How to fix this error error: ‘g’ undeclared (first use in this function)
friend_server.c:160:29: note: in expansion of macro ‘PORT’
  160 |     server.sin_port = htons(PORT);
      |                             ^~~~
<command-line>: note: each undeclared identifier is reported only once for each function it appears in
friend_server.c:160:29: note: in expansion of macro ‘PORT’
  160 |     server.sin_port = htons(PORT);
      |                             ^~~~
// Create socket
    int listen_soc = socket(AF_INET, SOCK_STREAM, 0);
    if (listen_soc == -1) {
        perror("server: socket");
        exit(1);
    }

    //initialize server address
    struct sockaddr_in server;
    server.sin_family = AF_INET;
    server.sin_port = htons(PORT);
    memset(&server.sin_zero, 0, 8);
    server.sin_addr.s_addr = INADDR_ANY;

    // bind socket to an address
    if (bind(listen_soc, (struct sockaddr *) &server, sizeof(struct sockaddr_in)) == -1) {
      perror("server: bind");
      close(listen_soc);
      exit(1);
    }


    // Set up a queue in the kernel to hold pending connections.
    if (listen(listen_soc, 5) < 0) {
        // listen failed
        perror("listen");
        exit(1);
    }

    struct sockaddr_in client_addr;
    unsigned int client_len = sizeof(struct sockaddr_in);
    client_addr.sin_family = AF_INET;

    int client_socket = accept(listen_soc, (struct sockaddr *)&client_addr, &client_len);
    if (client_socket == -1) {
        perror("accept");
        return -1;
    }

    write(client_socket, "Welcome to FriendMe!\nPlease type a command:\n> ", 49);

    char line[INPUT_BUFFER_SIZE];
    read(client_socket, line, INPUT_BUFFER_SIZE);
    line[INPUT_BUFFER_SIZE - 1] = '\0';
    printf("reading line");
