console(n)                   Tk Built-In Commands                   console(n)



______________________________________________________________________________

NAME
       console - Control the console on systems without a real console

SYNOPSIS
       console subcommand ?arg ...?
______________________________________________________________________________

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. Except
       for TkAqua, this command is not available when Tk is loaded into a
       tclsh interpreter with "package require Tk", as a conventional terminal
       is expected to be present in that case.  In TkAqua, this command is
       only available when stdin is /dev/null (as is the case e.g. when the
       application embedding Tk is started from the Mac OS X Finder).

       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
              deiconifying 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
              interpreter.

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::ConsoleExit 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}

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

KEYWORDS
       console, interpreter, window, interactive, output channels



Tk                                    8.4                           console(n)
