# CommandSection

title: COMMON USE CASES
content:
<b>lvconvert</b> is frequently used to transform existing logical volumes. A common scenario is converting a standard logical volume into a mirrored volume to enhance data redundancy and availability, often after the system has been in production. It's also the primary command for managing LVM snapshots, allowing administrators to create point-in-time copies for backup verification or to test software upgrades, and then merge these changes back to the origin or discard them. The command also enables the integration of caching layers to accelerate I/O operations for frequently accessed data on slower storage, or to manage thin provisioning for efficient space utilization.


title: CONSIDERATIONS FOR PERFORMANCE
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When converting LVs to mirrored or cached types, there can be a performance overhead during the initial synchronization or population process. Merging snapshots can also be I/O intensive, impacting system performance until the merge operation is complete. Planning these operations during off-peak hours is often recommended to minimize disruption.


title: HISTORY
content:
<b>lvconvert</b> is an integral part of the Logical Volume Manager (LVM) version 2 (LVM2) suite, which superseded the original LVM implementation to provide enhanced capabilities and flexibility. LVM2 was developed by Red Hat and its community, aiming to offer a more robust and feature-rich logical volume management system for Linux. <b>lvconvert</b> itself evolved with LVM2 to handle complex LV transformations, moving beyond simple creation and extension to include advanced features like mirroring, snapshots, caching, and thin provisioning, reflecting the growing demands for flexible and dynamic storage management in modern systems.


title: SYNOPSIS
content:
<b>lvextend</b> {<i>-L</i>|<i>--size</i> [+|-]<i>Size</i>[B|S|K|M|G|T|P|E]} | {<i>-l</i>|<i>--extents</i> [+|-]<i>Extents</i>[%{VG|LV|PVS|FREE|ORIGIN}]} [<i>-r</i>|<i>--resizefs</i>] [<i>-n</i>|<i>--nofsck</i>] [<i>-t</i>|<i>--test</i>] <i>LogicalVolumePath</i> [<i>PhysicalVolumePath</i>...]<br>


title: PARAMETERS
content:
<b><i>LogicalVolumePath</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the logical volume to extend, typically in the format <i>/dev/vgname/lvname</i>.<br><br><b><i>-L</i>, <i>--size</i> [+|-]<i>Size</i>[B|S|K|M|G|T|P|E]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the new absolute size or the amount to add/subtract from the logical volume. Units include B (bytes), S (sectors), K (kilobytes), M (megabytes), G (gigabytes), T (terabytes), P (petabytes), and E (exabytes).<br><br><b><i>-l</i>, <i>--extents</i> [+|-]<i>Extents</i>[%{VG|LV|PVS|FREE|ORIGIN}]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the new absolute or relative number of logical extents. Can be a percentage of the volume group's free space (<i>%VG</i>), logical volume's size (<i>%LV</i>), or other options.<br><br><b><i>-r</i>, <i>--resizefs</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Extends the underlying filesystem to the new logical volume size. This option supports <i>ext2</i>, <i>ext3</i>, <i>ext4</i>, and <i>xfs</i> filesystems, automating the filesystem resize after the LV is extended.<br><br><b><i>-n</i>, <i>--nofsck</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents <i>fsck</i> from being run before resizing the filesystem. Use with caution, as it skips a consistency check that can prevent data corruption.<br><br><b><i>-t</i>, <i>--test</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs the command in test mode. All checks are performed, and actions are displayed, but no actual changes are committed to disk.<br><br><b><i>-f</i>, <i>--force</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the operation, overriding certain warnings or prompts.<br><br><b><i>-v</i>, <i>--verbose</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more detailed information about the operation.<br><br>


title: DESCRIPTION
content:
The <b>lvextend</b> command is a crucial utility within the Logical Volume Manager (LVM) framework, used to increase the size of an existing logical volume (LV). LVM provides a flexible way to manage storage by abstracting physical storage into logical volumes, allowing for dynamic resizing.<br><br>When executed, <b>lvextend</b> allocates additional free physical extents from the volume group (VG) to the specified logical volume. It can extend an LV by a specific increment (e.g., +10GB) or to an absolute total size (e.g., 50GB). A key distinction is that <b>lvextend</b> primarily modifies the size of the logical volume container itself. To make the increased space usable, the filesystem residing on that logical volume must also be resized. For convenience, the <i>-r</i> (or <i>--resizefs</i>) option automates the filesystem resizing for common filesystems like ext2/3/4 and xfs.


title: CAVEATS
content:
<b>Filesystem Resizing</b>: While <b>lvextend</b> increases the logical volume's size, the filesystem on it will <i>not</i> automatically recognize the new space unless the <i>-r</i> option is used. If <i>-r</i> is not used (or for unsupported filesystems), you must manually resize the filesystem using commands like <i>resize2fs</i> (for ext2/3/4) or <i>xfs_growfs</i> (for xfs). Failing to do so will result in the filesystem still reporting its original size.<br><br><b>Data Loss</b>: Although <b>lvextend</b> is generally safe for expansion, always back up critical data before performing any disk or volume management operations to prevent potential data loss in case of unexpected errors.<br><br><b>Shrinking LVs</b>: <b>lvextend</b> is exclusively for increasing logical volume size. To reduce an LV's size, you must use the <i>lvreduce</i> command, ensuring the filesystem is shrunk first to avoid data corruption.


title: ONLINE RESIZING
content:
For most modern filesystems (like <i>ext4</i> and <i>xfs</i>) and kernels, <b>lvextend</b> with the <i>-r</i> option can extend both the logical volume and its filesystem while the filesystem is mounted and actively in use. This capability significantly minimizes downtime for critical services. However, if <i>-r</i> is not used or not supported for your specific filesystem/LVM version, you will need to manually invoke the filesystem resizing tool (e.g., <i>xfs_growfs</i>) after <b>lvextend</b> has completed.


title: INSUFFICIENT FREE SPACE
content:
<b>lvextend</b> requires sufficient free physical extents within the associated volume group (VG) to perform the extension. If the volume group does not have enough free space, the operation will fail. In such cases, you must first extend the volume group by adding new physical volumes (e.g., using the <i>vgextend</i> command) before attempting to extend the logical volume.


title: HISTORY
content:
The Logical Volume Manager (LVM) was introduced in Linux to provide a more flexible and dynamic way to manage disk space compared to traditional static partitioning. <b>lvextend</b> is a fundamental utility within the LVM framework, designed from its inception to enable the dynamic resizing of logical volumes—a key feature distinguishing LVM from older disk management paradigms. Its functionality has continuously evolved alongside LVM itself, with improvements in online resizing capabilities and deeper filesystem integration (e.g., the <i>-r</i> option introduced later to simplify the process).


title: SEE ALSO
content:
lvreduce(8), lvdisplay(8), vgextend(8), pvs(8), vgs(8), lvs(8), resize2fs(8), xfs_growfs(8), fsck(8)


title: SYNOPSIS
content:
The `lvm` command acts as a front-end for the entire LVM suite, dispatching to various subcommands:<br><b>lvm</b> [<i>--commandoptions</i>] [<i>--options</i>] [<i>--arg</i>] [<i>...</i>] <i>command</i> [<i>command_options</i>] [<i>command_args</i>]<br>Or for an interactive shell:<br><b>lvm</b><br>Or to list all available commands:<br><b>lvm help</b>


title: PARAMETERS
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<b><b>--help</b> | <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the <b>lvm</b> command itself or a specific subcommand if provided.<br><br><b><b>--version</b> | <b>-V</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the LVM version and basic build information.<br><br><b><b>--debug</b> | <b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose debugging output, useful for troubleshooting LVM operations.<br><br><b><b>--yes</b> | <b>-y</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assumes 'yes' to all confirmation prompts, proceeding with operations without user interaction. Use with caution.<br><br><b><b>--nolocking</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables LVM's internal locking mechanism. Use with extreme caution as it can lead to data corruption if multiple LVM processes run concurrently.<br><br><b><b>--config</b> <i><value></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses the specified configuration file or applies configuration values directly from the command line, overriding default settings.<br><br><b><b>--readonly</b> | <b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the command in a read-only mode, preventing any modifications to LVM metadata or data. Useful for inspection.<br><br><b><b>--quiet</b> | <b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses output messages, making the command suitable for scripting where only errors or specific outputs are desired.<br><br>


title: DESCRIPTION
content:
LVM (Logical Volume Manager) is a powerful storage management solution for Linux and other Unix-like systems. It provides an abstraction layer over physical storage devices, allowing for flexible and dynamic management of disk space. Instead of directly working with physical partitions, LVM introduces concepts of <i>Physical Volumes (PVs)</i>, <i>Volume Groups (VGs)</i>, and <i>Logical Volumes (LVs)</i>. PVs are physical disk partitions or entire disks initialized for LVM. VGs are collections of one or more PVs, pooling their storage capacity. LVs are virtual partitions created from the aggregated space of a VG.<br><br>This layered approach enables features like online resizing of LVs, creating snapshots, striping data across multiple disks, and mirroring for redundancy, all without unmounting or reformatting file systems in many cases. LVM simplifies tasks such as adding new disks, migrating data, and adapting storage to changing needs, offering greater flexibility than traditional disk partitioning.


title: CAVEATS
content:
LVM operations, especially those involving resizing, creating, or deleting volumes, carry inherent risks of data loss if not performed correctly. Incorrect usage, power failures during operations, or corrupted metadata can lead to unrecoverable data. Always ensure proper backups before performing significant LVM changes.<br><br>LVM also introduces a layer of complexity; understanding the hierarchy of PVs, VGs, and LVs is crucial. While flexible, managing LVM can be more challenging than simple disk partitioning, especially for beginners. The system must have the appropriate kernel modules loaded (e.g., <i>device-mapper</i>) for LVM to function properly.


title: LVM OBJECT HIERARCHY
content:
LVM organizes storage into a three-tier hierarchy:<br><i><b>Physical Volumes (PVs)</b></i>: Raw disk partitions or entire disks that are initialized for LVM use. They serve as the foundational building blocks.<br><i><b>Volume Groups (VGs)</b></i>: Collections of one or more PVs. A VG pools the storage capacity of its PVs, creating a large, unified storage pool.<br><i><b>Logical Volumes (LVs)</b></i>: Virtual partitions created from the free space within a VG. LVs are analogous to traditional disk partitions, but they offer advanced features like online resizing, snapshots, and mirroring.


title: OPERATING MODES
content:
The <b>lvm</b> command can be executed in several modes:<br><i><b>Command-line mode</b></i>: The most common usage, where subcommands are executed directly (e.g., `lvm vgcreate my_vg /dev/sdb1`).<br><i><b>Interactive shell mode</b></i>: By running `lvm` without arguments, it enters an interactive shell, allowing multiple LVM commands to be run sequentially within the same context.<br><i><b>Scripted mode</b></i>: LVM commands are frequently used within shell scripts for automated storage provisioning and management, often utilizing the <b>--yes</b> or <b>--config</b> options.


title: HISTORY
content:
LVM originated in the HP-UX operating system, later adopted and implemented for Linux by Joe Thornber and Heinz Mauelshagen as part of the <i>device-mapper</i> framework. The first stable version of LVM for Linux (LVM1) was released around 1999-2000. LVM2, a significant rewrite with improved performance, scalability, and new features (like snapshots and thin provisioning), became the standard in the mid-2000s and is what is predominantly used today. Its development has been driven by the increasing need for flexible storage management in servers and virtualized environments, where static partitions prove insufficient.


title: SEE ALSO
content:
pvcreate(8), vgcreate(8), lvcreate(8), pvdisplay(8), vgdisplay(8), lvdisplay(8), resize2fs(8), xfs_growfs(8), fdisk(8), gparted(8), mdadm(8)


title: SYNOPSIS
content:
lvmchange [OPTIONS] {<I>LogicalVolumeName</I> | <I>LogicalVolumePath</I> | <I>VolumeGroupName</I>/<I>LogicalVolumeName</I>}...


title: PARAMETERS
content:
<b>-a, --activate {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activate (y) or deactivate (n) a logical volume. This is one of the most frequently used options.<br><br><b>-l, --persistent {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the persistent activation state for the logical volume. If 'y', the LV will be automatically activated on system startup; if 'n', it won't.<br><br><b>-p, --permission {r|rw}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the access permission of the logical volume to read-only (r) or read/write (rw).<br><br><b>--readahead {auto|None|Number}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the read-ahead size for the logical volume. 'auto' lets the kernel decide, 'None' disables it, or specify a 'Number' of 512-byte sectors.<br><br><b>-Z, --zero {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls whether to zero the first 4KB of a new data segment. This is usually done automatically but can be explicitly controlled.<br><br><b>-s, --rebuildmirror</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rebuilds a faulty mirror logical volume. This option is specific to LVM RAID/mirror volumes.<br><br><b>-C, --cleared {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mark a RAID or mirror logical volume as cleared. This can be used after a manual rebuild or recovery operation.<br><br><b>-m, --monitor {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables (y) or disables (n) monitoring of a RAID logical volume by dmeventd (device-mapper event daemon).<br><br><b>-P, --partial</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows commands to proceed with a partial view of the LVM system. Useful in clustered environments where not all PVs might be visible.<br><br><b>--setactivationskip {y|n}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the activation skip flag for a logical volume. If 'y', LVM will skip activation of this LV during a normal 'vgchange -a y' operation.<br><br>


title: DESCRIPTION
content:
<b>lvmchange</b> is a fundamental command within the <I>Logical Volume Manager (LVM)</I> suite in Linux. Its primary function is to control the activation and deactivation state of logical volumes (LVs).<br><br>When a logical volume is <I>activated</I>, LVM creates a device node (typically in <I>/dev/mapper/</I>) making the volume accessible for read/write operations by the kernel and applications, such as mounting a filesystem or using it as a raw block device. Conversely, <I>deactivating</I> an LV unmaps the device, rendering it inaccessible.<br><br>This command is essential for managing the availability of storage resources. Common scenarios include:<br><ul><li>Bringing logical volumes online during system boot.</li><li>Taking volumes offline before maintenance, backups, or snapshot operations.</li><li>Managing the state of logical volumes in clustered environments where shared storage is used.</li><li>Modifying various properties of an LV, such as its read-ahead size, permissions, or its persistent activation behavior across reboots.</li></ul><br>Proper use of <b>lvmchange</b> ensures that LVM-managed storage is available when needed and safely taken offline when not.


title: CAVEATS
content:
<ul><li>Always <b>unmount filesystems</b> before deactivating their underlying logical volumes (using <I>-a n</I>) to prevent data corruption.</li><li>Incorrect usage of <b>lvmchange</b>, especially with options like <I>--zero</I> or <I>--cleared</I>, can lead to data loss or integrity issues if not fully understood.</li><li>When using <I>--persistent y</I>, ensure the logical volume is intended to be activated on every boot.</li><li>In clustered LVM environments, ensure proper fencing and coordination to avoid split-brain scenarios when activating/deactivating shared LVs.</li><li>Requires root privileges to execute.</li></ul>


title: ACTIVATION MODES
content:
When activating logical volumes, LVM supports different modes, often controlled globally by <I>lvm.conf</I> or explicitly by options:<br><ul><li><I>complete</I>: All components (e.g., all mirror legs, all PVs) must be present for activation.</li><li><I>degraded</I>: Allows activation even if some components are missing (e.g., a missing mirror leg in a RAID1 volume).</li><li><I>partial</I>: Activates even if some PVs belonging to the VG are missing from the system. This is often used with the <I>-P</I> option.</li><li><I>systemid</I>: Activates volumes matching the local system ID.</li></ul>


title: INTERACTION WITH SYSTEM STARTUP
content:
Logical volumes marked with <I>--persistent y</I> are typically activated automatically during system boot by an init script or systemd service that runs <I>vgchange -a y</I> or <I>lvchange -a y</I> for all volumes. Deactivating a volume with <I>-a n</I> does not inherently prevent its re-activation on next boot if <I>--persistent y</I> is set; to prevent activation on boot, you must explicitly use <I>lvchange --persistent n</I> for that volume.


title: HISTORY
content:
<b>lvmchange</b> has been a core component of the LVM (Logical Volume Manager) suite since its early versions, providing essential functionality for managing the operational state of logical volumes. Its role has remained consistently vital in the evolution of LVM on Linux, adapting to new features like RAID volumes and clustered LVM, while maintaining its fundamental purpose of activation and deactivation.


title: PARAMETERS
content:
<b>--disable <i>{item}</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Disable specified LVM configuration items or features, such as <b>scan_lvs</b> or <b>use_lvmetad</b>.</i><br><br><b>--enable <i>{item}</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Enable specified LVM configuration items or features.</i><br><br><b>--with-system-dir <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specify an alternative system directory path where LVM expects to find certain files and binaries.</i><br><br><b>--config <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Use an alternative LVM configuration file instead of the default <b>/etc/lvm/lvm.conf</b>.</i><br><br><b>--type <i>&lt;keyword&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Filter output by a specific configuration section or type (e.g., <b>devices</b>, <b>metadata</b>, <b>activation</b>) when dumping or checking the configuration.</i><br><br><b>--defaults</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display the compiled-in default configuration settings of LVM. This shows the baseline without any <b>lvm.conf</b> modifications.</i><br><br><b>--dump</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display the current effective LVM configuration, including values from <b>lvm.conf</b> and any command-line overrides. This is useful for auditing.</i><br><br><b>--check</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Check the syntax and validity of the LVM configuration file without applying any changes. This helps to identify errors before they cause operational issues.</i><br><br><b>--update</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Notify the <b>lvmetad</b> daemon to re-read its configuration from <b>lvm.conf</b>. This is crucial for applying changes made to the configuration file without a full system reboot.</i><br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display a help message outlining the command's usage and options, then exit.</i><br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display LVM version information and exit.</i><br><br>


title: DESCRIPTION
content:
The <b>lvmconf</b> command is an integral part of the Logical Volume Manager 2 (LVM2) suite in Linux. Its primary function is to manage and inspect the system-wide LVM configuration file, <i>lvm.conf</i>, which typically resides in <i>/etc/lvm/</i>. This file dictates various aspects of LVM behavior, including device scanning, metadata handling, locking mechanisms, and integration with other system components.<br><br><b>lvmconf</b> enables system administrators and scripts to programmatically view the effective LVM configuration, display default settings, and apply changes. It allows for the controlled modification of LVM parameters, ensuring consistent operation across system reboots and during runtime. While direct manual editing of <i>lvm.conf</i> is possible, <b>lvmconf</b> offers a validated and structured approach to managing these critical settings, helping to prevent syntax errors and maintain system stability. It is also used to inform the <i>lvmetad</i> daemon of configuration changes.


title: CAVEATS
content:
<i>Modifying the LVM configuration requires root privileges. Incorrect changes to <b>lvm.conf</b> can lead to LVM malfunctions, data access issues, or system instability. Always backup <b>lvm.conf</b> before making significant changes. Changes made via <b>lvmconf</b> or direct editing of the file may not take effect until the <b>lvmetad</b> daemon is updated (using <b>--update</b>) or the system is rebooted.</i>


title: COMMON USE CASES
content:
<i><b>lvmconf</b> is frequently used for: <br> - Rapidly inspecting the active or default LVM settings. <br> - Enabling or disabling specific LVM features such as automatic volume group activation or the use of the <b>lvmetad</b> caching daemon. <br> - Forcing the <b>lvmetad</b> daemon to reload its configuration after manual edits to <b>lvm.conf</b>. <br> - Incorporating LVM configuration adjustments into automated deployment or system management scripts.</i>


title: HISTORY
content:
The <b>lvmconf</b> command is part of the Logical Volume Manager 2 (LVM2) project, which superseded the original LVM1 implementation and was integrated into the Linux kernel around version 2.6. Prior to LVM2, configuration was less centralized or relied more on manual adjustments. <b>lvmconf</b> provides a standardized and scriptable interface for managing LVM's central configuration file, <i>lvm.conf</i>, enhancing automation and consistency in LVM administration.


title: PARAMETERS
content:
<b>-a, --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include all possible information in the dump. This is the default behavior.<br><br><b>-c, --cachedir <I>path</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a directory to store temporary files created during the dump process.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>-l, --logfiles</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include LVM-related log files in the dump.<br><br><b>-m, --metadata</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include LVM metadata backups in the dump.<br><br><b>-p, --pvs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include the output of `pvs -a -o +uuid,devices` command.<br><br><b>-r, --raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include raw metadata from devices directly. This option usually requires root privileges.<br><br><b>-s, --system-info</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include various system information, such as disk usage, mount points, block device layouts, kernel messages, and system architecture.<br><br><b>-u, --udev</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include udev information, which is relevant for device management.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run lvmdump in verbose mode, showing more detailed output during execution.<br><br><b>-x, --exclude-logs</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Exclude log files from being included in the dump, overriding the default or `-l` option.<br><br><b>-z, --compress</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress the resulting tarball using gzip by default.<br><br><b>--since <I>date</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter log files to include only entries created on or after the specified date/time.<br><br><b>--until <I>date</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter log files to include only entries created on or before the specified date/time.<br><br>


title: DESCRIPTION
content:
lvmdump is a diagnostic tool for the Linux Logical Volume Manager (LVM2). Its primary purpose is to collect comprehensive system and LVM-related information into a single tarball, making it easier for users to report bugs or seek support. The generated tarball typically includes LVM configuration details, command outputs (like pvs, vgs, lvs), LVM metadata backups, relevant log files, and various system information (df, mount, lsblk, dmesg, uname -a, etc.).<br><br>By consolidating this data, lvmdump streamlines the process of debugging LVM issues, as it provides a snapshot of the system's LVM state and environment. This dump is invaluable for LVM developers and support personnel to understand the context of a problem without requiring direct access to the affected system. It's designed to gather as much relevant data as possible by default, though specific content can be controlled via command-line options.


title: CAVEATS
content:
lvmdump often requires root privileges to collect all comprehensive system and LVM information, especially when including raw metadata (`-r`).<br>The generated tarball can potentially contain sensitive system information, including log files, device paths, and configuration details. Care should be taken when sharing these dumps.<br>The size of the output tarball can be substantial, particularly on systems with many LVM components or extensive log files.<br>The `--raw` option attempts to read raw LVM metadata directly from physical devices, which might be risky if the underlying devices are unstable or uninitialized.


title: OUTPUT FILE
content:
By default, lvmdump creates a gzipped tarball named `lvmdump.<timestamp>.<hostname>.tar.gz` in the current working directory. The timestamp ensures uniqueness, and the hostname helps identify the source system.


title: CONTENTS OF THE DUMP
content:
The tarball typically includes subdirectories like `logs/` (for LVM logs), `config/` (for LVM configuration files), `output/` (for command outputs like `pvs`, `vgs`, `lvs`, `dmsetup`, etc.), and `system/` (for general system info like `df`, `mount`, `lsblk`). The exact content varies based on specified options.


title: HISTORY
content:
lvmdump is an integral part of the LVM2 suite, designed to aid in diagnostics and bug reporting. Its development closely mirrors the evolution of LVM2 itself, providing a standardized method for collecting a snapshot of LVM's operational state. While its core functionality has remained consistent, specific options and the scope of collected information have expanded over time to accommodate new LVM features and broader debugging requirements. It's a testament to the maintainers' commitment to providing robust tools for users to report and resolve issues efficiently.


title: PARAMETERS
content:
<b><b>start</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initializes and begins the LVM activity data collection process. This command is typically configured to run periodically via <i>cron</i> to ensure continuous data capture.<br><br><b><b>stop</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Halts the LVM activity data collection process, preventing further LVM metrics from being recorded.<br><br><b><b>status</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current status of the <b>lvmsadc</b> collector, indicating whether data collection is active or not.<br><br><b><b>report</b> [<i>options</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates reports from the collected LVM activity data. This subcommand acts as a wrapper for <b>sar -S LVM</b> and often accepts standard <b>sar</b> options for filtering and formatting the output (e.g., <i>-f filename</i> to specify a data file, <i>-s HH:MM:SS</i> and <i>-e HH:MM:SS</i> for time range).<br><br>


title: DESCRIPTION
content:
The <b>lvmsadc</b> command is an LVM2 system activity data collector. It integrates LVM2 activity metrics with the standard <b>sadc</b> (System Activity Data Collector) and <b>sar</b> (System Activity Reporter) utilities. Its primary purpose is to enable detailed performance monitoring and historical analysis of LVM operations, such as volume group and logical volume usage, I/O statistics, and other LVM-specific events.<br><br>Data collected by <b>lvmsadc</b> is stored in the same binary data files as other system activity statistics (typically in <i>/var/log/sa/saXX</i>), allowing users to view LVM-specific metrics alongside other system performance data using the <b>sar</b> command, specifically with the <i>-S LVM</i> option. This integration is crucial for administrators needing to diagnose performance bottlenecks or understand resource consumption related to LVM storage infrastructure over time.


title: CAVEATS
content:
The <b>lvmsadc</b> command requires the <i>sysstat</i> package (which provides <b>sadc</b> and <b>sar</b>) to be installed and properly configured. It typically needs root privileges to execute. Ensure that the <b>sadc</b> cron jobs are correctly set up to capture LVM activity data periodically. The collected data can consume disk space, so monitoring <i>/var/log/sa/</i> is advisable.


title: INTEGRATION WITH SAR
content:
After collection is started by <b>lvmsadc start</b>, LVM activity data can be viewed using the <b>sar</b> command with the <i>-S LVM</i> option. For example, <b>sar -S LVM -f /var/log/sa/saXX</b> will display LVM-specific statistics from the specified daily activity file. This allows for detailed analysis of LVM performance over time, including metrics like LVM metadata operations, I/O rates on logical volumes, and more.


title: TYPICAL SETUP
content:
To use <b>lvmsadc</b> effectively, it's typically set up via <i>cron</i>. The <b>sadc</b> cron job (e.g., <i>/etc/cron.d/sysstat</i> on some systems) should be configured to run <b>sadc -S LVM</b> periodically (e.g., every 10 minutes). The <b>lvmsadc start</b> command itself might also be added to system startup scripts to ensure continuous monitoring after a reboot.


title: HISTORY
content:
<b>lvmsadc</b> is part of the <i>lvm2</i> suite of tools. Its development aimed to provide deeper insight into LVM-specific performance characteristics, complementing the general system activity monitoring capabilities of <b>sadc</b> and <b>sar</b>. It was introduced to bridge the gap in detailed LVM performance metrics that were not natively captured by standard system monitoring tools, enabling administrators to get a holistic view of storage performance that includes the LVM layer.


title: PARAMETERS
content:
<b><I>interval</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The time in seconds between each reported sample. When specified without <I>count</I>, <I>lvmsar</I> reports statistics continuously until interrupted.<br><br><b><I>count</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of samples to be displayed. This parameter is typically used in conjunction with <I>interval</I> to collect a specific number of reports.<br><br><b><b>-f</b> <I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reads statistics from a <I>sar</I> data file previously saved by <I>sar</I> or <I>sadc</I>. This allows for analysis of historical LVM activity collected over time.<br><br><b><b>-s</b> <I>hh:mm:ss</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the starting time of the data for extraction. <I>lvmsar</I> will display records recorded from or after the specified time when reading from a data file.<br><br><b><b>-e</b> <I>hh:mm:ss</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the ending time of the data for extraction. <I>lvmsar</I> will display records recorded up to or before the specified time when reading from a data file.<br><br><b><b>-o</b> <I>filename</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Saves the collected <I>sar</I> data to a file. This is typically used when <I>lvmsar</I> runs in data collection mode, often by implicitly calling <I>sadc</I> or <I>sar -o</I> internally.<br><br>


title: DESCRIPTION
content:
<I>lvmsar</I> is a command-line utility used to collect and report statistics related to Logical Volume Manager (LVM) activity. It provides detailed insights into I/O operations on LVM logical volumes, including read/write requests, blocks transferred, and average queue lengths.<br><br>While <I>lvmsar</I> is often implemented as a wrapper script or an alias around the <I>sar</I> (System Activity Reporter) command using its LVM-specific options (e.g., <I>sar -L</I>), its purpose is to simplify access to LVM performance metrics.<br><br>System administrators utilize <I>lvmsar</I> to monitor the performance of their LVM-based storage infrastructure in real-time or analyze historical data. This helps in identifying potential bottlenecks, understanding I/O patterns, and making informed decisions regarding LVM configuration and optimization. It presents data in a human-readable format, making it easier to track LVM volume throughput and latency.


title: CAVEATS
content:
<I>lvmsar</I> is often a custom script or an alias wrapping the <I>sar</I> command with LVM-specific options rather than a standalone binary. Therefore, its exact availability, behavior, and supported options may vary between different Linux distributions or system configurations. It relies on the underlying <I>sysstat</I> package and <I>sar</I>'s ability to collect LVM statistics. For historical data analysis, the <I>sadc</I> daemon (part of <I>sysstat</I>) must be running to regularly record system activity.


title: OUTPUT METRICS
content:
When run, <I>lvmsar</I> typically reports various metrics for each LVM logical volume. Key metrics often include:<br><b><I>rd_sec/s</I></b>: Number of sectors read per second.<br><b><I>wr_sec/s</I></b>: Number of sectors written per second.<br><b><I>avgrq-sz</I></b>: The average size (in sectors) of the requests that were issued to the logical volume.<br><b><I>avgqu-sz</I></b>: The average queue length of the requests that were issued to the logical volume.<br><b><I>%util</I></b>: Percentage of CPU time during which I/O requests were issued to the logical volume (indicating its utilization rate).


title: HISTORY
content:
The core functionality of reporting system activity, including disk I/O, has been present in Unix-like systems through <I>sar</I> since its inception (part of System V). As Logical Volume Management (LVM) became a standard feature for flexible storage administration on Linux, support for LVM-specific statistics was integrated into the <I>sar</I> utility (often via the <I>-L</I> option). The concept of a dedicated <I>lvmsar</I> command or script arose from the need to provide a more focused and convenient way for administrators to monitor LVM performance without sifting through the broader <I>sar</I> output. It reflects the evolution of system monitoring tools to cater to specialized storage technologies.


title: SYNOPSIS
content:
lvreduce { <B>-L</B> | <B>--size</B> [+]<I>Size</I>[<I>bBsSkKmMgGtTpPeE</I>] | <B>-l</B> | <B>--extents</B> [+]<I>LogicalExtents</I>[%<I>{VG|LV}</I>] } [ <B>--poolmetadatasize</B> <I>Size</I>[<I>bBsSkKmMgGtTpPeE</I>] | <B>--poolmetadatapercent</B> <I>Percent</I> ] [ <B>-r</B> | <B>--resizefs</B> ] [ <B>-f</B> | <B>--force</B> ] [ <B>-t</B> | <B>--test</B> ] [ <B>-y</B> | <B>--yes</B> ] <I>LogicalVolumePath</I>


title: PARAMETERS
content:
<b><B>-L</B>, <B>--size</B> <I>Size[bBsSkKmMgGtTpPeE]</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the new exact size for the logical volume, or the amount to reduce by if preceded by '+'. Suffixes like 'm' (MB) or 'g' (GB) are supported.<br><br><b><B>-l</B>, <B>--extents</B> <I>LogicalExtents[%{VG|LV}]</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the new size in logical extents, or the number of extents to reduce by if preceded by '+'.<br><br><b><B>-r</B>, <B>--resizefs</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to resize the filesystem on the logical volume before reducing the logical volume. <B>Caution:</B> This only works for filesystems that support shrinking (e.g., ext2/3/4) and might fail or lead to data loss if the filesystem is in use or corrupted. XFS cannot be shrunk.<br><br><b><B>-f</B>, <B>--force</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Reduce the logical volume without requiring confirmation. <B>Use with extreme caution</B>, as this can lead to data loss if not combined with prior filesystem resizing.<br><br><b><B>-t</B>, <B>--test</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in test mode. Do not make any real changes, just show what would happen. Useful for verifying commands.<br><br><b><B>-y</B>, <B>--yes</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume yes to all questions; do not prompt for confirmation.<br><br>


title: DESCRIPTION
content:
<code>lvreduce</code> is a command-line utility used to decrease the size of an existing <I>Logical Volume</I> (LV) within a <I>Logical Volume Manager</I> (LVM) setup. This operation is critical for optimizing disk space, especially when a volume was over-provisioned or data has been migrated elsewhere.<br><br>Before reducing an LV, it is paramount to first shrink the filesystem residing on that LV. Failing to do so will almost certainly result in irreversible data loss, as <code>lvreduce</code> does not inspect the filesystem content and will truncate the volume regardless. Tools like <code>resize2fs</code> (for ext2/3/4) or <code>xfs_growfs</code> (XFS can only grow, not shrink) are used for filesystem resizing. After the filesystem is safely reduced, <code>lvreduce</code> can then be used to cut the underlying LV to the new, smaller size. The command supports specifying the absolute new size or the amount to reduce by. It also offers an option to attempt automatic filesystem resizing, though manual resizing is often preferred for control and safety, particularly for filesystems that do not support shrinking (like XFS).<br><br>Always back up critical data before performing any LV resizing operations.


title: CAVEATS
content:
<ul><li><B>Data Loss Risk:</B> Reducing a logical volume <I>before</I> shrinking the filesystem on it will almost certainly lead to severe and unrecoverable data loss. The <code>lvreduce</code> command operates on the block device level and does not understand the filesystem's structure.</li><li><B>Filesystem Support:</B> Not all filesystems can be shrunk. For instance, XFS filesystems can only be grown, not reduced. Other filesystems like ext2/3/4 require explicit unmounting or online resizing tools (<I>e.g.</I>, <code>resize2fs</code>).</li><li><B>Unmounting:</B> It is generally safest to unmount the filesystem before reducing the LV, especially if not using the <code>-r</code> option with an online-resizable filesystem.</li><li><B>Backup:</B> Always back up critical data before performing any LVM resizing operations.</li></ul>


title: <B>ONLINE VS. OFFLINE RESIZING</B>
content:
While some filesystems (like ext4) support online resizing (shrinking while mounted), it is generally safer and recommended to unmount the filesystem before shrinking the logical volume to prevent data corruption, especially if you are not using the <code>-r</code> option or are unsure about your filesystem's online shrinking capabilities.


title: <B>PHYSICAL EXTENTS</B>
content:
LVM manages storage in units called <I>Physical Extents</I> (PEs). When you reduce an LV, <code>lvreduce</code> reclaims these PEs from the end of the logical volume, making them available back to the volume group for other logical volumes.


title: HISTORY
content:
<code>lvreduce</code> is an integral part of the <I>Logical Volume Manager</I> (LVM) suite, which has been a standard feature in Linux distributions for managing disk space more flexibly than traditional partitioning. LVM was initially developed by Joe Thornber and first integrated into the Linux kernel in 1998. The ability to dynamically resize volumes, both to extend and reduce them, has been a core capability of LVM from its early days, making it a crucial tool for system administrators managing storage resources. Its usage has evolved with improvements in online filesystem resizing, but the fundamental principle of careful pre-resizing of the filesystem remains unchanged.


title: SYNOPSIS
content:
<b>lvremove</b> [<i>OPTIONS</i>] <i>LogicalVolumePath</i> | <i>VolumeGroupName</i>/<i>LogicalVolumeName</i> [<i>LogicalVolumePath</i> | <i>VolumeGroupName</i>/<i>LogicalVolumeName</i>...]


title: PARAMETERS
content:
<b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes the logical volume without asking for confirmation. <B><I>Use with extreme caution!</I></B> Can remove active LVs, potentially leading to system instability or data corruption.<br><br><b>-y, --yes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume 'yes' to all questions, bypassing interactive prompts (e.g., confirmation of LV removal).<br><br><b>-t, --test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs in test mode. No actual changes are made, but the command output will show what would happen.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity, providing more detailed information about the command's execution process.<br><br><b>--noudevsync</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables udev synchronization. Use with caution, as it can lead to inconsistent device states in some scenarios.<br><br>


title: DESCRIPTION
content:
<b>lvremove</b> is a fundamental command-line utility within the <I>Logical Volume Manager (LVM)</I> framework on Linux. Its primary function is to permanently delete one or more specified logical volumes (LVs). When a logical volume is removed, all data residing on it is irretrievably lost, and the space it occupied within its parent volume group becomes free, available for new LVs. This operation is crucial for managing and optimizing storage, allowing administrators to reclaim unused space or restructure their LVM setup. <br><br>Before attempting to remove an LV, it is crucial to ensure that any filesystem on it is unmounted and that the LV is not actively in use by any application or service. By default, <b>lvremove</b> prompts for confirmation to prevent accidental data loss, emphasizing the destructive nature of the operation. It's an essential tool for maintaining flexible and dynamic storage environments.


title: CAVEATS
content:
<B>Data Loss:</B> Removing a logical volume is a permanent and irreversible operation. All data on the volume will be lost forever.<br><br><B>Unmount First:</B> Always ensure that any filesystem mounted on the logical volume is properly unmounted before attempting to remove it. Failure to do so can lead to errors, data corruption, or an inability to remove the volume.<br><br><B>Active Volumes:</B> By default, LVM prevents the removal of logical volumes that are currently active (in use or mounted). While the <I>--force</I> option can override this, it is highly risky and should only be used by experienced administrators who fully understand the implications.


title: USAGE BEST PRACTICES
content:
Always double-check the logical volume path or name before execution to prevent accidental deletion of critical data. Utilize the <I>--test</I> option to simulate the removal and confirm the intended action without risking data loss. Ensure no applications are accessing the LV before proceeding.


title: REQUIRED PERMISSIONS
content:
Executing <B>lvremove</B> typically requires root privileges (or `sudo`) because it modifies system-level storage configurations and can affect the entire system's data integrity.


title: HISTORY
content:
LVM (Logical Volume Manager) was developed to provide a more flexible and dynamic way of managing disk storage compared to traditional fixed partitioning. Introduced to Linux, LVM allows for dynamic resizing, snapshots, and easier data migration. <B>lvremove</B> has been a core and indispensable part of the LVM toolset since its early versions, enabling administrators to efficiently reclaim and reorganize storage space as system requirements evolve.


title: SYNOPSIS
content:
<b>lvrename</b> [<i>OPTIONS</i>] <i>OldLogicalVolumePath NewLogicalVolumePath</i><br><b>lvrename</b> [<i>OPTIONS</i>] <i>VolumeGroupName OldLogicalVolumeName NewLogicalVolumeName</i>


title: PARAMETERS
content:
<b>-y, --yes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume yes to all questions.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Proceed without prompting.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show verbose information.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message.<br><br><b>--noudevsync</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable udev synchronization. Use with caution in scripts.<br><br>


title: DESCRIPTION
content:
<b>lvrename</b> is a utility used to rename a logical volume (LV) in the Logical Volume Manager (LVM) system. It allows administrators to change the name of an existing logical volume, which can be useful for organizational purposes or when re-purposing storage.<br><br>The command can rename a logical volume by specifying its current full path (e.g., <i>/dev/VolumeGroup/LogicalVolumeName</i>) to a new full path, or by providing the volume group name, old logical volume name, and new logical volume name. Renaming an active logical volume is generally safe, as <b>lvrename</b> updates the LVM metadata accordingly. However, it's crucial to update any applications or scripts that refer to the old path or name after the rename operation is complete. This command primarily modifies LVM metadata and does not affect the data stored on the logical volume itself.


title: CAVEATS
content:
While renaming an active LV is usually safe, any applications or entries in <i>/etc/fstab</i> referring to the old name or path must be updated manually after the rename operation. If the LV is mounted, the mount point will still refer to the old path until remounted or the system restarts. It's generally a good practice to unmount the logical volume if possible before renaming it.


title: PATH VS. NAME
content:
<b>lvrename</b> can operate using full device paths (e.g., <i>/dev/vg_name/lv_name</i>) or by specifying the volume group name and old/new logical volume names separately. Both methods achieve the same result of updating the LVM metadata.


title: UPDATING FSTAB
content:
After renaming a logical volume that is automatically mounted at boot, it is crucial to update the corresponding entry in <i>/etc/fstab</i> to reflect the new logical volume path or UUID/LABEL if those are used for mounting. Failure to do so will result in mount failures on reboot.


title: HISTORY
content:
LVM (Logical Volume Manager) has been a fundamental part of Linux storage management for many years, offering a more flexible alternative to traditional partitioning. <b>lvrename</b>, as a core LVM utility, has been present since the early versions of LVM2, which became the standard in Linux distributions around the early 2000s, replacing the older LVM1. Its consistent functionality reflects the stable and mature nature of LVM for managing logical volumes.


title: SYNOPSIS
content:
<i>lvresize</i> [<i>options</i>] {<i>LogicalVolumePath</i>} [<b>-L</b>|<b>--size</b> [<b>+</b>|<b>-</b>]<i>Size</i>[<i>bBsSkKmMgGtTpPeE</i>]] [<b>-l</b>|<b>--extents</b> [<b>+</b>|<b>-</b>]<i>Extents</i>[<i>%VG</i>|<i>%LV</i>|<i>%ORIGIN</i>|<i>%FREE</i>|<i>%PVS</i>|<i>%PVS_FREE</i>]]


title: PARAMETERS
content:
<b><i>LogicalVolumePath</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The full path to the logical volume to be resized (e.g., <i>/dev/vg_name/lv_name</i>).<br><br><b><b>-L</b>, <b>--size</b> <i>Size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the new absolute or relative size of the logical volume. Size can be specified with units (e.g., <i>10G</i>, <i>512M</i>). Use <b>+</b> or <b>-</b> prefix for relative resizing.<br><br><b><b>-l</b>, <b>--extents</b> <i>Extents</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the new absolute or relative size of the logical volume in logical extents. Can use percentages (e.g., <i>100%FREE</i>, <i>50%VG</i>).<br><br><b><b>-r</b>, <b>--resizefs</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Resize the filesystem on the logical volume as part of the <i>lvresize</i> operation. This is highly recommended for safety.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Bypass confirmation prompts and potential warnings, proceeding with the operation immediately. Use with caution.<br><br><b><b>-t</b>, <b>--test</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a dry run. Show what would be done without actually making any changes.<br><br><b><b>-i</b>, <b>--intervals</b> <i>ReportInterval</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Report progress at intervals during a resize operation.<br><br><b><b>-y</b>, <b>--yes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assume 'yes' to all prompts, effectively disabling interactive confirmation.<br><br><b><b>--fs</b> <i>FileSystemType</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the filesystem type on the logical volume if it cannot be detected automatically (e.g., <i>ext4</i>, <i>xfs</i>).<br><br>


title: DESCRIPTION
content:
<i>lvresize</i> is a command-line utility used to change the size of a Logical Volume (LV) within the Linux Logical Volume Manager (LVM) framework. It allows administrators to either grow (expand) or shrink (reduce) an existing logical volume, providing significant flexibility in storage management. When growing an LV, <i>lvresize</i> extends it into available free space within its parent Volume Group (VG). Conversely, when shrinking, it reduces the LV's size, potentially freeing space back to the VG.<br><br>A critical feature of <i>lvresize</i> is its ability to integrate with the filesystem residing on the logical volume. With the <b>--resizefs</b> (or <b>-r</b>) option, <i>lvresize</i> can automatically resize a supported filesystem (like ext2/3/4, XFS, Btrfs) simultaneously with the LV. This ensures data integrity and prevents data loss. Careful consideration and backups are paramount when shrinking an LV, especially if the new size is smaller than the data stored on the filesystem, as it can lead to data corruption.


title: CAVEATS
content:
<ul><li><b>Shrinking Data Loss Risk</b>: Shrinking an LV without properly resizing the filesystem first, or shrinking it to a size smaller than the data stored on the filesystem, will lead to irreparable data loss. Always backup critical data before shrinking.</li><li><b>Filesystem Compatibility</b>: While <i>--resizefs</i> is powerful, not all filesystems support online shrinking (e.g., XFS cannot be shrunk online). Always verify filesystem capabilities.</li><li><b>Insufficient Space</b>: When growing an LV, ensure there is sufficient free space in the Volume Group to accommodate the new size.</li><li><b>Performance</b>: Very large resize operations, especially when moving data, can be time-consuming and impact system performance.</li></ul>


title: FILESYSTEM RESIZING SPECIFICS
content:
The behavior of <i>--resizefs</i> depends on the filesystem type:<br><ul><li>For <b>ext2/3/4</b> filesystems, <i>lvresize -r</i> can both grow and shrink the filesystem.</li><li>For <b>XFS</b> filesystems, <i>lvresize -r</i> will only grow the filesystem. Shrinking XFS online is generally not supported; it typically requires backing up data, reformatting, and restoring.</li><li>For <b>Btrfs</b>, it supports both grow and shrink operations with <i>lvresize -r</i>.</li></ul>Always consult the filesystem's documentation for precise resizing capabilities and limitations.


title: SAFETY BEST PRACTICES
content:
Before undertaking any significant resize operation, particularly when shrinking a logical volume:<br><ul><li><b>Backup Data</b>: Always ensure you have a complete and verified backup of all critical data on the logical volume.</li><li><b>Check Filesystem</b>: It's good practice to run a filesystem check (e.g., <i>e2fsck -f</i> for ext2/3/4, or verify XFS integrity) before shrinking to ensure no underlying filesystem issues.</li><li><b>Monitor Progress</b>: For long operations, use the <b>-i</b> option to monitor progress.</li></ul>


title: RELATIVE RESIZING
content:
You can specify sizes relative to the current LV size, the Volume Group's free space, or other metrics:<br><ul><li><b>+5G</b>: Add 5 Gigabytes to the current LV size.</li><li><b>-100M</b>: Remove 100 Megabytes from the current LV size.</li><li><b>100%FREE</b>: Extend the LV to consume all available free space in the Volume Group.</li><li><b>50%VG</b>: Set the LV size to 50% of the total Volume Group size.</li></ul>


title: HISTORY
content:
<i>lvresize</i> is an integral command within the Logical Volume Manager (LVM) framework, which became a standard component of the Linux kernel in the early 2000s. Its development has mirrored the evolution of LVM, gaining new features like support for thin provisioning, snapshot resizing, and enhanced filesystem integration. The ability to dynamically adjust storage allocations provided by commands like <i>lvresize</i> has been fundamental to flexible and efficient server and storage management on Linux.


title: PARAMETERS
content:
<b>--all | -a</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show information about all logical volumes, including internal ones (e.g., for snapshots).<br><br><b>--aligned</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ensure all output columns are aligned for better readability.<br><br><b>--columns <column_list> | -o <column_list></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the columns to display. Common columns include <I>lv_name</I>, <I>vg_name</I>, <I>lv_size</I>, <I>lv_attr</I>, <I>lv_path</I>, <I>data_percent</I>, <I>metadata_percent</I>.<br><br><b>--config <config_string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a specified configuration string for this command instead of default LVM configuration.<br><br><b>--foreign</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display logical volumes that are not part of known volume groups on the system (e.g., from external arrays).<br><br><b>--nameprefixes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add 'LVM2_' prefixes to column names when using --columns for easier programmatic parsing.<br><br><b>--noheadings</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not display header lines in the output.<br><br><b>--reportformat {basic|json}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select the report output format. 'basic' is the default human-readable format, 'json' outputs structured JSON data.<br><br><b>--rows | -t</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display each logical volume on a separate row, useful for very wide outputs.<br><br><b>--select <selection_string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only rows that match the selection criteria. E.g., <I>lvs -S 'lv_size>10G'</I>.<br><br><b>--separator <separator_string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the field separator for non-aligned output, useful for scripting.<br><br><b>--sort <sort_string></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the output by specified columns. E.g., <I>lvs --sort lv_name</I>.<br><br><b>--segments | -s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display information about logical volume segments, providing more granular details about LV composition.<br><br><b>--units {B|K|M|G|T|P|E}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the units for size display (Bytes, Kilobytes, Megabytes, Gigabytes, Terabytes, Petabytes, Exabytes).<br><br><b>--verbose | -v</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increase verbosity level, providing more detailed information about the command execution.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information of the LVM tools.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help information and exit.<br><br>


title: DESCRIPTION
content:
<b>lvs</b> is a command-line utility used in Linux to display information about <I>logical volumes</I> (LVs) managed by the <I>Logical Volume Manager</I> (LVM). It provides a structured view of LVs, including their names, sizes, volume groups, attributes (such as thin provisioning or snapshots), and allocation details. This command is essential for system administrators to monitor and manage storage configurations, allowing quick inspection of the state and properties of logical volumes without needing to parse output from other LVM tools like lvdisplay. It supports various output formats and powerful filtering options, making it versatile for scripting and detailed reporting.


title: CAVEATS
content:
<b>lvs</b> relies on the LVM metadata. If metadata is corrupt or inaccessible, <b>lvs</b> might not show accurate information or could fail.<br>For very large systems with many LVs, running <b>lvs</b> without filters might be slow. Using <I>LV_PATH</I> arguments or <b>--select</b> can speed up queries.<br>The output of <b>lvs</b> can vary slightly across different LVM versions, especially regarding available columns and their exact names. Always consult the <I>man lvs</I> page for the specific LVM version being used.


title: CUSTOM OUTPUT FORMATTING
content:
<b>lvs</b> allows users to highly customize its output using the <b>--columns</b> (or <b>-o</b>) option. This is extremely useful for scripting, as specific data points can be extracted precisely. For instance, <I>lvs -o lv_name,lv_size --noheadings</I> will output just the name and size without headers, ideal for piping into other commands or for automated parsing.


title: FILTERING AND SELECTION
content:
The <b>--select</b> option provides powerful filtering capabilities, allowing users to query LVs based on various criteria like size, attributes, or names using a SQL-like syntax. This is crucial for managing large LVM setups and quickly finding specific volumes. Example: <I>lvs --select 'lv_size > 100G && vg_name=myvg'</I> to find all logical volumes larger than 100GB in 'myvg'.


title: HISTORY
content:
The <I>Logical Volume Manager</I> (LVM) for Linux was initially developed by Joe Thornber around 1998, drawing inspiration from HP-UX's LVM. It became a standard part of the Linux kernel around version 2.4. <b>lvs</b> is a core utility within the LVM toolset, designed to provide a concise and tabular view of logical volumes. Its design evolved to support increasingly complex LVM features like thin provisioning, snapshots, and RAID LVs, making it an indispensable tool for understanding the storage layout managed by LVM. The command has maintained a consistent interface while adding new columns and filtering capabilities to adapt to new LVM functionalities.


title: SEE ALSO
content:
pvs(8): Report information about <I>physical volumes</I>., vgs(8): Report information about <I>volume groups</I>., lvcreate(8): Create a logical volume., lvdisplay(8): Display attributes of a logical volume in a more detailed format., lvremove(8): Remove a logical volume., lvextend(8): Extend the size of a logical volume., lvreduce(8): Reduce the size of a logical volume., vgcreate(8): Create a volume group., pvcreate(8): Initialize a physical volume for use by LVM.


title: DESCRIPTION
content:
The term `intercept` in the Linux context primarily denotes concepts like monitoring, diverting, or redirecting system calls, network packets, or signals. It is <b>not</b> a standalone, general-purpose command-line utility found in standard Linux distributions. Instead, 'interception' functionality is provided by specialized tools or kernel features. For instance, system call interception can be achieved via the `ptrace` system call (utilized by tools like `strace`), and network packet interception by utilities such as `tcpdump` or `wireshark`, or kernel frameworks like Netfilter (configured via `iptables`). This term describes a functional capability or a programming paradigm rather than a specific executable.


title: CAVEATS
content:
As `intercept` is not a standard Linux command, attempting to execute it directly will typically result in a 'command not found' error. Functionality related to 'intercepting' system operations or network traffic is achieved through specific system calls, kernel modules, or other specialized user-space tools that implement these interception capabilities.


title: HISTORY
content:
The concept of 'intercepting' system operations or network traffic has been a fundamental aspect of operating system design and security for decades. While specific kernel APIs (like `ptrace`) and user-space utilities (`strace`, `tcpdump`) have been developed over time to provide such capabilities, no single, general-purpose command named `intercept` has been established as a standard part of Linux distributions. The term itself is often used generically to describe the act of monitoring or controlling data flow.


title: TLDR
content:
<b>Read and output raw input events from a given input device file (the system will not see any key presses)</b>`sudo intercept -g [/dev/input/eventX]`<br><b>Read and output raw input events from a given input device file (the system can see key presses and does not block other programs from reading them)</b>`sudo intercept [/dev/input/eventX]`


title: SYNOPSIS
content:
<i>The 'mux' command is not a standard Linux utility. If you are referring to a terminal multiplexer, commands like <I>tmux</I> or <I>screen</I> are commonly used.</i>


title: DESCRIPTION
content:
The term "mux" is not a standard, standalone Linux command found in most distributions. It is commonly used as an abbreviation for "multiplexer" or "multiplexing." In the context of Linux, "mux" most often informally refers to <b>terminal multiplexers</b> such as <I>tmux</I> or <I>GNU Screen</I>.<br><br>These powerful utilities allow users to manage multiple independent terminal sessions within a single window. They enable users to: <br> - Detach from a session and reattach later, even after network disconnections or logging out, keeping processes running in the background.<br> - Create multiple windows or panes within a single terminal window, each running a different command or process.<br> - Share terminal sessions with other users for collaborative work.<br><br>While highly valuable for development, system administration, and managing long-running tasks, remember that executing "mux" directly will typically result in a "command not found" error, as it's not an executable command itself.


title: CAVEATS
content:
It's crucial to understand that 'mux' itself is not a predefined command in most standard Linux distributions. Its usage implies either a custom script named 'mux' or, more commonly, an informal reference to terminal multiplexing software like <I>tmux</I> or <I>GNU Screen</I>. Attempting to execute 'mux' directly will likely result in a 'command not found' error unless a specific alias or script has been set up on the system.


title: WHAT IS A TERMINAL MULTIPLEXER?
content:
A terminal multiplexer is a software application that allows a user to create and control multiple virtual terminals or 'panes' within a single physical terminal window. Key functionalities include: <br> - <b>Session Persistence:</b> Detach from a session and reattach later, even from a different machine, keeping processes running in the background. <br> - <b>Multiple Windows/Panes:</b> Divide the terminal into multiple independent windows or panes, each running a different command or process. <br> - <b>Shared Sessions:</b> Allow multiple users to connect to and interact with the same terminal session collaboratively. <br> These tools are invaluable for remote work, long-running processes, and organizing complex command-line workflows.


title: HISTORY
content:
The concept of a 'multiplexer' (often abbreviated 'mux') has roots in electronics and telecommunications, referring to a device that selects one of several analog or digital input signals and forwards the selected input into a single output line. In computing, this concept extends to software that allows multiple sessions or processes to share a single terminal interface or network connection. While the term 'mux' isn't a command, it historically influenced the naming and development of utilities like <I>GNU Screen</I> (first released in 1987) and later <I>tmux</I> (released in 2007), which popularized terminal multiplexing on Unix-like systems, enabling persistent terminal sessions and organized workflows.


title: TLDR
content:
<b>Create a new muxer with a specified name</b>`mux -c [muxer_name1 muxer_name2 ...]`<br><b>Set the muxer's internal queue size (default is 100)</b>`mux -s [size]`<br><b>Read input from a named muxer (can be repeated in "switch mode")</b>`mux -i [input_muxer_name]`<br><b>Write output to a named muxer (can be repeated)</b>`mux -o [output_muxer_name]`


title: PARAMETERS
content:
<b><b>--help</b>, <b>-h</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b><b>--version</b>, <b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show program's version number and exit.<br><br><b><b>--config</b> <i>&lt;path&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternative configuration file path.<br><br><b><b>--headless</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run the command in a non-interactive, background mode.<br><br><b><b>--log-level</b> <i>&lt;level&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the logging verbosity (e.g., <i>debug</i>, <i>info</i>, <i>warning</i>, <i>error</i>).<br><br><b><b>start</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Begin a new Pokémon GO session or task.<br><br><b><b>stop</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Terminate the current Pokémon GO session or task.<br><br><b><b>status</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the current operational status of the pokego script.<br><br><b><b>update</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempt to update the pokego script to the latest version.<br><br><b><b>configure</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Launch an interactive configuration wizard or open the configuration file for editing.<br><br>


title: DESCRIPTION
content:
The <i>pokego</i> command is a hypothetical command-line interface for an unofficial script designed to interact with or automate aspects of the Pokémon GO game on Linux systems. It is <b>not a standard Linux utility</b> but represents a type of community-developed tool often used for botting, spoofing, or enhancing gameplay experience. Such tools typically manage game sessions, simulate player actions, or retrieve game data. Due to its unofficial nature, its functionality can vary widely based on the specific script it controls, and its use often violates the game's terms of service. This description outlines a conceptual implementation of such a command, as it would likely function if officially documented.


title: CAVEATS
content:
The <i>pokego</i> command is <b>not a standard Linux utility</b> and does not ship with any major distribution. It refers to a class of unofficial, community-developed scripts for playing Pokémon GO on Linux. Use of such tools may violate Niantic's (the game developer) Terms of Service, potentially leading to account suspension or termination. Furthermore, as these are often third-party projects, their security and stability cannot be guaranteed. Users should exercise extreme caution and be aware of the risks involved.


title: INSTALLATION
content:
Since <i>pokego</i> is not a standard command, its installation typically involves cloning a Git repository, installing dependencies (often via <i>pip</i> for Python scripts), and then running the main script directly, or creating a symbolic link to make it callable as <i>pokego</i> from the PATH. Specific steps vary per project.


title: DISCLAIMER
content:
This entry describes a hypothetical command and its likely features based on common practices for unofficial community tools. It is provided for illustrative purposes and does not represent an actual, officially supported Linux command.


title: HISTORY
content:
The concept of a 'pokego' command likely emerged shortly after the release of Pokémon GO in 2016, driven by a community desire to play the mobile game on desktop Linux systems or to automate gameplay. These tools often started as simple Python or Node.js scripts developed by enthusiasts. Their development was largely reactive, adapting to game updates and anti-cheat measures. Over time, various unofficial projects emerged, each with its own command-line interface, though none became an 'official' or widely standardized Linux command.


title: TLDR
content:
<b>Print a specific Pokémon</b>`pokego --name charizard`<br><b>Print a specific shiny Pokémon</b>`pokego --name spheal -shiny`<br><b>Print an alternative form of a Pokémon</b>`pokego --name blastoise --form mega`<br><b>Print random Pokémon from generations 1-3 (range)</b>`pokego --random 1-3`<br><b>Do not display Pokémon name (default: false)</b>`pokego --random 1-3 --no-title`


title: SYNOPSIS
content:
<i><br><b>Not a standalone command.</b> User-space applications interact with the `uinput` facility by opening the `/dev/uinput` device file and issuing specific `ioctl` commands to create, configure, and send events from virtual input devices.<br></i>


title: PARAMETERS
content:
<b>N/A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;As `uinput` is a kernel module interface accessed programmatically, it does not have command-line parameters like typical shell commands. Interaction is performed through `ioctl` system calls and writing data to the `/dev/uinput` device file.<br><br>


title: DESCRIPTION
content:
The `uinput` (User Input) facility is a Linux kernel module that enables user-space applications to create and manage virtual input devices. Instead of being a standalone shell command executed directly from the terminal, `uinput` provides a programmatic interface, typically exposed via the `/dev/uinput` device file.<br><br>This powerful capability allows user-space programs to simulate hardware input events, effectively emulating keyboards, mice, joysticks, touchpads, or other input devices. By writing specific `ioctl` commands and `input_event` structures to the `/dev/uinput` file, applications can send synthetic events directly into the kernel's input subsystem.<br><br>`uinput` is widely utilized for purposes such as: <br><i>&nbsp;&nbsp;•&nbsp;Input automation and scripting<br>&nbsp;&nbsp;•&nbsp;Remote control software<br>&nbsp;&nbsp;•&nbsp;Gaming emulation and custom controller setups<br>&nbsp;&nbsp;•&nbsp;Testing frameworks that require simulated user interaction</i><br>It bridges the gap between software logic and the kernel's native input handling, making it a fundamental component for advanced input management in Linux.


title: CAVEATS
content:
<i><br><b>Requires Root Privileges:</b> Creating and managing virtual input devices typically requires root access or specific Linux capabilities (e.g., `CAP_SYS_ADMIN` or `CAP_NET_ADMIN`) to interact with `/dev/uinput`.<br><br><b>Security Implications:</b> Malicious use of `uinput` could allow an unauthorized program to simulate user input, leading to potential security vulnerabilities or system compromise.<br><br><b>Programming Required:</b> Utilizing `uinput` involves writing code (e.g., in C, Python, etc.) to interact with the device file and its specific `ioctl` commands, rather than simple shell scripting.<br><br><b>Kernel Module Dependency:</b> The `uinput` kernel module must be loaded (`modprobe uinput`) for the `/dev/uinput` device file to exist and be functional.<br></i>


title: LOADING THE MODULE
content:
<i><br>The `uinput` kernel module needs to be loaded into the kernel before it can be used. This can usually be done temporarily with: `<b>sudo modprobe uinput</b>`.<br><br>To ensure the module is loaded automatically on system boot, you can add `<b>uinput</b>` to a configuration file like `/etc/modules-load.d/uinput.conf` (or similar distribution-specific configuration paths).<br></i>


title: COMMON USE CASES
content:
<i><br>`uinput` is extensively used for:<br>`<b>&nbsp;&nbsp;•&nbsp;Input Automation:</b> Scripting keyboard presses, mouse movements, or other input events for automated tasks and macros.<br>`<b>&nbsp;&nbsp;•&nbsp;Remote Control:</b> Implementing software that allows one system to control the input of another, such as virtual KVMs or desktop sharing.<br>`<b>&nbsp;&nbsp;•&nbsp;Gaming Emulation:</b> Creating virtual gamepads, joysticks, or custom controllers to map unusual input devices or software logic to standard game inputs.<br>`<b>&nbsp;&nbsp;•&nbsp;Software Testing:</b> Generating synthetic input events to rigorously test application behavior and responsiveness under various input conditions.<br>`</i>


title: PROGRAMMING INTERFACE OVERVIEW
content:
<i><br>Using `uinput` typically involves the following steps in a user-space program:<br>`<b>&nbsp;&nbsp;1.&nbsp;Open `/dev/uinput`:</b> Obtain a file descriptor to the `uinput` device.<br>`<b>&nbsp;&nbsp;2.&nbsp;Set Capabilities:</b> Use `ioctl` calls (e.g., `UI_SET_EVBIT`, `UI_SET_KEYBIT`, `UI_SET_RELBIT`, `UI_SET_ABSBIT`) to specify which event types (keys, relative movements, absolute positions, etc.) the virtual device will support.<br>`<b>&nbsp;&nbsp;3.&nbsp;Create Device:</b> Populate a `uinput_user_dev` structure with device information (name, vendor/product IDs, bus type) and use `ioctl(UI_DEV_CREATE)` to register the virtual device with the kernel.<br>`<b>&nbsp;&nbsp;4.&nbsp;Send Events:</b> Write `input_event` structures to the `uinput` file descriptor to generate synthetic input events.<br>`<b>&nbsp;&nbsp;5.&nbsp;Destroy Device:</b> When finished, use `ioctl(UI_DEV_DESTROY)` and close the file descriptor to unregister the virtual device.<br>`</i>


title: HISTORY
content:
The `uinput` facility has been an integral part of the Linux kernel's input subsystem since its introduction. Designed to provide a standardized, programmatic interface for user-space applications to create and control virtual input devices, it has evolved alongside the kernel's capabilities. Its development was driven by the need for robust methods to automate input, facilitate remote control, and enable various emulation scenarios, solidifying its role as a fundamental component for advanced input management in Linux.


title: TLDR
content:
<b>Show resulting YAML device description merge and exit (dry-run)</b>`uinput -p`<br><b>Merge YAML device description(s) to resulting virtual device</b>`sudo uinput -c [path/to/device1.yaml path/to/device2.yaml ...]`<br><b>Merge reference device description from device node(s) to resulting virtual device</b>`sudo uinput -d [/dev/input/eventX /dev/input/eventY ...]`


title: SYNOPSIS
content:
<b>az quantum</b> <I>group</I> <I>subcommand</I> [<I>options</I>]<br><b>az quantum</b> <I>execute</I> [<I>options</I>]<br><br><i>Examples:</i><br><b>az quantum workspace</b> create --name <I>my-workspace</I> --resource-group <I>my-rg</I> --location <I>eastus</I><br><b>az quantum job</b> submit --workspace <I>my-workspace</I> --target-id <I>microsoft.estimator</I> --entry-point <I>MyApp.EntryPoint</I> --input-args <I>{\"shots\": 100}</I> <I>my_quantum_code.qs</I>


title: PARAMETERS
content:
<b>workspace</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages Azure Quantum workspaces, including creation, deletion, and listing.<br><br><b>job</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages quantum jobs submitted to various quantum providers, allowing submission, listing, cancellation, and retrieval of results.<br><br><b>target</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages quantum execution targets (Quantum Processing Units - QPUs and simulators) available within a workspace.<br><br><b>provider</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Manages quantum providers associated with a workspace.<br><br><b>execute</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directly executes quantum programs or Q# code files on a specified target within a quantum workspace.<br><br><b>--help, -h</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the help message for the <b>az quantum</b> command or its specific subcommands.<br><br><b>--output, -o</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format for the command's results (e.g., <I>json</I>, <I>table</I>, <I>tsv</I>).<br><br><b>--query</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A JMESPath query string used to filter or transform the command's output.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases logging verbosity to show more detailed information.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows all debug logs for troubleshooting purposes.<br><br>


title: DESCRIPTION
content:
The <b>az quantum</b> command is an official extension for the Azure Command-Line Interface (CLI), designed to facilitate interaction with the Azure Quantum service.<br>It empowers developers and researchers to manage quantum workspaces, submit quantum jobs to various providers, track job execution, and retrieve results directly from their command line.<br>This tool integrates quantum development workflows with Microsoft Azure's cloud infrastructure, providing a unified interface for quantum resource management and job orchestration.


title: CAVEATS
content:
Requires the Azure CLI to be installed and the <b>quantum</b> extension to be added (e.g., <code>az extension add --name quantum</code>).<br>An active Azure subscription and a configured Azure Quantum workspace are necessary to utilize its full capabilities.<br>Familiarity with Azure concepts (resource groups, subscriptions) and basic quantum computing principles is beneficial.


title: HISTORY
content:
The <b>az quantum</b> command was developed by Microsoft as part of its Azure Quantum service offering.<br>It was introduced as an Azure CLI extension to provide command-line tooling for interacting with Azure's cloud-based quantum computing platform.<br>Its development enables developers to integrate quantum workloads into their existing Azure DevOps practices and scripts, aligning with Microsoft's broader strategy to make quantum computing accessible through cloud services.


title: SEE ALSO
content:
az(1): The main Azure CLI command., az account(1): Manages Azure subscriptions and authentication., az group(1): Manages Azure resource groups.


title: TLDR
content:
<b>Create a new Azure Quantum workspace</b>`az quantum workspace create [[-g|--resource-group]] [ResourceGroup] [[-l|--location]] [Location] [[-w|--workspace-name]] [Workspace] [[-a|--storage-account]] [MyStorageAccountName]`<br><b>List all Azure Quantum workspaces</b>`az quantum workspace list`<br><b>Set a default Azure Quantum workspace</b>`az quantum workspace set [[-g|--resource-group]] [ResourceGroup] [[-w|--workspace-name]] [Workspace]`<br><b>Submit a QIR quantum job to a target</b>`az quantum job submit [[-g|--resource-group]] [ResourceGroup] [[-w|--workspace-name]] [Workspace] [[-l|--location]] [Location] [[-t|--target-id]] [Id] --job-name [Job] --job-input-file [QirBitcode.bc] --job-input-format [qir.v1]`<br><b>List all jobs in a Quantum Workspace</b>`az quantum job list [[-g|--resource-group]] [ResourceGroup] [[-l|--location]] [Location] [[-w|--workspace-name]] [Workspace]`<br><b>Get the output of a quantum job</b>`az quantum job output [[-g|--resource-group]] [ResourceGroup] [[-w|--workspace-name]] [Workspace] --job-id [Job]`<br><b>List available provider offerings in a location</b>`az quantum offerings list [[-l|--location]] [Location]`<br><b>Set a default target for job submissions</b>`az quantum target set [[-t|--target-id]] [Id]`


title: SYNOPSIS
content:
<b>ludusavi</b> <I><i>[OPTIONS]</i></I> <I><i>[COMMAND]</i></I><br><br>Common Commands:<br> &nbsp; <b>backup</b> &nbsp; &nbsp; &nbsp; &nbsp; Back up game saves<br> &nbsp; <b>restore</b> &nbsp; &nbsp; &nbsp; &nbsp; Restore game saves<br> &nbsp; <b>dry-run</b> &nbsp; &nbsp; &nbsp; &nbsp; Scan for games and show what would be backed up/restored<br> &nbsp; <b>scan</b> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; List all supported games and their save paths<br> &nbsp; <b>find</b> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Search for a specific game<br> &nbsp; <b>changelog</b> &nbsp; &nbsp; &nbsp; Show recent changes<br> &nbsp; <b>api</b> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Start the API server<br> &nbsp; <b>launch</b> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Launch the GUI


title: PARAMETERS
content:
<b>--path <PATH></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the root directory for backups.<br><br><b>--output <PATH></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a path for output files (e.g., dry-run report).<br><br><b>--force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrite existing backups/saves without confirmation.<br><br><b>--merge</b><br>&nbsp;&nbsp;&nbsp;&nbsp;When restoring, merge with existing saves rather than overwriting.<br><br><b>--by-game <GAME_NAME></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter by specific game name for backup/restore.<br><br><b>--by-id <GAME_ID></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter by specific game ID for backup/restore.<br><br><b>--by-name <GAME_NAME></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter by specific game name for backup/restore (alias for by-game).<br><br><b>--no-confirm</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip confirmation prompts.<br><br><b>--config <PATH></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a custom path for the configuration file.<br><br><b>--log <PATH></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a path for logging.<br><br><b>--verbosity <LEVEL></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the logging verbosity (e.g., <i>info</i>, <i>debug</i>, <i>trace</i>).<br><br><b>--roots <PATH_LIST></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add custom root directories for scanning for games.<br><br><b>--no-scan</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skip the game scan when launching the GUI.<br><br><b>--no-cli</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run only the GUI (when launching from CLI).<br><br><b>--portable</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use portable mode (config/saves in current directory).<br><br><b>--update-manifest</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Download the latest game manifest for save locations.<br><br>


title: DESCRIPTION
content:
Ludusavi is a free, open-source command-line and GUI utility designed to back up and restore game save data for PC games. It automates the process of finding and preserving save files, which can often be scattered across various directories and obscure locations by different game launchers (like Steam, GOG, Epic Games Store, or standalone executables). It supports a vast database of known game save locations and allows users to define custom paths. Ludusavi aims to simplify the migration of game saves between different systems or after reinstallation, ensuring players don't lose their progress.


title: CAVEATS
content:
Ludusavi is a third-party application, not a standard Linux distribution utility. It needs to be installed separately (e.g., via Cargo, pre-compiled binaries, or Flatpak).<br>While it has a large database of known game save locations, it may not cover every single game, especially obscure or newly released titles, requiring manual configuration.<br>For proper function, Ludusavi needs permissions to read and write to game save directories, which can sometimes be in protected user directories.<br>The <i>manifest.yaml</i> file, which contains game save definitions, needs to be updated periodically to ensure coverage of new games or changes in save locations.


title: INSTALLATION
content:
Ludusavi can be installed in several ways:<br><b>From source via Cargo</b>: <i>cargo install ludusavi</i><br><b>Pre-compiled binaries</b>: Download executable from GitHub releases.<br><b>Flatpak</b>: <i>flatpak install org.cxx.Ludusavi</i><br><b>AUR (Arch Linux)</b>: Available in the Arch User Repository.


title: CONFIGURATION
content:
The application uses a <i>config.yaml</i> file (usually located in <i>~/.config/ludusavi/</i> on Linux) where users can define custom roots for scanning games, specify ignored games or files, and manage other settings. This allows for fine-tuning its behavior beyond command-line arguments.


title: MODES OF OPERATION
content:
Ludusavi provides both a command-line interface (CLI) for scripting and automation, and a graphical user interface (GUI) for easy visual management of backups and restores. The GUI can be launched directly or via the <i>ludusavi launch</i> CLI command.


title: BACKUP STRUCTURE
content:
Backups are typically stored in a structured directory tree, with each game having its own directory containing the save files and potentially metadata. This makes it easy to browse and manage backed-up saves.


title: HISTORY
content:
Ludusavi was initially developed by <i>@cxx</i> (now cxx.org) as an open-source project. Its primary motivation was to create a robust and user-friendly solution for managing PC game saves, addressing the common issue of scattered and hard-to-find save data across different games and launchers. The project gained traction in the PC gaming community due to its cross-platform compatibility (supporting Windows, macOS, and Linux) and extensive database of game save locations. It has seen continuous development, with regular updates to its game manifest and new features, establishing itself as a go-to tool for game save management.


title: TLDR
content:
<b>Backup games</b>`ludusavi backup --path [path/to/backup]`<br><b>Restore games</b>`ludusavi restore --path [path/to/backup] ["game1" "game2" ...]`<br><b>List backups</b>`ludusavi backups --path [path/to/backup]`<br><b>Wrap launcher game</b>`ludusavi wrap --gui --infer [heroic|lutris|steam] -- [game_launch_commands]`<br><b>Wrap standalone game</b>`ludusavi wrap --gui --name [name] -- [game_launch_commands]`


title: SYNOPSIS
content:
<b>ip</b> <b>tunnel</b> { <b>add</b> | <b>change</b> | <b>del</b> } <i>NAME</i> <b>type</b> <i>TYPE</i> [ <i>OPTIONS</i> ]<br><b>ip</b> <b>tunnel</b> { <b>show</b> | <b>help</b> }


title: PARAMETERS
content:
<b><b>add</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new tunnel device.<br><br><b><b>change</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Modifies an existing tunnel device.<br><br><b><b>del</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes a tunnel device.<br><br><b><b>show</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all configured tunnel devices and their parameters.<br><br><b><i>NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the tunnel device (e.g., <i>tun0</i>).<br><br><b><b>type</b> <i>TYPE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the tunnel type. Common types include <i>ipip</i>, <i>gre</i>, <i>sit</i>, <i>vti</i>, <i>fou</i>, <i>gretap</i>, <i>ip6tnl</i>.<br><br><b><b>local</b> <i>ADDRESS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The local IP address to use as the tunnel source endpoint.<br><br><b><b>remote</b> <i>ADDRESS</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The remote IP address to use as the tunnel destination endpoint.<br><br><b><b>dev</b> <i>NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the underlying physical device through which tunnel traffic will be sent.<br><br><b><b>ttl</b> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the Time-To-Live (TTL) for encapsulated packets. <i>0</i> indicates inheritance from the inner packet.<br><br><b><b>tos</b> <i>N</i> | <b>dsfield</b> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the Type of Service (ToS) or Differentiated Services field (DSCP) for encapsulated packets.<br><br><b><b>nopmtudisc</b> | <b>nopmssdiscovery</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables Path MTU Discovery for the tunnel, meaning the MTU won't be dynamically adjusted.<br><br><b><b>key</b> <i>N</i> | <b>ikey</b> <i>N</i> | <b>okey</b> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a GRE key for identifying the tunnel. <i>key</i> applies to both input and output, while <i>ikey</i> and <i>okey</i> are for input and output separately.<br><br><b><b>mode</b> { <b>ipip</b> | <b>gre</b> | <b>fou</b> | <b>vti</b> }</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the encapsulation mode. Primarily used with <i>FOU</i> (Foo over UDP) to indicate the inner protocol.<br><br><b><b>encaptype</b> { <b>none</b> | <b>fou</b> | <b>udp</b> }</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the encapsulation type for the tunnel, e.g., <i>fou</i> for UDP encapsulation of IP packets.<br><br><b><b>encapsport</b> <i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the UDP source/destination port for FOU (Foo over UDP) encapsulation.<br><br><b><b>inherit</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Causes the tunnel to inherit certain parameters (like TTL, TOS) from the outer IP header of the underlying device.<br><br>


title: DESCRIPTION
content:
The <b>ip tunnel</b> command, part of the <b>iproute2</b> suite, is a powerful utility for configuring and managing IP tunnels on Linux systems. It allows administrators to create, modify, delete, and display various types of IP-over-IP tunnels, such as <i>GRE (Generic Routing Encapsulation)</i>, <i>IPIP (IP-over-IP)</i>, <i>SIT (Simple Internet Transition, often for IPv6-in-IPv4)</i>, <i>VTI (Virtual Tunnel Interface)</i>, and <i>FOU (Foo Over UDP)</i>. <br><br>These tunnels encapsulate IP packets within another IP header, enabling communication between networks that are not directly connected or providing a means for VPN-like connectivity without native encryption. It's an essential tool for setting up site-to-site VPNs, routing traffic through non-native IP protocols, or overcoming network topology limitations. Unlike older tools, <b>ip tunnel</b> provides fine-grained control over tunnel parameters, including local/remote endpoints, keys, TTL, and DSCP values.


title: CAVEATS
content:
IP tunnels, by themselves, do not provide encryption. For secure communication, they should be used in conjunction with encryption protocols like <i>IPsec</i>. <br>Kernel modules specific to the tunnel type (e.g., <i>ip_gre</i>, <i>ip_ipip</i>, <i>fou</i>) must be loaded. <br>Tunnel configurations made via <b>ip tunnel</b> are not persistent across reboots by default; they require integration with network configuration scripts or services.


title: TUNNEL TYPES
content:
<ul><li><b>IPIP</b>: Simple IP-in-IP encapsulation, primarily for IPv4-in-IPv4.</li><li><b>GRE</b>: Generic Routing Encapsulation, more flexible than IPIP, supporting arbitrary network layer protocols over IP, often used with keys for identification.</li><li><b>SIT</b>: Simple Internet Transition, typically used for IPv6-in-IPv4 tunnels.</li><li><b>VTI</b>: Virtual Tunnel Interface, often used in conjunction with IPsec for secure tunnels, as it provides a dedicated interface for encapsulated traffic.</li><li><b>FOU</b>: Foo over UDP, a generic UDP encapsulation mechanism that can carry various protocols (like IP, GRE) over UDP, useful for firewall traversal.</li><li><b>GRETAP</b>: A variant of GRE that creates a Layer 2 tunnel, allowing Ethernet frames to be encapsulated.</li><li><b>IP6TNL</b>: IPv6-in-IPv6 tunnels, similar to IPIP but for IPv6.


title: HISTORY
content:
The <b>ip tunnel</b> command is an integral part of the <i>iproute2</i> utility suite, which has been the standard for Linux networking configuration since its inception in the late 1990s. Developed to overcome the limitations of older tools like <i>ifconfig</i> and <i>route</i>, <i>iproute2</i> provides a unified and more powerful command-line interface for managing all aspects of TCP/IP networking, including advanced routing, traffic shaping, and tunnel management. The <b>ip tunnel</b> subcommand specifically evolved to support various IP encapsulation methods as network requirements for VPNs, data center networking, and IPv6 transitions grew.


title: SYNOPSIS
content:
<b>jhipster</b> &lt;subcommand&gt; [arguments] [options]<br><br>Common subcommands include:<br>  <b>jhipster generate</b> [<i>application-type</i>] [<i>options</i>]<br>  <b>jhipster entity</b> &lt;<i>entity-name</i>&gt; [<i>options</i>]<br>  <b>jhipster import-jdl</b> &lt;<i>jdl-file</i>&gt; [<i>options</i>]<br>  <b>jhipster upgrade</b> [<i>options</i>]<br>  <b>jhipster help</b> [<i>subcommand</i>]


title: PARAMETERS
content:
<b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays help information for the main command or a specific subcommand.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the current JHipster version.<br><br><b><b>--no-insight</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deactivates JHipster's anonymous usage insights.<br><br><b><b>--skip-install</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Commonly used with `generate`)</i> Skips installing Node.js and Maven/Gradle dependencies after generation.<br><br><b><b>--skip-git</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Commonly used with `generate`)</i> Skips initializing a Git repository.<br><br><b><b>--skip-cache</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Commonly used with `generate`)</i> Skips Yeoman's generator cache, forcing all prompts.<br><br><b><b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>(Commonly used with `generate`)</i> Overwrites existing files without prompting for confirmation.<br><br>


title: DESCRIPTION
content:
JHipster is a comprehensive development platform designed to rapidly generate, develop, and deploy modern web applications and microservices. It combines popular technologies like Spring Boot for the backend and Angular, React, or Vue.js for the frontend, providing a robust and opinionated full-stack development environment.<br><br>The platform leverages a suite of industry-standard tools including Yeoman for scaffolding, Webpack for frontend asset management, Maven or Gradle for build automation, and Liquibase for database versioning. JHipster offers a wide array of options during generation, supporting various application types (monolithic, microservices, gateway), authentication methods, database choices (SQL, NoSQL), and deployment targets (Docker, Kubernetes, Cloud Foundry, Heroku).<br><br>Its primary goal is to boost developer productivity by providing a ready-to-use application scaffold with common functionalities already implemented, such as user management, security, and REST APIs. This allows developers to focus predominantly on business logic, accelerating the development lifecycle from inception to deployment.


title: CAVEATS
content:
JHipster is not a native Linux command; it is an application generator installed globally via npm.<br><br>Requires Node.js, npm/yarn, Java Development Kit (JDK), and a build tool like Maven or Gradle to be pre-installed on the system.<br><br>The generated applications are full-stack and can be extensive; deep customization may require familiarity with all underlying technologies.<br><br>Upgrading existing JHipster projects can sometimes be complex, though the <b>jhipster upgrade</b> subcommand assists in the process, manual adjustments may still be required.<br><br>Some commands (e.g., `generate`) are interactive by default, prompting the user for various configuration options.


title: INSTALLATION
content:
The <b>jhipster</b> command-line tool is installed globally via npm (Node Package Manager). Ensure Node.js and npm are installed, then execute:<br><b>npm install -g generator-jhipster</b><br>This command makes the `jhipster` executable available in your system's PATH.


title: KEY CONCEPTS
content:
<i>Monolithic vs. Microservices</i>: JHipster supports generating both traditional monolithic applications and complex microservice architectures, including gateways, microservices, and service registries.<br><br><i>JDL (JHipster Domain Language)</i>: A powerful, concise, and YAML-like language that allows developers to define applications, entities, relationships, and deployment configurations in a single file, which can then be imported using `jhipster import-jdl` to generate the code.<br><br><i>Module System</i>: JHipster provides a vibrant module system, allowing the community to contribute and integrate various third-party tools, frameworks, and features into JHipster-generated applications.


title: HISTORY
content:
JHipster was created by <i>Julien Dubois</i> and first open-sourced in 2013. Initially, it started as a simple Yeoman generator for Spring MVC and AngularJS. Over the years, it underwent significant evolution, integrating Spring Boot as the backend framework and expanding frontend options to include Angular, React, and Vue.js. The project's scope grew to support advanced architectures like microservices, diverse database systems (SQL and NoSQL), and various deployment strategies, including Docker and Kubernetes.<br><br>The core philosophy behind JHipster has always been to provide a comprehensive, opinionated, and community-driven solution to accelerate full-stack development, making it easier for developers to build modern web applications by focusing on business value rather than boilerplate configuration. It has cultivated a large and active global community that contributes to its ongoing development and ecosystem of modules.


title: SYNOPSIS
content:
Not applicable for a standard command-line utility. If referring to the W3C Jigsaw server, its invocation would depend on its specific installation and Java environment, often involving wrapper scripts or direct Java commands like: <br><code>java -jar jigsaw.jar [options]</code><br>or via a specific startup script provided with its distribution.


title: PARAMETERS
content:
<b>None</b><br>&nbsp;&nbsp;&nbsp;&nbsp;No standard command-line parameters exist for 'jigsaw' as a common Linux utility. If the context is the W3C Jigsaw server, its configuration and runtime options are typically managed via property files, XML configuration, or server-specific startup arguments rather than general command-line parameters akin to typical Linux commands.<br><br>


title: DESCRIPTION
content:
The command <i>jigsaw</i> is not a standard, pre-installed utility found in most common Linux distributions. There is no common manual page or executable with this name in typical environments (e.g., coreutils, busybox, standard package repositories). It is highly probable that <i>jigsaw</i>, if encountered, refers to a custom-developed script, an alias on a specific system, or a component of a specialized application.<br><br>Historically, 'Jigsaw' is the name of a well-known open-source web server developed by the World Wide Web Consortium (W3C), written in Java. While this server can be launched and managed, it doesn't operate as a typical command-line utility with a fixed set of shell arguments in the way common Linux tools (e.g., <i>ls</i>, <i>grep</i>) do. Therefore, analyzing 'jigsaw' as a standard, standalone Linux command is not feasible as it doesn't commonly exist.


title: CAVEATS
content:
The name <i>jigsaw</i> does not correspond to a universally recognized or pre-installed command in standard Linux operating systems. Any utility named <i>jigsaw</i> would be specific to a particular system, project, or custom setup, and its functionality, syntax, and options would vary widely. Users encountering 'jigsaw' should consult local documentation or the source of the software/script.


title: POSSIBLE CUSTOM USAGE
content:
If you have encountered a 'jigsaw' command, it is highly likely to be a custom script, an alias defined in a shell configuration (e.g., <code>.bashrc</code>, <code>.zshrc</code>), or a binary specific to a niche application or development environment. To understand its precise purpose and usage, you would need to inspect its source code, execution path (e.g., <code>which jigsaw</code>), or consult local system administrators/developers.


title: HISTORY
content:
There is no documented history of a standard Linux command named <i>jigsaw</i> within common operating system development. The most prominent software with this name is the W3C Jigsaw HTTP server, which was developed starting in the mid-1990s by the World Wide Web Consortium. Its development focused on being a flexible, extensible, and standards-compliant web server written in Java, aiming to provide a reference implementation for web technologies. This history pertains to a server application, not a direct shell command-line utility.


title: SEE ALSO
content:
No directly related standard Linux commands due to the non-existence of 'jigsaw' as a common utility.


title: SYNOPSIS
content:
<I>jmap</I> [<I>options</I>] <I>pid</I><br><I>jmap</I> [<I>options</I>] <I>executable</I> <I>core</I><br><I>jmap</I> [<I>options</I>] <I>server-id</I><B>@</B><I>remote-ip-or-hostname</I>


title: PARAMETERS
content:
<b>-heap</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a summary of the Java heap, including information about garbage collection (GC) configuration and memory usage.<br><br><b>-histo[:live]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a histogram of the heap, showing the total size and instance count for each Java class. The optional <B>live</B> sub-option counts only live objects.<br><br><b>-dump:<dump-options></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the Java heap into a specified file. Common <B>dump-options</B> include <B>format=b</B> (for binary HPROF format) and <B>file=&lt;filename&gt;</B> (to specify the output file path). The <B>live</B> sub-option can be used to dump only live objects.<br><br><b>-clstats</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints statistics about the class loaders and the objects they load.<br><br><b>-finalizerinfo</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays information about objects that are waiting for finalization.<br><br><b><I>pid</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The process ID of the running Java Virtual Machine (JVM) for which to obtain memory information.<br><br><b><I>executable</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) The path to the Java executable if analyzing a core dump.<br><br><b><I>core</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) The path to the core dump file to analyze.<br><br><b><I>server-id</I><B>@</B><I>remote-ip-or-hostname</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Optional) Connects to a remote debug server for analysis, specified by an ID and a hostname or IP address.<br><br>


title: DESCRIPTION
content:
<I>jmap</I> is a command-line utility provided with the Java Development Kit (JDK). It's designed to print shared object memory maps or detailed heap memory statistics for a running Java Virtual Machine (JVM) process. This tool is invaluable for diagnosing memory-related issues such as memory leaks, analyzing the overall memory consumption of a Java application, and understanding the distribution of objects within the Java heap.<br><br>By connecting to a specified Java process via its process ID (PID), <I>jmap</I> can provide insights into object sizes, instance counts, and classloader information. It's often used in conjunction with other JDK tools like <I>jstat</I> and <I>jstack</I> for comprehensive JVM monitoring and troubleshooting.


title: CAVEATS
content:
Using <I>jmap</I>, particularly with the <B>-dump</B> option, can temporarily pause the target JVM, potentially affecting application performance. It requires appropriate user permissions (same user as the JVM process or root). In newer JDK versions (JDK 9+), <I>jmap</I> is often recommended to be used via <I>jhsdb jmap</I> for certain functionalities, and some of its standalone options for printing shared object memory maps have been deprecated or their behavior has changed, with <I>jhsdb</I> being the preferred tool for post-mortem analysis.


title: HEAP DUMP ANALYSIS
content:
Heap dumps generated by <I>jmap</I> (especially with <B>-dump:format=b</B>) are typically in HPROF binary format. These files can be loaded into specialized memory analysis tools like Eclipse Memory Analyzer (MAT), VisualVM, or YourKit Java Profiler to visualize object graphs, identify memory leaks, analyze shallow vs. retained sizes, and understand object distribution in detail.


title: PERMISSIONS
content:
To successfully execute <I>jmap</I> against a running Java process, the user executing the <I>jmap</I> command must have sufficient permissions to inspect the target Java process. This typically means running as the same user that started the Java application or as the root user. Without proper permissions, <I>jmap</I> will fail to attach to the JVM.


title: HISTORY
content:
<I>jmap</I> has been a standard utility within the Java Development Kit (JDK) since early versions, notably from Java 5 onwards. Its core functionality of providing heap and memory statistics has remained consistent. With the introduction of JDK 9, the <I>jhsdb</I> tool was introduced, aiming to unify and supersede some of the standalone diagnostic commands like <I>jmap</I>, <I>jstack</I>, and <I>jinfo</I>, especially for attaching to processes and analyzing core dumps. While <I>jmap</I> continues to function as a direct command, its usage often overlaps with <I>jhsdb</I> for advanced debugging and post-mortem analysis in more recent JDK environments.


title: PARAMETERS
content:
<b><i>&lt;query&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The JSON path or <i>jq</i> filter to apply to the input JSON. Often supports simplified dot notation (e.g., <b>user.name</b>) or a direct <i>jq</i> expression.<br><br><b>[<i>FILE...</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more JSON files to process. If no files are specified, <i>jql</i> reads JSON input from standard input (stdin).<br><br><b>-r, --raw-output</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output raw strings, rather than JSON strings. This is useful when the output is a string and you want to use it directly, e.g., in shell scripts.<br><br><b>-c, --compact-output</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produce compact (not pretty-printed) output. This can be useful for saving space or for piping output to other commands that expect a single line.<br><br><b>-s, --slurp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read all input files into a single array. Each file's JSON content becomes an element in the array, allowing for processing multiple JSON documents as one collection.<br><br><b>-S, --sort-keys</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sort the keys of JSON objects when pretty-printing. This helps ensure consistent output for comparison or storage.<br><br><b>--indent <i>&lt;n&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the indentation level for pretty-printed output to <i>n</i> spaces. Default is often 2 or 4 spaces.<br><br>


title: DESCRIPTION
content:
<i>jql</i> acts as a user-friendly wrapper around the powerful <i>jq</i> command-line JSON processor. It aims to streamline common JSON querying tasks, often allowing users to access nested data using intuitive dot notation (e.g., <b>field.subfield</b> instead of <b>'.field.subfield'</b>). Many <i>jql</i> implementations automatically pretty-print JSON output, making it more readable and easier to parse. It's designed to abstract away some of <i>jq</i>'s more complex syntax for everyday use, making JSON data exploration faster and more accessible for those less familiar with <i>jq</i>'s full capabilities.<br><br>It's particularly useful for quick data inspection, filtering, and transformation directly from the terminal, making it a valuable tool in scripting and data analysis pipelines for DevOps, developers, and system administrators working with JSON-formatted logs, API responses, or configuration files.


title: CAVEATS
content:
<i>jql</i> is not a standard, pre-installed Linux command. It is typically a third-party script or utility that users install manually. Its exact behavior, available options, and level of abstraction can vary significantly depending on the specific <i>jql</i> implementation being used. It relies heavily on <i>jq</i> being installed and accessible in the system's PATH. While it simplifies basic queries, complex JSON manipulations or advanced filtering often still require direct use of <i>jq</i>'s powerful and extensive syntax.


title: UNDERLYING ENGINE
content:
Most <i>jql</i> implementations function as thin wrappers. They parse the user's simplified query and translate it into an equivalent <i>jq</i> filter (e.g., converting <b>user.name</b> to <b>.user.name</b> or a more complex <i>jq</i> pipeline) before executing the <i>jq</i> command and presenting the results. This means <i>jql</i>'s capabilities are fundamentally limited by <i>jq</i>'s power.


title: INSTALLATION
content:
Since <i>jql</i> is not standard, it typically requires manual installation. This often involves downloading a script (e.g., from a GitHub repository) and placing it in a directory included in the system's PATH (e.g., <b>/usr/local/bin</b>), after ensuring <i>jq</i> itself is installed via a package manager (e.g., <b>apt install jq</b> or <b>brew install jq</b>).


title: HISTORY
content:
The need for a streamlined way to interact with JSON data on the command line led Stephen Dolan to create <i>jq</i> in 2012. <i>jq</i> quickly became the de-facto standard for JSON manipulation due to its flexibility and powerful filtering capabilities. As <i>jq</i>'s syntax, while powerful, can be terse for newcomers, various community-driven efforts emerged to provide a more intuitive, often SQL-like or dot-notation, interface. <i>jql</i> utilities represent these efforts, aiming to lower the entry barrier and simplify common tasks, abstracting away some of <i>jq</i>'s intricacies for daily use.


title: SYNOPSIS
content:
<b>json_pp</b> [-v|-V] [--pretty-print | --no-pretty-print] [--indent | --no-indent] [--canonical] [--sort-keys] [--bare-value] [<i>file</i>...]


title: PARAMETERS
content:
<b>--pretty-print</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs JSON in a human-readable, indented format. This is typically the default behavior of the command.<br><br><b>--no-pretty-print</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs JSON in a compact, unindented format without extra whitespace, effectively disabling the default pretty-printing.<br><br><b>--indent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables indentation of the output. This option is usually active by default when pretty-printing is enabled.<br><br><b>--no-indent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables indentation, leading to output on a single line where possible. If <i>--pretty-print</i> is also active, it will still add newlines but no spaces.<br><br><b>--canonical</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs JSON in a canonical form: with all keys sorted, no whitespace, and numerically stable floating-point numbers. This option implicitly enables <i>--no-pretty-print</i> and <i>--no-indent</i>.<br><br><b>--sort-keys</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts all hash (object) keys alphabetically in the output. This is beneficial for ensuring consistent ordering, useful for diffing or caching JSON data.<br><br><b>--bare-value | --allow_nonref</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allows the top-level JSON entity to be a scalar (e.g., a number, string, boolean, or null) instead of strictly requiring it to be an object or an array.<br><br><b>-v | -V</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of <i>json_pp</i> and then exits.<br><br>


title: DESCRIPTION
content:
<i>json_pp</i> is a command-line utility designed to format JSON (JavaScript Object Notation) data, making it significantly more readable for humans. It processes raw JSON input, typically sourced from standard input or a specified file, and outputs a nicely indented and structured version to standard output.<br><br>This tool proves particularly useful for debugging API responses, inspecting configuration files, or simply organizing large JSON payloads into a more digestible format. It provides various options to control the output format, including indentation levels, alphabetical sorting of keys, and outputting in a canonical (minimal whitespace) form. <i>json_pp</i> is distributed as part of the <b>JSON::PP</b> Perl module, ensuring its wide availability on systems with a Perl installation.


title: CAVEATS
content:
<b>Perl Dependency</b>: <i>json_pp</i> is a Perl script and thus requires a Perl interpreter along with the <b>JSON::PP</b> module to be installed on the system.<br><br><b>Error Handling</b>: If the input JSON is malformed or invalid, <i>json_pp</i> will typically output an error message to standard error and exit. The exact error message format may vary.<br><br><b>Performance with Large Files</b>: For extremely large JSON files, its performance might be somewhat slower compared to similar tools written in compiled languages, though it generally remains efficient enough for most common use cases.<br><br><b>Default Behavior Variation</b>: The precise default pretty-printing behavior, such as the specific indentation level used, can sometimes vary slightly between different versions of the <b>JSON::PP</b> module.


title: USAGE EXAMPLES
content:
Here are some common ways to use <i>json_pp</i>:<br><br><b>Pretty-print from standard input</b>:<br><i>echo '{"name":"Alice","age":30}' | json_pp</i><br><br><b>Pretty-print a file to another file</b>:<br><i>json_pp mydata.json > formatted_data.json</i><br><br><b>Pretty-print an API response with sorted keys</b>:<br><i>curl https://api.example.com/data | json_pp --sort-keys</i><br><br><b>Convert to canonical form</b>:<br><i>cat ugly.json | json_pp --canonical</i>


title: HISTORY
content:
<i>json_pp</i> originated as a command-line utility bundled with the <b>JSON::PP</b> Perl module. <b>JSON::PP</b> (Pure Perl JSON) was developed to provide JSON serialization and deserialization capabilities implemented entirely in Perl, without reliance on external C libraries, thus ensuring high portability. As JSON became a ubiquitous data interchange format in web development and system administration, tools like <i>json_pp</i> became indispensable for developers and system administrators working with JSON data on the command line. Its ongoing development is closely tied to the evolution and maintenance of the <b>JSON::PP</b> module itself, managed within the Perl community on CPAN (Comprehensive Perl Archive Network). It serves as a pure-Perl alternative to the <b>JSON::XS</b> module and its accompanying <i>json_xs</i> utility, which provides similar functionality but leverages C bindings for potentially faster performance.


title: PARAMETERS
content:
<b>--port &lt;port&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the network port for the server to listen on.<br><br><b>--no-browser</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents JupyterLab from automatically opening a web browser.<br><br><b>--ip &lt;ip&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the IP address the server will bind to. Default is <i>127.0.0.1</i> (localhost).<br><br><b>--allow-root</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Permits running the server as the root user. Use with <b>extreme caution</b> due to security risks.<br><br><b>--notebook-dir &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the working directory for JupyterLab.<br><br><b>--collaborative</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables real-time collaboration features in notebooks.<br><br><b>--config &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative path to a Jupyter configuration file.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Activates verbose logging for debugging purposes.<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the command-line help message and exits.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the installed JupyterLab version and exits.<br><br>


title: DESCRIPTION
content:
JupyterLab is the <b>advanced</b>, web-based user interface for Project Jupyter, designed to provide a <i>comprehensive</i> and <i>flexible</i> environment for interactive computing. It integrates the familiar Jupyter Notebook experience with a modern, extensible workspace.<br><br>Users can work with notebooks, code consoles, terminals, file editors, and view outputs like data visualizations – all within a <i>single</i>, unified interface. It supports various kernels (e.g., Python, R, Julia) and allows for customization through extensions, making it a <i>versatile</i> tool for data science, machine learning, scientific computing, and education. JupyterLab aims to be a robust IDE for data exploration and analysis, supporting a wide range of workflows.


title: CAVEATS
content:
The <i>--allow-root</i> flag should be used with <b>extreme caution</b>, as running JupyterLab as root can pose significant security risks by allowing arbitrary code execution with elevated privileges.<br><br>JupyterLab can consume significant system resources (CPU, RAM), especially when running multiple notebooks or complex computations.<br><br>Network configuration is crucial for remote access; ensure proper firewall rules and secure communication (HTTPS) when deploying on a server.


title: EXTENSIBILITY
content:
JupyterLab's architecture is <i>highly extensible</i>, allowing users to install various extensions (e.g., themes, language support, file format viewers, Git integration) to customize functionality and workflow. These are often installed via <b>pip</b> or <b>conda</b> or directly through the JupyterLab extension manager.


title: VIRTUAL ENVIRONMENTS
content:
It's highly recommended to install and run JupyterLab within a Python <i>virtual environment</i> (e.g., <b>venv</b>, <b>conda env</b>) to manage dependencies and avoid conflicts with system-wide Python installations.


title: HISTORY
content:
JupyterLab emerged as the successor to the classic Jupyter Notebook, addressing its limitations and providing a more modern, integrated development environment. Development began around <i>2015-2016</i>, with the goal of creating a flexible, extensible web-based UI. It reached its <b>1.0 release in 2019</b> and continues to be actively developed by the Project Jupyter community, constantly adding new features and improving usability.


title: SYNOPSIS
content:
<b>k8sec</b> <I>command</I> [<I>options</I>] [<I>arguments</I>]<br><br>Common commands include: <br><b>k8sec get</b> <I>type</I> [<I>name</I>] [<I>options</I>] <br><b>k8sec create</b> <I>type</I> <I>name</I> [<I>options</I>] <br><b>k8sec edit</b> <I>type</I> <I>name</I> [<I>options</I>] <br><b>k8sec delete</b> <I>type</I> <I>name</I> [<I>options</I>]


title: PARAMETERS
content:
<b>-n, --namespace <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the Kubernetes namespace for the operation.<br><br><b>--from-literal=<key>=<value></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify data directly from the command line. Can be used multiple times to add multiple key-value pairs.<br><br><b>--from-file=<key>=<path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify data from a file path. Can be used multiple times to add data from different files or under different keys.<br><br><b>--from-env-file=<path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify data from an environment file, where each line represents a KEY=VALUE pair.<br><br><b>-o, --output <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output format for displaying resources. Common options include <I>yaml</I>, <I>json</I>, and <I>wide</I>.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information of the <i>k8sec</i> tool.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the help message for <i>k8sec</i> or a specific subcommand.<br><br>


title: DESCRIPTION
content:
<i>k8sec</i> is a command-line interface (CLI) tool designed to simplify the management of Kubernetes <I>Secrets</I> and <I>ConfigMaps</I>. It provides a consistent and user-friendly experience for interacting with these Kubernetes resources, often wrapping complex <I>kubectl</I> commands and automating tasks like Base64 encoding/decoding. <br><br>The primary goal of <i>k8sec</i> is to enhance the developer and operator experience by streamlining common operations such as creating, viewing, editing, and deleting secrets and configmaps, especially those containing sensitive or binary data. It helps in avoiding direct manipulation of Base64 encoded values, thereby reducing errors and improving workflow efficiency.


title: CAVEATS
content:
<i>k8sec</i> relies on a properly configured <I>kubectl</I> environment to interact with Kubernetes clusters. It handles sensitive data, so users must ensure that appropriate access controls (RBAC) are in place for the user or service account executing the command. While convenient, <i>k8sec</i> may not support all advanced functionalities or edge cases offered by direct <I>kubectl</I> commands for secret or configmap management, focusing primarily on common and simplified workflows.


title: SECURITY CONSIDERATIONS
content:
While <i>k8sec</i> simplifies secret management, users should always adhere to Kubernetes security best practices. This includes limiting access to secrets using Kubernetes <I>RBAC</I>, encrypting secrets at rest where possible, and considering external secret management systems (e.g., HashiCorp Vault, cloud-specific secret managers) for production environments to centralize and secure sensitive data more robustly. Direct manipulation of secrets on the command line should always be done in secure environments.


title: INTEROPERABILITY
content:
<i>k8sec</i> is designed to work seamlessly with any Kubernetes cluster where <I>kubectl</I> is configured and authenticated. Its focus on simplifying common operations makes it a valuable tool for local development, testing, and even scripting within CI/CD pipelines to automate the deployment and management of configuration and sensitive data within Kubernetes.


title: HISTORY
content:
<i>k8sec</i> emerged as an open-source solution to address common pain points faced by developers and operators when managing Kubernetes <I>Secrets</I> and <I>ConfigMaps</I>. Historically, users often had to manually handle Base64 encoding/decoding for secret values, which was error-prone and cumbersome. Its development was driven by the need for a more intuitive and secure command-line interface for these sensitive Kubernetes resources, aiming to provide a convenient wrapper around <I>kubectl</I> that simplifies complex operations and enhances usability for everyday tasks.


title: PARAMETERS
content:
<b><b>-c</b>, <b>--context</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Kubernetes context to use for connecting to the cluster.<br><br><b><b>-n</b>, <b>--namespace</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default Kubernetes namespace to display when <i>k9s</i> starts.<br><br><b><b>-A</b>, <b>--all-namespaces</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays resources from all namespaces instead of just the default or specified one.<br><br><b><b>--config</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides the path to the <i>k9s</i> configuration file, overriding the default location.<br><br><b><b>--log-file</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path where <i>k9s</i> should write its operational logs.<br><br><b><b>--log-level</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the logging verbosity (e.g., <i>trace</i>, <i>debug</i>, <i>info</i>, <i>warn</i>, <i>error</i>, <i>fatal</i>, <i>panic</i>).<br><br><b><b>--kubeconfig</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the path to the <i>kubeconfig</i> file to use for Kubernetes API access.<br><br><b><b>--refresh</b> <i>int</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the screen refresh rate in seconds (default is 2 seconds).<br><br><b><b>--screen</b> <i>string</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the default screen or view to open on startup (e.g., <i>pods</i>, <i>deployments</i>).<br><br>


title: DESCRIPTION
content:
<i>k9s</i> is an open-source, terminal-based user interface (TUI) designed to simplify the interaction with Kubernetes clusters. It provides a curses-like interface that offers a real-time, comprehensive view of your Kubernetes resources, such as <b>pods</b>, <b>deployments</b>, <b>services</b>, <b>nodes</b>, and more. Users can navigate through various cluster components, inspect logs, exec into containers, delete resources, and perform other administrative tasks directly from the terminal without complex <i>kubectl</i> commands. Its intuitive keyboard-driven navigation and real-time data updates make it an invaluable tool for developers and operations teams managing Kubernetes deployments, streamlining daily cluster operations and troubleshooting.


title: CAVEATS
content:
<i>k9s</i> is a third-party utility and not a core Linux command. It requires a correctly configured <i>kubectl</i> environment and access to a Kubernetes cluster. While generally efficient, it might consume notable resources on very large clusters or during extensive data retrieval. It complements, but does not entirely replace, the functionality of the <i>kubectl</i> command-line tool, especially for advanced scripting or automation.


title: INTERACTIVE NAVIGATION
content:
<i>k9s</i> is primarily keyboard-driven, offering a wide array of hotkeys and shortcuts for quick navigation, filtering, sorting, and executing actions on Kubernetes resources. This allows users to efficiently drill down into cluster details without touching the mouse.


title: CUSTOMIZATION AND EXTENSIBILITY
content:
Users can highly customize <i>k9s</i> through configuration files. This includes defining custom aliases for commands, modifying themes, and even creating custom resource views. It also supports plugins for extending its functionality beyond the built-in features.


title: HISTORY
content:
<i>k9s</i> was developed by Fernand Galiana (derailed) and released as an open-source project. It quickly gained significant traction within the Kubernetes community due to its intuitive design, rich features, and ability to greatly simplify the daily operational tasks on Kubernetes clusters. Its continuous development and active community support have cemented its place as a popular tool for Kubernetes cluster management.


title: SYNOPSIS
content:
<b>kafkacat</b> [<i>options</i>]<br><br><b>Producer Mode:</b><br><b>kafkacat</b> <b>-P</b> [<i>producer-options</i>] <b>-t</b> <i>&lt;topic&gt;</i><br><br><b>Consumer Mode:</b><br><b>kafkacat</b> <b>-C</b> [<i>consumer-options</i>] <b>-t</b> <i>&lt;topic&gt;</i><br><br><b>Metadata List Mode:</b><br><b>kafkacat</b> <b>-L</b> [<i>list-options</i>]


title: PARAMETERS
content:
<b><b>-b</b> <i>&lt;broker,...,broker&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Comma-separated list of Kafka broker host:port pairs to connect to (bootstrap servers). Example: <i>localhost:9092,otherhost:9093</i>.<br><br><b><b>-t</b> <i>&lt;topic&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the Kafka topic name for producing or consuming messages.<br><br><b><b>-p</b> <i>&lt;partition&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a specific partition ID. For producers, <i>-1</i> means a random partition; for consumers, <i>-1</i> means all partitions (default).<br><br><b><b>-o</b> <i>&lt;offset&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Consumer start offset. Can be an absolute offset number, <i>beginning</i> (or <i>-2</i>), or <i>end</i> (or <i>-1</i>). Default is <i>end</i>.<br><br><b><b>-C</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable consumer mode. Messages are consumed from the specified topic/partition.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable producer mode. Messages are read from <i>stdin</i> and produced to the specified topic.<br><br><b><b>-L</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable metadata list mode. Lists brokers, topics, and partitions available in the cluster.<br><br><b><b>-X</b> <i>&lt;property=value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a <i>librdkafka</i> configuration property. Can be specified multiple times. Example: <i>-X compression.codec=snappy</i>, <i>-X security.protocol=SASL_SSL</i>. Refer to <i>librdkafka</i> documentation for available properties.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode: Suppress debug and error messages to <i>stderr</i>.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verbose mode: Print verbose errors and debug messages to <i>stderr</i>.<br><br><b><b>-D</b> <i>&lt;debug-contexts&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable librdkafka debugging contexts (e.g., <i>broker,topic,protocol</i>, or <i>all</i>). Useful for troubleshooting.<br><br><b><b>-Z</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output Kafka message headers for consumer mode or add headers for producer mode if specified via input.<br><br><b><b>-d</b> <i>&lt;delimiter&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For consumer mode, set the message delimiter for output (e.g., <i>'\n'</i> for newline). For producer mode, it indicates the delimiter between key and value in input.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In consumer mode, exit after the last message has been consumed from the assigned partitions.<br><br><b><b>-f</b> <i>&lt;format_string&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For consumer mode, format the output message using a <i>printf</i>-like format string. E.g., <i>'%t/%p/%o/%k/%s\n'</i> for topic/partition/offset/key/payload.<br><br><b><b>-J</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;For consumer mode, output messages as JSON, including metadata like topic, partition, offset, timestamp, key, and payload.<br><br><b><b>-K</b> <i>&lt;delimiter&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In producer mode, specifies the delimiter between the key and value in the input line from <i>stdin</i>. In consumer mode with <i>-J</i>, specifies the expected delimiter in the payload to split into key/value if not using a separate key field.<br><br><b><b>-H</b> <i>&lt;header=value&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In producer mode, add a static header to all produced messages. Can be specified multiple times.<br><br><b><b>-k</b> <i>&lt;key&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In producer mode, use the specified key for all messages, overriding any key read from input.<br><br><b><b>-s</b> <i>&lt;string&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In producer mode, send the specified string as a message, instead of reading from <i>stdin</i>.<br><br><b><b>-z</b> <i>&lt;compression_codec&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;In producer mode, specify the compression codec (e.g., <i>none, gzip, snappy, lz4, zstd</i>). Overrides <i>compression.codec</i> property.<br><br>


title: DESCRIPTION
content:
<b>kafkacat</b> is a versatile and lightweight command-line utility for interacting with Apache Kafka clusters, often referred to as 'Kafka's netcat' or 'Kafka's cat'. Built on <i>librdkafka</i> (a C client library), it offers a non-JVM alternative for producing, consuming, and inspecting Kafka topics. It's ideal for scripting, debugging, and performing ad-hoc operations without the overhead of Java-based tools. <b>kafkacat</b> can read messages from <i>stdin</i> and write them to a Kafka topic, or consume messages from a topic and print them to <i>stdout</i>. It also provides robust capabilities for listing cluster metadata, including brokers, topics, and partitions, and supports extensive Kafka client configuration via the <i>-X</i> option.


title: CAVEATS
content:
<b>kafkacat</b> is a highly efficient tool, but it's not a full-fledged Kafka client for all use cases. It does not natively support advanced consumer group rebalancing or exactly-once semantics as a default. It's primarily designed for lightweight, scripting-oriented interactions and debugging rather than as a replacement for robust application-level Kafka clients. High-volume operations can stress network and disk resources.


title: COMMON USAGE PATTERNS
content:
<b><I>Produce a message:</I></b><br><i>echo 'Hello Kafka!' | kafkacat -P -b localhost:9092 -t my_topic</i><br><br><b><I>Consume from beginning of a topic:</I></b><br><i>kafkacat -C -b localhost:9092 -t my_topic -o beginning</i><br><br><b><I>List cluster metadata:</I></b><br><i>kafkacat -L -b localhost:9092</i><br><br><b><I>Produce JSON messages with key and headers:</I></b><br><i>echo '{"key":"id_123", "value":{"data":"test"}}' | kafkacat -P -b localhost:9092 -t json_topic -K ':' -H 'event=test_event' -H 'source=kafkacat'</i>


title: LIBRDKAFKA CONFIGURATION OPTIONS
content:
The <b>-X</b> option is exceptionally powerful, allowing users to configure nearly any aspect of the underlying <i>librdkafka</i> client. This includes security settings (SSL, SASL), client IDs, request timeouts, and more. For a comprehensive list of configurable properties, refer to the official <i>librdkafka</i> documentation or the <i>kafkacat</i> man page. Example: <i>-X 'sasl.mechanisms=PLAIN' -X 'sasl.username=user' -X 'sasl.password=pass'</i>.


title: HISTORY
content:
<b>kafkacat</b> was created by <i>Magnus Edenhill</i>, the lead developer of <i>librdkafka</i> (the C/C++ client for Apache Kafka). It was developed to provide a simple, robust, and fast command-line interface to Kafka without the need for the Java Virtual Machine (JVM). Its first public release was around 2014. It has since become a widely adopted tool in the Kafka ecosystem for quick data manipulation, debugging, and integration into shell scripts.


title: DESCRIPTION
content:
The command '<I>kahlan</I>' is not a recognized or standard command within common Linux distributions or POSIX specifications. It is highly probable that this command either:<br><br>1. Is a custom script or alias created by a user on a specific system.<br>2. Refers to a character from a fantasy novel series (Kahlan Amnell from 'The Sword of Truth') and is not related to Linux commands.<br>3. Is a typo or a misunderstanding of an existing command.<br><br>As a standard Linux utility, '<I>kahlan</I>' does not exist and therefore has no predefined functionality, options, or manual pages.


title: CAVEATS
content:
Since '<I>kahlan</I>' is not a standard Linux command, attempting to execute it on most systems will result in a 'command not found' error. Its behavior, if it exists on a particular system, would be entirely dependent on how it was custom-defined.


title: IF YOU CREATED THIS COMMAND:
content:
If '<I>kahlan</I>' is a custom script or alias on your system, you can check its definition using commands like <I>type kahlan</I> or by inspecting your shell's configuration files (e.g., <I>.bashrc</I>, <I>.zshrc</I>).


title: HISTORY
content:
There is no documented history of a standard Linux command named '<I>kahlan</I>'. Its name is more commonly associated with fiction than with operating system utilities.


title: SYNOPSIS
content:
<i>kdeconnect-cli</i> [<i>options</i>] [<i>command</i>] [<i>arguments</i>]<br>Example usage:<br><i>kdeconnect-cli --list-devices</i><br><i>kdeconnect-cli --device &lt;device_id&gt; --ping</i><br><i>kdeconnect-cli --device &lt;device_id&gt; --send-sms 1234567890 "Hello there!"</i><br><i>kdeconnect-cli --device &lt;device_id&gt; --send-file /path/to/document.pdf</i>


title: PARAMETERS
content:
<b><b>--list-devices</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all paired KDE Connect devices with their unique IDs and names.<br><br><b><b>--device &lt;id&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the target device using its unique ID for subsequent commands. This option is mandatory for most device-specific operations.<br><br><b><b>--ping</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends a ping request to the specified device to check connectivity.<br><br><b><b>--battery</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the battery status (level and charging state) of the specified device.<br><br><b><b>--send-sms &lt;number&gt; &lt;message&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sends an SMS message from the specified device to the given phone number.<br><br><b><b>--send-file &lt;file&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Transfers a local file to the specified device.<br><br><b><b>--open-url &lt;url&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens a URL in the default browser on the specified device.<br><br><b><b>--share-text &lt;text&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shares text content from the desktop to the specified device.<br><br><b><b>--find-my-phone</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Makes the specified device ring to help locate it.<br><br><b><b>--run-command &lt;command&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes a predefined command on the specified device. Requires the command to be enabled in device settings.<br><br><b><b>--list-commands</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available predefined commands that can be executed via <b>--run-command</b> on the specified device.<br><br><b><b>--media-pause</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Pauses media playback on the specified device.<br><br><b><b>--media-play</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Plays or resumes media playback on the specified device.<br><br><b><b>--media-next</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips to the next media track on the specified device.<br><br><b><b>--media-previous</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Skips to the previous media track on the specified device.<br><br><b><b>--mute-volume</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Mutes the volume on the specified device.<br><br><b><b>--unmute-volume</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unmutes the volume on the specified device.<br><br><b><b>--set-volume &lt;level&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the volume level (0-100) on the specified device.<br><br><b><b>--clipboard-get</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Retrieves the current clipboard content from the specified device.<br><br><b><b>--clipboard-set &lt;text&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the clipboard content on the specified device to the given text.<br><br><b><b>--pair</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initiates the pairing process with a new device.<br><br><b><b>--unpair</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Unpairs the specified device.<br><br><b><b>--plugin-setting &lt;plugin&gt; &lt;key&gt; &lt;value&gt;</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets a specific setting for a KDE Connect plugin on the device.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the version information and exits.<br><br>


title: DESCRIPTION
content:
The <b>kdeconnect-cli</b> command provides a powerful command-line interface for interacting with devices paired via KDE Connect. KDE Connect is a versatile project that enables seamless communication and integration between your desktop, phone, and other devices. While a graphical application (kdeconnect-app) offers an intuitive user experience, <b>kdeconnect-cli</b> extends this functionality to the terminal, making it ideal for scripting, automation, and headless environments.<br><br>With <b>kdeconnect-cli</b>, users can perform a variety of actions remotely, such as sending SMS messages, transferring files, checking device battery levels, controlling media playback, locating a lost phone, and even executing custom commands on the paired device. It leverages the underlying KDE Connect daemon (kdeconnectd) and D-Bus system to facilitate robust cross-device communication, offering a programmatic way to manage your connected ecosystem without needing a graphical session.


title: CAVEATS
content:
For <b>kdeconnect-cli</b> to function, the KDE Connect application must be installed and running on both your desktop system and the target mobile device. <br><br>Devices must be properly paired through the KDE Connect application, and strong network connectivity (Wi-Fi or LAN) is essential for reliable communication. Some commands, such as sending SMS or running remote commands, may require specific permissions to be granted within the KDE Connect mobile app settings. Device IDs obtained via <b>--list-devices</b> are unique and persistent for a given pairing, but will change if a device is unpaired and re-paired.


title: OBTAINING DEVICE IDS
content:
Many <b>kdeconnect-cli</b> commands require a device ID to specify which paired device the action should be performed on. You can obtain a list of all currently paired devices, along with their unique IDs, by running: <br><b><I>kdeconnect-cli --list-devices</I></b><br>This command will output a list like:<br><b><I>- my_phone_name: abcd1234efgh5678</I></b><br>where <i>abcd1234efgh5678</i> is the device ID you'll use with the <b>--device</b> option.


title: SCRIPTING AND AUTOMATION
content:
<b>kdeconnect-cli</b> is invaluable for scripting. For instance, you could create a script to automatically send an SMS when a certain system event occurs, or to control media playback on your phone from a custom hotkey on your keyboard, without needing to open the full KDE Connect application. This flexibility makes it a powerful tool for power users and system administrators.


title: HISTORY
content:
KDE Connect emerged as a project to seamlessly integrate Android devices with the KDE Plasma desktop, aiming to bridge the gap between mobile and desktop computing. Its development has been driven by the KDE community, continuously adding features like notification sync, file sharing, remote input, and more. The <b>kdeconnect-cli</b> utility was developed to complement the graphical application, providing a non-GUI interface for these features. This allows users to integrate KDE Connect functionalities into shell scripts, custom keyboard shortcuts, or other automation workflows, expanding its utility beyond interactive desktop usage.


title: SYNOPSIS
content:
<br><b>keybase</b> [<i>global-options</i>] &lt;<i>command</i>&gt; [<i>command-options</i>] [<i>arguments</i>]<br><br>Examples of common usage:<br><i><b>keybase login</b></i><br><i><b>keybase chat send teamname "Hello, world!"</b></i><br><i><b>keybase fs ls /keybase/private/yourusername</b></i><br><i><b>keybase pgp encrypt -i file.txt -o file.txt.pgp username</b></i><br><i><b>keybase git create myrepo</b></i>


title: PARAMETERS
content:
<b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose debugging output for diagnostics and troubleshooting.<br><br><b>--json</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs command results in machine-readable JSON format, useful for scripting and integration.<br><br><b>--force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces an operation that might otherwise require confirmation or be prevented. Use with caution.<br><br><b>--home <<i>path</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the Keybase home directory, overriding the default system location.<br><br><b>--log-file <<i>path</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Directs Keybase's log output to the specified file instead of standard error.<br><br><b>-U, --username <<i>name</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the username to use for commands that require a specific identity.<br><br><b>-P, --paperkey <<i>key</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides a paper key directly for login or device provisioning without interactive prompts.<br><br>


title: DESCRIPTION
content:
Keybase is a cross-platform application that leverages public-key cryptography to provide secure communication, file storage, and identity verification. It allows users to cryptographically prove their online identities (e.g., Twitter, GitHub) by signing them with their Keybase cryptographic key. The <b>keybase</b> command-line interface provides access to a comprehensive suite of features, including end-to-end encrypted chat, a secure Git repository hosting service (Keybase Git), and a distributed, encrypted file system (KBFS). It acts as a powerful tool for developers and security-conscious individuals to manage cryptographic keys, sign and verify data, and interact securely within the Keybase ecosystem. The command-line utility interacts with a background service/daemon that handles the cryptographic operations and network communication.


title: CAVEATS
content:
Keybase's functionality heavily relies on its background service (daemon), which must be running for most commands to work. While Keybase aims for strong security, the security of your account ultimately depends on the security of your devices and master key. Some features, like the 'public folders' on KBFS, are publicly readable, so care must be taken with sensitive data. The Keybase service was acquired by Zoom in 2020, which has led to some community discussion regarding its future and independence.


title: KEY CONCEPTS
content:
<br>Keybase utilizes <I>public-key cryptography</I> to establish a chain of trust, linking users' social media identities to their cryptographic keys. It supports <I>identity proofs</I> (e.g., verifying Twitter or GitHub accounts) and <I>device management</I>, allowing users to securely add and revoke devices. The platform offers end-to-end encryption for all communications and file storage.


title: CLIENT-SERVER ARCHITECTURE
content:
<br>The <b>keybase</b> command-line utility acts as a client that communicates with a persistent background service, or <I>daemon</I>. This daemon handles the complex cryptographic operations, network interactions, and file system mounting (for KBFS). Users typically interact with the <b>keybase</b> command, which then relays requests to the running service.


title: HISTORY
content:
Keybase was publicly launched in 2014-2015, initially focusing on providing an easy-to-use interface for PGP and cryptographically proving online identities. Over time, it expanded significantly to include a secure chat client, an encrypted file system (KBFS), and a Git hosting service. The development focused on integrating cryptographic primitives into everyday tools for mass adoption. In May 2020, Keybase was acquired by Zoom, which continues to maintain and develop the service, though some features like Keybase Teams for businesses were discontinued post-acquisition.


title: SYNOPSIS
content:
<i>kotlinc</i> [<i>options</i>] <<i>source files or directories</i>><br><i>kotlinc</i> -script <<i>script file</i>> [<i>arguments</i>]


title: PARAMETERS
content:
<b>-d <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the destination for compiled classes or the name of the output JAR file.<br><br><b>-classpath <path>, -cp <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the search path for application classes and resources, typically used for external libraries.<br><br><b>-include-runtime</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Bundles the Kotlin runtime library into the resulting JAR file, making it self-contained and runnable.<br><br><b>-jvm-target <version></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the target JVM bytecode version (e.g., <i>1.8</i>, <i>11</i>, <i>17</i>) for compatibility.<br><br><b>-version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Kotlin compiler version and exits.<br><br><b>-help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a summary of common command-line options.<br><br><b>-script</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs the compiler to interpret the input as a Kotlin script (<i>.kts</i>) and execute it.<br><br><b>-nowarn</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses all compiler warnings.<br><br><b>-verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing detailed compilation process information.<br><br><b>-module-name <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the module being compiled, used for module-info.class and JAR manifests.<br><br>


title: DESCRIPTION
content:
<i>kotlinc</i> is the command-line compiler for the <b>Kotlin</b> programming language, developed by JetBrains. It processes Kotlin source files (<i>.kt</i> and <i>.kts</i>) and translates them into various target formats.<br><br>Its primary use is compiling to <b>JVM bytecode</b> (<i>.class</i> files or executable JARs), enabling Kotlin applications to run on the Java Virtual Machine. Additionally, it supports compilation to <b>JavaScript</b> for web environments and <b>native binaries</b> via Kotlin/Native for platform-specific applications. The compiler performs essential tasks like type checking, error detection, and bytecode generation. It's a fundamental tool for developers building Kotlin projects outside of IDEs or higher-level build tools like Gradle or Maven, offering direct control over the compilation process and output.


title: CAVEATS
content:
For large or complex projects, <i>kotlinc</i> is typically invoked indirectly via build tools like <b>Gradle</b> or <b>Maven</b>, which manage dependencies, incremental compilation, and project structure more effectively. Direct <i>kotlinc</i> usage can be cumbersome for multi-module projects, and compilation can be memory-intensive for very large codebases.


title: CROSS-PLATFORM TARGETS
content:
Beyond the JVM, <i>kotlinc</i> can also compile Kotlin code to <b>JavaScript</b> (for web development) and <b>native binaries</b> (using Kotlin/Native for platforms like iOS, macOS, Windows, and Linux), showcasing its versatility as a multi-platform language compiler.


title: INTEGRATION WITH BUILD TOOLS
content:
While <i>kotlinc</i> can be used directly, it's most commonly integrated into build systems like <b>Gradle</b> or <b>Maven</b>. These tools provide comprehensive dependency management, incremental compilation, test execution, and deployment capabilities, streamlining the development workflow for Kotlin projects, making direct <i>kotlinc</i> calls less frequent in day-to-day development.


title: HISTORY
content:
<b>Kotlin</b> was developed by JetBrains and first publicly released in 2011. The <i>kotlinc</i> compiler has been the core component since its inception, continuously evolving with the language. It gained significant popularity after Google announced it as a first-class language for Android development in 2017, leading to wider adoption and continuous improvements in the compiler's performance and features.


title: DESCRIPTION
content:
The command 'kr' is not a recognized standard Linux command or utility found in typical Linux distributions. <br>It is highly probable that 'kr' is: <br>1. A typo for another common command (e.g., 'mkdir', 'grep', 'kill'). <br>2. A custom alias or function defined in your shell's configuration files (e.g., .bashrc, .zshrc). <br>3. A user-defined script located in your system's PATH. <br>4. A command specific to a particular, non-standard software package or application that you have installed. <br>Unlike well-known utilities like 'ls' or 'grep', 'kr' does not have a universally defined purpose, syntax, or set of options. Its functionality would be entirely dependent on how it is implemented on a specific system.


title: CAVEATS
content:
As 'kr' is not a standard Linux command, its behavior is unpredictable without knowing its source. <br>Using an unknown 'kr' command could lead to unexpected actions, file modifications, or system issues if it's a malicious script or an incorrectly configured alias. <br>Always verify the origin and purpose of non-standard commands before execution.


title: IDENTIFYING AN UNKNOWN 'KR' COMMAND
content:
If you encounter 'kr' on your system, you can use the following commands to investigate its nature: <br><b><I>type kr</I></b>: This command will tell you if 'kr' is an alias, a function, a built-in command, or an executable. <br><b><I>which kr</I></b>: If 'type kr' indicates it's an executable, 'which kr' will show its full path. You can then inspect the file (e.g., using 'cat' or 'less'). <br><b><I>alias | grep kr</I></b>: Checks if 'kr' is an alias. <br><b><I>declare -f kr</I></b>: Checks if 'kr' is a shell function. <br><b><I>man kr</I></b>: While unlikely for a non-standard command, it's worth checking if a manual page exists.


title: HISTORY
content:
N/A - There is no documented history for a standard Linux command named 'kr'. <br>Any usage or development history would be specific to individual systems where 'kr' has been defined as a custom command or alias.


title: SYNOPSIS
content:
<b>kube-capacity</b> [<i>options</i>]<br><b>kube-capacity</b> --output <i>format</i><br><b>kube-capacity</b> --sort <i>field</i>


title: PARAMETERS
content:
<b>--output <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format. Supported values: <b>table</b> (default), <b>json</b>, <b>yaml</b>.<br><br><b>--sort <field></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sorts the output by a specific field. Examples include <b>cpu.request</b>, <b>memory.limit</b>, or <b>cpu.utilization</b>.<br><br><b>--utilization</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If present, calculates and displays resource utilization percentage (requests vs. current usage). Requires <i>metrics-server</i> in the cluster.<br><br><b>--pods</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes individual pod resource requests/limits and usage in the output.<br><br><b>--containers</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes individual container resource requests/limits and usage in the output. This option implies <b>--pods</b>.<br><br><b>--namespaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Aggregates and groups the output by Kubernetes namespace.<br><br><b>--nodes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Aggregates and groups the output by Kubernetes node.<br><br><b>--all-namespaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Includes resources from all namespaces in the cluster.<br><br><b>--namespace <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters the output to include resources only from the specified namespace(s). Can be used multiple times.<br><br><b>--exclude-system-namespaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Excludes the <b>kube-system</b> and <b>kube-public</b> namespaces from the output.<br><br><b>--kubeconfig <path></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to the kubeconfig file to use for connecting to the Kubernetes API.<br><br><b>--context <name></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the kubeconfig context to use for the Kubernetes API connection.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output for more detailed information.<br><br>


title: DESCRIPTION
content:
<i>kube-capacity</i> is a command-line interface (CLI) tool designed to provide a clear and concise overview of resource requests, limits, and current usage within a Kubernetes cluster. It helps administrators and developers understand how effectively resources (CPU and memory) are allocated across nodes, namespaces, and pods.<br><br>By aggregating data from the Kubernetes API, <i>kube-capacity</i> enables users to quickly identify potential resource overcommitments, underutilization, or bottlenecks, aiding in capacity planning and troubleshooting. It presents a tabular view of resource consumption, making it easier to visualize the cluster's overall health and resource distribution. This tool is invaluable for ensuring optimal resource management and preventing performance issues in production Kubernetes environments.


title: CAVEATS
content:
<i>kube-capacity</i> requires <i>kubectl</i> to be properly configured and connected to a Kubernetes cluster.<br>Resource utilization data (shown with <b>--utilization</b>) depends on the presence and proper functioning of <i>metrics-server</i> in your cluster; if not available, utilization values may appear as 0 or N/A.<br>The tool provides a snapshot of current resource states and does not offer historical data or trend analysis.<br>Frequent execution on very large clusters might incur significant Kubernetes API calls, potentially hitting API rate limits.


title: INSTALLATION
content:
As <i>kube-capacity</i> is an external utility, it needs to be installed separately. Common installation methods include:<br><b>Homebrew (macOS/Linux):</b> Use `brew install robscott/tap/kube-capacity`.<br><b>Krew (kubectl plugin manager):</b> Use `kubectl krew install capacity`.<br><b>Direct Download:</b> Download the pre-compiled binary from its GitHub releases page and add it to your system's PATH.


title: TYPICAL USE CASES
content:
<i>kube-capacity</i> is highly useful for:<br><b>Capacity Planning:</b> Understanding current resource usage to plan for future cluster growth.<br><b>Troubleshooting:</b> Identifying pods or nodes that are requesting excessive resources or are underutilized.<br><b>Cost Optimization:</b> Pinpointing opportunities to right-size resource requests and limits to reduce cloud infrastructure costs.<br><b>Resource Governance:</b> Ensuring teams are adhering to resource allocation policies across namespaces.


title: HISTORY
content:
<i>kube-capacity</i> is an open-source, community-driven utility, not a native Kubernetes command. It was developed to address the need for a comprehensive, cluster-wide view of resource allocation and usage, which was not readily available through standard <i>kubectl</i> commands. Its development is maintained by a community of contributors, continually adding features and improving its analytical capabilities.


title: SYNOPSIS
content:
<b>kubectl scale</b> <b>--replicas</b>=<I>&lt;COUNT&gt;</I> (<b>TYPE NAME</b> | <b>TYPE/NAME</b> | <b>-f</b> <I>&lt;FILENAME&gt;</I> | <b>--selector</b>=<I>&lt;LABELS&gt;</I> <b>TYPE</b>) [<I>options</I>]<br><br>Example: <b>kubectl scale --replicas=3 deployment/my-app</b>


title: PARAMETERS
content:
<b>--replicas=COUNT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The number of desired replicas for the resource. This is a mandatory option for scaling.<br><br><b>--current-replicas=COUNT</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A pre-condition for optimistic locking. The scale operation will only proceed if the resource's current replica count matches this value.<br><br><b>--resource-version=VERSION</b><br>&nbsp;&nbsp;&nbsp;&nbsp;A pre-condition for optimistic locking. The scale operation will only proceed if the resource's resource version matches this value.<br><br><b>-f, --filename=FILE</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Path to a file, directory, or URL that contains the resource configuration to scale.<br><br><b>-l, --selector=LABELS</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selector (label query) to filter resources. Used to scale multiple resources of the same type that match the specified labels.<br><br><b>--timeout=DURATION</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The maximum time to wait for the scale operation to be applied (e.g., '5s', '2m').<br><br><b>--dry-run=<client|server|none></b><br>&nbsp;&nbsp;&nbsp;&nbsp;If set, only print the object that would be sent to the server, without actually performing the scale operation.<br><br>


title: DESCRIPTION
content:
The <b>kubectl scale</b> command is used to imperatively change the desired number of replicas for scalable Kubernetes resources such as <i>Deployments</i>, <i>ReplicaSets</i>, <i>StatefulSets</i>, and <i>ReplicationControllers</i>. This operation directly updates the <I>spec.replicas</I> field of the specified resource via the Kubernetes API server.<br><br>It is a fundamental tool for performing horizontal scaling, allowing administrators and developers to quickly scale applications in or out to adapt to varying load demands, manage resource consumption, or perform maintenance tasks. While manual scaling with <b>kubectl scale</b> is effective for immediate adjustments, for dynamic and automatic scaling, <i>Horizontal Pod Autoscalers (HPAs)</i> are typically preferred.


title: CAVEATS
content:
<b>RBAC Permissions:</b> Requires appropriate <I>Role-Based Access Control (RBAC)</I> permissions to modify the specified resource's replica count.<br><b>Scalable Resources Only:</b> Only applicable to Kubernetes resources that support scaling, primarily <I>Deployments</I>, <I>ReplicaSets</I>, <I>StatefulSets</I>, and <I>ReplicationControllers</I>.<br><b>HPA Interaction:</b> If a <I>Horizontal Pod Autoscaler (HPA)</I> is managing the target resource, manual scaling via <b>kubectl scale</b> might be immediately overridden by the HPA's logic as it strives to maintain its desired metrics.<br><b>Optimistic Locking:</b> Using <b>--current-replicas</b> and <b>--resource-version</b> helps prevent race conditions when multiple users or processes might try to scale the same resource simultaneously.<br><b>Imperative Nature:</b> This command performs an immediate, imperative change. For declarative management, it's often better to update the resource's YAML definition or use HPAs.


title: OPTIMISTIC LOCKING EXPLAINED
content:
The <b>--current-replicas</b> and <b>--resource-version</b> flags are used for optimistic locking. This mechanism ensures that the scale operation only proceeds if the resource is in the expected state before the update. If the resource's replica count or version has changed since it was last read, the command will fail, preventing unintended concurrent modifications and data inconsistencies. This is crucial in environments where multiple automated systems or users might be attempting to modify the same resource.


title: SCALABLE RESOURCE TYPES
content:
Common Kubernetes resource types that can be scaled using <b>kubectl scale</b> include:<br><I>Deployments</I>: Manages a replicated application, handling updates and rollbacks.<br><I>ReplicaSets</I>: Ensures a specified number of pod replicas are running at any given time. Deployments internally manage ReplicaSets.<br><I>StatefulSets</I>: Used for stateful applications, ensuring stable, unique network identifiers and persistent storage.<br><I>ReplicationControllers</I> (Legacy): Similar to ReplicaSets but is an older, deprecated API object.


title: HISTORY
content:
The <b>scale</b> command has been an integral part of <b>kubectl</b> since the early days of Kubernetes, providing a straightforward and essential mechanism for managing application scalability. Its core functionality has remained consistent, adapting to new scalable resource types as Kubernetes has evolved. It exemplifies <b>kubectl</b>'s role as a powerful, imperative control plane interface for Kubernetes clusters.


title: SEE ALSO
content:
<I>kubectl autoscale(1)</I>, <I>kubectl get(1)</I>, <I>kubectl apply(1)</I>, <I>kubectl edit(1)</I>, <I>kubectl describe(1)</I>


title: SYNOPSIS
content:
<b>kubectl wait</b> (<i>TYPE NAME</i> | <i>TYPE/NAME</i> | <i>TYPE --all</i> | <i>TYPE -l key=value</i> | <i>-f FILENAME</i>) <b>--for=</b>{<i>delete</i>|<i>condition=NAME[=VALUE]</i>|<i>jsonpath='EXPR'</i>} [<b>--timeout=</b><i>DURATION</i>] [<i>options</i>]


title: PARAMETERS
content:
<b><i>TYPE NAME</i> | <i>TYPE/NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the kind of resource and its name (e.g., <i>pod my-pod</i> or <i>deployment/nginx-deployment</i>) to wait on.<br><br><b><i>TYPE --all</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits for all resources of the specified <i>TYPE</i> within the current namespace.<br><br><b><i>TYPE -l key=value</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits for resources of the specified <i>TYPE</i> that match the given label selector (e.g., <i>pod -l app=nginx</i>).<br><br><b>--for=delete</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits for the specified resource(s) to be completely deleted from the cluster.<br><br><b>--for=condition=&lt;condition-name&gt;[=&lt;condition-value&gt;]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits for a specific <i>&lt;condition-name&gt;</i> on the resource(s) to become true. Optionally, a <i>&lt;condition-value&gt;</i> (e.g., <i>True</i>, <i>False</i>, <i>Unknown</i>) can be specified; defaults to <i>True</i>.<br><br><b>--for=jsonpath='&lt;jsonpath-expression&gt;'</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits until the provided JSON path expression evaluates to a non-empty, non-false value within the resource's status.<br><br><b>--timeout=duration</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The maximum time to wait for the condition to be met (e.g., <i>5m</i> for 5 minutes, <i>30s</i> for 30 seconds). A value of <i>0</i> indicates no timeout.<br><br><b>-f, --filename strings</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies one or more filenames, directories, or URLs containing resource definitions to wait for.<br><br><b>-A, --all-namespaces</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If present, waits for resources across all namespaces. Only applicable when using selectors or when waiting for all resources of a type.<br><br><b>-n, --namespace string</b><br>&nbsp;&nbsp;&nbsp;&nbsp;If present, the namespace scope for this CLI request. Overrides the default namespace.<br><br><b>-l, --selector string</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Selector (label query) to filter on. Supports '=', '==', and '!='.<br><br>


title: DESCRIPTION
content:
<i>kubectl wait</i> is a powerful command-line utility for Kubernetes that allows users to block execution until one or more specified resources reach a desired state or condition. It's an essential tool for scripting, automation, and CI/CD pipelines, ensuring that subsequent operations only proceed once a resource is fully ready, available, or deleted. Instead of manual polling or complex scripting logic, <i>kubectl wait</i> provides a native and reliable mechanism to monitor resource conditions like <i>Ready</i>, <i>Complete</i>, <i>Available</i>, or <i>Deleted</i>. The command continuously polls the Kubernetes API server until the specified condition evaluates to true or a defined timeout duration is reached. It supports waiting for various resource types, identified by name, label selectors, or even from manifest files. This capability simplifies the orchestration of complex deployments, ensuring dependencies are met before progressing to the next step in a workflow.


title: CAVEATS
content:
<i>kubectl wait</i> polls the API server periodically. Frequent use on many resources or with very short polling intervals (which are not directly configurable) can put a light load on the API server.<br>It provides a timeout mechanism but doesn't inherently offer detailed debugging information about <b>why</b> a condition wasn't met, beyond simply timing out.<br>For complex, inter-resource dependencies, it might be necessary to chain multiple <i>kubectl wait</i> commands or use more advanced orchestration tools.


title: POLLING INTERVAL
content:
The exact polling interval for <i>kubectl wait</i> is not directly configurable by the user and is typically hardcoded within <i>kubectl</i> (often a few seconds, e.g., 1 second). This means users cannot fine-tune the frequency of API server queries.


title: SUPPORTED RESOURCE TYPES
content:
<i>kubectl wait</i> can be used with virtually any Kubernetes resource type, including built-in resources like <i>Pods</i>, <i>Deployments</i>, <i>Services</i>, and also <i>Custom Resources (CRs)</i>, as long as they expose conditions or can be tracked for deletion.


title: HISTORY
content:
<i>kubectl wait</i> was introduced in Kubernetes to provide a more robust and declarative way for scripts and automation to synchronize with the state of Kubernetes resources. Prior to its inclusion, users often relied on less reliable methods like `kubectl get -w` (watch mode) combined with `grep` or custom polling loops in shell scripts. Its development aimed to streamline CI/CD pipelines and operator patterns by offering a native, idempotent, and timeout-aware mechanism for waiting on resource conditions, thereby improving the reliability and readability of Kubernetes automation scripts.


title: SYNOPSIS
content:
<b>lame</b> [<i>options</i>] <i>input_file</i> [<i>output_file</i>]<br><i><br>Example:</i> <b>lame</b> <i>audio.wav audio.mp3</i><br><i>Example:</i> <b>lame</b> <i>--preset standard input.flac output.mp3</i><br><i>Example:</i> <b>cat</b> <i>input.pcm |</i> <b>lame</b> <i>-r -s 44.1 - output.mp3</i>


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief usage message and exit.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the LAME version number and exit.<br><br><b>-r, --raw-input</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Input is raw PCM (WAV header not present).<br><br><b>--raw-input-smpfreq <Hz></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify raw input sample frequency (e.g., 44.1 for 44100 Hz).<br><br><b>--mp3input</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Input file is an MP3 file. LAME will decode it and then re-encode it.<br><br><b>-b <bitrate></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify Constant Bitrate (CBR) in kbps (e.g., -b 128).<br><br><b>-V <quality></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify Variable Bitrate (VBR) quality (0=highest, 9=lowest).<br><br><b>-q <quality></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify algorithm quality (0=best, 9=fastest). Usually set by presets.<br><br><b>--preset <type></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use predefined quality presets (e.g., --preset standard, --preset extreme).<br><br><b>-m <mode></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set stereo mode (s=stereo, j=joint stereo, m=mono, a=auto).<br><br><b>--silent</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Don't print any processing info, only warnings or errors.<br><br><b>-x</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Swap bytes in the input file (for big-endian machines).<br><br><b>--lowpass <freq></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a lowpass filter at freq Hz.<br><br><b>--highpass <freq></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Apply a highpass filter at freq Hz.<br><br>


title: DESCRIPTION
content:
<i>LAME</i> (Lame Ain't an MP3 Encoder) is a widely used, open-source software encoder for converting audio into the <i>MP3</i> format (MPEG-1 Audio Layer III). <br>It began as a research project to improve the psychoacoustic model and quality of other existing MP3 encoders. Over time, it evolved into a powerful, standalone command-line tool, renowned for its superior audio quality, especially at lower bitrates, and its rich set of encoding options. <br>LAME implements various encoding modes, including Constant Bitrate (CBR), Average Bitrate (ABR), and Variable Bitrate (VBR), allowing users to balance file size and audio fidelity. <br>It's frequently used by audiophiles, developers, and integrated into many multimedia applications and frameworks like <i>FFmpeg</i> and <i>Audacity</i>, making it a cornerstone in digital audio processing.


title: CAVEATS
content:
While LAME is widely used and highly regarded, users should be aware of past <i>MP3</i> patent issues. Although most relevant patents have expired, some countries may still have specific intellectual property laws that could affect commercial use. Always verify the legal status in your jurisdiction. <br>Additionally, LAME's extensive array of options can be overwhelming for new users; using the recommended <i>--preset</i> options is often the best starting point for quality encoding without deep dives into technical specifics.


title: MP3 PRESETS
content:
<i>LAME</i> offers convenient <i>--preset</i> options that automatically configure multiple encoding parameters for optimal quality-to-filesize ratios. <br>Common presets include: <br><b>--preset standard</b>: Very good quality, suitable for most uses. <br><b>--preset extreme</b>: Higher quality, larger file sizes. <br><b>--preset insane</b>: Maximum quality (CBR 320kbps), largest files. <br><b>--preset fast</b>: Faster encoding, slightly lower quality than standard. <br>These presets simplify the encoding process, allowing users to achieve excellent results without needing to understand every technical option.


title: LICENSE
content:
<i>LAME</i> is distributed under the <i>GNU Lesser General Public License (LGPL)</i>, which allows it to be linked with proprietary applications provided certain conditions are met. This open-source licensing has contributed significantly to its widespread adoption and integration into various commercial and non-commercial software products.


title: HISTORY
content:
The <i>LAME</i> project was started by <i>Mike Cheng</i> in 1998 as a set of improvements (patches) to an existing <i>MP3</i> encoder called <i>8hz-mp3</i>. The goal was to enhance its psychoacoustic model, which is crucial for achieving high audio quality at lower bitrates by intelligently discarding inaudible information. <br>As the project grew and became more sophisticated, it evolved into a standalone encoder. The development focus shifted towards continuous quality improvements, especially for variable bitrate (VBR) encoding, and implementing a more accurate psychoacoustic model. <br>LAME quickly surpassed other available <i>MP3</i> encoders in terms of sound quality and became the de facto standard for <i>MP3</i> encoding due to its open-source nature, continuous development, and commitment to delivering the best possible audio fidelity.


title: SYNOPSIS
content:
<b>laravel</b> <i>new</i> <<i>project-name</i>> [<i>--git</i>] [<i>--branch</i>] [<i>--dev</i>] [<i>--force</i>] [<i>--jet</i>]


title: PARAMETERS
content:
<b><i>new</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The primary subcommand to create a new Laravel application.<br><br><b><<i>project-name</i>></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The name of the directory where the new Laravel application will be created. This is a required argument.<br><br><b><i>--git</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Initialize a Git repository after creating the project.<br><br><b><i>--branch=<branch-name></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a particular branch of the Laravel framework to install.<br><br><b><i>--dev</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install the development version of the Laravel framework.<br><br><b><i>--force</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force the creation of the project even if the directory already exists. <br> <b>Use with caution!</b><br><br><b><i>--jet</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Install Laravel Jetstream with a specific stack (e.g., Livewire, Inertia). <br> Requires an additional argument for the stack and optionally <i>--teams</i>.<br><br>


title: DESCRIPTION
content:
The <b>laravel</b> command on Linux primarily refers to the global Laravel installer, a command-line tool used to quickly scaffold new Laravel projects. It streamlines the initial setup process, downloading the necessary framework files and dependencies. Once a Laravel project is created using this installer, the main command-line utility for interacting with the framework shifts to <i>Artisan</i>, which is invoked via <code>php artisan</code> from within the project directory. Artisan provides a rich set of commands for various development tasks, including database migrations, code generation, testing, and server management. The <b>laravel</b> command itself is a convenient wrapper for getting a new project up and running without manually running Composer create-project commands.


title: CAVEATS
content:
The <b>laravel</b> command requires PHP and Composer to be installed and configured on your system. It's typically installed globally via Composer (<code>composer global require laravel/installer</code>). <br> This command is primarily for *creating* new projects; for daily development tasks within a Laravel project, the <code>php artisan</code> command is used.


title: ARTISAN COMMAND-LINE INTERFACE
content:
Once a Laravel project is created using the <b>laravel new</b> command, most command-line interactions happen through Artisan, Laravel's built-in CLI tool. Artisan is invoked using <code>php artisan</code> from within the project's root directory. It offers hundreds of commands for tasks like running migrations (<code>php artisan migrate</code>), creating controllers/models (<code>php artisan make:controller</code>), serving the application locally (<code>php artisan serve</code>), and managing queues (<code>php artisan queue:work</code>).


title: INSTALLATION
content:
The <b>laravel</b> command is not part of a standard Linux distribution. To use it, you must first install PHP and Composer, then execute: <br> <code>composer global require laravel/installer</code> <br> Ensure your Composer global binaries directory is in your system's PATH environment variable.


title: HISTORY
content:
Laravel, created by Taylor Otwell, first released in 2011, quickly gained popularity for its elegant syntax and developer-friendly features. The global <b>laravel</b> installer was introduced to simplify the process of setting up new projects, abstracting away the underlying Composer commands. This made onboarding new developers and quickly spinning up new applications much easier, contributing to Laravel's widespread adoption as one of the leading PHP frameworks.


title: SYNOPSIS
content:
<b>latexdiff</b> [<i>OPTIONS</i>] <i>&lt;old.tex&gt; &lt;new.tex&gt;</i> [<i>&gt; &lt;diff.tex&gt;</i>]<br><br>Compares <i>&lt;old.tex&gt;</i> with <i>&lt;new.tex&gt;</i> and outputs the marked-up differences to standard output or a specified file.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>--style=&lt;style&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the markup style. Common styles include <i>CFONT</i> (color and font changes, default), <i>CTRADITIONAL</i> (strikethrough and underline), and <i>CSCRIPT</i> (uses margin notes).<br><br><b>--type=&lt;type&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the document type, e.g., <i>ARTICLE</i>, <i>REPORT</i>, <i>BOOK</i>. This affects how certain commands or environments are handled.<br><br><b>--flatten</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Recursively includes and expands all included LaTeX files (e.g., via <i>\input</i> or <i>\include</i>) from the original documents before diffing.<br><br><b>--config=&lt;key&gt;=&lt;value&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides a configuration variable. For example, <i>--config="COLOR{added}=blue"</i> changes the color for added text.<br><br><b>--ignore-comments</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Instructs <i>latexdiff</i> to ignore any changes that occur solely within LaTeX comments.<br><br><b>--ignore-changes=&lt;category&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignores certain categories of changes, such as <i>Preamble</i>, <i>Whitespace</i>, <i>Comments</i>, <i>Floats</i>. Can be specified multiple times.<br><br><b>--exclude-text-markup=&lt;regexp&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prevents text markup for content matching a regular expression (e.g., for specific environments or commands like <i>\label</i>).<br><br><b>--math-markup=&lt;method&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines how mathematical content is marked up. Options include <i>COMMENTS</i>, <i>COLOR</i>, <i>NONE</i>, or <i>STRIKE</i>.<br><br><b>--graphics-markup=&lt;method&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls how graphic files (e.g., included via <i>\includegraphics</i>) are handled. Options include <i>INLINE</i>, <i>FIGURES</i>, <i>COMMENTS</i>, <i>NONE</i>.<br><br>


title: DESCRIPTION
content:
<i>latexdiff</i> is a powerful Perl script designed to compare two LaTeX documents and produce a new LaTeX file where the differences are visually marked. This tool is invaluable for collaborative writing, tracking revisions, or managing document versions. It intelligently parses LaTeX syntax, identifying changes in text, commands, and environments, and then applies configurable markup styles. The output <code>.tex</code> file typically uses color, strikethrough, or underlining to highlight additions and deletions. <i>latexdiff</i> handles complex document structures, including included files, equations, and figures, making it an indispensable utility for anyone working with LaTeX documents.


title: CAVEATS
content:
While powerful, <i>latexdiff</i> might be slow for extremely large documents or those with very complex macro definitions. It relies on <i>perl</i> and a standard diff utility (like <i>diff</i>) being available on the system. The output is a new LaTeX file, which must be compiled (e.g., using <i>pdflatex</i>) to render the visual differences in a PDF or DVI viewer.


title: COMPILATION OF OUTPUT
content:
The result of running <i>latexdiff</i> is a new LaTeX file (e.g., <i>diff.tex</i>). This file contains specific LaTeX packages and commands (e.g., <i>soul</i>, <i>xcolor</i>, <i>changes</i>) to apply the visual markup. To see the highlighted differences, this output file must be compiled using a LaTeX compiler (e.g., <i>pdflatex diff.tex</i>) to generate a viewable PDF document.


title: MARKUP STYLES OVERVIEW
content:
<i>latexdiff</i> offers several markup styles to suit different preferences. The <b>CFONT</b> style (the default) uses color and font changes (e.g., italic for added text, strike-through for deleted text). The <b>CTRADITIONAL</b> style mimics traditional proofreading marks, using strikethrough for deleted text and underlining for added text. Other styles like <b>CSCRIPT</b> can insert margin notes for changes, providing a flexible way to visualize document revisions.


title: HISTORY
content:
<i>latexdiff</i> was originally developed by J. R. Ryder and first released in 2004. It quickly gained traction as a crucial tool for LaTeX users due to its robust handling of LaTeX syntax compared to generic text diff tools. The project has seen continuous development and maintenance, evolving into the de-facto standard for comparing and highlighting changes in LaTeX documents.


title: DESCRIPTION
content:
The <B>laydown</B> command is <I>not a standard, widely recognized utility</I> in common Linux distributions. It does not appear in core utilities, typical system management tools, or common package repositories. It is possible this refers to a custom script, a very niche application, or a typo for another command. As such, detailed analysis of its syntax, parameters, and historical development <I>cannot be provided</I> based on publicly available documentation.


title: CAVEATS
content:
This command is <I>not part of standard GNU coreutils</I> or typical Linux system management tools. If you encountered this command, it might be a custom script or an application-specific utility unique to a particular environment. Users should verify if this command exists in their specific environment or if it is a custom script rather than a universally available Linux command.


title: COMMAND EXISTENCE
content:
Before attempting to use <B>laydown</B>, it is highly recommended to check its existence on your system using commands like <B>which laydown</B>, <B>type laydown</B>, or by consulting your system's manual pages (e.g., <B>man laydown</B>). If these commands do not yield results, it confirms that <B>laydown</B> is not a recognized executable on your PATH.


title: HISTORY
content:
No documented history for a standard <B>laydown</B> command exists within widely adopted Linux distributions or projects. It is unlikely to be a historical or deprecated standard command.


title: SYNOPSIS
content:
<code><b>lein</b> <i>[global-options]</i> <b>&lt;task&gt;</b> <i>[task-options] [args...]</i></code><br><br>Examples:<br><code><b>lein new</b> app my-app</code><br><code><b>lein deps</b></code><br><code><b>lein test</b></code><br><code><b>lein run</b></code><br><code><b>lein repl</b></code><br><code><b>lein uberjar</b></code>


title: PARAMETERS
content:
<b><code>--help</code>, <code>-h</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays general help or help for a specific task.<br><br><b><code>--version</code>, <code>-v</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the Leiningen version.<br><br><b><code>--verbose</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases verbosity of output.<br><br><b><code>--silent</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses most output except errors.<br><br><b><code><b>new</b> <i>&lt;template&gt; &lt;name&gt;</i></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a new project from a template (e.g., <code>app</code>, <code>lib</code>).<br><br><b><code><b>deps</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads and installs project dependencies.<br><br><b><code><b>run</b> <i>[args...]</i></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Executes the project's main function.<br><br><b><code><b>test</b> <i>[namespaces...]</i></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Runs project tests.<br><br><b><code><b>repl</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts a Clojure REPL (Read-Eval-Print Loop) for interactive development.<br><br><b><code><b>jar</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a standalone JAR file for the project.<br><br><b><code><b>uberjar</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Packages the project and all its dependencies into a single executable JAR.<br><br><b><code><b>install</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Installs the project's JAR into the local Maven repository.<br><br><b><code><b>clean</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Removes compiled class files and other build artifacts.<br><br><b><code><b>check</b></code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Checks the project for common errors.<br><br>


title: DESCRIPTION
content:
Leiningen (often just `lein`) is the most popular build automation and dependency management tool for Clojure projects. It provides a convenient way to manage the entire lifecycle of a Clojure application, from project creation to deployment. Similar to Maven for Java or npm for Node.js, Leiningen handles tasks such as fetching dependencies, running tests, compiling code, packaging applications (JARs, uberjars), and running development environments (REPLs). It simplifies the build process by allowing developers to define project settings, dependencies, and tasks in a `project.clj` file. Its plugin architecture also allows for extending its functionality, making it highly versatile for various development needs.


title: CAVEATS
content:
<i><b>JVM Dependency:</b></i> Leiningen requires a Java Virtual Machine (JVM) to run, as it's built on Java and targets the JVM. Ensure a compatible JDK is installed and configured.<br><br><i><b>Project Configuration:</b></i> The <code>project.clj</code> file uses a specific EDN (Extensible Data Notation) syntax. Incorrect syntax or misconfigurations can lead to build failures.<br><br><i><b>Plugin Ecosystem:</b></i> While powerful, managing and understanding the various Leiningen plugins can sometimes add complexity, especially for new users.


title: <I><B>`PROJECT.CLJ` FILE:</B></I>
content:
This is the core configuration file for any Leiningen project, located in the project's root directory. It's written in Clojure syntax (EDN) and defines essential project metadata, dependencies, plugins, profiles, and tasks. It's crucial for Leiningen to understand how to build and run your project.


title: <I><B>PROFILES:</B></I>
content:
Leiningen allows defining different "profiles" within <code>project.clj</code> or <code>~/.lein/profiles.clj</code>. Profiles enable conditional configuration, useful for development, testing, or production environments. For example, a development profile might include specific plugins or dependencies not needed in production builds.


title: <I><B>PLUGINS:</B></I>
content:
Leiningen's functionality can be extended through plugins. Plugins are themselves Leiningen projects that provide additional tasks or modify existing ones. They are declared in <code>project.clj</code> and can be used to integrate with other tools, perform static analysis, deploy artifacts, and more.


title: HISTORY
content:
Leiningen was created by Phil Hagelberg and first released around 2010. It quickly became the de facto standard build tool for Clojure projects due to its simplicity, extensibility, and seamless integration with the Clojure ecosystem. It abstracts away much of the complexity of classpath management and Java interoperability, making Clojure development more approachable. Its design was inspired by tools like Maven and RubyGems, aiming to provide a comprehensive solution for dependency management, testing, and deployment specific to Clojure's needs.


title: PARAMETERS
content:
<b><i>subcommand</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the action to perform. Common subcommands include:<br><b>list-devices</b>: Lists all detected input devices.<br><b>debug-events</b>: Shows input events in real-time.<br><b>debug-gestures</b>: Displays gesture events for touchpads.<br><b>measure</b>: Provides tools for measuring device properties (e.g., touchpad size, button wobble).<br><b>record</b>: Records input events to a file.<br><b>replay</b>: Replays recorded input events from a file.<br><b>locate-device</b>: Locates a <i>libinput</i> device based on its syspath.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>list-devices</b> and <b>debug-events</b>) <br>Provides more detailed output. For <b>list-devices</b>, it shows device capabilities and configurations. For <b>debug-events</b>, it shows initial device configurations.<br><br><b>--raw</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>debug-events</b>) <br>Prints raw, unparsed input events as received from the kernel, in addition to processed <i>libinput</i> events.<br><br><b>--tablet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>debug-events</b>) <br>Filters output to only show events from tablet devices.<br><br><b>--strip-details</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>debug-events</b>) <br>Omits detailed event information like coordinates, useful for focusing on event types.<br><br><b>[device]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>debug-events</b>, <b>debug-gestures</b>) <br>Specifies a particular device node (e.g., <i>/dev/input/eventX</i>) to monitor, instead of all devices.<br><br><b>output_file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>record</b>) <br>The file path where recorded input events will be saved.<br><br><b>input_file</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>replay</b>) <br>The file path from which recorded input events will be read and replayed.<br><br><b>syspath</b><br>&nbsp;&nbsp;&nbsp;&nbsp;(Applicable to <b>locate-device</b>) <br>The syspath of the input device (e.g., <i>/sys/devices/...</i>) to locate its <i>libinput</i> device.<br><br>


title: DESCRIPTION
content:
<i>libinput</i> is a foundational library in modern Linux, responsible for handling input devices like touchpads, mice, keyboards, and tablets. It provides a unified and robust interface for Wayland compositors and X.Org drivers.<br><br>The <b>libinput</b> command-line utility serves as a powerful suite of tools to inspect, debug, and measure various aspects of these input devices. It allows users and developers to understand how <i>libinput</i> processes events, identify configuration issues, and test device behavior. These tools are crucial for troubleshooting input-related problems, analyzing specific device interactions, and developing effective input handling solutions within the Linux graphics stack. They can display raw kernel events, show processed gesture recognition, measure physical properties of devices, and record/replay input streams for detailed analysis and automated testing.


title: CAVEATS
content:
Many <i>libinput</i> subcommands (e.g., <b>debug-events</b>, <b>record</b>) require root privileges to access input device nodes directly in <i>/dev/input/</i>. The output of <b>debug-events</b> can be very verbose; using filters like <b>--tablet</b>, <b>--strip-details</b>, or specifying a device is highly recommended for focused analysis. These tools are primarily intended for debugging and development rather than general user interaction.


title: USAGE CONTEXT
content:
The <b>libinput</b> tools are invaluable for diagnosing and resolving issues related to input device behavior, such as touchpad scrolling inconsistencies, mouse pointer acceleration problems, keyboard layout issues, and tablet input errors. They help differentiate between hardware malfunctions, kernel driver bugs, and <i>libinput</i>-specific configuration discrepancies.


title: CONFIGURATION
content:
While the <b>libinput</b> command itself is for debugging, the configuration of <i>libinput</i>'s behavior (e.g., touchpad settings, pointer speed) is typically managed through desktop environment settings, graphical control panels, or system-wide Udev rules and configuration files in <i>/etc/libinput/</i>. The <b>libinput debug-events --verbose</b> output can be helpful in understanding what configuration settings <i>libinput</i> is currently applying to a device.


title: HISTORY
content:
<i>libinput</i> emerged as a modern input stack for Linux, specifically to address the architectural limitations and complexities of the older X.Org input system. Its development gained significant momentum with the rise of Wayland, aiming to provide a robust, unified, and secure method for handling input devices in a compositor-centric environment. The command-line utilities, initially separate tools like <i>libinput-debug-events</i> and <i>libinput-list-devices</i>, were developed as essential companions to the library. They enable developers and system administrators to inspect and troubleshoot input device behavior in Wayland-native setups, much like <i>xinput</i> served the X.Org world. Over time, these individual utilities were consolidated under the single <b>libinput</b> command for streamlined access.


title: PARAMETERS
content:
<b>bucket-create</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new Object Storage bucket in a specified region.<br><br><b>bucket-delete</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes an existing Object Storage bucket. This operation is irreversible and will remove all contents.<br><br><b>bucket-ls</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all Object Storage buckets accessible by your account. Can also list objects within a specified bucket if given a bucket name.<br><br><b>bucket-ssl-upload</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uploads a custom SSL certificate for a specific bucket, enabling HTTPS access with your domain.<br><br><b>bucket-ssl-delete</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes a custom SSL certificate previously associated with a bucket.<br><br><b>object-delete</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes an object from a specified bucket.<br><br><b>object-get</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Downloads an object from a specified bucket to your local machine.<br><br><b>object-ls</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists objects within a specified bucket. This is an alias for 'bucket-ls <bucket-name>'.<br><br><b>object-put</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uploads a file as an object to a specified bucket.<br><br><b>object-url</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates a URL for an object in a specified bucket, optionally a presigned URL for temporary public access.<br><br><b>access-key-create</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new Object Storage access key (access key ID and secret access key) for programmatic S3-compatible access.<br><br><b>access-key-delete</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes an existing Object Storage access key.<br><br><b>access-key-ls</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all Object Storage access keys associated with your account.<br><br><b>access-key-regenerate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Regenerates the secret key for an existing Object Storage access key, invalidating the old one.<br><br><b>access-key-update</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Updates the label or permissions (e.g., read_only) for an existing Object Storage access key.<br><br>


title: DESCRIPTION
content:
The <b>linode-cli object-storage</b> command (often referred to as <i>linode-cli-object-storage</i>) is a powerful interface for interacting with Linode's S3-compatible Object Storage service. It enables users to programmatically manage their storage resources, including creating, deleting, and listing storage buckets, as well as uploading, downloading, listing, and deleting individual objects within those buckets.<br><br>This command streamlines workflows for developers and system administrators by providing a consistent way to automate storage tasks, integrate with applications, and perform bulk operations directly from the command line. It handles authentication and region configuration through the main <b>linode-cli</b> setup, making it easy to manage geographically diverse storage assets.


title: CAVEATS
content:
Requires the <b>linode-cli</b> to be installed and configured with an API token. Operations are region-specific; ensure you specify the correct region (e.g., via <i>--region</i> flag) when creating buckets or interacting with them.<br>Deleting a bucket is a permanent action and cannot be undone. Ensure the bucket is empty before attempting deletion to avoid errors.


title: S3 COMPATIBILITY
content:
Linode Object Storage is highly S3-compatible. This means many tools, libraries, and SDKs designed for Amazon S3 can be configured to work with Linode Object Storage by simply changing the endpoint URL to Linode's Object Storage URL for your chosen region and using your Linode Object Storage access keys.


title: AUTHENTICATION AND API TOKENS
content:
All <b>linode-cli object-storage</b> operations rely on the Linode API token configured for your <b>linode-cli</b> installation. This token grants the CLI permission to interact with your Linode account. For direct S3-compatible access from other applications or tools, you'll use specific Object Storage access keys (an access key ID and a secret access key), which can be managed via the <b>access-key</b> subcommands.


title: HISTORY
content:
Linode Object Storage was officially launched in 2018, providing an S3-compatible cloud storage solution. Support for Object Storage through the Linode CLI followed shortly thereafter, integrating seamlessly into the existing CLI framework. This development allowed for greater automation and programmatic control over Linode's storage offerings, enhancing its utility for cloud-native applications and data management strategies.


title: SYNOPSIS
content:
<b>lkbib</b> [<i>OPTION</i>]... <i>KEY</i>...<br><b>lkbib</b> [<i>OPTION</i>]... -f <i>FILE</i> <i>KEY</i>...


title: PARAMETERS
content:
<b><i>KEY</i>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more search terms or keys to look for in the BibTeX database.<br><br><b><b>-a</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret multiple <i>KEY</i>s as a logical AND search; all keys must match. This overrides the default OR behavior.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the entire matching BibTeX entry, including all its fields, instead of just the key.<br><br><b><b>-f</b> <i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Search exclusively in the specified BibTeX <i>FILE</i> instead of the directories listed in the <i>BIBINPUTS</i> environment variable.<br><br><b><b>-i</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a case-insensitive search for <i>KEY</i>s or when searching within fields (with <b>-s</b>).<br><br><b><b>-o</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret multiple <i>KEY</i>s as a logical OR search (this is the default behavior); an entry will be returned if any of the keys match.<br><br><b><b>-q</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Quiet mode; suppress warning messages and other non-essential output, showing only results or errors.<br><br><b><b>-r</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>KEY</i>s as regular expressions for more flexible and powerful pattern matching.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Search all fields of the BibTeX entries (e.g., author, title, year, abstract) instead of just the primary entry keys.<br><br><b><b>-t</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force an exact match for the specified <i>KEY</i>s. This is often implied for key searches but can be particularly useful when combined with <b>-s</b> for precise field matching.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print only unique matches, eliminating duplicate entries if an entry matches multiple search criteria or if the same entry is found in different files.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Verbose mode; print additional information, potentially including debugging output about the search process.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a brief help message showing usage and options, then exit.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information about <i>lkbib</i> and exit.<br><br>


title: DESCRIPTION
content:
<i>lkbib</i> is a command-line utility designed for searching BibTeX databases. It allows users to quickly locate bibliographic entries based on specified keys or by searching within all fields (like author, title, year). The command is particularly useful for LaTeX users who manage their references using BibTeX and need to quickly retrieve or verify entries.<br><br>By default, <i>lkbib</i> searches for exact matches of keys within <i>.bib</i> files specified by the <i>BIBINPUTS</i> environment variable or explicitly provided on the command line. It can return just the matching keys or the full BibTeX entries. Its functionality is relatively simple compared to more advanced bibliography managers, but it provides a lightweight and efficient way to query BibTeX data directly from the terminal, making it a valuable tool for scripting and quick lookups within a LaTeX workflow. It supports case-insensitive and regular expression searches, as well as logical AND/OR operations for multiple search terms.


title: CAVEATS
content:
The utility primarily relies on the <i>BIBINPUTS</i> environment variable to locate BibTeX files. If this variable is not set or does not point to the correct directories, <b>lkbib</b> may not find any entries unless files are explicitly specified with the <b>-f</b> option. Its searching capabilities, while functional, are basic and do not offer the advanced features of dedicated bibliography management software. It's often used for simple lookups rather than complex database management or formatting.


title: ENVIRONMENT VARIABLE
content:
The <b>lkbib</b> command uses the <i>BIBINPUTS</i> environment variable to determine which directories to search for BibTeX (<i>.bib</i>) files. This variable should contain a colon-separated list of directories (on Unix-like systems) where your BibTeX databases are located. For example: <code>export BIBINPUTS=/path/to/my/bibs:/another/path</code>


title: TYPICAL USAGE PATTERN
content:
Typically, <b>lkbib</b> is used to quickly verify if a BibTeX entry exists or to retrieve a full entry for inclusion in a <i>.tex</i> document. For example, <code>lkbib -e specific_key</code> will print the entire entry associated with 'specific_key' to standard output, which can then be piped or redirected for further use. It can also be used to quickly check for authors or titles: <code>lkbib -s 'Knuth, Donald'</code>.


title: HISTORY
content:
<i>lkbib</i> is part of the TeX Live distribution, a comprehensive TeX system. Its development dates back to the early days of TeX and LaTeX, reflecting the need for command-line tools to manage bibliographic data within the academic and publishing workflows common with TeX. It has been maintained as a stable utility within the TeX Live project, serving its niche function of quick BibTeX database lookups and remaining relevant for command-line driven LaTeX users.


title: PARAMETERS
content:
<b><b>-o</b> <i>&lt;filename&gt;</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output filename. If <i>&lt;filename&gt;</i> is "-", output goes to standard output. If this option is omitted, output defaults to standard output.<br><br><b><b>-force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces disassembly even if the input file does not have a standard LLVM bitcode extension (e.g., .bc or .ll).<br><br><b><b>-help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a summary of command-line options.<br><br><b><b>-version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version of <b>llvm-dis</b>.<br><br><b><b>-stats</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints statistics about the processed bitcode file.<br><br><b><b>-time-passes</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Times each pass during the disassembly process, useful for performance analysis.<br><br><b><b>-disable-output</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Discards the disassembled output, primarily used in conjunction with <b>-time-passes</b> for benchmarking purposes.<br><br>


title: DESCRIPTION
content:
<i><b>llvm-dis</b></i> is a fundamental utility within the <i>LLVM compiler infrastructure</i>, designed to translate LLVM bitcode files back into human-readable <i>LLVM assembly language</i> (LLVM IR). LLVM bitcode is a platform-independent binary representation of compiled code. This tool is invaluable for developers, debuggers, and researchers who need to inspect the intermediate representation of code, understand compiler optimizations, or debug issues at a low level.<br><br>It effectively allows one to see the "assembly" generated by the LLVM frontend before it's compiled down to native machine code by the backend. By default, <b>llvm-dis</b> prints the disassembled output to standard output, but an output file can be specified using the <b>-o</b> option. It supports various options for fine-tuning the disassembly process or for obtaining additional diagnostic information.


title: CAVEATS
content:
The input file must be valid LLVM bitcode; otherwise, <b>llvm-dis</b> will report an error. Note that this tool disassembles to LLVM IR, not native machine code assembly. For native assembly, consider using <b>llc</b> or <b>llvm-objdump</b>.


title: DEFAULT OUTPUT
content:
By default, the disassembled LLVM IR is printed to standard output. Redirecting it to a file using shell redirection (e.g., `>`) or the <b>-o</b> option is common practice for saving the output.


title: EXIT STATUS
content:
The command exits with a zero status code upon successful execution. A non-zero status code indicates an error, such as an invalid or corrupted input bitcode file.


title: HISTORY
content:
<b>llvm-dis</b> is a fundamental tool that has been an integral part of the LLVM project since its early days. LLVM, initiated by Chris Lattner at the University of Illinois in 2000, was designed from the ground up with a robust intermediate representation (IR). Tools like <b>llvm-dis</b> were essential from the start to allow developers to inspect and debug this IR, making the LLVM toolchain transparent and extensible. Its development closely mirrors the evolution of the LLVM IR itself.


title: PARAMETERS
content:
<b><b>-a</b>, <b>--all-locales</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a list of all locales currently available on the system. These are typically compiled and installed from locale definition files.<br><br><b><b>-c</b>, <b>--category=NAME</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the values for a specific locale category (e.g., <b>LC_CTYPE</b>, <b>LC_NUMERIC</b>). When used without a keyword, it displays all keywords for that category.<br><br><b><b>-k</b>, <b>--keyword=KEYWORD</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the value of a specific locale keyword (e.g., <i>decimal_point</i>, <i>thousands_sep</i>). This allows querying individual locale properties.<br><br><b><b>-m</b>, <b>--locale-archive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates the locale archive file, often used in conjunction with <b>localedef</b> for system-wide locale compilation. This is generally a system administration task.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides more detailed output, showing how locale values are determined, including the environment variables influencing them.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message with usage information and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version information for the <b>locale</b> command and exits.<br><br>


title: DESCRIPTION
content:
The <b>locale</b> command is a fundamental utility for managing and querying the internationalization and localization settings on a Linux system. It allows users and applications to adapt to different linguistic and cultural conventions, such as character encoding, date and time formats, currency symbols, numerical representations, and collation rules. <br><br>When executed without options, <b>locale</b> displays the current settings for all active locale categories, which are primarily controlled by environment variables like <b>LANG</b>, <b>LC_ALL</b>, and individual <b>LC_*</b> variables (e.g., <b>LC_CTYPE</b> for character handling, <b>LC_TIME</b> for time formats). <br><br>By providing specific options, <b>locale</b> can list all available locales installed on the system, show the values associated with particular locale keywords, or verify the validity of locale settings. This command is crucial for ensuring that applications behave correctly according to the user's regional preferences, providing a consistent and localized user experience across the operating system.


title: CAVEATS
content:
<b>Locale Generation</b>: While <b>locale</b> displays information, setting up new locales or modifying existing ones often requires generating them using <b>localedef</b> or a system-specific tool like <b>locale-gen</b>. Incorrectly generated or missing locale data can lead to errors or unexpected application behavior.<br><br><b>Environment Variable Precedence</b>: The effective locale is determined by a strict precedence: <b>LC_ALL</b> > specific <b>LC_*</b> variables > <b>LANG</b>. Misunderstanding this can lead to surprising locale settings.<br><br><b>Application Support</b>: Not all applications fully support or correctly interpret locale settings. Some older or simpler programs might ignore them, while others might require specific fonts or character sets to display correctly.<br><br><b>Performance Impact</b>: Loading large locale definitions can sometimes have a minor performance impact on application startup, especially if the locale archive is not optimized or frequently regenerated.


title: LOCALE CATEGORIES AND PRECEDENCE
content:
The locale settings are organized into several categories, each controlled by a specific <b>LC_</b> environment variable. The <b>locale</b> command, when run without arguments, shows the values for these:<br><b>LC_CTYPE</b>: Character classification and conversion (e.g., character encoding, uppercase/lowercase conversion).<br><b>LC_NUMERIC</b>: Non-monetary numeric formatting (e.g., decimal point, thousands separator).<br><b>LC_TIME</b>: Date and time formatting (e.g., month names, date order, 12/24-hour clock).<br><b>LC_COLLATE</b>: String collation (sorting) order.<br><b>LC_MONETARY</b>: Monetary formatting (e.g., currency symbol, positive/negative format).<br><b>LC_MESSAGES</b>: Format of informative and diagnostic messages, and yes/no responses.<br><b>LC_PAPER</b>: Paper size (e.g., A4, letter).<br><b>LC_NAME</b>: Name format.<br><b>LC_ADDRESS</b>: Address format.<br><b>LC_TELEPHONE</b>: Telephone number format.<br><b>LC_MEASUREMENT</b>: Measurement units (e.g., metric, imperial).<br><b>LC_IDENTIFICATION</b>: Information about the locale.<br>The <b>LANG</b> variable sets the default locale for all categories not explicitly set by an <b>LC_</b> variable. The <b>LC_ALL</b> variable overrides all other <b>LC_</b> and <b>LANG</b> settings, providing a strong override for all locale aspects. The precedence is <b>LC_ALL</b> > <b>LC_*</b> > <b>LANG</b>.


title: HISTORY
content:
The concept of "locale" in Unix-like systems dates back to the early 1990s, driven by the increasing need for internationalization (I18n) and localization (L10n) support in computing. The POSIX standard (IEEE Std 1003.1) formalized the locale concept to allow applications to adapt to cultural and linguistic conventions. <br><br> The <b>locale</b> utility itself is part of the GNU C Library (glibc) internationalization efforts. Its development reflects the evolution of glibc's comprehensive support for various character sets, collation rules, monetary formats, and other culturally sensitive data. It provides a standard way for users and system administrators to inspect and manage these settings, moving beyond simple ASCII-only environments to truly globalized computing. The command continues to be a core component in modern Linux distributions, ensuring that applications can correctly represent and process information for users worldwide.


title: PARAMETERS
content:
<b><b>-r</b> <i>retries</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the maximum number of attempts to acquire the lock. If set to -1, it will retry indefinitely. Default is 9.<br><br><b><b>-l</b> <i>lifetime</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the maximum age (in seconds) of the lock file. If the lock file is older than this, it is considered stale and removed. Default is 0 (no lifetime limit).<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operates silently; suppresses error messages to standard output or standard error. Only the exit status indicates success or failure.<br><br><b><b>-!</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Inverts the exit status; exits with 0 on failure and 1 on success. Useful for 'if lockfile ...; then ... else ... fi' constructs.<br><br><b><b>-ml</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Make the lock file a symlink to the process's PID. This helps in identifying which process holds the lock and provides a mechanism for robust stale lock detection.<br><br><b><b>-t</b> <i>timeout</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the time (in seconds) to wait between retries when attempting to acquire a lock. Default is 8 seconds.<br><br><b><i>filename</i>...</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more files for which a lock is to be acquired. For each file, a corresponding lock file (e.g., <i>.filename.lock</i>) is created.<br><br>


title: DESCRIPTION
content:
The <i>lockfile-progs</i> package provides a suite of programs designed to manage file-based locks, primarily to ensure that multiple processes do not simultaneously access or modify shared resources, thus preventing data corruption and race conditions. While the package itself is not a single command, its most prominent utility is the <b>lockfile</b> command. These tools are commonly used in scenarios requiring atomic locking, such as managing mail spools, NFS files, or any other shared data where mutual exclusion is critical.<br><br>The principle behind these programs is to create a unique lock file (often a 'dot-file' or a link) in an atomic operation. If the creation succeeds, the lock is acquired. If it fails, another process already holds the lock. The utilities handle retry mechanisms, timeouts, and can even clean up stale or expired lock files, providing a more robust locking solution than simple file creation checks.<br><br>Other utilities in the suite include <b>dotlockfile</b> (for traditional mail spool locking), <b>mail-lock</b>, <b>mail-unlock</b>, and <b>mail-touchlock</b> (specific to mail operations), and <b>nfs-lock</b> (for NFS-specific locking considerations).


title: CAVEATS
content:
File-based locking, while simple, has limitations. It relies on the atomicity of underlying file system operations (like <b>link(2)</b> or <b>mkdir(2)</b>) which might behave inconsistently across different NFS implementations. Deadlocks can occur if processes do not properly release locks or if a process crashes while holding a lock and the stale lock cleanup isn't sufficient. These utilities do not provide advisory locking (like <b>flock(1)</b> or <b>fcntl(2)</b>), meaning applications must explicitly check for and honor the presence of lock files.


title: LOCKING MECHANISMS
content:
The primary locking mechanism employed by <b>lockfile-progs</b> is 'dot-locking' or 'link-locking'. This involves attempting to create a unique file (e.g., <i>.filename.lock</i>) using an atomic operation like <b>link(2)</b> to a unique temporary file, or atomically creating a directory (for 'dot-directory' locks). The atomicity ensures that only one process can successfully acquire the lock at any given moment. This differs from advisory locking (like <b>flock(1)</b>) where the kernel manages locks, and applications must explicitly request and respect them. File-based locks are external to the kernel and rely on agreement between applications.


title: ATOMICITY AND ROBUSTNESS
content:
The core strength of these utilities lies in their use of atomic file system operations for lock acquisition. This means the operation to create the lock either fully succeeds or fully fails, preventing race conditions where multiple processes might incorrectly believe they have acquired a lock. Furthermore, features like configurable retries, timeouts, and stale lock detection (especially with the <b>-ml</b> option for PID-based locks) contribute to the robustness of these locking solutions, making them suitable for environments where processes might crash or become unresponsive.


title: HISTORY
content:
The concept of using lock files for mutual exclusion dates back to the earliest days of Unix, especially for critical system resources like mail spools. The `dot-locking` mechanism (creating files like `.filename.lock`) became a de facto standard. The `lockfile-progs` package emerged to standardize and enhance these common locking utilities, providing robust, configurable tools that handle various edge cases like stale locks and retries, evolving from simple shell script implementations to more reliable compiled binaries.


title: PARAMETERS
content:
<b>-s</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Silent mode, suppress all messages except for specified tags.<br><br><b>-d</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dump the entire log buffer and exit.<br><br><b>-c</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clear the entire default log buffer and exit.<br><br><b>-C</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Clear the specified log buffer and exit.<br><br><b>-v <format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the log output format (e.g., <i>brief</i>, <i>process</i>, <i>tag</i>, <i>thread</i>, <i>raw</i>, <i>time</i>, <i>long</i>).<br><br><b>-b <buffer></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select an alternate log buffer (e.g., <i>main</i>, <i>system</i>, <i>radio</i>, <i>events</i>, <i>crash</i>, <i>kernel</i>, <i>security</i>).<br><br><b>-f <filename></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write log output to a specified file instead of stdout.<br><br><b>-r <kbytes></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Rotate log files every specified kilobyte size.<br><br><b>-n <count></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Limit the number of rotated log files to a specific count.<br><br><b>-L</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print only the last specified number of kilobytes of log data from the buffer.<br><br><b>-P <pid></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print only messages from the specified process ID (PID).<br><br><b>-g</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the log buffer to stdout and exit (similar to <i>-d</i>).<br><br><b>-t <time_format></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the time format for log entries (e.g., <i>UTC</i>, <i>local</i>, <i>epoch</i>).<br><br><b>-D</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display current date/time on output.<br><br><b>-e <expr></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter out log messages matching a specified regular expression.<br><br><b>-A</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Assert. Display assert messages (fatal errors).<br><br>


title: DESCRIPTION
content:
<br><i>logcat</i> is a command-line tool integral to the Android Debug Bridge (ADB) suite, primarily used by developers and system administrators to view system messages and logs from an Android device or emulator. It captures and displays a continuous stream of messages produced by the device's operating system, applications, and services. These logs are essential for debugging, monitoring application behavior, identifying errors, and understanding system events.<br><br><i>logcat</i> allows users to filter log output based on various criteria, such as tag, priority, and process ID, enabling focused analysis of specific log streams. It interacts with different log buffers (e.g., main, system, radio, events, crash, kernel), each storing different types of messages. Without <i>logcat</i>, debugging and troubleshooting on Android devices would be significantly more challenging. It is typically invoked through <i>adb shell logcat</i> or directly as <i>adb logcat</i> from a Linux terminal connected to an Android device.


title: CAVEATS
content:
<i>logcat</i> is primarily designed for Android device logging and requires an Android device or emulator connected via <i>ADB</i> (Android Debug Bridge). It is not a general-purpose Linux logging tool like <i>dmesg</i> or <i>journalctl</i>.<br><br>The raw output can be extremely verbose; effective filtering using <i>filterspecs</i> is crucial for practical use.<br><br>Access to certain log buffers or functionalities might require specific Android permissions or root access on the device.<br><br>Log retention is limited; older logs are overwritten as new ones come in, unless specifically captured or rotated.


title: UNDERSTANDING FILTERSPECS
content:
<i>logcat</i> allows sophisticated filtering using <i>filterspecs</i>. A <i>filterspec</i> is in the format <i>TAG:PRIORITY</i>, where <i>TAG</i> is the source component (e.g., "ActivityManager", "MyApp") and <i>PRIORITY</i> is the minimum priority level to display. Multiple <i>filterspecs</i> can be provided, separated by spaces. For example, <i>adb logcat ActivityManager:I MyApp:D *:S</i> would show "ActivityManager" messages at Info level or higher, "MyApp" messages at Debug level or higher, and suppress all other tags.


title: LOG PRIORITIES
content:
Android log messages are assigned a priority level, from lowest to highest severity:<br><i>V</i>: Verbose (lowest priority, typically for debug messages)<br><i>D</i>: Debug (debug messages)<br><i>I</i>: Info (informational messages)<br><i>W</i>: Warn (warnings)<br><i>E</i>: Error (errors)<br><i>F</i>: Fatal (fatal errors, highest priority)<br><i>S</i>: Silent (used for suppressing all messages, e.g., in <i>filterspecs</i>)


title: LOG BUFFERS
content:
Android maintains several distinct log buffers, each storing different types of messages:<br><i>main</i>: The default buffer for most application and system component logs.<br><i>system</i>: Logs from the Android system server and system services.<br><i>radio</i>: Messages related to the radio and telephony stack.<br><i>events</i>: Binary buffer for system events (requires decoding).<br><i>crash</i>: Logs specifically related to crashes (ANRs, native crashes).<br><i>kernel</i>: Kernel messages (similar to <i>dmesg</i> output on standard Linux).<br><i>security</i>: Security-related events.<br>You can select a specific buffer using the <i>-b</i> option (e.g., <i>adb logcat -b radio</i>).


title: HISTORY
content:
<i>logcat</i> has been an integral part of the Android SDK and platform since its early versions, evolving alongside the Android operating system. Its development has focused on enhancing filtering capabilities, improving performance for large log streams, and adding support for new log buffers and formats as the complexity of Android devices and applications grew. It remains a foundational tool for debugging and system analysis in the Android ecosystem.


title: SEE ALSO
content:
<i>adb(1)</i>: The Android Debug Bridge, essential for connecting to and interacting with Android devices., <i>dmesg(1)</i>: Displays kernel ring buffer messages on Linux systems (general Linux logging)., <i>journalctl(1)</i>: Query the systemd journal (general Linux logging).


title: SYNOPSIS
content:
<b>loginctl</b> [<i>OPTIONS</i>...] <i>COMMAND</i> [<i>ARGS</i>...]<br><br><b>Common Commands:</b><br><b>loginctl</b> list-sessions<br><b>loginctl</b> show-session <i>ID</i><br><b>loginctl</b> terminate-session <i>ID</i><br><b>loginctl</b> lock-session <i>ID</i><br><b>loginctl</b> unlock-session <i>ID</i><br><b>loginctl</b> list-users<br><b>loginctl</b> show-user <i>USERNAME</i><br><b>loginctl</b> terminate-user <i>USERNAME</i><br><b>loginctl</b> suspend<br><b>loginctl</b> hibernate<br><b>loginctl</b> poweroff<br><b>loginctl</b> reboot


title: PARAMETERS
content:
<b>--no-pager</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Do not pipe output into a pager.</i><br><br><b>-H, --host=</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Operate on a remote host via SSH.</i><br><br><b>-M, --machine=</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Operate on a local container or VM.</i><br><br><b>-l, --full</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show full entries, even if they don't fit on the screen.</i><br><br><b>-a, --all</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show all properties, including those not typically shown.</i><br><br><b>--user</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Operate on the calling user's session, typically when run as a regular user.</i><br><br><b>--uid=</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Operate on a specific user ID.</i><br><br><b>--session=</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specify a session by its ID.</i><br><br><b>--seat=</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Specify a seat by its ID.</i><br><br><b>--property=</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>When used with show-session/user/etc., displays only the specified property.</i><br><br><b>--value</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>When used with --property, shows only the value, not the property name.</i><br><br><b>--no-legend</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Do not print the column headers.</i><br><br><b>--json=</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Format output as JSON. Accepted values: 'pretty', 'short', 'full', 'compact'.</i><br><br><b>-h, --help</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Display a short help text and exit.</i><br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Show package version.</i><br><br>


title: DESCRIPTION
content:
<i>loginctl</i> is a command-line utility for controlling the <i>systemd</i> login manager, <i>systemd-logind.service</i>. It provides a unified interface for managing user logins, sessions, seats, and users on a Linux system.<br><br>Administrators and users can use <i>loginctl</i> to query the current state of logged-in users and their sessions, terminate specific sessions, lock/unlock the screen, or initiate system-wide actions like suspend, hibernate, or shutdown. It replaces older mechanisms for session tracking and offers a modern, D-Bus-based approach to integrate seamlessly with various desktop environments and display managers. Its functionality extends to managing multiple physical seats and virtual sessions, offering granular control over the system's login environment.


title: CAVEATS
content:
<i>loginctl</i> relies on the <i>systemd-logind.service</i> being active and running. Many commands require root privileges or specific user permissions (e.g., membership in the <i>systemd-journal</i> group for certain logging operations or proper Polkit policies). Misuse of termination commands can lead to data loss if users are not properly warned or sessions are not saved.


title: COMMON USE CASES
content:
<b>Listing Sessions and Users:</b><br>To see all active login sessions: <i>loginctl list-sessions</i><br>To see all logged-in users: <i>loginctl list-users</i><br><br><b>Detailed Information:</b><br>To show detailed information about a specific session (e.g., 'c1'): <i>loginctl show-session c1</i><br>To show details for a user (e.g., 'johndoe'): <i>loginctl show-user johndoe</i><br><br><b>Session Control:</b><br>To lock a session (e.g., 'c1'): <i>loginctl lock-session c1</i><br>To terminate a session: <i>loginctl terminate-session c1</i><br><br><b>System Control:</b><br>To initiate system suspend: <i>loginctl suspend</i><br>To initiate system hibernate: <i>loginctl hibernate</i>


title: HISTORY
content:
<i>loginctl</i> was introduced as part of the <i>systemd</i> init system, first widely adopted in the early 2010s. It was designed to replace or integrate with existing login management components like ConsoleKit and PolicyKit, providing a more robust and unified D-Bus-based interface for session tracking and management. Its development aimed to streamline the handling of multiple user sessions, virtual terminals, and physical seats, aligning with <i>systemd</i>'s broader goal of modernizing Linux system management.


title: SYNOPSIS
content:
<B>logrotate</B> [<I>option</I>...] <I>config_file</I><br><br>Common options include:<br><B>-d</B> (--debug)<br><B>-f</B> (--force)<br><B>-v</B> (--verbose)<br><B>-s</B> &lt;statefile&gt; (--state &lt;statefile&gt;)<br><B>-l</B> &lt;logfile&gt; (--log &lt;logfile&gt;)


title: PARAMETERS
content:
<b><b>-d</b>, <b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug mode. No actual changes are made to log files or the state file; <I>logrotate</I> only prints what it would do.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces log rotation, even if <I>logrotate</I> determines it's not necessary (e.g., not enough time has passed or size threshold not met).<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays detailed messages about what <I>logrotate</I> is doing, including log file names, rotation actions, and errors.<br><br><b><b>-s</b> <I>statefile</I>, <b>--state</b> <I>statefile</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses an alternative state file instead of the default (<B>/var/lib/logrotate/status</B>). This file keeps track of when each log was last rotated.<br><br><b><b>-l</b> <I>logfile</I>, <b>--log</b> <I>logfile</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes its own verbose output to the specified log file instead of standard output.<br><br><b><b>-m</b> <I>command</I>, <b>--mail-command</b> <I>command</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the command to use when mailing rotated logs. Overrides the compiled-in default or the one specified in the configuration.<br><br><b><b>-o</b> <I>directive</I>=<I>value</I>, <b>--option</b> <I>directive</I>=<I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides a configuration directive with the given value. This allows for temporary modifications without changing the configuration file.<br><br>


title: DESCRIPTION
content:
<I>logrotate</I> is a powerful utility designed to manage system log files automatically. It prevents log files from consuming excessive disk space and makes them easier to manage by systematically archiving or deleting old logs. It operates by rotating log files based on criteria like size or time. When a log file is rotated, the current log is moved (e.g., <I>mylog.log</I> becomes <I>mylog.log.1</I>), a new empty log file is created, and older rotated logs might be compressed or deleted. This process is typically invoked daily via a <I>cron</I> job. Its behavior is highly configurable through a main configuration file (<B>/etc/logrotate.conf</B>) and additional application-specific configuration files (<B>/etc/logrotate.d/</B>), allowing administrators to define specific rotation policies for different log sets, including frequency, number of old logs to keep, compression options, and post-rotation script execution.


title: CAVEATS
content:
While <I>logrotate</I> automates log management, careful configuration is essential. Misconfigurations can lead to <B>disk space exhaustion</B> (if logs are not rotated or too many are kept), <B>loss of critical log data</B> (if rotated too aggressively or deleted prematurely), or <B>permission issues</B>. It typically relies on a <B>cron job</B> (usually daily) to run; if cron is not functioning, <I>logrotate</I> will not execute. Ensure log files have correct permissions for <I>logrotate</I> to read and write them.


title: CONFIGURATION FILES
content:
Logrotate's behavior is controlled by configuration files. The main configuration is at <B>/etc/logrotate.conf</B>. This file often includes other configuration files from the <B>/etc/logrotate.d/</B> directory, allowing individual applications or services to define their own log rotation rules (e.g., <I>apache2</I>, <I>nginx</I>, <I>syslog</I>). Each configuration block can specify rules like rotation frequency (daily, weekly, monthly), log retention count, compression, and post-rotation commands.


title: STATE FILE
content:
Logrotate uses a state file, typically located at <B>/var/lib/logrotate/status</B>, to keep track of when each log file was last rotated. This file is crucial for <I>logrotate</I> to determine if a log needs rotation based on its configured frequency or size. It's a simple plain-text file that <I>logrotate</I> updates after each successful rotation.


title: HISTORY
content:
Before automated tools, system administrators manually managed ever-growing log files, a tedious and error-prone process. The need for an efficient, automated solution led to the development of utilities like <I>logrotate</I>. It became a standard component in Unix-like operating systems, addressing the critical challenge of preventing disk space exhaustion by managing logs and ensuring system stability. Its design allows for highly flexible configuration, adapting to diverse logging needs across various applications and services.


title: PARAMETERS
content:
<b>-s, --status</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show the status of each file (e.g., '!', '+', '-' for modified, added, or deleted) alongside its name.<br><br><b>-l, --long</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display output in a long format, similar to 'ls -l', for unified diffs. This includes file mode, size, and timestamp if available in the diff headers.<br><br><b>-F <I>FORMAT</I>, --format=<I>FORMAT</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output format using a format string. This allows for customized display of file information, similar to the 'ls --format' option. Common specifiers include '%f' (full filename), '%b' (basename), '%d' (dirname), '%m' (mode), '%s' (size), '%t' (timestamp), '%c' (change type).<br><br><b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br>


title: DESCRIPTION
content:
The <i>lsdiff</i> command is a utility from the GNU Diffutils package designed to parse the output of the <i>diff</i> command and extract the names of the files that have been modified, added, or deleted.<br><br>It's particularly useful for summarizing changes without needing to read the entire diff content. While <i>diff</i> generates the line-by-line differences between files or directories, <i>lsdiff</i> acts as a parser, allowing users to quickly identify which files are involved in a given patch or change set.<br><br>It commonly processes standard unified (<i>-u</i>) or context (<i>-c</i>) diff formats, making it an invaluable tool for scripting, version control analysis, or simply getting a high-level overview of a set of changes.<br><br>It does not generate diffs itself; its input is always the output of another <i>diff</i> command, usually piped to its standard input.


title: CAVEATS
content:
<i>lsdiff</i> is designed to parse standard <i>diff</i> output (unified or context format). It may produce incorrect or unexpected results if the input is not a recognized diff format or is heavily customized.<br><br>It does not generate diffs; it only interprets existing diff output.


title: USAGE EXAMPLES
content:
<b>1. Basic usage to list changed files:</b><br><br><i>diff -u file1.txt file2.txt | lsdiff</i><br><br>This command will output the names of files that differ between <i>file1.txt</i> and <i>file2.txt</i>.<br><br><b>2. Listing files with their status:</b><br><br><i>diff -ruN old_dir new_dir | lsdiff -s</i><br><br>This will show files that are modified, added, or deleted between <i>old_dir</i> and <i>new_dir</i>, along with their respective status indicators (e.g., '!', '+', '-').<br><br><b>3. Customizing output format:</b><br><br><i>diff -u file_a.txt file_b.txt | lsdiff -F '%b (%c)'</i><br><br>This example uses a custom format string to display the base name of the file followed by its change type (e.g., 'file_a.txt (!)').


title: HISTORY
content:
<i>lsdiff</i> is a part of the GNU Diffutils package, which is a fundamental set of tools for comparing files and directories in Unix-like operating systems. Developed by the GNU Project, it embodies the philosophy of small, focused tools that can be chained together in pipelines to perform more complex tasks. Its development reflects the need for programmatic analysis of change sets, enhancing the utility of the core <i>diff</i> command for scripting and automated workflows.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br><b>-J, --json</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use JSON output format, ideal for scripting.<br><br><b>-H, --human</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print human-readable sizes (e.g., 1K, 234M, 2G) for shared memory segments.<br><br><b>-l, --list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all IPC objects (this is the default behavior).<br><br><b>-i <I>id</I>, --id <I>id</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show details for a specific IPC object identified by its ID. Can be used with <B>--ipc</B> or type-specific options.<br><br><b>-ipc <I>type</I>, --ipc <I>type</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show only IPC objects of a specific <I>type</I>. Valid types are <B>shm</B> (shared memory), <B>msg</B> (message queues), and <B>sem</B> (semaphores).<br><br><b>-m, --shm</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only shared memory segments. This is a shorthand for <B>--ipc shm</B>.<br><br><b>-q, --msg</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only message queues. This is a shorthand for <B>--ipc msg</B>.<br><br><b>-s, --sem</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only semaphore arrays. This is a shorthand for <B>--ipc sem</B>.<br><br><b>-t, --time</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the time of the last control operation and the last operation for each object.<br><br><b>-B, --bytes</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display shared memory sizes in bytes rather than a human-readable format (default when <B>-H</B> is not used).<br><br><b>--output <I>list</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify which output columns to display. <I>list</I> is a comma-separated list of column names (e.g., <B>ID,KEY,OWNER,SIZE</B>). Use <B>--help</B> to see available columns.<br><br><b>--output-all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output all available columns. This option can be used with <B>--json</B>.<br><br>


title: DESCRIPTION
content:
<i>lsipc</i> is a utility that lists inter-process communication (IPC) facilities in Linux. It is part of the <B>util-linux</B> project and provides a modern, user-friendly interface for inspecting System V IPC objects, which include shared memory segments, message queues, and semaphore arrays.<br><br>It offers significant improvements over the older <B>ipcs</B> command, particularly with its ability to output information in a structured, machine-readable JSON format, making it ideal for scripting and automation. <br><br>Users can filter results by IPC type, display detailed information for specific IDs, and customize the output columns. It's an essential tool for system administrators and developers debugging applications that rely on IPC mechanisms or for general system monitoring.


title: CAVEATS
content:
<i>lsipc</i> primarily focuses on System V IPC objects. It does <B>not</B> display information about POSIX IPC objects (e.g., POSIX message queues, semaphores, or shared memory created with <B>shm_open</B>).<br><br>To view detailed information for all IPC objects, the command usually requires root privileges or <B>CAP_IPC_OWNER</B> capability. Non-privileged users may only see limited information for objects they own or have explicit permissions for.


title: OUTPUT CUSTOMIZATION
content:
Beyond basic filtering, <B>lsipc</B> allows extensive customization of its output via the <B>--output</B> and <B>--output-all</B> options. This enables users to select specific columns, such as ID, Key, Owner, Permissions, Size, Nattach, and Time, to tailor the information displayed to their exact needs, enhancing readability and usefulness for specific tasks.


title: JSON OUTPUT
content:
A key advantage of <B>lsipc</B> over traditional IPC tools like <B>ipcs</B> is its native support for JSON output via the <B>-J</B> or <B>--json</B> option. This structured data format makes it significantly easier to parse <B>lsipc</B>'s output programmatically, facilitating integration into scripts, monitoring tools, and automated system checks.


title: HISTORY
content:
<i>lsipc</i> is a relatively modern command introduced as part of the <B>util-linux</B> project. It was developed to provide a more consistent, user-friendly, and especially scriptable interface for listing System V IPC facilities, addressing limitations of the older <B>ipcs</B> command. Its inclusion of JSON output capabilities highlights its design for modern scripting and automation workflows, making it a preferred tool for system diagnostics and monitoring in contemporary Linux environments.


title: PARAMETERS
content:
<b><code>--all</code>, <code>-a</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays all accessible namespaces, including non-persistent ones like PID namespaces that might not have a running process within them directly.<br><br><b><code>--canonical</code>, <code>-c</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Uses a canonical format for output, which can make it easier to parse programmatically.<br><br><b><code>--json</code>, <code>-J</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the information in JSON format, suitable for machine parsing.<br><br><b><code>--list</code>, <code>-l</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Presents the output in a list-like format, enhancing readability.<br><br><b><code>--noheadings</code>, <code>-n</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the printing of header lines in the output.<br><br><b><code>--output &lt;list&gt;</code>, <code>-o &lt;list&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which columns to display. <I>list</I> is a comma-separated string of column names (e.g., <code>PID,NS,TYPE,NSPID,COMMAND</code>). Use <code>lsns --help</code> for available columns.<br><br><b><code>--pids &lt;list&gt;</code>, <code>-p &lt;list&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters the output to show namespaces associated with the specified process IDs. <I>list</I> is a comma-separated string of PIDs.<br><br><b><code>--raw</code>, <code>-r</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Produces raw output without any column alignment, useful for scripting.<br><br><b><code>--types &lt;list&gt;</code>, <code>-t &lt;list&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filters the output to show only namespaces of specified types. <I>list</I> is a comma-separated string of types (e.g., <code>mnt,net,pid</code>).<br><br><b><code>--verbose</code>, <code>-v</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more detailed information.<br><br><b><code>--help</code>, <code>-h</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><code>--version</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs version information and exits.<br><br>


title: DESCRIPTION
content:
<code>lsns</code> is a command-line utility from the <i>util-linux</i> package used to list and inspect Linux namespaces. Namespaces are a fundamental feature of the Linux kernel that partition kernel resources, enabling isolated environments like containers. <code>lsns</code> provides a comprehensive overview of active namespaces, including their type (mount, UTS, IPC, network, PID, cgroup, user), unique inode number, and associated process IDs (PIDs). It can display the hierarchy of PID namespaces, showing parent-child relationships, and reveal which processes are currently running within each namespace. This tool is invaluable for system administrators and developers working with containers (e.g., Docker, LXC) or understanding process isolation, allowing them to examine the namespace topology, debug isolation issues, and gain insights into the resource partitioning on a Linux system. It typically reads information from the <code>/proc</code> filesystem.


title: CAVEATS
content:
Viewing all namespaces, especially user and PID namespaces, often requires root privileges. Without elevated permissions, <code>lsns</code> might only show namespaces owned by the current user or those globally accessible.<br>The output can be extensive on systems with many containers or processes, making filtering with options like <code>-t</code> and <code>-p</code> essential for specific queries.


title: NAMESPACE TYPES
content:
Linux namespaces isolate various system resources. <code>lsns</code> can identify the following types:<br><b><I>mnt</I></b>: Mount namespace, isolates mount points.<br><b><I>uts</I></b>: UTS namespace, isolates hostname and NIS domain name.<br><b><I>ipc</I></b>: IPC namespace, isolates System V IPC and POSIX message queues.<br><b><I>net</I></b>: Network namespace, isolates network devices, IP addresses, routing tables, etc.<br><b><I>pid</I></b>: PID namespace, isolates process IDs, providing a separate PID numbering sequence.<br><b><I>cgroup</I></b>: Cgroup namespace, isolates cgroup root directory and hierarchy view.<br><b><I>user</I></b>: User namespace, isolates user and group IDs, allowing unprivileged users to have root privileges within the namespace.


title: USAGE EXAMPLES
content:
To list only network and PID namespaces in a human-readable format:<br><code>lsns -t net,pid -l</code><br>To see all available columns and their descriptions:<br><code>lsns --help</code>


title: HISTORY
content:
The <code>lsns</code> command is part of the <i>util-linux</i> project, a collection of essential Linux utilities. Its development is closely tied to the evolution and increasing adoption of Linux kernel namespaces, which began appearing in the kernel around version 2.6.24 (for types like mount, UTS, IPC, PID, network) and later with user namespaces (kernel 3.8). <code>lsns</code> provides a user-friendly interface to query the namespace information exposed via the <code>/proc</code> filesystem, making it a critical tool for managing and understanding containerized environments.


title: SYNOPSIS
content:
<b>php artisan</b> <i>&lt;command&gt;</i> [<i>options</i>] [<i>arguments</i>]<br><i>Example:</i> <b>php artisan migrate</b>


title: PARAMETERS
content:
<b>make:controller {name}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a new controller class.<br><br><b>make:middleware {name}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a new middleware class.<br><br><b>make:migration {name}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a new migration file.<br><br><b>migrate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run the database migrations.<br><br><b>migrate:rollback</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Roll back the last database migration.<br><br><b>db:seed</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Seed the database with records.<br><br><b>serve</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Serve the application using the PHP development server.<br><br><b>key:generate</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the application key.<br><br><b>optimize</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Optimize the framework for better performance.<br><br><b>help {command}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help for a specific command.<br><br><b>list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all available Artisan commands.<br><br>


title: DESCRIPTION
content:
The term 'lumen' on Linux typically refers to the <i>Lumen PHP micro-framework</i>, not a standalone system command. Lumen is a lightweight, high-performance web application framework built on top of Laravel's components, specifically optimized for building fast APIs and microservices. It provides a foundational structure and essential tools for rapid development of back-end services. Its command-line interface (CLI) is powered by <b>Artisan</b>, Laravel's powerful command-line tool. You interact with a Lumen application's features—such as database migrations, route caching, code generation for controllers, middleware, and migrations, as well as serving the application locally—through the <b>php artisan</b> command. This command must be executed from within the root directory of a Lumen project. It significantly facilitates development workflows by automating repetitive tasks and providing scaffolding functionalities, streamlining the creation and management of Lumen applications.


title: CAVEATS
content:
The `lumen` command itself does not exist as a standalone executable in standard Linux distributions. CLI functionality is accessed via <b>php artisan</b> within a Lumen project.<br>Requires PHP and Composer installed on the system, and a properly configured Lumen project.<br>The available Artisan commands depend on the Lumen version and installed packages.


title: HISTORY
content:
Lumen was created by Taylor Otwell, the creator of Laravel, and was first released in 2015. It was designed to be a faster, leaner micro-framework for building high-performance APIs and microservices, using many of the same components as Laravel but with less overhead. Over time, some of Lumen's unique performance benefits have been integrated into Laravel itself, leading to a closer alignment between the two frameworks. While still maintained, for many API-only projects, modern Laravel itself with its API features can serve a similar purpose.


title: PARAMETERS
content:
<b><b>-L</b> <i>Size</i>[<i>bBsSkKmMgGtTpPeE</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a logical volume of a specific <i>Size</i>. This is the most common way to specify the logical volume's extent in bytes, kilobytes, megabytes, gigabytes, etc. (e.g., <b>-L 10G</b>).<br><br><b><b>-l</b> <i>LogicalExtents</i> | <i>Percentage</i>{<i>VG</i>|<i>PV</i>|<i>LV</i>|<i>FREE</i>|<i>ORIGIN</i>}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a logical volume using a number of <i>LogicalExtents</i> or a <i>Percentage</i> of the volume group, physical volume, or existing logical volume's free space. For example, <b>-l 50%FREE</b> uses half of the available free space.<br><br><b><b>-n</b> <i>LogicalVolumeName</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the <i>LogicalVolumeName</i> for the new logical volume. If not provided, LVM typically generates a default name like 'lvol#'.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a snapshot logical volume. This option must be used with an existing logical volume as the origin for the snapshot.<br><br><b><b>-V</b> <i>VirtualSize</i>[<i>bBsSkKmMgGtTpPeE</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a thin provisioned logical volume with a given <i>VirtualSize</i>. This logical volume will consume space from a thin pool only as data is written to it.<br><br><b><b>--thinpool</b> <i>ThinPoolLVPath</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the existing thin pool logical volume from which a new thin logical volume should consume space. Required when creating thin LVs with <b>-V</b>.<br><br><b><b>--type</b> {<i>snapshot</i>|<i>mirror</i>|<i>raidX</i>|<i>thin-pool</i>}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the type of logical volume to create. Common types include <i>snapshot</i>, <i>mirror</i>, <i>raidX</i> (e.g., raid1, raid5), and <i>thin-pool</i>.<br><br><b><b>-C</b>|<b>--contiguous</b> {<i>y</i>|<i>n</i>}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force the allocation of contiguous logical extents on the physical volume. This can limit flexibility but might be useful for specific performance requirements.<br><br><b><b>-m</b> <i>Mirrors</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Create a mirrored logical volume with the specified number of additional data copies (<i>Mirrors</i>). For example, <b>-m 1</b> creates a two-copy mirror (original + 1 mirror).<br><br><b><b>-r</b>|<b>--regionsize</b> <i>RegionSize</i>[<i>bBsSkKmMgGtTpPeE</i>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the size of regions for RAID or mirror LVs. Smaller regions can improve performance for random I/O but increase metadata overhead.<br><br><b><b>-Z</b>|<b>--zero</b> {<i>y</i>|<i>n</i>}</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Controls whether the first KBytes of the new logical volume are zeroed. Default is 'y' for most types of LVs to ensure data integrity, especially for filesystems.<br><br><b><b>-K</b>|<b>--skipactivation</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not activate the logical volume immediately after creation. Useful for maintenance or when the LV needs to be configured before activation.<br><br>


title: DESCRIPTION
content:
The <b>lvcreate</b> command is a fundamental utility within the Linux Logical Volume Manager (LVM) framework. It is used to create new logical volumes (LVs) from the free space within an existing volume group (VG). Logical volumes serve as flexible, resizable 'partitions' that can span multiple physical volumes (PVs) and provide advanced storage management features such as snapshots, striping, and mirroring. <b>lvcreate</b> allows administrators to specify the size, name, and type of the new logical volume, tailoring it to specific application or system requirements. It's a crucial step in setting up storage before it can be formatted with a filesystem or used by applications, offering greater flexibility than traditional disk partitioning.


title: CAVEATS
content:
Creating a logical volume consumes free space from the volume group; ensure sufficient capacity before creation. While <b>lvcreate</b> itself doesn't typically cause data loss, incorrect sizing or misidentification of the volume group can lead to unexpected behavior or resource depletion. For thin provisioned LVs, it's crucial to monitor the thin pool's usage to prevent out-of-space conditions, which can halt I/O for all LVs within that pool. Snapshot LVs are dependent on their origin LV; if the origin is removed or heavily modified, the snapshot may become unusable.


title: THIN PROVISIONING
content:
<b>lvcreate</b> is central to thin provisioning in LVM. You can create a <i>thin pool</i> (e.g., <b>lvcreate --type thin-pool -L 100G -n my_pool my_vg</b>) and then create <i>thin logical volumes</i> within that pool (e.g., <b>lvcreate -V 500G --thinpool my_vg/my_pool -n my_thin_lv</b>). Thin LVs appear significantly larger than their actual allocated space, only consuming physical storage from the pool as data is written. This allows for efficient space utilization and over-provisioning.


title: SNAPSHOTS
content:
Using the <b>-s</b> option, <b>lvcreate</b> can create a point-in-time snapshot of an existing logical volume. Snapshots are copy-on-write, meaning only changes to the origin or snapshot are stored, making them highly efficient for backups, testing, or quick rollback operations. Example: <b>lvcreate -s -L 5G -n my_lv_snap my_vg/my_lv</b>. The snapshot size determines how many changes it can record before running out of space.


title: HISTORY
content:
Logical Volume Manager (LVM) in Linux was first introduced around the year 2000, inspired by similar implementations in commercial Unix systems. <b>lvcreate</b> has been a core command since LVM's inception, providing the fundamental capability to carve out flexible storage units from underlying physical storage. Over time, its functionality has expanded to include support for advanced features like snapshots, mirroring, striping (RAID), and more recently, thin provisioning, reflecting the evolving needs of modern storage management and virtualization.


title: SYNOPSIS
content:
<b>lvdisplay</b> [<I>OPTIONS</I>] [<I>LogicalVolumePath</I>|<I>VolumeGroupName</I>/<I>LogicalVolumeName</I>...]<br><b>lvdisplay</b> [<I>OPTIONS</I>] -a|--all


title: PARAMETERS
content:
<b><b>-a</b>, <b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays information about all logical volumes on the system, regardless of whether they are active or inactive.<br><br><b><b>-c</b>, <b>--colon</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Generates output in a colon-separated format, which is easily parseable by scripts and other programs. This is useful for automated data extraction.<br><br><b><b>-o</b>, <b>--options</b> <I>field1</I>[,<I>field2</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which fields (columns) of information to display. Common fields include <i>lv_name</i>, <i>vg_name</i>, <i>lv_size</i>, <i>lv_attr</i>, <i>lv_uuid</i>, etc. Multiple fields can be separated by commas.<br><br><b><b>-S</b>, <b>--select</b> <I>selection</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays only logical volumes that match the specified selection criteria. The criteria use SQL-like syntax (e.g., 'lv_size > 10G').<br><br><b><b>-s</b>, <b>--segments</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays information about the segments that make up the logical volume. This can show how the LV is distributed across physical extents and devices.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output, providing more detailed information, which can be useful for debugging or in-depth analysis.<br><br><b><b>-u</b>, <b>--units</b> <I>unit</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the units to use for displayed sizes (e.g., 'b' for bytes, 'k' for kilobytes, 'm' for megabytes, 'g' for gigabytes, 't' for terabytes, 'p' for petabytes, 'e' for exabytes, or 'h' for human-readable).<br><br><b><b>--noheadings</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the display of column headings when outputting in table format, often used when scripting.<br><br><b><b>--nosuffix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the unit suffix (e.g., 'G', 'M') from size values in the output.<br><br>


title: DESCRIPTION
content:
The <b>lvdisplay</b> command is a crucial utility within the Logical Volume Manager (LVM) framework on Linux systems. It is designed to provide comprehensive and detailed information about one or more logical volumes (LVs). This information includes, but is not limited to, the logical volume's name, UUID, size, current status (e.g., active, inactive, snapshot), allocation policy, associated volume group, and underlying physical volume segments.<br><br>Administrators use <b>lvdisplay</b> to monitor the state of their LVM configurations, troubleshoot issues, verify creation or modification operations, and gather data for capacity planning. When executed without any arguments, it displays information for all logical volumes detected on the system. Users can also specify particular logical volumes by name or path to get targeted details. The command offers various options to control the verbosity and format of its output, making it adaptable for both human readability and script parsing.


title: CAVEATS
content:
Running <b>lvdisplay</b> typically requires root privileges or sudo access to view all logical volume information.<br>The interpretation of certain output fields, such as the <i>LV Attributes</i> string (<i>lv_attr</i>), requires familiarity with LVM's internal attribute flags. While powerful, the <b>-o</b>/<b>--options</b> and <b>--select</b> features necessitate knowledge of available field names and query syntax.


title: OUTPUT FORMATS
content:
Beyond the default human-readable output, <b>lvdisplay</b> offers significant flexibility. The <b>-o</b> or <b>--options</b> flag allows users to precisely define which columns of data are displayed, enabling custom reports. For programmatic parsing, the <b>-c</b> or <b>--colon</b> option provides a stable, machine-readable format. Modern versions also support <b>--reportformat json</b> for structured JSON output, which is ideal for integration with scripting languages and automated systems.


title: LV ATTRIBUTES (LV_ATTR)
content:
The <i>lv_attr</i> field in the output (when requested via <b>-o lv_attr</b> or in default verbose output) is a string of characters representing various attributes of the logical volume. Each character denotes a specific characteristic, such as accessibility (e.g., 'w' for writeable), allocation type (e.g., 'l' for linear, 's' for snapshot), and health status (e.g., 'a' for active). Understanding these attributes is key to fully interpreting the state of a logical volume.


title: HISTORY
content:
The Logical Volume Manager (LVM) was originally conceived by Sistina Software. LVM2, a complete rewrite of the original LVM, was integrated into the Linux kernel starting from version 2.6.0. <b>lvdisplay</b> has been a fundamental utility within LVM from its early stages, serving as the primary tool for administrators to inspect the state and configuration of logical volumes. Its evolution has focused on enhancing output flexibility (e.g., support for JSON, customizable columns via <b>-o</b>), improving performance, and adapting to new LVM features such as thin provisioning, RAID LVs, and VDO, ensuring its continued relevance as a core LVM diagnostic and reporting command.


title: PARAMETERS
content:
<b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the program version number and exits.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increases the verbosity of the output. Use multiple times for more detail (e.g., -vvv).<br><br><b>-d, --debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debugging output, providing more detailed information about the scanning process.<br><br><b>--devices <I>PVs|device_list</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restricts scanning to a specified list of devices. Devices can be separated by commas.<br><br><b>--ignorelockingfailure</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Continues scanning even if an LVM locking failure occurs, which can be useful in specific recovery scenarios.<br><br><b>--config <I>value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overrides configuration settings. This allows specifying LVM configuration parameters directly on the command line.<br><br><b>--reportformat <I>basic|json</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the output format for the report. 'basic' is the default human-readable format, while 'json' provides machine-readable output.<br><br>


title: DESCRIPTION
content:
The <b>lvmdiskscan</b> command is a utility within the <I>Logical Volume Manager (LVM)</I> suite. Its primary function is to scan all accessible block devices on the system for LVM physical volume signatures and metadata. It identifies devices that are currently LVM physical volumes or contain LVM metadata, making them potential candidates for LVM usage. This command is particularly useful for troubleshooting, identifying disks that might have been part of an LVM setup, or simply getting an overview of which disks are LVM-managed on a system.<br><br>The output typically lists device paths, indicating their size and whether they are recognized as LVM physical volumes (PV) or just regular disks. It also provides information if LVM filters, defined in the <I>lvm.conf</I> configuration file, are applied, which can affect which devices are scanned and reported. Importantly, <b>lvmdiskscan</b> performs a read-only scan and does not modify any disk data.


title: CAVEATS
content:
<b>lvmdiskscan</b> only identifies LVM metadata signatures; it does not provide information about filesystems or other partition types. The devices scanned and reported can be significantly affected by device filters defined in the <I>lvm.conf</I> configuration file. For comprehensive scanning, it typically requires root privileges.


title: LVM FILTERS
content:
The behavior of <b>lvmdiskscan</b> is heavily influenced by the <I>device filters</I> configured in the <I>lvm.conf</I> file (typically located at <I>/etc/lvm/lvm.conf</I>). These filters use regular expressions to include or exclude specific devices from being scanned by LVM commands. For example, if a filter is set to exclude <I>/dev/sdX</I>, <b>lvmdiskscan</b> will not report any LVM metadata found on that device, even if it exists. It's crucial to be aware of these filters when troubleshooting missing LVM devices.


title: OUTPUT INTERPRETATION
content:
The default output of <b>lvmdiskscan</b> typically shows a list of devices, their size, and a designation indicating whether they are recognized as <I>LVM physical volumes (PV)</I> or simply <I>regular disks</I>. For instance, a line might look like <I>'/dev/sda [  931.51 GiB] LVM physical volume'</I> or <I>'/dev/sdb [  232.88 GiB]'</I>. The presence of 'LVM physical volume' indicates that LVM metadata has been detected on that device. The <I>--reportformat json</I> option can provide a more structured and machine-parsable output for scripting purposes.


title: HISTORY
content:
<b>lvmdiskscan</b> is an integral part of the <I>LVM2</I> suite, which superseded the original LVM1 implementation and became the standard Logical Volume Manager on Linux. Its core function – to scan for and identify LVM-related block devices – has remained consistent throughout LVM2's development. While more advanced commands like <I>pvs</I> and <I>vgscan</I> often provide more structured and detailed information, <b>lvmdiskscan</b> continues to serve as a quick and simple tool for initial device discovery and sanity checks in LVM environments.


title: PARAMETERS
content:
<b>-a, --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Include all Logical Volumes, including internal ones like snapshot origins.<br><br><b>-b, --block-device-info</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display block device major:minor numbers and size.<br><br><b>-C, --columns <list></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Customize which columns are displayed and their format.<br><br><b>-d, --debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable debug logging, showing more detailed internal operations.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b>-P, --partial</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Allow commands to proceed with partial LVM metadata (e.g., missing PVs).<br><br><b>-r, --readonly</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run commands in read-only mode, preventing any modifications.<br><br><b>-S, --select <selection></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select LVM objects to process using a selection string.<br><br><b>-s, --short</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show only the LV paths, one per line, simplifying scripting.<br><br><b>-t, --test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Run in test mode; do not commit any actual changes to the system.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increase verbosity level, providing more detailed output.<br><br><b>--active</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter and display only active Logical Volumes.<br><br><b>--inactive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Filter and display only inactive Logical Volumes.<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<I>lvscan</I> is a command-line utility used in Linux to scan for and display information about <I>Logical Volumes (LVs)</I> managed by the <I>Logical Volume Manager (LVM)</I> framework. It provides a quick overview of existing LVs, including their paths, volume group, size, and current status (e.g., active, inactive, snapshot). This command is essential for system administrators to quickly ascertain the state and properties of their storage volumes without requiring detailed knowledge of the underlying physical or volume group structures. It's often used as a preliminary step before performing operations like activation, deactivation, or resizing of LVs.


title: CAVEATS
content:
The output of <I>lvscan</I> typically shows LVs that are known to the LVM cache. If LVM metadata is inconsistent or damaged, the reported status might not accurately reflect the true state of the LV on disk.<br>Always ensure LVM metadata is backed up before making significant changes to your volume groups or logical volumes.


title: OUTPUT FORMAT
content:
The default output of <I>lvscan</I> provides a concise summary, typically showing the LV path (e.g., `/dev/volumegroup/logicalvolume`), its access mode (e.g., `read/write`), current state (e.g., `active`), size, and UUID.<br>The `-s, --short` option simplifies this to just the LV paths, useful for scripting.


title: SCANNING PROCESS
content:
When executed, <I>lvscan</I> scans all known <I>Volume Groups (VGs)</I> for their constituent <I>Logical Volumes (LVs)</I>. It uses the LVM metadata found on disk to build a comprehensive list of all discovered LVs, making it an essential tool for discovering newly added or previously unknown logical volumes.


title: HISTORY
content:
The <I>Logical Volume Manager (LVM)</I> framework, of which <I>lvscan</I> is a part, has been a standard component of Linux distributions since kernel version 2.4. <I>lvscan</I> specifically gained prominence with <I>LVM2</I>, which introduced many enhancements over the original LVM. Its primary role has consistently been to provide a quick and easy way to list all detected logical volumes on a system, aiding in system inventory and status checks.


title: SYNOPSIS
content:
<B>lwp-request</B> [<I>options</I>] <I>URL</I> [<I>URL</I>...]<br><B>lwp-request</B> <B>-m</B> <I>method</I> [<I>options</I>] <I>URL</I> [<I>URL</I>...]


title: PARAMETERS
content:
<b><B>-m</B> <I>method</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the HTTP request <I>method</I> to use (e.g., GET, POST, HEAD, PUT, DELETE).<br><br><b><B>-d</B> <I>data</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provide <I>data</I> to send with POST or PUT requests. Can be used multiple times for form data.<br><br><b><B>-H</B> <I>header:value</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Add a custom HTTP <I>header</I> to the request. Can be used multiple times.<br><br><b><B>-u</B> <I>user:pass</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify <I>username</I> and <I>password</I> for basic authentication.<br><br><b><B>-U</B> <I>user-agent</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the <I>User-Agent</I> string for the request, overriding the default.<br><br><b><B>-i</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display only the response headers, without the content body.<br><br><b><B>-s</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the HTTP status line (e.g., 'HTTP/1.1 200 OK') before the content or headers.<br><br><b><B>-p</B> <I>proxy</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a <I>proxy</I> server to use for the request (e.g., http://proxy.example.com:8080).<br><br><b><B>-L</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Follow HTTP redirects automatically (this is often the default behavior).<br><br><b><B>-z</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not follow HTTP redirects; return the response from the initial URL.<br><br><b><B>-t</B> <I>seconds</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set a <I>timeout</I> for the request in <I>seconds</I>.<br><br><b><B>-k</B></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not verify SSL certificates; this is insecure and should only be used for testing or trusted environments.<br><br>


title: DESCRIPTION
content:
<I>lwp-request</I> is a versatile command-line utility provided as part of the <I>libwww-perl</I> (LWP) library. It acts as a client for making various types of requests over the network, primarily HTTP and HTTPS, but also supports FTP and local files. It provides a simple interface to the robust functionalities of the LWP Perl module, allowing users to fetch web pages, submit form data (POST), inspect headers (HEAD), upload files (PUT), or delete resources (DELETE). This tool is invaluable for scripting web interactions, debugging web services, testing APIs, and performing quick fetches directly from the terminal without writing a full Perl script. It supports features like setting custom headers, handling redirects, authentication, and proxy configuration.


title: CAVEATS
content:
<I>lwp-request</I> relies on the <I>libwww-perl</I> library, which may not be pre-installed on all systems. While powerful, for very complex HTTP/HTTPS interactions or extremely high performance, dedicated tools like <I>curl</I> might offer more granular control or better optimized handling of specific protocols. Using the <B>-k</B> option (disabling SSL certificate verification) should be done with caution and only in trusted environments, as it bypasses critical security checks.


title: <B>INSTALLATION</B>
content:
If <I>lwp-request</I> is not available on your system, it can usually be installed via your distribution's package manager. For Debian/Ubuntu, it's typically part of the <B>libwww-perl</B> package (e.g., <I>sudo apt-get install libwww-perl</I>). On Red Hat/CentOS, it might be <B>perl-libwww-perl</B> (e.g., <I>sudo yum install perl-libwww-perl</I> or <I>sudo dnf install perl-libwww-perl</I>).


title: <B>USAGE EXAMPLES</B>
content:
Fetch a web page:<br><I>lwp-request http://example.com</I><br><br>Send a POST request with data:<br><I>lwp-request -m POST -d 'name=test&value=123' http://example.com/api</I><br><br>Get only response headers:<br><I>lwp-request -i http://example.com</I><br><br>Set a custom User-Agent:<br><I>lwp-request -U 'MyCustomBrowser/1.0' http://example.com</I>


title: HISTORY
content:
<I>lwp-request</I> emerged as a utility bundled with the <I>libwww-perl</I> (LWP) project, which started in the mid-1990s. LWP quickly became the de-facto standard for programmatic web access in Perl, providing a robust and flexible framework for HTTP, FTP, and other protocols. The <I>lwp-request</I> script was designed to offer a simple command-line wrapper around the core LWP functionalities, allowing developers and system administrators to quickly interact with web resources without writing full Perl programs. Its development has mirrored the evolution of web standards, continually updated to support new HTTP features and security protocols.


title: SYNOPSIS
content:
<b>lxc</b> [<i>GLOBAL_OPTIONS</i>] <i>&lt;subcommand&gt;</i> [<i>SUBCOMMAND_OPTIONS</i>] [<i>ARGUMENTS</i>]<br><br>Common <i>subcommands</i> include: <b>launch</b>, <b>start</b>, <b>stop</b>, <b>delete</b>, <b>list</b>, <b>exec</b>, <b>file</b>, <b>snapshot</b>, <b>image</b>, <b>network</b>, <b>storage</b>, <b>profile</b>, <b>monitor</b>, and many more, each with its own specific options and arguments.


title: PARAMETERS
content:
<b>--help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the help message for the <i>lxc</i> command or a specific subcommand when used with it (e.g., <i>lxc launch --help</i>).<br><br><b>--version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the LXD client version.<br><br><b>--verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, showing more details about operations.<br><br><b>--debug</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables debug output, providing extensive logging for troubleshooting.<br><br><b>--force-local</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the operation to be performed on the local LXD daemon, overriding any default remote configuration.<br><br><b>--config &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative client configuration directory to use.<br><br><b>--project &lt;name&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the LXD project to operate within. This allows segmenting instances and resources within a single LXD daemon.<br><br><b>--remote &lt;name&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the remote LXD server to connect to. This allows managing instances on different LXD deployments.<br><br>


title: DESCRIPTION
content:
<i>lxc</i> is the primary command-line client for <B>LXD</B>, a powerful system container and virtual machine manager. It allows users to interact with LXD servers to create, start, stop, delete, and manage <B>Linux containers (LXC)</B> and <B>virtual machines</B>. LXD aims to provide a user experience similar to traditional virtual machines but with the density and performance benefits of containers where applicable. <br><br>Through the <i>lxc</i> command, administrators and users can perform a wide array of operations including snapshot management, image publishing, network configuration, storage pool management, and remote server administration. It provides a consistent interface for managing instances whether they are local or on remote LXD servers, making it an essential tool for modern Linux system administration and cloud environments.


title: CAVEATS
content:
<b>LXD Daemon Requirement</b>: <i>lxc</i> is purely a client and requires a running LXD daemon (server) to operate. It cannot function standalone without a daemon to connect to.<br><b>Permissions</b>: To interact with the LXD daemon, users typically need to be part of the 'lxd' Unix group or use <i>sudo</i> for privileged operations.<br><b>Networking Complexity</b>: Configuring network bridges, NAT, and public IP assignments for containers/VMs can become complex depending on the desired setup and host network environment.<br><b>Storage Backends</b>: The performance and features of LXD instances are highly dependent on the chosen storage backend (e.g., ZFS, Btrfs, LVM, Ceph). Improper configuration can lead to performance issues or data loss.<br><b>Updates</b>: LXD updates might occasionally require daemon restarts or specific migration steps, especially for significant version changes or underlying database schema changes.


title: LXD ARCHITECTURE
content:
<i>lxc</i> operates on a <B>client-server model</B>. The <i>lxc</i> command is the client that communicates with the <B>LXD daemon</B> (<i>lxd.socket</i> or <i>lxd.service</i>) running in the background. This daemon manages all containers, virtual machines, storage, and networking. This architecture enables local and remote management of LXD servers, allowing a single <i>lxc</i> client to control instances across multiple physical or virtual hosts.


title: INSTANCE TYPES: CONTAINERS VS. VMS
content:
While LXC stands for Linux Containers, modern LXD and the <i>lxc</i> command provide unified management for both <B>system containers</B> (LXC) and <B>full virtual machines</B>. System containers are lightweight, share the host kernel, and are ideal for high density. Virtual machines run their own kernel, providing stronger isolation and compatibility with various operating systems. This dual capability makes <i>lxc</i> a highly versatile tool for different virtualization and isolation needs.


title: IMAGE MANAGEMENT
content:
<i>lxc</i> provides robust image management capabilities. Users can <B>publish instances as new images</B>, allowing for quick replication of specific setups or creation of custom base images. It also enables pulling images from various sources (e.g., official LXD image servers like <i>images.linuxcontainers.org</i>, custom remote servers, or local tarballs) to launch new instances rapidly and consistently.


title: HISTORY
content:
<b>LXC (Linux Containers)</b>, the underlying container technology, emerged around 2008, leveraging Linux kernel features like namespaces and cgroups for process isolation. <br><br><b>LXD</b> was developed by <B>Canonical</B> and first introduced in 2014. It was designed as a 'hypervisor' or management layer specifically for LXC containers, providing a daemonized service with a REST API, improved security, and a much more user-friendly experience compared to the raw <i>lxc-</i> tools. The <i>lxc</i> command-line tool serves as the primary client for interacting with this LXD daemon. <br><br>Over time, LXD has significantly evolved, notably adding support for full <B>virtual machines</B> alongside containers in 2018, making it a versatile tool for managing various types of instances from a single, unified interface.


title: SYNOPSIS
content:
<b>lxc-attach</b> <b>-n</b> <i>name</i> [<b>-e</b>] [<b>-s</b> <i>namespace</i>]... [<b>-P</b>] [<b>-v</b>] [<b>--</b>] <i>command</i> [<i>arguments...</i>]


title: PARAMETERS
content:
<b><b>-n</b> <i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the LXC container to attach to. This is a mandatory option.<br><br><b><b>-e</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keeps the environment variables from the host process when executing the command inside the container. By default, the environment is cleared.<br><br><b><b>-s</b> <i>namespace</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies which namespaces to attach to. Multiple <b>-s</b> options can be provided, or a comma-separated list (e.g., <i>PID,NET,MOUNT</i>). Common namespaces include <i>PID</i> (process ID), <i>NET</i> (network), <i>UTS</i> (hostname), <i>IPC</i> (inter-process communication), <i>MOUNT</i> (filesystem), and <i>USER</i> (user ID). By default, <b>lxc-attach</b> attempts to join all namespaces except the user namespace.<br><br><b><b>-P</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the PID (Process ID) of the process that was created inside the container.<br><br><b><b>-v</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose output, providing more detailed information about the attachment process.<br><br><b><b>--</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;A conventional separator used to distinguish options passed to <b>lxc-attach</b> from the command and its arguments that are to be executed inside the container. Everything following <b>--</b> is treated as the command and its arguments.<br><br><b><i>command</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The command to execute inside the specified container (e.g., <i>/bin/bash</i>, <i>ls -l</i>).<br><br><b><i>arguments...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Any arguments to pass to the <i>command</i> being executed inside the container.<br><br>


title: DESCRIPTION
content:
The <b>lxc-attach</b> command allows users to execute arbitrary commands inside a running Linux Container (LXC) instance. Unlike commands that start a new container or execute a one-off command upon container launch, <b>lxc-attach</b> connects to an already active container, placing the user directly within its isolated environment. It achieves this by leveraging Linux kernel features like namespaces (PID, network, mount, UTS, IPC, user) and cgroups, effectively making the executed command run as if it were launched from within the container itself.<br><br>This utility is invaluable for administrative tasks, debugging containerized applications, installing software, or simply exploring the container's filesystem and processes without needing to restart it. It ensures that the command inherits the container's resource limits and isolation, making it a robust tool for container management.


title: CAVEATS
content:
The container specified by <b>-n</b> must be in a <i>RUNNING</i> state for <b>lxc-attach</b> to succeed. It cannot attach to stopped or frozen containers.<br><br>Typically, <b>lxc-attach</b> requires root privileges on the host system to perform namespace manipulations, unless user namespace configuration is specifically set up to allow unprivileged users to attach.<br><br>The command executed inside the container will run with the privileges of the user that <b>lxc-attach</b> maps to within that container. If the container uses user namespace ID mapping, a host user may map to a non-root user inside the container. Otherwise, a host root user executing <b>lxc-attach</b> will typically execute the command as root inside the container.


title: HOW IT WORKS
content:
At its core, <b>lxc-attach</b> utilizes the <i>setns(2)</i> system call. This call allows a process to enter a different namespace (e.g., PID, network, mount) than its own. When you execute <b>lxc-attach</b>, it identifies the target container's namespaces and then uses <i>setns(2)</i> to effectively 'move' the newly spawned command process into those namespaces, thereby making it appear as if it originated from within the container.


title: DEFAULT NAMESPACE ATTACHMENT
content:
By default, when <b>lxc-attach</b> is used without explicit <b>-s</b> options, it attempts to join all namespaces associated with the target container except the user namespace. This ensures that the attached command runs within the container's isolated network, process tree, filesystem, and hostname, providing a comprehensive container environment for interaction.


title: HISTORY
content:
<b>lxc-attach</b> is a core component of the Linux Containers (LXC) project, which pioneered OS-level virtualization on Linux. LXC emerged as a light-weight alternative to traditional virtual machines, leveraging Linux kernel features like control groups (cgroups) and namespaces that became available in the mid-2000s.<br><br>As LXC matured, <b>lxc-attach</b> was developed as a direct and efficient way to interact with running containers, providing administrators with the ability to enter and manage the container's environment without the overhead of re-spawning processes or reconfiguring container startup. Its design is intrinsically tied to the kernel's namespace functionality, making it a fundamental tool in the LXC ecosystem for operational control and debugging of containerized workloads.


title: DESCRIPTION
content:
lxc-checkconfig is a crucial diagnostic utility within the Linux Containers (LXC) framework. Its primary purpose is to <I>assess the currently running Linux kernel's configuration</I> for features and capabilities essential for the proper functioning of LXC containers. It meticulously checks for the presence and enablement of various kernel components, including <I>cgroup filesystems</I> (such as <B>cpu</B>, <B>memory</B>, <B>devices</B>, <B>freezer</B>, <B>pid</B>, <B>blkio</B>), different <I>namespace types</I> (<B>pid</B>, <B>uts</B>, <B>ipc</B>, <B>net</B>, <B>user</B>, <B>cgroup</B>), as well as security modules like <I>AppArmor</I> or <I>SELinux</I> support, and <I>swap accounting</I>.<br><br>By executing this command, users can quickly identify if their kernel is adequately configured to support LXC's full feature set. This prevents common issues where containers fail to start or operate correctly due to missing kernel support. The output clearly indicates which features are <B>ENABLED</B> (green), <B>DISABLED</B> (red), or <B>UNKNOWN</B> (yellow), providing actionable insights into potential kernel-related hurdles for LXC deployment. It serves as a vital first step in troubleshooting containerization problems, guiding users on whether a custom kernel compilation or specific kernel module loading might be necessary.


title: CAVEATS
content:
The output of <b>lxc-checkconfig</b> reflects the <I>kernel build options</I>, not necessarily the <I>runtime activation</I> or correct mounting of certain features (e.g., cgroup filesystems might be compiled in but not mounted). <br>Some critical features might be available as <I>loadable kernel modules</I> rather than being built directly into the kernel; this tool primarily verifies the kernel's ability to support them rather than confirming module load status. <br>A feature marked as <B>DISABLED</B> does not always render LXC unusable, but it often <I>limits functionality</I> (e.g., a disabled <B>user_namespaces</B> prevents unprivileged containers). <br>The tool relies on kernel configuration files, typically found in <B>/proc/config.gz</B> or <B>/boot/config-&lt;kernel_version&gt;</B>, which might not always be perfectly aligned with highly customized or older kernels.


title: INTERPRETING OUTPUT
content:
Each line in the output corresponds to a specific kernel feature or configuration:<BR><UL><LI><B>ENABLED</B> (often in green): The feature is compiled into your kernel or is readily available and active. This is the desired state.</LI><LI><B>DISABLED</B> (often in red): The feature is not present or enabled in your kernel. This might prevent certain LXC functionalities or types of containers (e.g., unprivileged containers if <B>user_namespaces</B> is disabled).</LI><LI><B>UNKNOWN</B> (often in yellow): The tool could not determine the status of the feature. This might occur if <B>/proc/config.gz</B> is missing or if the kernel's configuration is highly unconventional.</LI></UL>


title: COMMON TROUBLESHOOTING STEPS
content:
If <b>lxc-checkconfig</b> reports <B>DISABLED</B> for essential features:<BR><UL><LI><B>Recompile Kernel:</B> For critical features like certain cgroups or namespaces, you might need to recompile your Linux kernel with the necessary options enabled (e.g., <B>CONFIG_NAMESPACES</B>, <B>CONFIG_CGROUP_FREEZER</B>).</LI><LI><B>Load Modules:</B> Ensure relevant kernel modules are loaded (e.g., <B>modprobe overlay</B>).</LI><LI><B>Mount Cgroups:</B> Verify that cgroup filesystems are correctly mounted (e.g., <B>mount -t cgroup -o memory none /sys/fs/cgroup/memory</B>). Most modern distributions handle this automatically via <B>systemd</B>.</LI><LI><B>User Namespaces:</B> If <B>user_namespaces</B> is <B>DISABLED</B>, you won't be able to run unprivileged containers, which are often preferred for security. Enabling this usually requires a kernel recompile.</LI></UL>


title: HISTORY
content:
The Linux Containers (LXC) project was initiated around <I>2008</I>, predating other prominent containerization technologies like Docker. <b>lxc-checkconfig</b> emerged as a core utility within the LXC toolset from its early stages. Its development was driven by the necessity to provide users with a <I>simple, standardized way</I> to verify kernel compatibility for container operations. In the nascent days of container technology, debugging kernel configuration was a significant hurdle, and this command played a crucial role in <I>streamlining the diagnostic process</I>, helping users ensure their system had the fundamental components for efficient and secure container deployment.


title: SYNOPSIS
content:
<b>lxc-console</b> <b>-n</b> <i>NAME</i> [<b>-t</b> <i>TTY_ID</i>] [<b>-L</b> <i>LOGLEVEL</i>] [<b>-o</b> <i>LOGFILE</i>]


title: PARAMETERS
content:
<b><b>-n</b> <i>NAME</i>, <b>--name</b> <i>NAME</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the container to which to connect the console. This is a mandatory option.<br><br><b><b>-t</b> <i>TTY_ID</i>, <b>--tty</b> <i>TTY_ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the TTY ID to connect to. The default is 0, which typically corresponds to the container's main console. Other IDs (e.g., 1, 2, etc.) may connect to additional virtual terminals if configured within the container.<br><br><b><b>-s</b>, <b>--session</b> <i>ID</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attach to an existing console session by its ID. This is typically used internally or for specific advanced use cases.<br><br><b><b>-L</b> <i>LOGLEVEL</i>, <b>--loglevel</b> <i>LOGLEVEL</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the log level for `lxc-console` itself. Common levels include `TRACE`, `DEBUG`, `INFO`, `NOTICE`, `WARN`, `ERROR`, and `CRIT`.<br><br><b><b>-o</b> <i>LOGFILE</i>, <b>--logfile</b> <i>LOGFILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a file to write log messages to. If not specified, logs are typically written to stderr or syslog depending on configuration.<br><br><b><b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b><b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows version information and exits.<br><br>


title: DESCRIPTION
content:
The `lxc-console` command provides a direct virtual console connection to a running Linux Container (LXC). It emulates connecting a physical terminal to the container's standard TTYs, allowing low-level interaction, similar to accessing a server via serial console or directly from a hypervisor's console.<br><br>Unlike `lxc-exec` or `lxc-attach`, which are designed for executing commands or attaching to namespaces, `lxc-console` focuses on persistent, interactive console sessions. This is particularly useful for debugging container startup issues, interacting with init systems (like Systemd or OpenRC within the container) that manage TTYs, or when network access to the container's SSH server isn't available or configured.<br><br>By default, it connects to TTY 0, but can be directed to other TTYs if the container's configuration and init system support them. It provides a robust method for deep interaction with the container's operating system environment.


title: CAVEATS
content:
Connecting to a container's console via `lxc-console` requires the target container to be in a <i>running</i> state. You generally need <i>root privileges</i> or appropriate capabilities (`CAP_SYS_ADMIN`) to use this command, as it interacts directly with container resources.<br><br>Exiting the `lxc-console` session often requires a specific escape sequence, commonly <i>Ctrl+a</i> followed by <i>q</i> (i.e., `Ctrl+a`, then `q`). Simply typing `exit` or `Ctrl+d` inside the console might only exit the shell within the container, not detach the `lxc-console` session, potentially leaving the TTY in an unexpected state if the shell restarts.<br><br>The availability and behavior of specific TTYs within the container depend heavily on the container's configuration and its init system (e.g., `systemd`, `sysvinit`). If the container's init system doesn't manage or provide TTYs as expected, `lxc-console` might not function as intended or might only connect to a non-interactive TTY.


title: EXITING THE CONSOLE
content:
Unlike standard SSH or terminal sessions, exiting `lxc-console` typically requires an <i>escape sequence</i>. The most common sequence is pressing <i>Ctrl+a</i>, releasing it, and then pressing <i>q</i>. This sequence sends a signal to the `lxc-console` client to detach from the container's TTY, returning control to the host shell. Failure to use the correct escape sequence may leave the `lxc-console` process running in the background or require manual termination.


title: COMPARISON WITH `LXC-ATTACH` AND `LXC-EXEC`
content:
While all three commands allow interaction with a running container, their methods differ significantly:<br><ul><li><i>`lxc-console`</i>: Connects directly to a specific virtual TTY (e.g., `/dev/tty0`) within the container, behaving like a physical console. It's best for interacting with the container's init system or low-level services.</li><li><i>`lxc-attach`</i>: Executes a command or provides a shell by attaching to the container's existing namespaces (PID, network, mount, etc.). It runs processes as though they were part of the container's existing process tree.</li><li><i>`lxc-exec`</i>: Executes a command inside the container's environment, often creating a new process that runs within the container's specific Cgroups and namespaces, but typically does not attach to existing TTYs. It's often preferred for one-off commands or script execution within the container.</li></ul>`lxc-console` provides the most 'bare-metal' console experience among these tools.


title: HISTORY
content:
The `lxc-console` command is a core component of the LXC (Linux Containers) project, which predates more widely known container runtimes like Docker. LXC began development in the mid-2000s, leveraging Linux kernel features like control groups (cgroups) and namespaces to provide OS-level virtualization. `lxc-console` has been a fundamental utility since the early days of LXC, offering a direct, low-level access mechanism to running containers, mirroring the experience of connecting to a physical server's console. Its utility remains significant for debugging and system administration in environments heavily reliant on LXC as a lightweight virtualization solution.


title: SYNOPSIS
content:
<b>lxc-create</b> <b>{-n</b> <i>name</i><b>} {-t</b> <i>template</i><b>}</b> [<b>-f</b> <i>config_file</i>] [<b>-B</b> <i>backingstore</i>] [<b>-s</b> <i>size</i>] [<b>-P</b> <i>path</i>] [<b>-L</b> <i>fssize</i>] [<b>--</b> <i>template-options</i>]


title: PARAMETERS
content:
<b><b>-n</b>, <b>--name=</b><i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the unique name for the new container. This name will be used to identify and manage the container.<br><br><b><b>-t</b>, <b>--template=</b><i>template</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Defines the template script to use for container creation. Common templates include <i>download</i>, <i>ubuntu</i>, <i>debian</i>, <i>busybox</i>, and more. These scripts handle the distribution-specific setup.<br><br><b><b>-f</b>, <b>--config=</b><i>config_file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Provides an alternative path to the container's configuration file. By default, LXC generates a config file at <i>LXC_PATH/containers/name/config</i>.<br><br><b><b>-B</b>, <b>--backingstore=</b><i>backingstore</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the storage backend type for the container's root filesystem. Options include <i>dir</i> (directory), <i>btrfs</i>, <i>lvm</i>, <i>zfs</i>, or <i>loop</i>. Each has different performance and management characteristics.<br><br><b><b>-s</b>, <b>--size=</b><i>size</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the size of the backing store for storage types like LVM or ZFS. For example, '10G' or '500M'.<br><br><b><b>-P</b>, <b>--path=</b><i>path</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative root directory where containers will be stored. Default is usually <i>/var/lib/lxc</i>.<br><br><b><b>-L</b>, <b>--fssize=</b><i>fssize</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the maximum size for the container's root filesystem, typically used with LVM or ZFS thin provisioning.<br><br><b><b>-d</b>, <b>--debug</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables verbose debugging output for troubleshooting container creation issues.<br><br><b><b>-o</b>, <b>--logfile=</b><i>logfile</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies a file to write debug and log messages to, instead of standard error.<br><br><b><b>-l</b>, <b>--logpriority=</b><i>level</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the log priority level for messages, such as <i>FATAL</i>, <i>CRIT</i>, <i>WARN</i>, <i>INFO</i>, or <i>DEBUG</i>.<br><br><b><b>--</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Separates <i>lxc-create</i> options from arguments that should be passed directly to the chosen template script. For example, specifying a release for an <i>lxc-download</i> template.<br><br>


title: DESCRIPTION
content:
<i>lxc-create</i> is a fundamental utility within the Linux Containers project, designed to instantiate new container environments. It leverages specialized template scripts to automate the setup of a container's root filesystem and initial configuration. When executed, <i>lxc-create</i> invokes a specified template (e.g., <i>lxc-ubuntu</i>, <i>lxc-download</i>) which handles tasks such as downloading base images, installing necessary packages, and configuring basic network settings. The result is a lightweight, isolated Linux environment with its own filesystem, process tree, and network interfaces, distinct from the host system. This command is essential for quickly provisioning various types of system containers, from minimal BusyBox installations to full-fledged distribution environments.


title: CAVEATS
content:
Creating LXC containers typically requires root privileges. <br>The command's success heavily depends on the chosen template script; network connectivity is often required for templates that download images. <br>Specific backing store types (e.g., LVM, ZFS) necessitate the corresponding tools and configuration to be present on the host system. <br>Resource limits (CPU, memory) are not set during creation; they must be configured manually in the container's config file or via other LXC commands after creation.


title: TEMPLATES
content:
LXC templates are executable scripts, typically found in <i>/usr/share/lxc/templates/</i>, that automate the setup of a container's root filesystem and basic configuration. They define the operating system (e.g., Ubuntu, Debian, Fedora, Alpine, BusyBox) and the initial state of the container. The flexibility of templates allows users to provision diverse container types efficiently. Arguments specified after the '<b>--</b>' option are passed directly to these template scripts, enabling customization like selecting a specific OS release or architecture.


title: CONTAINER CONFIGURATION FILE
content:
Upon creation, each LXC container receives its own configuration file, commonly located at <i>/var/lib/lxc/&lt;name&gt;/config</i>. This file is crucial as it dictates the container's behavior, including its root filesystem path, network configuration (e.g., bridge, veth pairs), cgroup limits for resource control (CPU, memory), and various mount points. While <i>lxc-create</i> sets up a basic configuration, administrators frequently modify this file post-creation to fine-tune the container's environment, such as assigning static IP addresses or adjusting resource allocations, following the syntax detailed in <i>lxc.container.conf(5)</i>.


title: HISTORY
content:
The LXC (Linux Containers) project emerged around 2008 as a pioneering lightweight virtualization technology, leveraging Linux kernel features like control groups (cgroups) and namespaces. <i>lxc-create</i> has been a cornerstone command since LXC's inception, providing a robust mechanism for provisioning new container instances. Its design, centered on extensible template scripts, has allowed it to adapt to various Linux distributions and support a growing array of storage backends (e.g., LVM, Btrfs, ZFS) as kernel capabilities evolved. While the container ecosystem has seen the rise of alternative technologies like Docker, <i>lxc-create</i> remains integral for users building and managing 'system containers' that closely mimic virtual machines, offering persistent and full operating system environments.


title: PARAMETERS
content:
<b>-n <i>name</i>, --name <i>name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the LXC container to be destroyed. This option is mandatory.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces the destruction of the container even if it is currently running. The command will attempt to stop the container before deleting it.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message and exits.<br><br><b>-v, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the version information and exits.<br><br>


title: DESCRIPTION
content:
The <b>lxc-destroy</b> command is used to permanently delete an LXC (Linux Container) instance from the system. When a container is destroyed, its entire root filesystem, configuration files, and any associated data are completely removed. This is an irreversible operation, and all data within the container will be lost. Before destruction, it's generally recommended that the container be stopped. If the container is still running and the -f or --force option is provided, <b>lxc-destroy</b> will first attempt to stop the container gracefully before proceeding with the deletion. This command is a critical part of managing the lifecycle of LXC containers, complementing <b>lxc-create</b> for container provisioning. It requires root privileges or sudo to execute successfully.


title: CAVEATS
content:
This is an <I>irreversible</I> and <I>destructive</I> operation. All data within the specified container will be permanently lost.<br>Ensure the correct container name is provided to avoid accidental data loss.<br>The command typically requires root privileges or <b>sudo</b> to execute.


title: USAGE EXAMPLE
content:
To destroy a container named "mycontainer", ensure it is stopped first or use the --force flag:<br><b>sudo lxc-stop</b> -n mycontainer<br><b>sudo lxc-destroy</b> -n mycontainer<br><br>To force destroy a running container:<br><b>sudo lxc-destroy</b> -n mycontainer --force


title: PERMISSIONS
content:
Executing <b>lxc-destroy</b> typically requires superuser privileges (<b>root</b> or <b>sudo</b>). Without sufficient permissions, the command will fail with an error indicating permission denied or that the container does not exist.


title: HISTORY
content:
<b>lxc-destroy</b> has been a fundamental command within the LXC project since its early days (around 2008-2009). As a core utility, its development has closely tracked the evolution of the LXC container runtime, providing a crucial mechanism for cleaning up and removing containers after their utility has expired, or to free up system resources. Its design emphasizes simplicity and direct action, reflecting the core philosophy of the LXC toolset.


title: SEE ALSO
content:
<I>lxc</I>(7), <I>lxc-create</I>(1), <I>lxc-start</I>(1), <I>lxc-stop</I>(1), <I>lxc-ls</I>(1), <I>lxc-info</I>(1)


title: SYNOPSIS
content:
<b>lxc-info</b> <i>-n name</i> [<i>-i</i>] [<i>-s</i>] [<i>-p</i>] [<i>-H</i>] [<i>--version</i>] [<i>-L</i>] [<i>-f config</i>]


title: PARAMETERS
content:
<b><i>-n name</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the <i>name</i> of the container to query. This option is mandatory.<br><br><b><i>-i</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the IP address(es) assigned to the container.<br><br><b><i>-s</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Shows the current state of the container (e.g., RUNNING, STOPPED, FROZEN).<br><br><b><i>-p</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Outputs the Process ID (PID) of the container's main process.<br><br><b><i>-H</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the header line from the output, useful for scripting or parsing.<br><br><b><i>--version</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version information of the <i>lxc-info</i> command.<br><br><b><i>-L</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the full path to the container's log file.<br><br><b><i>-f config</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternate <i>configuration file</i> for the container instead of the default location.<br><br>


title: DESCRIPTION
content:
<i>lxc-info</i> is a command-line utility within the Linux Containers (LXC) framework. Its primary purpose is to retrieve and display specific information about a designated LXC container. By default, when executed with only a container name, it provides the container's current state (e.g., RUNNING, STOPPED), its main process ID (PID), and its assigned IP address(es). Users can refine the output using various options: for instance, <i>-s</i> will only show the state, <i>-p</i> the PID, and <i>-i</i> the IP addresses. This command is essential for quickly checking the operational status and network connectivity of LXC containers, aiding in monitoring and troubleshooting tasks. It acts as a quick diagnostic tool for administrators managing containerized environments.


title: CAVEATS
content:
Requires root privileges or appropriate CAP_SYS_ADMIN capabilities to access container information.<br>The IP address reported is typically the one assigned to the container's main network interface. Multiple IPs might be shown if multiple interfaces are configured.<br>The command relies on the LXC system being properly configured and the container definition files being accessible.


title: DEFAULT OUTPUT
content:
If no specific display options (<i>-i</i>, <i>-s</i>, <i>-p</i>) are provided, <i>lxc-info</i> defaults to displaying the container's state, PID, and IP addresses. This provides a quick overview of the container's status without needing to specify multiple flags.


title: HISTORY
content:
LXC (Linux Containers) has been under active development since 2008, providing a lightweight virtualization solution prior to the widespread adoption of other container runtimes. <i>lxc-info</i> has been a fundamental utility within the LXC toolset from its early stages, serving as a basic but crucial command for querying the operational status of containers. Its functionality has remained largely consistent, reflecting its core role in container management. As LXC evolved, <i>lxc-info</i> continued to be an essential part of the suite, supporting quick diagnostics for container lifecycle management.


title: SYNOPSIS
content:
<pre>lxc-ls [options]</pre><p>This command lists LXC containers and their attributes. Options allow for filtering by state, custom output formats, and specifying container paths.</p>


title: PARAMETERS
content:
<b>-a, --all</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all containers, including those that are stopped or frozen. This is the default behavior.<br><br><b>-s, --stopped</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only list containers that are currently in the <i>STOPPED</i> state.<br><br><b>-r, --running</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only list containers that are currently in the <i>RUNNING</i> state.<br><br><b>-f, --fast</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Perform a fast listing. This option avoids querying the actual state of each container, making the command execute faster, especially with a large number of containers.<br><br><b>-P, --lxcpath &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify an alternative LXC path from which to list containers. By default, it uses the system-wide LXC path.<br><br><b>-F, --defined-path &lt;path&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Only show containers that are defined at the specified path, typically used within an LXC path.<br><br><b>-c, --config &lt;file&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use an alternative configuration file for LXC operations instead of the default.<br><br><b>-n, --name &lt;name&gt;</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Show details specifically for the container with the given name.<br><br><b>-L, --list-options</b><br>&nbsp;&nbsp;&nbsp;&nbsp;List all available output field options that can be used with the <code>-o</code> (<code>--output</code>) parameter.<br><br><b>-p, --print-defined-path</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the path where the container is defined, in addition to other details.<br><br><b>-o, --output &lt;field&gt;[,&lt;field&gt;...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify a comma-separated list of fields to output. Common fields include <i>name</i>, <i>state</i>, <i>ipv4</i>, <i>pid</i>, and <i>autostart</i>.<br><br><b>-H, --no-headers</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not print the header line when listing container information, useful for scripting.<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;Print the LXC version information and exit.<br><br>


title: DESCRIPTION
content:
<p>The <b><code>lxc-ls</code></b> command is a fundamental utility within the Linux Containers (LXC) framework, designed to enumerate and display information about existing LXC containers on a system. It provides a quick overview of which containers are defined, their current states (running, stopped, frozen, etc.), and other relevant details such as their IP addresses or unique identifiers.</p><br><p>By default, <b><code>lxc-ls</code></b> lists all containers. However, it offers various options to filter the output, allowing users to view only running containers, stopped containers, or to customize the displayed fields for more specific information. This command is crucial for container management, helping administrators and users quickly assess the container landscape and the operational status of their LXC environments.</p>


title: CAVEATS
content:
<ul><li><b><code>lxc-ls</code></b> is designed to interact specifically with containers managed by the LXC runtime. It will <i>not</i> list containers managed by other containerization technologies like Docker, Podman, or Kubernetes.</li><li>By default or when filtering by state (e.g., <code>-s</code>, <code>-r</code>), <b><code>lxc-ls</code></b> queries the state of each container, which can introduce a slight delay for a large number of containers. The <code>-f</code> (<code>--fast</code>) option can be used to skip state checks and speed up listing.</li></ul>


title: COMMON OUTPUT FIELDS FOR <CODE>-O</CODE>
content:
<p>When using the <code>-o</code> (<code>--output</code>) option, you can specify various fields to display. Common and useful fields include:</p><ul><li><code>name</code>: The name of the container.</li><li><code>state</code>: The current operational state (e.g., <i>RUNNING</i>, <i>STOPPED</i>, <i>FROZEN</i>).</li><li><code>ipv4</code>: The primary IPv4 address assigned to the container.</li><li><code>ipv6</code>: The primary IPv6 address assigned to the container.</li><li><code>pid</code>: The process ID of the container's init process.</li><li><code>autostart</code>: Indicates if the container is configured to autostart.</li><li><code>uuid</code>: The unique identifier of the container.</li><li><code>path</code>: The path where the container's configuration is defined.</li></ul><p>You can get a full list of supported fields by running <code>lxc-ls -L</code>.</p>


title: FILTERING CONTAINERS
content:
<p>While <b><code>lxc-ls</code></b> lists all containers by default, you can easily filter them using specific options:</p><pre><code>lxc-ls -r</code></pre><p>...will only list containers that are currently in the <i>RUNNING</i> state.</p><pre><code>lxc-ls -s</code></pre><p>...will only list containers that are currently in the <i>STOPPED</i> state.</p>


title: HISTORY
content:
<p>The <b><code>lxc-ls</code></b> command has been an integral part of the LXC project since its early days, evolving alongside the container technology itself. As a core utility, its development has focused on providing efficient and flexible ways to query the status of containers, adapting to new features and performance requirements of the LXC ecosystem. It is a fundamental tool for managing and overseeing LXC environments.</p>


title: SYNOPSIS
content:
<code><b>lxc-network</b></code> <i>command</i> [options]<br>Where <i>command</i> can be <code><b>up</b></code>, <code><b>down</b></code>, or <code><b>status</b></code>.


title: PARAMETERS
content:
<b>up</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Brings up and configures the default LXC network bridge (e.g., <code><b>lxcbr0</b></code>), typically assigning it an IP address and enabling NAT to the host's external network.<br><br><b>down</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Takes down and unconfigures the default LXC network bridge, releasing its resources.<br><br><b>status</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the current operational status of the default LXC network bridge, indicating if it is up, down, or misconfigured.<br><br>


title: DESCRIPTION
content:
<code><b>lxc-network</b></code> is a utility script integral to the Linux Containers (LXC) ecosystem, primarily designed to manage the default network bridge (<code><b>lxcbr0</b></code>) used by LXC containers. It provides a straightforward way to bring up, bring down, or check the status of this dedicated network interface, ensuring that containers have network connectivity to the host and external networks. While not a general-purpose network configuration tool, <code><b>lxc-network</b></code> simplifies the setup and teardown of the specific network infrastructure required for LXC, often being invoked automatically by LXC services or used by administrators for manual initialization and troubleshooting. It plays a crucial role in isolating container networks while enabling communication where needed.


title: CAVEATS
content:
<code><b>lxc-network</b></code> is primarily focused on the default LXC network setup (e.g., <code><b>lxcbr0</b></code>) and is not a general-purpose network management utility for all system interfaces. It requires root privileges to execute its commands as it modifies system network configurations. Its functionality may vary slightly across different LXC versions or Linux distributions, as it is often a wrapper script.


title: DEFAULT NETWORK BRIDGE (LXCBR0)
content:
The default LXC network bridge, <code><b>lxcbr0</b></code>, is a virtual Ethernet bridge created and managed by <code><b>lxc-network</b></code>. It acts as a central point for all containers to connect to, providing them with IP addresses (often via DHCP) and enabling them to communicate with each other and, through NAT, with the external network. This setup simplifies container networking significantly.


title: USAGE CONTEXT
content:
While <code><b>lxc-network</b></code> can be invoked manually by administrators, it is most often called automatically by the LXC system services or other <code><b>lxc</b></code> commands (like <code><b>lxc-start</b></code>) to ensure the necessary network infrastructure is in place before containers are launched. It's an essential background utility for LXC's default network configuration.


title: HISTORY
content:
The <code><b>lxc-network</b></code> script has been a fundamental component of the Linux Containers (LXC) project since its early days, evolving alongside the kernel's containerization features like cgroups and namespaces. Its purpose has consistently been to provide a simplified, consistent method for managing the default network bridge (<code><b>lxcbr0</b></code>) that enables network connectivity for LXC containers. It reflects LXC's design philosophy of providing robust yet easy-to-use tools for container lifecycle management.


title: PARAMETERS
content:
<b>list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Lists all available LXD profiles.<br><br><b>show <I>profile_name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays the YAML configuration of a specific profile.<br><br><b>create <I>profile_name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Creates a new empty profile.<br><br><b>edit <I>profile_name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Opens the specified profile's configuration in a text editor for modification.<br><br><b>apply <I>container_name</I> <I>profile_name</I> [<I>profile_name</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Applies one or more profiles to a specified container. Multiple profiles are merged, with later ones taking precedence.<br><br><b>delete <I>profile_name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Deletes an existing profile.<br><br><b>rename <I>old_profile_name</I> <I>new_profile_name</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Renames an existing profile.<br><br><b>copy <I>source_profile</I> <I>destination_profile</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Copies an existing profile to a new one.<br><br>


title: DESCRIPTION
content:
The `lxc-profile` command is an integral part of the <b>LXD</b> command-line client, specifically designed for managing container profiles. In the context of LXD, a profile is a named collection of configuration options and devices that can be easily applied to one or more containers. This mechanism allows administrators to define and reuse common configurations, such as network settings, resource limits, storage mounts, or specific device passthroughs. <br><br>By leveraging profiles, organizations can ensure consistency across their container deployments, standardize environments, and significantly reduce the overhead associated with configuring individual containers. The `lxc-profile` command provides a comprehensive set of subcommands to interact with these profiles, enabling users to <b>list</b> existing profiles, <b>show</b> their detailed configurations, <b>create</b> new ones, <b>edit</b> their properties, <b>copy</b> or <b>rename</b> them, <b>delete</b> unneeded profiles, and most importantly, <b>apply</b> them to containers. This centralized profile management approach enhances the flexibility and scalability of LXD-based container infrastructures.


title: CAVEATS
content:
Profiles are powerful tools that can significantly alter container behavior and security. Extreme care should be exercised when editing or applying them, especially in production environments.<br><br>When multiple profiles are applied to a container, their configurations are merged. In cases where the same configuration key is defined in multiple profiles, the setting from the <b>last applied profile</b> (or the one appearing last in the container's configuration output) takes precedence.<br><br>Deleting a profile using `lxc profile delete` does not automatically remove it from containers it's already applied to. Containers will continue to operate with the configuration they had before the profile's deletion until their configuration is explicitly updated.


title: DEFAULT PROFILE
content:
LXD automatically creates a <b>'default'</b> profile upon initialization. This profile is typically applied to all new containers by default, providing essential configurations like basic network connectivity. Users can modify this default profile or explicitly specify other profiles during container creation to override its settings.


title: PROFILE MERGING AND PRECEDENCE
content:
When a container has multiple profiles assigned, LXD merges their configurations. If a specific configuration key or device is defined in more than one applied profile, the setting from the profile that appears <i>last</i> in the container's list of applied profiles takes precedence. This order of precedence is crucial for understanding the final configuration of a container.


title: HISTORY
content:
The concept of profiles was introduced early in <b>LXD's</b> development, building upon the success of <b>LXC</b>. As a daemon designed for system containers, LXD needed a robust mechanism to manage common configurations efficiently. Profiles filled this gap, allowing for standardized environments and simplifying the deployment of complex container setups. The `lxc-profile` command provides the primary command-line interface for interacting with this powerful profile management system, evolving alongside LXD to support new features and configuration options.


title: PARAMETERS
content:
<b><code>-n, --name &lt;container_name&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies the name of the container to start. This is a mandatory option.<br><br><b><code>-F, --foreground</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Runs the container in the foreground. If a <i>command</i> is specified after <code>--</code>, this is the default behavior; otherwise, the container's init process runs in the foreground. The command waits for the container's process to exit.<br><br><b><code>-d, --daemon</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Runs the container in the background as a daemon. The <code>lxc-start</code> command will return immediately after successfully starting the container.<br><br><b><code>-f, --config &lt;config_file&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies an alternate configuration file for the container. By default, LXC looks for <code>lxc.conf</code> within the container's directory (e.g., <code>/var/lib/lxc/&lt;name&gt;/config</code>).<br><br><b><code>-o, --rcfile &lt;rc_file&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies a path to a file containing <code>lxc-start</code> options. Each non-empty line in the file is interpreted as a command-line argument.<br><br><b><code>-L, --logfile &lt;logfile_path&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies a path to the log file where <code>lxc-start</code>'s own logs will be written. By default, logs go to stderr or syslog.<br><br><b><code>-P, --logpriority &lt;priority&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Sets the log priority level for <code>lxc-start</code>'s output. Accepted values include TRACE, DEBUG, INFO, NOTICE, WARN, ERROR, and FATAL.<br><br><b><code>-c, --console &lt;tty_number&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Connects to a specific virtual console (TTY) of the container. If not specified, it connects to tty0. This implies foreground operation.<br><br><b><code>-t, --tty &lt;tty_number&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Equivalent to <code>--console</code>. Connects to a specific virtual console of the container.<br><br><b><code>-s, --setuid &lt;uid&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies the UID to drop privileges to after initializing the container, for unprivileged LXC environments.<br><br><b><code>-g, --setgid &lt;gid&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Specifies the GID to drop privileges to after initializing the container, for unprivileged LXC environments.<br><br><b><code>-W, --wait &lt;timeout&gt;</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Waits for a specified timeout (in seconds) for the container to reach the RUNNING state. The command returns a non-zero exit code if the timeout is exceeded.<br><br><b><code>--</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Separates <code>lxc-start</code> options from the command to be executed inside the container. If a command is specified, it replaces the container's default init process (e.g., <code>/sbin/init</code>) for this specific startup.<br><br><b><code>-v, --version</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Displays the program version number and exits.<br><br><b><code>-h, --help</code></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Displays a help message describing the command's options and exits.<br><br>


title: DESCRIPTION
content:
<code>lxc-start</code> is a command-line utility used to initiate a previously created and stopped Linux Containers (LXC) instance. It manages the complex process of bringing a container into an active, running state by handling kernel features like cgroup isolation and namespace creation (PID, UTS, IPC, network, mount, user). This command executes the container's configured init process or a specific command provided by the user.<br><br>Users can choose to run containers in the foreground, attaching to their console, or detach them to run in the background as a daemon. Successful startup heavily relies on proper container configuration, especially concerning network setup, storage mounts, and resource limits defined in the container's configuration file.


title: CAVEATS
content:
<ul><li><b>Root Privileges:</b> <code>lxc-start</code> typically requires root privileges to interact with kernel features like namespaces and cgroups, unless explicitly configured for unprivileged containers.</li><li><b>Container State:</b> The container must be in a 'STOPPED' state to be started. Attempting to start an already 'RUNNING' container will result in an error. Use <code>lxc-ls</code> to check the state.</li><li><b>Resource Availability:</b> Ensure the host system has sufficient resources (CPU, memory, disk I/O) to accommodate the container. Resource limits can be defined in the container's configuration.</li><li><b>Network Configuration:</b> Any network setup defined in the container's configuration file (<code>lxc.conf</code>) must be valid and supported by the host system to ensure proper network connectivity within the container.</li><li><b>Foreground vs. Daemon:</b> When running in foreground (<code>-F</code> or with <code>-- command</code>), closing the terminal will typically terminate the container's processes. For persistent background operation, the <code>-d</code> (daemon) option is recommended.</li></ul>


title: CONTAINER LIFECYCLE
content:
<code>lxc-start</code> is a critical step in the container's lifecycle, transitioning it from an inactive (STOPPED) state to an active, isolated environment. After starting, the container's init process (or the specified command after <code>--</code>) takes over, responsible for the container's internal operations and managing its services.


title: UNPRIVILEGED CONTAINERS
content:
While traditionally requiring root privileges, modern LXC implementations extensively support unprivileged containers. In such setups, <code>lxc-start</code> can be run by a non-root user, relying on user namespace remapping to achieve isolation without elevated privileges, significantly enhancing security.


title: HISTORY
content:
LXC (Linux Containers) emerged as an early lightweight virtualization technology, leveraging Linux kernel features like namespaces and cgroups that became available in the early 2000s. The <code>lxc-start</code> command is a core component of the LXC user-space tools, developed as part of the broader LXC project, which aimed to provide a user-friendly interface for managing containers. It predates and influenced the development of more modern container runtimes like Docker, demonstrating the fundamental principles of containerization before the rise of comprehensive container platforms. Its design and functionality have evolved with the Linux kernel and user-space tooling to support more robust isolation and resource management, including the advent of unprivileged containers.


title: PARAMETERS
content:
<b><b>-n</b> <I>&lt;name&gt;</I>, <b>--name</b> <I>&lt;name&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the name of the container to stop.<br><br><b><b>-t</b> <I>&lt;timeout&gt;</I>, <b>--timeout</b> <I>&lt;timeout&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the timeout in seconds for a graceful shutdown before resorting to <I>SIGKILL</I>. Default is 30 seconds.<br><br><b><b>-W</b>, <b>--wait</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Waits for the container to fully stop before the command exits.<br><br><b><b>-k</b>, <b>--kill</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Immediately sends a <I>SIGKILL</I> signal to the container, forcing an abrupt termination without graceful shutdown.<br><br><b><b>-r</b>, <b>--reboot</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Attempts to gracefully reboot the container instead of stopping it.<br><br><b><b>-a</b>, <b>--all</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Stops all currently running LXC containers on the host.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses output messages from the command.<br><br><b><b>-P</b> <I>&lt;path&gt;</I>, <b>--rcfile</b> <I>&lt;path&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies the LXC configuration file or directory to use.<br><br><b><b>-o</b> <I>&lt;file&gt;</I>, <b>--logfile</b> <I>&lt;file&gt;</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Writes log messages to the specified file.<br><br>


title: DESCRIPTION
content:
The <b>lxc-stop</b> command is used to gracefully or forcefully halt a running Linux Container (LXC). It initiates a shutdown by sending a <I>SIGPWR</I> signal to the container's <I>init</I> process, allowing for a clean termination of services and proper cleanup. If the container fails to stop within a specified or default timeout, <b>lxc-stop</b> escalates to a forceful termination using a <I>SIGKILL</I> signal, ensuring all container processes are immediately ended and its resources are released. This command is crucial for managing the lifecycle of LXC containers, enabling operations such as backup, migration, or removal. It supports stopping a specific container by name or halting all active containers on the host system.


title: CAVEATS
content:
Requires root privileges or appropriate capabilities (e.g., <I>CAP_SYS_ADMIN</I>).<br>Forceful termination (via <b>-k</b> or timeout) can lead to data corruption if container applications do not handle abrupt exits.<br>The <b>-r</b> option performs a graceful reboot, not a forceful one.


title: SHUTDOWN PROCESS DETAILS
content:
When invoked, <b>lxc-stop</b> first attempts a clean shutdown by sending a <I>SIGPWR</I> signal to the container's <I>init</I> process. This allows the <I>init</I> system (e.g., <I>systemd</I>, <I>sysvinit</I>) within the container to execute its configured shutdown scripts, ensuring services are terminated gracefully and data is synchronized to disk. If the container does not stop within the default 30-second timeout (or a user-specified timeout), <b>lxc-stop</b> will escalate to sending a <I>SIGKILL</I> signal. This signal immediately terminates all processes running inside the container, forcefully releasing its resources back to the host system.


title: PERMISSIONS
content:
Executing <b>lxc-stop</b> typically requires root privileges on the host system. This is necessary because the command interacts with system-level resources and processes managed by the kernel that are associated with the container. While unprivileged containers run with mapped UIDs/GIDs, operations like stopping them from the host still demand elevated permissions.


title: HISTORY
content:
LXC (Linux Containers) emerged as a key technology for lightweight virtualization, bridging the gap between simple chroot environments and full virtual machines. <b>lxc-stop</b> has been a fundamental utility since the early stages of LXC development, providing essential lifecycle management for containers. Its design incorporates both graceful shutdown mechanisms (similar to system <I>poweroff</I>) and forceful termination capabilities, crucial for unresponsive containers. Over time, options like <b>-t</b> for timeout and <b>-W</b> for waiting for completion have been integrated to enhance scripting and control, reflecting the evolving needs of container orchestration.


title: PARAMETERS
content:
<b><b>-dump</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Dumps the formatted output of a specified URL to standard output, without entering interactive mode. Useful for scripting and extracting content.<br><br><b><b>-crawl</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables the internal web crawler. Often used with <i>-dump</i> for automated content extraction and link discovery.<br><br><b><b>-anony</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disables sending personal information, such as email address or referrer, to remote sites, enhancing privacy.<br><br><b><b>-cfg=</b><i>file</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specifies an alternative configuration file to use instead of the default <i>lynx.cfg</i>, allowing custom settings.<br><br><b><b>-display_charset=</b><i>charset</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the character set for display output, useful for proper rendering of international characters.<br><br><b><b>-vikeys</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables VI-like key bindings for navigation within the browser, familiar to VI/Vim users.<br><br><b><b>-emacskeys</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables Emacs-like key bindings for navigation within the browser, familiar to Emacs users.<br><br><b><b>-reload</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Forces a reload of cached pages from the remote server, ensuring the latest content is displayed.<br><br><b><b>-width=</b><i>N</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the desired display width for text formatting, overriding the terminal's default width.<br><br><b><b>-restrict</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enables various restrictions on browsing, such as disallowing file access or saving content, for security or controlled environments.<br><br><b><b>-list_url</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints a list of all URLs found in the specified document to standard output, without entering interactive mode.<br><br>


title: DESCRIPTION
content:
<i>lynx</i> is a widely used text-based web browser that operates in a command-line environment. It allows users to browse websites, view documents, and navigate the internet without a graphical interface.<br><br>Renowned for its speed and low resource usage, <i>lynx</i> is particularly useful for low-bandwidth connections, scripting, accessibility (screen readers), and accessing information on servers without a GUI. It interprets HTML and displays text, links, and forms in a character-based format, making it an invaluable tool for developers, system administrators, and users who prefer terminal-based interactions.


title: CAVEATS
content:
<i>lynx</i> does not support JavaScript, Flash, Java applets, or other complex multimedia content. Modern web pages relying heavily on these technologies may not render correctly or be navigable, leading to a loss of visual context and layout. Security updates for <i>lynx</i> have been less frequent compared to graphical browsers, potentially leaving older versions vulnerable to unpatched issues. It also lacks support for CSS, which means page aesthetics are entirely lost.


title: ACCESSIBILITY
content:
<i>lynx</i> is highly valued for its accessibility features. Its text-only nature makes it ideal for use with screen readers and for users with visual impairments, providing a direct and uncluttered representation of web content without visual distractions.


title: SCRIPTING AND AUTOMATION
content:
Due to its command-line interface and powerful options like <i>-dump</i> and <i>-crawl</i>, <i>lynx</i> is frequently used in shell scripts for tasks such as scraping data, checking website availability, converting web pages to plain text, or generating sitemaps for further processing.


title: HISTORY
content:
Developed at the University of Kansas by Lou Montulli, Michael Grobe, and Charles Rezac, <i>lynx</i> was originally conceived in 1992 as a distributed information system client. It evolved into a full-fledged WWW browser in 1993, making it one of the oldest web browsers still in use today. Its early development predates graphical browsers like Mosaic, and it played a crucial role in making the internet accessible in a command-line environment, especially for educational and research institutions and for users with limited graphical capabilities.


title: SYNOPSIS
content:
<b>lzip</b> [<i>options</i>] [<i>files...</i>]<br><b>lzip -d</b> [<i>options</i>] [<i>files...</i>]<br><b>lzip --test</b> [<i>options</i>] [<i>files...</i>]


title: PARAMETERS
content:
<b><b>-d</b>, <b>--decompress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decompress files. This is the opposite of the default action.<br><br><b><b>-z</b>, <b>--compress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress files. This is the default action if no other action is specified.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrite existing output files without prompting.<br><br><b><b>-k</b>, <b>--keep</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not delete input files after successful compression or decompression.<br><br><b><b>-c</b>, <b>--stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to standard output; keep input files unchanged. Useful for piping.<br><br><b><b>-t</b>, <b>--test</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Test the integrity of compressed files by decompressing them in memory.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all warning and informational messages.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Increase verbosity, showing progress and detailed information.<br><br><b><b>-0</b>..<b>-9</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the compression level. <b>-0</b> provides the fastest compression with the least compression ratio, while <b>-9</b> provides the best compression ratio but is the slowest. The default level is 6.<br><br><b><b>--fast</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Equivalent to <b>-0</b>, selects the fastest compression method.<br><br><b><b>--best</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Equivalent to <b>-9</b>, selects the best compression method.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Output version information and exit.<br><br>


title: DESCRIPTION
content:
<i><b>lzip</b></i> is a free, open-source data compressor based on the Lempel-Ziv-Markov chain Algorithm (LZMA). It is designed for high compression ratios and robust data integrity, making it particularly suitable for long-term archiving and data distribution.<br><br><i><b>lzip</b></i> employs a dictionary-based compression method, which allows it to achieve significantly better compression than older algorithms like Deflate (used by <i><b>gzip</b></i>) or Burrows-Wheeler (used by <i><b>bzip2</b></i>). A key feature is its strong data integrity, incorporating a 64-bit checksum to reliably detect corruption. While it offers excellent compression and good decompression speeds, compression itself can be slower than very fast compressors like <i><b>lz4</b></i> or <i><b>lzop</b></i>, and it may require more memory, especially for higher compression levels. Files compressed with <i><b>lzip</b></i> typically carry a <i>.lz</i> extension.


title: CAVEATS
content:
The command '<i>lz</i>' itself is not a standard, universally installed Linux command and is often a common misconception or refers to an alias. This analysis describes the functionalities of '<i><b>lzip</b></i>', which is a widely used data compressor that utilizes the LZMA algorithm and typically creates files with a <i>.lz</i> extension.<br><br>While <i><b>lzip</b></i> offers superior compression ratios compared to older tools like <i><b>gzip</b></i> or <i><b>bzip2</b></i>, its compression process can be significantly slower. It can also be memory intensive, particularly when compressing large files or using higher compression levels. Decompression, however, is generally fast.


title: HISTORY
content:
The <i><b>lzip</b></i> compressor was created by Antonio Diaz Diaz, with its first stable version released in 2008. Its development was primarily motivated by the need for a free, efficient, and robust compressor specifically designed for long-term data archiving. Leveraging the powerful LZMA algorithm, <i><b>lzip</b></i> was developed to offer superior compression capabilities and strong data integrity checking, aiming to be a better alternative to proprietary or less efficient compression formats for critical archival purposes.


title: SYNOPSIS
content:
<b>lz4</b> [<i>OPTIONS</i>] [<i>FILE...</i>]<br><b>lz4</b> <b>-d</b> [<i>OPTIONS</i>] [<i>FILE...</i>]<br><b>unlz4</b> [<i>OPTIONS</i>] [<i>FILE...</i>]


title: PARAMETERS
content:
<b><b>-d</b>, <b>--decompress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decompress files.<br><br><b><b>-z</b>, <b>--compress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Compress files (default action).<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwrite of existing output files.<br><br><b><b>-k</b>, <b>--keep</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not delete source files after successful operation.<br><br><b><b>-1</b> to <b>-12</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set compression level (1 is fastest, 12 is high compression).<br><br><b><b>-l</b>, <b>--fast</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Alias for compression level 1 (fastest).<br><br><b><b>-B</b><i>SIZE</i>, <b>--block-size</b><i>SIZE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set frame block size (e.g., 4KB, 64KB, 256KB, 1MB, 4MB).<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all messages.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output.<br><br><b><b>-c</b>, <b>--stdout</b>, <b>--to-stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to standard output, keep original files.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Operate on files and directories recursively.<br><br><b><b>--rm-suffix</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force removal of <i>.lz4</i> suffix when decompressing.<br><br><b><b>--no-checksum</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Disable checksums for increased speed (not recommended for critical data).<br><br>


title: DESCRIPTION
content:
The <b>lz4</b> command is a high-performance lossless data compression utility that leverages the LZ4 algorithm. It is primarily known for its incredibly fast compression and decompression speeds, often surpassing other common compressors like gzip or bzip2. This speed comes at the cost of a slightly lower compression ratio, making <b>lz4</b> ideal for scenarios where throughput is more critical than absolute file size reduction. <br><br>Typical use cases include compressing large log files, speeding up backups, in-memory data compression, and real-time data processing. <b>lz4</b> can operate on standard input/output, process specified files, and supports recursive operations on directories. It creates files with a <i>.lz4</i> extension by default and can easily decompress them back to their original form.


title: CAVEATS
content:
While exceptionally fast, <b>lz4</b> generally provides a lower compression ratio compared to algorithms like <i>gzip</i>, <i>bzip2</i>, or <i>xz</i>. Users should choose <b>lz4</b> when speed is the primary concern over maximum file size reduction. Also, content checksums are optional in the LZ4 stream format and might need to be explicitly enabled (or disabled) for enhanced data integrity or speed optimization respectively.


title: COMPRESSION LEVELS AND MODES
content:
<b>lz4</b> offers a range of compression levels (from <i>-1</i> for fastest to <i>-12</i> for higher compression ratio, albeit still very fast). It also supports different stream modes, including independent blocks for parallel processing and optional checksums for data integrity, which can be configured via specific options. These features allow users to fine-tune the balance between speed, compression, and data safety for diverse applications.


title: HISTORY
content:
The LZ4 algorithm and the <b>lz4</b> command-line utility were developed by Yann Collet, with the first public release occurring in 2011. It was designed from the ground up to prioritize extreme speed in both compression and decompression. Its high performance has led to widespread adoption across various industries and applications, including fast storage systems (like ZFS and Btrfs), databases (e.g., RocksDB, ClickHouse), and network communication protocols, making it a staple for high-throughput data processing.


title: SYNOPSIS
content:
<br><code>lzcat [<i>OPTION</i>]... [<i>FILE</i>]...</code><br><br><i><br>Example:</i><br><code>lzcat document.xz</code><br><code>lzcat archive.lzma > output.txt</code><br><code>ls -l /var/log/ | lzcat -</code> (for a compressed stream from stdin)


title: PARAMETERS
content:
<b><i>FILE</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the .xz or .lzma compressed file(s) to decompress. If no file is specified, or if <i>FILE</i> is `-`, `lzcat` reads from <i>standard input</i>.<br><br><b><b>-d</b>, <b>--decompress</b>, <b>--uncompress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;These options are implied by `lzcat` and explicitly decompress the input file(s).<br><br><b><b>-k</b>, <b>--keep</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not delete input files after successful decompression. By default, the original compressed file is removed.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force decompression, even if the output file already exists, or if there are multiple hard links to the input file, or if there are read or write errors.<br><br><b><b>-c</b>, <b>--stdout</b>, <b>--to-stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to <i>standard output</i>. This is the default and primary behavior of `lzcat`.<br><br><b><b>-q</b>, <b>--quiet</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all warnings and error messages.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display verbose information (e.g., compression ratio, file names) during processing.<br><br><b><b>-S</b> <i>SUFFIX</i>, <b>--suffix=</b><i>SUFFIX</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the suffix of compressed files. The default suffix is `.xz` or `.lzma`.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message and exit.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<i>lzcat</i> is a command-line utility used to decompress files compressed with the <i>LZMA</i> or <i>XZ</i> compression algorithms and print their uncompressed content to <i>standard output</i> (stdout). It functions similarly to the standard `cat` command, but for compressed data. It is typically a symbolic link to `xzcat` or directly to the `xz` executable with the decompression (`-d`) and output to stdout (`-c`) flags implicitly set.<br><br>This makes it convenient for quickly viewing the content of a compressed file without explicitly decompressing it to disk, or for piping its uncompressed output to other commands for further processing. For instance, `lzcat file.xz | grep "pattern"` allows searching within a compressed file without extracting it first. It only performs decompression; it cannot be used for compression.


title: CAVEATS
content:
<ul><li>`lzcat` is typically a symbolic link or a script wrapper for `xz -d -c`. Its behavior is therefore largely governed by the underlying `xz` utility.</li><li>It only handles decompression; it cannot compress files.</li><li>It primarily outputs to <i>standard output</i>. If you want to save the decompressed content to a file, you must redirect the output (e.g., `lzcat file.xz > output.txt`).</li><li>It expects `.xz` or `.lzma` file formats. It will not work for `.gz`, `.bz2`, or other compressed file types.</li></ul>


title: <I>USAGE EXAMPLES</I>
content:
<ul><li>`<b>lzcat document.xz</b>`: Decompress `document.xz` and print its content to the terminal.</li><li>`<b>lzcat access.log.xz | less</b>`: View the content of a compressed log file page by page.</li><li>`<b>lzcat old_data.tar.lzma > new_data.tar</b>`: Decompress `old_data.tar.lzma` and save the uncompressed tar archive as `new_data.tar`.</li><li>`<b>curl example.com/file.xz | lzcat</b>`: Download a compressed file from the internet and decompress it on-the-fly, printing to stdout.</li><li>`<b>lzcat -k myfile.xz</b>`: Decompress `myfile.xz` to stdout, but keep the original `myfile.xz` file.</li></ul>


title: <I>EXIT STATUS</I>
content:
<ul><li>`0`: Success.</li><li>`1`: An error occurred.</li><li>`2`: Something went wrong with the input file(s).</li></ul>


title: HISTORY
content:
The `lzcat` command is part of the `xz` utilities, which were developed to provide superior compression ratios compared to older tools like `gzip` and `bzip2`. `xz` and the underlying <i>LZMA2</i> compression format gained prominence in the Linux ecosystem, becoming the default compression for many package managers and archives (e.g., `.tar.xz` archives). `lzcat` (and `xzcat`) was introduced to provide a familiar `cat`-like interface for viewing these modern compressed files, mirroring the functionality of `zcat` and `bzcat` for their respective formats. Development of the `xz` tools began around 2005-2006.


title: PARAMETERS
content:
<b>FILE1</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the first LZMA or XZ compressed file to compare.<br><br><b>[FILE2]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;The path to the second LZMA or XZ compressed file to compare. If omitted, the behavior might vary or result in an error depending on the underlying `cmp` implementation, as `cmp` typically requires two files for comparison.<br><br><b>[CMP_OPTIONS]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Options to be passed directly to the underlying <b>cmp</b> utility. These options, such as <i>-s</i> (silent mode) or <i>-l</i> (detailed byte-by-byte listing), control the comparison behavior itself. They are typically placed before or after the filenames depending on the specific `cmp` implementation and context.<br><br><b>[XZ_OPTIONS]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Options specific to the <b>xz</b> or <b>lzma</b> decompression utility. These options, such as <i>-q</i> (quiet mode during decompression), typically need to be placed before the filenames. They control the decompression process itself and not the comparison.<br><br>


title: DESCRIPTION
content:
The <b>lzcmp</b> command is a utility designed to compare two LZMA or XZ compressed files without the need for manual decompression. It acts as a shell script wrapper around the standard <b>cmp</b> command, leveraging the <b>xz</b> or <b>lzma</b> utilities to decompress the files on-the-fly via pipes. This allows for efficient byte-by-byte comparison of large compressed archives, saving disk space and avoiding the creation of temporary uncompressed files.<br><br>When invoked, <b>lzcmp</b> pipes the decompressed content of each specified file to <b>cmp</b>, which then performs the comparison. By default, it uses <b>cmp</b> to determine if the files are identical or where the first difference occurs. If the files are identical, <b>lzcmp</b> exits with a status of 0. If they differ, it exits with a non-zero status.<br><br>While primarily designed for `cmp` functionality, similar tools like `lzdiff` (or `xzdiff`) exist for `diff`-style comparisons. <b>lzcmp</b> is part of the `xz` utilities package, which supersedes the older `lzma` utilities, providing robust compression and decompression capabilities.


title: CAVEATS
content:
<ul><li><b>Dependency:</b> <b>lzcmp</b> relies on the presence of the `cmp` utility and either `xz` or `lzma` for decompression. Without these, it cannot function.</li><li><b>Performance:</b> Comparing large compressed files can still be CPU and I/O intensive due to the on-the-fly decompression.</li><li><b>Error Handling:</b> Errors during decompression (e.g., corrupt archives) or comparison (e.g., permission issues) will result in a non-zero exit status, often greater than 1.</li><li><b>Wrapper Nature:</b> As a shell script wrapper, its exact behavior and supported options can sometimes depend on the specific implementation of the script on your system, or the versions of `cmp` and `xz`/`lzma` installed.</li></ul>


title: EXIT STATUS
content:
The exit status of <b>lzcmp</b> primarily reflects the exit status of the underlying <b>cmp</b> command:<br><i>0</i>: The files are identical.<br><i>1</i>: The files differ.<br><i>&gt;1</i>: An error occurred (e.g., invalid arguments, input/output error, or cannot open a file).


title: ENVIRONMENT VARIABLES
content:
<b>lzcmp</b> respects the following environment variables, which can override the default comparator program:<br><i>CMP</i>: Specifies the path to the `cmp` utility to be used instead of the default `/usr/bin/cmp`.<br><i>DIFF</i>: While <b>lzcmp</b> primarily uses `cmp`, this variable is relevant for its `lzdiff` (or `xzdiff`) counterpart, allowing specification of the `diff` utility to use.


title: HISTORY
content:
The <b>lzcmp</b> command is part of the `xz` utilities, which are the modern successor to the `lzma` utilities. Its development lineage traces back to the need for efficient handling of compressed files in Unix-like systems. Before such wrappers, users would manually decompress files to temporary locations, compare them, and then delete the temporary files. This was cumbersome and inefficient. The creation of `lzcmp` (and its counterparts like `xzcmp` and `lzdiff`) streamlined this process by transparently piping decompressed content to comparison tools, making it a staple for developers and system administrators working with compressed data. It embodies the Unix philosophy of combining small, specialized tools (like `cmp` and `xz`) to achieve a more complex task.


title: PARAMETERS
content:
<b><I>PATTERN</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>The regular expression or fixed string to search for within the compressed files.</I><br><br><b><I>FILE...</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>One or more paths to lzip-compressed files (<I>.lz</I>) to be searched. If no files are specified, <I>lzegrep</I> reads from standard input, which must be lzip-compressed data.</I><br><br><b>[<I>grep_options</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<I>Any valid option supported by the <I>grep</I> command. <I>lzegrep</I> passes these options directly to the underlying <I>grep</I> process. Common options include:</I><br><I>-i, --ignore-case</I>: <I>Ignore case distinctions.</I><br><I>-v, --invert-match</I>: <I>Select non-matching lines.</I><br><I>-n, --line-number</I>: <I>Prefix output lines with line numbers.</I><br><I>-l, --files-with-matches</I>: <I>Print only names of files containing matches.</I><br><I>-c, --count</I>: <I>Print only a count of matching lines.</I><br><I>-E, --extended-regexp</I>: <I>Interpret PATTERN as an extended regular expression (like <I>egrep</I>).</I><br><I>-F, --fixed-strings</I>: <I>Interpret PATTERN as a list of fixed strings (like <I>fgrep</I>).</I><br><br>


title: DESCRIPTION
content:
<I>lzegrep</I> is a utility program provided as part of the <I>lzip</I> compression suite. It enables users to search for regular expression patterns within files compressed using the <I>lzip</I> format (typically identified by the <I>.lz</I> extension) without needing to decompress them first. Functionally, it acts as a wrapper around the <I>lzip</I> decompressor and the standard <I>grep</I> command. When invoked, <I>lzegrep</I> pipes the decompressed output of the specified <I>.lz</I> files to <I>grep</I>, which then performs the pattern matching. This significantly streamlines the workflow for handling compressed logs, archives, or data, saving disk space and time by avoiding explicit decompression. It supports most standard <I>grep</I> options, passing them directly to the underlying <I>grep</I> command, allowing for flexible and powerful searches.


title: CAVEATS
content:
<I>Dependency</I>: <I>lzegrep</I> requires both <I>lzip</I> and <I>grep</I> to be installed and accessible in the system's PATH.<br><I>Performance</I>: While convenient, searching compressed files involves on-the-fly decompression, which can be slower than searching uncompressed files directly, especially for very large files or on systems with limited CPU resources.<br><I>No Native Directory Recursion</I>: Unlike some <I>grep</I> implementations with <I>-r</I>, <I>lzegrep</I> itself does not natively traverse directories to find <I>.lz</I> files. Users typically combine it with <I>find</I> to search across multiple directories (e.g., <I>find . -name "*.lz" -print0 | xargs -0 lzegrep "pattern"</I>).<br><I>Archive Content Limitation</I>: It searches individual <I>.lz</I> files, not contents of archives like <I>tar.lz</I> directly. To search such archives, they would need to be first extracted or piped via <I>tar -xO</I> or similar commands.


title: UNDERLYING MECHANISM
content:
<I>lzegrep</I> is typically a shell script that acts as a simple wrapper. It executes the command <I>lzip -cd</I> (decompress to standard output) on the specified <I>.lz</I> files and pipes the resulting decompressed stream to the standard input of the <I>grep</I> command. All arguments provided to <I>lzegrep</I> after the command name are passed directly to <I>grep</I> once the decompression pipeline is established. This simple yet effective approach allows it to leverage the full power and options of the standard <I>grep</I> utility on compressed data.


title: USAGE EXAMPLES
content:
<I>Search for a pattern in a single lzip file:</I><br>lzegrep "error message" log.lz<br><I>Search case-insensitively across multiple lzip files:</I><br>lzegrep -i "keyword" report_*.lz<br><I>Find files containing a specific phrase without showing the lines:</I><br>lzegrep -l "critical failure" data/*.lz<br><I>Search all lzip files recursively in current directory for a pattern:</I><br>find . -name "*.lz" -print0 | xargs -0 lzegrep "target string"


title: HISTORY
content:
<I>lzegrep</I> is part of the <I>lzip</I> utilities, a compression program developed by Antonio Diaz Diaz. <I>lzip</I> utilizes the LZMA algorithm, known for its high compression ratios and data integrity features. Conceived as a modern alternative to existing compression formats, <I>lzip</I> introduced a suite of complementary tools, including <I>lzegrep</I>, to facilitate common operations on <I>.lz</I> files. Its inclusion mirrors the functionality provided by <I>zgrep</I> for <I>gzip</I> files, acknowledging the common need to search through compressed data without manual decompression steps. Its development is inherently linked to the evolution of the <I>lzip</I> format itself, providing essential usability for its users.


title: SEE ALSO
content:
<I>grep(1)</I>, <I>lzip(1)</I>, <I>lzcat(1)</I>, <I>zgrep(1)</I>, <I>bzgrep(1)</I>, <I>xzgrep(1)</I>, <I>find(1)</I>


title: PARAMETERS
content:
<b>-i, --ignore-case</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Ignore case distinctions in both the <i>PATTERNS</i> and the input files.<br><br><b>-v, --invert-match</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Invert the sense of matching, to select non-matching lines.<br><br><b>-r, --recursive</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read all files under each directory, recursively, following symbolic links only if they are on the command line.<br><br><b>-n, --line-number</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prefix each line of output with the 1-based line number within its input file.<br><br><b>-c, --count</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress normal output; instead print a count of matching lines for each input file.<br><br><b>-l, --files-with-matches</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>-L, --files-without-matches</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress normal output; instead print the name of each input file from which no output would normally have been printed.<br><br><b>-w, --word-regexp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select only those lines containing matches that form whole words.<br><br><b>-x, --line-regexp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Select only those matches that match the whole line.<br><br><b>-A NUM, --after-context=NUM</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of trailing context after matching lines.<br><br><b>-B NUM, --before-context=NUM</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of leading context before matching lines.<br><br><b>-C NUM, --context=NUM</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of output context around matching lines.<br><br><b>-E, --extended-regexp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERNS</i> as extended regular expressions (EREs).<br><br><b>-F, --fixed-strings</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERNS</i> as fixed strings, not regular expressions.<br><br><b>-P, --perl-regexp</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERNS</i> as Perl regular expressions (PRCE).<br><br>


title: DESCRIPTION
content:
<i>lzfgrep</i> is a hypothetical command, conceptualized to mimic the functionality of <i>lzgrep</i>. Its purpose would be to allow users to efficiently search for text patterns within files compressed using the LZMA algorithm (commonly found with <i>.lzma</i> or <i>.lz</i> extensions) without requiring manual decompression.<br><br>Functionally, <i>lzfgrep</i> would act as a wrapper around the standard <i>grep</i> utility. It would transparently decompress the content of the specified LZMA file on-the-fly and pipe this uncompressed stream directly to <i>grep</i>. This method offers significant advantages in terms of disk space utilization and workflow efficiency when dealing with large compressed datasets. Like its counterparts, <i>lzfgrep</i> would likely support the vast majority of standard <i>grep</i> options, enabling fine-grained control over search behavior, output formatting, and context display.


title: CAVEATS
content:
<i>lzfgrep</i> is not a standard Linux command and is generally not found in default distributions. Its analysis here is based on inferring its functionality from common naming conventions for compressed file utilities (e.g., <i>zgrep</i>, <i>lzgrep</i>). If encountered, it is most likely a custom alias, a user-defined script, or potentially a typo for <i>lzgrep</i>. Users should verify its existence and behavior in their specific environment.<br><br>Its operational efficiency would rely heavily on the performance of the underlying LZMA decompression utility (such as <i>lzip</i>) and the standard <i>grep</i> command. Handling of corrupted or malformed compressed files would depend on the robustness of the chosen decompression tool.


title: TYPICAL USAGE SCENARIO
content:
<i>lzfgrep</i> would be invaluable for system administrators, data analysts, or developers who frequently work with large log files, database backups, or archives that are stored in LZMA compressed format to conserve disk space. Instead of enduring the time-consuming process of decompressing a multi-gigabyte file just to perform a quick search, <i>lzfgrep</i> would allow for immediate, on-the-fly pattern matching, thereby minimizing temporary storage requirements and speeding up diagnostic or analysis tasks.


title: UNDERLYING MECHANISM (HYPOTHETICAL)
content:
A theoretical implementation of <i>lzfgrep</i> would typically leverage a pipeline involving a decompression utility. It would likely execute a command similar to `lzip -cd <compressed_file>` to decompress the file's content to standard output, and then pipe this output directly to the standard <i>grep</i> command, passing along all user-specified patterns and options. This 'decompress-on-the-fly' piping mechanism is a common and robust approach for all *grep utilities, ensuring compatibility with <i>grep</i>'s powerful regular expression and filtering capabilities.


title: HISTORY
content:
The design concept of <i>lzfgrep</i> is a continuation of the established pattern set by utilities like <i>zgrep</i>, which enabled searching within <i>gzip</i> compressed files without explicit decompression. As more efficient compression algorithms like LZMA (Lempel–Ziv–Markov chain algorithm) became prevalent, the need for similar transparent search capabilities arose. This led to the development of tools like <i>lzgrep</i> (part of the <i>lzip</i> utility suite). While <i>lzfgrep</i> itself is not a historically standard command, its hypothetical existence reflects the ongoing evolution of command-line tools to provide seamless interaction with diverse compressed data formats.


title: PARAMETERS
content:
<b><i>grep_options</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i><b>lzgrep</b></i> is primarily a wrapper around <i><b>grep</b></i>. All options provided to <i><b>lzgrep</b></i> (except those handled by the wrapper script itself, which are rare) are passed directly to the underlying <i><b>grep</b></i> command. This means you can use most standard <i><b>grep</b></i> options, such as:<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;Invert the sense of matching, to select non-matching lines.<br><br><b><b>-c</b>, <b>--count</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress normal output; instead print a count of matching lines for each input file.<br><br><b><b>-n</b>, <b>--line-number</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print the 1-based line number with each output line.<br><br><b><b>-r</b>, <b>--recursive</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Read all files under each directory, recursively. This option is typically handled by <i><b>grep</b></i> itself.<br><br><b><b>-A</b> <i>NUM</i>, <b>--after-context=</b><i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of trailing context after matching lines.<br><br><b><b>-B</b> <i>NUM</i>, <b>--before-context=</b><i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of leading context before matching lines.<br><br><b><b>-C</b> <i>NUM</i>, <b>--context=</b><i>NUM</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print <i>NUM</i> lines of context (<i>NUM</i> lines before and <i>NUM</i> lines after) around matching lines.<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>-F</b>, <b>--fixed-strings</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Interpret <i>PATTERN</i> as a list of fixed strings, separated by newlines, any of which is to be matched.<br><br><b><b>-a</b>, <b>--text</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Process a binary file as if it were text. This is particularly relevant for <i><b>lzgrep</b></i>, as compressed files are inherently binary.<br><br><b><i>PATTERN</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;The regular expression or fixed string to search for.<br><br><b><i>FILE...</i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more <i>.xz</i> or <i>.lzma</i> compressed files (or plain text files) to search. If no <i>FILE</i> is specified, <i><b>lzgrep</b></i> reads from standard input.<br><br>


title: DESCRIPTION
content:
<i><b>lzgrep</b></i> allows users to search for patterns within files compressed with the <i>LZMA</i> or <i>XZ</i> compression algorithms (typically with <i>.xz</i> or <i>.lzma</i> extensions) without explicitly decompressing them first. It functions as a convenient wrapper around the standard <i><b>grep</b></i> utility, piping the decompressed output of a utility like <i><b>xzcat</b></i> or <i><b>lzcat</b></i> directly into <i><b>grep</b></i>. This eliminates the need for manual decompression and re-compression, streamlining the process of searching through compressed logs, archives, and other data. <i><b>lzgrep</b></i> supports most of <i><b>grep</b></i>'s standard options, making it a familiar and powerful tool for regular expression searching on compressed data.


title: CAVEATS
content:
<i><b>lzgrep</b></i>'s performance depends on the decompression speed of the underlying utility (<i><b>xzcat</b></i>/<i><b>lzcat</b></i>) and the processing speed of <i><b>grep</b></i>. Searching very large compressed files can be slower than searching uncompressed versions.<br><br>It relies on the presence and correct functioning of the <i><b>xz</b></i> utilities suite. If a compressed file is corrupted, <i><b>lzgrep</b></i> might fail or produce incomplete output, as the decompression utility will encounter an error.<br><br>While primarily designed for <i>.xz</i> and <i>.lzma</i> files, some <code>xzgrep</code> implementations (which <code>lzgrep</code> often points to) might attempt to handle other compressed formats like <i>.gz</i> or <i>.bz2</i> if the appropriate decompression tools are available and detected based on file extensions.


title: HOW IT WORKS
content:
At its core, <i><b>lzgrep</b></i> operates by piping the output of a decompression command to <i><b>grep</b></i>. For example, when you run <code>lzgrep 'pattern' file.xz</code>, it internally executes something similar to <code>xzcat file.xz | grep 'pattern'</code>. This on-the-fly decompression and piping allow seamless searching without creating temporary uncompressed files.


title: SUPPORTED FILE TYPES
content:
<i><b>lzgrep</b></i> is specifically designed for files compressed with the <i>LZMA</i> and <i>XZ</i> algorithms, typically identified by <i>.xz</i> or <i>.lzma</i> file extensions. While some <code>xzgrep</code> implementations might have logic to detect and handle other compression types (like <i>.gz</i> or <i>.bz2</i>) if the corresponding decompression utilities are present, its primary and guaranteed function is with <i>XZ</i>-compressed data.


title: HISTORY
content:
<i><b>lzgrep</b></i> emerged as part of the <i><b>xz</b></i> utilities package, which provides command-line tools for <i>LZMA</i> and <i>XZ</i> compression. Its development was driven by the need to offer functionality analogous to <i><b>zgrep</b></i> (for <i>gzip</i> files) and <i><b>bzgrep</b></i> (for <i>bzip2</i> files), but for the more modern and often more efficient <i>XZ</i> compression format. It typically exists as a shell script wrapper or a symlink to <i><b>xzgrep</b></i>, embodying a common Unix philosophy of combining existing, robust tools (like <i><b>grep</b></i> and <i><b>xzcat</b></i>) to create new, specialized functionalities without reinventing the wheel.


title: SYNOPSIS
content:
<b>lzip</b> [<i>option</i>]... [<i>file</i>]...<br><b>lzip</b> -d | --decompress [<i>option</i>]... [<i>file</i>]...


title: PARAMETERS
content:
<b>-0...-9</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set compression level. <i>-0</i> is fastest, <i>-9</i> is best compression. Default is <i>-6</i>.<br><br><b>--fast</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Alias for compression level <i>-0</i>.<br><br><b>--best</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Alias for compression level <i>-9</i>.<br><br><b>-c, --stdout, --to-stdout</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to standard output, keep original files.<br><br><b>-d, --decompress</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decompress files.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Overwrite existing output files without prompting.<br><br><b>-h, --help</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display help message and exit.<br><br><b>-k, --keep</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Keep (don't delete) original input files after compression/decompression.<br><br><b>-L, --lazy</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use lazy match finding. Improves compression ratio at the expense of speed.<br><br><b>-m, --memory=<i><limit></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set memory usage limit for compression (e.g., <i>20MB</i>, <i>100%</i>).<br><br><b>-o, --output=<i><file></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to a specific <i>file</i> instead of modifying the original.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppress all messages and warnings.<br><br><b>-S, --suffix=<i><suffix></i></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Use a specified <i>suffix</i> (e.g., <i>.lz</i>) instead of the default <i>.lz</i> for compressed files.<br><br><b>-t, --test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Test compressed file integrity without decompressing.<br><br><b>-U, --uncompressed</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Restore uncompressed size. Primarily used with <i>--force</i> when target disk space might be an issue.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Print verbose messages during operation.<br><br><b>-V, --version</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display version information and exit.<br><br>


title: DESCRIPTION
content:
<b>lzip</b> is a free, powerful, and lossless data compressor based on the <i>LZMA</i> (Lempel-Ziv-Markov chain Algorithm) algorithm. It aims for a very high compression ratio, often surpassing <b>gzip</b>, <b>bzip2</b>, and even <b>xz</b> for many data types, especially large files. While <b>lzip</b> offers superior compression, it typically comes at the cost of increased compression and decompression time, and higher memory consumption during the compression phase. <br><br>It processes single files, replacing the original with a compressed version, or can output to standard output. <b>lzip</b> is designed with data integrity in mind, including an integrity check (CRC-32) in its file format to detect corruption. Its primary use case is for archiving and distributing large files where maximum compression is desired, and speed is less critical than file size.


title: CAVEATS
content:
While <b>lzip</b> offers excellent compression, its main drawbacks are:<br><i>Speed</i>: Both compression and decompression can be significantly slower than <b>gzip</b> or <b>bzip2</b>, and often <b>xz</b>.<br><i>Memory Usage</i>: Compression, especially at higher levels, can consume a substantial amount of RAM. Decompression uses less but still more than <b>gzip</b>.<br><i>Parallelism</i>: The standard <b>lzip</b> program is single-threaded. For parallel operation, <b>plzip</b> (parallel lzip) is available, but it's a separate utility.<br><i>Adoption</i>: Less widely adopted than <b>gzip</b> or <b>xz</b>, which might make it less convenient for general file distribution without prior coordination.


title: FILE INTEGRITY
content:
The <b>lzip</b> file format includes a 32-bit CRC (Cyclic Redundancy Check) to ensure data integrity. This allows detection of corrupted files during decompression or testing.


title: LONG-TERM ARCHIVING
content:
Due to its stable file format, strong integrity checks, and high compression ratio, <b>lzip</b> is considered suitable for long-term data archiving where data fidelity is paramount.


title: CONVENIENCE SCRIPTS
content:
<b>lzip</b> typically comes with helper scripts like <b>lzcat</b> (for decompressing to stdout), <b>lzless</b> (for viewing compressed text files), <b>lzdiff</b> (for comparing compressed files), and <b>lzgrep</b> (for searching patterns in compressed files).


title: HISTORY
content:
The <b>lzip</b> project, led by Antonio Diaz Diaz, began in 2008 with the goal of providing a free and open-source implementation of the <i>LZMA</i> algorithm, focusing on a clean and robust file format suitable for long-term archiving. It was designed to address perceived limitations in other LZMA implementations, such as <b>lzma</b> (part of XZ Utils prior to XZ) regarding data integrity and format stability. The project emphasizes data recovery and error detection. Its development has been driven by a commitment to software freedom and a stable file format.


title: PARAMETERS
content:
<b>[<I>less_options</I>]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Options accepted by <b><I>lzless</I></b> are typically passed directly to the <b><I>less</I></b> pager. <b><I>lzless</I></b> itself does not have unique command-line options beyond those for the decompressor or pager. Common <b><I>less</I></b> options that can be used include:<br><b>-i</b>: Ignore case in searches.<br><b>-N</b>: Display line numbers.<br><b>-S</b>: Chop long lines rather than wrapping.<br><b>+G</b>: Start at the end of the file.<br><b>-R</b>: Output "raw" control characters (e.g., for colored text).<br><br><b>[<I>file</I>...]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more paths to LZMA or LZMA2 compressed files to be viewed. If no file is specified, <b><I>lzless</I></b> reads LZMA/LZMA2 compressed data from standard input.<br><br>


title: DESCRIPTION
content:
The <b><I>lzless</I></b> command is a convenient shell script that allows users to view the content of LZMA or LZMA2 compressed files without explicitly decompressing them to disk.<br><br>It functions by piping the output of the <b><I>xz</I></b> (or older <b><I>lzma</I></b>) decompressor directly into the <b><I>less</I></b> pager. This provides an interactive viewing experience, similar to viewing regular text files with <b><I>less</I></b>, including scrolling, searching, and navigating. Users do not need to worry about managing temporary decompressed files, as <b><I>lzless</I></b> handles the decompression and piping on the fly.<br><br>It's particularly useful for quickly inspecting log files, documentation, or other data that has been stored in LZMA or LZMA2 format to save space.


title: CAVEATS
content:
<b><I>lzless</I></b> relies on the availability of the <b><I>xz</I></b> (or <b><I>lzma</I></b>) decompressor and the <b><I>less</I></b> pager. If these commands are not installed or are not in the system's PATH, <b><I>lzless</I></b> will fail. The input file(s) must be valid LZMA or LZMA2 compressed data; otherwise, decompression errors will occur, and content may not be displayed correctly.


title: ENVIRONMENT VARIABLES
content:
<b><I>lzless</I></b>'s behavior can be influenced by environment variables, primarily those used by its underlying commands:<br><b><I>LESS</I></b>: Specifies command-line options for <b><I>less</I></b> that are automatically applied.<br><b><I>XZ_DECOMPRESS_OPTS</I></b>: Options passed to the <b><I>xz</I></b> decompressor (less common for <b><I>lzless</I></b>, as <b><I>lzless</I></b> usually only needs default decompression).


title: HISTORY
content:
The concept of transparently viewing compressed files through a pager has existed for a long time in Unix-like systems, notably with <b><I>zless</I></b> (for gzip) and <b><I>bzless</I></b> (for bzip2). <b><I>lzless</I></b> emerged as LZMA and later LZMA2 (used by <b><I>xz</I></b>) compression gained popularity for its higher compression ratios. It is typically part of the <b><I>xz-utils</I></b> package, which superseded older <b><I>lzma_utils</I></b>, ensuring compatibility with the modern <b><I>xz</I></b> command for LZMA2 decompression.


title: SYNOPSIS
content:
<b>lzma</b> [<i>options</i>] [<i>file...</i>]<br><b>lzma -d</b> [<i>options</i>] [<i>file...</i>]<br><b>lzcat</b> [<i>options</i>] [<i>file...</i>] <i>(alias for lzma -dc)</i>


title: PARAMETERS
content:
<b>-d, --decompress, --uncompress</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Decompress</i> files.<br><br><b>-z, --compress</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Compress</i> files. This is the default action.<br><br><b>-k, --keep</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Do not delete</i> input files after compression or decompression.<br><br><b>-f, --force</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Force overwrite</i> of existing output files.<br><br><b>-c, --stdout, --to-stdout</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to <i>standard output</i>, keeping input files intact.<br><br><b>-v, --verbose</b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display <i>progress and verbose information</i> during operation.<br><br><b>-q, --quiet</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Suppress</i> all messages and warnings.<br><br><b>-t, --test</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Test the integrity</i> of compressed files.<br><br><b>-l, --list</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>List the contents</i> of compressed files.<br><br><b>-[0-9]</b><br>&nbsp;&nbsp;&nbsp;&nbsp;<i>Compression preset</i>. <i>-0</i> is fastest/least compression, <i>-9</i> is slowest/best compression.<br><br>


title: DESCRIPTION
content:
The <b>lzma</b> command is a powerful utility for compressing and decompressing files using the <i>Lempel-Ziv-Markov chain Algorithm</i> (LZMA).<br><br>Known for its exceptionally high compression ratios, especially on large files, <b>lzma</b> often achieves better compression than older algorithms like <i>gzip</i> or <i>bzip2</i>. By default, it replaces the original input file with the compressed or decompressed version. Compressed files typically have a <i>.lzma</i> extension.<br><br>On modern Linux systems, <b>lzma</b> is frequently provided as a compatibility symlink to the more advanced <b>xz</b> utility, which uses the LZMA2 algorithm. While <b>lzma</b> can often decompress <i>.xz</i> files, <b>xz</b> is generally recommended for new compression tasks due to its improved features, better error handling, and support for multi-threading.


title: CAVEATS
content:
Although powerful, <b>lzma</b> has largely been <i>superseded by <b>xz</b></i> for most modern compression tasks. <b>xz</b> offers better features, including multi-threading and more robust error handling.<br><br>While <b>lzma</b> provides high compression ratios, it can be <i>significantly slower</i> than <b>gzip</b> or <b>bzip2</b>, especially at higher compression levels.<br><br>It's important to note that, unlike some other compression tools, <b>lzma</b> <i>does not perform integrity checks by default</i> during compression, only during decompression or when explicitly using the <b>-t</b> option.


title: USING WITH STANDARD INPUT/OUTPUT
content:
<b>lzma</b> can be effectively used in pipelines by reading from standard input and writing to standard output using the <b>-c</b> (or <b>--stdout</b>) option. This is common when compressing or decompressing archives without creating intermediate files. For example, to compress a tar archive: <i>tar cf - . | lzma -c > archive.tar.lzma</i>


title: HISTORY
content:
The <i>LZMA algorithm</i> itself was developed by Igor Pavlov as part of the <i>7-Zip project</i>, renowned for its high compression efficiency. The standalone <b>lzma</b> command-line utility emerged from this work to provide a dedicated tool for LZMA compression and decompression in Unix-like environments.<br><br>Over time, the need for a more versatile and feature-rich utility led to the development of <b>xz</b>. <b>xz</b> incorporated the improved LZMA2 algorithm and provided a unified interface for both LZMA and LZMA2 formats, along with better error handling and support for features like multi-threading. Consequently, <b>lzma</b> is now often provided as a <i>symbolic link to <b>xz</b></i> on modern Linux distributions, ensuring backward compatibility for scripts and users familiar with the original command.


title: SEE ALSO
content:
<b>xz(1)</b>: The modern successor to <b>lzma</b>, using the LZMA2 algorithm and offering more features., <b>gzip(1)</b>: A widely used compression utility based on the DEFLATE algorithm., <b>bzip2(1)</b>: Another popular compression utility known for good compression ratios, using the Burrows-Wheeler transform., <b>tar(1)</b>: An archiving utility often used in conjunction with compression tools (e.g., `tar Jcvf` for <b>xz</b>).


title: PARAMETERS
content:
<b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays a help message outlining the command's usage and options, then exits.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prints the version number of the <b>lzmainfo</b> utility and exits.<br><br>


title: DESCRIPTION
content:
<b>lzmainfo</b> is a command-line utility used to display detailed information about files compressed with the <i>LZMA</i> (Lempel–Ziv–Markov chain algorithm) compression algorithm. It reads the header of an <i>.lzma</i> file and extracts critical properties such as the uncompressed size of the original data, the compressed size of the file itself, the achieved compression ratio, and the dictionary size used during the compression process. This tool is invaluable for quickly inspecting <i>.lzma</i> archives without requiring the entire file to be decompressed, which can be time-consuming for large files.<br><br>It helps users to verify the integrity of the file's header information, understand the parameters used for compression, or simply obtain quick statistics. While the <i>.lzma</i> format has largely been superseded by the more advanced <i>.xz</i> format (which uses LZMA2), <b>lzmainfo</b> remains a useful tool for managing and inspecting legacy <i>.lzma</i> archives. It is typically part of the <i>xz</i> utilities package, providing a cohesive set of tools for handling both LZMA and LZMA2 compressed data.


title: CAVEATS
content:
<b>lzmainfo</b> is specifically designed for the older <i>.lzma</i> file format and does not directly support the newer <i>.xz</i> format (which uses the LZMA2 algorithm), although the overarching <i>xz</i> command suite can handle both. The command only reads the file header and does not perform full decompression, meaning it cannot detect data corruption or errors within the compressed payload itself, only issues with the header information. If the <i>.lzma</i> file header is corrupted or incomplete, <b>lzmainfo</b> may fail to provide accurate information or report an error.


title: OUTPUT FORMAT
content:
The default output of <b>lzmainfo</b> provides several key pieces of information about the <i>.lzma</i> file:<br><i>Uncompressed size</i>: The size of the data before it was compressed.<br><i>Compressed size</i>: The size of the file after LZMA compression.<br><i>Ratio</i>: The compression ratio achieved, typically expressed as a percentage.<br><i>Dictionary size</i>: The size of the dictionary (in MiB or KiB) used during compression, which is crucial for decompression.<br><i>Number of filters</i>: Indicates the number of filters applied, typically 1 for standard LZMA.<br><br>For example, running <br><code>lzmainfo my_document.lzma</code><br> might produce output similar to:<br><code>Uncompressed size: 1234567, Compressed size: 456789, Ratio: 37.0%, Dictionary size: 8 MiB, Filters: 1</code>


title: PACKAGE INFORMATION
content:
On most Linux distributions, <b>lzmainfo</b> is provided as part of the <i>xz-utils</i> package (commonly found on Debian, Ubuntu, and derivatives) or simply the <i>xz</i> package (typical for Fedora, RHEL, and Arch Linux). Installing this package provides a complete suite of tools including <b>xz</b>, <b>unxz</b>, <b>lzma</b>, <b>unlzma</b>, and <b>lzmainfo</b>, ensuring comprehensive support for LZMA and LZMA2 compression formats.


title: HISTORY
content:
The <i>LZMA</i> (Lempel–Ziv–Markov chain algorithm) compression algorithm was originally developed by Igor Pavlov and introduced as a core component of the 7-Zip archiver in 1998. The command-line utilities for LZMA, including <b>lzmainfo</b>, originated from the LZMA SDK. As compression technology evolved, the <i>LZMA2</i> algorithm was developed, offering improvements in performance and features. This led to the creation of the <i>xz</i> command-line utilities, which aimed to provide a modern and unified suite of compression tools for Linux and Unix-like systems. <b>lzmainfo</b> was integrated into the <i>xz</i> utilities package, ensuring backward compatibility for users needing to inspect older <i>.lzma</i> archives while encouraging the adoption of the newer <i>.xz</i> format for new compression tasks.


title: PARAMETERS
content:
<b><b>-num</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Displays <i>num</i> lines at a time. For example, <b>-20</b> displays 20 lines per screen.<br><br><b><b>-d</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Prompts with `[Press space to continue, 'q' to quit.]` and `[Press 'h' for help]` messages instead of ringing the bell when waiting for user input.<br><br><b><b>-f</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Counts logical lines rather than screen lines, meaning long lines are not folded (wrapped) when determining screen size.<br><br><b><b>-l</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses the pause after a form feed (Ctrl+L) character is encountered in the input.<br><br><b><b>-s</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Squeezes multiple consecutive blank lines into a single blank line, useful for cleaning up formatted text.<br><br><b><b>-u</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Suppresses underlining, which can be useful on terminals that don't support it well or when it interferes with readability.<br><br><b><b>-c</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Does not scroll; instead, it redraws the screen from the top, which can prevent flicker on some terminals.<br><br><b><b>+/<i>pattern</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts displaying output two lines before the first occurrence of the specified <i>pattern</i> in the file.<br><br><b><b>+<i>num</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Starts displaying at line number <i>num</i> of the file.<br><br><b><b><i>file...</i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;One or more <i>LZMA</i> or <i>XZ</i> compressed files to view. If multiple files are given, <i>lzmore</i> displays them one after another.<br><br>


title: DESCRIPTION
content:
<i>lzmore</i> is a convenient shell script that allows users to view the content of compressed files (using <i>LZMA</i> or <i>XZ</i> compression algorithms) without explicitly decompressing them first. It acts as a wrapper around the <i>xz</i> (or <i>unlzma</i>) decompression utility and the <i>more</i> pager. When invoked, <i>lzmore</i> decompresses the specified file(s) on-the-fly and pipes the output to <i>more</i>, enabling a page-by-page viewing experience. This is particularly useful for quickly inspecting large compressed logs or data files without consuming large amounts of disk space for temporary uncompressed versions. If no file is specified, <i>lzmore</i> reads from standard input.


title: CAVEATS
content:
<i>lzmore</i> is a wrapper script, so its functionality depends on the underlying <i>xz</i> decompression utility and the <i>more</i> pager being available on the system. It is designed for sequential viewing and does not support random access or backward scrolling within the compressed data. For more advanced features like backward scrolling or searching, consider using <i>lzless</i> or piping <i>xz</i> output to <i>less</i> directly.


title: READING FROM STANDARD INPUT
content:
If no <i>file</i> argument is provided, <i>lzmore</i> reads from standard input, allowing it to be used efficiently in pipelines (e.g., `cat file.lzma | lzmore` or `curl example.com/log.xz | lzmore`).


title: EXIT STATUS
content:
<i>lzmore</i> typically exits with the exit status of the underlying <i>more</i> command. A status of 0 usually indicates success, while a non-zero status indicates an error during decompression or paging.


title: HISTORY
content:
The concept of 'more' tools for compressed files emerged with the popularization of compression utilities like <i>gzip</i> (leading to <i>zmore</i>) and <i>bzip2</i> (leading to <i>bzmore</i>). As <i>LZMA</i> and later <i>XZ</i> compression gained prominence for their high compression ratios and integrity checking, <i>lzmore</i> was developed as part of the <i>xz-utils</i> package to provide a similar convenient viewing mechanism for these new formats. It follows the established pattern of integrating decompression on-the-fly with a pager, providing a seamless user experience.


title: PARAMETERS
content:
<b><b>-1</b> ... <b>-9</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Sets the compression level. <b>-1</b> provides the fastest compression (lowest ratio), while <b>-9</b> offers the best compression (highest ratio, but still very fast). The default is usually <b>-3</b>.<br><br><b><b>-d</b>, <b>--decompress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decompress the specified files. This is the inverse operation of compression.<br><br><b><b>-x</b>, <b>--extract</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;An alias for <b>--decompress</b>, used to extract compressed files.<br><br><b><b>-c</b>, <b>--stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to standard output instead of a file. The original input files remain unchanged. Useful for piping output to other commands.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwriting of existing output files without prompting for confirmation.<br><br><b><b>-o <i><file></i></b>, <b>--output=<i><file></i></b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the name of the output file. This option can only be used when compressing or decompressing a single input file.<br><br><b><b>-n</b>, <b>--no-name</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Do not store or restore the original file name, modification time, or file mode/permissions during compression or decompression.<br><br><b><b>-N</b>, <b>--name</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Store the original file name, modification time, and file mode/permissions (this is the default behavior for compression).<br><br><b><b>-l</b>, <b>--list</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;List the contents of a compressed LZO file, including details like compressed size, uncompressed size, and original file name.<br><br><b><b>-t</b>, <b>--test</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Test the integrity of a compressed LZO file to check for corruption without decompressing it.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose output, displaying progress information and detailed messages during operations.<br><br><b><b>-h</b>, <b>--help</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display a help message with command usage and options, then exit.<br><br><b><b>-V</b>, <b>--version</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Display the version information of the <b>lzop</b> utility and exit.<br><br>


title: DESCRIPTION
content:
The <b>lzo</b> command, commonly implemented as <b>lzop</b> on Linux systems, is a utility for compressing and decompressing files using the LZO (Lempel-Ziv-Oberhumer) algorithm. Unlike compression tools like <b>gzip</b> or <b>bzip2</b> that prioritize maximum compression ratio, LZO's primary design goal is extremely fast compression and decompression speeds, often at the expense of a higher compression ratio. This characteristic makes it particularly well-suited for applications where speed is critical, such as real-time data processing, embedded systems, network communications, and kernel-level compression (e.g., for initramfs or SquashFS filesystems). The <b>lzo</b> command operates on single files, typically appending a <i>.lzo</i> or <i>.lzop</i> suffix to compressed files. It can also decompress files with these suffixes back to their original form.


title: CAVEATS
content:
<i>Compression Ratio</i>: While exceptionally fast, LZO typically achieves lower compression ratios compared to other algorithms like <b>gzip</b>, <b>bzip2</b>, or <b>xz</b>.<br><i>Single File Operation</i>: <b>lzop</b> primarily operates on single files. It does not natively support recursive directory compression; for archiving entire directories, it's typically used in conjunction with archiving tools like <b>tar</b>.<br><i>Ubiquity</i>: Although widely used in specific domains, <b>lzop</b> might not be as universally installed or recognized on all Linux systems as <b>gzip</b> or <b>bzip2</b>.


title: ALGORITHM FOCUS
content:
The LZO algorithm is specifically optimized for extreme speed, making it suitable for scenarios where CPU cycles are at a premium and latency needs to be minimized, even if it means larger compressed file sizes. This makes it a popular choice for fast data streaming and temporary storage.


title: FILE EXTENSION
content:
Files compressed with <b>lzo</b> (or <b>lzop</b>) typically carry the <i>.lzo</i> or <i>.lzop</i> file extension. When decompressing, this suffix is usually removed to restore the original file name, unless otherwise specified by the user.


title: HISTORY
content:
The LZO (Lempel-Ziv-Oberhumer) algorithm and its associated tools, including <b>lzop</b>, were developed by Markus F.X.J. Oberhumer, with the initial version released in 1998. The project's primary goal was to create a compression library that excelled in speed and had low memory requirements, making it ideal for resource-constrained environments and high-performance applications. Over the years, LZO has found widespread adoption in various critical systems, including the Linux kernel (e.g., for <i>initramfs</i>, <i>squashfs</i>, <i>zram</i>), embedded devices, and applications where real-time compression/decompression is paramount.


title: SYNOPSIS
content:
<b>lzop</b> [<I>options</I>] [<I>files...</I>]<br><b>lzop</b> <b>-d</b> [<I>options</I>] [<I>files...</I>]<br><b>lzop</b> <b>-x</b> [<I>options</I>] [<I>files...</I>]<br><b>lzop</b> <b>-h</b> | <b>--help</b><br><b>lzop</b> <b>-V</b> | <b>--version</b>


title: PARAMETERS
content:
<b><b>-d</b>, <b>--decompress</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Decompress the specified <b>.lzo</b> file(s).<br><br><b><b>-x</b>, <b>--extract</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Alias for <b>-d</b>; decompress and extract the file(s).<br><br><b><b>-c</b>, <b>--stdout</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Write output to standard output, keeping original files unchanged.<br><br><b><b>-o</b> <I>file</I>, <b>--output</b>=<I>file</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the output filename for compressed or decompressed data. Only valid with a single input file.<br><br><b><b>-f</b>, <b>--force</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Force overwrite of existing output files without prompting.<br><br><b><b>-v</b>, <b>--verbose</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Enable verbose mode, displaying progress and additional information.<br><br><b><b>-t</b>, <b>--test</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Test the integrity of the compressed file(s) without decompressing.<br><br><b><b>-1</b> to <b>-9</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Set the compression level. <b>-1</b> is the fastest (least compression), <b>-9</b> is the best compression (slowest). The default level is <b>-3</b>.<br><br><b><b>-S</b> <I>.suf</I>, <b>--suffix</b>=<I>.suf</I></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Specify the filename suffix for compressed files. The default suffix is <b>.lzo</b>.<br><br><b><b>-U</b>, <b>--undo</b></b><br>&nbsp;&nbsp;&nbsp;&nbsp;Remove the input file if the operation (compression or decompression) was successful.<br><br>


title: DESCRIPTION
content:
<b>lzop</b> is a command-line utility for compressing and decompressing files using the LZO (Lempel-Ziv-Oberhumer) algorithm. Its primary design goal is extremely high speed, often sacrificing optimal compression ratio for faster processing. This makes it an excellent choice for applications where rapid data throughput is critical, such as processing large log files, temporary data storage, or real-time streaming where latency must be minimized.<br><br>While other tools like <b>gzip</b> or <b>bzip2</b> might achieve smaller file sizes, <b>lzop</b> typically offers significantly faster compression and decompression speeds, making it ideal when CPU cycles and time are more valuable than disk space. It can operate on individual files, process data from standard input, and write to standard output, allowing seamless integration into shell scripts and pipelines.


title: CAVEATS
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While exceptionally fast, <b>lzop</b> generally provides a lower compression ratio compared to other popular tools like <b>gzip</b>, <b>bzip2</b>, or <b>xz</b>. This trade-off means compressed files will typically be larger.


title: SPEED VS. COMPRESSION RATIO
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The primary design principle behind <b>lzop</b> and the LZO algorithm is speed. It often outperforms other compression algorithms in terms of both compression and decompression speed, making it highly suitable for I/O-bound tasks or when CPU resources are abundant but time is critical. Users should be aware that this speed comes at the cost of a lower compression ratio, meaning the resulting compressed files will generally be larger than those produced by <b>gzip</b>, <b>bzip2</b>, or <b>xz</b>.


