#!/usr/bin/env bash
trap 'kill -TERM 0' EXIT
read s <<< "$1"; files=(/var/irclogs/_esoteric/????-??-??.txt)
for i in "${!files[@]}"; do line=; file="${files[${#files[@]} - i]}"
while read -r t n m; do [[ $n =~ $s ]] && line="$t $n $m"; done <"$file"
[[ -n "$line" ]] && { printf '%s:%s\n' "${file##*/}" "$line"; exit;}; done
echo 'well, not lately'