Check if an environment variable is defined without command extensions and without using a batch file?

Question

I need to use a cmd.exe command line (cmd.exe is being called from the gyp build tool) to determine whether an environment variable is defined or not. How can I do this? I

Answer 1

I tried this and it worked:

@echo off

setlocal disableextensions

set x=%path%
if "%x%"=="" (echo "PATH" does not exist) else (echo "PATH" exists)

set x=%pathx%
if "%x%"=="" (echo "PATHX" does not exist) else (echo "PATHX" exists)

endlocal

It returned:

"PATH" exists
"PATHX" does not exist