add tests for gunzip

[oweals/busybox.git] / libbb / llist.c

diff --git a/libbb/llist.c b/libbb/llist.c
index cb87176c5292bfa379479ae6298cc96c7beff33b..4b3971bbe58968b924355217834f450f4c8aa84d 100644 (file)
--- a/libbb/llist.c
+++ b/libbb/llist.c
@@ -1,43 +1,108 @@
-#include <stdlib.h>
-#include <string.h>
-#include "unarchive.h"
+/* 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 "libbb.h"
 
-#ifdef L_llist_add_to
-extern llist_t *llist_add_to(llist_t *old_head, char *new_item)
+/* Add data to the start of the linked list.  */
+void llist_add_to(llist_t **old_head, void *data)
 {
-       llist_t *new_head;
-
-       new_head = xmalloc(sizeof(llist_t));
-       new_head->data = new_item;
-       new_head->link = old_head;
+       llist_t *new_head = xmalloc(sizeof(llist_t));
 
-       return (new_head);
+       new_head->data = data;
+       new_head->link = *old_head;
+       *old_head = new_head;
 }
-#endif
 
-#ifdef L_llist_add_to_end
-extern llist_t *llist_add_to_end(llist_t *list_head, char *data)
+/* Add data to the end of the linked list.  */
+void llist_add_to_end(llist_t **list_head, void *data)
 {
-       llist_t *new_item, *tmp, *prev;
+       llist_t *new_item = xmalloc(sizeof(llist_t));
 
-       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 (!*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;
+               }
        }
-       if (prev) {
-               prev->link = new_item;
-       } else {
-               list_head = new_item;
+}
+
+/* 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;
 
-       return (list_head);
+       while (list) {
+               llist_t *next = list->link;
+
+               list->link = rev;
+               rev = list;
+               list = next;
+       }
+       return rev;
 }
 #endif
-