QDir::root ()

[RenanBS]

Hello,

I'm trying to get the root drive from my application. I'm using Windows 7 and I have 2 drives (C:\ and D:\). The drive C:\ is where my OS is installed and the drive D:\ is where my application is running.

This is a piece of code from my application:

QString m_app_dir = "D:/slave";
QDir dir;
dir.setPath (m_app_dir);

QString m_app_dir = "D:/slave";
QDir dir;
dir.setPath (m_app_dir);

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QString r = dir.root ().path ();

QString r = dir.root ().path ();

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or

QString r = dir.root ().absolutePath ();

QString r = dir.root ().absolutePath ();

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Both codes return C:\, is that the expected result?
If so, what would return D:\?

From Qt docs about root (): http://qt-project.org/doc/qt-5/qdir.html#root

Returns the root directory.
The directory is constructed using the absolute path of the root directory, ensuring that its path() will be the same as its absolutePath().

So I was assuming D:\ would be the return of the root() method.

Thanks,
Renan

[anda_skoa]

If you look at the method declaration of root() in the documentation, then you'll see that root() is a static method
So it does not use "dir" at all.

Since Windows does not have the concept of a unified root, the best thing the Windows implementation can return is C:\ since this basically is always the root of the system installation.

Cheers,
_

[RenanBS]

So, is there a way to get the drive from that path (d:\slave) or any other path (since I cannot assume it will always be d:\slave)?

[sulliwk06]

I suspect you'll have to get the current path and just extract the drive label from the string

[Alundra]

So, is there a way to get the drive from that path (d:\slave) or any other path (since I cannot assume it will always be d:\slave)?

Yea of course : String.left(indexOf('\') + 1);

[RenanBS]

Yeah, of course, that's what I didn't want to do. But ok, that's the solution anyway.
There could be a QDir method to do this.
How can I request such feature?

Thanks

[Alundra]

They will not accept it because it's a bad function.

[RenanBS]

They will not accept it because it's a bad function.

Well, that doesn't answer my question.

Check Poco::Path implementation, you can check it here: http://pocoproject.org/docs/Poco.Path.html

const std::string & getDevice() const;

const std::string & getDevice() const;

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This method gives me exactly what I was asking.

Any way, thanks for all your answers.

[wysota]

So, is there a way to get the drive from that path (d:\slave) or any other path (since I cannot assume it will always be d:\slave)?

How about going up the directory tree in a loop until there is nowhere to go?

QDir getDrive(const QDir &path) {
  QDir dir(path.canonicalPath());
  while(dir.cdUp());
  return dir;
}

QDir getDrive(const QDir &path) {
  QDir dir(path.canonicalPath());
  while(dir.cdUp());
  return dir;
}

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[Alundra]

Looks like the more safe function can be, but this function has to be used carefully about performance.

[RenanBS]

How about going up the directory tree in a loop until there is nowhere to go?

QDir getDrive(const QDir &path) {
  QDir dir(path.canonicalPath());
  while(dir.cdUp());
  return dir;
}

QDir getDrive(const QDir &path) {
  QDir dir(path.canonicalPath());
  while(dir.cdUp());
  return dir;
}

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Really nice! I like that.
Thanks