Q. User tom is a member of a group called sales and printer. I'd like to remove tom from a group called printer without editing any user configuration text files stored at /etc/ directory?
A. /etc/groups file defines group membership for each user. usermod command has -G option to set a list of supplementary groups which the user is also a member of. Each group is separated from the next by a comma, with no intervening whitespace. If the user is currently a member of a group which is not listed, the user will be removed from the group.
Step # 1: Find out user group identity
Use id command:
# id -nG {user-name}
# id -nG tom
Output:
sales printer
Step # 2: Remove user from printer group
Use the following syntax:
# usermod -G {groupname1,groupname2,...} {username}
To keep membership for sales only group (remove user tom from printer group), enter:
# usermod -G sales tom
# id -nG tom
Output:
sales
The following example remove user vivek from all groups except admin, audio, video and powerdev group:
# id -nG vivek
Output:
vivek adm dialout cdrom floppy audio dip video plugdev scanner netdev lpadmin powerdev admin
Modify group membership, enter:
# usermod -G admin, audio, video, powerdev vivek
# id -nG tom
Sample output:
vivek audio video powerdev admin
For more information, read usermod(8) command man page:
$ man usermod
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{ 9 comments… read them below or add one }
Thanks for your website.
it’s very helpful.
lets say i want to add an existing user to an existing group. when the user belongs to other groups already. what command will i use.
using usermod-g “groupname” user will change the initial gropu of the user and delete him from another group.
usermod -G this will lead from the user being deleted ffrom all other groups except the one sspecified.
A user (pop)who is belong to SALES group. i want that pop is remove from SALES group. how can i do it. not tell me manually. i want command to remove it..
In one line (and nice for scripts):
Add a group: usermod -aG GROUP USER
Remove a group: usermod -G $(id -nG USER| sed -e ’s/GROUP //’ -e ’s/ /,/g’) USER
Can anyone tell me command(s) to add an user to a new group without mentioning all the groups the user previously belongs to? (I haven’t gone thru man)
Please add me in your group and please gime update and help for any my query..
Thanks
Bhagyesh
Hi,
I have added user to a group called sales using smbldap-usermod -G .
How do I remove this user from the supplementary group. I was once succesful in removing the user by using the command smbldap-usermod -g . But when I give the time id -nG the supplementary group still shows up.
Can you explain why this happens and how to overcome this problem.
Appreciate your help
Cheri
to remove a user from one supplemental group only:-
gpasswd -d USER GROUP
this dint help me
id -nG aares00
OutPut= aaresusers rootmembers
gpasswd -d aares00 rootmembers
OutPut= Removing user aares00 from group rootmembers
id -nG aares00
OutPut= aaresusers rootmembers