From: Daniel Berger <djberg96@...>
Date: 2009-02-26T04:44:22+09:00
Subject: Re: require 'diff/lcs/Array'



On Feb 25, 10:55 am, James Gray <ja...@grayproductions.net> wrote:
> On Feb 25, 2009, at 11:17 AM, Venkat Kumar wrote:
>
> > I need compare two text files. I should require 'diff/lcs/Array'  
> > when i
> > do this iam getting error.
>
> I've tried using that library in the past, but its interface just  
> makes it crazy hard to work with.

I came up with this for diff'ing 2 files and spitting the results to
stdout. It's meant to simulate "diff -u" output, but it's not quite
identical and is definitely not tested thoroughly:

# diff_test.rb
require 'diff/lcs'

# The file 'test1.txt' contains the following 3 lines:
#
# This is a house
# Hello World
# My favorite color is blue
#
# The file 'test2.txt' contains the following 3 lines:
#
# This is a car
# Hello World
# My favorite color is green

module Diff
   module LCS
      def self.diff_files(file1, file2)
         array1 = IO.readlines(file1)
         array2 = IO.readlines(file2)
         diffs = diff(array1, array2)

         print diffs.first[0].action * 3 + ' '
         print file1
         print "\t" + File.mtime(file1).to_s

         puts

         print diffs.first[1].action * 3 + ' '
         print file2
         print "\t" + File.mtime(file2).to_s

         puts

         diffs.each_with_index{ |diff, i|
            diff.each{ |d|
               puts d.action + d.element
            }
         }
      end
   end
end

Diff::LCS.diff_files('test1.txt', 'test2.txt')

Here was the output of Diff::LCS.diff_files:

--- test1.txt   Wed Feb 25 12:18:42 -0700 2009
+++ test2.txt   Wed Feb 25 12:18:53 -0700 2009
-This is a house
+This is a car
-My favorite color is blue
+My favorite color is green

Hope that was useful.

Regards,

Dan