platform_system_core/base/properties.cpp

83 lines
2.9 KiB
C++

/*
* Copyright (C) 2016 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 "android-base/properties.h"
#include <sys/system_properties.h>
#include <string>
#include <android-base/parseint.h>
namespace android {
namespace base {
std::string GetProperty(const std::string& key, const std::string& default_value) {
const prop_info* pi = __system_property_find(key.c_str());
if (pi == nullptr) return default_value;
char buf[PROP_VALUE_MAX];
if (__system_property_read(pi, nullptr, buf) > 0) return buf;
// If the property exists but is empty, also return the default value.
// Since we can't remove system properties, "empty" is traditionally
// the same as "missing" (this was true for cutils' property_get).
return default_value;
}
bool GetBoolProperty(const std::string& key, bool default_value) {
std::string value = GetProperty(key, "");
if (value == "1" || value == "y" || value == "yes" || value == "on" || value == "true") {
return true;
} else if (value == "0" || value == "n" || value == "no" || value == "off" || value == "false") {
return false;
}
return default_value;
}
template <typename T>
T GetIntProperty(const std::string& key, T default_value, T min, T max) {
T result;
std::string value = GetProperty(key, "");
if (!value.empty() && android::base::ParseInt(value, &result, min, max)) return result;
return default_value;
}
template <typename T>
T GetUintProperty(const std::string& key, T default_value, T max) {
T result;
std::string value = GetProperty(key, "");
if (!value.empty() && android::base::ParseUint(value, &result, max)) return result;
return default_value;
}
template int8_t GetIntProperty(const std::string&, int8_t, int8_t, int8_t);
template int16_t GetIntProperty(const std::string&, int16_t, int16_t, int16_t);
template int32_t GetIntProperty(const std::string&, int32_t, int32_t, int32_t);
template int64_t GetIntProperty(const std::string&, int64_t, int64_t, int64_t);
template uint8_t GetUintProperty(const std::string&, uint8_t, uint8_t);
template uint16_t GetUintProperty(const std::string&, uint16_t, uint16_t);
template uint32_t GetUintProperty(const std::string&, uint32_t, uint32_t);
template uint64_t GetUintProperty(const std::string&, uint64_t, uint64_t);
bool SetProperty(const std::string& key, const std::string& value) {
return (__system_property_set(key.c_str(), value.c_str()) == 0);
}
} // namespace base
} // namespace android