c语言实现简单的udp传输( c/s 模型)

2016-08-26

客户端代码:

/*client.c*/ #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <string.h> #include <arpa/inet.h> #define MAXBUF 256 int main(int argc, char const *argv[]) { 	int s = 0; 	int n = 0; 	int reuse = 1; 	int port = 1987; 	struct sockaddr_in srv; 	char buf[MAXBUF] = {0}; 	/*解析参数*/ 	if (argc != 2) 	{ 		printf("Usage:%s ServerIP
", argv[0]); 		return -1; 	}  	bzero(&srv, sizeof(srv)); 	srv.sin_family = PF_INET; 	srv.sin_addr.s_addr = inet_addr(argv[1]); 	srv.sin_port = htons(port); 	/*创建 UDP 套节字*/ 	s = socket(AF_INET, SOCK_DGRAM, 0); 	if(s<0){ 		perror("socket"); 		return -1; 	}  	while(1){ 		memset(buf, 0, MAXBUF); 		/*读取用户输入到buf中*/ 		fgets(buf, MAXBUF, stdin);  		/*通过套节字 s 向服务器发送数据*/ 		if ((n = sendto(s, buf, strlen(buf), 0, (struct sockaddr *) &srv, sizeof(struct sockaddr))) < 0) 		{ 			perror("sendto"); 			return -1; 		}else{ 			printf("send to %s(port=%d) len %d:%s
", argv[1], port, n, buf); 		} 	} }

服务器端代码:

/*server.c*/ #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <string.h> #include <arpa/inet.h>  #define MAXBUF 256 int main(int argc, char const *argv[]) { 	int s = 0; 	int n = 0; 	int reuse = 1; 	int cli_len = sizeof(struct sockaddr); 	int port = 1987; 	char buf[MAXBUF] = {0}; 	struct sockaddr_in addr, cli;  	/*初始化本地监听端口信息*/ 	bzero(&addr, sizeof(addr)); 	addr.sin_family = PF_INET; 	addr.sin_addr.s_addr = INADDR_ANY; 	addr.sin_port = htons(port);  	/*创建UDP套节字*/ 	s = socket(AF_INET, SOCK_DGRAM, 0); 	if (s<0) 	{ 		perror("socket"); 		return -1; 	}  	/*允许端口复用*/ 	setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));  	/*绑定指定端口*/ 	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) 	{ 		perror("bind"); 		return -1; 	}  	while(1){ 		memset(buf, 0, MAXBUF); 		/*从套节字s中读取数据*/ 		n = recvfrom(s, buf, MAXBUF, 0, (struct sockaddr *)&cli, &cli_len); 		if(n<0){ 			perror("recvfrom"); 			return -1; 		}else{ 			printf("receive msg from %s(port=%d) len %d: %s
",inet_ntoa(cli.sin_addr), port, n, buf); 		} 	} 	 	return 0; }
编译命令:

客户端:

gcc client.c -o client ./client 127.0.0.1

服务端:

gcc server.c -o server ./server