Chapter 14 File processing

1. All data items processed by a computer are reduced to combinations of zeros 
   and ones.

2. Digits, letters, and special symbols are referred to as characters. The set 
   of all characters that may be used to write programs and represent data items 
   on a particular computer is called that computer's character set. Every 
   character in the character set is repsented as a bit pattern.

3. Sequential access is the most popular method of processing data in a file.

4. A collection of programs designed to create and manage databases is called a 
   database management system (DBMS).

5. C++ views each file as a sequential stream of bytes.

6. The header files <iostream.h> and <fstream.h> must be included in a program 
   to perform C++ file I/O. Header <fstream.h> includes the definitions for the 
   stream classes ifstream, ofstream, and fstream.

7. Files are opened simply by instantiating objects of stream classes ifstream, 
   ofstream and fstream.

8. C++ imposes no structure on a file. Thus, notions like "record" do not exist 
   in C++. The programmer must structure a file to meet the requirements of a 
   particular application.

9. A "get pointer" indicates the position in the file from which the next input 
   is to occur, and a "put pointer" indicates the position in the file at which 
   the next output is to be placed. Both the istream class and the ostream class 
   provide member functions for repositioning the file position pointer. The 
   functions are seekg ("seek get") for class istream and seep ("seek put") for 
   the ostream class.

10. Member functions tellp and tellg return the current locations of the "put" 
    and "get" pointers, respectively.

11. A convenient way to implement random access files is by using only 
    fixed-length records. Using this technique, a program can quickly calculate 
    the exact location of a record relative to the beginning of the file.

12. Data can be inserted in a random access file without destroying other data 
    in the file. Data can be updated or deleted without rewriting the entire file.

13. The ostream member function write outputs to a specified stream some number 
    of bytes beginning at a designated location in memory.

14. The istream member function read inputs some number of bytes from the  
    specified stream to an area in memory beginning at a designated address.

15. The write function expects a first argument of type const char *, so this 
    argument must be cast to const char * if it is of some other pointer type. 
    The second argument is an integer that specifies the number of bytes to be 
    written.

16. The ios member function eof determines if the end of file indicator has been 
    set for the designated stream. End-of-file is set after an attempted read 
    fails.

17. Open a file for input only (using ios::in) if the contents of the file should
    not be modified. This is an example of the principle of least privilege.

18. Explicitly close each file as soon as it is known that the program will not 
    reference the file again. This practice also improve the program clarity.