Linux add Users (user) to user groups (group)

Add a user to a user group and never use it directly:

Usermod-g Groupa

Doing so will allow you to leave the other user groups, just as members of this user group Groupa.

Should be added with the-a option:

Usermod-a-G Groupa User

(fc4:usermod-g GROUPA,GROUPB,GROUPC user)

-A represents append, which is to add itself to the user group Groupa without having to leave another user group.

All the options for the command, and what it means:

Options:

-c,–comment comment New value of the GECOS field

-d,–home home_dir New Home directory for the user account

-e,–expiredate expire_date Set account expiration DATE to Expire_date

-f,–inactive inactive Set Password inactive after expiration to inactive

-g,–gid Group Force use Group as new primary group

-g,–groups groups new List of supplementary groups

-a,–append append the user to the supplemental GROUPS

                            mentioned by the -G option without removing                             

-H,–HELP Display this help message and exit

-l,–login New_login NEW value of the login name

-l,–lock Lock the user account

-m,–move-home move contents of the home directory to the new

-o,–non-unique allow using duplicate (Non-unique) UID

-p,–password Password use encrypted password for the new password

-s,–shell Shell New Login shell for the user account

-u,–uid UID New UID for the user account

-u,–unlock Unlock the user account

To view the groups that the user belongs to using the command: $ groups User

or view files: $ cat/etc/group

Linux add Users (user) to user groups (group)