sysdeps/posix/gethostname.c

   1 /* Copyright (C) 1992-2024 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 <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 (char *name, size_t len)
  28 {
  29   struct utsname buf;
  30   size_t node_len;
  31
  32   if (__uname (&buf))
  33     return -1;
  34
  35   node_len = strlen (buf.nodename) + 1;
  36   memcpy (name, buf.nodename, len < node_len ? len : node_len);
  37
  38   if (node_len > len)
  39     {
  40       __set_errno (ENAMETOOLONG);
  41       return -1;
  42     }
  43   return 0;
  44 }
  45
  46 weak_alias (__gethostname, gethostname)