/terminal_alias-and-functions

How to write basic aliases & functions

Aliases & Functions in Bash and Zsh

Aliases or Functions ?

An alias is nothing more than text substitution, if all you need is to shorten a command down to a few characters, an alias is probably what you're looking for.
If you need to shorten multiple commands or handle multiple arguments, you're more than likely going to want a function to handle this properly (and optionally add some logic on top).

Linux (default shell: Bash)

The (default) bash configuration file resides in $HOME/.bashrc, inside of this file will be our bash configuration with our aliases and/or functions.

  • An alias is written like so:

    alias 'lsa'='ls -a'

    Here, lsa is the name we give to our alias, while ls -a is the command we want to run when we execute it. The equal sign assigns the command(s) on the right to the name on the left.

    There's not much more to it than that !


  • Functions are where the fun begins:

    function gac() {
    git add "$1"
    git commit -m "$2"
}

    Our function begins with the keyword of the same name (function) and the main body resides inside of curly braces ({})

    Sounds familiar...

    Each successive command is separated by a newline to separate them, and arguments are surrounded by double quotes (") followed by $ and the number of the argument.

MacOS (default shell: Zsh)

The config file is also (by default) at the root of our user (~), if it doesn't already exist you can create it with touch ~/.zshrc.

  • Aliases work practically the same in zsh with a minor difference, the name of the alias is not surrounded by quotes:

    alias rmfr="rm -f -r"

  • Functions work "mostly" the same, but you don't need the function keyword and you have access to an argument array (among other things):

    del() {
    rm -f $*
}

Git Bash on Windows

Same as Linux; if it doesn't already exist, create %USER%\.bashrc and put your config inside.

For aliases in Powershell check the documentation

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