For Alfe

#include <stdio.h>#include <string.h>#include <stdlib.h>struct person{  char name[25];  int age;  struct person *next;};void append (struct person *head);void display(struct person *h);int main(int argc, char *argv[]){	struct person * head = NULL;	  printf("Addy before: %u\n", head);  append(head);  printf("Addy after: %u\n", head);  display(head);	return 0;}void append (struct person *head){  struct person *tmp, **t;  tmp = (struct person *) malloc(sizeof(struct person));  scanf("%s %d", tmp->name, &tmp->age);  tmp->next = NULL;  printf("HERE1");  t = &head;  printf("HERE2");  if(*t != NULL)  {    printf("HERE3");    while((*t)->next != NULL)    {      *t = (*t)->next;    }    (*t)->next = tmp;  } else {    printf("HERE");    printf("tmp addy: %u\n", tmp);    *t = tmp;  }}void display(struct person *h){  struct person *tmp;  tmp = h;  while(tmp != NULL)  {    printf("%s\t%i\n", tmp->name, tmp->age);    tmp = tmp->next;  }}void insert_first(struct person *head){  struct person *tmp;  tmp = (struct person *) malloc(sizeof(struct person));  scanf("%s %d", tmp->name, &tmp->age);  tmp->next = NULL;  tmp->next = head;  head = tmp;}void insert(struct person * head){  int pos, i = 0;  struct person *tmp, *t = head;  scanf("%d", &pos);  tmp = (struct person *) malloc(sizeof(struct person));  scanf("%s %d", tmp->name, &tmp->age);  tmp->next = NULL;    while(t != NULL)  {     if(pos == i)    {      tmp->next = t->next;      t->next = tmp;    }    i ++;    t = t->next;  }}void remove_all(struct person * head){  struct person * tmp = head, *h;    while(tmp != NULL)  {    h = tmp;    tmp = tmp->next;    free(h);  }  head = NULL;}void removeAt(struct person *head){  int pos, i = 0;  struct person *tmp;  scanf("%d", &pos);  tmp = head;  /*  while(tmp != NULL)  {    if(pos == i)    {          }  }*/}