将optarg作为C++字符串对象获取

#include<iostream>
#include<string>
#include <cstring>
#include <unistd.h>

int main(int argc, char *argv[]) {
    int c;
    std::string optarg_str;

    while ((c = getopt(argc, argv, "s:")) != -1) {
        switch (c) {
            case 's':
                optarg_str = std::string(optarg);
                std::cout << "Option -s has argument: "<< optarg_str<< std::endl;
                break;
            default:
                abort();
        }
    }

    return 0;
}