套接字编程——多进程并发服务器

【服务器代码】

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


//子进程函数
void profun(int client_sockfd)
{
	char buf[100];
	int ret;

	while (1)
	{
		memset(buf, 0, sizeof(buf));

		ret = read(client_sockfd, buf, sizeof(buf)-1);
		if (ret < 0)
		{
			perror("read");
			exit(1);
		}
		else if (ret == 0)
		{
			perror("Client close");
			break;
		}
		else
		{
			printf("%s", buf);
			ret = write(client_sockfd, buf, strlen(buf));
			if (ret < 0)
			{
				perror("write");
				exit(1);
			}
		}
	}
}


//循环回收子进程的结束状态
void sigfun()
{
	while ((waitpid(-1, NULL, WNOHANG)) > 0);
}


int main()
{
	pid_t pid;
	int sockfd = -1;
	int client_sockfd = -1;//会话描述符
	int ret = -1;
	struct sockaddr_in server_addr;
	struct sockaddr_in client_addr;
	int len;
	char buf[16];

	//安装子进程结束信号	
	signal(17, sigfun);

	//创建套接字
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("socket");
		exit(1);
	}
	
	//设置sockaddr_in结构体
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(3000);	
	server_addr.sin_addr.s_addr = INADDR_ANY;
	memset(server_addr.sin_zero, 0, sizeof(server_addr.sin_zero));

	//绑定
	if ((ret = bind(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr))) < 0)
	{
		perror("bind");
		exit(1);
	}

	//创建等待队列
	if ((ret = listen(sockfd, 5)) < 0)
	{
		perror("listen");
		exit(1);
	}

	//接收客户端请求
	while (1)
	{
		len = sizeof(client_addr);
		client_sockfd = accept(sockfd, (struct sockaddr *)&client_addr, &len);
		if (client_sockfd < 0)
		{
			perror("accept");
			exit(1);
		}
			
		//链接成功
		pid = fork();

		//子进程
		if (pid == 0)
		{
			close(sockfd);

			//打印客户端IP
			memset(buf, 0, 16);
 			inet_ntop(AF_INET, &client_addr.sin_addr.s_addr, buf, sizeof(buf));
			printf("IP = %s\n", buf);

			//执行子进程函数
			profun(client_sockfd);
	
			close(client_sockfd);
			exit(1);
		}

		//父进程
		else if (pid > 0)
		{
			close(client_sockfd);
		}

		//fork失败
		else
		{
			perror("fork");
			exit(1);
		}
	}
	//关闭套接字
	close(sockfd);
}

【客户端代码】

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main()
{
	int sockfd = -1;
	int ret = -1;
	struct sockaddr_in server_addr;
	char buf[100];
	

	//创建套接字
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0)
	{
		perror("sockfd");
		exit(1);
	}
//	printf("sockfd = %d\n", sockfd);

	//设置sockaddr_in结构体
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(3000);
	inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr.s_addr);
	memset(server_addr.sin_zero, 0, sizeof(server_addr.sin_zero));

	//向服务器发起连接
	ret = connect(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
	if (ret < 0)
	{
		perror("connet");
		exit(1);
	}

	//读写
	while (1)
	{
		memset(buf, 0, sizeof(buf));
		printf(">>");
		fflush(stdout);

		ret = read(0, buf, sizeof(buf)-1);
		if (ret < 0)
		{
			perror("read");
			exit(1);
		}

		else if (strncmp(buf, "exit", 4) == 0)
		{
			break;
		}

		else
		{
			ret = write(sockfd, buf, strlen(buf));
			if (ret < 0)
			{
				perror("write");
				exit(1);
			}

			memset(buf, 0, sizeof(buf));
			ret = read(sockfd, buf, sizeof(buf)-1);
			if (ret < 0)
			{
				perror("read");
				exit(1);
			}
			else if (ret == 0)
			{
				perror("Server close");
				break;
			}
			else
			{
				printf("<<%s", buf);
			}
		}
	}
}