封装获取网络信息Linux—API类

　　封装获取网络信息Linux—API类

封装好的库：

#ifndef NETINFORMATION_H
#define NETINFORMATION_H

#include <netdb.h>//包含gethostbyname gethostbyaddr
#include <netinet/in.h>
class NetInformation
{
    private:

            struct hostent *hostInformation;
            struct servent *hostServer;

    public:
            void reset();

            void getHostInfoByAddr();
            void getHostInfoByName();
            void printHostInformation();

            void getHostServer(const char *name,const char *proto);
            void getHostServer(int port,const char *proto);
            void printHostServer();


};

#endif

#include "NetInformation.h"


#include <unistd.h>//包含 gethostname
#include <netinet/in.h>//此文件中包含 in_addr
#include <arpa/inet.h> //此文件中包含 inet_ntoa
#include <iostream>
#include <cstring>
using std::cout;
using std::endl;


void NetInformation::getHostInfoByName()
{
    char hostName[256];

    if(gethostname(hostName,255)==0) ;//成功时返回0，失败时返回－1
        else cout<<"gethostname failed";
    hostInformation=gethostbyname(hostName);
}

void NetInformation::getHostInfoByAddr()
{
    struct in_addr hostAddr;
    char addr[12];

    strcpy(addr,"127.0.0.1");
    inet_aton(addr,&hostAddr);
    hostInformation=gethostbyaddr(&hostAddr,sizeof(&hostAddr),AF_INET);
}

void NetInformation::printHostInformation()
{
      char **ptr,**pptr,str[32];
      cout<<"主机名:"<<hostInformation->h_name<<endl;

      cout<<"主机别名:";
      ptr = hostInformation->h_aliases;
      if(*ptr==0)
        cout<<"没有查询到主机别名";
        while(*ptr)
        {
            cout<<*ptr;
            ++ptr;
        };
      cout<<endl;

    //根据地址类型，将地址打出来
    switch(hostInformation->h_addrtype)
    {
            case AF_INET:
            case AF_INET6:
                    pptr=hostInformation->h_addr_list;
                    //将刚才得到的所有地址都打出来。其中调用了inet_ntop()函数
                    while(*pptr)
                         {
                             cout<<"主机地址："<<inet_ntop(hostInformation->h_addrtype, *pptr, str, sizeof(str));
                             ++pptr;
                         }
                    cout<<endl;
                    break;
            default:
                    cout<<"unknown address type
";
                    break;
    }
}

void NetInformation::getHostServer(const char *name,const char *proto)
{
    hostServer=getservbyname(name,proto);
}

void NetInformation::getHostServer(int port,const char *proto)
{
    hostServer=getservbyport(port,proto);
}

void NetInformation::printHostServer()
{
    if(hostServer!=0)
    {
        cout<<"服务名   :"<<hostServer->s_name<<endl;

        char **alisases=hostServer->s_aliases;
        cout<<"服务别名：";
        if(*alisases==0) cout<<"未查询到别名"<<endl;
        else
        {
            while(*alisases)
            {
                cout<<*alisases;
                ++alisases;
            }
            cout<<endl;
        }
        cout<<"端口号:"<<hostServer->s_port<<endl;
        cout<<"套接字类型:"<<hostServer->s_proto<<endl;
    }
}

void NetInformation::reset()
{
    hostInformation=0;
    hostServer=0;

}

测试代码：

#include <iostream>
#include <unistd.h>
#include <netinet/in.h>
#include "NetInformation.h"
using namespace std;
int main()
{
    NetInformation test;
    cout<<"/**<  方式一*/"<<endl;

    test.getHostInfoByName();
    test.printHostInformation();
    cout<<"/**< 方式二 */"<<endl;
    test.reset();
    test.getHostInfoByAddr();
    test.printHostInformation();

    cout<<"/**< 方式三 */"<<endl;
    test.reset();
    test.getHostServer("daytime","tcp");
    test.printHostServer();

    cout<<"/**< 方式四 */"<<endl;
    test.reset();
    test.getHostServer(3328,"tcp");
    test.printHostServer();
    return 0;
}