Here's a simple command line example that might be appropriate for a small design:
% calibre -spice layout.spi rules > log
For a larger design you might want to use something like this instead:
% calibre -turbo -hyper -spice layout.spi rules > log
Assuming the rule file "rules" in the examples above contained the necessary statements for path to the layout database and name of the primary cell in the layout etc. the job should run in batch mode while you end up with a log file called "log" and a layout netlist called "layout.spi".