title: Build .so file from .c file using gcc command line
body: <p>I'm trying to create a hello world project for Linux dynamic libraries (.so files). So I have a file hello.c:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  void hello()
  {
      printf("Hello world!\n");
  }
  </code></pre>
  
  <p>How do I create a .so file that exports <code>hello()</code>, using gcc from the command line?</p>