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David Bagley
Maintainer of xlock.

Interview of David Bagley


LF: Hi, Could you introduce yourself ?


D.Bagley: Yes, I'm David Bagley, a unicycler (yeah and before you ask I can juggle too), a vegetarian (I love animals), and father of 2 cute girls.

LF: You maintain xlock, could you tell me the history of xlock ?


D.Bagley: Well it all started when I got on an HP and found there was no way to lock my screen on the X Window System. I was familiar with xlock from Sun and although I new of xscreensaver ... I preferred the modes from xlock. So I ported xlock to the HP and added a few more modes (spline, maze, sphere, hyper, helix, rock, & blot) most stolen from xscreensaver. I asked Patrick Naughton, the original author of xlock, if he would like to add it to his distribution. Patrick said he was too busy and that I could maintain xlock.

LF: Under which OS or computer do you maintain or test xlockmore ?


D.Bagley: I used to test using HP, SunOS, and VMS but now I only have access to Solaris (work) and Linux (home).

LF: How many different kinds of computers does this software support?


D.Bagley: I try to make it so its only requirements are X and UNIX/VMS. I have a lead on an NT port but I am pretty die-hard UNIX advocate. I added the requirement of an ANSI-C compiler. It cut out a few old UNIX boxes but they can always get gcc. This made maintenance a little easier since patches in my mail would always come in ANSI-C.

LF: Do you know how many copies of xlock now run in the world ( on Linux box, on BSD , on Sun, on HP ...) May be hundred may be million ?


D.Bagley: Yeah I do not keep track. On many distributions of Linux, xlock is loaded by default if they load the X, so it could be up there.

LF: The license I prefer for software, is cardware, everyone who likes your software should send you a post card ? :) look at http://www.xbae.syd.net.au/postcards.html you could see my name :) ?


D.Bagley: Yeah. I prefer BSD style copyright. I prefer as few restrictions as possible while preserving the author's name on the code. Also I can not really change it anyway since I am not the original author of xlock. How about Belgian Chocolate ware... if you live in Belgium and use xlock you are required to send 500g of assorted chocolates (no coconut please).

LF: On how many computers is the software installed (may be with all Linux, on BSD Sun, on HP , on .....)?


D.Bagley: I don't know. My estimate is to multiply my monthly mail by 1000. So I guess maybe 80000 know enough about xlock to run it from the command line. (I find Christmas time depressing because I do not get much xlock mail :( ).

LF: What kind of problems do you encounter with xlock ?


D.Bagley: Finding time. There is so much I would like to do. I am always suffering from sleep deprivation. After 5 years maintaining xlock, there are parts of xlock where I am not comfortable changing. I usually try to tackle easy problems first in my extensive TODO list. TrueColor problems are hard for me to figure out, especially lately since I no longer have a 24 bit display to play with. :(

LF: xlock(more) has around 70 modes ? Which one do you prefer, and why ?


D.Bagley: Yeah I recently counted 90. Its getting out of hand. I guess I like the "boring" life modes, and ant, crystal, and penrose. Fixing up "life" was one of my initial inspirations in taking on xlockmore. Some of the initial life configurations in the Sun version of xlock have small mistakes which cause them to eventually die. Penrose is really neat besides all the complicated math behind it, it sometimes makes mistakes and it later figures out that it can not tile anymore without creating an imperfection (run with -verbose to have it notify you).

LF: How many people work on this software ?


D.Bagley: I usually have 6 or so regulars who bombard me with fixes and updates. Many others have sent patches, suggestions and modes. I want to take this time to especially thank Jouk Jansen who has been helping me very consistently for many years (author of the crystal mode).

LF: Do you think the command line interface is dead, and now everything is GUI (Graphical User Interface)?


D.Bagley: Its kind of sad. I think I can get more work out of a command line than a mouse. I still like games like Adventure and hack too. Its kind of restrictive to have text screensavers though... the only thing I can think of hand is falling letters. ( without intervue ) ( SCO got one text-screensaver , I may be I'll make it :) ?

LF: Xlock has a competitor, xscreensaver. What kind of contact do you have together ?


D.Bagley: Jamie Zawinski (the author and maintainer of xscreensaver) and I have had many arguments and discussions. I admit xscreensaver is a superior product, but I prefer the ease of running xlock (just one "simple" command). During periods of cooperation we (Jamie did the bigger part) made it so that xlock modes can be easily compiled into xscreensaver. We still make it a point to steal good ideas from each other. We recently have a agreement to share files (i.e. no changes) where practical. We'll see how it goes.

LF: What do you think about the other screensavers like after dark or screensavers for Microsoft ?


D.Bagley: It has a nice user interface, if you are into that sort of thing. I think xlock has some weird options that would never show up on Microsoft... like -use3d, just in case you have 3d glasses handy. Its the kind of option that is not likely to appear unless source code is freely distributed and patches can be fed back to the maintainer.

LF: Some 3D modes have appeared in xlock, after the third version. How do you analyse this evolution?


D.Bagley: In retrospect, earlier main version changes have been quite arbitrary. However, from version 3 to version 4, I adopted OpenGL and GNU's configure and also broke up the source into separate directories. The 3d stuff (OpenGL) is pretty cool. Its here to stay, especially since Microsoft adopted it. I would like to see more modes written using it. A text3d mode is currently in development.

LF: How does the community of UNIX or Linux users react to your work ? Tell us about the CD SuSE gave you a CD, email, a story board someone sent you.


D.Bagley: About half my mail is from Linux users. I always enjoy receiving mail and patches about xlock. Support from the web is a major component of xlock. I am also very grateful for SuSE (a major Linux distributor) in distributing their Linux CD to me, because I am a developer/maintainer.

LF: Will you stop maintaining xlock soon ?


D.Bagley: I have a standing offer for anyone with more time than me to take it up. (I would like some patches for xlock first so I know its going into safe hands). Then I could concentrate on improving modes (which was why I got into this). Much of my time is taken up answering mail, testing, maintaining the main part of the xlock program and adding patches. In reality though, I think it would be hard for me to give xlock up, since I always seem to make time for it (my wife says I should get paid for it). I recently got a more demanding job so I have less time to devote to xlock... I also want to update xabacus someday, but my email is just about 100% about xlock, so I never get around to it.

LF: What do you think about Linux Free BSD, and free software in general ( GNU gcc, emacs, Open source netscape ) ?


D.Bagley: Its great to have the source. Its also great to allow users to feedback suggestions and patches back in to the distribution. I think more work should be done in getting gcc to work faster on different architectures. I have no expertise in that department. I use gcc and SunC all the time. emacs, yuck, I am a vi user even on my "DOS" machine. I like vi since as an administrator its guaranteed to be on the system (at least in the commercial world). One problem I have with vi on Linux is there is no standard vi. I love the new features, like multiple undo's, but other features of vi that I am used to sometimes do not work. Open source netscape, yeah I think that was Jamie Zawinski's idea (one of his many cool ideas). I do not know how he finds so much time to put into xscreensaver too.

LF: What do you think about Solaris giving the source code free ( 20 $ for the CD with port ).


D.Bagley: Wow. Thats the first I have heard of it. If I did not know about Linux I would probably get it. Since I need different operating systems to test, I'll keep my Linux machine for home use. I would really hate to choose though if I could only have one. DEC should do the same thing with VMS but they are probably not likely to. By the way, I really hate the name xlockmore... but what can I do now? I did not give it too much thought when I first started maintaining it. I wanted a name where it was easy to tell I was not the original developer.

Submitted in English.


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