rindex_.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char	*sccsid = "@(#)rindex_.c	4.1	(ULTRIX)	7/3/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
*
*			Modification History
*
*	David Metsky, 04-Dec-1985
*
* 001	Replaced a broken version of rindex with a working version from
*	BSD 4.3.  This answers BAR 5m.
*
* 	Based on: 	rindex_.c	5.2	6/7/85
*
*************************************************************************/

/*
 * find last occurrence of substring in string
 *
 * calling sequence:
 *	character*(*) substr, string
 *	indx = rindex (string, substr)
 * where:
 *	indx will be the index of the first character of the last occurence
 *	of substr in string, or zero if not found.
 */

long rindex_(str, substr, slen, sublen)
char *str, *substr; long slen, sublen;
{
	register char	*p = str + (slen - sublen);
	register char	*p1, *p2;
	register int	len;

	if (sublen == 0)
		return(0L);
	while (p >= str) {
		p1 = p;
		p2 = substr;
		len = sublen;
		while ( *p1++ == *p2++ && --len > 0) ;
		if ( len <= 0 )
			return((long)(++p - str));
		p--;
	}
	return(0L);
}