my $pid;

if ( $^O eq 'MSWin32' ) {
    $pid = system 1, $^X, 'mon2.pl', $port;
}
else {
    $SIG{CHLD} = 'IGNORE';
    $pid = fork; die "Could not fork: $!\n" unless defined $pid;
    exec( $^X, 'mon2.pl', $port ) if ( $pid == 0 );
}