read stdout/stderr without blocking

[Jacek Popławski]

Grant Edwards wrote:
> On 2005-09-12, Jacek Pop?awski <jpopl at interia.pl> wrote:
> 
>>>        ready = select.select(tocheck, [], [], 0.25) ##continues after 0.25s
>>>        for file in ready[0]:
>>>            try:
>>>                text = os.read(file, 1024)
>>
>>How do you know here, that you should read 1024 characters?
>>What will happen when output is shorter?
> 
> 
> It will return however much data is available.

My tests showed, that it will block.