18.10.1. Problem

18.10.2. Solution

use MIME::Parser;

$parser = MIME::Parser->new( );
$parser->output_to_core(1);      # don't write attachments to disk

$message  = $parser->parse_data($MESSAGE);    # die( )s if can't parse
# OR
$message  = $parser->parse($FILEHANDLE);      # die( )s if can't parse

$head     = $message->head( );                 # object--see docs
$preamble = $message->preamble;               # ref to array of lines
$epilogue = $message->epilogue;               # ref to array of lines

$num_parts = $message->parts;
for (my $i=0; $i < $num_parts; $i++) {
  my $part         = $message->parts($i);
  my $content_type = $part->mime_type;
  my $body         = $part->as_string;
}

18.10.3. Discussion

Figure 18-1. Composition of a MIME message

In the Solution, we disable the default behavior of MIME::Parser that writes the attachments to disk. Doing so increases memory consumption because now the decoded attachments must be stored in memory, but prevents the need to clean up temporary files and directories once the attachments are no longer needed.

To write attachments to a file, replace the call to output_to_core with calls to methods that specify the directory in which to store the attachments and what to name the files. The output_under method specifies a directory under which each message will get its own subdirectory; those subdirectories will contain the decoded attachments:

$parser->output_under("/tmp");
# parsing creates files like /tmp/msg-1048509652-16134-0/foo.png

Alternatively, output_dir specifies a directory into which all attachment files go:

$parser->output_dir("/tmp");
# parsing creates files like /tmp/foo.png

To clean up temporary files once parsing is done, say:

$parser->filer->purge;

Because parsing can trigger exceptions, catch the exceptions if you want to clean up:

eval { $message = $parser->parse($FILEHANDLE) };
# ...
$parser->filer->purge;

Whether you create files on disk, you can still treat the attachments as files by using the open method on an individual part:

for (my $i=0; $i < $num_parts; $i++) {
  my $part = $message->parts($i);
  my $fh = $part->open("r") or die "Can't open for reading: $!\n";
  while (<$fh>) {
    # reading lines from the current attachment
  }
}

There are actually six different classes that form part of the MIME-Tools distribution, and each is well-documented. Start with the MIME::Tools manpage and explore from there.