#include <stdio.h>
#include <stdlib.h>
struct client_s
{
 int fd;
 struct client_s *next;
} client_n;
int main()
{
 int i;
 struct client_s *ptr, *root;
 ptr = root = calloc(1, sizeof(struct client_s));
 for(i=0;i<=10;i++)
 {
  if(ptr->fd == NULL)
  {
   ptr->fd = i;
  }
  else
  {
   ptr = root;
   while(ptr->next!=NULL)
   {
    ptr = ptr->next;
   }
   ptr->next = calloc(1, sizeof(struct client_s));
   ptr = ptr->next;
   ptr->fd = i;
  }
 }
 ptr = root;
 do
 {
  printf("%d\n", ptr->fd);
  ptr = ptr->next;
 }while(ptr!=NULL);
 while(ptr!=NULL)
 {
  ptr = root;
  root = root->next;
  free(ptr);
 }
}