Shell Programming and Scripting

Hi,

I think you're very nearly there, but perhaps have just over-complicated things a bit. You can do all this with just the one input file, the one output file, and the groups command.

Here's my proposed solution. I've assumed that the input file simply contains usernames listed one per line (since there's no sample input to go on in your post) Other than that, I believe this should do what you need.

Code:

$ cat $(/bin/hostname)_unlist.txt
pulse
root
unixforum
$ cat script.sh 
#!/bin/bash

for uname in `/bin/cat $(/bin/hostname)_unlist.txt`
do
        groups=`/usr/bin/groups "$uname" | /usr/bin/awk -F": " '{print $NF}'`
        echo "$uname","$groups" >> uglist.txt
done

$ ./script.sh 
$ cat uglist.txt
pulse,pulse audio
root,root bin daemon sys adm disk wheel audio
unixforum,users
$

So the basic idea is that for each username we run the groups command to get the list of UNIX groups for that user, then use awk to just print out the part of the output of the groups command that we need. We then write the username and our list of groups to a single line in the output file, and move on to the next user until there is no input left to read.

Hope this helps ! If not, then if you can clarify what aspects of this script don't fit with your expectations in terms of behaviour or output, then we can take things from there.