Archive-Date: XXX, 9 Jul 1996 19:28:53 GMT
Subject: Vax Basic Socket Programming
Message-ID: <4rubtl$qe9@news0-alterdial.uu.net>
From: Kuff@Access.Digex.Net (Hal Kuff)
Date: 9 Jul 1996 19:28:53 GMT
Reply-To: Kuff@Access,Digex.Net
Content-Type: Text/Plain; charset=US-ASCII

Hi,

   Anyone done Vax Basic socket programming? Any examples?

Hal Kuff
Kuff@tessco.com



================================================================================
Archive-Date: XXX, 11 Jul 1996 15:19:16 -0400
Subject: Re: Vax Basic Socket Programming
Message-ID: <1996Jul11.151916@process.com>
From: volz@process.com (Bernie Volz)
Date: 11 Jul 96 15:19:16 -0400
References: <4rubtl$qe9@news0-alterdial.uu.net>

In article <4rubtl$qe9@news0-alterdial.uu.net>, Kuff@Access.Digex.Net (Hal Kuff) writes:
> Hi,
> 
>    Anyone done Vax Basic socket programming? Any examples?
> 
> Hal Kuff
> Kuff@tessco.com
> 

I'd recommend using the SYS$QIO/SYS$QIOW calls directly if you can. This
should be easier than dealing with the socket routines directly (and for
the most part isn't that difficult to do). How to use system-services in
general is documented (if I recall) in the BASIC documentation set.
Another nice feature of using these is you can use the nice VMS services
(such as event flags and asynchronous system traps) to do real-time
event driven programming. Doing that via sockets means you have to use
polling (select).

Calling the socket routines from BASIC should be doable provided you
understand the calling standards and how C passes arguments. C passes
arguments by value and by reference. Strings are null-byte terminated
and passed by reference. You also have to make sure that you allocate
sufficient space for strings that return data and understand that a
null-byte will terminate them. This means if you're going to use them
with BASIC, you need to "fix" them up upon return (as well as before
calling the routine).

Access to C data structures is also possible. Perhaps using something
like the MAP/REMAP statements in BASIC? Or, declaring the entire 
structure as a string and pulling out the various pieces (via the CVT$x
functions).

- Bernie Volz
  Process Software Corporation

BTW: It has been a while since I used VAX BASIC and I never did use it
much.