#!/usr/athena/bin/perl
foreach $foo ($ARGV[1]..$ARGV[2])
{
        print"Checking machine $ARGV[0]-$foo\n";
        $_ = `f @$ARGV[0]-$foo`;
        (@outa) = split(/[\n]+/, $_);
        foreach $word (@outa)
        {
                (@outb) = split(/[ ]+/, $word);
                if ($outb[0] eq $ARGV[3])
                {
                        print"$ARGV[3] is logged in on $ARGV[0]-$foo\n";
                }
        }
}