[Info-vax] Help wanted : Porting code from Linux to VMS

[gezelter at rlgsc.com]

On Tuesday, January 22, 2019 at 3:44:20 PM UTC-5, Marc Van Dyck wrote:
> My job today is mainly system administration. But I have done software
> development in the past, and still enjoy doing some programming when 
> the
> opportunity arises. What I have been asked to do today is however a bit
> more challenging for me than usual.
> 
> It'll basically consist of porting C code written for a linux platform
> to OpenVMS. And it won't be the trivial 'copy the code and recompile'
> job :
> 
> 1) it contains several system calls which I'll need to find an adequate
> equivalent for. I think I can manage that one, even if I know nothing
> about Linux.
> 
> 2) I will port the code from C to Pascal, which is the only language I
> feel comfortable with. Not afraid by that one, have done it several
> times already.
> 
> 3) The code contains a good dose of TCP/IP programming. And there I'm
> somewhat lost, because I never touched that in the past. So I'd
> appreciate a bit of help to get me started...
> 
> Hence the following questions :
> 
> 1) Is there any documentation about that ? How to write, on OpenVMS,
> code to establish a TCP/IP communication with another host ? Like what
> you would do with DECnet non transparent task to task communication ?
> 
> 2) Any coding examples availabe somewhere, or that someone would agree
> to share ? Preferably in Pascal, but I'll understand if only C is
> available...
> 
> 3) Are the TCP/IP calls definitions that I'll need to use available
> in pascal environment files somewhere ? Or SDL definitions that I
> could translate and compile ?
> 
> If you want to send me something, the address is
> marc dot gr dot vandyck at skynet dot be.
> 
> Many thanks in advance for all your hints !
> 
> 
> -- 
> Marc Van Dyck

Marc,

I would also recommend not translating from C to PASCAL. It is generally a shorter path to learn C than to translate an entire codebase.

The standard socket calls are generally available on OpenVMS. One can also use the QIO-level calls, which allow asynchronous operation and ASTs. I have done both for various client situations in the past.

Translating the Linux system calls to the OpenVMS environment depends upon the system calls involved. Some are straightforward, others not so much.

If I can be of assistance, please let me know by email.

- Bob Gezelter, http://www.rlgsc.com 
- Bob Gezelter, http://www.rlgsc.com