#!/usr/bin/env bash
trap 'kill -TERM 0' EXIT

read s <<< "$1"
files=(/var/irclogs/_esoteric/????-??-??.txt)
line=

for i in "${!files[@]}"
do {
	file="${files[${#files[@]} - i - 1]}"
	while read -r t n m
	do [[ $n =~ $s ]] && line="$t $n $m"
	done <"$file"
} & done

wait

[[ -n "$line" ]] \
	&& { printf '%s:%s\n' "${file##*/}" "$line"; exit;} \
	|| echo 'well, not lately'