write - LOG

void write(string str, string IP)
{
     mutex.lock(); //sem_wait(&semaph);

  ofstream myfile;
     myfile.open ("example.txt");
   myfile << "IP: \n\n" << IP[0]
          << "\n\n", <<str[0]);
      myfile.close();
    mutex.unlock(); // sem_post(&semaph);


}