ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: mulisses <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2021/10/29 18:17:45 by mulisses          #+#    #+#             */
/*   Updated: 2021/10/29 18:17:49 by mulisses         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

int	ft_atoi(const char *str)
{
	size_t	i;
	int		neg;
	int		ret;

	i = 0;
	neg = 1;
	ret = 0;
	while ((str[i] >= 9 && str[i] <= 13) || str[i] == 32)
	{
		i++;
	}
	if (str[i] == '-' || str[i] == '+')
	{	
		if (str[i] == '-')
		{
			neg *= -1;
		}
		i++;
	}
	while (str[i] >= '0' && str[i] <= '9')
	{
		ret = (ret * 10) + (str[i] - '0');
		i++;
	}
	return (ret * neg);
}