pipe(TALK,LISTEN);
my $child = fork();

if ($child) {
    my $anger = 0;
    close(TALK);
    while (my $in = <LISTEN>) {
        print TALK "reply" || $anger++;
        last if ($anger > 10);
    }
} else {
    close(LISTEN);
    $SIG{CHLD} = 'IGNORE';
    while ($child < 18) {
        print TALK "commands\n";
    }
}

##</code><code>##

$ perl -e 'do() || ! do() ;'
Undefined subroutine &main::try