Read text file and store it in an array

I have a text file with this in it.
Smith,John,91,95,100
Jones,Mary,91,90,88
Simon,Simple,52,61,70
Clause,Kris,75,80,82

I have a Project8.h file with:
typedef struct{
char firstName[20];
char lastName[20];
int hw1;
int hw2;
int hw3;
}student;

and a Project8.c file with:
int main() {
int length = 20;
student grades[length];
readData( "scores.txt", grades, length );
printAveForHW( 2, grades, length );
printHighest( 3, grades, length );
return 0;

These I know are correct because they are given and I have to use the names.

The problem I'm trying to solve is this:

The readData function reads data from a file named filename and stores it into an array of students of length len. You may create an intermediate file as I did in my example to replace commas with spaces so that reading strings works as desired.

This is what I have but I'm completely lost. I changed the commas to spaces but I don't know what to do after this. I don't know how to read the data from a file named filename and store it into an array of students of length len.

#include "Project8.h"

void readData( char *filename, student arr[], int len );

int main(){
FILE *from, *to;

from = fopen("scores.txt", "r");

to = fopen("temp.txt", "w");

char c;
while(fscanf(from, "%c", &c) != EOF){
if(c != ',')
fprintf(to, "%c", c);
else
fprintf(to, " ");
}

fclose(from);
fclose(to);

void readData( char *filename, student arr[], int len )

FILE *filename = fopen("temp.txt", "r");
char lastName[20];
char firstName[20];
int hw1;
int hw2;
int hw3;
while(fscanf(filename, "%s %s %d %d %d", &lastName, &firstName, hw1, hw2, hw3)

use code tage and indent your code. Your code is very difficult to read.

You don't need intermediate file.
Just read line by line, and use strtok with delimiter ",".

Code:

---

while( NOT EOF ) {
    read line;
    tokens = parse(line,",");          // use strtok in real code.
    // convert token to number,etc...
}

---