Re: io.popen processes hanging around after close

[Rena <hyperhacker@...>]

On Mon, Oct 28, 2013 at 12:42 PM, Justin Cormack <justin@specialbusservice.com> wrote:

On Mon, Oct 28, 2013 at 4:29 PM, Rena <hyperhacker@gmail.com> wrote:
> On Mon, Oct 28, 2013 at 11:51 AM, Justin Cormack
> <justin@specialbusservice.com> wrote:
>>
>> On Mon, Oct 28, 2013 at 3:35 PM, Rena <hyperhacker@gmail.com> wrote:
>> > In my app I open a few processes using io.popen(), then read their
>> > output
>> > using posix.fileno() and posix.rpoll() to see if there's data available.
>> > When my app shuts down however (using os.exit(0)), even if I close the
>> > process file handles, they remain running in the background. How do I
>> > prevent this? I do both process:close() and posix.close(fd). (I found
>> > without the latter, the former would just hang...)
>>
>> You can either send a kill (posix.kill) signal to the child, or make
>> the child test to see if the pipe is still open - it depends if it is
>> doing anything or is blocked, and how much it is under your control.
>>
>> Justin
>>
>
> But how do I get the child's PID?

Ah yes. Try using 0 (all processes in process group), at least that
works for Linux and NetBSD, not sure about OSX.

Justin

Thanks, that seems to do the job. (It kills the process that called kill() too, but no big deal for my case...)

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