Remove Linux User From a Secondary Group ( Supplementary Groups )

by on March 3, 2008 · 18 comments· LAST UPDATED March 3, 2008

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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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{ 18 comments… read them below or add one }

1 test March 25, 2009 at 3:21 pm

Thanks for your website.
it’s very helpful.

Reply

2 shingai April 2, 2009 at 1:42 pm

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.

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3 kailash bhandari April 25, 2009 at 6:38 pm

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..

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4 BAReFOOt April 28, 2009 at 3:41 pm

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

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5 ashim June 10, 2009 at 5:42 am

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)

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6 Bhagyesh Dhamecha July 15, 2009 at 10:39 am

Please add me in your group and please gime update and help for any my query..

Thanks
Bhagyesh

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7 cheri August 13, 2009 at 6:22 pm

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

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8 Mike September 23, 2009 at 10:12 am

to remove a user from one supplemental group only:-

gpasswd -d USER GROUP

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9 Mario September 23, 2009 at 8:02 pm

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

Reply

10 Rajesh R December 6, 2011 at 10:22 am

[root@localhost ~]# gpasswd -d new tes
Removing user new from group tes
gpasswd: unknown member new

while trying getting this error
need to remove new (new-user from group- tes)

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11 Deyaa April 28, 2012 at 8:35 pm

You must log out then back in after removing a user from a group using gpasswd ;)

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12 Chris July 17, 2010 at 7:44 pm

I don’t know if it’s available from other platforms or not, but I have this command on Arch which seems more intuitive and easier to do:

groupmems -g [group_name] -d [user_name]

For example, if I want to remove sally from group admins:

groupmems -g admins -d sally

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13 Andrew July 27, 2010 at 5:13 pm

lol late reply, @ ashim

usermod -a -G GROUP1,GROUP2,GROUPETC USER

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14 ankit gupta October 9, 2010 at 11:38 am

Thank Dear

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15 dario boring February 26, 2011 at 11:53 am

to remove all groups from user
usermod -G “” javito

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16 renato silva March 18, 2011 at 12:37 pm

Remove:
groupmod -R user group

ADD:
groupmod -A user group

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17 Juan Manuel May 22, 2011 at 6:13 pm

Renato, the -R argument don’t exist for groupmod command in Ubuntu. Try man groupmod.

Reply

18 Alex December 21, 2011 at 4:24 pm

If you want to add/remove a user only to/from a single secondary group, use gpasswd command

Following your example

Remove tom from sales group
gpasswd -d tom sales

Add tom to printer group
gpasswd -a tom printer

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