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NAME

Reflex::PID - Watch the exit of a subprocess by its SIGCHLD signal.

VERSION

This document describes version 0.100, released on April 02, 2017.

SYNOPSIS

# Not a complete program. Please see the source for # Reflex::POE::Wheel::Run for one example.

        use Reflex::PID;

        watches pid_watcher => (
                isa   => 'Reflex::PID|Undef',
                role  => 'process',
        );

        sub some_method {
                my $self = shift;

                my $pid = fork();
                die $! unless defined $pid;
                exec("some-program.pl") unless $pid;

                # Parent here.
                $self->sigchild_watcher(
                        Reflex::PID->new(pid => $pid)
                );
        }

        sub on_process_exit {
                # Handle the event.
        }

DESCRIPTION

Reflex::PID waits for a particular child process to exit. It emits a "signal" event with information about the child process when it has detected the child has exited.

Since Reflex::PID waits for a particular process ID, it's pretty much useless afterwards. Consider pairing it with Reflex::Collection if you have to maintain several transient processes.

Reflex::PID extends Reflex::Signal to handle a particular kind of signal---SIGCHLD.

TODO - However, first we need to make Reflex::PID objects stop themselves and emit "stopped" events when they're done. Otherwise Reflex::Collection won't know when to destroy them.

Public Events

exit

Reflex::PID's "exit" event includes two named parameters. "pid" contains the process ID that exited. "exit" contains the process' exit value---a copy of $? at the time the process exited. Please see "$?" in perlvar for more information about that special Perl variable.

SEE ALSO

Please see those modules/websites for more information related to this module.

BUGS AND LIMITATIONS

You can make new bug reports, and view existing ones, through the web interface at http://rt.cpan.org/Public/Dist/Display.html?Name=Reflex.

AUTHOR

Rocco Caputo <rcaputo@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2017 by Rocco Caputo.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit http://www.perl.com/CPAN/ to find a CPAN site near you, or see https://metacpan.org/module/Reflex/.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.