usr/src/usr.bin/make/lst.lib/lstFindFrom.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.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)lstFindFrom.c       8.2 (Berkeley) %G%";
#endif /* not lint */

/*-
 * LstFindFrom.c --
 *      Find a node on a list from a given starting point. Used by Lst_Find.
 */

#include        "lstInt.h"

/*-
 *-----------------------------------------------------------------------
 * Lst_FindFrom --
 *      Search for a node starting and ending with the given one on the
 *      given list using the passed datum and comparison function to
 *      determine when it has been found.
 *
 * Results:
 *      The found node or NILLNODE
 *
 * Side Effects:
 *      None.
 *
 *-----------------------------------------------------------------------
 */
LstNode
Lst_FindFrom (l, ln, d, cProc)
    Lst                 l;
    register LstNode    ln;
    register ClientData d;
    register int        (*cProc) __P((ClientData, ClientData));
{
    register ListNode   tln;
    Boolean             found = FALSE;

    if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
        return (NILLNODE);
    }

    tln = (ListNode)ln;

    do {
        if ((*cProc) (tln->datum, d) == 0) {
            found = TRUE;
            break;
        } else {
            tln = tln->nextPtr;
        }
    } while (tln != (ListNode)ln && tln != NilListNode);

    if (found) {
        return ((LstNode)tln);
    } else {
        return (NILLNODE);
    }
}