1 /* $OpenPackages$ */ 2 /* $OpenBSD: lstConcat.c,v 1.14 2001/05/29 12:53:45 espie Exp $ */ 3 /* $NetBSD: lstConcat.c,v 1.6 1996/11/06 17:59:34 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 /*- 42 * listConcat.c -- 43 * Function to copy a list and append it to another. 44 */ 45 46 #include "lstInt.h" 47 #include <sys/types.h> 48 #include <stddef.h> 49 #include "memory.h" 50 51 /*- 52 *----------------------------------------------------------------------- 53 * Lst_Concat -- 54 * Concatenate two lists. New elements are created to hold the data 55 * elements but the elements themselves are not copied. 56 * If the elements themselves should be duplicated to avoid 57 * confusion with another list, the Lst_Duplicate function 58 * should be called first. 59 * 60 * Side Effects: 61 * New elements are created and appended the the first list. 62 *----------------------------------------------------------------------- 63 */ 64 void 65 Lst_Concat(l1, l2) 66 Lst l1; /* The list to which l2 is to be appended */ 67 Lst l2; /* The list to append to l1 */ 68 { 69 LstNode ln; /* original LstNode */ 70 LstNode nln; /* new LstNode */ 71 LstNode last; /* the last element in the list. Keeps 72 * bookkeeping until the end */ 73 if (l2->firstPtr != NULL) { 74 /* The loop simply goes through the entire second list creating new 75 * LstNodes and filling in the nextPtr, and prevPtr to fit into l1 76 * and its datum field from the datum field of the corresponding 77 * element in l2. The 'last' node follows the last of the new nodes 78 * along until the entire l2 has been appended. Only then does the 79 * bookkeeping catch up with the changes. During the first iteration 80 * of the loop, if 'last' is NULL, the first list must have been empty 81 * so the newly-created node is made the first node of the list. */ 82 for (last = l1->lastPtr, ln = l2->firstPtr; 83 ln != NULL; 84 ln = ln->nextPtr) { 85 PAlloc(nln, LstNode); 86 nln->datum = ln->datum; 87 if (last != NULL) 88 last->nextPtr = nln; 89 else 90 l1->firstPtr = nln; 91 nln->prevPtr = last; 92 last = nln; 93 } 94 95 /* Finish bookkeeping. The last new element becomes the last element 96 * of l1. */ 97 l1->lastPtr = last; 98 last->nextPtr = NULL; 99 } 100 } 101 102