A Leiningen template for generating clojure repl shells (crsh).

A crsh is a little shell script that allows you to write other shell script in Clojure as in the following hello world script

#!/usr/bin/env crsh
(println "Hello World!")

This template is inspired by the blog post Replacing Shell Scripts With Clojure+JamVM written by Max Gonzih and by drip written by Justin Balthrop.

To create a new crsh, run the following command

lein new crsh crsh

Edit the generated project.clj to add your favorite dependencies for scripting. In addition, you should edit the [:resource :extra-keys] map to configure the generation of the crsh shell script. The 2 following keys are used.

You can use any Java executable (e.g. java): the executable will be used to start clojure every time the shell script crsh is invoked. To speed up the execution of your script, I recommend you to use drip, a Java launching utility.

Beside dependencies, you can also add any utilities functions in the namespace of your crsh project.

After the configuration of the project.clj file and the edition of the clojure files of the crsh project, run the following command to build the project:

lein uberjar

This command will build a standalone jar file with all the dependencies and will create a shell script crsh in the directory target/bin. Finally, put target/bin on your PATH or link crsh to a directory that is on your PATH. From now on, you can use the crsh script either directly to start a Clojure repl or embedded in a shebang as #!/usr/bin/env crsh at the beginning of a shell script.

If you use drip and recreate the crsh script, you should either change the version of your crsh project or kill the current drip jvm to ensure that a new jvm will be spun up.

The name of the crsh executable is given by the name of the project.

Copyright © 2015 Stanislas Nanchen

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.