Letters to the Editor
I found the article [Setting up Services in the April 1995 issue] interesting. I think that there was one major point that was missed. Administrators should not randomly assign ports to services. In fact there is an RFC that lists the ports. The latest is rfc1700. This is very important for novices to learn.
—Matthew B. Guest email@example.com
I agree emphatically with the letter from Graham Leach (firstname.lastname@example.org) in the April 1995 issue of Linux Journal. Your magazine is excellent. But the “linked list” format is annoying. Please avoid it, or at least minimize it.
I disagree with one of your justifications, namely that readers expect “important” articles near the front of the magazine. I certainly don't. I would guess that most of your regular readers, like me, would read each issue cover-to-cover, and more than once. Perhaps you could poll your readers, to find out for sure.
As I said, your magazine is superb. But the format makes it difficult to read, needlessly so.
—Carl Renneberg email@example.com
Just received my first issue of Linux Journal: April. Great!
WRT the split article issue raised by Graham Leach in a letter to the editor, may I suggest something that worked well for me back in the dark ages of paste-ups: Instead of “no jumps”, which is really tough, how about a goal of no more than one jump per article. It would also be helpful to add the article name to the “continued from...” at the top of jump pages.
Thanks for an interesting, readable book.
—John Miller, N4VU jsm@n4vu.Atl.GA.US
We have been discussing this and this issue has a keyword from the article title added to the “continued from” lines, as you suggest. Also, I agree with the one jump max rule and we will try for that. From more information on our new layout, please see Stop the Presses.
I was very pleased to read Robert A. Dalrymple's article on Scilab. I've been using Scilab for 7 years and I think that it is a terrific product (much more powerful than Matlab). It's wonderful that INRIA decided to make this tool available to the public as free software.
My purpose for writing this letter is that I think your readers will be interested in knowing some additional facts about Scilab which did not come out in the article. One of the most powerful aspects of Scilab is its ability to easily perform data abstraction and operator overloading.
Scilab is delivered with several pre-defined abstract data types such as rational polynomials and linear dynamic systems. Overloading of the usual operators such as “+”, “-”, “*”, “/”, and “=” allows the user to easily manipulate these abstract data types and the development of higher level operations is greatly simplified. Here is an example with two rationals:
^> r1=(2+3*s)/(1+s**2) r1 = 2 + 3s ^^^- 2 1 + s ^> r2=s/(5+s) r2 = s ^^^ 5 + s ^> r3=r1+r2 r3 = 2 3 10 + 18s + 3s + s ^^^^^^^^^ 2 3 5 + s + 5s + s
Notice that even though the rationals in the example are user defined objects, the overloading of the “=” operator gives rise to a user friendly on-screen representation which is recognizable as that of a rational. Furthermore since the “+” operator is overloaded for rationals, their sum is defined and requires no special function (like r3=poly_add(r1,r2) as an example).
The implementation of the rational abstract data type in Scilab allows all the usual operations that one would expect between two rationals as well as between a rational and other data types (such as scalars and matrices).
The user of Scilab can easily define new abstract data types and develop Scilab macros for the implementation of user transparent operator overloading. These Scilab features are unique in the Matlab-like class of products and is the reason for which I believe that Scilab is a much more powerful product than Matlab.
I hope that these comments will be of use to your readers.
—Carey Bunks firstname.lastname@example.org
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.View Now!
|The Firebird Project's Firebird Relational Database||Jul 29, 2016|
|Stunnel Security for Oracle||Jul 28, 2016|
|SUSE LLC's SUSE Manager||Jul 21, 2016|
|My +1 Sword of Productivity||Jul 20, 2016|
|Non-Linux FOSS: Caffeine!||Jul 19, 2016|
|Murat Yener and Onur Dundar's Expert Android Studio (Wrox)||Jul 18, 2016|
- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- SUSE LLC's SUSE Manager
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Doing for User Space What We Did for Kernel Space
- Google's SwiftShader Released
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide