xref: /titanic_51/usr/src/lib/libast/common/dir/seekdir.c (revision c10c16dec587a0662068f6e2991c29ed3a9db943)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 
24 /*
25  * seekdir
26  *
27  * seek on directory stream
28  * this is not optimal because there aren't portable
29  * semantics for directory seeks
30  */
31 
32 #include "dirlib.h"
33 
34 #if _dir_ok
35 
36 NoN(seekdir)
37 
38 #else
39 
40 void
41 seekdir(register DIR* dirp, long loc)
42 {
43 	off_t	base;		/* file location of block */
44 	off_t	offset; 	/* offset within block */
45 
46 	if (telldir(dirp) != loc)
47 	{
48 		lseek(dirp->dd_fd, 0L, SEEK_SET);
49 		dirp->dd_loc = dirp->dd_size = 0;
50 		while (telldir(dirp) != loc)
51 			if (!readdir(dirp))
52 				break; 	/* "can't happen" */
53 	}
54 }
55 
56 #endif
57