Re: About fwrite(s, 0, 1, fp)

[Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>]

Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> writes:

|> > > > I am not sure about it. If everyone else returns 0, it doesn't make
|> > > > glibc look good. Can someone check VC++?
|> > 
|> > On the contrary!  The C standard is very clearly worded on this point, and
|> > our implementation is definitely correct.  This not the first time by far
|> > that GNU libc has been the only library around to actually conform to the
|> > standards, and the commercial vendors slowly come around.
|> 
|> I agree with you that the C standard is the authorative resource here.
|> However, I just checked the Single Unix specification
|> (http://www.rdg.opengroup.org:80/onlinepubs/7908799/), and discovered
|> for fwrite():
|> 
|>           The fwrite() function returns the number of members
|>      successfully written, which may be less than nitems if a write error
|>                                                         ^ note no `only' here!
|>      is encountered. If size or nitems is 0, fwrite() returns 0 and the
|>      state of the stream remains unchanged. Otherwise, if a write error
|>      occurs, the error indicator for the stream is set and errno is set
|>      to indicate the error.
|> 
|> So it appears to me that there is a conflict of standards here :-(.
|> What can be done to resolve such a conflict ?  Is it advisable to
|> contact the Open Group about it ?

Note that this standard contradicts itself in the description of fread:

    Upon successful completion, fread() returns the number of members
    successfully read which is less than nitems only if a read error or
                                                ^^^^
    end-of-file is encountered. If size or nitems is 0, fread() returns 0
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

So i'd say the bug is on the Open Group.

-- 
Andreas Schwab                                      "And now for something
schwab@issan.cs.uni-dortmund.de                      completely different"
schwab@gnu.org