Iphone application development

Project name:Brain Smart address book for iOS using Mind Wave Mobile Headset


In this project ,we take brain signals from headset and then via Bluetooth,these signals are sent to iPhone by headset.signals show some numbers.These signals act as control signal for activating a particular task (calling).

we are working on mac iOS .we have a code which has a "main" function.this code gets values from headset and create a txt file and save results in that file.the problem is that while starting a xcode,we should specify format of file.which format we select for this file?
i m attaching that file with this mail.