sysdeps/generic/_strerror.c

   1 /* Copyright (C) 1991, 93, 95, 96, 97, 98, 2000 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <libintl.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <sys/param.h>
  23 #include <stdio-common/_itoa.h>
  24
  25 #ifndef HAVE_GNU_LD
  26 # define _sys_errlist sys_errlist
  27 # define _sys_nerr sys_nerr
  28 #endif
  29
  30 /* It is critical here that we always use the `dcgettext' function for
  31    the message translation.  Since <libintl.h> only defines the macro
  32    `dgettext' to use `dcgettext' for optimizing programs this is not
  33    always guaranteed.  */
  34 #ifndef dgettext
  35 # include <locale.h>            /* We need LC_MESSAGES.  */
  36 # define dgettext(domainname, msgid) dcgettext (domainname, msgid, LC_MESSAGES)
  37 #endif
  38
  39 /* Return a string describing the errno code in ERRNUM.  */
  40 char *
  41 __strerror_r (int errnum, char *buf, size_t buflen)
  42 {
  43   if (errnum < 0 || errnum >= _sys_nerr || _sys_errlist[errnum] == NULL)
  44     {
  45       /* Buffer we use to print the number in.  For a maximum size for
  46          `int' of 8 bytes we never need more than 20 digits.  */
  47       char numbuf[21];
  48       const char *unk = _("Unknown error ");
  49       const size_t unklen = strlen (unk);
  50       char *p, *q;
  51
  52       numbuf[20] = '\0';
  53       p = _itoa_word (errnum, &numbuf[20], 10, 0);
  54
  55       /* Now construct the result while taking care for the destination
  56          buffer size.  */
  57       q = __mempcpy (buf, unk, MIN (unklen, buflen));
  58       if (unklen < buflen)
  59         memcpy (q, p, MIN ((size_t) (&numbuf[21] - p), buflen - unklen));
  60
  61       /* Terminate the string in any case.  */
  62       if (buflen > 0)
  63         buf[buflen - 1] = '\0';
  64
  65       return buf;
  66     }
  67
  68   return (char *) _(_sys_errlist[errnum]);
  69 }
  70 weak_alias (__strerror_r, strerror_r)