Oil is a new Unix shell. It's our upgrade path from bash to a better language and runtime! It's also for Python and JavaScript users who avoid shell. (Why Create a New Unix Shell?)
It's written in Python, so the code is short and easy to change. But we automatically translate it to C++ with custom tools, to make it fast and small. The deployed executable doesn't depend on Python.
This README is at the root of the git repo.
- Try making the dev build of Oil with the instructions on the Contributing page. This should take 1 to 5 minutes if you have a Linux machine.
- If it doesn't, let us know. You can post on the
#oil-devchannel of oilshell.zulipchat.com, or file an issue on Github. - Feel free to grab an issue from Github. Let us know what you're thinking before you get too far.
After following the instructions on the Contributing page, you'll have a Python program that you can quickly run and change! Try it interactively:
bash$ bin/osh
osh$ name=world
osh$ echo "hello $name"
hello world
- Try running a shell script you wrote with
bin/osh myscript.sh. - Try the Oil language
with
bin/oil.
Let us know if any of these things don't work! The continuous build tests them at every commit.
Again, note that the developer build is very different from the release tarball. The Contributing page describes this difference in detail.
The release tarballs are linked from the home page. (Developer builds don't work on OS X, so use the release tarballs on OS X.)
Oil is full of many ideas, which may be intimidating at first.
But the bar to contribution is very low. It's basically a medium size Python program with many tests, and many programmers know how to change such programs. It's great for prototyping.
- For OSH compatibility, I often merge failing spec
tests. You don't even
have to write code! The tests alone help. I search for related tests with
grep xtrace spec/*.test.sh, wherextraceis a shell feature. - You only have to make your code work in Python. Plain Python programs are easy to modify. The semi-automated translation to C++ is a separate step, although it often just works.
- You can influence the design of the Oil language. If you have an itch to scratch, be ambitious. For example, you might want to show us how to implement nonlinear pipelines.
The Wiki has many developer docs. Feel free to edit them. If you make a major change, let us know on Zulip!
There are also READMEs in some subdirectories, like opy/ and mycpp/.
If you're confused, the best thing to do is to ask on Zulip and someone should produce a pointer and/or improve the docs.
Docs for end users are linked from each release page.
Try this to show a summary of what's in the repo and their line counts:
$ metrics/source-code.sh overview
(Other functions in this file may be useful as well.)
Oil is naturally structured as a set of mutually recursive parsers and evaluators. These interpreters are specified at a high-level: with regular languages, Zephyr ASDL, and a statically-typed subset of Python.
bin/ # Main entry points like bin/osh (source in bin/oil.py)
frontend/ # Lexing/Parsing code common to Oil and OSH
osh/ # OSH parsers and evaluators (cmd, word, sh_expr)
oil_lang/ # Oil parser and evaluator
core/ # Other code shared between Oil and OSH
pyext/ # Python extension modules, e.g. libc.c
pylib/ # Borrowed from the Python standard library.
qsn_/ # QSN serialization format
tools/ # User-facing tools, e.g. the osh2oil translator
Here are the tools that transform that high-level code to efficient code:
asdl/ # ASDL implementation, derived from CPython
pgen2/ # Parser Generator, borrowed from CPython
mycpp/ # Experimental translator from typed Python to C++.
# Depends on MyPy. See mycpp/README.md
pea/ # Perhaps a cleaner version of mycpp
opy/ # Python compiler in Python (mycpp/ will replace it)
We have native code to support both the dev build (running under CPython) and the oil-native build (pure C++):
NINJA-config.sh # Generates build.ninja
build/ # High level build
NINJA-steps.sh
NINJA_main.py # invoked by NINJA-config.sh
NINJA_subgraph.py
oil-defs/ # Files that define our slice of CPython.
py.sh # For development builds, running CPython
cpp/ # C++ code which complements the mycpp translation
NINJA-steps.sh
NINJA_subgraph.py
mycpp/ # Runtime for the translator
NINJA-steps.sh
NINJA_subgraph.py
prebuilt/ # Prebuilt files committed to git, instead of in _gen/
Python-2.7.13/ # For the slow Python build
# Temp dirs (see below)
_bin/
_build/
_gen/
_test/
Unit tests are named foo_test.py and live next to foo.py.
test/ # Test automation
gold/ # Gold Test cases
gold.sh
sh_spec.py # shell spec test framework
spec.sh # Types of test runner: spec, unit, gold, wild
unit.sh
wild.sh
testdata/
spec/ # Spec test cases
bin/ # tools used in many spec tests
testdata/ # scripts for specific test cases
stateful/ # Tests that use pexpect
We use a lot of automation to improve the dev process. It's largely written in shell, of course!
benchmarks/ # Benchmarks should be run on multiple machines.
metrics/ # Metrics don't change between machines (e.g. code size)
client/ # Demonstration of OSH as a headless server.
deps/ # Dev dependencies and Docker images
devtools/ # For Oil developers (not end users)
release.sh # The (large) release process.
services/ # talk to cloud services
demo/ # Demonstrations of bash/shell features. Could be
# moved to tests/ if automated.
old/ # A junk drawer.
web/ # HTML/JS/CSS for tests and tools
soil/ # Multi-cloud continuous build (e.g. sourcehut, Github)
Directories that begin with _ are not stored in git. The dev tools
above create and use these dirs.
_bin/ # Native executables are put here
cxx-dbg/
_build/ # Temporary build files
_cache/ # Dev dependency tarballs
_devbuild/ # Generated Python code, etc.
_gen/ # Generated C++ code that mirrors the repo
frontend/
_release/ # Source release tarballs are put here
VERSION/ # Published at oilshell.org/release/$VERSION/
benchmarks/
doc/
metrics/
test/
spec.wwz
wild.wwz
...
web/ # Static files, copy of $REPO_ROOT/web
table/
_test/ # Unit tests, mycpp examples
tasks/
_tmp/ # Output of other test suites; temp files
spec/
wild/
raw/
www/
osh-parser/
osh-runtime/
vm-baseline/
oheap/
startup/
...
These tools are built from shell scripts in soil/. The oil_DEPS dir is
"parallel" to Oil because it works better with container bind mounds.
../oil_DEPS/
re2c/ # to build the lexer
cmark/ # for building docs
spec-bin/ # shells to run spec tests against
mypy/ # MyPy repo
mycpp-venv/ # MyPy binaries deps in a VirtualEnv
py3/ # for mycpp and pea/
cpython-full/ # for boostrapping Oil-CPython
These files make the slow "Oil Python" build, which is very different than the developer build of Oil.
Makefile
configure
install
These files are for oil-native (in progress):
_build/
oil-native.sh
doc/ # A mix of docs
doctools/ # Tools that use lazylex/ to transform Markdown/HTML
lazylex/ # An HTML lexer which doctools/ builds upon.
README.md # This page, which is For Oil developers
LICENSE.txt # For end users
INSTALL.txt
- The blog has updates on the project status.
- Oil Home Page
- oilshell.zulipchat.com is for any kind of discussion
- Subscribe for updates:
mycpp/
mylib.py # statically typed equivalents of Python's data structures
pylib/ # copied from Python stdlib
core/
py{error,os,util}.py # too complicated to translate
*/*_def.py # abstract definitions
*/*_gen.py # code generators