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Question

Is there any way to retrieve headers from <img> tag using PHP? The <img> has src attribute set to a randomly and dynamic generated PHP image, which sends header that I want to retrieve containing dynamic content based on content of the image.

Answer 1

The HTTP headers are determined by the web server when they serve the image. You can override the headers by serving the content directly from PHP. However, this is much, much slower than the web server serving the image directly. Most web servers allow for configuration to determine the HTTP headers for a given file extension.

UPDATE: Add code to respond to comment.

HTML

<a href="/images/my-image.php?type=png" />

In my-image.php:

<?php
   if( $_REQUEST['type'] == 'png' ){
        header( 'Content-Type: image/png' );
        echo file_get_contents( '/websites/mywebsite.com/web/images/my-image.jpg' );
            exit();
   }

More checks and code is available here:
http://www.php.net/manual/en/function.header.php#102175