C++中main函数的参数解析argc和argv是啥？

argc和argv是什么意思？

int main(int argc, char **argv)
{
return 0;
}

其中，

argc是argument count的简写，即参数个数； argv是argument value的简写，即参数值；

以ros编码为例

   #include "ros/ros.h"
   #include "beginner_tutorials/AddTwoInts.h"//AddTwoInts.h是重新编译beginner_tutorials包自动生成的
 
   bool add(beginner_tutorials::AddTwoInts::Request  &req,
            beginner_tutorials::AddTwoInts::Response &res)
   {
     res.sum = req.a + req.b;
     ROS_INFO("request: x=%ld, y=%ld", (long int)req.a, (long int)req.b);
     ROS_INFO("sending back response: [%ld]", (long int)res.sum);
     return true;
  }
 
  int main(int argc, char **argv)
  {
    ros::init(argc, argv, "add_two_ints_server");
    ros::NodeHandle n;
 
    ros::ServiceServer service = n.advertiseService("add_two_ints", add);//广告服务名add_two_ints
    ROS_INFO("Ready to add two ints.");
    ros::spin();
 
    return 0;
  }

其中，init中就用了argc和argv；