create gem automatically

gem-create.rb

#!/usr/bin/env ruby -w

#Usage: ./gem-create.rb your_gem_name

def dump(file_name, content, executable = false)
  content ||= ''
  lines = content.split('\n')
  File.open(file_name, 'w') do |f|
    lines.each do |line|
      f.puts line
    end
  end
  File.chmod(0755, file_name) if executable
end

def create_gem(gem_name)
  fail 'please specify your gem name' unless gem_name

  fail "#{gem_name} already exists in current dir" if File.exists?(gem_name)

  Dir.mkdir(gem_name)
  Dir.chdir(gem_name)

  Dir.mkdir('bin')
  Dir.mkdir('spec')

  lib_dir = 'lib'
  Dir.mkdir(lib_dir)
  Dir.chdir(lib_dir)
  Dir.mkdir(gem_name)
  gem_file = "#{gem_name}.rb"
  gem_file_content = %q{#!/usr/bin/env ruby}
  dump(gem_file, gem_file_content)
  Dir.chdir('..')

  gem_file = 'Gemfile'
  gem_file_content = %q{source 'https://rubygems.org\ngemspec}
  dump(gem_file, gem_file_content)

  rake_file = 'Rakefile'
  rake_file_content = %q{#!/usr/bin/env rake\nrequire "bundler/gem_tasks"}
  dump(rake_file, rake_file_content)

  gem_spec_file = "#{gem_name}.gemspec"
  system "touch #{gem_spec_file}"

  system "git init;git add .; git commit -am 'first commit'"
end

create_gem(ARGV[0])