Return a list of all users in the system

krystian · 01-31-2006, 03:26 PM

Hello,

Is there shell command which returns the list of all users in the system? (its expected this is to be run as user: root)

The command: "users" only returns a list of all users logged in currently.
If I view /etc/group I can see which users are assigned to what groups, but I can't see the list of all users within the system.

My Thoughts:
I think every user in my system has an entry in /etc/passwd.
- However, services have entries too. ex: sshd is a service. Is sshd also a "user", then?

Thanks,
Krystian.

pljvaldez · 01-31-2006, 03:29 PM

If you just want "real" users, one method that works pretty good is ls /home. Of course, some of the directories there are services like ftp...

krystian · 01-31-2006, 03:36 PM

Quote:

Originally Posted by pljvaldez

If you just want "real" users, one method that works pretty good is ls /home. Of course, some of the directories there are services like ftp...

Problem with that is if root added users as so:
adduser -d /not-in-home

pljvaldez · 01-31-2006, 03:45 PM

Try this: awk -F: '{ if ($3 > 99 && $3 < 100000) { print $1 " " $3 }}' /etc/passwd

This script basically is only printing usernames ($1) and GID's ($3) with a GID of greater than 99. You might try playing with the number 99 and 100000 to see if there's a range that works for you to get rid of all the services stuff. Mine is actually more like 999 and 2000.

Once you've got that trimmed down how you like it, you can delete the " " $3 in the print command to only get usernames.

You can even run this as a regular user.

krystian · 02-01-2006, 12:59 AM

Quote:

Originally Posted by pljvaldez

Try this:...

Hey, that's awesome. I guess there is no discrete way to cleanly disect services from users.

I like the oneliner. Though it doesn't include root with it's given parameters, it's a bump in the right direction.

I was hoping there was some shell command I overlooked that returned the information I was looking for.

btmiller · 02-01-2006, 01:27 AM

Most services such as the sshd also have a user account associated with them so that they don't have to run as root (this is a good thing, security wise). You could always check for a valid shell (bash, csh, or the like).

pljvaldez · 02-01-2006, 10:08 AM

Actually, you can include root if you change $3 > 99 to $3 >= 0 because root's uid is 0. Of course, then you get all the system services too, like daemon, bin, sys, sync, man, lp, etc...

Hmmm actually, you can do this to include root:
awk -F: '{ if ($3 = 0 || ($3 > 99 && $3 < 100000)) { print $1 " " $3 }}' /etc/passwd