wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 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
  51   /* Tell where we want the result.  */
  52   data.invocation_counter = 0;
  53   data.internal_use = 1;
  54   data.is_last = 1;
  55   data.statep = ps ?: &state;
  56
  57   if (nwc == 0)
  58     return 0;
  59   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  60
  61   /* Make sure we use the correct function.  */
  62   update_conversion_ptrs ();
  63
  64   /* We have to handle DST == NULL special.  */
  65   if (dst == NULL)
  66     {
  67       unsigned char buf[256];           /* Just an arbitrary value.  */
  68       const wchar_t *inbuf = *src;
  69       size_t dummy;
  70
  71       result = 0;
  72       data.outbufend = buf + sizeof (buf);
  73
  74       do
  75         {
  76           data.outbuf = buf;
  77
  78           status = (*__wcsmbs_gconv_fcts.tomb->fct) (__wcsmbs_gconv_fcts.tomb,
  79                                                      &data,
  80                                                      (const unsigned char **) &inbuf,
  81                                                      (const unsigned char *) srcend,
  82                                                      &dummy, 0);
  83
  84           /* Count the number of bytes.  */
  85           result += data.outbuf - buf;
  86         }
  87       while (status == GCONV_FULL_OUTPUT);
  88
  89       if ((status == GCONV_OK || status == GCONV_EMPTY_INPUT)
  90           && data.outbuf[-1] == '\0')
  91         /* Don't count the NUL character in.  */
  92         --result;
  93     }
  94   else
  95     {
  96       /* This code is based on the safe assumption that all internal
  97          multi-byte encodings use the NUL byte only to mark the end
  98          of the string.  */
  99       size_t dummy;
 100
 101       data.outbuf = dst;
 102       data.outbufend = dst + len;
 103
 104       status = (*__wcsmbs_gconv_fcts.tomb->fct) (__wcsmbs_gconv_fcts.tomb,
 105                                                  &data,
 106                                                  (const unsigned char **) src,
 107                                                  (const unsigned char *) srcend,
 108                                                  &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 || status == GCONV_FULL_OUTPUT);
 130
 131   if (status != GCONV_OK && status != GCONV_FULL_OUTPUT
 132       && status != GCONV_EMPTY_INPUT)
 133     {
 134       result = (size_t) -1;
 135       __set_errno (EILSEQ);
 136     }
 137
 138   return result;
 139 }
 140 weak_alias (__wcsnrtombs, wcsnrtombs)