When reviewing the history file in bash, it’s terrible not knowing when a command was executed. Using the HISTTIMEFORMAT variable in a .bashrc file, the timestamp can be added to all commands.
HISTTIMEFORMAT=”%m/%d/%y %I:%M:%S %p ”
525 05/21/09 07:56:46 PM tail -f /var/log/messages /var/log/secure
As you can see, the command is preceeded by the line number and a timestamp.