PHP Detecting if source image url link leads to a “broken” image?

Question

Suppose you have a thumbnail generator script that accepts source images in the form of a URL. Is there a way to detect if the source URL is \"broken\" - whether nonexistent

Answer 1

I have used the following to detect attributes for remote images

$src='http://example.com/image.jpg';
list($width, $height, $type, $attr) = @getimagesize($src);

example (checking stackoverflows "Careers 2.0" image)

$src='http://sstatic.net/ads/img/careers2-ad-header-so.png';
list($width, $height, $type, $attr) = @getimagesize($src);

echo '
';
echo $width.'
';
echo $height.'
';
echo $type.'
';
echo $attr.'
';
echo '
';

If $height, $width etc is null the image is obvious not an image or the file does not exists. Using cURL is overkill and slower (even with CURLOPT_HEADER)