C++獲取本機IP地址信息

1、簡潔版：

#include<winsock2.h>  
#include<iostream>  
#include<string>
using namespace std;
#pragma comment(lib, "WS2_32.lib")

string getIP()
{
	WSADATA WSAData;
	char hostName[256];
	if (!WSAStartup(MAKEWORD(2, 0),&WSAData))
	{  
		if(!gethostname(hostName,sizeof(hostName)))
		{
			hostent *host=gethostbyname(hostName);
			if(host!=NULL)
			{
				return inet_ntoa(*(struct in_addr*)*host->h_addr_list);
			}
		}
	}  	
	return "Get IP failed.";  
}

int main()
{
	cout<<"IP地址爲："<<getIP()<<endl;
	system("pause");
	return 0;   
}

2、擴展板：

#include <winsock2.h>  
#include <iostream>  
using namespace std;
#pragma comment(lib, "WS2_32.lib")

void getIP()
{
	WSADATA WSAData;								//WSADATA結構被用來儲存調用AfxSocketInit全局函數返回的Windows Sockets初始化信息。
	if (WSAStartup(MAKEWORD(2, 0),&WSAData))		// 初始化Windows sockets API
	{  
		printf("WSAStartup failed %s\n", WSAGetLastError());
		exit(-1);		//異常退出 
	}  

	char hostName[256];
	if(gethostname(hostName,sizeof(hostName)))		//獲取主機名
	{
		printf("Error: %u\n", WSAGetLastError());
		exit(-1);
	}

	hostent *host=gethostbyname(hostName);	// 根據主機名獲取主機信息(含IP)
	if(host==NULL)
	{
		printf("Error: %u\n", WSAGetLastError());
		exit(-1);
	}

	cout<<"正式的主機名:        "<<host->h_name<<endl
		<<"主機地址類型:        "<<host->h_addrtype<<endl
		<<"地址清單:            "<<host->h_addr_list<<endl
		<<"別名列表:            "<<host->h_aliases<<endl
		<<"地址長度:            "<<host->h_length<<endl;

	for(int i=0;host->h_addr_list[i]!=0;i++)
	{
		cout<<"該主機IP"<<i+1<<":           "<<inet_ntoa(*(struct in_addr*)*host->h_addr_list)<<endl;
	}
	WSACleanup();  
}

int main()
{
	getIP();
	system("pause");
	return 0;   
}