Utilities¶

Writing command line interfaces often involves more than just parsing the command line. Clikt also provides functions to perform actions commonly used in command line programs.

Launching Editors¶

If you need to ask users for multi-line input, or need to have the user edit a file, you can do so through editText and editFile. These functions open the program defined in the VISUAL or EDITOR environment variables, or a sensible default if neither are defined. The functions return the edited text if the user saved their changes.

Example

fun getCommitMessage(): String? {
    val message = """
    # Enter your message.
    # Lines starting with # are ignored
    """.trimIndent()
    return editText(message, requireSave = true)
            ?.replace(Regex("#[^\n]*\n"), "")
}

Input Prompts¶

Options can prompt for values automatically, but you can also do so manually by using Mordant’s prompt functionality directly. By default, it accepts any input string, but you can also pass in a conversion function. If the conversion returns a ConversionResult.Invalid, the prompt will ask the user to enter a different value.

ExampleInteractive Session

val input = terminal.prompt("Enter a number") {
    it.toIntOrNull()
        ?.let { ConversionResult.Valid(it) }
        ?: ConversionResult.Invalid("$it is not a valid integer")
}
echo("Twice your number is ${input * 2}")

Enter a number: foo
Error: foo is not a valid integer
Enter a number: 11
Twice your number is 22

Confirmation Prompts¶

You can also ask the user for a yes or no response with Mordant’s YesNoPrompt:

if (YesNoPrompt("Continue?", terminal).ask() == true) {
    echo("Ok!")
}