Checking if the application is running in NSIS before uninstalling

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}