PowerShell: opening a file in default txt editor

Question

I am trying to find a way to open a non-txt file (in this case, the hosts file) in the default text editor using PowerShell.

I made some progress after seeing this Reddit post, but the $txt_editor result always returns Notepad.exe, even though Notepad++ is my default editor for txt files.

$hosts_file = "$env:windir\System32\drivers\etc\hosts"
$txt_editor = ((Get-ItemProperty -Path 'Registry::HKEY_CLASSES_ROOT\txtfile\shell\open\command').'(Default)').trimend(" %1")
Start-Process -FilePath $txt_editor -Verb Runas -ArgumentList $hosts_file

This also returns Notepad.exe:

(Get-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.txt\OpenWithList' -Name a).a

If I look at the above location in Registry Editor, I do see Notepad++ listed with the key d, but I don't know how to tell from only looking at a Registry key what the default text editor is, because the two solutions I saw in Reddit do not work.

I am using Windows 10, and the solution I am looking for will return the actual default text editor file location, so that it can be used to open a file as shown above.

This question still has not received an answer to my actual question, since the only answer doesn't show how to open a non-txt file using the configured default text file editor.

Update: I'm now trying to replicate this on Windows 11, and the registry key HKEY_CLASSES_ROOT\txtfile\shell\open\command doesn't exist. I need a solution that will include a solution for this aspect as well, if the registry is involved. I configured Notepad++ as the default, and a key was created at HKEY_CLASSES_ROOT\txtfilelegacy\shell\printto\command.

Techno

assuming notepad++ allows such thing (notepad.exe allows to pass a path as argument), you can simply do: & (Get-ItemProperty -Path 'HKCU:\.....' -Name a).a C:\Windows\System32\drivers\etc\hosts – Litalitany

What is a default text editor? Is it the program that is used to open filenames that end with .txt? – Name

@Name Yes, it's not a default text editor, it's the default text editor, meaning the program configured to open .txt files on Windows when the file is double-clicked. For me, that's Notepad++. You can find them in Settings > Apps > Default apps > Choose defaults by file type. – Techno

Answer 1

Using the information in @FoxDeploy's answer, I was able to construct a working PowerShell function.

function Edit-HostsFile {
    # Self-elevate if required
    if (-Not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] 'Administrator')) {
        if ([int](Get-CimInstance -Class Win32_OperatingSystem | Select-Object -ExpandProperty BuildNumber) -ge 6000) {
            $hosts_file = "$env:windir\System32\drivers\etc\hosts"
            # Get the configured application default for editing .txt files.
            $txt_app = ((Get-ItemProperty -Path Registry::HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.txt\UserChoice -Name ProgId).ProgId)
            $txt_editor = ((Get-ItemProperty -Path Registry::HKEY_CLASSES_ROOT\$($txt_app)\shell\open\command).'(Default)').replace(' "%1"', '')
            # Open the hosts file in the editor.
            Start-Process -FilePath $txt_editor -Verb Runas -ArgumentList $hosts_file
        }
    }
}

I hadn't gotten a working solution using the information in the answer when I tried a few years ago, but I was able to figure it out after trying again. A more complete solution with code would have been helpful, but it didn't take too long to create.

Techno

Answer 2

The Start command (which is an alias for Start-Process) will launch any file in its default editor.

start .\MyCoolbmp.bmp
#Opens in MSPaint

start .\SomeNotes.txt
#Opens in Notepad

start .\SomeJason.json
#Opens in Visual Studio, go ahead and grab a coffee...

If I had to guess why yours isn't working, it's that the registry key you gave is the one used for the system, while the user's default editor is stored, from Windows 7 and up, within the HKEY_CURRENT_USER hive instead, at this path Windows\CurrentVersion\Explorer\FileExts\.txt\UserChoice'.

Here's the pertinent values:

$txtKey = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.txt\UserChoice"
Get-ItemProperty -Path $txtKey | tee-object -variable txtPath

Hash         : noCJnt8yX5Y=
ProgId       : VSCode.txt

This ties over to info found within HKCR:\Applications, where the true path can be found.

get-itemproperty Registry::\HKEY_CLASSES_ROOT\$($txtPath.ProgId)\shell\open\command


(default)    : "C:\Program Files\Microsoft VS Code\Code.exe" "%1"
#...

If you grab that (Default) value, now you've got the true path for the editor associated with text files.

To read a bit more on the topic, this blog post is pretty good and goes in detail into how associations work.

Nixie

Just a note that Start is an alias for the Start-Process command. You might also want to look at the Invoke-Item command. – Melancholy

@MikeShepard It looks like Invoke-Item uses the default action when invoking an item, but I don't want to open the extension-less hosts file using the default action, because that wouldn't be to open in a text editor. – Techno

Does this answer not solve your ask? It shows you how to open a file with the users text editor, regardless of the file extension – Nixie

@Techno - that makes sense. Just thought I'd point out a similar command. – Melancholy

@Nixie No, it doesn't work. Try running it yourself to a file with no extension. I want to open a NON-TXT file with the default txt editor. start C:\Windows\System32\drivers\etc\hosts will ask the user to select a program. – Techno

@Nixie I was able to create a working solution finally using the info in your answer. I have awarded you the bounty. – Techno

Answer 3

Beginning with Windows 8, you will find your file type associations in the registry at HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\<FILE_TYPE>\UserChoice. There you will find a ProgId. Get it:

$ProgId = Get-ItemPropertyValue -Path HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.txt\UserChoice -Name ProgId

With the ProgId you can look for the shell command in HKCR:

$Command = Get-ItemPropertyValue -Path Registry::HKEY_CLASSES_ROOT\$ProgId\shell\open\command -Name '(Default)'

In the command, replace %1 by your text file, e. g.:

$Command = $Command -replace '%1', 'C:\Windows\System32\drivers\etc\hosts'

You can then execute the command:

cmd /c $Command

This works with notepad++.exe.

---

Be aware, that not all programs directly register with a shell command. Some (like notepad.exe (no ++)) have a DelegateExecute value that contains a GUID. Afaik, you have to look that up by querying a DLL. As a workaround, you may still be able to guess the shell command by just appending the path of the text file. So, you could use the following logic to get your shell command:

$textfile = 'C:\Windows\System32\drivers\etc\hosts'
if ($Command.Contains('%1')) {
  $Command = $Command -replace '%1', $textfile
} else {
  $Command += " `"$textfile`""
}

You can then execute the command:

cmd /c $Command

This will at least work for notepad++.exe and for notepad.exe.

Name

8 mins too late I guess... – Name

Still, thanks very much for the work and your answer. I'm sure it can be helpful for other users who view this question as well. – Techno