[En-Nut-Discussion] how to assign stdout, stdin and sterr to the same uart?

[Matthias Ringwald]

hi there

after years of using nut/os, I've just stumbled about a newbie  
question/problem.

how do I correctly assign stdout AND stdin to the uart?

the default code in many examples is:

     NutRegisterDevice(&devUsartAvr0, 0, 0);
     freopen(devUsartAvr0.dev_name, "w", stdout);

so far, that's fine. printf works. But when you call e.g. kbhit() it  
never returns as stdin was never assigned.

Browsing the mail archive I've seen people doing it like this:

   NutRegisterDevice(&devUsartAvr0, 0, 0);
   freopen(devUsartAvr0.dev_name, "w", stdout);
   freopen(devUsartAvr0.dev_name, "r", stdin);

this sounds logical, but with the current nut/os code (or the one  
from last year..) this is not perfect / probably incorrect.

_freopen first looks for the proper __iob entry and then calls _open  
for the given device with the given flags.
the usart on the avr is not written to be opened twice, especially  
with different mode flags, everything is reset.

any clues how to do it properly?

cheers,
matthias ringwald