twitppを使ったC++11製update_name. Tosainu/twitppとdropbox/json11, 最新のBoostと(gcc|clang)が要ります.

Makefile

update_name: update_name.cc json11/json11.cpp
	clang++ -Wall -Wextra -std=c++14 -ltwitpp $^ -o $@

update_name.cc

#include <iostream>
#include <regex>
#include <boost/optional.hpp>
#include <twitpp/twitpp.hh>
#include "json11/json11.hpp"

boost::optional<json11::Json> json_parse(const std::string& str) {
  std::string err;
  auto json = json11::Json::parse(str, err);
  return err.empty() ? json : boost::none;
}

auto main() -> int {
  const std::regex update_name_regex("^@myon___\\supdate_name\\s(.+)$");

  twitpp::oauth::client client(twitpp::oauth::account("CK", "CS", "AT", "AS"));

  client.stream_get("https://userstream.twitter.com/1.1/user.json", [&](auto& response) {
    if (response.status_code != 200) {
      std::cerr << "Error!!" << std::endl;
      return;
    }

    if (const auto tweet = json_parse(response.body)) {
      response.body.clear();

      if ((*tweet)["created_at"].is_null()) return;
      if (!(*tweet)["retweeted_status"].is_null()) return;

      auto id          = (*tweet)["id_str"].string_value();
      auto screen_name = (*tweet)["user"]["screen_name"].string_value();
      auto text        = (*tweet)["text"].string_value();

      std::smatch res;
      if (std::regex_match(text, res, update_name_regex)) {
        if (client.post("https://api.twitter.com/1.1/account/update_profile.json", {{"name", res.str(1)}}).status_code == 200) {
          client.post("https://api.twitter.com/1.1/statuses/update.json", {
            {"in_reply_to_status_id", id},
            {"status", "@" + screen_name + " [" + res.str(1) + "] になりました."}
          });
        }
      }
    }
  });
}