su: ignore --preserve-environment, it's mutually exclusive to --login.
Error in parse(file, keep.source = FALSE, srcfile = src, encoding = enc) : 
  /home/czv146/ShinyApps/apptest/app.R:6:1: unexpected ')'
5: shiny::shinyAppDir(system.file("apps/RMDitemfit", package = "RASCHplot"), options = list(launch.browser = FALSE))
6: )
   ^
Possible unmatched ')' at:
6:)
  ^
Error in sourceUTF8(fullpath, envir = new.env(parent = sharedEnv)) : 
  Error sourcing /home/czv146/ShinyApps/apptest/app.R
Calls: runApp ... shinyAppDir -> shinyAppDir_appR -> appObj -> func -> sourceUTF8
Execution halted