Sure, cat in itself isn't very interesting. But cat is just a simple
case of a more interesting problem, that of writing what Unix calls
"filters": programs that take some input from a file or pipe or other
similar source and transform it into some output.
It seems to me that functional languages out to be pretty good for
writing transformations, and if their I/O system makes them unsuitable
for transforming files and simular sources, then their I/O system
ought to be fixed. (I'm not saying Haskell implementations actually
have losing I/O systems, of course.)
Dismissing (in effect) this whole class of problems because cat is
uninteresting, or a job for imperative languages, or a trivial
standard Unix utility seems to me a mistake.
-- jd
