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 If you set the variable $MIME::Entity::BOUNDARY_DELIMITER to a string,
186 that string will be used as the line-end delimiter on output. If it is
187 not set, the line ending will be a newline character (\n)
188 NOTE that $MIME::Entity::BOUNDARY_DELIMITER only applies to structural
190 parts of the MIME data generated by this package and to the Base64
191 encoded output; if a part internally uses a different line-end
192 delimiter and is output as-is, the line-ending is not changed to match
193 $MIME::Entity::BOUNDARY_DELIMITER.
194 ### Stringify the entire message:
196 print $top->stringify; ### or $top->as_string
197 ### Stringify just the header:
199 print $top->stringify_header; ### or $top->header_as_string
200 ### Stringify just the (encoded) body... includes parts as well!
202 print $top->stringify_body; ### or $top->body_as_string
203 Debug:
205 ### Output debugging info:
207 $entity->dump_skeleton(\*STDERR);
208
210 Construction
211 new [SOURCE]
212 Class method. Create a new, empty MIME entity. Basically, this
213 uses the Mail::Internet constructor...
214 If SOURCE is an ARRAYREF, it is assumed to be an array of lines
216 that will be used to create both the header and an in-core body.
217 Else, if SOURCE is defined, it is assumed to be a filehandle from
219 which the header and in-core body is to be read.
220 Note: in either case, the body will not be parsed: merely read!
222 add_part ENTITY, [OFFSET]
224 Instance method. Assuming we are a multipart message, add a body
225 part (a MIME::Entity) to the array of body parts. Returns the part
226 that was just added.
227 If OFFSET is positive, the new part is added at that offset from
229 the beginning of the array of parts. If it is negative, it counts
230 from the end of the array. (An INDEX of -1 will place the new part
231 at the very end of the array, -2 will place it as the penultimate
232 item in the array, etc.) If OFFSET is not given, the new part is
233 added to the end of the array. Thanks to Jason L Tibbitts III for
234 providing support for OFFSET.
235 Warning: in general, you only want to attach parts to entities with
237 a content-type of "multipart/*").
238 attach PARAMHASH
240 Instance method. The real quick-and-easy way to create multipart
241 messages. The PARAMHASH is used to "build" a new entity; this
242 method is basically equivalent to:
243 $entity->add_part(ref($entity)->build(PARAMHASH, Top=>0));
245 Note: normally, you attach to multipart entities; however, if you
247 attach something to a singlepart (like attaching a GIF to a text
248 message), the singlepart will be coerced into a multipart
249 automatically.
250 build PARAMHASH
252 Class/instance method. A quick-and-easy catch-all way to create an
253 entity. Use it like this to build a "normal" single-part entity:
254 $ent = MIME::Entity->build(Type => "image/gif",
256 Encoding => "base64",
257 Path => "/path/to/xyz12345.gif",
258 Filename => "saveme.gif",
259 Disposition => "attachment");
260 And like this to build a "multipart" entity:
262 $ent = MIME::Entity->build(Type => "multipart/mixed",
264 Boundary => "---1234567");
265 A minimal MIME header will be created. If you want to add or
267 modify any header fields afterwards, you can of course do so via
268 the underlying head object... but hey, there's now a prettier
269 syntax!
270 $ent = MIME::Entity->build(Type =>"multipart/mixed",
272 From => $myaddr,
273 Subject => "Hi!",
274 'X-Certified' => ['SINED',
275 'SEELED',
276 'DELIVERED']);
277 Normally, an "X-Mailer" header field is output which contains this
279 toolkit's name and version (plus this module's RCS version). This
280 will allow any bad MIME we generate to be traced back to us. You
281 can of course overwrite that header with your own:
282 $ent = MIME::Entity->build(Type => "multipart/mixed",
284 'X-Mailer' => "myprog 1.1");
285 Or remove it entirely:
287 $ent = MIME::Entity->build(Type => "multipart/mixed",
289 'X-Mailer' => undef);
290 OK, enough hype. The parameters are:
292 (FIELDNAME)
294 Any field you want placed in the message header, taken from the
295 standard list of header fields (you don't need to worry about
296 case):
297 Bcc Encrypted Received Sender
299 Cc From References Subject
300 Comments Keywords Reply-To To
301 Content-* Message-ID Resent-* X-*
302 Date MIME-Version Return-Path
303 Organization
304 To give experienced users some veto power, these fields will be
306 set after the ones I set... so be careful: don't set any MIME
307 fields (like "Content-type") unless you know what you're doing!
308 To specify a fieldname that's not in the above list, even one
310 that's identical to an option below, just give it with a
311 trailing ":", like "My-field:". When in doubt, that always
312 signals a mail field (and it sort of looks like one too).
313 Boundary
315 Multipart entities only. Optional. The boundary string. As
316 per RFC-2046, it must consist only of the characters
317 "[0-9a-zA-Z'()+_,-./:=?]" and space (you'll be warned, and your
318 boundary will be ignored, if this is not the case). If you
319 omit this, a random string will be chosen... which is probably
320 safer.
321 Charset
323 Optional. The character set.
324 Data
326 Single-part entities only. Optional. An alternative to Path
327 (q.v.): the actual data, either as a scalar or an array
328 reference (whose elements are joined together to make the
329 actual scalar). The body is opened on the data using
330 MIME::Body::InCore.
331 Note that for text parts, the Data scalar or array is assumed
333 to be encoded in a suitable character encoding (as if by
334 "Encode::encode") rather than a native Perl string. The
335 encoding you use must, of course, match the "charset" option of
336 the "MIME-Type" header.
337 Description
339 Optional. The text of the content-description. If you don't
340 specify it, the field is not put in the header.
341 Disposition
343 Optional. The basic content-disposition ("attachment" or
344 "inline"). If you don't specify it, it defaults to "inline"
345 for backwards compatibility. Thanks to Kurt Freytag for
346 suggesting this feature.
347 Encoding
349 Optional. The content-transfer-encoding. If you don't specify
350 it, a reasonable default is put in. You can also give the
351 special value '-SUGGEST', to have it chosen for you in a heavy-
352 duty fashion which scans the data itself.
353 Filename
355 Single-part entities only. Optional. The recommended filename.
356 Overrides any name extracted from "Path". The information is
357 stored both the deprecated (content-type) and preferred
358 (content-disposition) locations. If you explicitly want to
359 avoid a recommended filename (even when Path is used), supply
360 this as empty or undef.
361 Id Optional. Set the content-id.
363 Path
365 Single-part entities only. Optional. The path to the file to
366 attach. The body is opened on that file using
367 MIME::Body::File.
368 Top Optional. Is this a top-level entity? If so, it must sport a
370 MIME-Version. The default is true. (NB: look at how
371 "attach()" uses it.)
372 Type
374 Optional. The basic content-type ("text/plain", etc.). If you
375 don't specify it, it defaults to "text/plain" as per RFC 2045.
376 Do yourself a favor: put it in.
377 dup Instance method. Duplicate the entity. Does a deep, recursive
379 copy, but beware: external data in bodyhandles is not copied to new
380 files! Changing the data in one entity's data file, or purging
381 that entity, will affect its duplicate. Entities with in-core data
382 probably need not worry.
383 Access
385 body [VALUE]
386 Instance method. Get the encoded (transport-ready) body, as an
387 array of lines. Returns an array reference. Each array entry is a
388 newline-terminated line.
389 This is a read-only data structure: changing its contents will have
391 no effect. Its contents are identical to what is printed by
392 print_body().
393 Provided for compatibility with Mail::Internet, so that methods
395 like "smtpsend()" will work. Note however that if VALUE is given,
396 a fatal exception is thrown, since you cannot use this method to
397 set the lines of the encoded message.
398 If you want the raw (unencoded) body data, use the bodyhandle()
400 method to get and use a MIME::Body. The content-type of the entity
401 will tell you whether that body is best read as text (via
402 getline()) or raw data (via read()).
403 bodyhandle [VALUE]
405 Instance method. Get or set an abstract object representing the
406 body of the message. The body holds the decoded message data.
407 Note that not all entities have bodies! An entity will have either
409 a body or parts: not both. This method will only return an object
410 if this entity can have a body; otherwise, it will return
411 undefined. Whether-or-not a given entity can have a body is
412 determined by (1) its content type, and (2) whether-or-not the
413 parser was told to extract nested messages:
414 Type: | Extract nested? | bodyhandle() | parts()
416 -----------------------------------------------------------------------
417 multipart/* | - | undef | 0 or more MIME::Entity
418 message/* | true | undef | 0 or 1 MIME::Entity
419 message/* | false | MIME::Body | empty list
420 (other) | - | MIME::Body | empty list
421 If "VALUE" is not given, the current bodyhandle is returned, or
423 undef if the entity cannot have a body.
424 If "VALUE" is given, the bodyhandle is set to the new value, and
426 the previous value is returned.
427 See "parts" for more info.
429 effective_type [MIMETYPE]
431 Instance method. Set/get the effective MIME type of this entity.
432 This is usually identical to the actual (or defaulted) MIME type,
433 but in some cases it differs. For example, from RFC-2045:
434 Any entity with an unrecognized Content-Transfer-Encoding must be
436 treated as if it has a Content-Type of "application/octet-stream",
437 regardless of what the Content-Type header field actually says.
438 Why? because if we can't decode the message, then we have to take
440 the bytes as-is, in their (unrecognized) encoded form. So the
441 message ceases to be a "text/foobar" and becomes a bunch of
442 undecipherable bytes -- in other words, an
443 "application/octet-stream".
444 Such an entity, if parsed, would have its effective_type() set to
446 "application/octet_stream", although the mime_type() and the
447 contents of the header would remain the same.
448 If there is no effective type, the method just returns what
450 mime_type() would.
451 Warning: the effective type is "sticky"; once set, that
453 effective_type() will always be returned even if the conditions
454 that necessitated setting the effective type become no longer true.
455 epilogue [LINES]
457 Instance method. Get/set the text of the epilogue, as an array of
458 newline-terminated LINES. Returns a reference to the array of
459 lines, or undef if no epilogue exists.
460 If there is a epilogue, it is output when printing this entity;
462 otherwise, a default epilogue is used. Setting the epilogue to
463 undef (not []!) causes it to fallback to the default.
464 head [VALUE]
466 Instance method. Get/set the head.
467 If there is no VALUE given, returns the current head. If none
469 exists, an empty instance of MIME::Head is created, set, and
470 returned.
471 Note: This is a patch over a problem in Mail::Internet, which
473 doesn't provide a method for setting the head to some given object.
474 is_multipart
476 Instance method. Does this entity's effective MIME type indicate
477 that it's a multipart entity? Returns undef (false) if the answer
478 couldn't be determined, 0 (false) if it was determined to be false,
479 and true otherwise. Note that this says nothing about whether or
480 not parts were extracted.
481 NOTE: we switched to effective_type so that multiparts with bad or
483 missing boundaries could be coerced to an effective type of
484 "application/x-unparseable-multipart".
485 mime_type
487 Instance method. A purely-for-convenience method. This simply
488 relays the request to the associated MIME::Head object. If there
489 is no head, returns undef in a scalar context and the empty array
490 in a list context.
491 Before you use this, consider using effective_type() instead,
493 especially if you obtained the entity from a MIME::Parser.
494 open READWRITE
496 Instance method. A purely-for-convenience method. This simply
497 relays the request to the associated MIME::Body object (see
498 MIME::Body::open()). READWRITE is either 'r' (open for read) or
499 'w' (open for write).
500 If there is no body, returns false.
502 parts
504 parts INDEX
505 parts ARRAYREF
506 Instance method. Return the MIME::Entity objects which are the sub
507 parts of this entity (if any).
508 If no argument is given, returns the array of all sub parts,
510 returning the empty array if there are none (e.g., if this is a
511 single part message, or a degenerate multipart). In a scalar
512 context, this returns you the number of parts.
513 If an integer INDEX is given, return the INDEXed part, or undef if
515 it doesn't exist.
516 If an ARRAYREF to an array of parts is given, then this method sets
518 the parts to a copy of that array, and returns the parts. This can
519 be used to delete parts, as follows:
520 ### Delete some parts of a multipart message:
522 $msg->parts([ grep { keep_part($_) } $msg->parts ]);
523 Note: for multipart messages, the preamble and epilogue are not
525 considered parts. If you need them, use the "preamble()" and
526 "epilogue()" methods.
527 Note: there are ways of parsing with a MIME::Parser which cause
529 certain message parts (such as those of type "message/rfc822") to
530 be "reparsed" into pseudo-multipart entities. You should read the
531 documentation for those options carefully: it is possible for a
532 diddled entity to not be multipart, but still have parts attached
533 to it!
534 See "bodyhandle" for a discussion of parts vs. bodies.
536 parts_DFS
538 Instance method. Return the list of all MIME::Entity objects
539 included in the entity, starting with the entity itself, in depth-
540 first-search order. If the entity has no parts, it alone will be
541 returned.
542 Thanks to Xavier Armengou for suggesting this method.
544 preamble [LINES]
546 Instance method. Get/set the text of the preamble, as an array of
547 newline-terminated LINES. Returns a reference to the array of
548 lines, or undef if no preamble exists (e.g., if this is a single-
549 part entity).
550 If there is a preamble, it is output when printing this entity;
552 otherwise, a default preamble is used. Setting the preamble to
553 undef (not []!) causes it to fallback to the default.
554 Manipulation
556 make_multipart [SUBTYPE], OPTSHASH...
557 Instance method. Force the entity to be a multipart, if it isn't
558 already. We do this by replacing the original [singlepart] entity
559 with a new multipart that has the same non-MIME headers ("From",
560 "Subject", etc.), but all-new MIME headers ("Content-type", etc.).
561 We then create a copy of the original singlepart, strip out the
562 non-MIME headers from that, and make it a part of the new
563 multipart. So this:
564 From: me
566 To: you
567 Content-type: text/plain
568 Content-length: 12
569 Hello there!
571 Becomes something like this:
573 From: me
575 To: you
576 Content-type: multipart/mixed; boundary="----abc----"
577 ------abc----
579 Content-type: text/plain
580 Content-length: 12
581 Hello there!
583 ------abc------
584 The actual type of the new top-level multipart will be
586 "multipart/SUBTYPE" (default SUBTYPE is "mixed").
587 Returns 'DONE' if we really did inflate a singlepart to a
589 multipart. Returns 'ALREADY' (and does nothing) if entity is
590 already multipart and Force was not chosen.
591 If OPTSHASH contains Force=>1, then we always bump the top-level's
593 content and content-headers down to a subpart of this entity, even
594 if this entity is already a multipart. This is apparently of use
595 to people who are tweaking messages after parsing them.
596 make_singlepart
598 Instance method. If the entity is a multipart message with one
599 part, this tries hard to rewrite it as a singlepart, by replacing
600 the content (and content headers) of the top level with those of
601 the part. Also crunches 0-part multiparts into singleparts.
602 Returns 'DONE' if we really did collapse a multipart to a
604 singlepart. Returns 'ALREADY' (and does nothing) if entity is
605 already a singlepart. Returns '0' (and does nothing) if it
606 can't be made into a singlepart.
607 purge
609 Instance method. Recursively purge (e.g., unlink) all external
610 (e.g., on-disk) body parts in this message. See
611 MIME::Body::purge() for details.
612 Note: this does not delete the directories that those body parts
614 are contained in; only the actual message data files are deleted.
615 This is because some parsers may be customized to create
616 intermediate directories while others are not, and it's impossible
617 for this class to know what directories are safe to remove. Only
618 your application program truly knows that.
619 If you really want to "clean everything up", one good way is to use
621 "MIME::Parser::file_under()", and then do this before parsing your
622 next message:
623 $parser->filer->purge();
625 I wouldn't attempt to read those body files after you do this, for
627 obvious reasons. As of MIME-tools 4.x, each body's path is
628 undefined after this operation. I warned you I might do this;
629 truly I did.
630 Thanks to Jason L. Tibbitts III for suggesting this method.
632 remove_sig [NLINES]
634 Instance method, override. Attempts to remove a user's signature
635 from the body of a message.
636 It does this by looking for a line matching "/^-- $/" within the
638 last "NLINES" of the message. If found then that line and all
639 lines after it will be removed. If "NLINES" is not given, a default
640 value of 10 will be used. This would be of most use in auto-reply
641 scripts.
642 For MIME entity, this method is reasonably cautious: it will only
644 attempt to un-sign a message with a content-type of "text/*".
645 If you send remove_sig() to a multipart entity, it will relay it to
647 the first part (the others usually being the "attachments").
648 Warning: currently slurps the whole message-part into core as an
650 array of lines, so you probably don't want to use this on extremely
651 long messages.
652 Returns truth on success, false on error.
654 sign PARAMHASH
656 Instance method, override. Append a signature to the message. The
657 params are:
658 Attach
660 Instead of appending the text, add it to the message as an
661 attachment. The disposition will be "inline", and the
662 description will indicate that it is a signature. The default
663 behavior is to append the signature to the text of the message
664 (or the text of its first part if multipart). MIME-specific;
665 new in this subclass.
666 File
668 Use the contents of this file as the signature. Fatal error if
669 it can't be read. As per superclass method.
670 Force
672 Sign it even if the content-type isn't "text/*". Useful for
673 non-standard types like "x-foobar", but be careful! MIME-
674 specific; new in this subclass.
675 Remove
677 Normally, we attempt to strip out any existing signature. If
678 true, this gives us the NLINES parameter of the remove_sig
679 call. If zero but defined, tells us not to remove any existing
680 signature. If undefined, removal is done with the default of
681 10 lines. New in this subclass.
682 Signature
684 Use this text as the signature. You can supply it as either a
685 scalar, or as a ref to an array of newline-terminated scalars.
686 As per superclass method.
687 For MIME messages, this method is reasonably cautious: it will only
689 attempt to sign a message with a content-type of "text/*", unless
690 "Force" is specified.
691 If you send this message to a multipart entity, it will relay it to
693 the first part (the others usually being the "attachments").
694 Warning: currently slurps the whole message-part into core as an
696 array of lines, so you probably don't want to use this on extremely
697 long messages.
698 Returns true on success, false otherwise.
700 suggest_encoding
702 Instance method. Based on the effective content type, return a
703 good suggested encoding.
704 "text" and "message" types have their bodies scanned line-by-line
706 for 8-bit characters and long lines; lack of either means that the
707 message is 7bit-ok. Other types are chosen independent of their
708 body:
709 Major type: 7bit ok? Suggested encoding:
711 -----------------------------------------------------------
712 text yes 7bit
713 text no quoted-printable
714 message yes 7bit
715 message no binary
716 multipart * binary (in case some parts are bad)
717 image, etc... * base64
718 sync_headers OPTIONS
720 Instance method. This method does a variety of activities which
721 ensure that the MIME headers of an entity "tree" are in-synch with
722 the body parts they describe. It can be as expensive an operation
723 as printing if it involves pre-encoding the body parts; however,
724 the aim is to produce fairly clean MIME. You will usually only
725 need to invoke this if processing and re-sending MIME from an
726 outside source.
727 The OPTIONS is a hash, which describes what is to be done.
729 Length
731 One of the "official unofficial" MIME fields is "Content-
732 Length". Normally, one doesn't care a whit about this field;
733 however, if you are preparing output destined for HTTP, you
734 may. The value of this option dictates what will be done:
735 COMPUTE means to set a "Content-Length" field for every non-
737 multipart part in the entity, and to blank that field out for
738 every multipart part in the entity.
739 ERASE means that "Content-Length" fields will all be blanked
741 out. This is fast, painless, and safe.
742 Any false value (the default) means to take no action.
744 Nonstandard
746 Any header field beginning with "Content-" is, according to the
747 RFC, a MIME field. However, some are non-standard, and may
748 cause problems with certain MIME readers which interpret them
749 in different ways.
750 ERASE means that all such fields will be blanked out. This is
752 done before the Length option (q.v.) is examined and acted
753 upon.
754 Any false value (the default) means to take no action.
756 Returns a true value if everything went okay, a false value
758 otherwise.
759 tidy_body
761 Instance method, override. Currently unimplemented for MIME
762 messages. Does nothing, returns false.
763 Output
765 dump_skeleton [FILEHANDLE]
766 Instance method. Dump the skeleton of the entity to the given
767 FILEHANDLE, or to the currently-selected one if none given.
768 Each entity is output with an appropriate indentation level, the
770 following selection of attributes:
771 Content-type: multipart/mixed
773 Effective-type: multipart/mixed
774 Body-file: NONE
775 Subject: Hey there!
776 Num-parts: 2
777 This is really just useful for debugging purposes; I make no
779 guarantees about the consistency of the output format over time.
780 print [OUTSTREAM]
782 Instance method, override. Print the entity to the given
783 OUTSTREAM, or to the currently-selected filehandle if none given.
784 OUTSTREAM can be a filehandle, or any object that responds to a
785 print() message.
786 The entity is output as a valid MIME stream! This means that the
788 header is always output first, and the body data (if any) will be
789 encoded if the header says that it should be. For example, your
790 output may look like this:
791 Subject: Greetings
793 Content-transfer-encoding: base64
794 SGkgdGhlcmUhCkJ5ZSB0aGVyZSEK
796 If this entity has MIME type "multipart/*", the preamble, parts,
798 and epilogue are all output with appropriate boundaries separating
799 each. Any bodyhandle is ignored:
800 Content-type: multipart/mixed; boundary="*----*"
802 Content-transfer-encoding: 7bit
803 [Preamble]
805 --*----*
806 [Entity: Part 0]
807 --*----*
808 [Entity: Part 1]
809 --*----*--
810 [Epilogue]
811 If this entity has a single-part MIME type with no attached parts,
813 then we're looking at a normal singlepart entity: the body is
814 output according to the encoding specified by the header. If no
815 body exists, a warning is output and the body is treated as empty:
816 Content-type: image/gif
818 Content-transfer-encoding: base64
819 [Encoded body]
821 If this entity has a single-part MIME type but it also has parts,
823 then we're probably looking at a "re-parsed" singlepart, usually
824 one of type "message/*" (you can get entities like this if you set
825 the "parse_nested_messages(NEST)" option on the parser to true).
826 In this case, the parts are output with single blank lines
827 separating each, and any bodyhandle is ignored:
828 Content-type: message/rfc822
830 Content-transfer-encoding: 7bit
831 [Entity: Part 0]
833 [Entity: Part 1]
835 In all cases, when outputting a "part" of the entity, this method
837 is invoked recursively.
838 Note: the output is very likely not going to be identical to any
840 input you parsed to get this entity. If you're building some sort
841 of email handler, it's up to you to save this information.
842 print_body [OUTSTREAM]
844 Instance method, override. Print the body of the entity to the
845 given OUTSTREAM, or to the currently-selected filehandle if none
846 given. OUTSTREAM can be a filehandle, or any object that responds
847 to a print() message.
848 The body is output for inclusion in a valid MIME stream; this means
850 that the body data will be encoded if the header says that it
851 should be.
852 Note: by "body", we mean "the stuff following the header". A
854 printed multipart body includes the printed representations of its
855 subparts.
856 Note: The body is stored in an un-encoded form; however, the idea
858 is that the transfer encoding is used to determine how it should be
859 output. This means that the "print()" method is always guaranteed
860 to get you a sendmail-ready stream whose body is consistent with
861 its head. If you want the raw body data to be output, you can
862 either read it from the bodyhandle yourself, or use:
863 $ent->bodyhandle->print($outstream);
865 which uses read() calls to extract the information, and thus will
867 work with both text and binary bodies.
868 Warning: Please supply an OUTSTREAM. This override method differs
870 from Mail::Internet's behavior, which outputs to the STDOUT if no
871 filehandle is given: this may lead to confusion.
872 print_header [OUTSTREAM]
874 Instance method, inherited. Output the header to the given
875 OUTSTREAM. You really should supply the OUTSTREAM.
876 stringify
878 Instance method. Return the entity as a string, exactly as "print"
879 would print it. The body will be encoded as necessary, and will
880 contain any subparts. You can also use "as_string()".
881 stringify_body
883 Instance method. Return the encoded message body as a string,
884 exactly as "print_body" would print it. You can also use
885 "body_as_string()".
886 If you want the unencoded body, and you are dealing with a
888 singlepart message (like a "text/plain"), use "bodyhandle()"
889 instead:
890 if ($ent->bodyhandle) {
892 $unencoded_data = $ent->bodyhandle->as_string;
893 }
894 else {
895 ### this message has no body data (but it might have parts!)
896 }
897 stringify_header
899 Instance method. Return the header as a string, exactly as
900 "print_header" would print it. You can also use
901 "header_as_string()".
902
904 Under the hood
905 A MIME::Entity is composed of the following elements:
906 • A head, which is a reference to a MIME::Head object containing the
908 header information.
909 • A bodyhandle, which is a reference to a MIME::Body object
911 containing the decoded body data. This is only defined if the
912 message is a "singlepart" type:
913 application/*
915 audio/*
916 image/*
917 text/*
918 video/*
919 • An array of parts, where each part is a MIME::Entity object. The
921 number of parts will only be nonzero if the content-type is not one
922 of the "singlepart" types:
923 message/* (should have exactly one part)
925 multipart/* (should have one or more parts)
926 The "two-body problem"
928 MIME::Entity and Mail::Internet see message bodies differently, and
929 this can cause confusion and some inconvenience. Sadly, I can't change
930 the behavior of MIME::Entity without breaking lots of code already out
931 there. But let's open up the floor for a few questions...
932 What is the difference between a "message" and an "entity"?
934 A message is the actual data being sent or received; usually this
935 means a stream of newline-terminated lines. An entity is the
936 representation of a message as an object.
937 This means that you get a "message" when you print an "entity" to a
939 filehandle, and you get an "entity" when you parse a message from a
940 filehandle.
941 What is a message body?
943 Mail::Internet: The portion of the printed message after the
944 header.
945 MIME::Entity: The portion of the printed message after the header.
947 How is a message body stored in an entity?
949 Mail::Internet: As an array of lines.
950 MIME::Entity: It depends on the content-type of the message. For
952 "container" types ("multipart/*", "message/*"), we store the
953 contained entities as an array of "parts", accessed via the
954 "parts()" method, where each part is a complete MIME::Entity. For
955 "singlepart" types ("text/*", "image/*", etc.), the unencoded body
956 data is referenced via a MIME::Body object, accessed via the
957 "bodyhandle()" method:
958 bodyhandle() parts()
960 Content-type: returns: returns:
961 ------------------------------------------------------------
962 application/* MIME::Body empty
963 audio/* MIME::Body empty
964 image/* MIME::Body empty
965 message/* undef MIME::Entity list (usually 1)
966 multipart/* undef MIME::Entity list (usually >0)
967 text/* MIME::Body empty
968 video/* MIME::Body empty
969 x-*/* MIME::Body empty
970 As a special case, "message/*" is currently ambiguous: depending on
972 the parser, a "message/*" might be treated as a singlepart, with a
973 MIME::Body and no parts. Use bodyhandle() as the final arbiter.
974 What does the body() method return?
976 Mail::Internet: As an array of lines, ready for sending.
977 MIME::Entity: As an array of lines, ready for sending.
979 What's the best way to get at the body data?
981 Mail::Internet: Use the body() method.
982 MIME::Entity: Depends on what you want... the encoded data (as it
984 is transported), or the unencoded data? Keep reading...
985 How do I get the "encoded" body data?
987 Mail::Internet: Use the body() method.
988 MIME::Entity: Use the body() method. You can also use:
990 $entity->print_body()
992 $entity->stringify_body() ### a.k.a. $entity->body_as_string()
993 How do I get the "unencoded" body data?
995 Mail::Internet: Use the body() method.
996 MIME::Entity: Use the bodyhandle() method! If bodyhandle() method
998 returns true, then that value is a MIME::Body which can be used to
999 access the data via its open() method. If bodyhandle() method
1000 returns an undefined value, then the entity is probably a
1001 "container" that has no real body data of its own (e.g., a
1002 "multipart" message): in this case, you should access the
1003 components via the parts() method. Like this:
1004 if ($bh = $entity->bodyhandle) {
1006 $io = $bh->open;
1007 ...access unencoded data via $io->getline or $io->read...
1008 $io->close;
1009 }
1010 else {
1011 foreach my $part (@parts) {
1012 ...do something with the part...
1013 }
1014 }
1015 You can also use:
1017 if ($bh = $entity->bodyhandle) {
1019 $unencoded_data = $bh->as_string;
1020 }
1021 else {
1022 ...do stuff with the parts...
1023 }
1024 What does the body() method return?
1026 Mail::Internet: The transport-encoded message body, as an array of
1027 lines.
1028 MIME::Entity: The transport-encoded message body, as an array of
1030 lines.
1031 What does print_body() print?
1033 Mail::Internet: Exactly what body() would return to you.
1034 MIME::Entity: Exactly what body() would return to you.
1036 Say I have an entity which might be either singlepart or multipart. How
1038 do I print out just "the stuff after the header"?
1039 Mail::Internet: Use print_body().
1040 MIME::Entity: Use print_body().
1042 Why is MIME::Entity so different from Mail::Internet?
1044 Because MIME streams are expected to have non-textual data...
1045 possibly, quite a lot of it, such as a tar file.
1046 Because MIME messages can consist of multiple parts, which are
1048 most-easily manipulated as MIME::Entity objects themselves.
1049 Because in the simpler world of Mail::Internet, the data of a
1051 message and its printed representation are identical... and in the
1052 MIME world, they're not.
1053 Because parsing multipart bodies on-the-fly, or formatting
1055 multipart bodies for output, is a non-trivial task.
1056 This is confusing. Can the two classes be made more compatible?
1058 Not easily; their implementations are necessarily quite different.
1059 Mail::Internet is a simple, efficient way of dealing with a "black
1060 box" mail message... one whose internal data you don't care much
1061 about. MIME::Entity, in contrast, cares very much about the
1062 message contents: that's its job!
1063 Design issues
1065 Some things just can't be ignored
1066 In multipart messages, the "preamble" is the portion that precedes
1067 the first encapsulation boundary, and the "epilogue" is the portion
1068 that follows the last encapsulation boundary.
1069 According to RFC 2046:
1071 There appears to be room for additional information prior
1073 to the first encapsulation boundary and following the final
1074 boundary. These areas should generally be left blank, and
1075 implementations must ignore anything that appears before the
1076 first boundary or after the last one.
1077 NOTE: These "preamble" and "epilogue" areas are generally
1079 not used because of the lack of proper typing of these parts
1080 and the lack of clear semantics for handling these areas at
1081 gateways, particularly X.400 gateways. However, rather than
1082 leaving the preamble area blank, many MIME implementations
1083 have found this to be a convenient place to insert an
1084 explanatory note for recipients who read the message with
1085 pre-MIME software, since such notes will be ignored by
1086 MIME-compliant software.
1087 In the world of standards-and-practices, that's the standard. Now
1089 for the practice:
1090 Some "MIME" mailers may incorrectly put a "part" in the preamble.
1092 Since we have to parse over the stuff anyway, in the future I may
1093 allow the parser option of creating special MIME::Entity objects
1094 for the preamble and epilogue, with bogus MIME::Head objects.
1095 For now, though, we're MIME-compliant, so I probably won't change
1097 how we work.
1098
1100 MIME::Tools, MIME::Head, MIME::Body, MIME::Decoder, Mail::Internet
1101
1103 Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com).
1104 Dianne Skoll (dianne@skoll.ca)
1105 All rights reserved. This program is free software; you can
1107 redistribute it and/or modify it under the same terms as Perl itself.
1108perl v5.36.0 2022-07-22 MIME::Entity(3)