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