tcp-ip-sockets-in-c/ch3/GetAddrInfo.c

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

#include "Practical.h"

int main(int argc, char **argv) { 
    if (argc != 3) {
        DieWithUserMessage("Parameter(s)", "<Address/Name> <Port/Service>");
    }

    char *addr_string = argv[1];
    char *port_string = argv[2];

    struct addrinfo addr_criteria = {0};
    addr_criteria.ai_family = AF_UNSPEC;
    addr_criteria.ai_socktype = SOCK_STREAM;
    addr_criteria.ai_protocol = proto_get_num("tcp");

    struct addrinfo *addr_list = nullptr;
    int res = getaddrinfo(addr_string, port_string, &addr_criteria, &addr_list);
    if (res != 0) {
        DieWithUserMessage("getaddrinfo() failed", gai_strerror(res));
    }

    for (struct addrinfo *addr = addr_list; addr != nullptr; addr = addr->ai_next) {
        PrintSocketAddress(addr->ai_addr, stdout);
        fputc('\n', stdout);
    }

    freeaddrinfo(addr_list);

    return 0;
}