Why are there multiple results from getaddrinfo?
<p>I am trying to create a simple program that gets the IP address given a certain hostname:</p>
<p>My code snipped is attached below:</p>
<pre><code>#include &lt;stdio.h&gt;
#include &lt;stdlib.h&gt;
#include &lt;stdio.h&gt;
#include &lt;netdb.h&gt;
#include &lt;sys/socket.h&gt;
#include &lt;errno.h&gt;
#include &lt;arpa/inet.h&gt;
#include &lt;string.h&gt;
#include &lt;unistd.h&gt;

int main(int argc, char *argv[]) {
    if(argc &lt; 2){
        printf(&quot;Please provide a hostname.\n&quot;);
        exit(1);
    }

    char *hostname = argv[1];
    char ip[100];
    get_ip(hostname, ip);
    printf(&quot;%s resolved to %s\n&quot;, hostname,ip);
}

int get_ip(char *hostname, char *ip){
    struct sockaddr_in *h;
    int sockfd;
    struct addrinfo hints, *servinfo,*res;
    struct addrinfo *iter;
    int rv;

    memset(&amp;hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    if((rv = getaddrinfo(hostname, &quot;HTTP&quot;, &amp;hints, &amp;res)) != 0) {
        fprintf(stderr, &quot;getaddrinfo %s\n&quot;, gai_strerror(rv));
        return 1;
    }
    for(iter=res; iter != NULL; iter=iter-&gt;ai_next){
      printf(&quot;%p\n&quot;, iter-&gt;ai_next);

       h=(struct sockaddr_in *)iter-&gt;ai_addr;
       strcpy(IP, inet_ntoa(h-&gt;sin_addr));
       printf(&quot;%s\n&quot;,ip);
    }
    freeaddrinfo(res);
    return 0;
}
</code></pre>
<p>I enter in the following arguments:</p>
<pre><code>gcc get_ip_addr.c -o get_ip_addr;
./get_ip_addr google-public-dns-b.google.com
</code></pre>
<p>This results in:</p>
<pre><code>0x2475330
8.8.4.4
(nil)
0.0.0.0
</code></pre>
<p>When I remove the <code>&quot;http&quot;</code> and <code>&amp;hints</code> and set them to <code>NULL</code> I get the following results:</p>
<pre><code>0x1b63310
8.8.4.4
0x1b63360
8.8.4.4
0x1b633b0
8.8.4.4
0x1b63410
0.0.0.0
0x1b63470
0.0.0.0
(nil)
0.0.0.0
</code></pre>
<p>So when I set the <code>service</code> and <code>hints</code> to <code>NULL</code> the <code>getaddrinfo()</code> returns multiple possible results I don't understand why I am getting multiple IP addresses instead of just getting one IP address?</p>