chown -- change owner
useful method:
chown root.root filename ---change the filename as root group root user .
chown bob.bob filename -- change the file as bob group bob user.
chmod --- change file pemission
the file have read write excute pemission .
use ls -l display the file pemission.
eg. chmod 777 file
chmod +x file
find ---find the file
use :find -name filename ---find the file reply the filename
find -mmin +0 -mmin -120 ---find the last 120min create and modify file .
find -mmin +0 -mmin -120 | less