Binary and ASCII Files

Binary and ASCII Files

1. Handling Binary Files

•  We can make use of two functions namely: read and write for handling the binary file format.

• The syntax of read and write functions will be ‒

output_obj. write ((char*) & variable, size of (variable));

• The memory block must be typecast to pointer to character type This block acts as a buffer in which read contents can stored or the data to be written in the file can be stored.

• Following is a simple program in which we have some data in array a. We will be writing the contents of array a to the file "input.dat". Then we will read the file and retrieve the contents in another array b. Finally the array b will be displayed on the console.

C++ Program

#include<iostream>

#include<fstream>

#include<cstdlib>

void main()

{

ofstream out_obj;

int a[5]={10,20,30,40,50};

int b[5];

out_obj.open("input.dat");

out_obj.write((char *)&a,sizeof(a));

out_obj.close();

ifstream in obj;

in_obj.open("input.dat");

in_obj.read((char *)&b,sizeof(b));

cout<<"\n The contents of input.dat file are...\n";

for(int i=0;i<5;i++)

cout<<"\n"<<b[i];

{

       in_obj.close();

}

Output

The contents of input.dat file are...

10

20

30

40

50

2. Handling ASCII Files

• An ASCII file is a plain text file whose bytes are in the ASCII range (0‒127). In practice most plain text files are UTF‒8, but the same C++ text APIs work for ASCII.

• Use <fstream>: std::ofstream for writing, std::ifstream for reading, std::fstream for read+write.

Refer previous section for the reading and writing to the file.