title: Read a txt file line by line without using fopen()
body: <p>I need to read a text file line by line. </p>
  
  <p>The problem is that in my code I cannot use <code>fopen()</code> and then <code>fgets()</code> to read the content of each line, because <code>fopen()</code> fails when I use a lot of threads (it seems that it gets overload because it is being opend so many times).</p>