How To: Run shell scripts containing relative paths from anywhere

Have you ever had the problem that you want to run a script but because it handles relative paths it depends on the directory it’s called from? Well, today I learned about a shell function that helps with that, called dirname.

It can be fed a path and will return it with the last non-slash component and trailing slash removed. So to refer to the location a script sits in you can do simply:

  dirname "$0"

Here $0 expands to the full path of the script. Now you can save it to a variable:

  SCRIPT_DIR=$(dirname "$0")

And from here on you can prefix any relative path with $SCRIPT_DIR and the script will behave the same, regardless of where it was called from.