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.

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 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.

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