WYNTK: UNIX System Admininistrator

You can have “aliases” for commands.

Most users have the ability to define aliases for commands. An alias is another way to “shorthand” a command. For example, if you often cd to the /usr/local/txtools/font/ps directory, and you don’t want to type out the complete command all the time, you can make an alias for it. If you always want to run a command with certain options — for example, if you always want to see slashes after directory names when you type ls — then you can alias the ls command to “ls -F”.

The way you define an alias depends on what shell you use. If you use the C shell or tcsh, then in your .cshrc or .tcshrc you might enter lines like these:

alias cdfont 'cd /usr/local/txtools/font/ps'
alias lf 'ls -F'

If you use the Korn shell or bash:

alias cdfont='cd /usr/local/txtools/font/ps'
alias lf='ls -F'

If there are two versions of a command on your system, you can use aliases to make sure you run the version you prefer. In many ways, this is preferable to changing your search path to ensure that you get the version of ls that you want.

alias ls '/usr/5bin/ls'

Sometimes you can get in trouble with aliases. For example, if you want to always ls a directory after you cd to it, you might be tempted to define the following alias:

alias cdls 'cd; ls'

However, this means that every time you run cdls, you’ll cd to your home directory. In the C shell or tcsh, you can use the special “\!*” syntax to pass the rest of the command line to cd:

alias cdls 'cd \!*; ls'

Now when you say “cdls /usr/local,” ...