This page contains automated test results for code from O'Reilly's Ruby Cookbook. If this code looks interesting or useful, you might want to buy the whole book.
Comparing the Contents of Two Files | ||
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Code | Expected | Actual |
class File def File.same_contents(p1, p2) return false if File.exists?(p1) != File.exists?(p2) return true if !File.exists?(p1) return true if File.expand_path(p1) == File.expand_path(p2) return false if File.ftype(p1) != File.ftype(p2) || File.size(p1) != File.size(p2) open(p1) do |f1| open(p2) do |f2| blocksize = f1.lstat.blksize same = true while same && !f1.eof? && !f2.eof? same = f1.read(blocksize) == f2.read(blocksize) end return same end end end end 1.upto(2) do |i| open("output#{i}", 'w') { |f| f << 'x' * 10000 } end File.same_contents('output1', 'output2') |
true | true |
open("output1", 'a') { |f| f << 'x' } open("output2", 'a') { |f| f << 'y' } File.same_contents('output1', 'output2') |
false | false |
File.same_contents('nosuchfile', 'output1') |
false | false |
File.same_contents('nosuchfile1', 'nosuchfile2') |
true | true |
require 'rubygems' require 'diff/lcs/hunk' def diff_as_string(data_old, data_new, format=:unified, context_lines=3) data_old = data_old.split(/\n/).map! { |e| e.chomp } data_new = data_new.split(/\n/).map! { |e| e.chomp } output = "" diffs = Diff::LCS.diff(data_old, data_new) return output if diffs.empty? oldhunk = hunk = nil file_length_difference = 0 diffs.each do |piece| begin hunk = Diff::LCS::Hunk.new(data_old, data_new, piece, context_lines, file_length_difference) file_length_difference = hunk.file_length_difference next unless oldhunk # Hunks may overlap, which is why we need to be careful when our # diff includes lines of context. Otherwise, we might print # redundant lines. if (context_lines > 0) and hunk.overlaps?(oldhunk) hunk.unshift(oldhunk) else output << oldhunk.diff(format) end ensure oldhunk = hunk output << "\n" end end #Handle the last remaining hunk output << oldhunk.diff(format) << "\n" end s1 = "This is line one.\nThis is line two.\nThis is line three.\n" s2 = "This is line 1.\nThis is line two.\nThis is line three.\n" + "This is line 4.\n" puts diff_as_string(s1, s2) |
@@ -1,4 +1,5 @@ -This is line one. +This is line 1. This is line two. This is line three. +This is line 4. |
@@ -1,4 +1,5 @@ -This is line one. +This is line 1. This is line two. This is line three. +This is line 4. |
open('old_file', 'w') { |f| f << s1 } open('new_file', 'w') { |f| f << s2 } puts %x{diff old_file new_file} |
1c1 < This is line one. --- > This is line 1. 3a4 > This is line 4. |
1c1 < This is line one. --- > This is line 1. 3a4 > This is line 4. |