wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2000 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
  53   /* Tell where we want the result.  */
  54   data.__invocation_counter = 0;
  55   data.__internal_use = 1;
  56   data.__flags = __GCONV_IS_LAST;
  57   data.__statep = ps ?: &state;
  58   data.__trans = NULL;
  59
  60   if (nwc == 0)
  61     return 0;
  62   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  63
  64   /* Make sure we use the correct function.  */
  65   update_conversion_ptrs ();
  66
  67   /* Get the structure with the function pointers.  */
  68   tomb = __wcsmbs_gconv_fcts.tomb;
  69
  70   /* We have to handle DST == NULL special.  */
  71   if (dst == NULL)
  72     {
  73       unsigned char buf[256];           /* Just an arbitrary value.  */
  74       const wchar_t *inbuf = *src;
  75       size_t dummy;
  76
  77       result = 0;
  78       data.__outbufend = buf + sizeof (buf);
  79
  80       do
  81         {
  82           data.__outbuf = buf;
  83
  84           status = DL_CALL_FCT (tomb->__fct,
  85                                 (tomb, &data, (const unsigned char **) &inbuf,
  86                                  (const unsigned char *) srcend, NULL,
  87                                  &dummy, 0, 1));
  88
  89           /* Count the number of bytes.  */
  90           result += data.__outbuf - buf;
  91         }
  92       while (status == __GCONV_FULL_OUTPUT);
  93
  94       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  95           && data.__outbuf[-1] == '\0')
  96         /* Don't count the NUL character in.  */
  97         --result;
  98     }
  99   else
 100     {
 101       /* This code is based on the safe assumption that all internal
 102          multi-byte encodings use the NUL byte only to mark the end
 103          of the string.  */
 104       size_t dummy;
 105
 106       data.__outbuf = dst;
 107       data.__outbufend = dst + len;
 108
 109       status = DL_CALL_FCT (tomb->__fct,
 110                             (tomb, &data, (const unsigned char **) src,
 111                              (const unsigned char *) srcend, NULL,
 112                              &dummy, 0, 1));
 113
 114       /* Count the number of bytes.  */
 115       result = data.__outbuf - (unsigned char *) dst;
 116
 117       /* We have to determine whether the last character converted
 118          is the NUL character.  */
 119       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 120           && data.__outbuf[-1] == '\0')
 121         {
 122           assert (data.__outbuf != (unsigned char *) dst);
 123           assert (__mbsinit (data.__statep));
 124           *src = NULL;
 125           --result;
 126         }
 127     }
 128
 129   /* There must not be any problems with the conversion but illegal input
 130      characters.  */
 131   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 132           || status == __GCONV_ILLEGAL_INPUT
 133           || status == __GCONV_INCOMPLETE_INPUT
 134           || status == __GCONV_FULL_OUTPUT);
 135
 136   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 137       && status != __GCONV_EMPTY_INPUT)
 138     {
 139       result = (size_t) -1;
 140       __set_errno (EILSEQ);
 141     }
 142
 143   return result;
 144 }
 145 weak_alias (__wcsnrtombs, wcsnrtombs)