just for fun: pop quiz

[Jerry Jensen]

On Feb 3, 2013, at 2:49 PM, Mark Wieder <mwieder at ahsoftware.net> wrote:

> Jacque-
> 
> Sunday, February 3, 2013, 1:51:24 PM, you wrote:
> 
>> On 2/3/13 3:08 PM, Mark Wieder wrote:
>>> Jacque-
>>> 
>>> Sunday, February 3, 2013, 12:40:43 PM, you wrote:
>>> 
>>>> In the case of sockets and drivers it is possible to read without error
>>>> but not receive all the data due to communication issues. In that case
>>>> you'd want to know if the read had paused or had really finished.
>>> 
>>> I was about to post the same, but then Bob would be on my case
>>> instead <g>, so I'm glad you beat me to it. I'd be happier if the read
>>> command had been written to return the number of characters read, in
>>> which case 0 or -1 would be an error, but we're stuck with what we've
>>> got.
>>> 
> 
>> If you're reading a serial port, you don't always know how many 
>> characters to expect. I'm not sure if that's still the same thing though.
> 
> Yeah, interesting point. I'm not sure what EOF means in that case
> either. Is that "I received an EOF char from the port"?

I don't think EOF is meaningful with a serial driver. The closest character is Ctrl-D, EOT, end of transmission.

I've always had to use 
read from driver tPort until empty in tTimeout milliseconds
and put that in a timed repeating loop, buffering until a "real" return char comes in.
.Jerry