Re: various questions about Win32::Process

[bulk88]

Your problem is Win32::Process doesn't fully expose the C function CreateProcess, where you can specify the initial (since the child can switch them out to whatever it wants programatically if it wants) standard handles the child process will get. I modified your script to get cmd.exe's child's PID and changed away from sleep.exe to perl.exe.

use warnings;
use strict;
use Win32::Process;
use Win32::Process 'STILL_ACTIVE';
use Win32::Process::Info qw{WMI};

my $child_pid;
my $real_child_pid;
my $child_proc;
my $cmd = 'perl -e"sleep 20"';

my $debug = 1;
my $exitcode = 1; 


my $stdout = 'out.txt';
my $stderr = 'err.txt';

Win32::Process::Create($child_proc, $ENV{COMSPEC}, "/c $cmd > $stdout 
+2>$stderr", 0, 0, ".") || print Win32::FormatMessage( Win32::GetLastE
+rror());
$child_pid = $child_proc->GetProcessID();
my $pi = Win32::Process::Info->new();

my ($min_time,$max_time,$kill_time) = (12,15,18);
if($child_pid!=0) {
    print "Started child process id $child_pid\n";
    my %subs = $pi->Subprocesses($child_pid);
        my $real_child_pid = $subs{$child_pid}[0];
        print "Real child process id $real_child_pid\n";
        #use Data::Dumper;
        #print Dumper(\%subs);
    my $i=0;
    while ( 'true' ) {
        $child_proc->Wait(1000);
        $i++;
        $child_proc->GetExitCode($exitcode);
        if ( $exitcode == STILL_ACTIVE ) {
            print "loop $i\n";
            if($i==$max_time) {
                print "max time : this is quite long...\n";
            }
            if($i==$kill_time) {
                print "kill time : kill $child_pid\n";
                $child_proc->Kill(-1);
            }
    
        } 
        else {
            print "### E = $^E ?=$? ###\n";
            print " Process terminated on it's own rc=$exitcode \n";
            
            if($i==$min_time) {
                print "min time : command was too short\n";
            }
            exit $exitcode;
        }
    }
}
else {
    print "Can't start process...\n";
}

What you want to use is IPC::Run3 or a Perl wrapper around CreateProcess that exposes http://msdn.microsoft.com/en-us/library/windows/desktop/ms686331%28v=vs.85%29.aspx, specifically "HANDLE hStdOutput" (and according to grep.cpan.me, there is only 1, and its a personal module intended to never be used by the public (https://metacpan.org/release/DAVEROTH/Win32_AdminMisc_Source_980511), choice 3 is using Win32::API and calling CreateProcess yourself with that struct.

[nabbo]

Thanks for the tip. I have tried this version, and indeed, I can recover the real PID of my process and kill it with

Win32::Process::KillProcess($real_child_pid, "-1");

(Note that for some reason, the standard

kill -9 , $real_child_pid

is not working. But I don't care much as long as I can kill the process, one way or another

Any idea about knowing if the process was killed or terminated on its own ?