ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jbrown <marvin@42.fr>                      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/01/17 14:28:41 by jbrown            #+#    #+#             */
/*   Updated: 2022/01/28 09:49:35 by jbrown           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

static int	checkspace(char c)
{
	if (c == '\t' || c == '\n' || c == '\v'
		|| c == '\f' || c == '\r' || c == ' ')
		return (1);
	return (0);
}

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

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