fs.h revision 4887842c925f304dc862bdd5810f27cdd2eaedcb 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef __CUTILS_FS_H
18#define __CUTILS_FS_H
19
20#include <sys/types.h>
21#include <unistd.h>
22
23/*
24 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of
25 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
26 * not already defined, then define it here.
27 */
28#ifndef TEMP_FAILURE_RETRY
29/* Used to retry syscalls that can return EINTR. */
30#define TEMP_FAILURE_RETRY(exp) ({         \
31    typeof (exp) _rc;                      \
32    do {                                   \
33        _rc = (exp);                       \
34    } while (_rc == -1 && errno == EINTR); \
35    _rc; })
36#endif
37
38#ifdef __cplusplus
39extern "C" {
40#endif
41
42/*
43 * Ensure that directory exists with given mode and owners.
44 */
45extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid);
46
47/*
48 * Read single plaintext integer from given file, correctly handling files
49 * partially written with fs_write_atomic_int().
50 */
51extern int fs_read_atomic_int(const char* path, int* value);
52
53/*
54 * Write single plaintext integer to given file, creating backup while
55 * in progress.
56 */
57extern int fs_write_atomic_int(const char* path, int value);
58
59/*
60 * Ensure that all directories along given path exist, creating parent
61 * directories as needed.  Validates that given path is absolute and that
62 * it contains no relative "." or ".." paths or symlinks.  Last path segment
63 * is treated as filename and ignored, unless the path ends with "/".
64 */
65extern int fs_mkdirs(const char* path, mode_t mode);
66
67#ifdef __cplusplus
68}
69#endif
70
71#endif /* __CUTILS_FS_H */
72