console(n)

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NAME

       console - Control the console on systems without a real console

SYNOPSIS

       console subcommand ?arg ...?
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DESCRIPTION

       The  console  window is a replacement for a real console to allow input
       and output on the standard I/O channels on platforms that do not have a
       real  console.  It is implemented as a separate interpreter with the Tk
       toolkit loaded, and control over this interpreter is given through  the
       console command.  The behaviour of the console window is defined mainly
       through the contents of the console.tcl file in the Tk library (or  the
       Console resource on Macintosh systems.)

       console eval script
              Evaluate  the  script  argument  as  a Tcl script in the console
              interpreter.  The normal interpreter  is  accessed  through  the
              consoleinterp command in the console interpreter.

       console hide
              Hide  the  console  window  from  view.  Precisely equivalent to
              withdrawing the . window in the console interpreter.

       console show
              Display the console window.  Precisely equivalent to  deiconify-
              ing the . window in the console interpreter.

       console title ?string?
              Query  or  modify the title of the console window.  If string is
              not specified, queries the title of the console window, and sets
              the  title of the console window to string otherwise.  Precisely
              equivalent to using the wm title command in the  console  inter-
              preter.

ACCESS TO THE MAIN INTERPRETER

       The  consoleinterp command in the console interpreter allows scripts to
       be evaluated in the main interpreter.   It  supports  two  subcommands:
       eval and record.

       consoleinterp eval script
              Evaluates script as a Tcl script at the global level in the main
              interpreter.

       consoleinterp record script
              Records and evaluates script as a Tcl script at the global level
              in  the  main  interpreter as if script had been typed in at the
              console.

ADDITIONAL TRAP CALLS

       There are several additional commands in the console  interpreter  that
       are  called in response to activity in the main interpreter.  These are
       documented here for completeness only; they form part of  the  internal
       implementation  of  the console and are likely to change or be modified
       without warning.

       Output to the console from the main  interpreter  via  the  stdout  and
       stderr channels is handled by invoking the tk::ConsoleOutput command in
       the console interpreter with two arguments.  The first argument is  the
       name  of  the  channel being written to, and the second argument is the
       string being written to the channel  (after  encoding  and  end-of-line
       translation processing has been performed.)

       When  the  .  window of the main interpreter is destroyed, the tk::Con-
       soleExit command in the console interpreter  is  called  (assuming  the
       console interpreter has not already been deleted itself, that is.)

DEFAULT BINDINGS

       The  default  script creates a console window (implemented using a text
       widget) that has the following behaviour:

       [1]    Pressing the tab key inserts a TAB character (as defined by  the
              Tcl \t escape.)

       [2]    Pressing  the return key causes the current line (if complete by
              the rules of info complete) to be passed to the main interpreter
              for evaluation.

       [3]    Pressing  the  delete key deletes the selected text (if any text
              is selected) or the character to the right of the cursor (if not
              at the end of the line.)

       [4]    Pressing  the  backspace  key  deletes the selected text (if any
              text is selected) or the character to the left of the cursor (of
              not at the start of the line.)

       [5]    Pressing  either  Control+A or the home key causes the cursor to
              go to the start of the line (but after the prompt, if  a  prompt
              is present on the line.)

       [6]    Pressing either Control+E or the end key causes the cursor to go
              to the end of the line.

       [7]    Pressing either Control+P or the  up  key  causes  the  previous
              entry in the command history to be selected.

       [8]    Pressing  either Control+N or the down key causes the next entry
              in the command history to be selected.

       [9]    Pressing either Control+B or the left key causes the  cursor  to
              move  one character backward as long as the cursor is not at the
              prompt.

       [10]   Pressing either Control+F or the right key causes the cursor  to
              move one character forward.

       [11]   Pressing  F9  rebuilds  the console window by destroying all its
              children and reloading the Tcl script that defined the console's
              behaviour.

       Most  other  behaviour is the same as a conventional text widget except
       for the way that the  <<Cut>>  event  is  handled  identically  to  the
       <<Copy>> event.

EXAMPLE

       Not all platforms have the console command, so debugging code often has
       the following code fragment in it so output produced  by  puts  can  be
       seen while during development:
              catch {console show}

KEYWORDS

       console, interpreter, window, interactive, output channels

SEE ALSO

       destroy(n),  fconfigure(n),  history(n),  interp(n),  puts(n), text(n),
       wm(n)

Tk                                    8.4                           console(n)