Subj : Re: Opening a file in exclusive mode
To   : comp.os.linux
From : ganesh.m
Date : Thu Jul 29 2004 10:48 pm

vanjina_murthy@rediffmail.com (murthy) wrote in message news:<1d1f73fd.0407280615.4db78145@posting.google.com>...
> I am developing an application using C 
> 
> I am facing a problem , when a file is opened by one process either in
> read/write mode using open function , at the same time the other
> process can delete the same file using unlink function.
> 
> What i want is that if a file is opened by one process either for
> reading/writing it should not be deleted or even can be opened by
> other process(i.e open should fail). Anyone knows, how it can
> achieved.
> 
> The purpose is that i want to open a file in exclusive mode.
> 
> Thanks in adavance
> 
> Murthy

Hi Murthy!

Record/File locking (using flock() fcntl()...) can be used to obtain
exclusive control over a (part of a) file. But this works among
co-operating processes only. means each of the processes should try to
obtain a lock bfore using the file. This is advisary but not
mandatory... means a process can still have control on the file
illegally. Em...
If ur system supports mandatory record locking (This is done by stting
some special flags in the files access-mode)...

But even this also cannot prevent a process from deleting the file...

Plzz let me know... If at u get some solution for this... Thanks...

- Gana

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