Environment variable management prototypes. More...

#include "structs.h"

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Detailed Description

Environment variable management prototypes.

Definition in file env.h.

Functions
t_env *	init_env (char **envp)
	Initialize the environment linked list from main()'s envp. More...

t_env *	create_env_node (char *env_string)
	Create a single environment node from a KEY=value string. More...

void	add_env_node (t_env *head, t_env new_node)
	Add a node to the end of the environment linked list. More...

char *	get_env_value (t_env env_list, char key)
	Look up an environment variable's value by its key. More...

int	set_env_value (t_env *env_list, char key, char *value)
	Set or create an environment variable. More...

void	handle_shlvl (t_env **env_list)
	Increment the SHLVL environment variable. More...

void	ensure_pwd (t_env **env_list)
	Ensure PWD exists in the environment. More...

void	free_env_list (t_env **env_list)
	Free all nodes in the env linked list. More...

int	env_list_size (t_env *env_list)
	Count the number of nodes in the environment list. More...

char **	env_to_array (t_env *env)
	Convert the env linked list to a NULL terminated string array. More...

Function Documentation

◆ init_env()

t_env* init_env ( char ** envp )

Initialize the environment linked list from main()'s envp.

Iterate through envp array while creating a t_env node for each entry
After building the list, increment SHLVL and ensure PWD is set

Parameters

envp	NULL terminated string array from main()

Returns: Head of the newly allocated environment list or NULL if env was empty

Note: On allocation failure in the middle, frees all already created nodes

Warning: The caller must free via free_env_list()

Definition at line 27 of file env_init.c.

References add_env_node(), create_env_node(), ensure_pwd(), free_env_list(), and handle_shlvl().

Referenced by main().

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◆ create_env_node()

t_env* create_env_node ( char * env_string )

Create a single environment node from a KEY=value string.

Allocate a t_env_node and populate key/value by splitting at the =

Strings without = are rejected (return NULL)

Parameters

env_string KEY=value string

Returns: New node with key and value set or NULL on failure

Definition at line 91 of file env_init.c.

References t_env::next, t_env::prev, and set_env_key_value().

Referenced by create_new_var(), and init_env().

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◆ add_env_node()

void add_env_node	(	t_env **	head,
		t_env *	new_node
	)

Add a node to the end of the environment linked list.

Parameters

head	Pointer to list head pointer
new_node	Node to add

Definition at line 121 of file env_init.c.

References t_env::next, and t_env::prev.

Referenced by create_new_var(), export_no_value(), and init_env().

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◆ get_env_value()

char* get_env_value	(	t_env *	env_list,
		char *	key
	)

Look up an environment variable's value by its key.

Parameters

env_list	List head to search
key	Variable name to find

Returns: Pointer to the value string or NULL if not found

Definition at line 23 of file env_operations.c.

References t_env::key, t_env::next, and t_env::value.

Referenced by ensure_pwd(), expand_tilde(), find_cmd_path(), get_append_value(), get_cd_path(), get_home_path(), handle_shlvl(), and process_dollar().

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◆ set_env_value()

int set_env_value	(	t_env **	env_list,
		char *	key,
		char *	value
	)

Set or create an environment variable.

It first tries to update and existing variable, and if the key is not found, it creates a new node and adds it to the list

Parameters

env_list	Pointer to list head pointer
key	Variable name
value	New value

Returns: 1 on success and 0 on allocation failure

Definition at line 115 of file env_operations.c.

References create_new_var(), and update_existing_var().

Referenced by ensure_pwd(), export_append(), export_assign(), handle_shlvl(), and update_pwd_vars().

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◆ handle_shlvl()

void handle_shlvl ( t_env ** env_list )

Increment the SHLVL environment variable.

Reads the current SHLVL, increments it by 1 and writes back
If SHLVL doesn't exist, it initializes it to 1

Parameters

env_list Pointer to list head pointer

Definition at line 24 of file env_utils.c.

References get_env_value(), and set_env_value().

Referenced by init_env().

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◆ ensure_pwd()

void ensure_pwd ( t_env ** env_list )

Ensure PWD exists in the environment.

If it's not already set, it reads the current working directory via getcwd() and creates the variable

Parameters

env_list Pointer to list head pointer

Definition at line 51 of file env_utils.c.

References get_env_value(), and set_env_value().

Referenced by init_env().

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◆ free_env_list()

void free_env_list ( t_env ** env_list )

Free all nodes in the env linked list.

Parameters

env_list Pointer to list head pointer

Definition at line 69 of file env_utils.c.

References t_env::key, t_env::next, and t_env::value.

Referenced by child_execute(), exec_child(), exec_left_pipe_child(), exec_right_pipe_child(), init_env(), and main().

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◆ env_list_size()

int env_list_size ( t_env * env_list )

Count the number of nodes in the environment list.

Parameters

env_list List head

Returns: Number of nodes

Definition at line 91 of file env_utils.c.

References t_env::next.

Referenced by env_to_array().

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◆ env_to_array()

char** env_to_array ( t_env * env )

Convert the env linked list to a NULL terminated string array.

Builds a char** destined to execve(). Each entry is in a KEY=value string

If the list is empty or NULL, it returns an array containing only NULL

Parameters

env List head

Returns: NULL terminated KEY=value array or NULL on allocation failure

Definition at line 107 of file env_conversion.c.

References env_list_size(), and fill_env_array().

Referenced by prepare_exec().

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Detailed Description

Functions

Function Documentation

◆ init_env()

◆ create_env_node()

◆ add_env_node()

◆ get_env_value()

◆ set_env_value()

◆ handle_shlvl()

◆ ensure_pwd()

◆ free_env_list()

◆ env_list_size()

◆ env_to_array()