Re: Compatible fstat()

[Parag Warudkar <kernel-stuff@comcast.net>]

On Nov 8, 2005, at 5:57 PM, Bill Davidsen wrote:

> Parag Warudkar wrote:
> > On Nov 8, 2005, at 2:39 PM, Bob Copeland wrote:
> > > Isn't this just because the device size is > 2**32?  What if you   
> > > use fseeko(3)
> > > and #define _FILE_OFFSET_BITS 64?
> > Yep. I got it to return the correct hard disk size (17Gb) using   
> > lseek64 and
> > #define _LARGEFILE64_SOURCE
> > #define _FILE_OFFSET_BITS 64
> > Here is what I did
> > -------------------------------------------------
> > #define _LARGEFILE64_SOURCE
> > #define _FILE_OFFSET_BITS 64
> > #include <stdio.h>
> > #include <unistd.h>
> > #include <fcntl.h>
> > int main()
> > {
> >         int f;
> >         off64_t off=0;
> Why is this initialized?
> >         f = open("/dev/hda", O_RDONLY );
> >         if(f <= 0){
> >                 perror("open");
> >                 exit(0);
> >         }
> >         off = lseek64(f, 0, SEEK_SET);
> Why do this? it always returns zero.
> >         off = lseek64(f, 0, SEEK_END);
> >         perror("llseek");
> >         printf ("Size %lld\n", off);
> >         close(f);
> >         return 0;
> > }
> RETURN VALUE
>   Upon successful completion, lseek returns the resulting offset
>   location as measured in bytes from the beginning of the  file.
>   Otherwise,  a  value  of  (off_t)-1 is returned and errno is
>   set to indicate the error.

You took it a little too seriously! It was from the scribble-and- 
shuffle-till-it-works department ;) Sole purpose was to figure out a  
way to print the disk size from the device - some how that is!

But thanks for pointing out anyway - it doesn't hurt to be correct no  
matter what the purpose is.

Parag
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