title: indexing and searching textfiles in ruby and sinatra
body: <p>I'm making a wiki with Ruby and Sinatra and need to search the wiki's that are stored as text files with markup in a few HTML-renderers (redcarpet, markdown, creole, slim, haml..).
  You have a lot of options in Ruby like ferret, solr or lucene gems that handle structured data in a database but not for searching files with free text.</p>
  
  <p>For now I open the text files and search with a regExp but as the wiki's grow that will soon be too slow. Are there any gems that index all the text files in a map and which index I can then use to search the files? It needs to be a Ruby only solution or something that can be easily used from Ruby.</p>
  
  <p>I'm not using one of the common wiki's since none has the features I need.</p>
  
  <p>I do use windows indexing service in a few old ASP apps but I'm far from satisfied with that solution.</p>
  
  <p>My OS'es are Windows Vista, 7 and Windows Server 8.</p>
  
  <p>EDIT: a no database installation needed/no keep server running solution is preferable, so eg with sqlite or file besed storage or something like that</p>