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Top Forums UNIX for Beginners Questions & Answers One parent, multiple children pipe with fork() Post 303017920 by Corona688 on Thursday 24th of May 2018 03:25:36 PM
Old 05-24-2018
In short, how fork() really works:

Code:
pid_t pid=fork();

if(pid < 0)
{
    perror("couldn't fork");
    exit(1);
}

if(pid == 0) {
        // Child code
        do_stuff();
        exit(0);
}

// Parent code

 

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IO::Async::PID(3pm)					User Contributed Perl Documentation				       IO::Async::PID(3pm)

NAME
"IO::Async::PID" - event callback on exit of a child process SYNOPSIS
use IO::Async::PID; use POSIX qw( WEXITSTATUS ); use IO::Async::Loop; my $loop = IO::Async::Loop->new; my $kid = $loop->fork( code => sub { print "Child sleeping.. "; sleep 10; print "Child exiting "; return 20; }, ); print "Child process $kid started "; my $pid = IO::Async::PID->new( pid => $kid, on_exit => sub { my ( $self, $exitcode ) = @_; printf "Child process %d exited with status %d ", $self->pid, WEXITSTATUS($exitcode); }, ); $loop->add( $pid ); $loop->run; DESCRIPTION
This subclass of IO::Async::Notifier invokes its callback when a process exits. For most use cases, a IO::Async::Process object provides more control of setting up the process, connecting filehandles to it, sending data to and receiving data from it. EVENTS
The following events are invoked, either using subclass methods or CODE references in parameters: on_exit $exitcode Invoked when the watched process exits. PARAMETERS
The following named parameters may be passed to "new" or "configure": pid => INT The process ID to watch. Must be given before the object has been added to the containing "IO::Async::Loop" object. on_exit => CODE CODE reference for the "on_exit" event. Once the "on_exit" continuation has been invoked, the "IO::Async::PID" object is removed from the containing "IO::Async::Loop" object. METHODS
$process_id = $pid->pid Returns the underlying process ID $pid->kill( $signal ) Sends a signal to the process AUTHOR
Paul Evans <leonerd@leonerd.org.uk> perl v5.14.2 2012-10-24 IO::Async::PID(3pm)
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