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From: ekuns@kilroy.chi.il.us (Eddie Kuns)
Newsgroups: comp.os.os9
Subject: Re: open() + sharable file = no disk
Summary: I've gotten open to work with S_ISHARE
Keywords: Sharable, open
Message-ID: <43@kilroy.chi.il.us>
Date: 12 Jun 91 02:49:47 GMT
References: <1991Jun11.012640.904@tkou02.enet.dec.com>
Distribution: usa
Lines: 33

zambotti@wpowz.enet.dec.com (Walter Zambotti DEC) writes:
>I having a small problem with the open() system call.
>
>I'm using a CoCo III OS9 Lvl 2 with the level 1 C compiler.
>
>When I open a file with the open mode OR'd with 0x40 (64 dec) which is
>supposed to be the shareable attribute.   The disk loses all directory
>information and I affectatively wipe out my entire disk.  This is even
>the case regardless of the file I open (dir or normal file).

I've gotten this to work, as desired.  As Zack, I'm using Carl Kreider's
C library.  Here is a short example:

#include <modes.h>

    ....

        /* open the active file in non-sharable mode, read-write */
        activepath = open(NGROUPS, S_IREAD | S_IWRITE | S_ISHARE);
        if (activepath == 0)
        {       printf("readactive: can't open active file\n");
                exit(0);
        }

And this code works.  (Other processes who open the file sleep until
this process closes the file.  They then awaken and can open the file.)

I also use the Dev Sys RAM Disk, and haven't noticed any weird behavior
with it.  (The file I open above is not on the RAM disk.)

My suggestion:  If you're not using Carl Kreider's C library, you should
get it.  It may fix the above problem; it is much more capable,
faster, and smaller.