Starting a process with Java.

Exec.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.stream.Collectors;

public class Exec {

    // Java makes it straightforward to create an OS process in any given OS.
    // The `ProcessBuilder` class handles everything: which command to
    // execute, what environment the process will run in, the working
    // directory, the source of the standard input and the destination of the
    // standard output, etc.
    //
    // As the name may imply, one `ProcessBuilder` instance may be called
    // multiple times.

    public static void main(String[] args) throws IOException {
        // Create a process.
        final ProcessBuilder processBuilder = new ProcessBuilder("echo", "hello", "world");
        final Process process = processBuilder.start();

        // Get the output stream of the process. Some Java craziness is
        // required to turn the input stream of the process into a string.
        final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));

        System.out.println(bufferedReader.lines().collect(Collectors.joining(System.lineSeparator())));
    }

}