builtin unset + fixed builtin export

srcs/generic.c

@@ -6,7 +6,7 @@
 /*   By: lperrey <lperrey@student.42.fr>            +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2021/10/08 09:25:35 by lperrey           #+#    #+#             */
-/*   Updated: 2021/11/30 18:51:00 by lperrey          ###   ########.fr       */
+/*   Updated: 2021/12/05 17:35:32 by lperrey          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -218,3 +218,76 @@ void	ft_free_null(void *ptr)
 	free(*(char**)ptr);
 	*(char**)ptr = NULL;
 }
+
+/*
+** Search for an environement variable,
+** and return a pointer to the first character after "env_var=" .
+** Return NULL if env_var not found.
+*/
+char	*ft_getenv(char *env_var)
+{
+	int		i;
+	char	*tmp;
+	size_t	env_var_len;
+
+	env_var_len = ft_strlen(env_var);
+	i = 0;
+	tmp = NULL;
+	while (!tmp && environ[i])
+	{
+		if (environ[i][env_var_len] == '=')
+		{
+			if (ft_strncmp(environ[i], env_var, env_var_len) == 0)
+				tmp = &environ[i][env_var_len + 1];
+			else
+				i++;
+		}
+		else
+			i++;
+	}
+	return (tmp);
+}
+
+/*
+** Like ft_getenv(), but return position of env_var instead of value.
+** If env_var not found, return last position of **environ (== NULL)
+*/
+size_t	ft_getenv_position(char *env_var)
+{
+	int		i;
+	int		found;
+	size_t	env_var_len;
+
+	env_var_len = ft_strlen(env_var);
+	i = 0;
+	found = 0;
+	while (!found && environ[i])
+	{
+		if (environ[i][env_var_len] == '=')
+		{
+			if (ft_strncmp(environ[i], env_var, env_var_len) == 0)
+				found = 1;
+			else
+				i++;
+		}
+		else
+			i++;
+	}
+	return (i);
+}
+
+int	ft_is_posix_name(char *str)
+{
+	unsigned int	i;
+
+	if (str[0] != '_' && !ft_isalpha(str[0]))
+		return (0);
+	i = 1;
+	while (str[i])
+	{
+		if (str[i] != '_' && !ft_isalnum(str[i]))
+			return (0);
+		i++;
+	}
+	return (i);
+}