Check if a file in the WP uploads folder actually does exist

functions.php

// Take the URL of a local file in the WP Uploads folder and check that it does actually exist
function uploaded_file_exists( $url ) {
	$local_exists = false;

	if ( $url ) {
		$uploads   = wp_upload_dir();
		$local_path = str_replace( $uploads['baseurl'], $uploads['basedir'], $url );
		$local_exists = file_exists($local_path);
	}

	return $local_exists;
}