1 /* $OpenPackages$ */ 2 /* $OpenBSD: lstRemove.c,v 1.18 2007/09/16 09:46:14 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 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