For CDL netlisting, you would create an si.env file, similar to that produced from the GUI, and then run:
si -batch -command netlist
(optionally you can pass the run dir at the end).
There's coverage of this in http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:ViewSolution;solutionNumber=11005433
For generating stream files, you can use "strmout". Type "strmout -help" for more detail.