Steve,
SVR 4.2 STREAMS Programmer's Guide: Section 6.5 Design Guidlines,
6.5.1 Modules and Drivers, 6.5.1.1 Rules for Open/Close Routines,
2. The open routine should return zero on success and an error number on
failure. ...
Under UNIX, error numbers are not negative.
On the POSIX ioctl manual page, only ENXIO is returned when the push
of a module fails. Thus OPENFAIL (sorry, not MODOPENFAIL).
--brian
On Mon, 08 May 2006, Steve Schefter wrote:
> Brian F. G. Bidulock wrote:
>
> > SVR 4.2 STREAMS modules do no return negative error numbers, they
> > return MODOPENFAIL, which is translated to ENXIO when returned to
> > the opening process. LiS does not comply to SVR 4.2 because it
> > does not accept a positive error code. Almost everywhere you point
> > LiS has an error. This is just an example where someone happened
> > to point.
>
> Does SVR 4.2 Streams say that MODOPENFAIL is a postive number?
>
> Your Streams programer's guide is a little more up to date than
> mine (System V/3.2). Mine indicates that >= 0 should be returned
> for success and OPENFAIL (must therefore be a negative number)
> for error. In my modules, I return OPENFAIL but as evidenced by
> the IBM modules, not everyone does that.
>
> The other references I have at hand are Solaris and UnixWare.
> Solaris docs indicate that "The return value from open is 0 for
> success and an error number for failure". UnixWare does likewise
> but specifically lists error codes (eg EACCESS, EADDRINUSE)
> which, on Linux, translate to negative numbers.
>
> If something other than OPENFAIL is coming out of the open
> routine, it's the module that's doing that, not LiS.
> In my opinion, Dave made a good choice in looking for _any_
> negative number. It could be strict about making sure that
> the driver returned OPENFAIL/MODOPENFAIL, but that would break
> drivers being ported from other OSes. And it begs the question
> about what Streams would do if the driver returned neither >= 0
> nor OPENFAIL/MODOPENFAIL. Indicate a error back to the app
> (which is what the driver is trying to do)?
>
> Steve
>
> ------------------------------------------------------------------------
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>
--
Brian F. G. Bidulock ¦ The reasonable man adapts himself to the ¦
[EMAIL PROTECTED] ¦ world; the unreasonable one persists in ¦
http://www.openss7.org/ ¦ trying to adapt the world to himself. ¦
¦ Therefore all progress depends on the ¦
¦ unreasonable man. -- George Bernard Shaw ¦
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