POCO庫中文編程參考指南（9）Poco::Net::DNS

POCO庫中文編程參考指南（9）Poco::Net::DNS

• Author: 柳大·Poechant（鐘超）
• Email: zhongchao.ustc@gmail.com
• Blog: Blog.CSDN.net/Poechant
• Date: April 20^{th, 2012}

1 Poco::Net::DNS

namespace Poco {namespace Net {class Net_API DNS {public:    static HostEntry hostByName(const std::string& hostname);    static HostEntry hostByAddress(const IPAddress& address);    static HostEntry resolve(const std::string& address);    static IPAddress resolveOne(const std::string& address);    static HostEntry thisHost();    static std::string hostName();};}}

HostEntry 中儲存 host primary name（canonical name）、alias name list、IP address list。

2 相關 API

得到一個 HostEntry 執行個體：

const HostEntry& entry = DNS::hostByName("google.com");

輸出網域名稱：

std::cout << entry.name() << std::endl;

Address 和 Alias：

const HostEntry::AliasList& aliases = entry.aliases();const HostEntry::AddressList& addrs = entry.addresses();

3 Source code

POCO 的官方文檔中的 Sample 有錯誤，以下提供一個正確的樣本，其中網域名稱是通過參數傳入的。

#include "Poco/Net/DNS.h"#include <iostream>using Poco::Net::DNS;using Poco::Net::IPAddress;using Poco::Net::HostEntry;int main(int argc, char** argv){    if (argc != 2) {        std::cout << "Invalid argument number." << std::endl;    }    const HostEntry& entry = DNS::hostByName(argv[1]);    std::cout << "Canonical Name: " << entry.name() << std::endl;    const HostEntry::AliasList& aliases = entry.aliases();    for (HostEntry::AliasList::const_iterator it = aliases.begin();        it !=   aliases.end(); ++it)        std::cout << "Alias: " << *it << std::endl;    const HostEntry::AddressList& addrs = entry.addresses();    for (HostEntry::AddressList::const_iterator it = addrs.begin();        it !=   addrs.end(); ++it)        std::cout << "Address: " << it->toString() << std::endl;    return 0;}

編譯：

$ g++ name_solver.cpp -o name_solver \-I/usr/local/include -I/usr/local/lib -lPocoNet

運行：

$ ./name_solver baidu.comCanonical Name: baidu.comAddress: 123.125.114.144Address: 123.125.114.144Address: 220.181.111.85Address: 220.181.111.85Address: 220.181.111.86Address: 220.181.111.86$ ./name_solver www.ustc.edu.cnCanonical Name: ustc.edu.cnAddress: 202.38.64.246Address: 202.38.64.246

-

轉載請註明來自柳大的CSDN部落格：Blog.CSDN.net/Poechant

-