imagecreatefromstring - catch fail - PHP

Question

I'm trying to detect if an image is an image when given a URL. To save an image from a url I used the following:

// create the image and save it
$imagefile = $URL;
$resource = imagecreatefromstring(file_get_contents($imagefile));
// X amount of quality is the last number
imagejpeg($resource, "images/covers/$imagepath.jpeg", 50);
imagedestroy($resource);

The $URL is simply an image link provided by the user.

I have tried the following:

$imagefile = $addBuildCover;
$resource = imagecreatefromstring(file_get_contents($imagefile));

if ($resource !== false) {
  $return['imageGood'] = true;  
} else {
  $return['imageBad'] = true;
}

I have tried that code and i returns the correct JSON return of 'imageBad' but it's giving me an error before which is:

Warning: file_get_contents(ewffw.png): failed to open stream: No such file or directory in /var/www/clients/client2/web3/web/process/addnewbuild.php on line 116

Warning: imagecreatefromstring(): Empty string or invalid image in /var/www/clients/client2/web3/web/process/addnewbuild.php on line 116

How do I try I catch the URL fail but not actually have an error return like above?

Answer 1

imagecreatefromstring will unfortunately warn if you pass it invalid data, so using it unnecessarily problematic.

You will have to shut it up with the error suppression operator @:

$resource = @imagecreatefromstring(file_get_contents($imagefile));

Using this operator is something usually frowned upon, but this case is one which you really do have a legitimate use case.

This approach will also take care of the warning given from file_get_contents if the file cannot be loaded. That function is not as badly behaved (there are ways to check with reasonable certainty if it will fail or not, e.g. is_readable) so you could check with code instead of using @, but since you need to suppress errors anyway and it makes no difference to you if the file read failed or not, just slapping a @ in front is IMHO fully warranted here.