       1mcommandloop  22m?1m-async22m?  ?1m-interactive  on  |  off  | tty22m? ?1m-prompt1 4m22mcmd24m?
       ?1m-prompt2 4m22mcmd24m? ?1m-endcommand 4m22mcmd24m?

              Create an interactive command loop reading commands  from  stdin
              and  writing  results to stdout.  Command loops are maybe either
              be blocking or event oriented.  This command is useful  for  Tcl
              scripts  that do not normally converse interactively with a user
              through a Tcl command interpreter, but which sometimes  want  to
              enter  this  mode,  perhaps for debugging or user configuration.
              The command loop terminates on EOF.

              The following options are available:

              1m-async 22mA command handler will be associated  with  stdin.   When
                     input  is available on stdin, it will be read and accumu-
                     lated until a full command is  available.   That  command
                     will  then  be  evaluated.  An event loop must be entered
                     for input to be read and processed.

              1m-interactive on | off | tty0m
                     Enable or disable interactive command mode.  In  interac-
                     tive  mode,  commands are prompted for and the results of
                     comments are printed.  The value maybe any boolean  value
                     or  1mtty22m.   If 1mtty 22mis used, interactive mode is enabled if
                     stdin is associated with a terminal or terminal emulator.
                     The default is 1mtty22m.

              1m-prompt1 4m22mcmd0m
                     If  specified,  4mcmd24m   is  used is evaluate and its result
                     used for the main command prompt.  If not specified,  the
                     command in 1mtcl_prompt1 22mis evaluated to output the prompt.
                     Note the difference in behavior,  4mcmd24m  results  is  used,
                     while  1mtcl_prompt1  22moutputs.  This is to allow for future
                     expansion to command loops that write to other than  std-
                     out.

              1m-prompt2 4m22mcmd0m
                     If specified, 4mcmd24m is used is evaluate and its result used
                     for the secondary (continuation) command prompt.  If  not
                     specified,  the  command  in  1mtcl_prompt2 22mis evaluated to
                     output the prompt.

              1m-endcommand 4m22mcmd0m
                     If specified, 4mcmd24m is evaluated when the command loop ter-
                     minates.

                     In interactive mode, the results of set commands with two
                     arguments are not printed.

                     If 1mSIGINT 22mis configured to generate a Tcl error,  it  can
                     be  used to delete the current command being type without
                     aborting the program in progress.
