View Open Files
# Processes working on a file
lsof <filename>
# Files Open by a process
lsof -p <pid>
# View files currently open by a User
lsof -u <username>View Port Information
lsof -i :<port>
lsof -i <protocol>PID of Process
pidof <process-name>Flags
-p: Port
-u: Username
-i: Listen to IP Sockets
-n: Disable DNS Lookup
-P: Show Port Number