Hi guys, I have a quick question.

I know how to add users and groups. Now if I forget the accounts of people on the system, how can I list all the accounts and groups that are currently on the system?

I've googled, but maybe I'm not googling the right thing. I just can't seem to find out how to do this.

"cat /etc/passwd" -- numbers in the third column up till 999 should be groups, 1000 and above users.

you could just browse the text files: /etc/passwd and /etc/group with your favourite text-editor.

or type

Thanks a bunch

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.