Bash script absolute path with OSX

Question

I am trying to obtain the absolute path to the currently running script on OS X.

I saw many replies going for readlink -f $0. However since OS X's readlink is the same as BSD's, it just doesn't work (it works with GNU's version).

Any suggestions for an out of the box solution to this?

Answer 1

There's a realpath() C function that'll do the job, but I'm not seeing anything available on the command-line. Here's a quick and dirty replacement:

#!/bin/bash

realpath() {
    [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}

realpath "$0"

This prints the path verbatim if it begins with a /. If not it must be a relative path, so it prepends $PWD to the front. The #./ part strips off ./ from the front of $1.

Answer 2

Here's a C snippet that resolves symbolic links as well as Mac-type aliases:

http://my-sample-code.googlecode.com/svn/trunk/realpath/realpath.c