The ‘history’ commands does not display the exact date and time of the commands executed. It just shows a numeric id followed by the command executed by the current user. Here is one way of putting a time stamp –
export HISTTIMEFORMAT='%F %T '
To make sure that it works every time you login or restart your machine, put it in $HOME/.bash_profile
Other useful environment variable related to the history command are –
1. HISTFILE
The name of the file in which command history is saved.
2. HISTFILESIZE
The maximum number of lines contained in the history file.
3. HISTIGNORE
A colon-separated list of patterns used to decide which command lines should be saved on the history list.
4. HISTSIZE
The number of commands to remember in the command history.
