NAME Linux::Inotify2 - scalable directory/file change notification SYNOPSIS use Linux::Inotify2; DESCRIPTION The Linux::Inotify2 Class This module implements an interface to the linux inotify file/directory change notification sytem. It has a number of advantages over the Linux::Inotfy module: - it is portable (Linux::Inotify only works on x86) - the equivalent of fullname works correctly - it is better documented - it has callback-style interface, which is better suited for integration. my $inotify = new Linux::Inotify2 Create a new notify object and return it. A notify object is kind of a container that stores watches on filesystem names and is responsible for handling event data. On error, "undef" is returned and $! will be set accordingly. The followign errors are documented: ENFILE The system limit on the total number of file descriptors has been reached. EMFILE The user limit on the total number of inotify instances has been reached. ENOMEM Insufficient kernel memory is available. $watch = $inotify2->watch ($name, $mask, $cb) Add a new watcher to the given notifier. The watcher will create events on the pathname $name as given in $mask, which can be any of the following constants (all exported by default) ORed together: IN_ACCESS File was accessed IN_MODIFY File was modified IN_ATTRIB Metadata changed IN_CLOSE_WRITE Writtable file was closed IN_CLOSE_NOWRITE Unwrittable file closed IN_OPEN File was opened IN_MOVED_FROM File was moved from X IN_MOVED_TO File was moved to Y IN_CREATE Subfile was created IN_DELETE Subfile was deleted IN_DELETE_SELF Self was deleted IN_ONESHOT only send event once IN_ALL_EVENTS All of the above events IN_CLOSE Same as IN_CLOSE_WRITE | IN_CLOSE_NOWRITE IN_MOVE Same as IN_MOVED_FROM | IN_MOVED_TO $cb is a perl code reference that is called for each event. It receives a "Linux::Inotify2::Event" object. The returned $watch object is of class "Linux::Inotify2::Watch". On error, "undef" is returned and $! will be set accordingly. The following errors are documented: EBADF The given file descriptor is not valid. EINVAL The given event mask contains no legal events. ENOMEM Insufficient kernel memory was available. ENOSPC The user limit on the total number of inotify watches was reached or the kernel failed to allocate a needed resource. EACCESS Read access to the given file is not permitted. Example, show when "/etc/passwd" gets accessed and/or modified once: $inotify->watch ("/etc/passwd", IN_ACCESS | IN_MODIFY, sub { my $e = shift; print "$e->{w}{name} was accessed\n" if $e->IN_ACCESS; print "$e->{w}{name} was modified\n" if $e->IN_MODIFY; print "$e->{w}{name} is no longer mounted\n" if $e->IN_UNMOUNT; print "events for $e->{w}{name} have been lost\n" if $e->IN_Q_OVERFLOW; $e->w->cancel; }); $inotify2->fileno Returns the fileno for this notify object. You are responsible for calling the "poll" method when this fileno becomes ready for reading. $count = $inotify2->poll Reads events from the kernel and handles them. If the notify fileno is blocking (the default), then this method waits for at least one event. Otherwise it returns immediately when no pending events could be read. Returns the count of events that have been handled. The Linux::Inotify2::Event Class Objects of this class are handed as first argument to the watch callback. It has the following members and methods: $event->w $event->{w} The watcher object for this event. $event->name $event->{name} The path of the filesystem object, relative to the watch name. $watch->fullname Returns the "full" name of the relevant object, i.e. including the "name" component of the watcher. $event->mask $event->{mask} The received event mask. In addition the the events described for "$inotify-"watch>, the following flags (exported by default) can be set: IN_ISDIR event occurred against dir IN_UNMOUNT Backing fs was unmounted IN_Q_OVERFLOW Event queued overflowed IN_IGNORED File was ignored (no more events will be delivered) $event->IN_xxx Returns a boolean that returns true if the event mask matches the event. All of the "IN_xxx" constants can be used as methods. $event->cookie $event->{cookie} The event cookie, can be used to synchronize two related events. The Linux::Inotify2::Watch Class Watch objects are created by calling the "watch" method of a notifier. It has the following members and methods: $watch->name $watch->{name} The name as specified in the "watch" call. For the object itself, this is the empty string. For directory watches, this is the name of the entry without leading path elements. $watch->mask $watch->{mask} The mask as specified in the "watch" call. $watch->cb ([new callback]) $watch->{cb} The callback as specified in the "watch" call. Can optionally be changed. $watch->cancel Cancels/removes this watch. Future events, even if already queued queued, will not be handled and resources will be freed. SEE ALSO Linux::Inotify. AUTHOR Marc Lehmann http://home.schmorp.de/