--- /dev/null
+/* mygethost.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.
+ */
+/*****************************************************************************
+ *
+ * File mygethost.c: An example host command
+ *
+ * Author: S. Piccardi Jul. 2004
+ *
+ * $Id$
+ *
+ *****************************************************************************/
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h> /* C standard library */
+#include <stdio.h> /* I/O standard library */
+#include <unistd.h>
+#include <arpa/inet.h>
+extern int h_errno;
+
+#include "Gapil.h"
+/*
+ * Program myhost
+ *
+ * Use gethostbyname and print results
+ */
+/* Help printing routine */
+void usage(void);
+
+int main(int argc, char *argv[])
+{
+/*
+ * Variables definition
+ */
+ int i;
+ struct hostent *data;
+ char **alias;
+ char *addr;
+ char buffer[INET6_ADDRSTRLEN];
+ /*
+ * Input section: decode command line parameters
+ * Use getopt function
+ */
+ opterr = 0; /* don't want writing to stderr */
+ while ( (i = getopt(argc, argv, "h")) != -1) {
+ switch (i) {
+ /*
+ * Handling options
+ */
+ case 'h': /* help option */
+ 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
+ *
+ * ***********************************************************/
+ if ((argc - optind) != 1) {
+ printf("Wrong number of arguments %d\n", argc - optind);
+ usage();
+ }
+ data = gethostbyname(argv[1]);
+ if (data == NULL) {
+ herror("Errore di risoluzione");
+ exit(1);
+ }
+ printf("Canonical name %s\n", data->h_name);
+ alias = data->h_aliases;
+ while (*alias != NULL) {
+ printf("Alias %s\n", *alias);
+ alias++;
+ }
+ if (data->h_addrtype == AF_INET) {
+ printf("Address are IPv4\n");
+ } else if (data->h_addrtype == AF_INET6) {
+ printf("Address are IPv6\n");
+ } else {
+ printf("Tipo di indirizzo non valido\n");
+ exit(1);
+ }
+ alias = data->h_addr_list;
+ while (*alias != NULL) {
+ addr = inet_ntop(data->h_addrtype, *alias, buffer, sizeof(buffer));
+ printf("Indirizzo %s\n", addr);
+ alias++;
+ }
+ exit(0);
+}
+/*
+ * routine to print usage info and exit
+ */
+void usage(void) {
+ printf("Program mygethost: do an hostname resolution \n");
+ printf("Usage:\n");
+ printf(" mygethost [-h] hostname \n");
+ printf(" -h print this help\n");
+ exit(1);
+}