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

    if (!defined($pid)) {
        die "fork failed: $!";
    }
    elsif ($pid == 0) {
        # child
        print "rshing to $wks\n";
        exec("$rsh_cmd $wks ls") || die "exec failed for $wks: $!";
    }
    else {
        push(@pids,$pid);
    }
}

foreach my $pid (@pids) {
    waitpid($pid,0);
    if ($? != 0) {
       print "non zero exit from $pid: $?";
    }
}