hostname.c

   1 /*
   2  * hostname   This file contains an implementation of the command
   3  *              that maintains the hostname and the domainname. It
   4  *              is also used to show the FQDN and the IP-Addresses.
   5  *
   6  * Usage:       hostname [-d|-f|-s|-a|-i|-y|-n]
   7  *              hostname [-h|-V]
   8  *              hostname {name|-F file}
   9  *              dnsdmoainname
  10  *              nisdomainname {name|-F file}
  11  *
  12  * Version:     hostname 1.96 (1996-02-18)
  13  *
  14  * Author:      Peter Tobias <tobias@et-inf.fho-emden.de>
  15  *
  16  * Changes:
  17  *      {1.90}  Peter Tobias :          Added -a and -i options.
  18  *      {1.91}  Bernd Eckenfels :       -v,-V rewritten, long_opts
  19  *                                      (major rewrite), usage.
  20  *960120 {1.95} Bernd Eckenfels :       -y/nisdomainname - support for get/
  21  *                                      setdomainname added
  22  *960218 {1.96} Bernd Eckenfels :       netinet/in.h added
  23  *980629 {1.97} Arnaldo Carvalho de Melo : gettext instead of catgets for i18n
  24  *20000213 {1.99} Arnaldo Carvalho de Melo : fixed some i18n strings
  25  *20010404 {1.100} Arnaldo Carvalho de Melo: use setlocale
  26  *
  27  *              This program is free software; you can redistribute it
  28  *              and/or  modify it under  the terms of  the GNU General
  29  *              Public  License as  published  by  the  Free  Software
  30  *              Foundation;  either  version 2 of the License, or  (at
  31  *              your option) any later version.
  32  */
  33 #include <stdio.h>
  34 #include <unistd.h>
  35 #include <stdlib.h>
  36 #include <getopt.h>
  37 #include <string.h>
  38 #include <netdb.h>
  39 #include <errno.h>
  40 #include <sys/param.h>
  41 #include <netinet/in.h>
  42 #include <arpa/inet.h>
  43 #include "config.h"
  44 #include "version.h"
  45 #include "../intl.h"
  46
  47 #if HAVE_AFDECnet
  48 #include <netdnet/dn.h>
  49 #endif
  50
  51 char *Release = RELEASE, *Version = "hostname 1.100 (2001-04-14)";
  52
  53 static char *program_name;
  54 static int opt_v;
  55
  56 static void sethname(char *);
  57 static void setdname(char *);
  58 static void showhname(char *, int);
  59 static void usage(void);
  60 static void version(void);
  61 static void setfilename(char *, int);
  62
  63 #define SETHOST         1
  64 #define SETDOMAIN       2
  65 #define SETNODE         3
  66
  67 #if HAVE_AFDECnet
  68 static void setnname(char *nname)
  69 {
  70     if (opt_v)
  71         fprintf(stderr, _("Setting nodename to `%s'\n"),
  72                 nname);
  73     if (setnodename(nname, strlen(nname))) {
  74         switch(errno) {
  75         case EPERM:
  76             fprintf(stderr, _("%s: you must be root to change the node name\n"), program_name);
  77             break;
  78         case EINVAL:
  79             fprintf(stderr, _("%s: name too long\n"), program_name);
  80             break;
  81         default:
  82         }
  83         exit(1);
  84     }
  85 }
  86 #endif /* HAVE_AFDECnet */
  87
  88 static void sethname(char *hname)
  89 {
  90     if (opt_v)
  91         fprintf(stderr, _("Setting hostname to `%s'\n"),
  92                 hname);
  93     if (sethostname(hname, strlen(hname))) {
  94         switch (errno) {
  95         case EPERM:
  96             fprintf(stderr, _("%s: you must be root to change the host name\n"), program_name);
  97             break;
  98         case EINVAL:
  99             fprintf(stderr, _("%s: name too long\n"), program_name);
 100             break;
 101         }
 102         exit(1);
 103     };
 104 }
 105
 106 static void setdname(char *dname)
 107 {
 108     if (opt_v)
 109         fprintf(stderr, _("Setting domainname to `%s'\n"),
 110                 dname);
 111     if (setdomainname(dname, strlen(dname))) {
 112         switch (errno) {
 113         case EPERM:
 114             fprintf(stderr, _("%s: you must be root to change the domain name\n"), program_name);
 115             break;
 116         case EINVAL:
 117             fprintf(stderr, _("%s: name too long\n"), program_name);
 118             break;
 119         }
 120         exit(1);
 121     };
 122 }
 123
 124 static void showhname(char *hname, int c)
 125 {
 126     struct hostent *hp;
 127     register char *p, **alias;
 128     struct in_addr **ip;
 129
 130     if (opt_v)
 131         fprintf(stderr, _("Resolving `%s' ...\n"), hname);
 132     if (!(hp = gethostbyname(hname))) {
 133         herror(program_name);
 134         exit(1);
 135     }
 136     if (opt_v) {
 137         fprintf(stderr, _("Result: h_name=`%s'\n"),
 138                 hp->h_name);
 139
 140         alias = hp->h_aliases;
 141         while (alias[0])
 142             fprintf(stderr, _("Result: h_aliases=`%s'\n"),
 143                     *alias++);
 144
 145         ip = (struct in_addr **) hp->h_addr_list;
 146         while (ip[0])
 147             fprintf(stderr, _("Result: h_addr_list=`%s'\n"),
 148                     inet_ntoa(**ip++));
 149     }
 150     if (!(p = strchr(hp->h_name, '.')) && (c == 'd'))
 151         return;
 152
 153     switch (c) {
 154     case 'a':
 155         while (hp->h_aliases[0])
 156             printf("%s ", *hp->h_aliases++);
 157         printf("\n");
 158         break;
 159     case 'i':
 160         while (hp->h_addr_list[0])
 161             printf("%s ", inet_ntoa(*(struct in_addr *) *hp->h_addr_list++));
 162         printf("\n");
 163         break;
 164     case 'd':
 165         printf("%s\n", ++p);
 166         break;
 167     case 'f':
 168         printf("%s\n", hp->h_name);
 169         break;
 170     case 's':
 171         if (p != NULL)
 172             *p = '\0';
 173         printf("%s\n", hp->h_name);
 174         break;
 175     }
 176 }
 177
 178 static void setfilename(char *name, int what)
 179 {
 180     register FILE *fd;
 181     register char *p;
 182     char fline[MAXHOSTNAMELEN];
 183
 184     if ((fd = fopen(name, "r")) != NULL) {
 185         while (fgets(fline, sizeof(fline), fd) != NULL) {
 186             if ((p = index(fline, '\n')) != NULL)
 187                 *p = '\0';
 188             if (opt_v)
 189                 fprintf(stderr, ">> %s\n", fline);
 190             if (fline[0] == '#')
 191                 continue;
 192             switch(what) {
 193             case SETHOST:
 194                 sethname(fline);
 195                 break;
 196             case SETDOMAIN:
 197                 setdname(fline);
 198                 break;
 199 #if HAVE_AFDECnet
 200             case SETNODE:
 201                 setnname(fline);
 202                 break;
 203 #endif /* HAVE_AFDECnet */
 204             }
 205         }
 206         (void) fclose(fd);
 207     } else {
 208         fprintf(stderr, _("%s: can't open `%s'\n"),
 209                 program_name, name);
 210         exit(1);
 211     }
 212 }
 213
 214 static void version(void)
 215 {
 216     fprintf(stderr, "%s\n%s\n", Release, Version);
 217     exit(5); /* E_VERSION */
 218 }
 219
 220 static void usage(void)
 221 {
 222     fprintf(stderr, _("Usage: hostname [-v] {hostname|-F file}      set hostname (from file)\n"));
 223     fprintf(stderr, _("       domainname [-v] {nisdomain|-F file}   set NIS domainname (from file)\n"));
 224 #if HAVE_AFDECnet
 225     fprintf(stderr, _("       nodename [-v] {nodename|-F file}      set DECnet node name (from file)\n"));
 226 #endif
 227     fprintf(stderr, _("       hostname [-v] [-d|-f|-s|-a|-i|-y|-n]  display formatted name\n"));
 228     fprintf(stderr, _("       hostname [-v]                         display hostname\n\n"));
 229     fprintf(stderr, _("       hostname -V|--version|-h|--help       print info and exit\n\n"));
 230     fprintf(stderr, _("    dnsdomainname=hostname -d, {yp,nis,}domainname=hostname -y\n\n"));
 231     fprintf(stderr, _("    -s, --short           short host name\n"));
 232     fprintf(stderr, _("    -a, --alias           alias names\n"));
 233     fprintf(stderr, _("    -i, --ip-address      addresses for the hostname\n"));
 234     fprintf(stderr, _("    -f, --fqdn, --long    long host name (FQDN)\n"));
 235     fprintf(stderr, _("    -d, --domain          DNS domain name\n"));
 236     fprintf(stderr, _("    -y, --yp, --nis       NIS/YP domainname\n"));
 237 #if HAVE_AFDECnet
 238     fprintf(stderr, _("    -n, --node            DECnet node name\n"));
 239 #endif /* HAVE_AFDECnet */
 240     fprintf(stderr, _("    -F, --file            read hostname or NIS domainname from given file\n\n"));
 241     fprintf(stderr, _(
 242 "   This command can read or set the hostname or the NIS domainname. You can\n"
 243 "   also read the DNS domain or the FQDN (fully qualified domain name).\n"
 244 "   Unless you are using bind or NIS for host lookups you can change the\n"
 245 "   FQDN (Fully Qualified Domain Name) and the DNS domain name (which is\n"
 246 "   part of the FQDN) in the /etc/hosts file.\n"));
 247
 248     exit(4); /* E_USAGE */
 249 }
 250
 251
 252 int main(int argc, char **argv)
 253 {
 254     int c;
 255     char type = '\0';
 256     int option_index = 0;
 257     int what = 0;
 258     char myname[MAXHOSTNAMELEN + 1] =
 259     {0};
 260     char *file = NULL;
 261
 262     static const struct option long_options[] =
 263     {
 264         {"domain", no_argument, 0, 'd'},
 265         {"file", required_argument, 0, 'F'},
 266         {"fqdn", no_argument, 0, 'f'},
 267         {"help", no_argument, 0, 'h'},
 268         {"long", no_argument, 0, 'f'},
 269         {"short", no_argument, 0, 's'},
 270         {"version", no_argument, 0, 'V'},
 271         {"verbose", no_argument, 0, 'v'},
 272         {"alias", no_argument, 0, 'a'},
 273         {"ip-address", no_argument, 0, 'i'},
 274         {"nis", no_argument, 0, 'y'},
 275         {"yp", no_argument, 0, 'y'},
 276 #if HAVE_AFDECnet
 277         {"node", no_argument, 0, 'n'},
 278 #endif /* HAVE_AFDECnet */
 279         {0, 0, 0, 0}
 280     };
 281 #if I18N
 282     setlocale (LC_ALL, "");
 283     bindtextdomain("net-tools", "/usr/share/locale");
 284     textdomain("net-tools");
 285 #endif
 286     program_name = (rindex(argv[0], '/')) ? rindex(argv[0], '/') + 1 : argv[0];
 287
 288     if (!strcmp(program_name, "ypdomainname") ||
 289         !strcmp(program_name, "domainname") ||
 290         !strcmp(program_name, "nisdomainname"))
 291         what = 3;
 292     if (!strcmp(program_name, "dnsdomainname"))
 293         what = 2;
 294 #if HAVE_AFDECnet
 295     if (!strcmp(program_name, "nodename"))
 296         what = 4;
 297 #endif /* HAVE_AFDECnet */
 298
 299     while ((c = getopt_long(argc, argv, "adfF:h?isVvyn", long_options, &option_index)) != EOF)
 300         switch (c) {
 301         case 'd':
 302             what = 2;
 303             break;
 304         case 'a':
 305         case 'f':
 306         case 'i':
 307         case 's':
 308             what = 1;
 309             type = c;
 310             break;
 311         case 'y':
 312             what = 3;
 313             break;
 314 #if HAVE_AFDECnet
 315         case 'n':
 316             what = 4;
 317             break;
 318 #endif /* HAVE_AFDECnet */
 319         case 'F':
 320             file = optarg;
 321             break;
 322         case 'v':
 323             opt_v++;
 324             break;
 325         case 'V':
 326             version();
 327         case '?':
 328         case 'h':
 329         default:
 330             usage();
 331
 332         };
 333
 334
 335     switch (what) {
 336     case 2:
 337         if (file || (optind < argc)) {
 338             fprintf(stderr, _("%s: You can't change the DNS domain name with this command\n"), program_name);
 339             fprintf(stderr, _("\nUnless you are using bind or NIS for host lookups you can change the DNS\n"));
 340             fprintf(stderr, _("domain name (which is part of the FQDN) in the /etc/hosts file.\n"));
 341             exit(1);
 342         }
 343         type = 'd';
 344         /* NOBREAK */
 345     case 0:
 346         if (file) {
 347             setfilename(file, SETHOST);
 348             break;
 349         }
 350         if (optind < argc) {
 351             sethname(argv[optind]);
 352             break;
 353         }
 354     case 1:
 355         gethostname(myname, sizeof(myname));
 356         if (opt_v)
 357             fprintf(stderr, _("gethostname()=`%s'\n"), myname);
 358         if (!type)
 359             printf("%s\n", myname);
 360         else
 361             showhname(myname, type);
 362         break;
 363     case 3:
 364         if (file) {
 365             setfilename(file, SETDOMAIN);
 366             break;
 367         }
 368         if (optind < argc) {
 369             setdname(argv[optind]);
 370             break;
 371         }
 372         getdomainname(myname, sizeof(myname));
 373         if (opt_v)
 374             fprintf(stderr, _("getdomainname()=`%s'\n"), myname);
 375         printf("%s\n", myname);
 376         break;
 377 #if HAVE_AFDECnet
 378     case 4:
 379         if (file) {
 380             setfilename(file, SETNODE);
 381             break;
 382         }
 383         if (optind < argc) {
 384             setnname(argv[optind]);
 385             break;
 386         }
 387         getnodename(myname, sizeof(myname));
 388         if (opt_v)
 389             fprintf(stderr, _("getnodename()=`%s'\n"), myname);
 390         printf("%s\n", myname);
 391         break;
 392 #endif /* HAVE_AFDECnet */
 393     }
 394     exit(0);
 395 }