[fpc-pascal]Re: fpc-pascal digest, Vol 1 #1470 - 5 msgs

[mili]

> On Thu, 22 Aug 2002, mili wrote:
> > Hello, Every one
> >
> > I opened a file with TFileStream, and I don't want any other program to
> > access this file. So I try to lock it with FLock function in unit Linux
> > as following:
> >
> >
> > var
> >   fs : TFileStream;
> >   h  : integer;
> > begin
> >   fs:=TFileStream.Create('test.dat',fmOpenReadWrite);
> >   h:=fs.Handle;
> >   if LockF(h,LOCK_EX) then writeln('Lock OK!') else writeln('Lock
> > Failed!'); readln;  //  ----> Now, I test if I can still open this file
> > with other program
> >   fs.Free;
> > end.
> > <<<<<<
> >
> > But, Still, I can open the same file with other programs.
> > So, Can you tell me how to lock a file correctly with free pascal?
>
> This is not possible on linux. Only other programs that also place a
> lock will fail when they try to place the lock; locking is advisory at
> best.
>
> Michael.
>

Hello, Michael

  I don't know exactly your idea by "not possible on linux". Do you mean "It's 
not possible to exclude other program to access the same file which has been 
locked under linux" or "The described phenomenon of this example is not 
possible to occur"?
  I am sure LockF has returned success because it output 'Lock OK!', but I 
still can open it with Kate,Kedit or any other program.

  Thank you,
  Yours,
  mili