109 lines
1.9 KiB
C
109 lines
1.9 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* linked list helper functions.
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*
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* Copyright (C) 2003 Glenn McGrath
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* Copyright (C) 2005 Vladimir Oleynik
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* Copyright (C) 2005 Bernhard Fischer
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* Copyright (C) 2006 Rob Landley <rob@landley.net>
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*/
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#include "libbb.h"
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/* Add data to the start of the linked list. */
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void llist_add_to(llist_t **old_head, void *data)
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{
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llist_t *new_head = xmalloc(sizeof(llist_t));
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new_head->data = data;
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new_head->link = *old_head;
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*old_head = new_head;
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}
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/* Add data to the end of the linked list. */
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void llist_add_to_end(llist_t **list_head, void *data)
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{
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llist_t *new_item = xmalloc(sizeof(llist_t));
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new_item->data = data;
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new_item->link = NULL;
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if (!*list_head)
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*list_head = new_item;
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else {
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llist_t *tail = *list_head;
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while (tail->link)
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tail = tail->link;
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tail->link = new_item;
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}
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}
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/* Remove first element from the list and return it */
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void *llist_pop(llist_t **head)
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{
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void *data, *next;
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if (!*head)
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return NULL;
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data = (*head)->data;
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next = (*head)->link;
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free(*head);
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*head = next;
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return data;
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}
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/* Unlink arbitrary given element from the list */
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void llist_unlink(llist_t **head, llist_t *elm)
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{
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llist_t *crt;
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if (!(elm && *head))
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return;
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if (elm == *head) {
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*head = (*head)->link;
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return;
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}
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for (crt = *head; crt; crt = crt->link) {
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if (crt->link == elm) {
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crt->link = elm->link;
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return;
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}
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}
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}
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/* Recursively free all elements in the linked list. If freeit != NULL
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* call it on each datum in the list */
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void llist_free(llist_t *elm, void (*freeit) (void *data))
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{
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while (elm) {
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void *data = llist_pop(&elm);
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if (freeit)
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freeit(data);
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}
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}
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#ifdef UNUSED
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/* Reverse list order. */
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llist_t *llist_rev(llist_t *list)
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{
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llist_t *rev = NULL;
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while (list) {
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llist_t *next = list->link;
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list->link = rev;
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rev = list;
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list = next;
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}
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return rev;
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}
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#endif
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