1 files changed, 78 insertions, 0 deletions
diff --git a/src/str/ft_strtol.c b/src/str/ft_strtol.c
new file mode 100644
index 0000000..447f1af
--- /dev/null
+++ b/src/str/ft_strtol.c
@@ -0,0 +1,78 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strtol.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cacharle <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2020/01/15 10:26:45 by cacharle          #+#    #+#             */
+/*   Updated: 2020/01/15 11:39:34 by cacharle         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+#define STRTOL_STD_BASE "0123456789abcdefghijklmnopqrstuvwxyz"
+
+static int	strtol_handle_base(int base, const char **str)
+{
+	if (base != 16 && base != 0)
+		return (base);
+	if (base == 16 && **str == '0' && (*str)[1] == 'x')
+	{
+		*str += 2;
+		return (base);
+	}
+	if (**str == '0')
+	{
+		(*str)++;
+		if (**str == 'x')
+		{
+			(*str)++;
+			return (16);
+		}
+		else
+			return (8);
+	}
+	return (10);
+}
+
+static long	errno_return(int err)
+{
+	errno = err;
+	return (0);
+}
+
+/*
+** If there is no digits doesn't put str in endptr like the original,
+** instead it puts the address of the char after spaces and sign.
+** Too much lines and annoyance, I can't be bothered.
+*/
+
+long		ft_strtol(const char *str, char **endptr, int base)
+{
+	t_bool		is_negative;
+	long long	nb;
+	char		base_str[37];
+
+	if (base > 36)
+		return (errno_return(EINVAL));
+	while (ft_isspace(*str))
+		str++;
+	is_negative = *str == '-' ? TRUE : FALSE;
+	if (*str == '-' || *str == '+')
+		str++;
+	base = strtol_handle_base(base, &str);
+	ft_strncpy(base_str, STRTOL_STD_BASE, base);
+	nb = 0;
+	while (ft_strchr(base_str, *str) != NULL)
+	{
+		nb *= base;
+		nb += ft_strchr(base_str, ft_tolower(*str)) - base_str;
+		if (((long)nb ^ (long)(nb / base)) < 0)
+			return (errno_return(ERANGE));
+	}
+	if (endptr != NULL)
+		*endptr = (char*)str;
+	return (is_negative ? -nb : nb);
+}