Proccess termination

[alexrait1]

I use popen.popen2 or popen.popen3 to start a new process and read from
it's stdout/ write to it's stdin.
But I need a way to know when a process terminates. If it closes it's
stdin/stdout, it doesn't mean it has really terminated...
And if possible, I would like to see an exception thrown when that
happens..
Do you know about a library that provides these tools other then the
standard os module... or should I use it otherwise?

Thanx Alex Rait.

[Diez B. Roggisch]

Re: Proccess termination

alexrait1 wrote:
[color=blue]
> I use popen.popen2 or popen.popen3 to start a new process and read from
> it's stdout/ write to it's stdin.
> But I need a way to know when a process terminates. If it closes it's
> stdin/stdout, it doesn't mean it has really terminated...[/color]

You can use the Popen-objects pid to see if a process still runs.
[color=blue]
> And if possible, I would like to see an exception thrown when that
> happens..[/color]

Not possible - that exception would be asynchronous to your program flow.
The only thing I can think of that would make this possible is to have a
second thread waiting for process termination - and sending the own process
a signal. If I'm not mistaken, that will be propagated to the main thread.

All this is meant to be running on unix - not sure how thinks work out on
windows.

--
Regards,

Diez B. Roggisch

[George Yoshida]

Re: Proccess termination

alexrait1 wrote:[color=blue]
> I use popen.popen2 or popen.popen3 to start a new process and read from
> it's stdout/ write to it's stdin.
> But I need a way to know when a process terminates.[/color]
[color=blue]
> Do you know about a library that provides these tools other then the
> standard os module... or should I use it otherwise?[/color]

popen2.Popen3, popen2.Popen4 and subprosess.Pope n have poll/wait methods.

These will do what you're looking for.

--
George