RosettaCodeData/Task/DNS-query/R/dns-query-1.r
2023-07-01 13:44:08 -04:00

47 lines
1,001 B
R

#include <Rcpp.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace Rcpp ;
// [[Rcpp::export]]
CharacterVector getNameInfo(std::string fqdn) {
struct addrinfo hints, *res, *res0;
int error;
char host[NI_MAXHOST];
memset(&hints, 0, sizeof hints);
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
error = getaddrinfo(fqdn.c_str(), NULL, &hints, &res0);
if (error) { return(NA_STRING); }
int i = 0 ;
for (res = res0; res; res = res->ai_next) {
error = getnameinfo(res->ai_addr, res->ai_addrlen,
host, sizeof host, NULL, 0, NI_NUMERICHOST);
if (!error) { i++ ; }
}
CharacterVector results(i) ;
i = 0;
for (res = res0; res; res = res->ai_next) {
error = getnameinfo(res->ai_addr, res->ai_addrlen,
host, sizeof host, NULL, 0, NI_NUMERICHOST);
if (!error) { results[i++] = host ; }
}
freeaddrinfo(res0);
return(results) ;
}