QProcess and powershell - checking if the disk is clean

[Piotrek102]

I need a command or a powershell script that will return all indexes of the mounted disks in the system and their used space. For example:
disk 0
120GB
disk 1
51GB
...

[JonB]

@Piotrek102
I don't think this is the right thing to do. But if that is what you want you will need something Windows-specific, if you want a PowerShell command then a PowerShell forum would likely give you better answers than a Qt forum.

UPDATE
If the information you require is available from Qt it would be via the QStorageInfo Class. That does have a static QList<QStorageInfo> mountedVolumes(), if that gives you the information you seek.

[artwaw]

@Piotrek102 This is not Qt related. If you'd like to know how to do that in Qt (simple) we can assist however PowerShell is outside the subject of this forum.

[Piotrek102]

OK, I have a powershell script:

function Get-Space
{
    foreach($disk in Get-CimInstance Win32_Diskdrive)
    {
        $diskMetadata = Get-Disk | Where-Object { $_.Number -eq $disk.Index } | Select-Object -First 1
        $partitions = Get-CimAssociatedInstance -ResultClassName Win32_DiskPartition -InputObject $disk
        foreach($partition in $partitions)
        {
            $drives = Get-CimAssociatedInstance -ResultClassName Win32_LogicalDisk -InputObject $partition
            foreach($drive in $drives)
            {
                $totalSpace = [math]::Round($drive.Size / 1GB, 3)
                $freeSpace  = [math]::Round($drive.FreeSpace / 1GB, 3)
                $usedSpace  = [math]::Round($totalSpace - $freeSpace, 3)
                $volume     = Get-Volume | Where-Object { $_.DriveLetter -eq $drive.DeviceID.Trim(":") } | Select-Object -First 1
                [PSCustomObject] @{
                    Number        = $disk.Index
                    UsedSpace    = $usedSpace
                }
            }
        }
    }
}
Get-Space

It returns the following results:

Number UsedSpace
------ ---------
     1   326,045
     2   363,873
     3         0
     0   228,094

Now I need a c ++ function which based on this data (the data is saved as QStringList - each line separately) will create a QStringList named disks which will assign values to them based on disk indexes. For example:
QStringList disks;
disks [1] = 326,045 // This is disk 1
disks [2] = 363.873 // This is disk 2

It should be something like this:
disks [1] = returned value of disk 1

I just don't know how to extract this data from the returned data.

[artwaw]

@Piotrek102 Open the file (you mentioned file, right?) then read it line by line adding to QStringList.
Btw., please avoid using [] indexes, use insert() and at() methods to add and read the content.
You can use QFile::readLine() for reading the file.

[JonB]

@Piotrek102
Did you see the UPDATE I added to my earlier post, about QStorageInfo? If that gives you the same information as you want from your PS script, it will be easier to use than running a script and parsing the output. Up to you.....

[Piotrek102]

I use my own function to work with QProcess:

#include "mainwindow.h"
#include "ui_mainwindow.h"

bool process_ok;
QStringList to_return;

void MainWindow::encodingFinished()
{
	process_ok=true;
}

void MainWindow::readyReadStandardOutput()
{
	to_return << process->readAllStandardOutput();
}

QStringList MainWindow::RunCommand(QString cmd, QStringList commands)
{
	to_return.clear();
	process_ok=false;
	process->start(cmd, commands);
	while(process_ok!=true) delay_MSec(100);
	return to_return;
}

So to call the ps1 script I use it like this:

QStringList returned;
command = qApp->applicationDirPath()+"/scripts/getdisk.ps1";
commands << command;
returned = RunCommand("powershell.exe", commands);

[Piotrek102]

@JonB
I will check it, thank you for the hint

[JonB]

@Piotrek102 said in QProcess and powershell - checking if the disk is clean:

while(process_ok!=true) delay_MSec(100);

You must/should not do this sort of thing in Qt programming. If you really want to wait, you must use QProcess::waitForFinished().

[Piotrek102]

@JonB
That's right, I know it, but QProcess :: waitForFinished () was freezing my gui. this feature doesn't do that and works fine, I have tested it multiple times in my other programs. I know this is not correct but it works.

void MainWindow::delay_MSec(unsigned int msec)
{
	QTime _Timer = QTime::currentTime().addMSecs(msec);
	while( QTime::currentTime() < _Timer )
	QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
}

To be clear, this is not my function, I found it on the internet

@JonB
As for your suggestion, QStorageInfo is what I need! It works very well. I have only one question. Is there also an option to specify a disk index - e.g. disk 0?

foreach (const QStorageInfo &storage, QStorageInfo::mountedVolumes()) 
	{
		if (storage.isValid() && storage.isReady())
		{
			if (!storage.isReadOnly())
			{
				qDebug() << "name:" << storage.name();
				qDebug() << "fileSystemType:" << storage.fileSystemType();
				qDebug() << "size:" << storage.bytesTotal()/1000/1000 << "MB";
				qDebug() << "availableSize:" << storage.bytesAvailable()/1000/1000 << "MB";
				//qDebug() << index of disk here too
			}
		}
	}

[JonB]

@Piotrek102 said in QProcess and powershell - checking if the disk is clean:

QProcess :: waitForFinished () was freezing my gui

void MainWindow::delay_MSec(unsigned int msec)

I did not know what was in your delay_MSec(). Using processEvents() like this is not ideal. The best way is no synchronicity/waits/loops/processEvents, rather let it run asynchronously and continue your code in your slot on QProcess::finished() signal.

If the code works for you fair enough. It's moot anyway if you choose to use QStorageInfo instead.

Is there also an option to specify a disk index - e.g. disk 0?

I know no more than whatever is in QStorageInfo doc page. I have never used it :) [You can use an integer indexer into mountedVolumes() instead of foreach of that's all your "disk index - e.g. disk 0" is, I don't know what order mountedVolumes() returns them in?]

[Piotrek102]

Thank you very much for all your help. Like @JonB said I will try with QStorageInfo. Thanks again for your help!

[artwaw]

@Piotrek102 Please read the documentation.

You can list mounted volumes using mountedVolumes() static method.

Also please drop foreach, it's obsolete. Just iterate over items in the list.

[JoeCFD]

@Piotrek102 Do this in a thread to avoid any delay call(==>as less as possible) since it may take a while to get all storage info. GUI is not blocked in this way.

[Bazooca]

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