Re: [PATCH] Support in du for showing both apparent and on-disk size and the ratio between them

[James Youngman]

On 1/31/07, Luca Barbieri <address@hidden> wrote:
> This patch allows to display simultaneously both the disk usage and
> apparent size and also allows to display the "completeness" (or
> "nonsparsity") of file, which is the ratio of the disk usage to the
> apparent size.

For what it's worth, findutils-4.3 in CVS implements a similar feature:

static double
file_sparseness(const struct stat *p)
{
 if (0 == p->st_size)
   {
     if (0 == p->st_blocks)
       return 1.0;
     else
       return p->st_blocks < 0 ? -HUGE_VAL : HUGE_VAL;
   }
 else
   {
     double blklen = file_blocksize(p) * (double)p->st_blocks;
     return blklen / p->st_size;
   }
}


> For instance, this is useful when dealing with software that download
> files by creating sparse files and filling them: the "completeness" then
> is approximately the progress of the download.

Personally, I don't like the name "completeness" very much; it
communicates nothing much to me.

James.