UDP编程源代码

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> int main(int argc, char *argv[]) { unsigned short port = 8000; // 本地端口 if(argc > 1) { port = atoi(argv[1]); } int sockfd; sockfd = socket(AF_INET, SOCK_DGRAM, 0); // 创建套接字 if(sockfd < 0) { perror("socket"); exit(-1); } // 本地网络地址 struct sockaddr_in my_addr; bzero(&my_addr, sizeof(my_addr)); // 清空结构体内容 my_addr.sin_family = AF_INET; // ipv4 my_addr.sin_port = htons(port); // 端口转换 my_addr.sin_addr.s_addr = htonl(INADDR_ANY); // 绑定网卡所有ip地址，INADDR_ANY为通配地址，值为0 printf("Binding server to port %d\n", port); int err_log; err_log = bind(sockfd, (struct sockaddr*)&my_addr, sizeof(my_addr)); // 绑定 if(err_log != 0) { perror("bind"); close(sockfd); exit(-1); } printf("receive data...\n"); while(1) { int recv_len; char recv_buf[512] = ""; struct sockaddr_in client_addr; char cli_ip[INET_ADDRSTRLEN] = "";//INET_ADDRSTRLEN=16 socklen_t cliaddr_len = sizeof(client_addr); // 接受数据 recv_len = recvfrom(sockfd, recv_buf, sizeof(recv_buf), 0, (struct sockaddr*)&client_addr, &cliaddr_len); inet_ntop(AF_INET, &client_addr.sin_addr, cli_ip, INET_ADDRSTRLEN); printf("\nip:%s ,port:%d\n",cli_ip, ntohs(client_addr.sin_port)); printf("data(%d):%s\n",recv_len,recv_buf); } close(sockfd); return 0; }