+/* UDP_echo_first.c
+ *
+ * Copyright (C) 2004 Simone Piccardi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/****************************************************************
+ *
+ * Program UDP_echo_first.c
+ * Simple UDP client for echo service (port 7)
+ * first version, no connected UDP socket
+ *
+ * Author: Simone Piccardi
+ * May 2004
+ *
+ * Usage: echo -h give all info's
+ *
+ * $Id: UDP_echo_first.c,v 1.1 2004/06/02 16:31:50 piccardi Exp $
+ *
+ ****************************************************************/
+/*
+ * Include needed headers
+ */
+#include <sys/types.h> /* predefined types */
+#include <unistd.h> /* include unix standard library */
+#include <arpa/inet.h> /* IP addresses conversion utiliites */
+#include <sys/socket.h> /* socket library */
+#include <stdio.h> /* include standard I/O library */
+#include <errno.h> /* include error codes */
+#include <string.h> /* include erroro strings definitions */
+
+#include "macros.h"
+
+#define MAXLINE 256
+void usage(void);
+void ClientEcho(FILE * filein, int socket, struct sockaddr_in *serv_add);
+void SigTERM_hand(int sig);
+
+/* Program begin */
+int main(int argc, char *argv[])
+{
+/*
+ * Variables definition
+ */
+ int sock, i;
+ struct sockaddr_in serv_add;
+ /*
+ * 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(1);
+ 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 ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+ perror("Socket creation error");
+ return 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(7); /* echo port is 7 */
+ /* build address using inet_pton */
+ if ( (inet_pton(AF_INET, argv[optind], &serv_add.sin_addr)) <= 0) {
+ perror("Address creation error");
+ return 1;
+ }
+ /* do read/write operations */
+ ClientEcho(stdin, sock, &serv_add);
+ /* normal exit */
+ return 0;
+}
+/*
+ * routine to print usage info and exit
+ */
+void usage(void) {
+ printf("Take daytime from a remote host \n");
+ printf("Usage:\n");
+ printf(" daytime [-h] [-v] [host in dotted decimal form] \n");
+// printf(" -v set verbosity on\n");
+ printf(" -r require reset on closing\n");
+ printf(" -h print this help\n");
+ exit(1);
+}
+
+void ClientEcho(FILE * filein, int socket, struct sockaddr_in * serv_addr)
+{
+ char sendbuff[MAXLINE+1], recvbuff[MAXLINE+1];
+ int nread, nwrite;
+ /* initialize file descriptor set */
+ while (1) {
+ if (fgets(sendbuff, MAXLINE, filein) == NULL) {
+ return; /* if no input just return */
+ } else { /* else we have to write to socket */
+ nwrite = sendto(socket, sendbuff, strlen(sendbuff), 0,
+ (struct sockaddr *) serv_addr, sizeof(*serv_addr));
+ if (nwrite < 0) { /* on error stop */
+ printf("Errore in scrittura: %s", strerror(errno));
+ return;
+ }
+ }
+ nread = recvfrom(socket, recvbuff, strlen(sendbuff), 0, NULL, NULL);
+ if (nread < 0) { /* error condition, stop client */
+ printf("Errore in lettura: %s\n", strerror(errno));
+ return;
+ }
+ recvbuff[nread] = 0; /* else read is ok, write on stdout */
+ if (fputs(recvbuff, stdout) == EOF) {
+ perror("Errore in scrittura su terminale");
+ return;
+ }
+ }
+}