Check if remote images exist PHP - php

Question

I'm using the last.fm API to get the recent tracks and to search albums and artists etc.
When images are returned from the API, they sometimes doesn't exist. An empty URL string is easily replaced with a placeholder image, but when an image url is given and it returns a 404, that's when my problem comes in.
I tried using fopen($url, 'r') for checking if images are available, but sometimes this gives me the following error:
Warning: fopen(http://ec1.images-amazon.com/images/I/31II3Cn67jL.jpg) [function.fopen]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in file.php on line 371
Also, I don't want to use cURL, because there are a lot of images to check and it slows the website down a lot.
What would the best solution be for checking images?
I'm now using the following solution:
<img src="..." onerror='this.src="core/img/no-image.jpg"' alt="..." title="..." />
Is this useful?
Any help is appreciated

Answer 1

You can use getimagesize since you are dealing with images it would also return mime type of the image
$imageInfo = #getimagesize("http://www.remoteserver.com/image.jpg");
You can also use CURL to check HTTP response code of am image or any URL
$ch = curl_init("http://www.remoteserver.com/image.jpg");
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 2);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
curl_exec($ch);
if(curl_getinfo($ch, CURLINFO_HTTP_CODE) == 200)
{
// Found Image
}
curl_close($ch);

Answer 2

function fileExists($path){
return (#fopen($path,"r")==true);
}
from the manual for file_exists()

Answer 3

Depending on the number of images and frequency of failures, it's probably best to stick with your current client-side approach. Also, it looks like the images are served through Amazon CloudFront - in that case, use the client-side approach because it could just be a propagation issue with a single edge server.
Applying server-side approach will be network intensive and slow (waste of resources), especially in php because you'll need to check each image sequentially.

Answer 4

Also might be useful check the request headers, using get_headers php function as follows:
$url = "http://www.remoteserver.com/image.jpg";
$imgHeaders = #get_headers( str_replace(" ", "%20", $url) )[0];
if( $imgHeaders == 'HTTP/1.1 200 Ok' ) {
//img exist
}
elseif( $imgHeaders == 'HTTP/1.1 404 Not Found' ) {
//img doesn't exist
}

Answer 5

The following function will try to get any online resource (IMG, PDF, etc.) given by URL using get_headers, read headers and searching for string 'Not Found' in it using function strpos. If this string is found, meaning the resource given by URL is not available, this function will return FALSE, otherwise TRUE.
function isResourceAvaiable($url)
{
return !strpos(#get_headers($url)[0],'Not Found')>0;
}