Shebang Script for Clojure

Tags: clojure

Written on January 2, 2017

Shebang lines come in handy when writing and running scripts in CLIs.

With Leiningen and its plugin, Clojure can also be run with shebang script.

1. Install something

Firstly, we need Java:

$ sudo apt-get install oracle-java8-jdk

After that, download and place lein script in a preferred place:

$ sudo wget "https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein" -O "/usr/local/bin/lein"

We need additional permissions for running lein:

$ sudo chown $USER.$USER "/usr/local/bin/lein"
$ sudo chmod uog+x "/usr/local/bin/lein"

After all things are setup correctly, we can see the version of lein with following command:

$ lein version
Leiningen 2.7.1 on Java 1.8.0_65 Java HotSpot(TM) Client VM
$

We need lein-exec for executing Clojure files with ease.

Add [lein-exec "0.3.6"] to your ~/.lein/profiles.clj, then it will look like:

{:user {:plugins [[lein-exec "0.3.6"]]}}

lein-exec will be installed automatically when next time you run lein.

Append following line on the first line of your script:

#!/usr/bin/env lein exec

and add execute permission to your script:

$ chmod +x aaaaaa.clj

then it will be runnable by itself:

$ ./aaaaaa.clj

Clojure may not be intended to be used like this,

but in this way, it will be a lot easier to run and test in the terminal :-)

Written on January 2, 2017