Kotlin Environment Setup

In this article, we will see how to setup the environment for Kotlin on command line compiler.

Prerequisite to install Kotlin

Kotlin runs on Java Virtual Machine, so it is necessary to install JDK and set the path in local system environment variable. Usually a JDK installation defines a JAVA_HOME env variable and then puts the binary forlder in the path. For example, on my mac I have:

export JAVA_HOME=$(/usr/libexec/java_home -v 11)
export PATH=${JAVA_HOME}/bin:${PATH}

Install Kotlin

To write and execute code written in Kotlin, you will need its runtime and the compiler. Every runtime release comes with its own compiler version. To get your hands on it, navigate to github, pick a release, scroll to the bottom of the page, and download and unpack the ZIP archive, kotlin-compiler-<version>.zip. At the time of writing, the latest stable release is Kotlin 1.5.10

Once extracted the kotlin release, configure your shell path to include the kotlin binaries. For example:

export KOTLIN_HOME="${HOME}/tools/kotlinc"
export PATH=${PATH}:${KOTLIN_HOME}/bin

Test the installation

Restar the shell, and issue kotlinc -version. You'll have something like this:

➜  ~ kotlinc -version
info: kotlinc-jvm 1.5.10 (JRE 11.0.10+9)

Good, you have now the Kotlin compiler installed. Let' try the classic hello-world example now. Create HelloWorld.kt with this content:

fun main(args: Array<String>) {
   println("Hello, World!")
}

To compile it use kotlinc HelloWorld.kt -include-runtime -d HelloWorld.jar. The -include-runtime parameter tells the compiler to include the Kotlin runtime in the resulting jar file. It is needed to run your program.

So, to recap, you need the Kotlin runtime and compiler!