wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996-2000, 2002, 2003, 2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <assert.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23 #include <gconv.h>
  24 #include <wchar.h>
  25 #include <wcsmbsload.h>
  26
  27 #include <sysdep.h>
  28
  29 #ifndef EILSEQ
  30 # define EILSEQ EINVAL
  31 #endif
  32
  33
  34 /* This is the private state used if PS is NULL.  */
  35 static mbstate_t state;
  36
  37 /* This is a non-standard function but it is very useful in the
  38    implementation of stdio because we have to deal with unterminated
  39    buffers.  At most NWC wide character will be converted.  */
  40 size_t
  41 __wcsnrtombs (dst, src, nwc, len, ps)
  42      char *dst;
  43      const wchar_t **src;
  44      size_t nwc;
  45      size_t len;
  46      mbstate_t *ps;
  47 {
  48   struct __gconv_step_data data;
  49   const wchar_t *srcend;
  50   int status;
  51   size_t result;
  52   struct __gconv_step *tomb;
  53   const struct gconv_fcts *fcts;
  54
  55   /* Tell where we want the result.  */
  56   data.__invocation_counter = 0;
  57   data.__internal_use = 1;
  58   data.__flags = __GCONV_IS_LAST;
  59   data.__statep = ps ?: &state;
  60   data.__trans = NULL;
  61
  62   if (nwc == 0)
  63     return 0;
  64   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  65
  66   /* Get the conversion functions.  */
  67   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  68
  69   /* Get the structure with the function pointers.  */
  70   tomb = fcts->tomb;
  71   __gconv_fct fct = tomb->__fct;
  72 #ifdef PTR_DEMANGLE
  73   if (tomb->__shlib_handle != NULL)
  74     PTR_DEMANGLE (fct);
  75 #endif
  76
  77   /* We have to handle DST == NULL special.  */
  78   if (dst == NULL)
  79     {
  80       unsigned char buf[256];           /* Just an arbitrary value.  */
  81       const unsigned char *inbuf = (const unsigned char *) *src;
  82       size_t dummy;
  83
  84       result = 0;
  85       data.__outbufend = buf + sizeof (buf);
  86
  87       do
  88         {
  89           data.__outbuf = buf;
  90
  91           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  92                                       (const unsigned char *) srcend, NULL,
  93                                       &dummy, 0, 1));
  94
  95           /* Count the number of bytes.  */
  96           result += data.__outbuf - buf;
  97         }
  98       while (status == __GCONV_FULL_OUTPUT);
  99
 100       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 101           && data.__outbuf[-1] == '\0')
 102         /* Don't count the NUL character in.  */
 103         --result;
 104     }
 105   else
 106     {
 107       /* This code is based on the safe assumption that all internal
 108          multi-byte encodings use the NUL byte only to mark the end
 109          of the string.  */
 110       size_t dummy;
 111
 112       data.__outbuf = (unsigned char *) dst;
 113       data.__outbufend = (unsigned char *) dst + len;
 114
 115       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 116                                   (const unsigned char *) srcend, NULL,
 117                                   &dummy, 0, 1));
 118
 119       /* Count the number of bytes.  */
 120       result = data.__outbuf - (unsigned char *) dst;
 121
 122       /* We have to determine whether the last character converted
 123          is the NUL character.  */
 124       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 125           && data.__outbuf[-1] == '\0')
 126         {
 127           assert (data.__outbuf != (unsigned char *) dst);
 128           assert (__mbsinit (data.__statep));
 129           *src = NULL;
 130           --result;
 131         }
 132     }
 133
 134   /* There must not be any problems with the conversion but illegal input
 135      characters.  */
 136   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 137           || status == __GCONV_ILLEGAL_INPUT
 138           || status == __GCONV_INCOMPLETE_INPUT
 139           || status == __GCONV_FULL_OUTPUT);
 140
 141   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 142       && status != __GCONV_EMPTY_INPUT)
 143     {
 144       result = (size_t) -1;
 145       __set_errno (EILSEQ);
 146     }
 147
 148   return result;
 149 }
 150 weak_alias (__wcsnrtombs, wcsnrtombs)