如何檢查遠程URL並防止重定向

Question

我想檢查現有的文件/網址。網上有很多解決方案，但他們不能給我實際的結果。我認爲這是因爲重定向而發生的。所以我使用的代碼從 https://stackoverflow.com/a/12628971/1312043

它的工作很好，但有時不完美的工作。 我的代碼：

function isValidUrl($url){ 
    // first do some quick sanity checks: 
    if(!$url || !is_string($url)){ 
     return false; 
    } 
    // quick check url is roughly a valid http request: (http://blah/...) 
    if(! preg_match('/^http(s)?:\/\/[a-z0-9-]+(.[a-z0-9-]+)*(:[0-9]+)?(\/.*)?$/i', $url)){ 
     return false; 
    } 
    // the next bit could be slow: 
    if(getHttpResponseCode_using_curl($url) != 200){ 
     return false; 
    } 
    // all good! 
    return true; 
} 

function getHttpResponseCode_using_curl($url, $followredirects = false){ 
    // returns int responsecode, or false (if url does not exist or connection timeout occurs) 
    // NOTE: could potentially take up to 0-30 seconds , blocking further code execution (more or less depending on connection, target site, and local timeout settings)) 
    // if $followredirects == false: return the FIRST known httpcode (ignore redirects) 
    // if $followredirects == true : return the LAST known httpcode (when redirected) 
    if(! $url || ! is_string($url)){ 
     return false; 
    } 
    $ch = @curl_init($url); 
    if($ch === false){ 
     return false; 
    } 
    @curl_setopt($ch, CURLOPT_HEADER   ,true); // we want headers 
    @curl_setopt($ch, CURLOPT_NOBODY   ,true); // dont need body 
    @curl_setopt($ch, CURLOPT_RETURNTRANSFER ,true); // catch output (do NOT print!) 
    if($followredirects){ 
     @curl_setopt($ch, CURLOPT_FOLLOWLOCATION ,true); 
     @curl_setopt($ch, CURLOPT_MAXREDIRS  ,10); // fairly random number, but could prevent unwanted endless redirects with followlocation=true 
    }else{ 
     @curl_setopt($ch, CURLOPT_FOLLOWLOCATION ,false); 
    } 
//  @curl_setopt($ch, CURLOPT_CONNECTTIMEOUT ,5); // fairly random number (seconds)... but could prevent waiting forever to get a result 
//  @curl_setopt($ch, CURLOPT_TIMEOUT  ,6); // fairly random number (seconds)... but could prevent waiting forever to get a result 
//  @curl_setopt($ch, CURLOPT_USERAGENT  ,"Mozilla/5.0 (Windows NT 6.0) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1"); // pretend we're a regular browser 
    @curl_exec($ch); 
    if(@curl_errno($ch)){ // should be 0 
     @curl_close($ch); 
     return false; 
    } 
    $code = @curl_getinfo($ch, CURLINFO_HTTP_CODE); // note: php.net documentation shows this returns a string, but really it returns an int 
    @curl_close($ch); 
    return $code; 
} 

例如，如果我想查這個網址：isValidUrl（「http://www.shawonbd.com.be/check_me.php」） 它的響應，例如確定，但其錯誤:( 有沒有什麼辦法讓完美的結果 感謝

？

Answer 1

您可以使用get_headers（http://php.net/manual/en/function.get-headers.php）功能。