Thread: Link error for gai_strerror and inet_ntop

  1. #1
    Registered User
    Join Date
    Oct 2009

    Link error for gai_strerror and inet_ntop

    the code aim is too display ip address of name passed in command line but the code is unable to link up
    I am using dev-c++ and i have added library wsock32 and ws_s32
    still it give link error for gai_strerror and inet_ntop
    here is the code:
    ** showip.c -- show IP addresses for a host given on the command line
    #include <stdio.h>
    #include <string.h>
    #include <windows.h>
    #include <winsock2.h>
    #include <ws2tcpip.h>
    int main(int argc, char *argv[])
    {struct addrinfo hints, *res, *p;
    int status;
    char ipstr[INET6_ADDRSTRLEN];
    WSADATA wsaData; // if this doesn't work
    //WSAData wsaData; // then try this instead
    // MAKEWORD(1,1) for Winsock 1.1, MAKEWORD(2,0) for Winsock 2.0:
    if (WSAStartup(MAKEWORD(2,0), &wsaData) != 0) {
    fprintf(stderr, "WSAStartup failed.\n");
    if (argc != 2) {
    fprintf(stderr,"usage: showip hostname\n");
    return 1;
    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC; // AF_INET or AF_INET6 to force version
    hints.ai_socktype = SOCK_STREAM;
    if ((status = getaddrinfo(argv[1], NULL, &hints, &res)) != 0) {
    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
    return 2;
    printf("IP addresses for %s:\n\n", argv[1]);
    for(p = res;p != NULL; p = p->ai_next) {
    void *addr;
    char *ipver;
    // get the pointer to the address itself,
    // different fields in IPv4 and IPv6:
    if (p->ai_family == AF_INET) { // IPv4
    struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
    addr = &(ipv4->sin_addr);
    ipver = "IPv4";
    } else { // IPv6
    struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;
    addr = &(ipv6->sin6_addr);
    ipver = "IPv6";
    // convert the IP to a string and print it:
    inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);
    printf(" %s: %s\n", ipver, ipstr);
    freeaddrinfo(res); // free the linked list
    return 0;

    Plz help

  2. #2
    Registered User
    Join Date
    Jul 2007
    Have you tried library MSDN tells to use?

    And frigging indent your code. Nobody can read that.

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