test.c

 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <arpa/inet.h>

 int main(int argc, char** argv) {
     struct addrinfo hints = {0}, *res;
     hints.ai_family = AF_INET;
     hints.ai_socktype = SOCK_STREAM;

     char* host = argv[1];
     char* port = argv[2];
     printf("host: %s\n", host);
     printf("port: %s\n", port);

     int ret = getaddrinfo(host, port, &hints, &res);
     if (ret != 0) {
         printf("getaddrinfo failed: %s\n", gai_strerror(ret));
         return 1;
     }

     // Count the number of address infos
     int count = 0;
     for (struct addrinfo *p = res; p != NULL; p = p->ai_next) {
         count++;
     }
     printf("Number of addr infos received: %d\n\n", count);

     // Print each address info
     int i = 0;
     for (struct addrinfo *p = res; p != NULL; p = p->ai_next) {
         printf("Address info #%d:\n", i++);
         printf("  Family: %d", p->ai_family);
         if (p->ai_family == AF_INET) printf(" (AF_INET)");
         else if (p->ai_family == AF_INET6) printf(" (AF_INET6)");
         printf("\n");

         printf("  Socktype: %d", p->ai_socktype);
         if (p->ai_socktype == SOCK_STREAM) printf(" (SOCK_STREAM)");
         else if (p->ai_socktype == SOCK_DGRAM) printf(" (SOCK_DGRAM)");
         printf("\n");

         printf("  Protocol: %d\n", p->ai_protocol);

         printf("  Addr len: %d\n", p->ai_addrlen);

         // Print IP address
         void *addr;
         char ipstr[INET6_ADDRSTRLEN];
         if (p->ai_family == AF_INET) {
             struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
             addr = &(ipv4->sin_addr);
             inet_ntop(p->ai_family, addr, ipstr, sizeof(ipstr));
             printf("  IP Address: %s\n", ipstr);
         } else if (p->ai_family == AF_INET6) {
             struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;
             addr = &(ipv6->sin6_addr);
             inet_ntop(p->ai_family, addr, ipstr, sizeof(ipstr));
             printf("  IP Address: %s\n", ipstr);
         }
         printf("\n");
     }

     int sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
     if (sock < 0) {
         printf("socket() failed: %s\n", strerror(errno));
         freeaddrinfo(res);
         return 1;
     }

     printf("Socket created: %d\n", sock);

     ret = connect(sock, res->ai_addr, res->ai_addrlen);
     if (ret < 0) {
         printf("connect() failed: %s\n", strerror(errno));
         close(sock);
         freeaddrinfo(res);
         return 1;
     }

     printf("Connected successfully!\n");

     close(sock);
     freeaddrinfo(res);
     return 0;
 }