ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: nlyamani <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/10/01 17:47:18 by nlyamani          #+#    #+#             */
/*   Updated: 2024/10/01 17:47:23 by nlyamani         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

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

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

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