How to set environment variables in vbs that can be read in calling batch script

Question

I have a batch file that calls a vbscript file. I am trying to have the vbscript file change an environment variable that is later used in the batch file that calls the vbsc

Answer 1

You can't. A process can pass environment variables to child processes, but not to its parent - and in this case the parent is cmd.exe, which is running your Parent.bat file.

There are of course other ways to communicate information back to the parent batch file - outputting to stdout or a file is an obvious way, e.g.

== Child.vbs ===
WScript.echo "New Value"

== Parent.cmd ===
for /f "tokens=*" %%i in ('cscript //nologo child.vbs') do set Value=%%i
echo %Value%