Running system commands UNIX with php?

Hello all, I've got a question about a project that is coming up for me. I have a company that is wanting me to build them a PHP front end to a server that basically allows them to admin some features of the server. Such as add e-mail address (user accounts) and modify some settings. Either way I'm looking for a solution to add user accounts to a system not a database with PHP and the web. I"m using UNIX as the servers (all) and current PHP and apache. Any help would be greatfull. Thanks ahead of time. ,Sloan -- --------------------------- Windows 95/NT - 32 bit extensions and a graphical shell for a 16 bit patch to an 8 bit operating system originally coded for a 4 bit microprocessor, written by a 2 bit company that can't stand 1 bit of competition.