- Document ttyname_r().
[dragonfly.git] / lib / libc / gen / readdir.c
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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 * $FreeBSD: src/lib/libc/gen/readdir.c,v 1.5.2.4 2002/02/26 22:53:57 alfred Exp $
b0e25abd 34 * $DragonFly: src/lib/libc/gen/readdir.c,v 1.8 2005/11/19 22:32:53 swildner Exp $
984263bc 35 *
1de703da 36 * @(#)readdir.c 8.3 (Berkeley) 9/29/94
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37 */
38
17ea2221 39#include "namespace.h"
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40#include <sys/param.h>
41#include <dirent.h>
42#include <errno.h>
43#include <string.h>
984263bc 44#include <pthread.h>
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45#include "un-namespace.h"
46
47#include "libc_private.h"
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48
49/*
50 * get next entry in a directory.
51 */
52struct dirent *
0f52d283 53_readdir_unlocked(DIR *dirp)
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54{
55 struct dirent *dp;
56
57 for (;;) {
58 if (dirp->dd_loc >= dirp->dd_size) {
59 if (dirp->dd_flags & __DTF_READALL)
60 return (NULL);
61 dirp->dd_loc = 0;
62 }
63 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
17ea2221 64 dirp->dd_size = _getdirentries(dirp->dd_fd,
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65 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
66 if (dirp->dd_size <= 0)
67 return (NULL);
68 }
69 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
01f31ab3 70 if (_DIRENT_DIRSIZ(dp) > dirp->dd_len + 1 - dirp->dd_loc)
984263bc 71 return (NULL);
01f31ab3 72 dirp->dd_loc += _DIRENT_DIRSIZ(dp);
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73 if (dp->d_ino == 0)
74 continue;
75 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
76 continue;
77 return (dp);
78 }
79}
80
17ea2221 81struct dirent *
0f52d283 82readdir(DIR *dirp)
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83{
84 struct dirent *dp;
85
01f31ab3 86 if (__isthreaded)
17ea2221 87 _pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
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88 dp = _readdir_unlocked(dirp);
89 if (__isthreaded)
17ea2221 90 _pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
01f31ab3 91
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92 return (dp);
93}
94
984263bc 95int
0f52d283 96readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
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97{
98 struct dirent *dp;
b0e25abd 99 int saved_errno;
984263bc 100
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101 saved_errno = errno;
102 errno = 0;
01f31ab3 103 if (__isthreaded)
17ea2221 104 _pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
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105 if ((dp = _readdir_unlocked(dirp)) != NULL)
106 memcpy(entry, dp, _DIRENT_MINSIZ(dp));
107 if (__isthreaded)
17ea2221 108 _pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
17ea2221 109
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110 if (errno != 0) {
111 if (dp == NULL) {
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112 return (errno);
113 }
114 } else
115 errno = saved_errno;
116
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117 if (dp != NULL)
118 *result = entry;
119 else
120 *result = NULL;
121
122 return (0);
123}