C File Manipulation Project.

I got a small project to do. I've done most part of the work but I am stuck with one major part. The project description is I have to write a program that reverses a given file that is it will start reading the first half of the file, and continue to read the second half and replacing it with the reversed first half. It will end the operation by going to the beginning of the file and filling the first half with the reversed second half. Notice that you need to handle one line input. Test it by reversing the file and print out the results. After that, reverse it again and print out the results. You should get the original text. Be careful when you handle new line characters. You cannot store more than half of the file at any time in memory (except using temporary variables) and I cannot use two files.