netcat command in c++ - c++

Question

I am a newbee when it comes to coding in C++.
I am currently using qt to make a simple GUI, where I want to send a command to a device via TCP/IP.
When i connect my computer to the device and via the terminal send the command:
echo '3b00010000001b010001000000120000013000002713000300030101' | xxd -r -p | nc 192.168.1.101 30013
The device does correspondently.
I need to be able to send this command in qt as a function. Can anyone help me? This is what i have so far (does not work)
Header:
#ifndef SOCKET_H
#define SOCKET_H
#include <QObject>
#include <QTcpSocket>
#include <QtDebug>
#include <string>
using namespace std;
class Socket : public QObject
{
Q_OBJECT
public:
explicit Socket(QObject *parent = nullptr);
void Connect(const QString &host, const string &cmd);
private:
QTcpSocket *socket;
};
#endif // SOCKET_H
Cpp:
#include "socket.h"
Socket::Socket(QObject *parent) : QObject(parent)
{
}
void Socket::Connect(const QString &host, const string &cmd)
{
//connect
socket = new QTcpSocket(this);
socket->connectToHost(host,30013);
if(socket->waitForConnected(1500))
{
qDebug() << "Connected";
//send
socket->write(cmd.c_str(), cmd.size());
socket->waitForBytesWritten(1000);
//close
socket->close();
}
else
qDebug() << "Not Connected";
}
Then I want to send the command by:
Socket.Test
Test.Connect("192.168.1.101","3b00010000001b010001000000120000013000002713000300030101")
Any help would be much appreciated. Thanks.

Answer 1

As your command is a fixed string you can simply enter the characters directly:
const char data[] = "\x3b\x00\x01\x00\x00\x00\x1b\x01\x00\x01\x00\x00\x00\x12\x00\x00\x01\x30\x00\x00\x27\x13\x00\x03\x00\x03\x01\x01";
Test.Connect("192.168.1.101",string(data, sizeof(data)-1));
Note that as your data has embedded null characters you can't simply pass the string literal to std::string as it would truncate the string before the first null character.