General UNIX Skills

UNIX and derivative operating system such as Solaris, HP-UX, AIX, SCO OpenServer, SCO UNIXWare, Linux and BSDs share a lot in common. In fact they are about 90% the same!

In my 20 plus years of experience working on UNIX, I have developed many skills that work well in all UNIX environments.

UNIX System Administration

I have worked as a UNIX system administrator for over 14 years and have been responsible for systems ranging in cost from a few thousands to systems worth hundreds of thousands of dollars.

Over that time I have been able to develop strong skills in:

• System Performance. Most UNIX systems do not come preconfigured for maximum performance. In fact, the opposite is often true. Systems, as shipped by the manufacturer, are often de-tuned so that resource use is modest, but so is performance.

  It is my experience that significant tuning opportunities exist in most commercial UNIXs. Often, simple tunes may yield a 10% through 50% increase in performance and/or the machine's ability to handle higher loads. In many cases, my clients were able to postpone significant system upgrades because their existing system was re-configured to handle more work.

• Database Performance. It is my experience that database administrators understand databases, not the UNIX systems the database runs on. I have seen many cases where a database was correctly, but not optimally installed.

  Like general system tuning, most UNIXs provide configuration opportunities that have a significant impact on a database product. Correctly distributing the database load, ensuring that sufficient semaphore, shared memory and network resources are available, matching block sizes, using raw volumes, and other tunes all contribute to database performance.

• Security. Security is a process, not a product. Your machine is critical business tool. Failure to actively monitor security could put your job, your data and your organization at risk. Lock your machine down and monitor it.

Shell Programming

I have been writing shell scripts for over 15 years. I prefer the Bourne Again Shell or bash. I'm also quite comfortable with the original Bourne Shell, sh and the Korn Shell, ksh (ksh93 preferred).

Some of the scripts I've written for clients include:

• Back up scripts to do master and incremental back ups. Usually includes a verify pass and an e-mail alert or pager alert whenever things go wrong.
• Service management scripts. I've written scripts to start/stop boot time services such as firewalls, databases, web servers, application back end code and more.
• User management scripts. Usually done to simplify user maintenance tasks such as adding a user (includes setting up mail, permissions, default files, etc.), removing a user, etc.
• Printer Interface Programs. System V printing can be a real headache. I've written or modified dozens of printer interface scripts to handle special cases including font loads, forms overlays, line conditioning, network printing and more.
• Utility Scripts. Usually needed to drive some application. A common example is a script to drive a utility from cron.
• Common Gateway Interface (CGI) Scripts Sometimes, when programming dynamic web content, you can get the fastest, most direct answer with a Shell Script. I've written shell script wrappers for search tools like Swish Enhanced as well as simple form mail scripts.

C Programming

I started my career as a C programmer. I was fortunate enough to be introduced to C back in 1981 (when the K&R C book was all you could buy). I've worked on many projects, usually performing system programming or programmer tool development.

Here's a bit more detail on some of my more substantial C programming efforts:

• B-Tree Indexing Tool. I wrote this for my under-graduate thesis. It performed n-way balanced tree indexing based on key, record pairs. It was fast, small, efficient and performed at about 2x the speed of the best commercial software available at the time. It was sold as Open Source back in 1982 through 1990!
• PC-Star. This was a GUI, PC based reporting system developed by myself and a small team of programmers for the Toronto Stock Exchange. (STAR is Strategic Trading Analysis Reports). The system required 5 programmer years to develop. In it's first 6 months in the field only 3 bugs were reported. (photo below).
• WebMinder. Web site ever go down? Sure it has but your ISP won't tell you. This was such a big problem in the late 1990's that I wrote a tool to probe web sites looking for failures. The tool would report on any problems, page the website administrator and provide specific details of the problem (network error, DNS error, server error, web server software error or content error). This helped reduce remediation time to minutes. And as a bonus, it's reports helped my clients recover thousands of dollars in rebades due to ISP's missing their availability targets.
• PerfectMail Scanner. My latest project. We rate e-mail like the motion picture industry rates movies. To accomplish this task, I wrote a phrase scanner that is blindingly fast. It can scan an e-mail for over 6,000 spam-ish phrases in .00005 seconds on a Celeron 1000. It's part of a package we are developing to help rid the world of the scourge of spam. Check out www.perfectmail.net for the latest.