Good day to all.

I'm accessing an ASCII file, a large one, and my application needs to insert a character in a certain position to update data. The question is related to physical memory handling in moving the part of file that follows the newly inserted character... It is the only way to create a new file in which copy the part that precedes the inserted new char, then append the char and finally paste the subsequent original second part of the file? Because of the size of the file, this is not very fast...
If it is the only way, does anybody have some hint on how to perform it faster?

Thanks in advances, and nice holidays to all!