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[];

     if(gethostname(hostName,)==) ;//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[];

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

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

       cout<<"主机别名:";
       ptr = hostInformation->h_aliases;
       if(*ptr==)
         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\n";
                     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!=)
     {
         cout<<"服务名   :"<<hostServer->s_name<<endl;

         char **alisases=hostServer->s_aliases;
         cout<<"服务别名：";
         if(*alisases==) 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=;
     hostServer=;

 }

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(,"tcp");
    test.printHostServer();
    return ;
}