linux --- UDP communication codes

udp connection characteristics :

• No connection : the connection may not be configured to communicate
• Unreliable : Data does not guarantee reliability
• Datagram-oriented : data each having a length limit, the whole data transmission to accept the entire data transfer is not flexible, but there will be no problem stick package.
  In principle sections explain network
  udp communication flow
  

c ++ udp package interfaces, an interface package for us to achieve a better

  1 /*
  2  *udp的封装接口
  3  */
  4 #include <iostream>
  5 #include <string>
  6 #include <stdio.h>
  7 #include <unistd.h>
  8 #include <sys/socket.h>
  9 #include <errno.h>
 10 #include <stdlib.h>
 11 #include <netinet/in.h>
 12 #include <arpa/inet.h>
 13 
 14 class UdpSocket{
 15 public:
 16     UdpSocket():_socket(-1){
 17     };
 18     ~UdpSocket(){
 19     };
 20     //创建socket
 21     bool Socket(){
 22         _socket = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
 23         if(_socket < 0){
 26         }
 27         return true;
 28     }
 29     //绑定连接
 30     bool Bind(std::string ip,uint16_t port){
 31         struct sockaddr_in addr;
 32         addr.sin_family = AF_INET;
 33         addr.sin_port = htons(port);
 34         addr.sin_addr.s_addr = inet_addr(ip.c_str());
 35 
 36         int len = sizeof(addr);
 37 
 38         int ret = bind(_socket,(struct sockaddr*)&addr,len);
 39         if(ret < 0){
 40             perror("bind error\n");
 41             return false;
 42         }
 43         return true;
 44     }
 45     //接受数据
 46     bool Recv(std::string &buf,struct sockaddr_in *saddr){
 47         //*daddr是发送的ip信息
 48         //  ssize_t recvfrom(int sockfd, void *buf, size_t len, int flags,
 49         //  struct sockaddr *src_addr, socklen_t *addrlen);
 50         char temp[1500];
 51         socklen_t len = sizeof(struct sockaddr_in);
 53         if(ret < 0){
 54             perror("recvfrom error\n");
 55             return false;
 56         }
 57         buf.assign(temp,ret);
 58         return true;
 59     }
 60     //发送数据
 61     bool Send(std::string& str,struct sockaddr_in* daddr){
 62     //  ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
 63     //  const struct sockaddr *dest_addr, socklen_t addrlen);
 64         int len = sizeof(struct sockaddr_in);
 65         int ret = sendto(_socket,str.c_str(),str.size(),0 
 66                 ,(struct sockaddr*)daddr,len);
 67         if(ret < 0){
 68             perror("sendto error\n");
 69             return false;
 70         }
 71         return true;
 72     }
 73     //关闭连接
 74     bool Close(){
 75         close(_socket);
 76         _socket = -1;
 77     }
 78     private:
 79     int  _socket;
 80 }; 

Udp implement server-side

4 #include "udpsocket.hpp"
  5 #define CHECK(T) if(!T) {return -1;}
  6 int main(int argc,char* argv[]){
  1 /*
  2  *实现udp服务器端
  3  */
  4 #include "udpsocket.hpp"
  5 #define CHECK(T) if(!T) {return -1;}
  6 int main(int argc,char* argv[]){
  7     //将我们的ip地址通过参数进行传递
  8     if(argc < 3){
  9         perror("./a.out ip port\n");
 10         return -1;
 11     }
 12     std::string ip = argv[1];//ip地址的信息
 13     uint16_t port = atoi(argv[2]);//port端口信息
 14     //创建封装的类
 15     UdpSocket sock;
 16     //创建我们的套接字
 17     CHECK(sock.Socket());
 18     //绑定
 19     CHECK(sock.Bind(ip,port));
 20     while(1){
 21         //接受数据
 22         std::string str;
 23         struct sockaddr_in client_addr;
 24         CHECK(sock.Recv(str,&client_addr));
 25         std::cout<<"client said:"<<str<<std::endl;
 26         std::string answer;
 27         std::cout<<"server say:";
 28         fflush(stdout);
 29         std::cin>>answer;
 30         CHECK(sock.Send(answer,&client_addr));
 31     }
 32     sock.Close();
 33     return 0;
 34 }  

udp client code implementation

  1 /*
  2  udp客户端程序实现
  3  */
  4 #include "udpsocket.hpp"
  5 
  6 #define CHECK(T) if(!T) {return -1;}
  7 int main(int argc,char* argv[]){
  8     if(argc < 3){
  9         perror("./a.out ip port\n");
  1 /*
  2  udp客户端程序实现
  3  */
  4 #include "udpsocket.hpp"
  5 
  6 #define CHECK(T) if(!T) {return -1;}
  7 int main(int argc,char* argv[]){
  8     if(argc < 3){
  9         perror("./a.out ip port\n");
 10         return -1;
 11     }
 12     std::string ip = argv[1];
 13     uint16_t port = atoi(argv[2]);
 14 
 15     UdpSocket sock;
 16     //创建套接字
 17     CHECK(sock.Socket());
 18     //客户端不用创建连接，绑定的是绑定的服务器端的地址信息
 19     struct sockaddr_in ser_addr;
 20     ser_addr.sin_family = AF_INET;
 21     ser_addr.sin_port = htons(port);
 22     ser_addr.sin_addr.s_addr = inet_addr(ip.c_str());
 23     
 24     while(1){
 25         //发送数据
 26         std::string str;
 27         std::cout<<"client say:";
 28         fflush(stdout);
 29         std::cin>>str;
 30         CHECK(sock.Send(str,&ser_addr));
 31         std::string answer;
 32         CHECK(sock.Recv(answer,&ser_addr));
 33         std::cout<<"server said:"<<answer<<std::endl;
 34     }
 35     sock.Close();
 36     return 0;
 37 }