Tutorial :Check whether image exists on remote URL


I am generating dynamic URLs of images for book ISBNs. I need a reliable way with PHP to check whether the images actually exist at the remote url. I tried various approaches with different PHP libraries, curl, etc., but none of them works well, some of them are downright slow. Given the fact that I need to generate (and check!) about 60 URLS for each book in my database, this is a huge waiting time. Any clues?


function checkRemoteFile($url)  {      $ch = curl_init();      curl_setopt($ch, CURLOPT_URL,$url);      // don't download content      curl_setopt($ch, CURLOPT_NOBODY, 1);      curl_setopt($ch, CURLOPT_FAILONERROR, 1);      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);        $result = curl_exec($ch);      curl_close($ch);      if($result !== FALSE)      {          return true;      }      else      {          return false;      }  }  

--> that is the fastest way if your host supports curl


Use getimagesize() method like this

$external_link = ‘http://www.example.com/example.jpg’;  if (@getimagesize($external_link)) {  echo  “image exists “;  } else {  echo  “image does not exist “;  }  


There is no "easy" way here - at a very minimum, you need to generate a HEAD request and check the resulting content type to make sure it's an image. That's not taking into account possible referrer issues. curl is the way to go here.


You could use curl. Just set the curl option CURLOPT_NOBODY to true. This will skip body information and only get the head (thus http code as well). Then, you could use the CURLOPT_FAILONERROR to turn this whole process into a true/false type check


You can use getimagesize()

Credit: http://junal.wordpress.com/2008/07/22/checking-if-an-image-url-exist/


I have been doing this for my real estate picture tracking...

$im = @imagecreatefromjpeg($pathtoimg);  if($im)    imagedestroy($im); // dont save, just ack...  elseif(!$missing[$inum])    $img404arr[] = $inum;  

It 'seems' faster than downloading the actual image, taking about .3 seconds for each from images that avg 100k.

I wish I could just do a header check and read whether I get a 200 vs a 404 without downloading anything. Anyone have that handy?


It's probably a mute point at this point, but this works for me:

function is_webfile($webfile)  {   $fp = @fopen($webfile, "r");   if ($fp !== false)    fclose($fp);     return($fp);  }  


Solution from https://www.experts-exchange.com

<?php  function url_exists($url) {      if (!$fp = curl_init($url)) return false;      return true;  }  ?>  


If the images all exist on the same remote server (or in the same network), you could run a web service on that server that will check the file system for the the image file and return a bool value indicating wheter the image exists or not.

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
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