Returns the current actual width of the widget called window. Note that this is not necessarily what the widget wants it to be — see winfo reqwidth for that — especially when the widget is first created (the actual width starts as a dummy value because there's no actual window there to start out with) but there can be disconnects for other reasons, such as geometry managers or window managers imposing changes for reasons of overall layout or user preference.
During most of the lifetime of window, this command reports the value that was provided in the last <Configure> event sent to the window.