NAME¶
File::ChangeNotify::Watcher - Base class for all watchers
VERSION¶
version 0.24
SYNOPSIS¶
my $watcher =
File::ChangeNotify->instantiate_watcher
( directories => [ '/my/path', '/my/other' ],
filter => qr/\.(?:pm|conf|yml)$/,
exclude => ['t', 'root', qr(/(?!\.)[^/]+$)],
);
if ( my @events = $watcher->new_events() ) { ... }
# blocking
while ( my @events = $watcher->wait_for_events() ) { ... }
DESCRIPTION¶
A "File::ChangeNotify::Watcher" class monitors a directory for changes
made to any file. You can provide a regular expression to filter out files you
are not interested in. It handles the addition of new subdirectories by adding
them to the watch list.
Note that the actual granularity of what each watcher subclass reports may vary
across subclasses. Implementations that hook into some sort of kernel event
interface (Inotify, for example) have much better knowledge of exactly what
changes are happening than one implemented purely in userspace code (like the
Default subclass).
By default, events are returned in the form File::ChangeNotify::Event objects,
but this can be overridden by providing an "event_class" attribute
to the constructor.
The watcher can operate in a blocking/callback style, or you can simply ask it
for a list of new events as needed.
METHODS¶
File::ChangeNotify::Watcher::Subclass->new(...)¶
This method creates a new watcher. It accepts the following arguments:
- •
- directories => $path
- •
- directories => \@paths
This argument is required. It can be either one or many paths which should
be watched for changes.
- •
- filter => qr/.../
This is an optional regular expression that will be used to check if a file
is of interest. This filter is only applied to files.
By default, all files are included.
- •
- exclude => [...]
An optional list of paths to exclude. This list can contain either plain
strings or regular expressions. If you provide a string it should contain
the complete path to be excluded.
The paths can be either directories or specific files. If the exclusion
matches a directory, all of its files and subdirectories are ignored.
- •
- follow_symlinks => $bool
By default, symlinks are ignored. Set this to true to follow them.
If this symlinks are being followed, symlinks to files and directories will
be followed. Directories will be watched, and changes for directories and
files reported.
- •
- sleep_interval => $number
For watchers which call "sleep" to implement the
"$watcher->wait_for_events()" method, this argument controls
how long it sleeps for. The value is a number in seconds.
The default is 2 seconds.
- •
- event_class => $class
This can be used to change the class used to report events. By default, this
is File::ChangeNotify::Event.
$watcher->wait_for_events()¶
This method causes the watcher to block until it sees interesting events, and
then return them as a list.
Some watcher subclasses may implement blocking as a sleep loop, while others may
actually block.
$watcher->new_events()¶
This method returns a list of any interesting events seen since the last time
the watcher checked.
$watcher->sees_all_events()¶
If this is true, the watcher will report on all events.
Some watchers, like the Default subclass, are not smart enough to track things
like a file being created and then immediately deleted, and can only detect
changes between snapshots of the file system.
Other watchers, like the Inotify subclass, see all events that happen and report
on them.
AUTHOR¶
Dave Rolsky <autarch@urth.org>
COPYRIGHT AND LICENSE¶
This software is Copyright (c) 2013 by Dave Rolsky.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)