set scrollback_ratio

Synopsis

/set scrollback_ratio [<percent>]

Default: 50. With no value, set displays the current value. Negative and nonnumeric values are rejected.

Description

Determines what percentage of a window's display height to move when scrolling backward or forward by the default amount. It applies to the scroll_backward and scroll_forward bindings and to window scroll_backward and window scroll_forward when they request the default distance.

For each action, EPIC clamps the effective percentage to 1 through 100, multiplies it by that window's display height, and divides by 100 with integer truncation. The resulting distance is at least one display row. For example, 50 moves ten rows in a twenty-row window, or ten rows in a twenty-one-row window.

Zero and values above 100 can remain stored: the clamp is applied when scrolling, without changing the setting. Zero therefore behaves like one percent, subject to the one-row minimum. This does not disable scrolling.

Scope

This is a global percentage read for each action, so differently sized windows move different distances. A window command with a nonzero explicit line count uses that count rather than this ratio. Movement stops at the available history boundaries; the calculated distance does not guarantee that many rows remain to traverse.

The setting does not control automatic scrolling when new output fills a window; see scroll_lines. It also does not change scrollback retention, hold-mode advancement, or start/end navigation. Changing it affects future actions and does not immediately move any window.

Example

/set scrollback_ratio 75
/window scroll_backward

In a twenty-row window, the default backward action requests fifteen rows. Use /set scrollback_ratio 50 to restore half-window movement.

Source references

• source/vars.c and include/config.h: integer registration and default 50.
• source/window.c: window_scrollback_backward and window_scrollback_forward clamp the percentage and calculate rows; window commands distinguish default and explicit counts; line movement stops at history boundaries.
• source/keys.c: registers the forward and backward scroll bindings.