1  /* Copyright (C) 1991-2023 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 Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the 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     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <unistd.h>
      19  #include <hurd.h>
      20  #include "hurdhost.h"
      21  
      22  /* Return the current machine's Internet number.  */
      23  long int
      24  gethostid (void)
      25  {
      26    /* The hostid is just the contents of the file /etc/hostid,
      27       kept as text of hexadecimal digits.  */
      28    /* XXX this is supposed to come from the hardware serial number */
      29    char buf[8];
      30    ssize_t n = _hurd_get_host_config ("/etc/hostid", buf, sizeof buf);
      31    if (n < 0)
      32      return -1;
      33    return strtol (buf, NULL, 16);
      34  }