list.h File Reference

Double linked list implementation in a single header file. More...

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Macros
#define	LIST_HEAD(t, name)
#define	LIST_FIELDS(t, name)
#define	LIST_HEAD_INIT(head)
#define	LIST_INIT(name, item)
#define	LIST_PREPEND(name, head, item)
#define	LIST_APPEND(name, head, item)
#define	LIST_REMOVE(name, head, item)
#define	LIST_FIND_HEAD(name, item, head)
#define	LIST_FIND_TAIL(name, item, tail)
#define	LIST_INSERT_AFTER(name, head, a, b)
#define	LIST_INSERT_BEFORE(name, head, a, b)
#define	LIST_JUST_US(name, item)
#define	LIST_FOREACH(name, i, head)
#define	LIST_FOREACH_SAFE(name, i, n, head)
#define	LIST_FOREACH_BEFORE(name, i, p)
#define	LIST_FOREACH_AFTER(name, i, p)
#define	LIST_FOREACH_OTHERS(name, i, p)
#define	LIST_LOOP_BUT_ONE(name, i, head, p)
#define	LIST_IS_EMPTY(head)

Detailed Description

Copyright

GNU Lesser General Public License 2.1

Stolen from the systemd project

Macro Definition Documentation

LIST_HEAD

#define LIST_HEAD	(		t,
			name
	)

The head of the linked list. Use this in the structure that shall contain the head of the linked list

LIST_FIELDS

#define LIST_FIELDS	(		t,
			name
	)

The pointers in the linked list's items. Use this in the item structure

LIST_HEAD_INIT

#define LIST_HEAD_INIT

(

head

)

Initialize the list's head

Parameters

[in,out]

head

Linked list begin variable

LIST_INIT

#define LIST_INIT	(		name,
			item
	)

Initialize a list item

Parameters

[in]	name	The name of the linked list member in the linked structure
[in,out]	item	The to be initialized item

LIST_PREPEND

#define LIST_PREPEND	(		name,
			head,
			item
	)

Prepend an item to the list

Parameters

[in]	name	The name of the linked list member in the linked structure
[in,out]	head	Linked list begin variable
[in,out]	item	The to be prepended item

LIST_APPEND

#define LIST_APPEND	(		name,
			head,
			item
	)

Append an item to the list

Parameters

[in]	name	The name of the linked list member in the linked structure
[in,out]	head	Linked list begin variable
[in,out]	item	The to be appended item

If the linked list is empty, head gets modified.

LIST_REMOVE

#define LIST_REMOVE	(		name,
			head,
			item
	)

Remove an item from the list

Parameters

[in]	name	The name of the linked list member in the linked structure
[in,out]	head	Linked list begin variable
[in]	item	The to be removed member

LIST_FIND_HEAD

#define LIST_FIND_HEAD	(		name,
			item,
			head
	)

Find the head of a list

Parameters

[in]	name	The name of the linked list member in the linked structure
[in]	item	Member to start the search
[in]	head	Where to store the pointer to the head element

const struct A *list_head;
struct A *some_element_in_the_list;
LIST_FIND_HEAD(list, some_element_in_the_list, list_head)

LIST_FIND_TAIL

#define LIST_FIND_TAIL	(		name,
			item,
			tail
	)

Find the tail of a list

Parameters

[in]	name	The name of the linked list member in the linked structure
[in]	item	Member to start the search
[in]	tail	Where to store the pointer to the tail element

const struct A *list_tail;
struct A *some_element_in_the_list;
LIST_FIND_HEAD(list, some_element_in_the_list, list_tail);

LIST_INSERT_AFTER

#define LIST_INSERT_AFTER	(		name,
			head,
			a,
			b
	)

Insert an item after another one (a = where, b = what)

LIST_INSERT_BEFORE

#define LIST_INSERT_BEFORE	(		name,
			head,
			a,
			b
	)

Insert an item before another one (a = where, b = what)

LIST_JUST_US

#define LIST_JUST_US	(		name,
			item
	)

Check if the given linked list member is the only member

Parameters

[in]	name	The name of the linked list member in the linked structure
[in]	item	The known member

Return values

true	If this member is the only member
false	There are more than this member in the linked list

LIST_FOREACH

#define LIST_FOREACH	(		name,
			i,
			head
	)

Iterate over all elements of a linked list beginning with head

Parameters

[in]	name	The name of the linked list member in the linked structure
[out]	i	A variable to receive a pointer to the current linked structure
[in]	head	Where everything starts

Attention

This macro creates code to iterate over the list in a read-only manner, e.g. you cannot change the current element. If you want to, refer LIST_FOREACH_SAFE() instead

Example: struct A is the linked list. It has one member defined via LIST_FIELDS, LIST_FIELDS(struct A, list);

To iterate over this list:

const struct A *current;
LIST_FOREACH(list, current, some_first_element_var)
{ read from current; }

LIST_FOREACH_SAFE

#define LIST_FOREACH_SAFE	(		name,
			i,
			n,
			head
	)

Iterate safely over all elements of a linked list beginning with head

Parameters

[in]	name	The name of the linked list member in the linked structure
[out]	i	A variable to receive a pointer to the current linked structure
[out]	n	A variable to receive a pointer to the next linked structure
[in]	head	Where everything starts

Note

Safely means you can modify the current element (deleting for example) and this loop will still continue

Example: struct A is the linked list. It has one member defined via LIST_FIELDS, LIST_FIELDS(struct A, list);

To iterate over this list:

struct A *current;
struct A *next;
LIST_FOREACH_SAFE(list, current, next, some_first_element_var)
{ remove current from list; }

LIST_FOREACH_BEFORE

#define LIST_FOREACH_BEFORE	(		name,
			i,
			p
	)

Iterate backwards over the list, beginning with the given member

Parameters

[in]	name	The name of the linked list member in the linked structure
[out]	i	A variable to receive a pointer to the current linked structure
[in]	p	A member in the middle of the list

Attention

This macro creates code to iterate over the list in a read-only manner, e.g. you cannot change the current element.

LIST_FOREACH_AFTER

#define LIST_FOREACH_AFTER	(		name,
			i,
			p
	)

Iterate forwards over the list, beginning with the given member

Parameters

[in]	name	The name of the linked list member in the linked structure
[out]	i	A variable to receive a pointer to the current linked structure
[in]	p	A member in the middle of the list

Attention

This macro creates code to iterate over the list in a read-only manner, e.g. you cannot change the current element.

LIST_FOREACH_OTHERS

#define LIST_FOREACH_OTHERS	(		name,
			i,
			p
	)

Iterate through all the members of the list p is included in, but skip over p

Parameters

[in]	name	The name of the linked list member in the linked structure
[out]	i	A variable to receive a pointer to the current linked structure
[in]	p	A member in the middle of the list

LIST_LOOP_BUT_ONE

#define LIST_LOOP_BUT_ONE	(		name,
			i,
			head,
			p
	)

Loop starting from p->next until p->prev. p can be adjusted meanwhile.

LIST_IS_EMPTY

#define LIST_IS_EMPTY

(

head

)

Check if the linked list is empty

Parameters

[in]

head

Start of the list

Return values

true	Linked list is empty
false	Linked list is filled