#!/usr/bin/perl
use warnings;
use strict;
use IO::Select;

my $pid = open(PIP, "|-");
if ($pid < 0) {
	die "open(): $!";
}
elsif ($pid > 0) {
	print scalar localtime time, " - Parent: sending something to child\n";
	print PIP "Hi, son!\n";
	print scalar localtime time, " - Parent: waiting for child to finish\n";
	close PIP;
	print scalar localtime time, " - Parent: exiting\n";
}
else {
	my $selector = IO::Select->new(\*STDIN);
	print scalar localtime time, " - Child: just born!\n";
	sleep(60);
	my @handles = $selector->can_read(0);
	if (@handles) {
		print scalar localtime time, " - Child: there are " . scalar(@handles) . " handles ready for reading\n";
		# It can only be STDIN...
		my $line = <STDIN>;
		chomp($line);
		print scalar localtime time, " - Child: parent says: [$line]\n";
	}
	print scalar localtime time, " - Child: exiting\n";
	exit(0);
}

__END__
Sun May 22 15:43:48 2005 - Parent: sending something to child
Sun May 22 15:43:48 2005 - Child: just born!
Sun May 22 15:43:48 2005 - Parent: waiting for child to finish
Sun May 22 15:44:48 2005 - Child: there are 1 handles ready for reading
Sun May 22 15:44:48 2005 - Child: exiting
Sun May 22 15:44:48 2005 - Parent: exiting