Simple file fuzzer: args: filename and count of iterations

fuzzer.rb

#! ruby

def main(fname, count)
    f = IO.binread(fname)

    sz = f.size

    count.to_i.times {
        f[ rand (sz) ] = rand(256).chr
    }

    File.open(fname, 'wb') {|fd| fd << f}
end

main(ARGV[0], ARGV[1])