Home | History | Annotate | Line # | Download | only in gen
readdir.c revision 1.4 
      1 /*
      2  * Copyright (c) 1983, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if defined(LIBC_SCCS) && !defined(lint)
     35 /*static char sccsid[] = "from: @(#)readdir.c	8.3 (Berkeley) 9/29/94";*/
     36 static char rcsid[] = "$Id: readdir.c,v 1.4 1994/12/28 03:06:06 mycroft Exp $";
     37 #endif /* LIBC_SCCS and not lint */
     38 
     39 #include <sys/param.h>
     40 #include <dirent.h>
     41 
     42 /*
     43  * get next entry in a directory.
     44  */
     45 struct dirent *
     46 readdir(dirp)
     47 	register DIR *dirp;
     48 {
     49 	register struct dirent *dp;
     50 
     51 	for (;;) {
     52 		if (dirp->dd_loc >= dirp->dd_size) {
     53 			if (dirp->dd_flags & __DTF_READALL)
     54 				return (NULL);
     55 			dirp->dd_loc = 0;
     56 		}
     57 		if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
     58 			dirp->dd_size = getdirentries(dirp->dd_fd,
     59 			    dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
     60 			if (dirp->dd_size <= 0)
     61 				return (NULL);
     62 		}
     63 		dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
     64 		if ((long)dp & 03)	/* bogus pointer check */
     65 			return (NULL);
     66 		if (dp->d_reclen <= 0 ||
     67 		    dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
     68 			return (NULL);
     69 		dirp->dd_loc += dp->d_reclen;
     70 		if (dp->d_ino == 0)
     71 			continue;
     72 		if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
     73 			continue;
     74 		return (dp);
     75 	}
     76 }
     77