#ex_07-5 #Learning Perl Appendix A, Exercise 7.5 while () { chomp; ($user, $gcos) = (split /:/)[0,4]; ($real) = split /,/, $gcos; ($first) = split /\s+/, $real; $names{$first} .= " $user"; } foreach (keys %names) { $this = $names{$_}; if ($this =~ /. /) { print "$_ is used by:$this\n"; } }