--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/day2.rb	Sat Dec 02 16:16:58 2023 +0000
@@ -0,0 +1,32 @@
+#! /usr/bin/env ruby
+
+if ARGV.length != 4
+        abort("Incorrect arguments - needs numbers for Red, Green and Blue then input file")
+elsif not File.exist? (ARGV[3])
+	abort("File #{ARGV[3]} did not exist")
+end
+
+max_colours = {
+	"red" => ARGV[0].to_i,
+	"green" => ARGV[1].to_i,
+	"blue" => ARGV[2].to_i
+}
+file = ARGV[3]
+
+sum = 0
+File.open(file, "r").each_line do |line|
+	game, all_picks = line.split(":")
+	all_valid = all_picks.split(";").all? do |pick|
+		pick.split(",").all? do |colour_pick|
+			num_picked, colour_picked = colour_pick.strip.split(" ")
+			# The last line of a Ruby block is the return value
+			num_picked.to_i <= max_colours[colour_picked]
+		end
+	end
+	if all_valid
+		puts game
+		sum += game.split(" ")[1].to_i
+	end
+end
+
+puts sum
\ No newline at end of file