Karl Berry wrote:
> I think it would be better to say*something*  about the fact that
> diff does not always read its input, in the event that it can determine the
> result via other methods.

Thanks, that sounds good; I installed the attached.

 > This is so unlike virtually every other program

Hmm, well, in diff's defense, lots of commonly-used programs avoid 
reading some or all their input in some cases, including 'grep', 'head', 
'tail', 'sed', 'awk', 'dd', 'more', and 'od'.  It's not just 'diff' and 
'cmp'.