Linux - /etc/passwd (public user information)

About

/etc/passwd is the text file that contains public user account information

The name is a little bit misleading because the password is no more present (replaced with a X) as this file is used by many application to lookup user information such as file ownerships with ls

The passwords and other sensitive information are know stored in the shadow file.

Format

Format of the file is:

• User (name normally all lower case)
• Password (only contains the letter 'x' as the password has moved to the shadow file)
• User ID - UID: a unique number of each user
• Primary Group ID: a unique number for each group
• Comment (Normally the person's full name)
• Home directory (normally /home/<user name>
• Default shell (normally /bin/bash)

Each field is separated by a colon.

cat /etc/passwd

root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
...............
gerardnico:x:500:500:Nicolas GERARD:/home/gerardnico:/bin/bash
applvis:x:501:501::/home/applvis:/bin/bash
oravis:x:502:501::/home/oravis:/bin/bash

Documentation / Reference

• https://www.tldp.org/LDP/lame/LAME/linux-admin-made-easy/shadow-file-formats.html