%hash = ('"', '"', '/*', '*/', '<-', '->');

foreach (keys(%hash))
{
$start = $_;
 $end   = $hash{$_};

   my $inside = 0;
   my $oldpos = 0;

  while ($string =~ /(?<!\\)(\Q$start\E|\Q$end\E)/g) {
      if ($inside == 0) {
   $oldpos = pos($string) - length($start);
  $inside++;
 } else {
 push (@a, substr($string, $oldpos, pos($string)-$oldpos));

$inside--;
}
                  }
}