windows下用c++获取本机ip地址的三种方法

#ifndef CMDEXC_H
#define CMDEXC_H

#include <string>


class CmdExc
{
public:
    CmdExc(std::string cmd,std::string mode="rt");
    virtual ~CmdExc();

    std::string getOutput() const;

private:
    std::string m_strOutput__;
    FILE* m_fp__;
};



CmdExc::CmdExc(std::string cmd, std::string mode)
{
    m_fp__=_popen(cmd.c_str(),mode.c_str());
    char buf[256]={0};
    if(NULL != m_fp__){
        int read_len;
        while((read_len=fread(buf,sizeof(buf)-1,1,m_fp__))>0){
            m_strOutput__+=buf;
            memset(buf,0,sizeof(buf));
        }
    }

}

CmdExc::~CmdExc()
{
    if(NULL != m_fp__){
        _pclose(m_fp__);
    }
}

std::string CmdExc::getOutput() const
{
    return m_strOutput__;
}

#endif // CMDEXC_H

CmdExc cmd("ipconfig");
cout<<cmd.getOutput().c_str()<<endl;

std::vector<string> IpDealer::getAdptInfo() {
    vector<string> result;
    IP_ADAPTER_INFO *pAdpFree=NULL;
    IP_ADAPTER_INFO *pIpAdpInfo=(IP_ADAPTER_INFO*)malloc(sizeof(IP_ADAPTER_INFO));
    unsigned long ulBufLen=sizeof(IP_ADAPTER_INFO);
    int ret;
    //第一次调用获取需要开辟的内存空间大小
    if((ret=GetAdaptersInfo(pIpAdpInfo,&ulBufLen))==ERROR_BUFFER_OVERFLOW){
        free(pIpAdpInfo);
        //分配实际所需要的内存空间
        pIpAdpInfo=(IP_ADAPTER_INFO*)malloc(ulBufLen);
        if(NULL == pIpAdpInfo){
            return result;
        }
    }

    char ip[256];
    if((ret=GetAdaptersInfo(pIpAdpInfo,&ulBufLen))==NO_ERROR){
        pAdpFree=pIpAdpInfo;

        for(int i=0;pIpAdpInfo;i++){
            string addr;
            snprintf(ip,sizeof(ip),"netcard%d ip addr:",i);
            addr+=ip;
            IP_ADDR_STRING *pIps=&pIpAdpInfo->IpAddressList;
            while(pIps){
                snprintf(ip,sizeof(ip),"ip:%s,mask:%s,gate:%s.",pIps->IpAddress.String,
                         pIps->IpMask.String,pIpAdpInfo->GatewayList.IpAddress.String);
                addr+=ip;
                cout<<pIps->IpAddress.String<<endl;
                cout<<pIps->IpMask.String<<endl;
                cout<<pIpAdpInfo->GatewayList.IpAddress.String<<endl;
                pIps=pIps->Next;
            }
            result.push_back(addr);
            pIpAdpInfo=pIpAdpInfo->Next;
        }
    }
    if(pAdpFree){
        free(pAdpFree);
    }
    return result;

}

std::vector<std::string> IpDealer::getIpList()
{
    std::vector<std::string> result;
    char name[256];

    int getNameRet=gethostname(name,sizeof(name));

    hostent *host=gethostbyname(name);

    if(NULL == host){
        return result;
    }

    in_addr *pAddr=(in_addr*)*host->h_addr_list;

    for(int i=0;i<(strlen((char*)*host->h_addr_list)-strlen(host->h_name) )/4 && pAddr;i++){
        string addr=inet_ntoa(pAddr[i]);
        cout<<addr.c_str()<<endl;
        result.push_back(addr);
    }

    return result;
}