UpFRONT
If you're running IP Masquerading and want to make services on your internal network available from the outside, just install rinetd on the IP Masquerding box available at http://www.boutell.com/rinetd/. (Also available as a package; check your distribution's web site.)
If you let other people run Perl scripts on your machine, make a symlink from /usr/local/bin/perl to the real location of Perl so they don't complain, “Hey, you don't have Perl.”
Another thing that shouldn't make any difference but sometimes fixes weird problems: switch PCI cards around in their slots.
If you have a complicated crontab, do a crontab -l > my_crontab_`date +%Y%m%d' to save it in case you royally mess up a crontab -e.
Use (, ), [, ], { and } for navigation marks in vi. The % command will move the cursor to the matching mark. For example, with
( some text [ some more stuff
another line
{ ]
} )
If you position the vi cursor on any of the marks, in command mode the % will move the cursor to the matching mark.
You can use this method in comments in a programming or scripting language to allow quick fast-forward and fast-backward over large blocks of code, as well as use it to find boundaries of functions in languages like C which use one of these marks to delimit functions.
Map an unused key to change files in vi. For example, if your .exrc or .vimrc has map , :e#^M when you've edited two files, for example, by giving
vi file1 file2<Enter> :n<Enter>
so that you're in file2 and in command mode, typing , (no Enter required) will switch you back to file1. Use it again, and you switch to file2 and so on.
by Reginald Charney
The falling fortunes of the dot-coms and the uncertainty of the election results, even before the election, have affected job figures. While the number of jobs offered has fallen since April, the decline has leveled off. Chart #1 shows the normalized job trends over the last 11 months. Ordinarily, things that don't change are not very interesting. But in this case, the fact that things have leveled off is good news.
(Note: Chart #1 is normalized for the number of jobs in January of this year. That is, the number of openings in January 2000 has been taken as 1.00.)
Over the last 18 months, a number of platforms have competed for dominance. One of the interesting aspects of this is how fast demand for the main platforms has been growing or shrinking. Demand is defined as the rate of acceleration/deceleration in the trend line for the period shown. From Chart #2, we can see that demand has been slowing for the older platforms, while the newer ones, like Windows 2000 and Linux, have accelerated faster than all others.
Again, the exception to the rule is Solaris. It is right up there with the newbies. This indicates that Sun is increasing its dominance of its markets. These demand lines are positive at the moment because of the long period of expansion. Over the last 30 days, demand for all platforms has followed the general trend and decelerated. However, the short term has not yet outweighed the long-term demand.
Doc Searls is Senior Editor of Linux Journal
Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
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Every security policy provides guidance and requirements for ensuring adequate protection of information and data, as well as high-level technical and administrative security requirements for a system in a given environment. Traditionally, providing security for a system focuses on the confidentiality of the information on it. However, protecting the data integrity and system and data availability is just as important. For example, when processing United States intelligence information, there are three attributes that require protection: confidentiality, integrity, and availability.
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| Designing Electronics with Linux | May 22, 2013 |
| Dynamic DNS—an Object Lesson in Problem Solving | May 21, 2013 |
| Using Salt Stack and Vagrant for Drupal Development | May 20, 2013 |
| Making Linux and Android Get Along (It's Not as Hard as It Sounds) | May 16, 2013 |
| Drupal Is a Framework: Why Everyone Needs to Understand This | May 15, 2013 |
| Home, My Backup Data Center | May 13, 2013 |
- Designing Electronics with Linux
- Making Linux and Android Get Along (It's Not as Hard as It Sounds)
- Dynamic DNS—an Object Lesson in Problem Solving
- New Products
- Using Salt Stack and Vagrant for Drupal Development
- Validate an E-Mail Address with PHP, the Right Way
- Build a Skype Server for Your Home Phone System
- A Topic for Discussion - Open Source Feature-Richness?
- Why Python?
- Tech Tip: Really Simple HTTP Server with Python
Enter to Win an Adafruit Pi Cobbler Breakout Kit for Raspberry Pi

It's Raspberry Pi month at Linux Journal. Each week in May, Adafruit will be giving away a Pi-related prize to a lucky, randomly drawn LJ reader. Winners will be announced weekly.
Fill out the fields below to enter to win this week's prize-- a Pi Cobbler Breakout Kit for Raspberry Pi.
Congratulations to our winners so far:
- 5-8-13, Pi Starter Pack: Jack Davis
- 5-15-13, Pi Model B 512MB RAM: Patrick Dunn
- 5-21-13, Prototyping Pi Plate Kit: Philip Kirby
- Next winner announced on 5-27-13!
Free Webinar: Hadoop
How to Build an Optimal Hadoop Cluster to Store and Maintain Unlimited Amounts of Data Using Microservers
Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
Some of key questions to be discussed are:
- What is the “typical” Hadoop cluster and what should be installed on the different machine types?
- Why should you consider the typical workload patterns when making your hardware decisions?
- Are all microservers created equal for Hadoop deployments?
- How do I plan for expansion if I require more compute, memory, storage or networking?




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