This is beside the point, and I'm being pedantic, but the unix pipeline and the clojure expression don't quite do the same thing.

The clojure expression reads the entire file into memory first, and then operates on that memory representation.

The pipeline processes the input in chunks. The two `sort`s might read the entire contents into memory, but an implementation like GNU sort will instead, for large inputs, create temporary files for sections of the input and then merge sort them to the output.

You could make clojure do the same thing, but it might not be as "simple" as the pipeline.