10 export HISTFILESIZE=20000
 11 export HISTSIZE=44000
 12 shopt -s histappend
 13 # Combine multiline commands into one in history
 14 shopt -s cmdhist
 15 # Ignore duplicates, ls without options and builtin commands
 16 HISTCONTROL=ignoredups
 17 export HISTIGNORE="&:ls:[bf]g:exit"