Software

Development Environment

We’ll be using Ubuntu Linux during this course. You have two options:

Easy Option: Use the Cloud9 development environment. You only need a computer (Windows, MacOS, or Linux) with an Internet connexion and a modern browser (Chrome, Firefox, Safari, etc.). This option does not work with tablets or smart phones, but it does work with Chromebooks.
Not So Easy Option: Install Ubuntu on a hard disc partition on your computer or on a virtual machine.
- It’s advisable to use the 64 bit 14.04.3 LTS ISO image.
- How to install Ubuntu 14.04.3 LTS.
- If you can’t or don’t want to do any changes to your computer, it’s possible to install Ubuntu in a 8 GB or larger USB flash drive or external hard drive: Installing Ubuntu to USB Drives.
- Official Ubuntu website: http://www.ubuntu.com.

The following instructions allow you to install the most recent version of Clojure on Ubuntu 14.04.

NOTE: You can skip this step if you’re using the Cloud9 development environment.

Verify that you have Java installed. Type at the terminal:
```
java -version
```
If you get a “command not found” error you can install Java with this instruction:
```
sudo apt-get install openjdk-7-jdk
```

Download the Leiningen script:

wget https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein

Make the script executable:
```
chmod +x lein
```
Move the script to the /usr/local/bin directory:
```
sudo mv lein /usr/local/bin
```
Run the Clojure REPL (Read-Eval-Print-Loop):
```
lein repl
```
Press Ctrl-D to quit the REPL.
Install lein-exec, which is a Leiningen plugin to execute Clojure scripts:
```
echo '{:user {:plugins [[lein-exec "0.3.5"]]}}' > ~/.lein/profiles.clj
```
Now, to run a Clojure script called my_script.cljjust type:
```
lein exec my_script.clj
```