Error message output

[David Christensen]

On 2020-09-21 01:09, Steve O'Hara-Smith wrote:

> I have
> long thought that there should be a stdctl then stdin/stdout are data flow
> and stdtctl/stderr are control flow.
> 
>> * Use stderr, log files, and the exit value for out-of-band/ non-data
>> output.

Similar thoughts here.  The three standard handles seem cover the basics 
of interactive and batch usage.  Beyond that, the programmer is free to 
keep it simple or make it more complex.


David