POCO C++庫學習和分析 — 平台與環境

POCO C++庫學習和分析 -- 平台與環境

          在寫程式的時候，有時候需要收集一些系統資訊，用作軟硬體的綁定或產生唯一的註冊碼資訊等。Poco中提供了一個很簡單的類Environment來實現這個功能。這個類的定義如下：

 

class Foundation_API Environment/// This class provides access to environment variables/// and some general system information.{public:typedef UInt8 NodeId[6]; /// Ethernet address.static std::string get(const std::string& name);/// Returns the value of the environment variable/// with the given name. Throws a NotFoundException/// if the variable does not exist.static std::string get(const std::string& name, const std::string& defaultValue);/// Returns the value of the environment variable/// with the given name. If the environment variable/// is undefined, returns defaultValue instead.static bool has(const std::string& name);/// Returns true iff an environment variable/// with the given name is defined.static void set(const std::string& name, const std::string& value);/// Sets the environment variable with the given name/// to the given value.static std::string osName();/// Returns the operating system name.static std::string osVersion();/// Returns the operating system version.static std::string osArchitecture();/// Returns the operating system architecture.static std::string nodeName();/// Returns the node (or host) name.static void nodeId(NodeId& id);/// Returns the Ethernet address of the first Ethernet/// adapter found on the system.////// Throws a SystemException if no Ethernet adapter is available.static std::string nodeId();/// Returns the Ethernet address (format "xx:xx:xx:xx:xx:xx")/// of the first Ethernet adapter found on the system.////// Throws a SystemException if no Ethernet adapter is available.static unsigned processorCount();/// Returns the number of processors installed in the system.////// If the number of processors cannot be determined, returns 1.static Poco::UInt32 libraryVersion();/// Returns the POCO C++ Libraries version as a hexadecimal/// number in format 0xAABBCCDD, where///    - AA is the major version number,///    - BB is the minor version number,///    - CC is the revision number, and///    - DD is the patch level number.////// Some patch level ranges have special meanings:///    - Dx mark development releases,///    - Ax mark alpha releases, and///    - Bx mark beta releases.};

          從定義中我們可以看到，它的功能包括：

 

          1.  擷取系統第一塊網卡的資訊

          2.  擷取、設定指定名稱的環境變數值

          3.  擷取作業系統名稱、版本、結構

          4.  擷取處理器數量

 

          下面是其的一個使用例子：

 

#include "stdafx.h"#include "Poco/Environment.h"#include <iostream>using Poco::Environment;int main(int argc, char** argv){std::cout<< "OS Name: " << Environment::osName() << std::endl<< "OS Version: " << Environment::osVersion() << std::endl<< "OS Arch: " << Environment::osArchitecture() << std::endl<< "Node Name: " << Environment::nodeName() << std::endl<< "Node ID: " << Environment::nodeId() << std::endl<< "Processor Count: " << Environment::processorCount() << std::endl<< "Library Version: " << Environment::libraryVersion() << std::endl;if (Environment::has("TEMP"))std::cout << "TEMP: " << Environment::get("TEMP") << std::endl;Environment::set("POCO", "foo");return 0;}

          Environment的內部的實現上很簡單，依賴於EnvironmentImpl類，每中作業系統實現了自己的EnvironmentImpl類，從而實現了對不同作業系統統一介面。

（著作權，轉載時請註明作者和出處  http://blog.csdn.net/arau_sh/article/details/8698406）