Re: SetEndOfFile fix

[Guy L. Albertelli]

----- Original Message -----
From: "Rein Klazes" 
To: "Guy L. Albertelli" 
Cc: 
Sent: Saturday, January 26, 2002 8:50 AM
Subject: Re: SetEndOfFile fix
> On Sat, 26 Jan 2002 01:48:06 -0500, you wrote:
>
> BTW, what goes wrong exactly? From the snippet above I understand that
> either ftruncate() moves the filepointer when it fails or that the
> sequence: lseek(fd,-1,SEEK_CUR);write(fd,&buf,1) moves the file
> pointer.

All the following is on the 2.2.12-20 kernel:

"ftruncate" would return a 0. However Scandisk said that the file was bad.
The length reported in the directory was larger than the allocated space.
Errors were also reported on attempts to move or copy the file.

Since ftruncate did not return a error, the rest of your code was never
executed. So the rewrite basically asked if the file was being extended,
then use the lseek and write. Use ftruncate only if shortening the file.
This process resulted in a "valid" file. The size in the directory seemed to
match the allocated space.

The oldoff offset was just to put the current file pointer back to where it
was on entry. I was not sure of the semantics of the SetEndOfFile and where
it would leave the file pointer.

Guy