May 2013
Beginner to intermediate
384 pages
7h 40m
English
book
Linux Shell Scripting Cookbook, Second Edition - Second Edition
by Shantanu Tushar, Sarath Lakshman
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Monitoring user logins to find intruders
Logfiles can be used to gather details about the state of the system. Here is an interesting scripting problem statement:
We have a system connected to the Internet with SSH enabled. Many attackers are trying to log in to the system, and we need to design an intrusion detection system by writing a shell script. Intruders are defined as users who are trying to log in with multiple attempts for more than two minutes and whose attempts are all failing. Such users are to be detected, and a report should be generated with the following details:
- User account to which a login is attempted
- Number of attempts
- IP address of the attacker
- Host mapping for the IP address
- Time for which login attempts were performed
Getting ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.