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 <getopt.h>
  36 #include <string.h>
  37 #include <netdb.h>
  38 #include <errno.h>
  39 #include <sys/param.h>
  40 #include <netinet/in.h>
  41 #include <arpa/inet.h>
  42 #include "config.h"
  43 #include "version.h"
  44 #include "../intl.h"
  45
  46 #if HAVE_AFDECnet
  47 #include <netdnet/dn.h>
  48 #endif
  49
  50 char *Release = RELEASE, *Version = "hostname 1.100 (2001-04-14)";
  51
  52 static char *program_name;
  53 static int opt_v;
  54
  55 static void sethname(char *);
  56 static void setdname(char *);
  57 static void showhname(char *, int);
  58 static void usage(void);
  59 static void version(void);
  60 static void setfilename(char *, int);
  61
  62 #define SETHOST         1
  63 #define SETDOMAIN       2
  64 #define SETNODE         3
  65
  66 #if HAVE_AFDECnet
  67 static void setnname(char *nname)
  68 {
  69     if (opt_v)
  70         fprintf(stderr, _("Setting nodename to `%s'\n"),
  71                 nname);
  72     if (setnodename(nname, strlen(nname))) {
  73         switch(errno) {
  74         case EPERM:
  75             fprintf(stderr, _("%s: you must be root to change the node name\n"), program_name);
  76             break;
  77         case EINVAL:
  78             fprintf(stderr, _("%s: name too long\n"), program_name);
  79             break;
  80         default:
  81         }
  82         exit(1);
  83     }
  84 }
  85 #endif /* HAVE_AFDECnet */
  86
  87 static void sethname(char *hname)
  88 {
  89     if (opt_v)
  90         fprintf(stderr, _("Setting hostname to `%s'\n"),
  91                 hname);
  92     if (sethostname(hname, strlen(hname))) {
  93         switch (errno) {
  94         case EPERM:
  95             fprintf(stderr, _("%s: you must be root to change the host name\n"), program_name);
  96             break;
  97         case EINVAL:
  98             fprintf(stderr, _("%s: name too long\n"), program_name);
  99             break;
 100         default:
 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         default:
 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     default:
 177     }
 178 }
 179
 180 static void setfilename(char *name, int what)
 181 {
 182     register FILE *fd;
 183     register char *p;
 184     char fline[MAXHOSTNAMELEN];
 185
 186     if ((fd = fopen(name, "r")) != NULL) {
 187         while (fgets(fline, sizeof(fline), fd) != NULL) {
 188             if ((p = index(fline, '\n')) != NULL)
 189                 *p = '\0';
 190             if (opt_v)
 191                 fprintf(stderr, ">> %s\n", fline);
 192             if (fline[0] == '#')
 193                 continue;
 194             switch(what) {
 195             case SETHOST:
 196                 sethname(fline);
 197                 break;
 198             case SETDOMAIN:
 199                 setdname(fline);
 200                 break;
 201 #if HAVE_AFDECnet
 202             case SETNODE:
 203                 setnname(fline);
 204                 break;
 205 #endif /* HAVE_AFDECnet */
 206             }
 207         }
 208         (void) fclose(fd);
 209     } else {
 210         fprintf(stderr, _("%s: can't open `%s'\n"),
 211                 program_name, name);
 212         exit(1);
 213     }
 214 }
 215
 216 static void version(void)
 217 {
 218     fprintf(stderr, "%s\n%s\n", Release, Version);
 219     exit(5); /* E_VERSION */
 220 }
 221
 222 static void usage(void)
 223 {
 224     fprintf(stderr, _("Usage: hostname [-v] {hostname|-F file}      set hostname (from file)\n"));
 225     fprintf(stderr, _("       domainname [-v] {nisdomain|-F file}   set NIS domainname (from file)\n"));
 226 #if HAVE_AFDECnet
 227     fprintf(stderr, _("       nodename [-v] {nodename|-F file}      set DECnet node name (from file)\n"));
 228 #endif
 229     fprintf(stderr, _("       hostname [-v] [-d|-f|-s|-a|-i|-y|-n]  display formatted name\n"));
 230     fprintf(stderr, _("       hostname [-v]                         display hostname\n\n"));
 231     fprintf(stderr, _("       hostname -V|--version|-h|--help       print info and exit\n\n"));
 232     fprintf(stderr, _("    dnsdomainname=hostname -d, {yp,nis,}domainname=hostname -y\n\n"));
 233     fprintf(stderr, _("    -s, --short           short host name\n"));
 234     fprintf(stderr, _("    -a, --alias           alias names\n"));
 235     fprintf(stderr, _("    -i, --ip-address      addresses for the hostname\n"));
 236     fprintf(stderr, _("    -f, --fqdn, --long    long host name (FQDN)\n"));
 237     fprintf(stderr, _("    -d, --domain          DNS domain name\n"));
 238     fprintf(stderr, _("    -y, --yp, --nis       NIS/YP domainname\n"));
 239 #if HAVE_AFDECnet
 240     fprintf(stderr, _("    -n, --node            DECnet node name\n"));
 241 #endif /* HAVE_AFDECnet */
 242     fprintf(stderr, _("    -F, --file            read hostname or NIS domainname from given file\n\n"));
 243     fprintf(stderr, _(
 244 "   This command can read or set the hostname or the NIS domainname. You can\n"
 245 "   also read the DNS domain or the FQDN (fully qualified domain name).\n"
 246 "   Unless you are using bind or NIS for host lookups you can change the\n"
 247 "   FQDN (Fully Qualified Domain Name) and the DNS domain name (which is\n"
 248 "   part of the FQDN) in the /etc/hosts file.\n"));
 249
 250     exit(4); /* E_USAGE */
 251 }
 252
 253
 254 int main(int argc, char **argv)
 255 {
 256     int c;
 257     char type = '\0';
 258     int option_index = 0;
 259     int what = 0;
 260     char myname[MAXHOSTNAMELEN + 1] =
 261     {0};
 262     char *file = NULL;
 263
 264     static const struct option long_options[] =
 265     {
 266         {"domain", no_argument, 0, 'd'},
 267         {"file", required_argument, 0, 'F'},
 268         {"fqdn", no_argument, 0, 'f'},
 269         {"help", no_argument, 0, 'h'},
 270         {"long", no_argument, 0, 'f'},
 271         {"short", no_argument, 0, 's'},
 272         {"version", no_argument, 0, 'V'},
 273         {"verbose", no_argument, 0, 'v'},
 274         {"alias", no_argument, 0, 'a'},
 275         {"ip-address", no_argument, 0, 'i'},
 276         {"nis", no_argument, 0, 'y'},
 277         {"yp", no_argument, 0, 'y'},
 278 #if HAVE_AFDECnet
 279         {"node", no_argument, 0, 'n'},
 280 #endif /* HAVE_AFDECnet */
 281         {0, 0, 0, 0}
 282     };
 283 #if I18N
 284     setlocale (LC_ALL, "");
 285     bindtextdomain("net-tools", "/usr/share/locale");
 286     textdomain("net-tools");
 287 #endif
 288     program_name = (rindex(argv[0], '/')) ? rindex(argv[0], '/') + 1 : argv[0];
 289
 290     if (!strcmp(program_name, "ypdomainname") ||
 291         !strcmp(program_name, "domainname") ||
 292         !strcmp(program_name, "nisdomainname"))
 293         what = 3;
 294     if (!strcmp(program_name, "dnsdomainname"))
 295         what = 2;
 296 #if HAVE_AFDECnet
 297     if (!strcmp(program_name, "nodename"))
 298         what = 4;
 299 #endif /* HAVE_AFDECnet */
 300
 301     while ((c = getopt_long(argc, argv, "adfF:h?isVvyn", long_options, &option_index)) != EOF)
 302         switch (c) {
 303         case 'd':
 304             what = 2;
 305             break;
 306         case 'a':
 307         case 'f':
 308         case 'i':
 309         case 's':
 310             what = 1;
 311             type = c;
 312             break;
 313         case 'y':
 314             what = 3;
 315             break;
 316 #if HAVE_AFDECnet
 317         case 'n':
 318             what = 4;
 319             break;
 320 #endif /* HAVE_AFDECnet */
 321         case 'F':
 322             file = optarg;
 323             break;
 324         case 'v':
 325             opt_v++;
 326             break;
 327         case 'V':
 328             version();
 329         case '?':
 330         case 'h':
 331         default:
 332             usage();
 333
 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 }