iconv.c

用于嵌入式Linux系统的标准C的库函数

/*-
 * Copyright (c) 1999,2000
 *    Konstantin Chuguev.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *    iconv (Charset Conversion Library) v2.0
 */

/*
FUNCTION
<<iconv>>, <<iconv_open>>, <<iconv_close>>---charset conversion routines

INDEX
	iconv
INDEX
	iconv_open
INDEX
	iconv_close
INDEX
	_iconv_r
INDEX
	_iconv_open_r
INDEX
	_iconv_close_r

ANSI_SYNOPSIS
	#include <iconv.h>
	iconv_t iconv_open (const char *<[to]>, const char *<[from]>);
	int iconv_close (iconv_t <[cd]>);
        size_t iconv (iconv_t <[cd]>, const char **<[inbuf]>, 
	              size_t *<[inbytesleft]>, 
		      char **<[outbuf]>, size_t *<[outbytesleft]>),

	iconv_t _iconv_open_r (struct _reent *<[rptr]>, 
			       const char *<[to]>, const char *<[from]>);
	int _iconv_close_r (struct _reent *<[rptr]>, iconv_t <[cd]>);
        size_t _iconv_r (struct _reent *<[rptr]>,
			 iconv_t <[cd]>, const char **<[inbuf]>, 
	                 size_t *<[inbytesleft]>, 
		         char **<[outbuf]>, size_t *<[outbytesleft]>),

TRAD_SYNOPSIS
	#include <iconv.h>
        size_t iconv (<[cd]>, <[in]>, <[inleft]>, <[out]>, <[outleft]>)
	iconv_t <[cd]>;
	const char **<[in]>;
	size_t *<[inleft]>; 
        char **<[out]>;
       	size_t *<[outleft]>);

	#include <iconv.h>
	iconv_t iconv_open (<[to]>, <[from]>);
	const char *<[to]>;
       	const char *<[from]>;

	#include <iconv.h>
	int iconv_close (<[cd]>);
	iconv_t <[cd]>;

	#include <iconv.h>
        size_t _iconv_r (<[rptr]>, <[cd]>, <[in]>, <[inleft]>, <[out]>, <[outleft]>)
	struct _reent *<[rptr]>;
	iconv_t <[cd]>;
	const char **<[in]>;
	size_t *<[inleft]>; 
        char **<[out]>;
       	size_t *<[outleft]>);

	#include <iconv.h>
	iconv_t _iconv_open_r (<[rptr]>, <[to]>, <[from]>);
	struct _reent *<[rptr]>;
	const char *<[to]>;
       	const char *<[from]>;

	#include <iconv.h>
	int iconv_close (<[rptr]>, <[cd]>);
	struct _reent *<[rptr]>;
	iconv_t <[cd]>;

DESCRIPTION
The function <<iconv>> converts characters from <[in]> which are in one
character set and converts them to characters of another character set,
outputting them to <[out]>.  The value <[inleft]> specifies the number
of input bytes to convert whereas the value <[outleft]> specifies the
size remaining in the <[out]> buffer.  The conversion descriptor <[cd]>
specifies the conversion being performed and is created via <<iconv_open>>.

An <<iconv>> conversion stops if: the input bytes are exhausted, the output
buffer is full, an invalid input character sequence occurs, or the
conversion specifier is invalid.

The function <<iconv_open>> is used to specify a conversion from one
character set: <[from]> to another: <[to]>.  The result of the call is
to create a conversion specifier that can be used with <<iconv>>.

The function <<iconv_close>> is used to close a conversion specifier after
it is no longer needed.

The <<_iconv_r>>, <<_iconv_open_r>>, and <<_iconv_close_r>> functions are
reentrant versions of <<iconv>>, <<iconv_open>>, and <<iconv_close>>,
respectively.  An additional reentrancy struct pointer: <[rptr]> is passed
to properly set <<errno>>.

RETURNS
The <<iconv>> function returns the number of non-identical conversions
performed.  If an error occurs, (size_t)-1 is returned and <<errno>>
is set appropriately.  The values of <[inleft]>, <[in]>, <[out]>,
and <[outleft]> are modified to indicate how much input was processed
and how much output was created.

The <<iconv_open>> function returns either a valid conversion specifier
or (iconv_t)-1 to indicate failure.  If failure occurs, <<errno>> is set
appropriately.

The <<iconv_close>> function returns 0 on success or -1 on failure.
If failure occurs <<errno>> is set appropriately.

PORTABILITY
<<iconv>>, <<iconv_open>>, and <<iconv_close>> are non-ANSI and are specified
by the Single Unix specification.

No supporting OS subroutine calls are required.
*/

#include <reent.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <iconv.h>
#include "local.h"

iconv_t
_DEFUN(iconv_open, (to, from), 
                   _CONST char *to _AND
                   _CONST char *from)
{
    return _iconv_open_r(_REENT, to, from);
}

size_t
_DEFUN(iconv, (cd, inbuf, inbytesleft, outbuf, outbytesleft),
              iconv_t cd          _AND
              _CONST char **inbuf _AND
              size_t *inbytesleft _AND
              char **outbuf       _AND
              size_t *outbytesleft)
{
    return _iconv_r(_REENT, cd, inbuf, inbytesleft, outbuf, outbytesleft);
}

int
_DEFUN(iconv_close, (cd), iconv_t cd)
{
    return _iconv_close_r(_REENT, cd);
}

#ifndef _REENT_ONLY
iconv_t
_DEFUN(_iconv_open_r, (rptr, to, from),
                      struct _reent *rptr _AND
                      _CONST char *to     _AND
                      _CONST char *from)
{
     iconv_converter_t *ic;
    _CONST char *nlspath;

    if(!to || !from)
            return (iconv_t)(-1);

    if ((nlspath = _getenv_r(rptr, NLS_ENVVAR_NAME)) == NULL || 
        *nlspath == '\0')
        nlspath = NLS_DEFAULT_NLSPATH;

    if ((to = _iconv_resolve_cs_name(rptr, (_CONST char *)to, 
                                        (_CONST char *)nlspath)) == NULL)
            return (iconv_t)(-1);
    if ((from = _iconv_resolve_cs_name(rptr, (_CONST char *)from, 
                                          (_CONST char *)nlspath)) == NULL)
    {
        _free_r(rptr, (_VOID_PTR)to);
        return (iconv_t)(-1);
    }

    ic = strcmp(from, to) ? _iconv_unicode_conv_init(rptr, to, from)
                          : _iconv_null_conv_init(rptr, to, from);
    _free_r(rptr, (_VOID_PTR)to);
    _free_r(rptr, (_VOID_PTR)from);
    return ic ? (iconv_t)(ic) : (iconv_t)(-1);
}

size_t
_DEFUN(_iconv_r, (rptr, cd, inbuf, inbytesleft, outbuf, outbytesleft),
                 struct _reent *rptr _AND
                 iconv_t cd          _AND
                 _CONST char **inbuf _AND
                 size_t *inbytesleft _AND
                 char **outbuf       _AND
                 size_t *outbytesleft)
{
    if ((_VOID_PTR)cd == NULL) {
        __errno_r(rptr) = EBADF;
        return (size_t)(-1);
    }
    if (outbytesleft == NULL ||
        outbuf == NULL || *outbuf == 0) {
        __errno_r(rptr) = E2BIG;
        return (size_t)(-1);
    }
    return ((iconv_converter_t *)cd)->convert(rptr, (iconv_converter_t *)cd + 1,
                                            (_CONST unsigned char**)inbuf,
                                            inbytesleft,
                                            (unsigned char**)outbuf,
                                            outbytesleft);
}

int
_DEFUN(_iconv_close_r, (rptr, cd),
                       struct _reent *rptr _AND
                       iconv_t cd)
{
    int res;

    if ((_VOID_PTR)cd == NULL || cd == (iconv_t)-1) {
        __errno_r(rptr) = EBADF;
        return -1;
    }
    res = ((iconv_converter_t *)cd)->close(rptr, (iconv_converter_t *)cd + 1);
    _free_r(rptr, (_VOID_PTR)cd);
    return res ? -1 : 0;
}
#endif /* #ifndef _REENT_ONLY */