code: def reference_viewer(sys_argv):
      
      viewer = ReferenceViewer(layout=default_layout)
      viewer.add_default_plugins()
      viewer.add_separately_distributed_plugins()
  
      # Parse command line options with optparse module
      from optparse import OptionParser
  
      usage = "usage: %prog [options] cmd [args]"
      optprs = OptionParser(usage=usage,
                            version=('%%prog %s' % version.version))
      viewer.add_default_options(optprs)
  
      (options, args) = optprs.parse_args(sys_argv[1:])
  
      if options.display:
          os.environ['DISPLAY'] = options.display
  
      # Are we debugging this?
      if options.debug:
          import pdb
  
          pdb.run('viewer.main(options, args)')
  
      # Are we profiling this?
      elif options.profile:
          import profile
  
          print(("%s profile:" % sys_argv[0]))
          profile.run('viewer.main(options, args)')
  
      else:
          viewer.main(options, args)
docs: Create reference viewer from command line.