console(n) Tk Built-In Commands console(n)
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NAME
console - Control the console on systems without a real console
SYNOPSIS
console title ?string?
console hide
console show
console eval script
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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 inter-preter interpreter
preter 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 charac-ter character
ter 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.
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)
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