*
acpi
Advanced Configuration and Power Interface (ACPI) is an open standard that operating systems can use to discover and configure computer hardware components, to perform power management (e.g. putting unused hardware components to sleep), auto c ...
— Show status of power sources and thermal devices.
*
adduser,
addgroup — Add a user or group to the system.
*
ar — Create, modify, and extract from archives.
*
arch
An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it.
Arches may be synonymous with vaul ...
— Print machine (hardware) name, same as uname -m.
*
arp — The Address Resolution Protocol (ARP)
*
arping — Send ARP REQUEST to a neighbour host
*
ascii
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
— Display ascii character set.
*
at — Execute commands at a later time.
*
awk
AWK (''awk'') is a domain-specific language designed for text processing and typically used as a data extraction and reporting tool. Like sed and grep, it is a filter, and is a standard feature of most Unix-like operating systems.
The AWK lang ...
— pattern scanning and processing language.
*
base32
Base32 is the base-32 numeral system. It uses a set of 32 digits, each of which can be represented by 5 bits (25). One way to represent Base32 numbers in a human-readable way is by using a standard 32-character set, such as the twenty-two upper- ...
— Encode or decode in base32.
*
base64
In computer programming, Base64 is a group of binary-to-text encoding schemes that represent binary data (more specifically, a sequence of 8-bit bytes) in sequences of 24 bits that can be represented by four 6-bit Base64 digits.
Common to all bina ...
— Encode or decode in base64.
*
basename
basename is a standard computer program on Unix and Unix-like operating systems. When basename is given a pathname, it will delete any prefix up to the last slash ('/') character and return the result. basename is described in the Single UNIX S ...
— Return non-directory portion of a pathname removing suffix.
*
bc — Arbitrary-precision arithmetic language.
*
blkdiscard — Discard device sectors.
*
blkid
In computing, the fdisk command-line utility provides disk-partitioning functions, preparatory to defining file systems. fdisk features in the DOS, DR FlexOS, IBM OS/2, and Microsoft Windows operating systems, and in certain ports of FreeBSD, ...
— Print type, label and UUID of filesystem on a block device or image.
* — Call ioctls on each listed block device.
*
bunzip2 — Decompress bzip2 files.
* — Decompress bzip2 files to stdout.
*
cal — Print a calendar.
*
cat
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...
— Copy (concatenate) files to stdout.
*
catv
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...
— Display nonprinting characters as escape sequences.
*
cd — Change the working directory.
*
chattr
is the command in Linux that allows a user to set certain attributes of a file. is the command that displays the attributes of a file.
Most BSD-like systems, including macOS, have always had an analogous command to set the attributes, but no ...
— Change file attributes on a Linux file system.
*
chgrp
The (from change group) command may be used by unprivileged users on various operating systems to change the group associated with a file system object (such as a computer file, directory, or link) to one of which they are a member. A file sys ...
— Change group of one or more files.
*
chmod
In Unix and Unix-like operating systems, is the command and system call used to change the access permissions and the special mode flags (the ''setuid'', ''setgid'', and ''sticky'' flags) of file system objects ( files and directories). Coll ...
— Change mode of listed files.
*
chown
The command , an abbreviation of ''change owner'', is used on Unix and Unix-like operating systems to change the owner of file system files, directories. Unprivileged (regular) users who wish to change the group membership of a file that they ...
— Change owner of one or more files.
*
chroot
A chroot on Unix and Unix-like operating systems is an operation that changes the apparent root directory for the current running process and its children. A program that is run in such a modified environment cannot name (and therefore normall ...
— Run command within a new root directory.
*
chrt — Get/set a process' real-time scheduling policy and priority.
*
chsh
chsh (an abbreviation of "change shell") is a command on Unix-like operating systems that is used to change a login shell. Users can either supply the pathname of the shell that they wish to change to on the command line, or supply no arguments ...
— Change your login shell.
* — Change to virtual terminal number N.
*
cksum
cksum is a command in Unix and Unix-like operating systems that generates a checksum value for a file or stream of data. The cksum command reads each file given in its arguments, or standard input if no arguments are provided, and outputs the fi ...
— For each file, output crc32 checksum value, length and name of file.
*
clear — Clear the screen.
*
cmp — Compare the contents of two files.
*
comm
The command in the Unix family of computer operating systems is a utility that is used to compare two files for common and distinct lines. is specified in the POSIX standard. It has been widely available on Unix-like operating systems since ...
— Select or reject lines common to two files.
*
count
Count (feminine: countess) is a historical title of nobility in certain European countries, varying in relative status, generally of middling rank in the hierarchy of nobility. Pine, L. G. ''Titles: How the King Became His Majesty''. New York: ...
— Copy stdin to stdout, displaying simple progress indicator to stderr.
*
cp — Copy files.
*
cpio
cpio is a general file archiver utility and its associated file format. It is primarily installed on Unix-like computer operating systems. The software utility was originally intended as a tape archiving program as part of the Programmer's Wor ...
— Copy files into and out of a "newc" format cpio archive.
*
crc32
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on t ...
— Output crc32 checksum for each file.
*
cut
Cut may refer to:
Common uses
* The act of cutting, the separation of an object into two through acutely-directed force
** A type of wound
** Cut (archaeology), a hole dug in the past
** Cut (clothing), the style or shape of a garment
** Cut (ea ...
— Print selected parts of lines from each FILE to standard output.
*
dd — Convert and copy a file.
*
date
Date or dates may refer to:
*Date (fruit), the fruit of the date palm (''Phoenix dactylifera'')
Social activity
*Dating, a form of courtship involving social activity, with the aim of assessing a potential partner
** Group dating
*Play date, a ...
— Set/get the current date/time.
*
devmem — Read/write physical address via /dev/mem.
*
df — Shows total/used/available disk space for each filesystem listed on the command line, or all currently mounted filesystems.
*
diff
In computing, the utility diff is a data comparison tool that computes and displays the differences between the contents of files. Unlike edit distance notions used for other purposes, diff is line-oriented rather than character-oriented, but ...
- Compare two files.
*
dirname
dirname is a standard computer program on Unix and Unix-like operating systems. When dirname is given a pathname, it will delete any suffix beginning with the last slash ('/') character and return the result. dirname is described in the Single U ...
— Show directory portion of path.
*
dmesg
dmesg (''diagnostic messages'') is a command on most Unix-like operating systems that prints the message buffer of the kernel. The output includes messages produced by the device drivers.
Command
On many Unix-like systems, the boot process g ...
— Print or control the kernel ring buffer.
*
dnsdomainname — Show domain this system belongs to (same as hostname -d).
*
dos2unix
(sometimes named or ) is a tool to convert Newline, line breaks in a text file from Unix format (Line feed) to DOS format (carriage return + Line feed) and vice versa. When invoked as the program will convert a Unix text file to DOS format, w ...
— Convert newline format from dos "\r\n" to unix "\n".
*
du — Show disk usage, space consumed by files and directories.
*
echo
In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...
— Write each argument to stdout, with one space between each, followed by a newline.
*
egrep
grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the sam ...
— Show lines matching extended regular expressions.
*
eject — Eject DEVICE or default /dev/cdrom.
*
env — Set the environment for command invocation, or list environment variables.
*
expand — Expand tabs to spaces according to tabstops.
*
factor
Factor, a Latin word meaning "who/which acts", may refer to:
Commerce
* Factor (agent), a person who acts for, notably a mercantile and colonial agent
* Factor (Scotland), a person or firm managing a Scottish estate
* Factors of production, suc ...
— Factor integers.
*
fallocate — Tell the filesystem to allocate space for a file.
*
false — Return nonzero.
*
fdisk
In computing, the fdisk command-line utility provides disk-partitioning functions, preparatory to defining file systems. fdisk features in the DOS, DR FlexOS, IBM OS/2, and Microsoft Windows operating systems, and in certain ports of FreeBS ...
— Manipulate disk partition table.
*
fgrep
grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the sam ...
— Show lines matching regular expressions.
*
file
File or filing may refer to:
Mechanical tools and processes
* File (tool), a tool used to ''remove'' fine amounts of material from a workpiece
**Filing (metalworking), a material removal process in manufacturing
** Nail file, a tool used to gent ...
— Examine the given files and describe their content types.
*
find
Find, FIND or Finding may refer to:
Computing
* find (Unix), a command on UNIX platforms
* find (Windows), a command on DOS/Windows platforms
Books
* ''The Find'' (2010), by Kathy Page
* ''The Find'' (2014), by William Hope Hodgson
Film and t ...
— Search directories for matching files.
*
flock — Manage advisory file locks.
*
fold — Filter for folding lines.
*
fmt — Reformat input to wordwrap at a given line length, preserving existing indentation level, writing to stdout.
*
free — Display the total, free and used amount of physical memory and swap space.
*
freeramdisk — Free all memory allocated to specified ramdisk.
* — Freeze or unfreeze a filesystem.
* — Print type of filesystem on a block device or image.
*
fsync — Synchronize a file's in-core state with storage device.
*
ftpget — Use File Transfer Protocol (FTP) to get a file from an FTP server.
*
ftpput — Use File Transfer Protocol (FTP) to put a file to an FTP server.
*
getconf — Get system configuration values.
*
grep
grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the sa ...
— Show lines matching regular expressions.
*
groups
A group is a number of persons or things that are located, gathered, or classed together.
Groups of people
* Cultural group, a group whose members share the same cultural identity
* Ethnic group, a group whose members share the same ethnic ide ...
— Print the groups a user is in.
*
gunzip — Decompress gz files.
*
halt — Restart, halt or powerdown the system.
*
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
— Copy first lines from files to stdout.
*
help
Help is a word meaning to give aid or signal distress.
Help may refer to:
Arts, entertainment, and media
Films
* ''Help'' (2010 film), a Bollywood horror film
* ''Help'' (2021 theatrical film), a British psychological thriller film
* '' ...
— Show usage information for toybox commands.
*
hexedit — Hexadecimal file editor.
*
hostname
In computer networking, a hostname (archaically nodename) is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication, such as the World Wide Web. Hos ...
— Get/set the current hostname.
* — Get/set the hardware clock.
*
i2cdetect — Detect i2c devices.
*
i2cdump — Dump i2c registers.
*
i2cget — Read an i2c register.
*
i2cset — Write an i2c register.
*
iconv
In Unix and Unix-like operating systems, iconv (an abbreviation of internationalization conversion) is a command-line program and a standardized application programming interface (API) used to convert between different character encodings. "It ...
— Convert character encoding of files.
*
id — Print user and group ID.
*
ifconfig
ifconfig (short for ''interface config'') is a system administration utility in Unix-like operating systems for network interface configuration.
The utility is a command-line interface tool and is also used in the system startup scripts of man ...
— Display or configure network interface.
* — Run a program when a filesystem event occurs.
*
insmod — Load the module named MODULE passing options if given.
*
install — Copy files and set attributes.
*
ionice
nice is a program found on Unix and Unix-like operating systems such as Linux. It directly maps to a kernel call of the same name. nice is used to invoke a utility or shell script with a particular CPU priority, thus giving the process more or ...
— Change the I/O scheduling priority of a process.
* — Display or change I/O priority of existing process.
*
iotop — Rank processes by I/O.
*
kill
Kill often refers to:
*Homicide, one human killing another
*cause death, to kill a living organism, to cause its death
Kill may also refer to:
Media
*'' Kill!'', a 1968 film directed by Kihachi Okamoto
* ''Kill'' (Cannibal Corpse album), 2006
* ...
— Send signal to process.
*
killall
killall is a command line utility available on Unix-like systems. There are two very different implementations.
* The implementation supplied with genuine UNIX System V (including Solaris) and with the Linux sysvinit tools kills all processes ...
— Send a signal (default: TERM) to all processes with the given names.
*
killall5 — Send a signal to all processes outside current session.
*
less
Less or LESS may refer to: fewer than,: not as much.
Computing
* less (Unix), a Unix utility program
* Less (stylesheet language), a dynamic stylesheet language
* Large-Scale Scrum (LeSS), a product development framework that extends Scrum
Othe ...
— opposite of more
*
link — Create hardlink to a file.
*
ln — Create a link between FROM and TO.
*
logger — Log message (or stdin) to syslog.
*
login
In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system by identifying and authenticating themselves. The user credentials are typically some fo ...
— Log in as a user, prompting for username and password if necessary.
*
logname
In computer software, logname (stands for Login Name) is a program in Unix and Unix-like operating systems that prints the name of the user who is currently logged in on the terminal. It usually corresponds to the LOGNAME variable in the system ...
— Print the current user name.
*
losetup In Unix-like operating systems, a loop device, vnd (vnode disk), or lofi (loop file interface) is a pseudo-device that makes a computer file accessible as a block device.
Before use, a loop device must be connected to an extant file in the file sy ...
— Associate a loopback device with a file, or show current file (if any) associated with a loop device.
*
ls — List files.
*
lsattr — List file attributes on a Linux file system.
*
lsmod
lsmod is a command on Linux systems. It shows which loadable kernel modules are currently loaded.
An example terminal print after running lsmod command:
Module Size Used by
af_packet 27392 2
8139too ...
— Display the currently loaded modules, their sizes and their dependencies.
*
lspci
lspci is a command on Unix-like operating systems that prints ("lists") detailed information about all PCI buses and devices in the system. It is based on a common portable library ''libpci'' which offers access to the PCI configuration space ...
— List PCI devices.
*
lsusb
lspci is a command on Unix-like operating systems that prints ("lists") detailed information about all PCI buses and devices in the system. It is based on a common portable library ''libpci'' which offers access to the PCI configuration space ...
— List USB hosts/devices.
* — Create a range of special files as specified in a device table.
*
mcookie — Generate a 128-bit strong random number.
*
md5sum
is a computer program that calculates and verifies 128-bit MD5 hashes, as described in RFC 1321. The MD5 hash functions as a compact digital fingerprint of a file. As with all such hashing algorithms, there is theoretically an unlimited number ...
— Calculate md5 hash for each input file, reading from stdin if none.
*
microcom
Microcom, Inc., was a major modem vendor during the 1980s, although never as popular as the "big three", Hayes, U.S. Robotics (USR) and Telebit. Nevertheless, Microcom holds an important place in modem history for introducing the MNP error-cor ...
— Simple serial console.
*
mix — List OSS sound channels (module snd-mixer-oss), or set volumes.
*
mkdir
The mkdir (make directory) command in the Unix, DOS, DR FlexOS, IBM OS/2, Microsoft Windows, and ReactOS operating systems is used to make a new directory. It is also available in the EFI shell and in the PHP scripting language. In DOS, OS/2, ...
— Create one or more directories.
*
mkfifo
In computing, a named pipe (also known as a FIFO for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 an ...
— Create FIFOs (named pipes).
*
mknod — Create a special file NAME with a given type.
*
mkpasswd — Crypt PASSWORD using crypt(3).
*
mkswap — Set up a Linux swap area on a device or file.
*
mktemp
mktemp is a command available in many Unix-like operating systems that creates a temporary file or directory. Originally released in 1997 as part of OpenBSD 2.1, a separate implementation exists as a part of GNU Coreutils.
There used to be a sim ...
— Safely create a new file "DIR/TEMPLATE" and print its name.
*
modinfo — Display module fields for modules specified by name or .ko path.
*
mount — Mount new filesystems on directories.
*
mountpoint — Check whether the directory or device is a mountpoint.
*
mv — Move files.
*
nbd-client — Connect to an NBD server.
*
nc/
netcat
netcat (often abbreviated to nc) is a computer networking utility for reading from and writing to network connections using TCP or UDP. The command is designed to be a dependable back-end that can be used directly or easily driven by other p ...
— Forward stdin/stdout to a file or network connection.
*
netstat
In computing, netstat (''network statistics'') is a command-line network utility that displays network connections for Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interf ...
— Display networking information.
*
nice
Nice ( , ; Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative c ...
— Run a command line at an increased or decreased scheduling priority.
*
nl — Number lines of input.
*
nohup
nohup is a POSIX command which means "no hang up". Its purpose is to execute a command such that it ignores the HUP (hangup) signal and therefore does not stop when the user logs out.
Output that would normally go to the terminal goes to a file ...
— Run a command that survives the end of its terminal.
*
nproc — Print number of processors.
* — Run COMMAND in an existing (set of) namespaces.
*
od — Dump data in octal/hex.
*
oneit — Simple init program that runs a single supplied command line
*
partprobe — Tell the kernel about partition table changes.
*
passwd
passwd is a command on Unix, Plan 9, Inferno, and most Unix-like operating systems used to change a user's password. The password entered by the user is run through a key derivation function to create a hashed version of the new password, wh ...
— Update user's authentication tokens.
*
paste — Merge corresponding lines from each input file.
*
patch
Patch or Patches may refer to:
Arts, entertainment and media
* Patch Johnson, a fictional character from ''Days of Our Lives''
* Patch (''My Little Pony''), a toy
* "Patches" (Dickey Lee song), 1962
* "Patches" (Chairmen of the Board song) ...
— Apply a unified diff to one or more files.
*
pgrep
pgrep is a command-line utility initially written for use with the Solaris 7 operating system by Mike Shapiro. It has since been available in illumos and reimplemented for the Linux and BSDs (DragonFly BSD, FreeBSD, NetBSD, and OpenBSD). It sea ...
— Search for process(es).
* — Print the PIDs of all processes with the given names.
*
ping
Ping may refer to:
Arts and entertainment Fictional characters
* Ping, a domesticated Chinese duck in the illustrated book '' The Story about Ping'', first published in 1933
* Ping, a minor character in ''Seinfeld'', an NBC sitcom
* Ping, a c ...
— Check network connectivity by sending packets to a host and reporting its response.
*
pivot root — Swap OLD and NEW filesystems (as if by simultaneous mount—move), and move all processes with chdir or chroot under OLD into NEW (including kernel threads) so OLD may be unmounted.
*
pkill
(see ) is a command-line utility initially written for use with the Solaris 7 operating system in 1998. It has since been reimplemented for Linux and some BSDs.
As with the and commands, is used to send signals to processes. The command a ...
— look up or signal processes based on name and other
*
pmap — Report the memory map of a process or processes.
*
poweroff — Restart, halt or powerdown the system.
*
printenv — Print environment variables.
*
printf
The printf format string is a control parameter used by a class of functions in the input/output libraries of C and many other programming languages. The string is written in a simple template language: characters are usually copied literal ...
— Format and print ARGUMENT according to FORMAT, using C printf syntax.
*
prlimit — Print or set resource limits for process number PID.
*
ps — List processes.
*
pwd
In Unix-like and some other operating systems, the pwd command (''print working directory'') writes the full pathname of the current working directory to the standard output.
Implementations
Multics had a pwd command (which was a short name of ...
— Print working (current) directory.
*
pwdx — Print working directory of processes listed on command line.
*
readahead
Readahead is a system call of the Linux kernel that loads a file's contents into the page cache. This prefetches the file so that when it is subsequently accessed, its contents are read from the main memory (RAM) rather than from a hard disk drive ...
— Preload files into disk cache.
*
readlink — Show what symlink points to.
*
realpath — Display the canonical absolute pathname
*
reboot
In computing, rebooting is the process by which a running computer system is restarted, either intentionally or unintentionally. Reboots can be either a cold reboot (alternatively known as a hard reboot) in which the power to the system is physi ...
— Restart, halt or powerdown the system.
*
renice — set nice values of running processes
*
reset — Reset the terminal.
*
rev — Output each line reversed, when no files are given stdin is used.
*
rfkill — Enable/disable wireless devices.
*
rm — Remove each argument from the filesystem.
*
rmdir
In computing, rmdir (or rd) is a command which will remove an empty directory on various operating systems.
Implementations
The command is available in Unix (e.g. macOS, Solaris, AIX, HP-UX), Unix-like (e.g. FreeBSD, Linux), DOS, Digital Resear ...
— Remove one or more directories.
*
rmmod — Unload the module named MODULE from the Linux kernel.
*
rtcwake — Enter the given sleep state until the given time.
*
sed
sed ("stream editor") is a Unix utility that parses and transforms text, using a simple, compact programming language. It was developed from 1973 to 1974 by Lee E. McMahon of Bell Labs,
and is available today for most operating systems.
sed w ...
— Stream editor.
*
seq — Count from first to last, by increment.
*
setfattr — Write POSIX extended attributes.
*
setsid — Run process in a new session.
*
sha1sum
is a computer program that calculates and verifies SHA-1 hashes. It is commonly used to verify the integrity of files. It (or a variant) is installed by default on most Linux distributions. Typically distributed alongside are , , and , whic ...
— Calculate sha hash for each input file, reading from stdin if none.
*
shred — Securely delete a file by overwriting its contents with random data.
*
sleep
Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefulness by a de ...
— Wait before exiting.
*
sntp
The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable- latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in c ...
— Simple Network Time Protocol client.
*
sort
Sort may refer to:
* Sorting, any process of arranging items in sequence or in sets
** Sorting algorithm, any algorithm for arranging elements in lists
** Sort (Unix), a Unix utility which sorts the lines of a file
** Sort (C++), a function in the ...
— Sort all lines of text from input files (or stdin) to stdout.
*
split
Split(s) or The Split may refer to:
Places
* Split, Croatia, the largest coastal city in Croatia
* Split Island, Canada, an island in the Hudson Bay
* Split Island, Falkland Islands
* Split Island, Fiji, better known as Hạfliua
Arts, enterta ...
— Copy INPUT (or stdin) data to a series of OUTPUT (or "x") files with alphabetically increasing suffix (aa, ab, ac... az, ba, bb...).
*
stat
STAT, Stat. , or stat may refer to:
* Stat (system call), a Unix system call that returns file attributes of an inode
* ''Stat'' (TV series), an American sitcom that aired in 1991
* Stat (website), a health-oriented news website
* STAT protein, a ...
— Display status of files or filesystems.
*
strings
String or strings may refer to:
*String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects
Arts, entertainment, and media Films
* ''Strings'' (1991 film), a Canadian anim ...
— Display printable strings in a binary file
*
su — Switch user, prompting for password of new user when not run as root.
*
swapoff
is a standard package distributed by the Linux Kernel Organization for use as part of the Linux operating system. A fork, (with meaning "next generation"), was created when development stalled, but has been renamed back to , and is the offi ...
— Disable swapping on a given swapregion.
*
swapon — Enable swapping on a given device/file.
*
switch root
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...
— Use from PID 1 under initramfs to free initramfs, chroot to NEW_ROOT, and exec NEW_INIT.
*
sync — Write pending cached data to disk (synchronize), blocking until done.
*
sysctl
sysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled ...
— Read/write system control data (under /proc/sys).
*
tac — Output lines in reverse order.
*
tail
The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, r ...
— Copy last lines from files to stdout.
*
tar
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bit ...
— Create, extract, or list files in a .tar (or compressed t?z) file.
*
taskset — Launch a new task which may only run on certain processors, or change the processor affinity of an existing PID.
*
tee
A tee is a stand used in sport to support and elevate a stationary ball prior to striking with a foot, club or bat. Tees are used extensively in golf, tee-ball, baseball, American football, and rugby.
Etymology
The word tee is derived from the ...
— Copy stdin to each listed file, and also to stdout.
*
test
Test(s), testing, or TEST may refer to:
* Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities
Arts and entertainment
* ''Test'' (2013 film), an American film
* ''Test'' (2014 film), ...
— Return true or false by performing tests.
*
time
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...
— Run command line and report real, user, and system time elapsed in seconds.
*
timeout
Time-out, Time Out, or timeout may refer to:
Time
* Time-out (sport), in various sports, a break in play, called by a team
* Television timeout, a break in sporting action so that a commercial break may be taken
* Timeout (computing), an enginee ...
— Run command line as a child process, sending child a signal if the command doesn't exit soon enough.
*
top
A spinning top, or simply a top, is a toy with a squat body and a sharp point at the bottom, designed to be spun on its vertical axis, balancing on the tip due to the gyroscopic effect.
Once set in motion, a top will usually wobble for a few ...
— Show process activity in real time.
*
touch
In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch ( haptic perception), as well as temperature ( thermoception), body position (proprioception), and pain. It ...
— Update the access and modification times of each FILE to the current time.
*
true
True most commonly refers to truth, the state of being in congruence with fact or reality.
True may also refer to:
Places
* True, West Virginia, an unincorporated community in the United States
* True, Wisconsin, a town in the United States
* ...
— Return zero.
*
truncate
In mathematics and computer science, truncation is limiting the number of digits right of the decimal point.
Truncation and floor function
Truncation of positive real numbers can be done using the floor function. Given a number x \in \mathbb ...
— Set length of files, extending sparsely if necessary.
*
tty — Show filename of terminal connected to stdin.
* — Create and delete tun/tap virtual ethernet devices.
*
ulimit — Print or set resource limits for process number PID.
*
umount
In computing, mount is a command in various operating systems. Before a user can access a file on a Unix-like machine, the file system on the device which contains the file needs to be mounted with the mount command. Frequently mount is used for ...
— Unmount the listed filesystems.
*
uname
uname (short for ''unix name'') is a computer program in Unix and Unix-like computer operating systems that prints the name, version and other details about the current machine and the operating system running on it.
History
The uname system cal ...
— Print system information.
*
unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...
— universal character set.
*
uniq
uniq is a utility command (computing), command on Unix, Plan 9 from Bell Labs, Plan 9, Inferno (operating system), Inferno, and Unix-like operating systems which, when fed a text file or Standard streams#Standard input (stdin), standard input, o ...
— Report or filter out repeated lines in a file.
*
unix2dos
(sometimes named or ) is a tool to convert line breaks in a text file from Unix format (Line feed) to DOS format ( carriage return + Line feed) and vice versa. When invoked as the program will convert a Unix text file to DOS format, when inv ...
— Convert newline format from unix "\n" to dos "\r\n".
*
unlink
In the mathematics, mathematical field of knot theory, an unlink is a Link (knot theory), link that is equivalent (under ambient isotopy) to finitely many disjoint circles in the plane.
Properties
* An ''n''-component link ''L'' ⊂&nbs ...
— Delete one file.
*
unshare — Create new container namespace for this process and its children, so some attribute is not shared with the parent process.
*
uptime
Uptime is a measure of system reliability, expressed as the percentage of time a machine, typically a computer, has been working and available. Uptime is the opposite of downtime.
It is often used as a measure of computer operating system reliab ...
— Tell the current time, how long the system has been running, the number of users, and the system load averages for the past 1, 5 and 15 minutes.
*
usleep — Pause for MICROSECONDS microseconds.
*
uudecode — Decode a uuencoded file.
*
uuencode — Encode a binary file.
* — Create and print a new RFC4122 random UUID.
*
vconfig — Create and remove virtual ethernet devices.
*
vmstat
vmstat (''virtual memory statistics'') is a computer system monitoring tool that collects and displays summary information about operating system memory, processes, interrupts, paging and block I/O. Users of vmstat can specify a sampling interv ...
— Print virtual memory statistics.
*
w — Show who is logged on and since how long they logged in.
*
watch
A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by ...
— Run PROG every -n seconds, showing output.
*
wc — Count lines, words, and characters in input.
*
which
Which may refer to:
* a relative pronoun
* an interrogative word
*which (command), an operating system command
*Which?, a UK charity and its magazine
See also
* English relative clauses
* Interrogative clause
* Whicher (disambiguation) Whicher ...
— Search $PATH for executable files matching filenames.
*
watchdog
Watchdog or watch dog may refer to:
Animals
*Guard dog, a dog that barks to alert its owners of an intruder's presence
* Portuguese Watch Dog, Cão de Castro Laboreiro, a dog breed
* Moscow Watchdog, a breed of dog that was bred in the Soviet ...
— software watchdog daemon.
*
who
Who or WHO may refer to:
* Who (pronoun), an interrogative or relative pronoun
* Who?, one of the Five Ws in journalism
* World Health Organization
Arts and entertainment Fictional characters
* Who, a creature in the Dr. Seuss book '' Horton He ...
— Print information about logged in users.
*
whoami — Print the current user name.
*
xargs
xargs (short for "extended arguments" ) is a command on Unix and most Unix-like operating systems used to build and execute commands from standard input. It converts input from standard input into arguments to a command.
Some commands such as gr ...
— Run command line one or more times, appending arguments from stdin.
*
xxd
In computing, a hex dump is a hexadecimal view (on screen or paper) of computer data, from memory or from a computer file or storage device. Looking at a hex dump of data is usually done in the context of either debugging, reverse engineering or ...
— Hexdump a file to stdout.
*
yes — Repeatedly output line until killed.
*
zcat — Decompress gz files to stdout.