The World Wide Web
By enabling individuals around the globe to communicate and cooperate, the Internet has sped up the pace of scientific innovation. With 20 million users and growing, it has created a culture based on instant information and hyperkinetic communication.
The challenge now is to expand the power of the Internet to a wider audience and make it more convenient for all. Rising to this challenge is a system called the World Wide Web. By bringing all of the Internet's old and new resources together, the Web stands to become the one simple, standard way to access all of the Internet's riches.
It stands to revolutionize the revolution.
To picture the World Wide Web, imagine a page from a book. By pressing your finger on any of the words, you receive a new page with more detailed information about eh subject selected. The Web is like a huge book being constructed on the Internet.
Tens of thousands of these pages are already scattered around the world. They are created by experts and novices of all disciplines who use the Internet. The amount of information available is stunning: an encyclopedia, a dictionary, world maps, complete information on US government agencies, extensive Linux documentation, and much much more. It's an amazing source of information.
The Web is really a collection of computers, hooked together over the Internet, that pass pages of information back and forth. A program called a Web browser is used to find and view information. When you select a word in your Web browser, a message goes out to another computer somewhere in the world. That computer will respond by sending back the page you requested.
The messages between computers are encoded in the form of a Universal Resource Locator. The URL describes what kind of information you want, and where to look for it. It's like a mail address for the Web.
The pages can contain text, images. sounds and more. A page can even contain fill-in-the-blank forms which you complete to send information off to another computer. A protocol called HTML describes, in general terms, how the text, images, and forms should be positioned on the page. Web browsers can use this general description to lay out pages in different ways. For example, a browser that works in text mode only can ignore all the images. Or an X Windows browser can shift the text and images of a page when the window is resized.
URLs describe the locations of a page, and HTML provides an adaptable description of the information. Together, they make the Web an extremely flexible system.
To everyone familiar with Internet newsgroups, FTP sites, and gopher servers, the Web may not seem groundbreaking. But the impact is, in fact, dramatic.
The most important advantage is simplicity. To maneuver around libraries of information, you need only click the mouse to learn or key combinations to memorize.
The Universal Resource Locator also provides an easy way to access other forms of Internet information such as gopher and archie. This way, there is only one, simple interface used to access a multitude of resources. New users benefit most from this simplicity.
Unlike newsgroups, Web information stays around as long as the author, or anyone else, wants to keep it available. Unlike information available vie FTP, the information is cataloged and categorized, so it is much easier to find and access. Unlike gopher, the information is laid out like one gigantic book. You can read what you like, and select more detail only if you're interested.
Many have predicted that cyberspace would become a chaotic mess where information is impossible to find. The World Wide Web is a system designed to bring order to the chaos.
Linux is one of the best systems, commercial or otherwise, for access to the Web. Linux is a version of Unix, the native platform of the Internet. So the best Web tools are often available on Linux before DOS, Windows, or Macintosh.
Two of the most popular tools for the Web are Mosaic and lynx. They are Web browsers with different goals. Lynx is small and text-only. Mosaic is large and full-featured. To browse the wealth of information on the Web, just pick one, install, and wander off to explore the wonders of the Web.
Lynx will display the text of a page without any images or fancy fonts. It only requires the keyboard arrow keys for navigation. This simplicity makes it fast and flexible. Lynx uses the VT100 protocol, so people without access to X Windows can still use lynx, including users logging in to a Linux system remotely.
Lynx is miserly with disk space and memory. It will only take up 320K of disk and consume about 620K of RAM while running. This makes lynx perfect for 4MB Linux workstations.
Lynx is not as common as Mosaic, however. This is primarily because lynx doesn't support the colorful images and different fonts that make the Web so expressive. For these, Mosaic or some other graphical browser is required to experience the full richness of the Web.
Lynx is freely available. To get lynx for Linux, check the Linux Software Map. For lynx source code, FTP to ftp2.cc.ukans.edu.
In contrast to lynx stands Mosaic. Mosaic is probably the best Web browsers available, and it is certainly the most famous. It takes full advantage of the Web.
Mosaic is a graphical browser, so it will only run on systems with X Windows (or MS Windows or Macintosh). A number of companies such as Quarterdeck have licensed the free Mosaic for commercial use rather than write their own. Mosaic is truly a high=quality application. But the price for beauty is more memory and disk space. Mosaic consumes over 1.3MB of disk space, and will use about 2MB of RAM while running.
Linux lynx, Mosaic is freely available. This freedom is slightly restricted, however, because Mosaic uses Motif programming libraries. This means you cannot recompile Mosaic yourself without a license for the Motif libraries.
To get Mosaic, search for it in the Linux Software Map. A copy of Mosaic can be found at sunsite.unc.edu and most other Linux sites. Assuming you have X Windows, no special installation procedures are needed. Just prepare to be impressed by a very professional program.
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.
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|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!
- SUSE LLC's SUSE Manager
- Managing Linux Using Puppet
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Parsing an RSS News Feed with a Bash Script
- Google's SwiftShader Released
- Doing for User Space What We Did for Kernel Space
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