1、超級簡單的頁面緩存
如果你的工程項目不是基於 CMS 系統或框架，打造一個簡單的緩存系統將會非常實在。下面的代碼很簡單，但是對小網站而言能切切實實解決問題。
- <?php
- // define the path and name of cached file
- $cachefile = 'cached-files/'.date('M-d-Y').'.php';
- // define how long we want to keep the file in seconds. I set mine to 5 hours.
- $cachetime = 18000;
- // Check if the cached file is still fresh. If it is, serve it up and exit.
- if (file_exists($cachefile) && time() - $cachetime < filemtime($cachefile)) {
- include($cachefile);
- exit;
- }
- // if there is either no file OR the file to too old, render the page and capture the HTML.
- ob_start();
- ?>
- <html>
- output all your html here.
- </html>
- <?php
- // We're done! Save the cached content to a file
- $fp = fopen($cachefile, 'w');
- fwrite($fp, ob_get_contents());
- fclose($fp);
- // finally send browser output
- ob_end_flush();
- ?>
點擊這裡查看詳細情況：http://wesbos.com/simple-php-page-caching-technique/
2、在 PHP 中計算距離
這是一個非常有用的距離計算函數，利用緯度和經度計算從 A 地點到 B 地點的距離。該函數可以返回英裡，公裡，海裡三種單位類型的距離。
- function distance($lat1, $lon1, $lat2, $lon2, $unit) {
- $theta = $lon1 - $lon2;
- $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
- $dist = acos($dist);
- $dist = rad2deg($dist);
- $miles = $dist * 60 * 1.1515;
- $unit = strtoupper($unit);
- if ($unit == "K") {
- return ($miles * 1.609344);
- } else if ($unit == "N") {
- return ($miles * 0.8684);
- } else {
- return $miles;
- }
- }
使用方法：
- echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k")." kilometers";
點擊這裡查看詳細情況：http://www.phpsnippets.info/calculate-distances-in-php
3、將秒數轉換為時間(年、月、日、小時…)
這個有用的函數能將秒數表示的事件轉換為年、月、日、小時等時間格式。
- function Sec2Time($time){
- if(is_numeric($time)){
- $value = array(
- "years" => 0, "days" => 0, "hours" => 0,
- "minutes" => 0, "seconds" => 0,
- );
- if($time >= 31556926){
- $value["years"] = floor($time/31556926);
- $time = ($time%31556926);
- }
- if($time >= 86400){
- $value["days"] = floor($time/86400);
- $time = ($time%86400);
- }
- if($time >= 3600){
- $value["hours"] = floor($time/3600);
- $time = ($time%3600);
- }
- if($time >= 60){
- $value["minutes"] = floor($time/60);
- $time = ($time%60);
- }
- $value["seconds"] = floor($time);
- return (array) $value;
- }else{
- return (bool) FALSE;
- }
- }
點擊這裡查看詳細情況：http://ckorp.net/sec2time.php
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