sysdeps/mach/hurd/sethostid.c

   1 /* Copyright (C) 1993, 1996 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library 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 GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include "hurdhost.h"
  23 #include "../stdio-common/_itoa.h"
  24
  25 /* Set the current machine's Internet number to ID.
  26    This call is restricted to the super-user.  */
  27 int
  28 DEFUN(sethostid, (id), long int id)
  29 {
  30   char buf[8], *bp;
  31   ssize_t n;
  32
  33   /* The hostid is kept in the file /etc/hostid,
  34      eight characters of upper-case hexadecimal.  */
  35
  36   bp = _itoa_word (id, &buf[sizeof buf], 16, 1);
  37   while (bp > buf)
  38     *--bp = '0';
  39
  40   n = _hurd_set_host_config ("/etc/hostid", buf, sizeof buf);
  41   return n < 0 ? -1 : 0;
  42 }