1 /* $OpenBSD: lstRemove.c,v 1.19 2010/07/19 19:46:44 espie Exp $ */ 2 /* $NetBSD: lstRemove.c,v 1.5 1996/11/06 17:59:50 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1989, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Adam de Boor. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /*- 37 * LstRemove.c -- 38 * Remove an element from a list 39 */ 40 41 #include "lstInt.h" 42 #include <stdlib.h> 43 44 45 /*- 46 *----------------------------------------------------------------------- 47 * Lst_Remove -- 48 * Remove the given node from the given list. 49 * 50 * Side Effects: 51 * The list's firstPtr will be set to NULL if ln is the last 52 * node on the list. firsPtr and lastPtr will be altered if ln is 53 * either the first or last node, respectively, on the list. 54 * 55 *----------------------------------------------------------------------- 56 */ 57 void 58 Lst_Remove(Lst l, LstNode ln) 59 { 60 if (ln == NULL) 61 return; 62 63 /* unlink it from the list */ 64 if (ln->nextPtr != NULL) 65 ln->nextPtr->prevPtr = ln->prevPtr; 66 if (ln->prevPtr != NULL) 67 ln->prevPtr->nextPtr = ln->nextPtr; 68 69 /* if either the firstPtr or lastPtr of the list point to this node, 70 * adjust them accordingly */ 71 if (l->firstPtr == ln) 72 l->firstPtr = ln->nextPtr; 73 if (l->lastPtr == ln) 74 l->lastPtr = ln->prevPtr; 75 76 /* note that the datum is unmolested. The caller must free it as 77 * necessary and as expected. */ 78 free(ln); 79 } 80 81