Greg A. Woods writes:

>Perhaps you're willing to write some test harnesses, test cases, etc.?
>Not everyone in the world does everything possible with even a
>relatively simple tool such as expr.  Dozens, and maybe even hundreds,

Seriously, he is right.. if nothing else, computer science education
should've indoctrinated into each of us at least some common sense
regarding tests, i.e., any program should (ideally) have a full
regression test suite available, for a) verifying that it works
exactly like the last version for a subset of input for which the
old version works correctly, and b) a thoroughly crafted set of tests
(often cannot be exhaustive of course) which probes the perimeters
of the algorithm as to catch as many new errors as possible (you of course
cannot show the absence of errors, as Dijkstra, who, to our general
amusement, prowls lectures in bare-socks, has hammered into our collective
brains already some time ago.)

--mkb