src/hostname.c

   1 /* hostname - set or print the name of current host system
   2    Copyright (C) 1994-1997, 1999-2004 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Jim Meyering.  */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25 #include "long-options.h"
  26 #include "error.h"
  27
  28 /* The official name of this program (e.g., no `g' prefix).  */
  29 #define PROGRAM_NAME "hostname"
  30
  31 #define AUTHORS "Jim Meyering"
  32
  33 #if !defined(HAVE_SETHOSTNAME) && defined(HAVE_SYSINFO) && \
  34      defined (HAVE_SYS_SYSTEMINFO_H) && defined(HAVE_LIMITS_H)
  35 # include <sys/systeminfo.h>
  36
  37 int
  38 sethostname (name, namelen)
  39      char *name;
  40      int namelen;
  41 {
  42   /* Using sysinfo() is the SVR4 mechanism to set a hostname. */
  43   int result;
  44
  45   result = sysinfo (SI_SET_HOSTNAME, name, namelen);
  46
  47   return (result == -1 ? result : 0);
  48 }
  49
  50 # define HAVE_SETHOSTNAME 1  /* Now we have it... */
  51 #endif
  52
  53 char *xgethostname ();
  54
  55 /* The name this program was run with. */
  56 char *program_name;
  57
  58 void
  59 usage (int status)
  60 {
  61   if (status != EXIT_SUCCESS)
  62     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  63              program_name);
  64   else
  65     {
  66       printf (_("\
  67 Usage: %s [NAME]\n\
  68   or:  %s OPTION\n\
  69 Print or set the hostname of the current system.\n\
  70 \n\
  71 "),
  72              program_name, program_name);
  73       fputs (HELP_OPTION_DESCRIPTION, stdout);
  74       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  75       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  76     }
  77   exit (status);
  78 }
  79
  80 int
  81 main (int argc, char **argv)
  82 {
  83   char *hostname;
  84
  85   initialize_main (&argc, &argv);
  86   program_name = argv[0];
  87   setlocale (LC_ALL, "");
  88   bindtextdomain (PACKAGE, LOCALEDIR);
  89   textdomain (PACKAGE);
  90
  91   atexit (close_stdout);
  92
  93   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  94                       usage, AUTHORS, (char const *) NULL);
  95
  96 #ifdef HAVE_SETHOSTNAME
  97   if (argc == 2)
  98     {
  99       int err;
 100
 101       /* Set hostname to argv[1].  */
 102       err = sethostname (argv[1], strlen (argv[1]));
 103       if (err != 0)
 104         error (EXIT_FAILURE, errno, _("cannot set hostname to `%s'"), argv[1]);
 105       exit (EXIT_SUCCESS);
 106     }
 107 #else
 108   if (argc == 2)
 109     error (EXIT_FAILURE, 0,
 110            _("cannot set hostname; this system lacks the functionality"));
 111 #endif
 112
 113   if (argc <= 1)
 114     {
 115       hostname = xgethostname ();
 116       if (hostname == NULL)
 117         error (EXIT_FAILURE, errno, _("cannot determine hostname"));
 118       printf ("%s\n", hostname);
 119     }
 120   else
 121     {
 122       error (0, 0, _("too many arguments"));
 123       usage (EXIT_FAILURE);
 124     }
 125
 126   exit (EXIT_SUCCESS);
 127 }