Objective C Framework for reading data file and converting to strings

I require a framework written in Objective C that can be used inside an existing program. This would read a file which is constantly being updated ( so a timer is required as well as storing last postion for the read) and parsing the data which is in this file out so that it has be parsed into a usable format (strings or dictonary). This would be a framework which is required to be called inside an existing program and which would return information about what is parsed. Open to suggestions, there is something similar in PHP as open source but I would require my own frameworks for Objective C.