linux check running processes on port command line code example

Example 1: ubuntu check process on port

sudo lsof -i:22

Example 2: linux query port use by pid

$ sudo ss -lptn 'sport = :80'
State   Local Address:Port  Peer Address:Port              
LISTEN  127.0.0.1:80        *:*                users:(("nginx",pid=125004,fd=12))
LISTEN  ::1:80              :::*               users:(("nginx",pid=125004,fd=11))

Example 3: check what ports are open linux

## if you use linux
sudo ss -tulw