Is it possible to detect if files on a drive were changed without scanning the drive?

[Grant Edwards]

On 2005-09-12, Oren Tirosh <oren.tirosh at gmail.com> wrote:

> Whenever a file is modified the last modification time of the directory
> containing it is also set.

Nope.

   $ ls -ld --time-style=full-iso .
   drwxr-xr-x  2 grante grante 4096 2005-09-12 12:38:04.749815352 -0500 ./
   
   $ touch asdf
   
   $ ls -ld --time-style=full-iso .
   drwxr-xr-x  2 grante grante 4096 2005-09-12 12:39:35.657995208 -0500 ./
   
   $ echo "hi" >asdf
   
   $ ls -ld --time-style=full-iso .
   drwxr-xr-x  2 grante grante 4096 2005-09-12 12:39:35.657995208 -0500 ./
   
   $ echo "foo" >asdf
   
   $ ls -ld --time-style=full-iso .
   drwxr-xr-x  2 grante grante 4096 2005-09-12 12:39:35.657995208 -0500 ./

Notice that writing to the file did not change the modification
date of the directory contining it.
   
-- 
Grant Edwards                   grante             Yow!  - if it GLISTENS,
                                  at               gobble it!!
                               visi.com