Tk Library Procedures - Tk

Tk_Init is the package initialization procedure for Tk. It is normally invoked by the Tcl_AppInit procedure for an application or by the load command. Tk_Init adds all of Tk's commands to interp and creates a new Tk application, including its main window. If the initialization is successful Tk_Init returns TCL_OK; if there is an error it returns TCL_ERROR. Tk_Init also leaves a result or error message in interp->result.

If there is a variable argv in interp, Tk_Init treats the contents of this variable as a list of options for the new Tk application. The options may have any of the forms documented for the wish application (in fact, wish uses Tk_Init to process its command-line arguments).

Tk_SafeInit is identical to Tk_Init except that it removes all Tk commands that are considered unsafe. Those commands and the reasons for their exclusion are:

bell: Continuous ringing of the bell is a nuisance.
clipboard: A malicious script could replace the contents of the clipboard with the string "rm -r *" and lead to surprises when the contents of the clipboard are pasted.
grab: Grab can be used to block the user from using any other applications.
menu: Menus can be used to cover the entire screen and to steal input from the user.
selection: See clipboard.
send: Send can be used to cause unsafe interpreters to execute commands.
tk: The tk command recreates the send command, which is unsafe.
tkwait: Tkwait can block the containing process forever
toplevel: Toplevels can be used to cover the entire screen and to steal input from the user.
wm: If toplevels are ever allowed, wm can be used to remove decorations, move windows around, etc.

KEYWORDS

safe, application, initialization, load, main window

Copyright © 1995-1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.