3 * Copyright (C) 2004 Simone Piccardi
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /****************************************************************
22 * Simple UDP client for echo service (port 7)
24 * Author: Simone Piccardi
27 * Usage: echo -h give all info's
29 * $Id: UDP_echo.c,v 1.4 2004/06/04 00:31:33 piccardi Exp $
31 ****************************************************************/
33 * Include needed headers
35 #include <sys/types.h> /* predefined types */
36 #include <unistd.h> /* include unix standard library */
37 #include <arpa/inet.h> /* IP addresses conversion utiliites */
38 #include <sys/socket.h> /* socket library */
39 #include <stdio.h> /* include standard I/O library */
40 #include <errno.h> /* include error codes */
41 #include <string.h> /* include erroro strings definitions */
47 void ClientEcho(FILE * filein, int socket);
48 void SigTERM_hand(int sig);
51 int main(int argc, char *argv[])
54 * Variables definition
57 struct sockaddr_in dst_addr;
59 * Input section: decode parameters passed in the calling
62 opterr = 0; /* don't want writing to stderr */
63 while ( (i = getopt(argc, argv, "h")) != -1) {
69 printf("Wrong -h option use\n");
73 case '?': /* unrecognized options */
74 printf("Unrecognized options -%c\n",optopt);
76 default: /* should not reached */
80 /* ***********************************************************
82 * Options processing completed
86 * ***********************************************************/
88 if ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
89 perror("Socket creation error");
92 /* initialize address */
93 memset((void *) &dst_addr, 0, sizeof(dst_addr)); /* clear address */
94 dst_addr.sin_family = AF_INET; /* address type is INET */
95 dst_addr.sin_port = htons(7); /* echo port is 7 */
96 /* build address using inet_pton */
97 if ( (inet_pton(AF_INET, argv[optind], &dst_addr.sin_addr)) <= 0) {
98 perror("Address creation error");
101 connect(sock, (struct sockaddr *) &dst_addr, sizeof(dst_addr));
102 /* do read/write operations */
103 ClientEcho(stdin, sock);
108 * routine to print usage info and exit
111 printf("Take daytime from a remote host \n");
113 printf(" daytime [-h] [-v] [host in dotted decimal form] \n");
114 // printf(" -v set verbosity on\n");
115 printf(" -r require reset on closing\n");
116 printf(" -h print this help\n");
120 void ClientEcho(FILE * filein, int socket)
122 char sendbuff[MAXLINE+1], recvbuff[MAXLINE+1];
124 /* initialize file descriptor set */
126 if (fgets(sendbuff, MAXLINE, filein) == NULL) {
127 return; /* if no input just return */
128 } else { /* else we have to write to socket */
129 nwrite = write(socket, sendbuff, strlen(sendbuff));
130 if (nwrite < 0) { /* on error stop */
131 printf("Errore in scrittura: %s", strerror(errno));
135 nread = read(socket, recvbuff, strlen(sendbuff));
136 if (nread < 0) { /* error condition, stop client */
137 printf("Errore in lettura: %s\n", strerror(errno));
140 recvbuff[nread] = 0; /* else read is ok, write on stdout */
141 if (fputs(recvbuff, stdout) == EOF) {
142 perror("Errore in scrittura su terminale");