TNEF(3)

okay bestie, gather round 💖 this is TNEF(3), the User Contributed Perl Documentation page for Convert::TNEF — the Perl module to read TNEF files. no cap, the whole page is right here and we’re gonna get you comfy with it. ✨

🌸 NAME 🌸

Convert::TNEF — Perl module to read TNEF files. yes, that’s the name, short and iconic. 👑

🦋 SYNOPSIS 🦋

here’s the group-chat cheat sheet, copy-paste exact:

use Convert::TNEF;

$tnef = Convert::TNEF->read($iohandle, \%parms)
 or die Convert::TNEF::errstr;

$tnef = Convert::TNEF->read_in($filename, \%parms)
 or die Convert::TNEF::errstr;

$tnef = Convert::TNEF->read_ent($mime_entity, \%parms)
 or die Convert::TNEF::errstr;

$tnef->purge;

$message = $tnef->message;

@attachments = $tnef->attachments;

$attribute_value      = $attachments[$i]->data($att_attribute_name);
$attribute_value_size = $attachments[$i]->size($att_attribute_name);
$attachment_name = $attachments[$i]->name;
$long_attachment_name = $attachments[$i]->longname;

$datahandle = $attachments[$i]->datahandle($att_attribute_name);

🎀 DESCRIPTION 🎀

okay so: TNEF stands for Transport Neutral Encapsulation Format, and if you’ve ever been unfortunate enough to receive one of these files as an email attachment, you may want to use this module. literally a whole “ma’am, why is this in my inbox” moment. 😭

read() takes as its first argument any file handle open for reading. The optional second argument is a hash reference which contains one or more of the following keys:

🧸 the optional \%parms hash keys 🧸

• output_dir — Path for storing TNEF attribute data kept in files (default: current directory).
• output_prefix — File prefix for TNEF attribute data kept in files (default: 'tnef').
• output_to_core — TNEF attribute data will be saved in core memory unless it is greater than this many bytes (default: 4096). May also be set to 'NONE' to keep all data in files, or 'ALL' to keep all data in core.
• buffer_size — Buffer size for reading in the TNEF file (default: 1024).
• debug — If true, outputs all sorts of info about what the read() function is reading, including the raw ascii data along with the data converted to hex (default: false).
• display_after_err — If debug is true and an error is encountered, reads and displays this many bytes of data following the error (default: 32).
• debug_max_display — If debug is true then read and display at most this many bytes of data for each TNEF attribute (default: 1024).
• debug_max_line_size — If debug is true then at most this many bytes of data will be displayed on each line for each TNEF attribute (default: 64).
• ignore_checksum — If true, will ignore checksum errors while parsing data (default: false).

read() returns an object containing the TNEF ‘attributes’ read from the file and the data for those attributes. If all you want are the attachments, then this is mostly garbage, but if you’re interested then you can see all the garbage by turning on debugging. If the garbage proves useful to you, then let me know how I can maybe make it more useful. (that’s the author talking, not me bestie 😭)

If an error is encountered, an undefined value is returned and the package variable $errstr is set to some helpful message. that’s your “bestie what happened” note. 🫶

💅 methods, in their natural habitat 💅

• read_in() — is a convienient front end for read() which takes a filename instead of a handle.
• read_ent() — is another convient front end for read() which can take a MIME::Entity object (or any object with like methods, specifically open("r"), read($buff,$num_bytes), and close ).
• purge() — deletes any on-disk data that may be in the attachments of the TNEF object.
• message() — returns the message portion of the tnef object, if any. The thing it returns is like an attachment, but its not an attachment. For instance, it more than likely does not have a name or any attachment data.
• attachments() — returns a list of the attachments that the given TNEF object contains. Returns a list ref if not called in array context.
• data() — takes a TNEF attribute name, and returns a string value for that attribute for that attachment. Its your own problem if the string is too big for memory. If no argument is given, then the 'AttachData' attribute is assumed, which is probably the attachment data you’re looking for.
• name() — is the same as data(), except the attribute 'AttachTitle' is the default, which returns the 8 character + 3 character extension name of the attachment.
• longname() — returns the long filename and extension of an attachment. This is embedded within a MAPI property of the 'Attachment' attribute data, so we attempt to extract the name out of that.
• size() — takes an TNEF attribute name, and returns the size in bytes for the data for that attachment attribute.
• datahandle() — is a method for attachments which takes a TNEF attribute name, and returns the data for that attribute as a handle which is the same as a MIME::Body handle. See MIME::Body for all the applicable methods. If no argument is given, then 'AttachData' is assumed.

🔥 EXAMPLES 🔥

this example is long af but it’s the whole thing, verbatim, so you can see the whole workflow: mail is retrieved from a POP3 server based on header information, then it is MIME parsed, and then the TNEF contents are extracted and converted. main character energy, honestly. 🌈

# Here's a rather long example where mail is retrieved
# from a POP3 server based on header information, then
# it is MIME parsed, and then the TNEF contents
# are extracted and converted.

use strict;
use Net::POP3;
use MIME::Parser;
use Convert::TNEF;

my $mail_dir = "mailout";
my $mail_prefix = "mail";

my $pop = new Net::POP3 ( "pop3server_name" );
my $num_msgs = $pop->login("user_name","password");
die "Can't login: $!" unless defined $num_msgs;

# Get mail by sender and subject
my $mail_out_idx = 0;
MESSAGE: for ( my $i=1; $i<= $num_msgs;  $i++ ) {
 my $header = join "", @{$pop->top($i)};

 for ($header) {
  next MESSAGE unless
   /^from:.*someone\@somewhere.net/im &&
   /^subject:\s*important stuff/im
 }

 my $fname = $mail_prefix."-".$$.++$mail_out_idx.".doc";
 open (MAILOUT, ">$mail_dir/$fname")
  or die "Can't open $mail_dir/$fname: $!";
 # If the get() complains, you need the new libnet bundle
 $pop->get($i, \*MAILOUT) or die "Can't read mail";
 close MAILOUT or die "Error closing $mail_dir/$fname";
 # If you want to delete the mail on the server
 # $pop->delete($i);
}

close MAILOUT;
$pop->quit();

# Parse the mail message into separate mime entities
my $parser=new MIME::Parser;
$parser->output_dir("mimemail");

opendir(DIR, $mail_dir) or die "Can't open directory $mail_dir: $!";
my @files = map { $mail_dir."/".$_ } sort
 grep { -f "$mail_dir/$_" and /$mail_prefix-$$-/o } readdir DIR;
closedir DIR;

for my $file ( @files ) {
 my $entity=$parser->parse_in($file) or die "Couldn't parse mail";
 print_tnef_parts($entity);
 # If you want to delete the working files
 # $entity->purge;
}

sub print_tnef_parts {
 my $ent = shift;

 if ( $ent->parts ) {
  for my $sub_ent ( $ent->parts ) {
   print_tnef_parts($sub_ent);
  }
 } elsif ( $ent->mime_type =~ /ms-tnef/i ) {

  # Create a tnef object
  my $tnef = Convert::TNEF->read_ent($ent,{output_dir=>"tnefmail"})
   or die $Convert::TNEF::errstr;
  for ($tnef->attachments) {
   print "Title:",$_->name,"\n";
   print "Data:\n",$_->data,"\n";
  }

  # If you want to delete the working files
  # $tnef->purge;
 }
}

and that’s the example, no edits, no cap. 🍓

🌈 SEE ALSO 🌈

go peek at these besties: perl(1), IO::Wrap(3), MIME::Parser(3), MIME::Entity(3), MIME::Body(3).

💀 CAVEATS 💀

caveat time, bestie. The parsing may depend on the endianness (see perlport) and width of integers on the system where the TNEF file was created. If this proves to be the case (check the debug output), I’ll see what I can do about it. so yeah, check that debug output if things get weird. 😭

👑 AUTHOR 👑

Douglas Wilson, dougw@cpan.org — the icon who wrote this. 💅

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okay that’s the whole page bestie 🫶 source/version: perl v5.40.2, date: 2024-02-25. bye and happy TNEF wrangling! ✨💖