php ob_start()函数实现当前页面内容缓存输出

<?php
ob_start(); //打开缓冲区
phpinfo(); //使用phpinfo函数
$info=ob_get_contents(); //得到缓冲区的内容并且赋值给$info
$file=fopen(’info.txt’,’w’); //打开文件info.txt
fwrite($file,$info); //写入信息到info.txt
fclose($file); //关闭文件info.txt
//或直接用 file_put_content('info.txt',$info);
?>

ob_start();
$phpinfo = phpinfo();
//写入文件
ob_end_flush();

或者还有这样的用途：

ob_start(); //打开缓冲区
echo "Hellon"; //输出
header("location:index.php"); //把浏览器重定向到index.php
ob_end_flush();//输出全部内容到浏览器

< ? php
function callback($buffer)
{
  // replace all the apples with oranges
  return (str_replace("apples", "oranges", $buffer));
}
ob_start("callback");
? >
< html >
< body >
<P>It's like comparing apples to oranges.</P>
< / body >
< / html >
< ?php
ob_end_flush();
? >

以上程序会输出：

< html >
< body >
< p>It's like comparing oranges to oranges.</ p>
< / body >
< / html >

public function gettime($time_s,$time_n){
$time_s = strtotime($time_s);
$time_n = strtotime($time_n);
$strtime = '';
$time = $time_n-$time_s;
if($time >= 86400){
return $strtime = date('Y-m-d H:i:s',$time_s);
}
if($time >= 3600){
$strtime .= intval($time/3600).'小时';
$time = $time % 3600;
}else{
$strtime .= '';
}
if($time >= 60){
$strtime .= intval($time/60).'分钟';
$time = $time % 60;
}else{
$strtime .= '';
}
if($time > 0){
$strtime .= intval($time).'秒前';
}else{
$strtime = "时间错误";
}
return $strtime;
}

$agent = strtolower($_SERVER['HTTP_USER_AGENT']); 
if(strpos($agent,"netfront") || strpos($agent,"iphone") || strpos($agent,"midp-2.0") || strpos($agent,"opera mini") || strpos($agent,"ucweb") || strpos($agent,"android") || strpos($agent,"windows ce") || strpos($agent,"symbianos")) {
    Header("HTTP/1.1 301 Moved Permanently");
    header("Location:####");  die;
}

function isMobile() {
    if(isset($_SERVER['HTTP_X_WAP_PROFILE'])) {
        return true;
    }
    if(isset ($_SERVER['HTTP_VIA'])) {
        //找不到为flase,否则为true
        return stristr($_SERVER['HTTP_VIA'], "wap") ? true : false;
    }
    if(isset($_SERVER['HTTP_USER_AGENT'])) {
        //此数组有待完善
        $clientkeywords = array (
        'nokia',
        'sony',
        'ericsson',
        'mot',
        'samsung',
        'htc',
        'sgh',
        'lg',
        'sharp',
        'sie-',
        'philips',
        'panasonic',
        'alcatel',
        'lenovo',
        'iphone',
        'ipod',
        'blackberry',
        'meizu',
        'android',
        'netfront',
        'symbian',
        'ucweb',
        'windowsce',
        'palm',
        'operamini',
        'operamobi',
        'openwave',
        'nexusone',
        'cldc',
        'midp',
        'wap',
        'mobile'
        );
        // 从HTTP_USER_AGENT中查找手机浏览器的关键字
        if(preg_match("/(" . implode('|', $clientkeywords) . ")/i", strtolower($_SERVER['HTTP_USER_AGENT']))) {
            return true;
        }
 
    }
 
    //协议法，因为有可能不准确，放到最后判断
    if (isset ($_SERVER['HTTP_ACCEPT'])) {
        // 如果只支持wml并且不支持html那一定是移动设备
        // 如果支持wml和html但是wml在html之前则是移动设备
        if ((strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') !== false) && (strpos($_SERVER['HTTP_ACCEPT'], 'text/html') === false || (strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') < strpos($_SERVER['HTTP_ACCEPT'], 'text/html')))) {
            return true;
        }
    }
     
return false;
}

echo floor(4.3); // 4
echo floor(9.999); // 9

echo round(3.4); // 3
echo round(3.5); // 4
echo round(3.6); // 4
echo round(3.6, 0); // 4
echo round(1.95583, 2); // 1.96
echo round(1241757, -3); // 1242000

<?php

echo intval(4.3);    //4

echo intval(4.6);  // 4  

?>

function http_request($url,$timeout=30,$header=array()){
        if (!function_exists('curl_init')) {
            throw new Exception('server not install curl');
        }
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, true);
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
        if (!empty($header)) {
            curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
        }
        $data = curl_exec($ch);
        list($header, $data) = explode("rnrn", $data);
        $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        if ($http_code == 301 || $http_code == 302) {
            $matches = array();
            preg_match('/Location:(.*?)n/', $header, $matches);
            $url = trim(array_pop($matches));
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_HEADER, false);
            $data = curl_exec($ch);
        }

        if ($data == false) {
            curl_close($ch);
        }
        @curl_close($ch);
        return $data;
}