If you are launching the process within the script then you can use Win32::Process to launch and manage the script. You don't need any threading or forking to support that.

In fact, if you have the pid of the process that you want to kill, you can kill it with Win32::Process::KillProcess($pid, $exitcode), irrespcective of how the process was started.

Cheers,
Rob

True, but finding the pid for a process is a right pita! Every time I want to do it (about 11 months apart on average) it seems to take an hour of trawling through MSDN to find what needs to be done. Then after 10 months I forget how to do it.

---

True laziness is hard work

#! perl -slw
use strict;
use threads;
use threads::shared;

$|++;

my $pid :shared;
async {
    $pid = system 1, 'perl', q[-E"sleep 600; say 'Done!'"];
    sleep 30;
    kill 2, $pid;
    undef $pid;
}->detach;

my $c = 0;
## get on with the rest of your program
while( sleep 1 ) {
    print ++$c, ' Is it done yet?';
    last unless $pid;
}

__END__
C:\test>\perl32\bin\perl.exe junk3.pl
1 Is it done yet?
2 Is it done yet?
3 Is it done yet?

...

27 Is it done yet?
28 Is it done yet?
29 Is it done yet?
30 Is it done yet?
Terminating on signal SIGINT(2)
31 Is it done yet?
[download]

If you don't need to do anything else whilst you wait for it, then a simple:

#! perl -slw
use strict;

my $pid = system 1, 'perl', q[ -E"sleep 600; say 'Done!'"];
sleep 30;
kill $pid, 2;

## rest  of program
[download]

will do it.

Generally, I prefer Win32::Job to Win32::Process for this type of thing. Notice that, unlike Win32::Process, Win32::Job allows you to reliably kill a process and all its children by launching the process in a job. Example code that uses Win32::Job can be found in Re: Timing Windows commands.

Is there any way to screen/read the current processes running in Windows to get their pid in Perl?

Yes. Win32::Process::Info will get you most the information you need to do that. The missing part is the command line (parameters) if you need those to distinguish between concurrent instances. Though you may be able to determine that by using the ->Subprocesses() method if you know the pid of the process that started the instance you are looking for.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

RIP PCW