"ls -al".runCommand()

RunTerminalCommand.kt

// https://stackoverflow.com/a/52441962
fun String.runCommand(
    workingDir: File = File("."),
    timeoutAmount: Long = 60,
    timeoutUnit: TimeUnit = TimeUnit.SECONDS,
    onErrorReturn: (Throwable) -> String = { "error: ${it.message}" }
): String {
    val result = runCatching {
        val parts = this.split("\\s".toRegex())
        val proc = ProcessBuilder(*parts.toTypedArray())
            .directory(workingDir)
            .redirectOutput(ProcessBuilder.Redirect.PIPE)
            .redirectError(ProcessBuilder.Redirect.PIPE)
            .start()
        proc.waitFor(timeoutAmount, timeoutUnit)
        proc.inputStream.bufferedReader().readText()
    }
    return result.recover(onErrorReturn).getOrNull() ?:  error("cannot get result.")
}