A bash wrapper for kotlin script (similar to gradlew), which will locate the kotlin compiler (downloading if needed), and execute your script

kotlinw.sh

#!/bin/sh

KOTLIN_VERSION="1.0.3"
KOTLIN_COMPILER_URL="https://github.com/JetBrains/kotlin/releases/download/v${KOTLIN_VERSION}/kotlin-compiler-$KOTLIN_VERSION.zip"
KOTLIN_COMPILER_HASH="37615f1d63e8500cd33c7f3e60b715263f65189d6d8f25defba78968c896dc97" # The hash of the compiler's zip-file
KOTLIN_INSTALATION_DIR="$HOME/.kotlin/$KOTLIN_VERSION"

if [ $# -lt 1 ]; then
    echo "Insufficient arguments: $#";
    exit 1;
fi;
SCRIPT_FILE=$1

if [ ! -f "$SCRIPT_FILE" ]; then
    echo "Unable to locate file $SCRIPT_FILE"
    exit 1;
fi;

debug() {
    if [ "$DEBUG" ]; then
        echo "$1"
    fi;
}

require_command() {
    if ! which "$1" >/dev/null 2>&1; then
        echo "Couldn't find the '$1' command"
        errMsg=$2
        if [ -z "$errMsg" ]; then
            errMsg="Unable to execute $SCRIPT_FILE"
        fi;
        echo "$errMsg"
        exit 1;
    fi;
}

verifyHash() {
    if [ ! -f "$1" ]; then
        echo "Unable to find file '$1' to verify hash"
        exit 1;
    fi;
    name=$(basename "$1")
    require_command sha256sum "Unable to verify hash: $name"
    hash=$(sha256sum "$1" | sed -r 's/(\w+).*/\1/')
    if [ "$hash" != "$2" ]; then
        echo "The actual hash of $name didn't match the expected value!!"
        echo "Expected '$2' but got '$hash'"
        exit 1;
    else
        echo "Verified sha256 hash of $name is $2";
    fi;
}

require_command "java"

download_kotlin() {
    echo "Downloading kotlin $KOTLIN_VERSION to $KOTLIN_INSTALATION_DIR"
    require_command "wget" "Unable to download the kotlin compiler"
    require_command "unzip" "Unable to download the kotlin compiler"
    if ! mkdir -p "$KOTLIN_INSTALATION_DIR"; then
        echo "Unable to create directory $KOTLIN_INSTALATION_DIR"
        exit 1;
    fi;
    KOTLIN_ZIP_FILE="$KOTLIN_INSTALATION_DIR/kotlin-compiler-$KOTLIN_VERSION.zip"
    if [ -f "$KOTLIN_ZIP_FILE" ]; then
        echo "Using existing zip file: $KOTLIN_ZIP_FILE"
        echo "Delete manually if this is unintended"
    else
        echo "Downloading $KOTLIN_COMPILER_URL to $KOTLIN_ZIP_FILE"
        wget -O "$KOTLIN_ZIP_FILE" "$KOTLIN_COMPILER_URL"
        if [ ! -f "$KOTLIN_ZIP_FILE" ]; then
            echo "Unable to download $KOTLIN_COMPILER_URL to $KOTLIN_ZIP_FILE"
            exit 1;
        fi;
    fi;
    verifyHash "$KOTLIN_ZIP_FILE" "$KOTLIN_COMPILER_HASH"
    echo "Extracting" "$(basename "$KOTLIN_ZIP_FILE")" to "${KOTLIN_INSTALATION_DIR}"/kotlinc
    old_dir=$(pwd)
    cd "$KOTLIN_INSTALATION_DIR" || exit 1
    unzip "$KOTLIN_ZIP_FILE"
    cd "$old_dir" || exit 1
    if [ ! -d "${KOTLIN_INSTALATION_DIR}/kotlinc/bin" ]; then
        echo "Unable to extract $KOTLIN_ZIP_FILE to ${KOTLIN_INSTALATION_DIR}/kotlinc";
        exit 1;
    fi;
    echo "Successfully downloaded, verified, and extracted kotlin compiler to ${KOTLIN_INSTALATION_DIR}/kotlinc"
}

KOTLIN_COMPILER=$(which kotlinc)

if [ -f "$KOTLIN_COMPILER" ]; then
    debug "Kotlin compiler successfully located on PATH at $KOTLIN_COMPILER"
else
    # Resort to auto-install
    KOTLIN_COMPILER="$KOTLIN_INSTALATION_DIR/kotlinc/bin/kotlinc"
    if [ ! -f "$KOTLIN_COMPILER" ]; then
        download_kotlin || exit 1
        if [ ! -f "$KOTLIN_COMPILER" ]; then
            echo "Looks like all these redundant checks paid off"
            echo "See XKCD panic sort: https://xkcd.com/1185/"
            exit 1;
        fi;
    else
        debug "Found existing auto-instalation at $KOTLIN_COMPILER"
    fi;
fi;

$KOTLIN_COMPILER "-script" "$SCRIPT_FILE"
if [ $? != 1 ]; then
    echo "Unable to execute $SCRIPT_FILE with $KOTLIN_COMPILER"
    exit 1;
fi;