My assignment involves reading a given .txt file and using the given data to assign values to a linked list of struct _student. My thought process was to use fgets to read each line of the txt file and assign the data accordingly. Unfortunately, I think my thought process is flawed, as I've been getting a seg fault for quite a few days now. Could anyone give any insight as to what I'm doing wrong? I'm assuming im not checking for something crucial that's breaking my code.
The input.txt file is as follows:
Calvin:21:M:1000403
Hobbes:18:M:53000
Sarah:18:F:60210
Jane:20:F:1004300
We also use scanf so the user can input the file name themself.
#include <stdio.h>
#include <stdlib.h>
struct _student{
char name[25];
unsigned int age;
char gender;
unsigned long id;
struct _student *next;
};
typedef struct _student Student;
void add_to_end_of_list(Student *head, Student *new_student){
if(!head){
head = new_student;
return;
}
while(head->next){
head = head->next;
}
head->next = new_student;
return;
}
void print_data(Student *head){
while(head->next){
printf("Node at: 0x%x\nName: %s\nAge: %d\nGender: %c\nID: %lu\n Next Node at: 0x%x", &head, head->name[0], head->age, head->gender, head->id, &(head->next));
head = head->next;
}
return;
}
int main(){
char fname[128];
printf("file name: ");
scanf("%s", fname);
FILE *file = fopen("input.txt", "r");
printf("\n");
char line[256];
Student *head = NULL;
while(fgets(line, 255, file)){
Student *new_student = (Student *) malloc(sizeof(Student));
sscanf(line, "%[^:]:%d:%c:%lu", (new_student->name), &(new_student->age), &(new_student->gender), &(new_student->id));
add_to_end_of_list(head, new_student);
}
print_data(head);
printf("\n");
fclose(file);
return 0;
}
Running this gives Segmentation Fault (Core Dumped) after inputting "input.txt". Including the line
if(!head){return;}
as the first line in print_data gets rid of the seg fault, but simply doesnt print any of the data in the structs. Anyone have any ideas?
