X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=util.c;h=325c2a2b8ab397dfcd7fd360d3abf0d4a3109d7b;hb=419e5080f7a94b1a5dc132fcea344181825a777c;hp=bf07b0283576cfc2a373609946c9120b18e1b4e5;hpb=b241210419fdf7f6c4e4cc881ff834c641d9bdd5;p=wmpus

diff --git a/util.c b/util.c
index bf07b02..325c2a2 100644
--- a/util.c
+++ b/util.c
@@ -1,9 +1,27 @@
+/*
+ * Copyright (C) 2011 Andy Spencer <andy753421@gmail.com>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 
 #include "util.h"
 
+/* Doubly linked lists */
 list_t *list_insert(list_t *next, void *data)
 {
 	list_t *node = new0(list_t);
@@ -15,10 +33,22 @@ list_t *list_insert(list_t *next, void *data)
 	return node;
 }
 
+void list_insert_after(list_t *prev, void *data)
+{
+	// prev must be valid,
+	// as we cannot return the original list head
+	list_t *node = new0(list_t);
+	node->data = data;
+	node->prev = prev;
+	node->next = prev->next;
+	prev->next = node;
+	if (node->next) node->next->prev = node;
+}
+
 list_t *list_append(list_t *head, void *data)
 {
 	list_t *last = head;
-	while (last->next)
+	while (last && last->next)
 		last = last->next;
 	list_t *node = new0(list_t);
 	node->data = data;
@@ -45,8 +75,19 @@ int list_length(list_t *node)
 	return len;
 }
 
-void list_move(list_t *node, int offset)
+list_t *list_last(list_t *list)
+{
+	while (list && list->next)
+		list = list->next;
+	return list;
+}
+
+list_t *list_find(list_t *list, void *data)
 {
+	for (list_t *cur = list; cur; cur = cur->next)
+		if (cur->data == data)
+			return cur;
+	return NULL;
 }
 
 /* Misc */