title: off_t without -D_FILE_OFFSET_BITS=64 on a file > 2GB
body: <p>1- I'm wondering, what would be the problem if I try to read a file greater than <code>2GB</code> in size without compiling my program with the option <code>-D_FILE_OFFSET_BITS=64</code> using <code>off_t</code> and using the second function on <a href="https://stackoverflow.com/questions/8236/how-do-you-determine-the-size-of-a-file-in-c/8384#8384">this page</a>? would it segfault?</p>
  
  <p>2- I'm planning to use <a href="https://stackoverflow.com/questions/8236/how-do-you-determine-the-size-of-a-file-in-c/8384#8384">this implementation</a> with <code>off64_t</code> and </p>
  
  <pre><code>#define _LARGEFILE64_SOURCE 1
  #define _FILE_OFFSET_BITS 64
  </code></pre>
  
  <p>Would there be any problem?</p>