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
17 #include <getopt.h>
18 #include <sys/system_properties.h>
19
20 #include <iostream>
21 #include <string>
22 #include <vector>
23
24 #include <android-base/properties.h>
25 #include <property_info_parser/property_info_parser.h>
26
27 using android::base::GetProperty;
28 using android::properties::PropertyInfoAreaFile;
29
30 PropertyInfoAreaFile property_info_file;
31
32 enum class ResultType {
33 Value,
34 Context,
35 Type,
36 };
37
PrintAllProperties(ResultType result_type)38 void PrintAllProperties(ResultType result_type) {
39 std::vector<std::pair<std::string, std::string>> properties;
40 __system_property_foreach(
41 [](const prop_info* pi, void* cookie) {
42 __system_property_read_callback(
43 pi,
44 [](void* cookie, const char* name, const char* value, unsigned) {
45 auto properties =
46 reinterpret_cast<std::vector<std::pair<std::string, std::string>>*>(cookie);
47 properties->emplace_back(name, value);
48 },
49 cookie);
50 },
51 &properties);
52
53 std::sort(properties.begin(), properties.end());
54
55 if (result_type != ResultType::Value) {
56 for (auto& [name, value] : properties) {
57 const char* context = nullptr;
58 const char* type = nullptr;
59 property_info_file->GetPropertyInfo(name.c_str(), &context, &type);
60 if (result_type == ResultType::Context) {
61 value = context;
62 } else {
63 value = type;
64 }
65 }
66 }
67
68 for (const auto& [name, value] : properties) {
69 std::cout << "[" << name << "]: [" << value << "]" << std::endl;
70 }
71 }
72
PrintProperty(const char * name,const char * default_value,ResultType result_type)73 void PrintProperty(const char* name, const char* default_value, ResultType result_type) {
74 switch (result_type) {
75 case ResultType::Value:
76 std::cout << GetProperty(name, default_value) << std::endl;
77 break;
78 case ResultType::Context: {
79 const char* context = nullptr;
80 property_info_file->GetPropertyInfo(name, &context, nullptr);
81 std::cout << context << std::endl;
82 break;
83 }
84 case ResultType::Type: {
85 const char* type = nullptr;
86 property_info_file->GetPropertyInfo(name, nullptr, &type);
87 std::cout << type << std::endl;
88 break;
89 }
90 }
91 }
92
getprop_main(int argc,char ** argv)93 extern "C" int getprop_main(int argc, char** argv) {
94 auto result_type = ResultType::Value;
95
96 while (true) {
97 static const struct option long_options[] = {
98 {"help", no_argument, nullptr, 'h'},
99 {nullptr, 0, nullptr, 0},
100 };
101
102 int arg = getopt_long(argc, argv, "TZ", long_options, nullptr);
103
104 if (arg == -1) {
105 break;
106 }
107
108 switch (arg) {
109 case 'h':
110 std::cout << "usage: getprop [-TZ] [NAME [DEFAULT]]\n"
111 "\n"
112 "Gets an Android system property, or lists them all.\n"
113 "\n"
114 "-T\tShow property types instead of values\n"
115 "-Z\tShow property contexts instead of values\n"
116 << std::endl;
117 return 0;
118 case 'T':
119 if (result_type != ResultType::Value) {
120 std::cerr << "Only one of -T or -Z may be specified" << std::endl;
121 return -1;
122 }
123 result_type = ResultType::Type;
124 break;
125 case 'Z':
126 if (result_type != ResultType::Value) {
127 std::cerr << "Only one of -T or -Z may be specified" << std::endl;
128 return -1;
129 }
130 result_type = ResultType::Context;
131 break;
132 case '?':
133 return -1;
134 default:
135 std::cerr << "getprop: getopt returned invalid result: " << arg << std::endl;
136 return -1;
137 }
138 }
139
140 if (result_type != ResultType::Value) {
141 property_info_file.LoadDefaultPath();
142 if (!property_info_file) {
143 std::cerr << "Unable to load property info file" << std::endl;
144 return -1;
145 }
146 }
147
148 if (optind >= argc) {
149 PrintAllProperties(result_type);
150 return 0;
151 }
152
153 if (optind < argc - 2) {
154 std::cerr << "getprop: Max 2 arguments (see \"getprop --help\")" << std::endl;
155 return -1;
156 }
157
158 PrintProperty(argv[optind], (optind == argc - 1) ? "" : argv[optind + 1], result_type);
159
160 return 0;
161 }
162