How do I show all combinations?

[3EBC]

I searched, can't find anything: How do I do this?I enter $x = 'tlagre';I want it to return every single letter combination, down to four.i.e. - "tlagr" "gratl" "lat" "rat" I've found some that can do this but none will do every number of letters (they all just do the exact same # of letters as given in $x