diff --git a/built-in.c b/built-in.c
index 039e301..30267c5 100755
--- a/built-in.c
+++ b/built-in.c
@@ -6,7 +6,7 @@
 /*   By: mea <mea@student.42.fr>                    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2022/01/06 09:02:57 by narnaud           #+#    #+#             */
-/*   Updated: 2022/05/18 13:45:47 by narnaud@stude    ###   ########.fr       */
+/*   Updated: 2022/05/18 16:26:51 by narnaud@stude    ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -107,8 +107,14 @@ int	ft_exit(t_datas *datas, t_command *cmd)
 	if (cmd->argc == 1)
 		halt(datas, EXIT_SUCCESS, 0);
 	else if (cmd->argc == 2)
-		halt(datas, ft_atoi(cmd->argv[1]), 0);
-	else
-		ft_putstr_fd("minishell: exit: too many arguments\n", 2);
-	return (1);
+	{
+		if (!ft_isnumber(cmd->argv[1]))
+		{
+			cmd_error("exit", "numeric argument required");
+			halt(datas, 2, 0);
+		}			
+		halt(datas, ft_atoi(cmd->argv[1]) % 255, 0);
+	}
+	cmd_error("exit", "too many arguments");
+	return (EXIT_FAILURE);
 }
diff --git a/errors.c b/errors.c
index 27f9cfa..2c9132c 100644
--- a/errors.c
+++ b/errors.c
@@ -6,7 +6,7 @@
 /*   By: mea <marvin@42.fr>                         +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2022/05/06 13:15:59 by narnaud           #+#    #+#             */
-/*   Updated: 2022/05/17 17:24:09 by narnaud          ###   ########.fr       */
+/*   Updated: 2022/05/18 14:45:53 by narnaud@stude    ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
diff --git a/libft/Makefile b/libft/Makefile
index 8a7ca8f..e3f3af6 100755
--- a/libft/Makefile
+++ b/libft/Makefile
@@ -1,7 +1,7 @@
 NAME =	libft.a
 
 SRCS =	is/ft_isalpha.c is/ft_isdigit.c is/ft_isascii.c is/ft_isprint.c \
-		is/ft_isalnum.c is/ft_isspace.c
+		is/ft_isalnum.c is/ft_isspace.c is/ft_isnumber.c
 
 SRCS +=	str/ft_len.c str/ft_lcpy.c str/ft_lcat.c str/ft_chr.c \
 		str/ft_rchr.c str/ft_ncmp.c str/ft_nstr.c str/ft_dup.c \
diff --git a/libft/is/ft_isnumber.c b/libft/is/ft_isnumber.c
new file mode 100644
index 0000000..6053f7a
--- /dev/null
+++ b/libft/is/ft_isnumber.c
@@ -0,0 +1,26 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isnumber.c                                      :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: narnaud@student.42nice.fr <marvin@42.fr>   +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/05/18 16:18:15 by narnaud@stude     #+#    #+#             */
+/*   Updated: 2022/05/18 16:21:52 by narnaud@stude    ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "../libft.h"
+
+int	ft_isnumber(char *str)
+{
+	if (*str == '-' || *str == '+')
+		str++;
+	while (*str)
+	{
+		if (!ft_isdigit(*str))
+			return (0);
+		str++;
+	}
+	return (1);
+}
diff --git a/libft/libft.h b/libft/libft.h
index b9d3edf..de7b0c1 100755
--- a/libft/libft.h
+++ b/libft/libft.h
@@ -6,7 +6,7 @@
 /*   By: narnaud <narnaud@student.42.fr>            +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2021/10/19 14:42:45 by narnaud           #+#    #+#             */
-/*   Updated: 2022/05/17 09:55:08 by narnaud          ###   ########.fr       */
+/*   Updated: 2022/05/18 16:25:27 by narnaud@stude    ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -45,6 +45,7 @@ int		ft_isdigit(int ch);
 int		ft_isprint(int ch);
 int		ft_isalnum(int ch);
 int		ft_isspace(int ch);
+int		ft_isnumber(char *str);
 void	*ft_memchr(const void *b, int c, size_t n);
 int		ft_memcmp(const void *s1, const void *s2, size_t n);
 void	*ft_memcpy(void *dst, const void *src, size_t n);