fuzzer

#!/usr/bin/env julia

# Load the moby dick source into one buffer
base = read("whale.txt")

# Generate random fuzz mutation
mutate(genome) = (genome .+ sprand(UInt8, size(genome)[1], .000001)) .% 256 

patch(original, genome) = (original .+ genome) .% 256

crossover(gen1, gen2) = map(a->rand(0:1)==0?gen1[a]:gen2[a], 1:size(gen1))

function fitness(genome)
	(so,si,pr) = readandwrite(`xz -z0 -`)
	write(si, patch(base, genome))
	close(si)
	wait(pr)
	size = read(so)
	compressed = size(read(pipeline(`xz -z0 -`,stdin=patch(base, genome))))[1]
	diff = nnz(genome)
	return diff - 2*compressed
end