title: Memory and file pointers
body: <p>I'm confused about how the OS actually "opens" a file in C when you do an <code>fopen</code> in the code. To elaborate, suppose I had a 100 binary files (say of size <code>1 MB</code>) which I open in C</p>
  
  <pre><code>FILE **fptr;
  
  fptr = calloc(100, sizeof(FILE *));
  
  for (ii = 0; ii &lt; 100; ii++) 
     fptr[ii] = fopen(filename[ii], "rb+");
  </code></pre>
  
  <p>Assume that <code>filename</code> and <code>ii</code> were already defined appropriately. </p>
  
  <p>Will the OS load <code>100 MB</code> into memory, or does the above code just tell the program to keep these files ready for access?</p>