Summary

This is the first post of two about a light weight way to implement a thesaurus. It is great for what I need, which is the occasional use of a thesaurus for writing text such as this article. Once it is set up, you can forget about it and just use K whenever you want to look up a word.

A nice bonus or synergy is that the website also returns a definition for the word, so it functions as a simple dictionary as well.

The second post will deal with how to use Vim's built in syntax rule sets to provide highlighting and nice colours.

There are two or three simple steps:

1. a vim script that passes the cursor word to an external shell script.
2. a shell script that looks up the word using an online thesaurus, then parses     [continued...]

I have been going through James Malloy's tutorial on writing your own operating system¹ , which involves some assembly and quite a bit of bit twiddling with shifts and masks in C.

I haven't written any assembly or done any serious bit manipulation for years. I can do simple (i.e. 1 byte) hexadecimal addition in my head, but nothing more complex than that, so I needed a quick calculator that showed me the results from doing things like bit shifts, rotates, masking, and so on.

A bit of googling found one contributor to Stackoverflow recommending calcc by Luigi Auriemma. A quick download of a small zip file and there it was, GPL'ed source code and pre-built binaries for unix and MS Windows.

It is quick and simple to use and has the usual unary and binary     [continued...]

There must be something in the water. First Steve Jobs, then Dennis Ritchie, and now we have received word that John McCarthy has died. He was 84.

McCarthy was the inventor of Lisp, the concept of garbage collection, and coined the term "Artificial Intelligence". He even (unbeknowingly) forecast cloud computing through his notion of computing as a general public utility. Although probably not recognised by the general public, he was very much one of the pioneers of computer science. He received one of the very early Turing Awards, in 1971.

At 84, we can't be too sad at his passing. Instead, we can celebrate his pioneering ideas.

Sad to read today that Dennis Ritchie died a few days ago. His death did not make the popular press, unlike Steve Jobs', and, in a way, that is an indicator of his life. He was the archetypal quiet achiever.

Ritchie was the co-author of the C programming language and the UNIX operating system. Both were hugely influential on the development of almost every computing device we use today.

Ritchie had a great influence on me. I had bought my first real computer, an Amiga 1000 (after having a System-80, the local equivalent of the TRS-80), and it was written in C. I knew nothing about C and set out to learn. The first book I bought was K&R (otherwise known as The C Programming Language), and the rest is history.

The Guardian has two nice articles, a eulogy, and a good historical piece.

Abbreviations

I use Vim's abbreviations a lot when I write this blog. I have abbreviations for most of the common HTML tags and, for HTML, I use abbreviations that start with < so that they don't get mixed up with any other abbreviations.

A quick refresher: vim lets you assign a string to a keystroke sequence, much like an auto-correct feature. I can assign "Nick Coleman" to NC and whenever I type NC{space} vim will change that to Nick Coleman. (You don't have to type space, you can actually type any delimiter character such as Tab or Esc.)

Back to abbreviations for HTML, an example: insert a <p> tag:

I just type <p{space} and vim expands it to the full tag. I only save one keystroke     [continued...]

Say you are editing in Vim and you need to edit a file owned by root. I have been using the sudo.vim plugin by Rich Paul, which lets you use sudo within Vim. It works fine, but here's a very simple alternative if you don't want to install a plugin just for this.

Thanks to Hacker News user drtse4, who gave this incredibly useful tip.

(It needs tee, which most unix systems have installed or easily available as a package.)

I wrote previously about setting up an iMac G4 to display photos and images. The images are from webcams around the world, pulled every few hours and displayed automatically. Now I go into some details about how I do that. (You can download the script at the bottom of this page.

What factors do you need to take into account when getting a webcam image? You need a URL. You might decide you want to get the image only during daylight, so you need some method of telling the script whether to download the image on this run or not. Some webcam URLs have a date or time embedded in them, so you need some way of generating that URL or of picking the latest image. You might want to display a caption with the image. Finally, you want to be able to rename the image since you could find name collisions (e.g. many websites use "webcam.jpg"), so you want to specify a name for the image.

    [continued...]

It's funny how you start off doing one thing only to realise that, before you do that thing, you need to do another thing first, only to realise that before you do that, you need another thing first...

So it was with my webcam downloader script, which I was going to write about, then realised I needed to do another thing first. (I will write about the webcam script later, mes amis.)

One of the things you soon realise when you capture webcam images from around the world is that you need some method of getting the image only during certain times. For example, the Grand Canyon is nice, but not at night when the webcam shows pitch black. Then you realise you need a tool to convert Grand Canyon time to your local time so you can easily instruct your download script whether to get the image on this run or to leave it for a later run. In this example of the Grand Canyon, I only want to grab the image if it is between 7am to 6pm their time and so I need to convert those two times to my local time to test if I should retrieve them or not.

It is easy enough to manually convert one or two times to your local time using, say,     [continued...]

If you can never remember where to place const in C, I read a handy tip recently.

Const always applies to the type to the left, the prefixed type. That's it. Except, if const is the first keyword then it applies to the following type. That's not really a cause of confusion though, because then it reads naturally.

Thus, these are all valid C:

The obvious gotcha is when using it with pointers and inadvertently applying it to the type instead of the pointer. So int const *ap; mean that the int is constant because the int type appears as a prefix to     [continued...]

There are a couple of plugins to manage Vim's buffers, of which the best known is probably MinuBufExplorer. I use that on a couple of machines and, while it gets the job done, I've never been completely happy with it¹ .

I really only use it for a display of the buffer list. It hasn't been maintained for several years, although there is a fork project available (see MiniBufExplorer's home page where the author lists a couple of alternatives).

Since you have to change buffers manually anyway using the :b xcommand, I figured why not just use a couple of key mappings to make life easier.

I never use F1 for help, so I mapped :ls<CR> to F1 like thismap <F1> :ls<CR>. Now, to change buffers, I just press F1 and I am presented with a list of buffers from which I can type :b1 and I am done. However, you can speed that up more if, like me, you find the : key     [continued...]