Linked list add, delete & display

Program:

#include <stdio.h>
#include <stdlib.h> // for calloc

typedef struct node {
    struct node *next;
    int value;
}node_t;

node_t *root = NULL;

void line_80(char *str)
{
    int i;
    for (i = 0; i < 80; printf("%s", str), i++);
    printf("\n");
}

void display_list(void)
{
    node_t *temp = NULL;
    if (root == NULL) {
        printf("List is empty \n");
    }
    printf("\tThe available list value is: ");
    for (temp = root; temp ; temp = temp->next) {
        printf("%d ", temp->value);
        if (temp->next) {
            printf("-> ");
        }
    }
    printf("\n\n");
}

int insert_list(node_t  **root_node, int value)
{
    node_t  *temp = NULL;
    temp = (node_t *) calloc(1, sizeof(node_t));
    temp->value = value;
    if (*root_node == NULL) {
        *root_node = temp;
    } else {
        temp->next = *root_node;
        *root_node = temp;
    }
}
void delete_list(node_t **root_node, int value)
{
    node_t *temp = NULL, *prev = NULL;
    if (*root_node == NULL) {
        printf("List is empty, so could not delete any value \n");
        return;
    }
    for (temp = prev = *root_node; temp ; prev = temp, temp = temp->next) {
        if (temp->value == value) {
            if (temp == *root_node) {
                *root_node = temp->next;
            } else {
                prev->next = temp->next;
            }
            free(temp);
            temp = NULL;
            printf("Delete the node with value %d \n", value);
            return;
        }
    }
}

int main()
{
    int input, choice = 0, value = 0;

    while (1) {
        line_80("*");
        printf("\t 1. Display the list\n\t 2. Insert to list: \n\t 3.Delete from list\n");
        line_80("*");
        printf("\n\t Enter your choice: ");
        scanf("%d", &choice);
        if (choice <= 0 || choice >= 4) {
            printf("Please choose correct choice \n");
            continue;
        }
        switch(choice)
        {
            case 1:
                display_list();
            break;
            case 2:
                printf("Enter the value to insert:");
                scanf("%d", &value);
                insert_list(&root, value);
            break;
            case 3:
                printf("Enter the value to delete:");
                scanf("%d", &value);
                delete_list(&root, value);
            break;
            default:
                printf("Wrong choice, select correct choice \n");
        }
    }
}

Output:

learn$ ./a.out
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 1
List is empty
        The available list value is:
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 2
Enter the value to insert:1
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 2
Enter the value to insert:2
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 2
Enter the value to insert:3
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 1
        The available list value is: 3 -> 2 -> 1
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 3
Enter the value to delete:2
Delete the node with value 2
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 1
        The available list value is: 3 -> 1
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 3
Enter the value to delete:1
Delete the node with value 1
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 1
        The available list value is: 3
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 3
Enter the value to delete:3
Delete the node with value 3
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************
         Enter your choice: 1
List is empty
        The available list value is:
********************************************************************************
         1. Display the list
         2. Insert to list:
         3.Delete from list
********************************************************************************