From: zdennis <zdennis@...>
Date: 2005-12-02T04:07:42+09:00
Subject: Re: What is the best way to edit a file to eliminate a line

Steve [RubyTalk] wrote:
> zdennis wrote:
> 
>> Hope this works better...
> 
> It will still permanently and irrecoverably loose data if the process 
> terminates (e.g. a process hard-limit is exceeded, an administrator 
> kills the process explicitly; or an old-fashioned power-cut etc.) just 
> after starting to write the updated file... so I wouldn't consider it 
> sufficiently robust for my purposes.
> 

You could modify for your needs:

require 'fileutils'

class File
   def self.modify filename
     if block_given?
       data = IO.read filename
       FileUtils.mv filename, "#{filename}.orig"
       begin
         file = File.open filename, 'w'
         yield file, data
       ensure
         file.close unless file.closed?
       end
     end
   end
end

File.modify( 'stuff.txt' ) do |writable_file, original_file_contents|
   writable_file.write original_file_contents.gsub( /foo(\n|$)/, '' )
end

Zach