用PHP判断远程图片（文件）是否存在

<?php
/*

*用PHP判断远程图片（文件）是否存在

*http://www.111cn.net

*/

function check_remote_file_exists($url) {
    $curl = curl_init($url);
    
// 不取回数据

    curl_setopt($curl, CURLOPT_NOBODY, true);
    
// 抓取跳转后的内容

    curl_setopt($curl, CURLOPT_FOLLOWLOCATION,1);
    
// 发送请求

    $result = curl_exec($curl);
    $found = false;
    
// 如果请求没有发送失败

    if ($result !== false) {
        
// 再检查http响应码是否为200

        $statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);
        var_dump($statusCode);
        if ($statusCode == 200) {
            
// $retcode >= 400 -> not found, $retcode = 200, found.

            $found = true;
        }
    }
    curl_close($curl);
 
    return $found;
}
 
$exists = check_remote_file_exists('http://www.111cn.net /allimg/090403/140941513J2-2.jpg');
if ($exists) {
    echo '存在';
} else {
    echo '不存在';
}
 
$exists = check_remote_file_exists('http://www.111cn.net /allimg/090403/140941513J2-4.jpg');
if ($exists) {
    echo '存在';
} else {
    echo '不存在';
}
exit;
?>

$days=array();

for($i=0;$i<=7;$i++){ //这里数字根据需要变动
 

$days[]=date("Y-m-d",strtotime('-'.$i.'day'));

}

echo '<pre>';print_r($days);

Array
(
    [0] => 2014-03-21
    [1] => 2014-03-20
    [2] => 2014-03-19
    [3] => 2014-03-18
    [4] => 2014-03-17
    [5] => 2014-03-16
    [6] => 2014-03-15
    [7] => 2014-03-14
)

echo $str = 'PHP点点通';
 
echo strlen($str); //3*1+3*3=12
echo mb_strlen($str, 'gb2312'); //3*1+3*2=9
echo mb_strlen($str, 'utf-8'); //6

<?php
function _strlen($str)
{
        preg_match_all("/./us", $str, $matches);
        return count(current($matches));
}
 
echo _strlen("PHP点点通");  //6

$url = 'http://t.cn/h5mwx';
$headers = get_headers($url, TRUE);

print_r($headers);

//输出跳转到的网址
echo $headers['Location'];

附：

Array
(
    [0] => HTTP/1.1 302 Moved Temporarily
    [Location] => http://www.111Cn.net
    [Content-Type] => Array
        (
            [0] => text/html;charset=UTF-8
            [1] => text/html;charset=utf-8
        )

    [Server] => Array
        (
            [0] => weibo
            [1] => BWS/1.0
        )

    [Content-Length] => Array
        (
            [0] => 203
            [1] => 16424
        )

    [Date] => Array
        (
            [0] => Thu, 12 Dec 2013 10:42:25 GMT
            [1] => Thu, 12 Dec 2013 10:42:25 GMT
        )

    [X-Varnish] => 2893360335
    [Age] => 0
    [Via] => 1.1 varnish
    [Connection] => Array
        (
            [0] => close
            [1] => Close
        )
)

$header = get_headers($url, 1);
if (strpos($header[0], '301') || strpos($header[0], '302')) {
if (is_array($header['Location'])) {
return $header['Location'][count($header['Location'])-1];
} else {
return $header['Location'];
}
} else {
return $url;
}