[RFC] Change sendfile header

[Bill Davidsen]

I suggest that the header holding the prototype for sendfile should not be
in unistd.h because:

1 - sendfile is not in SuS, an is extremely non-standard
2 - there is a sendfile in BSD and it's totally different
3 - there is no man page for sendfile in Solaris, but there is a
    definition in one of the libraries which is not Linux compatible
4 - just putting the "not portable" warning in the man page to counteract
    the impression given by the <unistd.h> is not enough, programmers
    usually only read the man page  to get the args right.

Since Linux sendfile is totally applicable only to Linux, it would seem
that a better name for the header file, like linux/sendfile.h, would be
better. This has the advantage of not breaking executables, and requiring
use of a header file which makes it much harder to overlook the
portability issue.

-- 
bill davidsen <[e-mail]>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.