获取本地IP的三种方法（转）

1.效果不理想

#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:\n ", hent->h_name);

    for(i = 0; hent->h_addr_list[i]; i++) {

        printf("%s\t\n", inet_ntoa(*(struct in_addr*)(hent->h_addr_list[i])));

    }

    return 0;

}

2.效果不错

#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;

}

3. 打开一个对外界服务器的网络连接，通过getsockname()反查自己的IP，效果待查