wish

Section: Tk Applications (1)
Updated: 8.0
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NAME

wish - Simple windowing shell

SYNOPSIS

wish ?-encoding name? ?fileName arg arg ...?

OPTIONS

-encoding name

Specifies the encoding of the text stored in fileName. This option is only recognized prior to the fileName argument.

-colormap new

Specifies that the window should have a new private colormap instead of using the default colormap for the screen.

-display display

Display (and screen) on which to display window.

-geometry geometry

Initial geometry to use for window. If this option is specified, its value is stored in the geometry global variable of the application's Tcl interpreter.

-name name

Use name as the title to be displayed in the window, and as the name of the interpreter for send commands.

-sync

Execute all X server commands synchronously, so that errors are reported immediately. This will result in much slower execution, but it is useful for debugging.

-use id

Specifies that the main window for the application is to be embedded in the window whose identifier is id, instead of being created as an independent toplevel window. Id must be specified in the same way as the value for the -use option for toplevel widgets (i.e. it has a form like that returned by the winfo id command).

: Note that on some platforms this will only work correctly if id refers to a Tk frame or toplevel that has its -container option enabled.

-visual visual

Specifies the visual to use for the window. Visual may have any of the forms supported by the Tk_GetVisual procedure.

--

Pass all remaining arguments through to the script's argv variable without interpreting them. This provides a mechanism for passing arguments such as -name to a script instead of having wish interpret them.

DESCRIPTION

Wish is a simple program consisting of the Tcl command language, the Tk toolkit, and a main program that reads commands from standard input or from a file. It creates a main window and then processes Tcl commands. If wish is invoked with arguments, then the first few arguments, ?-encoding name? ?fileName? specify the name of a script file, and, optionally, the encoding of the text data stored in that script file. A value for fileName is recognized if the appropriate argument does not start with ``-''.

If there are no arguments, or the arguments do not specify a fileName, then wish reads Tcl commands interactively from standard input. It will continue processing commands until all windows have been deleted or until end-of-file is reached on standard input. If there exists a file ``.wishrc'' in the home directory of the user, wish evaluates the file as a Tcl script just before reading the first command from standard input.

If arguments to wish do specify a fileName, then fileName is treated as the name of a script file. Wish will evaluate the script in fileName (which presumably creates a user interface), then it will respond to events until all windows have been deleted. Commands will not be read from standard input. There is no automatic evaluation of ``.wishrc'' when the name of a script file is presented on the wish command line, but the script file can always source it if desired.

Note that on Windows, the wishversion.exe program varies from the tclshversion.exe program in an additional important way: it does not connect to a standard Windows console and is instead a windowed program. Because of this, it additionally provides access to its own console command.

OPTION PROCESSING

Wish automatically processes all of the command-line options described in the OPTIONS summary above. Any other command-line arguments besides these are passed through to the application using the argc and argv variables described later.

APPLICATION NAME AND CLASS

The name of the application, which is used for purposes such as send commands, is taken from the -name option, if it is specified; otherwise it is taken from fileName, if it is specified, or from the command name by which wish was invoked. In the last two cases, if the name contains a ``/'' character, then only the characters after the last slash are used as the application name.

The class of the application, which is used for purposes such as specifying options with a RESOURCE_MANAGER property or .Xdefaults file, is the same as its name except that the first letter is capitalized.

VARIABLES

Wish sets the following Tcl variables:

argc: Contains a count of the number of arg arguments (0 if none), not including the options described above.
argv: Contains a Tcl list whose elements are the arg arguments that follow a -- option or do not match any of the options described in OPTIONS above, in order, or an empty string if there are no such arguments.
argv0: Contains fileName if it was specified. Otherwise, contains the name by which wish was invoked.
geometry: If the -geometry option is specified, wish copies its value into this variable. If the variable still exists after fileName has been evaluated, wish uses the value of the variable in a wm geometry command to set the main window's geometry.
tcl_interactive: Contains 1 if wish is reading commands interactively (fileName was not specified and standard input is a terminal-like device), 0 otherwise.

SCRIPT FILES

If you create a Tcl script in a file whose first line is


#!/usr/local/bin/wish

then you can invoke the script file directly from your shell if you mark it as executable. This assumes that wish has been installed in the default location in /usr/local/bin; if it is installed somewhere else then you will have to modify the above line to match. Many UNIX systems do not allow the #! line to exceed about 30 characters in length, so be sure that the wish executable can be accessed with a short file name.

An even better approach is to start your script files with the following three lines:


#!/bin/sh
# the next line restarts using wish \
exec wish "$0" "$@"

This approach has three advantages over the approach in the previous paragraph. First, the location of the wish binary does not have to be hard-wired into the script: it can be anywhere in your shell search path. Second, it gets around the 30-character file name limit in the previous approach. Third, this approach will work even if wish is itself a shell script (this is done on some systems in order to handle multiple architectures or operating systems: the wish script selects one of several binaries to run). The three lines cause both sh and wish to process the script, but the exec is only executed by sh. sh processes the script first; it treats the second line as a comment and executes the third line. The exec statement cause the shell to stop processing and instead to start up wish to reprocess the entire script. When wish starts up, it treats all three lines as comments, since the backslash at the end of the second line causes the third line to be treated as part of the comment on the second line.

The end of a script file may be marked either by the physical end of the medium, or by the character, ``\032'' (``\u001a'', control-Z). If this character is present in the file, the wish application will read text up to but not including the character. An application that requires this character in the file may encode it as ``\032'', ``\x1a'', or ``\u001a''; or may generate it by use of commands such as format or binary.

PROMPTS

When wish is invoked interactively it normally prompts for each command with ``% ''. You can change the prompt by setting the variables tcl_prompt1 and tcl_prompt2. If variable tcl_prompt1 exists then it must consist of a Tcl script to output a prompt; instead of outputting a prompt wish will evaluate the script in tcl_prompt1. The variable tcl_prompt2 is used in a similar way when a newline is typed but the current command is not yet complete; if tcl_prompt2 is not set then no prompt is output for incomplete commands.

KEYWORDS

shell, toolkit