Re: Two users writing to the same file at the same time.
Lo, on Saturday, May 4, AE Roy did write:
> I've set up my system with 15 computers and 60 users so that they have a
> directory where they all can share files, under /home/staff, I have
> them belongign to the group teacher who is the owner of /home/staff, and
> the GUID is set on /home/staff.
>
> And I have a problem; If two teachers deceides to work on the same file at
> the same time, then all changes made by the first to exit will be lost,
> without him noticing.
Yup. Standard race condition.
> I know CVS, but thats not an option. People I've talked to that know MS
> say that in MS under the same situation, you'd gett a warning when someone
> already had that file open, does anything similar exist for linux?
> They all use OpenOffice.org to write these files.
First, why is CVS not an option? Is it because you're working with
binary files?
Second: AFAIK, no, nothing similar to MS's behavior (``another program
already has this file open'') exists for Linux, unless you implement it
yourself. It's a fundamental difference in the semantics of the
filesystem interface. The Unix/Linux answer is to provide a separate
synchronization mechanism to prevent the race condition from occurring.
It's up to the appliation. Most version-control systems like CVS, RCS,
et al do this. If OpenOffice doesn't provide this functionality
already, using some sort of lockfile as another poster suggested is
the only other alternative I can think of.
HTH,
Richard
--
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Reply to: