Blue Hens

Blue Hens is an interpreted programming language by User:ProfNinja designed for a CTF competition, inspired by Chicken.

Language Overview

Your input is a text file.

Each line may have the word "blue" some number of times followed by the word "hens" some number of times, space-separated.

The number of "blues" on the line is the OPCODE the number of "hens" on that line is the ARG.

The line numbers matter and they start at 1.

Our architecture has 2 variables, a register REG and a counter CTR both start at 0.

OPCODES 1,2,3,4 are arithmetic operations

OPCODES 5,6,7 are gotos

OPCODES 8,9,10 are control flow:

OPCODE 11 is print

The OPCODEs

There are 11 opcodes:

OPCODE	MNEMONIC	ARG?	DESCRIPTION OF CODE
1	SET	Y	Set REG to ARG
2	ADD	Y	Add ARG to REG
3	SUB	Y	Sub ARG from REG
4	MUL	Y	Multiply REG by ARG
5	GTL	Y	Goto line ARG
6	GBL	Y	Go back ARG lines
7	GUL	Y	Go up ARG lines
8	CTA	Y	Add ARG to CTR
9	CTS	Y	Sub ARG from CTR
10	SKP	N	If CTR 0 skip next line
11	PRT	N	Print REG (ascii)

Examples

The Hello, World! program:

blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue hens
blue hens hens hens hens hens hens
blue blue blue blue hens hens hens hens hens hens
blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens
blue blue blue blue blue hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens
blue blue blue blue blue hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens hens
blue blue blue blue blue hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens hens hens
blue blue blue blue blue hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue hens hens hens hens
blue blue blue blue hens hens hens hens
blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens
blue hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue hens hens hens hens hens hens hens hens
blue blue blue hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue hens
blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue hens hens
blue blue blue blue blue blue blue hens hens hens hens hens hens hens hens hens hens hens hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens
blue blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens
blue blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens hens
blue blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue blue blue
blue blue blue blue blue blue blue blue hens hens hens hens hens
blue blue blue blue blue hens hens
blue blue blue blue blue blue blue blue blue blue blue

Implementation

A Python interpreter by DaveP

A compiler from opcode arg to 'blue's and 'hens'