Re: File System Performance

[Peter Wächtler]

Mike Castle wrote:
> 
> On Mon, Nov 12, 2001 at 02:36:08PM -0800, Andrew Morton wrote:
> >   /* Detect if outputting to "/dev/null".  */
> >   {
> >     static char const dev_null[] = "/dev/null";
> >     struct stat dev_null_stat;
> >
> >     dev_null_output =
> >       (strcmp (archive_name_array[0], dev_null) == 0
> >        || (! _isrmt (archive)
> >            && stat (dev_null, &dev_null_stat) == 0
> >            && S_ISCHR (archive_stat.st_mode)
> >            && archive_stat.st_rdev == dev_null_stat.st_rdev));
> >   }
> >
> > It's actually a bug.  I may _want_ an ISREG /dev/null...
> 
> Doesn't the S_ISCHR() handle that case?
> 

No. It is: if (A || B)
If A is true, B is not even evaluated.