.git/hooks/pre-commit

gistfile1.rb

#!/Users/moro/opt/ruby192/bin/ruby
excludes = ['db/schema.rb']
invalids = `git diff --name-only --cached`.each_line.inject([]) do |r, f|
  f.strip!
  if (f =~ /\.rb\Z/) && !excludes.include?(f) && (File.open(f, "r", &:gets) !~ /\A\#coding:/)
    r << f
  else
    r
  end
end

if invalids.empty?
  exit 0
else
  $stderr.puts "-- WARN: no magic-comment --"
  puts invalids
  exit 1
end

#vim:set ft=ruby:

injectつかわないでselectでいいよねぇ。