It is also common to need to add or modify users and groups to our filesystem. This recipe explains how it is done.
The user information is stored in the
/etc/passwd file, a text file that is used as a database for the system user's information. The
passwd file is human-readable.
Each line on it corresponds to one user in the system, and it has the following format:
<username>:<password>:<uid>:<gid>:<comment>:<home directory>:<login shell>
Let's see each of the parameters of this format:
username: A unique string that identifies the user at login
uid: User ID, a number that Linux uses to identify the user
gid: Group ID, a number that Linux uses to identify the user's primary group
comment: Comma-separated values ...