I bought The Ruby Way a few weeks ago and thought it would be nice to write a short review about it. But I won’t, because there are already many reviews about it. The excecutive summary: it’s good, really good.

I stumbled over three very handy shell variables CDPATH, HISTCONTROL and HISTIGNORE.

• CDPATH takes (just like PATH) a list of directories to use for tab-completion for cd, e.g. export CDPATH=".:~/:~/work/:~/download/" gives me a tab completion for the current (don’t forget this one!), my home, my word and my download directory.
• HISTCONTROL can be set to ignorespace, ignoredups or ignoreboth. The first ignores lines starting with a space (I’m not sure, why this is useful ) but the second causes bash to ignore duplicates. The last one turns turns both options on.
• HISTIGNORE takes a list of patterns for commands which should not be saved, e.g. export HISTIGNORE="rm *:cd *:[a-z][a-z]" ignores rm and cd with any parameter and every 2 letter command.

Related entries:

• A few new useful bash keybindings

This morning I finally ordered an Ipod Nano Red. I submitted the order around 10:00, I received an order confirmation at 10:40 saying my order will be posted today or tomorrow. A few minutes ago (19:40) I received the shipment notification saying my Nano is on its way. It took them less than 10 hours to process my order, which included engraving the Ipod, which earned them another happy customer and some free advertising

Update 29.11.
I received my Nano yesterday, less than 36h after posting the order. I’m quite happy with it, except for one annoyance which is completely my fault: I forgot that the port on my laptop is only USB 1 and it took ages to put all the music I wanted on the Nano.

Just a short note for people like me who wanted to purchase Getting Real but forgot about it: it is available for online reading.

I love ThinkGeek and all the useless gizmos they sell. But it has one huge disadvantage: obscene costs for shipping. I was happy to find out about GetDigital.de, a German online store, that sells similar stuff.

Rubyforge seems to be down again. A working mirror is http://rubyforge.planetargon.com/gems.rubyforge.org (thanks Robby Russell).

Kopete allows you to quickly add a message whenever you change your online status. Just click Set Status -> Online -> New Message and enter a new message.

But there is no way (at least in the graphical UI) to remove these messages again. These messages pile up and the UI is cluttered with useless old messages.

To remove unwanted messages, close kopete and edit .kde/share/config/kopeterc. You will find a section [Away Message] with a Messages entry. As you have probably guessed by now, this entry contains a comma-separated list of your away messages.

.kde/share/config/kopeterc
...
[Away Messages]
Messages=work,bughunting...,meeting,Essen
...

And now I have to set my online status to work again

Related Posts:

• Using Google Talk with kopete
• Install new themes for kopete

[tags]kopete[/tags]

My old PDA (Palm V) is slowly falling apart and I’m thinking about buying a new one. The Palm TX has all the features I really want: PDA with WiFi. A smartphone would be nice, but I’m not willing to do without WiFi.

Here is my perfect PDA wishlist, if someone knows of any other PDA/Smartphone that fits these criterias and is available in Germany, please leave a comment.

• default PDA functionality (this should be no problem)
• small and shiny (~Palm V – Apple should build a PDA)
• WiFi
• decent runtime (this will probably clash with WiFi)
• able to sync IMAP-mailboxes
• any kind memory card, I’m not picky

And now to the contest part of this post: If someone recommends a PDA and I follow this recommendation, he or she will get all my old PDAs (2 * Palm V, 1 with Titanium Case)

I stumbled over this funny site called CodeGolf.com and tried my luck on the first problem (actually it’s the sixth, but it was the last and therefore appeared first on their page – confused?) Writing a Brainfuck Interpreter:

The brainfuck language uses a simple model of a computer consisting of an array of memory cells, a movable pointer into the array, an output stream, an input stream and the program itself. The program is formed from a sequence of the below commands :

• > – Increment the pointer to point to the next cell to the right.
• < – Decrement the pointer to point to the next cell to the left.
• + – Increment the byte pointed to by the pointer.
• - – Decrement the byte pointed to by the pointer.
• [ - Jump forward to the command after the corresponding ] if the byte at the pointer is zero.
• ] – Jump back to the command after the corresponding [ if the byte at the pointer is non-zero.
• . – Output the value of the byte at the pointer.
• , – Accept one byte of input, storing its value in the byte at the pointer.

It didn’t take me very long to write a running interpreter. My first version was more than a thousand characters. Even after renaming the variables and stripping all the whitespaces I still needed around 700 characters, which is huge compared to the best Ruby solution with only 142 characters. Read the rest of this entry »

This is a great thread on Lamba the Ultimate. The quality of posts at LtU is usually pretty good, but this one is even better. What really suprised me is the lack of flaming. Probably because of the “that you can’t prove (yet)” in the original question, which labeled everything as speculation.

The whole discussion is worth reading and there is a wealth of interesting pointers. Below is the list of links I followed or will follow as soon as I find the time.

• Lively Linear Lisp — ‘Look Ma, No Garbage!’
• ‘Use-Once’ Variables and Linear Objects
• Philip Wadler: Linear Logic
• omake
• Patterns of Software (pdf)
• Psychological criticism of the Prototype-based object-oriented languages
• E
• Partial Evaluation and Automatic Program Generation or pdf
• partial-eval.org
• Partial Evaluation – An Overview