Important commands in your everyday life.

echo 'obase=2; ibase=10; 0.1' | bc	convert 0.1 to binary
echo 'obase=10; ibase=2; .0001' | bc	and convert it back

(cd dir && command)			run command in dir without changing to it
pushd, popd				push and pop directories
ls /usr/bin | pr -T9 -W$COLUMNS		9 zeilige Ausgabe

look					words beginning with a string (default: dictionary)


References:
http://www.pixelbeat.org/cmdline.html