This will open the given file in ULSViewer
(You can omit the -file: and if the file exists, it will still work)
This will open the real-time ULS tracing in a tab in the ULSViewer window.
This will make ULSViewer monitor a specific path for real-time ULS tracing.
Running UlsViewer.exe without parameters will show the ULSViewer UI.