opendir.c revision 1.1.1.1 
1/* Start reading the entries of a directory.
2   Copyright (C) 2006-2020 Free Software Foundation, Inc.
3
4   This program is free software: you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 3 of the License, or
7   (at your option) any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
16
17#include <config.h>
18
19/* Specification.  */
20#include <dirent.h>
21
22#include <errno.h>
23#include <stddef.h>
24
25#if HAVE_OPENDIR
26
27/* Override opendir(), to keep track of the open file descriptors.
28   Needed because there is a function dirfd().  */
29
30#else
31
32# include <stdlib.h>
33
34# include "dirent-private.h"
35# include "filename.h"
36
37#endif
38
39#if REPLACE_FCHDIR
40# include <unistd.h>
41#endif
42
43#ifdef __KLIBC__
44# include <io.h>
45# include <fcntl.h>
46#endif
47
48#if defined _WIN32 && ! defined __CYGWIN__
49/* Don't assume that UNICODE is not defined.  */
50# undef WIN32_FIND_DATA
51# define WIN32_FIND_DATA WIN32_FIND_DATAA
52# undef GetFullPathName
53# define GetFullPathName GetFullPathNameA
54# undef FindFirstFile
55# define FindFirstFile FindFirstFileA
56#endif
57
58DIR *
59opendir (const char *dir_name)
60{
61#if HAVE_OPENDIR
62# undef opendir
63  DIR *dirp;
64
65  dirp = opendir (dir_name);
66  if (dirp == NULL)
67    return NULL;
68
69# ifdef __KLIBC__
70  {
71    int fd = open (dir_name, O_RDONLY);
72    if (fd == -1 || _gl_register_dirp_fd (fd, dirp))
73      {
74        int saved_errno = errno;
75
76        close (fd);
77        closedir (dirp);
78
79        errno = saved_errno;
80
81        return NULL;
82      }
83  }
84# endif
85#else
86
87  char dir_name_mask[MAX_PATH + 1 + 1 + 1];
88  int status;
89  HANDLE current;
90  WIN32_FIND_DATA entry;
91  struct gl_directory *dirp;
92
93  if (dir_name[0] == '\0')
94    {
95      errno = ENOENT;
96      return NULL;
97    }
98
99  /* Make the dir_name absolute, so that we continue reading the same
100     directory if the current directory changed between this opendir()
101     call and a subsequent rewinddir() call.  */
102  if (!GetFullPathName (dir_name, MAX_PATH, dir_name_mask, NULL))
103    {
104      errno = EINVAL;
105      return NULL;
106    }
107
108  /* Append the mask.
109     "*" and "*.*" appear to be equivalent.  */
110  {
111    char *p;
112
113    p = dir_name_mask + strlen (dir_name_mask);
114    if (p > dir_name_mask && !ISSLASH (p[-1]))
115      *p++ = '\\';
116    *p++ = '*';
117    *p = '\0';
118  }
119
120  /* Start searching the directory.  */
121  status = -1;
122  current = FindFirstFile (dir_name_mask, &entry);
123  if (current == INVALID_HANDLE_VALUE)
124    {
125      switch (GetLastError ())
126        {
127        case ERROR_FILE_NOT_FOUND:
128          status = -2;
129          break;
130        case ERROR_PATH_NOT_FOUND:
131          errno = ENOENT;
132          return NULL;
133        case ERROR_DIRECTORY:
134          errno = ENOTDIR;
135          return NULL;
136        case ERROR_ACCESS_DENIED:
137          errno = EACCES;
138          return NULL;
139        default:
140          errno = EIO;
141          return NULL;
142        }
143    }
144
145  /* Allocate the result.  */
146  dirp =
147    (struct gl_directory *)
148    malloc (offsetof (struct gl_directory, dir_name_mask[0])
149            + strlen (dir_name_mask) + 1);
150  if (dirp == NULL)
151    {
152      if (current != INVALID_HANDLE_VALUE)
153        FindClose (current);
154      errno = ENOMEM;
155      return NULL;
156    }
157  dirp->status = status;
158  dirp->current = current;
159  if (status == -1)
160    memcpy (&dirp->entry, &entry, sizeof (WIN32_FIND_DATA));
161  strcpy (dirp->dir_name_mask, dir_name_mask);
162
163#endif
164
165#if REPLACE_FCHDIR
166  {
167    int fd = dirfd (dirp);
168    if (0 <= fd && _gl_register_fd (fd, dir_name) != fd)
169      {
170        int saved_errno = errno;
171        closedir (dirp);
172        errno = saved_errno;
173        return NULL;
174      }
175  }
176#endif
177
178  return dirp;
179}
180