6.linux下获取ip地址（C++代码）

方法一：

#include 
#include 
#include 
#include 
#include 
#include 

int main() 
{
    char hname[128];
    struct hostent *hent;
    int i;

    gethostname(hname, sizeof(hname));

    //hent = gethostent();
    hent = gethostbyname(hname);

    printf("hostname: %s/naddress list: ", hent->h_name);
    for(i = 0; hent->h_addr_list[i]; i++) 
    {
        printf("%s/t", inet_ntoa(*(struct in_addr*)(hent->h_addr_list[i])));
    }
    return 0;
}

方法2： 通过枚举网卡，API接口可查看man 7 netdevice

#include      
#include 
#include 
#include 
#include 
#include 

int main (int argc, const char * argv[]) 
{
    struct ifaddrs * ifAddrStruct=NULL;
    void * tmpAddrPtr=NULL;

    getifaddrs(&ifAddrStruct);

    while (ifAddrStruct!=NULL) 
    {
        if (ifAddrStruct->ifa_addr->sa_family==AF_INET) { // check it is IP4
            // is a valid IP4 Address
           tmpAddrPtr=&((struct sockaddr_in*)ifAddrStruct->ifa_addr)->sin_addr;
            char addressBuffer[INET_ADDRSTRLEN];
           inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
           printf("%s IP Address %s/n", ifAddrStruct->ifa_name, addressBuffer);
        } else if (ifAddrStruct->ifa_addr->sa_family==AF_INET6) { // check it is IP6
            // is a valid IP6 Address
           tmpAddrPtr=&((struct sockaddr_in*)ifAddrStruct->ifa_addr)->sin_addr;
            char addressBuffer[INET6_ADDRSTRLEN];
           inet_ntop(AF_INET6, tmpAddrPtr, addressBuffer, INET6_ADDRSTRLEN);
           printf("%s IP Address %s/n", ifAddrStruct->ifa_name, addressBuffer);
        }
        ifAddrStruct=ifAddrStruct->ifa_next;
    }
    return 0;
}