title: Modifying environment variable within a C program
body: <p>Is it possible to modify an environment variable within a C program. Something like this:</p>
  
  <pre><code>#include &lt;stdlib.h&gt;
  int main( void )
  {
      system( "echo $VARIABLE" );
      system( "VARIABLE=somethig");
      system( "echo $VARIABLE" );
      return 0;
  }
  </code></pre>