Shell Programming and Scripting

#! /bin/bash                                                                   

clear
cd /home/pi/int_lib
# where macadresser resides
echo Running nmap and arp to scan the network...
echo These machines are connected to Yakuza_III:
echo

for word in $(nmap -sL 192.168.1.0/24 | grep "(192" | grep -ioE '([0-9]{1,3}\.){3}[0-9]{1,3}' | grep -v -)

# Run nmap to scan for machines in local network 
# (tried nmap -sn - which didn't echo all active clients
#   - thus switched to -sL filtering out the items listed as no answer)
# -sL still doesn't seem to echo all machines connected

do
    
# nmap found a host at $word. Pinging it to plant the mac in arp table
    
    ping -c 1 $word > nil:
    mac=$(arp $word | grep -ioE '([A-Fa-f0-9]{2}:){5}[A-Fa-f0-9]{2}')
    hit=no_intruder
    if [ -z $mac ]
	
    # mac might be empty since current machine may be down
	
    then
	echo $word: This machine seems to be down...
    else
	
    # get current machines macaddress
	
	if grep -q $mac macadresser

        # check for previous record of this machine
	
	then
            echo $word: $(cat macadresser | grep $mac)
	else

        # machine not found. adding line ...

            current_time=$(date +%Y-%m-%d%kh%Mm%Ss)
            echo ... $mac at $word is new for us...
            nl=$(echo $mac $(echo $(arp $word) | cut -d " " -f 7) at $current_time)
            echo Adding $nl to macadresser. Use maced to edit if desired...

            # maced is a script calling emacs on macadresser

            echo $nl >> macadresser

            # make a new record last in macadresser

            hit=intruder_detected

            # and signal to exit that something has occurred
	fi
    fi
done

#exit:
current_time=$(date +%Y-%m-%d%kh%Mm%Ss)
if [ $hit==no_intruder ]

# script found no intruders
    
then
    echo $current_time: Nothing to report... >> intr_log.txt

# add a line to the log

else
    echo $current_time: One or more intruders reported! See macadresser >> intr_log.txt

# add a line to the log

    echo We had an intruder! Read int_lib/macadresser >> intr_log.txt
fi

pi@Ono-Sendai_II:~$ nmap -sL 192.168.1.0/24 | grep "(192"
Nmap scan report for api.premiumzone.com (192.168.1.1)
Nmap scan report for Eriks-fonan.lan (192.168.1.105)
Nmap scan report for nas-79-71-C5.lan (192.168.1.151)
Nmap scan report for AnnaKrinsiPhone.lan (192.168.1.186)
Nmap scan report for SonosZB.lan (192.168.1.193)
Nmap scan report for Hosaka-III.lan (192.168.1.197)
Nmap scan report for Samsung-TV.lan (192.168.1.224)
Nmap scan report for Skrivare.lan (192.168.1.242)
pi@Ono-Sendai_II:~$ nmap -sL 192.168.1.0/24 | grep "(192"
Nmap scan report for api.premiumzone.com (192.168.1.1)
Nmap scan report for SonosZP.lan (192.168.1.72)
Nmap scan report for Sino-Logic-IV.lan (192.168.1.150)
Nmap scan report for nas-84-CC-E3.lan (192.168.1.152)
Nmap scan report for AnnaKrinsiPhone.lan (192.168.1.186)
Nmap scan report for Hosaka-III.lan (192.168.1.197)
Nmap scan report for Samsung-TV.lan (192.168.1.224)
Nmap scan report for Skrivare.lan (192.168.1.242)
pi@Ono-Sendai_II:~$ nmap -sL 192.168.1.0/24 | grep "(192"
Nmap scan report for api.premiumzone.com (192.168.1.1)
Nmap scan report for SonosZP.lan (192.168.1.72)
Nmap scan report for Eriks-fonan.lan (192.168.1.105)
Nmap scan report for nas-79-71-C5.lan (192.168.1.151)
Nmap scan report for Google-Home-Mini.lan (192.168.1.157)
Nmap scan report for AnnaKrinsiPhone.lan (192.168.1.186)
Nmap scan report for SonosZB.lan (192.168.1.193)
Nmap scan report for Hosaka-III.lan (192.168.1.197)
Nmap scan report for Samsung-TV.lan (192.168.1.224)
Nmap scan report for Skrivare.lan (192.168.1.242)
pi@Ono-Sendai_II:~$ nmap -sL 192.168.1.0/24 | grep "(192"
Nmap scan report for api.premiumzone.com (192.168.1.1)
Nmap scan report for SonosZP.lan (192.168.1.72)
Nmap scan report for nas-79-71-C5.lan (192.168.1.151)
Nmap scan report for Google-Home-Mini.lan (192.168.1.157)
Nmap scan report for Apple-TV.lan (192.168.1.177)
Nmap scan report for AnnaKrinsiPhone.lan (192.168.1.186)
Nmap scan report for SonosZB.lan (192.168.1.193)
Nmap scan report for Hosaka-III.lan (192.168.1.197)
Nmap scan report for Samsung-TV.lan (192.168.1.224)
Nmap scan report for Skrivare.lan (192.168.1.242)