## [S4] Filtering a linked list

You have a linked list. Each element of the list is a struct node.

struct node {
struct node *next;
int hash;
int id;
char name[20];
char buffer[100];
unsigned int timestamp;
char acl;
short flow;
char *parent;
void *fifo;
};


##### Question 1: Includes

Please insert here the #include that are required to use the functions that you use to answer this question. These includes are specified in the man pages of the functions that you use.

##### Question 2: Filtering

We want to filter this list and extract the elements with an even index (the index starts at 0, hence the first, the third, the fifth, ... elements of the linked list have to be taken), without modifying the initial list.

Write the body of the function pair_filter.

Hint : You should use memcpy(3) for this question

/* pair_filter
* only taking the elements with an even index
*