Comments on: User management from the command line

By: George Notaras

George Notaras — Tue, 18 Oct 2011 12:35:27 +0000

Unfortunately it’s not possible to lock all the members of a group. As a workaround, I’d suggest looping through the group members and calling the usermod -L ... for each user.

By: chenna

chenna — Wed, 12 Oct 2011 19:05:52 +0000

how to lock entire group users using a single line command

By: GNot

GNot — Tue, 20 Feb 2007 06:00:29 +0000

Hi, actually you should decide which users you would like to list. System accounts or normal users? Users with a home directory or with the ability to use a shell or just print all of them? There is no such command. The users are kept in the /etc/passwd file. I found a useful discussion on this that might interest you. Also, in order to list all the currently logged-in users you issue any of the following commands:

users

or (this displays more info):

I hope these help.

By: vijay

vijay — Tue, 20 Feb 2007 04:09:48 +0000

Hi,
what is the command to list all the users in system.

By: Zarquan

Zarquan — Tue, 02 Jan 2007 19:38:42 +0000

If your user accounts are in a LDAP server, you can’t use usermod to add them to a local group.

[root@localhost ~]# usermod -a -G localgroup Frog
usermod: Frog not found in /etc/passwd

Hand editing the /etc/group file and adding the username seems to work.

By: GNot

GNot — Mon, 27 Nov 2006 09:10:55 +0000

Exactly. First we create the group and then we add the user to it. But, take a note that on a Red Hat/Fedora system, there is the -a switch which is actually required to be used in such an occasion. If -a is not included in usermod (like it happens in your usermod command), then the user will be removed from all groups and it will be added to the group1 group only. This is how it works on these systems. So, it should be:

# groupadd group1
# usermod -a -G group1 username

From the usermod man page on fedora 6 about the -G switch:

If the user is currently a member of a group which is not listed, the user will be removed from the group. This behaviour can be changed via -a option, which appends user to the current supplementary group list.

Please refer to your distribution's usermod man page, so to know exactly if a -a switch is supported or if there is another switch that should be used when adding a user to a group.

By: Sarkis Karagozian

Sarkis Karagozian — Mon, 27 Nov 2006 03:56:39 +0000

As a beginner to Linux, I learned a lot from these commands, comments.
One comment I have:
Before adding a user to a group, we need to add/create a the group [group1]
in the example. i.e:

# groupadd group1 (then add username to group)
# usermod -G group1 username

Thanks

By: GNot

GNot — Sat, 04 Nov 2006 04:54:05 +0000

This is very interesting. I don’t have a Fedora 3 installation handy, but I will try to investigate the “-a” switch issue and modify this document accordingly.
Thanks for your feedback.

By: Paul

Paul — Fri, 03 Nov 2006 13:36:02 +0000

answered my own question.
omitting the -a just meant that the user was added to the new group. It didn’t delete me from my home group.

so doing usermod -G psb svn

left me as a member of psb and svn groups. Not just psb as previously.

By: Paul

Paul — Fri, 03 Nov 2006 13:33:36 +0000

I get the same no -a option error when attempting this on Fedora Core 3 distro.

Any ideas what I should do instead?

Regards,

Paul