diff --git a/src/env_manip.h b/src/env_manip.h
index 30888f3..fa1be09 100644
--- a/src/env_manip.h
+++ b/src/env_manip.h
@@ -6,7 +6,7 @@
 /*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/02/14 13:46:39 by jguelen           #+#    #+#             */
-/*   Updated: 2025/02/18 16:47:34 by khais            ###   ########.fr       */
+/*   Updated: 2025/02/19 13:07:32 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -14,6 +14,7 @@
 # define ENV_MANIP_H
 
 # include <stdlib.h>
+# include <stdbool.h>
 # include "libft.h"
 
 typedef struct s_env
@@ -39,5 +40,6 @@ void	env_destroy_node(t_env *node);
 void	env_destroy(t_env *env);
 void	envp_destroy(char **envp);
 t_env	*env_find_node_bykey(t_env *env, char *key);
+bool	identifier_isvalid(char *id);
 
 #endif
diff --git a/src/env_manip_utils.c b/src/env_manip_utils.c
index a5fbb2a..2049e6a 100644
--- a/src/env_manip_utils.c
+++ b/src/env_manip_utils.c
@@ -3,15 +3,16 @@
 /*                                                        :::      ::::::::   */
 /*   env_manip_utils.c                                  :+:      :+:    :+:   */
 /*                                                    +:+ +:+         +:+     */
-/*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
+/*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
-/*   Created: 2025/02/14 18:31:38 by jguelen           #+#    #+#             */
-/*   Updated: 2025/02/18 16:40:32 by khais            ###   ########.fr       */
+/*   Created: 2025/02/19 13:16/49 by khais             #+#    #+#             */
+/*   Updated: 2025/02/19 13:16:49 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #include "env_manip.h"
 #include "libft.h"
+#include <stdbool.h>
 
 /*
 ** Free all memory related to a given envp structure
@@ -79,3 +80,25 @@ t_env	*env_find_node_bykey(t_env *env, char *key)
 	}
 	return (NULL);
 }
+
+/*
+** Return true if id is a valid bash identifier, false otherwise.
+**
+** A valid identifier starts with one of a-zA-Z_
+** It can contain any char a-zA-Z0-9_
+** It must contain at least one char
+*/
+bool	identifier_isvalid(char *id)
+{
+	if (id == NULL || id[0] == '\0')
+		return (false);
+	if (!ft_isalpha(id[0]) && id[0] != '_')
+		return (false);
+	while (*id != '\0')
+	{
+		if (!ft_isalpha(*id) && !ft_isdigit(*id) && *id != '_')
+			return (false);
+		id++;
+	}
+	return (true);
+}