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 22/* 23 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of 24 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's 25 * not already defined, then define it here. 26 */ 27#ifndef TEMP_FAILURE_RETRY 28/* Used to retry syscalls that can return EINTR. */ 29#define TEMP_FAILURE_RETRY(exp) ({ \ 30 typeof (exp) _rc; \ 31 do { \ 32 _rc = (exp); \ 33 } while (_rc == -1 && errno == EINTR); \ 34 _rc; }) 35#endif 36 37#ifdef __cplusplus 38extern "C" { 39#endif 40 41/* 42 * Ensure that directory exists with given mode and owners. 43 */ 44extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid); 45 46/* 47 * Read single plaintext integer from given file, correctly handling files 48 * partially written with fs_write_atomic_int(). 49 */ 50extern int fs_read_atomic_int(const char* path, int* value); 51 52/* 53 * Write single plaintext integer to given file, creating backup while 54 * in progress. 55 */ 56extern int fs_write_atomic_int(const char* path, int value); 57 58#ifdef __cplusplus 59} 60#endif 61 62#endif /* __CUTILS_FS_H */ 63