int write_page(int fd, void *page, int i) { return file_op(fd, page, i, &my_write); }
void File::save(const string &filename, string* content) { fstream file_op(filename.c_str(),ios::out); file_op << *content; file_op.close(); }
int read_page(int fd, void *page, int i) { return file_op(fd, page, i, &read); }