

          commandloop [prompt] [prompt2]
               Create an interactive command loop for the current TCL
               interpreter.  This command receives commands from stdin
               and executes them.  It is useful TCL scripts that do
               not normally converse interactively with a user through
               a Tcl command interpreter, but which sometimes want to
               enter this mode.

               Prompt is a Tcl command string that is evaluated to
               determine the text of the prompt string.  Prompt2 is a
               command string that is evaluated to determine the
               ``downlevel prompt'', which is the prompt which is
               issued for continuation input.  When the command
               terminates, the variables for the prompt hooks will be
               set to their old value.  If these arguments are not
               specified, the prompt hooks use their current value.
               Prompt hooks are TCL code that return as their result
               the prompt to output.  The result of the last command
               executed in the command string (which may be a return)
               will be used as the prompt.
