Linux Bash Commands Cheatsheet.sh

#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
  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
#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
#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     # Find files
  logname  # Print current login name
  logout   # Exit a login shell •
  look     # Display lines beginning with a given string
  lpc      # 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      # Mass Move and rename (files)
#n
  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
  quotactl # Set disk quotas
#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.
  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