1 /* Display hostname in various forms.
2 Copyright (C) 2001-2003, 2006 Free Software Foundation, Inc.
3 Written by Bruno Haible <haible@clisp.cons.org>, 2001.
4
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, or (at your option)
8 any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
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 Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18
19
20 #ifdef HAVE_CONFIG_H
21 # include "config.h"
22 #endif
23
24 #include <errno.h>
25 #include <getopt.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <locale.h>
30
31 #if defined _WIN32 || defined __WIN32__
32 # define WIN32_NATIVE
33 #endif
34
35 /* Get gethostname(). */
36 #include <unistd.h>
37
38 #ifdef WIN32_NATIVE
39 /* Native Woe32 API lacks gethostname() but has GetComputerName() instead. */
40 # include <windows.h>
41 #else
42 /* Some systems, like early Solaris versions, lack gethostname() but
43 have uname() instead. */
44 # if !HAVE_GETHOSTNAME
45 # include <sys/utsname.h>
46 # endif
47 #endif
48
49 /* Get MAXHOSTNAMELEN. */
50 #include <sys/param.h>
51 #ifndef MAXHOSTNAMELEN
52 # define MAXHOSTNAMELEN 64
53 #endif
54
55 /* Support for using gethostbyname(). */
56 #if HAVE_GETHOSTBYNAME
57 # include <sys/types.h>
58 # include <sys/socket.h> /* defines AF_INET, AF_INET6 */
59 # include <netinet/in.h> /* declares ntohs(), defines struct sockaddr_in */
60 # if HAVE_ARPA_INET_H
61 # include <arpa/inet.h> /* declares inet_ntoa(), inet_ntop() */
62 # endif
63 # if HAVE_IPV6
64 # if !defined(__CYGWIN__) /* Cygwin has only s6_addr, no s6_addr16 */
65 # if defined(__APPLE__) && defined(__MACH__) /* MacOS X */
66 # define in6_u __u6_addr
67 # define u6_addr16 __u6_addr16
68 # endif
69 /* Use s6_addr16 for portability. See RFC 2553. */
70 # ifndef s6_addr16
71 # define s6_addr16 in6_u.u6_addr16
72 # endif
73 # define HAVE_IN6_S6_ADDR16 1
74 # endif
75 # endif
76 # include <netdb.h> /* defines struct hostent, declares gethostbyname() */
77 #endif
78
79 /* Include this after <sys/socket.h>, to avoid a syntax error on BeOS. */
80 #include <stdbool.h>
81
82 #include "closeout.h"
83 #include "error.h"
84 #include "error-progname.h"
85 #include "progname.h"
86 #include "relocatable.h"
87 #include "basename.h"
88 #include "xalloc.h"
89 #include "exit.h"
90 #include "propername.h"
91 #include "gettext.h"
92
93 #define _(str) gettext (str)
94
95
96 /* Output format. */
97 static enum { default_format, short_format, long_format, ip_format } format;
98
99 /* Long options. */
100 static const struct option long_options[] =
101 {
102 { "fqdn", no_argument, NULL, 'f' },
103 { "help", no_argument, NULL, 'h' },
104 { "ip-address", no_argument, NULL, 'i' },
105 { "long", no_argument, NULL, 'f' },
106 { "short", no_argument, NULL, 's' },
107 { "version", no_argument, NULL, 'V' },
108 { NULL, 0, NULL, 0 }
109 };
110
111
112 /* Forward declaration of local functions. */
113 static void usage (int status)
114 #if defined __GNUC__ && ((__GNUC__ == 2 && __GNUC_MINOR__ >= 5) || __GNUC__ > 2)
115 __attribute__ ((noreturn))
116 #endif
117 ;
118 static void print_hostname (void);
119
120 int
main(int argc,char * argv[])121 main (int argc, char *argv[])
122 {
123 int optchar;
124 bool do_help;
125 bool do_version;
126
127 /* Set program name for messages. */
128 set_program_name (argv[0]);
129 error_print_progname = maybe_print_progname;
130
131 #ifdef HAVE_SETLOCALE
132 /* Set locale via LC_ALL. */
133 setlocale (LC_ALL, "");
134 #endif
135
136 /* Set the text message domain. */
137 bindtextdomain (PACKAGE, relocate (LOCALEDIR));
138 textdomain (PACKAGE);
139
140 /* Ensure that write errors on stdout are detected. */
141 atexit (close_stdout);
142
143 /* Set default values for variables. */
144 do_help = false;
145 do_version = false;
146 format = default_format;
147
148 /* Parse command line options. */
149 while ((optchar = getopt_long (argc, argv, "fhisV", long_options, NULL))
150 != EOF)
151 switch (optchar)
152 {
153 case '\0': /* Long option. */
154 break;
155 case 'f':
156 format = long_format;
157 break;
158 case 's':
159 format = short_format;
160 break;
161 case 'i':
162 format = ip_format;
163 break;
164 case 'h':
165 do_help = true;
166 break;
167 case 'V':
168 do_version = true;
169 break;
170 default:
171 usage (EXIT_FAILURE);
172 /* NOTREACHED */
173 }
174
175 /* Version information requested. */
176 if (do_version)
177 {
178 printf ("%s (GNU %s) %s\n", basename (program_name), PACKAGE, VERSION);
179 /* xgettext: no-wrap */
180 printf (_("Copyright (C) %s Free Software Foundation, Inc.\n\
181 This is free software; see the source for copying conditions. There is NO\n\
182 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
183 "),
184 "2001-2003");
185 printf (_("Written by %s.\n"), proper_name ("Bruno Haible"));
186 exit (EXIT_SUCCESS);
187 }
188
189 /* Help is requested. */
190 if (do_help)
191 usage (EXIT_SUCCESS);
192
193 /* Test for extraneous arguments. */
194 if (optind != argc)
195 error (EXIT_FAILURE, 0, _("too many arguments"));
196
197 /* Get and print the hostname. */
198 print_hostname ();
199
200 exit (EXIT_SUCCESS);
201 }
202
203 /* Display usage information and exit. */
204 static void
usage(int status)205 usage (int status)
206 {
207 if (status != EXIT_SUCCESS)
208 fprintf (stderr, _("Try `%s --help' for more information.\n"),
209 program_name);
210 else
211 {
212 printf (_("\
213 Usage: %s [OPTION]\n\
214 "), program_name);
215 printf ("\n");
216 printf (_("\
217 Print the machine's hostname.\n"));
218 printf ("\n");
219 printf (_("\
220 Output format:\n"));
221 printf (_("\
222 -s, --short short host name\n"));
223 printf (_("\
224 -f, --fqdn, --long long host name, includes fully qualified domain\n\
225 name, and aliases\n"));
226 printf (_("\
227 -i, --ip-address addresses for the hostname\n"));
228 printf ("\n");
229 printf (_("\
230 Informative output:\n"));
231 printf (_("\
232 -h, --help display this help and exit\n"));
233 printf (_("\
234 -V, --version output version information and exit\n"));
235 printf ("\n");
236 fputs (_("Report bugs to <bug-gnu-gettext@gnu.org>.\n"),
237 stdout);
238 }
239
240 exit (status);
241 }
242
243 /* Returns an xmalloc()ed string containing the machine's host name. */
244 static char *
xgethostname()245 xgethostname ()
246 {
247 #ifdef WIN32_NATIVE
248 char hostname[MAX_COMPUTERNAME_LENGTH+1];
249 DWORD size = sizeof (hostname);
250
251 if (!GetComputerName (hostname, &size))
252 error (EXIT_FAILURE, 0, _("could not get host name"));
253 return xstrdup (hostname);
254 #elif HAVE_GETHOSTNAME
255 char hostname[MAXHOSTNAMELEN+1];
256
257 if (gethostname (hostname, MAXHOSTNAMELEN) < 0)
258 error (EXIT_FAILURE, errno, _("could not get host name"));
259 hostname[MAXHOSTNAMELEN] = '\0';
260 return xstrdup (hostname);
261 #else
262 struct utsname utsname;
263
264 if (uname (&utsname) < 0)
265 error (EXIT_FAILURE, errno, _("could not get host name"));
266 return xstrdup (utsname.nodename);
267 #endif
268 }
269
270 /* Converts an AF_INET address to a printable, presentable format.
271 BUFFER is an array with at least 15+1 bytes. ADDR is 'struct in_addr'. */
272 #if HAVE_INET_NTOP
273 # define ipv4_ntop(buffer,addr) \
274 inet_ntop (AF_INET, &addr, buffer, 15+1)
275 #else
276 # define ipv4_ntop(buffer,addr) \
277 strcpy (buffer, inet_ntoa (addr))
278 #endif
279
280 #if HAVE_IPV6
281 /* Converts an AF_INET6 address to a printable, presentable format.
282 BUFFER is an array with at least 45+1 bytes. ADDR is 'struct in6_addr'. */
283 # if HAVE_INET_NTOP
284 # define ipv6_ntop(buffer,addr) \
285 inet_ntop (AF_INET6, &addr, buffer, 45+1)
286 # elif HAVE_IN6_S6_ADDR16
287 # define ipv6_ntop(buffer,addr) \
288 sprintf (buffer, "%x:%x:%x:%x:%x:%x:%x:%x", \
289 ntohs ((addr).s6_addr16[0]), \
290 ntohs ((addr).s6_addr16[1]), \
291 ntohs ((addr).s6_addr16[2]), \
292 ntohs ((addr).s6_addr16[3]), \
293 ntohs ((addr).s6_addr16[4]), \
294 ntohs ((addr).s6_addr16[5]), \
295 ntohs ((addr).s6_addr16[6]), \
296 ntohs ((addr).s6_addr16[7]))
297 # else
298 # define ipv6_ntop(buffer,addr) \
299 sprintf (buffer, "%x:%x:%x:%x:%x:%x:%x:%x", \
300 ((addr).s6_addr[0] << 8) | (addr).s6_addr[1], \
301 ((addr).s6_addr[2] << 8) | (addr).s6_addr[3], \
302 ((addr).s6_addr[4] << 8) | (addr).s6_addr[5], \
303 ((addr).s6_addr[6] << 8) | (addr).s6_addr[7], \
304 ((addr).s6_addr[8] << 8) | (addr).s6_addr[9], \
305 ((addr).s6_addr[10] << 8) | (addr).s6_addr[11], \
306 ((addr).s6_addr[12] << 8) | (addr).s6_addr[13], \
307 ((addr).s6_addr[14] << 8) | (addr).s6_addr[15])
308 # endif
309 #endif
310
311 /* Print the hostname according to the specified format. */
312 static void
print_hostname()313 print_hostname ()
314 {
315 char *hostname;
316 char *dot;
317 #if HAVE_GETHOSTBYNAME
318 struct hostent *h;
319 size_t i;
320 #endif
321
322 hostname = xgethostname ();
323
324 switch (format)
325 {
326 case default_format:
327 /* Print the hostname, as returned by the system call. */
328 printf ("%s\n", hostname);
329 break;
330
331 case short_format:
332 /* Print only the part before the first dot. */
333 dot = strchr (hostname, '.');
334 if (dot != NULL)
335 *dot = '\0';
336 printf ("%s\n", hostname);
337 break;
338
339 case long_format:
340 /* Look for netwide usable hostname and aliases using gethostbyname(). */
341 #if HAVE_GETHOSTBYNAME
342 h = gethostbyname (hostname);
343 if (h != NULL)
344 {
345 printf ("%s\n", h->h_name);
346 if (h->h_aliases != NULL)
347 for (i = 0; h->h_aliases[i] != NULL; i++)
348 printf ("%s\n", h->h_aliases[i]);
349 }
350 else
351 #endif
352 printf ("%s\n", hostname);
353 break;
354
355 case ip_format:
356 /* Look for netwide usable IP addresses using gethostbyname(). */
357 #if HAVE_GETHOSTBYNAME
358 h = gethostbyname (hostname);
359 if (h != NULL && h->h_addr_list != NULL)
360 for (i = 0; h->h_addr_list[i] != NULL; i++)
361 {
362 #if HAVE_IPV6
363 if (h->h_addrtype == AF_INET6)
364 {
365 char buffer[45+1];
366 ipv6_ntop (buffer, *(const struct in6_addr*) h->h_addr_list[i]);
367 printf("[%s]\n", buffer);
368 }
369 else
370 #endif
371 if (h->h_addrtype == AF_INET)
372 {
373 char buffer[15+1];
374 ipv4_ntop (buffer, *(const struct in_addr*) h->h_addr_list[i]);
375 printf("[%s]\n", buffer);
376 }
377 }
378 #endif
379 break;
380
381 default:
382 abort ();
383 }
384 }
385