php - 使用 mbstring 在 PHP 中将 Unicode 引用转换为 UTF-8 字符

Answer 1

I guess what you're looking for, are multibyte versions of ord and chr.

I wrote the following polyfill for that :

if (!function_exists('mb_internal_encoding')) {
    function mb_internal_encoding($encoding = NULL) {
        return ($from_encoding === NULL) ? iconv_get_encoding() : iconv_set_encoding($encoding);
    }
}

if (!function_exists('mb_convert_encoding')) {
    function mb_convert_encoding($str, $to_encoding, $from_encoding = NULL) {
        return iconv(($from_encoding === NULL) ? mb_internal_encoding() : $from_encoding, $to_encoding, $str);
    }
}

if (!function_exists('mb_chr')) {
    function mb_chr($ord, $encoding = 'UTF-8') {
        if ($encoding === 'UCS-4BE') {
            return pack("N", $ord);
        } else {
            return mb_convert_encoding(mb_chr($ord, 'UCS-4BE'), $encoding, 'UCS-4BE');
        }
    }
}

if (!function_exists('mb_ord')) {
    function mb_ord($char, $encoding = 'UTF-8') {
        if ($encoding === 'UCS-4BE') {
            list(, $ord) = (strlen($char) === 4) ? @unpack('N', $char) : @unpack('n', $char);
            return $ord;
        } else {
            return mb_ord(mb_convert_encoding($char, 'UCS-4BE', $encoding), 'UCS-4BE');
        }
    }
}

---

Demo

echo "\nGet string from numeric DEC value\n";
var_dump(mb_chr(25105));
var_dump(mb_chr(22909));

echo "\nGet string from numeric HEX value\n";
var_dump(mb_chr(0x6211));
var_dump(mb_chr(0x597D));

echo "\nGet numeric value of character as DEC int\n";
var_dump(mb_ord('我'));
var_dump(mb_ord('好'));

echo "\nGet numeric value of character as HEX string\n";
var_dump(dechex(mb_ord('我')));
var_dump(dechex(mb_ord('好')));

Output:

Get string from numeric DEC value
string(3) "我"
string(3) "好"

Get string from numeric HEX value
string(3) "我"
string(3) "好"

Get numeric value of character as DEC string
int(25105)
int(22909)

Get numeric value of character as HEX string
string(4) "6211"
string(4) "597d"

Answer 2

See if this can help you: hex2ascii and ascii2hex

ADDED on 09-19-2012:

function ascii2hex($ascii)
{
    $hex = '';
    for ($i = 0; $i < strlen($ascii); $i++)
    {
        $byte = strtoupper(dechex(ord($ascii{$i})));
        $byte = str_repeat('0', 2 - strlen($byte)).$byte;
        $hex .= $byte." ";
    }
    return $hex;
}

function hex2ascii($hex)
{
    $ascii = '';
    $hex = str_replace(" ", "", $hex);
    for($i = 0; $i < strlen($hex); $i = $i+2)
        $ascii .= chr(hexdec(substr($hex, $i, 2)));

    return($ascii);
}