title: Convert a char with va_arg
body: <p>I need to get from va_arg a char.
  i use an integer, but my problem it's does not work !</p>
  
  <pre><code>char c = (char)va_arg(ap, int);
  write(1, &amp;c, 1);
  </code></pre>
  
  <p>it's gave the ascii code of something else.</p>