/**
* 编码互换
*
* @param string $source
* @param string $source_lang 输入编码 'utf-8' or 'gb2312' or 'big5'
* @param string $target_lang 输出编码 'utf-8' or 'gb2312' or 'big5'
* @return string
*/
public static function convert($source, $source_lang, $target_lang = 'utf-8')
{
if ($source_lang != '') {
$source_lang = str_replace(array('gbk', 'utf8', 'big-5'), array('gb2312', 'utf-8', 'big5'), strtolower($source_lang));
}
if ($target_lang != '') {
$target_lang = str_replace(array('gbk', 'utf8', 'big-5'), array('gb2312', 'utf-8', 'big5'), strtolower($target_lang));
}
if ($source_lang == $target_lang || $source == '') {
return $source;
}
$index = $source_lang . "_" . $target_lang;
if (USEEXISTS && !in_array($index, array('gb2312_big5', 'big5_gb2312'))) {
//繁简互换并不是交换字符集编码
if (function_exists('iconv')) {
return iconv($source_lang, $target_lang, $source);
}
if (function_exists('mb_convert_encoding')) {
return mb_convert_encoding($source, $target_lang, $source_lang);
}
}
$table = self::loadtable($index);
if (!$table) {
return $source;
}
self::$string = $source;
self::$source_lang = $source_lang;
self::$target_lang = $target_lang;
if ($source_lang == 'gb2312' || $source_lang == 'big5') {
if ($target_lang == 'utf-8') {
self::$table = $table;
return self::CHS2UTF8();
}
if ($target_lang == 'gb2312') {
self::$table = array_flip($table);
} else {
self::$table = $table;
}
return self::BIG2GB();
} elseif (self::$source_lang == 'utf-8') {
self::$table = array_flip($table);
return self::UTF82CHS();
}
return NULL;
}
protected static function BIG2GB()
{
$ret = '';
while (self::$string) {
if (ord(self::$string[0]) > 0x80) {
$index = hexdec(bin2hex(self::$string[0] . self::$string[1]));
$value = self::$table[$index];
$ret .= self::hex2bin(dechex($value));
self::$string = substr(self::$string, 2);
} else {
$ret .= self::$string[0];
self::$string = substr(self::$string, 1);
}
}
return $ret;
}