Ferret

A Quick Example: Indexing the Filesystem

With the explosion of the Internet, a huge amount of information has become available to us. But it doesn’t matter how much information is available if we can’t find what we are looking for. Luckily, companies like Google and Yahoo! have come to the rescue by helping us find the information we need with their search engines.

More recently, the same thing has been happening on our personal computers. More and more of our personal lives are being stored on hard drives—everything from work documents and email to multimedia files and family photos. Carefully categorizing all this data and scanning through large hierarchies of folders just doesn’t cut it anymore. We need a fast way to access the data we need. Presently, some of the tools commonly used for this task, such as the built-in search in Windows, leave a lot to be desired. Spotlight on OS X is much closer to what we need.

By the end of this book, you’ll have built a search application that will make searching your hard drive as easy as searching the Web. In this section, we start with plain old text files. Let’s begin by writing a command-line indexing program that takes two arguments: the name of the directory we want to index, and the name of the directory in which the index will be stored. Take a look at Example 1-2.

Example 1-2. index.rb

  0 #!/usr/bin/env ruby
  1 require 'rubygems'
  2 require 'ferret'
  3 require 'fileutils'
  4 include Ferret
  5 include Ferret::Index
  6 
  7 def usage(