title: perror and std::cerr use
body: <p>Can anyone please tell me what are the usage differences between <code>std::cerr</code> and <code>perror</code></p>
  
  <pre><code>void perror ( const char * str );
  </code></pre>
  
  <p>I wonder which one is preferable in C++ applications and why it's preferable.</p>