> 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.
.. and if standard Unix interface to filters looks
old fashioned then it might be worthwhile to point
out that they could be used in a very modern way.
As an example, NextStep used to provide excellent
interprocess mechanism and standard for writing
cool applications (in Objective C). Filters, such
as converters from one graphic format to another,
could not only be silently used by applications
- such as web browsers, but they could also register
themselves in applications' menus.
Jan
