1 /* $OpenPackages$ */
2 /* $OpenBSD: lstRemove.c,v 1.15 2004/04/07 13:11:36 espie Exp $ */
3 /* $NetBSD: lstRemove.c,v 1.5 1996/11/06 17:59:50 christos Exp $ */
4
5 /*
6 * Copyright (c) 1988, 1989, 1990, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * Adam de Boor.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 /*-
38 * LstRemove.c --
39 * Remove an element from a list
40 */
41
42 #include "lstInt.h"
43 #include <stdlib.h>
44
45
46 /*-
47 *-----------------------------------------------------------------------
48 * Lst_Remove --
49 * Remove the given node from the given list.
50 *
51 * Side Effects:
52 * The list's firstPtr will be set to NULL if ln is the last
53 * node on the list. firsPtr and lastPtr will be altered if ln is
54 * either the first or last node, respectively, on the list.
55 *
56 *-----------------------------------------------------------------------
57 */
58 void
Lst_Remove(Lst l,LstNode ln)59 Lst_Remove(Lst l, LstNode ln)
60 {
61 if (ln == NULL)
62 return;
63
64 /* unlink it from the list */
65 if (ln->nextPtr != NULL)
66 ln->nextPtr->prevPtr = ln->prevPtr;
67 if (ln->prevPtr != NULL)
68 ln->prevPtr->nextPtr = ln->nextPtr;
69
70 /* if either the firstPtr or lastPtr of the list point to this node,
71 * adjust them accordingly */
72 if (l->firstPtr == ln)
73 l->firstPtr = ln->nextPtr;
74 if (l->lastPtr == ln)
75 l->lastPtr = ln->prevPtr;
76
77 /* note that the datum is unmolested. The caller must free it as
78 * necessary and as expected. */
79 free(ln);
80 }
81
82