Basically, you found a bug in the implementation: 

BOOL
KillProcess(pid, exitcode)
    DWORD pid
    unsigned int exitcode
CODE:
    {
        HANDLE ph = OpenProcess(PROCESS_ALL_ACCESS, 0, pid);
        if (ph) {
            RETVAL = TerminateProcess(ph, exitcode);
            if (RETVAL)
                CloseHandle(ph);
        }
    }
OUTPUT:
    RETVAL

[download]

Or maybe several bugs.

  1. If your perl process is not running with sufficient priviledges to open the target process PROCESS_ALL_ACCESS, then RETVAL is never being (visibly) set and you are getting whatever value it is initialised to by XSUBPP (if any, the docs are less than clear about this), or some random value in the ram it inherits.
  2. If OpenProcess() succeeds, then you get the return value of TerminateProcess(), which is non-zero for success, or zero for failure in which case calling GetLastError() should tell you why it failed.

It's possible that when it fails, the arbitrarily large number you are getting is the OS failure code. It would be worth comparing it against the numeric realisation of $^E.

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.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

In reply to Re: Killing a Win32 process, a return value ? by BrowserUk
in thread Killing a Win32 process, a return value ? by abachus

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