带有“getopt”的分段错误

我有一个处理参数两个三个全局变量的函数。它适用于program -s3，但是如果我在s和参数之间放置一个空格，即使我使用 atoi 删除空格，我也会出现分段错误。

这是代码：

bool handleArgs(int argc, char *argv[])
{
    int arg;
    bool rtVal = true;
    while (true)
    {
        static struct option long_options[] =
             {
               {"steps",             optional_argument, 0, 's'},
               {"walks",         optional_argument, 0, 'w'},
               {"dimensions",  optional_argument, 0, 'd'},
               {nullptr, 0, 0, 0}
             };
        int option_index = 0;
        arg = getopt_long (argc, argv, "s::w::d::",long_options, &option_index);
    if(arg == -1)
        {
            break;
        }

        switch(arg)
        {
         case 0:
                     std::cout << long_options[option_index].name  << std::endl;
                     if (optarg)
                         std::cout << " with arg " << optarg << std::endl;
                     break;
            case 's':
                    std::cout << "option -s with value " << atoi(optarg) << std::endl;
                break;
            case 'w':
                    std::cout << "option -w with value " << atoi(optarg) << std::endl;
                break;
            case 'd':
                    std::cout << "option -d with value " << atoi(optarg) << std::endl;
                    break;
            case '?':
                /* getopt_long already printed an error message. */
                rtVal = false;
                break;
            default:
            rtVal = false;
        }
    }
    return rtVal;
}