Generalization of uniq

Question

The uniq(1) command can be viewed as a tiny map/reduce-style program:

• map consecutive, identical input lines into groups;
• reduce the list of lines (which are all identical) to a single line.

Are there more examples of programs in this (functional) style in Unix? And, if I would like to use another map or reduce function, are there more generic tools out there that let one provide custom mappers and reducers?

Maybe something like this:

mapreducer -mapper prog1 -reducer prog2 < input > output

Answer 1

There's a tool out there called "bashreduce"

Article: http://www.linux-mag.com/id/7407/

GitHub: https://github.com/erikfrey/bashreduce