busybox/libbb/llist.c

/* vi: set sw=4 ts=4: */
/*
 * linked list helper functions.
 *
 * Copyright (C) 2003 Glenn McGrath
 * Copyright (C) 2005 Vladimir Oleynik
 * Copyright (C) 2005 Bernhard Fischer
 * Copyright (C) 2006 Rob Landley <rob@landley.net>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include <stdlib.h>
#include "libbb.h"

/* Add data to the start of the linked list.  */
void llist_add_to(llist_t **old_head, void *data)
{
	llist_t *new_head = xmalloc(sizeof(llist_t));
	new_head->data = data;
	new_head->link = *old_head;
	*old_head = new_head;
}

/* Add data to the end of the linked list.  */
void llist_add_to_end(llist_t **list_head, void *data)
{
	llist_t *new_item = xmalloc(sizeof(llist_t));
	new_item->data = data;
	new_item->link = NULL;

	if (!*list_head) *list_head = new_item;
	else {
		llist_t *tail = *list_head;
		while (tail->link) tail = tail->link;
		tail->link = new_item;
	}
}

/* Remove first element from the list and return it */
void *llist_pop(llist_t **head)
{
	void *data;

	if(!*head) data = *head;
	else {
		void *next = (*head)->link;
		data = (*head)->data;
		free(*head);
		*head = next;
	}

	return data;
}

/* Recursively free all elements in the linked list.  If freeit != NULL
 * call it on each datum in the list */
void llist_free(llist_t *elm, void (*freeit)(void *data))
{
	while (elm) {
		void *data = llist_pop(&elm);
		if (freeit) freeit(data);
	}
}

/* Reverse list order. Useful since getopt32 saves option params
 * in reverse order */
llist_t* rev_llist(llist_t *list)
{
	llist_t *new = NULL;
	while (list) {
		llist_t *next = list->link;
		list->link = new;
		new = list;
		list = next;
	}
	return new;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* linked list helper functions.
4	*
5	* Copyright (C) 2003 Glenn McGrath
6	* Copyright (C) 2005 Vladimir Oleynik
7	* Copyright (C) 2005 Bernhard Fischer
8	* Copyright (C) 2006 Rob Landley <rob@landley.net>
9	*
10	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
11	*/
12
13	#include <stdlib.h>
14	#include "libbb.h"
15
16	/* Add data to the start of the linked list. */
17	void llist_add_to(llist_t *old_head, void data)
18	{
19	llist_t *new_head = xmalloc(sizeof(llist_t));
20	new_head->data = data;
21	new_head->link = *old_head;
22	*old_head = new_head;
23	}
24
25	/* Add data to the end of the linked list. */
26	void llist_add_to_end(llist_t *list_head, void data)
27	{
28	llist_t *new_item = xmalloc(sizeof(llist_t));
29	new_item->data = data;
30	new_item->link = NULL;
31
32	if (!list_head) list_head = new_item;
33	else {
34	llist_t tail = list_head;
35	while (tail->link) tail = tail->link;
36	tail->link = new_item;
37	}
38	}
39
40	/* Remove first element from the list and return it */
41	void llist_pop(llist_t *head)
42	{
43	void *data;
44
45	if(!head) data = head;
46	else {
47	void next = (head)->link;
48	data = (*head)->data;
49	free(*head);
50	*head = next;
51	}
52
53	return data;
54	}
55
56	/* Recursively free all elements in the linked list. If freeit != NULL
57	* call it on each datum in the list */
58	void llist_free(llist_t elm, void (freeit)(void *data))
59	{
60	while (elm) {
61	void *data = llist_pop(&elm);
62	if (freeit) freeit(data);
63	}
64	}
65
66	/* Reverse list order. Useful since getopt32 saves option params
67	* in reverse order */
68	llist_t* rev_llist(llist_t *list)
69	{
70	llist_t *new = NULL;
71	while (list) {
72	llist_t *next = list->link;
73	list->link = new;
74	new = list;
75	list = next;
76	}
77	return new;
78	}