[olgeni]

> #!/bin/bash

If there's nothing bash-specific you may wish to use "#!/bin/sh" (or "#!/usr/bin/env bash" if bash is required.)

[minimax]

It's full of bashisms. Arrays, double equals (==) in conditionals, and the function keyword stand out to me.

[kokey]

I found at least one bash specific thing: $(which dscacheutil)