Linux Commands

From HostPedia

Index of the Linux bash commands, view the various commands and functions detailed instructions for each of those commands:

• alias Create an alias
• apropos Search Help manual pages (man -k)
• awk Find and Replace text, database sort/validate/index
• break Exit from a loop
• builtin Run a shell builtin
• bzip2 Compress or decompress named file(s)
• cal Display a calendar
• case Conditionally perform a command
• cat Display the contents of a file
• 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
• 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
• cut Divide a file into several parts
• date Display or change the date & time
• dc Desk Calculator
• dd Data Dump - Convert and copy a file
• 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
• du Estimate file space usage
• 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
• expand Convert tabs to spaces
• export Set an environment variable
• expr Evaluate expressions
• false Do nothing, unsuccessfully
• fdformat Low-level format a floppy disk
• fdisk Partition table manipulator for Linux
• 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
• gawk Find and Replace text within file(s)
• getopts Parse positional parameters
• grep Search file(s) for lines that match a given pattern
• groups Print group names a user is in
• gzip Compress or decompress named file(s)
• hash Remember the full pathname of a name argument
• head Output the first part of file(s)
• history Command History
• hostname Print or set system name
• id Print user and group id's
• if Conditionally perform a command
• ifconfig Configure a network interface
• import Capture an X server screen and save the image to file
• install Copy files and set attributes
• join Join lines on a common field
• kill Stop a process from running
• less Display output one screen at a time
• let Perform arithmetic on shell variables
• ln Make links between files
• 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
• 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
• mount Mount a file system
• mtools Manipulate MS-DOS files
• mv Move or rename files or directories
• 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
• nslookup Query Internet name servers interactively
• passwd Modify a user password
• paste Merge lines of files
• pathchk Check file name portability
• ping Test a network connection
• 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
• pwd Print Working Directory
• quota Display disk usage and limits
• quotacheck Scan a file system for disk usage
• quotactl Set disk quotas
• ram ram disk device
• rcp Copy files between two machines.
• read read a line from standard input
• readonly Mark variables/functions as readonly
• remsync Synchronize remote files via email
• return Exit a shell function
• rm Remove files
• rmdir Remove folder(s)
• rsync Remote file copy (Synchronize file trees)
• 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
• 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)
• strace Trace system calls and signals
• su Substitute user identity
• sudo Execute a command as another user
• sum Print a checksum for a file
• symlink Make a new name for a file
• sync Synchronize data on disk with memory
• tail Output the last part of files
• tar Tape ARchiver
• tee Redirect output to multiple files
• test Evaluate a conditional expression
• time Measure Program running time
• times User and system times
• touch Change file timestamps
• top List processes running on the system
• 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
• 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
• unset Remove variable or function names
• unshar Unpack shell archive scripts
• until Execute commands (until error)
• useradd Create new 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 Verbosely list directory contents (`ls -l -b')
• vdir Verbosely list directory contents (`ls -l -b')
• vi Text Editor
• watch Execute/display a program periodically
• wc Print byte, word, and line counts
• whereis Report all known instances of a command
• which Locate a program file in the user's path.
• 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
• xargs Execute utility, passing constructed argument list(s)
• yes Print a string until interrupted