my $pid = fork();
 unless defined $pid {
    warn "Can't fork: $!\n";
    ...; # do something else
    exit;
 }
 if ($pid == 0) {
    # child
    exec @cmd_and_parameters;
    die "Could not exec $cmd_and_parameters[0]: $!\n";
 } else {
    # parent
    ...; # do other things
    waitpid($pid,0) == $pid or die "Error waiting for child: $!\n";
    ...; # do more (if needed)
 }