USER ID or UID as known as user identifier identify a user by a value. UID and GID along with the access control criteria ,is used to determine which system resources you can access.

Get USERID or UID using command ID


As you can see the screenshot above, id command shows my UID is 1000, GID is also 1000.

j@ubuntu:~$ id -u

Using option -u , command id print your user id only.

Get userid of specific user


Without a username ,command id prints current user’s information. So if you want to get other user’s USERID , you can specify that username.

For example ,below command shows the USERID and GROUPID of root

j@ubuntu:~$ id root
uid=0(root) gid=0(root) groups=0(root)

More examples

Print user id only for specific user

id -u USER

Print group ID only for specific user

id -g user

Get user ID using getent

The getent command displays entries from databases supported by the Name Service Switch libraries, which are configured in /etc/nsswitch.conf.

getent passwd USER

For example

j@ubuntu:~$ getent passwd j

You can see getent also shows more information about user j

  • Ubuntu01 : user’s description
  • /home/j : location of home directory
  • /bin/bash : default shell