Mail::Transport::Dbx - Parse Outlook Express mailboxes |
Mail::Transport::Dbx - Parse Outlook Express mailboxes
use Mail::Transport::Dbx;
my $dbx = eval { Mail::Transport::Dbx->new("box.mbx") }; die $@ if $@;
for my $i (0 .. $dbx->msgcount - 1) { my $msg = $dbx->get($i); print $msg->subject; ... }
# more convenient for my $msg ($dbx->emails) { print $msg->subject; ... }
Read dbx files (mailbox files of Outlook Express)
Mail::Transport::Dbx gives you platform independent access to Outlook Express' dbx files. Extract subfolders, messages etc. from those or use it to convert dbx archives into a more portable format (such as standard mbox format).
It relies on LibDBX to do its job. The bad news: LibDBX knows nothing about the endianness of your machine so it does not work on big-endian machines such as Macintoshs or SUNs. The good news: I made the appropriate patches so that it in fact does work even on machines with the 'wrong' byteorder (exception: machines with an even odder byteorder such as Crays are not suppored; exception from the exception: If you buy me a Cray I'll promise to fix it. :-).
You have to understand the structure of .dbx files to make proper use of this module. Outlook Express keeps a couple of those files on your harddisk. For instance:
Folders.dbx folder1.dbx comp.lang.perl.misc.dbx
The nasty thing about that is that there are really two different kinds of such files: One that contains the actual messages and one that merely holds references to other .dbx files. Folders.dbx could be considered the toplevel file since it lists all other available .dbx files. As for folder1.dbx and comp.lang.perl.misc.dbx you can't yet know whether they contain messages or subfolders (though comp.lang.perl.misc.dbx probably contains newsgroup messages that are treated as mere emails).
Fortunately this module gives you the information you need. A common approach would be the following:
1) create a new Mail::Transport::Dbx object from "Folders.dbx"
2) iterate over its items using the get() method 2.1 if it returns a Mail::Transport::Dbx::Email => a message 2.2 if it returns a Mail::Transport::Dbx::Folder => a folder
3) if message 3.1 call whatever method from Mail::Transport::Dbx::Email you need
4) if folder 4.1 call whatever method from Mail::Transport::Dbx::Folder you need OR 4.2 call dbx() on it to create a new Mail::Transport::Dbx object 4.2.1 if dbx() returned something defined => rollback to item 2)
The confusing thing is that .dbx files may contain references to other folders that don't really exist! If Outlook Express was used a newsclient this is a common scenario since Folders.dbx lists all newsgroups as separate Mail::Transport::Dbx::Folder
objects no matter whether you are subscribed to any of those or not. So in essence calling dbx()
on a folder will only return a new object if the corresponding .dbx file exists.
The following are methods for Mail::Transport::Dbx objects:
new()
will construct a Mail::Transport::Dbx object from that.
This happens regardless of whether you open an ordinary dbx file or the special Folders.dbx file that contains an overview over all available dbx subfolders.
If opening fails for some reason your program will instantly die()
so be sure to wrap the constructor into an eval()
and check for $@
:
my $dbx = eval { Mail::Transport::Dbx->new( "file.dbx" ) }; die $@ if $@;
Be careful with using a filehandle, though. On Windows, you might need to use binmode()
on your handle or otherwise the stream from your dbx file might get corrupted.
msgcount()
returns the number of subfolders in it. Otherwise it returns the number of messages. msgcount() - 1
is the index of the last item.
if ($dbx->emails) { print "I contain emails"; } else { print "I contain subfolders"; }
This is useful for iterations:
for my $msg ($dbx->emails) { ... }
Mail::Transport::Dbx::Folder
objects. In boolean (scalar) context it returns true of the file contains subfolders and false if it contains emails.
Remember that you still have to call dbx()
on these subfolders if you want to do something useful with them:
for my $sub ($dbx->subfolders) { if (my $d = $sub->dbx) { # $d now a proper Mail::Transport::Dbx object # with content } else { print "Subfolder referenced but non-existent"; } }
get()
is actually a factory method so it either returns a Mail::Transport::Dbx::Email
or Mail::Transport::Dbx::Folder
object. This depends on the folder you call this method upon:
my $dbx = Mail::Transport::Dbx->new( "Folders.dbx" ); my $item = $dbx->get(0);
$item
will now definitely be a Mail::Transport::Dbx::Folder
object since Folders.dbx doesn't contain emails but references to subfolders.
You can use the is_email()
and is_folder()
method to check for its type:
if ($item->is_email) { print $item->subject; } else { # it's a subfolder ... }
On an error, this method returns an undefined value. Check $dbx->errstr
to find out what went wrong.
errstr()
will contain a string giving you further help what went wrong.
WARNING: Internally it relies on a global variable so all objects will have the same error-string! That means it only makes sense to use it after an operation that potentially raises an error:
# example 1 my $dbx = Mail::Transport::Dbx->new("box.dbx") or die Mail::Transport::Dbx->errstr;
# example 2 my $msg = $dbx->get(5) or print $dbx->errstr;
errstr()
, only that it will return an error code. See ``Exportable constants/Error-Codes'' under EXPORT for codes that can be returned.
The following are the methods for Mail::Transport::Dbx::Email objects:
Note that the string still contains the raw newlines as used by DOSish systems (\015\012). If you want newlines to be represented in the native format of your operating system, use the following:
my $email = $msg->as_string; $email =~ s/\015\012/\n/g;
On Windows this is a no-op so you can ommit this step.
Especially for news-articles this method may return undef
. This always happens when the particular articles was only partially downloaded (that is, only header retrieved from the newsserver). There is no way to retrieve this header literally with header
. Methods like subject
etc. however do work.
With respect to newlines the same as described under as_string()
applies.
With respect to newlines the same as described under as_string()
applies.
localtime()
applied to the date this message was received. It returns a string in scalar context and a list with nine elements in list context. See 'perldoc -f localtime' for details.
rcvd_localtime()
but returning a date conforming to GMT.
localtime()
.
Without additional arguments, the string returned looks something like
Sun Apr 14 02:27:57 2002
The optional first argument is a string describing the format of the date line. It is passed unchanged to strftime(3)
. Please consult your system's documentation for strftime(3)
to see how such a string has to look like. The default string to render the date is ``%a %b %e %H:%M:%S %Y''.
The optional second argument is the max string length to be returned by date_received()
. This parameter is also passed unaltered to strftime()
. This method uses 25 as default
The third argument can be set to a true value if you rather want to get a date in GMT. So if you want to get the GMT of the date but want to use the default rendering settings, you will have to provide them yourself:
print $msg->date_received("%a %b %e %H:%M:%S %Y", 25, 1);
The following methods exist for Mail::Transport::Dbx::Folder objects:
Mail::Transport::Dbx
object from the folder object. If the folder is only mentioned but not physically existing on your hard-drive (either because you deleted the .dbx file or it was actually never there which especially happens for newsgroup files) dbx
returns an undefined value.
Please read DESCRIPTION again to learn why dbx()
can return an undefined value.
$dbx->get()
to retrieve this folder.
DBX_TYPE_FOLDER
or DBX_TYPE_EMAIL
. Use it to check whether the folder contains emails or other folders.
Mail::Transport::Dbx
object:
# $folder is a Mail::Transport::Dbx::Folder object my $new_dbx = Mail::Transport::Dbx->new( $folder->file );
Consider using the dbx()
method instead.
This method returns an undefined value if there is no .dbx file belonging to this folder.
None by default.
If you intend to use any of the following constants, you have to import them when use()
ing the module. You can import them all in one go thusly:
use Mail::Transport::Dbx qw(:all);
Or you import only those you need:
use Mail::Transport::Dbx qw(DBX_TYPE_EMAIL DBX_TYPE_FOLDER);
$folder->type
so you can check whether the folder contains emails or subfolders. Note that only DBX_TYPE_EMAIL and DBX_TYPE_FOLDER are ever returned so even newsgroup postings are of the type DBX_TYPE_EMAIL.
You can't retrieve the internal state of the objects using Data::Dumper
or so since Mail::Transport::Dbx
uses a blessed scalar to hold a reference to the respective C structures. That means you have to use the provided methods for each object. Call that strong encapsultion if you need an euphemism for that.
There are currently no plans to implement write access to .dbx files. I leave that up to the authors of libdbx.
Other than that I don't know yet of any. This, of course, has never actually been a strong indication for the absence of bugs.
http://sourceforge.net/projects/ol2mbox hosts the libdbx package. It contains the library backing this module along with a description of the file format for .dbx files.
Tassilo von Parseval, <tassilo.von.parseval@rwth-aachen.de>
Copyright 2003 by Tassilo von Parseval
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
Mail::Transport::Dbx - Parse Outlook Express mailboxes |