c - Linked List Insert and Delete -

i'm trying program inserts , deletes students linked list , when try insert student @ end of list doesn't work. i'm pretty sur function algorithm right, still. anyways, here's code:

void insetend(){  stud *temp, *newnode;    char n[15]; int a;  printf("student: \n"); printf("name: "); scanf("%s", n); printf("age: "); scanf("%d", &a);  strcpy(newnode->name, n); newnode->age=a;  temp=head;  while(temp!=null){     temp=temp->next; } temp = (stud *) malloc (sizeof(stud));  newnode->next = null;    temp->next = newnode; } 

for starters pointer newnode has indeterminate value. these statements

strcpy(newnode->name, n); newnode->age=a; 

result in undefined behavior.

this loop

while(temp!=null){     temp=temp->next; } 

does not make sense because evident after loop pointer temp equal null.

and have change last pointer in list after new node inserted.

the function can @ least following way (though using function scanf character array used in program unsafe)

void insetend() {     stud *newnode;     stud **temp;        char n[15];     int a;      printf("student: \n");     printf("name: ");     scanf("%s", n);     printf("age: ");     scanf("%d", &a);      newnode = ( stud * )malloc( sizeof( stud ) );      strcpy( newnode->name, n );     newnode->age = a;     newnode->next = null;      temp = &head;      while ( *temp != null ) temp = &( *temp )->next;      *temp = newnode; }