/* 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, *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 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 llist_free(llist_t *elm, void (*freeit) (void *data)) { while (elm) { void *data = llist_pop(&elm); if (freeit) freeit(data); } } #ifdef UNUSED /* Reverse list order. */ llist_t *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; } #endif