What's running on a specified port?

portcheck.sh

# What's running on a specified port?
# https://gist.github.com/TomK/b8c5bebe1e29f62d3ecff7e5223c8ff6

if [ -z "$1" ]; then
  echo 'You must specify a port'
  exit 1
fi

PIDS=$(lsof -nP -i:$1 |grep LISTEN |awk '{print $2}')

for PID in $PIDS; do
  echo "[$PID] $(ps -p $PID -o command |tail -n1)"
done;