基于TCP/IP的回声服务器 (Linux环境)

注意：

1. 需要联网
2. 需要修改IP地址为自己的IP地址。
   ifconfig查看自己的IP地址

服务器端

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define BUF_SIZE (4096)

void* server(void* arg)
{
	int cli_fd = *(int*)arg;

	char buf[BUF_SIZE];
	for(;;)
	{
		// 接收数据
		int recv_size = read(cli_fd,buf,BUF_SIZE);
		if(0 >= recv_size || 0 == strcmp(buf,"quit"))
		{
			printf("客户端%d退出\n",cli_fd);
			close(cli_fd);
			pthread_exit(NULL);
		}
		printf("read:[%s]，size:%d\n",buf,recv_size);
		strcat(buf,":return");

		// 发送数据
		int send_size = write(cli_fd,buf,strlen(buf)+1);
		if(0 >= send_size)
		{
			printf("客户端%d退出\n",cli_fd);
			close(cli_fd);
			pthread_exit(NULL);
		}
	}
}

int main()
{
	// 创建socket对象
	int svr_fd = socket(AF_INET,SOCK_STREAM,0);
	if(0 > svr_fd)
	{
		perror("socket");
		return -1;
	}

	// 准备通信地址(自己)
	struct sockaddr_in addr = {};
	addr.sin_family = AF_INET;
	addr.sin_port = htons(6789);
	addr.sin_addr.s_addr = inet_addr("192.168.43.92");
	socklen_t addrlen = sizeof(addr);

	// 绑定socket对象与地址
	if(bind(svr_fd,(struct sockaddr*)&addr,addrlen))
	{
		perror("bind");
		return -1;
	}

	// 设置监听和排除数量
	if(listen(svr_fd,10))
	{
		perror("listen");
		return -1;
	}

	for(;;)
	{
		// 等待连接
		int cli_fd = accept(svr_fd,(struct sockaddr*)&addr,&addrlen);
		if(0 > cli_fd)
		{
			perror("accept");
			return -1;
		}

		// 创建线程服务客户端
		pthread_t tid;
		pthread_create(&tid,NULL,server,&cli_fd);
	}
}

客户端

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define BUF_SIZE (4096)

int main()
{
	// 创建socket对象
	int cli_fd = socket(AF_INET,SOCK_STREAM,0);
	if(0 > cli_fd)
	{
		perror("socket");
		return -1;
	}

	// 准备通信地址(服务端)
	struct sockaddr_in addr = {};
	addr.sin_family = AF_INET;
	addr.sin_port = htons(6789);
	addr.sin_addr.s_addr = inet_addr("192.168.43.92");

	// 连接服务端
	if(connect(cli_fd,(struct sockaddr*)&addr,sizeof(addr)))
	{
		perror("connect");
		return -1;
	}

	char buf[4096];
	for(;;)
	{
		printf(">>");
		gets(buf);
		int send_size = write(cli_fd,buf,strlen(buf)+1);
		if(0 >= send_size || 0 == strcmp(buf,"quit"))
		{
			printf("结束通信!\n");
			close(cli_fd);
			return 0;
		}

		int recv_size = read(cli_fd,buf,BUF_SIZE);
		if(0 >= recv_size)
		{
			printf("结束通信!\n");
			close(cli_fd);
			return 0;
		}
		printf("read:[%s]，size:%d\n",buf,recv_size);
	}
}