1Mail::Box(3)          User Contributed Perl Documentation         Mail::Box(3)
2
3
4

NAME

6       Mail::Box - manage a mailbox, a folder with messages
7

INHERITANCE

9        Mail::Box
10          is a Mail::Reporter
11
12        Mail::Box is extended by
13          Mail::Box::Dir
14          Mail::Box::File
15          Mail::Box::Net
16

SYNOPSIS

18        use Mail::Box::Manager;
19        my $mgr    = Mail::Box::Manager->new;
20        my $folder = $mgr->open(folder => $ENV{MAIL}, ...);
21        print $folder->name;
22
23        # Get the first message.
24        print $folder->message(0);
25
26        # Delete the third message
27        $folder->message(3)->delete;
28
29        # Get the number of messages in scalar context.
30        my $emails = $folder->messages;
31
32        # Iterate over the messages.
33        foreach ($folder->messages) {...} # all messages
34        foreach (@$folder) {...}          # all messages
35
36        $folder->addMessage(Mail::Box::Message->new(...));
37
38       Tied-interface:
39
40        tie my(@inbox), 'Mail::Box::Tie::ARRAY', $inbox;
41
42        # Four times the same:
43        $inbox[3]->print;                 # tied
44        $folder->[3]->print;              # overloaded folder
45        $folder->message(3)->print;       # usual
46        print $folder->[3];               # overloaded message
47
48        tie my(%inbox), 'Mail::Box::Tie::HASH', $inbox;
49
50        # Twice times the same
51        $inbox{$msgid}->print;            # tied
52        $folder->messageId($msgid)->print;# usual
53

DESCRIPTION

55       A Mail::Box::Manager creates "Mail::Box" objects.  But you already
56       knew, because you started with the Mail::Box-Overview manual page.
57       That page is obligatory reading, sorry!
58
59       "Mail::Box" is the base class for accessing various types of mailboxes
60       (folders) in a uniform manner.  The various folder types vary on how
61       they store their messages, but when some effort those differences could
62       be hidden behind a general API. For example, some folders store many
63       messages in one single file, where other store each message in a
64       separate file within the same directory.
65
66       No object in your program will be of type "Mail::Box": it is only used
67       as base class for the real folder types.  "Mail::Box" is extended by
68
69       Extends "DESCRIPTION" in Mail::Reporter.
70

OVERLOADED

72       overload: ""
73           (stringification) The folder objects stringify to their name.  This
74           simplifies especially print statements and sorting a lot.
75
76           example: use overloaded folder as string
77
78            # Three lines with overloading: resp. cmp, @{}, and ""
79            foreach my $folder (sort @folders)
80            {   my $msgcount = @$folder;
81                print "$folder contains $msgcount messages\n";
82            }
83
84       overload: @{}
85           When the folder is used as if it is a reference to an array, it
86           will show the messages, like messages() and message() would do.
87
88           example: use overloaded folder as array
89
90            my $msg = $folder->[3];
91            my $msg = $folder->message(3);          # same
92
93            foreach my $msg (@$folder) ...
94            foreach my $msg ($folder->messages) ... # same
95
96       overload: cmp
97           (string comparison) folders are compared based on their name.  The
98           sort rules are those of the build-in "cmp".
99

METHODS

101       Extends "METHODS" in Mail::Reporter.
102
103   Constructors
104       Extends "Constructors" in Mail::Reporter.
105
106       Mail::Box->new(%options)
107           Open a new folder. A list of labeled %options for the mailbox can
108           be supplied. Some options pertain to Mail::Box, and others are
109           added by sub-classes.
110
111           To control delay-loading of messages, as well the headers as the
112           bodies, a set of *_type options are available. "extract" determines
113           whether we want delay-loading.
114
115            -Option           --Defined in     --Default
116             access                              'r'
117             body_delayed_type                   Mail::Message::Body::Delayed
118             body_type                           <folder specific>
119             coerce_options                      []
120             create                              <false>
121             extract                             10240
122             field_type                          undef
123             fix_headers                         <false>
124             folder                              $ENV{MAIL}
125             folderdir                           undef
126             head_delayed_type                   Mail::Message::Head::Delayed
127             head_type                           Mail::Message::Head::Complete
128             keep_dups                           <false>
129             lock_file                           undef
130             lock_timeout                        1 hour
131             lock_type                           Mail::Box::Locker::DotLock
132             lock_wait                           10 seconds
133             locker                              undef
134             log                Mail::Reporter   'WARNINGS'
135             manager                             undef
136             message_type                        <folder-class>::Message
137             multipart_type                      Mail::Message::Body::Multipart
138             remove_when_empty                   <true>
139             save_on_exit                        <true>
140             trace              Mail::Reporter   'WARNINGS'
141             trusted                             <depends on folder location>
142
143           access => MODE
144             Access-rights to the folder.  Folders are opened for read-only
145             (which means write-protected) by default! MODE can be
146
147             'r': read-only (default)
148             'a': append
149             'rw': read-write
150             'd': delete
151
152             These MODE has no relation to the modes actually used to open the
153             folder files within this module.  For instance, if you specify
154             "rw", and open the folder, only read permission on the folder-
155             file is required.
156
157             Be warned: writing a MBOX folder may create a new file to replace
158             the old folder.  The permissions and owner of the file may get
159             changed by this.
160
161           body_delayed_type => CLASS
162             The bodies which are delayed: which will be read from file when
163             it is needed, but not before.
164
165           body_type => CLASS|CODE
166             When messages are read from a folder-file, the headers will be
167             stored in a "head_type" object.  For the body, however, there is
168             a range of choices about type, which are all described in
169             Mail::Message::Body.
170
171             Specify a CODE-reference which produces the body-type to be
172             created, or a CLASS of the body which is used when the body is
173             not a multipart or nested.  In case of a code reference, the
174             header structure is passed as first argument to the routine.
175
176             Do not return a delayed body-type (like "::Delayed"), because
177             that is determined by the "extract" option while the folder is
178             opened.  Even delayed message will require some real body type
179             when they get parsed eventually.  Multiparts and nested messages
180             are also outside your control.
181
182             For instance:
183
184              $mgr->open('InBox', body_type => \&which_body);
185
186              sub which_body($) {
187                  my $head = shift;
188                  my $size = $head->guessBodySize || 0;
189                  my $type = $size > 100000 ? 'File' : 'Lines';
190                  "Mail::Message::Body::$type";
191              }
192
193             The default depends on the mail-folder type, although the general
194             default is Mail::Message::Body::Lines.  Please check the
195             applicable manual pages.
196
197           coerce_options => ARRAY
198             Keep configuration information for messages which are coerced
199             into the specified folder type, starting with a different folder
200             type (or even no folder at all).  Messages which are coerced are
201             always fully read, so this kind of information does not need to
202             be kept here.
203
204           create => BOOLEAN
205             Automatically create the folder when it does not exist yet.  This
206             will only work when access is granted for writing or appending to
207             the folder.
208
209             Be careful: you may create a different folder type than you
210             expect unless you explicitly specify
211             Mail::Box::Manager::open(type).
212
213           extract => INTEGER | CODE | METHOD | 'LAZY'|'ALWAYS'
214             Defines when to parse (process) the content of the message.  When
215             the header of a message is read, you may want to postpone the
216             reading of the body: header information is more often needed than
217             the body data, so why parse it always together?  The cost of
218             delaying is not too high, and with some luck you may never need
219             parsing the body.
220
221             If you supply an INTEGER to this option, bodies of those messages
222             with a total size less than that number will be extracted from
223             the folder only when necessary.  Messages where the size (in the
224             "Content-Length" field) is not included in the header, like often
225             the case for multiparts and nested messages, will not be
226             extracted by default.
227
228             If you supply a CODE reference, that subroutine is called every
229             time that the extraction mechanism wants to determine whether to
230             parse the body or not. The subroutine is called with the
231             following arguments:
232
233              CODE->(FOLDER, HEAD)
234
235             where FOLDER is a reference to the folder we are reading.  HEAD
236             refers to the Mail::Message::Head::Complete head of the message
237             at hand.  The routine must return a "true" value (extract now) or
238             a "false" value (be lazy, do not parse yet).  Think about using
239             the Mail::Message::Head::guessBodySize() and
240             Mail::Message::guessTimestamp() on the header to determine your
241             choice.
242
243             The third possibility is to specify the NAME of a method.  In
244             that case, for each message is called:
245
246              FOLDER->NAME(HEAD)
247
248             Where each component has the same meaning as described above.
249
250             The fourth way to use this option involves constants: with "LAZY"
251             all messages will be delayed. With "ALWAYS" you enforce
252             unconditional parsing, no delaying will take place.  The latter
253             is usuful when you are sure you always need all the messages in
254             the folder.
255
256              $folder->new(extract => 'LAZY');  # Very lazy
257              $folder->new(extract => 10000);   # Less than 10kB
258
259              # same, but implemented yourself
260              $folder->new(extract => &large);
261              sub large($) {
262                 my ($f, $head) = @_;
263                 my $size = $head->guessBodySize;
264                 defined $size ? $size < 10000 : 1
265              };
266
267              # method call by name, useful for Mail::Box
268              # extensions. The example selects all messages
269              # sent by you to be loaded without delay.
270              # Other messages will be delayed.
271              $folder->new(extract => 'sent_by_me');
272              sub Mail::Box::send_by_me($) {
273                  my ($self, $header) = @_;
274                  $header->get('from') =~ m/\bmy\@example.com\b/i;
275              }
276
277           field_type => CLASS
278             The type of the fields to be used in a header. Must extend
279             Mail::Message::Field.
280
281           fix_headers => BOOLEAN
282             Broken MIME headers usually stop the parser: all lines not parsed
283             are added to the body of the message.  With this flag set, the
284             erroneous line is added to the previous header field and parsing
285             is continued.  See
286             Mail::Box::Parser::Perl::new(fix_header_errors).
287
288           folder => FOLDERNAME
289             Which folder to open (for reading or writing). When used for
290             reading (the "access" option set to "r" or "a") the mailbox
291             should already exist and must be readable. The file or directory
292             of the mailbox need not exist if it is opened for reading and
293             writing ("rw").  Write-permission is checked when opening an
294             existing mailbox.
295
296             The folder name can be preceded by a "=", to indicate that it is
297             named relative to the directory specified in new(folderdir).
298             Otherwise, it is taken as relative or absolute path.
299
300           folderdir => DIRECTORY
301             Where are folders to be found by default?  A folder-name may be
302             preceded by a equals-sign ("=", a "mutt" convension) to
303             explicitly state that the folder is located below the default
304             directory.  For example: in case "folderdir => '/tmp'" and
305             "folder => '=abc'", the name of the folder-file is '/tmp/abc'.
306             Each folder type has already some default set.
307
308           head_delayed_type => CLASS
309             The headers which are delayed: which will be read from file when
310             it is needed, but not before.
311
312           head_type => CLASS
313             The type of header which contains all header information.  Must
314             extend Mail::Message::Head::Complete.
315
316           keep_dups => BOOLEAN
317             Indicates whether or not duplicate messages within the folder
318             should be retained.  A message is considered to be a duplicate if
319             its message-id is the same as a previously parsed message within
320             the same folder. If this option is false (the default) such
321             messages are automatically deleted, because it is considered
322             useless to store the same message twice.
323
324           lock_file => FILENAME
325             The name of the file which is used to lock.  This must be
326             specified when locking is to be used.
327
328           lock_timeout => SECONDS
329             When the lock file is older than the specified number of SECONDS,
330             it is considered a mistake.  The original lock is released, and
331             accepted for this folder.
332
333           lock_type => CLASS|STRING|ARRAY
334             The type of the locker object.  This may be the full name of a
335             CLASS which extends Mail::Box::Locker, or one of the known locker
336             types "DotLock", "Flock", "FcntlLock", "Mutt", "NFS", "POSIX", or
337             "NONE".  If an ARRAY is specified, then a Multi locker is built
338             which uses the specified list.
339
340           lock_wait => SECONDS
341             SECONDS to wait before failing on opening this folder.
342
343           locker => OBJECT
344             An OBJECT which extends Mail::Box::Locker, and will handle folder
345             locking replacing the default lock behavior.
346
347           log => LEVEL
348           manager => MANAGER
349             A reference to the object which manages this folder -- typically
350             an Mail::Box::Manager instance.
351
352           message_type => CLASS
353             What kind of message objects are stored in this type of folder.
354             The default is constructed from the folder class followed by
355             "::Message".  For instance, the message type for
356             "Mail::Box::POP3" is "Mail::Box::POP3::Message"
357
358           multipart_type => CLASS
359             The default type of objects which are to be created for multipart
360             message bodies.
361
362           remove_when_empty => BOOLEAN
363             Determines whether to remove the folder file or directory
364             automatically when the write would result in a folder without
365             messages nor sub-folders.
366
367           save_on_exit => BOOLEAN
368             Sets the policy for saving the folder when it is closed.  A
369             folder can be closed manually (see close()) or in a number of
370             implicit ways, including on the moment the program is terminated.
371
372           trace => LEVEL
373           trusted => BOOLEAN
374             Flags whether to trust the data in the folder or not.  Folders
375             which reside in your "folderdir" will be trusted by default (even
376             when the names if not specified staring with "=").  Folders which
377             are outside the folderdir or read from STDIN
378             (Mail::Message::Construct::read()) are not trused by default, and
379             require some extra checking.
380
381             If you do not check encodings of received messages, you may print
382             binary data to the screen, which is a security risk.
383
384   The folder
385       $obj->addMessage($message, %options)
386           Add a message to the folder.  A message is usually a
387           Mail::Box::Message object or a sub-class thereof.  The message
388           shall not be in an other folder, when you use this method.  In case
389           it is, use Mail::Box::Manager::moveMessage() or
390           Mail::Box::Manager::copyMessage() via the manager.
391
392           Messages with id's which already exist in this folder are not
393           added.
394
395           BE WARNED that message labels may get lost when a message is moved
396           from one folder type to an other.  An attempt is made to translate
397           labels, but there are many differences in interpretation by
398           applications.
399
400            -Option--Default
401             share   <not used>
402
403           share => BOOLEAN
404             Try to share the physical resource of the current message with
405             the indicated message.  It is sometimes possible to share
406             messages between different folder types.  When the sharing is not
407             possible, than this option is simply ignored.
408
409             Sharing the resource is quite dangerous, and only available for a
410             limited number of folder types, at the moment only some
411             Mail::Box::Dir folders; these file-based messages can be
412             hardlinked (on platforms that support it).  The link may get
413             broken when one message is modified in one of the folders.... but
414             maybe not, depending on the folder types involved.
415
416           example:
417
418            $folder->addMessage($msg);
419            $folder->addMessages($msg1, $msg2, ...);
420
421       $obj->addMessages(@messages)
422           Adds a set of message objects to the open folder at once.  For some
423           folder types this may be faster than adding them one at a time.
424
425           example:
426
427            $folder->addMessages($msg1, $msg2, ...);
428
429       Mail::Box->appendMessages(%options)
430           Append one or more messages to an unopened folder.  Usually, this
431           method is called by the Mail::Box::Manager::appendMessage(), in
432           which case the correctness of the folder type is checked.
433
434           For some folder types it is required to open the folder before it
435           can be used for appending.  This can be fast, but this can also be
436           very slow (depends on the implementation).  All %options passed
437           will also be used to open the folder, if needed.
438
439            -Option  --Default
440             folder    <required>
441             message   undef
442             messages  undef
443             share     <false>
444
445           folder => FOLDERNAME
446             The name of the folder to which the messages are to be appended.
447             The folder implementation will avoid opening the folder when
448             possible, because this is resource consuming.
449
450           message => MESSAGE
451           messages => ARRAY-OF-MESSAGES
452             One reference to a MESSAGE or a reference to an ARRAY of
453             MESSAGEs, which may be of any type.  The messages will be first
454             coerced into the correct message type to fit in the folder, and
455             then will be added to it.
456
457           share => BOOLEAN
458             Try to share physical storage of the message.  Only available for
459             a limited number of folder types, otherwise no-op.
460
461           example:
462
463            my $message = Mail::Message->new(...);
464            Mail::Box::Mbox->appendMessages
465             ( folder    => '=xyz'
466             , message   => $message
467             , folderdir => $ENV{FOLDERS}
468             );
469
470           better:
471
472            my Mail::Box::Manager $mgr;
473            $mgr->appendMessages($message, folder => '=xyz');
474
475       $obj->close(%options)
476           Close the folder, which usually implies writing the changes.  This
477           will return "false" when writing is required but fails.  Please do
478           check this result.
479
480           WARNING: When moving messages from one folder to another, be sure
481           to write the destination folder before writing and closing the
482           source folder.  Otherwise you may lose data if the system crashes
483           or if there are software problems.
484
485            -Option      --Default
486             force         <false>
487             save_deleted  false
488             write         MODIFIED
489
490           force => BOOLEAN
491             Override the new(access) setting which was specified when the
492             folder was opened. This option only has an effect if its value is
493             TRUE. NOTE: Writing to the folder may not be permitted by the
494             operating system, in which case even "force" will not help.
495
496           save_deleted => BOOLEAN
497             Do also write messages which where flagged to be deleted to their
498             folder.  The flag for deletion is conserved (when possible),
499             which means that a re-open of the folder may remove the messages
500             for real.  See write(save_deleted).
501
502           write => 'ALWAYS'|'NEVER'|'MODIFIED'
503             Specifies whether the folder should be written.  As could be
504             expected, "ALWAYS" means always (even if there are no changes),
505             "NEVER" means that changes to the folder will be lost, and
506             "MODIFIED" only saves the folder if there are any changes.
507
508           example:
509
510            my $f = $mgr->open('spam', access => 'rw')
511                or die "Cannot open spam: $!\n";
512
513            $f->message(0)->delete
514                if $f->messages;
515
516            $f->close
517                or die "Couldn't write $f: $!\n";
518
519       $obj->copyTo($folder, %options)
520           Copy the folder's messages to a new folder.  The new folder may be
521           of a different type.
522
523            -Option       --Default
524             delete_copied  <false>
525             select         'ACTIVE'
526             share          <not used>
527             subfolders     <folder type dependent>
528
529           delete_copied => BOOLEAN
530             Flag the messages from the source folder to be deleted, just
531             after it was copied.  The deletion will only take effect when the
532             originating folder is closed.
533
534           select => 'ACTIVE'|'DELETED'|'ALL'|LABEL|!LABEL|FILTER
535             Which messages are to be copied. See the description of
536             messages() about how this works.
537
538           share => BOOLEAN
539             Try to share the message between the folders.  Some
540             Mail::Box::Dir folder types do support it by creating a hardlink
541             (on UNIX/Linux).
542
543           subfolders => BOOLEAN|'FLATTEN'|'RECURSE'
544             How to handle sub-folders.  When false (0 or "undef"), sub-
545             folders are simply ignored.  With "FLATTEN", messages from sub-
546             folders are included in the main copy.  "RECURSE" recursively
547             copies the sub-folders as well.  By default, when the destination
548             folder supports sub-folders "RECURSE" is used, otherwise
549             "FLATTEN".  A value of true will select the default.
550
551           example:
552
553            my $mgr  = Mail::Box::Manager->new;
554            my $imap = $mgr->open(type => 'imap', host => ...);
555            my $mh   = $mgr->open(type => 'mh', folder => '/tmp/mh',
556                create => 1, access => 'w');
557
558            $imap->copyTo($mh, delete_copied => 1);
559            $mh->close; $imap->close;
560
561       $obj->delete(%options)
562           Remove the specified folder file or folder directory (depending on
563           the type of folder) from disk.  Of course, THIS IS DANGEROUS: you
564           "may" lose data.  Returns a "true" value on success.
565
566           WARNING: When moving messages from one folder to another, be sure
567           to write the destination folder before deleting the source folder.
568           Otherwise you may lose data if the system crashes or if there are
569           software problems.
570
571            -Option   --Default
572             recursive  1
573
574           recursive => BOOLEAN
575
576           example: removing an open folder
577
578            my $folder = Mail::Box::Mbox->new(folder => 'InBox', access => 'rw');
579            ... some other code ...
580            $folder->delete;
581
582           example: removing an closed folder
583
584            my $folder = Mail::Box::Mbox->new(folder => 'INBOX', access => 'd');
585            $folder->delete;
586
587       $obj->folderdir( [$directory] )
588           Get or set the $directory which is used to store mail-folders by
589           default.
590
591           example:
592
593            print $folder->folderdir;
594            $folder->folderdir("$ENV{HOME}/nsmail");
595
596       $obj->name()
597           Returns the name of the folder.  What the name represents depends
598           on the actual type of mailbox used.
599
600           example:
601
602            print $folder->name;
603            print "$folder";       # overloaded stringification
604
605       $obj->organization()
606           Returns how the folder is organized: as one "FILE" with many
607           messages, a "DIRECTORY" with one message per file, or by a "REMOTE"
608           server.
609
610       $obj->size()
611           Returns the size of the folder in bytes, not counting in the
612           deleted messages.  The error in the presented result may be as
613           large as 10%, because the in-memory representation of messages is
614           not always the same as the size when they are written.
615
616       $obj->type()
617           Returns a name for the type of mail box.  This can be "mbox", "mh",
618           "maildir", or "pop3".
619
620       $obj->update(%options)
621           Read new messages from the folder, which where received after
622           opening it. This is quite dangerous and shouldn't be possible:
623           folders which are open are locked. However, some applications do
624           not use locks or the wrong kind of locks. This method reads the
625           changes (not always failsafe) and incorporates them in the open
626           folder administration.
627
628           The %options are extra values which are passed to the
629           updateMessages() method which is doing the actual work here.
630
631       $obj->url()
632           Represent the folder as a URL (Universal Resource Locator) string.
633           You may pass such a URL as folder name to
634           Mail::Box::Manager::open().
635
636           example:
637
638            print $folder->url;
639            # may result in
640            #   mbox:/var/mail/markov   or
641            #   pop3://user:password@pop.aol.com:101
642
643   Folder flags
644       $obj->access()
645           Returns the access mode of the folder, as set by new(access)
646
647       $obj->isModified()
648           Checks if the folder, as stored in memory, is modified.  A true
649           value is returned when any of the messages is to be deleted, has
650           changed, or messages were added after the folder was read from
651           file.
652
653           WARNING: this flag is not related to an external change to the
654           folder structure on disk.  Have a look at update() for that.
655
656       $obj->modified( [BOOLEAN] )
657           Sets whether the folder is modified or not.
658
659       $obj->writable()
660           Checks whether the current folder is writable.
661
662           example:
663
664            $folder->addMessage($msg) if $folder->writable;
665
666   The messages
667       $obj->current( [$number|$message|$message_id] )
668           Some mail-readers keep the current message, which represents the
669           last used message.  This method returns [after setting] the current
670           message.  You may specify a $number, to specify that that message
671           number is to be selected as current, or a $message/$message_id (as
672           long as you are sure that the header is already loaded, otherwise
673           they are not recognized).
674
675           example:
676
677            $folder->current(0);
678            $folder->current($message);
679
680       $obj->find($message_id)
681           Like messageId(), this method searches for a message with the
682           $message_id, returning the corresponding message object.  However,
683           "find" will cause unparsed message in the folder to be parsed until
684           the message-id is found.  The folder will be scanned back to front.
685
686       $obj->findFirstLabeled( $label, [BOOLEAN, [$msgs]] )
687           Find the first message which has this $label with the correct
688           setting. The BOOLEAN indicates whether any true value or any false
689           value is to be found in the ARRAY of $msgs.  By default, a true
690           value is searched for.  When a message does not have the requested
691           label, it is taken as false.
692
693           example: looking for a labeled message
694
695            my $current = $folder->findFirstLabeled('current');
696
697            my $first   = $folder->findFirstLabeled(seen => 0);
698
699            my $last    = $folder->findFirstLabeled(seen => 0,
700                            [ reverse $self->messages('ACTIVE') ] )
701
702       $obj->message( $index, [$message] )
703           Get or set a message with on a certain index.  Messages which are
704           flagged for deletion are counted.  Negative indexes start at the
705           end of the folder.
706
707           example:
708
709            my $msg = $folder->message(3);
710            $folder->message(3)->delete;   # status changes to `deleted'
711            $folder->message(3, $msg);
712            print $folder->message(-1);    # last message.
713
714       $obj->messageId( $message_id, [$message] )
715           With one argument, returns the message in the folder with the
716           specified $message_id. If a reference to a message object is passed
717           as the optional second argument, the message is first stored in the
718           folder, replacing any existing message whose message ID is
719           $message_id. (The message ID of $message need not match
720           $message_id.)
721
722           !!WARNING!!: when the message headers are delay-parsed, the message
723           might be in the folder but not yet parsed into memory. In this
724           case, use find() instead of "messageId()" if you really need a
725           thorough search.  This is especially the case for directory
726           organized folders without special indexi, like Mail::Box::MH.
727
728           The $message_id may still be in angles, which will be stripped.  In
729           that case blanks (which origin from header line folding) are
730           removed too.  Other info around the angles will be removed too.
731
732           example:
733
734            my $msg = $folder->messageId('<complex-message.id>');
735            $folder->messageId("<complex-message\n.id>", $msg);
736            my $msg = $folder->messageId('complex-message.id');
737            my $msg = $folder->messageId('garbage <complex-message.id> trash');
738
739       $obj->messageIds()
740           Returns a list of all message-ids in the folder, including those of
741           messages which are to be deleted.
742
743           For some folder-types (like MH), this method may cause all message-
744           files to be read.  See their respective manual pages.
745
746           example:
747
748            foreach my $id ($folder->messageIds) {
749               $folder->messageId($id)->print;
750            }
751
752       $obj->messages( <'ALL'|$range|'ACTIVE'|'DELETED'|$label|
753       !$label|$filter> )
754           Returns multiple messages from the folder.  The default is "ALL"
755           which will return (as expected maybe) all the messages in the
756           folder.  The "ACTIVE" flag will return the messages not flagged for
757           deletion.  This is the opposite of "DELETED", which returns all
758           messages from the folder which will be deleted when the folder is
759           closed.
760
761           You may also specify a $range: two numbers specifying begin and end
762           index in the array of messages.  Negative indexes count from the
763           end of the folder.  When an index is out-of-range, the returned
764           list will be shorter without complaints.
765
766           Everything else than the predefined names is seen as labels.  The
767           messages which have that label set will be returned.  When the
768           sequence starts with an exclamation mark (!), the search result is
769           reversed.
770
771           For more complex searches, you can specify a $filter, which is
772           simply a code reference.  The message is passed as only argument.
773
774           example:
775
776            foreach my $message ($folder->messages) {...}
777            foreach my $message (@$folder) {...}
778
779            # twice the same
780            my @messages   = $folder->messages;
781            my @messages   = $folder->messages('ALL');
782
783            # Selection based on a range (begin, end)
784            my $subset     = $folder->messages(10,-8);
785
786            # twice the same:
787            my @not_deleted= grep {not $_->isDeleted}
788                                $folder->messages;
789            my @not_deleted= $folder->messages('ACTIVE');
790
791            # scalar context the number of messages
792            my $nr_of_msgs = $folder->messages;
793
794            # third message, via overloading
795            $folder->[2];
796
797            # Selection based on labels
798            $mgr->moveMessages($spam, $inbox->message('spam'));
799            $mgr->moveMessages($archive, $inbox->message('seen'));
800
801       $obj->nrMessages(%options)
802           Simply calls messages() in scalar context to return a count instead
803           of the messages itself.  Some people seem to understand this
804           better.  Note that nrMessages() will default to returning a count
805           of "ALL" messages in the folder, including both "ACTIVE" and
806           "DELETED".
807
808           The %options are passed to (and explained in) messages().
809
810       $obj->scanForMessages($message, $message_ids, $timespan, $window)
811           You start with a $message, and are looking for a set of messages
812           which are related to it.  For instance, messages which appear in
813           the 'In-Reply-To' and 'Reference' header fields of that message.
814           These messages are known by their $message_ids and you want to find
815           them in the folder.
816
817           When all message-ids are known, then looking-up messages is simple:
818           they are found in a plain hash using messageId().  But Mail::Box is
819           lazy where it can, so many messages may not have been read from
820           file yet, and that's the preferred situation, because that saves
821           time and memory.
822
823           It is not smart to search for the messages from front to back in
824           the folder: the chances are much higher that related message reside
825           closely to each other.  Therefore, this method starts scanning the
826           folder from the specified $message, back to the front of the
827           folder.
828
829           The $timespan can be used to terminate the search based on the time
830           enclosed in the message.  When the constant string "EVER" is used
831           as $timespan, then the search is not limited by that.  When an
832           integer is specified, it will be used as absolute time in time-
833           ticks as provided by your platform dependent "time" function.  In
834           other cases, it is passed to timespan2seconds() to determine the
835           threshold as time relative to the message's time.
836
837           The $window is used to limit the search in number of messages to be
838           scanned as integer or constant string "ALL".
839
840           Returned are the message-ids which were not found during the scan.
841           Be warned that a message-id could already be known and therefore
842           not found: check that first.
843
844           example: scanning through a folder for a message
845
846            my $refs   = $msg->get('References') or return;
847            my @msgids = $ref =~ m/\<([^>]+\>/g;
848            my @failed = $folder->scanForMessages($msg, \@msgids, '3 days', 50);
849
850   Sub-folders
851       $obj->listSubFolders(%options)
852       Mail::Box->listSubFolders(%options)
853           List the names of all sub-folders to this folder, not recursively
854           decending.  Use these names as argument to openSubFolder(), to get
855           access to that folder.
856
857           For MBOX folders, sub-folders are simulated.
858
859            -Option    --Default
860             check       <false>
861             folder      <from calling object>
862             folderdir   <from folder>
863             skip_empty  <false>
864
865           check => BOOLEAN
866             Should all returned foldernames be checked to be sure that they
867             are of the right type?  Each sub-folder may need to be opened to
868             check this, with a folder type dependent penalty (in some cases
869             very expensive).
870
871           folder => FOLDERNAME
872             The folder whose sub-folders should be listed.
873
874           folderdir => DIRECTORY
875           skip_empty => BOOL
876             Shall empty folders (folders which currently do not contain any
877             messages) be included?  Empty folders are not useful to open, but
878             may be useful to save to.
879
880           example:
881
882            my $folder = $mgr->open('=in/new');
883            my @subs = $folder->listSubFolders;
884
885            my @subs = Mail::Box::Mbox->listSubFolders(folder => '=in/new');
886            my @subs = Mail::Box::Mbox->listSubFolders; # toplevel folders.
887
888       $obj->nameOfSubFolder( $subname, [$parentname] )
889       Mail::Box->nameOfSubFolder( $subname, [$parentname] )
890           Returns the constructed name of the folder with NAME, which is a
891           sub-folder of this current one.  You have either to call this
892           method as instance method, or specify a $parentname.
893
894           example: how to get the name of a subfolder
895
896            my $sub = Mail::Box::Mbox->nameOfSubfolder('xyz', 'abc');
897            print $sub;                        # abc/xyz
898
899            my $f = Mail::Box::Mbox->new(folder => 'abc');
900            print $f->nameOfSubfolder('xyz');  # abc/xyz
901
902            my $sub = Mail::Box::Mbox->nameOfSubfolder('xyz', undef);
903            print $sub;                        # xyz
904
905       $obj->openRelatedFolder(%options)
906           Open a folder (usually a sub-folder) with the same options as this
907           one.  If there is a folder manager in use, it will be informed
908           about this new folder.  %options overrule the options which where
909           used for the folder this method is called upon.
910
911       $obj->openSubFolder($subname, %options)
912           Open (or create, if it does not exist yet) a new subfolder in an
913           existing folder.
914
915           example:
916
917            my $folder = Mail::Box::Mbox->new(folder => '=Inbox');
918            my $sub    = $folder->openSubFolder('read');
919
920       $obj->topFolderWithMessages()
921       Mail::Box->topFolderWithMessages()
922           Some folder types can have messages in the top-level folder, some
923           other can't.
924
925   Internals
926       $obj->coerce($message, %options)
927           Coerce the $message to be of the correct type to be placed in the
928           folder.  You can specify Mail::Internet and MIME::Entity objects
929           here: they will be translated into Mail::Message messages first.
930
931       $obj->create($foldername, %options)
932       Mail::Box->create($foldername, %options)
933           Create a folder.  If the folder already exists, it will be left
934           unchanged.  The folder is created, but not opened!  If you want to
935           open a file which may need to be created, then use
936           Mail::Box::Manager::open() with the create flag, or
937           Mail::Box::new(create).
938
939            -Option   --Default
940             folderdir  undef
941
942           folderdir => DIRECTORY
943             When the foldername is preceded by a "=", the "folderdir"
944             directory will be searched for the named folder.
945
946       $obj->determineBodyType($message, $head)
947           Determine which kind of body will be created for this message when
948           reading the folder initially.
949
950       Mail::Box->foundIn( [$foldername], %options )
951           Determine if the specified folder is of the type handled by the
952           folder class. This method is extended by each folder sub-type.
953
954           The $foldername specifies the name of the folder, as is specified
955           by the application.  You need to specified the "folder" option when
956           you skip this first argument.
957
958           %options is a list of extra information for the request.  Read the
959           documentation for each type of folder for type specific options,
960           but each folder class will at least support the "folderdir" option:
961
962            -Option   --Default
963             folderdir  undef
964
965           folderdir => DIRECTORY
966             The location where the folders of this class are stored by
967             default.  If the user specifies a name starting with a "=", that
968             indicates that the folder is to be found in this default
969             DIRECTORY.
970
971           example:
972
973            Mail::Box::Mbox->foundIn('=markov',
974                folderdir => "$ENV{HOME}/Mail");
975            Mail::Box::MH->foundIn(folder => '=markov');
976
977       $obj->lineSeparator( [<STRING|'CR'|'LF'|'CRLF'>] )
978           Returns the character or characters used to separate lines in the
979           folder file, optionally after setting it to STRING, or one of the
980           constants.  The first line of the folder sets the default.
981
982           UNIX uses a LF character, Mac a CR, and Windows both a CR and a LF.
983           Each separator will be represented by a "\n" within your program.
984           However, when processing platform foreign folders, complications
985           appear.  Think about the "Size" field in the header.
986
987           When the separator is changed, the whole folder me be rewritten.
988           Although, that may not be required.
989
990       $obj->locker()
991           Returns the locking object.
992
993       $obj->read(%options)
994           Read messages from the folder into memory.  The %options are folder
995           specific.  Do not call "read()" yourself: it will be called for you
996           when you open the folder via the manager or instantiate a folder
997           object directly.
998
999           NOTE: if you are copying messages from one folder to another, use
1000           addMessages() instead of "read()".
1001
1002           example:
1003
1004            my $mgr = Mail::Box::Manager->new;
1005            my $folder = $mgr->open('InBox');             # implies read
1006            my $folder = Mail::Box::Mbox->new(folder => 'Inbox'); # same
1007
1008       $obj->readMessages(%options)
1009           Called by read() to actually read the messages from one specific
1010           folder type.  The read() organizes the general activities.
1011
1012           The %options are "trusted", "head_type", "field_type",
1013           "message_type", "body_delayed_type", and "head_delayed_type" as
1014           defined by the folder at hand.  The defaults are the constructor
1015           defaults (see new()).
1016
1017       $obj->storeMessage($message)
1018           Store the message in the folder without the checks as performed by
1019           addMessage().
1020
1021       $obj->toBeThreaded($messages)
1022           The specified message is ready to be removed from a thread.  This
1023           will be passed on to the mail-manager, which keeps an overview on
1024           which thread-detection objects are floating around.
1025
1026       $obj->toBeUnthreaded($messages)
1027           The specified message is ready to be included in a thread.  This
1028           will be passed on to the mail-manager, which keeps an overview on
1029           which thread-detection objects are floating around.
1030
1031       $obj->updateMessages(%options)
1032           Called by update() to read messages which arrived in the folder
1033           after it was opened.  Sometimes, external applications dump
1034           messages in a folder without locking (or using a different lock
1035           than your application does).
1036
1037           Although this is quite a dangerous, it only fails when a folder is
1038           updated (reordered or message removed) at exactly the same time as
1039           new messages arrive.  These collisions are sparse.
1040
1041           The options are the same as for readMessages().
1042
1043       $obj->write(%options)
1044           Write the data to disk.  The folder (a "true" value) is returned if
1045           successful.  Deleted messages are transformed into destroyed
1046           messages: their memory is freed.
1047
1048           WARNING: When moving messages from one folder to another, be sure
1049           to write (or close()) the destination folder before writing (or
1050           closing) the source folder: otherwise you may lose data if the
1051           system crashes or if there are software problems.
1052
1053           To write a folder to a different file, you must first create a new
1054           folder, then move all the messages, and then write or close() that
1055           new folder.
1056
1057            -Option      --Default
1058             force         <false>
1059             save_deleted  <false>
1060
1061           force => BOOLEAN
1062             Override write-protection with new(access) while opening the
1063             folder (whenever possible, it may still be blocked by the
1064             operating system).
1065
1066           save_deleted => BOOLEAN
1067             Do also write messages which where flagged to be deleted to their
1068             folder.  The flag for deletion is conserved (when possible),
1069             which means that a re-open of the folder may remove the messages
1070             for real.  See close(save_deleted).
1071
1072       $obj->writeMessages(%options)
1073           Called by write() to actually write the messages from one specific
1074           folder type.  The "write" organizes the general activities.  All
1075           options to write() are passed to "writeMessages" as well.  Besides,
1076           a few extra are added by "write" itself.
1077
1078            -Option  --Default
1079             messages  <required>
1080
1081           messages => ARRAY
1082             The messages to be written, which is a sub-set of all messages in
1083             the current folder.
1084
1085   Other methods
1086       $obj->timespan2seconds($time)
1087       Mail::Box->timespan2seconds($time)
1088           $time is a string, which starts with a float, and then one of the
1089           words 'hour', 'hours', 'day', 'days', 'week', or 'weeks'.  For
1090           instance: '1 hour' or '4 weeks'.
1091
1092   Error handling
1093       Extends "Error handling" in Mail::Reporter.
1094
1095       $obj->AUTOLOAD()
1096           Inherited, see "Error handling" in Mail::Reporter
1097
1098       $obj->addReport($object)
1099           Inherited, see "Error handling" in Mail::Reporter
1100
1101       $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level,
1102       $callback] )
1103       Mail::Box->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level,
1104       $callback] )
1105           Inherited, see "Error handling" in Mail::Reporter
1106
1107       $obj->errors()
1108           Inherited, see "Error handling" in Mail::Reporter
1109
1110       $obj->log( [$level, [$strings]] )
1111       Mail::Box->log( [$level, [$strings]] )
1112           Inherited, see "Error handling" in Mail::Reporter
1113
1114       $obj->logPriority($level)
1115       Mail::Box->logPriority($level)
1116           Inherited, see "Error handling" in Mail::Reporter
1117
1118       $obj->logSettings()
1119           Inherited, see "Error handling" in Mail::Reporter
1120
1121       $obj->notImplemented()
1122           Inherited, see "Error handling" in Mail::Reporter
1123
1124       $obj->report( [$level] )
1125           Inherited, see "Error handling" in Mail::Reporter
1126
1127       $obj->reportAll( [$level] )
1128           Inherited, see "Error handling" in Mail::Reporter
1129
1130       $obj->trace( [$level] )
1131           Inherited, see "Error handling" in Mail::Reporter
1132
1133       $obj->warnings()
1134           Inherited, see "Error handling" in Mail::Reporter
1135
1136   Cleanup
1137       Extends "Cleanup" in Mail::Reporter.
1138
1139       $obj->DESTROY()
1140           This method is called by Perl when an folder-object is no longer
1141           accessible by the rest of the program.
1142

DETAILS

1144   Different kinds of folders
1145       In general, there are three classes of folders: those who group
1146       messages per file, those who group messages in a directory, and those
1147       do not provide direct access to the message data.  These folder types
1148       are each based on a different base class.
1149
1150       ·   File based folders Mail::Box::File
1151
1152           File based folders maintain a folder (a set of messages) in one
1153           single file.  The advantage is that your folder has only one single
1154           file to access, which speeds-up things when all messages must be
1155           accessed at once.
1156
1157           One of the main disadvantages over directory based folders is that
1158           you have to construct some means to keep all message apart.  For
1159           instance MBOX adds a message separator line between the messages in
1160           the file, and this line can cause confusion with the message's
1161           contents.
1162
1163           Where access to all messages at once is faster in file based
1164           folders, access to a single message is (much) slower, because the
1165           whole folder must be read.  However, in directory based folders you
1166           have to figure-out which message you need, which may be a hassle as
1167           well.
1168
1169           Examples of file based folders are MBOX, DBX, and NetScape.
1170
1171       ·   Directory based folders Mail::Box::Dir
1172
1173           In stead of collecting multiple messages in one file, you can also
1174           put each message in a separate file and collect those files in a
1175           directory to represent a folder.
1176
1177           The main disadvantages of these folders are the enormous amount of
1178           tiny files you usually get in your file-system.  It is extremely
1179           slow to search through your whole folder, because many files have
1180           to be opened to do so.
1181
1182           The best feature of this organization is that each message is kept
1183           exactly as it was received, and can be processed with external
1184           scripts as well: you do not need any mail user agent (MUA).
1185
1186           Examples of directory organized folders are MH, Maildir, EMH and
1187           XMH.
1188
1189       ·   Network (external) folders Mail::Box::Net
1190
1191           Where both types described before provide direct access to the
1192           message data, maintain these folder types the message data for you:
1193           you have to request for messages or parts of them.  These folders
1194           do not have a filename, file-system privileges and system locking
1195           to worry about, but typically require a hostname, folder and
1196           message IDs, and authorization.
1197
1198           Examples of these folder types are the popular POP and IMAP, and
1199           database oriented message storage.
1200
1201   Available folder types
1202       ·   Mail::Box::Dbx (read only)
1203
1204           Dbx files are created by Outlook Express. Using the external
1205           (optional) Mail::Transport::Dbx module, you can read these folders,
1206           even when you are running MailBox on a UNIX/Linux platform.
1207
1208           Writing and deleting messages is not supported by the library, and
1209           therefore not by MailBox. Read access is enough to do folder
1210           conversions, for instance.
1211
1212       ·   Mail::Box::IMAP4 (partially)
1213
1214           The IMAP protocol is very complex.  Some parts are implemented to
1215           create (sub-optimal but usable) IMAP clients.  Besides, there are
1216           also some parts for IMAP servers present.  The most important
1217           lacking feature is support for encrypted connections.
1218
1219       ·   Mail::Box::Maildir
1220
1221           Maildir folders have a directory for each folder.  A folder
1222           directory contains "tmp", "new", and "cur" sub-directories, each
1223           containing messages with a different purpose.  Files with new
1224           messages are created in "tmp", then moved to "new" (ready to be
1225           accepted).  Later, they are moved to the "cur" directory
1226           (accepted).  Each message is one file with a name starting with
1227           timestamp.  The name also contains flags about the status of the
1228           message.
1229
1230           Maildir folders can not be used on Windows by reason of file-name
1231           limitations on that platform.
1232
1233       ·   Mail::Box::Mbox
1234
1235           A folder type in which all related messages are stored in one file.
1236           This is a very common folder type for UNIX.
1237
1238       ·   Mail::Box::MH
1239
1240           This folder creates a directory for each folder, and a message is
1241           one file inside that directory.  The message files are numbered
1242           sequentially on order of arrival.  A special ".mh_sequences" file
1243           maintains flags about the messages.
1244
1245       ·   Mail::Box::POP3 (read/delete only)
1246
1247           POP3 is a protocol which can be used to retrieve messages from a
1248           remote system.  After the connection to a POP server is made, the
1249           messages can be looked at and removed as if they are on the local
1250           system.
1251
1252       ·   Mail::Box::Netzwert
1253
1254           The Netzwert folder type is optimized for mailbox handling on a
1255           cluster of systems with a shared NFS storage.  The code is not
1256           released under GPL (yet)
1257
1258       Other folder types are on the (long) wishlist to get implemented.
1259       Please, help implementing more of them.
1260
1261   Folder class implementation
1262       The class structure of folders is very close to that of messages.  For
1263       instance, a Mail::Box::File::Message relates to a Mail::Box::File
1264       folder.  The folder types are:
1265
1266                           Mail::Box::Netzwert
1267        Mail::Box::Mbox   | Mail::Box::Maildir Mail::Box::POP3
1268        |  Mail::Box::Dbx | | Mail::Box::MH    |  Mail::Box::IMAP4
1269        |  |               | | |                 |  |
1270        |  |               | | |                 |  |
1271        Mail::Box::File   Mail::Box::Dir       Mail::Box::Net
1272              |                  |                   |
1273              `--------------.   |   .---------------'
1274                             |   |   |
1275                             Mail::Box
1276                                 |
1277                                 |
1278                           Mail::Reporter (general base class)
1279
1280       By far most folder features are implemented in Mail::Box, so available
1281       to all folder types.  Sometimes, features which appear in only some of
1282       the folder types are simulated for folders that miss them, like sub-
1283       folder support for MBOX.
1284

DIAGNOSTICS

1286       Warning: Changes not written to read-only folder $self.
1287           You have opened the folder read-only --which is the default set by
1288           new(access)--, made modifications, and now want to close it.  Set
1289           close(force) if you want to overrule the access mode, or close the
1290           folder with close(write) set to "NEVER".
1291
1292       Error: Copying failed for one message.
1293           For some reason, for instance disc full, removed by external
1294           process, or read-protection, it is impossible to copy one of the
1295           messages.  Copying will proceed for the other messages.
1296
1297       Error: Destination folder $name is not writable.
1298           The folder where the messages are copied to is not opened with
1299           write access (see new(access)).  This has no relation with write
1300           permission to the folder which is controlled by your operating
1301           system.
1302
1303       Warning: Different messages with id $msgid
1304           The message id is discovered more than once within the same folder,
1305           but the content of the message seems to be different.  This should
1306           not be possible: each message must be unique.
1307
1308       Error: Folder $name is opened read-only
1309           You can not write to this folder unless you have opened the folder
1310           to write or append with new(access), or the "force" option is set
1311           true.
1312
1313       Error: Folder $name not deleted: not writable.
1314           The folder must be opened with write access via new(access),
1315           otherwise removing it will be refused.  So, you may have write-
1316           access according to the operating system, but that will not
1317           automatically mean that this "delete" method permits you to.  The
1318           reverse remark is valid as well.
1319
1320       Error: Invalid timespan '$timespan' specified.
1321           The string does not follow the strict rules of the time span syntax
1322           which is permitted as parameter.
1323
1324       Warning: Message-id '$msgid' does not contain a domain.
1325           According to the RFCs, message-ids need to contain a unique random
1326           part, then an "@", and then a domain name.  This is made to avoid
1327           the creation of two messages with the same id.  The warning emerges
1328           when the "@" is missing from the string.
1329
1330       Error: No folder name specified.
1331           You did not specify the name of a folder to be opened.  Use the
1332           new(folder) option or set the "MAIL" environment variable.
1333
1334       Error: Package $package does not implement $method.
1335           Fatal error: the specific package (or one of its superclasses) does
1336           not implement this method where it should. This message means that
1337           some other related classes do implement this method however the
1338           class at hand does not.  Probably you should investigate this and
1339           probably inform the author of the package.
1340
1341       Error: Unable to create subfolder $name of $folder.
1342           The copy includes the subfolders, but for some reason it was not
1343           possible to copy one of these.  Copying will proceed for all other
1344           sub-folders.
1345
1346       Error: Writing folder $name failed
1347           For some reason (you probably got more error messages about this
1348           problem) it is impossible to write the folder, although you should
1349           because there were changes made.
1350

SEE ALSO

1352       This module is part of Mail-Box distribution version 3.008, built on
1353       October 04, 2019. Website: http://perl.overmeer.net/CPAN/
1354

LICENSE

1356       Copyrights 2001-2019 by [Mark Overmeer]. For other contributors see
1357       ChangeLog.
1358
1359       This program is free software; you can redistribute it and/or modify it
1360       under the same terms as Perl itself.  See http://dev.perl.org/licenses/
1361
1362
1363
1364perl v5.30.1                      2020-01-30                      Mail::Box(3)
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