88 lines
2.8 KiB
C
88 lines
2.8 KiB
C
/* $NetBSD: lstDeQueue.c,v 1.14 2009/01/23 21:26:30 dsl Exp $ */
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/*
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* Copyright (c) 1988, 1989, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Adam de Boor.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef MAKE_NATIVE
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static char rcsid[] = "$NetBSD: lstDeQueue.c,v 1.14 2009/01/23 21:26:30 dsl Exp $";
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#else
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#include <sys/cdefs.h>
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)lstDeQueue.c 8.1 (Berkeley) 6/6/93";
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#else
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__RCSID("$NetBSD: lstDeQueue.c,v 1.14 2009/01/23 21:26:30 dsl Exp $");
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#endif
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#endif /* not lint */
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#endif
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/*-
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* LstDeQueue.c --
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* Remove the node and return its datum from the head of the list
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*/
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#include "lstInt.h"
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/*-
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*-----------------------------------------------------------------------
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* Lst_DeQueue --
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* Remove and return the datum at the head of the given list.
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*
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* Results:
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* The datum in the node at the head or NULL if the list
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* is empty.
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*
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* Side Effects:
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* The head node is removed from the list.
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*
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*-----------------------------------------------------------------------
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*/
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void *
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Lst_DeQueue(Lst l)
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{
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void *rd;
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ListNode tln;
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tln = Lst_First(l);
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if (tln == NULL) {
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return NULL;
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}
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rd = tln->datum;
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if (Lst_Remove(l, tln) == FAILURE) {
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return NULL;
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} else {
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return (rd);
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}
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}
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