[ Thanks to PmaBox for this link.
]
“Many times we are confronted with the doubt if a
software is working or not. Either the process stopped or crashed,
sometimes it’s hard to figure out. This is specially true when we
are using the command shell and or the software offers no GUI or
way to explicitly tell us if it’s running or not. Another very
important reason, or maybe the most important, security reasons.
Any expert IT “guy” needs to know what processes are runing and
what ports are being used by it.“Few quick methods / programs that we can use to find out
running processes and associated ports“Remember that some of these might require you to run them as
root.“Netstat
$ sudo -i
$ netstat -tulpn