400K+ Exim MTA affected by overflow vulnerability on Linux/Unix

in Categories Linux News, Security last updated March 8, 2018

Exim is a free and open source message transfer agent (MTA) developed at the University of Cambridge. It is famous on Unix and Linux systems connected to the Internet. It is freely available under the terms of the GNU General Public Licence. There is a buffer overflow in base64d() of Exim MTA that allows an attacker to run code remotely. ALL versions of Exim MTA affected by overflow vulnerability i.e. CVE-2018-6789.
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How to use Chomper Internet blocker for Linux to increase productivity

in Categories Command Line Hacks last updated February 20, 2018

Chomper is a free and open source Python cli for Linux desktop. It lets you block access to distracting websites for specified periods of time. The program is intended to help you with issues being productive on a desktop due to Internet distractions. One can set a period to block websites. Until that timer expires, you will be unable to access sites.

Monitor Linux CPU temperature, frequency, power in a graphical way

in Categories Command Line Hacks, Howto, Python last updated December 9, 2017

S-tui is a free and open source terminal UI for monitoring your computer. s-tui allows to monitor CPU temperature, frequency, power and utilization in a graphical way from the terminal. It is written in Python and need root permission to use the s-tui. It is useful for:

  1. Watch your CPU temperature/utilization/frequency/power
  2. See performance dips caused by thermal throttling
  3. No need to use X-server. Perfect for headless usage including Raspberry PI

Let us see how to install and use s-tui on a Linux based system.

How to record statistics about a Linux machine’s uptime

in Categories Command Line Hacks, Hardware last updated November 15, 2017

Linux/Unix sysadmins have a weird obsession with server uptime. There is a xkcd comic devoted to this subject where a good sysadmin is an unstoppable force that it stands between the forces of darkness and your cat blog’s servers.
Fig.01: Devotion to Duty https://xkcd.com/705/
One can tell how long the Linux system has been running using the uptime command or w command or top command. I can get a report of the historical and statistical running time of the system, keeping it between restarts using tuptime tool. Like uptime command but with the more impressive output. Recently I discovered another tool called uptimed that records statistics about a machine’s uptime. Let us see how to get uptime record statistics using uptimed and uprecords on Linux operating system.

Improve your bash/sh shell script with ShellCheck lint script analysis tool

in Categories Command Line Hacks, Howto, Programming last updated January 28, 2018

ShellCheck is a static analysis tool for shell scripts. One can use it to finds bugs in your shell scripts. It is written in Haskell. You can find warnings and suggestions for bash/sh shell scripts with this tool. Let us see how to install and use ShellCheck on a Linux or Unix-like system to enhance your shell scripts, avoid errors and productivity.