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
);
137 // -----------------------------------------------------------------------------
139 namespace file_util
{
141 // Read the file at |path| into |contents|, returning true on success.
142 // This function fails if the |path| contains path traversal components ('..').
143 // |contents| may be NULL, in which case this function is useful for its
144 // side effect of priming the disk cache.
145 // Useful for unit tests.
146 BASE_EXPORT
bool ReadFileToString(const base::FilePath
& path
,
147 std::string
* contents
);
149 #if defined(OS_POSIX)
150 // Read exactly |bytes| bytes from file descriptor |fd|, storing the result
151 // in |buffer|. This function is protected against EINTR and partial reads.
152 // Returns true iff |bytes| bytes have been successfully read from |fd|.
153 BASE_EXPORT
bool ReadFromFD(int fd
, char* buffer
, size_t bytes
);
155 // Creates a symbolic link at |symlink| pointing to |target|. Returns
157 BASE_EXPORT
bool CreateSymbolicLink(const base::FilePath
& target
,
158 const base::FilePath
& symlink
);
160 // Reads the given |symlink| and returns where it points to in |target|.
161 // Returns false upon failure.
162 BASE_EXPORT
bool ReadSymbolicLink(const base::FilePath
& symlink
,
163 base::FilePath
* target
);
165 // Bits ans masks of the file permission.
166 enum FilePermissionBits
{
167 FILE_PERMISSION_MASK
= S_IRWXU
| S_IRWXG
| S_IRWXO
,
168 FILE_PERMISSION_USER_MASK
= S_IRWXU
,
169 FILE_PERMISSION_GROUP_MASK
= S_IRWXG
,
170 FILE_PERMISSION_OTHERS_MASK
= S_IRWXO
,
172 FILE_PERMISSION_READ_BY_USER
= S_IRUSR
,
173 FILE_PERMISSION_WRITE_BY_USER
= S_IWUSR
,
174 FILE_PERMISSION_EXECUTE_BY_USER
= S_IXUSR
,
175 FILE_PERMISSION_READ_BY_GROUP
= S_IRGRP
,
176 FILE_PERMISSION_WRITE_BY_GROUP
= S_IWGRP
,
177 FILE_PERMISSION_EXECUTE_BY_GROUP
= S_IXGRP
,
178 FILE_PERMISSION_READ_BY_OTHERS
= S_IROTH
,
179 FILE_PERMISSION_WRITE_BY_OTHERS
= S_IWOTH
,
180 FILE_PERMISSION_EXECUTE_BY_OTHERS
= S_IXOTH
,
183 // Reads the permission of the given |path|, storing the file permission
184 // bits in |mode|. If |path| is symbolic link, |mode| is the permission of
185 // a file which the symlink points to.
186 BASE_EXPORT
bool GetPosixFilePermissions(const base::FilePath
& path
,
188 // Sets the permission of the given |path|. If |path| is symbolic link, sets
189 // the permission of a file which the symlink points to.
190 BASE_EXPORT
bool SetPosixFilePermissions(const base::FilePath
& path
,
192 #endif // defined(OS_POSIX)
194 // Return true if the given directory is empty
195 BASE_EXPORT
bool IsDirectoryEmpty(const base::FilePath
& dir_path
);
197 // Get the temporary directory provided by the system.
198 // WARNING: DON'T USE THIS. If you want to create a temporary file, use one of
199 // the functions below.
200 BASE_EXPORT
bool GetTempDir(base::FilePath
* path
);
201 // Get a temporary directory for shared memory files.
202 // Only useful on POSIX; redirects to GetTempDir() on Windows.
203 BASE_EXPORT
bool GetShmemTempDir(base::FilePath
* path
, bool executable
);
205 // Get the home directory. This is more complicated than just getenv("HOME")
206 // as it knows to fall back on getpwent() etc.
207 BASE_EXPORT
base::FilePath
GetHomeDir();
209 // Creates a temporary file. The full path is placed in |path|, and the
210 // function returns true if was successful in creating the file. The file will
211 // be empty and all handles closed after this function returns.
212 BASE_EXPORT
bool CreateTemporaryFile(base::FilePath
* path
);
214 // Same as CreateTemporaryFile but the file is created in |dir|.
215 BASE_EXPORT
bool CreateTemporaryFileInDir(const base::FilePath
& dir
,
216 base::FilePath
* temp_file
);
218 // Create and open a temporary file. File is opened for read/write.
219 // The full path is placed in |path|.
220 // Returns a handle to the opened file or NULL if an error occurred.
221 BASE_EXPORT
FILE* CreateAndOpenTemporaryFile(base::FilePath
* path
);
222 // Like above but for shmem files. Only useful for POSIX.
223 // The executable flag says the file needs to support using
224 // mprotect with PROT_EXEC after mapping.
225 BASE_EXPORT
FILE* CreateAndOpenTemporaryShmemFile(base::FilePath
* path
,
227 // Similar to CreateAndOpenTemporaryFile, but the file is created in |dir|.
228 BASE_EXPORT
FILE* CreateAndOpenTemporaryFileInDir(const base::FilePath
& dir
,
229 base::FilePath
* path
);
231 // Create a new directory. If prefix is provided, the new directory name is in
232 // the format of prefixyyyy.
233 // NOTE: prefix is ignored in the POSIX implementation.
234 // If success, return true and output the full path of the directory created.
235 BASE_EXPORT
bool CreateNewTempDirectory(
236 const base::FilePath::StringType
& prefix
,
237 base::FilePath
* new_temp_path
);
239 // Create a directory within another directory.
240 // Extra characters will be appended to |prefix| to ensure that the
241 // new directory does not have the same name as an existing directory.
242 BASE_EXPORT
bool CreateTemporaryDirInDir(
243 const base::FilePath
& base_dir
,
244 const base::FilePath::StringType
& prefix
,
245 base::FilePath
* new_dir
);
247 // Creates a directory, as well as creating any parent directories, if they
248 // don't exist. Returns 'true' on successful creation, or if the directory
249 // already exists. The directory is only readable by the current user.
250 // Returns true on success, leaving *error unchanged.
251 // Returns false on failure and sets *error appropriately, if it is non-NULL.
252 BASE_EXPORT
bool CreateDirectoryAndGetError(const base::FilePath
& full_path
,
253 base::PlatformFileError
* error
);
255 // Backward-compatible convenience method for the above.
256 BASE_EXPORT
bool CreateDirectory(const base::FilePath
& full_path
);
258 // Returns the file size. Returns true on success.
259 BASE_EXPORT
bool GetFileSize(const base::FilePath
& file_path
, int64
* file_size
);
261 // Sets |real_path| to |path| with symbolic links and junctions expanded.
262 // On windows, make sure the path starts with a lettered drive.
263 // |path| must reference a file. Function will fail if |path| points to
264 // a directory or to a nonexistent path. On windows, this function will
265 // fail if |path| is a junction or symlink that points to an empty file,
266 // or if |real_path| would be longer than MAX_PATH characters.
267 BASE_EXPORT
bool NormalizeFilePath(const base::FilePath
& path
,
268 base::FilePath
* real_path
);
272 // Given a path in NT native form ("\Device\HarddiskVolumeXX\..."),
273 // return in |drive_letter_path| the equivalent path that starts with
274 // a drive letter ("C:\..."). Return false if no such path exists.
275 BASE_EXPORT
bool DevicePathToDriveLetterPath(const base::FilePath
& device_path
,
276 base::FilePath
* drive_letter_path
);
278 // Given an existing file in |path|, set |real_path| to the path
279 // in native NT format, of the form "\Device\HarddiskVolumeXX\..".
280 // Returns false if the path can not be found. Empty files cannot
281 // be resolved with this function.
282 BASE_EXPORT
bool NormalizeToNativeFilePath(const base::FilePath
& path
,
283 base::FilePath
* nt_path
);
286 // This function will return if the given file is a symlink or not.
287 BASE_EXPORT
bool IsLink(const base::FilePath
& file_path
);
289 // Returns information about the given file path.
290 BASE_EXPORT
bool GetFileInfo(const base::FilePath
& file_path
,
291 base::PlatformFileInfo
* info
);
293 // Sets the time of the last access and the time of the last modification.
294 BASE_EXPORT
bool TouchFile(const base::FilePath
& path
,
295 const base::Time
& last_accessed
,
296 const base::Time
& last_modified
);
298 // Set the time of the last modification. Useful for unit tests.
299 BASE_EXPORT
bool SetLastModifiedTime(const base::FilePath
& path
,
300 const base::Time
& last_modified
);
302 #if defined(OS_POSIX)
303 // Store inode number of |path| in |inode|. Return true on success.
304 BASE_EXPORT
bool GetInode(const base::FilePath
& path
, ino_t
* inode
);
307 // Wrapper for fopen-like calls. Returns non-NULL FILE* on success.
308 BASE_EXPORT
FILE* OpenFile(const base::FilePath
& filename
, const char* mode
);
310 // Closes file opened by OpenFile. Returns true on success.
311 BASE_EXPORT
bool CloseFile(FILE* file
);
313 // Truncates an open file to end at the location of the current file pointer.
314 // This is a cross-platform analog to Windows' SetEndOfFile() function.
315 BASE_EXPORT
bool TruncateFile(FILE* file
);
317 // Reads the given number of bytes from the file into the buffer. Returns
318 // the number of read bytes, or -1 on error.
319 BASE_EXPORT
int ReadFile(const base::FilePath
& filename
, char* data
, int size
);
321 // Writes the given buffer into the file, overwriting any data that was
322 // previously there. Returns the number of bytes written, or -1 on error.
323 BASE_EXPORT
int WriteFile(const base::FilePath
& filename
, const char* data
,
325 #if defined(OS_POSIX)
326 // Append the data to |fd|. Does not close |fd| when done.
327 BASE_EXPORT
int WriteFileDescriptor(const int fd
, const char* data
, int size
);
329 // Append the given buffer into the file. Returns the number of bytes written,
331 BASE_EXPORT
int AppendToFile(const base::FilePath
& filename
,
332 const char* data
, int size
);
334 // Gets the current working directory for the process.
335 BASE_EXPORT
bool GetCurrentDirectory(base::FilePath
* path
);
337 // Sets the current working directory for the process.
338 BASE_EXPORT
bool SetCurrentDirectory(const base::FilePath
& path
);
340 // Attempts to find a number that can be appended to the |path| to make it
341 // unique. If |path| does not exist, 0 is returned. If it fails to find such
342 // a number, -1 is returned. If |suffix| is not empty, also checks the
343 // existence of it with the given suffix.
344 BASE_EXPORT
int GetUniquePathNumber(const base::FilePath
& path
,
345 const base::FilePath::StringType
& suffix
);
347 #if defined(OS_POSIX)
348 // Creates a directory with a guaranteed unique name based on |path|, returning
349 // the pathname if successful, or an empty path if there was an error creating
350 // the directory. Does not create parent directories.
351 BASE_EXPORT
base::FilePath
MakeUniqueDirectory(const base::FilePath
& path
);
354 #if defined(OS_POSIX)
355 // Test that |path| can only be changed by a given user and members of
356 // a given set of groups.
357 // Specifically, test that all parts of |path| under (and including) |base|:
359 // * Are owned by a specific user.
360 // * Are not writable by all users.
361 // * Are owned by a member of a given set of groups, or are not writable by
363 // * Are not symbolic links.
364 // This is useful for checking that a config file is administrator-controlled.
365 // |base| must contain |path|.
366 BASE_EXPORT
bool VerifyPathControlledByUser(const base::FilePath
& base
,
367 const base::FilePath
& path
,
369 const std::set
<gid_t
>& group_gids
);
370 #endif // defined(OS_POSIX)
372 #if defined(OS_MACOSX) && !defined(OS_IOS)
373 // Is |path| writable only by a user with administrator privileges?
374 // This function uses Mac OS conventions. The super user is assumed to have
375 // uid 0, and the administrator group is assumed to be named "admin".
376 // Testing that |path|, and every parent directory including the root of
377 // the filesystem, are owned by the superuser, controlled by the group
378 // "admin", are not writable by all users, and contain no symbolic links.
379 // Will return false if |path| does not exist.
380 BASE_EXPORT
bool VerifyPathControlledByAdmin(const base::FilePath
& path
);
381 #endif // defined(OS_MACOSX) && !defined(OS_IOS)
383 // Returns the maximum length of path component on the volume containing
384 // the directory |path|, in the number of FilePath::CharType, or -1 on failure.
385 BASE_EXPORT
int GetMaximumPathComponentLength(const base::FilePath
& path
);
387 // A class to handle auto-closing of FILE*'s.
388 class ScopedFILEClose
{
390 inline void operator()(FILE* x
) const {
397 typedef scoped_ptr_malloc
<FILE, ScopedFILEClose
> ScopedFILE
;
399 #if defined(OS_POSIX)
400 // A class to handle auto-closing of FDs.
401 class ScopedFDClose
{
403 inline void operator()(int* x
) const {
405 if (HANDLE_EINTR(close(*x
)) < 0)
406 DPLOG(ERROR
) << "close";
411 typedef scoped_ptr_malloc
<int, ScopedFDClose
> ScopedFD
;
414 #if defined(OS_LINUX)
415 // Broad categories of file systems as returned by statfs() on Linux.
416 enum FileSystemType
{
417 FILE_SYSTEM_UNKNOWN
, // statfs failed.
418 FILE_SYSTEM_0
, // statfs.f_type == 0 means unknown, may indicate AFS.
419 FILE_SYSTEM_ORDINARY
, // on-disk filesystem like ext2
423 FILE_SYSTEM_MEMORY
, // in-memory file system
424 FILE_SYSTEM_CGROUP
, // cgroup control.
425 FILE_SYSTEM_OTHER
, // any other value.
426 FILE_SYSTEM_TYPE_COUNT
429 // Attempts determine the FileSystemType for |path|.
430 // Returns false if |path| doesn't exist.
431 BASE_EXPORT
bool GetFileSystemType(const base::FilePath
& path
,
432 FileSystemType
* type
);
435 } // namespace file_util
437 // Internal --------------------------------------------------------------------
442 // Same as Move but allows paths with traversal components.
443 // Use only with extreme care.
444 BASE_EXPORT
bool MoveUnsafe(const FilePath
& from_path
,
445 const FilePath
& to_path
);
447 // Same as CopyFile but allows paths with traversal components.
448 // Use only with extreme care.
449 BASE_EXPORT
bool CopyFileUnsafe(const FilePath
& from_path
,
450 const FilePath
& to_path
);
453 // Copy from_path to to_path recursively and then delete from_path recursively.
454 // Returns true if all operations succeed.
455 // This function simulates Move(), but unlike Move() it works across volumes.
456 // This function is not transactional.
457 BASE_EXPORT
bool CopyAndDeleteDirectory(const FilePath
& from_path
,
458 const FilePath
& to_path
);
459 #endif // defined(OS_WIN)
461 } // namespace internal
464 #endif // BASE_FILE_UTIL_H_