| From: DEC:.REO.REOVTX::HUDSON "[email protected] - UK Software
Partner Engineering 830-4121" 18-MAR-1997 15:14:56.28
To: nm%vbormc::"[email protected]"
CC: HUDSON
Subj: RE: ASAP call 22906, use RMS with TCP
Hello John van der Beck
>Has own database with OpenVMS 6.* and decnet. Client wants to change to tcp
>only. Is it possible to use rms with tcp, and is there a simple solution to map
>the decnet node names to a tcp environment.
Thanks for your ASAP question above.
I think the answer to your question is going to be "no".
VMS "knows" about how to deal with filenames that have a DECnet node component.
If you say "HELP SPECIFY FILESPEC", you'll see that the definition of a VMS
file specification is
node::device:[directory]filename.type;version
It's therefore possible to use a remote file in any place where a file spec is
called for. E.g.
infile = fopen("node::[dir]fred.dat","r");
DECnet provides "DECnet objects" which respond to incoming requests from remote
nodes. Specifically, the FAL object deals with providing access to files, and
so enables most RMS operations to be carried out over DECnet, where the client
program doesn't see a difference between accessing a local and remote file.
If you are using TCP/IP as your network, then there are two problems. Firstly
there is no way to specify an TCP/IP node's address in a VMS filespec, and
secondly there's not going to be an equivalent software component on TCP/IP to
the "FAL" object that DECnet provides.
If you have an application which is accessing files over DECnet using RMS and
you want to remove DECnet from the picture, then I guess you'll probably need
to implement some protocol of your own where client and server communicate
through sockets to move the data from the file on the server to the client.
In this case, you would effectively be writing an equivalent to "FAL" - that is
an internet service which uses a specified inet port to talk to clients. This
might not be too difficult, if, for example, all you want to do is read a
remote file (e.g. "$ type node::[dir]file.dat"). But if you need anything more
complicated then it could be a lot of work.
Does this help to answer your question? Please give me some more details if I
haven't given you the information you need.
Regards
Nick Hudson
Digital Software Partner Engineering
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