1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 // This file contains utility functions for dealing with the local
8 #ifndef BASE_FILE_UTIL_H_
9 #define BASE_FILE_UTIL_H_
11 #include "build/build_config.h"
15 #elif defined(OS_POSIX)
26 #include "base/base_export.h"
27 #include "base/basictypes.h"
28 #include "base/files/file_path.h"
29 #include "base/memory/scoped_ptr.h"
30 #include "base/platform_file.h"
31 #include "base/strings/string16.h"
34 #include "base/file_descriptor_posix.h"
35 #include "base/logging.h"
36 #include "base/posix/eintr_wrapper.h"
43 extern bool g_bug108724_debug
;
45 //-----------------------------------------------------------------------------
46 // Functions that involve filesystem access or modification:
48 // Returns an absolute version of a relative path. Returns an empty path on
49 // error. On POSIX, this function fails if the path does not exist. This
50 // function can result in I/O so it can be slow.
51 BASE_EXPORT FilePath
MakeAbsoluteFilePath(const FilePath
& input
);
53 // Returns the total number of bytes used by all the files under |root_path|.
54 // If the path does not exist the function returns 0.
56 // This function is implemented using the FileEnumerator class so it is not
57 // particularly speedy in any platform.
58 BASE_EXPORT int64
ComputeDirectorySize(const FilePath
& root_path
);
60 // Deletes the given path, whether it's a file or a directory.
61 // If it's a directory, it's perfectly happy to delete all of the
62 // directory's contents. Passing true to recursive deletes
63 // subdirectories and their contents as well.
64 // Returns true if successful, false otherwise. It is considered successful
65 // to attempt to delete a file that does not exist.
67 // In posix environment and if |path| is a symbolic link, this deletes only
68 // the symlink. (even if the symlink points to a non-existent file)
70 // WARNING: USING THIS WITH recursive==true IS EQUIVALENT
71 // TO "rm -rf", SO USE WITH CAUTION.
72 BASE_EXPORT
bool DeleteFile(const FilePath
& path
, bool recursive
);
75 // Schedules to delete the given path, whether it's a file or a directory, until
76 // the operating system is restarted.
78 // 1) The file/directory to be deleted should exist in a temp folder.
79 // 2) The directory to be deleted must be empty.
80 BASE_EXPORT
bool DeleteFileAfterReboot(const FilePath
& path
);
83 // Moves the given path, whether it's a file or a directory.
84 // If a simple rename is not possible, such as in the case where the paths are
85 // on different volumes, this will attempt to copy and delete. Returns
87 // This function fails if either path contains traversal components ('..').
88 BASE_EXPORT
bool Move(const FilePath
& from_path
, const FilePath
& to_path
);
90 // Renames file |from_path| to |to_path|. Both paths must be on the same
91 // volume, or the function will fail. Destination file will be created
92 // if it doesn't exist. Prefer this function over Move when dealing with
93 // temporary files. On Windows it preserves attributes of the target file.
94 // Returns true on success, leaving *error unchanged.
95 // Returns false on failure and sets *error appropriately, if it is non-NULL.
96 BASE_EXPORT
bool ReplaceFile(const FilePath
& from_path
,
97 const FilePath
& to_path
,
98 PlatformFileError
* error
);
100 // Copies a single file. Use CopyDirectory to copy directories.
101 // This function fails if either path contains traversal components ('..').
102 BASE_EXPORT
bool CopyFile(const FilePath
& from_path
, const FilePath
& to_path
);
104 // Copies the given path, and optionally all subdirectories and their contents
107 // If there are files existing under to_path, always overwrite. Returns true
108 // if successful, false otherwise. Wildcards on the names are not supported.
110 // If you only need to copy a file use CopyFile, it's faster.
111 BASE_EXPORT
bool CopyDirectory(const FilePath
& from_path
,
112 const FilePath
& to_path
,
115 // Returns true if the given path exists on the local filesystem,
117 BASE_EXPORT
bool PathExists(const FilePath
& path
);
119 // Returns true if the given path is writable by the user, false otherwise.
120 BASE_EXPORT
bool PathIsWritable(const FilePath
& path
);
122 // Returns true if the given path exists and is a directory, false otherwise.
123 BASE_EXPORT
bool DirectoryExists(const FilePath
& path
);
125 // Returns true if the contents of the two files given are equal, false
126 // otherwise. If either file can't be read, returns false.
127 BASE_EXPORT
bool ContentsEqual(const FilePath
& filename1
,
128 const FilePath
& filename2
);
130 // Returns true if the contents of the two text files given are equal, false
131 // otherwise. This routine treats "\r\n" and "\n" as equivalent.
132 BASE_EXPORT
bool TextContentsEqual(const FilePath
& filename1
,
133 const FilePath
& filename2
);
135 // Read the file at |path| into |contents|, returning true on success.
136 // This function fails if the |path| contains path traversal components ('..').
137 // |contents| may be NULL, in which case this function is useful for its
138 // side effect of priming the disk cache.
139 // Useful for unit tests.
140 BASE_EXPORT
bool ReadFileToString(const FilePath
& path
, std::string
* contents
);
144 // -----------------------------------------------------------------------------
146 namespace file_util
{
148 #if defined(OS_POSIX)
149 // Read exactly |bytes| bytes from file descriptor |fd|, storing the result
150 // in |buffer|. This function is protected against EINTR and partial reads.
151 // Returns true iff |bytes| bytes have been successfully read from |fd|.
152 BASE_EXPORT
bool ReadFromFD(int fd
, char* buffer
, size_t bytes
);
154 // Creates a symbolic link at |symlink| pointing to |target|. Returns
156 BASE_EXPORT
bool CreateSymbolicLink(const base::FilePath
& target
,
157 const base::FilePath
& symlink
);
159 // Reads the given |symlink| and returns where it points to in |target|.
160 // Returns false upon failure.
161 BASE_EXPORT
bool ReadSymbolicLink(const base::FilePath
& symlink
,
162 base::FilePath
* target
);
164 // Bits ans masks of the file permission.
165 enum FilePermissionBits
{
166 FILE_PERMISSION_MASK
= S_IRWXU
| S_IRWXG
| S_IRWXO
,
167 FILE_PERMISSION_USER_MASK
= S_IRWXU
,
168 FILE_PERMISSION_GROUP_MASK
= S_IRWXG
,
169 FILE_PERMISSION_OTHERS_MASK
= S_IRWXO
,
171 FILE_PERMISSION_READ_BY_USER
= S_IRUSR
,
172 FILE_PERMISSION_WRITE_BY_USER
= S_IWUSR
,
173 FILE_PERMISSION_EXECUTE_BY_USER
= S_IXUSR
,
174 FILE_PERMISSION_READ_BY_GROUP
= S_IRGRP
,
175 FILE_PERMISSION_WRITE_BY_GROUP
= S_IWGRP
,
176 FILE_PERMISSION_EXECUTE_BY_GROUP
= S_IXGRP
,
177 FILE_PERMISSION_READ_BY_OTHERS
= S_IROTH
,
178 FILE_PERMISSION_WRITE_BY_OTHERS
= S_IWOTH
,
179 FILE_PERMISSION_EXECUTE_BY_OTHERS
= S_IXOTH
,
182 // Reads the permission of the given |path|, storing the file permission
183 // bits in |mode|. If |path| is symbolic link, |mode| is the permission of
184 // a file which the symlink points to.
185 BASE_EXPORT
bool GetPosixFilePermissions(const base::FilePath
& path
,
187 // Sets the permission of the given |path|. If |path| is symbolic link, sets
188 // the permission of a file which the symlink points to.
189 BASE_EXPORT
bool SetPosixFilePermissions(const base::FilePath
& path
,
191 #endif // defined(OS_POSIX)
193 // Return true if the given directory is empty
194 BASE_EXPORT
bool IsDirectoryEmpty(const base::FilePath
& dir_path
);
196 // Get the temporary directory provided by the system.
197 // WARNING: DON'T USE THIS. If you want to create a temporary file, use one of
198 // the functions below.
199 BASE_EXPORT
bool GetTempDir(base::FilePath
* path
);
200 // Get a temporary directory for shared memory files.
201 // Only useful on POSIX; redirects to GetTempDir() on Windows.
202 BASE_EXPORT
bool GetShmemTempDir(base::FilePath
* path
, bool executable
);
204 // Get the home directory. This is more complicated than just getenv("HOME")
205 // as it knows to fall back on getpwent() etc.
206 BASE_EXPORT
base::FilePath
GetHomeDir();
208 // Creates a temporary file. The full path is placed in |path|, and the
209 // function returns true if was successful in creating the file. The file will
210 // be empty and all handles closed after this function returns.
211 BASE_EXPORT
bool CreateTemporaryFile(base::FilePath
* path
);
213 // Same as CreateTemporaryFile but the file is created in |dir|.
214 BASE_EXPORT
bool CreateTemporaryFileInDir(const base::FilePath
& dir
,
215 base::FilePath
* temp_file
);
217 // Create and open a temporary file. File is opened for read/write.
218 // The full path is placed in |path|.
219 // Returns a handle to the opened file or NULL if an error occurred.
220 BASE_EXPORT
FILE* CreateAndOpenTemporaryFile(base::FilePath
* path
);
221 // Like above but for shmem files. Only useful for POSIX.
222 // The executable flag says the file needs to support using
223 // mprotect with PROT_EXEC after mapping.
224 BASE_EXPORT
FILE* CreateAndOpenTemporaryShmemFile(base::FilePath
* path
,
226 // Similar to CreateAndOpenTemporaryFile, but the file is created in |dir|.
227 BASE_EXPORT
FILE* CreateAndOpenTemporaryFileInDir(const base::FilePath
& dir
,
228 base::FilePath
* path
);
230 // Create a new directory. If prefix is provided, the new directory name is in
231 // the format of prefixyyyy.
232 // NOTE: prefix is ignored in the POSIX implementation.
233 // If success, return true and output the full path of the directory created.
234 BASE_EXPORT
bool CreateNewTempDirectory(
235 const base::FilePath::StringType
& prefix
,
236 base::FilePath
* new_temp_path
);
238 // Create a directory within another directory.
239 // Extra characters will be appended to |prefix| to ensure that the
240 // new directory does not have the same name as an existing directory.
241 BASE_EXPORT
bool CreateTemporaryDirInDir(
242 const base::FilePath
& base_dir
,
243 const base::FilePath::StringType
& prefix
,
244 base::FilePath
* new_dir
);
246 // Creates a directory, as well as creating any parent directories, if they
247 // don't exist. Returns 'true' on successful creation, or if the directory
248 // already exists. The directory is only readable by the current user.
249 // Returns true on success, leaving *error unchanged.
250 // Returns false on failure and sets *error appropriately, if it is non-NULL.
251 BASE_EXPORT
bool CreateDirectoryAndGetError(const base::FilePath
& full_path
,
252 base::PlatformFileError
* error
);
254 // Backward-compatible convenience method for the above.
255 BASE_EXPORT
bool CreateDirectory(const base::FilePath
& full_path
);
257 // Returns the file size. Returns true on success.
258 BASE_EXPORT
bool GetFileSize(const base::FilePath
& file_path
, int64
* file_size
);
260 // Sets |real_path| to |path| with symbolic links and junctions expanded.
261 // On windows, make sure the path starts with a lettered drive.
262 // |path| must reference a file. Function will fail if |path| points to
263 // a directory or to a nonexistent path. On windows, this function will
264 // fail if |path| is a junction or symlink that points to an empty file,
265 // or if |real_path| would be longer than MAX_PATH characters.
266 BASE_EXPORT
bool NormalizeFilePath(const base::FilePath
& path
,
267 base::FilePath
* real_path
);
271 // Given a path in NT native form ("\Device\HarddiskVolumeXX\..."),
272 // return in |drive_letter_path| the equivalent path that starts with
273 // a drive letter ("C:\..."). Return false if no such path exists.
274 BASE_EXPORT
bool DevicePathToDriveLetterPath(const base::FilePath
& device_path
,
275 base::FilePath
* drive_letter_path
);
277 // Given an existing file in |path|, set |real_path| to the path
278 // in native NT format, of the form "\Device\HarddiskVolumeXX\..".
279 // Returns false if the path can not be found. Empty files cannot
280 // be resolved with this function.
281 BASE_EXPORT
bool NormalizeToNativeFilePath(const base::FilePath
& path
,
282 base::FilePath
* nt_path
);
285 // This function will return if the given file is a symlink or not.
286 BASE_EXPORT
bool IsLink(const base::FilePath
& file_path
);
288 // Returns information about the given file path.
289 BASE_EXPORT
bool GetFileInfo(const base::FilePath
& file_path
,
290 base::PlatformFileInfo
* info
);
292 // Sets the time of the last access and the time of the last modification.
293 BASE_EXPORT
bool TouchFile(const base::FilePath
& path
,
294 const base::Time
& last_accessed
,
295 const base::Time
& last_modified
);
297 // Set the time of the last modification. Useful for unit tests.
298 BASE_EXPORT
bool SetLastModifiedTime(const base::FilePath
& path
,
299 const base::Time
& last_modified
);
301 #if defined(OS_POSIX)
302 // Store inode number of |path| in |inode|. Return true on success.
303 BASE_EXPORT
bool GetInode(const base::FilePath
& path
, ino_t
* inode
);
306 // Wrapper for fopen-like calls. Returns non-NULL FILE* on success.
307 BASE_EXPORT
FILE* OpenFile(const base::FilePath
& filename
, const char* mode
);
309 // Closes file opened by OpenFile. Returns true on success.
310 BASE_EXPORT
bool CloseFile(FILE* file
);
312 // Truncates an open file to end at the location of the current file pointer.
313 // This is a cross-platform analog to Windows' SetEndOfFile() function.
314 BASE_EXPORT
bool TruncateFile(FILE* file
);
316 // Reads the given number of bytes from the file into the buffer. Returns
317 // the number of read bytes, or -1 on error.
318 BASE_EXPORT
int ReadFile(const base::FilePath
& filename
, char* data
, int size
);
320 // Writes the given buffer into the file, overwriting any data that was
321 // previously there. Returns the number of bytes written, or -1 on error.
322 BASE_EXPORT
int WriteFile(const base::FilePath
& filename
, const char* data
,
324 #if defined(OS_POSIX)
325 // Append the data to |fd|. Does not close |fd| when done.
326 BASE_EXPORT
int WriteFileDescriptor(const int fd
, const char* data
, int size
);
328 // Append the given buffer into the file. Returns the number of bytes written,
330 BASE_EXPORT
int AppendToFile(const base::FilePath
& filename
,
331 const char* data
, int size
);
333 // Gets the current working directory for the process.
334 BASE_EXPORT
bool GetCurrentDirectory(base::FilePath
* path
);
336 // Sets the current working directory for the process.
337 BASE_EXPORT
bool SetCurrentDirectory(const base::FilePath
& path
);
339 // Attempts to find a number that can be appended to the |path| to make it
340 // unique. If |path| does not exist, 0 is returned. If it fails to find such
341 // a number, -1 is returned. If |suffix| is not empty, also checks the
342 // existence of it with the given suffix.
343 BASE_EXPORT
int GetUniquePathNumber(const base::FilePath
& path
,
344 const base::FilePath::StringType
& suffix
);
346 #if defined(OS_POSIX)
347 // Creates a directory with a guaranteed unique name based on |path|, returning
348 // the pathname if successful, or an empty path if there was an error creating
349 // the directory. Does not create parent directories.
350 BASE_EXPORT
base::FilePath
MakeUniqueDirectory(const base::FilePath
& path
);
353 #if defined(OS_POSIX)
354 // Test that |path| can only be changed by a given user and members of
355 // a given set of groups.
356 // Specifically, test that all parts of |path| under (and including) |base|:
358 // * Are owned by a specific user.
359 // * Are not writable by all users.
360 // * Are owned by a member of a given set of groups, or are not writable by
362 // * Are not symbolic links.
363 // This is useful for checking that a config file is administrator-controlled.
364 // |base| must contain |path|.
365 BASE_EXPORT
bool VerifyPathControlledByUser(const base::FilePath
& base
,
366 const base::FilePath
& path
,
368 const std::set
<gid_t
>& group_gids
);
369 #endif // defined(OS_POSIX)
371 #if defined(OS_MACOSX) && !defined(OS_IOS)
372 // Is |path| writable only by a user with administrator privileges?
373 // This function uses Mac OS conventions. The super user is assumed to have
374 // uid 0, and the administrator group is assumed to be named "admin".
375 // Testing that |path|, and every parent directory including the root of
376 // the filesystem, are owned by the superuser, controlled by the group
377 // "admin", are not writable by all users, and contain no symbolic links.
378 // Will return false if |path| does not exist.
379 BASE_EXPORT
bool VerifyPathControlledByAdmin(const base::FilePath
& path
);
380 #endif // defined(OS_MACOSX) && !defined(OS_IOS)
382 // Returns the maximum length of path component on the volume containing
383 // the directory |path|, in the number of FilePath::CharType, or -1 on failure.
384 BASE_EXPORT
int GetMaximumPathComponentLength(const base::FilePath
& path
);
386 // A class to handle auto-closing of FILE*'s.
387 class ScopedFILEClose
{
389 inline void operator()(FILE* x
) const {
396 typedef scoped_ptr_malloc
<FILE, ScopedFILEClose
> ScopedFILE
;
398 #if defined(OS_POSIX)
399 // A class to handle auto-closing of FDs.
400 class ScopedFDClose
{
402 inline void operator()(int* x
) const {
404 if (HANDLE_EINTR(close(*x
)) < 0)
405 DPLOG(ERROR
) << "close";
410 typedef scoped_ptr_malloc
<int, ScopedFDClose
> ScopedFD
;
413 #if defined(OS_LINUX)
414 // Broad categories of file systems as returned by statfs() on Linux.
415 enum FileSystemType
{
416 FILE_SYSTEM_UNKNOWN
, // statfs failed.
417 FILE_SYSTEM_0
, // statfs.f_type == 0 means unknown, may indicate AFS.
418 FILE_SYSTEM_ORDINARY
, // on-disk filesystem like ext2
422 FILE_SYSTEM_MEMORY
, // in-memory file system
423 FILE_SYSTEM_CGROUP
, // cgroup control.
424 FILE_SYSTEM_OTHER
, // any other value.
425 FILE_SYSTEM_TYPE_COUNT
428 // Attempts determine the FileSystemType for |path|.
429 // Returns false if |path| doesn't exist.
430 BASE_EXPORT
bool GetFileSystemType(const base::FilePath
& path
,
431 FileSystemType
* type
);
434 } // namespace file_util
436 // Internal --------------------------------------------------------------------
441 // Same as Move but allows paths with traversal components.
442 // Use only with extreme care.
443 BASE_EXPORT
bool MoveUnsafe(const FilePath
& from_path
,
444 const FilePath
& to_path
);
446 // Same as CopyFile but allows paths with traversal components.
447 // Use only with extreme care.
448 BASE_EXPORT
bool CopyFileUnsafe(const FilePath
& from_path
,
449 const FilePath
& to_path
);
452 // Copy from_path to to_path recursively and then delete from_path recursively.
453 // Returns true if all operations succeed.
454 // This function simulates Move(), but unlike Move() it works across volumes.
455 // This function is not transactional.
456 BASE_EXPORT
bool CopyAndDeleteDirectory(const FilePath
& from_path
,
457 const FilePath
& to_path
);
458 #endif // defined(OS_WIN)
460 } // namespace internal
463 #endif // BASE_FILE_UTIL_H_