[CentOS] the correct way to add users to another group???

Sun Feb 19 01:06:56 UTC 2006
rado <rado at rivers-bend.com>

On Sat, 2006-02-18 at 18:59 -0600, rado wrote:
> > > I want to add a user to another group w/out removing the groups the user
> > > already belongs to.
> > >
> > > in man usermod:
> > >       -G group,[...]
> > >               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.   The  groups  are subject to the
> > > same restrictions as the group given with the  -g  option.   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.
> > >
> > > ok...I kinda get this but unclear of the exact format and I am super
> > > fearful of ripping up my userbase.
> > >
> > > Here is what I think it should be:
> > >
> > > # usermod <user> -a -G <group> 
> > >
> > > where the user's name is say..."pete" and I want him to be added to the
> > > group "tech":
> > >
> > > # usermod pete -a -G tech
> > >
> > > Say pete is already in groups ummm, sales,admin, and help. After
> > > administering the above command, would pete still be in sales,
> > > admin,help, and now tech? I am interested in the simplest, correct way
> > > to do this.
> > >
> > > thx,
> > >
> > > John Rose
> > >
> > > _______________________________________________
> > > CentOS mailing list
> > > CentOS at centos.org
> > > http://lists.centos.org/mailman/listinfo/centos
> > >
> > >   
> > 
> > The command should be
> > # usermod -G <group1,group2...> <username>
> > When doing it this way you need to specify ALL the groups the user 
> > belongs to as this does not append to the current list. So to get a list 
> > of groups a user may be associated with type
> > # groups <username>
> > Then take the output to be used with usermod command. Or you can just 
> > edit the /etc/groups file by hand
> > 
> > Zeb
> 
> ok, thx, Zeb! sure works for me

incidently tho, all I had read up on it, I never did really see or
thought to just edit /etc/group but then only in the current (4.2) man
useradd did I see mention of the "-a" command for append. Must be some
pretty recent new addition I guess.

John