如何通过PHP检查URL是否存在？

Answers:

296

这里：

$file = 'http://www.domain.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;
}

从这里和上面帖子的下面，有一个curl解决方案：

function url_exists($url) {
    if (!$fp = curl_init($url)) return false;
    return true;
}
— karim79
source
18
恐怕CURL方式不能这样工作。检查了这一点： stackoverflow.com/questions/981954/...
— viam0Zah
4
一些网站的$file_headers[0]错误页面上有所不同。例如youtube.com。其错误页面的值为HTTP/1.0 404 Not Found（差异为1.0和1.1）。那该怎么办呢？
— 克里希纳（Krishna Raj）K
21
也许使用strpos($headers[0], '404 Not Found')可能会达到目的
— alexandru.topliceanu 2012年
12
@马克同意了！要澄清，strpos($headers[0], '404')更好！
— alexandru.topliceanu 2015年
1
@ karim79谨防SSRF和XSPA攻击
— M
55

当确定php中是否存在URL时，需要注意以下几点：

  • 网址本身是否有效（字符串，不能为空，语法良好），因此可以快速检查服务器端。
  • 等待响应可能会花费一些时间并阻塞代码执行。
  • 并非get_headers（）返回的所有标头格式都正确。
  • 使用curl（如果可以）。
  • 阻止获取整个正文/内容，但仅请求标头。
  • 考虑重定向网址：
    • 您是否要返回第一个代码？
    • 还是遵循所有重定向并返回最后的代码？
    • 您可能最终得到200，但可以使用meta标签或javascript进行重定向。弄清楚之后会发生什么很难。

请记住，无论使用哪种方法，等待响应都需要时间。
所有代码都可能（并且可能会）停止，直到您知道结果或请求超时。

例如：如果网址无效或无法访问，以下代码可能需要很长时间才能显示页面：

<?php
$urls = getUrls(); // some function getting say 10 or more external links

foreach($urls as $k=>$url){
  // this could potentially take 0-30 seconds each
  // (more or less depending on connection, target site, timeout settings...)
  if( ! isValidUrl($url) ){
    unset($urls[$k]);
  }
}

echo "yay all done! now show my site";
foreach($urls as $url){
  echo "<a href=\"{$url}\">{$url}</a><br/>";
}

以下功能可能会有所帮助，您可能需要对其进行修改以适合您的需求：

    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){
//      if(getHttpResponseCode_using_getheaders($url) != 200){  // use this one if you cant use curl
            return false;
        }
        // all good!
        return true;
    }

    function getHttpResponseCode_using_curl($url, $followredirects = true){
        // 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;
    }

    function getHttpResponseCode_using_getheaders($url, $followredirects = true){
        // returns string responsecode, or false if no responsecode found in headers (or url does not exist)
        // 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;
        }
        $headers = @get_headers($url);
        if($headers && is_array($headers)){
            if($followredirects){
                // we want the the last errorcode, reverse array so we start at the end:
                $headers = array_reverse($headers);
            }
            foreach($headers as $hline){
                // search for things like "HTTP/1.1 200 OK" , "HTTP/1.0 200 OK" , "HTTP/1.1 301 PERMANENTLY MOVED" , "HTTP/1.1 400 Not Found" , etc.
                // note that the exact syntax/version/output differs, so there is some string magic involved here
                if(preg_match('/^HTTP\/\S+\s+([1-9][0-9][0-9])\s+.*/', $hline, $matches) ){// "HTTP/*** ### ***"
                    $code = $matches[1];
                    return $code;
                }
            }
            // no HTTP/xxx found in headers:
            return false;
        }
        // no headers :
        return false;
    }
— MoonLite
source
由于某种原因，在我的情况下，getHttpResponseCode_using_curl（）始终返回200。
— TD_Nijboer 2014年
2
如果有人遇到相同的问题，请检查dns-nameservers。使用不带Followredirects的opendns stackoverflow.com/a/11072947/1829460
— TD_Nijboer 2014年
+1是处理重定向的唯一答案。改变了return $code以if($code == 200){return true;} return false;理清只成功
— Birrel
@PKHunter：否。我的快速preg_match正则表达式是一个简单的示例，不会匹配其中列出的所有URL。请参见以下测试网址：regex101.com/r/EpyDDc/2 如果您想要更好的网址，请使用diegoperini中链接（mathiasbynens.be/demo/url-regex）上列出的网址替换该网址；似乎都匹配，请参见以下测试链接：regex101.com/r/qMQp23/1
— MoonLite
46 
$headers = @get_headers($this->_value);
if(strpos($headers[0],'200')===false)return false;

因此，只要您与网站联系并获得200以外的其他信息，它就可以正常工作

— 月球网76
source
13
但是，如果是重定向该怎么办？该域仍然有效，但将被忽略。
— 埃里克·莱罗伊
4
上面一行：return strpos(@get_headers($url)[0],'200') === false ? false : true。可能有用。
— Dejv 2015年
PHP中的$ this是对当前对象的引用。参考：php.net/manual/en/language.oop5.basic.php入门：phpro.org/tutorials/Object-Oriented-Programming-with-PHP.html 最有可能的代码片段来自一类，并且没有相应地修复。
— Marc Witteveen
18

您不能在某些服务器上使用curl您可以使用此代码

<?php
$url = 'http://www.example.com';
$array = get_headers($url);
$string = $array[0];
if(strpos($string,"200"))
  {
    echo 'url exists';
  }
  else
  {
    echo 'url does not exist';
  }
?>
— 明哈兹
source
它可能不适用于302-303重定向，例如304 Not Modified
— Zippp'1
8 
$url = 'http://google.com';
$not_url = 'stp://google.com';

if (@file_get_contents($url)): echo "Found '$url'!";
else: echo "Can't find '$url'.";
endif;
if (@file_get_contents($not_url)): echo "Found '$not_url!";
else: echo "Can't find '$not_url'.";
endif;

// Found 'http://google.com'!Can't find 'stp://google.com'.
— 兰迪·斯克雷特卡（Randy Skretka）
source
2
如果关闭allow-url-fopen，则此功能将无效。- php.net/manual/en/...
— 丹尼尔·保罗瑟尔斯
2
我建议只读取第一个字节... if（@file_get_contents（$ url，false，NULL，0,1））
— Daniel Valland '16
8 
function URLIsValid($URL)
{
    $exists = true;
    $file_headers = @get_headers($URL);
    $InvalidHeaders = array('404', '403', '500');
    foreach($InvalidHeaders as $HeaderVal)
    {
            if(strstr($file_headers[0], $HeaderVal))
            {
                    $exists = false;
                    break;
            }
    }
    return $exists;
}
— 蕾拉
source
8

我使用此功能：

/**
 * @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";
    }
}
— 易山
source
5

karim79的get_headers（）解决方案对我不起作用，因为我在Pinterest上获得了疯狂的结果。

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] => 
)

无论如何，该开发人员演示了cURL比get_headers（）更快：

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

由于许多人要求karim79修复cURL解决方案，因此这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;
}

让我解释一下卷曲选项：

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：在字符串中包含标题

CURLOPT_NOBODY：不要在字符串中包含主体

CURLOPT_USERAGENT：某些网站需要正常运行（例如：https : //plus.google.com）

附加说明：在此函数中，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：我将标头字符串和用户标头[0]展开，以确保仅验证返回码和消息（例如：200、404、405等）

附加说明3：有时仅验证代码404是不够的（请参阅单元测试），因此有一个可选的$ failCodeList参数提供要拒绝的所有代码列表。

当然，这是使我的代码合法化的单元测试（包括所有流行的社交网络）：

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"));
}

所有人都取得了巨大的成功，

蒙特利尔的JonathanParent-Lévesque

— 乔纳森·父母·勒维斯克
source
4 
function urlIsOk($url)
{
    $headers = @get_headers($url);
    $httpStatus = intval(substr($headers[0], 9, 3));
    if ($httpStatus<400)
    {
        return true;
    }
    return false;
}
— 尖顶
source
3

相当快：

function http_response($url){
    $resURL = curl_init(); 
    curl_setopt($resURL, CURLOPT_URL, $url); 
    curl_setopt($resURL, CURLOPT_BINARYTRANSFER, 1); 
    curl_setopt($resURL, CURLOPT_HEADERFUNCTION, 'curlHeaderCallback'); 
    curl_setopt($resURL, CURLOPT_FAILONERROR, 1); 
    curl_exec ($resURL); 
    $intReturnCode = curl_getinfo($resURL, CURLINFO_HTTP_CODE); 
    curl_close ($resURL); 
    if ($intReturnCode != 200 && $intReturnCode != 302 && $intReturnCode != 304) { return 0; } else return 1;
}

echo 'google:';
echo http_response('http://www.google.com');
echo '/ ogogle:';
echo http_response('http://www.ogogle.com');
— 塞巴斯蒂安·拉斯（Sebastian Lasse）
source
— 杰克
当网址存在时，我得到此异常：无法调用CURLOPT_HEADERFUNCTION
— safiot 2012年
3

以上所有解决方案+多余的糖。（最终的AIO解决方案） 

/**
 * Check that given URL is valid and exists.
 * @param string $url URL to check
 * @return bool TRUE when valid | FALSE anyway
 */
function urlExists ( $url ) {
    // Remove all illegal characters from a url
    $url = filter_var($url, FILTER_SANITIZE_URL);

    // Validate URI
    if (filter_var($url, FILTER_VALIDATE_URL) === FALSE
        // check only for http/https schemes.
        || !in_array(strtolower(parse_url($url, PHP_URL_SCHEME)), ['http','https'], true )
    ) {
        return false;
    }

    // Check that URL exists
    $file_headers = @get_headers($url);
    return !(!$file_headers || $file_headers[0] === 'HTTP/1.1 404 Not Found');
}

例： 

var_dump ( urlExists('http://stackoverflow.com/') );
// Output: true;
— 朱尼德·阿塔里（Junaid Atari）
source
3

检查网址是在线还是离线-

function get_http_response_code($theURL) {
    $headers = @get_headers($theURL);
    return substr($headers[0], 9, 3);
}
— 霍萨姆·阿尔扎
source
2

这是一个仅读取源代码的第一个字节的解决方案...如果file_get_contents失败，则返回false ...这也适用于图像之类的远程文件。

 function urlExists($url)
{
    if (@file_get_contents($url,false,NULL,0,1))
    {
        return true;
    }
    return false;
}
— 丹尼尔·瓦兰德
source
0

简单的方法是卷曲（也更快）

<?php
$mylinks="http://site.com/page.html";
$handlerr = curl_init($mylinks);
curl_setopt($handlerr,  CURLOPT_RETURNTRANSFER, TRUE);
$resp = curl_exec($handlerr);
$ht = curl_getinfo($handlerr, CURLINFO_HTTP_CODE);


if ($ht == '404')
     { echo 'OK';}
else { echo 'NO';}

?>
— 托杜亚
source
0

检查URL是否有效的其他方法可以是：

<?php

  if (isValidURL("http://www.gimepix.com")) {
      echo "URL is valid...";
  } else {
      echo "URL is not valid...";
  }

  function isValidURL($url) {
      $file_headers = @get_headers($url);
      if (strpos($file_headers[0], "200 OK") > 0) {
         return true;
      } else {
        return false;
      }
  }
?>
— 安东尼奥·卡洛斯·巴博萨
source
0

get_headers（）返回一个数组，其中包含服务器响应HTTP请求而发送的标头。 

$image_path = 'https://your-domain.com/assets/img/image.jpg';

$file_headers = @get_headers($image_path);
//Prints the response out in an array
//print_r($file_headers); 

if($file_headers[0] == 'HTTP/1.1 404 Not Found'){
   echo 'Failed because path does not exist.</br>';
}else{
   echo 'It works. Your good to go!</br>';
}
— Jeacovy Gayle
source
0

cURL可以返回HTTP代码我不认为所有这些额外的代码都是必需的吗？

function urlExists($url=NULL)
    {
        if($url == NULL) return false;
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_TIMEOUT, 5);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $data = curl_exec($ch);
        $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch); 
        if($httpcode>=200 && $httpcode<300){
            return true;
        } else {
            return false;
        }
    }
— 阿伦·维托（Arun Vitto）
source
0

检查404的标头时要考虑的一件事是站点不会立即生成404的情况。

许多站点会检查PHP / ASP（et cetera）源中是否存在页面，并将您转发到404页面。在那些情况下，头基本上由生成的404的头扩展。在这种情况下，404错误不是出现在标题的第一行，而是出现在第十行。

$array = get_headers($url);
$string = $array[0];
print_r($string) // would generate:

Array ( 
[0] => HTTP/1.0 301 Moved Permanently 
[1] => Date: Fri, 09 Nov 2018 16:12:29 GMT 
[2] => Server: Apache/2.4.34 (FreeBSD) LibreSSL/2.7.4 PHP/7.0.31 
[3] => X-Powered-By: PHP/7.0.31 
[4] => Set-Cookie: landing=%2Freed-diffuser-fig-pudding-50; path=/; HttpOnly 
[5] => Location: /reed-diffuser-fig-pudding-50/ 
[6] => Content-Length: 0 
[7] => Connection: close 
[8] => Content-Type: text/html; charset=utf-8 
[9] => HTTP/1.0 404 Not Found 
[10] => Date: Fri, 09 Nov 2018 16:12:29 GMT 
[11] => Server: Apache/2.4.34 (FreeBSD) LibreSSL/2.7.4 PHP/7.0.31 
[12] => X-Powered-By: PHP/7.0.31 
[13] => Set-Cookie: landing=%2Freed-diffuser-fig-pudding-50%2F; path=/; HttpOnly 
[14] => Connection: close 
[15] => Content-Type: text/html; charset=utf-8 
)
— Lexib0y
source
0

我进行了一些测试，以查看我网站上的链接是否有效-当第三方更改链接时提醒我。我的网站存在证书配置错误的问题，这意味着php的get_headers无法正常工作。

所以，我读到卷曲更快，因此决定尝试一下。然后我遇到了一个linkedin问题，这给了我一个999错误，原来是用户代理问题。

我不在乎证书是否对该测试无效，并且我不在乎响应是否为重定向。

然后我想如果卷曲失败的话还是要使用get_headers。

搏一搏....

/**
 * 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;
}
— pgee70
source
-2

有点旧的线程，但是..我这样做：

$file = 'http://www.google.com';
$file_headers = @get_headers($file);
if ($file_headers) {
    $exists = true;
} else {
    $exists = false;
}
— hackdotslashdotkill
source
Sorta ..但不完全是。
— hackdotslashdotkill
您的答案如何更好？
— 贾哈
@Jah显然不是-2。我大概张贴了这个下旬的一个晚上，当我整天盯着屏幕后，半睡半醒..
— hackdotslashdotkill
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