IP and Port scanner in bash and nc

readme.md

Makeshift scanners.

Slightly modified and expanded version of this work: https://linuxconfig.org/bash-scripts-to-scan-and-monitor-network

Example

Port Scanner

PORTS="{80,443,22}" ./scan_ports.sh 192.168.{1..4}.{1..255}

IP Scanner

./scan_ips.sh 192.168.{1..4}.{1..255}

scan_ips.sh

#!/bin/bash

is_alive_ping()
{
  ping -c 1 $1 > /dev/null
  local result=$?
  local prefix="%s: "
  local suffix="\n\x1b[0m"
  [ $result -eq 0 ] && printf "$prefix \x1b[32mup$suffix" $1
  [ $result -gt 0 ] && printf "$prefix \x1b[31mdown$suffix" $1
}

declare -a ips=( $@ )

for ip in ${ips[@]}
do
is_alive_ping $ip &
done

scan_ports.sh

#!/bin/bash

is_open_nc()
{
  local prefix="%s:%s "
  local suffix="\n\x1b[0m"

  local result="$(echo "\n\n\n" | nc $1 $2)"
  [ ${#result} -gt 0 ] && printf "$prefix\x1b[32m open$suffix" $1 $2
  [ ${#result} -eq 0 ] && printf "$prefix\x1b[31m closed$suffix" $1 $2
}

declare -a ips=( $@ )
declare -a ports="( $PORTS )"

for ip in ${ips[@]}; do
  for port in ${ports[@]}; do
    is_open_nc $ip $port &
  done
done