How To Properly Specify Command and Arguments to Exec in Perl

Author: , December 11th, 2019

When using Perl’s exec() call, the best way to invoke it is as follows:

This syntax does some important things: – passes a scalar value as the first argument which exec interprets as PROGRAM – passes an array as the second argument which exec will use as the arguments to pass into PROGRAM Note […]

Slick Command-Line Tricks for a Tungsten MySQL / MariaDB Database Cluster

Author: , July 16th, 2019

Tungsten Clustering provides high availability, disaster recovery, and a host of other benefits for MySQL / MariaDB / Percona Server databases. In this blog post we will explore some of the shell aliases I use every day to administer various Tungsten Clusters.

How To Restart Apache Using cron If the Load Gets Too High

Author: , February 3rd, 2016

There are times when the hackers slam my servers and the load gets too high. I use a very simple bash script as a cron job to monitor the load and take action when it gets too high. The script will stop httpd, sleep for a configurable period of time (currently 3 minutes), then start […]

How To Eject a Volume from the Terminal Command Line in MacOSX

Author: , December 8th, 2015

As always, YMMV…

How To Auto-Restart Apache If the Load Gets Too High

Author: , September 15th, 2015

The script to check and restart apache…works on CentOS – YMMV!

Add to cron * * * * * /root/restart_apache_if_load_hits_threshold.sh >> /var/log/restart_apache_if_load_hits_threshold.log 2>&1

How To Disable the Bash Terminal Bell

Author: , July 7th, 2015

The Readline library has a bell-style variable that controls what happens when Readline wants to ring the terminal bell. If set to ‘none’, Readline never rings the bell. If set to ‘visible’, Readline uses a visible bell if one is available. If set to ‘audible’ (the default), Readline attempts to ring the terminal’s bell. Edit […]

How To: for loops in bash

Author: , February 27th, 2015

How To Add a Column of Numbers Using AWK

Author: , January 1st, 2015

awk ‘{sum+=$1}END{print sum}’ inputFile

How To Patch the ShellShock bash Bug on Older or Beta AWS Linux AMI’s

Author: , October 1st, 2014

This is the standard upgrade method for AWS Linux AMI’s:

Or use this for the version 2012.09, 2012.03, or 2011.09 repositories:

For older AWS Linux AMI’s, you may not be able to use the standard upgrade method as described in this link: https://alas.aws.amazon.com/ALAS-2014-419.html These are the steps needed to manually patch bash 4.1: […]