clipmenu-spmenu/clipmenu

#!/bin/bash

major_version=3

shopt -s nullglob

cache_dir=/tmp/clipmenu.$major_version.$USER
cache_file=$cache_dir/line_cache

# It's okay to hardcode `-l 8` here as a sensible default without checking
# whether `-l` is also in "$@", because the way that dmenu works allows a later
# argument to override an earlier one. That is, if the user passes in `-l`, our
# one will be ignored.
chosen_line=$(tac "$cache_file" | awk '!seen[$0]++' | dmenu -l 8 "$@")

[[ $chosen_line ]] || exit 1

file=$cache_dir/$(cksum <<< "$chosen_line")

if ! [[ -f "$file" ]]; then
    # We didn't find this in cache
    printf 'FATAL: %s not in cache\n' "$chosen_line" >&2
    exit 2
fi

for selection in clipboard primary; do
    xsel --logfile /dev/stderr -i --"$selection" < "$file"
done