javascript - Message is not sent to Chrome extension -

i can read messages come extension, not able send message c++ native app chrome extension. using win 8 64bit. chrome log not report error, no info there.

here code:

void sendmessage(string msg){     _setmode(_fileno(stdout), _o_binary);     unsigned int len =  msg.length();     cout.write((char*)&len,4);     //cout.write(reinterpret_cast<char*>(&len),4);     std::cout << msg << flush; }  string readmessage(){     string msg = "";     std::cout.setf( std::ios_base::unitbuf );     unsigned int ch;//, len = 0;      //another way length     _uint32t len = 0;     cin.read(reinterpret_cast<char*>(&len) ,4);      //  read len number of characters message     (int i=0; < len; i++) {         ch = getchar();         msg += ch;     }     return msg; }  int _tmain(int argc, _tchar* argv[]) {     //reading messages extension     string msg = readmessage();     //here write msg log , it's there.      //sending message     sendmessage ("sent c++");      return 0; } 

what's wrong code? have tried many combinations writing message. also, have tried or without _setmode function, still not working.

thanks help.