diff --git a/src/main.c b/src/main.c
index 107549b..e4674ed 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,15 +3,19 @@
 /*                                                        :::      ::::::::   */
 /*   main.c                                             :+:      :+:    :+:   */
 /*                                                    +:+ +:+         +:+     */
-/*   By: freddy </var/spool/mail/freddy>            +#+  +:+       +#+        */
+/*   By: tchampio <tchampio@student.42lehavre.      +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
-/*   Created: 2025/05/05 16:59:32 by freddy            #+#    #+#             */
-/*   Updated: 2025/05/06 09:54:39 by freddy           ###   ########.fr       */
+/*   Created: 2025/05/06 13:16:11 by tchampio          #+#    #+#             */
+/*   Updated: 2025/05/06 13:16:18 by tchampio         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #include "../includes/libft.h"
 #include "../includes/mlx.h"
+#include "../includes/filecheck.h"
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
 
 typedef struct s_mlx_data
 {
@@ -22,6 +26,13 @@ typedef struct s_mlx_data
 	int		endian;
 }	t_mlx_data;
 
+typedef struct s_mapdata
+{
+	char	*filename;
+	bool	isvalid;
+	char	error[1024];
+}	t_mapdata;
+
 void	my_mlx_pixel_put(t_mlx_data *data, int x, int y, int color)
 {
 	char	*dst;
@@ -30,15 +41,36 @@ void	my_mlx_pixel_put(t_mlx_data *data, int x, int y, int color)
 	*(unsigned int*)dst = color;
 }
 
+bool	check_filename(char *file)
+{
+	(void)file;
+	return (false);
+}
+
+bool	check_cubfile(char *file, t_mapdata *map)
+{
+	int	fd;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return (ft_strlcpy(map->error, "Can't open file", 16), false);
+	if (!check_filename(file))
+		return (ft_strlcpy(map->error, "File is not a .cub file", 25), false);
+	close(fd);
+	return (true);
+}
+
 int	main(int argc, char **argv)
 {
 	void		*mlx;
 	void		*mlx_win;
 	t_mlx_data	data;
+	t_mapdata	map;
 
 	if (argc < 2)
 		return (ft_printf("Error: Missing cub3d filename\n"), 1);
-	(void)argv;
+	if (!check_cubfile(argv[1], &map))
+		return (ft_printf("Error: Wrong map file. Reason: %s\n", map.error), 1);
 	mlx = mlx_init();
 	mlx_win = mlx_new_window(mlx, 800, 600, "Cub3d");
 	data.img = mlx_new_image(mlx, 800, 600);