Trying to launch powershell script from .bat file and get a value returned

Question

Using information I found here, I am still unable to get this to work.

I have created the following .bat file, to call the PowerShell script on Windows 10 Professional.

for /f "delims=" %%a in ('powershell.exe -executionpolicy remotesigned ".\dang.ps1"') do (set "$crap=%%a")
powershell.exe .\dang.ps1
echo %$crap%

You will notice that it calls the PowerShell script two different ways.

This is the PowerShell script which is being launched from the batch file.

$crap="Pain in my butt"
return $crap

The strange thing is about this. When the batch file tries to launch the PowerShell script from the for /f loop, I receive the following error message:

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again." )

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=At line:1 char:1" )

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=+ .\dang.ps1

:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=+ ~~~~~~~~~~~" )

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=    + CategoryInfo          : ObjectNotFound: (.\dang.ps1String) [], CommandNotFoundException" )

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap=    + FullyQualifiedErrorId : CommandNotFoundException" )

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>(set "$crap= " )

BUT, when I launch the same PowerShell script, (see last line of batch file), without using the for /f, it has no problem executing the script.

C:\Users\pgmrd\My Drive\DLSR Notes and backup\Software\Scripts>powershell.exe .\dang.ps1
Pain in my butt

The scripts I typed are very stripped down so that I could concentrate on making it work. BUT, the final batch file runs some backups. Will launch the PowerShell script to read a xml file and return a file path. Then use that file path in the rest of the backup batch file.

Answer 1

:: Note the use of -File
for /f "delims=" %%a in ('powershell.exe -executionpolicy remotesigned -File ".\dang.ps1"') do set "$crap=%%a"

Use the -File parameter of powershell.exe, the Windows PowerShell CLI, when invoking a script file (.ps1), which ensures that:

• script file paths with spaces are correctly recognized
• all subsequent arguments are passed through to the script without additional interpretation (except possibly by the calling shell).

Note that pwsh, the PowerShell (Core) 7+ CLI, now defaults to -File, whereas powershell.exe defaults to -Command, which is what happened in your case.

• Passing a "..."-enclosed .ps1 script path to -Command is not enough, because unescaped " chars. are stripped before PowerShell interprets the resulting argument(s) as PowerShell code - see this answer for details.