Checking if the application is running in NSIS before uninstalling - nsis

Question

I am new to NSIS, and I need to know that in the uninstaller, how I can check if the application (which is in C++) is running and close it before uninstalling.

Answer 1

Here is a slightly more friendly version for using NSProcess that requests the app to close rather than terminates it (Owen's answer)
${nsProcess::FindProcess} "${APP_EXE}" $R0
${If} $R0 == 0
DetailPrint "${AppName} is running. Closing it down"
${nsProcess::CloseProcess} "${APP_EXE}" $R0
DetailPrint "Waiting for ${AppName} to close"
Sleep 2000
${Else}
DetailPrint "${APP_EXE} was not found to be running"
${EndIf}
${nsProcess::Unload}

Answer 2

Use the NsProcess plugin. Download it here -> NSProcess
How to use it? As simple as:
${nsProcess::KillProcess} "${APP_EXE}" $R4
where APP_EXE is the name of your application...
The download will also tell you how to use it... :)

Answer 3

Depending on the application, you have a couple of choices:
If your application has a window with a somewhat unique class name, you could use FindWindow
If your application creates a named kernel object (Mutex etc) you can check for it by calling the correct native win32 API with the system plugin
Use a 3rd party plugin like FindProcDLL

Answer 4

Just make sure that the first thing that install or un-install does is to delete all xyz.tmp files in %TEMP (or any other app writable directory) before the below for loop runs. No plugins required.
!macro IsRunning
ExecWait "cmd /c for /f $\"tokens=1,2$\" %i in ('tasklist') do (if /i %i EQU xyz.exe fsutil file createnew $TEMP\xyz.tmp 0)"
IfFileExists $TEMP\xyz.tmp 0 notRunning
;we have atleast one main window active
MessageBox MB_OK|MB_ICONEXCLAMATION "XYZ is running. Please close all instances and retry." /SD IDOK
Abort
notRunning:
!macroEnd