History options in bashrc ubuntu default file

.bashrc-history

$ grep -ri hist ~/.bashrc | grep -v alias
# don't put duplicate lines or lines starting with space in the history.
#HISTCONTROL=ignoreboth
# append to the history file, don't overwrite it
shopt -s histappend
# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
#HISTSIZE=1000
#HISTFILESIZE=2000
export HISTSIZE=100000
export HISTFILESIZE=50000
export HISTCONTROL=ignoredups
export PROMPT_COMMAND="history -a; history -n; $PROMPT_COMMAND"