history.txt

# the man page is for the history library or somesuch? use help:
$ help history
# for when you're doing password things on the cli:
-c         clear history
# random other things that you'll never ever need
-s args..  store the rest of the args in history without executing them (the command that does or calls this will
           not be stored itself)
-p !foo    echo the most recent history entry that starts with foo, without running it
# this ties in with bash' expansion of !stuff. !-3 will run the third-last command again,
#   !123 runs command nr 123 (according to the history list)

# Disable & re-enable storing commands in history:
$ set +o history
$ set -o history

# the following is mostly copy/pasted from a random .bashrc file:

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
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

# show with timestamps
HISTTIMEFORMAT="%F %T "