CODEWITHSUNDEEP
c++google-chromegoogle-chrome-extensionutf8-decodechrome-native-messaging
Himanshu kukreja
Himanshu kukreja

Reputation: 74

How to use Native Host Message in Native Application For Chrome Native Messaging Extension

I am working on Chrome Extension with Native Host messaging. I am not able to use message text in my host application. Everything working fine from the establishing connection to get response in extension. I need to use Message text in my application for further use/execution in simple text datatype (string/char). I know message is in UTF8 encoded form i tried to decode but still getting problem, can any one help me out?

When i decode message chrome extension console show Error: "Error when communicating with the native messaging host." and if i use that message text after "cout" same error is there "Error when communicating with the native messaging host". Direct sending and receiving message works fine for me.

Code is something like this :

 std::string mycode(std::string data){
    data= data+"abc"; //changing text to any thing.
    cout<< data;
    anotherFunction(data);//killing processes using string data
}
int main(int argc, char* argv[])
{
    std::cout.setf( std::ios_base::unitbuf );
    while (true)
    {
        unsigned int ch, inMsgLen = 0, outMsgLen = 0;
        std::string input = "", response = "";
        std::cin.read((char*)&inMsgLen, 4);
        if (inMsgLen == 0)
        {
            break;
        }
        else
        {
            for (int i=0; i < inMsgLen; i++)
            {
                ch = getchar();
                input += ch;
            }
        }
        response.append("{\"echo\":").append(input).append("}");
        outMsgLen = response.length();
        std::cout.write((char*)&outMsgLen, 4);
        std::cout << response;
        cout<< input;
        //using "input" variable for further user 
        mycode(input);
    }
    return 0;
}

Upvotes: 1

Views: 1813

Answers (1)

Jo&#227;o Augusto
Jo&#227;o Augusto

Reputation: 2305

That's wrong, did you read the docs ? Try something like this...

_setmode( _fileno( stdin ), _O_BINARY ); 
    _setmode( _fileno( stdout ), _O_BINARY ); 

    char cBuffer[65536] = {0}; 
    while(true)
    {       
        unsigned int uiSize = 0;                        
        std::cin.read((char*)&uiSize, sizeof(unsigned int));

        if(uiSize != 0 && uiSize < 65536)
        {                       
            memset(cBuffer, 0, 65536);
            std::cin.read(cBuffer, uiSize);

            std::string strIn(cBuffer);

            std::string strOut = "{\"result\":\"This is a Test\"}";                 
            uiSize = strOut.length();

            std::cout << char(((uiSize>>0) & 0xFF));
            std::cout << char(((uiSize>>8) & 0xFF));
            std::cout << char(((uiSize>>16) & 0xFF));
            std::cout << char(((uiSize>>24) & 0xFF));   
            std::cout << strOut.c_str();                
        }
        else
            break;
    }

You need to set the io to binary, otherwise things like this could happen... if a byte with the value 00011010 (CTRL ALT Z = 26) is present it will be treated as a EOF and end the communication. :)

Upvotes: 1

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