edit file .bashrc
Set HISTSIZE and HISTFILESIZE to an empty string:
`
HISTSIZE=
HISTFILESIZE=
`
In bash 4.3 and later you can also use HISTSIZE=-1 HISTFILESIZE=-1:
> n. Setting HISTSIZE to a value less than zero causes the history list to be
> unlimited (setting it 0 zero disables the history list).
> o. Setting HISTFILESIZE to a value less than zero causes the history file size
> to be unlimited (setting it to 0 causes the history file to be truncated
> to zero size).
bash --version to check your bash version.
> Change the file location because certain bash sessions truncate .bash_history file upon close.
> http://superuser.com/questions/575479/bash-history-truncated-to-500-lines-on-each-login
> Force prompt to write history after every command.
> http://superuser.com/questions/20900/bash-history-loss
> Use timestamp HISTTIMEFORMAT="[%F %T] "
Finally:
`
HISTSIZE=-1
HISTFILESIZE=-1:
HISTFILE=~/.basheternalhistory
PROMPTCOMMAND="history -a; $PROMPTCOMMAND"
`