KiloBug

 
/* 过滤危险html */
function filter_html( $str ) {
	/* 过滤style标签 */
	return preg_replace_callback(
			/* 过滤style标签内容 */
			'/(\<\s*style[^\>]*\>)((?:(?!\<\s*\/\s*style\s*\>).)*)(\<\s*\/\s*style\s*\>)?/i',
			create_function('$str', 'return $str[1] . filter_css($str[2]) . $str[3];'),
			preg_replace(
				array(
					/* 删除html注释 */
					'/\<\!\-\-.*?\-\-\>/i',
					/* 删除标签：script、link、object、embed、iframe、frame、frameset */
					'/\<\s*(script|object|embed|link|i?frame(set)?)[^\>]*\>(.*?\<\s*\/\s*\\1\s*\>)?/i',
					/* 删除事件、javascript协议、css表达式 */
					'/\<[^\>]+((on[a-z]+\s*\=|(javascript|vbscript|behavior)\s*\:[^\;\"\\\']|(import|expression)\s*\()[^\>]*)+\>?/i',
				),
				'',
				$str
			)
	);
}
 
 
/* 过滤样式正文 */
function filter_css( $str ) {
	/* 删除注释、javascript协议、表达式 */
	return preg_replace(array('/(\/\*((?!\*\/).)*\*\/|\/\*|\*\/)/i', '/(expression|import)\s*\((.*?\))?|(javascript|vbscript|behavior)\s*\:/i',), '', $str);
}

/* 数组排序 */
function array_sort( $data, $order = array() ) {
	if( !$data || !$order ) return $data;
 
	$arglist = array();
	foreach($data as $k => $v)
		foreach($order as $k2 => $v2) {
			if( !isset($arglist[$k2]) ) $arglist[$k2] = array();
			$arglist[$k2][$k] = $v[$k2];
		}
 
	$argstr = '';
	foreach( $order as $k => $v )
		$argstr .= ',$arglist[\''.$k.'\'], SORT_'.$v;
	$argstr{0} = ' ';
 
	eval('array_multisort('.$argstr.',$data);');
	return $data;
}

$array = array(
    array(
        'uid' => 100,
        'username' => 'kilobug',
    ),
    array(
        'uid' => 99,
        'username' => 'kilobug',
    ),
    ....
);
$array = array_sort($array, array('uid' => 'DESC', 'username' => 'ASC'));
var_dump($array);

function random( $min, $max = NULL ) {
	$len = isset($max) ? mt_rand($min, $max) : $min;
	$str = '';
	for($i = 0; $i < $len; ++$i)
		$str .= chr(mt_rand(32, 128));
	return $str;
}

function xxtea_encode(string $str, string $key[, bool $is_base64])

function xxtea_decode($str, $key[, $is_base64])

/[\x{4e00}-\x{9fa5}]+/i

function mb_substr($str, $start = 0, $length = 0, $encode = 'utf-8') {
    /* 该编码每个非英文字符的字节长度 */
    $encode_len = $encode == 'utf-8' ? 3 : 2;
    /* 计算开始字节 */
    for($byteStart = $i = 0; $i < $start; ++$i) {
        $byteStart += ord($str{$byteStart}) < 128 ? 1 : $encode_len;
        /* 当起始坐标超出字符串，则返回空值 */
        if( $str{$byteStart} == '' ) return '';
    }
    /* 计算字节长度 */
    for($i = 0, $byteLen = $byteStart; $i < $length; ++$i)
        $byteLen += ord($str{$byteLen}) < 128 ? 1 : $encode_len;
 
    return substr( $str, $byteStart, $byteLen-$byteStart );
}

array unpack ( string $format, string $data )