Anyone good with powershell want to try helping to troubleshoot a long single line command?

hsehestedt · Nov 24, 2023

I have a command that I am trying to develop that I will call from within a batch file.

I have a large part of this working. Here is what currently works:

powershell.exe -executionpolicy bypass -command "Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 1 -and $_.mbrtype -eq '0x0c' } | Set-Partition -mbrtype '0x1c'; Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 2 -and $_.mbrtype -eq '0x07' } | Set-Partition -mbrtype '0x17'"

This command will look at the first 2 partitions on each drive. If the first partition has an MBR type of 0x0c (a FAT32 MBR partition) it will change the partition type ID to 0x1c, making it hidden.

The same thing is repeated for the second partition, changing the type from 0x07 (an NTFS MBR partition) to 0x17, again, making it hidden.

For safety, I want to add one thing to this command: I want it to look for a file called VOL1_M_MEDIA.WIM or VOL2_M_MEDIA.WIM on the root of the partitions and only change the type if those files are present.

Here is what I have tried, but this is not working. The command completes with no failure, but the type is not being changed even though the expected files are present.

powershell.exe -executionpolicy bypass -command "Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 1 -and $_.mbrtype -eq '0x0c' -and (test-path '$($_.uniqueid)\\VOL1_M_MEDIA.WIM') } | Set-Partition -mbrtype '0x1c'; Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 2 -and $_.mbrtype -eq '0x07' -and (test-path '$($_.uniqueid)\\VOL2_M_MEDIA.WIM') } | Set-Partition -mbrtype '0x17'"

NOTE: I need the command to find the specified files without using a drive letter.

pseymour · Nov 24, 2023

You're using single-quoted strings, which don't allow variable substitution. Switch to double-quoted strings for your Test-Paths.

hsehestedt · Nov 24, 2023

pseymour said:
You're using single-quoted strings, which don't allow variable substitution. Switch to double-quoted strings for your Test-Paths.

Thanks for the suggestion. Unfortunately that still does not work.

mark491 · Nov 24, 2023

Remove the outer double quotes around the command.
Replace the curly braces '{}' with parentheses '()' in the Where-Object filters.
Replace the single quotes around hexadecimal values with double quotes.
Remove the unnecessary semicolon between the two commands.

After correcting the syntax, the command will look like this:

Powershell:

powershell.exe -executionpolicy bypass -command Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 1 -and $_.mbrtype -eq "0x0c" } | Set-Partition -mbrtype "0x1c"; Get-Disk | Get-Partition | Where-Object { $_.PartitionNumber -eq 2 -and $_.mbrtype -eq "0x07" } | Set-Partition -mbrtype "0x17"

pseymour · Nov 24, 2023

Does the Test-Path part even work, on its own? Looking at my system, that wouldn't make a valid path. I would use a value from the AccessPaths property. Just a sample to look for a text file; change the name to your WIM, and I think you'll find the UniqueID property does not form a valid path.

File path formats on Windows systems

Powershell:

Get-Disk | Get-Partition |
Where-Object { $_.mbrtype -eq 0x07 } |
ForEach-Object {
    "$($_.uniqueid)\testfile.txt"
    Test-Path -LiteralPath "$($_.uniqueid)\testfile.txt"
    $_.AccessPaths | Where-Object { $_ -match "^\\\\\?\\" } |
     ForEach-Object { 
        "$($_)testfile.txt"
        Test-Path -LiteralPath "$($_)testfile.txt"
     }
}

garlin · Nov 25, 2023

Update: I figured out a better way.

~~1. There's no possible way to shorten this solution to fit a single PS command line, especially if you're checking for mounted files.~~

2. "Get-Disk | Get-Partition" is redundant. Get-Partition returns the same results.

3. You do need a drive letter. While searching for matching partitions, it's possible that your volume is already mounted with a drive letter, or it's unassigned. The first task is to find an unused drive letter, and mount $_.AccessPaths[0] if it's not a drive letter. After checking for the file, the volume can be unmounted.

hsehestedt · Nov 25, 2023

Thanks all for your comments. I won't get a chance to play with this more until this evening, but we'll see where we end up then.

pseymour · Nov 25, 2023

Just a little comment… you do not need a drive letter. I specifically did not use one in my sample. The DOS device paths work just fine.

example from the MS article I linked:
\\.\Volume{b75e2c83-0000-0000-0000-602f00000000}\Test\Foo.txt

garlin · Nov 25, 2023

After seeing @pseymour's advice, I managed to rework this into an one-liner. This still works if you have a drive letter assigned to either partition.

Original PS script:

Code:

Get-Disk | Where-Object { $_.PartitionStyle -eq 'MBR' } | ForEach-Object {
    $Part = Get-Partition -DiskNumber $_.DiskNumber -PartitionNumber 1
    if ($Part.MbrType -eq 0x0c -and (Test-Path -LiteralPath "$($Part.AccessPaths[-1])\VOL1_M_MEDIA.WIM")) {
        $Part | Set-Partition -MbrType 0x1c
    }

    $Part = Get-Partition -DiskNumber $_.DiskNumber -PartitionNumber 2
    if ($Part.MbrType -eq 0x07 -and (Test-Path -LiteralPath "$($Part.AccessPaths[-1])\VOL2_M_MEDIA.WIM")) {
        $Part | Set-Partition -MbrType 0x17
    }
 }

CMD one-liner:

Code:

powershell "Get-Disk | where {$_.PartitionStyle -eq 'MBR'} | foreach {$Part = Get-Partition -DiskNumber $_.DiskNumber -PartitionNumber 1; if ($Part.MbrType -eq 0x0c -and (Test-Path -LiteralPath """"$($Part.AccessPaths[-1])\VOL1_M_MEDIA.WIM"""")) {$Part | Set-Partition -MbrType 0x1c}; $Part = Get-Partition -DiskNumber $_.DiskNumber -PartitionNumber 2; if ($Part.MbrType -eq 0x07 -and (Test-Path -LiteralPath """"$($Part.AccessPaths[-1])\VOL2_M_MEDIA.WIM"""")) {$Part | Set-Partition -MbrType 0x17}}"

hdmi · Nov 26, 2023

Powershell:

Get-Disk |Get-Partition |? {"$($_.PartitionNumber) $($_.MbrType)" -in @('1 12','2 7')} |% {$p=$_;$_.AccessPaths |? {$_ -match '^\\\\\?\\Volume{'} |% {if (Test-Path -Path "$($_)VOL$($p.PartitionNumber)_M_MEDIA.WIM") {$m=$p.MbrType+16;Set-Partition -InputObject $p -MbrType $m}}}

LesFerch · Nov 26, 2023

Have you considered rewriting the entire script in PowerShell? That would eliminate the need to construct one-liners.

Try3 · Nov 26, 2023

Hannes,

Another way to avoid long, difficult-to-debug one-liners yet stay within your preferred scripting method is to echo each conventionally-laid-out line {such as is illustrated by garlin above} to a ps1 file then run that file.

I do it all the time in my batch files.
I echo commands into .vbs files then run the vbs
e.g.

:: Announcement
Set VBSScript="%TEMP%\%RANDOM%-WakeMonitor.vbs"
Echo WScript.CreateObject("WScript.Shell").SendKeys "{F14}">%VBSScript%
If %Completed% EQU 0 Echo CreateObject("SAPI.SPVoice").Speak "It's taking a bit longer than usual, but it should be ready soon.">>%VBSScript%
If %Completed% EQU 1 Echo CreateObject("SAPI.SPVoice").Speak "Transfer completed">>%VBSScript%
If %Completed% GTR 0 Echo CreateObject("SAPI.SPVoice").Speak "You can disconnect the bleedin thing now">>%VBSScript%
Call %VBSScript%
del %VBSScript%

And if I'm trying something new that does not behave as I expected, both the batch file creating the vbs and the vbs itself are decently laid out and can readily be debugged.

Your only significant difference would be that your Call line would be something like
Call PowerShell.exe %PSScript%
to avoid merely displaying the PS1 in a Notepad window.

All the best,
Denis

Griff79 · Nov 26, 2023

I'm not even gonna attempt to assist here coz i have no idea what's going on but I'm quite curious to see how it finally turns out and works

LesFerch · Nov 26, 2023

Try3 said:
Another way to avoid long, difficult-to-debug one-liners yet stay within your preferred scripting method is to echo each conventionally-laid-out line {such as is illustrated by garlin above} to a ps1 file then run that file.

Indeed that works, but it's ugly, adds complication (writing and executing a temp file), is more work to maintain, and doesn't play well with code-highlighting editors.

As a long time batch file writer, and someone that resisted PowerShell for a long time, I can say it's worth making the change. With ChatGPT's help, converting to PowerShell is much easier than it used to be.

hsehestedt · Nov 26, 2023

Thanks for all the advice. I still need to play with this, but in experimenting, I'm having more difficulties.

I want to run some of these commands in Windows PE. I have prepped Windows PE by adding powershell components into Windows PE. I can run Windows PE commands but get no output, not even an error message. For example, if I issue a "Get-Disk" I get no visible output at all.

LesFerch · Nov 26, 2023

hsehestedt said:
Thanks for all the advice. I still need to play with this, but in experimenting, I'm having more difficulties.

I want to run some of these commands in Windows PE. I have prepped Windows PE by adding powershell components into Windows PE. I can run Windows PE commands but get no output, not even an error message. For example, if I issue a "Get-Disk" I get no visible output at all.

Was this the guide you followed?

WinPE: Adding Windows PowerShell support to Windows PE

learn.microsoft.com

hsehestedt · Nov 26, 2023

LesFerch said:
Was this the guide you followed?

WinPE: Adding Windows PowerShell support to Windows PE

WinPE: Adding Windows PowerShell support to Windows PE

learn.microsoft.com

I believe so. It's something that I incorporated into a program of mine to automate the whole process and I did that probably well over a year ago, but I'm pretty sure that article was the source of the steps that I am taking.