Here's the code:

#!/usr/bin/perl -w

use strict;
use Getopt::Std;
my $what;

$| = 1;

my @hosts;
my %opts;

while (<STDIN>) {
  chomp;
  push(@hosts, $_);
}

getopts(':dw', \%opts);

$what .= ' bla' if $opts{'d'};
$what .= ' blabla' if $opts{'w'};

print "OK? [Y|n]>\n";
my $yesno = <STDIN>; chomp $yesno;
exit 1 if $yesno =~ /^[nN]$/;

print "Did not stop, sorry!\n";
[download]

However, running it looks like this:

$ echo -e "aaa\nbbb\nccc\n" | script.pl -d
OK? [Y|n]>
Use of uninitialized value in scalar chomp at script.pl line 23, <STDI
+N> line 4.
Use of uninitialized value in pattern match (m//) at script.pl line 24
+, <STDIN> line 4.
Did not stop, sorry!
[download]

and does not stop to ask for input. I already tried different stuff and also supersearched, but to no avail.
Any hints greatly appreciated!