Two ways to connect a server through a socket

1. using getaddrinfo()

int main(int argc, char *argv[])
{
    int sockfd, portno;
 
    portno = atoi(argv[2]);
 
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
 
    struct addrinfo hints, *res;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
 
    int status;
    if ((status = getaddrinfo(argv[1], argv[2], &hints, &res) != 0))
        { 
          // print error msg;
          exit(1);
          }
 
    connect(sockfd, res->ai_addr, res->ai_addrlen);
    
   // ...
   freeaddrinfo(res);
   // ....
   return 0;
}

2. using  gethostbyname()

int main(int argc, char *argv[])
{
    int sockfd, portno, n;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    portno = atoi(argv[2]);

    sockfd = socket(AF_INET, SOCK_STREAM, 0);

    if (sockfd < 0)
        // print error msg here

    server = gethostbyname(argv[1]);

    if (server == NULL) {
        // print error msg...;
        exit(0);
    }

    bzero((char *) &serv_addr, sizeof(serv_addr));

    serv_addr.sin_family = AF_INET;

    bcopy((char *)server->h_addr,
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);

    serv_addr.sin_port = htons(portno);

    if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");
    
    //.....
    return 0;
}