wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996,1997,1998,1999,2000,2002 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 <dlfcn.h>
  21 #include <errno.h>
  22 #include <gconv.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <assert.h>
  27
  28 #ifndef EILSEQ
  29 # define EILSEQ EINVAL
  30 #endif
  31
  32
  33 /* This is the private state used if PS is NULL.  */
  34 static mbstate_t state;
  35
  36 /* This is a non-standard function but it is very useful in the
  37    implementation of stdio because we have to deal with unterminated
  38    buffers.  At most NWC wide character will be converted.  */
  39 size_t
  40 __wcsnrtombs (dst, src, nwc, len, ps)
  41      char *dst;
  42      const wchar_t **src;
  43      size_t nwc;
  44      size_t len;
  45      mbstate_t *ps;
  46 {
  47   struct __gconv_step_data data;
  48   const wchar_t *srcend;
  49   int status;
  50   size_t result;
  51   struct __gconv_step *tomb;
  52   const struct gconv_fcts *fcts;
  53
  54   /* Tell where we want the result.  */
  55   data.__invocation_counter = 0;
  56   data.__internal_use = 1;
  57   data.__flags = __GCONV_IS_LAST;
  58   data.__statep = ps ?: &state;
  59   data.__trans = NULL;
  60
  61   if (nwc == 0)
  62     return 0;
  63   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  64
  65   /* Get the conversion functions.  */
  66   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  67
  68   /* Get the structure with the function pointers.  */
  69   tomb = fcts->tomb;
  70
  71   /* We have to handle DST == NULL special.  */
  72   if (dst == NULL)
  73     {
  74       unsigned char buf[256];           /* Just an arbitrary value.  */
  75       const wchar_t *inbuf = *src;
  76       size_t dummy;
  77
  78       result = 0;
  79       data.__outbufend = buf + sizeof (buf);
  80
  81       do
  82         {
  83           data.__outbuf = buf;
  84
  85           status = DL_CALL_FCT (tomb->__fct,
  86                                 (tomb, &data, (const unsigned char **) &inbuf,
  87                                  (const unsigned char *) srcend, NULL,
  88                                  &dummy, 0, 1));
  89
  90           /* Count the number of bytes.  */
  91           result += data.__outbuf - buf;
  92         }
  93       while (status == __GCONV_FULL_OUTPUT);
  94
  95       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  96           && data.__outbuf[-1] == '\0')
  97         /* Don't count the NUL character in.  */
  98         --result;
  99     }
 100   else
 101     {
 102       /* This code is based on the safe assumption that all internal
 103          multi-byte encodings use the NUL byte only to mark the end
 104          of the string.  */
 105       size_t dummy;
 106
 107       data.__outbuf = dst;
 108       data.__outbufend = dst + len;
 109
 110       status = DL_CALL_FCT (tomb->__fct,
 111                             (tomb, &data, (const unsigned char **) src,
 112                              (const unsigned char *) srcend, NULL,
 113                              &dummy, 0, 1));
 114
 115       /* Count the number of bytes.  */
 116       result = data.__outbuf - (unsigned char *) dst;
 117
 118       /* We have to determine whether the last character converted
 119          is the NUL character.  */
 120       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 121           && data.__outbuf[-1] == '\0')
 122         {
 123           assert (data.__outbuf != (unsigned char *) dst);
 124           assert (__mbsinit (data.__statep));
 125           *src = NULL;
 126           --result;
 127         }
 128     }
 129
 130   /* There must not be any problems with the conversion but illegal input
 131      characters.  */
 132   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 133           || status == __GCONV_ILLEGAL_INPUT
 134           || status == __GCONV_INCOMPLETE_INPUT
 135           || status == __GCONV_FULL_OUTPUT);
 136
 137   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 138       && status != __GCONV_EMPTY_INPUT)
 139     {
 140       result = (size_t) -1;
 141       __set_errno (EILSEQ);
 142     }
 143
 144   return result;
 145 }
 146 weak_alias (__wcsnrtombs, wcsnrtombs)