Windows – How to append to the user %PATH% from command line

batchenvironment-variableswindows

I found plenty of questions like this one on StackExchange but no one work in my specific case.

I would like to easily add literally %FOO% to the user environment variable PATH.

I found the solution below. Unfortunately it doesn't work as expected. 

for /f "skip=2 tokens=3*" %a in ('reg query HKCU\Environment /v PATH') do @if [%b]==[] ( @setx PATH "%~a;%FOO%" ) else ( @setx PATH "%~a %~b;%FOO%" )

It doesn't work if:

  • The user PATH variable doesn't exist
  • The user PATH exists and is empty
  • The user PATH is almost 255 char long.

Moreover it doesn't add the %FOO% literally but expands it.

Is there any possibility to easily do it?

Best Answer

It depends on what you're trying to do:

  • To update the PATH in your current commandline session only, use: set PATH=%PATH%;%FOO%.
  • To edit it for the current user only, use: setx PATH "%PATH%;%FOO%". Note that this change is not visible in your current command line session; you need to start a new command line.
  • To edit it for all users on the machine, use: setx /M PATH "%PATH%;%FOO%".

You can view the path by typing ECHO %PATH% in a command line or by checking it in the Windows environment settings.

Also, in Windows 7 and 8, the maximum environment variable string size is 32,767 characters. Although this is also valid for the PATH variable, a command in command console has a maximum length of 8191 characters, so you need to take that into consideration when using the PATH variable in command line commands. Anyhow, you have some more head-space above the 256 characters you have right now.

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