C program displays its own source code as output

Comprehensive Collection of C Programming Examples

In this example, you will learn to use the __FILE__ macro to display the source code of the program.

To understand this example, you should understand the followingC programming languageTopic:

• C preprocessor and macros

• C file processing

Although this problem looks complex, the concept of this program is very simple. Display the content of the file with the same source code as the written source code.

In C programming, there is a predefined macro __FILE__, which gives the name of the current input file.

#include <stdio.h>
int main() {
　　　//Locate the current input file.
　　　printf("%s", __FILE__);
}

C program displays its own source code

#include <stdio.h>
int main() {
　　　　FILE　*fp;
　　　　int c;
　　　
　　　　//Open the current input file
　　　　fp = fopen(__FILE__, "r");
　　　　do {
　　　　　　　　　c = getc(fp);　　　//Read character
　　　　　　　　　putchar(c);　　　　　//Display character
　　　　}
　　　　while(c != EOF);　　//Loop until the end of the file is reached
　　　　
　　　　fclose(fp);
　　　　return 0;
}

Comprehensive Collection of C Programming Examples