Provided by: tk8.6-doc_8.6.13-2_all bug

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. 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 disabled when there is a startup script and stdin is /dev/null (as is the  case
       e.g. when a bundled application embedding Tk is started by the macOS Launcher).  To enable
       the command in that case, define the environment variable TK_CONSOLE.  This can be done by
       modifying the Info.plist file by adding the LSEnvironment key to the main dict and setting
       its value to be a dict with the key TK_CONSOLE.

       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(3tk),   fconfigure(3tcl),   history(3tcl),  interp(3tcl),  puts(3tcl),  text(3tk),
       wm(3tk)

KEYWORDS

       console, interpreter, window, interactive, output channels