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

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.

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: " $PSBoundParameters.Keys.Countforeach ($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

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.