LJ Archive


And Now for Something Completely Different

There is a nice Python tutorial in the June 2007 issue [“Programming Python, Part I” by José P. E. Fernandez]. It would be wonderful if, after the tutorial is done, a monthly Python column would appear in the pages of Linux Journal. (I have seen columns on other languages, for example, Perl, but never a column on Python.)


BSD Script Modification

In the “Displaying Image Directories in Apache, Part IV” article by Dave Taylor [July 2007], I ran into a problem using the script on my hosting company's BSD-based system. Specifically, the problem was in the figuresize function returning an invalid width value.

The figuresize function can be changed to the following:

    width="$(identify -format %w $1)"
   height="$(identify -format %h $1)"

This change solved my problem and makes the function more efficient by eliminating four invocations of cut for every image.

Doug Winterburn

Recognize This

I've been more than getting my money's worth from LJ just from Dave Taylor's Work the Shell articles, but this month, my introduction to Tesseract doubled my pleasure [“Tesseract: an Open-Source Optical Character Recognition Engine” by Anthony Kay, July 2007]. I have been looking for an OCR program since I quit Microsoft seven years ago, and now I have one. Tesseract is outstanding, and Anthony Kay did a great job with the article.

Bruce Bales

Error Handling Instead of Ignoring

I am writing regarding to the article “Writing Your Own Image Gallery Application with the UNIX Shell” by Girish Venkatachalam, published in the July 2007 issue of Linux Journal.

In the script on page 71, Girish suppressed the mkdir error by redirecting the error message to the bit bucket:

# we don't want mkdir shouting at us for
# directories that exist!
mkdir $dimension 2>/dev/null

My suggestion is to do it this way instead:

# use -e instead of -d, since an existing 
# file with the same name could also prevent 
# you from creating the directory
[ -e $dimension ] || mkdir $dimension

Even better, handle the mkdir error this way after the mkdir error:

if [ $? -ne 0 ]; then
        echo Handle my error here

Thanks for the great magazine, and keep up the good work.


Response to the “Don't Just Beat Me, Teach Me” Letter, July 2007

Writing instructional software from scratch for Linux (or any other OS for that matter) is a time-consuming and nontrivial activity. For people to invest their time and energy in this, there would definitely need to be a payoff to make it a worthwhile undertaking. I think a much more promising approach would be a Linux port of existing instructional software. ChessMaster is indeed a very fine instructional package, and I highly recommend it to my students. Several years ago, I contacted Ubisoft regarding a Linux version of ChessMaster. Unfortunately, the predictable response was “not planned for the foreseeable future”. Linux has gained a lot of traction since then, even in relatively small market niches like chess.

A good example is one of the world's strongest programs, Shredder (www.shredderchess.com), which has been made available for Linux. I also happen to work as a consultant for a North American distributor and retailer (www.chesscountry.com) of chess software. My recommendation for Convekta (which produces very good instructional software) Linux software was favorably received, although I can't make any predictions. As Linux gains critical mass in the chess sphere, companies like Ubisoft will find it difficult to ignore Linux lest they risk being displaced by a newcomer. An intense lobbying effort might be persuasive, and they very well might consider porting to Linux. There certainly are enough capable developers available to make this happen.

Until then, I unfortunately have no better recommendation than to make do with one of the Windows-Linux integration techniques that are available to us. Mr Colon is quite right not to struggle with Wine. I have made the determination that running Windows apps via Wine is hit or miss—half will run after intense configuration effort, and half won't run at all.

The two preferable options are VMware or VNC. If you have only one computer and money is no object, VMware might be the way to go. My preferred solution is VNC (which is free). I utilize a multiboot laptop for my IT-consulting work. The laptop can boot Debian, Red Hat or XP (I recently removed SUSE for reasons covered in recent issues of LJ). If I need to access XP from my desktop, I simply connect the laptop to my home wireless network, boot XP and start a VNC server. Windows shares are made visible via Samba. The combination of VNC and Samba yields complete seamless access to the laptop running XP from my Debian workstation. Despite the fact that all my hosts are on a wireless network, the VNC performance is actually quite good. Of course, if you have an exclusively wired network, performance will even be better.

I think the VNC solution is a good fit for most Linux users, as most tend to have more than one computer that already may be networked together. Adding network connectivity is relatively inexpensive as compared to going the VMware route.

Unfortunately, I don't know of a Linux equivalent for ChessMaster, but until one arrives on the scene, I hope these suggestions will tide ChessMaster users over.

Peter Stein

Picture Imperfect

I just noticed the Pixel article [“Interview with Pavel Kanzelsberger, Creator of Pixel” by James Gray, July 2007]. Please do not promote that project; it is nothing more than a fraud. You should really look through their forums. There are many people who have been scammed. It is not current, it does not work, and there is a one-man team working on it. Besides that, it is closed source. The project is doomed and a scam, and I just ask you to please let it die.


256MB of RAM Is Plenty

In Nicholas Petreley's “Amazing Free Distributions Abound” [July 2007], it says, “I run Damn Small Linux on my old Compaq notebook with 256MB of RAM simply because it won't run anything more bloated than that”, but I run a full Ubuntu install on a Pentium 2 with 192MB of RAM. It's a bit slow, but not as bad as Windows XP was. I'm going to install XFCE instead of GNOME to give it a little boost, but 256MB is plenty of RAM for the average distro. Debian + IceWM would be pretty fast too.

Mackenzie Morgan

Let's Make a Deal

Nicholas, Your distro shopping spree in July's issue was entertaining, but it would be even nicer to read about other source-based distros besides Gentoo. Any chance of that happening?

I'm probably not the first one to bring this up, but I have to ask you if your anticipation of the next Linspire has faded by now. The recent deal between Microsoft and Linspire must have been announced right when you guys were busy getting the issue printed.


I'm very disappointed in the recent deals between Microsoft and Linspire, Xandros and others. Deals like these with Microsoft usually send Microsoft's new “partners” to the morgue. Time will tell if Linspire and others find a way to take the money and run or if Microsoft has the last laugh.—Ed.

LJ Archive