POCO C++库学习和分析 -- 平台与环境

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mob60475702a1ff 2013-03-31 18:46:00

文章标签 #include c++ ios 使用例子 ide 文章分类 运维

POCO C++库学习和分析 -- 平台与环境

在写程序的时候，有时候需要收集一些系统信息，用作软硬件的绑定或生成唯一的注册码信息等。Poco中提供了一个很简单的类Environment来实现这个功能。这个类的定义如下：

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.
};

从定义中我们可以看到，它的功能包括：

1. 获取系统第一块网卡的信息

2. 获取、设置指定名称的环境变量值

3. 获取操作系统名称、版本、结构

4. 获取处理器数量

下面是其的一个使用例子：

#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;

}