Sep 282009

In IPv4 environment(usually) we used to call function gethostbyname() to do DNS lookups.then the information is load into a struct hostent.

#include <netdb.h>
struct hostent *gethostbyname(const char *name);

struct  hostent {
        char    *h_name;        /* official name of host */
        char    **h_aliases;    /* alias list */
        int     h_addrtype;     /* host address type */
        int     h_length;       /* length of address */
        char    **h_addr_list;  /* list of addresses from name server */
#define h_addr  h_addr_list[0]  /* address, for backward compatibility */

So, the easiest way to get information from gethostbyname() call is by extracting hostent structure.

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