Call another application with administrator priviliges

km2442

Hi, all!
In my application I need to call another Qt application (small helper app) with administrator priviliges and some arguments. I don't know exactly how to do this.
Only one method which works on my computer is (I have Windows 10 pro):

    QString program = QDir::toNativeSeparators("\"" + QDir::currentPath() + "/Appname.exe\"  arg1 arg2");
    system(program.toStdString().c_str());

But I have tested it on another computers, and It'nt work for everyone.
Could you tell me how to do this in right way?

SGaist

Hi and welcome to devnet,

Do you also build that other program ?

km2442

Yes, program is working but it needs admin priviliges and arguments...

SGaist

So if you are building both application yourself, you need to embed a manifest file your Appname application to tell the system that it requires elevated privileges. You have an example on how to to that here

km2442

Yes, my HelperApp is starting with adminstrator privileges, but I cant call it from main application to show UAC (give privileges), send arguments, and get return code. That's the problem. The way with console don't work with all computers.

SGaist

Did you took a look at QProcess ?

km2442

Yes, I have looked, but I can't call my helpr application with admin by QProcess....

mrjj

hi
Its not possible to use runas for it ?

void MainWindow::on_pushButton_released() {
QString exeFileName;
exeFileName = "notepad.exe";
#ifdef Q_OS_WIN
// Requesting elevation
int result = (int)::ShellExecuteA(0, "runas", exeFileName.toUtf8().constData(), 0, 0, SW_SHOWNORMAL);
if (result <= 32) {
// error handling
}
#endif
}

km2442

@mrjj Hi, I can run my helper app (UAC is showing) with code:

QString exeFileName = QDir::toNativeSeparators("\"" + QDir::currentPath() + "/app.exe\"");
        int result = (int)::ShellExecuteA(0, "runas", exeFileName.toUtf8().constData(), 0, 0, SW_SHOWNORMAL);

but, I can't provide any arguments with this method, moreover I'm getting unexpected return code: 42.

I have tried option with arguments:

QString exeFileName = QDir::toNativeSeparators("\"" + QDir::currentPath() + "/app.exe\" arg1 arg2");
        int result = (int)::ShellExecuteA(0, "runas", exeFileName.toUtf8().constData(), 0, 0, SW_SHOWNORMAL);

mrjj

@km2442 said:
Hi, do you use the right place for the paramters?
They should not be part of the exename/path

ShellExecuteA(0, "runas", exeFileName.toUtf8().constData(),** THIS IS FOR PARAMS**, 0, SW_SHOWNORMAL);

https://msdn.microsoft.com/en-us/library/windows/desktop/bb762153(v=vs.85).aspx

Else im not sure what u mean with
" I can't provide any arguments "

km2442

@mrjj Ok, Now, your solution is working, but there is one problem: I'm getting Return Code 42 all time. My app is sending code 1 or 24 or 25. Do you know how to fix it?

mrjj

@km2442
Super.
I dont think it can return the "return value"
Docs says
"If the function succeeds, it returns a value greater than 32. "

For return value , I think u need to use ( the Ex version)
https://msdn.microsoft.com/en-us/library/windows/desktop/bb762154(v=vs.85).aspx
and use
https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx
for the return code.

SHELLEXECUTEINFO ShExecInfo = {0};
ShExecInfo.cbSize = sizeof(SHELLEXECUTEINFO);
ShExecInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
ShExecInfo.hwnd = NULL;
ShExecInfo.lpVerb =  L"runas";
ShExecInfo.lpFile = "c:\\MyProgram.exe";        
ShExecInfo.lpParameters = "";   
ShExecInfo.lpDirectory = NULL;
ShExecInfo.nShow = SW_SHOW;
ShExecInfo.hInstApp = NULL; 
ShellExecuteEx(&ShExecInfo);
WaitForSingleObject(ShExecInfo.hProcess,INFINITE);

(code not tested)

km2442

Thank you, your solution is working :)

mrjj

super :)
thanks for the feedback.