341 lines
8.7 KiB
C
341 lines
8.7 KiB
C
/*
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* Copyright 2005 John M Bell <jmb202@ecs.soton.ac.uk>
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*
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* This file is part of NetSurf, http://www.netsurf-browser.org/
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*
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* NetSurf is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* NetSurf is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/** \file
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* UTF-8 manipulation functions (implementation).
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*/
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#define _GNU_SOURCE /* for strndup */
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#include <assert.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <strings.h>
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#include <iconv.h>
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#include <parserutils/charset/utf8.h>
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#include "utils/config.h"
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#include "utils/log.h"
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#include "utils/utf8.h"
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static utf8_convert_ret utf8_convert(const char *string, size_t len,
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const char *from, const char *to, char **result);
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/**
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* Convert a UTF-8 multibyte sequence into a single UCS4 character
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*
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* Encoding of UCS values outside the UTF-16 plane has been removed from
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* RFC3629. This function conforms to RFC2279, however.
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*
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* \param s The sequence to process
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* \param l Length of sequence
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* \return UCS4 character
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*/
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uint32_t utf8_to_ucs4(const char *s_in, size_t l)
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{
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uint32_t ucs4;
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size_t len;
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parserutils_error perror;
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perror = parserutils_charset_utf8_to_ucs4((const uint8_t *) s_in, l,
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&ucs4, &len);
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if (perror != PARSERUTILS_OK)
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ucs4 = 0xfffd;
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return ucs4;
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}
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/**
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* Convert a single UCS4 character into a UTF-8 multibyte sequence
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*
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* Encoding of UCS values outside the UTF-16 plane has been removed from
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* RFC3629. This function conforms to RFC2279, however.
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*
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* \param c The character to process (0 <= c <= 0x7FFFFFFF)
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* \param s Pointer to 6 byte long output buffer
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* \return Length of multibyte sequence
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*/
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size_t utf8_from_ucs4(uint32_t c, char *s)
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{
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uint8_t *in = (uint8_t *) s;
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size_t len = 6;
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parserutils_error perror;
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perror = parserutils_charset_utf8_from_ucs4(c, &in, &len);
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if (perror != PARSERUTILS_OK) {
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s[0] = 0xef;
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s[1] = 0xbf;
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s[2] = 0xbd;
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return 3;
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}
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return 6 - len;
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}
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/**
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* Calculate the length (in characters) of a NULL-terminated UTF-8 string
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*
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* \param s The string
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* \return Length of string
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*/
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size_t utf8_length(const char *s)
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{
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return utf8_bounded_length(s, strlen(s));
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}
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/**
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* Calculated the length (in characters) of a bounded UTF-8 string
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*
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* \param s The string
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* \param l Maximum length of input (in bytes)
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* \return Length of string, in characters
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*/
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size_t utf8_bounded_length(const char *s, size_t l)
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{
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size_t len;
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parserutils_error perror;
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perror = parserutils_charset_utf8_length((const uint8_t *) s, l, &len);
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if (perror != PARSERUTILS_OK)
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return 0;
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return len;
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}
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/**
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* Calculate the length (in bytes) of a UTF-8 character
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*
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* \param s Pointer to start of character
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* \return Length of character, in bytes
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*/
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size_t utf8_char_byte_length(const char *s)
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{
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size_t len;
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parserutils_error perror;
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perror = parserutils_charset_utf8_char_byte_length((const uint8_t *) s,
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&len);
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assert(perror == PARSERUTILS_OK);
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return len;
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}
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/**
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* Find previous legal UTF-8 char in string
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*
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* \param s The string
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* \param o Offset in the string to start at
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* \return Offset of first byte of previous legal character
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*/
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size_t utf8_prev(const char *s, size_t o)
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{
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uint32_t prev;
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parserutils_error perror;
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perror = parserutils_charset_utf8_prev((const uint8_t *) s, o, &prev);
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assert(perror == PARSERUTILS_OK);
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return prev;
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}
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/**
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* Find next legal UTF-8 char in string
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*
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* \param s The string
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* \param l Maximum offset in string
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* \param o Offset in the string to start at
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* \return Offset of first byte of next legal character
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*/
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size_t utf8_next(const char *s, size_t l, size_t o)
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{
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uint32_t next;
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parserutils_error perror;
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perror = parserutils_charset_utf8_next((const uint8_t *) s, l, o,
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&next);
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assert(perror == PARSERUTILS_OK);
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return next;
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}
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/* Cache of previous iconv conversion descriptor used by utf8_convert */
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static struct {
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char from[32]; /**< Encoding name to convert from */
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char to[32]; /**< Encoding name to convert to */
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iconv_t cd; /**< Iconv conversion descriptor */
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} last_cd;
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/**
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* Finalise the UTF-8 library
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*/
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void utf8_finalise(void)
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{
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if (last_cd.cd != 0)
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iconv_close(last_cd.cd);
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/* paranoia follows */
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last_cd.from[0] = '\0';
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last_cd.to[0] = '\0';
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last_cd.cd = 0;
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}
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/**
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* Convert a UTF8 string into the named encoding
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*
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* \param string The NULL-terminated string to convert
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* \param encname The encoding name (suitable for passing to iconv)
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* \param len Length of input string to consider (in bytes), or 0
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* \param result Pointer to location to store result (allocated on heap)
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* \return Appropriate utf8_convert_ret value
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*/
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utf8_convert_ret utf8_to_enc(const char *string, const char *encname,
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size_t len, char **result)
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{
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return utf8_convert(string, len, "UTF-8", encname, result);
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}
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/**
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* Convert a string in the named encoding into a UTF-8 string
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*
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* \param string The NULL-terminated string to convert
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* \param encname The encoding name (suitable for passing to iconv)
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* \param len Length of input string to consider (in bytes), or 0
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* \param result Pointer to location to store result (allocated on heap)
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* \return Appropriate utf8_convert_ret value
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*/
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utf8_convert_ret utf8_from_enc(const char *string, const char *encname,
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size_t len, char **result)
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{
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return utf8_convert(string, len, encname, "UTF-8", result);
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}
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/**
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* Convert a string from one encoding to another
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*
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* \param string The NULL-terminated string to convert
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* \param len Length of input string to consider (in bytes), or 0
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* \param from The encoding name to convert from
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* \param to The encoding name to convert to
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* \param result Pointer to location in which to store result
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* \return Appropriate utf8_convert_ret value
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*/
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utf8_convert_ret utf8_convert(const char *string, size_t len,
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const char *from, const char *to, char **result)
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{
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iconv_t cd;
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char *temp, *out, *in;
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size_t slen, rlen;
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assert(string && from && to && result);
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if (string[0] == '\0') {
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/* On AmigaOS, iconv() returns an error if we pass an
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* empty string. This prevents iconv() being called as
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* there is no conversion necessary anyway. */
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*result = strdup("");
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if (!(*result)) {
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*result = NULL;
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return UTF8_CONVERT_NOMEM;
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}
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return UTF8_CONVERT_OK;
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}
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if (strcasecmp(from, to) == 0) {
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/* conversion from an encoding to itself == strdup */
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slen = len ? len : strlen(string);
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*(result) = strndup(string, slen);
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if (!(*result)) {
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*(result) = NULL;
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return UTF8_CONVERT_NOMEM;
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}
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return UTF8_CONVERT_OK;
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}
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in = (char *)string;
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/* we cache the last used conversion descriptor,
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* so check if we're trying to use it here */
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if (strncasecmp(last_cd.from, from, sizeof(last_cd.from)) == 0 &&
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strncasecmp(last_cd.to, to, sizeof(last_cd.to)) == 0) {
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cd = last_cd.cd;
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}
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else {
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/* no match, so create a new cd */
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cd = iconv_open(to, from);
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if (cd == (iconv_t)-1) {
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if (errno == EINVAL)
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return UTF8_CONVERT_BADENC;
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/* default to no memory */
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return UTF8_CONVERT_NOMEM;
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}
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/* close the last cd - we don't care if this fails */
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if (last_cd.cd)
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iconv_close(last_cd.cd);
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/* and copy the to/from/cd data into last_cd */
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strncpy(last_cd.from, from, sizeof(last_cd.from));
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strncpy(last_cd.to, to, sizeof(last_cd.to));
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last_cd.cd = cd;
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}
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slen = len ? len : strlen(string);
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/* Worst case = ACSII -> UCS4, so allocate an output buffer
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* 4 times larger than the input buffer, and add 4 bytes at
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* the end for the NULL terminator
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*/
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rlen = slen * 4 + 4;
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temp = out = malloc(rlen);
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if (!out)
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return UTF8_CONVERT_NOMEM;
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/* perform conversion */
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if (iconv(cd, &in, &slen, &out, &rlen) == (size_t)-1) {
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free(temp);
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/* clear the cached conversion descriptor as it's invalid */
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if (last_cd.cd)
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iconv_close(last_cd.cd);
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last_cd.from[0] = '\0';
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last_cd.to[0] = '\0';
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last_cd.cd = 0;
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/** \todo handle the various cases properly
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* There are 3 possible error cases:
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* a) Insufficiently large output buffer
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* b) Invalid input byte sequence
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* c) Incomplete input sequence */
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return UTF8_CONVERT_NOMEM;
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}
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*(result) = realloc(temp, out - temp + 4);
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if (!(*result)) {
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free(temp);
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*(result) = NULL; /* for sanity's sake */
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return UTF8_CONVERT_NOMEM;
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}
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/* NULL terminate - needs 4 characters as we may have
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* converted to UTF-32 */
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memset((*result) + (out - temp), 0, 4);
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return UTF8_CONVERT_OK;
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}
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