1MIME::Entity(3) User Contributed Perl Documentation MIME::Entity(3)
2
6 MIME::Entity - class for parsed-and-decoded MIME message
7
9 Before reading further, you should see MIME::Tools to make sure that
10 you understand where this module fits into the grand scheme of things.
11 Go on, do it now. I'll wait.
12 Ready? Ok...
14 ### Create an entity:
16 $top = MIME::Entity->build(From => 'me@myhost.com',
17 To => 'you@yourhost.com',
18 Subject => "Hello, nurse!",
19 Data => \@my_message);
20 ### Attach stuff to it:
22 $top->attach(Path => $gif_path,
23 Type => "image/gif",
24 Encoding => "base64");
25 ### Sign it:
27 $top->sign;
28 ### Output it:
30 $top->print(\*STDOUT);
31
33 A subclass of Mail::Internet.
34 This package provides a class for representing MIME message entities,
36 as specified in RFC 1521, Multipurpose Internet Mail Extensions.
37
39 Construction examples
40 Create a document for an ordinary 7-bit ASCII text file (lots of stuff
42 is defaulted for us):
43 $ent = MIME::Entity->build(Path=>"english-msg.txt");
45 Create a document for a text file with 8-bit (Latin-1) characters:
47 $ent = MIME::Entity->build(Path =>"french-msg.txt",
49 Encoding =>"quoted-printable",
50 From =>'jean.luc@inria.fr',
51 Subject =>"C'est bon!");
52 Create a document for a GIF file (the description is completely
54 optional; note that we have to specify content-type and encoding since
55 they're not the default values):
56 $ent = MIME::Entity->build(Description => "A pretty picture",
58 Path => "./docs/mime-sm.gif",
59 Type => "image/gif",
60 Encoding => "base64");
61 Create a document that you already have the text for, using "Data":
63 $ent = MIME::Entity->build(Type => "text/plain",
65 Encoding => "quoted-printable",
66 Data => ["First line.\n",
67 "Second line.\n",
68 "Last line.\n"]);
69 Create a multipart message, with the entire structure given explicitly:
71 ### Create the top-level, and set up the mail headers:
73 $top = MIME::Entity->build(Type => "multipart/mixed",
74 From => 'me@myhost.com',
75 To => 'you@yourhost.com',
76 Subject => "Hello, nurse!");
77 ### Attachment #1: a simple text document:
79 $top->attach(Path=>"./testin/short.txt");
80 ### Attachment #2: a GIF file:
82 $top->attach(Path => "./docs/mime-sm.gif",
83 Type => "image/gif",
84 Encoding => "base64");
85 ### Attachment #3: text we'll create with text we have on-hand:
87 $top->attach(Data => $contents);
88 Suppose you don't know ahead of time that you'll have attachments? No
90 problem: you can "attach" to singleparts as well:
91 $top = MIME::Entity->build(From => 'me@myhost.com',
93 To => 'you@yourhost.com',
94 Subject => "Hello, nurse!",
95 Data => \@my_message);
96 if ($GIF_path) {
97 $top->attach(Path => $GIF_path,
98 Type => 'image/gif');
99 }
100 Copy an entity (headers, parts... everything but external body data):
102 my $deepcopy = $top->dup;
104 Access examples
106 ### Get the head, a MIME::Head:
108 $head = $ent->head;
109 ### Get the body, as a MIME::Body;
111 $bodyh = $ent->bodyhandle;
112 ### Get the intended MIME type (as declared in the header):
114 $type = $ent->mime_type;
115 ### Get the effective MIME type (in case decoding failed):
117 $eff_type = $ent->effective_type;
118 ### Get preamble, parts, and epilogue:
120 $preamble = $ent->preamble; ### ref to array of lines
121 $num_parts = $ent->parts;
122 $first_part = $ent->parts(0); ### an entity
123 $epilogue = $ent->epilogue; ### ref to array of lines
124 Manipulation examples
126 Muck about with the body data:
128 ### Read the (unencoded) body data:
130 if ($io = $ent->open("r")) {
131 while (defined($_ = $io->getline)) { print $_ }
132 $io->close;
133 }
134 ### Write the (unencoded) body data:
136 if ($io = $ent->open("w")) {
137 foreach (@lines) { $io->print($_) }
138 $io->close;
139 }
140 ### Delete the files for any external (on-disk) data:
142 $ent->purge;
143 Muck about with the signature:
145 ### Sign it (automatically removes any existing signature):
147 $top->sign(File=>"$ENV{HOME}/.signature");
148 ### Remove any signature within 15 lines of the end:
150 $top->remove_sig(15);
151 Muck about with the headers:
153 ### Compute content-lengths for singleparts based on bodies:
155 ### (Do this right before you print!)
156 $entity->sync_headers(Length=>'COMPUTE');
157 Muck about with the structure:
159 ### If a 0- or 1-part multipart, collapse to a singlepart:
161 $top->make_singlepart;
162 ### If a singlepart, inflate to a multipart with 1 part:
164 $top->make_multipart;
165 Delete parts:
167 ### Delete some parts of a multipart message:
169 my @keep = grep { keep_part($_) } $msg->parts;
170 $msg->parts(\@keep);
171 Output examples
173 Print to filehandles:
175 ### Print the entire message:
177 $top->print(\*STDOUT);
178 ### Print just the header:
180 $top->print_header(\*STDOUT);
181 ### Print just the (encoded) body... includes parts as well!
183 $top->print_body(\*STDOUT);
184 Stringify... note that "stringify_xx" can also be written
186 "xx_as_string"; the methods are synonymous, and neither form will be
187 deprecated:
188 ### Stringify the entire message:
190 print $top->stringify; ### or $top->as_string
191 ### Stringify just the header:
193 print $top->stringify_header; ### or $top->header_as_string
194 ### Stringify just the (encoded) body... includes parts as well!
196 print $top->stringify_body; ### or $top->body_as_string
197 Debug:
199 ### Output debugging info:
201 $entity->dump_skeleton(\*STDERR);
202
204 Construction
205 new [SOURCE]
207 Class method. Create a new, empty MIME entity. Basically, this
208 uses the Mail::Internet constructor...
209 If SOURCE is an ARRAYREF, it is assumed to be an array of lines
211 that will be used to create both the header and an in-core body.
212 Else, if SOURCE is defined, it is assumed to be a filehandle from
214 which the header and in-core body is to be read.
215 Note: in either case, the body will not be parsed: merely read!
217 add_part ENTITY, [OFFSET]
219 Instance method. Assuming we are a multipart message, add a body
220 part (a MIME::Entity) to the array of body parts. Returns the part
221 that was just added.
222 If OFFSET is positive, the new part is added at that offset from
224 the beginning of the array of parts. If it is negative, it counts
225 from the end of the array. (An INDEX of -1 will place the new part
226 at the very end of the array, -2 will place it as the penultimate
227 item in the array, etc.) If OFFSET is not given, the new part is
228 added to the end of the array. Thanks to Jason L Tibbitts III for
229 providing support for OFFSET.
230 Warning: in general, you only want to attach parts to entities with
232 a content-type of "multipart/*").
233 attach PARAMHASH
235 Instance method. The real quick-and-easy way to create multipart
236 messages. The PARAMHASH is used to "build" a new entity; this
237 method is basically equivalent to:
238 $entity->add_part(ref($entity)->build(PARAMHASH, Top=>0));
240 Note: normally, you attach to multipart entities; however, if you
242 attach something to a singlepart (like attaching a GIF to a text
243 message), the singlepart will be coerced into a multipart automati‐
244 cally.
245 build PARAMHASH
247 Class/instance method. A quick-and-easy catch-all way to create an
248 entity. Use it like this to build a "normal" single-part entity:
249 $ent = MIME::Entity->build(Type => "image/gif",
251 Encoding => "base64",
252 Path => "/path/to/xyz12345.gif",
253 Filename => "saveme.gif",
254 Disposition => "attachment");
255 And like this to build a "multipart" entity:
257 $ent = MIME::Entity->build(Type => "multipart/mixed",
259 Boundary => "---1234567");
260 A minimal MIME header will be created. If you want to add or mod‐
262 ify any header fields afterwards, you can of course do so via the
263 underlying head object... but hey, there's now a prettier syntax!
264 $ent = MIME::Entity->build(Type =>"multipart/mixed",
266 From => $myaddr,
267 Subject => "Hi!",
268 'X-Certified' => ['SINED',
269 'SEELED',
270 'DELIVERED']);
271 Normally, an "X-Mailer" header field is output which contains this
273 toolkit's name and version (plus this module's RCS version). This
274 will allow any bad MIME we generate to be traced back to us. You
275 can of course overwrite that header with your own:
276 $ent = MIME::Entity->build(Type => "multipart/mixed",
278 'X-Mailer' => "myprog 1.1");
279 Or remove it entirely:
281 $ent = MIME::Entity->build(Type => "multipart/mixed",
283 'X-Mailer' => undef);
284 OK, enough hype. The parameters are:
286 (FIELDNAME)
288 Any field you want placed in the message header, taken from the
289 standard list of header fields (you don't need to worry about
290 case):
291 Bcc Encrypted Received Sender
293 Cc From References Subject
294 Comments Keywords Reply-To To
295 Content-* Message-ID Resent-* X-*
296 Date MIME-Version Return-Path
297 Organization
298 To give experienced users some veto power, these fields will be
300 set after the ones I set... so be careful: don't set any MIME
301 fields (like "Content-type") unless you know what you're doing!
302 To specify a fieldname that's not in the above list, even one
304 that's identical to an option below, just give it with a trail‐
305 ing ":", like "My-field:". When in doubt, that always signals
306 a mail field (and it sort of looks like one too).
307 Boundary
309 Multipart entities only. Optional. The boundary string. As
310 per RFC-1521, it must consist only of the characters
311 "[0-9a-zA-Z'()+_,-./:=?]" and space (you'll be warned, and your
312 boundary will be ignored, if this is not the case). If you
313 omit this, a random string will be chosen... which is probably
314 safer.
315 Charset
317 Optional. The character set.
318 Data
320 Single-part entities only. Optional. An alternative to Path
321 (q.v.): the actual data, either as a scalar or an array refer‐
322 ence (whose elements are joined together to make the actual
323 scalar). The body is opened on the data using
324 MIME::Body::InCore.
325 Description
327 Optional. The text of the content-description. If you don't
328 specify it, the field is not put in the header.
329 Disposition
331 Optional. The basic content-disposition ("attachment" or
332 "inline"). If you don't specify it, it defaults to "inline"
333 for backwards compatibility. Thanks to Kurt Freytag for sug‐
334 gesting this feature.
335 Encoding
337 Optional. The content-transfer-encoding. If you don't specify
338 it, a reasonable default is put in. You can also give the spe‐
339 cial value '-SUGGEST', to have it chosen for you in a heavy-
340 duty fashion which scans the data itself.
341 Filename
343 Single-part entities only. Optional. The recommended filename.
344 Overrides any name extracted from "Path". The information is
345 stored both the deprecated (content-type) and preferred (con‐
346 tent-disposition) locations. If you explicitly want to avoid a
347 recommended filename (even when Path is used), supply this as
348 empty or undef.
349 Id Optional. Set the content-id.
351 Path
353 Single-part entities only. Optional. The path to the file to
354 attach. The body is opened on that file using
355 MIME::Body::File.
356 Top Optional. Is this a top-level entity? If so, it must sport a
358 MIME-Version. The default is true. (NB: look at how
359 "attach()" uses it.)
360 Type
362 Optional. The basic content-type ("text/plain", etc.). If you
363 don't specify it, it defaults to "text/plain" as per RFC-1521.
364 Do yourself a favor: put it in.
365 dup Instance method. Duplicate the entity. Does a deep, recursive
367 copy, but beware: external data in bodyhandles is not copied to new
368 files! Changing the data in one entity's data file, or purging
369 that entity, will affect its duplicate. Entities with in-core data
370 probably need not worry.
371 Access
373 body [VALUE]
375 Instance method. Get the encoded (transport-ready) body, as an
376 array of lines. This is a read-only data structure: changing its
377 contents will have no effect. Its contents are identical to what
378 is printed by print_body().
379 Provided for compatibility with Mail::Internet, so that methods
381 like "smtpsend()" will work. Note however that if VALUE is given,
382 a fatal exception is thrown, since you cannot use this method to
383 set the lines of the encoded message.
384 If you want the raw (unencoded) body data, use the bodyhandle()
386 method to get and use a MIME::Body. The content-type of the entity
387 will tell you whether that body is best read as text (via get‐
388 line()) or raw data (via read()).
389 bodyhandle [VALUE]
391 Instance method. Get or set an abstract object representing the
392 body of the message. The body holds the decoded message data.
393 Note that not all entities have bodies! An entity will have either
395 a body or parts: not both. This method will only return an object
396 if this entity can have a body; otherwise, it will return unde‐
397 fined. Whether-or-not a given entity can have a body is determined
398 by (1) its content type, and (2) whether-or-not the parser was told
399 to extract nested messages:
400 Type: ⎪ Extract nested? ⎪ bodyhandle() ⎪ parts()
402 -----------------------------------------------------------------------
403 multipart/* ⎪ - ⎪ undef ⎪ 0 or more MIME::Entity
404 message/* ⎪ true ⎪ undef ⎪ 0 or 1 MIME::Entity
405 message/* ⎪ false ⎪ MIME::Body ⎪ empty list
406 (other) ⎪ - ⎪ MIME::Body ⎪ empty list
407 If "VALUE" is not given, the current bodyhandle is returned, or
409 undef if the entity cannot have a body.
410 If "VALUE" is given, the bodyhandle is set to the new value, and
412 the previous value is returned.
413 See "parts" for more info.
415 effective_type [MIMETYPE]
417 Instance method. Set/get the effective MIME type of this entity.
418 This is usually identical to the actual (or defaulted) MIME type,
419 but in some cases it differs. For example, from RFC-2045:
420 Any entity with an unrecognized Content-Transfer-Encoding must be
422 treated as if it has a Content-Type of "application/octet-stream",
423 regardless of what the Content-Type header field actually says.
424 Why? because if we can't decode the message, then we have to take
426 the bytes as-is, in their (unrecognized) encoded form. So the mes‐
427 sage ceases to be a "text/foobar" and becomes a bunch of undeci‐
428 pherable bytes -- in other words, an "application/octet-stream".
429 Such an entity, if parsed, would have its effective_type() set to
431 "application/octet_stream", although the mime_type() and the con‐
432 tents of the header would remain the same.
433 If there is no effective type, the method just returns what
435 mime_type() would.
436 Warning: the effective type is "sticky"; once set, that effec‐
438 tive_type() will always be returned even if the conditions that
439 necessitated setting the effective type become no longer true.
440 epilogue [LINES]
442 Instance method. Get/set the text of the epilogue, as an array of
443 newline-terminated LINES. Returns a reference to the array of
444 lines, or undef if no epilogue exists.
445 If there is a epilogue, it is output when printing this entity;
447 otherwise, a default epilogue is used. Setting the epilogue to
448 undef (not []!) causes it to fallback to the default.
449 head [VALUE]
451 Instance method. Get/set the head.
452 If there is no VALUE given, returns the current head. If none
454 exists, an empty instance of MIME::Head is created, set, and
455 returned.
456 Note: This is a patch over a problem in Mail::Internet, which
458 doesn't provide a method for setting the head to some given object.
459 is_multipart
461 Instance method. Does this entity's effective MIME type indicate
462 that it's a multipart entity? Returns undef (false) if the answer
463 couldn't be determined, 0 (false) if it was determined to be false,
464 and true otherwise. Note that this says nothing about whether or
465 not parts were extracted.
466 NOTE: we switched to effective_type so that multiparts with bad or
468 missing boundaries could be coerced to an effective type of "appli‐
469 cation/x-unparseable-multipart".
470 mime_type
472 Instance method. A purely-for-convenience method. This simply
473 relays the request to the associated MIME::Head object. If there
474 is no head, returns undef in a scalar context and the empty array
475 in a list context.
476 Before you use this, consider using effective_type() instead, espe‐
478 cially if you obtained the entity from a MIME::Parser.
479 open READWRITE
481 Instance method. A purely-for-convenience method. This simply
482 relays the request to the associated MIME::Body object (see
483 MIME::Body::open()). READWRITE is either 'r' (open for read) or
484 'w' (open for write).
485 If there is no body, returns false.
487 parts
489 parts INDEX
490 parts ARRAYREF
491 Instance method. Return the MIME::Entity objects which are the sub
492 parts of this entity (if any).
493 If no argument is given, returns the array of all sub parts,
495 returning the empty array if there are none (e.g., if this is a
496 single part message, or a degenerate multipart). In a scalar con‐
497 text, this returns you the number of parts.
498 If an integer INDEX is given, return the INDEXed part, or undef if
500 it doesn't exist.
501 If an ARRAYREF to an array of parts is given, then this method sets
503 the parts to a copy of that array, and returns the parts. This can
504 be used to delete parts, as follows:
505 ### Delete some parts of a multipart message:
507 $msg->parts([ grep { keep_part($_) } $msg->parts ]);
508 Note: for multipart messages, the preamble and epilogue are not
510 considered parts. If you need them, use the "preamble()" and "epi‐
511 logue()" methods.
512 Note: there are ways of parsing with a MIME::Parser which cause
514 certain message parts (such as those of type "message/rfc822") to
515 be "reparsed" into pseudo-multipart entities. You should read the
516 documentation for those options carefully: it is possible for a
517 diddled entity to not be multipart, but still have parts attached
518 to it!
519 See "bodyhandle" for a discussion of parts vs. bodies.
521 parts_DFS
523 Instance method. Return the list of all MIME::Entity objects
524 included in the entity, starting with the entity itself, in depth-
525 first-search order. If the entity has no parts, it alone will be
526 returned.
527 Thanks to Xavier Armengou for suggesting this method.
529 preamble [LINES]
531 Instance method. Get/set the text of the preamble, as an array of
532 newline-terminated LINES. Returns a reference to the array of
533 lines, or undef if no preamble exists (e.g., if this is a single-
534 part entity).
535 If there is a preamble, it is output when printing this entity;
537 otherwise, a default preamble is used. Setting the preamble to
538 undef (not []!) causes it to fallback to the default.
539 Manipulation
541 make_multipart [SUBTYPE], OPTSHASH...
543 Instance method. Force the entity to be a multipart, if it isn't
544 already. We do this by replacing the original [singlepart] entity
545 with a new multipart that has the same non-MIME headers ("From",
546 "Subject", etc.), but all-new MIME headers ("Content-type", etc.).
547 We then create a copy of the original singlepart, strip out the
548 non-MIME headers from that, and make it a part of the new multi‐
549 part. So this:
550 From: me
552 To: you
553 Content-type: text/plain
554 Content-length: 12
555 Hello there!
557 Becomes something like this:
559 From: me
561 To: you
562 Content-type: multipart/mixed; boundary="----abc----"
563 ------abc----
565 Content-type: text/plain
566 Content-length: 12
567 Hello there!
569 ------abc------
570 The actual type of the new top-level multipart will be "multi‐
572 part/SUBTYPE" (default SUBTYPE is "mixed").
573 Returns 'DONE' if we really did inflate a singlepart to a multi‐
575 part. Returns 'ALREADY' (and does nothing) if entity is already
576 multipart and Force was not chosen.
577 If OPTSHASH contains Force=>1, then we always bump the top-level's
579 content and content-headers down to a subpart of this entity, even
580 if this entity is already a multipart. This is apparently of use
581 to people who are tweaking messages after parsing them.
582 make_singlepart
584 Instance method. If the entity is a multipart message with one
585 part, this tries hard to rewrite it as a singlepart, by replacing
586 the content (and content headers) of the top level with those of
587 the part. Also crunches 0-part multiparts into singleparts.
588 Returns 'DONE' if we really did collapse a multipart to a sin‐
590 glepart. Returns 'ALREADY' (and does nothing) if entity is already
591 a singlepart. Returns '0' (and does nothing) if it can't be
592 made into a singlepart.
593 purge
595 Instance method. Recursively purge (e.g., unlink) all external
596 (e.g., on-disk) body parts in this message. See
597 MIME::Body::purge() for details.
598 Note: this does not delete the directories that those body parts
600 are contained in; only the actual message data files are deleted.
601 This is because some parsers may be customized to create intermedi‐
602 ate directories while others are not, and it's impossible for this
603 class to know what directories are safe to remove. Only your
604 application program truly knows that.
605 If you really want to "clean everything up", one good way is to use
607 "MIME::Parser::file_under()", and then do this before parsing your
608 next message:
609 $parser->filer->purge();
611 I wouldn't attempt to read those body files after you do this, for
613 obvious reasons. As of MIME-tools 4.x, each body's path is unde‐
614 fined after this operation. I warned you I might do this; truly I
615 did.
616 Thanks to Jason L. Tibbitts III for suggesting this method.
618 remove_sig [NLINES]
620 Instance method, override. Attempts to remove a user's signature
621 from the body of a message.
622 It does this by looking for a line matching "/^-- $/" within the
624 last "NLINES" of the message. If found then that line and all
625 lines after it will be removed. If "NLINES" is not given, a default
626 value of 10 will be used. This would be of most use in auto-reply
627 scripts.
628 For MIME entity, this method is reasonably cautious: it will only
630 attempt to un-sign a message with a content-type of "text/*".
631 If you send remove_sig() to a multipart entity, it will relay it to
633 the first part (the others usually being the "attachments").
634 Warning: currently slurps the whole message-part into core as an
636 array of lines, so you probably don't want to use this on extremely
637 long messages.
638 Returns truth on success, false on error.
640 sign PARAMHASH
642 Instance method, override. Append a signature to the message. The
643 params are:
644 Attach
646 Instead of appending the text, add it to the message as an
647 attachment. The disposition will be "inline", and the descrip‐
648 tion will indicate that it is a signature. The default behav‐
649 ior is to append the signature to the text of the message (or
650 the text of its first part if multipart). MIME-specific; new
651 in this subclass.
652 File
654 Use the contents of this file as the signature. Fatal error if
655 it can't be read. As per superclass method.
656 Force
658 Sign it even if the content-type isn't "text/*". Useful for
659 non-standard types like "x-foobar", but be careful! MIME-spe‐
660 cific; new in this subclass.
661 Remove
663 Normally, we attempt to strip out any existing signature. If
664 true, this gives us the NLINES parameter of the remove_sig
665 call. If zero but defined, tells us not to remove any existing
666 signature. If undefined, removal is done with the default of
667 10 lines. New in this subclass.
668 Signature
670 Use this text as the signature. You can supply it as either a
671 scalar, or as a ref to an array of newline-terminated scalars.
672 As per superclass method.
673 For MIME messages, this method is reasonably cautious: it will only
675 attempt to sign a message with a content-type of "text/*", unless
676 "Force" is specified.
677 If you send this message to a multipart entity, it will relay it to
679 the first part (the others usually being the "attachments").
680 Warning: currently slurps the whole message-part into core as an
682 array of lines, so you probably don't want to use this on extremely
683 long messages.
684 Returns true on success, false otherwise.
686 suggest_encoding
688 Instance method. Based on the effective content type, return a
689 good suggested encoding.
690 "text" and "message" types have their bodies scanned line-by-line
692 for 8-bit characters and long lines; lack of either means that the
693 message is 7bit-ok. Other types are chosen independent of their
694 body:
695 Major type: 7bit ok? Suggested encoding:
697 -----------------------------------------------------------
698 text yes 7bit
699 text no quoted-printable
700 message yes 7bit
701 message no binary
702 multipart * binary (in case some parts are bad)
703 image, etc... * base64
704 sync_headers OPTIONS
706 Instance method. This method does a variety of activities which
707 ensure that the MIME headers of an entity "tree" are in-synch with
708 the body parts they describe. It can be as expensive an operation
709 as printing if it involves pre-encoding the body parts; however,
710 the aim is to produce fairly clean MIME. You will usually only
711 need to invoke this if processing and re-sending MIME from an out‐
712 side source.
713 The OPTIONS is a hash, which describes what is to be done.
715 Length
717 One of the "official unofficial" MIME fields is "Con‐
718 tent-Length". Normally, one doesn't care a whit about this
719 field; however, if you are preparing output destined for HTTP,
720 you may. The value of this option dictates what will be done:
721 COMPUTE means to set a "Content-Length" field for every non-
723 multipart part in the entity, and to blank that field out for
724 every multipart part in the entity.
725 ERASE means that "Content-Length" fields will all be blanked
727 out. This is fast, painless, and safe.
728 Any false value (the default) means to take no action.
730 Nonstandard
732 Any header field beginning with "Content-" is, according to the
733 RFC, a MIME field. However, some are non-standard, and may
734 cause problems with certain MIME readers which interpret them
735 in different ways.
736 ERASE means that all such fields will be blanked out. This is
738 done before the Length option (q.v.) is examined and acted
739 upon.
740 Any false value (the default) means to take no action.
742 Returns a true value if everything went okay, a false value other‐
744 wise.
745 tidy_body
747 Instance method, override. Currently unimplemented for MIME mes‐
748 sages. Does nothing, returns false.
749 Output
751 dump_skeleton [FILEHANDLE]
753 Instance method. Dump the skeleton of the entity to the given
754 FILEHANDLE, or to the currently-selected one if none given.
755 Each entity is output with an appropriate indentation level, the
757 following selection of attributes:
758 Content-type: multipart/mixed
760 Effective-type: multipart/mixed
761 Body-file: NONE
762 Subject: Hey there!
763 Num-parts: 2
764 This is really just useful for debugging purposes; I make no guar‐
766 antees about the consistency of the output format over time.
767 print [OUTSTREAM]
769 Instance method, override. Print the entity to the given OUT‐
770 STREAM, or to the currently-selected filehandle if none given.
771 OUTSTREAM can be a filehandle, or any object that reponds to a
772 print() message.
773 The entity is output as a valid MIME stream! This means that the
775 header is always output first, and the body data (if any) will be
776 encoded if the header says that it should be. For example, your
777 output may look like this:
778 Subject: Greetings
780 Content-transfer-encoding: base64
781 SGkgdGhlcmUhCkJ5ZSB0aGVyZSEK
783 If this entity has MIME type "multipart/*", the preamble, parts,
785 and epilogue are all output with appropriate boundaries separating
786 each. Any bodyhandle is ignored:
787 Content-type: multipart/mixed; boundary="*----*"
789 Content-transfer-encoding: 7bit
790 [Preamble]
792 --*----*
793 [Entity: Part 0]
794 --*----*
795 [Entity: Part 1]
796 --*----*--
797 [Epilogue]
798 If this entity has a single-part MIME type with no attached parts,
800 then we're looking at a normal singlepart entity: the body is out‐
801 put according to the encoding specified by the header. If no body
802 exists, a warning is output and the body is treated as empty:
803 Content-type: image/gif
805 Content-transfer-encoding: base64
806 [Encoded body]
808 If this entity has a single-part MIME type but it also has parts,
810 then we're probably looking at a "re-parsed" singlepart, usually
811 one of type "message/*" (you can get entities like this if you set
812 the "parse_nested_messages(NEST)" option on the parser to true).
813 In this case, the parts are output with single blank lines separat‐
814 ing each, and any bodyhandle is ignored:
815 Content-type: message/rfc822
817 Content-transfer-encoding: 7bit
818 [Entity: Part 0]
820 [Entity: Part 1]
822 In all cases, when outputting a "part" of the entity, this method
824 is invoked recursively.
825 Note: the output is very likely not going to be identical to any
827 input you parsed to get this entity. If you're building some sort
828 of email handler, it's up to you to save this information.
829 print_body [OUTSTREAM]
831 Instance method, override. Print the body of the entity to the
832 given OUTSTREAM, or to the currently-selected filehandle if none
833 given. OUTSTREAM can be a filehandle, or any object that reponds
834 to a print() message.
835 The body is output for inclusion in a valid MIME stream; this means
837 that the body data will be encoded if the header says that it
838 should be.
839 Note: by "body", we mean "the stuff following the header". A
841 printed multipart body includes the printed representations of its
842 subparts.
843 Note: The body is stored in an un-encoded form; however, the idea
845 is that the transfer encoding is used to determine how it should be
846 output. This means that the "print()" method is always guaranteed
847 to get you a sendmail-ready stream whose body is consistent with
848 its head. If you want the raw body data to be output, you can
849 either read it from the bodyhandle yourself, or use:
850 $ent->bodyhandle->print($outstream);
852 which uses read() calls to extract the information, and thus will
854 work with both text and binary bodies.
855 Warning: Please supply an OUTSTREAM. This override method differs
857 from Mail::Internet's behavior, which outputs to the STDOUT if no
858 filehandle is given: this may lead to confusion.
859 print_header [OUTSTREAM]
861 Instance method, inherited. Output the header to the given OUT‐
862 STREAM. You really should supply the OUTSTREAM.
863 stringify
865 Instance method. Return the entity as a string, exactly as "print"
866 would print it. The body will be encoded as necessary, and will
867 contain any subparts. You can also use "as_string()".
868 stringify_body
870 Instance method. Return the encoded message body as a string,
871 exactly as "print_body" would print it. You can also use
872 "body_as_string()".
873 If you want the unencoded body, and you are dealing with a sin‐
875 glepart message (like a "text/plain"), use "bodyhandle()" instead:
876 if ($ent->bodyhandle) {
878 $unencoded_data = $ent->bodyhandle->as_string;
879 }
880 else {
881 ### this message has no body data (but it might have parts!)
882 }
883 stringify_header
885 Instance method. Return the header as a string, exactly as
886 "print_header" would print it. You can also use
887 "header_as_string()".
888
890 Under the hood
891 A MIME::Entity is composed of the following elements:
893 · A head, which is a reference to a MIME::Head object containing the
895 header information.
896 · A bodyhandle, which is a reference to a MIME::Body object contain‐
898 ing the decoded body data. This is only defined if the message is
899 a "singlepart" type:
900 application/*
902 audio/*
903 image/*
904 text/*
905 video/*
906 · An array of parts, where each part is a MIME::Entity object. The
908 number of parts will only be nonzero if the content-type is not one
909 of the "singlepart" types:
910 message/* (should have exactly one part)
912 multipart/* (should have one or more parts)
913 The "two-body problem"
915 MIME::Entity and Mail::Internet see message bodies differently, and
917 this can cause confusion and some inconvenience. Sadly, I can't change
918 the behavior of MIME::Entity without breaking lots of code already out
919 there. But let's open up the floor for a few questions...
920 What is the difference between a "message" and an "entity"?
922 A message is the actual data being sent or received; usually this
923 means a stream of newline-terminated lines. An entity is the rep‐
924 resentation of a message as an object.
925 This means that you get a "message" when you print an "entity" to a
927 filehandle, and you get an "entity" when you parse a message from a
928 filehandle.
929 What is a message body?
931 Mail::Internet: The portion of the printed message after the
932 header.
933 MIME::Entity: The portion of the printed message after the header.
935 How is a message body stored in an entity?
937 Mail::Internet: As an array of lines.
938 MIME::Entity: It depends on the content-type of the message. For
940 "container" types ("multipart/*", "message/*"), we store the con‐
941 tained entities as an array of "parts", accessed via the "parts()"
942 method, where each part is a complete MIME::Entity. For "sin‐
943 glepart" types ("text/*", "image/*", etc.), the unencoded body data
944 is referenced via a MIME::Body object, accessed via the "bodyhan‐
945 dle()" method:
946 bodyhandle() parts()
948 Content-type: returns: returns:
949 ------------------------------------------------------------
950 application/* MIME::Body empty
951 audio/* MIME::Body empty
952 image/* MIME::Body empty
953 message/* undef MIME::Entity list (usually 1)
954 multipart/* undef MIME::Entity list (usually >0)
955 text/* MIME::Body empty
956 video/* MIME::Body empty
957 x-*/* MIME::Body empty
958 As a special case, "message/*" is currently ambiguous: depending on
960 the parser, a "message/*" might be treated as a singlepart, with a
961 MIME::Body and no parts. Use bodyhandle() as the final arbiter.
962 What does the body() method return?
964 Mail::Internet: As an array of lines, ready for sending.
965 MIME::Entity: As an array of lines, ready for sending.
967 If an entity has a body, does it have a soul as well?
969 The soul does not exist in a corporeal sense, the way the body
970 does; it is not a solid [Perl] object. Rather, it is a virtual
971 object which is only visible when you print() an entity to a
972 file... in other words, the "soul" it is all that is left after the
973 body is DESTROY'ed.
974 What's the best way to get at the body data?
976 Mail::Internet: Use the body() method.
977 MIME::Entity: Depends on what you want... the encoded data (as it
979 is transported), or the unencoded data? Keep reading...
980 How do I get the "encoded" body data?
982 Mail::Internet: Use the body() method.
983 MIME::Entity: Use the body() method. You can also use:
985 $entity->print_body()
987 $entity->stringify_body() ### a.k.a. $entity->body_as_string()
988 How do I get the "unencoded" body data?
990 Mail::Internet: Use the body() method.
991 MIME::Entity: Use the bodyhandle() method! If bodyhandle() method
993 returns true, then that value is a MIME::Body which can be used to
994 access the data via its open() method. If bodyhandle() method
995 returns an undefined value, then the entity is probably a "con‐
996 tainer" that has no real body data of its own (e.g., a "multipart"
997 message): in this case, you should access the components via the
998 parts() method. Like this:
999 if ($bh = $entity->bodyhandle) {
1001 $io = $bh->open;
1002 ...access unencoded data via $io->getline or $io->read...
1003 $io->close;
1004 }
1005 else {
1006 foreach my $part (@parts) {
1007 ...do something with the part...
1008 }
1009 }
1010 You can also use:
1012 if ($bh = $entity->bodyhandle) {
1014 $unencoded_data = $bh->as_string;
1015 }
1016 else {
1017 ...do stuff with the parts...
1018 }
1019 What does the body() method return?
1021 Mail::Internet: The transport-encoded message body, as an array of
1022 lines.
1023 MIME::Entity: The transport-encoded message body, as an array of
1025 lines.
1026 What does print_body() print?
1028 Mail::Internet: Exactly what body() would return to you.
1029 MIME::Entity: Exactly what body() would return to you.
1031 Say I have an entity which might be either singlepart or multipart. How
1033 do I print out just "the stuff after the header"?
1034 Mail::Internet: Use print_body().
1035 MIME::Entity: Use print_body().
1037 Why is MIME::Entity so different from Mail::Internet?
1039 Because MIME streams are expected to have non-textual data... pos‐
1040 sibly, quite a lot of it, such as a tar file.
1041 Because MIME messages can consist of multiple parts, which are
1043 most-easily manipulated as MIME::Entity objects themselves.
1044 Because in the simpler world of Mail::Internet, the data of a mes‐
1046 sage and its printed representation are identical... and in the
1047 MIME world, they're not.
1048 Because parsing multipart bodies on-the-fly, or formatting multi‐
1050 part bodies for output, is a non-trivial task.
1051 This is confusing. Can the two classes be made more compatible?
1053 Not easily; their implementations are necessarily quite different.
1054 Mail::Internet is a simple, efficient way of dealing with a "black
1055 box" mail message... one whose internal data you don't care much
1056 about. MIME::Entity, in contrast, cares very much about the mes‐
1057 sage contents: that's its job!
1058 Design issues
1060 Some things just can't be ignored
1062 In multipart messages, the "preamble" is the portion that precedes
1063 the first encapsulation boundary, and the "epilogue" is the portion
1064 that follows the last encapsulation boundary.
1065 According to RFC-1521:
1067 There appears to be room for additional information prior
1069 to the first encapsulation boundary and following the final
1070 boundary. These areas should generally be left blank, and
1071 implementations must ignore anything that appears before the
1072 first boundary or after the last one.
1073 NOTE: These "preamble" and "epilogue" areas are generally
1075 not used because of the lack of proper typing of these parts
1076 and the lack of clear semantics for handling these areas at
1077 gateways, particularly X.400 gateways. However, rather than
1078 leaving the preamble area blank, many MIME implementations
1079 have found this to be a convenient place to insert an
1080 explanatory note for recipients who read the message with
1081 pre-MIME software, since such notes will be ignored by
1082 MIME-compliant software.
1083 In the world of standards-and-practices, that's the standard. Now
1085 for the practice:
1086 Some "MIME" mailers may incorrectly put a "part" in the preamble.
1088 Since we have to parse over the stuff anyway, in the future I may
1089 allow the parser option of creating special MIME::Entity objects
1090 for the preamble and epilogue, with bogus MIME::Head objects.
1091 For now, though, we're MIME-compliant, so I probably won't change
1093 how we work.
1094
1096 Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com).
1097 David F. Skoll (dfs@roaringpenguin.com) http://www.roaringpenguin.com
1098 All rights reserved. This program is free software; you can redis‐
1100 tribute it and/or modify it under the same terms as Perl itself.
1101
1103 $Revision: 1.18 $ $Date: 2006/03/17 21:15:49 $
1104perl v5.8.8 2006-03-17 MIME::Entity(3)