It occurred to me that Steven M. Bellovin wrote in gmane.os.netbsd.devel.kernel:
>>Looking through my scripts directory, I found a couple faults due to
>>this misunderstanding. ie: if [ -f $(basename "$URL") ]
>>
>
> I'd leave the quotes in that spot.  The issue is whether or not URL 
> has, say, embedded blanks.

It shouldn't, ofcourse, but that's wasted on quite a few web"designers" :(