Saving data from a file to a struct in c - c

Question

I have two structs that I have to fill with student data. The data is in the format:
age, name, grade, age, group, turn
and in the header of the file is the number of student in the data.
struct school //school
{
char group; //A,B,C,D,E,F
char turn; //Morning, AFTERNOON
};
struct student
{
char *name;
char *grade;
int age;
struct school *E;
}student[6];
I tried to save first the data from a text with only the age, name, and grade to see if I could do it:
void get_file(const char* file, int *n){ //n is the amount of students
FILE* fptr;
fptr = fopen(file, "r");
if (fptr == NULL){
printf( "\n Error \n");
exit(1);
}
char* temp;
int tam = 0;
fscanf(fptr, "%d", n); //size of the list of students
for(int i= 0; i < *n; i++){
fscanf(fptr, "%d,%s,%s", &student.age[i],temp, student[i].grade);
tam = strlen(temp);
student[i].name = (char*)malloc(tam * sizeof(char));
strcpy(student[i].name, temp);
printf("%s\n", student[i].name);//to see if it's correct the content
}
fclose(fptr);
}
But, student.name store for example "Josh, A+" when it should only be "Josh". How can I fix this?
It's for an assignment.
EDIT:
My data looks like this
4 //size of list
Josh,A,20,D,M
Amber,B,23,E,M
Kevin,C,22,D,A
Adam,A+,21,C,A
Using the Remy Lebeau's solution, I got this
void get_file(const char* file, int *n){
*n = 0;
FILE* fptr = fopen(file, "r");
if (fptr == NULL){
printf( "\n Error \n");
exit(1);
}
char name[80];
char grade[2];
fscanf(fptr, "%d", n); //size of the list of students
for(int i = 0; i < *n; i++){
fscanf(fptr, "%80[^,],%2[^,],%d,%c,%c", &student[i].age, name, grade,&student[i].group, &student[i].turn);
student[i].name = strdup(name);
student[i].grade = strdup(grade);
}
fclose(fptr);
}
But I got a problem, because I made this change
struct student
{
char *name;
char *grade;
int age;
struct school E; //it was struct school *E
}student[6];
to pass the information, but my Teacher said that I couldn't change it, so how can I load information in struct school *E?

Answer 1

There are multiple problems with your call to fscanf():
&student.age[i] needs to be &student[i].age.
temp and student::grade are uninitialized pointers, they don't point anywhere, so reading data to memory pointed by them is undefined behavior. fscanf() will not allocate memory for you, you need to pre-allocate char[] buffers yourself for fscanf() to then read into.
%s reads non-whitespace characters including ',', which is why your code is not stopping on the , following Josh. Try using %[^,] instead of %s for that field.
Try something more like this:
void get_file(const char* file, int *n){
*n = 0;
FILE* fptr = fopen(file, "r");
if (fptr == NULL){
printf( "\n Error \n");
exit(1);
}
char name[256];
char grade[5];
fscanf(fptr, "%d", n); //size of the list of students
for(int i = 0; i < *n; i++){
fscanf(fptr, "%d,%255[^,],%4s", &student[i].age, name, grade);
student[i].name = strdup(name);
student[i].grade = strdup(grade);
printf("%d %s %s\n", student[i].age, student[i].name, student[i].grade);
}
fclose(fptr);
}
UPDATE:
The file data you have now shown does not match the format you described, which your code is expecting. You described (and coded) the file data as:
age, name, grade, age, group, turn (why 2 ages?)
But what you have shown looks more like:
name, grade, age, group, turn
You changed your format string in fscanf() to this new format, but you didn't change the order of the variables being read into to match this format. So, you are reading the name value into your age field, the grade value into the name field, and the age value into the grade field.
Also, you are not even attempting to handle group and turn correctly. They reside in a completely different structure, which you are not allocating any memory for. You need to allocate a school object, read group and turn into it, and then assign it to student[i].E.
With that said, try something more like this:
struct school
{
char group; //A,B,C,D,E,F
char turn; //Morning, AFTERNOON
} school[6];
struct student
{
char *name;
char *grade;
int age;
struct school *E;
}student[6];
void get_file(const char* file, int *n){
*n = 0;
FILE* fptr = fopen(file, "r");
if (fptr == NULL){
printf( "\n Error \n");
exit(1);
}
char name[81];
char grade[3];
fscanf(fptr, "%d", n); //size of the list of students
for(int i = 0; i < *n; i++){
student[i].E = &school[i]; // or, use malloc() instead, if needed...
fscanf(fptr, " %80[^,],%2[^,],%d,%c,%c", name, grade, &(student[i].age), &(student[i].E->group), &(student[i].E->turn));
student[i].name = strdup(name);
student[i].grade = strdup(grade);
}
fclose(fptr);
}