1 /*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 *
15 * Description: FileUtils implements
16 */
17 #include "file_utils.h"
18
19 #include <cerrno>
20 #include <cstring>
21 #include <dirent.h>
22 #include <fcntl.h>
23 #include <unistd.h>
24 #include "logging.h"
25
26 namespace {
27 constexpr size_t DEFAULT_READ_SIZE = 4096;
28 }
29
ReadFile(int fd)30 std::string FileUtils::ReadFile(int fd)
31 {
32 std::string content;
33 size_t count = 0;
34 while (true) {
35 if (content.size() - count < DEFAULT_READ_SIZE) {
36 content.resize(content.size() + DEFAULT_READ_SIZE);
37 }
38 ssize_t nBytes = TEMP_FAILURE_RETRY(read(fd, &content[count], content.size() - count));
39 if (nBytes <= 0) {
40 break;
41 }
42 count += nBytes;
43 }
44 content.resize(count);
45 return content;
46 }
47
ReadFile(const std::string & path)48 std::string FileUtils::ReadFile(const std::string& path)
49 {
50 char realPath[PATH_MAX + 1] = {0};
51
52 if ((path.length() > PATH_MAX) || (realpath(path.c_str(), realPath) == nullptr)) {
53 return "";
54 }
55 int fd = open(realPath, O_RDONLY);
56 if (fd < 0) {
57 const int bufSize = 1024;
58 char buf[bufSize] = { 0 };
59 strerror_r(errno, buf, bufSize);
60 HILOG_WARN(LOG_CORE, "open file %s FAILED: %s!", path.c_str(), buf);
61 return "";
62 }
63
64 std::string content = ReadFile(fd);
65 CHECK_TRUE(close(fd) != -1, content, "close %s failed, %d", path.c_str(), errno);
66 return content;
67 }
68
WriteFile(const std::string & path,const std::string & content)69 int FileUtils::WriteFile(const std::string& path, const std::string& content)
70 {
71 return WriteFile(path, content, O_WRONLY);
72 }
73
WriteFile(const std::string & path,const std::string & content,int flags)74 int FileUtils::WriteFile(const std::string& path, const std::string& content, int flags)
75 {
76 return WriteFile(path, content, flags, 0);
77 }
78
WriteFile(const std::string & path,const std::string & content,int flags,int mode)79 int FileUtils::WriteFile(const std::string& path, const std::string& content, int flags, int mode)
80 {
81 if (path.empty() || (path.length() >= PATH_MAX) || (path.find("..") != std::string::npos)) {
82 HILOG_ERROR(LOG_CORE, "%s:path is invalid: %s, errno=%d", __func__, path.c_str(), errno);
83 return -1;
84 }
85 int fd = open(path.c_str(), flags, mode);
86 CHECK_TRUE(fd >= 0, -1, "open %s failed, %d", path.c_str(), errno);
87
88 int retval = write(fd, content.data(), content.size());
89 CHECK_TRUE(close(fd) != -1, -1, "close %s failed, %d", path.c_str(), errno);
90 HILOG_DEBUG(LOG_CORE, "write(%s) with '%s' done!", path.c_str(), content.c_str());
91 return retval;
92 }
93
ListDir(const std::string & dirPath)94 std::vector<std::string> FileUtils::ListDir(const std::string& dirPath)
95 {
96 std::vector<std::string> result;
97 DIR* dir = opendir(dirPath.c_str());
98 if (dir == nullptr) {
99 return result;
100 }
101
102 struct dirent* ent = nullptr;
103 while ((ent = readdir(dir)) != nullptr) {
104 std::string name = ent->d_name;
105 if (name == "." || name == "..") {
106 continue;
107 }
108 result.push_back(name);
109 }
110 closedir(dir);
111 return result;
112 }
113