Leiningen
"Leiningen!" he shouted. "You're insane! They're not creatures you can fight—they're an elemental—an 'act of God!' Ten miles long, two miles wide—ants, nothing but ants! And every single one of them a fiend from hell..."
- from Leiningen Versus the Ants by Carl Stephenson
Leiningen is for automating Clojure projects without setting your hair on fire.
Installation
If your preferred package manager has a relatively recent version of Leiningen, try that first. Otherwise you can install by hand:
Leiningen bootstraps itself using the lein
shell script; there is no
separate install script. It handles installing its own dependencies,
which means the first run will take longer.
- Make sure you have a Java JDK version 6 or later.
- Download the script.
- Place it on your
$PATH
. (~/bin
is a good choice if it is on your path.) - Set it to be executable. (
chmod 755 ~/bin/lein
)
Windows
There is a custom installer which will handle downloading and placing Leiningen and its dependencies.
You can also put
the batch file.
on your PATH
and run lein self-install
. If you have
Cygwin you should be able to use the shell
script above rather than the batch file.
Basic Usage
The tutorial has a detailed walk-through of the steps involved in creating a new project, but here are the commonly-used tasks:
$ lein new [TEMPLATE] NAME # generate a new project skeleton
$ lein test [TESTS] # run the tests in the TESTS namespaces, or all tests
$ lein repl # launch an interactive REPL session
$ lein run -m my.namespace # run the -main function of a namespace
$ lein uberjar # package the project and dependencies as standalone jar
Use lein help
to see a complete list. lein help $TASK
shows the
usage for a specific task.
You can also chain tasks together in a single command by using the
do
task with comma-separated tasks:
$ lein do clean, test foo.test-core, jar
Most tasks need to be run from somewhere inside a project directory to
work, but some (new
, help
, search
, version
, and repl
) may
run from anywhere.
Configuration
The project.clj
file in the project root should look like this:
(defproject myproject "0.5.0-SNAPSHOT"
:description "A project for doing things."
:license "Eclipse Public License 1.0"
:url "http://github.com/technomancy/myproject"
:dependencies [[org.clojure/clojure "1.5.1"]]
:plugins [[lein-ring "0.4.5"]])
The lein new
task generates a project skeleton with an appropriate
starting point from which you can work. See the
sample.project.clj
file (also available via lein help sample
) for a detailed listing of
configuration options.
The project.clj
file can be customized further with the use of
profiles.
Documentation
Leiningen documentation is organized as a number of guides:
- Tutorial
- Polyglot (e.g. Clojure/Java) projects
- Leiningen Profiles
- Deployment & Distribution of Libraries
- Sample project.clj
- Writing Plugins
- FAQ
- Contributing
Plugins
Leiningen supports plugins which may contain both new tasks and hooks
that modify behaviour of existing tasks. See
the plugins wiki page
for a full list. If a plugin is needed for successful test or build
runs, (such as lein-tar
) then it should be added to :plugins
in
project.clj, but if it's for your own convenience (such as
swank-clojure
) then it should be added to the :plugins
list in the
:user
profile in ~/.lein/profiles.clj
. See the
profiles guide
for details on how to add to your :user
profile. The
plugin guide
explains how to write plugins.
License
Source Copyright © 2009-2013 Phil Hagelberg, Alex Osborne, Dan Larkin, and contributors. Distributed under the Eclipse Public License, the same as Clojure uses. See the file COPYING.
Thanks to Stuart Halloway for Lancet and Tim Dysinger for convincing me that good builds are important.
Images Copyright © 2010 Phil Hagelberg. Distributed under the Creative Commons Attribution + ShareAlike License. Full-size version available.