removes trailing spaces on every line, leading and trailing empty lines; ensures files end with a line feed

filetrim.rb

#!/usr/bin/env ruby -pi
#
# Copyright © 2010 Caio Chassot
# Licensed under the WTFPL <http://sam.zoy.org/wtfpl/COPYING>
#
#   File Trim. (Vertical and Right trim.)
#   Command receives file paths as arguments. Modifies them in-place.
#     - removes trailing spaces on every line;
#     - removes leading and trailing empty lines;
#     - ensures files end with a line feed.

next !$<.eof? && $s && $s << "\n" if $_ !~ /\S/
$_ = $s.to_s << $_.sub(/\s*\z/, "\n")
$s = ("" unless $<.eof?)