| /* |
| * Copyright (C) 2015 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. |
| */ |
| |
| #include "utils/file.h" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #include <utils/Compat.h> // For TEMP_FAILURE_RETRY on Darwin. |
| |
| bool android::ReadFdToString(int fd, std::string* content) { |
| content->clear(); |
| |
| char buf[BUFSIZ]; |
| ssize_t n; |
| while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], sizeof(buf)))) > 0) { |
| content->append(buf, n); |
| } |
| return (n == 0) ? true : false; |
| } |
| |
| bool android::ReadFileToString(const std::string& path, std::string* content) { |
| content->clear(); |
| |
| int fd = TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_CLOEXEC | O_NOFOLLOW)); |
| if (fd == -1) { |
| return false; |
| } |
| bool result = ReadFdToString(fd, content); |
| TEMP_FAILURE_RETRY(close(fd)); |
| return result; |
| } |
| |
| bool android::WriteStringToFd(const std::string& content, int fd) { |
| const char* p = content.data(); |
| size_t left = content.size(); |
| while (left > 0) { |
| ssize_t n = TEMP_FAILURE_RETRY(write(fd, p, left)); |
| if (n == -1) { |
| return false; |
| } |
| p += n; |
| left -= n; |
| } |
| return true; |
| } |
| |
| static bool CleanUpAfterFailedWrite(const std::string& path) { |
| // Something went wrong. Let's not leave a corrupt file lying around. |
| int saved_errno = errno; |
| unlink(path.c_str()); |
| errno = saved_errno; |
| return false; |
| } |
| |
| #if !defined(_WIN32) |
| bool android::WriteStringToFile(const std::string& content, const std::string& path, |
| mode_t mode, uid_t owner, gid_t group) { |
| int fd = TEMP_FAILURE_RETRY(open(path.c_str(), |
| O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW, |
| mode)); |
| if (fd == -1) { |
| return false; |
| } |
| |
| // We do an explicit fchmod here because we assume that the caller really meant what they |
| // said and doesn't want the umask-influenced mode. |
| bool result = (fchmod(fd, mode) != -1 && fchown(fd, owner, group) == -1 && WriteStringToFd(content, fd)); |
| TEMP_FAILURE_RETRY(close(fd)); |
| return result || CleanUpAfterFailedWrite(path); |
| } |
| #endif |
| |
| bool android::WriteStringToFile(const std::string& content, const std::string& path) { |
| int fd = TEMP_FAILURE_RETRY(open(path.c_str(), |
| O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW, |
| DEFFILEMODE)); |
| if (fd == -1) { |
| return false; |
| } |
| |
| bool result = WriteStringToFd(content, fd); |
| TEMP_FAILURE_RETRY(close(fd)); |
| return result || CleanUpAfterFailedWrite(path); |
| } |