Avoid org.apache.commons.cli.UnrecognizedOptionException when String argument starts with dash (-) in Kotlin

Question

I am programming a morse code translator in Kotlin, for the input I use the arguments of the main method:

fun main(args: Array<String>)

I use org.apache.commons.cli to manage the command options (-d to decode and -e to encode). The thing is that when entering morse code the program confuses it with command options (because it uses dashes).

Example of use of the program:

morse-translator -d --. .- .

Returns:

Exception in thread "main" org.apache.commons.cli.UnrecognizedOptionException: Unrecognized option: --.

I enclose the class that handles the command options:

import org.apache.commons.cli.CommandLine
import org.apache.commons.cli.DefaultParser
import org.apache.commons.cli.Options

class Input(args: Array<String>) {
private var flags: Options = Options()
private var parser: DefaultParser = DefaultParser()
private var cli: CommandLine

init {
    setupOptions()
    cli = parser.parse(flags, args)
}

/** Determine the flags allowed */
private fun setupOptions() {
    flags.addOption("e", "encode", false, "Encode message")
    flags.addOption("d", "decode", false, "Decode message")
}
}

I tried surrounding the morse code with double quotation marks, but same problem.

Answer 1

Commons-cli observes the default solution on Unix to specify "--" to instruct the commandline parser that no more options should be parsed.

The following Java snippet include "--" in the list of arguments, then it properly parses the string as a trailing argument:

    Options options = new Options();

    options.addOption("d", "decode", false, "Decode message");
    options.addOption("e", "encode", false, "Encode message");

    CommandLineParser parser = new DefaultParser();
    CommandLine cmd = parser.parse(options, new String[] {"-d", "--", "--. .- ."});
    assertTrue(cmd.hasOption("d"));
    assertFalse(cmd.hasOption("e"));

    assertEquals("[--. .- .]", cmd.getArgList().toString());
    assertEquals("[--. .- .]", Arrays.toString(cmd.getArgs()));