List open TCP and UDP ports

lsopen

#!/bin/sh

# usage: lstcp [options] [port]
lstcp() (
	while getopts : o; do opts="$opts -$OPTARG"; done; shift $((OPTIND-1))
	lsof -i tcp"${1+:}$1" -s tcp:listen $opts
)

# usage: lsudp [options] [port]
lsudp() (
	while getopts : o; do opts="$opts -$OPTARG"; done; shift $((OPTIND-1))
	lsof -i udp"${1+:}$1" $opts | grep -vF -e '*:*' -e '->'
)

# usage: lsport [options] [port]
lsport() (
	while getopts : o; do opts="$opts -$OPTARG"; done; shift $((OPTIND-1))
	lsof -i"${1+:}$1" -s tcp:listen $opts | grep -vF -e '*:*' -e '->'
)