Enable fine-grained control on the mailboxes to consider.

Add 3 options:
  - list-mailbox
  - list-select-opts
  - ignore-mailbox

The first two control the initial LIST command, while the last one is a
regular expression to filter out mailboxes to exclude from the LIST
response.

3 files changed, 57 insertions, 7 deletions

diff --git a/imapsync b/imapsync
index 2a1bfcc..cc34287 100755
--- a/imapsync
+++ b/imapsync
@@ -66,7 +66,11 @@ usage(1) if defined $COMMAND and (($COMMAND eq 'delete' and !@ARGV) or $COMMAND
 my $CONF = read_config( delete $CONFIG{config} // $NAME
                       , [qw/_ local remote/]
                       , database => qr/\A(\P{Control}+)\z/
-                      , logfile => qr/\A(\P{Control}+)\z/ );
+                      , logfile => qr/\A(\/\P{Control}+)\z/
+                      , 'list-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
+                      , 'list-select-opts' => qr/\A([\x21\x23\x24\x26\x27\x2B-\x5B\x5E-\x7A\x7C-\x7E]+)\z/
+                      , 'ignore-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
+                      );
 my ($DBFILE, $LOCKFILE, $LOGGER_FD);
 
 {
@@ -238,7 +242,8 @@ foreach my $name (qw/local remote/) {
     my $list = '"" ';
     my @params;
     if (!defined $COMMAND or $COMMAND eq 'repair') {
-        $list .= '"*"' unless @ARGV;
+        $list  = '('.uc($CONF->{_}->{'list-select-opts'}).') '.$list if defined $CONF->{_}->{'list-select-opts'};
+        $list .= (defined $CONF->{_}->{'list-mailbox'} ? '('.$CONF->{_}->{'list-mailbox'}.')' : '*') unless @ARGV;
         @params = ('SUBSCRIBED', 'STATUS (UIDVALIDITY UIDNEXT HIGHESTMODSEQ)');
     }
     $list .= $#ARGV == 0 ? Net::IMAP::Sync::quote($ARGV[0])
@@ -404,6 +409,8 @@ my @MAILBOXES;
     my $sth_subscribe = $DBH->prepare(q{UPDATE mailboxes SET subscribed = ? WHERE idx = ?});
 
     @MAILBOXES = keys %mailboxes;
+    @MAILBOXES = grep !/$CONF->{_}->{'ignore-mailbox'}/, @MAILBOXES
+        if defined $CONF->{_}->{'ignore-mailbox'};
 
     foreach my $mailbox (@MAILBOXES) {
         check_delim($mailbox); # ensure that the delimiter match
diff --git a/imapsync.1 b/imapsync.1
index e274943..59093ef 100644
--- a/imapsync.1
+++ b/imapsync.1
@@ -73,8 +73,14 @@ Go back to step 1 to proceed with the next unsynchronized mailbox.
 .PP
 By default \fBimapsync\fR synchronizes each mailbox listed by the
 \(lqLIST "" "*"\(rq IMAP command;
-providing extra arguments limits the synchronization to the given
-\fIMAILBOX\fRes only.
+the \fIlist-mailbox\fR, \fIlist-select-opts\fR and \fIignore-mailbox\fR
+options from the configuration file can be used to shrink that list and
+save bandwidth.
+However if some extra argument are provided on the command line,
+\fBimapsync\fR ignores said options and synchronizes the given
+\fIMAILBOX\fRes instead.  Note that each \fIMAILBOX\fR is taken \(lqas
+is\(rq; in particular, it must be UTF-7 encoded, unquoted, and the list
+wildcards \(oq*\(cq and \(oq%\(cq are not interpolated.
 
 .PP
 If the synchronization was interrupted during a previous run while some
@@ -182,6 +188,42 @@ This option is only available in the default section.
 \(lq[remote]\(rq or \(lq[local]\(rq sections, in that order.
 
 .TP
+.I list-mailbox
+A space separated list of mailbox patterns to use when issuing the
+initial LIST command (overridden by the \fIMAILBOX\fRes given as
+command-line arguments).
+Note that each pattern containing special characters such as spaces or
+brackets (see [RFC3501] for the exact syntax) must be quoted.
+Furthermore, non-ASCII names must be UTF\-7 encoded.
+Two wildcards are available: a \(oq*\(cq character matches zero or more
+characters, while a \(oq%\(cq character matches zero or more characters
+up to the mailbox's hierarchy delimiter.
+This option is only available in the default section.
+(The default pattern, \(lq*\(rq, matches all visible mailboxes on the
+server.)
+
+.TP
+.I list-select-opts
+An optional space separated list of selectors for the initial LIST
+command.  (Requires a server supporting the LIST-EXTENDED [RFC5258]
+extension.)  Useful values are
+\(lqSUBSCRIBED\(rq (to list only subscribed mailboxes),
+\(lqREMOTE\(rq (to also list remote mailboxes on a server supporting
+mailbox referrals), and \(lqRECURSIVEMATCH\(rq (to list parent mailboxes
+with children matching one of the \fIlist-mailbox\fR pattern above).
+This option is only available in the default section.
+
+.TP
+.I ignore-mailbox
+An optional Perl Compatible Regular Expressions (PCRE) covering
+mailboxes to exclude:
+any (UTF-7 encoded, unquoted) mailbox listed in the initial LIST
+responses is ignored if it matches the given expression.
+Note that the \fIMAILBOX\fRes given as command-line arguments bypass the
+check and are always considered for synchronization.
+This option is only available in the default section.
+
+.TP
 .I logfile
 A file name to use to log debug and informational messages.  This option is
 only available in the default section.
diff --git a/lib/Net/IMAP/Sync.pm b/lib/Net/IMAP/Sync.pm
index 3faab63..48f61c1 100644
--- a/lib/Net/IMAP/Sync.pm
+++ b/lib/Net/IMAP/Sync.pm
@@ -78,10 +78,11 @@ sub read_config($$%) {
     foreach my $section (@$sections) {
         my $conf = defined $h->{_} ? { %{$h->{_}} } : {}; # default section
         $configs{$section} = $conf;
-        next unless defined $section and $section ne '_';
 
-        die "No such section $section\n" unless defined $h->{$section};
-        $conf->{$_} = $h->{$section}->{$_} foreach keys %{$h->{$section}};
+        if ($section ne '_') {
+            die "No such section $section\n" unless defined $h->{$section};
+            $conf->{$_} = $h->{$section}->{$_} foreach keys %{$h->{$section}};
+        }
 
         # default values
         $conf->{type} //= 'imaps';