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March 2, 2022 – 2:00 pm

Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …

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Article Archive for December 2017

Obfuscating Passwords in Shell Scripts

December 17, 2017 – 9:41 am
security_004

At the risk of repeating myself, I must say that this article is about obfuscating passwords – rendering obscure, unclear, or unintelligible – not hiding them. This can still be useful.

Extracting Email Addresses from TCP Streams

December 5, 2017 – 7:06 pm
shell

Here’s a quick example of using tshark to extract email addresses from TCP streams. Let’s say some application on your server is sending emails and you want to find out who is receiving those emails. …

Occupy Subnet

December 1, 2017 – 2:15 pm
DSC_6214 copy copy

The script below (tested on RHEL 7) will use arp-scan to identify unused IPs on your subnet and configure virtual interfaces attached to your primary NIC to take over every available IP.