FOCUS(9)FOCUS(9)NAMEfocus - change or query keyboard focusSYNOPSISfocus ?what?
DESCRIPTION
With no arguments, focus returns the name of the widget to which key‐
board events are currently delivered, known as the keyboard focus.
When given an argument, focus changes the keyboard focus. If what is
the name of a widget, that widget will be made the keyboard focus. If
what is next, the keyboard focus will be changed to the next item in
the focus order for that window. If what is previous, the keyboard
focus will be changed to the previous item in the focus order for that
window. The focus order is determined automatically by Tk.
FOCUS(9)