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From: gceych@juliet.caltech.edu (Eychaner, Glenn C.)
Newsgroups: comp.lang.c
Subject: Common areas/common data/data sharing
Message-ID: <1990Dec13.014044.9258@nntp-server.caltech.edu>
Date: 13 Dec 90 01:29:14 GMT
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I'm not sure that this is the right place to post this, but...
I want to get the effect of FORTRAN group common blocks in C.  In other words,
I want to be able to have 3 or 4 programs all sharing the same block of data,
some reading from it and some writing to it, without storing it all to a file
(file access is rather slow).  In FORTRAN, I would create a common block and
INSTALL it using the VAX Installer.  when I try to INSTALL a variable list
(linked shared) as a shareable image, it fails with:  cannot create writable
section to read only file.  Any ideas from anyone out there?

An example:
	I want some programs to share some data...say the variables i,j,k.
	So i create a program:
	/* Common block */
	int i,j,k;

	compile it, and link it /SHARED.  In each program I want to use it, I
	declare the variables as extern and link the program with the block.
	This allows the programs to share the variables.

	Now, to get them to share the DATA, I INSTALL it.  This fails as
	described above.

Thanks in advance for any suggestions you might have.

Glenn Eychaner   |Eychaner@SunCub.Caltech.edu|Remember: It is easier to ride a
40386 N Shore Ln |gceych@iago.caltech.edu    |camel through the eye of a needle
Big Bear City, CA|                           |than to drive a Buick through the
            92314|!*** G O   N I N E R S ***!|hole in a doughnut.