diff options
Diffstat (limited to 'libbb/llist.c')
-rw-r--r-- | libbb/llist.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/libbb/llist.c b/libbb/llist.c new file mode 100644 index 0000000..7e78f7c --- /dev/null +++ b/libbb/llist.c @@ -0,0 +1,106 @@ +/* vi: set sw=4 ts=4: */ +/* + * linked list helper functions. + * + * Copyright (C) 2003 Glenn McGrath + * Copyright (C) 2005 Vladimir Oleynik + * Copyright (C) 2005 Bernhard Reutner-Fischer + * Copyright (C) 2006 Rob Landley <rob@landley.net> + * + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + */ + +#include "libbb.h" + +/* Add data to the start of the linked list. */ +void FAST_FUNC 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 FAST_FUNC 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* FAST_FUNC llist_pop(llist_t **head) +{ + void *data, *next; + + if (!*head) + return NULL; + + data = (*head)->data; + next = (*head)->link; + free(*head); + *head = next; + + return data; +} + +/* Unlink arbitrary given element from the list */ +void FAST_FUNC llist_unlink(llist_t **head, llist_t *elm) +{ + llist_t *crt; + + if (!(elm && *head)) + return; + + if (elm == *head) { + *head = (*head)->link; + return; + } + + for (crt = *head; crt; crt = crt->link) { + if (crt->link == elm) { + crt->link = elm->link; + return; + } + } +} + +/* Recursively free all elements in the linked list. If freeit != NULL + * call it on each datum in the list */ +void FAST_FUNC llist_free(llist_t *elm, void (*freeit) (void *data)) +{ + while (elm) { + void *data = llist_pop(&elm); + + if (freeit) + freeit(data); + } +} + +/* Reverse list order. */ +llist_t* FAST_FUNC llist_rev(llist_t *list) +{ + llist_t *rev = NULL; + + while (list) { + llist_t *next = list->link; + + list->link = rev; + rev = list; + list = next; + } + return rev; +} |