Open a command file with Windows PowerShell running it directly

• PowerShell script files, across all versions, use the .ps1 filename extension.

• From within PowerShell, you can invoke them directly, e.g., .\script.ps1

  • Note that, unlike in cmd.exe, you must use .\ (or a full path) in order to execute a file located in the current directory - just script.ps1 won't work - see this answer for background information.

• From cmd.exe, you must use PowerShell's CLI (powershell.exe in Windows PowerShell / pwsh in PowerShell [Core] v6+) in order to execute a script file:

  • powershell.exe -File script.ps1
  • pwsh -File script.ps1 (-File may be omitted)

Note that with -File the .\-prefix is not required.

However, if you use -Command (-c) instead (which is the default with powershell.exe, whereas pwsh now defaults to -File), you do need the .\, because the -Command argument(s) are interpreted as a piece of PowerShell code, i.e. as if you had submitted it inside a PowerShell session.

You've discovered this in your own answer, where you pass a PowerShell command directly to the (implied) -Command parameter.

Note, however, that it's better to double-quote such commands, so as to prevent cmd.exe from interpreting certain characters itself, which breaks the call.

For instance, the following call would break, if you didn't enclose the -Command (-c) argument in "...":

# From cmd.exe; "..." required.
C:\>powershell.exe -c "Write-Output 'a & b'"
a & b

Another important consideration is that you need to escape embedded " chars. as \" for the CLI (even though PowerShell-internally you would use `" or ""):

# From cmd.exe; note the inner " escaped as \"
C:\>powershell.exe -c "Write-Output \"hi there\""
hi there