sysdeps/posix/gethostname.c

   1 /* Copyright (C) 1992-2014 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <sys/utsname.h>
  22
  23 /* Put the name of the current host in no more than LEN bytes of NAME.
  24    The result is null-terminated if LEN is large enough for the full
  25    name and the terminator.  */
  26 int
  27 __gethostname (name, len)
  28      char *name;
  29      size_t len;
  30 {
  31   struct utsname buf;
  32   size_t node_len;
  33
  34   if (uname (&buf))
  35     return -1;
  36
  37   node_len = strlen (buf.nodename) + 1;
  38   memcpy (name, buf.nodename, len < node_len ? len : node_len);
  39
  40   if (node_len > len)
  41     {
  42       __set_errno (ENAMETOOLONG);
  43       return -1;
  44     }
  45   return 0;
  46 }
  47
  48 weak_alias (__gethostname, gethostname)