To retrieve information about the files that active processes on your

Linux system have open, we use the list of open files (lsof) command. Running lsof without options lists all of the open files on the system.
What commands would you use to show the open files in use by a specific filesystem (/var/log)?
A specific user (not root)?
A specific protocol (IPv6)?
A specific port (80 or 443)?
Provide your terminal output and discuss your findings.