source: MondoRescue/branches/stable/mindi-busybox/libbb/llist.c@ 821

/* 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, see the file LICENSE in this tarball.
 */
#include <stdlib.h>
#include "libbb.h"

#ifdef L_llist_add_to
/* 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;
}
#endif

#ifdef L_llist_add_to_end
/* 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;
    }
}
#endif

#ifdef L_llist_pop
/* 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;
}
#endif

#ifdef L_llist_free
/* 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);
    }
}
#endif