Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!hao!ames!ptsfa!ihnp4!occrsh!occrsh.ATT.COM!rjd From: rjd@occrsh.ATT.COM Newsgroups: comp.unix.wizards Subject: Re: Setting up groups (LONG) Message-ID: <142700020@occrsh.ATT.COM> Date: 14 Dec 87 16:41:00 GMT References: <228@hub.ucsb.edu> Lines: 56 Nf-ID: #R:hub.ucsb.edu:-22800:occrsh.ATT.COM:142700020:000:2784 Nf-From: occrsh.ATT.COM!rjd Dec 14 10:41:00 1987 > > How do you assign a user to more than one group? > > [... stuff deleted ...] > > I know how to create groups -- add an entry for the group name, > >password, group number, and a comma-delimited member list in /etc/group. > > > I know how to assign a given user to _one_ group -- put the group > >number in the 4th column of his/her/its entry in /etc/passwd. > > I don't believe this is sufficient to add a user to a group. I think you > also have to add their login name to the group line in /etc/group. I think > this field is superseded by the /etc/group file. Wrong. The original poster is correct: All that you need to have in place in order to assign a user to ONE group is the number in the fourth field in the /etc/passwd file. It need not even be defined in the /etc/group file. If you want an alphanumeric string associated with it (such as for ls -l listings), you need to have it in the group file. It is common at some sites I have used that they use a user's department number as a group and not even define it in /etc/group, since the number will appear on ls -l listings in the absence of a defined alphanumeric string. > > But if I want to have users be in _two_ or more groups (so they can > > read and write files in several different areas, I don't know how to do it. > > I don't have root permission anymore, so I can't check out my answer, but > I'm pretty sure it's correct. If not, please feel free to flame me (and, > of course, correct me). > > To add a user to more than one group, you need only add the user name to > each group line in /etc/group that you want the user to be in. Where I Correct, yet he need not be in his login group, unless, I think, he wants to newgrp back to his login group?? > used to work, I was in the wheel group (group 0), in addition to about 5 > other groups. To accomplish this, I simply edited /etc/group. Note that > you must log out and log back in after you edit /etc/group, because groups > are initialized during login. I am not 100% sure but I don't think you need to log out. Maybe we are talking different flavors of unix here (I'm on AT&T System V), but the /etc/group file is only looked at during a command that is looking up the alphanumeric string (such as ls) or when you execute 'newgrp' to adopt the permissions of a group other than you logged in as (in which case your login in must appear in the fourth field of /etc/group). At no other time that I am aware of is the file even opened. > Here at our site, root is in almost every group. I'm sure it is similar > at your site. No, root is in no groups here. In fact, every group has its fourth field completely empty, yet 'newgrps' called by root always succeed (yet others always fail - I just checked both). Randy