Sep 10 2017

mail Command in Shell Scripting

mail is an intelligent mail processing system which has a command syntax reminiscent of ed with lines replaced by messages.
mail is part of mailutils package in Debian-Based distros and is a very useful and powerful tool which can be used in scripts.
Continue reading


Oct 3 2014

Protect Servers Against Shellshock Bash Vulnerability.

On September 24, 2014, a GNU Bash vulnerability (Shellshock or “Bash Bug”), was discovered and published.
The vulnerability allows remote attackers to execute arbitrary code given specific conditions, by injecting strings of code following environment variable assignments.
Because of Bash’s large utilization (Ex: Linux, BSD, OsX), many computers are vulnerable to Shellshock Bash Bug.
All unpatched Bash versions between 1.14 through 4.3 seems to be compromised.
Continue reading


Oct 24 2012

Count and Visualize Traffic Sources (by IP) using shell commands in Linux.

While suspecting to be victim of a DoS or DDoS Attack, could be useful to identify TOP Source of Connections.
This information can be retreived “On-The-Fly” by using some shell commands.
Continue reading


Nov 8 2011

Shell Scripting: Get METARs & TAFs from “aviationweather.gov” and “weather.noaa.gov”

This small script is what I use to get METARs and TAFs for my preferred stations from aviationweather.gov or weather.noaa.gov WebSite (data is displayed by GeekTool on my iMac desktop).
Continue reading


Nov 4 2011

Linux: Clear Bash Shell history

Clear content for current and, in some cases, global command shell history can be important for System Administrators.

This procedures are (for example) very useful when some cleat-text password has been passed via command-line and the System Administrator needs to clear them from history.
Continue reading