Golfing

golf_inject-tap.rb

# abuse of `inject` and `tap`
#
# it's not really short
# but shows some nice Ruby stuff
%w[bigdecimal /util].inject(""){|a,e|(a<<e).tap{|r|require r}}

golf_sig.rb

# binary to hex string - and back to binary
sig = "<bin data>"

hexsig = sig.unpack("H*").first #=> "3c62696e20646174613e"
sig2   = hexsig.scan(/../).map{|hx| Integer("0x#{hx}").chr}.join

sig2 == sig #=> true

golf_slicing.rb

# can be useful in some cases:
(1..23).each_slice(9).with_index.map{|c,i|[i,c]}
#=> [ [0,[1..9]], [1,[10..19]], [2,[20..23]] ]