t.rb

#!/usr/bin/env ruby

CASES = {
	"" => ["", "", "", "", ""],
	"Some random data." => ["Some random data.", "", "", "", ""],
	"This information should be ignored RECORD_NUM 02 This is the information for record 2 RECORD_NUM 01 This is the information for record 1 RECORD_NUM 04 This is the information for record 4" =>
		[" This is the information for record 1 ", " This is the information for record 2 ", "", " This is the information for record 4", ""],
}

def process(input, expected_record_count=5)
	return ([input] + ([""] * (expected_record_count-1))) unless input =~ /RECORD_NUM/
	(1..expected_record_count).collect do |num|
		input =~ /RECORD_NUM #{sprintf("%02i", num)}(.+?)(?=RECORD_NUM|$)/ ? $1 : ""
	end
end

def process1(input, expected_record_count=5)
	return ([input] + ([""] * (expected_record_count-1))) unless input =~ /RECORD_NUM/
	records = Hash[input.scan(/RECORD_NUM 0?(\d+)(.+?)(?=RECORD_NUM|$)/)]
	(1..expected_record_count).collect{|num| records[num.to_s] || ""}
end

CASES.each do |input, expected_output|
	actual_output = process1(input)

	if actual_output != expected_output
		puts "-> EXPECTED"
		puts expected_output.inspect
		puts "-> BUT WAS"
		puts actual_output.inspect
	end
end