C programming. File I/O, Link List and Struct - c

Question

I have an assignment that requires me to edit a C program provided to me so that it can read from a text document where each line looks like:
int%char%char%Double%int%int%int
with any number of lines and an empty line at the end of the file.
This text file is passed to this program:
#include <stdlib.h>
#include <stdio.h>
struct node{
int element;
struct node * next;
};
// node structure
struct node * head = NULL; // head node
void add_node(int num) {
if (head == NULL){
head = (struct node *) malloc(sizeof(struct node));
head->element = num;
}
else{
struct node * p = head;
while(p->next != NULL)
p = p->next;
p->next = (struct node *) malloc(sizeof(struct node));
p->next->element = num;
}
}
void print_list() {
struct node * p = head;
while(p != NULL){
printf("%d ", p->element);
p = p->next;
}
}
void free_list() {
struct node * p = head;
while(head != NULL){
p = head->next;
free(head);
head = p;
}
}
int main(int argc, char const *argv[]) {
int n, i;
for (i = 0; i < 10; i++) {
scanf("%d", &n);
add_node(n);
}
print_list();
free_list();
return 0;
}
I need to edit this program to include the 7 fields from the file (ID, Category, Detail, Amount, Year, Month, Day) in the struct node. Then have it read from the text file (File_name.txt for now) add the fields without the % separator between them in the struct node, and then print them out in order as such (RecordID: (ID) Category: (category) Amount: $(amount) Date: (Month)-(Day)-(Year) Detail: (detail)) and free all pointers before the program is terminated. I don't expect you all to do the assignment for me, its just that I have no idea how C programming works and I need to do this so if anyone can help point me in the right direction on how to go about this it would be much appreciated.

Answer 1

From what I see.
You'd be having to Create a struct of your own with specified variables from the file.
Read every line and intelligently parse them... the function strtok should do be able to do this in C.
Extract variable to store in created struct using a function which should not be too hard to write
And the rest you can or should be able to take care of
This might have not been as useful as you hope would buh you can try to make me understand so I can help do better

Answer 2

This should get you started on the right path:
int main(int argc, char const *argv[]) {
char filename[100];
printf("Enter the name of the file: ");
/*stdin is a FILE pointer to standard input */
fgets(filename, 100, stdin);
/*Now you open the file for reading "r" means read mode*/
FILE *fp = fopen(filename, "r");
/*Basic error checking*/
if (!fp) {
perror("File opening failed");
return EXIT_FAILURE; /*This is macro defined in stdlib.h*/
}
int id, year, month, day;
char category, detail;
double amt;
/* Here the fun begins. Use fscanf*/
while(fscanf(fp, "ID(%d)%%Category(%c)%%Detail(%c)%%Amount(%lf)%%Year(%d)%%Month(%d)%%Day(%d)",
&id, &category, &detail, &amt, &year, &month, &day) == 7) {
/* Do what ever you want with those values - create a node or something*/
}
/* Finally close the file */
fclose(fp);
return 0;
}
Remember that each time through the loop, the variables change.