Re: [HACKERS] Win32 WEXITSTATUS too

On Tue, Jan 23, 2007 at 10:40:40AM -0500, Bruce Momjian wrote:
> >
> > Depends on what you mean with OS.
> > There are a *lot* of tools that will return exitcodes >0x100 that are
> > part of the OS. As a relevant example, Windows installer will return
> > exitcode 3010 means "needs to reboot but didn't reboot". MSI is a part
> > of the OS, but it's not kernel... Same thing for things like the service
> > control manager (trying to operate on a service that has been removed
> > gives you error 1060).
>
> Is there a portable way to get the _exception_ value from system(),
> rather than the error code? We could go with just > 0xC0000000 values
> as exceptions. (This is clearly showing the mess that is the WIN32
> API.)

AFAIK, the way to do that is to use SEH. But this is not supported by
MingW.

> > > > would break that assumption. (And yes, it works)
> > > > exit() takes a 32-bit signed integer, and that's what comes out to the
> > > > calling program (verified both with console and standalone program)
> > > >
> > > > The MSDN link referes to the DDK which has to do with driver
> > > > development, not userspace. AFAIK, that list is not relevant here, and
> > > > I've seen no actual reference so far that it should be used to look up
> > > > exit codes.
> > > >
> > > > Now, if we're only caring about exit() from *postgresqls own processes*,
> > > > that might hold true. In which case I withdraw that objection as long as
> > > > the comment i updated to reflect this ;-) But if we're talking about
> > > > exit() in general of any process, then it's simply wrong.
> > >
> > > Right, that code is only used by the backend and tools.
> >
> > We should be very clear about that in our comment then, and the current
> > comment is not. And the part referring to the DDK should just be
> > removed, because it's simply incorrect.
> >
> > For example, don't we call cmd for PITR scripts? If we're using any of
> > these macros on the return value from there we are *NOT* certain of what
> > it will be, and then need to document that as a requirement on those
> > scripts.
>
> The major place we use it is for backend termination checking, and we
> know the return values there. The other place is for the return value
> of pipe().

I assume you mean popen()/pclose()? Because pipe() is implemented using
sockets in our win32 ports layer.

//Magnus