title: What does "f" stand for in C standard library function names?
body: <p>What does <code>f</code> stand for in the name of C standard library functions? I have noticed that a lot of functions have an <code>f</code> in their name, and this does not really make sense to me.</p>
  
  <p>For example: <code>fgets</code>, <code>fopen</code>, <code>printf</code>, <code>scanf</code>, <code>sqrtf</code> and so on.</p>