wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999   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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <gconv.h>
  22 #include <wchar.h>
  23 #include <wcsmbsload.h>
  24
  25 #include <assert.h>
  26
  27 #ifndef EILSEQ
  28 # define EILSEQ EINVAL
  29 #endif
  30
  31
  32 /* This is the private state used if PS is NULL.  */
  33 static mbstate_t state;
  34
  35 /* This is a non-standard function but it is very useful in the
  36    implementation of stdio because we have to deal with unterminated
  37    buffers.  At most NWC wide character will be converted.  */
  38 size_t
  39 __wcsnrtombs (dst, src, nwc, len, ps)
  40      char *dst;
  41      const wchar_t **src;
  42      size_t nwc;
  43      size_t len;
  44      mbstate_t *ps;
  45 {
  46   struct __gconv_step_data data;
  47   const wchar_t *srcend;
  48   int status;
  49   size_t result;
  50   struct __gconv_step *tomb;
  51
  52   /* Tell where we want the result.  */
  53   data.__invocation_counter = 0;
  54   data.__internal_use = 1;
  55   data.__is_last = 1;
  56   data.__statep = ps ?: &state;
  57
  58   if (nwc == 0)
  59     return 0;
  60   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  61
  62   /* Make sure we use the correct function.  */
  63   update_conversion_ptrs ();
  64
  65   /* Get the structure with the function pointers.  */
  66   tomb = __wcsmbs_gconv_fcts.tomb;
  67
  68   /* We have to handle DST == NULL special.  */
  69   if (dst == NULL)
  70     {
  71       unsigned char buf[256];           /* Just an arbitrary value.  */
  72       const wchar_t *inbuf = *src;
  73       size_t dummy;
  74
  75       result = 0;
  76       data.__outbufend = buf + sizeof (buf);
  77
  78       do
  79         {
  80           data.__outbuf = buf;
  81
  82           status = (*tomb->__fct) (__wcsmbs_gconv_fcts.tomb, &data,
  83                                    (const unsigned char **) &inbuf,
  84                                    (const unsigned char *) srcend, &dummy, 0);
  85
  86           /* Count the number of bytes.  */
  87           result += data.__outbuf - buf;
  88         }
  89       while (status == __GCONV_FULL_OUTPUT);
  90
  91       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  92           && data.__outbuf[-1] == '\0')
  93         /* Don't count the NUL character in.  */
  94         --result;
  95     }
  96   else
  97     {
  98       /* This code is based on the safe assumption that all internal
  99          multi-byte encodings use the NUL byte only to mark the end
 100          of the string.  */
 101       size_t dummy;
 102
 103       data.__outbuf = dst;
 104       data.__outbufend = dst + len;
 105
 106       status = (*tomb->__fct) (__wcsmbs_gconv_fcts.tomb, &data,
 107                                (const unsigned char **) src,
 108                                (const unsigned char *) srcend, &dummy, 0);
 109
 110       /* Count the number of bytes.  */
 111       result = data.__outbuf - (unsigned char *) dst;
 112
 113       /* We have to determine whether the last character converted
 114          is the NUL character.  */
 115       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 116           && data.__outbuf[-1] == '\0')
 117         {
 118           assert (data.__outbuf != (unsigned char *) dst);
 119           assert (__mbsinit (data.__statep));
 120           *src = NULL;
 121           --result;
 122         }
 123     }
 124
 125   /* There must not be any problems with the conversion but illegal input
 126      characters.  */
 127   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 128           || status == __GCONV_ILLEGAL_INPUT
 129           || status == __GCONV_INCOMPLETE_INPUT
 130           || status == __GCONV_FULL_OUTPUT);
 131
 132   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 133       && status != __GCONV_EMPTY_INPUT)
 134     {
 135       result = (size_t) -1;
 136       __set_errno (EILSEQ);
 137     }
 138
 139   return result;
 140 }
 141 weak_alias (__wcsnrtombs, wcsnrtombs)