putw return value

[VLD/VMB]

There have been various versions of putw() on UNIX systems.
Some returned the word written or EOF on failure, which was
ambiguous.  Somebody then decided that putw() should return
0 on success, EOF on failure.  However, the implementation
didn't follow the new spec.  SVR3 has it that putw() should
return ferror() or EOF on failure.  I think this is the
same as 0 or EOF.  My feeling is that you should ignore the
return value of putw() since there's no telling what it
will be next week, and use ferror() to detect an error.