showip using c program

#include

#include

#include

#include

#include

#include

#include

int main(int argc, char *argv[])

{

 struct addrinfo hints, *res, *p;

 int status;

 char ipstr[INET6_ADDRSTRLEN];

 if (argc != 2) {

 fprintf(stderr,"usage: showip hostname\n");

 return 1;

 }

 memset(&hints, 0, sizeof hints);

 hints.ai_family = AF_UNSPEC; // AF_INET or AF_INET6 to force version

 hints.ai_socktype = SOCK_STREAM;

 if ((status = getaddrinfo(argv[1], NULL, &hints, &res)) != 0) {

 fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));

 return 2;

 }

 printf("IP addresses for %s:\n\n", argv[1]);

 for(p = res;p != NULL; p = p->ai_next) {

 void *addr;

 char *ipver;

 // get the pointer to the address itself,

 // different fields in IPv4 and IPv6:

 if (p->ai_family == AF_INET) { // IPv4

 struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;

 addr = &(ipv4->sin_addr);

 ipver = "IPv4";

 } else { // IPv6

 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;

 addr = &(ipv6->sin6_addr);

 ipver = "IPv6";

 }

 // convert the IP to a string and print it:

 inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);

 printf(" %s: %s\n", ipver, ipstr);

 }

 freeaddrinfo(res); // free the linked list

 return 0;

}