C Program to Display its own Source Code as Output of Program

C Program to Display its own Source Code as Output of Program.

In this article, you will learn how to write a c program that produces its own source code as its output of the program.

• In this given program __FILE__ macros will return the current file name of the program.
• Then fopen function will open this input file.
• After that with the help of getc & putchar functions, It will read the characters.
• Then It will display these characters immediately.
• In the last given program, It will print the itself code.

You should know about the following topics in C programming to understand this program:

• C Pointers
• C __FILE__ Macros
• C fopen Function
• C getc Function
• C putchar Function

Source

// C program to Display its own Source Code as Output
#include <stdio.h>

// It's the main function of the program
int main() {
    FILE *file_pointer;
    int program_character;
   
    // Step-1 Open the current file as an input
    file_pointer = fopen(__FILE__,"r");

    // Step-2 Read character's from the input file & Then display these characters on time
    do {
        program_character = getc(file_pointer);
        putchar(program_character);
    }
    while (program_character != EOF);  // Loop will stop until the end of the file is reached
    
    // Step-3 Close the input file
    fclose(file_pointer);
    printf("\n");
    return 0;
}

Run

Output