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bash magic

02 Jan 2015

Bash has a bunch of features that are (somewhat) undocumented but are extremely powerful. There are magic variables, shortcuts and shorthands that can help you improve your shell-fu. This post is a compilation of some of the best features Bash has to offer (many of which apply to zsh as well).

Shortcuts

  • Ctrl E: Move cursor to the end of the current command.
  • Ctrl A: Move cursor to the beginning of the current command.
  • Ctrl U: Delete to beginning of command from current cursor position.
  • Ctrl K: Delete to end of command from current cursor position.
  • Ctrl R: Reverse search history
  • Ctrl X Ctrl-E: Open the current command in $EDITOR (very useful for long commands).
  • Ctrl -: Incremental undo
  • Ctrl L: Clear screen to the top (same thing as clear command)

Shorthands and Magic variables

  • !!: The last command
  • !$: The last argument from the last command.
  • ![word]: The last command starting with [word]
  • ![word]:p: Print the last command starting with [word] (but do not run)
  • ^[word]^[replacement]: Find last command starting with [word] and re-run it with [replacement].
  • [command] [argument]{a,b,c}: Run [command] with [argument] three times, each time changing the postfix to a, then b, then c. For example, mkdir test{1,2} would make two directories: test1 and test2
  • set -o vi: Use vi-like movement to edit commands :)

PS1 Variables for Prompt Customization

  • \t: Time (HH:MM:SS)
  • \d: Date (Weekday Month Day)
  • \w: pwd
  • \W: basename of pwd
  • \u: username
  • \h: hostname