打印getaddrinfo()返回的地址信息

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include "DieWithMessage.h"

void PrintSocketAddress(const struct sockaddr *address, FILE *stream);

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

    char *addrString = argv[1];
    char *portString = argv[2];

    struct addrinfo addrCriteria;
    memset(&addrCriteria, 0, sizeof(addrCriteria));

    addrCriteria.ai_family = AF_UNSPEC;
    addrCriteria.ai_socktype = SOCK_STREAM;
    addrCriteria.ai_protocol = IPPROTO_TCP;

    struct addrinfo *addrList;

    int rtnVal = getaddrinfo(addrString, portString, &addrCriteria, &addrList);

    if(rtnVal != 0)
        DieWithUserMessage("getaddrinfo() failed", gai_strerror(rtnVal));

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

    freeaddrinfo(addrList);

    exit(0);
}


void PrintSocketAddress(const struct sockaddr *address, FILE *stream)
{
    if(address == NULL || stream == NULL)
        return;

    void *numericAddress;
    char addrBuffer[INET6_ADDRSTRLEN];
    in_port_t port;
    switch(address->sa_family)
    {
        case AF_INET:
            numericAddress = &((struct sockaddr_in* ) address)->sin_addr;
            port = ntohs(((struct sockaddr_in *)address)->sin_port);
            break;
        case AF_INET6:
            numericAddress = &((struct sockaddr_in6 *)address)->sin6_addr;
            port = ntohs(((struct sockaddr_in6 *)address)->sin6_port);
            break;
        default:
            fputs("[unknown type]", stream);
            return;
    }

    if(inet_ntop(address->sa_family, numericAddress, addrBuffer, sizeof(addrBuffer)) == NULL)
        fputs("[invalid address]", stream);
    else
    {
        fprintf(stream, "%s", addrBuffer);
        if(port != 0)
            fprintf(stream, "-%u", port);
    }
}