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]
   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  *
  25  *              This program is free software; you can redistribute it
  26  *              and/or  modify it under  the terms of  the GNU General
  27  *              Public  License as  published  by  the  Free  Software
  28  *              Foundation;  either  version 2 of the License, or  (at
  29  *              your option) any later version.
  30  */
  31 #include <stdio.h>
  32 #include <unistd.h>
  33 #include <getopt.h>
  34 #include <string.h>
  35 #include <netdb.h>
  36 #include <errno.h>
  37 #include <sys/param.h>
  38 #include <netinet/in.h>
  39 #include <arpa/inet.h>
  40 #include "config.h"
  41 #include "version.h"
  42 #include "../intl.h"
  43
  44 char *Release = RELEASE,
  45      *Version = "hostname 1.97 (1998-06-29)";
  46
  47 static char *program_name;
  48 static int  opt_v;
  49
  50 static void sethname(char *);
  51 static void setdname(char *);
  52 static void showhname(char *, int);
  53 static void usage(void);
  54 static void version(void);
  55 static void setfilename(char *,int);
  56
  57 #define SETHOST         1
  58 #define SETDOMAIN       2
  59
  60 static void sethname(char *hname)
  61 {
  62         if (opt_v)
  63                 fprintf(stderr,_("Setting hostname to `%s'\n"),
  64                         hname);
  65         if(sethostname(hname, strlen(hname))) {
  66                 switch(errno) {
  67                         case EPERM:
  68                                 fprintf(stderr,_("%s: you must be root to change the host name\n"), program_name);
  69                                 break;
  70                         case EINVAL:
  71                                 fprintf(stderr,_("%s: name too long\n"), program_name);
  72                                 break;
  73                         default:
  74                 }
  75                 exit(1);
  76         };
  77 }
  78
  79 static void setdname(char *dname)
  80 {
  81         if (opt_v)
  82                 fprintf(stderr,_("Setting domainname to `%s'\n"),
  83                         dname);
  84         if(setdomainname(dname, strlen(dname))) {
  85                 switch(errno) {
  86                         case EPERM:
  87                                 fprintf(stderr,_("%s: you must be root to change the domain name\n"), program_name);
  88                                 break;
  89                         case EINVAL:
  90                                 fprintf(stderr,_("%s: name too long\n"), program_name);
  91                                 break;
  92                         default:
  93                 }
  94                 exit(1);
  95         };
  96 }
  97
  98 static void showhname(char *hname, int c)
  99 {
 100         struct hostent *hp;
 101         register char *p,**alias;
 102         struct in_addr **ip;
 103
 104         if (opt_v)
 105                 fprintf(stderr,_("Resolving `%s' ...\n"),hname);
 106         if (!(hp = gethostbyname(hname))) {
 107                 herror(program_name);
 108                 exit(1);
 109         }
 110
 111         if (opt_v) {
 112                 fprintf(stderr,_("Result: h_name=`%s'\n"),
 113                         hp->h_name);
 114
 115                 alias=hp->h_aliases;
 116                 while(alias[0])
 117                         fprintf(stderr,_("Result: h_aliases=`%s'\n"),
 118                                 *alias++);
 119
 120                 ip=(struct in_addr **)hp->h_addr_list;
 121                 while(ip[0])
 122                         fprintf(stderr,_("Result: h_addr_list=`%s'\n"),
 123                                 inet_ntoa(**ip++));
 124         }
 125
 126         if (!(p = strchr(hp->h_name, '.')) && (c == 'd')) return;
 127
 128         switch(c) {
 129                 case 'a':
 130                         while (hp->h_aliases[0])
 131                                 printf("%s ", *hp->h_aliases++);
 132                         printf("\n");
 133                         break;
 134                 case 'i':
 135                         while (hp->h_addr_list[0])
 136                                 printf("%s ", inet_ntoa(*(struct in_addr *) * hp->h_addr_list++));
 137                         printf("\n");
 138                         break;
 139                 case 'd':
 140                         printf("%s\n", ++p);
 141                         break;
 142                 case 'f':
 143                         printf("%s\n", hp->h_name);
 144                         break;
 145                 case 's':
 146                         if (p != NULL) *p = '\0';
 147                         printf("%s\n", hp->h_name);
 148                         break;
 149                 default:
 150         }
 151 }
 152
 153 static void setfilename(char * name,int what)
 154 {
 155   register FILE *fd;
 156   register char *p;
 157   char fline[MAXHOSTNAMELEN];
 158
 159   if ((fd = fopen(name, "r")) != NULL) {
 160         while (fgets(fline, sizeof(fline), fd) != NULL) {
 161                 if ((p = index(fline, '\n')) != NULL)
 162                         *p = '\0';
 163                         if (opt_v) fprintf(stderr, ">> %s\n", fline);
 164                         if (fline[0] == '#')
 165                                 continue;
 166                         if (what == SETHOST) {
 167                                 sethname(fline);
 168                         } else {
 169                                 setdname(fline);
 170                         }
 171         }
 172         (void) fclose(fd);
 173   } else {
 174         fprintf(stderr,_("%s: can't open `%s'\n"),
 175                         program_name, optarg);
 176         exit(1);
 177   }
 178 }
 179
 180 static void version(void)
 181 {
 182         fprintf(stderr,"%s\n%s\n",Release,Version);
 183         exit(-1);
 184 }
 185
 186 static void usage(void)
 187 {
 188         fprintf(stderr,_("Usage: hostname [-v] {hostname|-F file}      set hostname (from file)\n"));
 189         fprintf(stderr,_("       domainname [-v] {nisdomain|-F file}   set NIS domainname (from file)\n"));
 190         fprintf(stderr,_("       hostname [-v] [-d|-f|-s|-a|-i|-y]     display formated name\n"));
 191         fprintf(stderr,_("       hostname [-v]                         display hostname\n\n"));
 192         fprintf(stderr,_("       hostname -V|--version|-h|--help       print info and exit\n\n"));
 193         fprintf(stderr,_("    dnsdomainname=hostname -d, {yp,nis,}domainname=hostname -y\n\n"));
 194         fprintf(stderr,_("    -s, --short           short host name\n"));
 195         fprintf(stderr,_("    -a, --alias           alias names\n"));
 196         fprintf(stderr,_("    -i, --ip-address      addresses for the hostname\n"));
 197         fprintf(stderr,_("    -f, --fqdn, --long    long host name (FQDN)\n"));
 198         fprintf(stderr,_("    -d, --domain          DNS domain name\n"));
 199         fprintf(stderr,_("    -y, --yp, --nis       NIS/YP domainname\n"));
 200         fprintf(stderr,_("    -F, --file            read hostname or nis domainname from given File\n\n"));
 201         fprintf(stderr,_("   This comand can get or set the hostname or the NIS domainname. You can\n"));
 202         fprintf(stderr,_("   also get the DNS domain or the FQDN (fully qualified domain name).\n"));
 203         fprintf(stderr,_("   Unless you are using bind or NIS for host lookups you can change the\n"));
 204         fprintf(stderr,_("   FQDN (Fully Qualified Domain Name) and the DNS domain name (which is\n"));
 205         fprintf(stderr,_("   part of the FQDN) in the /etc/hosts file.\n"));
 206         exit(-1);
 207 }
 208
 209
 210 int main(int argc, char **argv)
 211 {
 212         int c;
 213         char type='\0';
 214         int option_index = 0;
 215         int what = 0;
 216         char myname[MAXHOSTNAMELEN+1] = { 0 };
 217         char *file=NULL;
 218
 219         static const struct option long_options[] =
 220         {
 221                 {"domain", no_argument, 0, 'd'},
 222                 {"file", required_argument, 0, 'F'},
 223                 {"fqdn", no_argument, 0, 'f'},
 224                 {"help", no_argument, 0, 'h'},
 225                 {"long", no_argument, 0, 'f'},
 226                 {"short", no_argument, 0, 's'},
 227                 {"version", no_argument, 0, 'V'},
 228                 {"verbose", no_argument, 0, 'v'},
 229                 {"alias", no_argument, 0, 'a'},
 230                 {"ip-address", no_argument, 0, 'i'},
 231                 {"nis", no_argument, 0, 'y'},
 232                 {"yp", no_argument, 0, 'y'},
 233                 {0, 0, 0, 0}
 234         };
 235 #if I18N
 236         bindtextdomain("net-tools", "/usr/share/locale");
 237         textdomain("net-tools");
 238 #endif
 239         program_name = (rindex(argv[0], '/')) ? rindex(argv[0], '/') + 1 : argv[0];
 240
 241         if (!strcmp(program_name,"ypdomainname") ||
 242             !strcmp(program_name,"domainname")   ||
 243             !strcmp(program_name,"nisdomainname"))
 244                 what = 3;
 245         if (!strcmp(program_name,"dnsdomainname"))
 246                 what = 2;
 247
 248         while((c = getopt_long(argc, argv, "adfF:h?isVvy", long_options, &option_index)) != EOF)
 249         switch(c)
 250         {
 251                 case 'd':
 252                         what = 2;
 253                         break;
 254                 case 'a':
 255                 case 'f':
 256                 case 'i':
 257                 case 's':
 258                         what = 1;
 259                         type=c;
 260                         break;
 261                 case 'y':
 262                         what = 3;
 263                         break;
 264                 case 'F':
 265                         file=optarg;
 266                         break;
 267                 case 'v':
 268                         opt_v++;
 269                         break;
 270                 case 'V':
 271                         version();
 272                 case '?':
 273                 case 'h':
 274                 default:
 275                         usage();
 276
 277         };
 278
 279
 280         switch(what) {
 281                 case 2:
 282                         if (file || (optind < argc)) {
 283                                 fprintf(stderr,_("%s: You can't change the DNS domain name with this command\n"), program_name);
 284                                 fprintf(stderr,_("\nUnless you are using bind or NIS for host lookups you can change the DNS\n"));
 285                                 fprintf(stderr,_("domain name (which is part of the FQDN) in the /etc/hosts file.\n"));
 286                                 exit(1);
 287                         }
 288                         type='d';
 289                         /* NOBREAK */
 290                 case 0:
 291                         if (file) {
 292                                 setfilename(file,SETHOST);
 293                                 break;
 294                         }
 295                         if (optind < argc) {
 296                                 sethname(argv[optind]);
 297                                 break;
 298                         }
 299                 case 1:
 300                         gethostname(myname, sizeof(myname));
 301                         if (opt_v)
 302                                 fprintf(stderr,_("gethostname()=`%s'\n"),myname);
 303                         if (!type)
 304                                 printf("%s\n",myname);
 305                         else
 306                                 showhname(myname,type);
 307                         break;
 308                 case 3:
 309                         if (file) {
 310                                 setfilename(file,SETDOMAIN);
 311                                 break;
 312                         }
 313                         if (optind < argc) {
 314                                 setdname(argv[optind]);
 315                                 break;
 316                         }
 317                         getdomainname(myname,sizeof(myname));
 318                         if (opt_v)
 319                                 fprintf(stderr,_("getdomainname()=`%s'\n"),myname);
 320                         printf("%s\n",myname);
 321                         break;
 322         }
 323         exit(0);
 324 }