# Joins all .piece files (eg. abc.ext.piece1, abc.ext.piece2 etc) in the current directory and creates a single file (eg. abc.ext)
# Does not do any error handling!
# Usage: ruby file_joiner.rb

class FileJoiner
	def initialize
		# sort the .piece filenames in the correct order i.e. if there are 10 .piece files in the current directory
		# we need to ensure that abc.ext.piece2 (and not abc.ext.piece10) follows abc.ext.piece1
		@pieces = Dir["*.piece*"].sort do |f1, f2|
					f1.split("piece").pop.to_i <=> f2.split("piece").pop.to_i
				end
		
		joined_filename = @pieces[0].split("\.")[0..1].join("\.")
		@joined_file = File.open(joined_filename, "wb")
	end
	
	def join
		@pieces.each { |file| @joined_file << File.open(file, "rb").read }
		@joined_file.close
	end
end

FileJoiner.new.join