The bars command controls the tics at the ends of error bars.
Syntax:
set bars {small | large | fullwidth | <size>} {front | back}
unset bars
show bars
`small` is a synonym for 0.0, and `large` for 1.0. The default is 1.0 if no size is given.
The keyword `fullwidth` is relevant only to histograms with errorbars. It sets the width of the errorbar ends to be the same as the width of the associated box in the histogram. It does not change the width of the box itself.
The `front` and `back` keywords are relevant only to errorbars attached to filled rectangles (boxes, candlesticks, histograms).