Hello, I'm new here

I could need some help to improve one of my subs, I've done some "google" but apparently to no awail.

The sub needs to make a PNG-file based on contents in a hash specified by one input used both as the hash key and the resulting filename.

My question is however if there's a more efficient way to write a hex string as binary to a file? Feedback appreciated. 

sub writeAnImage {
  my $hashCode = $_[0];
  my %pngData = (
  'blank', '89504e470d0a1a0a0000000d49484452000000320000005a0803000000
+cd46f5b400000003504c5445efefefec97ba8d0000001b494441545885edc1010d000
+000c2a0f74f6d0f0714000000003f0611ee00013060c47e0000000049454e44ae4260
+82'
  );
  my $dataString = "";
  my $twoHex = "";
  my $dataLength = 0;
  my $byteCounter = 0;
#
  if ($hashCode) {
    if ($pngData{$hashCode}) {
      $dataString = $pngData{$hashCode};
      $dataLength = length($dataString);
      open(MyPNG, ">$hashCode") or die("Write Error: $hashCode");
      binmode(MyPNG);
      for ($byteCounter = 0; $byteCounter <= $dataLength; $byteCounter
+ += 2) {
        $twoHex = substr($dataString, $byteCounter, 2);
        print MyPNG chr(hex($twoHex));
      }
      close(MyPNG);
    }
    else {
      print "No such code in the hash ($hashCode)\n";
    }
  }
  else {
    print "No code specified\n";
  }
}

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In reply to What is the best method to print hex string in bin-file? by cosmofield

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