How can I refresh the PATH environment variable in a Batch script

Question

I have a batch file "file.bat" that will call an installer with the following command:

msiexec.exe /i "%~dp0\installer.msi"

The installer will install a program and update the Path variable. While this works fine, the problem is when I try to start the program it's not found because apparently the PATH variable was not updated. I tried restarting the batch file from within itself with:

start cmd /c file.bat 

but it didn't work. Is there a way to refresh the PATH variable or maybe restart the batch file in a new process so that it detects the new environment?

PS: restarting the batch file manually works of course but it's not what I want.

Thanks.

Solution 1

Easiest way, use Chocolatey (freeare). Then you will be able to reload PATH (with variable expansion) with a simple command:

refreshenv

Installation from cmd (requires admin rights):

@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"

Example usage:

> SET JAVA_HOME=c:/java/jdk6
> SET PATH=%JAVA_HOME%/bin
> ECHO %PATH%
c:/java/jdk6/bin

> SET JAVA_HOME=c:/java/jdk8
> refreshenv
Refreshing environment variables from registry for cmd.exe. Please wait...Finished..
> echo %PATH%
c:/java/jdk8/bin

Solution 2

IN Windows PowerShell exit and run again

Solution 3

simple batch file that refreshes the %path% environment variable:

@echo off
echo.
echo Refreshing PATH from registry

:: Get System PATH
for /f "tokens=3*" %%A in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /v Path') do set syspath=%%A%%B

:: Get User Path
for /f "tokens=3*" %%A in ('reg query "HKCU\Environment" /v Path') do set userpath=%%A%%B

:: Set Refreshed Path
set PATH=%userpath%;%syspath%

echo Refreshed PATH
echo %PATH%

Comments

[jfajunior]

It is a good answer J03L, but the problem is when I set path like this: JAVA_7 = C:\Program Files\Java\jdk1.7xxxx JAVA_8 = C:\Program Files\Java\jdk1.8xxxx JAVA_HOME = %JAVA_8% Path = %JAVA_HOME%\bin;%MAVEN_HOME%\bin Because this will generate a PATH with %JAVA_8%\bin;C:\windows\System32\WindowsPowerShell\v1.0\;C:\‌​windows\idmu\common;‌​etc. Do you think it's possible to change the batch file to generate a second level variable substituion on user variables? Just curious, still a nice answer tho!

[script'n'code]

For some reason, not all spaces in a path are preserved (i.e. the original path shows 'Program Files (x86)', but the set variable shows 'ProgramFiles (x86)' ).