~/bin/rinse_cpus

gistfile1.rb

#!/usr/bin/env ruby
# Only works on OS X
# Spins up enough `yes > /dev/null` instances inside a 
# `screen` to use 100% of all your cpu cores
# 
# This just starts screen eating your cores, currently
# when you're done you need to kill the screen manually.

require "tempfile"

# Figure out CPU Count
CPUCount = `sysctl machdep.cpu.core_count`.split(": ").last.to_i

# Use a config to start screen
ScreenConfig = <<-EOF
startup_message off
vbell off

#{Array.new(CPUCount) { %{screen -L /bin/sh -c "yes > /dev/null"} }.join("\n")}
EOF

# Write config into a temp file
tfile = Tempfile.new("rinse_cpus.")
tfile.puts ScreenConfig
tfile.close

# Kick off the thing!
system("screen -md -S cpu_rinse -c #{tfile.path}")