my @pids;
foreach my $wks (@wkslist) {
    my $pid = fork;

    if ($pid == 0) {
        # child
        print "rshing to $wks \n";
        system("$rsh_cmd $wks ls");
        exit;
    }
    else {
        push(@pids,$pid);
    }
}

foreach my $pid (@pids) {
    waitpid($pid,0);
}