[GRASS-dev] obtain the progress percentage of a command run from python

[Markus Neteler]

On Thu, Dec 1, 2011 at 7:57 AM, Glynn Clements <glynn at gclements.plus.com> wrote:
...
> If you want to parse the output, set GRASS_MESSAGE_FORMAT=gui in the
> environment when running the command and read from the command's
> stderr; e.g.
>
>        import grass.script as grass
>        env = os.environ.copy()
>        env['GRASS_MESSAGE_FORMAT'] = 'gui'
>        p = grass.start_command(..., stderr = grass.PIPE, env = env)
>        # read from p.stderr
>        p.wait()
>
> If you need to capture both stdout and stderr, you need to use
> threads, select, or non-blocking I/O to consume data from both streams
> as it is generated in order to avoid deadlock.

Thanks, added to
http://grass.osgeo.org/wiki/GRASS_and_Python#Percentage_output_for_progress_of_computation

Markus