lib/uniconv/u8-strconv-to-enc.c

   1 /* Conversion from UTF-8 to legacy encodings.
   2    Copyright (C) 2002, 2006-2007, 2009-2019 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify it
   5    under the terms of the GNU Lesser General Public License as published
   6    by the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <bruno@clisp.org>.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include "uniconv.h"
  23
  24 #include <errno.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "c-strcaseeq.h"
  29 #include "striconveha.h"
  30 #include "unistr.h"
  31
  32 char *
  33 u8_strconv_to_encoding (const uint8_t *string,
  34                         const char *tocode,
  35                         enum iconv_ilseq_handler handler)
  36 {
  37   char *result;
  38   size_t length;
  39
  40   if (STRCASEEQ (tocode, "UTF-8", 'U','T','F','-','8',0,0,0,0))
  41     {
  42       /* Conversion from UTF-8 to UTF-8.  No need to go through iconv().  */
  43       length = u8_strlen (string) + 1;
  44       if (u8_check (string, length))
  45         {
  46           errno = EILSEQ;
  47           return NULL;
  48         }
  49       result = (char *) malloc (length);
  50       if (result == NULL)
  51         {
  52           errno = ENOMEM;
  53           return NULL;
  54         }
  55       memcpy (result, (const char *) string, length);
  56       return result;
  57     }
  58   else
  59     {
  60       result = NULL;
  61       length = 0;
  62       if (mem_iconveha ((const char *) string, u8_strlen (string) + 1,
  63                         "UTF-8", tocode,
  64                         handler == iconveh_question_mark, handler,
  65                         NULL, &result, &length) < 0)
  66         return NULL;
  67       /* Verify the result has exactly one NUL byte, at the end.  */
  68       if (!(length > 0 && result[length-1] == '\0'
  69             && strlen (result) == length-1))
  70         {
  71           free (result);
  72           errno = EILSEQ;
  73           return NULL;
  74         }
  75       return result;
  76     }
  77 }