1、超级简单的页面缓存
如果你的工程项目不是基于 CMS 系统或框架,打造一个简单的缓存系统将会非常实在。下面的代码很简单,但是对小网站而言能切切实实解决问题。 代码如下:
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();
?>
output all your html here.
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();
?>
// 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();
?>
output all your html here.
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();
?>
点击这里查看详细情况:http://wesbos.com/simple-PHP-page-caching-technique/
2、在 PHP 中计算距离
这是一个非常有用的距离计算函数,利用纬度和经度计算从 A 地点到 B 地点的距离。该函数可以返回英里,公里,海里三种单位类型的距离。
代码如下:
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;
}
}
$dist = sin(deg2rad($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 $miles;
}
}
使用方法:
代码如下:
echo distance(32.9697,-96.80322,29.46786,-98.53506,"k")." kilometers";
点击这里查看详细情况:http://www.PHPsnippets.info/calculate-distances-in-PHP
3、将秒数转换为时间(年、月、日、小时…)
这个有用的函数能将秒数表示的事件转换为年、月、日、小时等时间格式。
代码如下:
function Sec2Time($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) $value;
}else{
return (bool) FALSE;
}
}
if(is_numeric($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) $value;
}else{
return (bool) FALSE;
}
}
点击这里查看详细情况:http://ckorp.net/sec2time.PHP
4、强制下载文件
一些诸如 mp3 类型的文件,通常会在客户端浏览器中直接被播放或使用。如果你希望它们强制被下载,也没问题。可以使用以下代码: 代码如下:
function downloadFile($file){
$file_name = $file;
$mime = 'application/force-download';
header('Pragma: public'); // required
header('Expires: 0'); // no cache
header('Cache-Control: must-revalidate,post-check=0,pre-check=0');
header('Cache-Control: private',false);
header('Content-Type: '.$mime);
header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
header('Content-Transfer-Encoding: binary');
header('Connection: close');
readfile($file_name); // push it out
exit();
}
$file_name = $file;
$mime = 'application/force-download';
header('Pragma: public'); // required
header('Expires: 0'); // no cache
header('Cache-Control: must-revalidate,post-check=0,pre-check=0');
header('Cache-Control: private',false);
header('Content-Type: '.$mime);
header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
header('Content-Transfer-Encoding: binary');
header('Connection: close');
readfile($file_name); // push it out
exit();
}
点击这里查看详细情况:Credit: Alessio Delmonti
5、使用 Google API 获取当前天气信息
想知道今天的天气?这段代码会告诉你,只需 3 行代码。你只需要把其中的 ADDRESS 换成你期望的城市。
代码如下:
$xml = simplexml_load_file('http://www.google.com/ig/api?weather=ADDRESS');
$information = $xml->xpath("/xml_api_reply/weather/current_conditions/condition");
echo $information[0]->attributes();
$information = $xml->xpath("/xml_api_reply/weather/current_conditions/condition");
echo $information[0]->attributes();
点击这里查看详细情况:http://ortanotes.tumblr.com/post/200469319/current-weather-in-3-lines-of-PHP
6、获得某个地址的经纬度
随着 Google Maps API 的普及,开发人员常常需要获得某一特定地点的经度和纬度。这个非常有用的函数以某一地址作为参数,返回一个数组,包含经度和纬度数据。 代码如下:
403">
function getLatLong($address){
if (!is_string($address))die("All Addresses must be passed as a string");
$_url = sprintf('http://maps.google.com/maps?output=js&q=%s',rawurlencode($address));
$_result = false;
if($_result = file_get_contents($_url)) {
if(strpos($_result,'errortips') > 1 || strpos($_result,'Did you mean:') !== false) return false;
preg_match('!center:\s*{lat:\s*(-?\d+\.\d+),lng:\s*(-?\d+\.\d+)}!U',$_result,$_match);
$_coords['lat'] = $_match[1];
$_coords['long'] = $_match[2];
}
return $_coords;
}
function getLatLong($address){
if (!is_string($address))die("All Addresses must be passed as a string");
$_url = sprintf('http://maps.google.com/maps?output=js&q=%s',rawurlencode($address));
$_result = false;
if($_result = file_get_contents($_url)) {
if(strpos($_result,'errortips') > 1 || strpos($_result,'Did you mean:') !== false) return false;
preg_match('!center:\s*{lat:\s*(-?\d+\.\d+),lng:\s*(-?\d+\.\d+)}!U',$_result,$_match);
$_coords['lat'] = $_match[1];
$_coords['long'] = $_match[2];
}
return $_coords;
}
点击这里查看详细情况:http://snipplr.com/view.PHP?codeview&id=47806
7、使用 PHP 和 Google 获取域名的 favicon 图标
有些网站或 Web 应用程序需要使用来自其他网站的 favicon 图标。利用 Google 和 PHP 很容易就能搞定,不过前提是 Google 不会连接被重置哦!
代码如下:
function get_favicon($url){
$url = str_replace("http://",'',$url);
return "http://www.google.com/s2/favicons?domain=".$url;
}
$url = str_replace("http://",'',$url);
return "http://www.google.com/s2/favicons?domain=".$url;
}
点击这里查看详细情况:http://snipplr.com/view.PHP?codeview&id=45928 原文链接:https://www.f2er.com/php/27423.html