find groups from /etc/passwd
<pre>
$ perl -e 'while (($user,$pw, $uid, $gid, $other) = split (":",
&lt;>, 5)) { $group_list{$gid} .= "$user,"; } foreach $group (keys
%group_list) { chop ($group_list{$group}); $group_name = getgrgid
($group); print "$group_name ($group): $group_list{$group}\n"; }' &lt; 
/etc/passwd
</pre>
(20/Sep/2000)
<hr>

list users in a group:
<pre>
awk -F:  '{ if ($1 == "adm") { n=split($4,members,","); for (member in
members) print members[member]; }}' < /etc/group
</pre>
(Where "adm" above is replaced with the group you are looking for.)
<br>
(25/Sep/2001)
<p>
<hr>
Read file of domain names, do the whois, and parse out the name servers
and output with hostname, nameservers, and blank line:
<pre>
 cat your-list | while read name; do echo $name ; whois $name | \
 grep 'Name Server' | sed -e 's/   Name Server: //'; echo ; done
</pre>
(28/Sep/2001)