[Tutor] How to Terminate a Popen call?

[eryksun]

On Tue, Oct 22, 2013 at 9:04 PM, SM <sunithanc at gmail.com> wrote:
>     def run(self):
>         (process, err) = Popen(self.fwcmd, stdout=PIPE,
>             stderr=PIPE).communicate()
>         if len(err) >  0:
>             # print("Error")
>             # Error handling code
>         else:
>             # print("Success")

Store the Popen() instance before calling its communicate() method:

    p = self.process = Popen(self.fwcmd, stdout=PIPE, stderr=PIPE)
    out, err = p.communicate()
    if p.returncode:
        raise CalledProcessError(p.returncode, self.fwcmd, (out, err))

communicate() sets returncode; an error is indicated by a non-zero
value. Some programs write non-error information to stderr, so use the
return code to detect an error.