Detecting TCC and Take Command

From a batch file, you can determine if TCC is loaded by testing for the variable function @EVAL, with a test like this:

if "%@eval[2 + 2]%" == "4" echo Take Command is loaded!

This test can never succeed in CMD.EXE. (Other variable functions could also be used for the same purpose.)

You can determine if TCC is running in a Take Command tab window with the internal variable _TCTAB:

if %_tctab == 1 echo TCC is running in a Take Command tab window!