How to check list of users in Unix?

Command to check list of users in Unix

On a FreeBSD/OpenBSD/NetBSD and many other Unix-like systems, just type the following cat command/more command/less command to get a list of all user accounts:

$ cat /etc/passwd
$ more /etc/passwd
$ less /etc/passwd

Understanding file format

Consider the last line:

vnstat:*:284:284:vnStat Network Monitor:/nonexistent:/usr/sbin/nologin

Where,

1. vnstat – Username
2. * – Encrypted password is stored in a separate file
3. 284 – UID (User Id)
4. 284 – GID (Group id)
5. vnStat Network Monitor – General information about the user
6. /nonexistent – User’s home directory
7. /usr/sbin/nologin – User’s login shell

How to just display a list of user names

Use the cut command as follows:

$ cut -d: -f1 /etc/passwd

OR use awk command:

$ awk -F':' '{ print $1}' /etc/passwd

How do I search for a given user name such as vyga

Use the grep command as follows:

$ grep '^userNameHere' /etc/passwd
$ grep '^vyga' /etc/passwd

vyga:*:1001:1001:vyga:/home/vyga:/bin/tcsh

How to use getent command to find out a list of users

To get entries from administrative database such as /etc/passwd use the getent command as follows:

$ getent passwd
$ getent passwd | more
$ getent passwd | grep vivek

A note about macOS Unix users

If you are using a macOS, try the following command to check list of users in Unix cli (open the Terminal app and type the following bash command):

$ dscl . list /Users

OR

$ dscacheutil -q user

The dscl is a general-purpose utility for operating on Directory Service directory nodes.

How to find which Unix users are logged in and what they are doing

Type the following w command/who command:

$ w

OR

$ who

How do I see available list of groups on my server?

Type any one of the following commands:

$ more /etc/group
$ less /etc/group
$ grep vyga/etc/group

That's it