cvsroot/Linux-Inotify2/Inotify2.pm

=head1 NAME

Linux::Inotify2 - scalable directory/file change notification

=head1 SYNOPSIS

=head2 Callback Interface

 use Linux::Inotify2;

 # create a new object
 my $inotify = new Linux::Inotify2
    or die "unable to create new inotify object: $!";
 
 # add watchers
 $inotify->watch ("/etc/passwd", IN_ACCESS, sub {
    my $e = shift;
    my $name = $e->fullname;
    print "$name was accessed\n" if $e->IN_ACCESS;
    print "$name is no longer mounted\n" if $e->IN_UNMOUNT;
    print "$name is gone\n" if $e->IN_IGNORED;
    print "events for $name have been lost\n" if $e->IN_Q_OVERFLOW;
 
    # cancel this watcher: remove no further events
    $e->w->cancel;
 });

 # integration into AnyEvent (works with EV, Glib, Tk, POE...)
 my $inotify_w = AE::io $inotify->fileno, 0, sub { $inotify->poll };

 # manual event loop
 1 while $inotify->poll;

=head2 Streaming Interface

 use Linux::Inotify2 ;

 # create a new object
 my $inotify = new Linux::Inotify2
    or die "Unable to create new inotify object: $!" ;

 # create watch
 $inotify->watch ("/etc/passwd", IN_ACCESS)
    or die "watch creation failed" ;

 while () {
   my @events = $inotify->read;
   unless (@events > 0) {
     print "read error: $!";
     last ;
   }
   printf "mask\t%d\n", $_->mask foreach @events ; 
 }

=head1 DESCRIPTION

This module implements an interface to the Linux 2.6.13 and later Inotify
file/directory change notification system.

It has a number of advantages over the Linux::Inotify 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.

=head2 The Linux::Inotify2 Class

=over 4

=cut

package Linux::Inotify2;

use Scalar::Util ();

use common::sense;

use Exporter qw(import);

BEGIN {
   our $VERSION = '1.22';
   our @EXPORT = qw(
      IN_ACCESS IN_MODIFY IN_ATTRIB IN_CLOSE_WRITE
      IN_CLOSE_NOWRITE IN_OPEN IN_MOVED_FROM IN_MOVED_TO
      IN_CREATE IN_DELETE IN_DELETE_SELF IN_MOVE_SELF
      IN_ALL_EVENTS
      IN_UNMOUNT IN_Q_OVERFLOW IN_IGNORED
      IN_CLOSE IN_MOVE
      IN_ISDIR IN_ONESHOT IN_MASK_ADD IN_DONT_FOLLOW IN_ONLYDIR
   );

   require XSLoader;
   XSLoader::load Linux::Inotify2, $VERSION;
}

=item 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 file system names and is responsible for
handling event data.

On error, C<undef> is returned and C<$!> will be set accordingly. The
following 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.

Example:

   my $inotify = new Linux::Inotify2
      or die "Unable to create new inotify object: $!";

=cut

sub new {
   my ($class) = @_;

   my $fd = inotify_init;

   return unless $fd >= 0;

   bless { fd => $fd }, $class
}

=item $watch = $inotify->watch ($name, $mask[, $cb])

Add a new watcher to the given notifier. The watcher will create events
on the pathname C<$name> as given in C<$mask>, which can be any of the
following constants (all exported by default) ORed together.

"file" refers to any file system object in the watched object (always a
directory), that is files, directories, symlinks, device nodes etc., while
"object" refers to the object the watcher has been set on itself:

 IN_ACCESS            object was accessed
 IN_MODIFY            object was modified
 IN_ATTRIB            object metadata changed
 IN_CLOSE_WRITE       writable fd to file / to object was closed
 IN_CLOSE_NOWRITE     readonly fd to file / to object closed
 IN_OPEN              object was opened
 IN_MOVED_FROM        file was moved from this object (directory)
 IN_MOVED_TO          file was moved to this object (directory)
 IN_CREATE            file was created in this object (directory)
 IN_DELETE            file was deleted from this object (directory)
 IN_DELETE_SELF       object itself was deleted
 IN_MOVE_SELF         object itself was moved
 IN_ALL_EVENTS        all of the above events

 IN_ONESHOT           only send event once
 IN_ONLYDIR           only watch the path if it is a directory
 IN_DONT_FOLLOW       don't follow a sym link
 IN_MASK_ADD          not supported with the current version of this module

 IN_CLOSE             same as IN_CLOSE_WRITE | IN_CLOSE_NOWRITE
 IN_MOVE              same as IN_MOVED_FROM | IN_MOVED_TO

C<$cb> is a perl code reference that, if given, is called for each
event. It receives a C<Linux::Inotify2::Event> object.

The returned C<$watch> object is of class C<Linux::Inotify2::Watch>.

On error, C<undef> is returned and C<$!> 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 C</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;
   });

=cut

sub watch {
   my ($self, $name, $mask, $cb) = @_;

   my $wd = inotify_add_watch $self->{fd}, $name, $mask;

   return unless $wd >= 0;
   
   my $w = $self->{w}{$wd} = bless {
      inotify => $self,
      wd      => $wd,
      name    => $name,
      mask    => $mask,
      cb      => $cb,
   }, "Linux::Inotify2::Watch";

   Scalar::Util::weaken $w->{inotify};

   $w
}

=item $inotify->fileno

Returns the file descriptor for this notify object. When in non-blocking
mode, you are responsible for calling the C<poll> method when this file
descriptor becomes ready for reading.

=cut

sub fileno {
   $_[0]{fd}
}

=item $inotify->blocking ($blocking)

Clears ($blocking true) or sets ($blocking false) the C<O_NONBLOCK> flag on the file descriptor.

=cut

sub blocking {
   my ($self, $blocking) = @_;

   inotify_blocking $self->{fd}, $blocking;
}

=item $count = $inotify->poll

Reads events from the kernel and handles them. If the notify file
descriptor is blocking (the default), then this method waits for at least
one event (and thus returns true unless an error occurs). Otherwise it
returns immediately when no pending events could be read.

Returns the count of events that have been handled.

=cut

sub poll {
   scalar &read
}

=item @events = $inotify->read

Reads events from the kernel. Blocks when the file descriptor is in
blocking mode (default) until any event arrives. Returns list of
C<Linux::Inotify2::Event> objects or empty list if none (non-blocking
mode) or error occurred ($! should be checked).

Normally you shouldn't use this function, but instead use watcher
callbacks and call C<< ->poll >>.

=cut

sub read {
   my ($self) = @_;

   my @ev = inotify_read $self->{fd};
   my @res;

   for (@ev) {
      my $w = $_->{w} = $self->{w}{$_->{wd}}
         or next; # no such watcher

      exists $self->{ignore}{$_->{wd}}
         and next; # watcher has been canceled

      bless $_, "Linux::Inotify2::Event";

      push @res, $_;

      $w->{cb}->($_) if $w->{cb};
      $w->cancel if $_->{mask} & (IN_IGNORED | IN_UNMOUNT | IN_ONESHOT | IN_DELETE_SELF);
   }

   delete $self->{ignore};

   @res
}

sub DESTROY {
   inotify_close $_[0]{fd}
}

=back

=head2 The Linux::Inotify2::Event Class

Objects of this class are handed as first argument to the watcher
callback. It has the following members and methods:

=over 4

=item $event->w

=item $event->{w}

The watcher object for this event.

=item $event->name

=item $event->{name}

The path of the file system object, relative to the watched name.

=item $event->fullname

Returns the "full" name of the relevant object, i.e. including the C<name>
member of the watcher (if the watch object is on a directory and a
directory entry is affected), or simply the C<name> member itself when the
object is the watch object itself.

=item $event->mask

=item $event->{mask}

The received event mask. In addition to the events described for C<<
$inotify->watch >>, the following flags (exported by default) can be set:

 IN_ISDIR             event object is a directory
 IN_Q_OVERFLOW        event queue overflowed

 # when any of the following flags are set,
 # then watchers for this event are automatically canceled
 IN_UNMOUNT           filesystem for watched object was unmounted
 IN_IGNORED           file was ignored/is gone (no more events are delivered)
 IN_ONESHOT           only one event was generated

=item $event->IN_xxx

Returns a boolean that returns true if the event mask contains any events
specified by the mask. All of the C<IN_xxx> constants can be used as
methods.

=item $event->cookie

=item $event->{cookie}

The event cookie to "synchronize two events". Normally zero, this value is
set when two events relating to the same file are generated. As far as I
know, this only happens for C<IN_MOVED_FROM> and C<IN_MOVED_TO> events, to
identify the old and new name of a file.

=back

=cut

package Linux::Inotify2::Event;

sub w       { $_[0]{w}      }
sub name    { $_[0]{name}   }
sub mask    { $_[0]{mask}   }
sub cookie  { $_[0]{cookie} }

sub fullname {
   length $_[0]{name}
      ? "$_[0]{w}{name}/$_[0]{name}"
      : $_[0]{w}{name};
}

for my $name (@Linux::Inotify2::EXPORT) {
   my $mask = &{"Linux::Inotify2::$name"};

   *$name = sub { $_[0]{mask} & $mask };
}

=head2 The Linux::Inotify2::Watch Class

Watcher objects are created by calling the C<watch> method of a notifier.

It has the following members and methods:

=over 4

=item $watch->name

=item $watch->{name}

The name as specified in the C<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.

=item $watch->mask

=item $watch->{mask}

The mask as specified in the C<watch> call.

=item $watch->cb ([new callback])

=item $watch->{cb}

The callback as specified in the C<watch> call. Can optionally be changed.

=item $watch->cancel

Cancels/removes this watcher. Future events, even if already queued queued,
will not be handled and resources will be freed.

=back

=cut

package Linux::Inotify2::Watch;

sub name    { $_[0]{name} }
sub mask    { $_[0]{mask} }

sub cb {
   $_[0]{cb} = $_[1] if @_ > 1;
   $_[0]{cb}
}

sub cancel {
   my ($self) = @_;

   my $inotify = delete $self->{inotify}
      or return 1; # already canceled

   delete $inotify->{w}{$self->{wd}}; # we are no longer there
   $inotify->{ignore}{$self->{wd}} = 1; # ignore further events for one poll

   (Linux::Inotify2::inotify_rm_watch $inotify->{fd}, $self->{wd})
      ? 1 : undef
}

=head1 SEE ALSO

L<AnyEvent>, L<Linux::Inotify>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1
Revision:	1.26
Committed:	Fri May 4 19:38:06 2012 UTC (14 years, 4 months ago) by root
Branch:	MAIN
Changes since 1.25:	+1 -3 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			Linux::Inotify2 - scalable directory/file change notification
4
5			=head1 SYNOPSIS
6
7	root	1.19	=head2 Callback Interface
8	root	1.11
9	root	1.1	use Linux::Inotify2;
10
11	root	1.4	# create a new object
12			my $inotify = new Linux::Inotify2
13	root	1.19	or die "unable to create new inotify object: $!";
14	root	1.4
15			# add watchers
16			$inotify->watch ("/etc/passwd", IN_ACCESS, sub {
17			my $e = shift;
18			my $name = $e->fullname;
19			print "$name was accessed\n" if $e->IN_ACCESS;
20			print "$name is no longer mounted\n" if $e->IN_UNMOUNT;
21			print "$name is gone\n" if $e->IN_IGNORED;
22			print "events for $name have been lost\n" if $e->IN_Q_OVERFLOW;
23
24	root	1.11	# cancel this watcher: remove no further events
25	root	1.4	$e->w->cancel;
26			});
27
28	root	1.20	# integration into AnyEvent (works with EV, Glib, Tk, POE...)
29	root	1.25	my $inotify_w = AE::io $inotify->fileno, 0, sub { $inotify->poll };
30	root	1.17
31			# manual event loop
32			1 while $inotify->poll;
33
34	root	1.11	=head2 Streaming Interface
35
36			use Linux::Inotify2 ;
37
38			# create a new object
39			my $inotify = new Linux::Inotify2
40			or die "Unable to create new inotify object: $!" ;
41
42			# create watch
43			$inotify->watch ("/etc/passwd", IN_ACCESS)
44			or die "watch creation failed" ;
45
46			while () {
47			my @events = $inotify->read;
48			unless (@events > 0) {
49			print "read error: $!";
50			last ;
51			}
52			printf "mask\t%d\n", $_->mask foreach @events ;
53			}
54
55	root	1.1	=head1 DESCRIPTION
56
57	root	1.3	This module implements an interface to the Linux 2.6.13 and later Inotify
58	root	1.24	file/directory change notification system.
59	root	1.2
60	root	1.3	It has a number of advantages over the Linux::Inotify module:
61	root	1.2
62			- it is portable (Linux::Inotify only works on x86)
63			- the equivalent of fullname works correctly
64			- it is better documented
65			- it has callback-style interface, which is better suited for
66			integration.
67
68	root	1.6	=head2 The Linux::Inotify2 Class
69
70	root	1.1	=over 4
71
72			=cut
73
74			package Linux::Inotify2;
75
76			use Scalar::Util ();
77
78	root	1.20	use common::sense;
79
80	root	1.26	use Exporter qw(import);
81	root	1.1
82			BEGIN {
83	root	1.24	our $VERSION = '1.22';
84	root	1.20	our @EXPORT = qw(
85	root	1.1	IN_ACCESS IN_MODIFY IN_ATTRIB IN_CLOSE_WRITE
86			IN_CLOSE_NOWRITE IN_OPEN IN_MOVED_FROM IN_MOVED_TO
87	root	1.9	IN_CREATE IN_DELETE IN_DELETE_SELF IN_MOVE_SELF
88	root	1.1	IN_ALL_EVENTS
89			IN_UNMOUNT IN_Q_OVERFLOW IN_IGNORED
90			IN_CLOSE IN_MOVE
91	root	1.15	IN_ISDIR IN_ONESHOT IN_MASK_ADD IN_DONT_FOLLOW IN_ONLYDIR
92	root	1.1	);
93
94			require XSLoader;
95			XSLoader::load Linux::Inotify2, $VERSION;
96			}
97
98			=item my $inotify = new Linux::Inotify2
99
100			Create a new notify object and return it. A notify object is kind of a
101	root	1.24	container that stores watches on file system names and is responsible for
102	root	1.1	handling event data.
103
104	root	1.22	On error, C<undef> is returned and C<$!> will be set accordingly. The
105			following errors are documented:
106	root	1.1
107			ENFILE The system limit on the total number of file descriptors has been reached.
108			EMFILE The user limit on the total number of inotify instances has been reached.
109			ENOMEM Insufficient kernel memory is available.
110
111	root	1.4	Example:
112
113			my $inotify = new Linux::Inotify2
114			or die "Unable to create new inotify object: $!";
115
116	root	1.1	=cut
117
118			sub new {
119			my ($class) = @_;
120
121			my $fd = inotify_init;
122
123			return unless $fd >= 0;
124
125			bless { fd => $fd }, $class
126			}
127
128	root	1.11	=item $watch = $inotify->watch ($name, $mask[, $cb])
129	root	1.1
130			Add a new watcher to the given notifier. The watcher will create events
131			on the pathname C<$name> as given in C<$mask>, which can be any of the
132	root	1.4	following constants (all exported by default) ORed together.
133
134	root	1.24	"file" refers to any file system object in the watched object (always a
135	root	1.4	directory), that is files, directories, symlinks, device nodes etc., while
136	root	1.24	"object" refers to the object the watcher has been set on itself:
137	root	1.4
138			IN_ACCESS object was accessed
139			IN_MODIFY object was modified
140			IN_ATTRIB object metadata changed
141			IN_CLOSE_WRITE writable fd to file / to object was closed
142			IN_CLOSE_NOWRITE readonly fd to file / to object closed
143			IN_OPEN object was opened
144			IN_MOVED_FROM file was moved from this object (directory)
145			IN_MOVED_TO file was moved to this object (directory)
146			IN_CREATE file was created in this object (directory)
147			IN_DELETE file was deleted from this object (directory)
148			IN_DELETE_SELF object itself was deleted
149	root	1.9	IN_MOVE_SELF object itself was moved
150	root	1.4	IN_ALL_EVENTS all of the above events
151	root	1.1
152			IN_ONESHOT only send event once
153	root	1.15	IN_ONLYDIR only watch the path if it is a directory
154			IN_DONT_FOLLOW don't follow a sym link
155			IN_MASK_ADD not supported with the current version of this module
156	root	1.1
157	root	1.4	IN_CLOSE same as IN_CLOSE_WRITE \| IN_CLOSE_NOWRITE
158			IN_MOVE same as IN_MOVED_FROM \| IN_MOVED_TO
159	root	1.1
160	root	1.11	C<$cb> is a perl code reference that, if given, is called for each
161			event. It receives a C<Linux::Inotify2::Event> object.
162	root	1.1
163			The returned C<$watch> object is of class C<Linux::Inotify2::Watch>.
164
165			On error, C<undef> is returned and C<$!> will be set accordingly. The
166			following errors are documented:
167
168			EBADF The given file descriptor is not valid.
169			EINVAL The given event mask contains no legal events.
170			ENOMEM Insufficient kernel memory was available.
171			ENOSPC The user limit on the total number of inotify watches was reached or the kernel failed to allocate a needed resource.
172			EACCESS Read access to the given file is not permitted.
173
174			Example, show when C</etc/passwd> gets accessed and/or modified once:
175
176			$inotify->watch ("/etc/passwd", IN_ACCESS \| IN_MODIFY, sub {
177			my $e = shift;
178			print "$e->{w}{name} was accessed\n" if $e->IN_ACCESS;
179			print "$e->{w}{name} was modified\n" if $e->IN_MODIFY;
180			print "$e->{w}{name} is no longer mounted\n" if $e->IN_UNMOUNT;
181			print "events for $e->{w}{name} have been lost\n" if $e->IN_Q_OVERFLOW;
182
183			$e->w->cancel;
184			});
185
186			=cut
187
188			sub watch {
189			my ($self, $name, $mask, $cb) = @_;
190
191			my $wd = inotify_add_watch $self->{fd}, $name, $mask;
192
193			return unless $wd >= 0;
194
195			my $w = $self->{w}{$wd} = bless {
196			inotify => $self,
197			wd => $wd,
198			name => $name,
199			mask => $mask,
200			cb => $cb,
201	root	1.13	}, "Linux::Inotify2::Watch";
202	root	1.1
203			Scalar::Util::weaken $w->{inotify};
204
205			$w
206			}
207
208	root	1.4	=item $inotify->fileno
209	root	1.1
210	root	1.24	Returns the file descriptor for this notify object. When in non-blocking
211			mode, you are responsible for calling the C<poll> method when this file
212			descriptor becomes ready for reading.
213	root	1.1
214			=cut
215
216			sub fileno {
217			$_[0]{fd}
218			}
219
220	root	1.11	=item $inotify->blocking ($blocking)
221
222			Clears ($blocking true) or sets ($blocking false) the C<O_NONBLOCK> flag on the file descriptor.
223
224			=cut
225
226			sub blocking {
227			my ($self, $blocking) = @_;
228
229			inotify_blocking $self->{fd}, $blocking;
230			}
231
232	root	1.4	=item $count = $inotify->poll
233	root	1.1
234	root	1.24	Reads events from the kernel and handles them. If the notify file
235			descriptor is blocking (the default), then this method waits for at least
236			one event (and thus returns true unless an error occurs). Otherwise it
237			returns immediately when no pending events could be read.
238	root	1.1
239			Returns the count of events that have been handled.
240
241			=cut
242
243			sub poll {
244	root	1.11	scalar &read
245			}
246
247	root	1.24	=item @events = $inotify->read
248	root	1.11
249	root	1.24	Reads events from the kernel. Blocks when the file descriptor is in
250			blocking mode (default) until any event arrives. Returns list of
251			C<Linux::Inotify2::Event> objects or empty list if none (non-blocking
252			mode) or error occurred ($! should be checked).
253
254			Normally you shouldn't use this function, but instead use watcher
255			callbacks and call C<< ->poll >>.
256	root	1.11
257			=cut
258
259			sub read {
260	root	1.1	my ($self) = @_;
261
262	root	1.4	my @ev = inotify_read $self->{fd};
263	root	1.11	my @res;
264	root	1.4
265			for (@ev) {
266			my $w = $_->{w} = $self->{w}{$_->{wd}}
267	root	1.1	or next; # no such watcher
268	root	1.4
269			exists $self->{ignore}{$_->{wd}}
270			and next; # watcher has been canceled
271
272	root	1.13	bless $_, "Linux::Inotify2::Event";
273	root	1.12
274	root	1.11	push @res, $_;
275
276	root	1.12	$w->{cb}->($_) if $w->{cb};
277	root	1.16	$w->cancel if $_->{mask} & (IN_IGNORED \| IN_UNMOUNT \| IN_ONESHOT \| IN_DELETE_SELF);
278	root	1.1	}
279	root	1.4
280			delete $self->{ignore};
281
282	root	1.11	@res
283	root	1.1	}
284
285			sub DESTROY {
286			inotify_close $_[0]{fd}
287			}
288
289			=back
290
291			=head2 The Linux::Inotify2::Event Class
292
293	root	1.24	Objects of this class are handed as first argument to the watcher
294	root	1.1	callback. It has the following members and methods:
295
296			=over 4
297
298			=item $event->w
299
300			=item $event->{w}
301
302			The watcher object for this event.
303
304			=item $event->name
305
306			=item $event->{name}
307
308	root	1.24	The path of the file system object, relative to the watched name.
309	root	1.1
310	root	1.23	=item $event->fullname
311	root	1.1
312			Returns the "full" name of the relevant object, i.e. including the C<name>
313	root	1.24	member of the watcher (if the watch object is on a directory and a
314			directory entry is affected), or simply the C<name> member itself when the
315			object is the watch object itself.
316	root	1.1
317			=item $event->mask
318
319			=item $event->{mask}
320
321	root	1.24	The received event mask. In addition to the events described for C<<
322			$inotify->watch >>, the following flags (exported by default) can be set:
323	root	1.1
324	root	1.4	IN_ISDIR event object is a directory
325			IN_Q_OVERFLOW event queue overflowed
326
327	root	1.10	# when any of the following flags are set,
328			# then watchers for this event are automatically canceled
329	root	1.24	IN_UNMOUNT filesystem for watched object was unmounted
330	root	1.4	IN_IGNORED file was ignored/is gone (no more events are delivered)
331	root	1.10	IN_ONESHOT only one event was generated
332	root	1.1
333			=item $event->IN_xxx
334
335	root	1.24	Returns a boolean that returns true if the event mask contains any events
336			specified by the mask. All of the C<IN_xxx> constants can be used as
337			methods.
338	root	1.1
339			=item $event->cookie
340
341			=item $event->{cookie}
342
343	root	1.10	The event cookie to "synchronize two events". Normally zero, this value is
344			set when two events relating to the same file are generated. As far as I
345			know, this only happens for C<IN_MOVED_FROM> and C<IN_MOVED_TO> events, to
346			identify the old and new name of a file.
347	root	1.1
348			=back
349
350			=cut
351
352			package Linux::Inotify2::Event;
353
354			sub w { $_[0]{w} }
355			sub name { $_[0]{name} }
356			sub mask { $_[0]{mask} }
357			sub cookie { $_[0]{cookie} }
358
359			sub fullname {
360			length $_[0]{name}
361			? "$_[0]{w}{name}/$_[0]{name}"
362			: $_[0]{w}{name};
363			}
364
365	root	1.20	for my $name (@Linux::Inotify2::EXPORT) {
366	root	1.1	my $mask = &{"Linux::Inotify2::$name"};
367
368	root	1.24	*$name = sub { $_[0]{mask} & $mask };
369	root	1.1	}
370
371			=head2 The Linux::Inotify2::Watch Class
372
373	root	1.24	Watcher objects are created by calling the C<watch> method of a notifier.
374	root	1.1
375			It has the following members and methods:
376
377	root	1.14	=over 4
378
379	root	1.1	=item $watch->name
380
381			=item $watch->{name}
382
383			The name as specified in the C<watch> call. For the object itself, this is
384			the empty string. For directory watches, this is the name of the entry
385			without leading path elements.
386
387			=item $watch->mask
388
389			=item $watch->{mask}
390
391			The mask as specified in the C<watch> call.
392
393			=item $watch->cb ([new callback])
394
395			=item $watch->{cb}
396
397			The callback as specified in the C<watch> call. Can optionally be changed.
398
399			=item $watch->cancel
400
401	root	1.24	Cancels/removes this watcher. Future events, even if already queued queued,
402	root	1.1	will not be handled and resources will be freed.
403
404	root	1.14	=back
405
406	root	1.1	=cut
407
408			package Linux::Inotify2::Watch;
409
410			sub name { $_[0]{name} }
411			sub mask { $_[0]{mask} }
412
413			sub cb {
414			$_[0]{cb} = $_[1] if @_ > 1;
415			$_[0]{cb}
416			}
417
418			sub cancel {
419			my ($self) = @_;
420
421	root	1.4	my $inotify = delete $self->{inotify}
422			or return 1; # already canceled
423
424			delete $inotify->{w}{$self->{wd}}; # we are no longer there
425			$inotify->{ignore}{$self->{wd}} = 1; # ignore further events for one poll
426
427			(Linux::Inotify2::inotify_rm_watch $inotify->{fd}, $self->{wd})
428	root	1.1	? 1 : undef
429			}
430
431			=head1 SEE ALSO
432
433	root	1.19	L<AnyEvent>, L<Linux::Inotify>.
434	root	1.1
435			=head1 AUTHOR
436
437			Marc Lehmann <schmorp@schmorp.de>
438			http://home.schmorp.de/
439
440			=cut
441
442			1