Read Certain Lines from File

Question

Hi just getting into Ruby, and I am trying to learn some basic file reading commands, and I haven't found any solid sources yet.

I am trying to go through certain lines from that file, til the end of the file.

So in the file where it says FILE_SOURCES I want to read all the sources til end of file, and place them in a file.

I found printing the whole file, and replacing words in the file, but I just want to read certain parts in the file.

Answer 1

Usually you follow a pattern like this if you're trying to extract a section from a file that's delimited somehow:

open(filename) do |f|
  state = nil

  while (line = f.gets)
    case (state)
    when nil
      # Look for the line beginning with "FILE_SOURCES"
      if (line.match(/^FILE_SOURCES/))
        state = :sources
      end
    when :sources
      # Stop printing if you hit something starting with "END"
      if (line.match(/^END/))
        state = nil
      else
        print line
      end
    end
  end
end

You can change from one state to another depending on what part of the file you're in.