auth.vala

using Rest;

public class SimpleTweet {
 private static const string CONSUMER_KEY = "#######################"; // this comes from your app's twitter account page
 private static const string CONSUMER_SECRET = "########################################"; // this comes from your app's twitter account 
 private static const string URL_FORMAT = "https://api.twitter.com";
 private static const string REQUEST_TOKEN_URL = "https://api.twitter.com/oauth/request_token";

 private static const string FUNCTION_ACCESS_TOKEN = "oauth/access_token";
 private static const string FUNCTION_STATUSES_UPDATE = "1/statuses/update.xml";

 private static const string PARAM_STATUS = "status";

 public static int main(string[] args) {
  // make sure there is a message to tweet
  if(args[1] == null || args[1] == "") {
   stdout.printf("No tweet message specified.\n");
   return 0;
  }

  /** Authenticating with Twitter */
  // initialize proxy
  var proxy = new OAuthProxy(CONSUMER_KEY, CONSUMER_SECRET, URL_FORMAT, false);

  // request token
  try {
   proxy.request_token("oauth/request_token", "oob");
  } catch (Error e) {
   stderr.printf("Couldn't get request token: %s\n", e.message);
   return 1;
  }

  // prompt user for pin
  stdout.printf("Go to http://twitter.com/oauth/authorize?oauth_token=%s then enter the PIN\n", proxy.get_token());
  string pin = stdin.read_line();

  // access token
  try { proxy.access_token(FUNCTION_ACCESS_TOKEN, pin); }
  catch (Error e) {
   stderr.printf("Couldn't get access token: %s\n", e.message);
   return 1;
  }

  /** sending the tweet */
  // setup call
  ProxyCall call = proxy.new_call();
  call.set_function(FUNCTION_STATUSES_UPDATE);
  call.set_method("POST");
  call.add_param(PARAM_STATUS, args[1]);
  try { call.sync(); } catch (Error e) {
   stderr.printf("Cannot make call: %s\n", e.message);
   return 1;
  }

  // print success
  stdout.printf("Tweet succeeded!\n");

  return 0;
 }
}