topic Re: scripting question in Operating System - HP-UX

scripting question

Michele Macintire — Fri, 11 Oct 2002 12:54:40 GMT

How would I go about scripting the following:

IF $user IN group
THEN
FI

Where group is on of the groups in /etc/group?

Thanks in advance!

Re: scripting question

Charles McCary — Fri, 11 Oct 2002 13:03:55 GMT

Not sure what you're asking, but:

GROUP=dba
USER=michele

ISIT=`cat /etc/group | grep "^$GROUP:" | grep $USER`

if [ "${ISIT}" != '' ]
then

echo "$USER in $GROUP

else

echo "$USER not in $GROUP"

fi

Re: scripting question

S.K. Chan — Fri, 11 Oct 2002 13:04:18 GMT

Why bother ? You can use the "groups" command to find out which group a valid username belongs to. For example..
# groups -l skchan
will list all groups to which user "skchan" belongs to. Isn't that what you wanted ?

Re: scripting question

MANOJ SRIVASTAVA — Fri, 11 Oct 2002 13:06:57 GMT

You can try like this

export A=` cat /etc/group | grep $user | wc -l `

if [ $A = 1 ]
then

command

exit

fi

2nd command

Manoj Srivastava

Re: scripting question

Charles McCary — Fri, 11 Oct 2002 13:07:02 GMT

I agree, the group command is probably the easier way to go.

Re: scripting question

Jean-Luc Oudart — Fri, 11 Oct 2002 13:07:18 GMT

use the id -G or id -nG (as root) to get the group of a specific user

man id for more information

Jean-Luc

Re: scripting question

A. Clay Stephenson — Fri, 11 Oct 2002 13:11:19 GMT

The groups command has one other advantage that you have overlooked. It will also work in an NIS and NIS+ environment as well as the vanilla /etc/group world.

Re: scripting question

Darrell Allen — Fri, 11 Oct 2002 13:39:17 GMT

A couple of things to be aware of...

You will need to use "groups username" or "groups -g username" instead of "groups -l username" if you don't use /etc/logingroups.

If the user is not listed in /etc/group for his primary group (as specified in /etc/passwd), "groups -g" will not list the user's primary group. "groups" and "id -Gn" will list the user's primary group.

If you have su'ed to an account, "groups" without specifying the username will default to whom you logged in as, not the current username. "id -Gn" defaults to the current username.

Personally, I like:
id -Gn $user | grep groupname >/dev/null
if [ $? = 0 ]
then
echo is a member of the group
fi

Darrell

Re: scripting question

Michele Macintire — Fri, 11 Oct 2002 13:53:39 GMT

Well, I needed something that I could put in a script to say if a user was in this group, do one thing and if not, skip it.

I've tried the "id -nG username" command and don't get any results, even if I use a username that I can clearly see in /etc/group as belonging to a group.

The cat /etc/group works for me. I guess I was thinking too complicated to not think of something so simple!

Thank you all for helping me with my mental block!

Michele