Adding new groups with groupadd
The groupadd command is used by a Systems Administrator to create new groups. The following options are available to the Linux groupadd command.
Groupadd Command available Options
Below are the options that can be used by the "groupadd" command.
Usage: groupadd [options] GROUP Options: -f, --force exit successfully if the group already exists, and cancel -g if the GID is already used -g, --gid GID use GID for the new group -h, --help display this help message and exit -K, --key KEY=VALUE override /etc/login.defs defaults -o, --non-unique allow to create groups with duplicate (non-unique) GID -p, --password PASSWORD use this encrypted password for the new group -r, --system create a system account -R, --root CHROOT_DIR directory to chroot into
Adding a group - groupadd
In its simplest from the "groupadd" command takes the syntax of:
By issuing the "groupadd" command followed by the name of a group you would like to create, you will create a group with the next available GID.
[root@fedsrv01a ~]# groupadd devops [root@fedsrv01a ~]# grep devops /etc/group devops:x:1011:
In the above example, the group "devops" was created. The system used the next available GID "1011".
Adding a group and specifying a GID
By using the "-g" or "--gid" option we can specify that when a group is created it should use the specified GID.
By issuing the "groupadd" command with the "-g" option we were able to create a new group with a specified GID.
[root@fedsrv01a ~]# groupadd -g 1020 operators [root@fedsrv01a ~]# grep operators /etc/group operators:x:1020:
In the above example, the group "operators" was created with a user specified GID of "1020".