set-window-scroll-bars

set-window-scroll-bars is a built-in function in `C source code'.

(set-window-scroll-bars WINDOW &optional WIDTH VERTICAL-TYPE HEIGHT HORIZONTAL-TYPE)

Set width and type of scroll bars of window WINDOW.
WINDOW must be a live window and defaults to the selected one.

Second parameter WIDTH specifies the pixel width for the vertical scroll
bar. If WIDTH is nil, use the scroll-bar width of WINDOW's frame.
Third parameter VERTICAL-TYPE specifies the type of the vertical scroll
bar: left, right, or nil. If VERTICAL-TYPE is t, this means use the
frame's scroll-bar type.

Fourth parameter HEIGHT specifies the pixel height for the horizontal
scroll bar. If HEIGHT is nil, use the scroll-bar height of WINDOW's
frame. Fifth parameter HORIZONTAL-TYPE specifies the type of the
horizontal scroll bar: nil, bottom, or t. If HORIZONTAL-TYPE is t, this
means to use the frame's horizontal scroll-bar type.

Return t if scroll bars were actually changed and nil otherwise.