title: How to calculate the numerical value of a string in C
body: <p>I'm trying to calculate the value a string in C.</p>
  
  <p>I define the string like: <code>char cadena[100] = "Esto es un text securizado$2516"</code> </p>
  
  <p>I need to transform 2516 into an int, I'm actually trying to use <code>atoi()</code>, but I don't know how to separate the string to use the function.</p>
  
  <p>PS: Excuse my English, it's not my native language, I hope you understand what I want to do.</p>