About the `-u' option of `cp' command

[Rodolfo Medina <rodolfo.medina@gmail.com>]

Hallo, Debian users.

In `cp' man it is said:

-u, --update
              copy only when the SOURCE file is  newer  than  the  destination
              file or when the destination file is missing


Now, it happens sometimes to me that, even with `-u', `cp' will copy the file
also when it isn't newer at all than the destination file, as here:

$ ls -lh ing.tex /mnt/pendrive2/ing.tex 
-rw-r--r-- 1 rodolfo rodolfo 163K 2011-08-31 18:44 ing.tex
-rwxr-xr-x 1 rodolfo rodolfo 163K 2011-08-31 18:44 /mnt/pendrive2/ing.tex
$ cp -viup ing.tex /mnt/pendrive2
cp: overwrite `/mnt/pendrive2/ing.tex'?

Why this, and how to avoid it?

Thanks for any help
Rodolfo