I’ve long been impressed by shell one-liners. They seem like magical incantations. Pipe a few terse commands together, et voilà! Out pops the solution to a problem that would seem to require pages of code.
Are these one-liners real or mythology? To some extent, they’re both. Below I’ll give a famous real example. Then I’ll argue that even though such examples do occur, they may create unrealistic expectations.
Bentley’s exercise
In 1986, Jon Bentley posted the following exercise:
Given a text file and an integer k, print the k most common words in the file (and the number of their occurrences) in decreasing frequency.
Donald Knuth wrote an elegant program in response. Knuth’s program runs for 17 pages in his book Literate Programming.
Read more at John D. Cook blog
