分享自定义的几个PHP功能函数

最近不是在折腾论坛嘛，各种类各种函数，原创一些，从别人那儿qiang过来一些，在此分享出来，希望有朋友能用的到~

注意：部分函数可能不够完善，由此造成的漏洞风险自担~

提交过滤

function filter($text)
{
//完全过滤注释
$text = preg_replace('/<!--?.*-->/', '', $text);
//完全过滤js
$text = preg_replace('/<script?.*\/script>/', '', $text);
//过滤危险的属性，如：过滤on事件lang js
while (preg_match('/(<[^><]+)( lang|action|background|codebase|dynsrc|lowsrc)[^><]+/i', $text, $mat)) {
$text = str_replace($mat[0], $mat[1], $text);
}
while (preg_match('/(<[^><]+)(window\.|javascript:|js:|about:|file:|document\.|vbs:|cookie)([^><]*)/i', $text, $mat)) {
$text = str_replace($mat[0], $mat[1] . $mat[3], $text);
}
//过滤多余html
$text = preg_replace('/<\/?(html|head|meta|link|base|basefont|body|bgsound|script|form|iframe|frame|frameset|applet|id|ilayer|layer|name|script|xml)[^><]*>/i', '', $text);
//反转换
$text = str_replace('[', '<', $text);
$text = str_replace(']', '>', $text);
$text = str_replace('|', '"', $text);
return $text;
}

提交过滤2

function stripslashes_array(&$array)
{
while (list($key, $var) = each($array)) {
if ($key != 'argc' && $key != 'argv' && (strtoupper($key) != $key || '' . intval($key) == "$key")) {
if (is_string($var)) {
$array[$key] = stripslashes($var);
}
if (is_array($var)) {
$array[$key] = stripslashes_array($var);
}
}
}
return $array;
}

字符串截取（这个是emlog里提出来的，其实也就是substr的增强版）

function subString($strings, $start, $length)
{
if (function_exists('mb_substr') && function_exists('mb_strlen')) {
$sub_str = mb_substr($strings, $start, $length, 'utf8');
return mb_strlen($sub_str, 'utf8') < mb_strlen($strings, 'utf8') ? $sub_str . '...' : $sub_str;
}
$str = substr($strings, $start, $length);
$char = 0;
for ($i = 0; $i < strlen($str); $i++) {
if (ord($str[$i]) >= 128)
$char++;
}
$str2 = substr($strings, $start, $length + 1);
$str3 = substr($strings, $start, $length + 2);
if ($char % 3 == 1) {
if ($length <= strlen($strings)) {
$str3 = $str3 .= '...';
}
return $str3;
}
if ($char % 3 == 2) {
if ($length <= strlen($strings)) {
$str2 = $str2 .= '...';
}
return $str2;
}
if ($char % 3 == 0) {
if ($length <= strlen($strings)) {
$str = $str .= '...';
}
return $str;
}
}

IP地址匿名化（最后一位替换为星号）

function AnonymousIP()
{
$ip = GetIP();
if ($ip == "Unknown") {
$removed_ip = "未知用户";
}
if (strpos($ip, ":")) {
$removed_ip = "IPv6用户";
} else {
$reg1 = '/((?:\d+\.){3})\d+/';
$reg2 = '~(\d+)\.(\d+)\.(\d+)\.(\d+)~';
$removed_ip = preg_replace($reg1, "\\1*", $ip);
}
return $removed_ip;
}

获取客户端IP地址

function GetIP()
{
if (@$_SERVER["HTTP_X_FORWARDED_FOR"])
$ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
else if (@$_SERVER["HTTP_CLIENT_IP"])
$ip = $_SERVER["HTTP_CLIENT_IP"];
else if (@$_SERVER["REMOTE_ADDR"])
$ip = $_SERVER["REMOTE_ADDR"];
else if (@getenv("HTTP_X_FORWARDED_FOR"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (@getenv("HTTP_CLIENT_IP"))
$ip = getenv("HTTP_CLIENT_IP");
else if (@getenv("REMOTE_ADDR"))
$ip = getenv("REMOTE_ADDR");
else
$ip = "Unknown";
return $ip;
}

字符串加密（支持中文）

function dencrypt($string, $isEncrypt = true, $key = "youdian")
{
if (!isset($string{0}) || !isset($key{0})) {
return false;
}
$dynKey = $isEncrypt ? hash('sha1', microtime(true)) : substr($string, 0, 40);
$fixedKey = hash('sha1', $key);
$dynKeyPart1 = substr($dynKey, 0, 20);
$dynKeyPart2 = substr($dynKey, 20);
$fixedKeyPart1 = substr($fixedKey, 0, 20);
$fixedKeyPart2 = substr($fixedKey, 20);
$key = hash('sha1', $dynKeyPart1 . $fixedKeyPart1 . $dynKeyPart2 . $fixedKeyPart2);
$string = $isEncrypt ? $fixedKeyPart1 . $string . $dynKeyPart2 : (isset($string{339}) ? gzuncompress(base64_decode(substr($string, 40))) : base64_decode(substr($string, 40)));
$n = 0;
$result = '';
$len = strlen($string);
for ($n = 0; $n < $len; $n++) {
$result .= chr(ord($string{$n}) ^ ord($key{$n % 40}));
}
return $isEncrypt ? $dynKey . str_replace('=', '', base64_encode($n > 299 ? gzcompress($result) : $result)) : substr($result, 20, -20);
}

检查字符串是否包含中文

function CheckChinese($string)
{
if (preg_match("/[\x7f-\xff]/", $string)) {
return true;
} else {
return false;
}
}

隐藏文件真实路径

function FileHeaderJump($file)
{
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=' . basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile($file);
exit;
}

生成随机字符串，自定义长度

function CreateRandomString($length)
{
$chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
$password = "";
for ($i = 0; $i < $length; $i++) {
$password .= $chars[mt_rand(0, strlen($chars) - 1)];
}
return $password;
}

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