Subcommand of [wm] to query or set the title of a toplevel window. For editor-like apps, it is convenient to put the current file name into the title bar: wm title $w $filename or, combined with the app name (Windows look & feel): wm title $w "$filename - $appname" You can even retrieve the filename from there with [regexp], avoiding a [global] variable: regexp "(.+) - $appname" [wm title $w] -> filename ;# RS ---- [Tk syntax help] - [Category Command]