<b_jonas> slashlearn block device/Block devices are a concession made in Unix to make raw hard disks and magnetic tape have a similar interface to regular files and terminals. Since magnetic tapes can\'t write individual bytes, only entire blocks, the interface isn\'t exactly the same, thus the dreaded dd obs= option was born.

#!/bin/bash
topic="$(echo "$1" | lowercase | sed 's/^\(an\?\|the\) //;s/s\? .*//')"
stuff=$(echo "$1" | cut -d' ' -f2-)
perl -i -p -e 's/\n/ /' "wisdom/$topic"
echo "$stuff" >>"wisdom/$topic"
echo -n "Learned '$topic': "
cat "wisdom/$topic"