src/Console.php
static function readln() : string {
        if (isset(self::$_stdin))
            self::$_stdin = fopen('php://stdin', 'r');
        return rtrim(fgets(self::$_stdin));
    }
static function readln() : string {
        if (isset(self::$_stdin))
            self::$_stdin = fopen('php://stdin', 'r');
        return rtrim(fgets(self::$_stdin));
    }
从标准输入流读取一行字符串
@return string