Path: utzoo!attcan!uunet!husc6!psuvax1!rutgers!att!chinet!jkingdon
From: jkingdon@chinet.chi.il.us (James Kingdon)
Newsgroups: comp.os.vms
Subject: Re: Multiple-access files in VMS?
Message-ID: <6113@chinet.chi.il.us>
Date: 28 Jul 88 04:00:33 GMT
References: <1391@csun.UUCP>
Reply-To: jkingdon@chinet.chi.il.us (James Kingdon)
Organization: Chinet - Public Access Unix
Lines: 20

In article <1391@csun.UUCP> mst@csun.UUCP (Mike Temkin) writes:
>Does anyone out there know how to make a file multi-accessible (readwise)
>in VMS?  There must be a way since I would think that the help file is
>that way.  Any help is appreciated.

I assume what you are saying is that you want 2 programs to both be able
to read a single file simultaneously.

RMS (Record Management Services) has 2 fields that you set when you open
a file:  FAC (File Access), which is what you want to be able to do to
the file, and SHR (Sharing), which is what you want to let other processes
do.  So in this case you set FAC to GET and SHR to include SHRGET (you
may also wish to include SHRPUT, SHRUPD, etc.)

If you are trying to use the language-specific file I/O routines in C,
Pascal, FORTRAN, etc. I don't know whether they let you specify both
of these fields.  It is possible you might have to go directly to RMS.

And if one of the programs is one you can't change, and it opens the file
without allowing sharing, as far as I know you are Simply Out of Luck.