Mail::Box::MH(3) User Contributed Perl Documentation Mail::Box::MH(3)NAMEMail::Box::MH - handle MH folders
INHERITANCEMail::Box::MH
is a Mail::Box::Dir
is a Mail::Box
is a Mail::Reporter
SYNOPSIS
use Mail::Box::MH;
my $folder = new Mail::Box::MH folder => $ENV{MAIL}, ...;
DESCRIPTION
This documentation describes how MH mailboxes work, and what you can do
with the MH folder object "Mail::Box::MH".
OVERLOADED
overload: ""
See "OVERLOADED" in Mail::Box
overload: @{}
See "OVERLOADED" in Mail::Box
overload: cmp
See "OVERLOADED" in Mail::Box
METHODS
Constructors
Mail::Box::MH->new(OPTIONS)-Option--Defined in --Default
access Mail::Box 'r'
body_delayed_type Mail::Box Mail::Message::Body::Delayed
body_type Mail::Box Mail::Message::Body::Lines
coerce_options Mail::Box []
create Mail::Box <false>
directory Mail::Box::Dir <derived from folder name>
extract Mail::Box 10240
field_type Mail::Box undef
fix_headers Mail::Box <false>
folder Mail::Box $ENV{MAIL}
folderdir Mail::Box $ENV{HOME}/.mh
head_delayed_type Mail::Box Mail::Message::Head::Delayed
head_type Mail::Box Mail::Message::Head::Complete
index undef
index_filename <foldername>/.index
index_type Mail::Box::MH::Index
keep_dups Mail::Box <false>
keep_index 0
labels undef
labels_filename <foldername>/.mh_sequence
labels_type Mail::Box::MH::Labels
lock_file Mail::Box <index_file>
lock_timeout Mail::Box 1 hour
lock_type Mail::Box Mail::Box::Locker::DotLock
lock_wait Mail::Box 10 seconds
locker Mail::Box undef
log Mail::Reporter 'WARNINGS'
manager Mail::Box undef
message_type Mail::Box Mail::Box::Message
multipart_type Mail::Box Mail::Message::Body::Multipart
remove_when_empty Mail::Box <true>
save_on_exit Mail::Box <true>
trace Mail::Reporter 'WARNINGS'
trusted Mail::Box <depends on folder location>
access => MODE
body_delayed_type => CLASS
body_type => CLASS|CODE
coerce_options => ARRAY
create => BOOLEAN
directory => DIRECTORY
extract => INTEGER | CODE | METHOD | 'LAZY'|'ALWAYS'
field_type => CLASS
fix_headers => BOOLEAN
folder => FOLDERNAME
folderdir => DIRECTORY
head_delayed_type => CLASS
head_type => CLASS
index => OBJECT
You may specify an OBJECT of a type which extends
Mail::Box::MH::Index (at least implements a "get()" method), as
alternative for an index file reader as created by
"Mail::Box::MH".
index_filename => FILENAME
The FILENAME which is used in each directory to store the headers
of all mails. The filename shall not contain a directory path.
(e.g. Do not use "/usr/people/jan/.index", nor "subdir/.index",
but say ".index".)
index_type => CLASS
keep_dups => BOOLEAN
keep_index => BOOLEAN
Keep an index file of the specified mailbox, one file per
directory. Using an index file will speed up things
considerably, because it avoids reading all the message files the
moment that you open the folder. When you open a folder, you can
use the index file to retrieve information such as the subject of
each message, instead of having to read possibly thousands of
messages.
labels => OBJECT
You may specify an OBJECT of a type which extends
Mail::Box::MH::Labels (at least implements the "get()" method),
as alternative for labels file reader as created by
"Mail::Box::MH".
labels_filename => FILENAME
In MH-folders, messages can be labeled, for instance based on the
sender or whether it is read or not. This status is kept in a
file which is usually called ".mh_sequences", but that name can
be overruled with this flag.
labels_type => CLASS
lock_file => FILENAME
lock_timeout => SECONDS
lock_type => CLASS|STRING|ARRAY
lock_wait => SECONDS
locker => OBJECT
log => LEVEL
manager => MANAGER
message_type => CLASS
multipart_type => CLASS
remove_when_empty => BOOLEAN
save_on_exit => BOOLEAN
trace => LEVEL
trusted => BOOLEAN
The folder
$obj->addMessage(MESSAGE, OPTIONS)
See "The folder" in Mail::Box
$obj->addMessages(MESSAGE [, MESSAGE, ...])
See "The folder" in Mail::Box
Mail::Box::MH->appendMessages(OPTIONS)
Append a message to a folder which is not open.
-Option--Defined in --Default
folder Mail::Box <required>
message Mail::Box undef
messages Mail::Box undef
share Mail::Box <false>
folder => FOLDERNAME
message => MESSAGE
messages => ARRAY-OF-MESSAGES
share => BOOLEAN
$obj->close(OPTIONS)
See "The folder" in Mail::Box
$obj->copyTo(FOLDER, OPTIONS)
See "The folder" in Mail::Box
$obj->delete(OPTIONS)
See "The folder" in Mail::Box
$obj->directory
See "The folder" in Mail::Box::Dir
$obj->folderdir([DIRECTORY])
See "The folder" in Mail::Box
$obj->name
See "The folder" in Mail::Box
$obj->organization
See "The folder" in Mail::Box
$obj->size
See "The folder" in Mail::Box
$obj->type
See "The folder" in Mail::Box
$obj->update(OPTIONS)
See "The folder" in Mail::Box
$obj->url
See "The folder" in Mail::Box
Folder flags
$obj->access
See "Folder flags" in Mail::Box
$obj->isModified
See "Folder flags" in Mail::Box
$obj->modified([BOOLEAN])
See "Folder flags" in Mail::Box
$obj->writable
See "Folder flags" in Mail::Box
The messages
$obj->current([NUMBER|MESSAGE|MESSAGE-ID])
See "The messages" in Mail::Box
$obj->find(MESSAGE-ID)
See "The messages" in Mail::Box
$obj->findFirstLabeled(LABEL, [BOOLEAN, [ARRAY-OF-MSGS]])
See "The messages" in Mail::Box
$obj->message(INDEX [,MESSAGE])
See "The messages" in Mail::Box
$obj->messageId(MESSAGE-ID [,MESSAGE])
See "The messages" in Mail::Box
$obj->messageIds
See "The messages" in Mail::Box
$obj->messages(['ALL',RANGE,'ACTIVE','DELETED',LABEL,!LABEL,FILTER])
See "The messages" in Mail::Box
$obj->nrMessages(OPTIONS)
See "The messages" in Mail::Box
$obj->scanForMessages(MESSAGE, MESSAGE-IDS, TIMESPAN, WINDOW)
See "The messages" in Mail::Box
Sub-folders
$obj->listSubFolders(OPTIONS)
Mail::Box::MH->listSubFolders(OPTIONS)
See "Sub-folders" in Mail::Box
$obj->nameOfSubFolder(SUBNAME, [PARENTNAME])
Mail::Box::MH->nameOfSubFolder(SUBNAME, [PARENTNAME])
See "Sub-folders" in Mail::Box
$obj->openRelatedFolder(OPTIONS)
See "Sub-folders" in Mail::Box
$obj->openSubFolder(SUBNAME, OPTIONS)
See "Sub-folders" in Mail::Box
$obj->topFolderWithMessages
Mail::Box::MH->topFolderWithMessages
See "Sub-folders" in Mail::Box
Internals
$obj->coerce(MESSAGE, OPTIONS)
See "Internals" in Mail::Box
$obj->create(FOLDERNAME, OPTIONS)
Mail::Box::MH->create(FOLDERNAME, OPTIONS)
-Option--Defined in--Default
folderdir Mail::Box undef
folderdir => DIRECTORY
$obj->determineBodyType(MESSAGE, HEAD)
See "Internals" in Mail::Box
$obj->folderToDirectory(FOLDERNAME, FOLDERDIR)
See "Internals" in Mail::Box::Dir
Mail::Box::MH->foundIn([FOLDERNAME], OPTIONS)
See "Internals" in Mail::Box
$obj->highestMessageNumber
Returns the highest number which is used in the folder to store a
file. This method may be called when the folder is read (then this
number can be derived without file-system access), but also when
the folder is not read (yet).
$obj->index
Create a index reader/writer object.
$obj->labels
Create a label reader/writer object.
$obj->lineSeparator([STRING|'CR'|'LF'|'CRLF'])
See "Internals" in Mail::Box
$obj->locker
See "Internals" in Mail::Box
$obj->read(OPTIONS)
See "Internals" in Mail::Box
$obj->readMessageFilenames(DIRECTORY)
See "Internals" in Mail::Box::Dir
$obj->readMessages(OPTIONS)
See "Internals" in Mail::Box
$obj->storeMessage(MESSAGE)
See "Internals" in Mail::Box
$obj->toBeThreaded(MESSAGES)
See "Internals" in Mail::Box
$obj->toBeUnthreaded(MESSAGES)
See "Internals" in Mail::Box
$obj->updateMessages(OPTIONS)
See "Internals" in Mail::Box
$obj->write(OPTIONS)
See "Internals" in Mail::Box
$obj->writeMessages(OPTIONS)-Option--Defined in --Default
messages Mail::Box <required>
renumber <true>
messages => ARRAY
renumber => BOOLEAN
Permit renumbering of message. By default this is true, but for
some unknown reason, you may be thinking that messages should not
be renumbered.
Other methods
$obj->timespan2seconds(TIME)
Mail::Box::MH->timespan2seconds(TIME)
See "Other methods" in Mail::Box
Error handling
$obj->AUTOLOAD
See "Error handling" in Mail::Reporter
$obj->addReport(OBJECT)
See "Error handling" in Mail::Reporter
$obj->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
Mail::Box::MH->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL,
CALLBACK])
See "Error handling" in Mail::Reporter
$obj->errors
See "Error handling" in Mail::Reporter
$obj->log([LEVEL [,STRINGS]])
Mail::Box::MH->log([LEVEL [,STRINGS]])
See "Error handling" in Mail::Reporter
$obj->logPriority(LEVEL)
Mail::Box::MH->logPriority(LEVEL)
See "Error handling" in Mail::Reporter
$obj->logSettings
See "Error handling" in Mail::Reporter
$obj->notImplemented
See "Error handling" in Mail::Reporter
$obj->report([LEVEL])
See "Error handling" in Mail::Reporter
$obj->reportAll([LEVEL])
See "Error handling" in Mail::Reporter
$obj->trace([LEVEL])
See "Error handling" in Mail::Reporter
$obj->warnings
See "Error handling" in Mail::Reporter
Cleanup
$obj->DESTROY
See "Cleanup" in Mail::Box
$obj->inGlobalDestruction
See "Cleanup" in Mail::Reporter
DETAILS
Different kinds of folders
Available folder types
Folder class implementation
How MH folders work
MH-type folders use a directory to store the messages of one folder.
Each message is stored in a separate file. This seems useful, because
changes in a folder change only a few of these small files, in contrast
with file-based folders where changes in a folder cause rewrites of
huge folder files.
However, MH-based folders perform very bad if you need header
information of all messages. For instance, if you want to have full
knowledge about all message-threads (see Mail::Box::Thread::Manager) in
the folder, it requires to read all header lines in all message files.
And usually, reading your messages in threads is desired.
So, each message is written in a separate file. The filenames are
numbers, which count from 1. Next to these message files, a directory
may contain a file named ".mh_sequences", storing labels which relate
to the messages. Furthermore, a folder-directory may contain sub-
directories, which are seen as sub-folders.
This implementation
This implementation supports the ".mh-sequences" file and sub-folders.
Next to this, considerable effort it made to avoid reading each
message-file. This should boost performance of the MailBox
distribution over other Perl-modules which are able to read folders.
Folder types which store their messages each in one file, together in
one directory, are bad for performance. Consider that you want to know
the subjects of all messages, while browser through a folder with your
mail-reading client. This would cause all message-files to be read.
Mail::Box::MH has two ways to try improve performance. You can use an
index-file, and use on delay-loading. The combination performs even
better. Both are explained in the next sections.
An index-file
If you specify new(keep_index), then all header-lines of all messages
from the folder which have been read once, will also be written into
one dedicated index-file (one file per folder). The default filename
is ".index"
However, index-files are not supported by any other reader which
supports MH (as far as I know). If you read the folders with such I
client, it will not cause unrecoverable conflicts with this index-file,
but at most be bad for performance.
If you do not (want to) use an index-file, then delay-loading may save
your day.
DIAGNOSTICS
Error: Cannot append message without lock on $folder.
It is impossible to append one or more messages to the folder which
is not opened, because locking it failes. The folder may be in use
by an other application, or you may need to specify some lock
related options (see new()).
Error: Cannot create MH folder $name: $!
For some reason, it is impossible to create the folder. Check the
permissions and the name of the folder. Does the path to the
directory to be created exist?
Error: Cannot write folder $name without lock.
It is impossible to get a lock on the folder, which means that the
changes can not be made. You may need to tune the lock related
options which are available at folder creation.
Warning: Changes not written to read-only folder $self.
You have opened the folder read-only --which is the default set by
new(access)--, made modifications, and now want to close it. Set
close(force) if you want to overrule the access mode, or close the
folder with close(write) set to "NEVER".
Error: Copying failed for one message.
For some reason, for instance disc full, removed by external
process, or read-protection, it is impossible to copy one of the
messages. Copying will proceed for the other messages.
Error: Destination folder $name is not writable.
The folder where the messages are copied to is not opened with
write access (see new(access)). This has no relation with write
permission to the folder which is controled by your operating
system.
Warning: Different messages with id $msgid
The message id is discovered more than once within the same folder,
but the content of the message seems to be different. This should
not be possible: each message must be unique.
Error: Folder $name is opened read-only
You can not write to this folder unless you have opened the folder
to write or append with new(access), or the "force" option is set
true.
Error: Folder $name not deleted: not writable.
The folder must be opened with write access via new(access),
otherwise removing it will be refused. So, you may have write-
access according to the operating system, but that will not
automatically mean that this "delete" method permits you to. The
reverse remark is valid as well.
Error: Invalid timespan '$timespan' specified.
The string does not follow the strict rules of the time span syntax
which is permitted as parameter.
Warning: Message-id '$msgid' does not contain a domain.
According to the RFCs, message-ids need to contain a unique random
part, then an "@", and then a domain name. This is made to avoid
the creation of two messages with the same id. The warning emerges
when the "@" is missing from the string.
Error: Package $package does not implement $method.
Fatal error: the specific package (or one of its superclasses) does
not implement this method where it should. This message means that
some other related classes do implement this method however the
class at hand does not. Probably you should investigate this and
probably inform the author of the package.
Error: Unable to create subfolder $name of $folder.
The copy includes the subfolders, but for some reason it was not
possible to copy one of these. Copying will proceed for all other
sub-folders.
Error: Unable to write message for $folder to $filename: $!
The new message could not be written to its new file, for the
specific reason.
Error: Writing folder $name failed
For some reason (you probably got more error messages about this
problem) it is impossible to write the folder, although you should
because there were changes made.
SEE ALSO
This module is part of Mail-Box distribution version 2.097, built on
January 26, 2011. Website: http://perl.overmeer.net/mailbox/
LICENSE
Copyrights 2001-2011 by Mark Overmeer. For other contributors see
ChangeLog.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. See
http://www.perl.com/perl/misc/Artistic.html
perl v5.14.1 2011-01-26 Mail::Box::MH(3)
