Linux RADIUS logs - linux

Question

I have a program called Radius which authenticates user login. It is running on CentOS server
The logs are in /var/log/radius.log
They are as follow
Mon Jul 24 22:17:08 2017 : Auth: Login incorrect: [faaiz.aleem] (from client PTCL-VPN port 28 cli 116.213.34.97) DeviceIP: 192.168.30.101
Mon Jul 24 23:32:41 2017 : Auth: Login OK: [muhammad.razzaq] (from client PTCL-VPN port 29 cli 45.116.233.62) DeviceIP: 192.168.30.101
Tue Jul 25 03:06:08 2017 : Auth: Login OK: [sadiq.akhter] (from client devices port 1 cli 192.168.141.1) DeviceIP: 1.8.3.11
Tue Jul 25 03:07:54 2017 : Auth: Login OK: [sadiq.akhter] (from client devices port 1 cli 10.88.33.2) DeviceIP: 1.6.16.1
Tue Jul 25 09:44:39 2017 : Auth: Login incorrect: [shariq.iqbal] (from client devices port 1 cli 10.10.10.173) DeviceIP: 1.6.10.11
Now I want to sort them out for each user for e.g sadiq.akhter against last login made by them. Please suggest a good bash script or Linux command to do so. I shall be thankful to you.

Answer 1

a quick solution to get only lines with a defined user (and write to a file):
grep "USERNAME" /var/log/radius.log > log_for_user.log
the last line you get from grep should be the last login record.
you can use tac to print your log file in reverse order and use "grep -m1 .." to get only one (the last) match.
returns the last line with USERNAME inside your log:
tac /var/log/radius.log | grep -m1 "USERNAME"
So in a shell script it can look like this, returns you all recent entries to all users:
#!/bin/bash
for i in `cat USERLIST`
do
tac LOGFILE | grep -m1 $i
done
where USERLIST is a file lists all usernames, separated by newline and LOGFILE is your radius logfile.