#define LIMIT 10000

FILE *infile;
FILE *outfile;
double prices[LIMIT];
char answer[10];
int i = 0;

infile  = fopen("ibm_stock_prices", "r");
outfile = fopen("buy_hold_or_sell", "w");

if (fp != NULL && output_file != NULL) {
  /*  Read the input data */
  while ((fscanf(infile, "%lf", prices[i]) != EOF) && i < LIMIT)
     i++;

  printf("%d prices read from the data file", i);

  /* Process the data... */
  :
  :

  /* Write the output */
  fprintf(output_file, "%s", answer);
}
else {
   printf("fopen unsuccessful!\n");
}