how to find proces listening on a port

[Srikrishna Murthy Annam]

netstat , fuser , lsof , /proc/$pid

# netstat -tulpn

# ls -l /proc/1138/exe 


# fuser 7000/tcp


lsof -i :portNumber
lsof -i tcp:portNumber
lsof -i udp:portNumber
lsof -i :80
lsof -i :80 | grep LISTEN

grep 443 /etc/services

Other useful commands lsof:

Specific user opened files : # lsof -u askm

Process running on specific port : lsof -i TCP:22

port range :  lsof -i TCP:1-1024

Exclude User :  lsof -i -u^root

who is looking what file :  lsof -i -u askm

Kill all activities of a user : kill -9 `lsof -t -u askm`