Ubuntu: Up and Running

Using Aliases

You can make up your own command names to replace those used in Ubuntu. For example, if you’re used to using the command md in Windows to create a directory and keep forgetting to enter mkdir, you can set an alias like this:

alias md="mkdir"

Thereafter both md and mkdir will refer to the mkdir command. Note that you can use either single or double quotation marks.

Note

An even more common and powerful use of aliases is to add options to commands. For instance, many people make sure they know exactly which files are removed by rm (because its deletions are irreversible) by aliasing it as follows:

alias rm="rm -i"

The -i option causes rm to ask you whether it’s OK before removing each file—a time-consuming addition, but a safe one.

And you’re free to create your own commands, like this:

alias newf="find ~ -type d -mtime -3"

Now when you type newf you will see all files under your home directory that were created or modified within the past three days. This will include a lot of hidden files created by your browser and other programs you use.

To find out which aliases have been created, just type alias on its own, like this:

alias

If you do this you may see that, among others, the ls command has been aliased as follows (having the effect of allowing color to be used to display files with different file and folder attributes, where applicable):

alias ls='ls --color=auto'

To remove an alias, use the unalias command. So, if you like, you can remove the color display option from the