<oerjan> learn print_args_or_input Is a utility command that makes it easy to create a shell script that can be used either as a pipe or directly as a HackEgo command. Use as print_args_or_input "$@" | yourShellCode . See also shebang_args_or_input.

#!/bin/sh
cd /var/irclogs/_esoteric
if [ "$1" ]; then
    grep -P -i -- "$1" ????-??-??.txt | shuf -n 1
else
    file=$(shuf -en 1 ????-??-??.txt)
    echo "$file:$(shuf -n 1 $file)"
fi