如何通过PHP检查URL是否存在?

我如何检查一个URL是否存在(不是404)在PHP?

当前回答

karim79的get_headers()解决方案并没有为我工作，因为我得到了疯狂的结果与Pinterest。

get_headers(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

Array
(
    [url] => https://www.pinterest.com/jonathan_parl/
    [exists] => 
)

get_headers(): Failed to enable crypto

Array
(
    [url] => https://www.pinterest.com/jonathan_parl/
    [exists] => 
)

get_headers(https://www.pinterest.com/jonathan_parl/): failed to open stream: operation failed

Array
(
    [url] => https://www.pinterest.com/jonathan_parl/
    [exists] => 
)

不管怎样，这个开发人员演示了cURL比get_headers()快得多:

http://php.net/manual/fr/function.get-headers.php#104723

由于许多人要求karim79修复的是cURL解决方案，这里是我今天构建的解决方案。

/**
* Send an HTTP request to a the $url and check the header posted back.
*
* @param $url String url to which we must send the request.
* @param $failCodeList Int array list of code for which the page is considered invalid.
*
* @return Boolean
*/
public static function isUrlExists($url, array $failCodeList = array(404)){

    $exists = false;

    if(!StringManager::stringStartWith($url, "http") and !StringManager::stringStartWith($url, "ftp")){

        $url = "https://" . $url;
    }

    if (preg_match(RegularExpression::URL, $url)){

        $handle = curl_init($url);


        curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);

        curl_setopt($handle, CURLOPT_SSL_VERIFYPEER, false);

        curl_setopt($handle, CURLOPT_HEADER, true);

        curl_setopt($handle, CURLOPT_NOBODY, true);

        curl_setopt($handle, CURLOPT_USERAGENT, true);


        $headers = curl_exec($handle);

        curl_close($handle);


        if (empty($failCodeList) or !is_array($failCodeList)){

            $failCodeList = array(404); 
        }

        if (!empty($headers)){

            $exists = true;

            $headers = explode(PHP_EOL, $headers);

            foreach($failCodeList as $code){

                if (is_numeric($code) and strpos($headers[0], strval($code)) !== false){

                    $exists = false;

                    break;  
                }
            }
        }
    }

    return $exists;
}

让我来解释一下旋度选项:

CURLOPT_RETURNTRANSFER:返回一个字符串，而不是在屏幕上显示调用页面。

CURLOPT_SSL_VERIFYPEER: cUrl不会签出证书

CURLOPT_HEADER:在字符串中包含头文件

CURLOPT_NOBODY:不要在字符串中包含body

CURLOPT_USERAGENT:一些站点需要它才能正常运行(例如:https://plus.google.com)

附加说明:在这个函数中，我使用Diego Perini的正则表达式在发送请求之前验证URL:

const URL = "%^(?:(?:https?|ftp)://)(?:\S+(?::\S*)?@|\d{1,3}(?:\.\d{1,3}){3}|(?:(?:[a-z\d\x{00a1}-\x{ffff}]+-?)*[a-z\d\x{00a1}-\x{ffff}]+)(?:\.(?:[a-z\d\x{00a1}-\x{ffff}]+-?)*[a-z\d\x{00a1}-\x{ffff}]+)*(?:\.[a-z\x{00a1}-\x{ffff}]{2,6}))(?::\d+)?(?:[^\s]*)?$%iu"; //@copyright Diego Perini

附加说明2:我将标题字符串和用户标题[0]分开，以确保只验证返回代码和消息(例如:200、404、405等)。

附加说明3:有时仅验证代码404是不够的(参见单元测试)，因此有一个可选的$failCodeList参数提供所有要拒绝的代码列表。

当然，这里还有单元测试(包括所有流行的社交网络)来证明我的代码是合法的:

public function testIsUrlExists(){

//invalid
$this->assertFalse(ToolManager::isUrlExists("woot"));

$this->assertFalse(ToolManager::isUrlExists("https://www.facebook.com/jonathan.parentlevesque4545646456"));

$this->assertFalse(ToolManager::isUrlExists("https://plus.google.com/+JonathanParentL%C3%A9vesque890800"));

$this->assertFalse(ToolManager::isUrlExists("https://instagram.com/mariloubiz1232132/", array(404, 405)));

$this->assertFalse(ToolManager::isUrlExists("https://www.pinterest.com/jonathan_parl1231/"));

$this->assertFalse(ToolManager::isUrlExists("https://regex101.com/546465465456"));

$this->assertFalse(ToolManager::isUrlExists("https://twitter.com/arcadefire4566546"));

$this->assertFalse(ToolManager::isUrlExists("https://vimeo.com/**($%?%$", array(400, 405)));

$this->assertFalse(ToolManager::isUrlExists("https://www.youtube.com/user/Darkjo666456456456"));


//valid
$this->assertTrue(ToolManager::isUrlExists("www.google.ca"));

$this->assertTrue(ToolManager::isUrlExists("https://www.facebook.com/jonathan.parentlevesque"));

$this->assertTrue(ToolManager::isUrlExists("https://plus.google.com/+JonathanParentL%C3%A9vesque"));

$this->assertTrue(ToolManager::isUrlExists("https://instagram.com/mariloubiz/"));

$this->assertTrue(ToolManager::isUrlExists("https://www.facebook.com/jonathan.parentlevesque"));

$this->assertTrue(ToolManager::isUrlExists("https://www.pinterest.com/"));

$this->assertTrue(ToolManager::isUrlExists("https://regex101.com"));

$this->assertTrue(ToolManager::isUrlExists("https://twitter.com/arcadefire"));

$this->assertTrue(ToolManager::isUrlExists("https://vimeo.com/"));

$this->assertTrue(ToolManager::isUrlExists("https://www.youtube.com/user/Darkjo666"));
}

祝大家取得巨大成功，

Jonathan Parent-Lévesque在蒙特利尔报道

2015-08-19 20:46:07

其他回答

这是一个解决方案，只读取源代码的第一个字节…如果file_get_contents失败，返回false…这也适用于远程文件，如图像。

 function urlExists($url)
{
    if (@file_get_contents($url,false,NULL,0,1))
    {
        return true;
    }
    return false;
}

2016-10-01 20:14:32

我使用这个函数:

/**
 * @param $url
 * @param array $options
 * @return string
 * @throws Exception
 */
function checkURL($url, array $options = array()) {
    if (empty($url)) {
        throw new Exception('URL is empty');
    }

    // list of HTTP status codes
    $httpStatusCodes = array(
        100 => 'Continue',
        101 => 'Switching Protocols',
        102 => 'Processing',
        200 => 'OK',
        201 => 'Created',
        202 => 'Accepted',
        203 => 'Non-Authoritative Information',
        204 => 'No Content',
        205 => 'Reset Content',
        206 => 'Partial Content',
        207 => 'Multi-Status',
        208 => 'Already Reported',
        226 => 'IM Used',
        300 => 'Multiple Choices',
        301 => 'Moved Permanently',
        302 => 'Found',
        303 => 'See Other',
        304 => 'Not Modified',
        305 => 'Use Proxy',
        306 => 'Switch Proxy',
        307 => 'Temporary Redirect',
        308 => 'Permanent Redirect',
        400 => 'Bad Request',
        401 => 'Unauthorized',
        402 => 'Payment Required',
        403 => 'Forbidden',
        404 => 'Not Found',
        405 => 'Method Not Allowed',
        406 => 'Not Acceptable',
        407 => 'Proxy Authentication Required',
        408 => 'Request Timeout',
        409 => 'Conflict',
        410 => 'Gone',
        411 => 'Length Required',
        412 => 'Precondition Failed',
        413 => 'Payload Too Large',
        414 => 'Request-URI Too Long',
        415 => 'Unsupported Media Type',
        416 => 'Requested Range Not Satisfiable',
        417 => 'Expectation Failed',
        418 => 'I\'m a teapot',
        422 => 'Unprocessable Entity',
        423 => 'Locked',
        424 => 'Failed Dependency',
        425 => 'Unordered Collection',
        426 => 'Upgrade Required',
        428 => 'Precondition Required',
        429 => 'Too Many Requests',
        431 => 'Request Header Fields Too Large',
        449 => 'Retry With',
        450 => 'Blocked by Windows Parental Controls',
        500 => 'Internal Server Error',
        501 => 'Not Implemented',
        502 => 'Bad Gateway',
        503 => 'Service Unavailable',
        504 => 'Gateway Timeout',
        505 => 'HTTP Version Not Supported',
        506 => 'Variant Also Negotiates',
        507 => 'Insufficient Storage',
        508 => 'Loop Detected',
        509 => 'Bandwidth Limit Exceeded',
        510 => 'Not Extended',
        511 => 'Network Authentication Required',
        599 => 'Network Connect Timeout Error'
    );

    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

    if (isset($options['timeout'])) {
        $timeout = (int) $options['timeout'];
        curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
    }

    curl_exec($ch);
    $returnedStatusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if (array_key_exists($returnedStatusCode, $httpStatusCodes)) {
        return "URL: '{$url}' - Error code: {$returnedStatusCode} - Definition: {$httpStatusCodes[$returnedStatusCode]}";
    } else {
        return "'{$url}' does not exist";
    }
}

2015-12-10 13:04:01

到目前为止使用get_headers()的最佳和最简单的答案最好检查字符串“200 ok”。这比检查要好得多

$file_headers = @get_headers($file-path);
$file_headers[0];

因为有时数组键值会变化。所以最好的办法是检查“200 ok”。任何URL都将在get_headers()响应的任何地方有“200 ok”。

function url_exist($url) {
        $urlheaders = get_headers($url);
        //print_r($urlheaders);
        $urlmatches  = preg_grep('/200 ok/i', $urlheaders);
         if(!empty($urlmatches)){
           return true;
         }else{
           return false;
         }
}

现在检查函数是否为真或假

if(url_exist(php-url-variable-here)
  URL exist
}else{
  URL don't exist
}

2020-08-08 05:57:39

我运行一些测试，看看我的网站上的链接是否有效-提醒我当第三方改变他们的链接。我有一个网站的问题，有一个配置不良的证书，这意味着php的get_headers不能工作。

所以，我读到卷曲更快，并决定给一个尝试。然后我在领英上遇到了一个问题，给了我一个999错误，后来证明是用户代理的问题。

我不关心证书是否对该测试无效，也不关心响应是否为重定向。

然后我认为使用get_headers无论如何，如果卷曲失败....

试试看....

/**
 * returns true/false if the $url is valid.
 *
 * @param string $url assumes this is a valid url.
 *
 * @return bool
 */
private function urlExists(string $url): bool
{
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);     // do not output response in stdout
    curl_setopt($ch, CURLOPT_NOBODY, true);             // this does a head request to make it faster.
    curl_setopt($ch, CURLOPT_HEADER, true);             // just the headers
    curl_setopt($ch, CURLOPT_SSL_VERIFYSTATUS, false);  // turn off that pesky ssl stuff - some sys admins can't get it right.
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    // set a real user agent to stop linkedin getting upset.
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36');
    curl_exec($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    if (($http_code >= 200 && $http_code < 400) || $http_code === 999) {
        curl_close($ch);
        return true;
    }
    //$error = curl_error($ch); // used for debugging.
    curl_close($ch);

    // just try the get_headers - it might work!
    stream_context_set_default(
        ['http' => ['method' => 'HEAD']]
    );
    $file_headers = @get_headers($url);

    if ($file_headers !== false) {
        $response_code = substr($file_headers[0], 9, 3);
        return $response_code >= 200 && $response_code < 400;
    }

    return false;
}

2018-11-15 11:46:44