Malta Linux User Group

Bash allows you to define new commands which translate to other, longer commands. For example, if you type the following...

alias lh="ls -l -a $HOME"

, then the command "lh" will become equivalent to the longer command "lh -l -a $HOME".

You can even use this to re-define existing commands. For example if you type "alias ls="ls -a"", then the ls command will always start showing hidden files. You can remove an existing alias by using the unalias command.

You can place these aliases into the .bashrc file as well, to be set up when you load bash.

You can even add "safety features" to certain commands. For example, if you create an alias which makes the copy (cp) command equal to "cp -i", then the copy command will prompt you every time you are about to copy onto an existing file, instead of overwriting it without warning. However you have to keep in mind that these settings will not exist when you’re working in a different user, until you add them to the .bashrc file of that user as well.