How to Get Started With Leiningen Clojure App Builds on GNU/Linux

How to Get Started

2. 2. Installing Leiningen

   How to Install Leiningen for Clojure on Ubuntu

   Installing Leiningen on Ubuntu

   Setup Leiningen Ubuntu

3. 3. Making Clojure App

   Finalize Leiningen Setup and Get a Clojure Build Hello-World App
   First, make the Target Folder:

   mkdir $HOME/Documents/Clojure && cd $HOME/Documents/Clojure

   And then Create it:

   lein new myapp

   The Command First, Finalize Leiningen Installation and then Create a Skeleton of a simple Clojure App…
   The Core of the App is in the myapp/src/myapp/core.cli File.
   Default content:

   (ns myapp.core)
   (defn foo"I don't do a whole lot."
   [x]
   (println x "Hello, World!"))
   

   Note that the Namespace declaration Matches the Folder Structure.
   Since the core namespace is inside the myapp folder, its name is myapp.core.

4. 4. Editing Clojure App

   Then Specify a Namespace in the project.cli File to Make a Working App
   Access the Target:

   cd myapp

   And then Edit it:
   (Here for simplicity with the nano Editor, but you can just use Anyone.)

   nano project.cli

   For example, we could Set the foo Function from the myapp.core namespace as the Entry Point for the application Using the :main Key like:

   (defproject myapp "0.1.0-SNAPSHOT"
   :description "FIXME: write description"
   :url "http://example.com/FIXME"
   :license {:name "Eclipse Public License"
   :url "http://www.eclipse.org/legal/epl-v10.html"}
   :dependencies [[org.clojure/clojure "1.6.0"]]
   ;;this will set foo as the main function
   :main myapp.core/foo)
   

   Ctrl+x to Save & Exit from nano Editor :)

5. 5. Running Clojure App

   The you can Run the Clojure Hello-World App
   With:

   lein run Happy

   That will Return as Output:

   Happy Hello, World!

   Troubleshooting Leiningen/Clojure Error loading project.cli

   Solve error loading project.cli

   Leiningen Troubleshooting