A way of doing that with a regular expression:
<?php
// Lucene characters that need escaping with \ are + - && || ! ( ) { } [ ] ^ " ~ * ? : \
$luceneReservedCharacters = preg_quote('+-&|!(){}[]^"~*?:\\');
$query = preg_replace_callback(
'/([' . $luceneReservedCharacters . '])/',
function($matches) {
return '\\' . $matches[0];
},
$query);
?>