How to change position in file using C++?

hese functions allow us to change the position of the get and put stream pointers. Both functions are overloaded with two different prototypes. The first prototype is:
seekg ( position );
seekp ( position );
Using this prototype the stream pointer is changed to the absolute position position (counting from the beginning of the file). The type for this parameter is the same as the one returned by functions tellg and tellp: the member type pos_type, which is an integer value.
The other prototype for these functions is:
seekg ( offset, direction );
seekp ( offset, direction );