Several operating systems support watching of filesystems for changes
of files. If configured properly, Emacs links a respective library
-like @file{gfilenotify}, @file{inotify}, or @file{w32notify}
-statically. These libraries enable watching of filesystems on the
-local machine.
+like @file{inotify}, @file{kqueue}, @file{gfilenotify}, or
+@file{w32notify} statically. These libraries enable watching of
+filesystems on the local machine.
It is also possible to watch filesystems on remote machines,
@pxref{Remote Files,, Remote Files, emacs, The GNU Emacs Manual}
Note that the @file{w32notify} library does not report
@code{attribute-changed} events. When some file's attribute, like
permissions or modification time, has changed, this library reports a
-@code{changed} event.
+@code{changed} event. Likewise, the @file{kqueue} library does not
+report reliably file attribute changes when watching a directory.
The @code{stopped} event reports, that watching the file has been
stopped. This could be because @code{file-notify-rm-watch} was called
@group
(write-region "bla" nil "/tmp/foo")
@result{} Event (35025468 created "/tmp/.#foo")
- Event (35025468 changed "/tmp/foo") [2 times]
+ Event (35025468 changed "/tmp/foo")
Event (35025468 deleted "/tmp/.#foo")
@end group
@example
@group
(make-directory "/tmp/foo")
- @result{} nil
+ @result{} Event (35025468 created "/tmp/foo")
@end group
@group
(setq desc
(file-notify-add-watch
"/tmp/foo" '(change) 'my-notify-callback))
- @result{} 35025468
+ @result{} 11359632
@end group
@group
@group
(write-region "bla" nil "/tmp/foo/bla")
- @result{} Event (35025468 created "/tmp/foo/.#bla")
- Event (35025468 created "/tmp/foo/bla")
- Event (35025468 changed "/tmp/foo/bla")
- Event (35025468 changed "/tmp/foo/.#bla")
+ @result{} Event (11359632 created "/tmp/foo/.#bla")
+ Event (11359632 created "/tmp/foo/bla")
+ Event (11359632 changed "/tmp/foo/bla")
+ Event (11359632 deleted "/tmp/foo/.#bla")
@end group
@group
;; Deleting a file in the directory doesn't invalidate the watch.
(delete-file "/tmp/foo/bla")
- @result{} Event (35025468 deleted "/tmp/foo/bla")
+ @result{} Event (11359632 deleted "/tmp/foo/bla")
@end group
@group
(write-region "bla" nil "/tmp/foo/bla")
- @result{} Event (35025468 created "/tmp/foo/.#bla")
- Event (35025468 created "/tmp/foo/bla")
- Event (35025468 changed "/tmp/foo/bla")
- Event (35025468 changed "/tmp/foo/.#bla")
+ @result{} Event (11359632 created "/tmp/foo/.#bla")
+ Event (11359632 created "/tmp/foo/bla")
+ Event (11359632 changed "/tmp/foo/bla")
+ Event (11359632 deleted "/tmp/foo/.#bla")
@end group
@group
;; Deleting the directory invalidates the watch.
+;; Events arrive for different watch descriptors.
(delete-directory "/tmp/foo" 'recursive)
- @result{} Event (35025468 deleted "/tmp/foo/bla")
- Event (35025468 deleted "/tmp/foo")
- Event (35025468 stopped "/tmp/foo")
+ @result{} Event (35025468 deleted "/tmp/foo")
+ Event (11359632 deleted "/tmp/foo/bla")
+ Event (11359632 deleted "/tmp/foo")
+ Event (11359632 stopped "/tmp/foo")
@end group
@group