Adding a Notification to Old WordPress Posts

While some articles may be timeless, depending on the type of content being published, many posts have a definite expiry date. It is the double edged sword of rapidly evolving technologies – they improve swiftly, but articles written about them become outdated just as fast. This site, for instance, is primarily about cloud computing and… Continue reading Adding a Notification to Old WordPress Posts

Easy Windows-Linux File Sharing with a LiveCD

The intent of this article is to address a very specific case – it is not meant as a best practices guide. Scenario: A. You have a windows computer (Computer 1) with files that are remotely accessed from second windows computer (Computer 2). B. Access from Computer 2 is via a program that expects the… Continue reading Easy Windows-Linux File Sharing with a LiveCD

Missing mail command on Amazon’s Linux

I recently noticed that the mail command is not available by default on the latest version of Amazon’s Linux AMI (v2011.09). This functionality is available in the mailx package, which can be installed with the following: yum install mailx

Showing the Firebug icon

While it is easy enough to use F12 to display Firebug in Firefox, I just like the status bar icon. Unfortunately, it has been hidden in the last few releases of Firebug. To display it, open about:config, and set extensions.firebug.showStatusIcon to true.

Optimize all MySQL Tables

A one-liner to optimize all MySQL tables, in all databases. Be advised that running optimize on InnoDB does a ‘recreate and analyze’. Run as root in the example below. mysqlcheck -o -u root -p –all-databases

Verify that SSL caching is working

To verify that SSL caching is on, check the Session-ID across multiple sessions (i.e. resume/reconnect) – they should be the same: openssl s_client -host HOSTNAME -port 443 -reconnect | grep ‘Session-ID:’ The equivalent, using gnutls-cli should be: gnutls-cli -V -r HOSTNAME |grep ‘Session ID’

Rotating EBS Snapshots: ec2-prune-snapshots

Following the significant disruption of EBS volumes in April, the importance of backups was once again brought to the forefront. Amazon’s method of generating EBS backups is the ‘snapshot’ – a differential backup stored in S3. While Amazon provides tools for creating snapshots (either command line, or via their API), a script that is quite… Continue reading Rotating EBS Snapshots: ec2-prune-snapshots

Rebuild Icon Cache

Recently, after upgrading a program (FileZilla in this case), the program’s icon would not display on the desktop (Windows 7). Even deleting and recreating the shortcut resulted in a broken icon (although, the shortcut itself worked fine). No amount of refreshing the desktop made a difference. The quick fix was to rebuild the icon cache,… Continue reading Rebuild Icon Cache

Prime Factoring with PHP

A surprisingly large number of math based computer problems appear to require factorization, finding prime number, or prime factoring. Presented below is a reasonably fast algorithm for prime factoring a number – it is limited to the integer size on PHP (231-1). It should be a fairly trivial exercise to modify the function below to… Continue reading Prime Factoring with PHP

Setting Windows’ Time Service’s Update Frequency

There are some instances when it is desirable to change the default interval between synchronizations by the Windows Time Service (i.e. NTP). For instance, I recently encountered a computer where the clock would run a few seconds fast each day (it was not a battery problem), for a quick fix, it was easy to simply have the… Continue reading Setting Windows’ Time Service’s Update Frequency

Merging Videos of the Same Type

While modern computers have greatly advanced in their ability to handle video editing, it remains one of the slowest commonly performed operations. Within the realm of video editing, common tasks include: splitting a video (e.g. into two files to fit onto a disk) merging a video (e.g. combining two videos into a single file) splicing… Continue reading Merging Videos of the Same Type