Unix as IDE. History

Execute last command again:

sudo !!
echo !! > new_script.sh
!! | grep Linux

Execute last command started with ls:

!ls

Arguments:

ls !^  # first arg of prev cmd
ls !$  # last arg of prev cmd
ls !*  # all args of prev cmd
ls !ls:2  # second arg of prev ls cmd

Execute command with given history number:

!2039

Hide command from history (use space before cmd):

 ls ~/eagle