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       mbstate_t temp_state;
  81       unsigned char buf[256];           /* Just an arbitrary value.  */
  82       const unsigned char *inbuf = (const unsigned char *) *src;
  83       size_t dummy;
  84
  85       temp_state = *data.__statep;
  86       data.__statep = &temp_state;
  87
  88       result = 0;
  89       data.__outbufend = buf + sizeof (buf);
  90
  91       do
  92         {
  93           data.__outbuf = buf;
  94
  95           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  96                                       (const unsigned char *) srcend, NULL,
  97                                       &dummy, 0, 1));
  98
  99           /* Count the number of bytes.  */
 100           result += data.__outbuf - buf;
 101         }
 102       while (status == __GCONV_FULL_OUTPUT);
 103
 104       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 105           && data.__outbuf[-1] == '\0')
 106         /* Don't count the NUL character in.  */
 107         --result;
 108     }
 109   else
 110     {
 111       /* This code is based on the safe assumption that all internal
 112          multi-byte encodings use the NUL byte only to mark the end
 113          of the string.  */
 114       size_t dummy;
 115
 116       data.__outbuf = (unsigned char *) dst;
 117       data.__outbufend = (unsigned char *) dst + len;
 118
 119       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 120                                   (const unsigned char *) srcend, NULL,
 121                                   &dummy, 0, 1));
 122
 123       /* Count the number of bytes.  */
 124       result = data.__outbuf - (unsigned char *) dst;
 125
 126       /* We have to determine whether the last character converted
 127          is the NUL character.  */
 128       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 129           && data.__outbuf[-1] == '\0')
 130         {
 131           assert (data.__outbuf != (unsigned char *) dst);
 132           assert (__mbsinit (data.__statep));
 133           *src = NULL;
 134           --result;
 135         }
 136     }
 137
 138   /* There must not be any problems with the conversion but illegal input
 139      characters.  */
 140   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 141           || status == __GCONV_ILLEGAL_INPUT
 142           || status == __GCONV_INCOMPLETE_INPUT
 143           || status == __GCONV_FULL_OUTPUT);
 144
 145   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 146       && status != __GCONV_EMPTY_INPUT)
 147     {
 148       result = (size_t) -1;
 149       __set_errno (EILSEQ);
 150     }
 151
 152   return result;
 153 }
 154 weak_alias (__wcsnrtombs, wcsnrtombs)