QProcess start netsh command with quotes and spaces in parameter argument question.

[teungri]

Hello,
I want to set my network interface adapter on windows to static/dhcp with the netsh command via QProcess.
The command should be:
netsh interface ipv4 set address "USB-Ethernet Adapter" dhcp
This command is working when I execute it from the windows command line. However I want to execute this
command in a Qt application via QProcess.

I read already various threads about this issue but I never reached a successful result. see
http://doc.qt.io/qt-5/qprocess.html#start-3
From this documentation I should use """"USB-Ethernet Adapter"""",
triple " to expand to ", the 4th one because a space in the parameter.
Here is my different code I use to set dhcp:

    //-----------------------------------------------------------------------------------------------------------
    void setDhcp()
    {
        QStringList args;
        QProcess proc;
        args.clear();
        args << "interface" << "ipv4" << "set" << "address";
         //    args << "\"" + nwAdapter + "\"";
        args << "\"\"\"\"" + nwAdapter + "\"\"\"\"";
        args << "dhcp";

     //    proc.start( "netsh", args );
    //    proc.waitForFinished();

    int exitCode = 0;
    //    exitCode = QProcess::execute("netsh", args );

    QString cmd = "netsh " + args.join(" ");
    qCDebug(DBG) << "cmd=" << cmd << "exitCode=" << exitCode;
    //    exitCode = QProcess::execute( cmd );
    proc.start( cmd );
    proc.waitForFinished();
}
//-----------------------------------------------------------------------------------------------------------

The result of printing cmd is:

cmd= "netsh interface ipv4 set address """"USB-Ethernet Adapter"""" dhcp" exitCode= 0

Is there anybody who has a clue to this problem?

currently i stick the the "system(cmd)';" solution which is working, but than annoying
windows popups occur.

Thanks in advance for your info.
Kind regards,

[teungri]

Hello,
Since no one is replying, there is possibly no qt solution. FYI, I solved my problem with old school
windows api, see code below (the netshName contains spaces):

cmd = QString("netsh interface ipv4 set address name=\"%1\" static").  arg(this->networkAdapter()->netshName());
cmd += " 169.254.1.1 255.255.255.0 169.254.1.1 1";
ExecuteNetsh( cmd.toStdString().c_str() );

---

static void ExecuteNetsh(const char* strCmd )
{
    char strPath[1024];
    STARTUPINFOA startinfo;
    PROCESS_INFORMATION process;
    DWORD dwRes;

    //fill start-info
    GetStartupInfoA(&startinfo);
    startinfo.cb = sizeof (startinfo);
    startinfo.dwFlags = STARTF_USESHOWWINDOW;
    startinfo.wShowWindow = SW_HIDE;

	//get netsh-path
	GetSystemDirectoryA(strPath, 1024);
	strcat( strPath, "\\netsh.exe" );

    //start netsh
    if (!CreateProcessA(strPath, (LPSTR)strCmd, NULL, NULL,
                        FALSE, 0, NULL, NULL, &startinfo, &process))
    {
        qCDebug(DBG) << QString("Error while trying to execute %1 %2").arg(strPath).arg(strCmd);
        return;
    }

	//wait until finished
	WaitForSingleObject(process.hProcess, INFINITE);

	//check exit-code
	GetExitCodeProcess(process.hProcess, &dwRes);
	if(dwRes != 0) qCCritical(DBG) << QString( "GetExitCodeProcess error %1\n\tcmd=%2").
            arg( GetLastError() ).
            arg( strCmd );

	//close handles
	CloseHandle(process.hThread);
	CloseHandle(process.hProcess);
}

Kind regards,
Teun Grinwis

[Chris Kawa]

Here's an example that will print info on all available interfaces:

QString command("netsh interface ipv4 show addresses \"%1\"");

auto infs = QNetworkInterface::allInterfaces();
for(auto inf : infs)
{
    QProcess proc;
    proc.start(command.arg(inf.humanReadableName()));
    proc.waitForFinished();
    qDebug() << proc.readAll();
}

You can adjust it to fit your needs.