stack.c

#include "monty.h"

void free_stack(stack_t **stack);
int init_stack(stack_t **stack);
int check_mode(stack_t *stack);

/**
 * free_stack - Frees a stack_t stack.
 *
 * @stack: A pointer to the top(stack) or bottom(queue) of list.
 */
void free_stack(stack_t **stack)
{
	stack_t *tmp = (*stack);

	while (*stack)
	{
		tmp = (*stack)->next;
		free(*stack);
		*stack = tmp;
	}
}

/**
 * init_stack - Initialize a stack_t stack with
 *              beginning stack and ending queue.
 *
 * @stack: A pointer to an unitialized stack_t stack.
 *
 * Return: If an error occurs - EXIT_FAILURE.
 *         Otherwise - EXIT_SUCCESS.
 */
int init_stack(stack_t **stack)
{
	stack_t *start;

	start = malloc(sizeof(stack_t));

	if (start == NULL)
		return (malloc_error());

	start->n = STACK;
	start->prev = NULL;
	start->next = NULL;
	*stack = start;

	return (EXIT_SUCCESS);
}

/**
 * check_mode - Checks if a stack_t linked list is in stack or queue mode.
 *
 * @stack:A pointer to the top (stack) or
 *          bottom (queue) of a stack_t linked list.
 *
 * Return: If the stack_t is in stack mode - STACK (0).
 *         If the stack_t is in queue mode - QUEUE (1).
 *         Otherwise - 2.
 */
int check_mode(stack_t *stack)
{
	if (stack->n == STACK)
		return (STACK);
	else if (stack->n == QUEUE)
		return (QUEUE);

	return (2);
}