How do I open the "Open with" GUI from console command on Windows?

Question

On Windows, if you right click a file in explorer, you get a context menu. One of the entries is Open With > Choose another program. Clicking this opens a GUI to choose a program to open the file. Is it possible to open this GUI from the command line?

Typically, all you would really need to do is point to the location of the program, followed by the path of whatever you want to open. So something like: `notepad.exe c:\file.txt`, or using `Start-Process` (*or just `start`*): `Start-Process "C:\VS Code\Code.exe" "c:\useres\abe\dt\file.ps1"`. You can also do the same with the *invocation* / *call* operator (`&`). — Abraham Zinala, Jan 02 '22 at 02:34
I am using obsidian.md to manage notes and am interested in having a context menu in the app that can open the "Open with" dialog. The easiest way to do it would be with a command line call. It would allow me to open the same file with different programs as convenient. — Jonathan Seaman, Jan 02 '22 at 07:56
This reads like the problem you are trying to solve the what you have asked for aren't the same thing. This is commonly known as the [XY Problem](http://xyproblem.info). — IInspectable, Jan 02 '22 at 09:14

zett42 · Accepted Answer · 2022-01-02T12:06:00.593

There is a shell API for this purpose that can be used from PowerShell using P/Invoke. This is more reliable than the often suggested but undocumented "RunDll32.exe OpenAs_RunDLL" method (see this answer for details why it is bad).

Save this code as "openas.ps1":

param (
    [Parameter(Mandatory)]
    [String] $Path
)

$ErrorActionPreference = 'Stop'

Add-Type -TypeDefinition @'

    using System;
    using System.Runtime.InteropServices;

    public class ShellOpenWith {

        [DllImport("shell32.dll", EntryPoint = "SHOpenWithDialog", CharSet = CharSet.Unicode)]
        private static extern int SHOpenWithDialog(IntPtr hWndParent, ref tagOPENASINFO oOAI);

        // http://msdn.microsoft.com/en-us/library/windows/desktop/bb773363(v=vs.85).aspx
        private struct tagOPENASINFO
        {
            [MarshalAs(UnmanagedType.LPWStr)]
            public string cszFile;

            [MarshalAs(UnmanagedType.LPWStr)]
            public string cszClass;

            [MarshalAs(UnmanagedType.I4)]
            public tagOPEN_AS_INFO_FLAGS oaifInFlags;
        }

        [Flags]
        private enum tagOPEN_AS_INFO_FLAGS
        {
            OAIF_ALLOW_REGISTRATION =  0x00000001,   // Show "Always" checkbox
            OAIF_REGISTER_EXT =    0x00000002,   // Perform registration when user hits OK
            OAIF_EXEC =        0x00000004,   // Exec file after registering
            OAIF_FORCE_REGISTRATION =  0x00000008,   // Force the checkbox to be registration
            OAIF_HIDE_REGISTRATION =   0x00000020,   // Vista+: Hide the "always use this file" checkbox
            OAIF_URL_PROTOCOL =    0x00000040,   // Vista+: cszFile is actually a URI scheme; show handlers for that scheme
            OAIF_FILE_IS_URI =     0x00000080    // Win8+: The location pointed to by the pcszFile parameter is given as a URI
        }

        public static void DoOpenFileWith(string sFilename, IntPtr hwndParent = new IntPtr())
        {
            tagOPENASINFO oOAI = new tagOPENASINFO();
            oOAI.cszFile = sFilename;
            oOAI.cszClass = String.Empty;
            oOAI.oaifInFlags = tagOPEN_AS_INFO_FLAGS.OAIF_ALLOW_REGISTRATION | tagOPEN_AS_INFO_FLAGS.OAIF_EXEC;
            SHOpenWithDialog(hwndParent, ref oOAI);
        }    
    }
'@

[ShellOpenWith]::DoOpenFileWith( $path )

Run this script from the commandline like this:

powershell.exe c:\openas.ps1 c:\file.txt

@SleepyBag From the [docs](https://learn.microsoft.com/en-us/windows/win32/api/shlobj_core/nf-shlobj_core-shopenwithdialog): _"Starting in Windows 10, the OAIF_ALLOW_REGISTRATION, OAIF_FORCE_REGISTRATION, and OAIF_HIDE_REGISTRATION flags will be ignored by SHOpenWithDialog. The Open With dialog box can no longer be used to change the default program used to open a file extension. You can only use SHOpenWithDialog to open a single file."_ — zett42, Feb 06 '23 at 12:09
@SleepyBag An alternative might be `Start-Process -Verb openas -FilePath MyFileName`. I have noticed a strange behavior though: After setting the default application for a completely new file extension ".foo42" by selecting "Run Always", calling `Start-Process` a 2nd time fails with error "The specified file does not have an associated application." — zett42, Feb 06 '23 at 22:05

How do I open the "Open with" GUI from console command on Windows?

1 Answers1