Code to get access to both basic and full linkedin profiles. You make one execution with the first code block to get token and token secret values and then can remove this code, assign values to variables and get the access_token directly

full_linkedin_profile

require 'oauth'

  # api_key and api_secret values are got from the registration of your application in LinkedIn:
  # http://developer.linkedin.com/ 
  api_key       = 'Your API Key'
  api_secret    = 'Your API Secret'
 
  # access_token and token_secret are known after the first execution code block 
  access_token  = 'The token we get below'
  token_secret  = 'The token secret we get below'
  
  # The configuration will ask for permission to get access to both basic and full profile     
  configuration = { :site => 'https://api.linkedin.com',
                    :authorize_path => '/uas/oauth/authenticate',
                    :request_token_path => '/uas/oauth/requestToken?scope=r_basicprofile+r_fullprofile',
                    :access_token_path => '/uas/oauth/accessToken' }
                                  
  consumer = OAuth::Consumer.new(api_key, api_secret, configuration)
  
  # FIRST EXECUTION CODE: You just execute this code to find out the access_token and token_secret
  # and then next executions just fill variables with these values and execute the next executions
  # code block
  request_token = consumer.get_request_token
  
  # Now get the access URL and paste it to your browser
  puts request_token.authorize_url
  
  # After granting access get the PIN value that appears in the page and put in the variable to get 
  # the acess_token and retrieve the token and secret for next executions
  pin = 'The PIN we get in the page after granting access to the app'
  access_token = request_token.get_access_token(:oauth_verifier => pin)
  
  # Now get access_token adn toekn_secret values and assign to above variables for further executions
  puts "Access Token: #{access_token.token}"
  puts "Access Token Secret: #{access_token.secret}"
  
  # NEXT EXECUTIONS CODE: Access token can be instantiated without having to go to browser, just with
  # variables we got in the first execution block
  access_token = OAuth::AccessToken.new(consumer, access_token, token_secret)
  
  # Get a field from the basic profile
  puts access_token.get('https://api.linkedin.com/v1/people/~:(first-name)').body
  
  # Get a field from the full profile
  puts access_token.get('https://api.linkedin.com/v1/people/~:(publications)').body