/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_long_utils.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: thrieg <thrieg@student.42mulhouse.fr>      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/10/30 10:11:17 by alier             #+#    #+#             */
/*   Updated: 2025/02/16 19:03:51 by thrieg           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include <errno.h>
#include "libft.h"

/*
 * Reimplementation of libc atol() but sets `errno` to `ERANGE` if an
 * domain error is encountered (overflow, underflow) or `EINVAL` if
 * no digits characters or invalid characters at end).
 */
long	ft_atole(const char *nptr)
{
	long	n;
	long	mult;

	n = 0;
	mult = -1;
	while (ft_isspace(*nptr))
		nptr++;
	if (*nptr == '+' || *nptr == '-')
	{
		if (*nptr == '-')
			mult = 1;
		nptr++;
	}
	if (!ft_isdigit(*nptr))
		errno = EINVAL;
	while (ft_isdigit(*nptr))
	{
		n = safe_long_sub(safe_long_mul(n, 10), *nptr - '0');
		nptr++;
	}
	if (*nptr != '\0')
		errno = EINVAL;
	return (safe_long_mul(n, mult));
}