Command line options

[John R. Sowden]

I would like to have separate icons on my ubuntu 13.10 desktop to open 
different database in gc.  For example a demo database with all of my 
account numbers so I can try a transaction prior to entering it, an 
empty copy to start a new fiscal year, and separate copies for each 
fiscal years.  Where do I find the command line options to select a 
particular datafile?

John