use strict;
use Time::HiRes qw(time sleep);
use Win32::Process;

select(STDERR);$|=1;select(STDOUT);$|=1;   # autoflush
### save original stdout and stderr
open(SAVEOUT, ">&STDOUT"); open(SAVEERR, ">&STDERR");

my $SysDir = "$ENV{SystemRoot}\\system32";  # is there a better way?
my $Outf   = "out-$$.tmp";
my $Errf   = "err-$$.tmp";

sub slurp_file {
  my $file = shift;
  local $/;
  open(my $fh, $file) or die "error:open '$file': $!";
  <$fh>;
}

sub write_result {
  my ($pid, $rc, $elap) = @_;
  warn "pid=$pid, rc=$rc, elapsed=$elap\n";
  my $outstr = slurp_file($Outf);
  my $errstr = slurp_file($Errf);
  unlink($Outf) or die "error: unlink '$Outf': $!";
  unlink($Errf) or die "error: unlink '$Errf': $!";
  warn "cmd stdout='$outstr'\n";
  warn "cmd stderr='$errstr'\n";
}

# Run command $cmd, timing out after $timeout seconds.
sub run_for {
  my ($cmd, $timeout) = @_;
  $timeout *= 1000;   # convert to millisecs
  warn "run $cmd->[0] ($cmd->[1]) at " . scalar(localtime) . "\n";
  my $t0 = time();
  ### redirect stdout and stderr
  open(STDOUT, '>'.$Outf) or die "error create '$Outf': $!";
  open(STDERR, '>'.$Errf) or die "error create '$Errf': $!";
  Win32::Process::Create(my $hProc,             # process object
                         $cmd->[0],             # executable
                         $cmd->[1],             # command line
                         1,                     # inherit handles
                         NORMAL_PRIORITY_CLASS, # priority
                         '.')                   # working dir
     or die "error create process: $!";
  ### parent continues (redirect back to original) ...
  close(STDOUT); close(STDERR);
  open(STDOUT, ">&SAVEOUT"); open(STDERR, ">&SAVEERR");
  my $pid = $hProc->GetProcessID();
  warn "in run_for, waiting for pid=$pid\n";
  $hProc->Wait($timeout) or $hProc->Kill(42), $hProc->Wait(INFINITE);
  $hProc->GetExitCode(my $rc) or warn "error GetExitCode: $!\n";
  my $t1 = time();
  write_result($pid, $rc, $t1 - $t0);
}

my @cmds = (
 [ "$SysDir\\netstat.exe", 'netstat -na'                           ],
 [ $^X,                    'perl -e "print STDERR Hello;sleep 15"' ],
 [ "$SysDir\\cmd.exe",     'cmd /c DIR'                            ],
);

for my $cmd (@cmds) {
  run_for($cmd, 10);
}