As described above, all widget classes have a widget command named configure. This command gives the user access to the widget resources. Usually, widgets have resources like: foreground, background, font, etc.. To set a specific resource, the Tcl
command representing the widget is called, followed by the configure widget command. Then follows the resource name. Resource names begin with a ``-''. Behind the resource name, the new value is specified. If no new value is specified, the current value of the resource is returned.
Some widgets (like buttons) have resources that allow it to bind functionality to them. The resources have names like -command, -xscrollcommand etc.. These resources contain Tcl scripts which are evaluated when the command is activated (for example when a button is pressed).
.b1 configure -command {puts stdout exit}
.b1 configure -foreground red