#include "unp.h" #include int main(int argc, char **argv) { int sockfd; ssize_t n; char buff[MAXLINE]; time_t ticks; socklen_t addrlen, len; struct sockaddr *cliaddr; if (argc == 2) sockfd = Udp_server_reuseaddr(NULL, argv[1], &addrlen); else if (argc == 3) sockfd = Udp_server_reuseaddr(argv[1], argv[2], &addrlen); else err_quit("usage: daytimeudpsrv [ ] "); cliaddr = Malloc(addrlen); for ( ; ; ) { len = addrlen; n = Recvfrom(sockfd, buff, MAXLINE, 0, cliaddr, &len); printf("datagram from %s\n", Sock_ntop(cliaddr, len)); ticks = time(NULL); snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks)); Sendto(sockfd, buff, strlen(buff), 0, cliaddr, len); } }