ocaml-cli

OCaml ports of the CLI tools from Command-Line Rust (Ken Youens-Clark). The goal is to learn OCaml by reimplementing the book’s exercises with Cmdliner and Dune.

Tools

Binary	Status	Notes
echor	Implemented	echo
catr	Implemented	cat
headr	Implemented (partial vs tests)	head
wcr	Stub (hello world)	wc
uniqr	Stub	uniq
findr	Stub	find
cutr	Stub	cut
grepr	Stub	grep
commr	Stub	comm
tailr	Stub	tail
fortuner	Stub	fortune
calr	Stub	cal
lsr	Stub	ls

Requirements

• OCaml ≥ 5.3 (see dune-project)
• opam and Dune
• Dependencies: cmdliner; for tests: alcotest, bos

opam install . --deps-only --with-test

Build & run

dune build @install
dune exec echor -- Hello world
dune exec catr -- path/to/file

Tests

OCaml integration tests (test/)

Alcotest + Bos suites under test/, one directory per tool (fixtures in inputs/ / expected/). Shared helpers live in test/cli_test/.

These OCaml tests were created by Cursor (Auto), ported from the book’s Rust CLI tests into this repo’s Alcotest layout.

dune runtest                 # all suites
dune runtest test/echor      # one suite

echor and catr are expected to pass. Suites for stub binaries will fail until those tools are implemented. headr has known failures vs the harness expectations.

Rust test harness (test-harness/)

Optional mirror of the book’s assert_cmd tests, adapted to run dune exec <tool> -- …:

just test            # or: just test echor::

Requires a Rust toolchain. Useful for comparing behavior while porting.

Layout

bin/<tool>/          # Cmdliner executables
test/<tool>/         # Alcotest + Bos integration tests
test/cli_test/       # shared test helpers
test-harness/        # Rust harness (reference)

License

See LICENSE / dune-project.