Problems with variables when trying to log output

Question

I'm currently working on a batch file, which runs several commands, reads values from text files, etc. The problem I'm facing is that I cannot set variables properly.

The following code snippet demonstrates my problem:

>> %userprofile%\AppData\Local\Temp\test.log 2>&1 (
    echo ### Fetching language...
    powershell -c "(Get-UICulture).Parent.Name" > lang.txt
    set /p LANG=<lang.txt
    echo Your language = %LANG%
)

Output:

### Fetching language...
Your language =

If remove the line >> %userprofile%\AppData\Local\Temp\test.log 2>&1 everything works fine, but the output is not written to a file.

What do I miss here?

Thank you so far!

Answer 1

Your %LANG%-Var is evaluated when the interpreter sees the opening bracket in your first line. This can be disabled this way:

SETLOCAL ENABLEDELAYEDEXPANSION
>> %userprofile%\AppData\Local\Temp\test.log 2>&1 (
  echo ### Fetching language...
  powershell -c "(Get-UICulture).Parent.Name" > lang.txt
  set /p LANG=<lang.txt
  echo Your language = !LANG!
  )