Poco library Chinese programming Reference Guide (9) poco: Net: DNS

Poco library Chinese programming Reference Guide (9) poco: Net: DNS

• Author: Liu Da-poechant (Zhong Chao)
• Email: zhongchao.ustc@gmail.com
• Blog: blog.csdn.net/poechant
• Date: Limit l 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 stores host Primary name (canonical name), alias name list, and IP address list.

2 related APIs

Get a hostentry instance:

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

Output Domain Name:

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

Address and alias:

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

3 source code

The sample in the official poco documentation is incorrect. The following provides a correct example, where the domain name is passed in through parameters.

#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;}

Compile:

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

Run:

$ ./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

-

Reprinted, please indicate the csdn blog from LIU Da: blog.csdn.net/poechant

-