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 RFCs 2045, 2046, 2047, 2048 and 2049.
37
39 Construction examples
40 Create a document for an ordinary 7-bit ASCII text file (lots of stuff
41 is defaulted for us):
42 $ent = MIME::Entity->build(Path=>"english-msg.txt");
44 Create a document for a text file with 8-bit (Latin-1) characters:
46 $ent = MIME::Entity->build(Path =>"french-msg.txt",
48 Encoding =>"quoted-printable",
49 From =>'jean.luc@inria.fr',
50 Subject =>"C'est bon!");
51 Create a document for a GIF file (the description is completely
53 optional; note that we have to specify content-type and encoding since
54 they're not the default values):
55 $ent = MIME::Entity->build(Description => "A pretty picture",
57 Path => "./docs/mime-sm.gif",
58 Type => "image/gif",
59 Encoding => "base64");
60 Create a document that you already have the text for, using "Data":
62 $ent = MIME::Entity->build(Type => "text/plain",
64 Encoding => "quoted-printable",
65 Data => ["First line.\n",
66 "Second line.\n",
67 "Last line.\n"]);
68 Create a multipart message, with the entire structure given explicitly:
70 ### Create the top-level, and set up the mail headers:
72 $top = MIME::Entity->build(Type => "multipart/mixed",
73 From => 'me@myhost.com',
74 To => 'you@yourhost.com',
75 Subject => "Hello, nurse!");
76 ### Attachment #1: a simple text document:
78 $top->attach(Path=>"./testin/short.txt");
79 ### Attachment #2: a GIF file:
81 $top->attach(Path => "./docs/mime-sm.gif",
82 Type => "image/gif",
83 Encoding => "base64");
84 ### Attachment #3: text we'll create with text we have on-hand:
86 $top->attach(Data => $contents);
87 Suppose you don't know ahead of time that you'll have attachments? No
89 problem: you can "attach" to singleparts as well:
90 $top = MIME::Entity->build(From => 'me@myhost.com',
92 To => 'you@yourhost.com',
93 Subject => "Hello, nurse!",
94 Data => \@my_message);
95 if ($GIF_path) {
96 $top->attach(Path => $GIF_path,
97 Type => 'image/gif');
98 }
99 Copy an entity (headers, parts... everything but external body data):
101 my $deepcopy = $top->dup;
103 Access examples
105 ### Get the head, a MIME::Head:
106 $head = $ent->head;
107 ### Get the body, as a MIME::Body;
109 $bodyh = $ent->bodyhandle;
110 ### Get the intended MIME type (as declared in the header):
112 $type = $ent->mime_type;
113 ### Get the effective MIME type (in case decoding failed):
115 $eff_type = $ent->effective_type;
116 ### Get preamble, parts, and epilogue:
118 $preamble = $ent->preamble; ### ref to array of lines
119 $num_parts = $ent->parts;
120 $first_part = $ent->parts(0); ### an entity
121 $epilogue = $ent->epilogue; ### ref to array of lines
122 Manipulation examples
124 Muck about with the body data:
125 ### Read the (unencoded) body data:
127 if ($io = $ent->open("r")) {
128 while (defined($_ = $io->getline)) { print $_ }
129 $io->close;
130 }
131 ### Write the (unencoded) body data:
133 if ($io = $ent->open("w")) {
134 foreach (@lines) { $io->print($_) }
135 $io->close;
136 }
137 ### Delete the files for any external (on-disk) data:
139 $ent->purge;
140 Muck about with the signature:
142 ### Sign it (automatically removes any existing signature):
144 $top->sign(File=>"$ENV{HOME}/.signature");
145 ### Remove any signature within 15 lines of the end:
147 $top->remove_sig(15);
148 Muck about with the headers:
150 ### Compute content-lengths for singleparts based on bodies:
152 ### (Do this right before you print!)
153 $entity->sync_headers(Length=>'COMPUTE');
154 Muck about with the structure:
156 ### If a 0- or 1-part multipart, collapse to a singlepart:
158 $top->make_singlepart;
159 ### If a singlepart, inflate to a multipart with 1 part:
161 $top->make_multipart;
162 Delete parts:
164 ### Delete some parts of a multipart message:
166 my @keep = grep { keep_part($_) } $msg->parts;
167 $msg->parts(\@keep);
168 Output examples
170 Print to filehandles:
171 ### Print the entire message:
173 $top->print(\*STDOUT);
174 ### Print just the header:
176 $top->print_header(\*STDOUT);
177 ### Print just the (encoded) body... includes parts as well!
179 $top->print_body(\*STDOUT);
180 Stringify... note that "stringify_xx" can also be written
182 "xx_as_string"; the methods are synonymous, and neither form will be
183 deprecated:
184 ### Stringify the entire message:
186 print $top->stringify; ### or $top->as_string
187 ### Stringify just the header:
189 print $top->stringify_header; ### or $top->header_as_string
190 ### Stringify just the (encoded) body... includes parts as well!
192 print $top->stringify_body; ### or $top->body_as_string
193 Debug:
195 ### Output debugging info:
197 $entity->dump_skeleton(\*STDERR);
198
200 Construction
201 new [SOURCE]
202 Class method. Create a new, empty MIME entity. Basically, this
203 uses the Mail::Internet constructor...
204 If SOURCE is an ARRAYREF, it is assumed to be an array of lines
206 that will be used to create both the header and an in-core body.
207 Else, if SOURCE is defined, it is assumed to be a filehandle from
209 which the header and in-core body is to be read.
210 Note: in either case, the body will not be parsed: merely read!
212 add_part ENTITY, [OFFSET]
214 Instance method. Assuming we are a multipart message, add a body
215 part (a MIME::Entity) to the array of body parts. Returns the part
216 that was just added.
217 If OFFSET is positive, the new part is added at that offset from
219 the beginning of the array of parts. If it is negative, it counts
220 from the end of the array. (An INDEX of -1 will place the new part
221 at the very end of the array, -2 will place it as the penultimate
222 item in the array, etc.) If OFFSET is not given, the new part is
223 added to the end of the array. Thanks to Jason L Tibbitts III for
224 providing support for OFFSET.
225 Warning: in general, you only want to attach parts to entities with
227 a content-type of "multipart/*").
228 attach PARAMHASH
230 Instance method. The real quick-and-easy way to create multipart
231 messages. The PARAMHASH is used to "build" a new entity; this
232 method is basically equivalent to:
233 $entity->add_part(ref($entity)->build(PARAMHASH, Top=>0));
235 Note: normally, you attach to multipart entities; however, if you
237 attach something to a singlepart (like attaching a GIF to a text
238 message), the singlepart will be coerced into a multipart
239 automatically.
240 build PARAMHASH
242 Class/instance method. A quick-and-easy catch-all way to create an
243 entity. Use it like this to build a "normal" single-part entity:
244 $ent = MIME::Entity->build(Type => "image/gif",
246 Encoding => "base64",
247 Path => "/path/to/xyz12345.gif",
248 Filename => "saveme.gif",
249 Disposition => "attachment");
250 And like this to build a "multipart" entity:
252 $ent = MIME::Entity->build(Type => "multipart/mixed",
254 Boundary => "---1234567");
255 A minimal MIME header will be created. If you want to add or
257 modify any header fields afterwards, you can of course do so via
258 the underlying head object... but hey, there's now a prettier
259 syntax!
260 $ent = MIME::Entity->build(Type =>"multipart/mixed",
262 From => $myaddr,
263 Subject => "Hi!",
264 'X-Certified' => ['SINED',
265 'SEELED',
266 'DELIVERED']);
267 Normally, an "X-Mailer" header field is output which contains this
269 toolkit's name and version (plus this module's RCS version). This
270 will allow any bad MIME we generate to be traced back to us. You
271 can of course overwrite that header with your own:
272 $ent = MIME::Entity->build(Type => "multipart/mixed",
274 'X-Mailer' => "myprog 1.1");
275 Or remove it entirely:
277 $ent = MIME::Entity->build(Type => "multipart/mixed",
279 'X-Mailer' => undef);
280 OK, enough hype. The parameters are:
282 (FIELDNAME)
284 Any field you want placed in the message header, taken from the
285 standard list of header fields (you don't need to worry about
286 case):
287 Bcc Encrypted Received Sender
289 Cc From References Subject
290 Comments Keywords Reply-To To
291 Content-* Message-ID Resent-* X-*
292 Date MIME-Version Return-Path
293 Organization
294 To give experienced users some veto power, these fields will be
296 set after the ones I set... so be careful: don't set any MIME
297 fields (like "Content-type") unless you know what you're doing!
298 To specify a fieldname that's not in the above list, even one
300 that's identical to an option below, just give it with a
301 trailing ":", like "My-field:". When in doubt, that always
302 signals a mail field (and it sort of looks like one too).
303 Boundary
305 Multipart entities only. Optional. The boundary string. As
306 per RFC-2046, it must consist only of the characters
307 "[0-9a-zA-Z'()+_,-./:=?]" and space (you'll be warned, and your
308 boundary will be ignored, if this is not the case). If you
309 omit this, a random string will be chosen... which is probably
310 safer.
311 Charset
313 Optional. The character set.
314 Data
316 Single-part entities only. Optional. An alternative to Path
317 (q.v.): the actual data, either as a scalar or an array
318 reference (whose elements are joined together to make the
319 actual scalar). The body is opened on the data using
320 MIME::Body::InCore.
321 Description
323 Optional. The text of the content-description. If you don't
324 specify it, the field is not put in the header.
325 Disposition
327 Optional. The basic content-disposition ("attachment" or
328 "inline"). If you don't specify it, it defaults to "inline"
329 for backwards compatibility. Thanks to Kurt Freytag for
330 suggesting this feature.
331 Encoding
333 Optional. The content-transfer-encoding. If you don't specify
334 it, a reasonable default is put in. You can also give the
335 special value '-SUGGEST', to have it chosen for you in a heavy-
336 duty fashion which scans the data itself.
337 Filename
339 Single-part entities only. Optional. The recommended filename.
340 Overrides any name extracted from "Path". The information is
341 stored both the deprecated (content-type) and preferred
342 (content-disposition) locations. If you explicitly want to
343 avoid a recommended filename (even when Path is used), supply
344 this as empty or undef.
345 Id Optional. Set the content-id.
347 Path
349 Single-part entities only. Optional. The path to the file to
350 attach. The body is opened on that file using
351 MIME::Body::File.
352 Top Optional. Is this a top-level entity? If so, it must sport a
354 MIME-Version. The default is true. (NB: look at how
355 "attach()" uses it.)
356 Type
358 Optional. The basic content-type ("text/plain", etc.). If you
359 don't specify it, it defaults to "text/plain" as per RFC 2045.
360 Do yourself a favor: put it in.
361 dup Instance method. Duplicate the entity. Does a deep, recursive
363 copy, but beware: external data in bodyhandles is not copied to new
364 files! Changing the data in one entity's data file, or purging
365 that entity, will affect its duplicate. Entities with in-core data
366 probably need not worry.
367 Access
369 body [VALUE]
370 Instance method. Get the encoded (transport-ready) body, as an
371 array of lines. Returns an array reference. Each array entry is a
372 newline-terminated line.
373 This is a read-only data structure: changing its contents will have
375 no effect. Its contents are identical to what is printed by
376 print_body().
377 Provided for compatibility with Mail::Internet, so that methods
379 like "smtpsend()" will work. Note however that if VALUE is given,
380 a fatal exception is thrown, since you cannot use this method to
381 set the lines of the encoded message.
382 If you want the raw (unencoded) body data, use the bodyhandle()
384 method to get and use a MIME::Body. The content-type of the entity
385 will tell you whether that body is best read as text (via
386 getline()) or raw data (via read()).
387 bodyhandle [VALUE]
389 Instance method. Get or set an abstract object representing the
390 body of the message. The body holds the decoded message data.
391 Note that not all entities have bodies! An entity will have either
393 a body or parts: not both. This method will only return an object
394 if this entity can have a body; otherwise, it will return
395 undefined. Whether-or-not a given entity can have a body is
396 determined by (1) its content type, and (2) whether-or-not the
397 parser was told to extract nested messages:
398 Type: | Extract nested? | bodyhandle() | parts()
400 -----------------------------------------------------------------------
401 multipart/* | - | undef | 0 or more MIME::Entity
402 message/* | true | undef | 0 or 1 MIME::Entity
403 message/* | false | MIME::Body | empty list
404 (other) | - | MIME::Body | empty list
405 If "VALUE" is not given, the current bodyhandle is returned, or
407 undef if the entity cannot have a body.
408 If "VALUE" is given, the bodyhandle is set to the new value, and
410 the previous value is returned.
411 See "parts" for more info.
413 effective_type [MIMETYPE]
415 Instance method. Set/get the effective MIME type of this entity.
416 This is usually identical to the actual (or defaulted) MIME type,
417 but in some cases it differs. For example, from RFC-2045:
418 Any entity with an unrecognized Content-Transfer-Encoding must be
420 treated as if it has a Content-Type of "application/octet-stream",
421 regardless of what the Content-Type header field actually says.
422 Why? because if we can't decode the message, then we have to take
424 the bytes as-is, in their (unrecognized) encoded form. So the
425 message ceases to be a "text/foobar" and becomes a bunch of
426 undecipherable bytes -- in other words, an
427 "application/octet-stream".
428 Such an entity, if parsed, would have its effective_type() set to
430 "application/octet_stream", although the mime_type() and the
431 contents of the header would remain the same.
432 If there is no effective type, the method just returns what
434 mime_type() would.
435 Warning: the effective type is "sticky"; once set, that
437 effective_type() will always be returned even if the conditions
438 that necessitated setting the effective type become no longer true.
439 epilogue [LINES]
441 Instance method. Get/set the text of the epilogue, as an array of
442 newline-terminated LINES. Returns a reference to the array of
443 lines, or undef if no epilogue exists.
444 If there is a epilogue, it is output when printing this entity;
446 otherwise, a default epilogue is used. Setting the epilogue to
447 undef (not []!) causes it to fallback to the default.
448 head [VALUE]
450 Instance method. Get/set the head.
451 If there is no VALUE given, returns the current head. If none
453 exists, an empty instance of MIME::Head is created, set, and
454 returned.
455 Note: This is a patch over a problem in Mail::Internet, which
457 doesn't provide a method for setting the head to some given object.
458 is_multipart
460 Instance method. Does this entity's effective MIME type indicate
461 that it's a multipart entity? Returns undef (false) if the answer
462 couldn't be determined, 0 (false) if it was determined to be false,
463 and true otherwise. Note that this says nothing about whether or
464 not parts were extracted.
465 NOTE: we switched to effective_type so that multiparts with bad or
467 missing boundaries could be coerced to an effective type of
468 "application/x-unparseable-multipart".
469 mime_type
471 Instance method. A purely-for-convenience method. This simply
472 relays the request to the associated MIME::Head object. If there
473 is no head, returns undef in a scalar context and the empty array
474 in a list context.
475 Before you use this, consider using effective_type() instead,
477 especially if you obtained the entity from a MIME::Parser.
478 open READWRITE
480 Instance method. A purely-for-convenience method. This simply
481 relays the request to the associated MIME::Body object (see
482 MIME::Body::open()). READWRITE is either 'r' (open for read) or
483 'w' (open for write).
484 If there is no body, returns false.
486 parts
488 parts INDEX
489 parts ARRAYREF
490 Instance method. Return the MIME::Entity objects which are the sub
491 parts of this entity (if any).
492 If no argument is given, returns the array of all sub parts,
494 returning the empty array if there are none (e.g., if this is a
495 single part message, or a degenerate multipart). In a scalar
496 context, this returns you the number of parts.
497 If an integer INDEX is given, return the INDEXed part, or undef if
499 it doesn't exist.
500 If an ARRAYREF to an array of parts is given, then this method sets
502 the parts to a copy of that array, and returns the parts. This can
503 be used to delete parts, as follows:
504 ### Delete some parts of a multipart message:
506 $msg->parts([ grep { keep_part($_) } $msg->parts ]);
507 Note: for multipart messages, the preamble and epilogue are not
509 considered parts. If you need them, use the "preamble()" and
510 "epilogue()" methods.
511 Note: there are ways of parsing with a MIME::Parser which cause
513 certain message parts (such as those of type "message/rfc822") to
514 be "reparsed" into pseudo-multipart entities. You should read the
515 documentation for those options carefully: it is possible for a
516 diddled entity to not be multipart, but still have parts attached
517 to it!
518 See "bodyhandle" for a discussion of parts vs. bodies.
520 parts_DFS
522 Instance method. Return the list of all MIME::Entity objects
523 included in the entity, starting with the entity itself, in depth-
524 first-search order. If the entity has no parts, it alone will be
525 returned.
526 Thanks to Xavier Armengou for suggesting this method.
528 preamble [LINES]
530 Instance method. Get/set the text of the preamble, as an array of
531 newline-terminated LINES. Returns a reference to the array of
532 lines, or undef if no preamble exists (e.g., if this is a single-
533 part entity).
534 If there is a preamble, it is output when printing this entity;
536 otherwise, a default preamble is used. Setting the preamble to
537 undef (not []!) causes it to fallback to the default.
538 Manipulation
540 make_multipart [SUBTYPE], OPTSHASH...
541 Instance method. Force the entity to be a multipart, if it isn't
542 already. We do this by replacing the original [singlepart] entity
543 with a new multipart that has the same non-MIME headers ("From",
544 "Subject", etc.), but all-new MIME headers ("Content-type", etc.).
545 We then create a copy of the original singlepart, strip out the
546 non-MIME headers from that, and make it a part of the new
547 multipart. So this:
548 From: me
550 To: you
551 Content-type: text/plain
552 Content-length: 12
553 Hello there!
555 Becomes something like this:
557 From: me
559 To: you
560 Content-type: multipart/mixed; boundary="----abc----"
561 ------abc----
563 Content-type: text/plain
564 Content-length: 12
565 Hello there!
567 ------abc------
568 The actual type of the new top-level multipart will be
570 "multipart/SUBTYPE" (default SUBTYPE is "mixed").
571 Returns 'DONE' if we really did inflate a singlepart to a
573 multipart. Returns 'ALREADY' (and does nothing) if entity is
574 already multipart and Force was not chosen.
575 If OPTSHASH contains Force=>1, then we always bump the top-level's
577 content and content-headers down to a subpart of this entity, even
578 if this entity is already a multipart. This is apparently of use
579 to people who are tweaking messages after parsing them.
580 make_singlepart
582 Instance method. If the entity is a multipart message with one
583 part, this tries hard to rewrite it as a singlepart, by replacing
584 the content (and content headers) of the top level with those of
585 the part. Also crunches 0-part multiparts into singleparts.
586 Returns 'DONE' if we really did collapse a multipart to a
588 singlepart. Returns 'ALREADY' (and does nothing) if entity is
589 already a singlepart. Returns '0' (and does nothing) if it
590 can't be made into a singlepart.
591 purge
593 Instance method. Recursively purge (e.g., unlink) all external
594 (e.g., on-disk) body parts in this message. See
595 MIME::Body::purge() for details.
596 Note: this does not delete the directories that those body parts
598 are contained in; only the actual message data files are deleted.
599 This is because some parsers may be customized to create
600 intermediate directories while others are not, and it's impossible
601 for this class to know what directories are safe to remove. Only
602 your application program truly knows that.
603 If you really want to "clean everything up", one good way is to use
605 "MIME::Parser::file_under()", and then do this before parsing your
606 next message:
607 $parser->filer->purge();
609 I wouldn't attempt to read those body files after you do this, for
611 obvious reasons. As of MIME-tools 4.x, each body's path is
612 undefined after this operation. I warned you I might do this;
613 truly I did.
614 Thanks to Jason L. Tibbitts III for suggesting this method.
616 remove_sig [NLINES]
618 Instance method, override. Attempts to remove a user's signature
619 from the body of a message.
620 It does this by looking for a line matching "/^-- $/" within the
622 last "NLINES" of the message. If found then that line and all
623 lines after it will be removed. If "NLINES" is not given, a default
624 value of 10 will be used. This would be of most use in auto-reply
625 scripts.
626 For MIME entity, this method is reasonably cautious: it will only
628 attempt to un-sign a message with a content-type of "text/*".
629 If you send remove_sig() to a multipart entity, it will relay it to
631 the first part (the others usually being the "attachments").
632 Warning: currently slurps the whole message-part into core as an
634 array of lines, so you probably don't want to use this on extremely
635 long messages.
636 Returns truth on success, false on error.
638 sign PARAMHASH
640 Instance method, override. Append a signature to the message. The
641 params are:
642 Attach
644 Instead of appending the text, add it to the message as an
645 attachment. The disposition will be "inline", and the
646 description will indicate that it is a signature. The default
647 behavior is to append the signature to the text of the message
648 (or the text of its first part if multipart). MIME-specific;
649 new in this subclass.
650 File
652 Use the contents of this file as the signature. Fatal error if
653 it can't be read. As per superclass method.
654 Force
656 Sign it even if the content-type isn't "text/*". Useful for
657 non-standard types like "x-foobar", but be careful! MIME-
658 specific; new in this subclass.
659 Remove
661 Normally, we attempt to strip out any existing signature. If
662 true, this gives us the NLINES parameter of the remove_sig
663 call. If zero but defined, tells us not to remove any existing
664 signature. If undefined, removal is done with the default of
665 10 lines. New in this subclass.
666 Signature
668 Use this text as the signature. You can supply it as either a
669 scalar, or as a ref to an array of newline-terminated scalars.
670 As per superclass method.
671 For MIME messages, this method is reasonably cautious: it will only
673 attempt to sign a message with a content-type of "text/*", unless
674 "Force" is specified.
675 If you send this message to a multipart entity, it will relay it to
677 the first part (the others usually being the "attachments").
678 Warning: currently slurps the whole message-part into core as an
680 array of lines, so you probably don't want to use this on extremely
681 long messages.
682 Returns true on success, false otherwise.
684 suggest_encoding
686 Instance method. Based on the effective content type, return a
687 good suggested encoding.
688 "text" and "message" types have their bodies scanned line-by-line
690 for 8-bit characters and long lines; lack of either means that the
691 message is 7bit-ok. Other types are chosen independent of their
692 body:
693 Major type: 7bit ok? Suggested encoding:
695 -----------------------------------------------------------
696 text yes 7bit
697 text no quoted-printable
698 message yes 7bit
699 message no binary
700 multipart * binary (in case some parts are bad)
701 image, etc... * base64
702 sync_headers OPTIONS
704 Instance method. This method does a variety of activities which
705 ensure that the MIME headers of an entity "tree" are in-synch with
706 the body parts they describe. It can be as expensive an operation
707 as printing if it involves pre-encoding the body parts; however,
708 the aim is to produce fairly clean MIME. You will usually only
709 need to invoke this if processing and re-sending MIME from an
710 outside source.
711 The OPTIONS is a hash, which describes what is to be done.
713 Length
715 One of the "official unofficial" MIME fields is "Content-
716 Length". Normally, one doesn't care a whit about this field;
717 however, if you are preparing output destined for HTTP, you
718 may. The value of this option dictates what will be done:
719 COMPUTE means to set a "Content-Length" field for every non-
721 multipart part in the entity, and to blank that field out for
722 every multipart part in the entity.
723 ERASE means that "Content-Length" fields will all be blanked
725 out. This is fast, painless, and safe.
726 Any false value (the default) means to take no action.
728 Nonstandard
730 Any header field beginning with "Content-" is, according to the
731 RFC, a MIME field. However, some are non-standard, and may
732 cause problems with certain MIME readers which interpret them
733 in different ways.
734 ERASE means that all such fields will be blanked out. This is
736 done before the Length option (q.v.) is examined and acted
737 upon.
738 Any false value (the default) means to take no action.
740 Returns a true value if everything went okay, a false value
742 otherwise.
743 tidy_body
745 Instance method, override. Currently unimplemented for MIME
746 messages. Does nothing, returns false.
747 Output
749 dump_skeleton [FILEHANDLE]
750 Instance method. Dump the skeleton of the entity to the given
751 FILEHANDLE, or to the currently-selected one if none given.
752 Each entity is output with an appropriate indentation level, the
754 following selection of attributes:
755 Content-type: multipart/mixed
757 Effective-type: multipart/mixed
758 Body-file: NONE
759 Subject: Hey there!
760 Num-parts: 2
761 This is really just useful for debugging purposes; I make no
763 guarantees about the consistency of the output format over time.
764 print [OUTSTREAM]
766 Instance method, override. Print the entity to the given
767 OUTSTREAM, or to the currently-selected filehandle if none given.
768 OUTSTREAM can be a filehandle, or any object that reponds to a
769 print() message.
770 The entity is output as a valid MIME stream! This means that the
772 header is always output first, and the body data (if any) will be
773 encoded if the header says that it should be. For example, your
774 output may look like this:
775 Subject: Greetings
777 Content-transfer-encoding: base64
778 SGkgdGhlcmUhCkJ5ZSB0aGVyZSEK
780 If this entity has MIME type "multipart/*", the preamble, parts,
782 and epilogue are all output with appropriate boundaries separating
783 each. Any bodyhandle is ignored:
784 Content-type: multipart/mixed; boundary="*----*"
786 Content-transfer-encoding: 7bit
787 [Preamble]
789 --*----*
790 [Entity: Part 0]
791 --*----*
792 [Entity: Part 1]
793 --*----*--
794 [Epilogue]
795 If this entity has a single-part MIME type with no attached parts,
797 then we're looking at a normal singlepart entity: the body is
798 output according to the encoding specified by the header. If no
799 body exists, a warning is output and the body is treated as empty:
800 Content-type: image/gif
802 Content-transfer-encoding: base64
803 [Encoded body]
805 If this entity has a single-part MIME type but it also has parts,
807 then we're probably looking at a "re-parsed" singlepart, usually
808 one of type "message/*" (you can get entities like this if you set
809 the "parse_nested_messages(NEST)" option on the parser to true).
810 In this case, the parts are output with single blank lines
811 separating each, and any bodyhandle is ignored:
812 Content-type: message/rfc822
814 Content-transfer-encoding: 7bit
815 [Entity: Part 0]
817 [Entity: Part 1]
819 In all cases, when outputting a "part" of the entity, this method
821 is invoked recursively.
822 Note: the output is very likely not going to be identical to any
824 input you parsed to get this entity. If you're building some sort
825 of email handler, it's up to you to save this information.
826 print_body [OUTSTREAM]
828 Instance method, override. Print the body of the entity to the
829 given OUTSTREAM, or to the currently-selected filehandle if none
830 given. OUTSTREAM can be a filehandle, or any object that reponds
831 to a print() message.
832 The body is output for inclusion in a valid MIME stream; this means
834 that the body data will be encoded if the header says that it
835 should be.
836 Note: by "body", we mean "the stuff following the header". A
838 printed multipart body includes the printed representations of its
839 subparts.
840 Note: The body is stored in an un-encoded form; however, the idea
842 is that the transfer encoding is used to determine how it should be
843 output. This means that the "print()" method is always guaranteed
844 to get you a sendmail-ready stream whose body is consistent with
845 its head. If you want the raw body data to be output, you can
846 either read it from the bodyhandle yourself, or use:
847 $ent->bodyhandle->print($outstream);
849 which uses read() calls to extract the information, and thus will
851 work with both text and binary bodies.
852 Warning: Please supply an OUTSTREAM. This override method differs
854 from Mail::Internet's behavior, which outputs to the STDOUT if no
855 filehandle is given: this may lead to confusion.
856 print_header [OUTSTREAM]
858 Instance method, inherited. Output the header to the given
859 OUTSTREAM. You really should supply the OUTSTREAM.
860 stringify
862 Instance method. Return the entity as a string, exactly as "print"
863 would print it. The body will be encoded as necessary, and will
864 contain any subparts. You can also use "as_string()".
865 stringify_body
867 Instance method. Return the encoded message body as a string,
868 exactly as "print_body" would print it. You can also use
869 "body_as_string()".
870 If you want the unencoded body, and you are dealing with a
872 singlepart message (like a "text/plain"), use "bodyhandle()"
873 instead:
874 if ($ent->bodyhandle) {
876 $unencoded_data = $ent->bodyhandle->as_string;
877 }
878 else {
879 ### this message has no body data (but it might have parts!)
880 }
881 stringify_header
883 Instance method. Return the header as a string, exactly as
884 "print_header" would print it. You can also use
885 "header_as_string()".
886
888 Under the hood
889 A MIME::Entity is composed of the following elements:
890 · A head, which is a reference to a MIME::Head object containing the
892 header information.
893 · A bodyhandle, which is a reference to a MIME::Body object
895 containing the decoded body data. This is only defined if the
896 message is a "singlepart" type:
897 application/*
899 audio/*
900 image/*
901 text/*
902 video/*
903 · An array of parts, where each part is a MIME::Entity object. The
905 number of parts will only be nonzero if the content-type is not one
906 of the "singlepart" types:
907 message/* (should have exactly one part)
909 multipart/* (should have one or more parts)
910 The "two-body problem"
912 MIME::Entity and Mail::Internet see message bodies differently, and
913 this can cause confusion and some inconvenience. Sadly, I can't change
914 the behavior of MIME::Entity without breaking lots of code already out
915 there. But let's open up the floor for a few questions...
916 What is the difference between a "message" and an "entity"?
918 A message is the actual data being sent or received; usually this
919 means a stream of newline-terminated lines. An entity is the
920 representation of a message as an object.
921 This means that you get a "message" when you print an "entity" to a
923 filehandle, and you get an "entity" when you parse a message from a
924 filehandle.
925 What is a message body?
927 Mail::Internet: The portion of the printed message after the
928 header.
929 MIME::Entity: The portion of the printed message after the header.
931 How is a message body stored in an entity?
933 Mail::Internet: As an array of lines.
934 MIME::Entity: It depends on the content-type of the message. For
936 "container" types ("multipart/*", "message/*"), we store the
937 contained entities as an array of "parts", accessed via the
938 "parts()" method, where each part is a complete MIME::Entity. For
939 "singlepart" types ("text/*", "image/*", etc.), the unencoded body
940 data is referenced via a MIME::Body object, accessed via the
941 "bodyhandle()" method:
942 bodyhandle() parts()
944 Content-type: returns: returns:
945 ------------------------------------------------------------
946 application/* MIME::Body empty
947 audio/* MIME::Body empty
948 image/* MIME::Body empty
949 message/* undef MIME::Entity list (usually 1)
950 multipart/* undef MIME::Entity list (usually >0)
951 text/* MIME::Body empty
952 video/* MIME::Body empty
953 x-*/* MIME::Body empty
954 As a special case, "message/*" is currently ambiguous: depending on
956 the parser, a "message/*" might be treated as a singlepart, with a
957 MIME::Body and no parts. Use bodyhandle() as the final arbiter.
958 What does the body() method return?
960 Mail::Internet: As an array of lines, ready for sending.
961 MIME::Entity: As an array of lines, ready for sending.
963 What's the best way to get at the body data?
965 Mail::Internet: Use the body() method.
966 MIME::Entity: Depends on what you want... the encoded data (as it
968 is transported), or the unencoded data? Keep reading...
969 How do I get the "encoded" body data?
971 Mail::Internet: Use the body() method.
972 MIME::Entity: Use the body() method. You can also use:
974 $entity->print_body()
976 $entity->stringify_body() ### a.k.a. $entity->body_as_string()
977 How do I get the "unencoded" body data?
979 Mail::Internet: Use the body() method.
980 MIME::Entity: Use the bodyhandle() method! If bodyhandle() method
982 returns true, then that value is a MIME::Body which can be used to
983 access the data via its open() method. If bodyhandle() method
984 returns an undefined value, then the entity is probably a
985 "container" that has no real body data of its own (e.g., a
986 "multipart" message): in this case, you should access the
987 components via the parts() method. Like this:
988 if ($bh = $entity->bodyhandle) {
990 $io = $bh->open;
991 ...access unencoded data via $io->getline or $io->read...
992 $io->close;
993 }
994 else {
995 foreach my $part (@parts) {
996 ...do something with the part...
997 }
998 }
999 You can also use:
1001 if ($bh = $entity->bodyhandle) {
1003 $unencoded_data = $bh->as_string;
1004 }
1005 else {
1006 ...do stuff with the parts...
1007 }
1008 What does the body() method return?
1010 Mail::Internet: The transport-encoded message body, as an array of
1011 lines.
1012 MIME::Entity: The transport-encoded message body, as an array of
1014 lines.
1015 What does print_body() print?
1017 Mail::Internet: Exactly what body() would return to you.
1018 MIME::Entity: Exactly what body() would return to you.
1020 Say I have an entity which might be either singlepart or multipart. How
1022 do I print out just "the stuff after the header"?
1023 Mail::Internet: Use print_body().
1024 MIME::Entity: Use print_body().
1026 Why is MIME::Entity so different from Mail::Internet?
1028 Because MIME streams are expected to have non-textual data...
1029 possibly, quite a lot of it, such as a tar file.
1030 Because MIME messages can consist of multiple parts, which are
1032 most-easily manipulated as MIME::Entity objects themselves.
1033 Because in the simpler world of Mail::Internet, the data of a
1035 message and its printed representation are identical... and in the
1036 MIME world, they're not.
1037 Because parsing multipart bodies on-the-fly, or formatting
1039 multipart bodies for output, is a non-trivial task.
1040 This is confusing. Can the two classes be made more compatible?
1042 Not easily; their implementations are necessarily quite different.
1043 Mail::Internet is a simple, efficient way of dealing with a "black
1044 box" mail message... one whose internal data you don't care much
1045 about. MIME::Entity, in contrast, cares very much about the
1046 message contents: that's its job!
1047 Design issues
1049 Some things just can't be ignored
1050 In multipart messages, the "preamble" is the portion that precedes
1051 the first encapsulation boundary, and the "epilogue" is the portion
1052 that follows the last encapsulation boundary.
1053 According to RFC 2046:
1055 There appears to be room for additional information prior
1057 to the first encapsulation boundary and following the final
1058 boundary. These areas should generally be left blank, and
1059 implementations must ignore anything that appears before the
1060 first boundary or after the last one.
1061 NOTE: These "preamble" and "epilogue" areas are generally
1063 not used because of the lack of proper typing of these parts
1064 and the lack of clear semantics for handling these areas at
1065 gateways, particularly X.400 gateways. However, rather than
1066 leaving the preamble area blank, many MIME implementations
1067 have found this to be a convenient place to insert an
1068 explanatory note for recipients who read the message with
1069 pre-MIME software, since such notes will be ignored by
1070 MIME-compliant software.
1071 In the world of standards-and-practices, that's the standard. Now
1073 for the practice:
1074 Some "MIME" mailers may incorrectly put a "part" in the preamble.
1076 Since we have to parse over the stuff anyway, in the future I may
1077 allow the parser option of creating special MIME::Entity objects
1078 for the preamble and epilogue, with bogus MIME::Head objects.
1079 For now, though, we're MIME-compliant, so I probably won't change
1081 how we work.
1082
1084 MIME::Tools, MIME::Head, MIME::Body, MIME::Decoder, Mail::Internet
1085
1087 Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com).
1088 David F. Skoll (dfs@roaringpenguin.com) http://www.roaringpenguin.com
1089 All rights reserved. This program is free software; you can
1091 redistribute it and/or modify it under the same terms as Perl itself.
1092perl v5.12.0 2010-04-22 MIME::Entity(3)