IO::Async::File(3) User Contributed Perl Documentation IO::Async::File(3)NAME
"IO::Async::File" - watch a file for changes
SYNOPSIS
use IO::Async::File;
use IO::Async::Loop;
my $loop = IO::Async::Loop->new;
my $file = IO::Async::File->new(
filename => "config.ini",
on_mtime_changed => sub {
my ( $self ) = @_;
print STDERR "Config file has changed\n";
reload_config( $self->handle );
}
);
$loop->add( $file );
$loop->run;
DESCRIPTION
This subclass of IO::Async::Notifier watches an open filehandle or
named filesystem entity for changes in its "stat()" fields. It invokes
various events when the values of these fields change. It is most often
used to watch a file for size changes; for this task see also
IO::Async::FileStream.
While called "File", it is not required that the watched filehandle be
a regular file. It is possible to watch anything that stat(2) may be
called on, such as directories or other filesystem entities.
EVENTS
The following events are invoked, either using subclass methods or CODE
references in parameters.
on_dev_changed $new_dev, $old_dev
on_ino_changed $new_ino, $old_ino
...
on_ctime_changed $new_ctime, $old_ctime
Invoked when each of the individual "stat()" fields have changed. All
the "stat()" fields are supported apart from "blocks" and "blksize".
Each is passed the new and old values of the field.
on_devino_changed $new_stat, $old_stat
Invoked when either of the "dev" or "ino" fields have changed. It is
passed two File::stat instances containing the complete old and new
"stat()" fields. This can be used to observe when a named file is
renamed; it will not be observed to happen on opened filehandles.
on_stat_changed $new_stat, $old_stat
Invoked when any of the "stat()" fields have changed. It is passed two
File::stat instances containing the old and new "stat()" fields.
PARAMETERS
The following named parameters may be passed to "new" or "configure".
handle => IO
The opened filehandle to watch for "stat()" changes if
"filename" is not supplied.
filename => STRING
Optional. If supplied, watches the named file rather than the
filehandle given in "handle". The file will be opened for
reading and then watched for renames. If the file is renamed,
the new filename is opened and tracked similarly after closing
the previous file.
interval => NUM
Optional. The interval in seconds to poll the filehandle using
stat(2) looking for size changes. A default of 2 seconds will
be applied if not defined.
METHODS
$handle = $file->handle
Returns the filehandle currently associated with the instance; either
the one passed to the "handle" parameter, or opened from the "filename"
parameter.
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.18.2 2014-05-14 IO::Async::File(3)
