1 /*
2 * Copyright (c) 1983 Regents of the University of California.
3 * 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[] = "@(#)readdir.c 5.7 (Berkeley) 6/1/90";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <dirent.h>
39
40 /*
41 * get next entry in a directory.
42 */
43 struct dirent *
readdir(dirp)44 readdir(dirp)
45 register DIR *dirp; {
46 register struct dirent *dp;
47
48 for (;;) {
49 if (dirp->dd_loc == 0) {
50 dirp->dd_size = _getdents (dirp->dd_fd,
51 dirp->dd_buf,
52 dirp->dd_len);
53
54 if (dirp->dd_size <= 0)
55 return NULL;
56 }
57 if (dirp->dd_loc >= dirp->dd_size) {
58 dirp->dd_loc = 0;
59 continue;
60 }
61 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
62 if ((int)dp & 03) /* bogus pointer check */
63 return NULL;
64 if (dp->d_reclen <= 0 ||
65 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
66 return NULL;
67 dirp->dd_loc += dp->d_reclen;
68 if (dp->d_ino == 0)
69 continue;
70 return (dp);
71 }
72 }
73