title: Equivalent of C++ std::setprecision(20) using printf in C
body: <p>I want to print doubles in decimal notation with full precision (but without extra zeros at the end of the number). In C++ I can use:</p>
  
  <pre><code>std::setprecision(20);
  cout &lt;&lt; d; // Here d is a double
  </code></pre>
  
  <p>What would be the equivalent C code using printf?</p>