Exercise 48: ed

If your process is working then you should be able to focus on one long project for a few weeks at a time. In this project your goal is to create the most accurate faithful copy of the ed command as you possibly can. The goal of this exercise is to not be creative at all but to do a methodical exact copy of another piece of software. Think of this as a forgery exercise. You'd want something so good that you could put it in place of the original ed and nobody would know.

This exercise will be to create a master copy of the ed command as exactly as you can, which means your test suite should run the real ed and your version against the same scripts to compare the output. This is like the Master Copy exercise you did when learning algorithms, except you're copying the behavior of an existing piece of software rather than trying to memorize it. The process is similar, but you get to use test suites to help make it go faster.