Content-Type: image/jpeg;
name="testbild.jpg"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="testbild.jpg"

4AAQSkZJRgABAgEASABIAAD/7RakUGhvdG9zaG9wIDMuMA
[+ weitere Zeilen des obigen Zahlensalates]

#!/usr/bin/perl

use strict;
use MIME::Parser;

die "Usage makeCSV Filename\n" if $#ARGV != 0;

my $infile      = $ARGV[0];
my $top_entity;
my $pfad        = "/csv";
my $prefix      = "Message";
my $filename;

# Datei mit MIME-Nachricht einlesen und parsen
$top_entity = &parse_MIME_Stream($infile);

# MIME-Nachricht rekursiv durchlaufen
&walk($top_entity);

exit;

sub parse_MIME_Stream
{
        my $file = shift;
        my $parser = '';
        die "NO FILE $!" unless defined $file;
        $parser = MIME::Parser->new();
        $parser->output_to_core('NONE');
        $parser->output_dir($pfad);
        $parser->output_prefix($prefix);

        open(INPUT,$file) or die $!;
        my $top_entity = $parser->read(\*INPUT);
        close(INPUT) or die $!;

        return $top_entity;
}

sub walk #(Entity)
  {
  my $entity = shift if @_;
  return unless defined $entity;

  my $head = $entity->head();

  if ($head->mime_type() =~ m/multipart/i)
    { # mehrteilige Nachricht
    my $i;
    my $num_alt_parts  = $entity->parts();
    my $current_entity;
    # alle Teile der Nachricht rekursiv abarbeiten
    for ($i = 0; $i < $num_alt_parts; $i++)
      {
      $current_entity = $entity->parts($i);
      &walk($current_entity);
      }
    }
  else
    { # einteilige Nachricht
    &handle_head($head) if (defined $head);
    }
  }

sub handle_head #(Header)
  {
  my $current_head = shift;
  $current_head->decode;
  $current_head->unfold;

  if (  $current_head->recommended_filename() =~ m/\.csv/i )
  {
        print $current_head->recommended_filename()."\n";
  }
}

use warnings;