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 1.101 (2003-10-11)
  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 (major rewrite), usage.
  19  *19960120 {1.95}  Bernd Eckenfels : -y/nisdomainname - support for get/setdomainname added
  20  *19960218 {1.96}  Bernd Eckenfels : netinet/in.h added
  21  *19980629 {1.97}  Arnaldo Carvalho de Melo : gettext instead of catgets for i18n
  22  *20000213 {1.99}  Arnaldo Carvalho de Melo : fixed some i18n strings
  23  *20010404 {1.100} Arnaldo Carvalho de Melo: use setlocale
  24  *20031011 {1.101} Maik Broemme: gcc 3.x fixes (default: break)
  25  *
  26  *              This program is free software; you can redistribute it
  27  *              and/or  modify it under  the terms of  the GNU General
  28  *              Public  License as  published  by  the  Free  Software
  29  *              Foundation;  either  version 2 of the License, or  (at
  30  *              your option) any later version.
  31  */
  32 #include <stdio.h>
  33 #include <stdlib.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             break;
  83         }
  84         exit(1);
  85     }
  86 }
  87 #endif /* HAVE_AFDECnet */
  88
  89 static void sethname(char *hname)
  90 {
  91     if (opt_v)
  92         fprintf(stderr, _("Setting hostname to `%s'\n"),
  93                 hname);
  94     if (sethostname(hname, strlen(hname))) {
  95         switch (errno) {
  96         case EPERM:
  97             fprintf(stderr, _("%s: you must be root to change the host name\n"), program_name);
  98             break;
  99         case EINVAL:
 100             fprintf(stderr, _("%s: name too long\n"), program_name);
 101             break;
 102         }
 103         exit(1);
 104     };
 105 }
 106
 107 static void setdname(char *dname)
 108 {
 109     if (opt_v)
 110         fprintf(stderr, _("Setting domainname to `%s'\n"),
 111                 dname);
 112     if (setdomainname(dname, strlen(dname))) {
 113         switch (errno) {
 114         case EPERM:
 115             fprintf(stderr, _("%s: you must be root to change the domain name\n"), program_name);
 116             break;
 117         case EINVAL:
 118             fprintf(stderr, _("%s: name too long\n"), program_name);
 119             break;
 120         }
 121         exit(1);
 122     };
 123 }
 124
 125 static void showhname(char *hname, int c)
 126 {
 127     struct hostent *hp;
 128     register char *p, **alias;
 129     struct in_addr **ip;
 130
 131     if (opt_v)
 132         fprintf(stderr, _("Resolving `%s' ...\n"), hname);
 133     if (!(hp = gethostbyname(hname))) {
 134         herror(program_name);
 135         exit(1);
 136     }
 137     if (opt_v) {
 138         fprintf(stderr, _("Result: h_name=`%s'\n"),
 139                 hp->h_name);
 140
 141         alias = hp->h_aliases;
 142         while (alias[0])
 143             fprintf(stderr, _("Result: h_aliases=`%s'\n"),
 144                     *alias++);
 145
 146         ip = (struct in_addr **) hp->h_addr_list;
 147         while (ip[0])
 148             fprintf(stderr, _("Result: h_addr_list=`%s'\n"),
 149                     inet_ntoa(**ip++));
 150     }
 151     if (!(p = strchr(hp->h_name, '.')) && (c == 'd'))
 152         return;
 153
 154     switch (c) {
 155     case 'a':
 156         while (hp->h_aliases[0])
 157             printf("%s ", *hp->h_aliases++);
 158         printf("\n");
 159         break;
 160     case 'i':
 161         while (hp->h_addr_list[0])
 162             printf("%s ", inet_ntoa(*(struct in_addr *) *hp->h_addr_list++));
 163         printf("\n");
 164         break;
 165     case 'd':
 166         printf("%s\n", ++p);
 167         break;
 168     case 'f':
 169         printf("%s\n", hp->h_name);
 170         break;
 171     case 's':
 172         if (p != NULL)
 173             *p = '\0';
 174         printf("%s\n", hp->h_name);
 175         break;
 176     }
 177 }
 178
 179 static void setfilename(char *name, int what)
 180 {
 181     register FILE *fd;
 182     register char *p;
 183     char fline[MAXHOSTNAMELEN];
 184
 185     if ((fd = fopen(name, "r")) != NULL) {
 186         while (fgets(fline, sizeof(fline), fd) != NULL) {
 187             if ((p = index(fline, '\n')) != NULL)
 188                 *p = '\0';
 189             if (opt_v)
 190                 fprintf(stderr, ">> %s\n", fline);
 191             if (fline[0] == '#')
 192                 continue;
 193             switch(what) {
 194             case SETHOST:
 195                 sethname(fline);
 196                 break;
 197             case SETDOMAIN:
 198                 setdname(fline);
 199                 break;
 200 #if HAVE_AFDECnet
 201             case SETNODE:
 202                 setnname(fline);
 203                 break;
 204 #endif /* HAVE_AFDECnet */
 205             }
 206         }
 207         (void) fclose(fd);
 208     } else {
 209         fprintf(stderr, _("%s: can't open `%s'\n"),
 210                 program_name, name);
 211         exit(1);
 212     }
 213 }
 214
 215 static void version(void)
 216 {
 217     fprintf(stderr, "%s\n%s\n", Release, Version);
 218     exit(5); /* E_VERSION */
 219 }
 220
 221 static void usage(void)
 222 {
 223     fprintf(stderr, _("Usage: hostname [-v] {hostname|-F file}      set hostname (from file)\n"));
 224     fprintf(stderr, _("       domainname [-v] {nisdomain|-F file}   set NIS domainname (from file)\n"));
 225 #if HAVE_AFDECnet
 226     fprintf(stderr, _("       nodename [-v] {nodename|-F file}      set DECnet node name (from file)\n"));
 227 #endif
 228     fprintf(stderr, _("       hostname [-v] [-d|-f|-s|-a|-i|-y|-n]  display formatted name\n"));
 229     fprintf(stderr, _("       hostname [-v]                         display hostname\n\n"));
 230     fprintf(stderr, _("       hostname -V|--version|-h|--help       print info and exit\n\n"));
 231     fprintf(stderr, _("    dnsdomainname=hostname -d, {yp,nis,}domainname=hostname -y\n\n"));
 232     fprintf(stderr, _("    -s, --short           short host name\n"));
 233     fprintf(stderr, _("    -a, --alias           alias names\n"));
 234     fprintf(stderr, _("    -i, --ip-address      addresses for the hostname\n"));
 235     fprintf(stderr, _("    -f, --fqdn, --long    long host name (FQDN)\n"));
 236     fprintf(stderr, _("    -d, --domain          DNS domain name\n"));
 237     fprintf(stderr, _("    -y, --yp, --nis       NIS/YP domainname\n"));
 238 #if HAVE_AFDECnet
 239     fprintf(stderr, _("    -n, --node            DECnet node name\n"));
 240 #endif /* HAVE_AFDECnet */
 241     fprintf(stderr, _("    -F, --file            read hostname or NIS domainname from given file\n\n"));
 242     fprintf(stderr, _(
 243 "   This command can read or set the hostname or the NIS domainname. You can\n"
 244 "   also read the DNS domain or the FQDN (fully qualified domain name).\n"
 245 "   Unless you are using bind or NIS for host lookups you can change the\n"
 246 "   FQDN (Fully Qualified Domain Name) and the DNS domain name (which is\n"
 247 "   part of the FQDN) in the /etc/hosts file.\n"));
 248
 249     exit(4); /* E_USAGE */
 250 }
 251
 252
 253 int main(int argc, char **argv)
 254 {
 255     int c;
 256     char type = '\0';
 257     int option_index = 0;
 258     int what = 0;
 259     char myname[MAXHOSTNAMELEN + 1] =
 260     {0};
 261     char *file = NULL;
 262
 263     static const struct option long_options[] =
 264     {
 265         {"domain", no_argument, 0, 'd'},
 266         {"file", required_argument, 0, 'F'},
 267         {"fqdn", no_argument, 0, 'f'},
 268         {"help", no_argument, 0, 'h'},
 269         {"long", no_argument, 0, 'f'},
 270         {"short", no_argument, 0, 's'},
 271         {"version", no_argument, 0, 'V'},
 272         {"verbose", no_argument, 0, 'v'},
 273         {"alias", no_argument, 0, 'a'},
 274         {"ip-address", no_argument, 0, 'i'},
 275         {"nis", no_argument, 0, 'y'},
 276         {"yp", no_argument, 0, 'y'},
 277 #if HAVE_AFDECnet
 278         {"node", no_argument, 0, 'n'},
 279 #endif /* HAVE_AFDECnet */
 280         {0, 0, 0, 0}
 281     };
 282 #if I18N
 283     setlocale (LC_ALL, "");
 284     bindtextdomain("net-tools", "/usr/share/locale");
 285     textdomain("net-tools");
 286 #endif
 287     program_name = (rindex(argv[0], '/')) ? rindex(argv[0], '/') + 1 : argv[0];
 288
 289     if (!strcmp(program_name, "ypdomainname") ||
 290         !strcmp(program_name, "domainname") ||
 291         !strcmp(program_name, "nisdomainname"))
 292         what = 3;
 293     if (!strcmp(program_name, "dnsdomainname"))
 294         what = 2;
 295 #if HAVE_AFDECnet
 296     if (!strcmp(program_name, "nodename"))
 297         what = 4;
 298 #endif /* HAVE_AFDECnet */
 299
 300     while ((c = getopt_long(argc, argv, "adfF:h?isVvyn", long_options, &option_index)) != EOF)
 301         switch (c) {
 302         case 'd':
 303             what = 2;
 304             break;
 305         case 'a':
 306         case 'f':
 307         case 'i':
 308         case 's':
 309             what = 1;
 310             type = c;
 311             break;
 312         case 'y':
 313             what = 3;
 314             break;
 315 #if HAVE_AFDECnet
 316         case 'n':
 317             what = 4;
 318             break;
 319 #endif /* HAVE_AFDECnet */
 320         case 'F':
 321             file = optarg;
 322             break;
 323         case 'v':
 324             opt_v++;
 325             break;
 326         case 'V':
 327             version();
 328             break; // not reached
 329         case '?':
 330         case 'h':
 331         default:
 332             usage();
 333             break; // not reached
 334         };
 335
 336
 337     switch (what) {
 338     case 2:
 339         if (file || (optind < argc)) {
 340             fprintf(stderr, _("%s: You can't change the DNS domain name with this command\n"), program_name);
 341             fprintf(stderr, _("\nUnless you are using bind or NIS for host lookups you can change the DNS\n"));
 342             fprintf(stderr, _("domain name (which is part of the FQDN) in the /etc/hosts file.\n"));
 343             exit(1);
 344         }
 345         type = 'd';
 346         /* NOBREAK */
 347     case 0:
 348         if (file) {
 349             setfilename(file, SETHOST);
 350             break;
 351         }
 352         if (optind < argc) {
 353             sethname(argv[optind]);
 354             break;
 355         }
 356     case 1:
 357         gethostname(myname, sizeof(myname));
 358         if (opt_v)
 359             fprintf(stderr, _("gethostname()=`%s'\n"), myname);
 360         if (!type)
 361             printf("%s\n", myname);
 362         else
 363             showhname(myname, type);
 364         break;
 365     case 3:
 366         if (file) {
 367             setfilename(file, SETDOMAIN);
 368             break;
 369         }
 370         if (optind < argc) {
 371             setdname(argv[optind]);
 372             break;
 373         }
 374         getdomainname(myname, sizeof(myname));
 375         if (opt_v)
 376             fprintf(stderr, _("getdomainname()=`%s'\n"), myname);
 377         printf("%s\n", myname);
 378         break;
 379 #if HAVE_AFDECnet
 380     case 4:
 381         if (file) {
 382             setfilename(file, SETNODE);
 383             break;
 384         }
 385         if (optind < argc) {
 386             setnname(argv[optind]);
 387             break;
 388         }
 389         getnodename(myname, sizeof(myname));
 390         if (opt_v)
 391             fprintf(stderr, _("getnodename()=`%s'\n"), myname);
 392         printf("%s\n", myname);
 393         break;
 394 #endif /* HAVE_AFDECnet */
 395     }
 396     exit(0);
 397 }