feature req for diff

[Koblinger Egmont]

Hi,

I'd really like to see an option for diff which I haven't found in the
documentation. When comparing two very large directory structures (e.g.
openoffice source :)  then a 'diff -ur' takes approx. half an hour on my
machine. It would be very nice if an option told 'diff' to assume that two
files with the equal size and timestamp have the same content. This would
reduce this half hour to approx. half minute, after I've changed some
files there.

(Okay, it's not hard to write a workaround: run rsync in test mode,
verbosely, catch which filenames it prints and then compare those files --
but it'd be much nicer if "diff" did it for me with one single option.
rsync is quite buggy, anyway...)


thx,

egmont