How to pass command-line arguments to a PowerShell ps1 file

Question

For years, I have used the cmd/DOS/Windows shell and passed command-line arguments to batch files. For example, I have a file, zuzu.bat and in it, I access %1, %2, etc. Now, I want to do the same when I call a PowerShell script when I am in a Cmd.exe shell. I have a script, xuxu.ps1 (and I've added PS1 to my PATHEXT variable and associated PS1 files with PowerShell). But no matter what I do, I seem unable to get anything from the $args variable. It always has length 0.

If I am in a PowerShell shell, instead of cmd.exe, it works (of course). But I'm not yet comfortable enough to live in the PowerShell environment full time. I don't want to type powershell.exe -command xuxu.ps1 p1 p2 p3 p4. I want to type xuxu p1 p2 p3 p4.

Is this possible, and if so, how?

The sample I cannot get to work is trivial, foo.ps1:

Write-Host "Num Args:" $args.Length;
foreach ($arg in $args) {
    Write-Host "Arg: $arg";
}

The results are always like this:

C:\temp> foo
Num Args: 0
C:\temp> foo a b c d
Num Args: 0
c:\temp>

Byte

Answer 1

This article helps. In particular, this section:

-File

Runs the specified script in the local scope ("dot-sourced"), so that the functions and variables that the script creates are available in the current session. Enter the script file path and any parameters. File must be the last parameter in the command, because all characters typed after the File parameter name are interpreted as the script file path followed by the script parameters.

i.e.

powershell.exe -File "C:\myfile.ps1" arg1 arg2 arg3

means run the file myfile.ps1 and arg1 arg2 & arg3 are the parameters for the PowerShell script.

Pacifistic

This still doesn't help with what the op wants ("I want to type xuxu p1 p2 p3 p4"). – Superstition

but what about the gaps? if arg1 it's a path with space. – Ormiston

@AndreiKrasutski The escaping mechanism would depend on how the script is being executed. Since it's expressed as "powershell.exe" I would assume that this would be run in a CMD.EXE (Windows) shell. In that case, you can just put quotes around the path, in the same way that the "C:\myfile.ps1" is escaped. Following the same example: powershell.exe -File "C:\myfile.ps1" "arg1a arg1b" arg2 arg3 would return: Num Args: 3 Arg: arg1a arg1b \r\n Arg: arg2 \r\n Arg: arg3 (I can't put new lines in a comment) – Cchaddie

@BenKeene Unfortunately, -File breaks down when the arguments contain a space AND a trailing backslash. For example: powershell.exe -file "C:\myfile.ps1" "C:\F 1\" "C:\F 2\" returns: C:\F 1" C:\F \r\n 2" – Sweetmeat

Answer 2

After digging through the PowerShell documentation, I discovered some useful information about this issue. You can't use the $args if you used the param(...) at the beginning of your file; instead you will need to use $PSBoundParameters. I copy/pasted your code into a PowerShell script, and it worked as you'd expect in PowerShell version 2 (I am not sure what version you were on when you ran into this issue).

If you are using $PSBoundParameters (and this ONLY works if you are using param(...) at the beginning of your script), then it is not an array, it is a hash table, so you will need to reference it using the key / value pair.

param($p1, $p2, $p3, $p4)
$Script:args=""
write-host "Num Args: " $PSBoundParameters.Keys.Count
foreach ($key in $PSBoundParameters.keys) {
    $Script:args+= "`$$key=" + $PSBoundParameters["$key"] + "  "
}
write-host $Script:args

And when called with...

PS> ./foo.ps1 a b c d

The result is...

Num Args:  4
$p1=a  $p2=b  $p3=c  $p4=d

Cowley

This doesn't account for OP starting his command line with powershell.exe or pwsh. The behavior changes when OP does that. – Snakebite

@EricHansen I don't know what you mean, I get the same result either way: ` Powershell>powershell.exe .\ParamTest.ps1 val1 val2 val3 val4 Num Args: 4 $p1=val1 $p2=val2 $p3=val3 $p4=val4 ` – Cowley

@RandallBrock The behavior of the arguments changes for me. If I'm in CMD/batch, and I do something like pwsh .\ParamTest.ps1 -arg1 val1 -listOfArgs val2 val3 val4, it really doesn't like that. On the other hand, if I'm in PowerShell and do .\ParamTest.ps1 -arg1 val1 -listOfArgs val2 val3 val4, that works like I'd expect. I've heard that this is how it's intended to function due to "security reasons." – Snakebite

@EricHansen I wonder if it is a version thing. For me, pwsh launches 6.2.0, but powershell.exe launches 5.1.17134.858, both of which produce the same results listed: Powershell>pwsh .\ParamTest.ps1 val1 val2 val3 val4 yields: Num Args: 4 $p1=val1 $p2=val2 $p3=val3 $p4=val4 – Cowley

@EricHansen One other thing I notice in your comment is that you are passing 2 of your variables as named parameters for parameters that aren't named (if you're using my script). One interesting thing that happens is that arg1 and listOfArgs end up in the $args variable as -arg1 val1 -listofargs val2 and val3 and val4 end up in $p1 and $p2. Is this what you are referring to? – Cowley

I wasn't going off of your script. In my head, I was imagining arg1 as [string] and arg2 as [string[]]. Sorry if I'm dragging this too off topic. – Snakebite

I get: param : Die Benennung "param" wurde nicht als Name eines Cmdlet, einer Funktion, einer Skriptdatei oder eines ausführbaren Programms erkannt. . I call it on the ps terminal: greatstuff.ps1 argu1 – Mule

@Mule I don't know what you are doing exactly, but param is a language construct, however it must be the first thing in the file. Did you declare a variable or something else before it? More info here: learn.microsoft.com/en-us/powershell/module/… – Cowley

"I copy/pasted [OP's] code [without changes] into a PowerShell script, and it worked as you'd expect in PowerShell version 2" Ditto here. $args works fine in 2023 in Powershell ISE, so Powershell v5.1.22000.2003: .\args.ps1 asdf adsf gives Num Args: 2 Arg: asdf Arg: adsf – Bromate

Answer 3

OK, so first this is breaking a basic security feature in PowerShell. With that understanding, here is how you can do it:

1. Open an Windows Explorer window
2. Menu Tools -> Folder Options -> tab File Types
3. Find the PS1 file type and click the advanced button
4. Click the New button
5. For Action put: Open
6. For the Application put: "C:\WINNT\system32\WindowsPowerShell\v1.0\powershell.exe" "-file" "%1" %*

You may want to put a -NoProfile argument in there too depending on what your profile does.

Tokoloshe

I think the key is in your step 6 where you pass in the parameters to powershell.exe. Daniel says he has associated PS1 files with PowerShell but that doesn't pass arguments without the extra %1 %* specs. Also note that the -File parameter is not available in V1. It is new to V2. – Lennalennard

Good catch regarding the -file parameter I had forgotten that. – Tokoloshe

I'll have to install V2 before I can try your suggestion. Thanks. When you say this is breaking a basic security feature, what does "this" you mean? Calling a PowerShell script from Cmd.exe as though it were a .com/.bat/.exe file? Passing parameters to the script? – Nay

Sorry I should have been more clear. The calling the script without explicitly calling powershell.exe. I'm not saying it is a significant security feature for you personally and it is security through obscurity which I am not always a fan of anyway. – Tokoloshe

To add to EBGreen's comment, the basic security problem that PowerShell's tries to avoid is folks double-clicking on PS1 files attached to email and having the script run. That's why PS1 files are only associated with an editor by default. Microsoft really doesn't want a PowerShell version of the ILoveYou virus e.g. "LOVE-LETTER-FOR-YOU.TXT.ps1" – Lennalennard

what is the meaning of "%1" %* ? – Kubiak

I'm not sure I buy the security argument - for me Powershell is just .cmd on steroids so I'd expect the same out-of-the-box functionality as .bat/.cmd files (I'm essentially using Powershell where I would have used batch files before). – Bravado

Also, it looks like these instructions won't work on Windows 10 - but @ta32's answer using ftype should (but also don't work) – Bravado

Answer 4

You could declare your parameters in the file, like param:

[string]$param1
[string]$param2

And then call the PowerShell file like so .\temp.ps1 param1 param2....param10, etc.

Radiotelephone

Answer 5

Maybe you can wrap the PowerShell invocation in a .bat file like so:

rem ps.bat
@echo off
powershell.exe -command "%*"

If you then placed this file under a folder in your PATH, you could call PowerShell scripts like this:

ps foo 1 2 3

Quoting can get a little messy, though:

ps write-host """hello from cmd!""" -foregroundcolor green

Murderous

+1 for showing the triple quotes. that had me stuck for a while. – Counterchange

Just for completeness - regarding quoting (and passing tab chars & interoperability); if you have a 'SetTabEV.cmd' named Command Prompt script, to set a "Tab" named environment variable to be set to/have a value of a tab character - 'Set Tab= ', run the script, then you can also use it with 4 quotes; e.g. from the Command Prompt: ``` SetTab.cmd powershell MyScript.ps1 -dol """"1%Tab%Dennis%Tab%2047"""" ``` But only 3/triple-quoting is required if you use/pass the PowerShell tab character escape-sequence instead - 't': ``` powershell MyScript.ps1 -dol """1tDennis`t2047""" ``` – Continuant

Answer 6

You may not get "xuxu p1 p2 p3 p4" as it seems. But when you are in PowerShell and you set

PS > Set-ExecutionPolicy Unrestricted -Scope CurrentUser

You can run those scripts like this:

./xuxu p1 p2 p3 p4

or

.\xuxu p1 p2 p3 p4

or

./xuxu.ps1 p1 p2 p3 p4

I hope that makes you a bit more comfortable with PowerShell.

Kamala

Answer 7

if you want to invoke ps1 scripts from cmd and pass arguments without invoking the script like

powershell.exe script.ps1 -c test
script -c test ( wont work )

you can do the following

setx PATHEXT "%PATHEXT%;.PS1;" /m
assoc .ps1=Microsoft.PowerShellScript.1
ftype Microsoft.PowerShellScript.1=powershell.exe "%1" %*

This is assuming powershell.exe is in your path

https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/ftype

Lodge

Worth noting that this requires running the cmd prompt as Administrator. Also, I am struggling to actually make it work on Windows 10 version 1903 (18362.778) - all commands run successfully but the arguments still don't get passed in. I think wrapping with a .bat file is the most portable solution. – Bravado

Answer 8

I wanted to automate the "Unblocking" of files downloaded from the internet in Windows, so I got my .ps1 file working, but when I wanted to make it as a "right-click" menu option, it never worked despite trying all possible combinations (passing params to cmd alone, then to powershell alone and to ps1, using single/double quotes, etc) !

After struggling for some hours, I was able to make it work by using both cmd and powershell in the same command like this :

cmd.exe /c start powershell "C:\folder\script.ps1 -folder '%1'"

where folder is a parameter referring to the right-clicked folder, and here is the ps1 file is someone is interested :

param (
    [string]$folder = "$env:userprofile\Downloads"
    #defaults to the current user Downloads folder
)
# Remove Recurse if you don't want to unblock inner folders
get-childitem "$folder" -Recurse | unblock-file

You can then make a .reg file to add this as a right-click option to unblock all files at once :

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\UnblockDL]
@="Unblock DL Files"

[HKEY_CLASSES_ROOT\Directory\shell\UnblockDL\command]
@="cmd.exe /c start powershell \"C:\\folder\\script.ps1 -folder '%1'\""

Remember to adjust "C:\folder\script.ps1" to your own ps1 file, and make sure its name/path don't contain any spaces (don't ask me why !).

Lap