Program

#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;
}

Result

#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;
}

Explanation :

fp = fopen(__FILE__,"r");

Suppose we have saved this source code at path –

c://tc/bin/file1.c

then

fp = fopen(__FILE__,"r");

will be expanded as –

fp = fopen("c://tc/bin/file1.c","r");