BASH PORT SCANNER

Find portscanner.sh 1#!/bin/bash 2 3 # Basic bash port scanner 5 host=$1 6. startport=$2 7 stopport=$3 8 9 function pingcheck 10 11 pingresult=$(ping -c 1 $host | grep bytes | WC-1) 12 if [ "$pingresult" -gt 1 ]; then echo "$host is up" 14 else 15 echo "$host is down, quitting" 16 exit 20 function portcheck 21 { 22 for ((counter=$startport; counterc=$stopport; counter++)) 23 do if timeout 2 bash-c "echo >/dev/tcp/$host/$counter" then 26 echo "$counter open" 27 else 28 echo "$counter closed" 29 30 done 31] 32 33 first check that the host is alive 34 pingcheck 35 # next, loop through the ports 36 portcheck 137 38 39 Modify your program to accept an optional command-line argument -t, followed by a space and an additional numerical argument, which sets the timeout value for the echo command in the portcheck function. The argument must come before the hostname and start and stop ports. If the argument is not given, the timeout should remain at a default value of 2. If the argument is given, in addition to changing the timeout, the script should print out an informational message "Timeout changed to ". For example, -/portscanner.sh -t 3 www.yahoo.com 40 80 should change the default timeout for each write to /dev/tcp to 3 seconds. Note: adding this feature will also require you to change the way you scan and save the command line arguments for hostnames. The number and place of command line arguments will now vary depending on whether the user uses the '-t' option or not. You will have to add program logic to account for this, so that everything works correctly in either case