title: c GTK g_signal_connect using the data field
body: <p>With g_signal connect, I'm trying to pass a parameter that is a simple character 'S' using the "data" field.</p>
  
  <p>???(I think I understand that the field is not for data, rather its for a pointer to the data.)???</p>
  
  <p>Anyway, I have code like this:</p>
  
  <pre><code>g_signal_connect (G_OBJECT(b_save), "clicked", my_test, (gpointer) 'S');
  </code></pre>
  
  <p>calling code like this:</p>
  
  <pre><code>void my_test(GtkMenuItem *menuitem, gpointer data)
  {
    printf("Pointer variable contains: %p\n", data);
  }
  </code></pre>
  
  <p>I'm not sure if my_test should accept two parameters or one?
  I'm not sure how to printf the pointed to value 'S'.
  (In my called function my_test how do I get at the 'S'?)</p>