Any code to Add/Remove drive letters like Disk Manager?

[Mbee]

Occasionally I need to make more drive letters available for other disks I will be using.  To do this using the Disk Manager, one selects a currently mounted drive that has a letter assigned, right-click, and choose "Change Drive Letter and Paths...", then click the Add or Remove buttons and so on. Note that I'm not trying to do anything even the slightest bit complex, such as mapping drives or folders or working over a network.  I just want to remove and later re-add drive letters to currently mounted disks/partitions.  I'd prefer to do this directly inside AutoIt rather than via the shell/explorer.

I see there are very promising _WinAPI functions that I could put together to do this, such as "_WinAPI_GetVolumeNameForVolumeMountPoint", "_WinAPI_SetVolumeMountPoint", and "_WinAPI_DeleteVolumeMountPoint".  I'm sure I could accomplish what I need with these.  But I don't want to re-invent the wheel if this work has already been done.  Does anyone know if it has?

If not, I'll code it up and submit it as a UDF, so let me know and I'll do that..

Thanks!

[BrewManNH]

Have you looked at DriveMapAdd and DriveMapDel in the help file?

[Mbee]

On 4/18/2018 at 9:56 AM, BrewManNH said:

Have you looked at DriveMapAdd and DriveMapDel in the help file?

Hi, BrewManNH! Yes, I looked at those, but with the second parameter being a network path string, it didn't look like the best way to go.

Edited April 24, 2018 by Mbee

[BrewManNH]

What exactly are you trying to do then? If they're not network drives, then what are they?

[Mbee]

2 hours ago, BrewManNH said:

What exactly are you trying to do then? If they're not network drives, then what are they?

First, I've made very good progress so far, but my next post will be a request for assistance in figuring out how to handle a parameter returned from a particular DLL call...

But to answer your question, I'm developing a desktop tool that will operate on hard disks, with or without drive letters (e.g., mounted or unmounted) currently on the system. I've got that part working. The primary purpose of the application is to allow the user to easily free up drive letters and later return those drive letters to the disks they were previously assigned to (if that drive letter is available).  I doubt anyone else will ever want or use it, but I'm writing it for myself.

To perform the necessary operations, I needed WinAPI calls that, to the best of my knowledge, have not had an AutoIt interface function written for them,  so what I'm doing now is preparing a UDF with those function interfaces. I have completed three of the probable 5 I'll need, which are: _WinAPI_FindFirstVolume(), _WinAPI_FindNextVolume(), and _WinAPI_FindVolumeClose(). These were needed because, since not all drives will currently have letters, I had to find a way to get that info some other way.

[Mbee]

I need some help coding up a WinAPI DLL call to GetVolumeNameForVolumeMountPoint(). The problem is that one of the returns to the WinAPI function is a null-terminated string that contains one or more null-terminated strings.  Here's the MSDN page: 

https://msdn.microsoft.com/en-us/library/windows/desktop/aa364994(v=vs.85).aspx

I checked the AutoIt help file looking for how to specify a nested string in a DLL call, but either my comprehension is terrible (a very distinct possibility!) or it offered no guidance.

 

.. NEVER MIND.  I think I know how to do it..

[BrewManNH]

Try with Mountvol <Driveletter:> /d to remove the name, but keep the drive mounted, or /p to remove the letter and unmount the drive.

[Mbee]

19 minutes ago, BrewManNH said:

Try with Mountvol <Driveletter:> /d to remove the name, but keep the drive mounted, or /p to remove the letter and unmount the drive.

Aww, you're no fun (you fell right over! - Firesign ref?).  Yeah, but I really want to do this internally in AutoIt rather than invoke external commands...

[Bilgus]

https://www.autoitscript.com/autoit3/docs/libfunctions/_WinAPI_GetVolumeNameForVolumeMountPoint.htm

and the include file..

;;WinAPIFiles.au3
Func _WinAPI_GetVolumeNameForVolumeMountPoint($sMountedPath)
    Local $aRet = DllCall('kernel32.dll', 'bool', 'GetVolumeNameForVolumeMountPointW', 'wstr', $sMountedPath, 'wstr', '', 'dword', 80)
    If @error Or Not $aRet[0] Then Return SetError(@error + 10, @extended, '')

    Return $aRet[2]
EndFunc   ;==>_WinAPI_GetVolumeNameForVolumeMountPoint

 

[Mbee]

36 minutes ago, Bilgus said:

https://www.autoitscript.com/autoit3/docs/libfunctions/_WinAPI_GetVolumeNameForVolumeMountPoint.htm

and the include file..

;;WinAPIFiles.au3
Func _WinAPI_GetVolumeNameForVolumeMountPoint($sMountedPath)
    Local $aRet = DllCall('kernel32.dll', 'bool', 'GetVolumeNameForVolumeMountPointW', 'wstr', $sMountedPath, 'wstr', '', 'dword', 80)
    If @error Or Not $aRet[0] Then Return SetError(@error + 10, @extended, '')

    Return $aRet[2]
EndFunc   ;==>_WinAPI_GetVolumeNameForVolumeMountPoint

 

Hi, Bilgus, and thanks!  Nice to hear from you...

Yeah, sorry about that.  I entered the wrong function name.  I needed _WinAPI_GetVolumePathNamesForVolumeName(), which I still can't find, so I started coding it, but I ran into a puzzle.  I'd certainly appreciate the help!

You see, the main return from that function is not purely an AutoIt-compatible (i.e., null-terminated) string. It's a MULTI_SZ, I guess, of zero-terminated strings, with a double zero terminating the entire string.  Now I figure that 98% of the time, it will only consist of a single ZTS -- namely the drive letter path.  But since MSDN states that it might well return multiple substrings, I don't know the best way of handling that return.

At first I was planning on dividing  it myself within _WinAPI_GetVolumePathNamesForVolumeName() such that it would return an array of strings, but I'm not at all sure that the multi-SZ string can properly be handled by native AutoIt functions.

How would you do it, wise sir?

Edited April 24, 2018 by Mbee

[Mbee]

By the way, I created a new thread on the multi-string topic here: Handling the equivalent of Multi_SZ strings (not from the registry)