I am looking for a routine that writes all data and retrive

I have a dynamic program containing many subroutines and their associated data , I would like that in an instant of time, store all the variables in a file and whenever I would like to start from this point, retrieve the data again. In this manner I can start my program from any time that I wish. Sometimes ago I saw that there is a subroutine for this, but I do not remember where I have seen that. Do you know any routine for this purposes, please guide me on that.