reading a file's content character by character and printing it in another file twice

 #include<stdio.h>

int main()

{

    FILE *ptr;

         FILE *fptr;

         fptr=fopen("write.txt","w");

    ptr=fopen("ab.txt","r");

    char c;

             c=fgetc(ptr);

    while(c!=EOF)

    {

         fputc(c,fptr);

                  fputc(c,fptr);

                  c=fgetc(ptr);

    }

    fclose(ptr);

        fclose(fptr);

}