#! /bin/sh

tmpfile="$(mktemp /tmp/st-cmd-output.XXXXXX)"
trap 'rm "$tmpfile"' 0 1 15
sed -n "w $tmpfile"
sed -i 's/\x0//g' "$tmpfile"
data="$(tac "$tmpfile")"
[ ! -z "$data" ] && printf '%s' "$data" | dmenu -i -l 15 -p 'Select Line' \
                                        | xargs \
                                        | xclip -r -sel c