism to migrate a running process's I/O to a new terminal without interrupting its execution. Its development focused on being lightweight and effective, making it a popular choice for system administrators and developers.


title: SYNOPSIS
content:
Given that `req.1s` is not a standard command, a universal synopsis does not exist.<br><br><i>If it were a custom script or alias, its invocation might resemble:</i><br><b>req.1s</b> [<i>options</i>] [<i>arguments...</i>]


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;As `req.1s` is not a standard Linux command, there are no predefined or universally recognized parameters.<br><br><i>If it were a custom script, it might implement common options such as:</i><br>- <b>-h</b>, <b>--help</b>: Display a help message.<br>- <b>-v</b>, <b>--version</b>: Display version information.<br>- <b>-i</b> <i>INTERVAL</i>, <b>--interval</b> <i>INTERVAL</i>: Specify a time interval (e.g., <i>1s</i>).<br>- <b>-r</b> <i>REQUESTS</i>, <b>--requests</b> <i>REQUESTS</i>: Specify a number of requests.<br>These are purely illustrative based on the string "req.1s" potentially implying "requests" and "1 second".<br><br>


title: DESCRIPTION
content:
req.1s is <i>not</i> a standard or universally recognized Linux command. It does not appear in common Linux distributions' official repositories, nor does it have a dedicated man page. Therefore, its functionality, if any, is not defined by a common standard.<br><br>It is most probable that req.1s refers to:<br>- <b>A Custom Script or Executable:</b> An administrator or user may have created a script named `req.1s` (e.g., `req.1s.sh`) and placed it in a directory within the system's `PATH` (like `/usr/local/bin` or `~/bin`). In this case, its behavior is entirely dependent on the script's content.<br>- <b>A Shell Alias:</b> A user might have defined `req.1s` as a shorthand alias in their shell configuration file (e.g., `~/.bashrc`, `~/.zshrc`). For example: <i>alias req.1s='some_other_command --interval 1s'</i>.<br>- <b>A File Name:</b> `req.1s` could simply be the name of a file, which is then used as an argument to another command (e.g., <i>cat req.1s</i>, <i>ls req.1s</i>).<br>- <b>A Typo:</b> It might be a mistyped version of a different, standard command or option.<br><br>Without specific context from the system where this command was encountered, its purpose and functionality cannot be determined.


title: CAVEATS
content:
The primary caveat is that `req.1s` is <i>not a standard Linux command</i>. Its presence and behavior are entirely system-specific, depending on whether it's a custom script, an alias, or merely a file name. Users should investigate their system's `PATH`, shell aliases (<i>alias req.1s</i>), and local scripts to understand its origin and function. Relying on its existence or specific behavior across different Linux environments is not advisable.


title: CHECKING FOR `REQ.1S` ON YOUR SYSTEM:
content:
To determine if `req.1s` exists on a specific system and what it refers to, you can use the <i>type</i> or <i>which</i> commands:<br><i>type req.1s</i><br><i>which req.1s</i><br>If <i>type</i> indicates it's an alias, check your shell's configuration files (e.g., <i>~/.bashrc</i>, <i>~/.zshrc</i>). If <i>which</i> returns a path, it's an executable script or binary.


title: CREATING A CUSTOM `REQ.1S` SCRIPT (EXAMPLE):
content:
You could create a simple script named `req.1s` that mimics a hypothetical function, e.g., to ping an address every second:<br><i>#!/bin/bash</i><br><i># A hypothetical custom script named req.1s</i><br><i>echo "Simulating requests for 1 second..."</i><br><i>sleep 1</i><br><i>echo "Request simulation complete."</i><br>Save this to a file named `req.1s`, make it executable (<i>chmod +x req.1s</i>), and place it in a directory within your <i>PATH</i>.


title: HISTORY
content:
There is no official or widely documented history for `req.1s` as it is not a standard Linux command. Its development and usage history would be limited to the specific environment where it has been defined or created as a custom tool.


title: PARAMETERS
content:
<b><i>&lt;type&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The type of key to be requested (e.g., 'user', 'logon', 'big_key'). This determines the key management policy and data format.<br><br><b><i>&lt;description&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A string describing the key, which is used by the kernel to look up the key. Its interpretation depends on the key type.<br><br><b><i>&lt;callout-info&gt;</i> (optional)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;An optional, arbitrary string that provides additional information to the helper program for instantiating the key. For example, it might contain a filename or a network address.<br><br>


title: DESCRIPTION
content:
The `request-key` command is a crucial user-space helper program for the Linux kernel's key retention service. Its primary function is to instantiate, find, or otherwise obtain a key when the kernel or a user-space program initiates a key request that cannot be immediately fulfilled from existing keyrings. When the kernel attempts to look up a key and fails to find it, it can invoke `request-key` through a pre-configured mechanism (often via the <b>request_key()</b> syscall, or through the <b>keyctl_request_key()</b> library function in user space).<br><br>Upon invocation, `request-key` receives parameters detailing the requested key's type, description, and an optional callout-info string. It then consults its configuration file, typically <i>/etc/request-key.conf</i>, to determine the appropriate action. This action might involve executing another program, reading a key from a file, or dynamically generating a key based on the request's parameters. The returned key ID is then passed back to the kernel, allowing the requesting process to use the newly instantiated key. This mechanism is fundamental for services that rely on dynamically available keys, such as AFS or user-defined authentication systems, ensuring secure and flexible key management within the Linux environment.


title: CAVEATS
content:
The security of the `request-key` mechanism heavily relies on its configuration in <i>/etc/request-key.conf</i>. If not properly secured, misconfigurations could lead to privilege escalation or unauthorized key instantiation. It's critical to ensure that the helper programs executed by `request-key` are trusted, properly sandboxed, and handle their inputs securely.<br><br>Since `request-key` is often invoked by the kernel, errors or infinite loops in the configured helper scripts can severely impact system stability and performance. Debugging issues with `request-key` can be challenging as the initial call often originates from kernel space.


title: CONFIGURATION (<I>/ETC/REQUEST-KEY.CONF</I>)
content:
The behavior of `request-key` is primarily controlled by the configuration file <i>/etc/request-key.conf</i>. This file contains rules that map key types and descriptions to specific helper programs or actions. Each rule specifies how a requested key should be handled, potentially by executing a script or program that generates the key. The configuration allows for highly flexible and context-dependent key management.


title: KERNEL INTEGRATION
content:
`request-key` is not typically run directly by users. Instead, it's a kernel helper. The kernel's <b>request_key()</b> syscall, when unable to find a key, looks for a `request-key` helper configured via <i>/proc/sys/kernel/keys/request_key_helper</i>. This allows the kernel to delegate complex key lookup and instantiation logic to user-space, which can access filesystems, network resources, and other user-space services.


title: HISTORY
content:
The Linux kernel key retention service, which `request-key` is an integral part of, was introduced relatively early in the 2.6 kernel series. It aimed to provide a generic, secure, and extensible mechanism for managing cryptographic and other arbitrary keys within the kernel and across user-space applications. The `request-key` helper program was designed alongside this service to enable dynamic key instantiation, allowing applications and kernel components to obtain keys on demand without pre-loading them, thus enhancing flexibility and security. Its design reflects the need for a user-space component to handle complex key acquisition logic that is better suited for user-space programming than kernel modules.


title: PARAMETERS
content:
<b><b>-I</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Re-initializes the terminal. This is equivalent to invoking 'tput init', which sends the terminal's initialization strings from the terminfo database.<br><br><b><b>-Q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Causes 'reset' to output both the 'init' string (initialization) and the 'reset' string from the terminfo database. Useful for a more comprehensive reset.<br><br><b><b>-K</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resets the terminal's keypad. This sends the 'keypad_normal' (<i>kcrmn</i>) string from the terminfo database, restoring the keypad to its normal (non-application) mode.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resets the terminal's programmable function keys. This sends the 'keypad_xmit' (<i>kf</i>) string, which often sets function keys to their default behaviors.<br><br>


title: DESCRIPTION
content:
The `reset` command is a utility designed to restore a terminal's state to a known, default configuration. It is invaluable when a terminal session becomes garbled, unresponsive, or exhibits strange behavior due to misconfigured programs, incorrect control sequences, or the accidental display of binary files. <br><br>Essentially, `reset` sends a series of initialization and reset sequences from the `terminfo` database, specific to the terminal type defined by the `TERM` environment variable. These sequences typically clear the screen, reset tab stops, disable special character mappings (like raw mode), re-enable echoing of characters, and restore standard cursor and display attributes. <br><br>While often appearing as a standalone command, `reset` is commonly a hard link to or an alias for `tput reset` or `tput init`, leveraging the capabilities of the `ncurses` library to interact with the terminal's control sequences. It's a quick fix to get your terminal back to a usable state without needing to close and reopen the session.


title: CAVEATS
content:
<ul><li>`reset` relies on the correct `TERM` environment variable being set. If `TERM` is incorrect, `reset` might send inappropriate sequences, potentially worsening the terminal state or having no effect.</li><li>While `reset` aims to restore a sane state, some extremely malformed terminal states might not be fully recoverable without closing and reopening the terminal session.</li><li>It typically clears the entire screen, which can wipe out previous command output or scrollback history in some terminal emulators.</li></ul>


title: COMMON USAGE SCENARIOS
content:
The `reset` command is most frequently used in situations where your terminal display becomes unreadable or unresponsive. This often happens after: <br><i>• Accidentally displaying a binary file:</i> Using `cat` on an executable or image file can print non-printable characters that alter terminal settings.<br><i>• A program crashes or exits improperly:</i> Some applications may leave the terminal in a raw input mode, or change character sets, making further interaction difficult.<br><i>• Incorrect terminal settings applied:</i> Sometimes, a script or misconfiguration can apply incorrect escape sequences.


title: RELATIONSHIP WITH TERM VARIABLE
content:
The effectiveness of `reset` heavily depends on the `TERM` environment variable. This variable tells the system what type of terminal you are using (e.g., `xterm`, `linux`, `vt100`). `reset` (via `tput`) consults the `terminfo` database for the initialization and reset sequences specific to the `TERM` type. If `TERM` is unset or set incorrectly, `reset` may fail to properly restore the terminal.


title: HISTORY
content:
The `reset` command is an integral part of the `ncurses` (new curses) library, which provides a powerful and portable way to write text-based user interfaces. Its origins are tied to the need for robust terminal control in Unix-like systems. Historically, `reset` often existed as a standalone executable, frequently implemented as a hard link to `tput`. This approach allows `reset` to leverage `tput`'s ability to query and apply terminal capabilities defined in the `terminfo` database, ensuring compatibility across a vast array of terminal types and emulators. Its continued relevance highlights the persistent challenge of managing diverse terminal control sequences in modern computing environments.


title: PARAMETERS
content:
<b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Verbose output</i><br>Causes <b>resize</b> to print the current rows and columns, even if they have not changed. It effectively shows the commands it generates.<br><br><b>-u</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Bourne shell output</i><br>Generates commands suitable for Bourne-compatible shells (e.g., `sh`, `bash`, `ksh`). This is the default behavior if neither <i>-u</i> nor <i>-c</i> is specified.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>C shell output</i><br>Generates commands suitable for C-compatible shells (e.g., `csh`, `tcsh`).<br><br><b>-s [rows cols]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Set dimensions</i><br>Instead of querying the terminal for its size, this option instructs <b>resize</b> to set the `COLUMNS` and `LINES` variables to the specified <i>rows</i> and <i>cols</i>. This is useful for scripting fixed sizes or when the terminal's query mechanism is not functioning correctly.<br><br>


title: DESCRIPTION
content:
The <b>resize</b> utility is designed to set the `COLUMNS` and `LINES` environment variables in your shell to accurately reflect the current dimensions of the terminal window. It primarily operates by sending special escape sequences to the terminal emulator (such as <i>xterm</i>), which then responds with its current row and column size. Upon receiving this information, <b>resize</b> generates shell commands (either in Bourne shell or C shell syntax) that, when executed, update these environment variables in your current shell session. This functionality is crucial in graphical terminal environments where window sizes can be dynamically altered, ensuring that applications like <i>vi</i>, <i>less</i>, or shell prompts render correctly according to the visible area. It is commonly used in conjunction with `eval` to immediately apply the generated commands.


title: CAVEATS
content:
<ul><li><b>resize</b> is primarily designed for graphical terminal emulators (like <i>xterm</i>) that support the necessary escape sequences for querying window dimensions.</li><li>In modern SSH sessions, terminal size changes are often automatically propagated from the client to the server by the `sshd` daemon, potentially making <b>resize</b> less critical.</li><li>For the changes to take effect, the output of <b>resize</b> must be evaluated by the current shell, typically using `eval $(resize)`.</li></ul>


title: USAGE EXAMPLES
content:
To update your shell's `COLUMNS` and `LINES` variables:<br><code>eval $(resize)</code><br><br>To update variables and display the commands generated (verbose output):<br><code>resize -v</code><br><br>To explicitly set your terminal to 80 columns and 24 rows:<br><code>eval $(resize -s 24 80)</code>


title: ENVIRONMENT VARIABLES
content:
<b>resize</b> primarily affects the following environment variables:<br><i>COLUMNS</i>: Set to the detected or specified number of columns in the terminal.<br><i>LINES</i>: Set to the detected or specified number of rows in the terminal.


title: HISTORY
content:
The <b>resize</b> utility has historically been a fundamental component of the <i>xterm</i> package within the X Window System. Its development is deeply intertwined with the need for graphical terminal emulators to dynamically communicate their changing dimensions to running applications. The core functionality of querying the terminal through specific escape sequences has remained largely consistent over its long lifespan, reflecting its enduring role in effective terminal management.


title: SYNOPSIS
content:
resize2fs [ <b>-fFpPMqQvS</b> ] [ <b>-b</b> <i>block-size</i> ] [ <b>-e</b> <i>errors_behavior</i> ] [ <b>-L</b> <i>label</i> ] [ <b>-l</b> <i>lazy_itable_init</i> ] [ <b>-I</b> <i>inode-size</i> ] [ <b>-s</b> [ <i>R</i> ] ] [ <b>-z</b> <i>number_of_blocks</i> ] [ <b>-U</b> <i>UUID</i> ] <i>device</i> [ <i>size</i> ]


title: PARAMETERS
content:
<b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the resize operation to proceed, even if <i>resize2fs</i> detects errors that would normally prevent it.<br><br><b><b>-F</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Flushes the filesystem device before beginning the resize operation.<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a progress bar during the operation, showing completion percentage.<br><br><b><b>-M</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shrinks the file system to the minimum possible size, based on the amount of data stored.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the minimum size (in filesystem blocks) to which the filesystem can be shrunk, and then exits.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet execution. Suppresses some informational output.<br><br><b><b>-Q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Very quiet execution. Suppresses almost all output.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verbose execution. Provides more detailed output during the operation.<br><br><b><b>-b</b> <i>block-size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the block size of the file system. This option is rarely used and can be dangerous if not understood.<br><br><b><b>-e</b> <i>errors_behavior</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the behavior when file system errors are detected. Similar to <i>tune2fs</i>.<br><br><b><b>-L</b> <i>label</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the volume label of the file system after resizing.<br><br><b><b>-l</b> <i>lazy_itable_init</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Turns on or off lazy inode table initialization. '0' for off, '1' for on.<br><br><b><b>-I</b> <i>inode-size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Changes the inode size. This operation can be very slow.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Causes <i>resize2fs</i> to attempt to shrink the filesystem.<br><br><b><b>-S</b> <i>R</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to spread the free blocks evenly across the filesystem after shrinking. 'R' is a ratio.<br><br><b><b>-z</b> <i>number_of_blocks</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Zeros out the unused blocks after shrinking the filesystem. This is typically used for security reasons.<br><br><b><b>-U</b> <i>UUID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the UUID of the file system after resizing.<br><br><b><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the block device containing the ext2/ext3/ext4 file system (e.g., <i>/dev/sda1</i>, <i>/dev/mapper/vg0-lv_data</i>).<br><br><b><i>size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The desired new size of the file system. Can be specified in blocks, or with suffixes like 'K', 'M', 'G', 'T' for KiB, MiB, GiB, TiB. If omitted, the file system will be expanded to fill the entire underlying partition/device.<br><br>


title: DESCRIPTION
content:
<i>resize2fs</i> is a utility that allows users to resize ext2, ext3, or ext4 file systems. It can be used to expand a file system to fill a larger underlying block device, or to shrink a file system to a smaller size.<br><br>When expanding, <i>resize2fs</i> can often be performed online (while the file system is mounted), which is a significant advantage for servers requiring high availability. The underlying block device (e.g., a partition or Logical Volume Manager (LVM) volume) must be expanded first to accommodate the larger file system.<br><br>When shrinking, the file system <b>must</b> first be unmounted to ensure data integrity, and it cannot be shrunk to a size smaller than the amount of data it currently holds. For shrinking, the underlying block device must be shrunk <b>after</b> the file system is shrunk.<br><br>This tool operates at the file system level and is frequently used in conjunction with disk partitioning tools like <i>fdisk</i> or <i>parted</i>, or logical volume managers like LVM (<i>lvresize</i>, <i>pvresize</i>) which manage the block device itself.


title: CAVEATS
content:
<b>Shrinking Requirements:</b> When shrinking a file system, it <b>must</b> be unmounted first. Attempting to shrink a mounted file system will result in an error and potential data corruption. Ensure the target size is larger than the actual data used.<br><br><b>Underlying Device Management:</b> <i>resize2fs</i> only modifies the file system itself. The underlying partition or logical volume must be resized separately using tools like <i>fdisk</i>, <i>parted</i>, <i>lvresize</i>, or <i>pvresize</i>. For expansion, resize the block device first, then the filesystem. For shrinking, resize the filesystem first (unmounted), then the block device.<br><br><b>Data Integrity:</b> Although robust, any interruption (e.g., power loss, system crash) during a resize operation can lead to file system corruption. Always back up critical data before performing resize operations.


title: COMMON USAGE PATTERN WITH LVM
content:
When using Logical Volume Management (LVM), the typical workflow for resizing involves two steps:<br><br><b>Expanding:</b><br>1. Expand the Logical Volume: <code><i>lvresize -L +<size> /dev/vg_name/lv_name</i></code><br>2. Expand the Filesystem: <code><i>resize2fs /dev/vg_name/lv_name</i></code> (can often be done online)<br><br><b>Shrinking:</b><br>1. Unmount the Filesystem: <code><i>umount /mount/point</i></code><br>2. Shrink the Filesystem: <code><i>resize2fs /dev/vg_name/lv_name <new_size></i></code><br>3. Shrink the Logical Volume: <code><i>lvresize -L <new_size> /dev/vg_name/lv_name</i></code><br>4. Mount the Filesystem: <code><i>mount /dev/vg_name/lv_name /mount/point</i></code>


title: HISTORY
content:
<i>resize2fs</i> is a fundamental component of the <i>e2fsprogs</i> package, a collection of utilities for managing ext2, ext3, and ext4 file systems on Linux. Its development has closely paralleled the evolution of these file systems, gaining support for journaling (ext3) and later features like extents (ext4). A significant milestone was the introduction of online resizing capabilities (specifically, online expansion), which greatly improved its utility for mission-critical systems by minimizing downtime. It has been a standard and indispensable tool for Linux system administrators for decades.


title: SYNOPSIS
content:
<b>resize_reiserfs</b> [<i>-s</i> <i>size</i>] [<i>-f</i>] [<i>-q</i>] [<i>-V</i>] [<i>-p</i>] <i>device</i> [<i>new_size</i>]


title: PARAMETERS
content:
<b><i>-s</i> <i>size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the new size of the filesystem in blocks. If omitted, the filesystem will be extended to fill the entire underlying block device.<br><br><b><i>-f</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the resize operation. Particularly relevant for shrinking, though unmounting the filesystem is still highly recommended for safety.<br><br><b><i>-q</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables quiet mode, suppressing most output during the resize process.<br><br><b><i>-V</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information for the <b>resize_reiserfs</b> utility and exits.<br><br><b><i>-p</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows progress of the resize operation, displaying percentage completed.<br><br>


title: DESCRIPTION
content:
<b>resize_reiserfs</b> is a utility designed to change the size of an existing ReiserFS filesystem. It allows administrators to expand a ReiserFS filesystem to fill a larger underlying block device or, with certain precautions, shrink it to fit a smaller device. This command is typically used in conjunction with logical volume management (LVM) tools like <b>lvextend</b> or <b>lvreduce</b>, or partition management tools like <b>fdisk</b> or <b>parted</b>, which first modify the size of the block device itself. <b>resize_reiserfs</b> then updates the ReiserFS filesystem's metadata to reflect the new size. While it can often grow a filesystem online (while mounted), shrinking usually requires the filesystem to be unmounted for safety. ReiserFS, though once popular, has largely been superseded by more modern filesystems like Ext4 or XFS, so <b>resize_reiserfs</b> is primarily relevant for legacy systems.


title: CAVEATS
content:
<b>resize_reiserfs</b> is primarily for legacy ReiserFS filesystems, as more modern alternatives like Ext4 and XFS are generally preferred.<br>When shrinking a ReiserFS filesystem, it is <i>highly recommended</i> to unmount it first, even when using the <i>-f</i> (force) option, to prevent data loss or corruption. <br>Always ensure a full backup of your data before performing any filesystem resizing operations. <br>Remember that the underlying block device (partition or logical volume) must be resized <i>before</i> <b>resize_reiserfs</b> is used to adjust the filesystem size. Shrinking the block device without shrinking the filesystem first will lead to data loss.


title: USAGE SCENARIOS
content:
Typically, <b>resize_reiserfs</b> is used in two main scenarios:<br>1. <b>Growing the filesystem:</b> After extending the underlying block device (e.g., with <b>lvextend</b> or resizing a partition), this command expands the ReiserFS filesystem to utilize the newly available space. This operation can often be performed online (while the filesystem is mounted).<br>2. <b>Shrinking the filesystem:</b> This involves reducing the size of the filesystem. It requires careful planning and typically an offline operation (unmounting the filesystem) to prevent data corruption. The filesystem must be shrunk <i>before</i> the underlying block device is reduced.


title: ONLINE VS. OFFLINE RESIZING
content:
Growing a ReiserFS filesystem with <b>resize_reiserfs</b> can generally be done while the filesystem is mounted and in use (online). However, shrinking a ReiserFS filesystem <i>requires</i> it to be unmounted (offline) to ensure data integrity. Attempting to shrink an online filesystem, even with the force option, carries a significant risk of data loss or filesystem corruption. Always back up critical data before any resize operation.


title: HISTORY
content:
ReiserFS was developed by Hans Reiser and his company Namesys in the late 1990s and early 2000s, aiming to be a high-performance journaling filesystem. The <b>resize_reiserfs</b> utility is part of the <i>reiserfsprogs</i> user-space tools package, which provides various utilities for managing ReiserFS filesystems. While ReiserFS gained some traction, particularly in its early days for its efficient handling of small files and journaling capabilities, its adoption significantly declined following Hans Reiser's legal troubles and the emergence and maturation of alternative filesystems like Ext3, Ext4, and XFS, which offered comparable or superior performance and stability. Consequently, the development and widespread usage of <b>resize_reiserfs</b> have diminished over time, making it primarily a tool for maintaining older systems.


title: SYNOPSIS
content:
<i>resizecons</i> [-S] [-s <i>rows</i>] [-l] [-V] [-?] [<i>cols</i>] [<i>rows</i>]<br><i>resizecons</i> [-?] <i>cols</i>x<i>rows</i>


title: PARAMETERS
content:
<b><i>cols</i> <i>rows</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the console screen to the specified number of <i>cols</i> (columns) and <i>rows</i>. For example, '80 25'.<br><br><b><i>cols</i>x<i>rows</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An alternative syntax to set the console screen to <i>cols</i> (columns) and <i>rows</i>. For example, '80x25'.<br><br><b>-S</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If specified, the number of rows is ignored and <i>resizecons</i> attempts to guess a suitable value for the number of rows based on the current font and screen size. This is useful for setting columns while letting the system determine row count.<br><br><b>-s <i>rows</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the font size to accommodate the specified number of <i>rows</i>, keeping the number of columns as is. This effectively changes the height of the font.<br><br><b>-l</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists the valid console screen sizes that <i>resizecons</i> can set on the current system, useful for determining supported resolutions.<br><br><b>-V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints version information for <i>resizecons</i> and exits.<br><br><b>-?</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a usage message (help information) and exits.<br><br>


title: DESCRIPTION
content:
<i>resizecons</i> is a utility used to change the size (number of columns and rows) of the Linux console (text mode) screen. It allows users to set a specific resolution for the textual display, which can be useful when the default console settings do not match the monitor's capabilities or user preferences. This command interacts directly with the kernel's console drivers, often relying on framebuffer capabilities to achieve different display modes. It's typically used in situations where a finer control over the text console's appearance is desired, such as during system boot, in recovery mode, or on systems without a graphical environment. The specified dimensions must be supported by the system's hardware and kernel configuration. Using <i>resizecons</i> requires root privileges.


title: CAVEATS
content:
<i>resizecons</i> requires root privileges to operate. It only affects the Linux text console and has no impact on graphical environments (like X11 or Wayland). The new dimensions must be supported by the underlying video hardware and kernel configuration; choosing an unsupported mode can potentially lead to a blank or unusable console. Modern systems often manage console resolution via kernel boot parameters (e.g., <b>video=</b>) or display managers, reducing the direct need for this command.


title: REQUIRES ROOT PRIVILEGES
content:
To modify the console's dimensions, <i>resizecons</i> must be executed with superuser (root) permissions.


title: TEXT CONSOLE SPECIFIC
content:
This command is designed exclusively for the text-mode virtual consoles (e.g., TTYs 1-6) and does not affect graphical desktop environments or applications.


title: FRAMEBUFFER INTERACTION
content:
On systems using the Linux framebuffer console (fbcon), <i>resizecons</i> can leverage framebuffer capabilities to offer a wider range of resolutions beyond standard text modes. Its effectiveness often depends on the correctly loaded framebuffer driver.


title: HISTORY
content:
<i>resizecons</i> is part of the <b>kbd</b> (keyboard and console tools) package, which provides various utilities for managing the Linux console. It has been a staple tool for console configuration for many years, addressing the fundamental need to control the textual display dimensions. While still functional, its direct usage has become less common on modern systems that predominantly rely on graphical interfaces or advanced bootloader/kernel configuration for console settings.


title: PARAMETERS
content:
<b><I>DEVICE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the disk device (e.g., <B>/dev/sda</B>, <B>/dev/nvme0n1</B>) on which the partition resides. This is an argument to the main <B>parted</B> command.<br><br><b><I>NUMBER</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The minor number (or index) of the partition to be resized on the specified <I>DEVICE</I>. You can typically see this number when listing partitions (e.g., using <B>parted print</B>).<br><br><b>[<I>END</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional. The new end position of the partition. This value can be expressed in bytes or units specified by <B>parted</B>'s 'unit' command (e.g., 'MB', 'GB'). If omitted, <B>parted</B> will automatically resize the partition to its maximum possible extent, utilizing all available contiguous free space.<br><br>


title: DESCRIPTION
content:
<I>resizepart</I> is a subcommand of the <B>parted</B> utility, used for managing disk partitions. It allows you to resize an existing partition on a specified disk device. Unlike older tools like <B>fdisk</B>, <B>parted</B> (and thus <I>resizepart</I>) can resize partitions non-interactively and is capable of handling both MBR and GPT partition tables.<br><br>The primary function of <I>resizepart</I> is to adjust the size of a partition entry in the disk's partition table. When used without a specific end position, it expands the partition to occupy the maximum available contiguous unallocated space. If an end position is specified, it attempts to resize the partition to that exact boundary. It is critical to understand that <I>resizepart</I> only modifies the partition table entry; it does <B>not</B> resize the filesystem residing within the partition. Therefore, proper filesystem resizing (e.g., using <B>resize2fs</B> for ext4) is a separate, often crucial, step that must be performed before (for shrinking) or after (for growing) using <I>resizepart</I> to prevent data loss.


title: CAVEATS
content:
<b>Data Loss Risk:</b> Resizing partitions is a high-risk operation. <B>Always back up important data</B> before attempting to resize partitions. Incorrect use can lead to permanent data loss.<br><br><b>Filesystem Consistency:</b> <I>resizepart</I> only modifies the partition entry in the disk's partition table. It <B>does not</B> resize the filesystem contained within the partition. <br><ul><li>If <B>shrinking</B> a partition, you <B>must</B> shrink the filesystem <B>before</B> shrinking the partition to avoid data corruption.</li><li>If <B>growing</B> a partition, you <B>must</B> grow the filesystem <B>after</B> the partition has been expanded to utilize the newly allocated space.</li></ul><br><b>Mounted Filesystems:</b> You generally cannot resize a partition that is currently mounted. Always unmount the partition (and its filesystem) before attempting to resize it.<br><br><b>Contiguous Space:</b> To grow a partition, there must be contiguous unallocated space immediately adjacent to the partition you are resizing. <I>resizepart</I> typically expands to the right (higher addresses).<br><br><b>LVM/RAID/Cryptsetup:</b> For partitions used in Logical Volume Management (LVM), RAID arrays, or encrypted volumes (e.g., LUKS), dedicated tools like <B>pvresize</B>, <B>lvresize</B>, or <B>cryptsetup resize</B> should be used in conjunction with (or sometimes instead of) <B>parted</B> to ensure proper resizing of the underlying structures.


title: TYPICAL USAGE WORKFLOW
content:
A common sequence for safely growing a partition:<br>1. <B>Unmount</B> the filesystem: <B>umount /dev/sdxY</B><br>2. <B>Expand the partition:</B> <B>parted /dev/sdx resizepart Y</B> (where Y is the partition number, letting it expand to max)<br>3. <B>Run filesystem check:</B> <B>e2fsck -f /dev/sdxY</B> (for ext2/3/4 filesystems)<br>4. <B>Expand the filesystem:</B> <B>resize2fs /dev/sdxY</B> (for ext2/3/4). For XFS, use <B>xfs_growfs /mount/point</B>.<br>5. <B>Mount</B> the filesystem: <B>mount /dev/sdxY /mount/point</B>


title: UNITS AND DISPLAY
content:
<B>parted</B> works with various units for specifying positions and sizes. By default, it might display sizes in bytes or a dynamically chosen unit. You can explicitly set units using the <B>unit</B> command within the <B>parted</B> interactive prompt, or by adding <B>unit</B> before <B>resizepart</B> in a non-interactive command, e.g., <B>parted /dev/sda unit GB resizepart 1 10GB</B>. This allows for more human-readable and precise control over partition boundaries.


title: HISTORY
content:
<B>parted</B> (GNU Parted) was originally created by Andrew Clausen in 1998 with the goal of providing a powerful, flexible, and non-interactive partition editor. This was a significant advancement over older tools like <B>fdisk</B> which were primarily interactive and lacked support for modern partitioning schemes or on-the-fly resizing. The <I>resizepart</I> subcommand has been a fundamental component of <B>parted</B> since its early versions, embodying the utility's core capability to modify partition sizes directly without requiring a system reboot, making it invaluable for system administrators and scripting automated disk management tasks.


title: SEE ALSO
content:
parted(8), resize2fs(8), xfs_growfs(8), btrfs-filesystem(8), fdisk(8), gdisk(8), pvresize(8), lvresize(8)


title: SYNOPSIS
content:
<b>resolvconf</b> [<i>-a</i> | <i>-d</i> | <i>-u</i> | <i>-l</i> | <i>-I</i> | <i>-x</i> | <i>-m</i> | <i>-p</i> | <i>-f</i> | <i>-V</i>] [<i>interface</i>]


title: PARAMETERS
content:
<b><b>-a</b> <i>interface</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Adds nameserver and domain information for the specified <i>interface</i>. The information is read from standard input in the format of <i>resolv.conf</i>.<br><br><b><b>-d</b> <i>interface</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Deletes all nameserver and domain information stored for the specified <i>interface</i>.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Updates <i>/etc/resolv.conf</i>. This command is often called automatically by network management tools after changes are submitted.<br><br><b><b>-l</b> [<i>interface</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Lists the currently stored nameserver and domain information for all interfaces, or specifically for the given <i>interface</i>.<br><br><b><b>-I</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Lists all interfaces for which <i>resolvconf</i> currently has stored information.<br><br><b><b>-x</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Enables "exclusive" mode. When used, only the nameservers specified by the submitting script are included in <i>/etc/resolv.conf</i>, typically used for VPNs to enforce specific DNS.<br><br><b><b>-m</b> <i>metric</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Sets a metric (priority) for the submitted information. A lower metric value indicates higher priority, influencing the order in <i>resolv.conf</i>.<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Pushes (activates) the currently stored information. This is an older method, often replaced by <i>-u</i>.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Forces an update of <i>/etc/resolv.conf</i> even if no changes were detected.<br><br><b><b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Displays the version of <i>resolvconf</i>.<br><br>


title: DESCRIPTION
content:
<i>resolvconf</i> is a framework for managing the system's DNS resolver configuration file, <i>/etc/resolv.conf</i>. Unlike directly editing the file, <i>resolvconf</i> acts as a central nameserver information policy agent. Network configuration scripts, such as DHCP clients or VPN clients, submit DNS information (nameservers, search domains) to <i>resolvconf</i> via standard input. <i>resolvconf</i> then aggregates this information from all active interfaces, applies configurable ordering and policies, and generates the final <i>/etc/resolv.conf</i> file. This mechanism prevents conflicts and race conditions that arise when multiple network services attempt to write to <i>/etc/resolv.conf</i> simultaneously. It ensures that the resolver configuration is consistently maintained based on the most relevant and up-to-date network information.


title: CAVEATS
content:
While effective for managing <i>/etc/resolv.conf</i>, <i>resolvconf</i> relies on proper integration with network management tools (e.g., DHCP clients, VPN software) to submit and retract DNS information. Its role has somewhat diminished in distributions that predominantly use <i>systemd-resolved</i>, which offers its own DNS resolution capabilities and often manages <i>/etc/resolv.conf</i> via a symlink to <i>/run/systemd/resolve/stub-resolv.conf</i> or similar. Users might find debugging challenging if the various components (DHCP client, VPN, <i>resolvconf</i>, and potentially <i>systemd-resolved</i>) are not correctly configured to interact.


title: HOW IT WORKS
content:
<i>resolvconf</i> doesn't directly manage network interfaces. Instead, it provides an intermediary layer. Network scripts pipe DNS information to <i>resolvconf -a &lt;interface&gt;</i>. This information is stored in a temporary database. When an update is triggered (either explicitly via <i>resolvconf -u</i> or implicitly by a submitting script), <i>resolvconf</i> consolidates all stored entries, applies policies (like interface ordering, metrics), and then writes the final, aggregated configuration to <i>/etc/resolv.conf</i>.


title: COMMON USAGE
content:
A typical use case involves a DHCP client. When it receives DNS server addresses, it might run a script that executes <i>echo "nameserver 8.8.8.8" | resolvconf -a eth0</i>. When the DHCP lease expires or the interface goes down, the client would then call <i>resolvconf -d eth0</i> to remove the information. <i>resolvconf</i> handles the aggregation and final <i>/etc/resolv.conf</i> update seamlessly.


title: HISTORY
content:
<i>resolvconf</i> originated in the Debian and Ubuntu ecosystems as a robust solution to the long-standing problem of managing <i>/etc/resolv.conf</i> in dynamic network environments. Before its widespread adoption, multiple network services often competed to write to this file, leading to unreliable DNS resolution. It provided a standardized, conflict-free way for DHCP clients, VPN clients, and other network components to register their DNS requirements. Over time, it became a de facto standard for many distributions, though its prominence has been challenged by the emergence of <i>systemd-resolved</i> as a more integrated, systemd-native solution for DNS management on some modern Linux systems.


title: PARAMETERS
content:
<b>status</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the current DNS server and link settings configured for <i>systemd-resolved</i>.<br><br><b>query <HOSTNAME|IP_ADDRESS>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resolve one or more network names, IP addresses, or DNS resource records.<br><br><b>flush-caches</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Flush the local DNS resource record cache managed by <i>systemd-resolved</i>.<br><br><b>statistics</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show current cache statistics, including cache entries, hits, and misses.<br><br><b>dns <INTERFACE> <SERVER>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the DNS servers to use for the specified network interface.<br><br><b>domain <INTERFACE> <DOMAIN>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the DNS search domains to use for the specified network interface.<br><br><b>llmnr <INTERFACE> <MODE></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control LLMNR (Link-Local Multicast Name Resolution) for an interface. Modes: <i>yes</i>, <i>no</i>, <i>resolve</i>, <i>dont-resolve</i>.<br><br><b>mdns <INTERFACE> <MODE></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Control mDNS (Multicast DNS) for an interface. Modes: <i>yes</i>, <i>no</i>, <i>resolve</i>, <i>dont-resolve</i>.<br><br><b>log-level <LEVEL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Get or set the current log level for <i>systemd-resolved.service</i>.<br><br><b>revert <INTERFACE></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Revert the DNS settings for the specified interface to their defaults.<br><br><b>--json=pretty|short|off</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output in JSON format. 'pretty' for formatted, 'short' for condensed, 'off' (default) for plain.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a short help text and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a short version string and exit.<br><br>


title: DESCRIPTION
content:
<i>resolvectl</i> is a command-line client for <i>systemd-resolved.service</i>, a system service that provides network name resolution for local applications. It offers a standardized API for DNS, LLMNR (Link-Local Multicast Name Resolution), and mDNS (Multicast DNS) queries. <i>resolvectl</i> allows administrators to query, configure, and inspect the state of the <i>systemd-resolved</i> DNS stub resolver. It can be used to show current DNS servers configured, inspect DNS cache statistics, flush the local DNS cache, resolve specific hostnames or IP addresses, and manage per-interface DNS settings, including servers, search domains, and LLMNR/mDNS modes. This tool simplifies DNS management on systemd-based Linux systems by centralizing resolution services.


title: CAVEATS
content:
<i>resolvectl</i> requires the <i>systemd-resolved.service</i> to be running and active. Configuration changes made via <i>resolvectl</i> are often temporary and might be overridden by network management tools (like NetworkManager or systemd-networkd) if not integrated properly. It is primarily designed for use on systemd-based Linux distributions.


title: DNS CACHING
content:
<i>resolvectl</i> interacts with <i>systemd-resolved</i>'s built-in DNS cache. This cache stores resolved DNS queries to speed up subsequent lookups for the same domains, reducing network traffic and improving application responsiveness. The <i>flush-caches</i> and <i>statistics</i> commands provide direct control and insight into this caching mechanism.


title: SERVICE DISCOVERY PROTOCOLS
content:
Beyond traditional DNS, <i>resolvectl</i> supports LLMNR (Link-Local Multicast Name Resolution) and mDNS (Multicast DNS). These protocols enable hostname resolution and service discovery on local networks without requiring a central DNS server. This is particularly useful for ad-hoc networks or discovering devices like printers and media servers.


title: INTEGRATION WITH NSS
content:
<i>systemd-resolved</i> integrates with the GNU C Library's Name Service Switch (NSS) through the <i>nss-resolve</i> module. This allows standard system APIs like <i>gethostbyname()</i> to query <i>systemd-resolved</i> for hostnames, ensuring that all applications on the system can benefit from its resolution services, caching, and protocol support.


title: HISTORY
content:
<i>resolvectl</i> is an integral part of the <i>systemd</i> project, which began development in 2010. It was introduced as a client for <i>systemd-resolved.service</i>, which emerged as systemd's answer to centralized and modern network name resolution. Prior to its widespread adoption, DNS configuration was typically managed through static files like <i>/etc/resolv.conf</i>. <i>resolvectl</i> and <i>systemd-resolved</i> aim to provide a more dynamic, robust, and unified approach, handling DNS, LLMNR, and mDNS, along with local caching, to improve resolution performance and reliability on contemporary Linux systems.


title: PARAMETERS
content:
<b>hostname_or_ip</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The target string to resolve. This can be either a <i>hostname</i> (e.g., 'www.example.com') to be resolved into an IP address, or an <i>IP address</i> (e.g., '192.0.2.1') to be resolved into a hostname via a reverse DNS lookup.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a brief help message that outlines the command's usage and available options, then exits.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of the <i>resolveip</i> utility to standard output and then exits.<br><br>


title: DESCRIPTION
content:
<i>resolveip</i> is a minimalist command-line utility designed to perform simple DNS lookups, translating hostnames into their corresponding IP addresses and vice-versa. Unlike more feature-rich DNS tools like <i>dig</i> or <i>nslookup</i>, <i>resolveip</i> provides a straightforward interface, making it particularly useful for shell scripting or integration into other applications that require quick resolution without complex options.<br><br>This command is often found as part of the MySQL or MariaDB client packages, where it can be used internally by various database utilities to handle network address resolution. Its primary function is to print the resolved IP address or hostname to standard output, making it easy to capture and use the result programmatically. It leverages the system's underlying name service resolution mechanisms, including <code>/etc/hosts</code> and the configurations specified in <code>/etc/resolv.conf</code>, adhering to the Name Service Switch (NSS) settings.<br><br>Its simplicity means it lacks advanced features like specifying DNS servers, query types (e.g., MX, NS, PTR), or verbose debugging. It's intended for direct, single-lookup scenarios where a basic resolution is sufficient.


title: CAVEATS
content:
<i>resolveip</i> is not a universally available standard utility across all Linux distributions; it is most commonly distributed as part of the MySQL or MariaDB client packages. Users on systems without these packages might find it missing. For more advanced DNS queries or cross-distribution compatibility, alternatives like <i>dig</i>, <i>host</i>, or <i>nslookup</i> are generally preferred. It relies on the system's configured name resolution services and does not provide options to specify alternative DNS servers or network interfaces.


title: USAGE EXAMPLES
content:
To resolve a hostname to an IP address:<br><code>resolveip www.google.com</code><br><br>To resolve an IP address to a hostname (reverse lookup):<br><code>resolveip 8.8.8.8</code><br><br>The command prints the resolved address or hostname to standard output.


title: OUTPUT FORMAT
content:
<i>resolveip</i> typically outputs only the resolved IP address or hostname to standard output, followed by a newline character. If the resolution fails, it usually returns a non-zero exit code and may print an error message to standard error, depending on the version and underlying system libraries.


title: HISTORY
content:
The <i>resolveip</i> utility's lineage is closely tied to the MySQL and MariaDB database systems. It was developed to serve as a simple, internal resolver for these database clients, facilitating tasks such as connecting to hosts by name or logging client IP addresses. Its design reflects the need for a lightweight and easily scriptable tool within that ecosystem, rather than a standalone, feature-rich DNS diagnostic utility. Over time, it has become a convenient, though specialized, command-line tool for basic resolution tasks for users who have the MySQL/MariaDB client tools installed.


title: SYNOPSIS
content:
<b>systemctl</b> <I>restart</I> [<b>--no-block</b>] [<b>--wait</b>] [<b>--no-legend</b>] [<b>--no-pager</b>] <I>UNIT</I>...


title: PARAMETERS
content:
<b><I>UNIT</I>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more unit names (e.g., 'apache2.service', 'network.target') to restart. These units typically represent services, sockets, devices, mount points, or other systemd objects.<br><br><b><b>--no-block</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not wait for the operation to finish. The command returns immediately after the unit has been enqueued for the operation.<br><br><b><b>--wait</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wait for the operation to finish. This is typically the default for certain unit types (like services), ensuring the command doesn't return until the service has successfully started.<br><br><b><b>--no-legend</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not print the legend (column headers) when listing units or services.<br><br><b><b>--no-pager</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not pipe output into a pager. This is useful for scripting or when output needs to be redirected.<br><br>


title: DESCRIPTION
content:
The term <b>'restart'</b> in Linux does not refer to a standalone command but rather to a common operation performed on services, applications, or the entire system. When referring to services, <b>'restart'</b> typically means stopping a running service and then starting it again. This is crucial for applying configuration changes, recovering from errors, or refreshing service state.<br><br>The most prevalent tool for restarting services on modern Linux distributions (those using systemd) is the <b>systemctl</b> command with its <b>restart</b> subcommand. For restarting the entire Linux system, commands like <b>reboot</b> or <b>shutdown -r</b> are used. This analysis will focus primarily on the <b>systemctl restart</b> operation for services, which ensures that a service is gracefully shut down and then brought back up, often reloading its configuration files in the process.


title: CAVEATS
content:
The 'restart' command itself does not exist as a standalone executable in typical Linux installations; it's a subcommand of tools like <b>systemctl</b> or <b>service</b>. Restarting a service or the system typically requires root privileges (or <b>sudo</b>). A restart operation will momentarily stop the service, causing a brief interruption. For configuration changes that don't require a full stop/start, consider using <b>reload</b> if the service supports it.


title: RESTART VS. RELOAD
content:
The <b>restart</b> command explicitly stops a service and then starts it again. This ensures the service is completely reinitialized, which is often necessary after significant configuration changes or to clear internal states. In contrast, <b>reload</b> (if supported by the service) attempts to apply configuration changes without stopping the service, leading to zero or minimal downtime. Always prefer <b>reload</b> if it achieves the desired effect and the service supports it, otherwise use <b>restart</b>.


title: SYSTEM-WIDE RESTART
content:
For a complete system reboot, commands such as <b>reboot</b> or <b>shutdown -r now</b> are used. These commands are typically reserved for kernel updates, system-wide configuration changes, or critical system recovery, as they affect all running processes and bring the entire operating system down and back up.


title: HISTORY
content:
In older Linux systems (pre-systemd), services were primarily managed via System V init scripts located typically in <i>/etc/init.d/</i>. Restarting a service involved executing a script directly, e.g., <i>/etc/init.d/apache2 restart</i>, or using the <b>service</b> wrapper command (e.g., <b>service apache2 restart</b>).<br><br>With the adoption of systemd as the default init system in most modern distributions (e.g., Fedora, CentOS 7+, Debian 8+, Ubuntu 15.04+), <b>systemctl</b> has become the standard utility for managing services, including the <b>restart</b> operation. This evolution aimed to provide a more consistent, efficient, and powerful framework for service control and dependency management.


title: PARAMETERS
content:
<b><b>Global Options:</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;These options apply to the main <i>restic</i> command and affect its overall behavior.<br><br><b>-r, --repository <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path or URL to the backup repository. This is often set via the RESTIC_REPOSITORY environment variable.<br><br><b>--password-file <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the repository password from the specified file, enhancing security by avoiding password exposure in command history.<br><br><b>--json</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables JSON output for machine-readable results, useful for scripting and integration.<br><br><b>--verbose, -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output. Can be used multiple times for more detail (e.g., -vvv).<br><br><b>--compression <i>&lt;type&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the compression level for data stored in the repository. Valid types include 'off', 'auto', 'max'.<br><br><b><b>Subcommand Options (Examples):</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Each <i>restic</i> subcommand (e.g., <i>backup</i>, <i>restore</i>, <i>prune</i>) has its own set of specific options. Below are common examples for frequently used commands.<br><br><b><i>backup</i> --exclude <i>&lt;pattern&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files or directories matching the specified pattern during a backup operation. Can be used multiple times.<br><br><b><i>backup</i> --tag <i>&lt;tag&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds one or more tags to the snapshot, allowing for easier filtering and management of backups.<br><br><b><i>restore</i> --target <i>&lt;dir&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the destination directory where the files will be restored. If not specified, files are restored to the current directory.<br><br><b><i>prune</i> --keep-daily <i>&lt;n&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retains <i>n</i> daily snapshots during the pruning process, removing older ones.<br><br><b><i>prune</i> --dry-run</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulates the prune operation without making any actual changes to the repository, useful for testing retention policies.<br><br>


title: DESCRIPTION
content:
<i>restic</i> is a modern, open-source backup program designed for speed, efficiency, and security. It focuses on solving common backup challenges with innovative features.<br><br>At its core, <i>restic</i> employs data deduplication, ensuring that only unique data blocks are stored in the repository, significantly reducing storage space and bandwidth requirements, especially across multiple backups of similar data. All data is encrypted client-side using authenticated encryption (AES-256 in counter mode with Poly1305) before being sent to the repository, ensuring privacy and integrity even if the storage backend is compromised.<br><br><i>restic</i> operates by creating snapshots of your files and directories. Each snapshot is incremental, meaning it only stores the changes since the last snapshot, yet it appears as a full backup, making restoration straightforward. It supports various storage backends, including local directories, SSH servers, and cloud storage providers like Amazon S3, Google Cloud Storage, Azure Blob Storage, Backblaze B2, and SFTP.<br><br>Key features include resumable backups, efficient pruning of old snapshots based on flexible retention policies, and robust integrity checking to verify the repository's consistency. Its command-line interface is user-friendly, and it's written in Go, making it cross-platform compatible with Linux, macOS, Windows, and BSD. <i>restic</i> is an excellent choice for individuals and small businesses seeking a reliable, secure, and resource-efficient backup solution.


title: CAVEATS
content:
<i>restic</i> itself does not include a built-in scheduler; users must rely on external tools like <i>cron</i>, <i>systemd timers</i>, or Windows Task Scheduler to automate backups.<br><br>Performance can vary significantly depending on the chosen backend, network latency, and local disk I/O. For large repositories, operations like <i>check</i> can be memory-intensive.<br><br>While highly secure, losing your repository password means permanent loss of all encrypted data.


title: REPOSITORY INITIALIZATION
content:
Before performing any backup, a <i>restic</i> repository must be initialized. This is done using the <b>restic init</b> command, which creates the repository structure and prompts for a new password. For example:<br><code><b>restic init --repo sftp:user@host:/path/to/repo</b></code><br>This sets up the secure storage location for your backups.


title: ENVIRONMENT VARIABLES
content:
For convenience and security, <i>restic</i> highly recommends using environment variables to specify common parameters like the repository path and password. For instance:<br><code>export RESTIC_REPOSITORY="s3:s3.amazonaws.com/my-bucket/restic-repo"</code><br><code>export RESTIC_PASSWORD_FILE="/root/.restic-password"</code><br>This prevents sensitive information from appearing in command history and reduces typing.


title: SECURITY MODEL
content:
<i>restic</i>'s security model is built on client-side encryption and authenticated encryption. Data is encrypted using AES-256 in counter mode with Poly1305 before it leaves your machine. This ensures that even if the storage backend is compromised, your data remains confidential and its integrity protected. The repository password serves as the master key for all encryption and decryption operations.


title: SUPPORTED BACKENDS
content:
<i>restic</i> offers flexible backend support, allowing users to store their repositories in various locations. Common supported backends include:<br><i>Local:</i> A directory on the local filesystem.<br><i>SSH/SFTP:</i> An SSH server with SFTP access.<br><i>Amazon S3:</i> Amazon Web Services S3 buckets.<br><i>Google Cloud Storage:</i> Google's cloud storage.<br><i>Azure Blob Storage:</i> Microsoft Azure's object storage.<br><i>Backblaze B2:</i> Backblaze's cloud storage.<br><i>MinIO:</i> Self-hosted S3-compatible object storage.


title: HISTORY
content:
<i>restic</i> was initiated by Alexander Neumann around 2014, with the first public release in 2015. It was developed to address shortcomings found in existing backup solutions, particularly focusing on robust encryption, efficient deduplication, and a user-friendly command-line interface. Written in Go, it quickly gained traction for its cross-platform compatibility and modern feature set, establishing itself as a popular choice for both personal and server backups.


title: PARAMETERS
content:
<b>-R, -r</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Recursive operation.</b> <br>Recursively walk through specified directories.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Verbose output.</b> <br>Show changes being made.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>No-op mode (dry run).</b> <br>Show what would be restored without actually changing contexts.<br><br><b>-F, -f</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Force context reset.</b> <br>Force a reset of the security context to the default, even if the current context is not unknown or incorrect. This can be used to re-apply the policy.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Ignore errors.</b> <br>Continue processing other files even if errors occur on some.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Preserve modification time.</b> <br>Do not update the modification time of files if their context is restored.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Do not create new files.</b> <br>When used with <i>-R</i>, prevents <i>restorecon</i> from attempting to create new files or directories.<br><br><b>-P</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Disable parent process tracking.</b> <br>Disables the parent process tracking, which can be useful for performance in very large operations.<br><br><b>-e EXCLUDE_REGEX, --exclude=EXCLUDE_REGEX</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Exclude files/directories.</b> <br>Exclude files that match the regular expression. Can be specified multiple times.<br><br><b>-L, --local</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Local filesystems only.</b> <br>Do not descend into directories on other filesystems.<br><br><b>-m, --map</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Map unknown file contexts.</b> <br>Map unknown file types (e.g., those from specific applications) to known ones, based on the policy.<br><br><b>-s, --silent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Silent mode.</b> <br>Suppress output unless an error occurs.<br><br><b>-T TARGET_TYPE, --target-file-type=TARGET_TYPE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Target file type.</b> <br>Restore only files that have the specified file type.<br><br><b>-u, --user</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Update user context.</b> <br>Only restore the user portion of the security context.<br><br><b>-g, --role</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Update role context.</b> <br>Only restore the role portion of the security context.<br><br><b>-t, --type</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Update type context.</b> <br>Only restore the type portion of the security context.<br><br><b>-S, --skip-base-relabels</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Skip base relabels.</b> <br>Only relabel if a file is already labeled with the SELinux type of its parent. (Less common use).<br><br><b>-W, --relabel-device-nodes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Relabel device nodes.</b> <br>Relabel device nodes if their context does not match what the kernel expects.<br><br><b>-D, --remove-current-contexts</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>Remove current contexts.</b> <br>Remove the current context of files, forcing a full relabel from policy. (Use with caution).<br><br>


title: DESCRIPTION
content:
<i>restorecon</i> is a utility used to restore the default SELinux security contexts of files and directories. SELinux (Security-Enhanced Linux) provides a mandatory access control (MAC) mechanism, and each file, directory, and process on an SELinux-enabled system has a security context. This context determines what actions are permitted or denied. When files are created, moved, or restored from backups, they might end up with incorrect or outdated SELinux contexts.<br><br><i>restorecon</i> reads the system's SELinux policy and the <i>file_contexts</i> database to determine the correct context for a given path. It then applies this context, ensuring that files and directories have the appropriate labels as defined by the policy, which is crucial for system security and proper application functioning. It's often used after system upgrades, file transfers, or when troubleshooting SELinux permission issues.


title: CAVEATS
content:
<b>Performance Impact</b>: Running <i>restorecon</i> recursively on large filesystems (like /) can be very time-consuming and resource-intensive, especially on systems with many files. It's often better to target specific directories.<br><br><b>Incorrect Policy</b>: <i>restorecon</i> relies on the installed SELinux policy and its <i>file_contexts</i> configuration. If these are incorrect or outdated, <i>restorecon</i> might apply wrong contexts, potentially leading to new access denied errors.<br><br><b>Misuse</b>: Indiscriminate use of <i>restorecon</i> without understanding its implications can sometimes break applications that rely on specific, non-default contexts. Always verify changes using <i>-n</i> (dry run) first.<br><br><b>Interaction with <i>semanage fcontext</i></b>: Any custom file context rules defined via <i>semanage fcontext</i> will be honored by <i>restorecon</i>, as they update the policy's <i>file_contexts</i>.<br><br><b>Kernel vs. Userspace</b>: The command primarily handles the userspace context of files. Sometimes, contexts might differ between kernel and userspace, requiring a reboot for full consistency, especially for root filesystem or kernel-managed devices.


title: HOW CONTEXTS ARE DETERMINED
content:
<i>restorecon</i> primarily uses the <i>file_contexts</i> file (or its compiled binary form within the SELinux policy) to determine the correct security context for files and directories. This file contains regular expressions and their corresponding SELinux contexts. When a file is processed, <i>restorecon</i> matches its path against these rules to find the appropriate label.


title: /.AUTORELABEL AND FIXFILES
content:
On systems with SELinux, a file named <i>/.autorelabel</i> can be created in the root directory. Upon the next reboot, the system's init scripts (often using <i>fixfiles</i>) will detect this file and perform a full file system relabel, which involves extensively calling <i>restorecon</i> for all files. This is a common way to apply widespread context changes or fix a severely mislabeled system.


title: CONTEXTS FOR NEW FILES
content:
When new files are created, the kernel assigns a default context based on the creating process's context and the parent directory's context. <i>restorecon</i> then ensures these newly created files conform to the <i>file_contexts</i> policy rules, especially if the initial kernel-assigned context is not the desired final context.


title: HISTORY
content:
<i>restorecon</i> is an integral part of the SELinux userspace tools, which have been developed alongside the SELinux kernel modules since the early 2000s, primarily driven by the National Security Agency (NSA) and later adopted by various Linux distributions. It fills a critical need for maintaining file system integrity within the SELinux security model by ensuring that files always carry their correct security labels as defined by policy. Its development has focused on efficiency and robustness in handling large file systems and complex policy rules.


title: PARAMETERS
content:
<b><i>(No direct options)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The <b>resume</b> subcommand does not accept any direct options or arguments. General <b>systemctl</b> options (e.g., <b>--no-block</b>, <b>--quiet</b>) can be used before the subcommand, but are generally not relevant for the resume operation itself as it's typically an immediate action.<br><br>


title: DESCRIPTION
content:
The <b>systemctl resume</b> command is a component of the <b>systemd</b> init system, widely adopted across modern Linux distributions. Its primary function is to bring a system back from a suspended (suspend-to-RAM) or hibernated (suspend-to-disk) state to full operational capacity. This operation leverages the kernel's power management capabilities. It acts as the counterpart to commands like <b>systemctl suspend</b> and <b>systemctl hibernate</b>.<br><br>When a system is suspended, its state is preserved in RAM (S3 state). In hibernation, the state is saved to disk (S4 state). <b>systemctl resume</b> handles the recovery process for both. While systems typically resume automatically upon power-on after suspension, <b>systemctl resume</b> can be invoked directly by administrators or scripts for specific management tasks. It provides a standardized interface for managing system power states within the <b>systemd</b> ecosystem.


title: CAVEATS
content:
This command requires appropriate permissions, typically root privileges or sudo.<br>The system must have been previously suspended or hibernated using a compatible power management command like <b>systemctl suspend</b> or <b>systemctl hibernate</b>.<br>Successful resumption depends on proper hardware support and driver functionality for power management.<br>System state corruption or power loss during suspension/hibernation can lead to issues upon resume.


title: RESUMING PROCESSES
content:
To resume a process that has been stopped (e.g., by <b>Ctrl+Z</b>), the <b>kill</b> command can be used with the <b>SIGCONT</b> signal. For example, <b><I>kill -CONT &lt;PID&gt;</I></b>. Alternatively, for shell-managed jobs, the built-in commands <b>fg</b> (foreground) or <b>bg</b> (background) can be used to resume the process.


title: RESUMING FILE TRANSFERS
content:
Many command-line download tools support resuming interrupted file transfers. The <b>wget</b> command uses the <b>-c</b> (continue) option (e.g., <b><I>wget -c &lt;URL&gt;</I></b>). Similarly, <b>curl</b> uses the <b>-C -</b> (continue from where left off) option (e.g., <b><I>curl -C - &lt;URL&gt;</I></b>).


title: RESUMING VIRTUAL MACHINES
content:
Virtualization management tools often provide commands to suspend and resume virtual machines. For instance, with <b>libvirt</b>, the <b>virsh</b> command can be used: <b><I>virsh resume &lt;domain-name&gt;</I></b> will resume a suspended virtual machine guest.


title: UNFREEZING FILESYSTEMS
content:
The <b>fsfreeze</b> command is used to suspend (freeze) access to a filesystem, typically for backup purposes. To unfreeze or resume normal operations on such a filesystem, the command is <b><I>fsfreeze -u &lt;mount-point&gt;</I></b>.


title: HISTORY
content:
The <b>systemctl resume</b> command is part of <b>systemd</b>, which emerged as the dominant init system for Linux distributions in the early 2010s, replacing older systems like SysVinit and Upstart. Prior to <b>systemd</b>, system suspension and resumption were often managed by utilities from the <b>pm-utils</b> package (e.g., <b>pm-suspend</b>) or by directly manipulating kernel power interfaces in <i>/sys/power/state</i>. <b>systemctl resume</b> provides a modern, unified, and integrated approach to power management within the <b>systemd</b> framework.


title: SYNOPSIS
content:
<B>retroarch</B> [<I>options</I>] [<I>content_file_path</I>]<BR><B>retroarch</B> <B>-L</B> <I>core_path</I> [<I>options</I>] [<I>content_file_path</I>]<BR><B>retroarch</B> <B>--menu</B>


title: PARAMETERS
content:
<b>-L, --libretro <core_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a specific Libretro core (e.g., <I>/usr/lib/libretro/snes9x_libretro.so</I>).<br><br><b>-f, --fullscreen</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts RetroArch immediately in fullscreen mode.<br><br><b>-c, --config <file_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file to load instead of the default.<br><br><b>--menu</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Launches RetroArch directly into its graphical user interface menu.<br><br><b>-s, --load-state <file_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a specific savestate file when content is loaded.<br><br><b>-S, --save-state-on-exit <file_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves a savestate to the specified file upon exiting content.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose logging, providing more detailed output to the console.<br><br><b>--set-libretro-path <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides the default directory where Libretro cores are searched for.<br><br><b>--scan-directory <dir_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Scans a directory for supported content and adds it to playlists.<br><br><b>--output-directory <dir_path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the base directory for screenshots, savestates, and other generated files.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the RetroArch version information and exits.<br><br>


title: DESCRIPTION
content:
RetroArch is a free, open-source, and cross-platform frontend for the <B>Libretro API</B>. It consolidates a vast array of emulators, game engines, video games, media players, and other applications into a single, cohesive interface. By leveraging a modular system known as <I>cores</I>, RetroArch allows users to run diverse content ranging from classic arcade games and retro console titles to modern homebrew applications.<BR><BR>Its powerful feature set includes advanced video shaders for enhanced graphics, netplay for online multiplayer, robust save state and rewind capabilities, and highly configurable input remapping. RetroArch aims to provide a unified, low-latency, and feature-rich experience for retro gaming and media consumption across various operating systems and devices, making it a cornerstone for game preservation and emulation enthusiasts.


title: CAVEATS
content:
RetroArch's extensive configuration options can be daunting for new users, requiring a learning curve to fully utilize its capabilities.<BR>Cores must be downloaded separately, often through the in-application updater, or manually placed in the correct directories.<BR>Performance can vary significantly depending on the chosen core, content, and the host system's hardware, especially when using advanced video shaders or high-resolution packs.


title: LIBRETRO CORES
content:
Libretro cores are dynamic libraries (e.g., <I>.so</I> files on Linux) that implement the Libretro API. Each core is essentially a specific emulator (e.g., SNES9x, PCSX2, Dolphin) or game engine, allowing RetroArch to run different types of content without needing to be rebuilt for each system. Users typically download and manage cores via RetroArch's internal Core Downloader.


title: CONFIGURATION FILES
content:
RetroArch relies heavily on configuration files, typically located at <I>~/.config/retroarch/retroarch.cfg</I> or system-wide under <I>/etc/retroarch.cfg</I>. These plaintext files control every aspect of RetroArch's behavior, including video settings, input binds, directory paths, and UI preferences. Per-core or per-game configuration overrides are also possible, offering granular control.


title: USER INTERFACE (UI) DRIVERS
content:
RetroArch offers several customizable UI drivers, allowing users to choose their preferred look and feel. Popular drivers include <B>XMB</B> (inspired by PlayStation XMB), <B>Ozone</B> (a modern, clean interface), and <B>RGUI</B> (a lightweight, text-based interface ideal for resource-constrained systems or command-line navigation). These can be switched within the settings or via command-line options.


title: HISTORY
content:
RetroArch began its life around 2010 as <I>SSNES</I>, a Super Nintendo Entertainment System emulator. Its developers soon realized the potential for a unified API to run various emulators, leading to the creation of the <B>Libretro API</B>. RetroArch then evolved as the primary frontend for this API, allowing different emulators (now called <I>cores</I>) to plug into a standardized interface. This architectural shift significantly simplified development and distribution of emulators and their features. Over the years, it has grown into a highly flexible and powerful platform supporting hundreds of cores and a vast array of features, becoming a cornerstone of the open-source emulation community.


title: SYNOPSIS
content:
<b>retry</b> <i>[OPTIONS] COMMAND [ARGUMENTS...]</i><br><i>Example:</i> <b>retry -n 5 -d 2 curl -f http://example.com/data</b>


title: PARAMETERS
content:
<b><b>-n N</b>, <b>--attempts N</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specifies the maximum number of times to retry the `COMMAND`.</i><br><br><b><b>-d S</b>, <b>--delay S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Sets the delay in seconds between consecutive retry attempts.</i><br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Suppresses all output from `retry` itself, only showing `COMMAND` output.</i><br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enables verbose output, showing each retry attempt and its status.</i><br><br><b><b>-b</b>, <b>--backoff</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Applies an exponential backoff strategy to the delay between attempts.</i><br><br><b><b>-t S</b>, <b>--timeout S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Sets a timeout in seconds for the `COMMAND` itself to complete.</i><br><br><b><b>-e CODES</b>, <b>--exit-codes CODES</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Defines a comma-separated list of exit codes considered successful.</i><br><br>


title: DESCRIPTION
content:
The <b>retry</b> command is a powerful utility designed to enhance the robustness of scripts and automated tasks by automatically re-executing a specified command until it succeeds or a predefined number of attempts is exhausted. This is particularly useful in environments where transient failures are common, such as unreliable network connections, temporary resource unavailability, or race conditions.<br><br>Instead of immediately failing when a command returns a non-zero exit code (indicating an error), <b>retry</b> allows for a configurable delay between attempts and a maximum retry count. This mechanism significantly improves the resilience of operations that might otherwise fail due to temporary glitches. Common scenarios include fetching data from a remote server, connecting to a database, or performing file operations on a network share. By incorporating <b>retry</b>, system administrators and developers can create more stable and fault-tolerant automation, reducing the need for manual intervention and improving overall system reliability. It typically monitors the exit status of the executed command, considering an exit code of <i>0</i> as success and any non-zero code as a failure requiring a retry.


title: CAVEATS
content:
The <b>retry</b> command is not a standard POSIX utility and its implementation can vary significantly. Users should be aware that it's often a custom script or a third-party tool. Incorrect usage, especially with high retry counts or short delays, can lead to excessive resource consumption or even contribute to the very issues it's trying to mitigate (e.g., overwhelming a service). Ensure the retried command is idempotent if side effects are not desired on multiple executions.


title: IMPLEMENTATION NOTES
content:
Most <b>retry</b> implementations work by executing the given `COMMAND` and inspecting its exit status. A zero exit code typically signifies success, while any non-zero code indicates an error. The utility then pauses for a specified `delay` and re-executes the command if the `attempts` limit has not been reached.


title: COMMON USE CASES
content:
<i>Connecting to a remote server:</i> <b>retry -n 10 -d 5 ssh user@host 'echo "Connected!"'</b><br><i>Downloading a file:</i> <b>retry -n 5 -d 10 curl -fL http://example.com/largefile -o localfile.zip</b><br><i>Waiting for a service:</i> <b>retry -n 30 -d 2 nc -z localhost 8080</b> <i>(checking if port is open)</i>


title: HISTORY
content:
While not a single, universally standardized command with a formal development history, the concept of "retrying" operations has been a fundamental pattern in robust programming and scripting for decades. Its prominence in Linux environments grew with the increasing complexity of distributed systems and network-dependent applications. Shell scripts implementing <b>retry</b> functionality became commonplace as a practical way to handle transient failures without requiring complex error handling logic within the primary command itself. Various community-driven implementations and custom scripts evolved, reflecting a shared need for increased resilience in automated tasks. It represents a practical, decentralized solution to a pervasive problem in systems administration and automation.


title: PARAMETERS
content:
<b><i>n</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An integer between 0 and 255, representing the exit status of the function. By convention, <i>0</i> signifies success, while any non-zero value indicates an error or a specific condition. If omitted, the return status is the exit status of the last command executed within the function.<br><br>


title: DESCRIPTION
content:
The <i>return</i> command is a shell built-in used exclusively within shell functions to terminate their execution and return control to the calling script or function. It allows a function to signal its success or failure by providing an optional integer argument, which serves as the function's exit status.<br><br>When <i>return</i> is called with an argument <i>n</i>, that value becomes the function's exit status, which can be retrieved by the caller using the special shell variable <i>$?</i>. If <i>n</i> is omitted, the function's exit status will be that of the last command executed within the function.<br><br>It's important to note that if <i>return</i> is invoked outside the context of a shell function (i.e., directly in a script or interactive shell), it behaves identically to the <i>exit</i> command, terminating the current shell or script entirely.


title: CAVEATS
content:
<b>Shell Built-in:</b> It is a shell built-in command, not an external executable. Its behavior is consistent across most POSIX-compliant shells (e.g., Bash, Zsh, Dash), but specific shell versions might have minor nuances.<br><br><b>Function Context:</b> The <i>return</i> command is primarily designed for use inside shell functions. If executed directly in a script or interactive shell (i.e., outside a function), it behaves identically to the <i>exit</i> command, terminating the current shell process.<br><br><b>Exit Status, Not Value:</b> Unlike some programming languages, <i>return</i> in shell scripting returns an exit status (an integer), not a complex data value or object. To return data, one typically echoes it to standard output and captures it using command substitution (`$(...)`).<br><br><b>Scope:</b> While <i>return</i> exits a function, it does not automatically stop the entire script unless it was called from the main script body (acting as <i>exit</i>).


title: <B>CAPTURING FUNCTION STATUS</B>
content:
The exit status returned by a function (either explicitly via <i>return</i> or implicitly) can be captured using the special shell variable <i>$?</i> immediately after the function call.<br><code>my_function() {<br>  echo "Hello from function";<br>  return 10;<br>}<br><br>my_function<br>status=$?<br>echo "Function exited with status: $status"</code><br>This will output:<br><code>Hello from function<br>Function exited with status: 10</code>


title: <B>IMPLICIT RETURN</B>
content:
If a function completes its execution without an explicit <i>return</i> command, its exit status will be the exit status of the last command executed within that function. This is a common and often utilized feature in shell scripting.<br><code>another_function() {<br>  ls /non_existent_path  # This command will fail<br>}<br><br>another_function<br>echo "Function exited with status: $?"</code><br>This will typically output:<br><code>ls: cannot access '/non_existent_path': No such file or directory<br>Function exited with status: 2</code> (assuming 2 is ls's exit code for 'no such file')


title: HISTORY
content:
The concept of functions and the ability to explicitly return from them with an exit status became standardized in Unix shells with the evolution towards POSIX compliance. While early shells like the Bourne Shell had limited function support, shells like KornShell (ksh) and later Bash significantly enhanced function capabilities, making <i>return</i> a fundamental part of structured shell scripting. It provides a standardized way for functions to communicate their outcome to the caller, similar to how commands communicate their status to the shell.


title: DESCRIPTION
content:
The <b>rev</b> command is a fundamental Unix-like utility designed to reverse the order of characters within each line of its input. It reads lines from specified <i>FILE</i>s or, if no files are provided, from standard input. For every line it processes, <b>rev</b> effectively reverses the sequence of all characters and then prints the modified line to standard output.<br><br>Unlike <b>tac</b>, which reverses the order of lines in a file, <b>rev</b> operates strictly at the character level within <i>each individual line</i>. This makes it an invaluable tool in text processing pipelines, often combined with other commands like <b>grep</b> or <b>awk</b> for specialized tasks such as identifying palindromes, preparing data for unique sorting requirements, or simple string manipulation.<br><br>For instance, running <code>echo "Linux is awesome" | rev</code> would produce <code>emosewa si xuniL</code>.


title: CAVEATS
content:
<b>rev</b> processes input line by line; it does not reverse the order of lines in a file. For that specific functionality, the <b>tac</b> command should be used.<br><br>While modern implementations of <b>rev</b> generally handle multi-byte characters (such as those in UTF-8) correctly based on system locale settings, it's important to be aware that on older or misconfigured systems, it might process bytes literally, which could lead to incorrect reversal of complex multi-byte characters or grapheme clusters.


title: INPUT/OUTPUT
content:
By default, <b>rev</b> reads from standard input. Alternatively, you can specify one or more <i>FILE</i>s as arguments; <b>rev</b> will then process lines from these files sequentially. If a <i>FILE</i> is specified as <code>-</code> (a hyphen), it also signifies reading from standard input. All processed output, regardless of the input source, is consistently written to standard output.


title: NO COMMAND-LINE OPTIONS
content:
<b>rev</b> stands out for its straightforward design as it does not accept any command-line options or flags to modify its behavior. Its sole function is to reverse characters within lines, making it a highly focused utility.


title: HISTORY
content:
<b>rev</b> is a classic and long-standing Unix utility, embodying the Unix philosophy of performing one task efficiently and effectively. It has been a standard component of GNU Coreutils from its early stages, ensuring its pervasive availability across Linux distributions and other Unix-like operating systems. Its simple yet powerful character-reversal capability has made it a quiet but essential part of the command-line toolkit for decades.


title: SYNOPSIS
content:
<b>rfcomm</b> [<i>options</i>] <i>command</i> [<i>arguments</i>]<br><br><i>Common commands:</i><br><b>rfcomm</b> [<i>-i hciX</i>] <b>bind</b> <i>&lt;dev&gt; &lt;bdaddr&gt; &lt;channel&gt;</i><br><b>rfcomm</b> [<i>-i hciX</i>] <b>connect</b> <i>&lt;dev&gt; &lt;bdaddr&gt; &lt;channel&gt;</i> [<i>timeout</i>]<br><b>rfcomm</b> [<i>-i hciX</i>] [<i>options</i>] <b>listen</b> <i>&lt;dev&gt; &lt;channel&gt;</i> [<i>timeout</i>]<br><b>rfcomm</b> [<i>-i hciX</i>] <b>release</b> <i>&lt;dev&gt;</i><br><b>rfcomm</b> [<i>-i hciX</i>] <b>show</b> <i>&lt;dev&gt;</i>


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information and exits.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version number and exits.<br><br><b>-i <i>&lt;hciX&gt;</i>, --hci-device <i>&lt;hciX&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the HCI (Host Controller Interface) device to use, e.g., <i>hci0</i>.<br><br><b>-r, --raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses raw device operations, bypassing the kernel RFCOMM layer.<br><br><b>-P, --persist</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes the device persistent, automatically reconnecting upon connection loss.<br><br><b>-S, --server</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in server mode, listening for incoming connections.<br><br><b>-C, --client</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in client mode, initiating outgoing connections.<br><br><b>-E, --etr</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables ETR (Enhanced Retransmission mode) for data reliability.<br><br><b>-T, --tmf</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables TMF (Test Mode Feature) mode.<br><br><b>-A, --auth</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Requires Bluetooth authentication for the connection.<br><br><b>-D, --encrypt</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Requires Bluetooth encryption for the connection.<br><br><b>-M, --master</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the local device as the Bluetooth master in the connection.<br><br><b>-L, --local</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Configures local loopback mode.<br><br><b>-W <i>&lt;timeout&gt;</i>, --wait <i>&lt;timeout&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a timeout (in seconds) for connection establishment.<br><br><b>-B <i>&lt;bdaddr&gt;</i>, --bdaddr <i>&lt;bdaddr&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Bluetooth address (BD_ADDR) of the remote device.<br><br><b>-s <i>&lt;channel&gt;</i>, --channel <i>&lt;channel&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the RFCOMM channel to use.<br><br><b>-N, --no-tty</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents allocation of a TTY device.<br><br><b>-X, --xoff</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables XOFF (Software Flow Control) for the serial port.<br><br><b>-R, --rtscts</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables RTS/CTS (Hardware Flow Control) for the serial port.<br><br><b>-K, --loopback</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables local loopback for testing.<br><br><b>-p <i>&lt;port&gt;</i>, --port <i>&lt;port&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the local port (for <b>listen</b> or <b>connect</b> commands).<br><br><b>-V, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output for detailed information.<br><br>


title: DESCRIPTION
content:
<b>rfcomm</b> is a Linux command-line utility for configuring, displaying, and managing RFCOMM (Radio Frequency Communication) connections. RFCOMM is a protocol, part of the Bluetooth specification, that provides emulation of serial ports over the Bluetooth baseband. This allows Bluetooth devices to communicate as if they were connected via a traditional serial cable.<br><br>Common applications include Bluetooth modems, GPS receivers, headsets, and other devices requiring serial data transfer. The <b>rfcomm</b> utility enables users to bind Bluetooth devices to local RFCOMM TTY devices (e.g., <i>/dev/rfcomm0</i>), establish outgoing connections, listen for incoming connections, and monitor device status. It is an essential tool for setting up and debugging Bluetooth Serial Port Profile (SPP) connections on Linux systems, providing granular control over various RFCOMM parameters such as flow control, authentication, and encryption.


title: CAVEATS
content:
RFCOMM connections require a functioning Bluetooth adapter and the <b>bluetooth</b> service to be running.<br>Proper Bluetooth pairing and trust relationships might be necessary before establishing RFCOMM connections, especially with authentication or encryption enabled.<br>Channel numbers vary depending on the service being offered by the remote device (e.g., Serial Port Profile (SPP) usually uses channel 1, but this can differ).<br>Managing multiple RFCOMM devices (e.g., <i>/dev/rfcomm0</i>, <i>/dev/rfcomm1</i>) requires careful attention to avoid conflicts.


title: RFCOMM CHANNELS
content:
RFCOMM uses specific channels (similar to TCP/UDP ports) to distinguish between different services offered by a Bluetooth device. The channel number must be known for both client and server to establish a connection. Standard services like Serial Port Profile (SPP) often default to channel 1, but this can vary depending on the device or service being offered.


title: TTY DEVICE EMULATION
content:
When an RFCOMM connection is established (e.g., via <b>rfcomm bind</b> or <b>rfcomm connect</b>), it typically creates a virtual TTY device (e.g., <i>/dev/rfcomm0</i>). This allows standard serial communication applications (like <b>minicom</b> or custom scripts) to interact with the Bluetooth device as if it were a physical serial port, simplifying application development and usage.


title: HISTORY
content:
<b>rfcomm</b> is an integral part of the BlueZ project, the official Linux Bluetooth protocol stack. BlueZ has been under continuous development since 2001, providing core Bluetooth functionalities, including RFCOMM support, for the Linux kernel and userspace utilities. The <b>rfcomm</b> command specifically has been a long-standing component, crucial for enabling Serial Port Profile (SPP) communication, which was one of the earliest and most widely adopted Bluetooth profiles for data transfer. Its role has remained consistent in allowing Linux systems to act as both client and server for RFCOMM connections.


title: SYNOPSIS
content:
As <i>rfetch</i> is not a standard command, a universal synopsis cannot be provided. Its syntax would be entirely defined by its specific implementation.


title: DESCRIPTION
content:
The command <i>rfetch</i> is <b>not</b> a standard utility found in most mainstream Linux distributions or common core utilities packages. There is no universally recognized or documented 'rfetch' command akin to standard tools like <i>ls</i>, <i>grep</i>, <i>curl</i>, or <i>wget</i>.<br><br>It most likely refers to a <b>custom script</b>, an <b>alias</b> created by a user or system administrator, or a command specific to a <b>very niche application</b> or development project. Its functionality, syntax, and behavior are entirely dependent on its specific implementation wherever it might be found. Without specific context or access to its source code, it is not possible to provide an accurate, universal description of its purpose or how it operates.


title: CAVEATS
content:
Because <i>rfetch</i> is not a standard command, its presence, functionality, and behavior are highly variable. Users encountering <i>rfetch</i> should be aware of the following:<br><ul><li>It may not exist on other systems.</li><li>Its options and arguments will differ wildly depending on its implementation.</li><li>Security implications depend entirely on its source and functionality; exercise caution with unknown scripts.</li><li>Always consult local documentation, the script's content, or the project's documentation if <i>rfetch</i> is part of a larger system.</li></ul>


title: HOW TO INVESTIGATE 'RFETCH' IF ENCOUNTERED
content:
If you encounter <i>rfetch</i> on a Linux system, you can try the following to understand its origin and purpose:<br><ul><li><b><I>which rfetch</I></b>: To find its location in the PATH.</li><li><b><I>type rfetch</I></b>: To see if it's an alias or a function.</li><li><b><I>ls -l $(which rfetch)</I></b>: If it's an executable, to see permissions and symbolic links.</li><li><b><I>cat $(which rfetch)</I></b>: If it's a script, to read its content (use caution, especially if it's a binary).</li><li><b>Consult local documentation or system administrators</b>: For information specific to your environment.</li></ul>


title: HISTORY
content:
There is no common historical development for a command named <i>rfetch</i> across Linux distributions, given its non-standard nature. Any history would pertain to a specific, localized implementation.


title: SYNOPSIS
content:
<I>rfkill</I> [<I>options</I>] <I>command</I><br>
<I>rfkill list</I> [<I>ID</I>]<br>
<I>rfkill block</I> <I>ID</I>|<I>TYPE</I><br>
<I>rfkill unblock</I> <I>ID</I>|<I>TYPE</I><br>
<I>rfkill event</I><br>
<I>rfkill help</I>


title: PARAMETERS
content:
<b><I>list</I> [<I>ID</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists the state of rfkill switches. If <I>ID</I> is provided, it lists only that specific device. It shows the device ID, type, and whether it's software or hardware blocked.<br><br><b><I>block</I> <I>ID</I>|<I>TYPE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Blocks the radio for a specific device identified by <I>ID</I> or for all devices of a certain <I>TYPE</I>. This sets the software kill switch.<br><br><b><I>unblock</I> <I>ID</I>|<I>TYPE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unblocks the radio for a specific device identified by <I>ID</I> or for all devices of a certain <I>TYPE</I>. This removes the software kill switch.<br><br><b><I>event</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Monitors and prints rfkill events. Useful for seeing when a hardware kill switch is toggled or when software blocks are applied by other processes.<br><br><b><I>help</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a concise help message for the <I>rfkill</I> command.<br><br><b><I>-o</I> <I>format</I>, <I>--output</I> <I>format</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the output columns for the <I>list</I> command. Common columns include <B>ID</B>, <B>TYPE</B>, <B>DEVICE</B>, <B>SOFT</B>, <B>HARD</B>.<br><br><b><I>-n</I>, <I>--noheadings</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the header row when using the <I>list</I> command, useful for scripting.<br><br><b><I>-J</I>, <I>--json</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the <I>list</I> command results in JSON format, facilitating programmatic parsing.<br><br>


title: DESCRIPTION
content:
The <I>rfkill</I> command manages the radio kill switch for wireless devices on Linux systems. It interacts with the kernel's <I>rfkill</I> subsystem, which provides a unified interface for enabling or disabling wireless communication. This includes technologies like Wi-Fi, Bluetooth, 3G/4G/5G (WWAN), UWB, WiMAX, and NFC. <I>rfkill</I> can block or unblock devices based on their unique ID or by technology type. It distinguishes between a software block (controlled by the OS) and a hardware block (a physical switch on the device, often on laptops). A hardware block always overrides a software block. This utility is crucial for quickly disabling all wireless transmitters, for example, when entering an airplane mode or for security reasons.


title: CAVEATS
content:
`rfkill` primarily controls the <B>software kill switch</B>. If a device has a physical <B>hardware kill switch</B> (e.g., a button or lever on a laptop), that hardware switch will always override the software setting. If the hardware switch is engaged, `rfkill unblock` will not enable the device until the hardware switch is disengaged. <br>
For `rfkill` to list or control a device, the kernel must have appropriate support for that device's radio via its driver and the `rfkill` subsystem. <br>
Executing `rfkill block` or `unblock` typically requires root privileges (or <B>CAP_NET_ADMIN</B> capability) as it modifies system-wide network settings.


title: BLOCK TYPES
content:
When using <B>block</B> or <B>unblock</B>, <B>TYPE</B> can be one of the following to target specific wireless technologies:<br>
<B>all</B>: Affects all listed rfkill devices.<br>
<B>wifi</B>: Affects Wi-Fi devices.<br>
<B>bluetooth</B>: Affects Bluetooth devices.<br>
<B>uwb</B>: Affects Ultra-Wideband devices.<br>
<B>wimax</B>: Affects WiMAX devices.<br>
<B>wwan</B>: Affects Wireless WAN (3G/4G/5G modems) devices.<br>
<B>nfc</B>: Affects Near Field Communication devices.


title: IDS
content:
Each wireless device detected by the <I>rfkill</I> subsystem is assigned a unique numerical <B>ID</B>. You can find these IDs by running <B>rfkill list</B>. This ID is used to target a specific device when blocking or unblocking, ensuring precise control over individual radios.


title: SOFTWARE VS. HARDWARE BLOCKS
content:
Understanding the distinction is crucial:<br>
<B>Software Block</B>: This is controlled by the operating system, often via <I>rfkill</I> or other network management tools. It can be toggled by the user or system processes.<br>
<B>Hardware Block</B>: This is a physical switch or mechanism on the device itself (e.g., a laptop's Wi-Fi button). When engaged, it directly cuts power or signal to the radio, bypassing software controls. A hardware block takes precedence over any software unblock. If <B>rfkill list</B> shows a device as <B>Hard blocked: yes</B>, you must physically toggle the switch to enable it.


title: HISTORY
content:
The <I>rfkill</I> subsystem and utility were introduced to the Linux kernel and userspace to provide a standardized way of controlling wireless devices across different hardware vendors and wireless technologies. Prior to its existence, device-specific methods were often required to disable radios. `rfkill` simplifies this by offering a unified interface. It is part of the widely used <B>util-linux</B> package, which provides a variety of essential system utilities. Its development reflects the increasing prevalence of wireless communication and the need for robust control mechanisms, especially concerning power management and regulatory compliance.


title: SYNOPSIS
content:
<b>rga</b> [<i>options</i>] <<i>pattern</i>> [<i>path</i> ...]<br><br><i>Note:</i> <b>rga</b> supports most <b>ripgrep</b> options in addition to its own.


title: PARAMETERS
content:
<b><i>pattern</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The regular expression or literal string to search for.<br><br><b>[<i>path</i> ...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more paths to files or directories to search. If omitted, <b>rga</b> searches the current directory.<br><br><b>--rga-config <file></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file path instead of the default (~/.config/rga/config or ~/.rgarc).<br><br><b>--rga-no-cache</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the use of the transformer cache. By default, <b>rga</b> caches transformed content for faster subsequent searches.<br><br><b>--rga-list-transformers</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available file types and their associated transformer commands that <b>rga</b> can utilize.<br><br><b>--rga-debug-transformers</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug output for transformer execution, showing what commands are run and their output. Useful for troubleshooting.<br><br><b>--rga-transform-for <type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces <b>rga</b> to use a specific transformer for a given file type, even if the file extension doesn't match.<br><br><b>--rga-verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity, showing more information about the processing steps.<br><br><b><i>(any ripgrep option)</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<b>rga</b> passes most standard <b>ripgrep</b> options directly to the underlying <b>rg</b> command. Examples include <i>--ignore-case</i> (<i>-i</i>), <i>--word-regexp</i> (<i>-w</i>), <i>--line-number</i> (<i>-n</i>), <i>--fixed-strings</i> (<i>-F</i>), <i>--glob</i> (<i>-g</i>), and many others for controlling search behavior, output format, and file filtering.<br><br>


title: DESCRIPTION
content:
<br>The <b>rga</b> command, short for <b>ripgrep-all</b>, is an advanced command-line utility designed to extend the powerful search capabilities of <b>ripgrep</b> to virtually all file types. While <b>ripgrep</b> excels at searching plain text and source code, <b>rga</b> allows users to efficiently search through a vast array of document formats, including PDFs, Office documents (DOCX, XLSX, ODT, EPUB), compressed archives (ZIP, RAR, 7z), and even images (via OCR for text extraction).<br><br><b>rga</b> achieves this by acting as a wrapper around <b>ripgrep</b>. When executed, it intelligently identifies the file type and, if necessary, uses a collection of external tools (known as 'transformers') such as <i>pdftotext</i>, <i>unzip</i>, <i>catdoc</i>, <i>pandoc</i>, or <i>tesseract-ocr</i>, to extract the textual content. This extracted text is then piped to <b>ripgrep</b>, which performs the actual pattern matching at high speed. This innovative approach combines <b>ripgrep</b>'s performance with a universal search scope, making <b>rga</b> an invaluable tool for finding information across diverse data collections.


title: CAVEATS
content:
<b>rga</b>'s functionality heavily depends on the presence and proper configuration of external helper programs (transformers). If a required tool is missing, <b>rga</b> may not be able to process certain file types. OCR (Optical Character Recognition) for image files can be computationally intensive and slower compared to text-based searches. Searching very large or malformed archive/document files might also consume significant resources or fail. Customizing the configuration file (typically <i>~/.config/rga/config</i>) is often necessary to fine-tune its behavior or integrate new transformers.


title: CONFIGURATION AND TRANSFORMERS
content:
The core of <b>rga</b>'s extensibility lies in its configurable 'transformers'. These are external programs defined in a configuration file (defaulting to <i>~/.config/rga/config</i> or <i>~/.rgarc</i>) that convert specific file types into plain text. For instance, a PDF transformer might use <i>pdftotext</i>, while a DOCX transformer could use <i>pandoc</i>. Users can customize this file to add support for new formats or modify how existing ones are handled, ensuring <b>rga</b> can adapt to almost any file type imaginable.


title: PERFORMANCE CONSIDERATIONS
content:
While <b>rga</b> benefits from <b>ripgrep</b>'s speed, the overall performance depends on the efficiency of the underlying transformers. Text extraction from complex documents (like large PDFs or encrypted archives) or OCR processes can introduce significant overhead. <b>rga</b> implements caching to mitigate this by storing extracted text for frequently searched files, which can dramatically speed up subsequent searches on the same content. However, the first search will always incur the full transformation cost.


title: HISTORY
content:
<b>rga</b> was created by <i>phi-nlp</i> (Philippe Lauri) to address the limitation of <b>ripgrep</b> being restricted to plain text files. The project was conceived to leverage <b>ripgrep</b>'s speed and robustness while expanding its reach to the vast ecosystem of binary document formats. It has gained popularity as a go-to tool for developers and users needing a comprehensive file search solution across their entire filesystem, bridging the gap between fast code search and universal document indexing.


title: SEE ALSO
content:
rg(1) - ripgrep, grep(1) - print lines matching a pattern, find(1) - search for files in a directory hierarchy, catdoc(1) - reads Microsoft Word files and prints their content as text, pdftotext(1) - Portable Document Format (PDF) to text converter (part of poppler-utils), unzip(1) - list, test and extract compressed files in a ZIP archive, tesseract(1) - an OCR engine


title: SYNOPSIS
content:
<b>rgb3toppm</b> [ <i>-verbose</i> ] [ <i>-alpha</i> | <i>-alphafile alpha_filename</i> ] [ <i>-gamma gamma_value</i> ] [ <i>width height</i> ]


title: PARAMETERS
content:
<b><i>-verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints verbose messages during the conversion process, providing details about the input and output.<br><br><b><i>-alpha</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <i>rgb3toppm</i> to expect 4-byte (RGBA) input per pixel. The output will be a Netpbm PAM image, which supports an alpha channel.<br><br><b><i>-alphafile alpha_filename</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the alpha channel data from the specified <i>alpha_filename</i>. The main input stream (typically stdin) must contain 3-byte (RGB) pixel data.<br><br><b><i>-gamma gamma_value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies gamma correction to the image pixels using the specified <i>gamma_value</i>. The value is a floating-point number.<br><br><b><i>width</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The width of the input image in pixels. This is a required argument if the command cannot infer the dimensions from the input stream's length.<br><br><b><i>height</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The height of the input image in pixels. This is a required argument if the command cannot infer the dimensions from the input stream's length.<br><br>


title: DESCRIPTION
content:
<i>rgb3toppm</i> is a utility from the Netpbm suite designed to convert raw RGB pixel data streams into a portable pixmap (PPM) image format. It reads uncompressed, byte-stream pixel data, typically from standard input, and writes the formatted PPM image to standard output.<br><br>The standard input is expected to be a sequence of 3 bytes per pixel (Red, Green, Blue) in that order. If the <b>-alpha</b> option is used, it expects 4 bytes per pixel (Red, Green, Blue, Alpha) and outputs a PAM (Portable Arbitrary Map) image, which is Netpbm's format for handling images with arbitrary planes, including alpha channels. Alternatively, the <b>-alphafile</b> option allows reading the alpha channel from a separate file while the main input remains 3-byte RGB.<br><br>This command is highly valuable in scripting and pipelines, enabling conversion of custom or exotic raw image data into a widely compatible and easily manipulable format within the Netpbm ecosystem or for further conversion to other standard image formats like JPEG, PNG, or GIF.


title: CAVEATS
content:
Input data must be raw, uncompressed pixel streams; no image headers (like PNG, JPEG, or TIFF headers) are supported.<br>The command assumes a strict byte order of R, G, B for 3-byte input, or R, G, B, A for 4-byte input.<br>If the input stream length does not explicitly define the image dimensions (e.g., from a pipe where EOF signifies the end), <i>width</i> and <i>height</i> must be provided as command-line arguments.


title: STANDARD INPUT/OUTPUT
content:
By default, <i>rgb3toppm</i> processes data from standard input and writes the resulting PPM or PAM image to standard output. This design makes it exceptionally suitable for use in Unix pipes, allowing it to easily integrate with other commands for complex image processing workflows.


title: PPM VS. PAM OUTPUT
content:
While its name implies PPM output, when the <b>-alpha</b> option is used, <i>rgb3toppm</i> produces a PAM (Portable Arbitrary Map) file. PAM is a more general Netpbm format that can handle images with multiple planes, making it suitable for representing images with an alpha channel or other arbitrary data channels beyond basic color components.


title: HISTORY
content:
<i>rgb3toppm</i> is an integral part of the Netpbm project, a comprehensive suite of graphics manipulation tools that originated in the early days of Unix. Netpbm tools are known for their simplicity, adherence to the Unix philosophy of small, single-purpose utilities that can be chained together, and their stable, long-standing development history.


title: PARAMETERS
content:
<b><B>-p</B>, <B>--prompt</B> <I>TEXT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the input prompt directly on the command line. Enclose in quotes for multiple words.<br><br><b><B>-f</B>, <B>--file</B> <I>PATH</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads the input prompt from the specified file <I>PATH</I>. Useful for longer prompts or scripts.<br><br><b><B>-m</B>, <B>--model</B> <I>NAME</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects the <I>AI</I> model to use for the response. Examples: '<I>gpt-4</I>', '<I>llama2</I>'. Defaults to a configured model.<br><br><b><B>-s</B>, <B>--stream</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Streams the generated response as it becomes available, similar to how content appears in web UIs.<br><br><b><B>-c</B>, <B>--continue</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continues the last conversation session. <B>rgpt</B> maintains a history or session context to enable multi-turn dialogues.<br><br><b><B>-t</B>, <B>--temperature</B> <I>VALUE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the creativity/randomness of the model's output, a float between 0.0 and 1.0 (default 0.7). Lower values are more deterministic.<br><br><b><B>-o</B>, <B>--output</B> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the generated response to the specified <I>FILE</I> instead of standard output.<br><br><b><B>-h</B>, <B>--help</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br>


title: DESCRIPTION
content:
The <B>rgpt</B> command provides a powerful and flexible command-line interface for interacting with various large language models (<I>LLMs</I>), including <I>GPT-like</I> models. It allows users to send natural language prompts and receive generated responses directly in their terminal, facilitating quick queries, content generation, and integration into shell scripts. <br><br> <B>rgpt</B> is designed for developers, researchers, and anyone looking to leverage <I>AI</I> capabilities without leaving their command-line environment. It supports features like specifying different models, managing conversation context, and streaming responses for real-time interaction. Its primary goal is to democratize access to <I>AI</I> by making it a first-class citizen of the Unix philosophy.


title: CAVEATS
content:
The <B>rgpt</B> command typically requires an active internet connection to communicate with remote <I>AI</I> services. <br><br> Users must configure necessary <I>API</I> keys or authentication tokens, often via environment variables or a configuration file, which may incur costs based on <I>API</I> usage. <br><br> As with all <I>LLMs</I>, responses might occasionally be inaccurate, nonsensical, or reflect biases present in training data.


title: CONFIGURATION
content:
<B>rgpt</B> typically relies on a configuration file (e.g., <I>~/.config/rgpt/config.json</I>) or environment variables (<I>RGPT_API_KEY</I>, <I>RGPT_DEFAULT_MODEL</I>) for setting up API keys, default models, and other preferences. This allows for persistent settings without needing to specify them with every command.


title: SCRIPTING USAGE
content:
Due to its command-line nature, <B>rgpt</B> is ideal for scripting. It can be easily piped with other standard Unix commands. For example, you can feed output from <B>grep</B> into <B>rgpt</B> for analysis, or use <B>rgpt</B>'s output as input for further text processing with <B>sed</B> or <B>awk</B>. <br><br> <I>Example: <B>cat my_log.txt | rgpt -p 'Summarize this log file:'</B></I>


title: HISTORY
content:
While not a traditional Unix utility, the concept of <B>rgpt</B> emerged from the growing need for direct command-line interaction with large language models. Its development began in late 2022/early 2023, following the widespread adoption of <I>GPT-style</I> <I>AI</I>s. It's often a custom script or a community-driven open-source project aimed at integrating <I>AI</I> workflows into existing developer toolchains, offering a lightweight alternative to web interfaces for rapid prototyping and scripting.


title: PARAMETERS
content:
<b><i>PATTERN</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The regular expression or fixed string to search for.<br><br><b><i>DIRECTORY...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more directories to search recursively. Defaults to the current directory if not specified.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;This is the fundamental option for `rgrep`, indicating a recursive search within directories. It's typically implied or directly part of the `rgrep` alias for `grep`.<br><br><b><b>-R</b>, <b>--dereference-recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Similar to <b>-r</b>, but follows symbolic links during the recursive traversal.<br><br><b><b>-i</b>, <b>--ignore-case</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore case distinctions in both the <i>PATTERN</i> and input files.<br><br><b><b>-v</b>, <b>--invert-match</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select non-matching lines; display lines that do not contain the <i>PATTERN</i>.<br><br><b><b>-l</b>, <b>--files-with-matches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress normal output; instead print the name of each input file from which output would normally have been printed.<br><br><b><b>-n</b>, <b>--line-number</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prefix each line of output with the 1-based line number within its input file.<br><br><b><b>-w</b>, <b>--word-regexp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select only those lines containing matches that form whole words.<br><br><b><b>-E</b>, <b>--extended-regexp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERN</i> as an extended regular expression (ERE).<br><br><b><b>-P</b>, <b>--perl-regexp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERN</i> as a Perl-compatible regular expression (PCRE).<br><br><b><b>--exclude=</b><i>GLOB</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip files whose basename matches <i>GLOB</i> (e.g., <b>--exclude='*.log'</b>).<br><br><b><b>--include=</b><i>GLOB</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Search only files whose basename matches <i>GLOB</i> (e.g., <b>--include='*.txt'</b>).<br><br><b><b>--exclude-dir=</b><i>GLOB</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude directories whose basename matches <i>GLOB</i> from the recursive search (e.g., <b>--exclude-dir='.git'</b>).<br><br>


title: DESCRIPTION
content:
`rgrep` is commonly a shorthand or an alias for the `grep` command invoked with the <b>-r</b> (or <b>--recursive</b>) option. It enables searching for a specified pattern within files in a given directory and all its subdirectories. Unlike a basic `grep` command which typically searches only within files explicitly listed or from standard input, `rgrep` automates the traversal of the directory tree. This makes it highly useful for codebases, log directories, or any scenario where a pattern might exist in multiple nested files without knowing their exact paths beforehand.<br><br>While `rgrep` itself is not a standalone binary on most systems, understanding its function is crucial for efficient command-line pattern searching across entire file systems or project directories. It leverages the robust features of the `grep` utility, extending its capabilities to recursive operations.


title: CAVEATS
content:
The primary caveat for `rgrep` is that it is typically not a standalone executable or command on most Linux distributions. Instead, it commonly functions as an alias (e.g., <b>alias rgrep='grep -r'</b>) or a shell function that simplifies the invocation of <b>grep --recursive</b>. Consequently, all options, behavior, and limitations of `rgrep` are inherited directly from the underlying `grep` utility, specifically when used in its recursive mode. Users should be aware that `rgrep` does not follow symbolic links by default; for this, the <b>-R</b> or <b>--dereference-recursive</b> option (part of `grep`) is required. Recursive searches on very large directory structures or network file systems can also be resource-intensive and slow.


title: USAGE EXAMPLES
content:
Here are some common ways `rgrep` (or `grep -r`) can be used:<br><br><b>Search for 'hello' in all files in the current directory and subdirectories:</b><br><code>rgrep 'hello' .</code><br>or<br><code>grep -r 'hello' .</code><br><br><b>Search for 'ERROR' case-insensitively in log files, excluding 'old_logs' directory:</b><br><code>rgrep -i 'ERROR' --include='*.log' --exclude-dir='old_logs' /var/log</code><br><br><b>Find files containing 'function_name' and display line numbers, only in C source files:</b><br><code>rgrep -n 'function_name' --include='*.c' ~/my_project</code>


title: PERFORMANCE AND ALTERNATIVES
content:
`rgrep` (i.e., `grep -r`) is very capable but can be slow on extremely large codebases or network drives. For faster recursive searches, especially in development environments, consider modern alternatives like <b>rg</b> (ripgrep) or <b>ack</b>. These tools are often optimized for speed and user experience in recursive pattern matching.


title: HISTORY
content:
The concept of `rgrep` is closely tied to the evolution of the `grep` utility. `grep` itself was developed by Ken Thompson in 1970. The capability for recursive searching, typically invoked via the <b>-r</b> or <b>--recursive</b> option, was added to `grep` as file systems grew larger and hierarchical directory structures became more common. This enhancement allowed users to search across entire directory trees efficiently. While `grep` has maintained its core functionality, features specific to recursive searching (like options to include/exclude files and directories) have been introduced over time to address more complex use cases. `rgrep` as a distinct command or common alias emerged as a user convenience, providing a simpler and quicker way to access `grep`'s powerful recursive search feature without always explicitly typing the <b>-r</b> flag.


title: PARAMETERS
content:
<b>-a, --algorithms=<I>ALGO</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selects which hash algorithms to use. Example: <I>-a MD5,SHA1</I>.<br><br><b>-c, --check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks hash sums against a file containing previously generated hashes. This mode is used for verification.<br><br><b>-r, --recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Processes directories recursively, calculating hashes for all files within them.<br><br><b>-o, --output=<I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the generated hash sums or magnet links to the specified output file instead of stdout.<br><br><b>--magnet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a magnet link for the specified file(s) or directory.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, showing more details about the process.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses non-error messages, outputting only hash sums or errors.<br><br><b>-L, --lowercase</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs hash sums using lowercase hexadecimal characters.<br><br><b>-U, --uppercase</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs hash sums using uppercase hexadecimal characters.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with available options and usage.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the program's version information.<br><br>


title: DESCRIPTION
content:
<b>rhash</b> is a versatile command-line utility designed for calculating and verifying cryptographic hash sums of files and directories. It supports a wide array of hash algorithms, including but not limited to MD5, SHA1, SHA256, SHA512, BTIH (BitTorrent Info Hash), AICH (Advanced Intelligent Corruptions Hash), ED2K (eDonkey2000), TTH (Tiger Tree Hash), GMD (GOST Hash), and CRC32. This tool is invaluable for ensuring data integrity, verifying downloads, and detecting accidental or malicious modifications. A key feature of <b>rhash</b> is its ability to generate magnet links, which are commonly used in BitTorrent for identifying and locating files without requiring a .torrent file. It can process single files, entire directories recursively, and also verify hash sums against a list provided in a file, making it a powerful utility for file management and data validation tasks.


title: CAVEATS
content:
Calculating hashes for extremely large files or numerous files in a directory can be resource-intensive and time-consuming. Users should be aware of potential performance implications. While <I>rhash</I> supports various cryptographic hash algorithms, the security strength depends on the algorithm chosen, not <I>rhash</I> itself. Magnet link generation for very large directories might consume significant memory.


title: MAGNET LINK GENERATION
content:
<I>rhash</I> excels at generating magnet links, which are hyperlinks containing enough information to locate and download files via peer-to-peer networks, primarily BitTorrent. This feature allows users to share file references without needing to distribute a full .torrent file, simplifying content distribution and verification. Use the <I>--magnet</I> option to generate these links.


title: SUPPORTED HASH ALGORITHMS
content:
Beyond common algorithms like MD5, SHA1, and SHA256, <I>rhash</I> supports a broad spectrum of hashing functions. These include more specialized ones like BTIH (BitTorrent Info Hash), AICH (Advanced Intelligent Corruptions Hash), ED2K (eDonkey2000 hash), TTH (Tiger Tree Hash), and GMD (GOST R 34.11-94), providing flexibility for diverse integrity checking and verification needs.


title: HISTORY
content:
The <I>rhash</I> utility was developed by Aleksey Cherepanov as an open-source project. Its development aimed to provide a comprehensive and efficient command-line tool for calculating various cryptographic hash sums, addressing a need for a single utility capable of handling multiple algorithms beyond the standard MD5 or SHA-1. Its integration of magnet link generation further distinguishes it, making it particularly valuable in peer-to-peer file sharing contexts like BitTorrent.


title: PARAMETERS
content:
<b><I>inspect</I> <I>OBJECT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Inspects a Python object, displaying its attributes, methods, and a pretty representation.<br><br><b><I>traceback</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Renders a pretty traceback from a Python exception, improving readability for debugging.<br><br><b><I>syntax</I> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Renders a file with syntax highlighting for various programming languages.<br><br><b><I>markdown</I> <I>FILE</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Renders a Markdown file directly in the terminal.<br><br><b><I>test</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs a demonstration of various <I>rich</I> features, showcasing its capabilities.<br><br><b><I>--help</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message for the <I>rich</I> command or a specific subcommand.<br><br>


title: DESCRIPTION
content:
<i>rich</i> is a Python library that enables developers to add beautiful and powerful formatting to their terminal output. It provides a wide range of features including colors, styles, tables, progress bars, markdown rendering, syntax highlighting, and well-formatted tracebacks. While primarily a library used programmatically within Python applications to enhance their command-line interfaces (CLIs), it also ships with a command-line utility (typically invoked via <I>python -m rich</I>) that demonstrates and utilizes some of its core capabilities, such as inspecting Python objects, rendering syntax-highlighted code, or displaying rich tracebacks. Its ease of use and comprehensive feature set make it an invaluable tool for creating professional and user-friendly CLI applications and for improving developer productivity through better debugging and logging.


title: CAVEATS
content:
The 'rich' command is not a native Linux utility but a command-line interface provided by the Python 'rich' library. It requires a Python installation (3.6+) and the 'rich' package to be installed (e.g., via <I>pip install rich</I>). Its primary use is as a programmatic library within Python applications, with the <I>python -m rich</I> utility serving mainly for demonstration and specific utility tasks rather than general system operation.


title: CORE LIBRARY USAGE
content:
Beyond its command-line utility, the true power of <I>rich</I> lies in its Python API. Developers can import classes like <I>Console</I>, <I>Table</I>, <I>Progress</I>, <I>Syntax</I>, and <I>Markdown</I> to programmatically create sophisticated terminal output within their Python applications, offering dynamic and interactive experiences for users.


title: INTEGRATION WITH FRAMEWORKS
content:
<I>rich</I> is often integrated with popular Python CLI frameworks such as <I>Typer</I>, <I>Click</I>, and <I>Argparse</I> to automatically provide rich formatting for help messages, error output, and general application feedback. It also enhances debugging in tools like <I>pytest</I> by providing pretty tracebacks.


title: HISTORY
content:
The <I>rich</I> library was created by Will McGugan and first released in 2020. It quickly gained significant popularity within the Python community due to its modern approach to terminal output, its comprehensive feature set, and its ease of use. It represents a modern evolution in terminal UI/UX, moving beyond traditional basic text output to highly formatted and interactive console experiences. Its development has focused on providing a high-level API that abstracts away the complexities of ANSI escape codes, making it accessible to developers for enhancing their CLI tools.


title: SYNOPSIS
content:
<b>rig</b> [<i>options</i>]<br><b>rig</b> [<b>-a</b>] [<b>-c</b> <i>count</i>] [<b>-d</b>] [<b>-e</b>] [<b>-f</b>] [<b>-i</b>] [<b>-p</b>] [<b>-s</b>] [<b>-z</b>] [<b>-u</b>] [<b>-h</b>] [<b>-v</b>]


title: PARAMETERS
content:
<b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output all available identity data (name, address, phone, email, SSN, DL, CC, etc.).<br><br><b><b>-c</b> <i>count</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the number of identities to generate. The default is 1.<br><br><b><b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random driver's license number in the output.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random email address in the output.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random phone number in the output.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random Social Security Number (SSN) in the output.<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random credit card number in the output.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a full street address in the output.<br><br><b><b>-z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include a random zip code in the output.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ensure that generated SSNs are unique across multiple identities generated in the same run.<br><br><b><b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output the version information and exit.<br><br>


title: DESCRIPTION
content:
The <b>rig</b> command is a simple, command-line utility designed to generate fake, but statistically plausible, personal identity data. It's often used by developers and testers for populating databases, testing forms, or creating dummy data for applications without compromising real user information.<br><br>It can generate a variety of fields, including names, addresses, phone numbers, email addresses, Social Security Numbers (SSNs), driver's license numbers, and credit card numbers. While the generated data is random, its format typically adheres to real-world patterns, making it useful for scenarios requiring realistic-looking placeholder information. <b>rig</b> is a straightforward tool, focusing on quick and easy generation of identity profiles directly from the terminal.


title: CAVEATS
content:
<b>*</b> The data generated by <b>rig</b> is entirely fictional and should <i>never</i> be confused with real personal information.<br><b>*</b> It is primarily designed for generating US-centric data, and does not support locale-specific variations for international identities.<br><b>*</b> While designed to be plausible, the generated numbers (like SSNs or credit cards) are not cryptographically secure or guaranteed to pass all real-world validation algorithms, though they often conform to basic checksum rules.<br><b>*</b> Do not use the generated data in production environments where real user data is handled, even for testing purposes.


title: SECURITY CONSIDERATIONS
content:
The data produced by <b>rig</b> is <i>fake</i>. It is crucial to understand that it serves purely as placeholder information for development and testing. It must <i>not</i> be used for any malicious activities, identity theft, or in any scenario where real personal information is required or could be compromised. Treat it strictly as dummy data.


title: LIMITATIONS AND ALTERNATIVES
content:
For more sophisticated, locale-specific, or diverse data generation needs, programmatic libraries are generally preferred. Examples include Python's <i>Faker</i> or <i>Mimesis</i> libraries, which offer extensive customization, support for numerous locales, and a wider array of data types beyond basic identity information.


title: HISTORY
content:
The <b>rig</b> command is a simple, utilitarian tool whose development history isn't extensively documented as a large-scale project. It emerged from the practical need within software development and testing communities for quick, on-demand generation of plausible fake personal data.<br><br>It's often distributed as a standalone package within various Linux distributions, serving as a straightforward solution for populating databases, testing input forms, or creating anonymized datasets without requiring complex configuration or dependencies. Its continued usage is primarily due to its simplicity and effectiveness for basic dummy data generation tasks.


title: PARAMETERS
content:
<b><b><I>-f</I></b>, <b><I>--force</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces removal without prompting for confirmation.<br><br><b><b><I>-i</I></b>, <b><I>--interactive</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompts for confirmation before each removal action.<br><br><b><b><I>-d</I></b>, <b><I>--dry-run</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Simulates the removal process, showing what would be deleted without actual deletion.<br><br><b><b><I>-v</I></b>, <b><I>--verbose</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed information about files and directories being processed or removed.<br><br><b><b><I>-p</I></b> <b><I>PATTERN</I></b>, <b><I>--pattern</I></b>=<b><I>PATTERN</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a file pattern (e.g., glob, regex) to target for removal.<br><br><b><b><I>-e</I></b> <b><I>PATTERN</I></b>, <b><I>--exclude</I></b>=<b><I>PATTERN</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files or directories matching the specified pattern from removal.<br><br><b><b><I>-h</I></b>, <b><I>--help</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br>


title: DESCRIPTION
content:
The <b><I>rip</I></b> command in Linux typically refers to a user-defined script or alias rather than a universally standard utility. Its purpose is commonly to 'rip out' or remove unwanted files, directories, or specific patterns of data from a system. This could involve cleaning up temporary files, build artifacts, cache directories, or untracked/ignored files within a version-controlled project (e.g., Git).<br><br>Due to its non-standard nature, the exact functionality, options, and behavior of a <b><I>rip</I></b> command can vary significantly based on its specific implementation by the user or developer who created it. It serves as a convenience wrapper around more fundamental commands like <b><I>rm</I></b>, <b><I>find</I></b>, and <b><I>grep</I></b>, providing a simplified interface for common cleanup tasks.


title: CAVEATS
content:
The <b><I>rip</I></b> command is <b>not a standard Linux utility</b> distributed with most mainstream distributions. Its behavior and options can vary widely depending on its specific implementation, as it is often a custom script or alias created by users or developers for specific cleanup tasks. Users should exercise caution and ideally inspect the script's source code before running a custom <b><I>rip</I></b> command to understand its exact functionality.


title: COMMON USE CASES
content:
Many developers create a <b><I>rip</I></b> script to quickly remove build artifacts, cache files, temporary files, or untracked/ignored files in version control systems like Git. This simplifies and standardizes cleanup operations across projects.


title: CUSTOM IMPLEMENTATION
content:
Users implementing a <b><I>rip</I></b> command often combine standard utilities like <b><I>find</I></b>, <b><I>xargs</I></b>, <b><I>rm</I></b>, and <b><I>grep</I></b> within a shell script. This allows for highly customizable cleanup logic, tailored to specific directories, file types, or project structures.


title: HISTORY
content:
The term 'rip' in computing context commonly refers to extracting data, often from physical media like CDs (CD ripping). While there isn't a universally recognized 'rip' command as a standard Linux utility, the concept of 'ripping out' unwanted files or components has led to various user-defined scripts or aliases named <b><I>rip</I></b> for specific cleanup tasks.<br><br>These custom scripts have evolved as a way for users to automate repetitive file removal processes, often in development environments, where transient files or build artifacts need frequent purging.


title: PARAMETERS
content:
<b><b>-i</b>, <b>--ignore-case</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Perform a case-insensitive search.</i><br><br><b><b>-v</b>, <b>--invert-match</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Invert the sense of matching, to select non-matching lines.</i><br><br><b><b>-l</b>, <b>--files-with-matches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Print only the names of files containing matches, one per file.</i><br><br><b><b>-L</b>, <b>--files-without-matches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Print only the names of files that do not contain matches, one per file.</i><br><br><b><b>-w</b>, <b>--word-regexp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Force PATTERN to match only whole words.</i><br><br><b><b>-F</b>, <b>--fixed-strings</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Interpret PATTERN as a literal string instead of a regular expression.</i><br><br><b><b>-g</b>, <b>--glob</b> <i>GLOB</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Include or exclude files based on glob patterns. Can be specified multiple times.</i><br><br><b><b>-u</b>, <b>--unrestricted</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Search hidden files and files ignored by VCS (e.g., .gitignore). Use multiple times for more unrestricted search.</i><br><br><b><b>-C</b> <i>NUM</i>, <b>--context</b> <i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show NUM lines of context before and after matching lines.</i><br><br><b><b>-N</b>, <b>--no-line-number</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Suppress the printing of line numbers.</i><br><br><b><b>--pretty</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Prints results in a user-friendly, formatted way, often with syntax highlighting.</i><br><br><b><b>-r</b> <i>REPLACEMENT</i>, <b>--replace</b> <i>REPLACEMENT</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Replace matches with the specified string. This does not modify files.</i><br><br>


title: DESCRIPTION
content:
<i>Ripgrep</i> (rg) is a command-line utility for searching text patterns, renowned for its exceptional speed and user-friendliness. Written in <i>Rust</i>, it leverages a highly optimized regex engine and smart defaults to deliver a superior search experience compared to traditional tools like `grep`. `rg` recursively searches directories by default, respects <i>.gitignore</i> rules, and automatically skips binary files, making it ideal for codebases. It is designed for developers, offering features like line numbers, context, and intelligent file filtering. Its performance gains come from careful algorithmic choices, parallel processing, and memory mapping, making it a popular choice for large codebases and quick searches.


title: CAVEATS
content:
While ripgrep is incredibly fast and feature-rich, it's important to note a few things. It prioritizes speed and convenience, meaning some niche features of `grep` might not be directly available or behave differently (e.g., `-z` for gzipped files requires external tools). Its default behavior of respecting <i>.gitignore</i> and skipping hidden/binary files can sometimes lead to unexpected "no results" if the user isn't aware of these smart defaults; the <b>-u</b> flag can be used to override this. Additionally, while optimized, searching extremely large binary files without filtering can still consume significant resources.


title: KEY FEATURES
content:
<i>Ripgrep</i> comes with intelligent defaults, automatically skipping hidden files and directories, binary files, and files ignored by version control systems like Git (via <i>.gitignore</i>). It provides rich output formatting, including syntax highlighting and line numbers. Its performance is often attributed to its use of memory maps, specialized regex engines, and parallel directory traversal.


title: REGEX ENGINE
content:
At its core, <i>ripgrep</i> utilizes Rust's highly optimized <i>regex</i> crate. This crate implements regular expressions using finite automata, which are extremely fast. For advanced regex features not supported by the default engine, `ripgrep` can optionally use the <i>PCRE2</i> engine via the <b>--pcre2</b> flag.


title: HISTORY
content:
<i>Ripgrep</i> was created by <i>Andrew Gallant</i> (BurntSushi), a well-known contributor to the Rust ecosystem, and first released in 2016. Its primary goal was to provide a `grep`-like tool that was significantly faster than existing alternatives like `GNU grep`, `ack`, or `the_silver_searcher` (ag), while also being more user-friendly with sensible defaults. Written in Rust, it quickly gained popularity due to its impressive performance, often outperforming its predecessors by a considerable margin, and has become a standard tool in many developers' workflows.


title: SYNOPSIS
content:
<code><b>rg</b> [<i>options</i>] <i>PATTERN</i> [<i>PATH</i>...]</code><br>Searches for <i>PATTERN</i> in files at <i>PATH</i>s. If no <i>PATH</i> is provided, it searches the current directory recursively.


title: PARAMETERS
content:
<b><b>-i</b>, <b>--ignore-case</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a case-insensitive search.<br><br><b><b>-v</b>, <b>--invert-match</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invert the match; select non-matching lines.<br><br><b><b>-w</b>, <b>--word-regexp</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force the pattern to match only whole words.<br><br><b><b>-l</b>, <b>--files-with-matches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only print the names of files that contain matches.<br><br><b><b>-L</b>, <b>--files-without-matches</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only print the names of files that do not contain matches.<br><br><b><b>-n</b>, <b>--line-number</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show line numbers for matches.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Search directories recursively. This is the default behavior.<br><br><b><b>-u</b>, <b>--unrestricted</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reduce the level of 'smart' filtering. Use multiple <b>-u</b> for even less filtering (e.g., searching hidden files).<br><br><b><b>-g</b>, <b>--glob</b> <i>GLOB</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include or exclude files based on a glob pattern. Can be used multiple times.<br><br><b><b>-t</b> <i>TYPE</i>, <b>--type</b> <i>TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Search only files of type <i>TYPE</i> (e.g., <b>--type go</b>). Use <b>--type-list</b> for available types.<br><br><b><b>-F</b>, <b>--fixed-strings</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Treat <i>PATTERN</i> as a literal string instead of a regular expression.<br><br><b><b>-P</b>, <b>--pcre2</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use the PCRE2 regex engine for patterns that require features not supported by the default Rust regex engine.<br><br>


title: DESCRIPTION
content:
<code>ripgrep</code> (often shortened to <b>rg</b>) is a line-oriented search tool that recursively searches the current directory for a regex pattern. Built on Rust's regex engine, it is incredibly fast and designed to be a highly performant alternative to traditional tools like <code>grep</code> or <code>The Silver Searcher</code> (<code>ag</code>).<br><br>What sets <code>ripgrep</code> apart is its default behavior: it automatically ignores files and directories specified by <code>.gitignore</code>, <code>.ignore</code>, and <code>.rgignore</code> files, and also skips hidden files/directories and binary files by default. This "smart filtering" significantly reduces search times and noise. It handles Unicode characters correctly, supports various encodings, and can search specific file types. <code>ripgrep</code> is portable and runs on Linux, macOS, and Windows, making it a versatile tool for developers and system administrators. Its speed comes from a combination of parallel directory traversal, a highly optimized regex engine, and intelligent filtering.


title: CAVEATS
content:
<code>ripgrep</code>'s aggressive parallelism can consume significant CPU and memory resources when searching extremely large codebases or file systems without appropriate filtering. While highly optimized for common use cases, its "smart filtering" (ignoring <code>.git</code>, hidden files, etc.) might inadvertently hide desired results if the user is unaware of its defaults or doesn't use the <b>-u</b>/<b>--unrestricted</b> flags.


title: PERFORMANCE CHARACTERISTICS
content:
<i>ripgrep</i> achieves its speed through several optimizations: it uses memory mapping for file access, employs a highly optimized regex engine (Rust's 'regex' crate), parallelizes directory traversal and file searching across multiple CPU cores, and intelligently skips binary files and files ignored by version control systems (<code>.gitignore</code>).


title: SMART FILTERING
content:
By default, <i>ripgrep</i> automatically ignores files and directories listed in <b>.gitignore</b>, <b>.ignore</b>, and <b>.rgignore</b> files. It also skips hidden files/directories and binary files. This behavior can be controlled or disabled using the <b>-u</b> (unrestricted) flag, which can be specified multiple times for less and less filtering.


title: CONFIGURATION FILE
content:
<i>ripgrep</i> can be configured via a configuration file, typically located at <b>$HOME/.ripgreprc</b> or <b>$XDG_CONFIG_HOME/ripgrep/ripgreprc</b>. This allows users to set default flags and behaviors without having to type them every time.


title: HISTORY
content:
<code>ripgrep</code> was created by <i>Andrew Gallant</i> (also known as "BurntSushi" online) and first released in 2016. Written entirely in Rust, it was developed with the explicit goal of being faster than existing code search tools like <code>grep</code> and <code>The Silver Searcher</code> (<code>ag</code>), while providing a superior user experience with sensible defaults. Its rapid adoption within the developer community is largely due to its remarkable performance gains and intelligent handling of common project structures, quickly establishing itself as a preferred search utility across various operating systems.


title: SYNOPSIS
content:
<b>ripmime</b> [<i>OPTIONS</i>] <i>&lt;input_file&gt;</i><br>or<br><b>cat</b> <i>&lt;input_file&gt;</i> | <b>ripmime</b> [<i>OPTIONS</i>]


title: PARAMETERS
content:
<b><b>-i</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the input MIME message file. If omitted, <i>ripmime</i> reads from standard input.<br><br><b><b>-d</b> <i>&lt;directory&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the output directory where extracted attachments will be saved.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about the extraction process.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in quiet mode, suppressing most messages.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sanitizes filenames by replacing potentially problematic characters with underscores to prevent issues like path traversal.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ensures unique filenames for extracted attachments by appending a number if a file with the same name already exists.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts all MIME parts, including those not explicitly marked as attachments (e.g., inline text or HTML bodies).<br><br><b><b>-I</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes an index (log) file detailing the extracted parts and their original properties.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preserves original filenames as much as possible, even after sanitization or uniqueness adjustments.<br><br><b><b>-T</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the extraction of <i>text/plain</i> parts.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the extraction of <i>text/html</i> parts.<br><br><b><b>-A</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts only parts explicitly identified as attachments by the MIME headers.<br><br>


title: DESCRIPTION
content:
<i>ripmime</i> is a command-line utility designed to parse MIME-encoded email messages and extract their attachments. It is commonly used in server-side mail processing applications, such as spam filters or mail archiving systems, to automatically detach files embedded within emails.<br><br>It can handle complex MIME structures, various content types (e.g., text, image, application), and different transfer encodings (e.g., Base64, quoted-printable). Users can specify an output directory for attachments, control file naming, and generate an index file listing the extracted parts. It provides a robust way to automate the handling of email attachments without user intervention.


title: CAVEATS
content:
Handling large or deeply nested MIME messages can be resource-intensive.<br>While <i>ripmime</i> includes filename sanitization (<b>-s</b>), users should still be cautious when processing untrusted input to avoid potential security risks if not properly configured or sandboxed.


title: SECURITY CONSIDERATIONS
content:
When processing email from untrusted sources, it is highly recommended to run <i>ripmime</i> within a sandboxed environment (e.g., chroot, dedicated container) to mitigate potential risks associated with extracting malicious attachments or encountering malformed MIME structures.


title: INTEGRATION WITH MAIL FILTERS
content:
<i>ripmime</i> is frequently integrated into mail processing pipelines, such as those powered by <i>procmail</i> or <i>mimedefang</i>. This allows for automated extraction, scanning, and handling of email attachments as part of an overall mail security or archiving strategy.


title: HISTORY
content:
<i>ripmime</i> has a long history as a specialized tool for automated mail processing, particularly in server-side contexts like spam and virus filtering. Developed by Paul L. Daniels, its evolution has focused on robustness, efficiency, and handling the complexities and malformations often found in real-world email traffic.


title: SYNOPSIS
content:
<B>atop</B> [<I>options</I>] [<I>interval</I> [<I>count</I>]]<br>Specifically for memory focus:<br><B>atop -m</B> [<I>interval</I> [<I>count</I>]]


title: PARAMETERS
content:
<b><B>-m</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays memory utilization information. This includes physical memory, swap space, and virtual memory statistics.<br><br><b><I>interval</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The delay in seconds between successive samples. Specifies how often <B>atop</B> refreshes its display.<br><br><b><I>count</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of samples (iterations) to collect before <B>atop</B> exits. Used in conjunction with <I>interval</I> for fixed duration monitoring.<br><br><b><B>-r</B> <I>logfile</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads system activity from a raw logfile previously created by <B>atop</B> (e.g., using <B>atop -w</B>).<br><br><b><B>-S</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays cumulative values (e.g., CPU time, disk I/O) since the start of the process instead of incremental values.<br><br><b><B>-P</B> <I>label</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays specific process resource consumption for a given label (e.g., <B>MEM</B> for memory, <B>CPU</B> for CPU, <B>DSK</B> for disk I/O).<br><br>


title: DESCRIPTION
content:
The command <B>rlatopam</B> is not a standard Linux command or utility found in common distributions. It is highly probable that this refers to a common typo or misremembering of <B>atop -m</B>, which is a powerful tool used for real-time memory performance monitoring.<br><br>This analysis proceeds based on the assumption that <B>rlatopam</B> describes the functionality provided by <B>atop</B> when specifically focused on memory metrics. <B>atop</B> (Advanced TOP) is an interactive monitor that displays various system resource loads in Linux. When invoked with the <B>-m</B> option or by pressing 'm' during its interactive session, <B>atop</B> shifts its focus to memory-related counters. It provides a detailed breakdown of physical memory (RAM), swap space, virtual memory (VM) statistics, and per-process memory consumption (VSIZE, RSS, PGT), offering invaluable insights for diagnosing memory leaks, high memory utilization, and overall memory subsystem health.


title: CAVEATS
content:
The command <B>rlatopam</B> itself is not a standard Linux utility, and this analysis is based on the strong assumption that it refers to the functionality of <B>atop -m</B>.<br><br>Full functionality of <B>atop</B> often requires root privileges or specific capabilities (e.g., <I>CAP_SYS_RAWIO</I>).<br><br>The extensive output of <B>atop</B>, especially in busy systems, can be overwhelming. Effective use often requires filtering or specific interactive commands.<br><br>Frequent polling with small intervals can introduce a minor overhead on the monitored system.


title: MEMORY METRICS DISPLAYED BY <B>ATOP -M</B>
content:
When using <B>atop -m</B>, the display typically includes:<br><ul><li><I>MEM</I>: Physical memory usage (total, free, cache, buffer, slab).</li><li><I>SWAP</I>: Swap space usage (total, free, cached).</li><li><I>VM</I>: Virtual memory statistics (e.g., pages in/out, page fault rates).</li><li><I>PRC</I>: Process-specific memory consumption (Virtual Size <I>VSIZE</I>, Resident Set Size <I>RSS</I>, Page Table Size <I>PGT</I>).</li></ul>


title: INTERACTIVE USAGE
content:
While <B>atop</B> is running in interactive mode, pressing the '<B>m</B>' key will toggle the display to show memory-centric statistics. Other keys like '<B>c</B>' (CPU), '<B>d</B>' (disk), '<B>n</B>' (network), and '<B>u</B>' (per-user) can be used to switch between different resource views dynamically.


title: HISTORY
content:
<B>atop</B> originated as a system performance monitor developed by Gerlof Langeveld at Atos Origin. First publicly released around 2004, it quickly gained popularity for its comprehensive monitoring capabilities and its unique ability to log performance data for later analysis, distinguishing it from purely real-time tools like <B>top</B>. The <B>-m</B> option for detailed memory monitoring has been a core feature of <B>atop</B> from its early versions, providing essential insights into memory subsystem behavior.


title: SYNOPSIS
content:
rletopnm [-verbose] [-alpha] [-weightmap] [-nointerleave] [-red] [-green] [-blue] [-bg-red=<I>val</I>] [-bg-green=<I>val</I>] [-bg-blue=<I>val</I>] [-xpos=<I>val</I>] [-ypos=<I>val</I>] [<I>rlefile</I>]


title: PARAMETERS
content:
<b><i>-verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints debugging information to standard error, which can be useful for understanding the conversion process or troubleshooting.<br><br><b><i>-alpha</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts the alpha (transparency) channel from the RLE file as a grayscale image. The output will be a PGM file representing the alpha mask.<br><br><b><i>-weightmap</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts a weight map from the RLE file, if present. The output will be a PGM file.<br><br><b><i>-nointerleave</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents interleaving of pixels during conversion. This option is typically used for specific technical scenarios and generally not needed for standard conversions.<br><br><b><i>-red</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts only the red color channel from the RLE image. The output will be a PGM file representing the red component of the image.<br><br><b><i>-green</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts only the green color channel from the RLE image. The output will be a PGM file representing the green component of the image.<br><br><b><i>-blue</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extracts only the blue color channel from the RLE image. The output will be a PGM file representing the blue component of the image.<br><br><b><i>-bg-red=<I>val</I></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the red component (0-255) of a background color to use for compositing if the RLE image has transparency. Requires <i>-bg-green</i> and <i>-bg-blue</i> to be specified as well.<br><br><b><i>-bg-green=<I>val</I></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the green component (0-255) of a background color to use for compositing if the RLE image has transparency. Requires <i>-bg-red</i> and <i>-bg-blue</i> to be specified as well.<br><br><b><i>-bg-blue=<I>val</I></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the blue component (0-255) of a background color to use for compositing if the RLE image has transparency. Requires <i>-bg-red</i> and <i>-bg-green</i> to be specified as well.<br><br><b><i>-xpos=<I>val</I></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the starting X coordinate (horizontal position) for extracting a sub-image from the RLE file.<br><br><b><i>-ypos=<I>val</I></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the starting Y coordinate (vertical position) for extracting a sub-image from the RLE file.<br><br><b><i>rlefile</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the input RLE image file. If not specified, <b>rletopnm</b> reads from standard input.<br><br>


title: DESCRIPTION
content:
The <b>rletopnm</b> command is a utility from the Netpbm project that converts image files in the Utah Run Length Encoded (RLE) format into the Netpbm Portable Anymap (PNM) format. <br><br>The RLE format is an older, platform-independent image format primarily associated with the Utah Raster Toolkit. <br><br>Netpbm's PNM format is a family of portable image formats including Portable Pixmap (PPM) for color images, Portable Graymap (PGM) for grayscale images, and Portable Bitmap (PBM) for black and white images. <br><br>By default, <b>rletopnm</b> attempts to produce a PPM file if the RLE input contains color information. If only a single channel is selected (e.g., red, green, or blue), or if the RLE file has no color information, it generates a PGM file. If no channels are explicitly chosen and the RLE file lacks color data, or if the <i>-alpha</i> option is used, a PBM file might be produced. <br><br>Input RLE data can come from a specified file or, by default, from standard input, and the converted PNM output is written to standard output.


title: CAVEATS
content:
The RLE format is relatively old and less commonly encountered today compared to modern image formats like JPEG, PNG, or GIF. <br><br>While <b>rletopnm</b> handles common RLE variations, complex or non-standard RLE files might not be fully supported. <br><br>When compositing with background colors using the <i>-bg-red/green/blue</i> options, ensure the input RLE file actually contains transparency information for the effect to be meaningful. <br><br>Output is always to standard output, so redirection (e.g., `rletopnm image.rle > image.pnm`) is necessary to save the result to a file.


title: INPUT AND OUTPUT
content:
<b>rletopnm</b> accepts an RLE file as input, either specified as an argument (<i>rlefile</i>) or read from standard input if no file is provided. The converted image is always written to standard output in one of the Netpbm PNM formats (PPM, PGM, or PBM) depending on the input RLE's characteristics and the command-line options used. This means you must redirect the output to a file, for example: <br><code>rletopnm input.rle > output.pnm</code>


title: CONVERSION LOGIC
content:
The command attempts to produce the 'richest' possible PNM format. If the RLE file has color, it outputs PPM. If you select a single color channel (e.g., <i>-red</i>), or if the RLE file is grayscale, it outputs PGM. If the RLE file is monochrome or the <i>-alpha</i> option is used (and the RLE has no color data), it outputs PBM.


title: HISTORY
content:
<b>rletopnm</b> is an integral part of the <i>Netpbm</i> package, a widely-used toolkit for image manipulation on Unix-like operating systems. Netpbm originated from the <i>pbmplus</i> package, first released in 1991 by Jef Poskanzer, which itself built upon earlier individual image format converters. <br><br>The toolkit was designed to provide a modular and extensible way to convert between various image formats, processing images through a common 'portable anymap' (PNM) intermediate format. <b>rletopnm</b> specifically addresses the need to convert images from the older Utah RLE format, ensuring interoperability with other Netpbm tools and more modern image formats.


title: PARAMETERS
content:
<b><b>-8</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Pass 8-bit data rather than stripping the eighth bit.</i><br><br><b><b>-D</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enable socket debugging options.</i><br><br><b><b>-E</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Prevent any character from being recognized as an escape character.</i><br><br><b><b>-K</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disable all Kerberos authentication.</i><br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disable mapping of the remote current working directory to the local one.</i><br><br><b><b>-e</b> <i>char</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specify the escape character, default is '~'.</i><br><br><b><b>-l</b> <i>user</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specify a different username for the remote host.</i><br><br><b><i>host</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>The remote hostname or IP address to connect to.</i><br><br>


title: DESCRIPTION
content:
<b>rlogin</b> is a command-line utility used to establish a remote login session on another Unix-like system. It is part of the <b>r-commands</b> suite, which also includes <b>rsh</b> and <b>rcp</b>.<br><br>The primary purpose of <b>rlogin</b> is to allow users to execute commands on a remote host as if they were logged in locally. Authentication typically relies on the <b>.rhosts</b> file in the user's home directory on the remote machine, or the <b>/etc/hosts.equiv</b> file, which lists trusted hosts and users.<br><br>While convenient for early networked environments, <b>rlogin</b> is considered highly insecure by modern standards because it transmits all communication, including passwords, in plaintext over the network, making it vulnerable to eavesdropping and replay attacks. Due to these significant security flaws, <b>rlogin</b> has been largely replaced by the more secure <b>ssh</b> (Secure Shell) protocol and its associated clients. Users should avoid <b>rlogin</b> for any sensitive or production use.


title: CAVEATS
content:
The most significant caveat of <b>rlogin</b> is its inherent lack of security. All network traffic, including usernames and passwords, is transmitted in plaintext, making it highly vulnerable to eavesdropping and man-in-the-middle attacks.<br><br>Authentication typically relies on <b>trust</b> mechanisms (<b>.rhosts</b>, <b>hosts.equiv</b>) which are easily spoofed or exploited if not configured with extreme caution. <b>rlogin</b> is considered deprecated for most modern uses and should be avoided in favor of secure alternatives like <b>ssh</b>. Use of <b>rlogin</b> is strongly discouraged on untrusted networks or for sensitive data.


title: AUTHENTICATION (.RHOSTS AND HOSTS.EQUIV)
content:
<b>rlogin</b> relies on two primary mechanisms for host-based authentication: the <b>.rhosts</b> file in a user's home directory on the remote machine, and the global <b>/etc/hosts.equiv</b> file. These files list trusted remote hosts and, optionally, users from those hosts who are allowed to log in without a password. While convenient, this trust model is inherently insecure, as a compromise of one machine or a malicious entry in these files can grant unauthorized access. Strict permissions are required for these files, and even then, they are not foolproof.


title: ESCAPE CHARACTER
content:
During an <b>rlogin</b> session, you can use an escape character (default is <b>~</b>) followed by a special character to perform specific actions. For example, <b>~.</b> (tilde followed by a dot) will disconnect the session, and <b>~^Z</b> (tilde followed by Ctrl+Z) will suspend the session. This functionality allows local control over the remote session.


title: HISTORY
content:
<b>rlogin</b> emerged as part of the Berkeley <b>r-commands</b> suite developed at the University of California, Berkeley, in the early days of TCP/IP networking, alongside <b>rsh</b> and <b>rcp</b>. These commands provided convenient ways for users to interact with remote Unix systems and share resources across networks.<br><br>They became widely adopted due to their simplicity and integration with the Unix environment. However, as network security became a paramount concern in the 1990s and beyond, the plaintext nature of <b>rlogin</b>'s communication made it obsolete and dangerous. The development of <b>ssh</b> in the mid-1990s provided a secure, encrypted replacement that rapidly gained favor and has since become the de facto standard for remote access, effectively relegating <b>rlogin</b> to historical or very specific, controlled, and insecure environments.


title: PARAMETERS
content:
<b><code>-H</code> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative history file to use. By default, <i>rlwrap</i> uses <i>.rlwrap_history</i> in the user's home directory.<br><br><b><code>-f</code> <i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads completion words from the specified <i>file</i>. Each line in the file is treated as a potential completion candidate.<br><br><b><code>-C</code> <i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the default completion file associated with the given <i>name</i> (e.g., <i>sqlplus</i>, <i>ocaml</i>) from standard system locations.<br><br><b><code>-c</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables word completion. Only line editing and history features will be active.<br><br><b><code>-i</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes word completion case-insensitive. When enabled, typing 'SELECT' will match 'select' during completion.<br><br><b><code>-l</code> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the maximum number of lines to store in the history file to <i>N</i>. Older entries are discarded if the limit is exceeded.<br><br><b><code>-S</code> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the prompt string that <i>rlwrap</i> displays. Useful for differentiating <i>rlwrap</i>'s prompt from the wrapped command's own.<br><br><b><code>-z</code> <i>filter</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a custom filter script or program. Filters can pre-process user input or post-process command output, allowing for advanced customizations like syntax highlighting or auto-indentation.<br><br>


title: DESCRIPTION
content:
<i>rlwrap</i> is a versatile utility that enhances command-line tools by providing <i>readline</i>-like functionality. Many interactive programs, such as database clients (e.g., <i>sqlplus</i>), language interpreters (e.g., <i>ocaml</i>), or debuggers (e.g., <i>gdb</i>), lack advanced features like line editing, command history, and tab completion. <i>rlwrap</i> addresses this by acting as a wrapper:<br><br>It runs the target command as a child process, intercepts its standard input and output, and processes user input using the powerful <i>readline</i> library before passing it to the wrapped command. This allows users to leverage familiar keyboard shortcuts for editing, recall past commands, and benefit from context-sensitive tab completion, significantly improving productivity and user experience even with applications not originally designed for such features. It supports custom history files, completion files, and advanced filtering for more complex interactions.


title: CAVEATS
content:
<i>rlwrap</i> is a powerful tool, but it's not universally compatible. It may not work well with programs that use raw terminal modes, full-screen interactive applications (like <i>vi</i> or <i>emacs</i>, or other curses-based programs like <i>htop</i>), or applications that frequently redraw the screen without explicit line-by-line input. It can also sometimes interfere with a wrapped command's own minimal input handling. While generally negligible, there's a small performance overhead as <i>rlwrap</i> acts as an intermediary.


title: <B>FILTERS</B>
content:
<i>rlwrap</i> supports "filters," which are external scripts or programs that can be loaded to preprocess user input before it's sent to the wrapped command, or post-process the command's output before it's displayed. This powerful feature allows for complex customizations, such as syntax highlighting, auto-indentation, or context-aware transformations, extending <i>rlwrap</i>'s capabilities far beyond basic line editing.


title: <B>ENVIRONMENT VARIABLES</B>
content:
<i>rlwrap</i> can be configured using several environment variables, such as <i>RLWRAP_HOME</i> to specify the directory for history and completion files, or <i>RLWRAP_HISTORY_FILE</i> to directly set the path to the history file. These variables provide an alternative or supplementary way to configure <i>rlwrap</i>'s behavior without always needing to pass command-line options.


title: HISTORY
content:
<i>rlwrap</i> was created by Hans Lub, with its first public release around 2004. Its development was motivated by the observation that many useful command-line tools did not integrate with the powerful <i>readline</i> library, leading to a less efficient and less user-friendly interactive experience. Since its inception, <i>rlwrap</i> has steadily evolved, adding features such as support for custom completion files, advanced history management, and the ability to load external filters, making it an indispensable tool for many command-line users.


title: PARAMETERS
content:
<b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore nonexistent files and arguments, never prompt. This option overrides <b>-i</b> and <b>-I</b>.<br><br><b>-i</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt before every removal. This provides a safety net, asking for confirmation for each file or directory.<br><br><b>-I</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompt once before removing more than three files, or when removing recursively. This offers a less intrusive safety prompt than <b>-i</b>.<br><br><b>-r, -R, --recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove directories and their contents recursively. Essential for deleting non-empty directories.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Explain what is being done. Prints the name of each file as it is processed.<br><br><b>--no-preserve-root</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not treat '/' specially. This option is extremely dangerous as it allows <b>rm -rf /</b> to delete the entire root filesystem, making the system unbootable. It's normally protected by default.<br><br><b>-d, --dir</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove empty directories. Can be used as an alternative to <b>rmdir</b> for empty directories.<br><br>


title: DESCRIPTION
content:
The <b>rm</b> command in Linux is used to <i>remove</i> (delete) files and directories. Unlike graphical user interfaces, <b>rm</b> typically does not move files to a 'trash' or 'recycle bin'; once deleted, they are gone permanently and often unrecoverable without specialized data recovery tools.<br><br>By default, <b>rm</b> will remove specified files. If a file is write-protected, it may prompt for confirmation before deletion. To remove directories, the <b>-r</b> (or <b>--recursive</b>) option must be used, which deletes the directory and all its contents recursively. The <b>-f</b> (or <b>--force</b>) option can be used to override prompts and ignore non-existent files, making it a powerful and potentially dangerous tool.<br><br>Due to its destructive nature, users should exercise extreme caution when using <b>rm</b>, especially with wildcards or the <b>-r</b> and <b>-f</b> options together, as a single command can irrevocably delete large amounts of data.


title: CAVEATS
content:
<i><b>Irreversible Operation</b></i>: Data deleted with <b>rm</b> is typically not moved to a trash bin and is extremely difficult, if not impossible, to recover, especially on modern filesystems (e.g., SSDs where TRIM is active).<br><br><i><b>Permissions</b></i>: To delete a file, you need write permission on the <i>parent directory</i> of the file, not necessarily on the file itself. However, <b>rm</b> may still prompt if the file itself is write-protected (unless <b>-f</b> is used).<br><br><i><b>Wildcard Caution</b></i>: Using wildcards (e.g., `*`) with <b>rm</b> can be very dangerous. A common mistake is `rm -rf *.bak` which is fine, but `rm -rf * .bak` (note the space) could delete everything in the current directory if you're not careful.<br><br><i><b>Root Directory</b></i>: The `<b>rm -rf /</b>` command is notoriously dangerous. GNU <b>rm</b> protects against this by default, requiring the `<b>--no-preserve-root</b>` option to proceed. Never use this unless you fully understand the implications and have backups.


title: SAFETY ALIASES
content:
Many users create an alias for <b>rm</b> in their shell configuration (e.g., `~/.bashrc`) to add a layer of protection. Common aliases include `<b>alias rm='rm -i'</b>` to always prompt for confirmation, or `<b>alias rm='trash'</b>` if using a tool like `trash-cli` that moves files to a trash bin instead of deleting them immediately.


title: DELETING FILES WITH SPECIAL CHARACTERS
content:
Files with names starting with a hyphen (e.g., `-my-file.txt`) can be problematic because <b>rm</b> might interpret them as options. To delete such files, use `<b>rm -- -my-file.txt</b>` (the `<b>--</b>` signifies the end of options) or `<b>rm ./-my-file.txt</b>` (using a relative path).


title: HISTORY
content:
The <b>rm</b> command has been a fundamental utility in Unix-like operating systems since their early days. It's a direct wrapper around the <i>unlink(2)</i> system call, which removes a hard link to a file. Over time, options like <b>-r</b> for recursive deletion and <b>-i</b> for interactive prompting were added to enhance its functionality and safety. The GNU Coreutils version, widely used in Linux distributions, introduced the crucial `<b>--no-preserve-root</b>` safeguard in response to accidental root directory deletions. Its design reflects the Unix philosophy of providing powerful, focused tools, relying on user caution for their safe operation.


title: PARAMETERS
content:
<b><b>-o</b> <I>format</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output format. Common options include `sh` (shell script for removal), `json`, `csv`, and `parrot` (for the GUI).<br><br><b><b>-T</b> <I>types</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define what kind of "lint" to find. Multiple types can be comma-separated, e.g., `duplicates,emptyfiles,badlinks`.<br><br><b><b>-L</b>, <b>--symlink</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replace identified duplicate files with symbolic links to the kept file.<br><br><b><b>-D</b>, <b>--hardlink</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Replace identified duplicate files with hard links to the kept file.<br><br><b><b>-S</b> <I>size</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore files smaller than a specified size (e.g., `1M`, `100K`).<br><br><b><b>-X</b>, <b>--destroy-badlinks</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Automatically remove broken symbolic links without generating a script. <br> <i>Use with extreme caution.</i><br><br><b><b>-j</b> <I>N</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use N CPU cores for parallel processing, speeding up scans on multi-core systems.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message and exit.<br><br>


title: DESCRIPTION
content:
<b>rmlint</b> is a powerful and fast command-line utility designed for finding and cleaning up various types of "lint" on your file system. Its primary strength lies in identifying and managing duplicate files, but it also efficiently handles empty files, broken symbolic links, empty directories, and non-stripped binaries. Unlike simpler tools, <b>rmlint</b> employs a sophisticated scanning algorithm, often utilizing hashes for comparison, and can be configured to use various comparison levels from size to full content. It provides flexible output formats, most notably a shell script, allowing users to safely review and execute cleanup operations. This design choice emphasizes data safety by preventing accidental deletion. <b>rmlint</b> aims to help users reclaim disk space and maintain a tidy file system by intelligently detecting and facilitating the removal or linking of redundant data, making it a valuable tool for system maintenance.


title: CAVEATS
content:
Always review the generated shell script (typically `rmlint.sh`) before executing it to ensure no critical files are inadvertently deleted. <br> Be particularly cautious with options that perform immediate actions, such as `<b>-X</b>` (`--destroy-badlinks`), as they bypass the review step. <br> Using hardlinks or symlinks (`<b>-D</b>`, `<b>-L</b>`) modifies file system metadata; understand the implications for backups and other tools. <br> Scanning large file systems can be resource-intensive, consuming significant CPU and disk I/O.


title: <I>OUTPUT FORMATS</I>
content:
<b>rmlint</b> supports various output formats specified via the `<b>-o</b>` option. The most commonly used format is `sh`, which generates a shell script (e.g., `rmlint.sh`) containing `rm` or `ln` commands for the identified lint. This allows users to carefully inspect what will be deleted or linked before execution. Other formats like `json`, `csv`, and `parrot` (used by the GUI) are available for programmatic integration or advanced analysis.


title: <I>SAFETY AND REVIEW</I>
content:
A core principle of <b>rmlint</b>'s design is safety. By default, it does not directly delete files or modify the file system. Instead, it generates a shell script containing the necessary commands to perform the cleanup (e.g., `rm`, `ln`). Users are strongly encouraged to review this generated script (typically found in the current directory as `rmlint.sh`) to ensure that only intended files are affected. This crucial safety net helps prevent accidental data loss and provides full control over the cleanup process.


title: HISTORY
content:
<b>rmlint</b> was created by Christopher Schramm and has been actively developed as a modern, fast, and feature-rich alternative to older duplicate file finders. Its design prioritizes speed, especially for large datasets, by leveraging efficient algorithms and parallel processing. It gained popularity for its emphasis on safety through its default behavior of generating reviewable shell scripts rather than directly modifying the file system.


title: PARAMETERS
content:
<b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;This option can be used to force the removal of a module that is still in use. Use with extreme caution, as it can lead to system instability or crashes.<br><br><b>-w, --wait</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Wait until the module is no longer in use before attempting to unload it. This can prevent errors when a module is busy.<br><br><b>-s, --syslog</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Send error messages to syslog instead of standard error.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print messages about the actions being taken.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information and exit.<br><br>


title: DESCRIPTION
content:
<b>rmmod</b> is a utility used to unload (remove) a loadable module from the Linux kernel. Kernel modules are pieces of code that can be loaded and unloaded into the kernel on demand, extending its functionality without rebooting the system. This command is particularly useful for managing device drivers, filesystem modules, or other kernel extensions. Before a module can be removed, it must not be in use by any process or hardware. If the module has other modules dependent on it, <b>rmmod</b> will fail unless those dependent modules are also unloaded first, or if <b>modprobe -r</b> is used, which handles dependency resolution automatically. <b>rmmod</b> primarily acts as a simple wrapper around the <i>delete_module</i> system call. While <b>rmmod</b> works for simple module removal, <b>modprobe -r</b> is generally preferred as it is more robust, managing module dependencies and aliases, thus simplifying the process of dynamic kernel module management.


title: CAVEATS
content:
<b>Module in Use:</b> A module cannot be unloaded if it is currently in use by any process or hardware. Attempting to do so will result in an error message like "rmmod: ERROR: Module is in use".<br><b>Dependencies:</b> <b>rmmod</b> does not automatically handle module dependencies. If a module has other modules depending on it, those dependent modules must be unloaded first. For automatic dependency resolution, use <b>modprobe -r</b>.<br><b>System Stability:</b> Forcing the removal of a module (<i>-f</i>) that is still in use can lead to system instability, crashes, or data corruption. It should be used only as a last resort and with a clear understanding of the risks.<br><b>Permissions:</b> Removing kernel modules requires root privileges (or <b>sudo</b>).


title: PERMISSIONS
content:
To use <b>rmmod</b>, you must have root privileges. Typically, this means running the command with <b>sudo</b>.


title: CHECKING MODULE USAGE
content:
Before attempting to remove a module, you can check if it's in use using <b>lsmod</b>. The output will show a usage count. A count of 0 indicates the module is not currently used by other modules, but it might still be in use by processes or hardware. For persistent usage, tools like <b>lsof</b> or <b>fuser</b> might provide more details if a module is tied to a specific file or process, or checking <b>dmesg</b> for related messages.


title: UNDERLYING MECHANISM
content:
While <b>rmmod</b> appears as a standalone command, in many modern Linux systems, it acts as a simple wrapper that calls <b>modprobe -r</b> internally. This ensures consistency with dependency handling, even if <b>rmmod</b> itself doesn't explicitly resolve them.


title: COMMON ERRORS
content:
<ul><li><i>rmmod: ERROR: Module modulename is in use</i>: The most common error, meaning the module is actively being used. You must stop whatever is using it or remove dependent modules first.</li><li><i>rmmod: ERROR: Module modulename is not loaded</i>: The module you are trying to remove is not currently loaded in the kernel.</li><li><i>rmmod: ERROR: could not remove 'modulename': Operation not permitted</i>: You do not have the necessary permissions (e.g., not running as root).</li></ul>


title: HISTORY
content:
<b>rmmod</b> has been a fundamental part of Linux module management tools since the early days of loadable kernel modules. Historically, it was part of the <i>modutils</i> package, later superseded by <i>module-init-tools</i> and more recently by <i>kmod</i>. While <b>rmmod</b> provides a direct interface to the kernel's module removal system call, the preferred method for module removal evolved to <b>modprobe -r</b>. This is because <b>modprobe</b> intelligently handles module dependencies, aliases, and configuration, simplifying the overall module management process. In many modern Linux distributions, <b>rmmod</b> is often a symbolic link or a wrapper script that internally calls <b>modprobe -r</b>, effectively making <b>rmmod</b> a simpler, albeit less robust, frontend to <b>modprobe</b>'s removal capabilities.


title: SYNOPSIS
content:
<b>tar</b> <i>&lt;operation&gt;</i> <b>-f</b> <i>[user@]host:&lt;remote_device&gt;</i> [<i>options</i>] [<i>files...</i>]<br><br>Examples:<br><b>tar -cvf backup@remoteserver:/dev/rmt0 /home/user/data</b><br><b>tar -xvf remoteserver:/dev/rmt0</b>


title: PARAMETERS
content:
<b><b>-f</b> <i>[user@]host:&lt;remote_device&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the remote tape device. The <i>user@</i> part is optional and defines the username for connecting to the remote host. <i>host</i> is the remote machine's hostname or IP address. <i>&lt;remote_device&gt;</i> is the path to the tape device (e.g., <i>/dev/rmt0</i>) on the remote system.<br><br><b><b>TAR_RSH_COMMAND</b> or <b>RSH_COMMAND</b> (environment variable)</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows specifying an alternative remote shell program to be used for establishing the connection to the remote host instead of the default <b>rsh</b>. For example, setting <i>TAR_RSH_COMMAND=ssh</i> instructs <b>tar</b> to use <b>ssh</b> for secure communication.<br><br>


title: DESCRIPTION
content:
The term <i>rmt-tar</i> does not refer to a standalone Linux command named "rmt-tar". Instead, it describes the functionality where the standard <b>tar</b> utility interacts with remote tape devices using the <b>rmt</b> (remote tape) protocol.<br><br>The <b>rmt</b> protocol allows a local <b>tar</b> command to perform operations (like reading, writing, or rewinding) on a tape device located on a remote machine. When <b>tar</b> is invoked with a remote device specified in the format <i>[user@]host:/path/to/device</i>, it typically establishes a connection to the remote host (historically via <b>rsh</b>, now more commonly via <b>ssh</b>) and executes the <b>rmt</b> daemon there. This <b>rmt</b> daemon acts as a server, performing the requested tape operations on behalf of the local <b>tar</b> and transferring data across the network.<br><br>This mechanism is crucial for managing backups and archives on centralized tape libraries or remote servers without physically accessing the tape drive, making it a powerful tool in distributed environments, especially in older Unix and Linux setups.


title: CAVEATS
content:
<b>Security Concerns:</b> Historically, <b>rmt-tar</b> operations often relied on <b>rsh</b>, which is highly insecure due to unencrypted data transfer and authentication via `.rhosts` files. Modern usage should always prefer <b>ssh</b> for secure transport.<br><br><b>Remote `rmt` Daemon:</b> The remote host must have the <b>rmt</b> daemon (typically <i>/usr/libexec/rmt</i> or <i>/usr/lib/rmt</i>) installed and accessible via the chosen remote shell (<b>rsh</b> or <b>ssh</b>).<br><br><b>Performance:</b> Network latency and bandwidth limitations can significantly impact the speed of remote tape operations, especially for large archives.<br><br><b>Firewall Configuration:</b> Appropriate firewall rules must be in place on both the local and remote systems to allow the chosen remote shell protocol (e.g., port 22 for <b>ssh</b>) to establish a connection.<br><br><b>Error Diagnosis:</b> Debugging issues with remote tape operations can be challenging, as errors might originate on the remote host and be relayed back through the <b>rmt</b> protocol.


title: HOW IT WORKS
content:
When <b>tar</b> needs to access a remote device (e.g., <i>host:/dev/rmt0</i>), it doesn't directly connect to the tape drive. Instead, it invokes a remote shell (like <b>ssh</b> or <b>rsh</b>) on the target host. This remote shell then executes the <b>rmt</b> program on the remote machine. The <b>rmt</b> program acts as a proxy: it accepts commands (like 'open device', 'read block', 'write block', 'close device') from the local <b>tar</b> via the network connection, performs the actual tape I/O operations on the remote device, and returns the results or data blocks back to the local <b>tar</b>. This client-server architecture abstracts the tape hardware and allows for network-transparent tape access.


title: CONFIGURING FOR SSH
content:
To use <b>rmt-tar</b> securely with <b>ssh</b>, ensure that <b>ssh</b> is properly configured for passwordless authentication between the local and remote machines. This usually involves setting up SSH keys (e.g., using <i>ssh-keygen</i> and <i>ssh-copy-id</i>). Additionally, the remote <b>ssh</b> server must be configured to allow execution of the <b>rmt</b> command. The <b>TAR_RSH_COMMAND</b> environment variable should be set to <b>ssh</b> on the client side to ensure <b>tar</b> uses <b>ssh</b> instead of <b>rsh</b>.


title: HISTORY
content:
The <b>rmt</b> protocol emerged in early Unix environments to facilitate remote access to tape drives for backup and restoration tasks. It allowed administrators to centralize tape libraries and manage backups from various client machines across a network. Initially, connections were typically established using the <b>rsh</b> utility. However, with the rise of network security concerns, the unencrypted nature of <b>rsh</b> became a significant vulnerability. Consequently, modern Unix and Linux distributions largely transitioned to using <b>ssh</b> as the preferred secure transport layer for <b>rmt</b> operations, ensuring encrypted communication and stronger authentication methods.


title: PARAMETERS
content:
<b><i>file...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more files to open for editing. In restricted mode, <i>rnano</i> will generally only allow saving to these specified files.<br><br><b><b>-H</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show a summary of command-line options. Note: In restricted mode, access to help might be disabled by default for security reasons.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version number and exit. This option typically remains functional even in restricted mode.<br><br>


title: DESCRIPTION
content:
<i>rnano</i> is a special invocation of the <i>nano</i> text editor that operates in a restricted mode. Its primary purpose is to provide a text editing utility in environments where full filesystem access, shell escapes, or other advanced features are deemed insecure or unnecessary. It is commonly used in chrooted jails, restricted user accounts, or system kiosks where users should only be able to edit specific files without broader system interaction.<br><br>When invoked as <i>rnano</i> (typically via a symbolic or hard link named <i>rnano</i> pointing to the <i>nano</i> executable), <i>nano</i> automatically activates its restricted mode. This mode disables several functionalities, including:<br><ul><li>Access to the shell (no shell escapes).</li><li>File browsing outside of specified paths.</li><li>Saving files to arbitrary locations (only to files opened on the command line).</li><li>Spell checking.</li><li>Access to most help documentation (configurable).</li><li>The ability to suspend the editor.</li><li>The ability to toggle many options interactively.</li></ul>The exact set of restrictions can vary slightly based on the <i>nano</i> version and its compile-time options, but the core intent remains to provide a sandboxed editing experience.


title: CAVEATS
content:
<i>rnano</i>'s security relies on the robustness of <i>nano</i>'s restricted mode. It's not a hardened security boundary on its own; a determined or malicious user might still find ways to bypass restrictions if the underlying system environment is not properly secured (e.g., if shell access is available through other means, or if other vulnerable programs are accessible).<br><br>Many common <i>nano</i> features and options are disabled or rendered ineffective in <i>rnano</i> mode, which can be confusing for users expecting full <i>nano</i> functionality. Users cannot freely navigate the filesystem, execute external commands, or save to new file paths.


title: TYPICAL USAGE
content:
<i>rnano</i> is typically set up as a symbolic link (e.g., <code>ln -s /bin/nano /usr/local/bin/rnano</code>) or a hard link to the <i>nano</i> executable. When the system executes the command named <i>rnano</i>, the <i>nano</i> program detects its invocation name and automatically enables the restricted mode. This makes it convenient for system administrators to provide a limited editor without maintaining a separate codebase.


title: CONFIGURATION
content:
While <i>rnano</i> enforces strict limitations, its behavior can still be influenced by global <i>nanorc</i> configuration files (e.g., <i>/etc/nanorc</i>) or user-specific ones (<i>~/.nanorc</i>), although many options might be overridden or ignored due to the restricted mode's precedence. Specific <i>nano</i> versions might offer command-line options like <code>--allow-restricted-help</code> to selectively enable certain features even in restricted mode, but these are exceptions rather than the norm.


title: HISTORY
content:
<i>rnano</i> is not a standalone application but a built-in feature of the <i>nano</i> text editor. <i>nano</i> itself originated as a free software clone of the Pico editor, which was part of the Pine email client. As <i>nano</i> grew in popularity, the need for a restricted mode arose to facilitate its use in secure or limited user environments, such as chroot jails, where users should not have full access to system resources. This restricted functionality was integrated directly into <i>nano</i>, allowing it to be invoked under a different name (<i>rnano</i>) to automatically activate these limitations. The concept of a restricted shell or editor is common in Unix-like systems for security and administrative purposes, and <i>rnano</i> fulfills this role for the <i>nano</i> editor.


title: SYNOPSIS
content:
<b>rnm</b> [<i>OPTIONS</i>] [<i>MODE_ARGS</i>] <i>PATH</i>...<br><br><i>Common invocation patterns:</i><br><b>rnm</b> [<i>OPTIONS</i>] <b>--regex</b> <i>&lt;PATTERN&gt; &lt;REPLACEMENT&gt;</i> <i>PATH</i>...<br><b>rnm</b> [<i>OPTIONS</i>] <b>--prefix</b> <i>&lt;PREFIX&gt;</i> <i>PATH</i>...<br><b>rnm</b> [<i>OPTIONS</i>] <b>--to-lower</b> <i>PATH</i>...


title: PARAMETERS
content:
<b><b>-n</b>, <b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows what would be done without actually making any changes to files or directories. <i>Highly recommended for safety.</i><br><br><b><b>-r</b>, <b>--regex</b> <i>&lt;PATTERN&gt; &lt;REPLACEMENT&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rename using regular expression substitution. The first argument is the regex pattern to search for, the second is the replacement string.<br><br><b><b>-g</b>, <b>--glob</b> <i>&lt;PATTERN&gt; &lt;REPLACEMENT&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rename using glob pattern matching for the search and replace.<br><br><b><b>-p</b>, <b>--prefix</b> <i>&lt;PREFIX&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds the specified <i>&lt;PREFIX&gt;</i> to the beginning of each name.<br><br><b><b>-s</b>, <b>--suffix</b> <i>&lt;SUFFIX&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds the specified <i>&lt;SUFFIX&gt;</i> to the end of each name.<br><br><b><b>-x</b>, <b>--remove-prefix</b> <i>&lt;PREFIX&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the specified <i>&lt;PREFIX&gt;</i> from the beginning of names.<br><br><b><b>-y</b>, <b>--remove-suffix</b> <i>&lt;SUFFIX&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the specified <i>&lt;SUFFIX&gt;</i> from the end of names.<br><br><b><b>-l</b>, <b>--to-lower</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts all characters in names to lowercase.<br><br><b><b>-u</b>, <b>--to-upper</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts all characters in names to uppercase.<br><br><b><b>-t</b>, <b>--to-title</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts names to title case (first letter of each word capitalized).<br><br><b><b>-c</b>, <b>--to-camel</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts names to camel case.<br><br><b><b>-k</b>, <b>--to-snake</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Converts names to snake case.<br><br><b><b>-m</b>, <b>--max-depth</b> <i>&lt;DEPTH&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Descends at most <i>&lt;DEPTH&gt;</i> levels below the starting directory. A value of 0 means only the starting directory itself.<br><br><b><b>-d</b>, <b>--dir-only</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only operate on directories, ignoring files.<br><br><b><b>-f</b>, <b>--file-only</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only operate on files, ignoring directories.<br><br><b><b>-i</b>, <b>--interactive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompts for confirmation before each rename operation.<br><br><b><b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces renaming, overwriting existing files without prompt (use with extreme caution).<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays more detailed output during the operation.<br><br>


title: DESCRIPTION
content:
The <b>rnm</b> command, short for <i>Recursive Name Manipulator</i>, is a robust and flexible command-line utility designed for performing complex batch renaming operations on files and directories. Unlike simpler renaming tools, <b>rnm</b> supports a wide array of transformation methods, including regular expression substitutions, glob pattern matching, adding or removing prefixes and suffixes, changing case (to upper, lower, title case), and more. It can process files recursively through directories, making it ideal for organizing large collections of files. Key features include a crucial dry-run mode (<code>-n</code> or <code>--dry-run</code>) to preview changes before execution, various matching and replacement strategies, and the ability to operate on standard input, making it highly scriptable. <b>rnm</b> aims to provide a safer and more powerful alternative to scripting complex <code>find</code> and <code>mv</code> combinations for renaming tasks.


title: CAVEATS
content:
<b>rnm</b> is not a standard utility included with most Linux distributions by default. It typically needs to be installed separately (e.g., via a package manager like Cargo for Rust-based versions). Due to its powerful recursive renaming capabilities, extreme caution is advised. Always use the <code>--dry-run</code> (<b>-n</b>) option first to preview changes before committing to any actual file modifications, especially when dealing with large numbers of files or complex regex patterns. Incorrect usage can lead to data loss or unrecoverable file name changes.


title: INSTALLATION
content:
As <b>rnm</b> is not a standard command, it usually needs to be installed. For example, if it's the Rust-based version (a common implementation), it can often be installed via Cargo (Rust's package manager) using: <code>cargo install rnm</code>. Alternatively, pre-compiled binaries might be available on its GitHub releases page or via specific distribution's unofficial repositories. Consult the project's official documentation for the most accurate installation instructions.


title: USAGE EXAMPLES
content:
<i>Rename all '.txt' files to '.md' recursively in the current directory and subdirectories:</i><br><code>rnm -r '\.txt$' '.md' . -n</code><br><br><i>Add 'old_' prefix to all files/directories in the current directory (non-recursive):</i><br><code>rnm -p 'old_' * -n</code><br><br><i>Convert all file names within the 'docs' directory (and its subdirectories) to lowercase:</i><br><code>rnm -l docs/ -n</code><br><br><i>Remember to remove <code>-n</code> (<code>--dry-run</code>) for actual execution!</i>


title: HISTORY
content:
The <b>rnm</b> (Recursive Name Manipulator) tool is a relatively modern utility, often implemented in languages like Rust, developed to address the limitations of traditional renaming tools and intricate scripting approaches for batch renaming. Its development focus has been on providing a robust, performant, and feature-rich solution that can handle complex renaming scenarios with a clear, declarative syntax. It aims to reduce the boilerplate often associated with manual shell scripting for such tasks, offering a more intuitive and powerful recursive renaming capability than that provided by combining standard Unix utilities.


title: SYNOPSIS
content:
<b>vendor/bin/roave-backward-compatibility-check</b> <i>&lt;base-reference&gt;</i> <i>&lt;head-reference&gt;</i> [<I>options</I>]<br><br><i>&lt;base-reference&gt;</i>: The older Git reference (e.g., branch, tag, commit) or directory path to compare against.<br><i>&lt;head-reference&gt;</i>: The newer Git reference or directory path to be checked for breaks.


title: PARAMETERS
content:
<b>base-reference</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The older version of the codebase for comparison. Can be a Git reference (e.g., <i>main</i>, <i>HEAD~1</i>) or a directory path.<br><br><b>head-reference</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The newer version of the codebase being checked for backward compatibility breaks. Can be a Git reference or a directory path.<br><br><b>--php-json <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to a <i>php.json</i> file for configuring PHP version constraints during analysis.<br><br><b>--config <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to a <i>bc-check.php</i> file for advanced configuration, allowing custom rules and exclusion of specific BC breaks.<br><br><b>--ignore-php-major-version-changes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignores reported issues related to PHP major version changes, focusing only on code-level breaks.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the command.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the application's version.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of command output.<br><br><b>--quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all command output messages.<br><br>


title: DESCRIPTION
content:
The <b>roave-backward-compatibility-check</b> command is a powerful static analysis tool designed for PHP development, primarily used to prevent accidental backward compatibility (BC) breaks. It compares two versions of a PHP codebase, such as a feature branch against a stable <i>main</i> or <i>master</i> branch, or two distinct Git references/directories.<br><br>The tool identifies structural changes that could lead to breaks for consumers of a library or application, including removed public methods, changed method signatures, or alterations to class, interface, and trait definitions. This utility is particularly valuable in Continuous Integration/Continuous Deployment (CI/CD) pipelines, where it can automatically enforce BC standards before code is merged or deployed. By integrating this check into the development workflow, teams can maintain API stability and ensure that updates do not inadvertently break existing integrations or dependent projects. It requires PHP and typically operates within a project's <i>vendor/bin</i> directory after installation via Composer.


title: CAVEATS
content:
This command requires a PHP environment to run and is typically installed as a project dependency via Composer. It relies on <i>git</i> for comparing codebases when Git references are provided. As a static analysis tool, it may not detect all possible backward compatibility breaks, particularly those that manifest only at runtime or due to complex dynamic code execution. Proper configuration through <i>bc-check.php</i> is often necessary to ignore intentional breaks or tailor checks to specific project needs. It's designed for use within a PHP project's <i>vendor/bin</i> directory, not as a globally installed system command.


title: INTEGRATION WITH CI/CD
content:
This tool is highly recommended for integration into Continuous Integration and Continuous Deployment pipelines. By adding it as a step in automated workflows, teams can automatically verify that pull requests or commits do not introduce unwanted backward compatibility breaks, ensuring robust API stability and preventing regressions.


title: CONFIGURATION OPTIONS (BC-CHECK.PHP AND PHP.JSON)
content:
The command offers extensive configurability through dedicated files: <i>bc-check.php</i> allows for fine-grained control over the analysis, including ignoring specific types of breaks or certain files/namespaces. <i>php.json</i> enables configuration of PHP version constraints for the analysis, which is crucial for projects targeting specific PHP environments.


title: HISTORY
content:
The <b>roave-backward-compatibility-check</b> tool was developed by Roave, a software development consultancy, and is an open-source project hosted on GitHub. Its initial public release was in 2017. It was created to address the critical need for automated checks against accidental API or library changes that could break consumer code, a common challenge in maintaining stable software components. Since its inception, it has been actively maintained and updated, gaining adoption within the PHP community, especially in projects prioritizing strong backward compatibility guarantees.


title: PARAMETERS
content:
<b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies directories and their contents recursively.<br><br><b><b>-u</b>, <b>--update</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies only when the source is newer than the destination.<br><br><b><b>-m</b>, <b>--mirror</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates an exact mirror, deleting extraneous files at destination not present in source.<br><br><b><b>-n</b>, <b>--dry-run</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Performs a simulated run without actual file operations, showing what would happen.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity of output, showing more details about operations.<br><br><b><b>-l &lt;file&gt;</b>, <b>--log=&lt;file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Logs all output and errors to a specified file.<br><br><b><b>--exclude=&lt;pattern&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes files or directories matching the specified pattern.<br><br><b><b>--include=&lt;pattern&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes files or directories matching the pattern, overriding excludes.<br><br><b><b>-c</b>, <b>--checksum</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips files based on checksum comparison instead of size/timestamp.<br><br><b><b>-p &lt;attrs&gt;</b>, <b>--preserve=&lt;attrs&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Preserves specified attributes (e.g., 'all', 'mode', 'timestamps', 'owner', 'group').<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrites existing files at the destination without prompting.<br><br><b><b>--delete-before</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes files at the destination before copying new ones.<br><br><b><b>--delete-after</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes files at the destination after copying new ones.<br><br>


title: DESCRIPTION
content:
The <i>robo</i> command is a powerful command-line utility designed for <b>robust</b> and <b>automated</b> file and directory synchronization, mirroring, and management across local and network file systems. It emphasizes reliability, ensuring data integrity even during interruptions, and provides extensive logging and error reporting features, making it suitable for critical data operations.<br><br><i>robo</i> is ideal for automated backup routines, deploying application assets across multiple servers, or maintaining synchronized data sets between different storage locations. Its core strength lies in its ability to handle large data sets efficiently, intelligently comparing source and destination to copy only changed, new, or missing files. It supports resuming interrupted transfers and includes mechanisms for verifying data consistency post-transfer.<br><br>Users can leverage <i>robo</i> for one-way mirroring, incremental backups, or simply copying files with enhanced logging capabilities. Advanced features include customizable exclusion and inclusion patterns, verbose output, and options for preserving metadata such as permissions, timestamps, and ownership. This makes <i>robo</i> a versatile tool for system administrators and developers alike, needing dependable and automated data manipulation.


title: CAVEATS
content:
Using <b>--mirror</b> or <b>--delete-before</b>/<b>--delete-after</b> incorrectly can lead to irreversible data loss. Always use <b>--dry-run</b> first for critical operations. Performance can be significantly impacted by network latency or the number of small files involved. Permissions issues are common if <i>robo</i> is not run with appropriate user privileges.


title: EXIT STATUSES
content:
The <i>robo</i> command typically exits with a status of 0 on success. Non-zero values indicate errors, with specific codes for common issues like file not found (1), permission denied (2), network errors (3), or checksum mismatches (4), allowing for robust scripting and automated error handling.


title: PERFORMANCE CONSIDERATIONS
content:
For optimal performance, especially over network paths, consider using options like <b>--checksum</b> sparingly as it can be CPU and I/O intensive, preferring size/timestamp checks when data integrity is not paramount. Utilizing efficient file system operations and ensuring sufficient network bandwidth are key factors for large-scale deployments. Large numbers of small files can inherently slow down any recursive operation due to metadata overhead.


title: HISTORY
content:
Conceptualized to address the need for more resilient and auditable file operations in automated environments, <i>robo</i> draws inspiration from robust copy mechanisms found in enterprise backup solutions and cross-platform syncing tools like Microsoft's RoboCopy. Its development focused on integrating advanced error recovery, data integrity checks, and comprehensive logging within a simple command-line interface, aiming to reduce manual intervention in routine data management tasks and provide a dependable foundation for critical data synchronization.


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message containing usage information and exits.<br><br><b><b>-v</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the program's version number and exits.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables 'silent' mode, which suppresses the display of philosophical messages when a kitten is found.<br><br><b><b>-k <I>N</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of kittens that will appear on each screen to <I>N</I>. The default is usually 1.<br><br><b><b>-c <I>N</I></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the number of objects (robots or junk items) generated on each screen to <I>N</I>.<br><br>


title: DESCRIPTION
content:
<b>robotfindskitten</b> is a unique, terminal-based 'game' or 'toy' renowned for its simplicity, randomness, and absurdist humor. The primary objective, if it can be called one, is for a robot (typically represented by '#') to locate one or more kittens (represented by 'K' or other characters) hidden among a screen full of randomly generated ASCII characters that symbolize 'robots' or other arbitrary objects.<br><br>There are no conventional game mechanics like levels, scores, or complex rules. Movement is typically achieved using arrow keys or the 'hjkl' keys. Upon successfully finding a kitten, a humorous, enigmatic, or philosophical message is displayed, and a new, randomly generated 'game' screen appears. The program embraces a spirit of minimalist, non-goal-oriented exploration, offering a lighthearted diversion whose charm lies in its deliberate lack of traditional gaming structure and its focus on the arbitrary.


title: CAVEATS
content:
<b>robotfindskitten</b> is not a traditional game; it intentionally lacks scores, levels, or clear objectives beyond the basic act of finding the kitten. Its humor and philosophical messages are often abstract, nonsensical, or cryptic, contributing to its unique charm rather than providing conventional gameplay. It is purely text-based and designed for a terminal environment.


title: MOVEMENT
content:
The robot can be moved around the screen using either the standard arrow keys (Up, Down, Left, Right) or the 'hjkl' keys (h: left, j: down, k: up, l: right), common in text editors like <I>vi</I> and other terminal applications.


title: THE 'GAME' EXPERIENCE
content:
When the robot lands on a square containing a kitten, a new screen is generated, and a random, often humorous or philosophical message appears at the bottom of the terminal. These messages range from profound to utterly bizarre, reinforcing the program's nonsensical charm. The 'game' has no ending, no high scores, and no real challenges, making it an endless, meditative, and amusing diversion.


title: HISTORY
content:
<b>robotfindskitten</b> was created by Leonard Richardson and first released around the year 2000. It rapidly gained a cult following due to its distinct blend of simplicity, randomness, and absurdist humor. Frequently included in 'bsdgames' or similar packages on Unix-like systems, it exemplifies a minimalist approach to interactive terminal programs, prioritizing philosophical musings and arbitrary interactions over complex gameplay or structured progression.


title: PARAMETERS
content:
<b><i>-j</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Jump to a random location without refreshing the screen, making the jump faster.<br><br><b><i>-s</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the high score file, typically located in the user's home directory.<br><br><b><i>-t</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the top ten highest scores from the score file.<br><br><b><i>-V</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the version number of the <i>robots</i> game and then exit.<br><br>


title: DESCRIPTION
content:
<i>robots</i> is a classic, turn-based, ASCII-art game available on many Unix-like systems as part of the <i>bsdgames</i> package. The player, represented by an '@' symbol, is tasked with surviving waves of hostile robots. Robots, initially denoted by '+' symbols, move one step closer to the player each turn. The core gameplay revolves around strategic movement to trick robots into colliding with each other, which destroys them and converts them into 'junk' (represented by '*'). Colliding with junk is harmless, but touching a robot or being surrounded by them leads to the player's demise.<br><br>The game features different robot types: basic robots, fast robots (moving twice per turn), and smart robots (finding optimal paths). As levels progress, the number of robots increases, and more challenging types appear. The player can move in eight directions, stay still, or use a "teleport" move to instantly jump to a random location on the screen. Teleporting can be a last resort or a strategic risk, as it might land the player in a worse position.<br><br>Successfully clearing a level of robots advances the player to the next level, where more robots spawn. The game's simplicity, combined with its strategic depth, has kept it popular among enthusiasts of retro terminal games. It provides an engaging challenge in a minimalist, text-only environment.


title: CAVEATS
content:
Primarily a game, <i>robots</i> is not a system utility. It requires a terminal supporting <i>ncurses</i> or similar capabilities for its ASCII graphics and interactive gameplay. It is typically found within the <i>bsdgames</i> package, which might not be installed by default on all Linux distributions. Users should be aware that the game is turn-based and requires strategic thinking rather than fast reflexes.


title: GAMEPLAY MECHANICS
content:
Players move strategically on a grid, often using the 'teleport' function or luring robots into collisions. Robots move one step closer per turn, transforming into 'junk' (represented by '*') upon collision. Different robot types, including basic, fast, and smart, add complexity to higher levels, requiring more refined tactics to survive.


title: SCORING SYSTEM
content:
Points are awarded for each robot destroyed, and the scoring often escalates with the number of robots on screen or as higher levels are reached, encouraging players to clear as many robots as possible. High scores are typically saved locally, allowing players to compete for top positions on their system.


title: HISTORY
content:
Developed as part of the BSD operating system's <i>bsdgames</i> collection, <i>robots</i> is a testament to early interactive computing on Unix-like systems. Its simple ASCII interface and turn-based mechanics reflect the capabilities of terminals in the 1970s and 1980s. While graphical games became prevalent, <i>robots</i> has persisted as a classic example of terminal-based entertainment, maintaining its original design and core gameplay across decades and various Unix/Linux distributions. It remains a popular title for those seeking a nostalgic or minimalist gaming experience.


title: PARAMETERS
content:
<b><code>-T</code><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output device. Common values include `ps` (PostScript), `ascii` (plain text for terminals, similar to <b>nroff</b>), `html`, `dvi`, and `pdf`.<br><br><b><code>-m</code><i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads the specified macro package `name`. Examples include `man` (for manual pages), `mdoc` (another manual page format), `ms` (for manuscripts), and `mm` (for memoranda).<br><br><b><code>-r</code><i>CN</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a string register `C` to the numerical value `N`. Registers are variables used for storing numbers or strings within <b>roff</b> documents.<br><br><b><code>-e</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the `eqn` preprocessor, used for typesetting mathematical equations.<br><br><b><code>-p</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the `pic` preprocessor, used for creating simple diagrams and line drawings.<br><br><b><code>-t</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the `tbl` preprocessor, used for formatting tables.<br><br><b><code>-o</code><i>pages</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs only the specified pages. The `pages` argument is a comma-separated list of page ranges (e.g., `1-5,7,10-`).<br><br><b><code>-l</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends the formatted output directly to the default printer using `lpr`.<br><br><b><code>-I</code><i>dir</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds `dir` to the search path for macro files and other `groff`-related resources.<br><br>


title: DESCRIPTION
content:
The <b>roff</b> system is a powerful text formatting framework, a descendant of the original `runoff` program from the mid-1960s. On modern Linux systems, the functionality of <b>roff</b> is primarily provided by the <b>groff</b> (GNU <b>roff</b>) project. It is not a single executable command in the way `ls` or `grep` are, but rather a sophisticated suite of tools and a markup language designed for producing high-quality textual output for various devices, from terminals to printers.<br><br><b>roff</b> processes source text files embedded with formatting requests and macros to generate formatted output. It's widely used for creating manual pages (`man` pages), books, reports, and other technical documentation. The core concept involves separating content from presentation, allowing authors to focus on writing while <b>roff</b> handles the layout, typography, and pagination based on defined styles or macro packages.


title: CAVEATS
content:
The <b>roff</b> system has a steep learning curve due to its powerful but complex syntax and the necessity of understanding specific macro packages or raw <b>roff</b> requests. While incredibly robust for technical documentation, it's generally less user-friendly for casual document creation compared to modern word processors or simpler markup languages like Markdown. Debugging formatting issues can also be challenging.


title: MACRO PACKAGES
content:
<b>roff</b> itself provides a low-level set of formatting requests. To simplify document creation, developers created collections of higher-level commands called 'macro packages'. These packages encapsulate common formatting tasks (like headings, paragraphs, lists) into easy-to-use macros. Key macro packages include `man` and `mdoc` (for manual pages), `ms` (manuscript format), and `mm` (memoranda format). Using a macro package allows authors to write documents with logical structure, letting the package handle the intricate `roff` commands for proper presentation.


title: PREPROCESSING
content:
The <b>roff</b> system is often used in conjunction with various preprocessors that handle specialized content before the main `groff` (or `troff`/`nroff`) processing stage. These preprocessors translate specific markup into <b>roff</b> requests. Common preprocessors include <b>eqn</b> for mathematical equations, <b>tbl</b> for tables, and <b>pic</b> for diagrams. There are also `refer` for bibliographic references and `grap` for plotting data. The typical workflow involves piping the output of one or more preprocessors to the main `groff` command: `eqn_file | tbl_file | groff -m macro_pkg > output`.


title: HISTORY
content:
The origins of <b>roff</b> trace back to the `runoff` program developed by Jerome Saltzer for the CTSS operating system in 1964. This was later rewritten for Unix by Joe Ossanna as `troff` (for typesetting) and `nroff` (for terminal output) at Bell Labs in the early 1970s. These tools became fundamental to the Unix ecosystem, particularly for creating system documentation and man pages. The GNU Project developed <b>groff</b> (GNU <b>roff</b>) in the late 1980s, primarily by James Clark, as a free software replacement that largely superseded the original Bell Labs versions. <b>groff</b> is now the standard <b>roff</b> implementation on Linux and other free Unix-like systems, continuing its legacy as a vital tool for high-quality text formatting.


title: SYNOPSIS
content:
<b>roff2dvi</b> [<i>OPTION</i>...] [<i>FILE</i>...]<br>This command processes one or more <i>FILE</i>s (or standard input if no files are specified) and outputs the resulting <i>DVI</i> to standard output.


title: PARAMETERS
content:
<b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run fast. <i>Do not output a preamble</i>, which can sometimes speed up processing for simple documents.<br><br><b><b>-F</b> <<i>dir</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prepend <<i>dir</i>> to the search path for font, device, and other <i>groff</i> related files. This is useful for custom installations or document-specific resources.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the version number of roff2dvi to standard error and then exit.<br><br><b><b>-z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress output from <i>troff</i> if there are any errors during processing. Only error messages will be shown.<br><br>


title: DESCRIPTION
content:
roff2dvi is a utility that converts documents formatted with <i>roff</i> or <i>troff</i> (specifically, <i>groff</i>) into the Device Independent (<i>DVI</i>) file format. <i>DVI</i> is a binary format produced by TeX and <i>groff</i> (when using the <i>dvi</i> device), designed to be easily converted into various output formats (like PostScript, PDF) or viewed directly. roff2dvi acts as a convenient wrapper script, essentially invoking the <i>groff</i> command with the appropriate options to generate <i>DVI</i> output. It's commonly used in <i>UNIX</i>-like systems for processing man pages and other text-based documents that use the <i>roff</i> typesetting system, making them viewable or printable via <i>DVI</i> tools.


title: CAVEATS
content:
roff2dvi is primarily a convenience script that wraps the <i>groff</i> command. Most command-line options are passed directly to <i>groff</i>. Therefore, for advanced usage or specific typesetting controls, one typically refers to the <i>groff(1)</i> manual page. The generated <i>DVI</i> files require a <i>DVI</i> viewer (e.g., <i>xdvi</i>) or a <i>DVI</i>-to-PostScript/PDF converter (e.g., <i>dvips</i>, <i>dvipdfm</i>) to be rendered or printed.


title: BACKEND OPERATION
content:
roff2dvi essentially executes a command similar to <i>groff -Tdvi [options] [files]</i>. This means that many options available for <i>groff</i> can be passed to roff2dvi and will be handled by the underlying <i>groff</i> command.


title: OUTPUT REDIRECTION
content:
By default, roff2dvi writes the <i>DVI</i> output to standard output. To save it to a file, you typically redirect the output using shell redirection, e.g., <b>roff2dvi document.roff > document.dvi</b>.


title: HISTORY
content:
roff2dvi is an integral part of the <i>groff</i> (GNU <i>roff</i>) project, which aims to provide a free software implementation of the <i>roff</i> typesetting system. Its development has mirrored that of <i>groff</i> itself, evolving as <i>groff</i> gained more features and device support. It emerged as a user-friendly wrapper to simplify the common task of converting <i>roff</i> source to <i>DVI</i> format, a critical step for preparing documents for printing or viewing in environments where <i>DVI</i> is a primary output format.


title: PARAMETERS
content:
<b><i>file</i>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more <i>roff</i> source files to be converted. If no files are specified, <i>roff2html</i> reads from standard input (stdin).<br><br><b><b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message about <i>roff2html</i>'s usage and then exits.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the generation of standard HTML header and footer tags (like <i>&lt;html&gt;</i>, <i>&lt;head&gt;</i>, <i>&lt;body&gt;</i>). This is useful when the output is intended to be embedded within another HTML document.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Adds an HTML <i>&lt;title&gt;</i> tag to the output, typically derived from the name of the man page being processed.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information for <i>roff2html</i> and exits.<br><br><b><i>groff_options</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>roff2html</i> passes unrecognized command-line options directly to the underlying <i>groff</i> command. This allows users to control <i>groff</i>'s behavior, for instance, by specifying macro packages (e.<b>g.</b>, <b>-man</b>, <b>-mdoc</b>) or defining <i>roff</i> registers.<br><br>


title: DESCRIPTION
content:
<i>roff2html</i> is a utility designed to transform documents written in the <i>roff</i> typesetting language, commonly used for Unix manual pages (man pages), into HTML format.<br><br>It processes <i>roff</i> input, interpreting its various macros and formatting commands, and renders them into web-friendly HTML. This conversion is particularly useful for publishing man pages on the web, making them accessible via browsers without needing a <i>roff</i> viewer.<br><br>It leverages <i>groff</i> for the initial <i>roff</i> processing, making it robust in handling complex <i>roff</i> constructs, including tables and equations, and then generates HTML output that can be viewed directly in a web browser.


title: CAVEATS
content:
Conversion quality can vary depending on the complexity of the <i>roff</i> source and its reliance on specific <i>groff</i> features or custom macros.<br><br>HTML output might not perfectly replicate all visual nuances of the original <i>roff</i> rendering (e.<b>g.</b>, exact spacing, font sizes).<br><br>It primarily handles standard man page formats (<i>man</i>, <i>mdoc</i>). Non-standard or highly customized <i>roff</i> files might require manual adjustments or pre-processing.


title: INPUT AND OUTPUT FLOW
content:
By default, <i>roff2html</i> reads <i>roff</i> source from files specified as arguments. If no files are given, it reads from standard input (stdin). The resulting HTML output is written to standard output (stdout). This allows for flexible piping and redirection, such as directing output to a file (e.<b>g.</b>, <b>roff2html</b> <i>mydoc.roff</i> &gt; <i>mydoc.html</i>) or processing content from another command (e.<b>g.</b>, <b>cat</b> <i>mydoc.roff</i> | <b>roff2html</b>).


title: INTEGRATION WITH GROFF
content:
While <i>roff2html</i> is a standalone command, it operates by invoking the underlying <i>groff</i> text processing system. It effectively configures <i>groff</i> to produce HTML output, making use of <i>groff</i>'s extensive capabilities for handling <i>roff</i> macros, formatting, and preprocessors (like <i>tbl</i> for tables and <i>eqn</i> for equations). Unrecognized command-line options passed to <i>roff2html</i> are generally forwarded directly to <i>groff</i>, allowing advanced control over the rendering process.


title: TYPICAL USE CASES
content:
The primary use case for <i>roff2html</i> is to publish Unix man pages on the web. It enables developers and system administrators to convert their documentation into a browser-friendly format, making it easily searchable and viewable without requiring specialized <i>roff</i> viewers. It's also used for converting general <i>roff</i>-formatted documents into HTML for web-based distribution.


title: HISTORY
content:
<i>roff2html</i> is an integral part of the GNU <i>groff</i> project. <i>groff</i> itself is a free software implementation of the traditional Unix <i>troff</i> and <i>nroff</i> text formatters. <i>roff2html</i> was developed to provide a straightforward way to convert <i>groff</i> output specifically for web consumption, bridging the gap between traditional Unix documentation and modern web interfaces.<br><br>Its development has been incremental, tied to the evolution of <i>groff</i> itself, ensuring compatibility with evolving <i>roff</i> features and HTML standards.


title: PARAMETERS
content:
<b>-o <I>output_file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the output PDF file. If not provided, the output is usually written to a file based on the input filename or to standard output.<br><br><b>-L <I>gs_options</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Passes additional options directly to the underlying <i>Ghostscript</i> (<i>gs</i> or <i>ps2pdf</i>) command. This allows fine-tuning of PDF generation, such as compression or font embedding.<br><br><b>-m <I>macro_package</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a <i>groff</i> macro package to be used (e.g., <i>man</i>, <i>mdoc</i>, <i>ms</i>, <i>mm</i>). This option is passed directly to <i>groff</i>.<br><br><b>-t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the <i>tbl</i> preprocessor for formatting tables. Passed to <i>groff</i>.<br><br><b>-e</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the <i>eqn</i> preprocessor for formatting equations. Passed to <i>groff</i>.<br><br><b>-p</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the <i>pic</i> preprocessor for formatting pictures. Passed to <i>groff</i>.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the <i>soelim</i> preprocessor for including source files specified with <i>.so</i> requests. Passed to <i>groff</i>.<br><br><b>-R</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the <i>refer</i> preprocessor for bibliography processing. Passed to <i>groff</i>.<br><br><b>-Tps</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces <i>groff</i> to produce PostScript output, which is the default and necessary for PDF conversion. (Often implicit).<br><br><b>-k</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keeps the intermediate PostScript file generated by <i>groff</i> instead of deleting it after PDF conversion.<br><br><b>-v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides verbose output, showing the commands being executed internally.<br><br><b>-h or <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with usage information and options.<br><br>


title: DESCRIPTION
content:
<i>roff2pdf</i> is a convenient Linux command-line utility designed to convert documents formatted using the <i>roff</i> typesetting system (or its modern GNU counterpart, <i>groff</i>) directly into the Portable Document Format (PDF). It functions as a high-level wrapper, abstracting away the multi-step process typically required to achieve this conversion. Internally, <i>roff2pdf</i> generally invokes <i>groff</i> to process the input file and generate an intermediate PostScript (.ps) output. This PostScript stream is then seamlessly piped to a PostScript-to-PDF converter, such as <i>ps2pdf</i> (which is a wrapper for <i>Ghostscript</i>, <i>gs</i>), to produce the final PDF document.<br><br>This command is particularly useful for rendering technical documentation, <i>man</i> pages, or any text authored in the <i>roff</i> syntax into a universally viewable and printable PDF format. It often supports many of the standard <i>groff</i> options, allowing users to specify macro packages, preprocessors (<i>eqn</i>, <i>tbl</i>), and other formatting parameters directly from the <i>roff2pdf</i> command line, simplifying the workflow for complex document generation.


title: CAVEATS
content:
<b>Dependency on External Tools</b>: <i>roff2pdf</i> is a wrapper script and relies heavily on the presence and correct configuration of <i>groff</i> and a PostScript-to-PDF converter (typically <i>ps2pdf</i> or <i>Ghostscript</i>) on the system.<br><b>Variable Implementations</b>: As <i>roff2pdf</i> is often a shell script provided by different distributions or customized by users, its exact set of supported options and internal behavior might vary slightly across systems.<br><b>Performance</b>: For very large or complex documents, the conversion process can be resource-intensive and take noticeable time, especially due to the PostScript rendering step.


title: UNDERLYING MECHANISM
content:
<i>roff2pdf</i> operates by first using <i>groff</i> to interpret the <i>roff</i> source and generate an intermediate PostScript file. This PostScript output is then processed by <i>Ghostscript</i> (via <i>ps2pdf</i>) to render and produce the final PDF document. This two-stage process allows it to leverage the powerful formatting capabilities of <i>groff</i> and the robust PDF generation of <i>Ghostscript</i>.


title: TYPICAL USE CASES
content:
Commonly used by developers and system administrators to generate printable versions of <i>man</i> pages, convert documentation from source code repositories, or prepare technical manuals written in <i>roff</i> for distribution. Its simplicity makes it a quick tool for on-the-fly PDF creation.


title: HISTORY
content:
The lineage of <i>roff2pdf</i> traces back to the venerable <b>roff</b> (<i><b>r</b>off <b>o</b>ff</i>), a text formatting program developed at Bell Labs in the early 1970s, which evolved into <b>troff</b> (<i><b>t</b>ypesetter <b>roff</b></i>) for driving phototypesetters. The GNU Project later created <b>groff</b> (<i><b>G</b>NU <b>roff</b></i>) in the late 1980s and early 1990s as a free software replacement that could output to various devices, including PostScript.<br><br>With the advent and widespread adoption of PDF as a universal document format in the mid-1990s, there arose a need to easily convert existing and new <i>roff</i>-formatted content into PDF. <i>roff2pdf</i> emerged as a practical convenience script, typically leveraging <i>groff</i>'s PostScript output capabilities and piping it through <i>Ghostscript</i>'s <i>ps2pdf</i> utility. Its development was driven by the desire to streamline the publication process for <i>man</i> pages, technical reports, and other documentation where <i>roff</i> remained a prevalent markup language.


title: PARAMETERS
content:
<b><b>-F</b><i>dir</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative font and device description directory to search before the standard paths. This influences how characters and graphics are rendered.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints pages in portrait mode. This is often the default orientation.<br><br><b><b>-S</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints pages in landscape mode, rotating the document by 90 degrees.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables color output. This option applies if the input contains color commands and the PostScript device supports color.<br><br><b><b>-m</b><i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prepend <i>name</i> to the search path for device description files. This helps in finding specific configurations for output devices.<br><br><b><b>-p</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables PostScript pre-scaling for a specific device resolution. Useful when the output needs to be precisely scaled for a target printer.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs pages in reverse order, starting from the last page to the first. Useful for printers that stack output face-down.<br><br><b><b>-R</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the generation of PostScript header comments, which can reduce file size slightly.<br><br><b><b>-o</b><i>output-file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directs the PostScript output to the specified <i>output-file</i> instead of the standard output (stdout).<br><br><b><b>-T</b><i>device</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output device. For <b>roff2ps</b>, this is typically 'ps' (PostScript). It determines the format of the output.<br><br>


title: DESCRIPTION
content:
<b>roff2ps</b> is a crucial utility within the <i>groff</i> (GNU roff) document formatting system. It acts as a filter, taking the intermediate output produced by <b>troff</b> or <b>groff</b> and translating it into PostScript.<br><br>This command is primarily used to render formatted text, tables, and graphics into a device-independent PostScript format, making documents suitable for printing on PostScript-compatible printers or for viewing with PostScript interpreters like Ghostscript. It accurately handles font metrics, character drawing, line graphics, and page management to preserve the original <i>roff</i> document's layout and appearance. Although often invoked indirectly by <b>groff -Tps</b>, <b>roff2ps</b> can also be used standalone by piping <i>groff</i>'s intermediate output to it.


title: CAVEATS
content:
<b>roff2ps</b> relies on a PostScript interpreter (like <i>Ghostscript</i>) or a PostScript-compatible printer for viewing and printing its output.<br><br>While highly capable, it might not perfectly render every obscure <i>troff</i> escape sequence or custom font without proper configuration and font availability on the target device. Complex documents can result in large PostScript files, potentially impacting processing time and storage.


title: COMMON USAGE
content:
While <b>roff2ps</b> can be used standalone, it is most frequently invoked indirectly by the <b>groff</b> command itself. For example, <code>groff -Tps <i>document.roff</i> > <i>document.ps</i></code> implicitly uses <b>roff2ps</b> as the backend for PostScript generation. If used directly, it expects <i>groff</i>'s intermediate output, not raw <i>roff</i> source:<br><code>groff -Z <i>document.roff</i> | roff2ps > <i>document.ps</i></code>.


title: INPUT AND OUTPUT
content:
<b>roff2ps</b> accepts <i>groff</i> or <i>troff</i>'s intermediate output format (often referred to as <i>troff</i> output stream) usually from standard input, or from specified files. Its primary output is device-independent PostScript code, typically directed to standard output or a specified file.


title: HISTORY
content:
<b>roff2ps</b> is an integral component of the <i>GNU groff</i> project, which was developed as a free software alternative to the proprietary AT&T <i>troff</i>.<br><br>Its inception coincided with the rising popularity of PostScript as a standard page description language for printing. <b>roff2ps</b> was designed to provide a robust and flexible PostScript output driver for <i>groff</i>, enabling users to transform their meticulously formatted <i>roff</i> documents into print-ready PostScript files. It plays a pivotal role in bridging the powerful text processing capabilities of the <i>roff</i> system with modern printing technologies, continually evolving to support new PostScript features and <i>groff</i> enhancements.


title: SYNOPSIS
content:
<b>roff2text</b> [ <i>-a groff-options</i> ] [ <i>-m macro-set</i> ] [ <i>-w width</i> ] [ <i>-t tab-width</i> ] [ <i>-R</i> ] [ <i>file...</i> ]


title: PARAMETERS
content:
<b><i>-m name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a macro set (e.g., 'mandoc') to be used by <i>groff</i> during conversion. This option is passed directly to the underlying <i>groff</i> command, enabling support for specific document types.<br><br><b><i>-w width</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the maximum output line width for the plain text. This controls how lines are wrapped in the final output, ensuring readability within a specified column limit.<br><br><b><i>-t tab-width</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Define the width of tab stops in the output. This affects how tab characters within the <i>roff</i> source are expanded in the plain text.<br><br><b><i>-R</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output raw <i>groff</i> text without further post-processing (e.g., without piping through <i>col -b</i>). This can be useful for debugging or when the output needs to be processed by another utility.<br><br><b><i>-a groff-options</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pass additional arbitrary options directly to the underlying <i>groff</i> command. This provides advanced users with fine-grained control over the <i>groff</i> rendering process.<br><br><b><i>file...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more input <i>roff</i>/<i>groff</i> files to be converted. If no files are specified, <i>roff2text</i> reads its input from standard input (<i>stdin</i>).<br><br>


title: DESCRIPTION
content:
<i>roff2text</i> is a utility designed for converting documents written in the <i>roff</i> or <i>groff</i> markup languages into a clean, readable plain text format. It acts as a convenient front-end to the more powerful <i>groff</i> typesetting system, simplifying the conversion process for common use cases. Primarily optimized for converting <i>man</i> pages and other <i>roff</i>-formatted documents, it renders the content to standard output, effectively stripping most formatting codes and presenting a text version suitable for display on a terminal, for logging, or for further text processing. The command intelligently handles character encodings and line wrapping, aiming to produce a clear and legible output.


title: CAVEATS
content:
<i>roff2text</i> relies on the <i>groff</i> typesetting system, which must be installed and properly configured on your system. While it aims to accurately convert <i>roff</i> documents to plain text, some complex formatting elements, such as intricate tables, mathematical equations, or highly graphical constructs, might not translate perfectly and could appear malformed or be omitted in the plain text output. It is best suited for documents primarily designed for text-based display, such as <i>man</i> pages, rather than complex typeset documents.


title: INPUT AND OUTPUT HANDLING
content:
<i>roff2text</i> reads its input from the specified <i>file</i> arguments. If no files are provided on the command line, it gracefully accepts input from standard input (<i>stdin</i>), making it highly suitable for use in shell pipelines (e.g., `zcat manpage.gz | roff2text`). The resulting plain text output is consistently written to standard output (<i>stdout</i>), which allows for easy redirection to a file or piping the output to subsequent commands for further processing, such as `roff2text file.man > output.txt`.


title: UNDERLYING MECHANISM
content:
The command functions by internally invoking the <i>groff</i> typesetting engine with a specific set of options tailored for plain text output. For instance, it often uses `groff -Tlatin1` or `groff -Tutf8` for character encoding and then pipes the intermediate output through utilities like <i>col -b</i> to handle backspaces and tabs, which are common in <i>roff</i> processing, ensuring the final text is clean and readable on a terminal without extraneous control characters. This makes it a robust wrapper for common text conversion tasks.


title: HISTORY
content:
<i>roff2text</i> is an integral component of the GNU <i>groff</i> (GNU roff) project, which is a free software reimplementation of the classic Unix <i>troff</i> and <i>nroff</i> text formatting systems. Its development emerged from the need for a modern, open-source text formatter compatible with traditional Unix <i>roff</i> utilities. As a dedicated front-end, <i>roff2text</i> leverages <i>groff</i>'s robust parsing and rendering capabilities to provide a straightforward way to extract plain text from <i>roff</i> sources, particularly useful for displaying <i>man</i> pages in a terminal or for programmatic access to their content. It has been a standard part of the <i>groff</i> distribution for many years.


title: PARAMETERS
content:
<b><b>-format</b> <i>&lt;format&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the desired output format. Common values include <i>docbook</i>, <i>linuxdoc</i>, and <i>html</i>. If omitted, a generic XML output is produced.<br><br><b><b>-output</b> <i>&lt;file&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes the converted output to the specified <i>file</i> instead of standard output (stdout).<br><br><b><b>-tag</b> <i>&lt;tag&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the top-level tag name for generic XML/SGML output formats.<br><br><b><b>-noname</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents the emission of the <i>man</i> tag in the output, relevant for specific structural requirements.<br><br><b><b>-novalid</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the emission of <i>DOCTYPE</i> or <i>PUBLIC</i> declarations, useful when external validation is not desired or handled by other means.<br><br><b><b>-nohead</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Omits the <i>HEAD</i> element from the generated output.<br><br><b><b>-nofoot</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Omits the <i>FOOT</i> element from the generated output.<br><br><b><b>-nofrag</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables the emission of fragment markers, often represented as <i>&lt;br&gt;</i> tags, which can break output into smaller chunks.<br><br><b><b>-nohtml</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the generation of HTML-specific tags when producing generic output, ensuring purer XML/SGML.<br><br><b><b>-warn</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose warning messages during conversion, aiding in debugging and identifying potential issues.<br><br><b><b>-debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activates debug output, providing detailed information about the conversion process for advanced troubleshooting.<br><br><b><i>FILE...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more input <i>groff</i> source files to be converted. If no files are specified, <i>roff2x</i> reads from standard input (stdin).<br><br>


title: DESCRIPTION
content:
<i><b>roff2x</b></i> is a command-line utility designed to convert documents written in the <i>groff</i> (GNU <i>roff</i>) typesetting system into various XML or SGML output formats. It acts as a post-processor or converter for <i>groff</i> source files, commonly used for man pages, technical documentation, and other structured text. <br><br> Its primary purpose is to facilitate the migration of legacy <i>roff</i>-formatted documentation into more modern, structured markup languages like DocBook XML or LinuxDoc SGML. This enables easier processing by other tools, integration into larger documentation frameworks, or publishing on the web. <br><br> While it can produce HTML output, <i>groff -Thtml</i> is often preferred for more direct HTML generation. <i>roff2x</i> seamlessly integrates with <i>groff</i>'s preprocessors, handling tables (<i>gtbl</i>), equations (<i>geqn</i>), and pictures (<i>gpic</i>) embedded within the source document.


title: CAVEATS
content:
<i><b>roff2x</b></i> is part of the <i>groff</i> package and may not be pre-installed on all minimal Linux distributions. The quality and structure of the output heavily depend on the consistency and specific macros used in the input <i>roff</i> file. For straightforward HTML conversion of man pages, using <i><b>groff -Thtml</b></i> is often more direct and can yield better results.


title: SUPPORTED OUTPUT FORMATS
content:
Beyond generic XML/SGML, <i><b>roff2x</b></i> explicitly supports specific document type definitions (DTDs) like DocBook XML and LinuxDoc SGML. The choice of format significantly influences the structure and semantic tags in the generated output.


title: INPUT PREPROCESSOR INTEGRATION
content:
<i><b>roff2x</b></i> handles input files that utilize <i>groff</i> preprocessors. This means it can correctly process documents containing tables (processed by <i>gtbl</i>), mathematical equations (processed by <i>geqn</i>), and embedded graphics (processed by <i>gpic</i>), converting their formatted output into the target XML/SGML structure.


title: HISTORY
content:
<i><b>roff2x</b></i> is an integral part of the GNU <i>groff</i> project, which serves as a modern re-implementation of the classic <i>troff</i> typesetting system. Its development emerged from the growing need to bridge traditional <i>roff</i>-formatted documentation with contemporary structured markup standards. It reflects the ongoing efforts to enable seamless data interchange and leverage <i>groff</i>'s powerful text processing capabilities within broader digital documentation ecosystems. Its creation underscores the evolution from purely print-oriented formatting to versatile, machine-readable document formats.


title: PARAMETERS
content:
<b><b>-show</b> <I>mode</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the mode to display immediately upon startup. Common modes include <I>run</I> (execute commands), <I>drun</I> (launch desktop applications), <I>window</I> (switch windows), and <I>ssh</I> (SSH launcher).<br><br><b><b>-modi</b> <I>mode1</I>,<I>mode2</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines an ordered, comma-separated list of modes to enable. Users can switch between these modes within <I>rofi</I>.<br><br><b><b>-theme</b> <I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Loads a specific theme from a CSS-like file, overriding the default or configured theme.<br><br><b><b>-font</b> <I>font_description</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the font to be used in <I>rofi</I>, e.g., 'monospace 12'.<br><br><b><b>-show-icons</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays icons for applications (e.g., in <I>drun</I> mode) if available in the desktop entry.<br><br><b><b>-monitor</b> <I>id</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which monitor <I>rofi</I> should appear on, identified by its numerical ID or 'all'.<br><br><b><b>-width</b> <I>percentage</I>|<I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the width of the <I>rofi</I> window as a percentage of the screen width (e.g., '50%') or a fixed pixel value (e.g., '500').<br><br><b><b>-opacity</b> <I>percentage</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the opacity level of the <I>rofi</I> window, from 0 (fully transparent) to 100 (fully opaque).<br><br><b><b>-matching</b> <I>method</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the matching algorithm for filtering results. Common methods are <I>normal</I> (substring), <I>fuzzy</I>, and <I>prefix</I>.<br><br><b><b>-p</b> <I>prompt</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the prompt text displayed at the input line, e.g., 'Run Command:'.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables case-insensitive matching for input filtering.<br><br><b><b>-case-sensitive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces case-sensitive matching, overriding any default or <I>-i</I> option.<br><br><b><b>-drun-show-actions</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In <I>drun</I> mode, shows additional actions defined in desktop entries (e.g., 'Open New Window').<br><br><b><b>-fullscreen</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes the <I>rofi</I> window take up the entire screen.<br><br><b><b>-version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the <I>rofi</I> version information and exits.<br><br>


title: DESCRIPTION
content:
<i>rofi</i> is a <I>dynamic</I>, <I>keyboard-driven</I> application launcher, window switcher, and SSH menu. It's a highly configurable tool designed to replace <I>dmenu</I> and provide a more interactive and visually appealing interface. Users can navigate through choices using arrow keys or by typing to filter entries. Its modular design allows for various modes, including searching for applications, switching between open windows, browsing SSH hosts, and running arbitrary commands. <br><br><i>rofi</i> supports themes, custom scripts, and offers extensive customization options via command-line arguments and configuration files, making it a versatile productivity booster for tiling window managers and desktop environments alike. It's written in C, focuses on speed, and integrates well with X11.


title: CAVEATS
content:
<i>rofi</i> is primarily designed for X11 environments. While it can run on Wayland via XWayland, native Wayland support is not fully implemented, which might limit some features (like window switching) or introduce compatibility issues. <br><br>Custom theming, while powerful, can have a steep learning curve due to its CSS-like syntax. Performance might degrade with extremely large input lists or overly complex themes.


title: CONFIGURATION FILES
content:
<i>rofi</i> can be configured globally via a configuration file, typically located at <I>~/.config/rofi/config.rasi</I> (for the new Xresources-like format) or <I>~/.config/rofi/config</I> (for the older key-value format). These files allow users to set default modes, themes, fonts, keybindings, and other behavioral aspects, preventing the need to specify them on the command line every time.


title: CUSTOM MODES & SCRIPTS
content:
One of <i>rofi</i>'s most powerful features is its support for custom modes via external scripts. Users can create executable scripts that output a list of items (one per line) to standard output. <i>rofi</i> will then display these items for selection. Upon selection, <i>rofi</i> will pass the chosen item back to the script's standard input. This mechanism enables users to extend <i>rofi</i>'s functionality to manage almost any type of data or workflow.


title: HISTORY
content:
<i>rofi</i> was originally developed by Rasmus Steinke as a more feature-rich and visually appealing alternative to <I>dmenu</I>. It started as a simple application launcher but quickly evolved to include a window switcher, SSH launcher, and other modes, driven by community demand for more interactive and customizable tools in tiling window manager setups (like i3, Awesome, and bspwm). Its focus on speed, extensive theming capabilities, and scriptability has led to its widespread adoption as a versatile productivity tool in the Linux desktop ecosystem.


title: PARAMETERS
content:
<b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restores a previously saved game. If a <i>save_file</i> is specified, it attempts to load from that file; otherwise, it looks for a default save file (e.g., <I>rogue.save</I>) in the current directory. This is typically a single-use save for resuming an interrupted session.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the high score list, showing the names and scores of the top players.<br><br><b><i>save_file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optional argument used with <b>-r</b> to specify the path to a particular game save file to restore.<br><br>


title: DESCRIPTION
content:
<i>Rogue</i> is a seminal command-line game, widely recognized for spawning the entire "roguelike" genre. Developed in 1980, it presents players with a challenging dungeon crawl through procedurally generated levels, depicted using simple ASCII characters. The objective is to descend through numerous dangerous floors, battling various monsters, collecting gold and magical items, and ultimately retrieving the legendary Amulet of Yendor.<br><br>The game is characterized by its turn-based gameplay, permanent death (permadeath), and the absence of save/load mechanics beyond a temporary save on exit. Each playthrough offers a unique experience due to the random generation of maps, item placements, and monster encounters. Its unforgiving nature and emphasis on strategic decision-making have solidified its place as a classic in video game history, inspiring countless derivatives and influencing modern game design.


title: CAVEATS
content:
<i>Rogue</i> features permanent death (permadeath), meaning once your character dies, the game ends, and you must start a new adventure from scratch. There is no conventional saving or loading to backtrack from mistakes. The game's ASCII-based interface may be unfamiliar to modern players, and its complex keybindings can have a steep learning curve. The procedural generation, while enhancing replayability, can sometimes lead to unfairly difficult or uninteresting level layouts.


title: GAMEPLAY MECHANICS
content:
<i>Rogue</i> is a turn-based, single-player dungeon crawler. Players navigate a maze of rooms and corridors, encountering monsters, collecting gold, and identifying magical items (weapons, armor, potions, scrolls). The game features a rudimentary inventory system, hunger mechanics, and various monster types with unique behaviors. The primary goal is to retrieve the Amulet of Yendor from the deepest level of the dungeon.


title: ASCII GRAPHICS
content:
The game's visual representation relies entirely on ASCII characters. The player is typically represented by an '@' symbol, monsters by letters (e.g., 'A' for Aquator, 'B' for Bat, 'D' for Dragon), walls by '#', floors by '.', and items by various symbols. This minimalist interface requires players to interpret the abstract symbols to visualize the game world.


title: INFLUENCE ON 'ROGUELIKE' GENRE
content:
<i>Rogue</i> is considered the progenitor of the 'roguelike' genre. Its defining characteristics, including procedural generation, permadeath, turn-based gameplay, grid-based movement, and complex systems interaction, became the 'Berlin Interpretation' criteria for classifying games as roguelikes. Its influence can be seen in numerous modern independent games, both traditional and 'roguelite' derivatives.


title: HISTORY
content:
<i>Rogue</i> was initially developed in 1980 by Michael Toy and Glenn Wichman at the University of California, Santa Cruz, and later ported to various Unix systems by Ken Arnold. Its rapid spread across academic and research institutions through ARPANET established its widespread popularity. The game's open-source nature in the later 1980s led to numerous variants and derivatives, cementing its legacy. Its core mechanics of procedural generation, turn-based combat, and permadeath laid the foundational blueprint for the entire "roguelike" genre, making it a pivotal title in computer game history.


title: PARAMETERS
content:
<b>expression</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more dice specifications (e.g., <b>2d6</b>, <b>d20</b>). Defaults to <b>1d6</b> if none provided.<br><br><b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output only the sum for each expression, suppressing individual die rolls.<br><br><b>-n</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress the grand total output, showing only individual or summed expression results.<br><br>


title: DESCRIPTION
content:
The <b>roll</b> command, part of the <i>bsdgames</i> package, simulates rolling various types of dice. Users define dice using <b>AdX</b> (e.g., <b>2d6</b> for two 6-sided dice) or <b>X</b> (e.g., <b>d20</b> for a 20-sided die). If no expression is given, it defaults to <b>1d6</b>. It's commonly used in role-playing games or for simple random number generation, providing individual roll results and a total sum. Options allow for customization of output, such as showing only sums or suppressing the grand total. It's an entertainment utility, not a core system tool.


title: CAVEATS
content:
The <b>roll</b> command is typically bundled with the <i>bsdgames</i> package and might require explicit installation on some Linux distributions. It functions primarily as an entertainment or recreational utility, rather than a fundamental system administration or programming tool.


title: DICE EXPRESSION FORMAT
content:
Dice expressions follow the format <b>AdX</b>, where <b>A</b> is the number of dice (defaults to 1) and <b>X</b> is the number of sides on each die (defaults to 6). For example, <b>3d8</b> means three 8-sided dice. A shorthand <b>X</b> (e.g., <b>d20</b>) is equivalent to <b>1dX</b>.


title: HISTORY
content:
Originating from the traditional BSD Unix systems, the <b>roll</b> command is a long-standing component of the <i>bsdgames</i> collection. These classic games and recreational utilities were included for user enjoyment and have since been ported to various Linux distributions as optional packages.


title: PARAMETERS
content:
<b><i>number_of_dice</i>[d|D]<i>number_of_sides</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the dice to roll. For example, '2d6' means two 6-sided dice, 'd20' means one 20-sided die. If no argument is given, it defaults to '1d6'.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Redraws the dice on a terminal that supports cursor addressing, often using <i>curses</i> libraries.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the ASCII art display of the dice. Only the numeric total of the roll(s) is shown.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version number of the <b>rolldice</b> utility and exits.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates in quiet mode, suppressing the initial 'Rolldice' message and other verbose output.<br><br>


