#! /usr/bin/perl
open(PW,"ypcat passwd|") || die "How did you get logged in?";
while (<PW>) {
    ($user,$gid,$gcos) = (split /:/)[0,3,4];
    if ($gid == $ARGV[0]) {
    	($real) = split /,/,$gcos;
    	write;
    }
}
format STDOUT =
@<<<<<<<  @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
$user,  $real
.

format STDOUT_TOP =
Page @<<<
$%
Username  Real Name
========  =========
.