if you have used any of the main file sharing apps out there you will notice how most of them save a large empty file at the begining of the download job.
For example if you are downloading a 1 Gb file called bigfile.zip they will save a 1 GB file called bigfile.zip immediatly
however this file is made of what? zeros maybe? anyways over the course of the download they right over this file with the real data as it is downloaded.
I am wondering how i should go about doing this because i need to write a app that saves big big files.