fzf --height 50% --style full:line --preview 'cat {}' \
    --bind 'focus:bg-transform-header(file {})+bg-transform-footer(wc {})'

seq 10000 | fzf --preview "awk '{sum += \$1} END {print sum}' {*f}"

• Use this with caution, as it can make fzf sluggish for large lists.

# Implement popup that disappears after 1 second
#   * Use footer as the popup
#   * Use `bell` to ring the terminal bell
#   * Use `bg-transform-footer` to clear the footer after 1 second
#   * Use `bg-cancel` to cancel currently running background transform actions
fzf --multi --list-border \
    --bind 'enter:execute-silent(echo -n {+} | pbcopy)+bell' \
    --bind 'enter:+transform-footer(echo Copied {} to clipboard)' \
    --bind 'enter:+bg-cancel+bg-transform-footer(sleep 1)'

# It's okay for the commands to take a little while because they run in the background
GETTER='curl -s http://metaphorpsum.com/sentences/1'
fzf --style full --border --preview : \
    --bind "focus:bg-transform-header:$GETTER" \
    --bind "focus:+bg-transform-footer:$GETTER" \
    --bind "focus:+bg-transform-border-label:$GETTER" \
    --bind "focus:+bg-transform-preview-label:$GETTER" \
    --bind "focus:+bg-transform-input-label:$GETTER" \
    --bind "focus:+bg-transform-list-label:$GETTER" \
    --bind "focus:+bg-transform-header-label:$GETTER" \
    --bind "focus:+bg-transform-footer-label:$GETTER" \
    --bind "focus:+bg-transform-ghost:$GETTER" \
    --bind "focus:+bg-transform-prompt:$GETTER"

for i in $(seq 16 255); do
  echo -e "\x1b[48;5;${i}m\x1b[0Khello"
done | fzf --ansi