Older blog entries for ingvar (starting at number 302)

Interesting (but rather pointless) self-replicating shell- script:

#! /bin/cat

Make sure it's executable, then you can replicate the whole script by running it... But, maybe, there's some usefulness to it? Doubt it, though.

IN slightly less whingeing news, since the latest (well, second) installment of the annual Snooper Report has been turned down, I'll let it loose on an unsuspecting public (and, of course, the URL is too wide for the Advogato editing window, so now I'll get bots come and look for URLs with %0A in them, grr).

In almost as exciting news, I cobbled up a proof-of-concept of a blackhole maintenance library (CLI client, web client, libarry code, DB backend and a reaper suitable to stick in cron, to remove blackholes once they expire).

One of the little web toys I knocked together and occasionally use for pontificating is my Essays site. Since its initial creation, I've added a comment functionality, but due to the prevalence of spam, everything requires manual verification.

Not, in and of itself, a major problem, but I've noticed something quite disturbing in the spam comments (most, alas). The latest is that they're pointing to the SourceForge forum (with URLs that start http:// cmr.sourceforge.net/forum/) and I am in two minds about that.

One mind says I shouldn't bother complaining, because they should already have noticed. The other mind says I should, indeed, point it out to them (with a slight risk that the forum is zapped; this happened last time I pointed the issue out).

Instead, I decided that thee Right and Proper thing to do is to have a semi-public whinge. Don't know that it makes me feel any betetr, but at least I am not feeling any worse.

I have previously written a short essay, or possibly a rant on "develop and release straight out of version control" or "release in versioned lumps of code, with the development being separate".

That whole thing just jumped to the fore-front of my mind, as it seems that SLIME has changed under my feet again (no, I didn't intentionally upgrade SLIME, but it seems as if I need to stop getting SLIME via Debian and instead pull it myself, so it stops changing when the rest of the system upgrade; I also need to downgrade the SLIME I have installed as whatever I run now is less functional (for me) than what I ran prior to the last upgrade).

I don't know if things would be better or worse if "package and release" was the dominant paradigm, though. It'd probably cause less friction with an auto-update system that is tailored to packaged and versioned releases.

So, upgrades happened at home and, as occasionally happens, X stopped working. X stopping working varies from "trivial" to "annoyingly painful" to troubleshoot, especially as there was NOTHING in the xorg.N.log file to indicate what the issue was and it wedged the console to the point where "shutdown, reload" was the only way to get it back (thankfully, I could log on from another machine to do that).

In the end, it was a surprisingly simple fix, after "startx 2>&1 > trace-file" gave me the crucial bits of info. An expected symbol was not around in a dynamic linking stage and chasing that down gave a simple(ish) fix. All I had to do, in the end, was to uninstall the fglrx driver (something I installed in the first place to get working accelerated 3D primitives and direct rendering).

But, it did made me wonder, if the Xorg server can write to stderr, why can't it log the lack of a symbol to the og file? Maybe, I don't know, because that writing happens in a non-X library? I should probably have a poke at that, at some point.

18 Jun 2009 (updated 18 Jun 2009 at 08:51 UTC) »

As Pierre Mai so eloquently writes, the evaluation order corner case is explicitly covered as "it depends" by the Standard, so any code that depended on it is, well, relying on implementation-specific details.</a>

17 Jun 2009 (updated 17 Jun 2009 at 11:41 UTC) »

Intriguing. I have found an interesting corner case, where I believe the Common Lisp standard doesn't have an opinion. I don't think it's really any critical corner case, as I (right now) can't see any legitimate use of the difference, but...

Basically, in the case of the following:

(defun frob (x) (format t "Frob: ~a~%" x))
(frob (defun frob (x) (format t "New frob: ~a~%" x))
does the printed line say "Frob" or "New frob"?

It is, I believe, fully specified what will happen when you do either of (funcall #'frob ...) or (funcall 'frob ...), but out of the two implementations I have tried (SBCL and CLisp), I have two different behaviours. SBCL prints "New frob" and CLisp prints "Frob".

I shall have to ponder this, for a bit, I think.

Been a while since the last post. Work has been hectic, what with having to battle through the amendments to my pre- takeover contract into my new post-takeover contract. Mostly it seemed to be down to the legal department just not getting FOSS and once the whole "he's doing this for fun?" clicked, they didn't seem to have a problem anymore.

Two papers finished off, both declined to Conference #1, but now submitted for the consideration of Conference #2.

Two essays, on data structures and time complexity and electronic fora finished off.

OK, as an addendum to my previous post, I ended up screen- scraping what I needed, parsed the data I wanted out of it and generated SQL statements to (later) populate a database with. It would probably have been more elegant to connect to the database and insert the data directly, but a FORMAT call is quite convenient, as it were.

The screen-scraper was constructed by using DRAKMA to fetch the pages and then some substring functions to extract the data I needed. Estimated 30 minutes of coding lisp and testing, then a further "lots" of actual scraping.

But, my main musing for today is something I've noticed recently, in my Apache logs. It seems as if there's an active business in "referring page" spam. I haven't run the numbers, but from eyeballing the logs, I am seeing at least a couple of page fetches per day, where the "referring page" field is several URLs that trigger my wetware "this is spam" detection. I wonder what the reasoning behind it is? Maybe they're banking on sites publishing their stats publicly?

Border-line silly question. Is there an easily-navigated (or searchable) repository of vulnerability reports that can list things in a time-span? Last time, I ended up going through the BugTraq mailing list archive, but if someone has already collated specific vulnerabilities by "first reported date", it'd make things slightly easier for me.

Looks as if SecurityFocus have the raw data, but (alas) no obvious navigational features to let me do what I want.

Yes, it's that time, again. Snooper Annual Report! MUCH less than a year since last, but probably about a year before the next time it gets done. This time, it also spans exactly one calendar year and overlaps slightly with the tail end of the last report's interval.

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