Random Rant

As if hunting down buffer overflows on RISC OS isn’t taxing enough… (in my own code)
My latest find is a real gem.
The BBC rss feed is giving random filenames ….
e.g.
/png/.png or
/gif/.gif

And guess the filetype? JPEG

So just wondering if the /jpg/.jpg are gifs and png’s ;-)

At least it proves all code is crappy, not just mine!

“If buildings were built the same way programmers wrote programs, the first woodpecker that came along would destroy civilisation.”

One of my favourite quotes I had on a mug I regret breaking many years ago, or it was something like that.

I made an error on the first version of my image watermarking (php for my blog) and it was returning everything as a JPEG instead of what it should be (PNG or JPEG). I only discovered this when doing a review of the code myself. I suspect the mainstream browsers look at the file header instead of doing something stupid like relying upon the file extension. ;-)

Yeah thankfully changefsi doesn’t care about the extension or file header.
I haven’t yet put in code to check the headers and set the filetype based on that yet.
Web servers rely on file extension to set the Mimetype (or apache does)
But I did find a “bug” in changefsi…
If you pass a file to changefsi to convert, and then modify the file whilst it’s converting it, changefsi falls over in a big pile of **** screwing the OS good style when you drop to the command line and execute *shut.

Yes that was definately my fault causing that issue to happen, which I’ve stopped now.
A nice race condition though!
Should I report that as a bug…
“If programmer is a fool and tries something daft, changefsi will die”
It did make me chuckle though when I found it…
I’m off to stab myself with a pen in my eye as penance.

“If buildings were built the same way programmers wrote programs, the first woodpecker that came along would destroy civilisation.”

One could claim with some legitimacy that some new-build housing is close to this… at least, closer than much of the existing stock, which is decades or centuries older.

Mmm, I see pictures of after forest fires in California and such and all that’s left is a burnt-out chimney. I can’t help but think “hang on, what was the REST of the house made of?”.

When there are fires in houses around here, the roof collapses. They can often be rescued by clearing out the debris, sand-blasting the walls, and putting another roof on. It is also common to see haphazard cement slapped on top of the walls, as it is water penetration that’ll do the damage…
Of course, these properties saw both World Wars, Napoloeon, poncey dudes-dressed-like-girls, and maybe even Charlemagne.

When we first came out, we were concerned by a damp patch on the wall. Our elderly neighbour said “it’s probably been there for four hundred years, I wouldn’t worry about it”.

I wonder if the new lego-block monopoly houses will have a hundred years in them, never mind an easy half-millennium.

If you pass a file to changefsi to convert, and then modify the file whilst it’s converting it, changefsi falls over in a big pile of **** screwing the OS good style when you drop to the command line and execute *shut.

Wait… are you complaining that something panics if you alter the data it is currently reading?!?

<aside>Thought occurs to me – how is that even possible? If you have the file open for read/write when you pass it to ChangeFSI then CFSI should fail to open the file as it is already open in a different sense. If the file is closed and CFSI opens it, you should not be able to open for read/write a file that is already open…</aside>

Lol, no I’m not complaining. Technically it may be a bug, but I put the point in about reporting a bug as humour.
The bug report would be funny to read, very funny – as you seem to have noticed ;-)

The file is opened w+ (not rw) and written to then closed, and passed to changefsi, which I assume will open it “r”
Then in the race condition, the same file is opened again w+ and closed, now every so often downloading the file takes less time than changefsi takes to process it…. in which case changefsi is still processing the file when it gets modified.
I hadn’t realised that the cmdline version of changefsi multitasks, I assumed it single tasked.
It’s something along those lines.

Of course, these properties saw both World Wars…

The flaw in the “we don’t make them like we used to” claim is that you are not comparing like with like.

After all, the ones that weren’t built that well are no longer here for you to compare with.

While you could validly argue that weaker structures were blown up (though that could apply to anything in the way of an explosive); I would have to question how many modern constructions will have ~500 or so years in them.

the ones that weren’t built that well are no longer here for you to compare with

True. What’s needed is an analysis of why they’re not there… war damage, slum conditions, redevelopment of an area, lack of maintenance, general delapidation through poor construction, etc.