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%

Answer 2

yes, you can.... however, you'll have to resetvars in your session. see the following link:

Is there a command to refresh environment variables from the command prompt in Windows?

'RESETVARS.vbs

Set oShell = WScript.CreateObject("WScript.Shell")
filename = oShell.ExpandEnvironmentStrings("%TEMP%\resetvars.bat")
Set objFileSystem = CreateObject("Scripting.fileSystemObject")
Set oFile = objFileSystem.CreateTextFile(filename, TRUE)

set oEnv=oShell.Environment("System")
for each sitem in oEnv 
    oFile.WriteLine("SET " & sitem)
next
path = oEnv("PATH")

set oEnv=oShell.Environment("User")
for each sitem in oEnv 
    oFile.WriteLine("SET " & sitem)
next

path = path & ";" & oEnv("PATH")
oFile.WriteLine("SET PATH=" & path)
oFile.Close

This is how I did it:

SET oShell = CREATEOBJECT("Wscript.Shell") 
dim varSet
SET varSet = NOTHING 

  SET varSet = oShell.Environment("SYSTEM") 
  varSet("WinVer") = "6.0.2008"

Then in a separate VB script (resetvars.vbs) I called from CMD script:

cscript //nologo \\%APPSERVER%\apps\IE9.0\restartvars.vbs   
call %TEMP%\resetvars.bat

Answer 3

Ho about this:

@echo off
set vbsFile=%temp%\createguid.vbs
call :CreateVbs
call :GetGuid NewGuid
echo.%NewGuid%
del %vbsFile%>nul
GOTO:EOF

:CreateVbs
echo.set obj = CreateObject("Scriptlet.TypeLib")>%vbsFile%  
echo.WScript.StdOut.WriteLine obj.GUID>>%vbsFile% 
GOTO:EOF

:GetGuid
for /f "tokens=*" %%i in ('cscript //nologo %vbsFile%') do set %1=%%i
GOTO:EOF

It is not pure batch script but works ok.

Answer 4

@echo off&color 4a&title %~n0&AT>NUL
IF %ERRORLEVEL% EQU 0 (
    goto 2
) ELSE (
    echo.
)
if not "%minimized%"=="" goto 1
set minimized=true & start /min cmd /C "%~dpnx0"&cls&exit
:1
wmic process where name="cmd.exe" CALL setpriority "realtime">nul&echo set shell=CreateObject("Shell.Application") > %~n0.vbs&echo shell.ShellExecute "%~dpnx0",,"%CD%", "runas", 1 >> %~n0.vbs&echo set shell=nothing >> %~n0.vbs&start %~n0.vbs /realtime&timeout 1 /NOBREAK>nul& del /Q %~n0.vbs&cls&exit
:2
echo %~dpnx0 admin mode look up&wmic process where name="cmd.exe" CALL setpriority "realtime"&timeout 3 /NOBREAK>nul
:3
echo x=msgbox("end of line" ,48, "%~n0") > %~n0.vbs&start %~n0.vbs /realtime&timeout 1 /NOBREAK>nul& del /Q %~n0.vbs&cls&exit

Answer 5

I don't think you can do this. At least, you would need to mess with the environment block in the calling process, and there's no guarantee that it will respect this...