[C] Lưu giá trị ra File

#include <stdio.h>

#include <stdlib.h>

int main()

{

   int num;

   FILE *fptr;

   fptr = fopen("C:\\program.txt","w");

   if(fptr == NULL)

   {

      printf("Error!");  

      exit(1);        

   }

   printf("Enter num: ");

   scanf("%d",&num);

   fprintf(fptr,"%d",num);

   fclose(fptr);

   return 0;

}