- Update to version 0.40.0:
- Added `zero` event that is triggered when there's no match
```sh
# Reload the candidate list when there's no match
echo $RANDOM | fzf --bind 'zero:reload(echo $RANDOM)+clear-query' --height 3
```
- New actions
- Added `track` action which makes fzf track the current item when the
search result is updated. If the user manually moves the cursor, or the
item is not in the updated search result, tracking is automatically
disabled. Tracking is useful when you want to see the surrounding items
by deleting the query string.
```sh
# Narrow down the list with a query, point to a command,
# and hit CTRL-T to see its surrounding commands.
export FZF_CTRL_R_OPTS="
--preview 'echo {}' --preview-window up:3:hidden:wrap
--bind 'ctrl-/:toggle-preview'
--bind 'ctrl-t:track+clear-query'
--bind 'ctrl-y:execute-silent(echo -n {2..} | pbcopy)+abort'
--color header:italic
--header 'Press CTRL-Y to copy command into clipboard'"
```
- Added `change-header(...)`
- Added `transform-header(...)`
- Added `toggle-track` action
- Fixed `--track` behavior when used with `--tac`
- However, using `--track` with `--tac` is not recommended. The resulting
behavior can be very confusing.
- Bug fixes and improvements