Preprocess text for search.
This hook is called to preprocess both the text added to the search index and the keywords users have submitted for searching.
Possible uses:
$text: The text to preprocess. This is a single piece of plain text extracted from between two HTML tags or from the search query. It will not contain any HTML entities or HTML tags.
The text after preprocessing. Note that if your module decides not to alter the text, it should return the original text. Also, after preprocessing, words in the text should be separated by a space.
function hook_search_preprocess($text) {
// Do processing on $text
return $text;
}