instance_eval { reduce(:+) / size.to_f }

0</dev/null script --quiet --flush --return --command "$(printf "%q " "$@")" /dev/null

A one-liner alternative for hash-only cases can be implemented using Enumerable#reduce: root = {} [:a, :b, :c].reduce(root){@1[@2]||={}}[:d] = 'E' # root => {:a=>{:b=>{:c=>{:d=>"E"}}}}

yell() { echo "$0: $*" >&2; } die() { yell "$*"; exit 111; } try() { "$@" || die "cannot $*"; }

I'm certainly not claiming that we should use clever tricks to scrunch our code into the most compact form possible at the expense of readability. Nor am I claiming that reducing lines of code is necessarily a worthwhile goal, since it encourages turning readable code like this...