Except that usually grep and sort can read files, or entire directories, which is considered a "side effect" in Haskell. (Not to mention checking locales to de

Except that usually grep and sort can read files, or entire directories, which is considered a "side effect" in Haskell. (Not to mention checking locales to decide how to sort, checking if the output is terminal so that we can add colors, but only if the environment variable says so, and on, and on...)