Fadjerx
14th January 2010 14:35 UTC

Set environnement variable problem
  Hello friends,

I have the need to create an environnement variable for my app. I went to the following link and I did exactly what is described in paragraph "Your own variable". It works fine, and the varibale is really created after installation.

http://nsis.sourceforge.net/Setting_...es_Permanently

Now I propose to the user to launch the program after installation finished :
+ If the user choose to launch the program later it continues to work fine, and my added variable is well recognised
+ But if the user choose to launch the program immediately after installation finished it does not work ! :-( I don't khnow why ?

Here is snippet of the code I use to propose launching after installation (found on NSIS site too):

.

.

.

!define MUI_FINISHPAGE_RUN

>!define MUI_FINISHPAGE_RUN_TEXT "Start $(^Name)"

>!define MUI_FINISHPAGE_RUN_FUNCTION "LaunchLink"

>.

.

.

Function LaunchLink

  ExecShell "" "$SMPROGRAMS\$StartMenuGroup\MyApp.lnk"

>FunctionEnd 

>

Thanks in advance for your help.

demiller9
14th January 2010 19:00 UTC

You should also do the piece of code that sets the variable temporarily (call the API Kernel32::SetEnvironmentVariableA as shown in the wiki you found). The permanent change loads the variables when the user starts the app from Explorer. The installer's variables are used when NSIS starts a process.

Fadjerx
15th January 2010 09:09 UTC

Hi demiller9,

Thanks a lot it works fine !

This is a summary who to do to add an environment variable permanently, while to be able to launch application immediately after installation finished :

# To add a environment var permanently

"winmessages.nsh"

>!define env_hklm 'HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"'

>!define env_hkcu 'HKCU "Environment"'    

>WriteRegExpandStr ${env_hklm} MY_VAR MY_VAR_VALUE

SendMessage${HWND_BROADCAST} ${WM_WININICHANGE} 0 "STR:Environment" /TIMEOUT=10000 

>

# To launch app aftrer install

.

.

.

!define MUI_FINISHPAGE_RUN

>!define MUI_FINISHPAGE_RUN_TEXT "Start $(^Name)"

>!define MUI_FINISHPAGE_RUN_FUNCTION "LaunchLink"

>.

.

.


Function LaunchLink

    System::Call 'Kernel32::SetEnvironmentVariableA(t, t) i("MY_VAR", "MY_VAR_VALUE").r0'

   StrCmp $0 0 error

    ExecWait ProgThatReadsEnv.exe

    Goto done

    error:

   MessageBox MB_OK "Can't set environment variable"

   done:

   ExecShell "" "$SMPROGRAMS\$StartMenuGroup\MyApp.lnk"

>FunctionEnd 

>

Good luck to you.