Making an alias for a command

Aliases allow you to assign long or complex commands to short comands or "nicknames" which are easier to remember as well as to type.

For example, instead of typing:

ls -alFs | more

you can make your account perform the same action (listing files) by aliasing the command to just:

l.

You can make temporary aliases or, for often-used commands, permanent ones.

The alias command can be used three ways.

• Examine existing aliases.
• Create temporary aliases.
• Create permanent aliases.

Use the unalias command to remove temporary aliases or disable permanent aliases (please see bottom of this page).

Examining existing aliases

Entering the alias command all by itself (with no arguments) lists all active aliases (there are several aliases which are pre-set for all Unity accounts).

Entering the command alias name displays the named alias' definition. For example, entering

alias goto

results in

[sparc03]...kaputnik>alias goto
set d1 = $cwd; cd !^ 
[sparc03]...kaputnik>

The goto command is clearly easier to type and remember than what it stands for!

Creating temporary aliases

You can create temporary aliases of your own by following the syntax

alias name definition

where name is the abbreviation you want to use in place of the big, nasty Unix command, and definition is the actual Unix command you want to replace.

Entering the alias at the command line creates a temporary alias.

For example, you can set cls to substitute for the clear command, which clears the screen, by entering

alias cls clear

Or you could establish an alias for the ls command (which lists files) that includes the -s option (which provides the size of the files) by entering

alias l ls -s

Aliases created in this way, however, will be active only for the current session. When you logout, your alias is lost.

Permanent aliases

To create permanent aliases you must modify your ".mycshrc" file. Open the file with an editor (such as TED or Nedit) and type the alias command you wish to activate. Be sure to put the command on a single line. The alias will be active until it is removed from the file or until you use the unalias command on it (see below).

For example, if you wanted to alias the command "zwho | grep 1004tuc ; zwho | grep -c 1004tuc" which makes a zwho list of the people in Tucker Lab:

1. Open the text editor by doing one of the following:
   
   • Type ted or Nedit at the prompt.
   • From the Application menu (mouse button 2), choose one of these from the Editors sub-menu.
     
2. Open the file ".mycshrc". if you don't have one, create a new file with this name. (The file must be located in the root directory!)
   
3. Add the line:

   alias tucker "zwho | grep 1004tuc ; zwho | grep -c 1004tuc"

4. Logout and log back in. Note: Changes to a file usually WILL NOT take effect until you do this.

The command tucker will now work the same as "zwho | grep 1004tuc ; zwho | grep -c 1004tuc" and tucker is also easier to remember and takes less time to type!

For more information about customizing your environment see Customizing your Unity account.

Removing aliases

To remove a temporary aliase use the command unalias name.

For example, if you had set scan as an alias for the command sequence more -cs, you would remove the alias by entering unalias scan.

Using the unalias command on a permanent alias (one which is defined in your ".mycshrc" file) removes the alias for that session only. When you logout and then login again the alias will still be in effect.

To remove a permanent alias permanently you must remove the line in your ".mycshrc" file that defines it.

Last modified July 20, 2004 by cawalker