title: Is it more efficient to rewind a file than closing it and opening it up again?
body: <p>I'm writing a little C++ program for myself. At the begining of it, I read a file all the way to the bottom, and later on, right before the program ends, I need to read that file again from the begining. <br><br>
  My question is, is it more efficient to have the file open during the execution (even thought I won't be using it) and just rewind it when I need it again, or should I close it the first time and then open it again when I need it?<br><br>
  Edit: Just to clarify, my question is not only related to the specific project that I'm working on. It is really small (less than 300 lines of code), so there won't be any noticeable performance difference. I'm asking about opening, closing and "rewinding" files in general, so it's aplicable to other big projects were performance and memory may actually matter</p>