Box::MH::Labels(3)

NAME
Mail::Box::MH::Labels - process file which maintains message related labels

CLASS HIERARCHY
 Mail::Box::MH::Labels
 is a Mail::Reporter

SYNOPSIS
 my $labels = Mail::Box::MH::Labels->new;
 $labels->read(...)
 $labels->write(...)

DESCRIPTION
MH type message folders use one dedicated file per folder-directory to list special tags to messages in that folder. By doing this, mail agents may avoid parsing all the messages, which is very resource consuming.

Labels can be used to group messages, for instance to reflect which messages have been read or which look like spam.

Typically, the file which contains the labels is called ".mh_sequences". The MH messages are numbered from 1. As example content for ".mh_sequences":

   cur: 93
   unseen: 32 35-56 67-80

To generalize labels on messages, two are treated specially:

* cur
    The "cur" specifies the number of the message where the user stopped reading mail from this folder at last access. Internally in these modules refered to as label "current".

* unseen
    With "unseen" is listed which message was never read. This must be a mistake in the design of MH: it must be a source of confusion. People should never use labels with a negation in the name:

        if($seen)           if(!$unseen)    #yuk!
        if(!$seen)          if($unseen)
        unless($seen)       unless($unseen) #yuk!

    So: label "unseen" is translated into "seen" for internal use.

METHOD INDEX
Methods prefixed with an abbreviation are described in Mail::Reporter (MR).

The general methods for "Mail::Box::MH::Labels" objects:

   MR errors                            MR reportAll [LEVEL]
   MR log [LEVEL [,STRINGS]]            MR trace [LEVEL]
   MR new OPTIONS                       MR warnings
   MR report [LEVEL]

The extra methods for extension writers:

   MR AUTOLOAD                          MR logPriority LEVEL
   MR DESTROY                           MR logSettings
   MR inGlobalDestruction               MR notImplemented

METHODS

    new OPTIONS
        This method is called by folder classes, and should not be called by client programs. If you wish to control how indexing occurs, use the following options when creating a folder.

         OPTION         DEFINED BY         DEFAULT
         filename       Mail::Box::Labels  <obligatory>
         log            Mail::Reporter     'WARNINGS'
         trace          Mail::Reporter     'WARNINGS'

        * filename => FILENAME
            The FILENAME which is used in each directory to store the headers of all mails. The filename must be an absolute path.

    read
        Read all label information from file.

    write MESSAGES
        Write the labels related to the specified messages to the label file.

    append MESSAGES
        Append the label information about the specified MESSAGES to the end of the label file. The information will not be merged with the information already present in the label file.

    print FILEHANDLE, MESSAGES
        Print the messages to the specified open file.

    get MSGNR
        Look if there is label info for message MSGNR.

METHODS for extension writers

filename
    Returns the name of the index file.

SEE ALSO
Mail::Box-Overview

For support and additional documentation, see http://perl.overmeer.net/mailbox/

AUTHOR
Mark Overmeer (mailbox@overmeer.net). All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

VERSION
This code is beta, version 2.018.

Copyright (c) 2001-2002 Mark Overmeer. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.