itk widget

option add *TextDisplay.wrap none widgetDefault
option add *TextDisplay.textBackground ivory widgetDefault
option add *TextDisplay.width 40 widgetDefault
option add *TextDisplay.height 10 widgetDefault

class TextDisplay {
    inherit itk::Widget

    constructor {args} {
        itk_component add text {
            text $itk_interior.info -state disabled
                -yscrollcommand [code $itk_interior.sbar set]
        } {
            usual
            keep -tabs -wrap -width -height
            rename -background -textbackground textBackground Background
        }
        pack $itk_component(text) -side left -expand yes -fill both

        itk_component add scrollbar {
            scrollbar $itk_interior.sbar
                -command [code $itk_interior.info yview]
        }
        pack $itk_component(scrollbar) -side right -fill y

        eval itk_initialize $args
    }

    public method display {info}
    public method append {info}
}

body TextDisplay::display {info} {
    $itk_component(text) configure -state normal
    $itk_component(text) delete 1.0 end
    $itk_component(text) insert 1.0 $info
    $itk_component(text) configure -state disabled
}

body TextDisplay::append {info} {
    $itk_component(text) configure -state normal
    $itk_component(text) insert end $info
    $itk_component(text) configure -state disabled
}

usual TextDisplay {
    keep -background -cursor -foreground -font
    keep -activebackground -activerelief
    keep -highlightcolor -highlightthickness
    keep -insertbackground -insertborderwidth -insertwidth
    keep -insertontime -insertofftime
    keep -selectbackground -selectborderwidth -selectforeground
    keep -textbackground -troughcolor
}

#
# EXAMPLE:  Display the /etc/passwd file
#
TextDisplay .file -background red
pack .file

.file display [exec cat /etc/passwd]