File handling notes

Data file handling

File:-
-A file is stream of bytes stored on some secondary storage device.
-Files are of 2 types:
Text file- A text file stores information in readable and printable form. Each line of text is terminated with an EOL (End of line) character.
Binary File- A binary file conatins information in the same format iun which it is held in a memory.

File stream:-
-Stream is a general term to used to state flow of data.
-ifstream: Used for read operations
-ofstream: Used for write operations
-fstream: Used for both read and write operations
-fstream.h: This header file includes definations for the stream classes ifstream, ofstream and fstream. It also contains pre-defined set of operations for input output.
-A file stored in secondary storage can be opened by 2 methods: 1-By constructor method-This will use default streamns for file input or output. This method is preffered when file is opened in input or output mode only, e.g- ofstream file("student.dat"); or ifstream file("student.dat");
-By the open() member function of the stream. It is prefferd when file is opened in various modes i.e ios::in, ios::out, ios::append, ios::ate. E.g fstream.open("book.dat",ios::in|ios::out|ios::binary);

File Modes:- (Read from book)
-out mode
-in mode
-append mode
-truncate mode
-no create mode
-no replace mode
-binary mode

File Functions:-
-eof() function: This function dertermines the end of files by returning 'true'
-close(): This functions termantes the connection between the file and stream associated e.g file.close();

Text-File Functions:-
-get(): It reads a single charcter from text file and stores it in a buffer. E.g file.get(ch);
-put(): It writes a single character in text file. E.g file.put(ch);
-getline(): It reads a line of text from text-file. E.g file.getline(ch,80); We can also use 'file>>ch' for reading and 'file<<ch' for writing but this operator does not accept white spaces.