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 39 extern "C" { 40 #endif 41 42 /* 43 * Ensure that directory exists with given mode and owners. If it exists 44 * with a different mode or owners, they are fixed to match the given values. 45 */ 46 extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid); 47 48 /* 49 * Ensure that directory exists with given mode and owners. If it exists 50 * with different owners, they are not fixed and -1 is returned. 51 */ 52 extern int fs_prepare_dir_strict(const char* path, mode_t mode, uid_t uid, gid_t gid); 53 54 /* 55 * Ensure that file exists with given mode and owners. If it exists 56 * with different owners, they are not fixed and -1 is returned. 57 */ 58 extern int fs_prepare_file_strict(const char* path, mode_t mode, uid_t uid, gid_t gid); 59 60 61 /* 62 * Read single plaintext integer from given file, correctly handling files 63 * partially written with fs_write_atomic_int(). 64 */ 65 extern int fs_read_atomic_int(const char* path, int* value); 66 67 /* 68 * Write single plaintext integer to given file, creating backup while 69 * in progress. 70 */ 71 extern int fs_write_atomic_int(const char* path, int value); 72 73 /* 74 * Ensure that all directories along given path exist, creating parent 75 * directories as needed. Validates that given path is absolute and that 76 * it contains no relative "." or ".." paths or symlinks. Last path segment 77 * is treated as filename and ignored, unless the path ends with "/". 78 */ 79 extern int fs_mkdirs(const char* path, mode_t mode); 80 81 #ifdef __cplusplus 82 } 83 #endif 84 85 #endif /* __CUTILS_FS_H */ 86
