Help with data files

[wuzertheloser]

Define the file-pointers *Infile and *Outfile and link them to
a given input file Sale.dat (which is in the homework/directory)
and the output file Comm.dat (which you will create in this
assignment). Use while(fgets()!=NULL) to read all the lines in
Sale.dat. For odd number lines (containing full names) sscanf
name and surname, print the full name on the screen and in
the output file Comm.dat. For even number lines (with amount of
sale), sscanf &sale and calculate the corresponding
commission by using the above table; then print the sale and the
commission on the screen and in the output file Comm.dat, as shown
below.

The objective is to scan the contents in a file and print it out. Somehow, I can't get the printout to show. This is the program I wrote.


#include <stdio.h>
main()
{
char line[81];
FILE *Infile;
FILE *Outfile;
Infile = fopen("Sale.dat", "r");
Outfile = fopen("Sale.dat", "w");
if((Infile == NULL) || (Outfile == NULL)){
printf("error opening the file\n");
exit(911);}
while(fgets(line, 81, Infile) != NULL){
printf("%s", line);}
fclose(Infile);
fclose(Outfile);
}


Thanks!