uuidgen is a command line tool to generate UUIDs.

On Linux this command returns a lowercase string of a UUID.
But on Mac OS X it returning an uppercase string of a UUID.

So how to change this?

I have created a simple alias as following:

uuidgen='uuidgen | tr "[:upper:]" "[:lower:]"'

Now executing uuidgen will output the following:

0ba34ef2-438a-4635-8f8b-86edec6aefdf

Simple :)