1 /*
2  * Copyright (C) 2017 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 #pragma once
17 
18 #include <sys/stat.h>
19 #include <sys/types.h>
20 
21 #include <chrono>
22 #include <optional>
23 #include <string>
24 #include <vector>
25 
26 #include "common/libs/utils/result.h"
27 
28 namespace cuttlefish {
29 bool FileExists(const std::string& path, bool follow_symlinks = true);
30 Result<dev_t> FileDeviceId(const std::string& path);
31 Result<bool> CanHardLink(const std::string& source,
32                          const std::string& destination);
33 Result<ino_t> FileInodeNumber(const std::string& path);
34 Result<bool> AreHardLinked(const std::string& source,
35                            const std::string& destination);
36 Result<std::string> CreateHardLink(const std::string& target,
37                                    const std::string& hardlink,
38                                    const bool overwrite_existing = false);
39 bool FileHasContent(const std::string& path);
40 Result<std::vector<std::string>> DirectoryContents(const std::string& path);
41 bool DirectoryExists(const std::string& path, bool follow_symlinks = true);
42 Result<void> EnsureDirectoryExists(const std::string& directory_path,
43                                    const mode_t mode = S_IRWXU | S_IRWXG |
44                                                        S_IROTH | S_IXOTH,
45                                    const std::string& group_name = "");
46 Result<void> ChangeGroup(const std::string& path,
47                          const std::string& group_name);
48 bool CanAccess(const std::string& path, const int mode);
49 bool IsDirectoryEmpty(const std::string& path);
50 Result<void> RecursivelyRemoveDirectory(const std::string& path);
51 bool Copy(const std::string& from, const std::string& to);
52 off_t FileSize(const std::string& path);
53 bool RemoveFile(const std::string& file);
54 Result<std::string> RenameFile(const std::string& current_filepath,
55                                const std::string& target_filepath);
56 std::string ReadFile(const std::string& file);
57 Result<std::string> ReadFileContents(const std::string& filepath);
58 bool MakeFileExecutable(const std::string& path);
59 std::chrono::system_clock::time_point FileModificationTime(
60     const std::string& path);
61 // Whether a file exists and is a unix socket
62 bool FileIsSocket(const std::string& path);
63 // Get disk usage of a path. If this path is a directory, disk usage will
64 // account for all files under this folder(recursively).
65 int GetDiskUsage(const std::string& path);
66 
67 // acloud related API
68 std::string FindImage(const std::string& search_path,
69                       const std::vector<std::string>& pattern);
70 
71 // The returned value may contain .. or . if these are present in the path
72 // argument.
73 // path must not contain ~
74 std::string AbsolutePath(const std::string& path);
75 
76 std::string CurrentDirectory();
77 
78 struct FileSizes {
79   off_t sparse_size;
80   off_t disk_size;
81 };
82 FileSizes SparseFileSizes(const std::string& path);
83 
84 // Find file with name |target_name| under directory |path|, return path to
85 // found file(if any)
86 std::string FindFile(const std::string& path, const std::string& target_name);
87 
88 Result<void> WalkDirectory(
89     const std::string& dir,
90     const std::function<bool(const std::string&)>& callback);
91 
92 #ifdef __linux__
93 Result<void> WaitForFile(const std::string& path, int timeoutSec);
94 Result<void> WaitForUnixSocket(const std::string& path, int timeoutSec);
95 Result<void> WaitForUnixSocketListeningWithoutConnect(const std::string& path,
96                                                       int timeoutSec);
97 #endif
98 
99 // parameter to EmulateAbsolutePath
100 struct InputPathForm {
101   /** If nullopt, uses the process' current working dir
102    *  But if there is no preceding .. or ., this field is not used.
103    */
104   std::optional<std::string> current_working_dir;
105   /** If nullopt, use SystemWideUserHome()
106    *  But, if there's no preceding ~, this field is not used.
107    */
108   std::optional<std::string> home_dir;
109   std::string path_to_convert;
110   bool follow_symlink;
111 };
112 
113 /**
114  * Returns emulated absolute path with a different process'/thread's
115  * context.
116  *
117  * This is useful when daemon(0, 0)-started server process wants to
118  * figure out a relative path that came from its client.
119  *
120  * The call mostly succeeds. It fails only if:
121  *  home_dir isn't given so supposed to relies on the local SystemWideUserHome()
122  *  but SystemWideUserHome() call fails.
123  */
124 Result<std::string> EmulateAbsolutePath(const InputPathForm& path_info);
125 
126 }  // namespace cuttlefish
127