cURL question, how to verify if URL is valid

[AndyB]

I would like to be able to use cURL and have the script determine if the file path is reachable. Here's an example of code that verifies the domain is reachable:

<?php

// Create a curl handle to a non-existing location
$ch = curl_init('http://www.google.com/');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

if (curl_exec($ch) === false) {
    echo 'Curl error: ' . curl_error($ch);
}
else
{
    echo 'Operation completed without any errors';
}

// Close handle
curl_close($ch);

?>

This works fine. But if I change the path to something like this:

http://www.google.com/path_to_invalid_image.jpg

it still shows as a valid path.

So how would I modify the code to show an error if the path to a file is invalid?

 

[Chris D]

I'm not sure how to do it with cURL actually.

I tend to use the XenForo_Helper_Http class.

Incredibly easy to use.

But in relation to the code you've already written, I think you need this:

$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

Obviously if $httpCode contains 404, 403 etc. then you can throw an error.

 

[KenSmith]

To do it with curl, add
curl_setopt($ch, CURLOPT_FAILONERROR, true);

If you just want to make sure the URL exists, you should be also doing a HEAD request instead of a GET to avoid transferring the data.

For that, see the option CURL_NOBODY.

 

[AndyB]

Hi Ken,

Thank you kindly for your information, works perfectly.

<?php

// Create a curl handle to a non-existing location
$ch = curl_init('http://www.google.com/path_to_invalid_image.jpg');

curl_setopt($ch, CURLOPT_FAILONERROR, true);
curl_setopt($ch, CURLOPT_NOBODY, true);

if (curl_exec($ch) === false) {
    echo 'Curl error: ' . curl_error($ch);
}
else
{
    echo 'Operation completed without any errors';
}

// Close handle
curl_close($ch);

?>

 

[DRE]

Is that related to this? http://xenforo.com/community/threads/broken-images-replacement.59180/

 

[AndyB]

Is that related to this? http://xenforo.com/community/threads/broken-images-replacement.59180/

Hi DRE,

Indeed it's related to that thread. However I needed to improve a custom code I wrote that converts linked images to attachments, one of the short comings was that I didn't verify if the linked image could be read.