readdir.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

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

/************************************************************************
 *									*
 *			Copyright (c) 1986 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.	*
 *									*
 ************************************************************************/

#include <sys/param.h>
#include <sys/dir.h>
#include <stdio.h>

/*
 * get next entry in a directory.
 */
struct direct *
readdir(dirp)
	register DIR *dirp;
{
	register struct direct *dp;
	extern int getdirentries();

	for (;;) {
		if (dirp->dd_loc == 0) {
			dirp->dd_size = getdirentries(dirp->dd_fd,
			    dirp->dd_buf, dirp->dd_bsize, &dirp->dd_bbase);
			if (dirp->dd_size <= 0)
				return (NULL);
			dirp->dd_entno = 0;
		}
		if (dirp->dd_loc >= dirp->dd_size) {
			dirp->dd_loc = 0;
			continue;
		}
		dp = (struct direct *)(dirp->dd_buf + dirp->dd_loc);
		if (dp->d_reclen <= 0) {
			return (NULL);
		}
		dirp->dd_loc += dp->d_reclen;
		dirp->dd_entno++;
		if (dp->d_fileno == 0)
			continue;
		return (dp);
	}
}