Popen - How can I read data before CTRL+C command is issued

[maffaz]

for anyone that is interested. I have found the problem but it is not Python Related, Rather the C implementation of the tool..

The problem here is probably, that the output of your CLI program is block buffered, since the output file descriptor is not associated with a terminal. You claim, that it works with "ping" instead of your cli program, so it definitively has to be an issue with the subprocess itself.

Since you programmed the cli program yourself, make sure that it does not buffer the output (i.e. put an fflush() after each line which is printed.

You can read the discussion here..

https://stackoverflow.com/questions/5103...1#51078297