kotenv

A lightweight Kotlin library for reading environment variables and reading dotenv files with interpolation support.

Supported Targets

• jvm
• linuxX64
• mingwX64

Usage

getEnv("PATH")
getEnvOrNull("PATH")

getEnv("YOUR_ENV_VARIABLE_NAME") getEnvOrNull("YOUR_ENV_VARIABLE_NAME")

Adding and Using Dotenv Files

1. First, create a .env file in the root of your project directory. Here's an example:

   DATABASE_URL=jdbc:mysql://localhost:3306/mydatabase
   API_KEY=123456789
   

2. Then, use the useDotEnv() function in your code to load the variables from the .env file:

   // Load environment variables from the .env file
   useDotEnv()
   
   // Now you can access them using getEnv or getEnvOrNull
   val dbUrl = getEnv("DATABASE_URL")
   val apiKey = getEnvOrNull("API_KEY")

Interpolation Support

Environment variables support interpolation, allowing you to reference other variables within your .env file:

```plaintext
HOST=localhost
PORT=3306
DATABASE_URL=jdbc:mysql://$HOST:$PORT/mydatabase
```

When using getEnv, the library will automatically interpolate these variables.

```kotlin
// After loading the .env file, variables will be interpolated
useDotEnv()
val dbUrl = getEnv("DATABASE_URL") // jdbc:mysql://localhost:3306/mydatabase
```

Error Handling

• getEnv(variableName: String) will throw an Exception if the variable does not exist.
• getEnvOrNull(variableName: String) will return null if the variable does not exist, allowing you to handle missing variables gracefully.

Example

```kotlin
import kotenv.useDotEnv
import kotenv.getEnv
import kotenv.getEnvOrNull

fun main() {
    // Load environment variables
    useDotEnv()

    // Accessing an existing environment variable
    val path = getEnv("PATH")
    println("PATH: $path")

    // Accessing a non-existing environment variable using getEnvOrNull
    val nonExistentVar = getEnvOrNull("NON_EXISTENT_VAR")
    if (nonExistentVar == null) {
        println("NON_EXISTENT_VAR not found")
    }
}
```

By following the above instructions, you can manage environment variables efficiently in your Kotlin applications using the kotenv library.