setup

#!/usr/bin/env bash
# Aircrack-ng/setup

# setup
#   Setup airodump-ng to capture WPA handshake

set -euo pipefail
# -e exit if any command returns non-zero status code
# -u prevent using undefined variables
# -o pipefail force pipelines to fail on first non-zero status code

IFS=$'\n\t'
# Set Internal Field Separator to newlines and tabs
# This makes bash consider newlines and tabs as separating words
# See: http://redsymbol.net/articles/unofficial-bash-strict-mode/


function usage {
  echo -e "\\n  ./setup [network-channel] [network-bssid] \\n"
  echo "  Setup airodump-ng to capture WPA handshake"
  echo -e "  Outputs demo.cap\\n"

  exit 0
}


function ctrl_c {
  echo -e "\\n[ ] ${USER} has chosen to quit!"
  exit 1
}


function main {

  declare -r channel=${1:-""}
  declare -r bssid=${2:-""}

  if [[ $# -eq 0 ]] ; then
    # If no args then print help
    usage
  elif ! [[ "${channel}" =~ ^-?[0-9]+$ ]]; then
    echo "[ ] network-channel must be an integer!"
    exit 1
  elif ! [[ "${bssid}" =~ ^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$ ]]; then
    echo "[ ] network-bssid is not a valid MAC address!"
    exit 1
  fi

  trap ctrl_c SIGINT
  # Detect and react to the user hitting CTRL + C

  airmon-ng check kill
  airmon-ng start wlan0

  airodump-ng -c "${channel}" --bssid "${bssid}" -w demo wlan0mon
}

main "$@"