Different distro's have different default UID number ranges for regular users. Mandrake starts at 500, SuSE starts at 1000. However once you determine the range that your distro uses, you can determine which /etc/password entries are for regular users. If you don't have users who's home directories are on a remote directory, the home directory entry containing '/home/' is another way to filter out the system users.
grep '/home/' etc/passwd
You may have some regular users without a home directory who have username/password entries for using a Samba service, if your Linux box is also a Samba File and/or Login server.
On most distro's, you can use a Users & Groups GUI config program which allows you to filter out system users and groups.
Last edited by jschiwal; 04-27-2007 at 06:48 PM.