How can I check if a URL exists via PHP?

Question

How do I check if a URL exists (not 404) in PHP?

Answer 1

karim79's get_headers() solution didn't worked for me as I gotten crazy results with 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] => 
) 

Anyway, this developer demonstrates that cURL is way faster than get_headers():

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

Since many people asked for karim79 to fix is cURL solution, here's the solution I built today.

/**
* 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;
}

Let me explains the curl options:

CURLOPT_RETURNTRANSFER: return a string instead of displaying the calling page on the screen.

CURLOPT_SSL_VERIFYPEER: cUrl won't checkout the certificate

CURLOPT_HEADER: include the header in the string

CURLOPT_NOBODY: don't include the body in the string

CURLOPT_USERAGENT: some site needs that to function properly (by example : https://plus.google.com)

---

Additional note: In this function I'm using Diego Perini's regex for validating the URL before sending the request:

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

Additional note 2: I explode the header string and user headers[0] to be sure to only validate only the return code and message (example: 200, 404, 405, etc.)

Additional note 3: Sometime validating only the code 404 is not enough (see the unit test), so there's an optional $failCodeList parameter to supply all the code list to reject.

And, of course, here's the unit test (including all the popular social network) to legitimates my coding:

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"));
}

Great success to all,

Jonathan Parent-Lévesque from Montreal

Answer 2

to check if url is online or offline ---

function get_http_response_code($theURL) {
    $headers = @get_headers($theURL);
    return substr($headers[0], 9, 3);
}

Answer 3

function url_exists($url) {
    $headers = @get_headers($url);
    return (strpos($headers[0],'200')===false)? false:true;
}

Answer 4

I run some tests to see if links on my site are valid - alerts me to when third parties change their links. I was having an issue with a site that had a poorly configured certificate that meant that php's get_headers didn't work.

SO, I read that curl was faster and decided to give that a go. then i had an issue with linkedin which gave me a 999 error, which turned out to be a user agent issue.

I didn't care if the certificate was not valid for this test, and i didn't care if the response was a re-direct.

Then I figured use get_headers anyway if curl was failing....

Give it a go....

/**
 * returns true/false if the $url is present.
 *
 * @param string $url assumes this is a valid url.
 *
 * @return bool
 */
private function url_exists (string $url): bool
{
  $ch = curl_init($url);
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($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 >= HTTP_OK && $http_code < HTTP_BAD_REQUEST) || $http_code === 999)
  {
    curl_close($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(array('http' => array('method' => 'HEAD')));
  $file_headers = @get_headers($url);
  if ($file_headers)
  {
    $response_code = substr($file_headers[0], 9, 3);
    return $response_code >= 200 && $response_code < 400;
  }
  return FALSE;
}

Answer 5

Here:

$file = 'http://www.example.com/somefile.jpg';
$file_headers = @get_headers($file);
if(!$file_headers || $file_headers[0] == 'HTTP/1.1 404 Not Found') {
    $exists = false;
}
else {
    $exists = true;
}

From here and right below the above post, there's a curl solution:

function url_exists($url) {
    return curl_init($url) !== false;
}

Answer 6

I use this function:

/**
 * @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";
    }
}