wish8.4
Simple windowing shell
Synopsis
wish
?fileName arg arg ...?
add an example, a script, a trick and tips
examples
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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
no arguments, or with a first argument that starts with
’’-’’, then it 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 wish
is invoked with an initial fileName argument, 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.
options
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.
keywords
shell, toolkit
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 isn’t yet complete; if
tcl_prompt2 isn’t set then no prompt is output for
incomplete commands.
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’s
installed somewhere else then you’ll 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
doesn’t 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.
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 don’t 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.