xref: /csrg-svn/usr.bin/make/lst.lib/lstCur.c (revision 40412)
1*40412Sbostic /*
2*40412Sbostic  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
3*40412Sbostic  * All rights reserved.
4*40412Sbostic  *
5*40412Sbostic  * This code is derived from software contributed to Berkeley by
6*40412Sbostic  * Adam de Boor.
7*40412Sbostic  *
8*40412Sbostic  * Redistribution and use in source and binary forms are permitted
9*40412Sbostic  * provided that the above copyright notice and this paragraph are
10*40412Sbostic  * duplicated in all such forms and that any documentation,
11*40412Sbostic  * advertising materials, and other materials related to such
12*40412Sbostic  * distribution and use acknowledge that the software was developed
13*40412Sbostic  * by the University of California, Berkeley.  The name of the
14*40412Sbostic  * University may not be used to endorse or promote products derived
15*40412Sbostic  * from this software without specific prior written permission.
16*40412Sbostic  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17*40412Sbostic  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18*40412Sbostic  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19*40412Sbostic  */
20*40412Sbostic 
21*40412Sbostic #ifndef lint
22*40412Sbostic static char sccsid[] = "@(#)lstCur.c	5.2 (Berkeley) 03/11/90";
23*40412Sbostic #endif /* not lint */
24*40412Sbostic 
2540411Sbostic /*-
2640411Sbostic  * LstCur.c --
2740411Sbostic  *	Return the current node in the list.
2840411Sbostic  *	The sequential functions access the list in a slightly different way.
2940411Sbostic  *	CurPtr points to their idea of the current node in the list and they
3040411Sbostic  *	access the list based on it. Because the list is circular, Lst_Next
3140411Sbostic  *	and Lst_Prev will go around the list forever. Lst_IsAtEnd must be
3240411Sbostic  *	used to determine when to stop.
3340411Sbostic  */
3440411Sbostic 
3540411Sbostic #include	"lstInt.h"
3640411Sbostic 
3740411Sbostic /*-
3840411Sbostic  *-----------------------------------------------------------------------
3940411Sbostic  * Lst_Cur --
4040411Sbostic  *	Return the current node if the list is open for sequential
4140411Sbostic  *	access.
4240411Sbostic  *
4340411Sbostic  * Results:
4440411Sbostic  *	The current node or NILLNODE if the list isn't open..
4540411Sbostic  *
4640411Sbostic  * Side Effects:
4740411Sbostic  *	None.
4840411Sbostic  *
4940411Sbostic  *-----------------------------------------------------------------------
5040411Sbostic  */
5140411Sbostic LstNode
Lst_Cur(l)5240411Sbostic Lst_Cur (l)
5340411Sbostic     Lst	    l;
5440411Sbostic {
5540411Sbostic     register List list = (List)l;
5640411Sbostic 
5740411Sbostic     if ((LstValid(l) == FALSE) ||
5840411Sbostic 	(list->isOpen == FALSE)) {
5940411Sbostic 	    return (NILLNODE);
6040411Sbostic     } else {
6140411Sbostic 	return ((LstNode)list->curPtr);
6240411Sbostic     }
6340411Sbostic }
6440411Sbostic 
65