fish-shell/doc_src/function.txt

\section function function - create a function

\subsection function-synopsis Synopsis
 <tt>function [OPTIONS] NAME; BODY; end </tt>

\subsection function-description Description

- <tt>-d DESCRIPTION</tt> or \c --description=DESCRIPTION is a description of what the function does, suitable as a completion description
- \c -b or \c --key-binding specifies that the function is a key biding. Key binding functions work exactly like regular functions except that they can not be tab-completed, and may contain the '-' character.

This builtin command is used to create a new function. A Function is a
list of commands that will be executed when the name of the function
is entered. The function 

<pre>
function hi
	echo hello
end
BB</pre> 

will write <tt>hello</tt> whenever the user enters \c hi.

If the user enters any additional arguments after the function, they
are inserted into the environment variable <a href="index.html#variables-arrays">array</a> argv.

\subsection function-example Example

<pre>function ll 
	ls -l $argv
</pre>

will run the \c ls command, using the \c -l option, while passing on any additional files and switches to \c ls.
A
<pre>
function mkdir -d "Create a directory and set CWD"
	mkdir $argv
	if test $status = 0 
		switch $argv[(count $argv)]
			case '-*'
				
			case '*'
				cd $argv[(count $argv)]
				return
		end
	end
end
</pre> 

will run the mkdir command, and if it is succesfull, change the
current working directory to the one just created.