Sometimes you want a .cmd wrapper for your PowerShell script. Usually for me this is so people who aren’t familiar with the command line can double-click to execute the script.

This batch file should be saved alongside your PowerShell script, like so.

.\
 |- my_script.ps1
 |- my_script.cmd

my_script.cmd will execute the same named .ps1 file in the same directory, so my_script.ps1 in this case. Any arguments passed to my_script.cmd will pass-through to the PowerShell script.

@ECHO OFF

SET SCRIPTNAME=%~d0%~p0%~n0.ps1
SET ARGS=%*
IF [%ARGS%] NEQ [] GOTO ESCAPE_ARGS

:POWERSHELL
PowerShell.exe -NoProfile -NonInteractive -NoLogo -ExecutionPolicy Unrestricted -Command "& { $ErrorActionPreference = 'Stop'; & '%SCRIPTNAME%' @args; EXIT $LASTEXITCODE }" %ARGS%
EXIT /B %ERRORLEVEL%

:ESCAPE_ARGS
SET ARGS=%ARGS:"=\"%
SET ARGS=%ARGS:`=``%
SET ARGS=%ARGS:'=`'%
SET ARGS=%ARGS:$=`$%
SET ARGS=%ARGS:{=`}%
SET ARGS=%ARGS:}=`}%
SET ARGS=%ARGS:(=`(%
SET ARGS=%ARGS:)=`)%
SET ARGS=%ARGS:,=`,%
SET ARGS=%ARGS:^%=%

GOTO POWERSHELL

What’s going on here?

• %SCRIPTNAME% variable holds the name of the PowerShell script to execute. %~d0%~p0%~n0 magic gets the full path of the current batch script without the file extension. By specifying the full path of the PowerShell script like this we can guarantee that it is always executed from the right place no matter what your working directory is.
• Escapes special characters in the arguments so that they are passed to PowerShell as you would expect.
• Runs PowerShell.exe with:
  • -NoProfile to improve startup performance. Scripts you are distributing shouldn’t rely on anything in your profile anyway.
  • -NonInteractive because usually my scripts don’t need input from the user.
  • -ExecutionPolicy Unrestricted to ensure that the PowerShell script can be executed regardless of the machine’s default Execution Policy.
  • -Command syntax for executing the command ensures that PowerShell returns the correct exit code from your script. Using -Command with $ErrorActionPreference = 'Stop' also ensures that errors thrown from your script cause PowerShell.exe to return a failing exit code (1). PowerShell is quite buggy when it comes to bubbling exit codes. This is the safest method I’ve found.

Batch file tips

Special characters in arguments

Remember that certain special characters need to be escaped in arguments passed to the batch file. These characters are: ^ & < > /?. Note that /? is a sequence and is recognized as a help flag when passed to a batch file.

my_script.cmd "I ""am"" quoted" passes a single argument I "am" quoted to PowerShell.

my_script.cmd "^&<>/?" passes ^&<>/?

Environment variable expansion

Environment variables get automatically expanded in batch file arguments.

my_script.cmd %PROGRAMFILES% passes C:\Program Files