diff options
Diffstat (limited to 'libbb/llist.c')
| -rw-r--r-- | libbb/llist.c | 54 |
1 files changed, 41 insertions, 13 deletions
diff --git a/libbb/llist.c b/libbb/llist.c index cb87176c5..ce7daddee 100644 --- a/libbb/llist.c +++ b/libbb/llist.c @@ -1,9 +1,18 @@ +/* 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 + * + * Licensed under the GPL v2, see the file LICENSE in this tarball. + */ #include <stdlib.h> -#include <string.h> -#include "unarchive.h" #include "libbb.h" #ifdef L_llist_add_to +/* Add data to the start of the linked list. */ extern llist_t *llist_add_to(llist_t *old_head, char *new_item) { llist_t *new_head; @@ -17,27 +26,46 @@ extern llist_t *llist_add_to(llist_t *old_head, char *new_item) #endif #ifdef L_llist_add_to_end +/* Add data to the end of the linked list. */ extern llist_t *llist_add_to_end(llist_t *list_head, char *data) { - llist_t *new_item, *tmp, *prev; + llist_t *new_item; new_item = xmalloc(sizeof(llist_t)); new_item->data = data; new_item->link = NULL; - prev = NULL; - tmp = list_head; - while (tmp) { - prev = tmp; - tmp = tmp->link; - } - if (prev) { - prev->link = new_item; - } else { + if (list_head == NULL) { list_head = new_item; + } else { + llist_t *tail = list_head; + while (tail->link) + tail = tail->link; + tail->link = new_item; } + return list_head; +} +#endif - return (list_head); +#ifdef L_llist_free_one +/* Free the current list element and advance to the next entry in the list. + * Returns a pointer to the next element. */ +extern llist_t *llist_free_one(llist_t *elm) +{ + llist_t *next = elm ? elm->link : NULL; +#if ENABLE_DMALLOC /* avoid warnings from dmalloc's error-free-null option */ + if (elm) +#endif + free(elm); + elm = next; + return elm; } #endif +#ifdef L_llist_free +/* Recursively free all elements in the linked list. */ +extern void llist_free(llist_t *elm) +{ + while ((elm = llist_free_one(elm))); +} +#endif |