Global classpaths are a really bad idea. In your example you could
just use scala -cp $CLASSPATH to use the defined exported variable. If
you really wanted to avoid typing that/you aren't using an IDE then
you could write a simple wrapper script myscala with contents looking
something like this (Unix, can do a similar thing on Windows):
scala -cp $CLASSPATH $*
Which gives the behaviour in a simple form.
PK