Task, parameter summary
-note, the example given is for a tool method but the same principles 
should apply for tasks

CASA [1]: task im.setdata
Out  [1]: "im.setdata"
CASA [2]: inp            # displays the current state
                         # for a fresh session this will just be the defaults
 -- im.setdata -- 
  mode      = velocity
  nchan     = [ 1 ]
  start     = [ 0 ]
  step      = [ 1 ]
  mstart    = { value=0.0, units=km/s }
  mstep     = { value=0.0, units=km/s }
  spwid     = [ 0 ]
  fieldid   = [ 0 ]
  msselect
  async     = false
----------------------------------------
CASA [3]: nchan = 40     # change an argument in the active task/method
CASA [4]: inp 
 -- im.setdata -- 
  mode      = velocity
  nchan     = [ 40 ]     # reflects user override
  start     = [ 0 ]
  step      = [ 1 ]
  mstart    = { value=0.0, units=km/s }
  mstep     = { value=0.0, units=km/s }
  spwid     = [ 0 ]
  fieldid   = [ 0 ]
  msselect
  async     = false
----------------------------------------
CASA [5]: go             # execute task with current parameter state
CASA [6]: save           # defaults to im.setdata.def (ascii file of key=value
                         # pairs)
Out  [6]: True           # True if successful (could write the file)
alternatively:
CASA [6]: save filename  # appends .def to filename
or:
CASA [6]: save directory_path/filename 

CASA [7]: restore im.setdata # retrieves information from state file/db
Out  [7]: True           # True if it found the file and restored the state
or:
CASA [7]: restore im.setdata default # restores to package defaults
Out  [7]: True
also:
CASA [7]: restore        # will restore all files with a .def in current dir
and:
CASA [7]: restore defaults # recover to base/default for all tasks/tools

--new session

CASA [1]: task im.setdata
Out  [1]: "im.setdata"
CASA [2]: inp
 -- im.setdata --
  mode      = velocity
  nchan     = [ 1 ]     
  start     = [ 0 ]
  step      = [ 1 ]
  mstart    = { value=0.0, units=km/s }
  mstep     = { value=0.0, units=km/s }
  spwid     = [ 0 ]
  fieldid   = [ 0 ]
  msselect
  async     = false
----------------------------------------
CASA [3]: restore im.setdata #finds im.setdata.def in local directory
Out  [3]: True
CASA [2]: inp
 -- im.setdata --
  mode      = velocity
  nchan     = [ 40 ]	# restores to modified defaults
  start     = [ 0 ]
  step      = [ 1 ]
  mstart    = { value=0.0, units=km/s }
  mstep     = { value=0.0, units=km/s }
  spwid     = [ 0 ]
  fieldid   = [ 0 ]
  msselect
  async     = false
----------------------------------------
CASA [4]: task		# resets to no task
Out  [4]: True
CASA [5]: inp           # no task selected so complain
No task selected
Out  [5]: False