#include <stdio.h>

 #include <arpa/inet.h>

 #include <netinet/in.h>

 #include <unistd.h>

 #include <netdb.h>

 int main()

 {

    char name[80]; /*store my hostname*/

    struct hostent *hostent_ptr;

    int ret = gethostname( name, 80 );

    if ( ret < 0 )

    {

       printf("gethostname failed\n");

    }

    else

    {

          hostent_ptr = gethostbyname(name);

          if ( hostent_ptr == NULL )

          {

             printf("hostent_ptr is null\n");

          }

          else

          {

             struct in_addr internet_address;

             internet_address.s_addr = ((struct in_addr *)hostent_ptr->h_addr_list[0])->s_addr;

             printf("%s\n",  inet_ntoa(internet_address) );

          }

    }

    return 0;

 }