1 /*-
2  * LstFindFrom.c --
3  *	Find a node on a list from a given starting point. Used by Lst_Find.
4  *
5  * Copyright (c) 1988 by University of California Regents
6  *
7  * Permission to use, copy, modify, and distribute this
8  * software and its documentation for any purpose and without
9  * fee is hereby granted, provided that the above copyright
10  * notice appears in all copies.  Neither the University of California nor
11  * Adam de Boor makes any representations about the suitability of this
12  * software for any purpose.  It is provided "as is" without
13  * express or implied warranty.
14  */
15 #ifndef lint
16 static char *rcsid =
17 "$Id: lstFindFrom.c,v 1.6 88/11/17 20:52:37 adam Exp $ SPRITE (Berkeley)";
18 #endif lint
19 
20 #include	"lstInt.h"
21 
22 /*-
23  *-----------------------------------------------------------------------
24  * Lst_FindFrom --
25  *	Search for a node starting and ending with the given one on the
26  *	given list using the passed datum and comparison function to
27  *	determine when it has been found.
28  *
29  * Results:
30  *	The found node or NILLNODE
31  *
32  * Side Effects:
33  *	None.
34  *
35  *-----------------------------------------------------------------------
36  */
37 LstNode
38 Lst_FindFrom (l, ln, d, cProc)
39     Lst		      	l;
40     register LstNode    ln;
41     register ClientData d;
42     register int	(*cProc)();
43 {
44     register ListNode	tln;
45     Boolean		found = FALSE;
46 
47     if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
48 	return (NILLNODE);
49     }
50 
51     tln = (ListNode)ln;
52 
53     do {
54 	if ((*cProc) (tln->datum, d) == 0) {
55 	    found = TRUE;
56 	    break;
57 	} else {
58 	    tln = tln->nextPtr;
59 	}
60     } while (tln != (ListNode)ln && tln != NilListNode);
61 
62     if (found) {
63 	return ((LstNode)tln);
64     } else {
65 	return (NILLNODE);
66     }
67 }
68 
69