144 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
<?php
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class Follow
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{
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    // constants
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    const USER_AGENT = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36";
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    const ERROR_CURL_INIT = "Couldn't initialize a cURL handle";
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    const ERROR_CURL_CODE = "Could not curl_getinfo the HTTP code";
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    const ERROR_CURL_REDIRECT = "Could not curl_getinfo the redirect URL";
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    // properties
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    public string $url;
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    public string $next;
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    public int $code;
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    public int $step;
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    public bool $redirect;
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    public array $path;
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    public array $error;
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    // constructor
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    public function __construct(string $url)
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    {
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        $this->url = $url;
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        $this->next = '';
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        $this->code = 0;
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        $this->step = 1;
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        $this->redirect = false;
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        $this->error = [];
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        $this->path[$this->step] = [
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          'step' => $this->step,
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          'url' => $this->url,
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          'code' => null,
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          'next' => null ];
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    }
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    // create an error message
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    private function setError(array $error): void
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    {
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        $this->error = $error;
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    }
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    // add an entry to the URL path
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    private function addPath(int $step, array $path): void
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    {
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        $this->path[$step] = $path;
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    }
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    // update a path entry
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    public function updatePath(int $step, string $key, string $value): void
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    {
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        $this->path[$step][$key] = $value;
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    }
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    // create a curl request for a URL
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    public function getHttpCode()
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    {
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        // initate curl request
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        $ch = curl_init();
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        if (!$ch) {
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            $this->setError = ['type' => 'curl', 'message' => self::ERROR_CURL_INIT];
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            return false;
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        }
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        // set request headers and execute
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        $response = curl_setopt($ch, CURLOPT_URL, $this->url);
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        $response = curl_setopt($ch, CURLOPT_HEADER, true); // enable this for debugging
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        $response = curl_setopt($ch, CURLOPT_HTTPGET, true); // redundant but making sure it's a GET
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        $response = curl_setopt($ch, CURLOPT_NOBODY, false); // settings this to true was returning 405s
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        $response = curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
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        $response = curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // return output instead of going to screen
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        $response = curl_setopt($ch, CURLOPT_TIMEOUT, 60);
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        $response = curl_setopt($ch, CURLOPT_USERAGENT, self::USER_AGENT);
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        $response = curl_exec($ch);
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        // check for a response
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        if (empty($response))
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        {
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            $this->setError(['type' => 'curl', 'message' => curl_error($ch)]);
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            curl_close($ch);
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        }
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        else
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        {
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            // get the http status code
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            if (curl_getinfo($ch, CURLINFO_HTTP_CODE))
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            {
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                $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
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                $this->code = ($code) ? $code : 0;
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                if ($code == 200) {
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                  $this->updatePath($this->step, 'code', $this->code);
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                  return true;
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                }
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            }
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            else
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            {
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                $this->code = 0;
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                $this->setError(['type' => 'curl', 'message' => self::ERROR_CURL_CODE]);
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                return false;
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            }
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            // get any redirect url to follow next
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            if (curl_getinfo($ch, CURLINFO_REDIRECT_URL))
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            {
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                $next = curl_getinfo($ch, CURLINFO_REDIRECT_URL);
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                $this->redirect = ($next) ? true : false;
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                $this->next = ($next) ? $next : '';
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            }
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            else
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            {
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                $this->redirect = false;
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                $this->next = '';
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            }
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            // close the session
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            curl_close($ch);
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            // update the current path
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            $this->updatePath($this->step, 'code', $this->code);
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            $this->updatePath($this->step, 'next', $this->next);
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            // start the next path
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            $this->step++;
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            $this->addPath(
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              $this->step,
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              [
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                'step' => $this->step,
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                'url' => $this->next,
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                'code' => null,
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                'next' => null
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              ]);
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            return true;
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        }
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        // return false if we get here
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        return false;
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    }
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    // get the final URL redirect
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    public function getFinalRedirect(): string
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    {
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        $last = end($this->path);
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        return $last['url'];
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    }
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}
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?>
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