Printing PDF

Hi! I have an app that needs to be created, and it is all running on linux. I am sure I shoulnd't really write it using PHP, but it's kinda what I know, and am familiar with... so I am thinking about doing with PHP. Anyway, for simplicity sake, i am creating a pdf through php (no problems there) and it needs to be printed. I've never done printing on linux, but is there an easy way to send the pdf print job via command lines to the local (or network) printer? a friend of mine said "postscript" or "cups", but I am not familiar with them, so I thought I would ask you GURU's here :) thank in advance! Steve