Util-linux is an open-source collection of Linux utilities that provides various security-related features, including password management and disk encryption.
Util-linux is a popular open-source collection of Linux utilities that provides various essential system tools to manage and maintain the Linux operating system. It includes more than 70 different utilities, such as fdisk, login, mount, and many others, that are commonly used by system administrators and end-users alike.
One of the critical utilities included in Util-linux is the security tool, which provides several security-related features for Linux systems. These features aim to secure the system against unauthorized access, prevent data loss, and maintain the system's integrity. In this article, we will discuss the different security-related features provided by the security tool in Util-linux.
One of the most crucial security features of the security tool is the password management utility. This utility allows administrators to manage user passwords and ensure that they are stored securely. It provides different password management options, such as setting password expiration dates, password length, and password complexity requirements. Additionally, the utility also provides a way to create new passwords, modify existing passwords, and verify password strength.
Another essential security feature provided by the security tool is the cryptsetup utility. This utility allows administrators to encrypt and decrypt the file system to protect sensitive data stored on the system. It supports different encryption methods, such as AES and Twofish, and provides various authentication options, such as passwords, keyfiles, and tokens. Additionally, cryptsetup also supports creating encrypted volumes on external devices such as USB drives.
Util-linux's security tool also includes a number of utilities that can be used to secure the boot process. The mkinitrd utility, for example, allows administrators to create a custom initramfs image, which can include different kernel modules and scripts that are required to boot the system. This can be used to ensure that only authorized users can boot the system, and that the system is protected against unauthorized modifications.
Finally, Util-linux's security tool also includes several utilities that can be used to audit the system and monitor its security. For example, the auditctl utility allows administrators to configure the Linux Audit System, which can be used to track system events and detect security-related issues. Additionally, the logname utility can be used to display the current user's login name, which can be useful for auditing purposes.
In conclusion, Util-linux's security tool provides several critical security-related features for Linux systems. These features aim to protect the system against unauthorized access, prevent data loss, and maintain the system's integrity. By using these tools, administrators can ensure that their Linux systems are secure and protected against potential security threats.
Packages and Binaries:
This package contains some extra BSD utilities: col, colcrt, colrm, column, hd, hexdump, look, ul and write. Other BSD utilities are provided by bsdutils and calendar.
Installed size:337 KBHow to install:sudo apt install bsdextrautils
Dependencies:
libc6
libsmartcols1
libtinfo6
col
Filter reverse line feeds from input
:~# col --help
Usage:
col [options]
Filter out reverse line feeds from standard input.
Options:
-b, --no-backspaces do not output backspaces
-f, --fine permit forward half line feeds
-p, --pass pass unknown control sequences
-h, --tabs convert spaces to tabs
-x, --spaces convert tabs to spaces
-l, --lines NUM buffer at least NUM lines
-H, --help display this help
-v, --version display version
For more details see col(1).
colcrt
Filter nroff output for CRT previewing
:~# colcrt -h
Usage:
colcrt [options] [<file>...]
Filter nroff output for CRT previewing.
Options:
-, --no-underlining suppress all underlining
-2, --half-lines print all half-lines
-h, --help display this help
-V, --version display version
For more details see colcrt(1).
colrm
Remove columns from a file
:~# colrm -h
Usage:
colrm [startcol [endcol]]
Filter out the specified columns.
Options:
-h, --help display this help
-V, --version display version
colrm reads from standard input and writes to standard output
For more details see colrm(1).
column
Columnate lists
:~# column -h
Usage:
column [options] [<file>...]
Columnate lists.
Options:
-t, --table create a table
-n, --table-name <name> table name for JSON output
-O, --table-order <columns> specify order of output columns
-N, --table-columns <names> comma separated columns names
-l, --table-columns-limit <num> maximal number of input columns
-E, --table-noextreme <columns> don't count long text from the columns to column width
-d, --table-noheadings don't print header
-e, --table-header-repeat repeat header for each page
-H, --table-hide <columns> don't print the columns
-R, --table-right <columns> right align text in these columns
-T, --table-truncate <columns> truncate text in the columns when necessary
-W, --table-wrap <columns> wrap text in the columns when necessary
-L, --keep-empty-lines don't ignore empty lines
-J, --json use JSON output format for table
-r, --tree <column> column to use tree-like output for the table
-i, --tree-id <column> line ID to specify child-parent relation
-p, --tree-parent <column> parent to specify child-parent relation
-c, --output-width <width> width of output in number of characters
-o, --output-separator <string> columns separator for table output (default is two spaces)
-s, --separator <string> possible table delimiters
-x, --fillrows fill rows before columns
-h, --help display this help
-V, --version display version
For more details see column(1).
hd
Display file contents in hexadecimal, decimal, octal, or ascii MFM/IDE hard disk devices
:~# hd -h
Usage:
hd [options] <file>...
Display file contents in hexadecimal, decimal, octal, or ascii.
Options:
-b, --one-byte-octal one-byte octal display
-c, --one-byte-char one-byte character display
-C, --canonical canonical hex+ASCII display
-d, --two-bytes-decimal two-byte decimal display
-o, --two-bytes-octal two-byte octal display
-x, --two-bytes-hex two-byte hexadecimal display
-L, --color[=<mode>] interpret color formatting specifiers
colors are enabled by default
-e, --format <format> format string to be used for displaying data
-f, --format-file <file> file that contains format strings
-n, --length <length> interpret only length bytes of input
-s, --skip <offset> skip offset bytes from the beginning
-v, --no-squeezing output identical lines
-h, --help display this help
-V, --version display version
Arguments:
<length> and <offset> arguments may be followed by the suffixes for
GiB, TiB, PiB, EiB, ZiB, and YiB (the "iB" is optional)
For more details see hexdump(1).
hexdump
Display file contents in hexadecimal, decimal, octal, or ascii
:~# hexdump -h
Usage:
hexdump [options] <file>...
Display file contents in hexadecimal, decimal, octal, or ascii.
Options:
-b, --one-byte-octal one-byte octal display
-c, --one-byte-char one-byte character display
-C, --canonical canonical hex+ASCII display
-d, --two-bytes-decimal two-byte decimal display
-o, --two-bytes-octal two-byte octal display
-x, --two-bytes-hex two-byte hexadecimal display
-L, --color[=<mode>] interpret color formatting specifiers
colors are enabled by default
-e, --format <format> format string to be used for displaying data
-f, --format-file <file> file that contains format strings
-n, --length <length> interpret only length bytes of input
-s, --skip <offset> skip offset bytes from the beginning
-v, --no-squeezing output identical lines
-h, --help display this help
-V, --version display version
Arguments:
<length> and <offset> arguments may be followed by the suffixes for
GiB, TiB, PiB, EiB, ZiB, and YiB (the "iB" is optional)
For more details see hexdump(1).
look
Display lines beginning with a given string
:~# look -h
Usage:
look [options] <string> [<file>...]
Display lines beginning with a specified string.
Options:
-a, --alternative use the alternative dictionary
-d, --alphanum compare only blanks and alphanumeric characters
-f, --ignore-case ignore case differences when comparing
-t, --terminate <char> define the string-termination character
-h, --help display this help
-V, --version display version
For more details see look(1).
ul
Do underlining
:~# ul -h
Usage:
ul [options] [<file> ...]
Do underlining.
Options:
-t, -T, --terminal TERMINAL override the TERM environment variable
-i, --indicated underlining is indicated via a separate line
-h, --help display this help
-V, --version display version
For more details see ul(1).
write
Send a message to another user
:~# write -h
Usage:
write [options] <user> [<ttyname>]
Send a message to another user.
Options:
-h, --help display this help
-V, --version display version
For more details see write(1).
bsdutils
This package contains the bare minimum of BSD utilities needed for a Debian system: logger, renice, script, scriptlive, scriptreplay and wall. The remaining standard BSD utilities are provided by bsdextrautils.
Installed size:355 KBHow to install:sudo apt install bsdutils
Dependencies:
libc6
libsystemd0
logger
Enter messages into the system log
:~# logger -h
Usage:
logger [options] [<message>]
Enter messages into the system log.
Options:
-i log the logger command's PID
--id[=<id>] log the given <id>, or otherwise the PID
-f, --file <file> log the contents of this file
-e, --skip-empty do not log empty lines when processing files
--no-act do everything except the write the log
-p, --priority <prio> mark given message with this priority
--octet-count use rfc6587 octet counting
--prio-prefix look for a prefix on every line read from stdin
-s, --stderr output message to standard error as well
-S, --size <size> maximum size for a single message
-t, --tag <tag> mark every line with this tag
-n, --server <name> write to this remote syslog server
-P, --port <port> use this port for UDP or TCP connection
-T, --tcp use TCP only
-d, --udp use UDP only
--rfc3164 use the obsolete BSD syslog protocol
--rfc5424[=<snip>] use the syslog protocol (the default for remote);
<snip> can be notime, or notq, and/or nohost
--sd-id <id> rfc5424 structured data ID
--sd-param <data> rfc5424 structured data name=value
--msgid <msgid> set rfc5424 message id field
-u, --socket <socket> write to this Unix socket
--socket-errors[=<on|off|auto>]
print connection errors when using Unix sockets
--journald[=<file>] write journald entry
-h, --help display this help
-V, --version display version
For more details see logger(1).
renice
Alter priority of running processes
:~# renice -h
Usage:
renice [-n] <priority> [-p|--pid] <pid>...
renice [-n] <priority> -g|--pgrp <pgid>...
renice [-n] <priority> -u|--user <user>...
Alter the priority of running processes.
Options:
-n, --priority <num> specify the nice value
-p, --pid interpret arguments as process ID (default)
-g, --pgrp interpret arguments as process group ID
-u, --user interpret arguments as username or user ID
-h, --help display this help
-V, --version display version
For more details see renice(1).
script
Make typescript of terminal session
:~# script -h
Usage:
script [options] [file]
Make a typescript of a terminal session.
Options:
-I, --log-in <file> log stdin to file
-O, --log-out <file> log stdout to file (default)
-B, --log-io <file> log stdin and stdout to file
-T, --log-timing <file> log timing information to file
-t[<file>], --timing[=<file>] deprecated alias to -T (default file is stderr)
-m, --logging-format <name> force to 'classic' or 'advanced' format
-a, --append append to the log file
-c, --command <command> run command rather than interactive shell
-e, --return return exit code of the child process
-f, --flush run flush after each write
--force use output file even when it is a link
-E, --echo <when> echo input in session (auto, always or never)
-o, --output-limit <size> terminate if output files exceed size
-q, --quiet be quiet
-h, --help display this help
-V, --version display version
For more details see script(1).
scriptlive
Re-run session typescripts, using timing information
:~# scriptlive -h
Usage:
scriptlive [options]
scriptlive [-t] timingfile [-I|-B] typescript
Execute terminal typescript.
Options:
-t, --timing <file> script timing log file
-T, --log-timing <file> alias to -t
-I, --log-in <file> script stdin log file
-B, --log-io <file> script stdin and stdout log file
-c, --command <command> run command rather than interactive shell
-d, --divisor <num> speed up or slow down execution with time divisor
-m, --maxdelay <num> wait at most this many seconds between updates
-h, --help display this help
-V, --version display version
For more details see scriptlive(1).
scriptreplay
Play back typescripts, using timing information
:~# scriptreplay -h
Usage:
scriptreplay [options]
scriptreplay [-t] timingfile [typescript] [divisor]
Play back terminal typescripts, using timing information.
Options:
-t, --timing <file> script timing log file
-T, --log-timing <file> alias to -t
-I, --log-in <file> script stdin log file
-O, --log-out <file> script stdout log file (default)
-B, --log-io <file> script stdin and stdout log file
-s, --typescript <file> deprecated alias to -O
--summary display overview about recorded session and exit
-d, --divisor <num> speed up or slow down execution with time divisor
-m, --maxdelay <num> wait at most this many seconds between updates
-x, --stream <name> stream type (out, in, signal or info)
-c, --cr-mode <type> CR char mode (auto, never, always)
-h, --help display this help
-V, --version display version
For more details see scriptreplay(1).
wall
Write a message to all users
:~# wall -h
Usage:
wall [options] [<file> | <message>]
Write a message to all users.
Options:
-g, --group <group> only send message to group
-n, --nobanner do not print banner, works only for root
-t, --timeout <timeout> write timeout in seconds
-h, --help display this help
-V, --version display version
For more details see wall(1).
eject
This program will eject CD-ROMs (assuming your drive supports the CDROMEJECT ioctl). It also allows setting the autoeject feature.
On supported ATAPI/IDE multi-disc CD-ROM changers, it allows changing the active disc.
You can also use eject to properly disconnect external mass-storage devices like digital cameras or portable music players.
Installed size:132 KBHow to install:sudo apt install eject
Dependencies:
libc6
libmount1
eject
Eject removable media
:~# eject -h
Usage:
eject [options] [<device>|<mountpoint>]
Eject removable media.
Options:
-a, --auto <on|off> turn auto-eject feature on or off
-c, --changerslot <slot> switch discs on a CD-ROM changer
-d, --default display default device
-f, --floppy eject floppy
-F, --force don't care about device type
-i, --manualeject <on|off> toggle manual eject protection on/off
-m, --no-unmount do not unmount device even if it is mounted
-M, --no-partitions-unmount do not unmount another partitions
-n, --noop don't eject, just show device found
-p, --proc use /proc/mounts instead of /etc/mtab
-q, --tape eject tape
-r, --cdrom eject CD-ROM
-s, --scsi eject SCSI device
-t, --trayclose close tray
-T, --traytoggle toggle tray
-v, --verbose enable verbose output
-x, --cdspeed <speed> set CD-ROM max speed
-X, --listspeed list CD-ROM available speeds
-h, --help display this help
-V, --version display version
By default tries -r, -s, -f, and -q in order until success.
For more details see eject(1).
fdisk
This package contains the classic fdisk, sfdisk and cfdisk partitioning utilities from the util-linux suite.
The utilities included in this package allow you to partition your hard disk. The utilities supports both modern and legacy partition tables (eg. GPT, MBR, etc).
The fdisk utility is the classical text-mode utility. The cfdisk utilitity gives a more userfriendly curses based interface. The sfdisk utility is mostly for automation and scripting uses.
Installed size:479 KBHow to install:sudo apt install fdisk
Dependencies:
libc6
libfdisk1
libmount1
libncursesw6
libreadline8
libsmartcols1
libtinfo6
cfdisk
Display or manipulate a disk partition table
:~# cfdisk -h
Usage:
cfdisk [options] <disk>
Display or manipulate a disk partition table.
Options:
-L, --color[=<when>] colorize output (auto, always or never)
colors are enabled by default
-z, --zero start with zeroed partition table
--lock[=<mode>] use exclusive device lock (yes, no or nonblock)
-r, --read-only forced open cfdisk in read-only mode
-h, --help display this help
-V, --version display version
For more details see cfdisk(8).
fdisk
Manipulate disk partition table
:~# fdisk -h
Usage:
fdisk [options] <disk> change partition table
fdisk [options] -l [<disk>...] list partition table(s)
Display or manipulate a disk partition table.
Options:
-b, --sector-size <size> physical and logical sector size
-B, --protect-boot don't erase bootbits when creating a new label
-c, --compatibility[=<mode>] mode is 'dos' or 'nondos' (default)
-L, --color[=<when>] colorize output (auto, always or never)
colors are enabled by default
-l, --list display partitions and exit
-x, --list-details like --list but with more details
-n, --noauto-pt don't create default partition table on empty devices
-o, --output <list> output columns
-t, --type <type> recognize specified partition table type only
-u, --units[=<unit>] display units: 'cylinders' or 'sectors' (default)
-s, --getsz display device size in 512-byte sectors [DEPRECATED]
--bytes print SIZE in bytes rather than in human readable format
--lock[=<mode>] use exclusive device lock (yes, no or nonblock)
-w, --wipe <mode> wipe signatures (auto, always or never)
-W, --wipe-partitions <mode> wipe signatures from new partitions (auto, always or never)
-C, --cylinders <number> specify the number of cylinders
-H, --heads <number> specify the number of heads
-S, --sectors <number> specify the number of sectors per track
-h, --help display this help
-V, --version display version
Available output columns:
gpt: Device Start End Sectors Size Type Type-UUID Attrs Name UUID
dos: Device Start End Sectors Cylinders Size Type Id Attrs Boot End-C/H/S
Start-C/H/S
bsd: Slice Start End Sectors Cylinders Size Type Bsize Cpg Fsize
sgi: Device Start End Sectors Cylinders Size Type Id Attrs
sun: Device Start End Sectors Cylinders Size Type Id Flags
For more details see fdisk(8).
sfdisk
Display or manipulate a disk partition table
:~# sfdisk -h
Usage:
sfdisk [options] <dev> [[-N] <part>]
sfdisk [options] <command>
Display or manipulate a disk partition table.
Commands:
-A, --activate <dev> [<part> ...] list or set bootable (P)MBR partitions
-d, --dump <dev> dump partition table (usable for later input)
-J, --json <dev> dump partition table in JSON format
-B, --backup-pt-sectors <dev> binary partition table backup (see -b and -O)
-g, --show-geometry [<dev> ...] list geometry of all or specified devices
-l, --list [<dev> ...] list partitions of each device
-F, --list-free [<dev> ...] list unpartitioned free areas of each device
-r, --reorder <dev> fix partitions order (by start offset)
-s, --show-size [<dev> ...] list sizes of all or specified devices
-T, --list-types print the recognized types (see -X)
-V, --verify [<dev> ...] test whether partitions seem correct
--delete <dev> [<part> ...] delete all or specified partitions
--part-label <dev> <part> [<str>] print or change partition label
--part-type <dev> <part> [<type>] print or change partition type
--part-uuid <dev> <part> [<uuid>] print or change partition uuid
--part-attrs <dev> <part> [<str>] print or change partition attributes
--disk-id <dev> [<str>] print or change disk label ID (UUID)
--relocate <oper> <dev> move partition header
Arguments:
<dev> device (usually disk) path
<part> partition number
<type> partition type, GUID for GPT, hex for MBR
Options:
-a, --append append partitions to existing partition table
-b, --backup backup partition table sectors (see -O)
--bytes print SIZE in bytes rather than in human readable format
--move-data[=<typescript>] move partition data after relocation (requires -N)
--move-use-fsync use fsync after each write when move data
-f, --force disable all consistency checking
--color[=<when>] colorize output (auto, always or never)
colors are enabled by default
--lock[=<mode>] use exclusive device lock (yes, no or nonblock)
-N, --partno <num> specify partition number
-n, --no-act do everything except write to device
--no-reread do not check whether the device is in use
--no-tell-kernel do not tell kernel about changes
-O, --backup-file <path> override default backup file name
-o, --output <list> output columns
-q, --quiet suppress extra info messages
-w, --wipe <mode> wipe signatures (auto, always or never)
-W, --wipe-partitions <mode> wipe signatures from new partitions (auto, always or never)
-X, --label <name> specify label type (dos, gpt, ...)
-Y, --label-nested <name> specify nested label type (dos, bsd)
-G, --show-pt-geometry deprecated, alias to --show-geometry
-L, --Linux deprecated, only for backward compatibility
-u, --unit S deprecated, only sector unit is supported
-h, --help display this help
-v, --version display version
Available output columns:
gpt: Device Start End Sectors Size Type Type-UUID Attrs Name UUID
dos: Device Start End Sectors Cylinders Size Type Id Attrs Boot End-C/H/S
Start-C/H/S
bsd: Slice Start End Sectors Cylinders Size Type Bsize Cpg Fsize
sgi: Device Start End Sectors Cylinders Size Type Id Attrs
sun: Device Start End Sectors Cylinders Size Type Id Flags
For more details see sfdisk(8).
libblkid-dev
The blkid library allows system programs such as fsck and mount to quickly and easily find block devices by filesystem UUID or label. This allows system administrators to avoid specifying filesystems by hard-coded device names and use a logical naming system instead.
This package contains the development environment for the blkid library.
Installed size:875 KBHow to install:sudo apt install libblkid-dev
Dependencies:
libblkid1
libc6-dev | libc-dev
uuid-dev
libblkid1
The blkid library allows system programs such as fsck and mount to quickly and easily find block devices by filesystem UUID or label. This allows system administrators to avoid specifying filesystems by hard-coded device names and use a logical naming system instead.
Installed size:398 KBHow to install:sudo apt install libblkid1
Dependencies:
libc6
libfdisk-dev
The libfdisk library is used for manipulating partition tables. It is the core of the fdisk, cfdisk, and sfdisk tools.
This package contains the development environment for the fdisk library.
Installed size:77 KBHow to install:sudo apt install libfdisk-dev
Dependencies:
libblkid-dev
libc6-dev | libc-dev
libfdisk1
uuid-dev
libfdisk1
The libfdisk library is used for manipulating partition tables. It is the core of the fdisk, cfdisk, and sfdisk tools.
Installed size:533 KBHow to install:sudo apt install libfdisk1
Dependencies:
libblkid1
libc6
libuuid1
libmount-dev
This device mounting library is used by mount and umount helpers.
This package contains the development environment for the mount library.
Installed size:81 KBHow to install:sudo apt install libmount-dev
Dependencies:
libblkid-dev
libc6-dev | libc-dev
libmount1
libselinux1-dev
libmount1
This device mounting library is used by mount and umount helpers.
Installed size:454 KBHow to install:sudo apt install libmount1
Dependencies:
libblkid1
libc6
libselinux1
libsmartcols-dev
This smart column output alignment library is used by fdisk utilities.
This package contains the development environment for the mount library.
Installed size:61 KBHow to install:sudo apt install libsmartcols-dev
Dependencies:
libc6-dev | libc-dev
libsmartcols1
libsmartcols1
This smart column output alignment library is used by fdisk utilities.
Installed size:289 KBHow to install:sudo apt install libsmartcols1
Dependencies:
libc6
libuuid1
The libuuid library generates and parses 128-bit Universally Unique IDs (UUIDs). A UUID is an identifier that is unique within the space of all such identifiers across both space and time. It can be used for multiple purposes, from tagging objects with an extremely short lifetime to reliably identifying very persistent objects across a network.
See RFC 4122 for more information.
Installed size:79 KBHow to install:sudo apt install libuuid1
Dependencies:
libc6
mount
This package provides the mount(8), umount(8), swapon(8), swapoff(8), and losetup(8) commands.
Installed size:393 KBHow to install:sudo apt install mount
Dependencies:
libblkid1
libc6
libmount1
libselinux1
libsmartcols1
losetup
Set up and control loop devices
:~# losetup -h
Usage:
losetup [options] [<loopdev>]
losetup [options] -f | <loopdev> <file>
Set up and control loop devices.
Options:
-a, --all list all used devices
-d, --detach <loopdev>... detach one or more devices
-D, --detach-all detach all used devices
-f, --find find first unused device
-c, --set-capacity <loopdev> resize the device
-j, --associated <file> list all devices associated with <file>
-L, --nooverlap avoid possible conflict between devices
-o, --offset <num> start at offset <num> into file
--sizelimit <num> device is limited to <num> bytes of the file
-b, --sector-size <num> set the logical sector size to <num>
-P, --partscan create a partitioned loop device
-r, --read-only set up a read-only loop device
--direct-io[=<on|off>] open backing file with O_DIRECT
--show print device name after setup (with -f)
-v, --verbose verbose mode
-J, --json use JSON --list output format
-l, --list list info about all or specified (default)
-n, --noheadings don't print headings for --list output
-O, --output <cols> specify columns to output for --list
--output-all output all columns
--raw use raw --list output format
-h, --help display this help
-V, --version display version
Available output columns:
NAME loop device name
AUTOCLEAR autoclear flag set
BACK-FILE device backing file
BACK-INO backing file inode number
BACK-MAJ:MIN backing file major:minor device number
MAJ:MIN loop device major:minor number
OFFSET offset from the beginning
PARTSCAN partscan flag set
RO read-only device
SIZELIMIT size limit of the file in bytes
DIO access backing file with direct-io
LOG-SEC logical sector size in bytes
For more details see losetup(8).
mount
Mount a filesystem
:~# mount -h
Usage:
mount [-lhV]
mount -a [options]
mount [options] [--source] <source> | [--target] <directory>
mount [options] <source> <directory>
mount <operation> <mountpoint> [<target>]
Mount a filesystem.
Options:
-a, --all mount all filesystems mentioned in fstab
-c, --no-canonicalize don't canonicalize paths
-f, --fake dry run; skip the mount(2) syscall
-F, --fork fork off for each device (use with -a)
-T, --fstab <path> alternative file to /etc/fstab
-i, --internal-only don't call the mount.<type> helpers
-l, --show-labels show also filesystem labels
-m, --mkdir[=<mode>] alias to '-o X-mount.mkdir[=<mode>]'
-n, --no-mtab don't write to /etc/mtab
--options-mode <mode>
what to do with options loaded from fstab
--options-source <source>
mount options source
--options-source-force
force use of options from fstab/mtab
-o, --options <list> comma-separated list of mount options
-O, --test-opts <list> limit the set of filesystems (use with -a)
-r, --read-only mount the filesystem read-only (same as -o ro)
-t, --types <list> limit the set of filesystem types
--source <src> explicitly specifies source (path, label, uuid)
--target <target> explicitly specifies mountpoint
--target-prefix <path>
specifies path used for all mountpoints
-v, --verbose say what is being done
-w, --rw, --read-write mount the filesystem read-write (default)
-N, --namespace <ns> perform mount in another namespace
-h, --help display this help
-V, --version display version
Source:
-L, --label <label> synonym for LABEL=<label>
-U, --uuid <uuid> synonym for UUID=<uuid>
LABEL=<label> specifies device by filesystem label
UUID=<uuid> specifies device by filesystem UUID
PARTLABEL=<label> specifies device by partition label
PARTUUID=<uuid> specifies device by partition UUID
ID=<id> specifies device by udev hardware ID
<device> specifies device by path
<directory> mountpoint for bind mounts (see --bind/rbind)
<file> regular file for loopdev setup
Operations:
-B, --bind mount a subtree somewhere else (same as -o bind)
-M, --move move a subtree to some other place
-R, --rbind mount a subtree and all submounts somewhere else
--make-shared mark a subtree as shared
--make-slave mark a subtree as slave
--make-private mark a subtree as private
--make-unbindable mark a subtree as unbindable
--make-rshared recursively mark a whole subtree as shared
--make-rslave recursively mark a whole subtree as slave
--make-rprivate recursively mark a whole subtree as private
--make-runbindable recursively mark a whole subtree as unbindable
For more details see mount(8).
swapoff
Enable/disable devices and files for paging and swapping
:~# swapoff -h
Usage:
swapoff [options] [<spec>]
Disable devices and files for paging and swapping.
Options:
-a, --all disable all swaps from /proc/swaps
-v, --verbose verbose mode
-h, --help display this help
-V, --version display version
The <spec> parameter:
-L <label> LABEL of device to be used
-U <uuid> UUID of device to be used
LABEL=<label> LABEL of device to be used
UUID=<uuid> UUID of device to be used
<device> name of device to be used
<file> name of file to be used
For more details see swapoff(8).
swapon
Enable/disable devices and files for paging and swapping
:~# swapon -h
Usage:
swapon [options] [<spec>]
Enable devices and files for paging and swapping.
Options:
-a, --all enable all swaps from /etc/fstab
-d, --discard[=<policy>] enable swap discards, if supported by device
-e, --ifexists silently skip devices that do not exist
-f, --fixpgsz reinitialize the swap space if necessary
-o, --options <list> comma-separated list of swap options
-p, --priority <prio> specify the priority of the swap device
-s, --summary display summary about used swap devices (DEPRECATED)
--show[=<columns>] display summary in definable table
--noheadings don't print table heading (with --show)
--raw use the raw output format (with --show)
--bytes display swap size in bytes in --show output
-v, --verbose verbose mode
-h, --help display this help
-V, --version display version
The <spec> parameter:
-L <label> synonym for LABEL=<label>
-U <uuid> synonym for UUID=<uuid>
LABEL=<label> specifies device by swap area label
UUID=<uuid> specifies device by swap area UUID
PARTLABEL=<label> specifies device by partition label
PARTUUID=<uuid> specifies device by partition UUID
<device> name of device to be used
<file> name of file to be used
Available discard policy types (for --discard):
once : only single-time area discards are issued
pages : freed pages are discarded before they are reused
If no policy is selected, both discard types are enabled (default).
Available output columns:
NAME device file or partition path
TYPE type of the device
SIZE size of the swap area
USED bytes in use
PRIO swap priority
UUID swap uuid
LABEL swap label
For more details see swapon(8).
umount
Unmount filesystems
:~# umount -h
Usage:
umount [-hV]
umount -a [options]
umount [options] <source> | <directory>
Unmount filesystems.
Options:
-a, --all unmount all filesystems
-A, --all-targets unmount all mountpoints for the given device in the
current namespace
-c, --no-canonicalize don't canonicalize paths
-d, --detach-loop if mounted loop device, also free this loop device
--fake dry run; skip the umount(2) syscall
-f, --force force unmount (in case of an unreachable NFS system)
-i, --internal-only don't call the umount.<type> helpers
-n, --no-mtab don't write to /etc/mtab
-l, --lazy detach the filesystem now, clean up things later
-O, --test-opts <list> limit the set of filesystems (use with -a)
-R, --recursive recursively unmount a target with all its children
-r, --read-only in case unmounting fails, try to remount read-only
-t, --types <list> limit the set of filesystem types
-v, --verbose say what is being done
-q, --quiet suppress 'not mounted' error messages
-N, --namespace <ns> perform umount in another namespace
-h, --help display this help
-V, --version display version
For more details see umount(8).
rfkill
rfkill is a simple tool for accessing the Linux rfkill device interface, which is used to enable and disable wireless networking devices, typically WLAN, Bluetooth and mobile broadband.
Installed size:97 KBHow to install:sudo apt install rfkill
Dependencies:
libc6
libsmartcols1
rfkill
Tool for enabling and disabling wireless devices
:~# rfkill -h
Usage:
rfkill [options] command [identifier ...]
Tool for enabling and disabling wireless devices.
Options:
-J, --json use JSON output format
-n, --noheadings don't print headings
-o, --output <list> define which output columns to use
--output-all output all columns
-r, --raw use the raw output format
-h, --help display this help
-V, --version display version
Available output columns:
DEVICE kernel device name
ID device identifier value
TYPE device type name that can be used as identifier
