SVR4 fwrite different?This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.
Authors: Per Bothner, Project Editor (P.J. Plauger)
Date: 1994-01-31
Submitted against: C90
Status: Closed
Converted from: dr.htm, dr_135.html
H.J. Lu points out that the SVR4 manual explicitly says that fwrite(ptr, 0, 1, stream) returns 0, not 1. I don't know what the SVID states.
I think it is more mathematically consistent to return 1 in this case. But in
that case fread(ptr, 0, 1, stream) should also return 1, but ANSI explicitly
states that it should return 0. I don't see any reason why these should be
different, so I think it is best to follow existing practice. I think the ANSI
specification for fwrite is a mistake; perhaps it should be fixed in the
revision.
Comment from WG14 on 1997-09-23:
There are no zero-length objects in C. Therefore, if the size argument to
fwrite is zero, it is outside the domain of the function and (by subclause
7.1.7), the result is undefined. The C Standard is not in conflict with the
cited behavior of SVR4.