C Program to Display its own Source Code as Output

Though this problem seems complex but, the concept behind this program is very simple; display the content from the same file you are writing the source code.

A predefined macro __FILE__ contains the location of a C programming file, it is working on. For example:

#include <stdio.h>
int main(){
   printf("%s",__FILE__);
}

The output of this program is the location of this C programming file.

C program to display its own source code using __FILE__

#include <stdio.h>
int main() {
    FILE *fp;
    char c;
    fp = fopen(__FILE__,"r");
    do {
         c = getc(fp);
         putchar(c);
    }
    while(c != EOF);
    fclose(fp);
    return 0;
}

This program displays the content of this particular C programming file(source code) because __FILE__ contains the location of this C programming file in a string.