title: Convert a hexadecimal string to an integer efficiently in C?
body: <p>In C, what is the most efficient way to convert a string of hex digits into a binary <code>unsigned int</code> or <code>unsigned long</code>?</p>
  
  <p>For example, if I have <code>0xFFFFFFFE</code>, I want an <code>int</code> with the base10 value <code>4294967294</code>.</p>