src/hostname.c

   1 /* hostname - set or print the name of current host system
   2    Copyright (C) 1994-1997, 1999-2005 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 /* Written by Jim Meyering.  */
  19
  20 #include <config.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26 #include "long-options.h"
  27 #include "error.h"
  28 #include "quote.h"
  29 #include "xgethostname.h"
  30
  31 /* The official name of this program (e.g., no `g' prefix).  */
  32 #define PROGRAM_NAME "hostname"
  33
  34 #define AUTHORS "Jim Meyering"
  35
  36 #if HAVE_SETHOSTNAME && !defined sethostname
  37 int sethostname ();
  38 #endif
  39
  40 #if !defined HAVE_SETHOSTNAME && defined HAVE_SYSINFO && \
  41      defined HAVE_SYS_SYSTEMINFO_H
  42 # include <sys/systeminfo.h>
  43
  44 int
  45 sethostname (char *name, size_t namelen)
  46 {
  47   /* Using sysinfo() is the SVR4 mechanism to set a hostname. */
  48   return (sysinfo (SI_SET_HOSTNAME, name, namelen) < 0 ? -1 : 0);
  49 }
  50
  51 # define HAVE_SETHOSTNAME 1  /* Now we have it... */
  52 #endif
  53
  54 /* The name this program was run with. */
  55 char *program_name;
  56
  57 void
  58 usage (int status)
  59 {
  60   if (status != EXIT_SUCCESS)
  61     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  62              program_name);
  63   else
  64     {
  65       printf (_("\
  66 Usage: %s [NAME]\n\
  67   or:  %s OPTION\n\
  68 Print or set the hostname of the current system.\n\
  69 \n\
  70 "),
  71              program_name, program_name);
  72       fputs (HELP_OPTION_DESCRIPTION, stdout);
  73       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  74       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  75     }
  76   exit (status);
  77 }
  78
  79 int
  80 main (int argc, char **argv)
  81 {
  82   char *hostname;
  83
  84   initialize_main (&argc, &argv);
  85   program_name = argv[0];
  86   setlocale (LC_ALL, "");
  87   bindtextdomain (PACKAGE, LOCALEDIR);
  88   textdomain (PACKAGE);
  89
  90   atexit (close_stdout);
  91
  92   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  93                       usage, AUTHORS, (char const *) NULL);
  94   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
  95     usage (EXIT_FAILURE);
  96
  97   if (argc == optind + 1)
  98     {
  99 #ifdef HAVE_SETHOSTNAME
 100       /* Set hostname to operand.  */
 101       char const *name = argv[optind];
 102       if (sethostname (name, strlen (name)) != 0)
 103         error (EXIT_FAILURE, errno, _("cannot set name to %s"), quote (name));
 104 #else
 105       error (EXIT_FAILURE, 0,
 106              _("cannot set hostname; this system lacks the functionality"));
 107 #endif
 108     }
 109
 110   if (argc <= optind)
 111     {
 112       hostname = xgethostname ();
 113       if (hostname == NULL)
 114         error (EXIT_FAILURE, errno, _("cannot determine hostname"));
 115       printf ("%s\n", hostname);
 116     }
 117
 118   if (optind + 1 < argc)
 119     {
 120       error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
 121       usage (EXIT_FAILURE);
 122     }
 123
 124   exit (EXIT_SUCCESS);
 125 }