Aliases are one of the most time-saving devices. An alias is a way to make a complicated command or set of commands simple. This is best demonstrated by an example.
In web development or computer programming, there are a lot of times we need to recompile some source file. Below we are recompiling a less file and looking at the tail of the result.
Note: The example below can be generalized to any set of commands.
cd /home/myuser/public_html/less/ lessc -c style.less > ../style.csscd ../
Wouldn’t it be easier to just type something like the following?
Luckily for us, this is simple to do in the bash-shell.
Our .bashrc file is located in our user directory. Open it in text editor.
$ vim ~/.bashrc
In vim, we can accomplish this just by hitting “G” (please note that it is capital).
A simple way to chain commands in Linux is to use the && operator. This operator will run a set of commands and only continue to the next command if the previous one was successful. For our example, we might have an alias that looks like this:
aliastailmyless='cd /home/myuser/public_html/less && lessc -c style.less > ../style.css && cd ../ && tail style.css'
This looks complicated but it really isn’t. Here’s the basic format:
There cannot be a space between the “aliasname” and the EQUAL sign. Also, there can’t be a space between the EQUAL sign and the opening quote for the command.
In vim, hit ESCAPE to get to normal mode and run the following command to write and quit:
The new .bashrc would be installed the next time we log out and log back in, but if you are impatient like me and just want it installed now, you can just source the file.
$ source ~/.bashrc
Well, that’s it. Now we can alias until our heart’s content. Remember, a few seconds saved here and there can dramatically increase our efficiency!