How to Check Port Usage on Linux?

Service startup says port is in use, want to find which process is using it

Solutions

# ss -tlnp # ss -tlnp | grep :3000 # Examples: # LISTEN 0 128 *:3000 *:* users:(("node",pid=1234,fd=12))

ss netstat,. -t=TCP -l= -n= -p=.

: Linux

# sudo lsof -i :3000 # Examples: # COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
# node 1234 dev 12u IPv4 12345 0t0 TCP *:3000 (LISTEN)

lsof -i. sudo.

netstat -tlnp | grep :3000

netstat New net-tools. ss.

: ss command

# 1: lsof + kill
kill $(lsof -t -i:3000) # 2: fuser
fuser -k 3000/tcp

lsof -t PID, kill. fuser -k.

kill

lsof sudo

Docker