Linux / Unix – How To – Add A User To A Group

QUESTION

How do I add a user to a group under Sun Solaris UNIX operating system from a shell prompt or command line?

A.. You can useadd command to administer a new user login on the UNIX system. Solaris UNIX / HP-UX UNIX uses /etc/passwd, /etc/shadow and /etc/group files to store user information.

Following information is compatible with the Solaris, AIX and HP-UX UNIX operating systems.

Add A New User To A Group

Add a new user called vivek to a group called vsftp, enter:

# useradd -G vsftp -d /data/home/v/vivek -m vivek
 # passwd vivek

Where:

• -G vsftp : Add vivek to secondary group called vsftp. This group must exists on the system.
• -d /data/home/v/vivek : Path to the vivek's home directory
• -m : Create the new user's home directory if it does not already exist.
• vivek : Username / login name

UNIX Add Existing User To A Secondary Group

Use usermod command to modify a user's login definition on the system including group membership. For, example add user vivek to sales group, enter:

# usermod -G sales vivek

Add user tom to sales but also keep his existing membership of ftpusers, enter:

# usermod -G ftpusers,sales tom

UNIX Add Existing User To A Primary Group

Add jerry to sales primary group and change its existing group membership:

# usermod -g sales jerry

For more information read following man pages:

$ man usermod
$ man useradd
$ man passwd