Parse search string a la Google (Regular expression?)

Hi, In my application I would like to offer a search interface like Google and other popular search engines. The complication for me is to explode the search string into proper array elements, like this: $search_str = "\"search for this sentence\" -NotForThisWord ButDefinitelyForThisWord"; $array[0]: "search for this sentence" $array[1]: "-NotForThisWord" $array[2]: "ButDefinitelyForThisWord" I have tried to use regular expressions but my case seems to be a bit more complicated for this (?). Does anybody have a code snippet, a class or something, that can help me with this? Thanks in advance, Joachim