# test2.pl
use File::Slurp;

$all_of_it = read_file('-');
print $all_of_it;
__END__
$ >echo -e "klöhlkhklhj\nlkjhlkhlkhkk\nlkjhklhlkhklh" | perl test2.pl
klöhlkhklhj
lkjhlkhlkhkk
lkjhklhlkhklh