man Mail::Box::File () - handle file-based folders

NAME

Mail::Box::File - handle file-based folders

INHERITANCE

 Mail::Box::File
   is a Mail::Box
   is a Mail::Reporter


 Mail::Box::File is extended by
   Mail::Box::Dbx
   Mail::Box::Mbox

SYNOPSIS

DESCRIPTION

CWMail::Box::File is the base-class for all file-based folders: folders which bundle multiple messages into one single file. Usually, these messages are separated by a special line which indicates the start of the next one.

OVERLOADED

overload: "" See OVERLOADED in Mail::Box

overload: @{} See OVERLOADED in Mail::Box

overload: cmp See OVERLOADED in Mail::Box

METHODS

Constructors

Mail::Box::File->new(OPTIONS) 

 Option             Defined in       Default                                                         
 access             L<Mail::Box>     C<'r'>                                                          
 body_delayed_type  L<Mail::Box>     L<Mail::Message::Body::Delayed|Mail::Message::Body::Delayed>    
 body_type                           <see description>                                               
 coerce_options     L<Mail::Box>     C<[]>                                                           
 create             L<Mail::Box>     <false>                                                         
 extract            L<Mail::Box>     C<10240>                                                        
 field_type         L<Mail::Box>     undef                                                           
 fix_headers        L<Mail::Box>     <false>                                                         
 folder             L<Mail::Box>     C<$ENV{MAIL}>                                                   
 folderdir          L<Mail::Box>     C<$ENV{HOME}.'/Mail'>                                           
 head_delayed_type  L<Mail::Box>     L<Mail::Message::Head::Delayed|Mail::Message::Head::Delayed>    
 head_type          L<Mail::Box>     L<Mail::Message::Head::Complete|Mail::Message::Head::Complete>  
 keep_dups          L<Mail::Box>     <false>                                                         
 lock_extension                      C<'.lock'>                                                      
 lock_file          L<Mail::Box>     <foldername><lock-extension>                                    
 lock_timeout       L<Mail::Box>     1 hour                                                          
 lock_type          L<Mail::Box>     L<Mail::Box::Locker::DotLock|Mail::Box::Locker::DotLock>        
 lock_wait          L<Mail::Box>     10 seconds                                                      
 locker             L<Mail::Box>     undef                                                           
 log                L<Mail::Reporter>  C<'WARNINGS'>                                                   
 manager            L<Mail::Box>     undef                                                           
 message_type       L<Mail::Box>     L<Mail::Box::File::Message|Mail::Box::File::Message>            
 multipart_type     L<Mail::Box>     L<Mail::Message::Body::Multipart|Mail::Message::Body::Multipart>
 remove_when_empty  L<Mail::Box>     <true>                                                          
 save_on_exit       L<Mail::Box>     <true>                                                          
 trace              L<Mail::Reporter>  C<'WARNINGS'>                                                   
 trusted            L<Mail::Box>     <depends on folder location>                                    
 write_policy                        undef
. access MODE . body_delayed_type CLASS . body_type CLASS|CODE The default CWbody_type option for CWFile folders, which will cause messages larger than 10kB to be stored in files and smaller files in memory, is implemented like this: 
 sub determine_body_type($$)
 {   my $head = shift;
     my $size = shift || 0;
     'Mail::Message::Body::'
        . ($size > 10000 ? 'File' : 'Lines');
 }
. coerce_options ARRAY . create BOOLEAN . extract INTEGER | CODE | METHOD | 'LAZY'|'ALWAYS' . field_type CLASS . fix_headers BOOLEAN . folder FOLDERNAME . folderdir DIRECTORY . head_delayed_type CLASS . head_type CLASS . keep_dups BOOLEAN . lock_extension FILENAME|STRING When the dotlock locking mechanism is used, the lock is created with a hardlink to the folder file. For CWMail::Box::File type of folders, this file is by default named as the folder-file itself followed by CW.lock. For example: the CWMail/inbox folder file will have a hardlink made as CWMail/inbox.lock. You may specify an absolute filename, a relative (to the folder's directory) filename, or an extension (preceded by a dot). So valid examples are: 
 .lock        # appended to the folder's filename
 my_own_lockfile.test   # full filename, same dir
 /etc/passwd            # somewhere else
When the program runs with less priviledges (as normal user), often the default inbox folder can not be locked with the lockfile name which is produced by default. . 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 . write_policy 'REPLACE'|'INPLACE'|undef Sets the default write policy, as default for a later call to write(policy). With CWundef, the best policy is autodetected.

The folder

$obj->addMessage(MESSAGE, OPTIONS) See The folder in Mail::Box

$obj->addMessages(MESSAGE [, MESSAGE, ...]) See The folder in Mail::Box

Mail::Box::File->appendMessages(OPTIONS) Appending messages to a file based folder which is not opened is a little risky. In practice, this is often done without locking the folder. So, an other application may write to the folder at the same time... :( Hopefully, all goes fast enough that the chance on collition is small. All OPTIONS of Mail::Box::Mbox::new() can be supplied. 

 Option     Defined in       Default   
 folder     L<Mail::Box>     <required>
 lock_type                   C<NONE>   
 message    L<Mail::Box>     undef     
 messages   L<Mail::Box>     undef     
 share      L<Mail::Box>     <false>
. folder FOLDERNAME . lock_type ... See Mail::Box::new(lock_type) for possible values. . 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->filename Returns the filename for this folder, which may be an absolute or relative path to the file. Example: 

 print $folder->filename;

$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::File->listSubFolders(OPTIONS) See Sub-folders in Mail::Box

$obj->nameOfSubFolder(SUBNAME, [PARENTNAME])

Mail::Box::File->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::File->topFolderWithMessages See Sub-folders in Mail::Box

Internals

$obj->coerce(MESSAGE, OPTIONS) See Internals in Mail::Box

$obj->create(FOLDERNAME, OPTIONS)

Mail::Box::File->create(FOLDERNAME, OPTIONS) 

 Option     Defined in    Default
 folderdir  L<Mail::Box>  undef
. folderdir DIRECTORY

$obj->determineBodyType(MESSAGE, HEAD) See Internals in Mail::Box

$obj->folderToFilename(FOLDERNAME, FOLDERDIR, [SUBEXT])

Mail::Box::File->folderToFilename(FOLDERNAME, FOLDERDIR, [SUBEXT]) Translate a folder name into a filename, using the FOLDERDIR value to replace a leading CW=. SUBEXT is only used for MBOX folders.

Mail::Box::File->foundIn([FOLDERNAME], OPTIONS) See Internals in Mail::Box

$obj->lineSeparator([STRING|'CR'|'LF'|'CRLF']) See Internals in Mail::Box

$obj->locker See Internals in Mail::Box

$obj->messageCreateOptions([TYPE, CONFIG]) Returns a key-value list of options to be used each time a new message is read from a file. The list is preceeded by the TYPE of message which has to be created. This data is used by readMessages() and updateMessages(). With TYPE and CONFIG, a new configuration is set.

$obj->moveAwaySubFolder(DIRECTORY, EXTENSION) The DIRECTORY is renamed by appending the EXTENSION, which defaults to CW".d", to make place for a folder file on that specific location. CWfalse is returned if this failed.

$obj->parser Create a parser for this mailbox. The parser stays alive as long as the folder is open.

$obj->read(OPTIONS) See Internals in Mail::Box

$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) For file based folders, the file handle stays open until the folder is closed. Update is therefore rather simple: move to the end of the last known message, and continue reading...

$obj->write(OPTIONS) 

 Option        Defined in       Default
 force         L<Mail::Box>     <false>
 policy                         undef  
 save_deleted  L<Mail::Box>     <false>
. force BOOLEAN . policy 'REPLACE'|'INPLACE'|undef In what way will the mail folder be updated. If not specified during the write, the value of the new(write_policy) at folder creation is taken. Valid values: First a new folder is written in the same directory as the folder which has to be updated, and then a call to move will throw away the old immediately replacing it by the new. Writing in CWREPLACE module is slightly optimized: messages which are not modified are copied from file to file, byte by byte. This is much faster than printing the data which is will be done for modified messages. The original folder file will be opened read/write. All message which where not changed will be left untouched, until the first deleted or modified message is detected. All further messages are printed again. As default, or when CWundef is explicitly specified, first CWREPLACE mode is tried. Only when that fails, an CWINPLACE update is performed. CWINPLACE will be much faster than CWREPLACE when applied on large folders, however requires the CWtruncate function to be implemented on your operating system (at least available for recent versions of Linux, Solaris, Tru64, HPUX). It is also dangerous: when the program is interrupted during the update process, the folder is corrupted. Data may be lost. However, in some cases it is not possible to write the folder with CWREPLACE. For instance, the usual incoming mail folder on UNIX is stored in a directory where a user can not write. Of course, the CWroot and CWmail users can, but if you want to use this Perl module with permission of a normal user, you can only get it to work in CWINPLACE mode. Be warned that in this case folder locking via a lockfile is not possible as well. . save_deleted BOOLEAN

$obj->writeMessages(OPTIONS) See Internals in Mail::Box

File based folders

File based folders maintain a folder (a set of messages) in one single file. The advantage is that your folder has only one single name, which speeds-up access to all messages at once.

The disadvantage over directory based folder (see Mail::Box::Dir) is that you have to construct some means to keep all message apart, for instance by adding a message separator, and this will cause problems. Where access to all messages at once is faster in file based folders, access to a single message is (much) slower, because the whole folder must be read.

File based folders

File based folders maintain a folder (a set of messages) in one single file. The advantage is that your folder has only one single name, which speeds-up access to all messages at once.

The disadvantage over directory based folder (see Mail::Box::Dir) is that you have to construct some means to keep all message apart, for instance by adding a message separator, and this will cause problems. Where access to all messages at once is faster in file based folders, access to a single message is (much) slower, because the whole folder must be read.

Other methods

$obj->timespan2seconds(TIME)

Mail::Box::File->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::File->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::File->log([LEVEL [,STRINGS]]) See Error handling in Mail::Reporter

$obj->logPriority(LEVEL)

Mail::Box::File->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

DIAGNOSTICS

Error: Cannot append messages to folder file CW$filename: $!

Appending messages to a not-opened file-organized folder may fail when the operating system does not allow write access to the file at hand.

Error: Cannot create directory CW$dir for folder CW$name.

While creating a file-organized folder, at most one level of directories is created above it. Apparently, more levels of directories are needed, or the operating system does not allow you to create the directory.

Error: Cannot create folder file CW$name: $!

The file-organized folder file cannot be created for the indicated reason. In common cases, the operating system does not grant you write access to the directory where the folder file should be stored.

Error: Cannot get a lock on CW$type folder CW$self.

A lock is required to get access to the folder. If no locking is needed, specify the NONE lock type.

Error: Cannot move away sub-folder CW$dir

Warning: Cannot remove folder CW$name file CW$filename: $!

Writing an empty folder will usually cause that folder to be removed, which fails for the indicated reason. new(remove_when_empty)

Warning: Cannot remove folder CW$name file CW$filename: $!

Writing an empty folder will usually cause that folder to be removed, which fails for the indicated reason. new(remove_when_empty) controls whether the empty folder will removed; setting it to false (CW0) may be needed to avoid this message.

Error: Cannot replace CW$filename by CW$tempname, to update folder CW$name: $!

The replace policy wrote a new folder file to update the existing, but was unable to give the final touch: replacing the old version of the folder file for the indicated reason.

Warning: Changes not written to read-only folder CW$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 CWNEVER.

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 CW$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 CW$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: File too short to get write message CW$nr ($size, CW$need)

Mail::Box is lazy: it tries to leave messages in the folders until they are used, which saves time and memory usage. When this message appears, something is terribly wrong: some lazy message are needed for updating the folder, but they cannot be retreived from the original file anymore. In this case, messages can be lost.

This message does appear regularly on Windows systems when using the 'replace' write policy. Please help to find the cause, probably something to do with Windows incorrectly handling multiple filehandles open in the same file.

Warning: Folder CW$name file CW$filename is write-protected.

The folder is opened writable or for appending via new(access), but the operating system does not permit writing to the file. The folder will be opened read-only.

Error: Folder CW$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 CWdelete 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 CW@, and then a domain name. This is made to avoid the creation of two messages with the same id. The warning emerges when the CW@ is missing from the string.

Error: Package CW$package does not implement CW$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 CW$name of CW$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 update folder CW$self.

When a folder is to be written, both replace and inplace write policies are tried, If both fail, the whole update fails. You may see other, related, error messages to indicate the real problem.

DETAILS

REFERENCES

See the MailBox website at <http://perl.overmeer.net/mailbox/> for more details.

COPYRIGHTS

Distribution version 2.063. Written by Mark Overmeer (mark@overmeer.net). See the ChangeLog for other contributors.

Copyright (c) 2001-2003 by the author(s). All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.