ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: ybolivar <ybolivar@student.42madrid.c      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/03/22 12:03:15 by ybolivar          #+#    #+#             */
/*   Updated: 2022/04/06 17:23:22 by ybolivar         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
#include"libft.h"

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

	num = 0;
	sign = 1;
	i = 0;
	while (str[i] == ' ' || str[i] == '\n' || str[i] == '\t'
		|| str[i] == '\f' || str[i] == '\r' || str[i] == '\v')
		i++;
	if (str[i] == '-' || str[i] == '+')
		if (str[i++] == '-')
			sign = -1;
	while (ft_isdigit(str[i]))
	{
		if (num * sign > 2147483647)
			return (-1);
		else if (num * sign < -2147483648)
			return (0);
		else
			num = num * 10 + (str[i] - '0');
		i++;
	}
	return ((int)(sign * num));
}