struct - Linked list in C seg faults -

having seg fault erros code posted below. new c , have been having trouble it. in main made struct node* head (pointer struct node) , assigned null. send struct node * head push function should insert user defined integers front of list. believe having issues inside push function, aprecciated.

~thanks

//node.h  struct node{         int val;         struct node* next;  };   int length(struct node *);  struct node* push(struct node *, int);  void print(struct node *, int);    //node.c   #include "./node.h"  #include<stdlib.h>  #include<stdio.h>  int length(struct node *current){        if(current->next != null)           return 1 + length(current->next);        else           return 1; }  struct node* push(struct node *head, int num){     struct node *temp = malloc(sizeof(struct node));    temp->val = num;    temp->next = head;    head = temp;    return head; }  void print(struct node* head, int size){    printf("the list %i", size);    printf(" long \n");    struct node* temp;    temp = head;    while(temp != null){    printf("%d", temp->val);    printf(" ");    temp = temp->next;    }    printf(" \n");  }    //main program   #include "./node.h"  #include<stdlib.h>  #include<stdio.h>    int main(){      char ans;     int num;     struct node* head = null;      do{        printf("enter integer linked list: ");        scanf("%d", &num);        head = push(head, num);        printf("add integer linked list? (y or n) ");        scanf("%1s", &ans);        }while(ans == 'y');         print(head, length(head));         return 0;        } 

scanf read n+1 characters provided buffer when use %ns because of null terminator.

use buffer of size 2 (char ans[2];) , check first character (ans[0] == 'y'). no longer need take address of ans when calling scanf).