Linux/macOS 服务端/客户端简单通信

嗯......，感觉还是CSDN界面友好点，博客园一股Windows风。

好久之前总结的简单Linux 服务器和客户端的通信代码现在搬过来。

client.cpp

#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <string>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define MSG_LEN 1024
#define PORT 8886
#define IP "127.0.0.1"

int main(int argc,char* argv[]){
	int socket_fd,ret = -1;
	char send_buf[MSG_LEN] = {0,};
	char recv_buf[MSG_LEN] = {0,};
	struct sockaddr_in serverAddr;
	
	socket_fd = socket(AF_INET,SOCK_STREAM,0);
	if(socket_fd < 0){
		std::cout << "Failed to create socket" << std::endl;
		exit(-1);
	}

	serverAddr.sin_family = AF_INET;
	serverAddr.sin_port = PORT;
	serverAddr.sin_addr.s_addr = inet_addr(IP);
	
	ret = connect(socket_fd,(struct sockaddr*) &serverAddr,sizeof(struct sockaddr));
	
	if(ret < 0){
		std::cout << "Failed to connect server" << std::endl;
		exit(-1);
	}

	while(1){
		memset(send_buf,0,MSG_LEN);
		std::cin >> send_buf;

		send_buf[MSG_LEN-1] = '\0';
		ret = send(socket_fd,send_buf,strlen(send_buf),0);
		if(ret < 0){
			std::cout << "Failed to send data" << std::endl;
			continue;
		}
		
		ret = recv(socket_fd,recv_buf,MSG_LEN,0);
		recv_buf[ret] = '\0';
		std::cout << "recv: " << recv_buf << std::endl;
		
	}
	close(socket_fd);
	return 0;
}

Server.cpp

#include <iostream>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define PORT 8886
#define MSG_LEN 1024
int main(int argc,char* argv[]){
	int socket_fd,accept_fd,ret = -1;
	int on = 1;
	int backlog = 10;
	char recv_buf[MSG_LEN] = {0,};
	
	struct sockaddr_in localAddr,remoteAddr;

	socket_fd = socket(AF_INET,SOCK_STREAM,0);
	if(socket_fd == -1){
		std::cout << "Failed to create socket!" << std::endl;
	}	
	// set socket options
 	ret = setsockopt(socket_fd,
						SOL_SOCKET,
						SO_REUSEADDR,
						&on,
						sizeof(on));
	if(ret == -1){
		std::cout << "Failed to set socket options" << std::endl;
	}
	localAddr.sin_family = AF_INET;
	localAddr.sin_port = PORT;
	localAddr.sin_addr.s_addr = INADDR_ANY;
	bzero(&(localAddr.sin_zero),8);
	
	// bind
 	ret = bind(socket_fd,(struct sockaddr*) &localAddr,sizeof(struct sockaddr));

	if(ret == -1){
		std::cout << "Failed to bind addr" << std::endl;
		exit(-1);
	}

	// listen
	ret = listen(socket_fd,backlog);
	if(ret == -1){
		std::cout << "Failed to listen socket" << std::endl;
		exit(-1);
	}

	// recv data
	while(1){
		socklen_t addr_len = sizeof(struct sockaddr);
		accept_fd = accept(socket_fd,(struct sockaddr*) &remoteAddr, &addr_len);
		while(1){
			ret = recv(accept_fd,(void *)recv_buf,MSG_LEN,0);
			if(ret == 0){
				break;
			}
		
			std::cout << "recv: " << recv_buf << std::endl;
			// response data
			send(accept_fd,(void *)recv_buf,MSG_LEN,0);
			memset(recv_buf,0,MSG_LEN);
		}
	}
	
	close(socket_fd);
	return 0;
}

这是最简单粗暴的服务端/客户端通信的例子了，如果开启一个server，开启多个客户端连接发送数据，server只能与最先连接的客户端交互。此程序可以使用fork和多线程解决该问题。