[RFC] compatibility issue with stdout stderr

[Torstein-Eide]

#184 #188 I think we should to break the compatibility of some programmes that uses a design "error", where all of the output send to stderr instead of stdout.

We can do this over period to allow migration to what is expected, for new users and programmers, to be inline with standard practises.

I think we can do the following:

1. Add a new flag for output to stdout (--stdout or --new)and stderr (--stderr or --old), and add a warning to stderr that it will changed, in sometime. and warning to stdout about some of the output is not print to stdout without --stdout flag.
2. change the default to --stdout.
3. delete the old --stderr

[schweikert]

I am against breaking backwards compatibility, even with a transition effort. I think the pain is not worth the effort.

[Torstein-Eide]

I think we should start with adding a option to use stdout, and info about the unusual output is done. so novice fping users know that there is unusual thing with fping.