Get Twitter OAuth AccessToken

get_twitter_access_token.rb

require 'uri'
require 'oauth'

CONSUMER_KEY = '<your consumer key>'
CONSUMER_SECRET = '<your consumer secret>'
CALLBACK_URL = '<your callback url>'

consumer = OAuth::Consumer.new(CONSUMER_KEY, CONSUMER_SECRET, {
  site: "https://api.twitter.com",
  scheme: :header
})

request_token = consumer.get_request_token(oauth_callback: CALLBACK_URL)
req_url = request_token.authorize_url(oauth_callback: CALLBACK_URL)
puts <<EOS
Go to the following URL and authorize your account on a browser:
#{req_url}

Copy the redirected url from the browser and paste it:
EOS

input = STDIN.gets
redirected_url = input.chomp
rurl = URI.parse(redirected_url)
params = {}.tap do |h|
  URI.decode_www_form(rurl.query).each do |entry|
    h[entry[0].to_sym] = entry[1]
  end
end

access_token = request_token.get_access_token(oauth_verifier: params[:oauth_verifier]) 
puts <<EOS

===================================
user_id: #{access_token.params[:user_id]}
screen_name: #{access_token.params[:screen_name]}

Access Token: #{access_token.token}
Access Token Secret: #{access_token.secret}
===================================
EOS