# Unlimited history.
 HISTSIZE="-1"
 
 # Do not save commands starting with a space. Only save the last usage of a
 # duplicate command.
 HISTCONTROL="ignorespace:ignoredups:erasedups"
 
 # Place history expansions into the editing buffer instead of executing them.
 shopt -s histverify
 
 # Reload failed history expansions.
 shopt -s histreedit
 
 # Append instead of replace.
 shopt -s histappend
 
 # Save all lines of multi-line command.
 shopt -s cmdhist
 
 # Do not replace newlines with semicolons.
 shopt -s lithist
 
 # Automatically perform history expansion when space is pressed.
 bind 'Space: magic-space'