I think he means the functions to save and load save files. I would use sscanf to input the file. It is the easiest and most flexable function to use.
This will scan one line from a binary formated(not ASCII text!) file and assign it to the respective variables. I copied this code from a model loading function in OpenGL, but it does the job. I'm afraid I don't know much about output, though. Hope this helps you!
void readstr(FILE *f,char *string)
fgets(string, 255, f); // Gets A String Of 255 Chars Max From f (File)
} while ((string == '/') || (string == '\n'));// Until End Of Line Is Reached
readstr(filein,oneline); // Reads In The Next Line Of Text
sscanf(oneline, "%f %f %f", &rx, &ry, &rz); // Searches For 3 Floating Point Numbers, Store In rx,ry & rz