platform_system_core/include/cutils/fs.h

86 lines
2.7 KiB
C

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CUTILS_FS_H
#define __CUTILS_FS_H
#include <sys/types.h>
#include <unistd.h>
/*
* TEMP_FAILURE_RETRY is defined by some, but not all, versions of
* <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
* not already defined, then define it here.
*/
#ifndef TEMP_FAILURE_RETRY
/* Used to retry syscalls that can return EINTR. */
#define TEMP_FAILURE_RETRY(exp) ({ \
typeof (exp) _rc; \
do { \
_rc = (exp); \
} while (_rc == -1 && errno == EINTR); \
_rc; })
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*
* Ensure that directory exists with given mode and owners. If it exists
* with a different mode or owners, they are fixed to match the given values.
*/
extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid);
/*
* Ensure that directory exists with given mode and owners. If it exists
* with different owners, they are not fixed and -1 is returned.
*/
extern int fs_prepare_dir_strict(const char* path, mode_t mode, uid_t uid, gid_t gid);
/*
* Ensure that file exists with given mode and owners. If it exists
* with different owners, they are not fixed and -1 is returned.
*/
extern int fs_prepare_file_strict(const char* path, mode_t mode, uid_t uid, gid_t gid);
/*
* Read single plaintext integer from given file, correctly handling files
* partially written with fs_write_atomic_int().
*/
extern int fs_read_atomic_int(const char* path, int* value);
/*
* Write single plaintext integer to given file, creating backup while
* in progress.
*/
extern int fs_write_atomic_int(const char* path, int value);
/*
* Ensure that all directories along given path exist, creating parent
* directories as needed. Validates that given path is absolute and that
* it contains no relative "." or ".." paths or symlinks. Last path segment
* is treated as filename and ignored, unless the path ends with "/".
*/
extern int fs_mkdirs(const char* path, mode_t mode);
#ifdef __cplusplus
}
#endif
#endif /* __CUTILS_FS_H */