Hints and tricks

This section contains some hints that might make working with Linux easier.

Tab auto-complete

If you press TAB on the keyboard after starting to type a command or a file, it will auto-complete if no other matches or else suggest possible matches.

Short-cuts on the CLI

CTRL-SOMEKEY refers to pressing down the CTRL key and then another key while continuing to hold down CTRL.

Examples:

  • CTRL-a: Go to the beginning of the line
  • CTRL-e: Go to the end of the line
  • CTRL-l: Clear the terminal
  • TAB: Auto-complete (i.e. start write a command or file name and then press TAB to auto-complete, if possible)
  • ARROW-UP: Pressing the arrow-up key repeatedly will let you cycle through recent commands
  • CTRL-r: you will get a prompt to write text to search in the list of recent commands. The list is saved in .bash.history in your $HOME.

Finding help

You can often get more info on flags/options and usage for a Linux command with

  • COMMAND --help
  • man COMMAND

where COMMAND is the Linux command you want information about, like ls, mkdir, gcc, etc.

Misc

  • Write ‘clear’ to clear the terminal
  • write ‘history’ to see a list of the most recent commands written in the terminal
    • You can change the number of saved commands by setting the environment variable HISTSIZE in your .bashrc file in your home directory.
    • Example: Open .bashrc with nano. Somewhere (at the end for instance) add: export HISTSIZE=NUMBER” where NUMBER is the number of commands to save, for instance 10000.
  • man PROGRAM will give you the manual for a specific program or command, if it exists
    • Example: man gcc will give open manual/help for the compiler gcc, containing flags to the compiler etc. Note that you need to first load a module that has gcc in.