Which of the following information does the /etc/passwd file contain? Each correct answer
represents a complete solution. Choose all that apply.

A.
Numerical group ID

B.
User name

C.
Shadow password

D.
Numerical user ID

E.
Reserved gecos ID

F.
User’s home directory

Explanation:

All these information are stored in the /etc/passwd file.
What is the /etc/passwd file?
In Linux operating systems, the /etc/passwd file lists information about each of the users that may
login to the system. The file is so named because originally it also contained the data used to
verify passwords. However, on
modern Unix systems, the security-sensitive password information is instead often stored in a
different file using shadow passwords.
The /etc/passwd file typically has world-readable permissions, though it may only be edited by the
superuser or by using a few special purpose commands.
The first field is the user name. Each record in the file must have a unique user name field.
The second field stores information used to confirm a user’s password; however, in most modern
uses, this field is usually set to “x” (or some other indicator) with the actual password information
being stored in a separate shadow password file.
The third field is the user identifier, the number that the operating system uses for internal
purposes. It does not have to be unique.
The fourth field is the group identifier. This number identifies the primary group of the user; all files
that are created by this user will initially belong to this group.

Reserved gecos ID (Typically, this is a set of comma-separated values including the user’s full
name
and contact details).
The sixth field is the path to the user’s home directory.
The seventh field is the shell program that is started every time the user logs into the system.
Answer option C is incorrect. The shadow password is stored in the /etc/shadow file.
What is /etc/shadow file?
The /etc/shadow file stores the account information in the following format: