Example of CLI tool with Scala, Picocli and GraalVM

Install GraalVM

1. Download GraalVM Community Edition from https://github.com/graalvm/graalvm-ce-builds/releases.
2. Add bin directory to PATH
3. Install native-image command

$ gu install native-image

Build

1. Build the project

$ sbt graalvm-native-image:packageBin

2. Run the command

$ ./target/graalvm-native-image/picocli-scala-example
Missing required parameter: <file>
Usage: checksum [-hV] [-a=<algorithm>] <file>
Prints the checksum (MD5 by default) of a file to STDOUT.
      <file>      The file whose checksum to calculate.
  -a, --algorithm=<algorithm>
                  MD5, SHA-1, SHA-256, ...
  -h, --help      Show this help message and exit.
  -V, --version   Print version information and exit.