NAME
Mail::Transport::Dbx - Parse Outlook Express mailboxes
SYNOPSIS
use Mail::Transport::Dbx;
my $dbx = Mail::Transport::Dbx->new("box.mbx");
for my $i (0 .. $dbx->msgcount - 1) {
my $msg = $dbx->get($i);
print $msg->subject;
...
}
ABSTRACT
Mail::Transport::Dbx reads dbx files (and the special
Folders.dbx) to extract contained subfolders or messages.
It can be used to convert a dbx file into the more standard
mbox format.
This module is also used as a backend by Mail::Box to
parse Outlook Express mailboxes.
DESCRIPTION
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.
METHODS
The following are methods for Mail::Transport::Dbx objects:
- new(filename)
- new(filehandle-ref)
-
Passed either a string being the filename or an already opened and readable filehandle ref,
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 aneval()
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 items stored in the dbx structure. If you previously opened Folders.dbx
msgcount()
returns the number of subfolders in it. Otherwise it returns the number of messages.msgcount() - 1
is the index of the last item. - get(n)
-
Get the item at the n-th position. First item is at position 0.
get()
is actually a factory method so it either returns aMail::Transport::Dbx::Email
orMail::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);
$item
will now definitely be aMail::Transport::Dbx::Folder
object since Folders.dbx doesn't contain emails but references to subfolders.You can use the
is_email()
andis_folder()
method to check for its type:if ($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
-
Whenever an error occurs,
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;
- error
-
Similar to
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:
- as_string
-
Returns the whole message (header and body) as one large string.
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.
- header
-
Returns the header-portion of the whole email.
With respect to newlines the same as described under
as_string()
applies. - body
-
Returns the body-portion of the whole email.
With respect to newlines the same as described under
as_string()
applies. - subject
-
Returns the subject of the email as a string.
- psubject
-
Returns the processed subject of the email as a string. 'Processed' means that additions such as "Re:" etc. are cut off.
- msgid
-
Returns the message-id of the message as a string.
- parents_ids
-
Returns the message-ids of the parent messages as a string.
- sender_name
-
Returns the name of the sender of this email as a string.
- sender_address
-
Returns the address of the sender of this email as a string.
- recip_name
-
Returns the name of the recipient of this email as a string. This might be your name. ;-)
- recip_address
-
Returns the address of the recipient of this email as a string.
- oe_account_name
-
Returns the Outlook Express account name this message was retrieved with as a string.
- oe_account_num
-
Outlook Express accounts also seem to have a numerical representation. This method will return this as a string (something like "0000001").
- fetched_server
-
Returns the name of the POP server that this message was retrieved from as a string.
- rcvd_localtime
-
This is the exact duplicate of Perl's builtin
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_gmtime
-
Same as
rcvd_localtime()
but returning a date conforming to GMT. - date_received( [format, [len, [gmtime]]] )
-
This method returns the date this message was received by you as a string. The date returned is calculated according to
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 forstrftime(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 tostrftime()
. This method uses 25 as defaultThe 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);
- is_seen
-
Returns a true value if this message has already been seen. False otherwise.
- is_email
-
Always returns true for this kind of object.
- is_folder
-
Always returns false for this kind of object.
The following methods exist for Mail::Transport::Dbx::Folder objects:
- dbx
-
This is a convenience method. It creates a
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. - num
-
The index number of this folder. This is the number you passed to
$dbx->get()
to retrieve this folder. - type
-
According to libdbx.h this returns one of
DBX_TYPE_FOLDER
orDBX_TYPE_EMAIL
. Use it to check whether the folder contains emails or other folders. - name
-
The name of the folder.
- file
-
The filename of the folder. Use this, to create a new
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.
- id
-
Numerical id of the folder. Not sure what this is useful for.
- parent_it
-
Numerical id of the parent's folder.
EXPORT
None by default.
Exportable constants
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);
- Error-Codes
-
DBX_NOERROR
No error occured.
DBX_BADFILE
Dbx file operation failed (open or close)
DBX_DATA_READ
Reading of data from dbx file failed
DBX_INDEXCOUNT
Index out of range
DBX_INDEX_OVERREAD
Request was made for index reference greater than exists
DBX_INDEX_UNDERREAD
Number of indexes read from dbx file is less than expected
DBX_INDEX_READ
Reading of Index Pointer from dbx file failed
DBX_ITEMCOUNT
Reading of Item Count from dbx file failed
DBX_NEWS_ITEM
Item is a news item not an email
- Dbx types
-
One of these is returned by
$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.DBX_TYPE_EMAIL
DBX_TYPE_FOLDER
DBX_TYPE_NEWS
Don't use this one!
DBX_TYPE_VOID
I have no idea what this is for.
CAVEATS
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.
KNOWN BUGS
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.
SEE ALSO
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.
AUTHOR
Tassilo von Parseval, <tassilo.von.parseval@rwth-aachen.de>
COPYRIGHT AND LICENSE
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.
1 POD Error
The following errors were encountered while parsing the POD:
- Around line 374:
You forgot a '=back' before '=head1'