Ah, OK. So you want to be able to kill off the offending sub-process when the alarm fires? Then you either need to walk the process table, looking for a process whose parent is your script, or start the process in a way which allows you to get the pid and the output.
e.g. run the code under a piped open, something like this (untested):
my $cmd = "your command";
my $pid = open(my $fh, "$cmd|");
$SIG{ALRM} = sub {
print "Alarm fired, killing pid $pid\n";
# Replace with windows-specific code to kill process
kill 15, $pid;
};
die "Can't run command [$cmd] : $!" unless $pid;
# Or do some other processing with $fh
push @result, $_ while (<$fh>);
close $fh
or die "Problem running [$cmd] : $?";
If your child process starts yet more children (and they don't exit when the parent is killed), you'll have to write more elaborate cleanup code.
Dig through the windows-related process modules on CPAN and you should find what you need for the cleanup. | 