A-Z Index of the Bash command line for Linux.

An A-Z Index of the Bash command line for Linux.

A

       alias                Create an alias • apropos Search Help manual pages (man -k)

       apt-get            Search for and install software packages (Debian/Ubuntu)

       aptitude          Search for and install software packages (Debian/Ubuntu)

       aspell              Spell Checker

       awk                Find and Replace text, database sort/validate/index

B

       basename       Strip directory and suffix from filenames

       bash               GNU Bourne-Again SHell 

       bc                  Arbitrary precision calculator language 

       bg                  Send to background

       break             Exit from a loop •

       builtin           Run a shell builtin

       bzip2            Compress or decompress named file(s)

C

      cal                  Display a calendar

      case                Conditionally perform a command

      cat                  Concatenate and print (display) the content of files

      cd                   Change Directory

      cfdisk             Partition table manipulator for Linux

      chgrp             Change group ownership

      chmod           Change access permissions

      chown           Change file owner and group

      chroot            Run a command with a different root directory

      chkconfig      System services (runlevel)

      cksum            Print CRC checksum and byte counts

      clear              Clear terminal screen

      cmp               Compare two files

      comm            Compare two sorted files line by line

      command      Run a command - ignoring shell functions •

      continue        Resume the next iteration of a loop •

      cp                  Copy one or more files to another location

      cron               Daemon to execute scheduled commands

      crontab          Schedule a command to run at a later time

      csplit             Split a file into context-determined pieces

      curl               Transfer data  from or to a server

      cut                Divide a file into several parts

D

      date               Display or change the date & time

      dc                  Desk Calculator

      dd                  Convert and copy a file, write disk headers, boot records

      ddrescue        Data recovery tool

      declare          Declare variables and give them attributes •

      df                  Display free disk space

      diff                Display the differences between two files

      diff3              Show differences among three files

      dig                 DNS lookup

      dir                 Briefly list directory contents

      dircolors       Colour setup for `ls'

      dirname        Convert a full pathname to just a path

      dirs               Display list of remembered directories

      dmesg           Print kernel & driver messages 

      du                 Estimate file space usage

E

      echo             Display message on screen •

      egrep            Search file(s) for lines that match an extended expression

      eject             Eject removable media

      enable          Enable and disable builtin shell commands •

      env               Environment variables

      ethtool          Ethernet card settings

      eval              Evaluate several commands/arguments

      exec             Execute a command

      exit              Exit the shell

      expect          Automate arbitrary applications accessed over a terminal

      expand        Convert tabs to spaces

      export         Set an environment variable

      expr            Evaluate expressions

F

      false           Do nothing, unsuccessfully

      fdformat     Low-level format a floppy disk

      fdisk          Partition table manipulator for Linux

      fg               Send job to foreground 

      fgrep          Search file(s) for lines that match a fixed string

      file             Determine file type

      find            Search for files that meet a desired criteria

      fmt             Reformat paragraph text

      fold            Wrap text to fit a specified width.

      for              Expand words, and execute commands

      format        Format disks or tapes

      free            Display memory usage

      fsck           File system consistency check and repair

      ftp              File Transfer Protocol

      function     Define Function Macros

      fuser          Identify/kill the process that is accessing a file

G

      gawk                Find and Replace text within file(s)

      getopts             Parse positional parameters

      grep                  Search file(s) for lines that match a given pattern

      groupadd          Add a user security group

      groupdel           Delete a group

      groupmod         Modify a group

      groups               Print group names a user is in

      gzip                  Compress or decompress named file(s)

H

      hash               Remember the full pathname of a name argument

      head              Output the first part of file(s)

      help               Display help for a built-in command •

      history          Command History

      hostname      Print or set system name

      htop              Interactive process viewer

I

      iconv             Convert the character set of a file

      id                   Print user and group id's

      if                    Conditionally perform a command

      ifconfig          Configure a network interface

      ifdown           Stop a network interface 

      ifup               Start a network interface up

      import           Capture an X server screen and save the image to file

      install            Copy files and set attributes

      ip                   Routing, devices and tunnels

J

      jobs           List active jobs •

      join           Join lines on a common field

K

      kill             Kill a process by specifying its PID

      killall         Kill processes by name

L

      less             Display output one screen at a time

      let               Perform arithmetic on shell variables •

      link             Create a link to a file 

      ln                Create a symbolic link to a file

      local           Create variables •

      locate         Find files

      logname     Print current login name

      logout        Exit a login shell •

      look           Display lines beginning with a given string

      lpc             Line printer control program

      lpr             Off line print

      lprint         Print a file

      lprintd       Abort a print job

      lprintq       List the print queue

      lprm          Remove jobs from the print queue

      ls               List information about file(s)

      lsof            List open files

M

      make           Recompile a group of programs

      man             Help manual

      mkdir          Create new folder(s)

      mkfifo         Make FIFOs (named pipes)

      mkisofs       Create an hybrid ISO9660/JOLIET/HFS filesystem

      mknod        Make block or character special files

      more            Display output one screen at a time

      most            Browse or page through a text file

      mount          Mount a file system

      mtools         Manipulate MS-DOS files

      mtr              Network diagnostics (traceroute/ping)

      mv               Move or rename files or directories

      mmv            Mass Move and rename (files)

N

       nc                    Netcat, read and write data across networks

       netstat             Networking information

       nice                 Set the priority of a command or job

       nl                     Number lines and write files

       nohup              Run a command immune to hangups

       notify-send      Send desktop notifications

       nslookup         Query Internet name servers interactively

O

       open          Open a file in its default application

       op              Operator access 

P

      passwd        Modify a user password

      paste            Merge lines of files

      pathchk       Check file name portability

      ping            Test a network connection

      pkill             Kill processes by a full or partial name.

      popd            Restore the previous value of the current directory

      pr                 Prepare files for printing

      printcap       Printer capability database

      printenv       Print environment variables

      printf           Format and print data •

      ps                 Process status

      pushd           Save and then change the current directory

      pv                 Monitor the progress of data through a pipe 

      pwd              Print Working Directory 

Q

      quota               Display disk usage and limits

      quotacheck     Scan a file system for disk usage

R

       ram              ram disk device

       rar                Archive files with compression

       rcp               Copy files between two machines

       read              Read a line from standard input •

       readarray      Read from stdin into an array variable •

       readonly       Mark variables/functions as readonly

       reboot           Reboot the system

       rename          Rename files

       renice            Alter priority of running processes 

       remsync        Synchronize remote files via email

       return            Exit a shell function

       rev                 Reverse lines of a file

       rm                  Remove files

       rmdir             Remove folder(s)

       rsync             Remote file copy (Synchronize file trees)

S

       screen          Multiplex terminal, run remote shells via ssh

       scp               Secure copy (remote file copy)

       sdiff             Merge two files interactively

       sed              Stream Editor

       select           Accept keyboard input

       seq               Print numeric sequences

       set                Manipulate shell variables and functions

       sftp              Secure File Transfer Program

       shift             Shift positional parameters

       shopt            Shell Options

       shutdown     Shutdown or restart linux

       sleep             Delay for a specified time

       slocate          Find files

       sort               Sort text files

       source           Run commands from a file '.'

       split              Split a file into fixed-size pieces

       ssh                Secure Shell client (remote login program)

       stat               Display file or file system status 

       strace           Trace system calls and signals

       su                  Substitute user identity

       sudo             Execute a command as another user

       sum             Print a checksum for a file

       suspend       Suspend execution of this shell •

       sync             Synchronize data on disk with memory

T

       tail              Output the last part of file

        tar              Store, list or extract files in an archive

        tee              Redirect output to multiple files

        test             Evaluate a conditional expression

        time            Measure Program running time

        timeout       Run a command with a time limit

        times           User and system times

        touch           Change file timestamps

        top               List processes running on the system

        tput              Set terminal-dependent capabilities, color, position

        traceroute    Trace Route to Host

        trap              Run a command when a signal is set(bourne)

        tr                  Translate, squeeze, and/or delete characters

        true               Do nothing, successfully

        tsort              Topological sort

        tty                 Print filename of terminal on stdin

        type              Describe a command •

U

        ulimit            Limit user resources •

        umask           Users file creation mask

        umount         Unmount a device

        unalias          Remove an alias •

        uname           Print system information

        unexpand      Convert spaces to tabs

        uniq              Uniquify files

        units              Convert units from one scale to another

        unrar             Extract files from a rar archive 

        unset             Remove variable or function names

        unshar           Unpack shell archive scripts

        until              Execute commands (until error)

        uptime          Show uptime

        useradd         Create new user account

        userdel          Delete a user account

        usermod        Modify user account

        users              List users currently logged in

        uuencode       Encode a binary file 

        uudecode       Decode a file created by uuencode

V

        v                    Verbosely list directory contents (`ls -l -b')

        vdir                Verbosely list directory contents (`ls -l -b')

        vi                   Text Editor

        vmstat            Report virtual memory statistics

W

        wait               Wait for a process to complete •

        watch             Execute/display a program periodically

        wc                  Print byte, word, and line counts

        whereis          Search the user's $path, man pages and source files for a program

        which             Search the user's $path for a program file

        while              Execute commands

        who                Print all usernames currently logged in

        whoami          Print the current user id and name (`id -un')

        wget               Retrieve web pages or files via HTTP, HTTPS or FTP

        write              Send a message to another user 

X

        xargs              Execute utility, passing constructed argument list(s)

        xdg-open       Open a file or URL in the user's preferred application.

         xz                  Compress or decompress .xz and .lzma files

         yes                Print a string until interrupted

         zip                Package and compress (archive) files.

         .                    Run a command script in the current shell

         !!                  Run the last command again

         ###               Comment / Remark

Commands marked • are bash built-ins

Many commands particularly the Core Utils are also available under alternate shells (C shell, Korn shell etc).