//      PROGRAM which prints itself
#include<iostream.h>
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<fstream.h>
void main()
 {
    char ch;
    clrscr();
    fstream fout;
    fout.open("itself.c",ios::in);
    if(!fout)
      {
	printf("\n cant open");
	exit(0);

      }
    while(ch!=EOF)
     {
      ch=fout.get();
      cout<<ch;
     }

    fout.close();

 }



//the file name is itself.c

Can u write above program in C

#include <stdio.h>
main()
 {
   FILE *fd;
   int c;

   fd= fopen("./file.c","r");
   while ( (c=fgetc(fd)) != EOF)
   {
     printf("%c", c);
   }
   
   fclose(fd);
 }

#include <stdio.h>

main()
{
  printf("%s\n", __FILE__);
  FILE* fp = fopen(__FILE__, "r");

  char buf[4096];
  while (!feof(fp))
  {
    fgets(buf, 4096, fp);
    printf("%s",buf);
  }

  fclose(fp);
}

#include<stdio.h>
int main(int argc,char *argv[])
{
 FILE *fp;
 char ch;
 fp=fopen(argv[0],"r");
 while(!feof(fp))
 {
   ch=fgetc(fp);
   printf("%c",ch);
 }
}

Compile the program as cc -o filename filename.c
and run as
./filename

#include<stdio.h>
main()
{
        char n;
        FILE *f;
        f=fopen("data.txt","r");
        while((fscanf(f,"%c",&n))!=EOF)
                printf("%c",n);
        fclose(f);
}

/*In above solution, data.txt contains d source code. But
its not a good solution. Plz post some better solution */

main(s)
{
        s="main(s){s=%c%s%c;printf(s,34,s,34);}";
        printf(s,34,s,34);
}