UNIX Tutorials, Tips, Tricks and Shell Scripts

Basic UNIX Commands for Beginners: UNIX Command Alias


As its name implies, a command alias is just an alias for a command and its options and/or arguments. Defining command aliases are helpful for command and option combinations that are frequently used or difficult to remember. The alias command is used to create a command alias:

$ alias listfiles=ls
Running this command will create the alias listfiles that will run the ls command when invoked. To display a complete list of your alias definitions, you would use the alias command with no arguments. To display a specific alias, you would type the alias command followed by the name of the alias:

$ alias listfiles
[ If you are new to UNIX and need an overview of important UNIX commands and concepts, check out our Basic UNIX Commands and Concepts Tutorial for Beginners ]

The unalias command is used for deleting alias definitions:

$ unalias listfiles
You can verify the removal of an alias by attempting to display the alias, or by attempting to run the alias:

$ alias listfiles
listfiles alias not found
OR

$ listfiles
ksh: listfiles: not found

TIP: If you want to include one or more options with a command when defining an alias, the command and option(s) need to be enclosed with single quotes. For example, if you wanted to include the -l option with the ls command you would use the following syntax:

$ alias longlist='ls -l'

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