#!/bin/bash

dmenu_lines=8

declare -A selections

for file in /tmp/clipmenu/*; do
    first_line=$(sed -n '1{p;q}' "$file")

    lines=$(wc -l "$file")
    lines=${lines%% *}

    if (( lines > 1 )); then
        first_line+=" ($lines lines)"
    fi

    selections[$first_line]=$file
done

printf '%s\n' "${!selections[@]}" | dmenu -l "$dmenu_lines"