#!/usr/bin/perl use strict; my %who; open (WHOFH,"who |") or die "Can't open who: $!"; while (<WHOFH>) { next unless /^(\S+)/; $who{$1}++; } foreach (sort {$who{$b}<=>$who{$a}} keys %who) { printf "%10s %d\n",$_,$who{$_}; } close WHOFH or die "Close error: $!";