title: Can the perror example be improved?
body: <p>When should I use perror and when not?
  I look at the <a href="http://pubs.opengroup.org/onlinepubs/009695399/functions/perror.html" rel="nofollow">example</a> and I think the example could be better for instance there is nothing about localizing, what I can pass to perror or if I should use perror if I implement something like a command-line interpreter or some other C program.. </p>