ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: nopereir <nopereir@student.42sp.org.br>    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/06/13 15:31:56 by nopereir          #+#    #+#             */
/*   Updated: 2022/06/14 11:27:03 by nopereir         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

static int	ft_isspace(char c);
static int	ft_issignal(char c);

int	ft_atoi(const char *str)
{
	int	res;
	int	sign;

	res = 0;
	sign = 1;
	while (ft_isspace(*str))
		str++;
	if (*str == '-')
		sign *= -1;
	if (ft_issignal(*str))
		str++;
	while (ft_isdigit(*str))
	{
		res = res * 10 + *str - '0';
		str++;
	}
	return (res * sign);
}

static int	ft_isspace(char c)
{
	return (c == 32 || (c >= 9 && c <= 13));
}

static int	ft_issignal(char c)
{
	return (c == '-' || (c == '+'));
}