Function to disable PHP script execution for WordPress wp-content/uploads folder

disable_php_script_execution.php

<?php
/**
 * Disable PHP script execution for WordPress wp-content/uploads folder.
 * - based off the WordPress permalinks rewrite code
 *
 * - https://www.saotn.org/secure-wordpress-uploads-folder-disable-php-execution/
 * - follow me on twitter: @Jan_Reilink
 * 
 * don't allow this file to be loaded directly
 */
if ( ! function_exists( 'add_action' ) ) {
	exit;
}

function disable_script_execution() {
	global $iis7;
	$path = WP_CONTENT_DIR . 'uploads';
	$filename = 'web.config';
	if ( $is_iis7 ) {
		if ( ! file_exists( $path . '/' . $filename ) ) {
			$fp = fopen( $path . '/' . $filename, 'w' );
			fwrite( $fp, '<configuration/>' );
			fclose( $fp );
		}
	
		$formatxml = PHP_EOL;
		$formatxml .= "	<handlers accessPolicy=\"Read\" />";
		$formatxml .= PHP_EOL;
			
		$doc = new DOMDocument();
		$doc->preserveWhiteSpace = false;
		if( $doc->load( $path . '/' . $filename ) === false ) {
		  return false;
		}
		$xpath = new DOMXPath( $doc );
		$read_accesspolicy = $xpath->query( '/configuration/system.webServer/handlers[starts-with(@accessPolicy,\'Read\')]' );
		if( $read_accesspolicy->length > 0 ) {
		  return true;
		}

		$xmlnodes = $xpath->query( '/configuration/system.webServer' );
		if ( $xmlnodes->length > 0 ) {
			$handlers_node = $xmlnodes->item(0);
		}
		else {
			$handlers_node = $doc->createElement( 'handlers' );
			$xmlnodes = $xpath->query( '/configuration/system.webServer' );
			if ( $xmlnodes->length > 0 ) {
				$system_webServer_node = $xmlnodes->item(0);
				$handler_fragment = $doc->createDocumentFragment();
				$rule_fragment->appendXML( $formatxml );
				$system_webServer_node->appendChild( $rule_fragment );
			}
			else {
				$system_webServer_node = $doc->createElement( 'system.webServer' );
				$rule_fragment = $doc->createDocumentFragment();
				$rule_fragment->appendXML( $formatxml );
				$system_webServer_node->appendChild( $rule_fragment );

				$xmlnodes = $xpath->query( '/configuration' );
				if ( $xmlnodes->length > 0 ) {
					$config_node = $xmlnodes->item(0);
					$config_node->appendChild( $system_webServer_node );
				}
				else {
					$config_node = $doc->createElement( 'configuration' );
					$doc->appendChild( $config_node );
					$config_node->appendChild( $system_webServer_node );
				}
			}
		}
		$doc->encoding = "UTF-8";
		$doc->formatOutput = true;
		$doc->save( $path .'/'. $filename );
		
	return true;
	}
}

disable_script_execution();
?>

More information and usage:
https://www.saotn.org/secure-wordpress-uploads-folder-disable-php-execution/
https://www.saotn.org/disallow-direct-access-to-php-files-in-wp-content-uploads/