Some of these commands are well known so I do not describe them some other are described in separate posts:

 

  • ! = logicaly inverts exist status or variable value
  • # = comment until end of the line
  • #!shell = only on the first line – invokes named shell (f.e. #!/bin/bash )
  • : = do nothing command (f.e. if [ … ]; then : else … fi )
  • . = read and execute file in current shell
  • [[ ]] = extended version of test command of [ ] command allows additional operators &&, ||, <, >
  • function in the script:
    • can be defined on any place in script but before its first usage
    • syntax:
      • name () { commands; }
      • function name () { commands; }
  • alias = shortcut for commands
  • bg = move current job or specified job id in the background
  • bind = key binding
  • break = exists loops
  • builtin = exectue built-in command
  • caller = used by debugger
  • case … esac = begin and end of case command
  • cd
  • command = executes command of prints info about command
  • compgen = generates possible competions
  • complete = specifies how to complete specific commands
  • compopt = print or change the completion for a command
  • continue = skips rest of loop
  • cp
  • declare = declaration of variables
  • dirs = directory stack
  • disown = stop managing one or more jobs
  • do … done = begin and end of the loop
  • echo
  • enable = enable/ disable shell built-in commands
  • eval
  • exec
  • exit
  • export
  • false, true = logical return values
  • fc = command line history
  • fg = move running background job into foreground
  • if … fi = begin and end of if command
  • for = start of loop
  • history = prints command line history
  • kill
  • let = performs arithmetic operation
  • pwd
  • return
  • test
  • time
  • wait = waits for process/ job to be completed