string/xpg-strerror.c

   1 /* Copyright (C) 1991, 1993, 1995-1998, 2000, 2002, 2004, 2010, 2011
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <sys/param.h>
  24
  25
  26 /* Fill buf with a string describing the errno code in ERRNUM.  */
  27 int
  28 __xpg_strerror_r (int errnum, char *buf, size_t buflen)
  29 {
  30   const char *estr = __strerror_r (errnum, buf, buflen);
  31   size_t estrlen = strlen (estr);
  32
  33   if (estr == buf)
  34     {
  35       assert (errnum < 0 || errnum >= _sys_nerr_internal
  36               || _sys_errlist_internal[errnum] == NULL);
  37       return EINVAL;
  38     }
  39   assert (errnum >= 0 && errnum < _sys_nerr_internal
  40           && _sys_errlist_internal[errnum] != NULL);
  41
  42   /* Terminate the string in any case.  */
  43   if (buflen > 0)
  44     *((char *) __mempcpy (buf, estr, MIN (buflen - 1, estrlen))) = '\0';
  45
  46   return buflen <= estrlen ? ERANGE : 0;
  47 }