Letters to the Editor

Readers sound off.
Webmaster Handbook Idea

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 sscott@blueghost.npt.nuwc.navy.mil

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.

Lotus Notes for Linux

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 evan@telly.org

Really Push League

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 max@prninfo.com

Zombie Processes

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 harry.gross@ix.netcom.com

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.