ENV: A small set of functions for internal env

src/env_get.c

@@ -6,7 +6,7 @@
 /*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/02/14 18:43:38 by jguelen           #+#    #+#             */
-/*   Updated: 2025/02/18 16:23:24 by khais            ###   ########.fr       */
+/*   Updated: 2025/02/18 16:33:10 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -66,3 +66,18 @@ char	*envp_get_val(char *line)
 	val_pointer++;
 	return (ft_strdup(val_pointer));
 }
+
+/*
+** Get the value corresponding to a given key in the given environment structure
+**
+** If not found, return null
+*/
+char	*env_get_val(t_env *env, char *key)
+{
+	t_env	*node;
+
+	node = env_find_node_bykey(env, key);
+	if (node)
+		return (node->value);
+	return (NULL);
+}

src/env_manip.c

@@ -0,0 +1,178 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   env_manip.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/02/12 18:29:12 by jguelen           #+#    #+#             */
+/*   Updated: 2025/02/18 18:41:30 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "env_manip.h"
+#include "libft.h"
+
+/*
+** Remove the first env node of the given linked list where the key matches the
+** given key.
+**
+** In any given env linked list, there should only be one entry for a given key.
+**
+** If the linked list is empty or the pointer is NULL, nothing is done.
+**
+** If the linked list does not contain an element matching the given key,
+** nothing is done.
+*/
+void	env_rm_entry(t_env **env, char *key)
+{
+	t_env	*current;
+	t_env	*next;
+
+	if (env == NULL || (*env) == NULL)
+		return ;
+	if (strncmp((*env)->key, key, INT_MAX) == 0)
+	{
+		next = (*env)->next;
+		env_destroy_node(*env);
+		(*env) = next;
+		return ;
+	}
+	current = *env;
+	while (current->next)
+	{
+		if (strncmp(current->next->key, key, INT_MAX) == 0)
+		{
+			next = current->next;
+			current->next = next->next;
+			env_destroy_node(next);
+			return ;
+		}
+		current = current->next;
+	}
+}
+
+/*
+** Add the given element to the end of the given linked list.
+*/
+static void	env_add_back(t_env **env, t_env *new)
+{
+	t_env	*last;
+
+	last = *env;
+	if (last == NULL)
+	{
+		*env = new;
+		return ;
+	}
+	while (last->next)
+		last = last->next;
+	last->next = new;
+}
+
+/*
+** In the given env linked list, if an element with the given key exist, set its
+** value to the one provided. If no such element exist, create a new one with
+** the provided value.
+**
+** The provided key and value must be allocated. In case of error, they will be
+** freed. In case a node matching the given key is found the provided key value
+** is freed.
+**
+** If key or value are null, both are freed and NULL is returned.
+**
+** If key is an empty string, key and value is freed and a non-error value is
+** returned.
+**
+** If there is a failure allocating a new node, NULL is returned.
+**
+** Returns a pointer to the first element in the linked list, or NULL on error.
+*/
+t_env	*env_set_entry(t_env **env, char *key, char *value)
+{
+	t_env	*node;
+
+	if (key == NULL || value == NULL)
+		return (free(key), free(value), NULL);
+	if (*key == '\0')
+		return (free(key), free(value), *env);
+	node = env_find_node_bykey(*env, key);
+	if (node == NULL)
+	{
+		node = ft_calloc(1, sizeof(t_env));
+		if (!node)
+			return (free(key), free(value), NULL);
+		node->key = key;
+		node->value = value;
+		env_add_back(env, node);
+	}
+	else
+	{
+		free(node->value);
+		free(key);
+		node->value = value;
+	}
+	return (*env);
+}
+
+/*
+** read an envp structure, and create a t_env linked list containing the same
+** information.
+**
+** the envp structure is not freed.
+**
+** in case of error, all memory is freed and null is returned.
+**
+** no checks additional checks than those of envp_get_key and envp_get_val are
+** performed
+*/
+t_env	*env_from_envp(char **envp)
+{
+	t_env	*env;
+
+	env = NULL;
+	while (*envp)
+	{
+		if (env_set_entry(&env, envp_get_key(*envp),
+				envp_get_val(*envp)) == NULL)
+		{
+			env_destroy(env);
+			return (NULL);
+		}
+		envp++;
+	}
+	return (env);
+}
+
+/*
+** Create an envp structure from the given env linked list.
+**
+** The linked list is not destroyed.
+**
+** in case of allocation error, all memory is freed and NULL is returned.
+*/
+char	**envp_from_env(t_env *env)
+{
+	char	**new_envp;
+	size_t	size;
+	size_t	i;
+
+	size = env_get_size(env);
+	new_envp = ft_calloc(size + 1, sizeof(char *));
+	if (new_envp == NULL)
+		return (NULL);
+	i = 0;
+	while (i < size)
+	{
+		new_envp[i] = ft_strjoin_sepc(env->key, env->value, '=');
+		if (new_envp[i] == NULL)
+		{
+			envp_destroy(new_envp);
+			return (NULL);
+		}
+		i++;
+		env = env->next;
+	}
+	new_envp[size] = NULL;
+	return (new_envp);
+}

src/env_manip.h

@@ -6,7 +6,7 @@
 /*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/02/14 13:46:39 by jguelen           #+#    #+#             */
-/*   Updated: 2025/02/16 12:55:27 by jguelen          ###   ########.fr       */
+/*   Updated: 2025/02/18 16:47:34 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -36,8 +36,8 @@ t_env	*env_from_envp(char **envp);
 /*env_manip_utils*/
 size_t	env_get_size(t_env *env);
 void	env_destroy_node(t_env *node);
-void	env_destroy(t_env **env);
-void	envp_destroy_envp(char **envp);
+void	env_destroy(t_env *env);
+void	envp_destroy(char **envp);
 t_env	*env_find_node_bykey(t_env *env, char *key);
 
 #endif

src/env_manip_utils.c

@@ -0,0 +1,97 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   env_manip_utils.c                                  :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/02/14 18:31:38 by jguelen           #+#    #+#             */
+/*   Updated: 2025/02/18 16:40:32 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "env_manip.h"
+#include "libft.h"
+
+/*
+** Free all memory related to a given envp structure
+*/
+void	envp_destroy(char **envp)
+{
+	int	i;
+
+	if (!envp)
+		return ;
+	i = 0;
+	while (envp[i])
+	{
+		free(envp[i]);
+		i++;
+	}
+	free(envp);
+}
+
+/*
+** Free the given env node.
+*/
+void	env_destroy_node(t_env *env)
+{
+	if (!env)
+		return ;
+	free(env->key);
+	free(env->value);
+	free(env);
+}
+
+/*
+** Free the given env linked list.
+*/
+void	env_destroy(t_env *env)
+{
+	t_env	*next;
+
+	if (!env)
+		return ;
+	while (env)
+	{
+		next = env->next;
+		env_destroy_node(env);
+		env = next;
+	}
+}
+
+/*
+** Get the number of mappings in the givne env linked list
+*/
+size_t	env_get_size(t_env *env)
+{
+	size_t	nb_elem;
+
+	nb_elem = 0;
+	while (env)
+	{
+		nb_elem++;
+		env = env->next;
+	}
+	return (nb_elem);
+}
+
+/*
+** Find and return a pointer to the node in the given env linked list where the
+** key matches the given key.
+**
+** If the node is not found, return NULL.
+**
+** Note that this is a pointer to the middle of the linked list, the node is not
+** copied.
+*/
+t_env	*env_find_node_bykey(t_env *env, char *key)
+{
+	while (env)
+	{
+		if (ft_strncmp(env->key, key, INT_MAX) == 0)
+			return (env);
+		env = env->next;
+	}
+	return (NULL);
+}