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

   1 /* Conversion from UTF-8 to legacy encodings.
   2    Copyright (C) 2002, 2006-2007, 2009-2024 Free Software Foundation, Inc.
   3
   4    This file is free software.
   5    It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   6    You can redistribute it and/or modify it under either
   7      - the terms of the GNU Lesser General Public License as published
   8        by the Free Software Foundation, either version 3, or (at your
   9        option) any later version, or
  10      - the terms of the GNU General Public License as published by the
  11        Free Software Foundation; either version 2, or (at your option)
  12        any later version, or
  13      - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  14
  15    This file is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License and the GNU General Public License
  19    for more details.
  20
  21    You should have received a copy of the GNU Lesser General Public
  22    License and of the GNU General Public License along with this
  23    program.  If not, see <https://www.gnu.org/licenses/>.  */
  24
  25 /* Written by Bruno Haible <bruno@clisp.org>.  */
  26
  27 #include <config.h>
  28
  29 /* Specification.  */
  30 #include "uniconv.h"
  31
  32 #include <errno.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include "c-strcaseeq.h"
  37 #include "striconveha.h"
  38 #include "unistr.h"
  39
  40 char *
  41 u8_strconv_to_encoding (const uint8_t *string,
  42                         const char *tocode,
  43                         enum iconv_ilseq_handler handler)
  44 {
  45   char *result;
  46   size_t length;
  47
  48   if (STRCASEEQ (tocode, "UTF-8", 'U','T','F','-','8',0,0,0,0))
  49     {
  50       /* Conversion from UTF-8 to UTF-8.  No need to go through iconv().  */
  51       length = u8_strlen (string) + 1;
  52       if (u8_check (string, length))
  53         {
  54           errno = EILSEQ;
  55           return NULL;
  56         }
  57       result = (char *) malloc (length);
  58       if (result == NULL)
  59         {
  60           errno = ENOMEM;
  61           return NULL;
  62         }
  63       memcpy (result, (const char *) string, length);
  64       return result;
  65     }
  66   else
  67     {
  68       result = NULL;
  69       length = 0;
  70       if (mem_iconveha ((const char *) string, u8_strlen (string) + 1,
  71                         "UTF-8", tocode,
  72                         handler == iconveh_question_mark, handler,
  73                         NULL, &result, &length) < 0)
  74         return NULL;
  75       /* Verify the result has exactly one NUL byte, at the end.  */
  76       if (!(length > 0 && result[length-1] == '\0'
  77             && strlen (result) == length-1))
  78         {
  79           free (result);
  80           errno = EILSEQ;
  81           return NULL;
  82         }
  83       return result;
  84     }
  85 }