git_tag.rb

#!/usr/bin/env ruby

tagname = ARGV.pop

def prompt(*args)
  print(*args)
  gets.chomp
end

if tagname.nil?
  STDOUT.puts "No tag given, usage: git_tag.rb tagname"
  exit 1
else
  cmd = system("git tag -a #{tagname} -m 'Tagging for release: #{tagname}'")
  if cmd
    answer = prompt("Tag '#{tagname}' created! Do you want to push it to origin? (y/n)")
     if answer == 'y'
       system("git push origin #{tagname}")
     end
  end
end