-
-#define MAXLINE 80
-#define BACKLOG 10
-/* Program begin */
-void usage(void);
-int main(int argc, char *argv[])
-{
-/*
- * Variables definition
- */
- int list_fd, conn_fd;
- int i;
- struct sockaddr_in serv_add;
- char buffer[MAXLINE];
- time_t timeval;
- /*
- * Input section: decode parameters passed in the calling
- * Use getopt function
- */
- opterr = 0; /* don't want writing to stderr */
- while ( (i = getopt(argc, argv, "h")) != -1) {
- switch (i) {
- /*
- * Handling options
- */
- case 'h':
- printf("Wrong -h option use\n");
- usage();
- return(0);
- break;
- case '?': /* unrecognized options */
- printf("Unrecognized options -%c\n",optopt);
- usage();
- default: /* should not reached */
- usage();
- }
- }
- /* ***********************************************************
- *
- * Options processing completed
- *
- * Main code beginning
- *
- * ***********************************************************/
- /* create socket */
- if ( (list_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
- perror("Socket creation error");
- exit(-1);
- }
- /* initialize address */
- memset((void *)&serv_add, 0, sizeof(serv_add)); /* clear server address */
- serv_add.sin_family = AF_INET; /* address type is INET */
- serv_add.sin_port = htons(13); /* daytime port is 13 */
- serv_add.sin_addr.s_addr = htonl(INADDR_ANY); /* connect from anywhere */
- /* bind socket */
- if (bind(list_fd, (struct sockaddr *)&serv_add, sizeof(serv_add)) < 0) {
- perror("bind error");
- exit(-1);
- }
- /* listen on socket */
- if (listen(list_fd, BACKLOG) < 0 ) {
- perror("listen error");
- exit(-1);
- }
- /* write daytime to client */
- while (1) {
- if ( (conn_fd = accept(list_fd, (struct sockaddr *) NULL, NULL)) <0 ) {
- perror("accept error");
- exit(-1);
- }
- timeval = time(NULL);
- snprintf(buffer, sizeof(buffer), "%.24s\r\n", ctime(&timeval));
- if ( (write(conn_fd, buffer, strlen(buffer))) < 0 ) {
- perror("write error");
- exit(-1);
- }
- close(conn_fd);
- }
-
- /* normal exit */
- exit(0);
-}
-/*
- * routine to print usage info and exit
- */
-void usage(void) {
- printf("Simple daytime server\n");
- printf("Usage:\n");
- printf(" daytimed [-h] \n");
- printf(" -h print this help\n");
- exit(1);
-}