Home  >  Article  >  Backend Development  >  【集锦】PHP常用小函数【概率,毫秒,IP】

【集锦】PHP常用小函数【概率,毫秒,IP】

WBOY
WBOYOriginal
2016-06-13 13:10:51773browse

【汇总】PHP常用小函数【概率,毫秒,IP】

/**
 * 概率计算
 * @param array('a'=>0.5, 'b'=>0.2)
 * @return string (key of array, eg. 'a' or 'b')
 */
function random($ps) {
    $arr = array();
    $key = md5(serialize($ps));

    if(!isset($arr[$key])) {
        $max = array_sum($ps);
        foreach($ps as $k => $v) {
            $v = $v / $max * 10000;
            for($i=0; $i
<p>?</p>
<pre name="code" class="php">/**
  * 返回毫秒数
  * 
  * @return float
  */
function microtime_float() {
	list($a, $b) = explode(' ', microtime());
	return ((float)$a + (float)$b) * 1000;
}

?

/**
  * 取得客户端IP
  */
function get_client_ip(){
   if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
       $ip = getenv("HTTP_CLIENT_IP");
   else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
       $ip = getenv("HTTP_X_FORWARDED_FOR");
   else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
       $ip = getenv("REMOTE_ADDR");
   else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
       $ip = $_SERVER['REMOTE_ADDR'];
   else
       $ip = "unknown";
   return($ip);
}
?

...

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn