find /var/ -name dpkg.log
locates historical records of the installation package
find /var/ -name dpkg.log 2 >/dev/null
to redirect the error messages and prevent them from being displayed
grep firefox /var/log/dpkg.log
to find the time that firefox was installed
grep rw password. – color
to find how many times the word passwords appears in files located in your home directory
“history”
shows all commands you have used
.bash_history
only contains the first lines of the history command