local (%rc, $running);

# turn off stdout buffering
$| = 1;

# catch return codes
local $SIG{CHLD} = sub { $rc{wait()} = $?; --$running; };

foreach my $wks (@wkslist) {
    if ( my $pid = fork() ) {
        # parent
        ++$running;
    } else {
        # child
        print "rshing to $wks\n";
        exec($rsh_cmd, $wks, "ls");
    }
}

sleep while ($running);