Another potentially useful property of most shells (not the original Bourne shell) is that of ``alias''. Alias allows the user to use a shorthand version of a command, complete with options. By example, if you or one of your users has a habit of deleting files that shouldn't be deleted, one can alias rm -i for rm. This way, whenever the user enters rm as a command, the shell first substitutes rm -i for rm, and then proceeds with parsing the command line.