Mike Meredith

Silly Tools for The Graphical Terminal: Flag

Jan 252019

If you are using the right kind of terminal that supports graphics inline (such as KiTTY), then you can write simple (or complex) tools that insert images into the terminal.

Being able to display the flag of a country (if you know its two-letter ISO code) is kind of trivial but useful if you need it.

And a shell function to do that is remarkably simple :-

function flag {
    wget -o /dev/null -O /var/tmp/flag.$$ http://flagpedia.net/data/flags/normal/${1}.png
    if [ $? -eq 0 ]
    then
        kitty +kitten icat /var/tmp/flag.$$ && rm /var/tmp/flag.$$
    else
        echo Not found
    fi
}

(that’s a Zsh function which may require adaption to Bash).

Southsea Photos

Photography No Responses »

Jan 192019

Vi Movement Keys Considered Harmful

Computing, Linux No Responses »

Jan 152019

Now that the click-bait is out of the way, vi movement keys are perfectly reasonable particularly to those who have been using them for decades (which includes me). But for ages, vi itself has supported the arrow keys for movement as well as the tradition cursor movement keys.

For the benefit of those who have not used vi and are wondering what those traditional cursor movement keys are, they are H (left), J (down), K (up), L (right). A bit like the gamer’s set of movement keys – W, A, S, and D, except that the vi movement keys pre-date arrow keys.

There are those who will claim that the traditional movement keys are more efficient as they require less hand movement. And they are. So it is perfectly understandable that many tiling window managers and other keyboard-centric software uses these movement keys.

But someone who hasn’t spend decades hard-wiring the vi movement keys into their brain, will find vi-style key bindings inscrutable. And the fix? Just use the arrow keys as well.

There is no harm in having two key sequences do the same thing; no harm in emphasising that the arrow keys work too. And indeed no harm encouraging the use of vi-style movement keys by emphasising their efficiency.

Don’t forget that someone learning a new tiling window manager (or most other things) can be put off by the silliest of things – such as inscrutable control keys.

Do RFID-Blocking Wallets Work?

Computing, Security No Responses »

Jan 052019

Well mine does (which I would recommend, but I’ve no idea what it is), but I don’t know about yours.

Send me it with some cash in it, and I’ll take a gander.

But …

Just how practical is RFID or NFC scanning anyway? The scaremongers would claim that there are people out there, slapping payment terminals to your bum and siphoning off your bank account.

I know from my own attempts at scanning (and you will know similarly from “tap & pay”) that the distance at which you can read RFID or NFC is normally fairly minimal. Sure you can get antennas which can read at distances of up to 700m, but they tend to resemble those old TV antennas.

Which is kind of obvious for someone trying to be at least relatively stealthy.

And if they do grab details they get to make a single limited payment (even a bank isn’t dumb enough to miss multiple payments) and you’ve probably got a good claim against the bank any way.

So it is pretty unlikely, the damage is limited (and may even be none).

So is an RFID/NFS blocking wallet really necessary? Well if you are in need of a new wallet any way, getting one with that feature makes sense. But it probably isn’t worth throwing away a perfectly fine wallet to get one.

But stick your wallet in your front pocket.

Photography: Let’s Lose The Film Sizes

Photography No Responses »

Jan 032019

I have been looking at slightly newer cameras than my ancient Canon 1DS III. There are two big things that have happened since I last took a serious look at cameras :-

Serious cameras are increasingly going mirror-less; last time I looked, electronic viewfinders were too low in resolution and suffered too much lag to really replace optical view finders.
So-called “medium format” digital cameras are becoming slightly less expensive.

Funny thing is that whilst the “film vs digital” argument has gotten a bit quieter, it is still bubbling away. And as a solely digital photographer, my position on “film vs digital” is simply: it is the final print that counts however you got there.

Back in the days when film was the only viable choice the quality difference between 35mm film and medium format film was dramatic. And similarly between medium format film and large format film.

In the digital world, the difference is more nuanced, and there is more choice in the size of the sensor (“film”) – Micro 4/3 (which is equivalent to the old 110 film format), APC, “full frame”, and “medium format”.

The least honest phrase is of course “medium format” – medium format film came in a variety of different sizes; all of which are actually larger than the medium format digital sensors. The largest “medium format” sensor is approximately 54mm x 40mm; the smallest film medium format is 60mm x 45mm.

Comparing digital and film sizes is pretty irrelevant; with film, quality is directly proportional to size whereas with digital many factors contribute to quality; sensor size being just one.

Part of that quality increase in size is simply down to the increased cost – if you have to make a digital sensor expensive because it is big (fewer sensors per wafer and a higher proportion of them won’t meet the quality standard), then you need to make it better in quality or nobody will buy it. Of course there are also scientific reasons why a bigger sensor is better – or the fancy car priced Phase One cameras wouldn’t have big sensors.

But back to digital sensor size – let us stop calling so-called medium format sensors “medium format” and come up with a new phrase – perhaps “super-frame” and give the crop-factor – 1.67 or whatever it is.

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