Letters to the Editor
As an avid reader/subscriber to LJ, I've been collecting your articles related to webmastering and running a network/web server. This spans the gamut from creating/using CGI scripts to how to use “TCP Wrappers” (August 1997). I've got quite a selection now, and it's occurred to me that others may have the same need.
So, may I suggest LJ package reprints of all the pertinent articles from years past, add an index and perhaps some advertising, then sell it for a reasonable/nominal price, perhaps $5.95US (myself knowing nothing about the publishing, especially the money).
As an alternate, perhaps you could put up a page on your web site with an index to the articles, with each a link to a summary page or the actual text, if available. This might encourage people to then buy the back issues. —Scott Daniel email@example.com
I'll put it on the “wish” list. We do put articles on the web site after a time, but it's never certain as to when someone will have the time to do the HTML. We are also planning to start putting past issues on CD-ROMs and sell them in that format. The 1996 issues are in the works now.
Half a year ago, I'd asked on the Caldera mailing list what kind of applications people would want on Linux that weren't yet available. The two most-requested applications were an accounting package and Lotus Notes. With the Appgen announcement, one of those is now covered. As for the other...
I was in conversation recently with someone who has been talking to IBM (at an appropriately high level) about porting Notes to Linux. That person told me that any testimonials about potential end-users who would buy Notes for Linux would be instrumental in convincing IBM to make it happen. There are no technical issues; this is only a matter of marketing and convincing the sales folk.
While I have no use for Notes, I believe its availability for Linux would be both an important application and yet another validation of Linux's suitability for corporate use.
Please e-mail me any relevant information and I promise to pass it on ASAP—added to a few stories of my own... —Evan Leibovitch, Ontario firstname.lastname@example.org
I read Doc Searls article, “Shoveling Push Media”, in Linux Journal, June 1997. I threw out my TV six years ago; if push ever comes to shove, I'll do the same with my computer systems, too.
I've been in this business for fun and profit since the days of CP/M, designing circuit boards, programming, etc. and on the Internet for about a decade. —Max Southall email@example.com
In the August 1997 issue (just received), I have spotted what I believe to be an error. On page 40, In the column “Best of Technical Support” there is a footnote to the paragraph headed “Mysterious Zombie Process” which states, “When a parent process dies or is ended, any child process started by the parent becomes a zombie process.”
The condition described is that of an orphan process, not a zombie. Orphan processes are created when their parent process terminates, and all orphans are automatically adopted by the scheduler process (process 1).
A zombie process, on the other hand, is any process that has terminated but not yet been cleaned out of the process table. In some of the original Unix literature from the folks at Bell Labs, they comment that a zombie process can only be resurrected by the use of arcane magic.
In the voodoo religion, a zombie is a dead person who has been reanimated via magic, so the appellation when applied to a Unix (or Linux) process is not quite appropriate, but it comes close.
As to the problem experienced by Scott (the author of the note), I would venture to guess that the process he is invoking (netcfg) performs a fork( ), exec( ) combination, and the parent process then exits. This is a typical hack used to prevent the invocation of a program from hanging up the terminal if the user forgets to use the & character to run it in the background.
Since the parent has terminated, the terminal is again available for command input. The child process will still be running in the background, however. For whatever reason, the parent process is not able to be cleaned out of the process table (perhaps until the child processes all terminate?), and so it shows up as a zombie. —Harry Gross firstname.lastname@example.org
The footnote in question is almost a direct quote from “Unix: An Open Systems Dictionary”, William H. Holt and Rockie J. Morgan, Resolution Business Press, 1994. This dictionary also defines an orphan process as being synonymous to a zombie process. I wanted something short for the footnote, and the Dictionary gave me that sentence—perhaps, I need to buy an updated version.
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
- SUSE LLC's SUSE Manager
- Managing Linux Using Puppet
- Non-Linux FOSS: Caffeine!
- 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