Programming Praxis

I recently found on the internet a delightful paper by Kenneth Ward Church called Unix™ for Poets that provides an introduction to the Unix command line utilities for text processing. The paper must be ancient, because it gives the author’s email address at research.att.com, but I’ve never seen it before. One of the examples in the paper is rhyming sort, in which words are sorted from the right rather than the left; the left column below is in normal alphabetical order, the right column is in rhyming order:

    falsely         freely
    fly             sorely
    freely          surely
    sorely          falsely
    surely          fly

Church says:

“freely” comes before “sorely” because “yleerf” (“freely” spelled backwards) comes before “yleros” (“sorely” spelled backwards) in lexicographic order. Rhyming dictionaries are often used to help poets (and linguists who are interested in morphology).

Church solved the problem with a rev | sort | rev pipeline.

Your task is to sort a file containing one word per line into rhyming order. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.

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