介绍

本文主要学习TCP socket编程的代码。socket常用于客户端发起连接，服务端一般都会用一些高性能网络框架，不会让你手写socket服务端的。客户端代码基本都差不多。

服务端

server.cpp:

#include <iostream>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>constexpr uint16_t port = 6000;int main() {int fd = socket(AF_INET, SOCK_STREAM, 0);   //创建用于监听的套接字if (fd < 0) {return -1;                              }sockaddr_in addr = {AF_INET, htons(port), 0};       //监听本机所有网络接口,并指定端口号if (bind(fd, (sockaddr*)&addr, sizeof(addr)) < 0) { //绑定close(fd);return -1;}if (listen(fd, 128) < 0) {  //开始监听；参数2：设置全连接(accept)队列长度return -1;}uint32_t addrLen = sizeof(addr);int cfd = accept(fd, (sockaddr*)&addr, &addrLen);   //阻塞等待，获取一条连接if (cfd < 0) {return -1;}//下面就是通信代码了//接收客户端消息char buf[1024] = {0};int size = recv(cfd, buf, sizeof(buf), 0); if (size <= 0) {return -1;  //<0:recv failed!    ==0:socket connect close!}std::cout << buf << std::endl;//向客户端发消息if (send(cfd, buf, strlen(buf), 0) < 0) {return -1;}close(cfd);close(fd);
}

客户端

client.cpp:

#include <iostream>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>constexpr uint16_t port = 6000;
const std::string ip("127.0.0.1");int main() {int cfd = socket(AF_INET, SOCK_STREAM, 0);  //创建用于通信的socketif (cfd < 0) {return -1;}sockaddr_in addr = {AF_INET, htons(port), inet_addr(ip.c_str())};//对于客户端来说，这里要指定服务器的ip、portif (connect(cfd, (sockaddr*)&addr, sizeof(addr)) < 0) {         //连接return -1;}//发送消息char buf[1024] = "12345";if (send(cfd, buf, strlen(buf), 0) < 0) {return -1;}//接收消息int size = recv(cfd, buf, strlen(buf), 0);if (size <= 0) {return -1; //<0:recv failed!    ==0:socket connect close!}std::cout << buf << std::endl;close(cfd);
}

编译运行

g++ server.cpp -o server
g++ client.cpp -o client
./server
./client