At 7PM -0500 on 30/01/13 you (Bret Martin) wrote:

On Jan 30, 2013, at 6:56 PM, Ben Morrow <ben@morrow.me.uk> wrote:

...

I would do this by scripting IMAP access. Perl's Mail::IMAPClient has explicit support for running dovecot/imap in preauth mode, so you don't even have to authenticate. Of course, you need a Dovecot user account with access to all the relevant messages.

Thanks so much for your help! This sounds like a great option to me.

For "explicit" support, I'm having a lot of trouble finding out how to have Mail::IMAPClient invoke /usr/lib/dovecot/imap instead of connecting over the network -- could you provide any pointers?

Ack, sorry, I was misremembering: it's Net::IMAP::Simple that has explicit support (note that the dovecot invocation example in the perldoc is for dovecot 1.x, for 2.x you just run $prefix/libexec/dovecot/imap directly).

Mail::IMAPClient (which I usually prefer) will work with a preauthenticated socket, but you need to create a socketpair explicitly, fork and exec dovecot/imap with one end of the pair on STDIN/STDOUT, then pass the other end to Mail::IMAPClient->new as the Socket parameter. Something like this (I've left out error checking)

use Socket;

socketpair my $DOVE, my $CLIENT, AF_UNIX, SOCK_STREAM, PF_UNSPEC;

unless (fork) {
    open STDIN, "<&", $CLIENT;
    open STDOUT, ">&", $CLIENT;
    exec "/usr/local/libexec/dovecot/imap";
}
close $CLIENT;

my $IMAP = Mail::IMAPClient->new(
    Socket  => $DOVE,
    # other options
);

# don't forget to wait for the imap process when you've finished

Ben

At 3PM -0500 on 12/02/13 you (Bret Martin) wrote:

To close the loop on this, I ended up doing the following, although it seems to fail on mailboxes with large numbers of messages (on the order of 10,000 or so; I didn't test carefully enough to find the exact number)

use Mail::IMAPClient;
use Socket;
use strict;

socketpair( my $dovecot, my $client, AF_UNIX, SOCK_STREAM, PF_UNSPEC );

unless ( fork() ) {
    open( STDIN,  '<&', $client );
    open( STDOUT, '>&', $client );
    exec( '/usr/lib/dovecot/imap' );
}
close( $client );

my $imap = Mail::IMAPClient->new( Socket => $dovecot );

foreach my $folder( sort $imap->folders() ) {
    print( "$folder\n" );
    $imap->select( $folder );
    $imap->set_flag( 'Seen', $imap->search( 'ALL' ) );
}

You're not specifying Ranges in the ->new call, and you're calling ->search in list context; either of these will force ->search to return a complete list of message numbers, which you are then trying to pass back in a single IMAP command. You want to either loop through the messages or set Ranges and call ->search in scalar context to get an (object which stringifies to an) IMAP range specification, which will be much shorter than the whole list.

Ben