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Getting Linux::Inotify2 and POE to work with select_read()

by jfroebe (Parson)
on Oct 06, 2008 at 21:32 UTC ( #715651=perlquestion: print w/replies, xml ) Need Help??
jfroebe has asked for the wisdom of the Perl Monks concerning the following question:

Hi all,

I'm sure it is something simple again, but for the life of me I'm not seeing it.

I'm trying to use Linux::Inotify2 with POE by calling the $inotify->poll through select_read: $_[KERNEL]->select_read( $_[HEAP]{inotify}->fileno, "inotify_poll" );

It should work but I'm running into an error with the $inotify->fileno being passed as a symbol ref.

Can't use string ("3") as a symbol ref while "strict refs" in use at /usr/share/perl5/POE/Resource/ line 330.

Ok, not a big deal, it is expecting a symbol ref. However, if I use a reference instead, I get an error about not being a glob reference:

Not a GLOB reference at /usr/share/perl5/POE/Resource/ line 291.

#!/usr/bin/perl use strict; use warnings; use Linux::Inotify2; use POE; $|++; POE::Session->create ( inline_states => { _start => sub { $_[KERNEL]->alias_set('notify'); $_[HEAP]{inotify} = new Linux::Inotify2 or die "Unable to create new inotify object: $!"; $_[HEAP]{inotify}->watch("/tmp/j", IN_CLOSE_WRITE, $_[SESS +ION]->postback("watch_dir")) or die "Unable to watch dir: $!"; printf "%s\n", $_[HEAP]{inotify}->fileno; $_[KERNEL]->select_read( $_[HEAP]{inotify}->fileno, "inoti +fy_poll" ); }, inotify_poll => sub { $_[HEAP]{inotify}->poll; }, watch_dir => \&watch_dir, }, ); sub watch_dir { my $event = $_[ARG0]; print "jjjj\n"; my $name = $event->fullname; print "$name was accessed\n" if $event->IN_ACCESS; print "$name is no longer mounted\n" if $event->IN_UNMOUNT; print "$name is gone\n" if $event->IN_IGNORED; print "$name is new\n" if $event->IN_CLOSE_WRITE; print "events for $name have been lost\n" if $event->IN_Q_OVERFLOW; } POE::Kernel->run(); exit 0;

Any ideas?

Update: Working code posted to the code section: Using Linux::Inotify2 with POE

Jason L. Froebe

Blog, Tech Blog

Replies are listed 'Best First'.
Re: Getting Linux::Inotify2 and POE to work with select_read()
by rcaputo (Chaplain) on Oct 06, 2008 at 21:41 UTC

    If we are using the same version of POE, line 291 is a fileno() call. Whatever you pass to select_read() should be sufficiently filehandly that fileno($it) works.


      ### Add a select to the session, and possibly begin a watcher. sub _data_handle_add { my ($self, $handle, $mode, $session, $event, $args) = @_; my $fd = fileno($handle);

      I receive the file descriptor from Linux::Inotify2 but I need a file handle to send to select_read(). Does anyone know how to convert a file descriptor to a file handle? This is definitely a Monday

      Jason L. Froebe

      Blog, Tech Blog

        open FH, "<&=".$fd or die "Can't fdopen $fd: $!\n";

        - tye        

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