Information about The Tk toolkit
Tk is a graphical toolkit for Tcl. It allows you to develop graphical applications that run on Windows, Linux, MacOSX and many other platforms. Tk stands for "toolkit".
As is well known, most Tcl distributions provide two interpreters, tclsh and wish. The main differences between these are that wish automatically starts Tk and on Windows doesn't pop up a DOS console window ([puts] commands to standard output just don't go anywhere). Until recently, for technical reasons using wish had to be the only way to get at Tk. However, in later versions by [using Tk as a loadable package you can use it via tclsh and still have full console access on all platforms.
Many other languages have Tk packages; some of which work by loading all of Tcl in and then executing Tk commands. Perl/Tk, on the other hand, rewrote all of Tk in a way that wasn't bound to Tcl, for example. See Tcl and other languages.
see Tk Package
tk is also the name of a Tk command. See:
http://www.tcl.tk/man/tcl/TkCmd/tk.htm
Tk has an Xlib Emulation Layer XLEL, which is one part in making Tk work across different platforms.
That there is such a level is an important reason why Tk generation when X11 headers are missing can be an issue: the Tk source uses X11 headers even when Tk at runtime uses some other windowing system.
double-buffering examples; ...]
RS 2013-10-08 - I just spent some time debugging an app where, mysteriously, switches disappeared from the command line (argv). Turned out that Tk snatched them away. Demonstrations in an interactive tclsh:
% set argv {-c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7}
-c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7
% package require Tk
this isn't a Tk applicationwindow "6" doesn't exist
% set argv
5The Tk options are documented:
-colormap new -display display -geometry geometry -name name -sync -use id -visual visual --
and a 1-character match is sufficient to take them away (the "5" remained because the -s option does not take an argument). Solution, if you don't want to use any of the Tk options: insert the protective -- at the beginning of argv:
% set argv {-c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7}
-c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7
% set argv [linsert $argv 0 --]
-- -c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7
% package require Tk
8.4
% set argv
-c 1 -d 2 -g 3 -n 4 -s 5 -u 6 -v 7Martyn Smith - The other choice is to protect the argv variable contents before running the package require that way the end user does not need any special action.
Has anyone been thinking adding a tutorial for Tk into the Tk source code distribution, similar in concept to the Tcl tutorial being added in Tcl 8.5?
DKF: Thinking? Yes. Doing anything about it? No. A set of lessons for Tk would be a very welcome addition!
[Things to explain: Bryan Schofield's posting on multiple Tk interpreters;
[Insert here pointers and discussions regarding Tk features]