#include #include #include #include #include #include #include #include #include #ifdef __EMSCRIPTEN__ #include #endif int main() { char str[INET_ADDRSTRLEN]; struct hostent *host = NULL; struct hostent hostData; struct in_addr addr; const char *res; char buffer[2048]; int err; // gethostbyname_r calls the same stuff as gethostbyname, so we'll test the // more complicated one. // resolve the hostname to an actual address gethostbyname_r("slashdot.org", &hostData, buffer, sizeof(buffer), &host, &err); assert(host->h_addrtype == AF_INET); assert(host->h_length == sizeof(uint32_t)); // convert the raw address to a string char **raw_addr_list = host->h_addr_list; int *raw_addr = (int*)*raw_addr_list; res = inet_ntop(host->h_addrtype, raw_addr, str, INET_ADDRSTRLEN); assert(res); // convert the string to an in_addr structure err = inet_pton(AF_INET, str, &addr); assert(err == 1); // do a reverse lookup on the ip address struct hostent *host1 = gethostbyaddr(&addr, sizeof(addr), host->h_addrtype); assert(strstr(host1->h_name, "slashdot.org")); puts("success"); return EXIT_SUCCESS; }