Dynamic queue essentials C

#include <stdio.h>
#include <stdlib.h>

struct noeud
{
    int donnees;
    struct noeud *suivant;
};

struct noeud *avant = NULL;
struct noeud *arriere = NULL;

void enfiler(int element)
{
    struct noeud *nptr = malloc(sizeof(struct noeud));
    nptr->donnees = element;
    nptr->suivant = NULL;
    if (arriere == NULL)
    {
        avant = nptr;
        arriere = nptr;
    }
    else
    {
        arriere->suivant = nptr;
        arriere = arriere->suivant;
    }
}

void afficher()
{
    struct noeud *temp;
    temp = avant;
    printf("\n");
    while (temp != NULL)
    {
        printf("%d\t", temp->donnees);
        temp = temp->suivant;
    }
}

void defiler()
{
    if (avant == NULL)
    {
        printf("\n\nLa file est vide \n");
    }
    else
    {
        struct noeud *temp;
        temp = avant;
        avant = avant->suivant;
        printf("\n\n%d supprime", temp->donnees);
        free(temp);
    }
}

int main()
{
    int n, ch;
    do
    {
        printf("\n\nMenu File\n1. Ajouter \n2. Retirer\n3. Afficher\n0. Quitter");
        printf("\nEntrer votre choix 0-3 ? : ");
        scanf("%d", &ch);
        switch (ch)
        {
            case 1:
                printf("\nEntrer un nombre ");
                scanf("%d", &n);
                enfiler(n);
                break;
            case 2:
                defiler();
                break;
            case 3:
                afficher();
                break;
        }
    }while (ch != 0);
}