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#include "port/sys.h"
#include "port/netdb.h" /* for getaddrinfo, NI_MAXHOST */
#include "port/stdlib.h" /* for exit, EXIT_SUCCESS, itoa */
#include <stdio.h> /* for fprintf */
#include <string.h> /* for memset */
int main( void ) {
struct addrinfo hints;
struct addrinfo *result;
struct addrinfo *res;
int error;
char port_or_service[10];
/* tell getaddrinfo what we want */
memset( &hints, 0, sizeof( struct addrinfo ) );
hints.ai_flags = AI_PASSIVE;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
/* resolve the domain name into a list of addresses */
itoa( 80, port_or_service, 10 );
error = getaddrinfo( "www.yahoo.com", port_or_service, &hints, &result );
if( error != 0 ) {
fprintf( stderr, "getaddrinfo failed: %s (%d)\n",
gai_strerror( error ), error );
return EXIT_FAILURE;
}
/* loop over all returned results and do inverse lookup */
for( res = result; res != NULL; res = res->ai_next ) {
char hostname[NI_MAXHOST] = "";
error = getnameinfo( res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST,
NULL, 0,
NI_NUMERICSERV | NI_NUMERICHOST );
if( error != 0 ) {
fprintf( stderr, "getnameinfo failed: %s (%d)\n",
gai_strerror( error ), error );
return EXIT_FAILURE;
}
if( *hostname != '\0' ) {
printf( "%d %d %s\n", res->ai_family, res->ai_socktype, hostname );
}
}
freeaddrinfo( result );
return EXIT_SUCCESS;
}
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