ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: knzeng-e <knzeng-e@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2016/03/18 05:45:00 by knzeng-e          #+#    #+#             */
/*   Updated: 2016/03/31 15:55:29 by knzeng-e         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

int	ft_atoi(const char *str)
{
	int	sign;
	int	number;
	int	i;

	number = 0;
	i = 0;
	while (ft_isspace(str[i]))
		i++;
	sign = (1 - 2 * (str[i] == '-'));
	if ((str[i] == '+') || (str[i] == '-'))
		i++;
	while (str[i] >= '0' && str[i] <= '9')
	{
		number *= 10;
		number += (str[i] - '0');
		i++;
	}
	return (sign * number);
}