Linux terminal won't display characters

Question

I'm writing a cross-platform console chat and having a strange problem:

1. I'm starting my server in one terminal.
2. I'm starting my client in another terminal.
3. Then I'm connecting from client to server.
4. Data is exchanged.
5. Server and client are closed.

Then comes the problem: the characters not displaying in terminal (as when you enter the password - OS gets my characters, but doesn't display it). It show when I type 'Enter' - all what I enter executing.

The server has a lot of threads: main (for sending messages to clients), for accepting and for each client connected.

The client has 2 threads: main (for sending messages to server) and for receiving messages.

All receive operations are asynchronous (I use select() method)
I'm using the following to get a message from user:

void Chat::getMessageFromUser(string &message) {
    message = "";
    strcpy(Chat::currentMessage, this->getMessageSigningUp().c_str());

    char newChar = '\0';
    int newCharPtr = this->getCurrentMessageLength();
    int minLength = newCharPtr;
    *this->output << Chat::currentMessage;

    while ((newChar = Chat::getch()) != '\n' && newCharPtr < Chat::MESSAGE_MAX_LENGTH) {
        if (newChar == 127) {     //127 is code of '\b' (backspace button)
            if (newCharPtr == minLength)
                continue;

            *this->output << "\b \b";
            --newCharPtr;
            continue;
        }
        *(Chat::currentMessage + newCharPtr) = newChar;
        *this->output << newChar;
        ++newCharPtr;
    }
    Chat::currentMessage[newCharPtr] = '\0';
    *this->output << endl;

    message = Chat::currentMessage;

    memset(Chat::currentMessage, 0, Chat::getCurrentMessageLength());
    strcpy(Chat::currentMessage, this->getMessageSigningUp().c_str());
}

I use it for processing next situation: One user enters the message, and in this time receiveThread gets new message. In this case I put new message using this:

void Chat::putMessageInChat(const char *message) {
    for (int i = 0; i < Chat::getCurrentMessageLength(); ++i)
        *this->output << "\b \b";
    *this->output << message << endl;
    *this->output << Chat::getCurrentMessage();
}

getch() method looks like:

int Chat::getch() {
    struct termios oldt,
    newt;
    int ch;
    tcgetattr( STDIN_FILENO, &oldt );
    newt = oldt;
    newt.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newt );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldt );
    return ch;
}

May be getch() is problem? Or I'm not close something? What's the problem?

Answer 1

Yes, the following code in your getch() function deactivates the direct output:

newt.c_lflag &= ~( ICANON | ECHO );
tcsetattr( STDIN_FILENO, TCSANOW, &newt );

You are removing the ECHO flag. This means that characters that are typed will no longer be shown directly.