1 /* ----------------------------------------------------------------------- *
3 * Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
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, Inc., 53 Temple Place Ste 330,
8 * Boston MA 02111-1307, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
11 * ----------------------------------------------------------------------- */
16 * Small program to use gethostbyname() to print out a hostname in
17 * hex and/or dotted-quad notation
23 #include <sys/socket.h>
26 #define _GNU_SOURCE /* For getopt_long */
29 const struct option options[] = {
30 {"hexadecimal", 0, NULL, 'x'},
31 {"decimal", 0, NULL, 'd'},
32 {"dotted-quad", 0, NULL, 'd'},
33 {"full-output", 0, NULL, 'f'},
34 {"name", 0, NULL, 'n'},
35 {"help", 0, NULL, 'h'},
41 void usage(int exit_code)
43 fprintf(stderr, "Usage: %s [-dxnf] hostname/ip...\n", program);
47 int main(int argc, char *argv[])
59 while ((opt = getopt_long(argc, argv, "dxfnh", options, NULL)) != -1) {
62 output |= 2; /* Decimal output */
65 output |= 4; /* Hexadecimal output */
68 output |= 1; /* Canonical name output */
71 output = 7; /* Full output */
86 output = 7; /* Default output */
88 for (i = optind; i < argc; i++) {
90 host = gethostbyname(argv[i]);
97 if (host->h_addrtype != AF_INET || host->h_length != 4) {
98 fprintf(stderr, "%s: No IPv4 address associated with name\n",
105 printf("%s%s", sep, host->h_name);
110 printf("%s%u.%u.%u.%u", sep,
111 ((unsigned char *)host->h_addr)[0],
112 ((unsigned char *)host->h_addr)[1],
113 ((unsigned char *)host->h_addr)[2],
114 ((unsigned char *)host->h_addr)[3]);
119 printf("%s%02X%02X%02X%02X", sep,
120 ((unsigned char *)host->h_addr)[0],
121 ((unsigned char *)host->h_addr)[1],
122 ((unsigned char *)host->h_addr)[2],
123 ((unsigned char *)host->h_addr)[3]);