env_manip: sort funcs per structure that is being manipulated

This is instead of the operation that is being performed.

I find it more logical this way, but if you prefer we can keep it as-is.

I also put the identifier_isvalid func into parser/matchers

src/env/env_manip.c

@@ -0,0 +1,158 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   env_manip.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/02/12 18:29:12 by jguelen           #+#    #+#             */
+/*   Updated: 2025/02/19 14:41:06 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "env_manip.h"
+#include "libft.h"
+#include "../ft_errno.h"
+
+/*
+** 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);
+}
+
+/*
+** 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. ft_errno is
+** set to FT_EINVAL.
+**
+** If key is an empty string, key and value is freed, ft_errno is set to
+** FT_EBADID, and NULL is returned.
+**
+** If there is a failure allocating a new node, NULL is returned and ft_errno is
+** set to FT_EERRNO (malloc would have set it to ENOMEM).
+**
+** Returns a pointer to the first element in the linked list, or NULL on error.
+**
+** Warning: does not check for validity of a key beyond what is described above.
+**
+** Implementation notes: free2 always returns NULL
+*/
+t_env	*env_set_entry(t_env **env, char *key, char *value)
+{
+	t_env	*node;
+
+	if (key == NULL || value == NULL)
+		return (ft_errno(FT_EINVAL), free2(key, value));
+	if (*key == '\0')
+		return (ft_errno(FT_EBADID), free2(key, value));
+	node = env_find_node_bykey(*env, key);
+	if (node == NULL)
+	{
+		node = ft_calloc(1, sizeof(t_env));
+		if (!node)
+			return (ft_errno(FT_EERRNO), free2(key, value));
+		node->key = key;
+		node->value = value;
+		env_add_back(env, node);
+	}
+	else
+	{
+		free(node->value);
+		free(key);
+		node->value = value;
+	}
+	return (*env);
+}
+
+/*
+** 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);
+}