42_libft/ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/09/27 16:14:34 by cchauvet          #+#    #+#             */
/*   Updated: 2022/09/28 18:15:04 by cchauvet         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

int	ft_atoi(const char *nptr)
{
	char	*str;
	int		out;
	int		sign;

	str = (char *) nptr;
	out = 0;
	while (*str == ' ' || *str == '\f' || *str == '\v' || *str == '\t'
		|| *str == '\r' || *str == '\n')
		str++;
	sign = 1;
	if (*str == '-' || *str == '+')
	{
		if (*str == '-')
			sign = -1;
		str++;
	}
	while (ft_isdigit(*str))
	{
		out = 10 * out + *str - 48;
		str++;
	}
	return (out * sign);
}