#! perl
use strict;
use warnings;
use threads;
use threads::shared;

my $startTime = time();

$|++;
my $semSTDOUT :shared;
sub tprint{
	lock $semSTDOUT;
	print STDERR (time() - $startTime) .  "s : Thread " . threads->tid() . " - " . join(" ", @_) . "\n";
}

my $command;
if (@ARGV) {
	print "### Running a perl script ###\n";
	$command = 'perl -e "print \"hello world\""';
}else{
	print "### Running a regular command ###\n";
	$command = 'echo hello world';
}

#all of these threads will be created while main thread is not reading from stdin
tprint("> Creating threads");
my @threads;

#threads that will execute command after main thread is reading from stdin again
push @threads, threads->create('threadWait') for 1..3;
sleep 1;
tprint("All Threads created");

tprint("> Waiting for input now. All threads should finish now without pressing enter");
<STDIN>;
tprint("> Input received, all done");

$_->join() for @threads;
tprint("All Threads joined");
exit 0;

sub threadWait{
	#close STDIN; #seemed to have no effect...
	tprint("Created");
	sleep 3;#just give main thread a little extra time to read stdin
	tprint("Starting '$command'");
	my $output = `$command`;
	chomp $output;
	tprint("Finished the command: $output");
}

##</code><code>##

C:\>test.pl
### Running a regular command ###
0s : Thread 0 - > Creating threads
1s : Thread 1 - Created
1s : Thread 2 - Created
1s : Thread 3 - Created
2s : Thread 0 - All Threads created
2s : Thread 0 - > Waiting for input now. All threads should finish now without pressing enter
4s : Thread 1 - Starting 'echo hello world'
4s : Thread 2 - Starting 'echo hello world'
4s : Thread 3 - Starting 'echo hello world'
4s : Thread 1 - Finished the command: hello world
4s : Thread 2 - Finished the command: hello world
4s : Thread 3 - Finished the command: hello world
<-- pressed enter here
7s : Thread 0 - > Input received, all done
7s : Thread 0 - All Threads joined

C:\>test.pl 1
### Running a perl script ###
0s : Thread 0 - > Creating threads
0s : Thread 1 - Created
0s : Thread 2 - Created
0s : Thread 3 - Created
1s : Thread 0 - All Threads created
1s : Thread 0 - > Waiting for input now. All threads should finish now without pressing enter
3s : Thread 1 - Starting 'perl -e "print \"hello world\""'
3s : Thread 3 - Starting 'perl -e "print \"hello world\""'
3s : Thread 2 - Starting 'perl -e "print \"hello world\""'
<-- pressed enter here
8s : Thread 0 - > Input received, all done
8s : Thread 1 - Finished the command: hello world
8s : Thread 3 - Finished the command: hello world
8s : Thread 2 - Finished the command: hello world
8s : Thread 0 - All Threads joined

##</code><code>##

C:\>perl -v

This is perl 5, version 18, subversion 2 (v5.18.2) built for MSWin32-x64-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2013, Larry Wall

Binary build 1801 [297964] provided by ActiveState http://www.ActiveState.com
Built Feb 24 2014 11:06:47

Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.

Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl".  If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.

##</code><code>##

C:\>test.pl 1
### Running a perl script ###
0s : Thread 0 - > Creating threads
0s : Thread 1 - Created
0s : Thread 2 - Created
0s : Thread 3 - Created
1s : Thread 0 - All Threads created
1s : Thread 0 - > Waiting for input now. All system commands should finish without pressing enter
3s : Thread 1 - Starting 'perl -e "print \"hello world\"" < nul'
3s : Thread 3 - Starting 'perl -e "print \"hello world\"" < nul'
3s : Thread 2 - Starting 'perl -e "print \"hello world\"" < nul'
3s : Thread 3 - Finished the command: hello world
3s : Thread 1 - Finished the command: hello world
3s : Thread 2 - Finished the command: hello world

7s : Thread 0 - > Input received, all done
7s : Thread 0 - All Threads joined