Tag Archives: Ubuntu Linux

Cheroot Privileges: a Potpourri of Pointlessness.

Cheroot (Tamil "shuruttu" meaning "a roll"): a cigar. Reputed to be pungent.
chroot (GNU coreutils, manual section 8): run command in special root directory.
Potpourri: a compost heap, montage, medley, or ragout. NB: never compost meat.
Root privileges: to have these is to be the super-user, operator, admin, etc.
Root: a dental nerve, et c.



My foregoing post touched on socket programming, when I mentioned TFTP. (BTW, MS
Windows has a TFTP client built-in: in the Programs & Features control panel app
open "turn Windows features on or off.")

Sockets are a hardware abstraction layer that deals with computer networking.
As usual, gritty details are beyond me and I gloss them over. (Tee hee. That's a
pun about oyster pearls.) Suffice to say that sockets are ports of call for data
transmitted between computers: hardware and protocol not withstanding, bytes fly
out one socket and land in another. We built this Internet on socket calls.
(A pun on Jefferson {Airplane,Starship}'s "We Built This City.")

For more information, consult the RFCs, and the IEEE's 802.* network specs.
Perhaps ftp.rfc-editor.org, www.faqs.org/rfcs, or www.ietf.org/rfc are of use?

And an update to my Javascript snippet in the remedial lecture...
    function initnary (ctr) { for (var i=0; i < ctr.length; ctr[i++] = 0); }
    function incnary (counter) { // Faster, but rollover instead of sentry.
        for (var L = counter.length, i = L - 1;
             (nary[i] = ((nary[i--] + 1) % L)) == 0 && i > -1;
        ) ; // Faster than the example in WP12, but rollover not sentry.
    } // end incnary(): Increments N-ary counter (length >= 1), by reference
    // ...
    var nary = new Array(items.length);
    initnary(nary); // nary's state: 0 0 0 ... 0
    incnary(nary); // nary's state: 0 0 0 ... 1
    // ...
... which is possibly a bit faster than the other one, although neither will be
optimized by an optimizing compiler (due to the complicated loop initializer), &
therefore both are of marginal utility.



It's 2017. To begin my new year on the right foot, I began it on the wrong foot.

My first hint that I'd need to effect some impromptu renovations to my skeleton
came to me when I noticed that I had begun to experience an unpleasant taste of
musty dust after picking clean my right anterior maxillar tricuspid. (The reason
why shattered teeth taste of moist chalk is probably because dentine & chalk are
both calcareous substances. I'd guess chalk rots too, if infected.) Another way
I could describe the taste of a rotten tooth is "like hard-boiled eggs that were
rotten before they were boiled," because they smell and taste alike. The dentine
(the material composing the interior of teeth) also feels distinctly like chalk,
or like gritty soil, when I palpate it with my tongue.

Anyway, my left anterior mandibular tricuspid has also been a goner since auld
lang syne, and the bone fragments left over inside my gums have really begun to
bug me, so a taste of fetor was the last straw.

Luckily, I had a small piece of surgical gauze left over from when I foolishly
had my wisdom teeth removed. (If you're considering removal of yours, then I am
here to tell you: DON'T! It's a waste of money, and, unless your teeth are truly
rotten or a source of pain, there is simply _no reason_ to remove even one.) If
you haven't tried to get a grip on one of your teeth before, you wouldn't know,
but even a tooth you've wiped dry is difficult to grasp without gauze.

I'm also the lucky owner of a pair of surgical forceps. These handy little tools
look like a long and delicate pair of pliers with the fulcrum very close to the
gripping side of the levers. ("They really pinch.")

In case you were curious, forceps are usually employed to grasp small objects in
surgical procedures. They can also be used as roach clips. (For avoiding burns &
stains of the fingers while smoking. Wide pipe stems containing packed cotton
accomplish the same end: you can make one from a hollow ballpoint pen and cotton
balls sold at any general store. Nevertheless a forcep is more generally utile.)

Those teeth's days had long been numbered. Their time had come!

So it was that I spent tedious hours doubled over with my fingers crammed in my
mouth, wiggling that thrice-damned curse of a bone to try and work it loose.
I quite unwisely, and disregarding the risk of breaking my jaw, channeled thirty
years of pent aggression into what remained of my tricuspid molar, as malodorous
flakes of rotten enamel & dentine fell upon my tongue like evil snow.

I knew I had effected some kind of progress when I heard a muffled click inside
of my head -- bones have eerie acoustic properties, like an unsettling resonance
and a tendency to produce a crunching sound (rather than a snap) when fractured
-- and felt a stabbing pain travel up the side of my head. Thankfully the pain I
felt due to prolonged migraine headache rendered this somewhat less intolerable.

I repeated this procedure until I lost consciousness.
Well, that's how I had hoped that this would end, but it didn't.
I could not bear the pain, and had to stop trying to pull my tooth.

Unfortunately for me, although I did manage to work the molar somewhat further
out of my jaw than it had loosened already (my dental hygiene, in case the memo
hasn't reached you, is worse than Austin Powers'), I didn't completely extract.
All I managed to do was cause a hairline fracture of my maxilla, which will un-
doubtedly be a source of major difficulty and pain to me in the decades to come.

Worse yet, my application of too much pressure via the forceps caused additional
shattering of the tooth; further attempts at extrication are counterindicated.
That's just as well, because the kind of general-purpose forceps I had available
aren't for dental extraction: this requires a special kind of forcep I hadn't.

I suppose it's just as well: considering the fact that some dentine remained in
the shell of the tooth, its nerve was probably still alive and well. The nerves
connecting teeth to the root canal are extremely sensitive, and interconnected;
what's worse, I could easily have broken my jaw by violently levering the tooth;
therefore, extracting my tooth myself would very likely have been suicide.

So, as far as sockets go, my teeth will be rotting in theirs for some time yet.



Other noteworthy pratfalls during January:
1. Accidentally locked myself out of Windows by attempting to install Ubuntu 16
   alongside, which occurred after it prompted me to designate a BIOS boot part
   (prior installs didn't manifest the prompt and gave me no trouble).
2. Locked myself out of Ubuntu too by trying to unbrick Windows.
3. Flashed in the backup EFI system partition and boot sector from a disk image,
   reset the partition table with fdisk, thanked lucky stars, began again at 1.
4. Broke shiny new laptop's fragile keyboard connector. Cursed fate.

Incidentally, I had some luck using this procedure to regain access to a Lenovo
IdeaPad 100-151BD 80QQ's UEFI Firmware Configurator after I had set my boot mode
to Legacy Support before installing Ubuntu, which locked me out of the config:
    1. At GRUB operating system selection screen key 'c' for a command line.
    2. normal_exit
    3. initrd
    (initrd fails because you didn't load the kernel, but then Windows Boot
     Manager tries to load in UEFI mode for some reason & presents a screen
     politely offering to give you the FW Config if you give it the ESC key,
     which it doesn't usually when your boot mode is Legacy Support instead
     of UEFI with or without secure boot.)
I ought note: Ubuntu 16 boots the configurator automagically in UEFI boot mode:
the option reappeared when I `sudo update-grub`ed while in UEFI mode.

Speaking of GRUB, here's a boot procedure (in case you've never driven stick):
    1. root=hd0,gpt8
       (Linux is at sda8 on my system)
    2. linux /vmlinuz
    3. initrd /initrd.img
    4. boot
Or, to shift gears into Windows:
    1. root=hd0,gpt1
    2. chainloader /EFI/Microsoft/Boot/bootmgfw.efi
    3. boot

While I'm on the topic, here's how to play a tune at boot time using GRUB:
    A.1. @ boot menu (operating system selection), key 'c' for a GRUB shell.
    A.2. play TEMPO PITCH1 DURATION1 PITCH2 DURATION2 P3 D3 ... ad infinitum
         Pitches are frequencies in Hertz; duration is a fraction of tempo.
or
    B.1. In Ubuntu, Control + Alt + T to open a terminal emulator window.
    B.2. sudo gedit /etc/default/grub
    B.3. Feed the recordable piano by editing the line at the bottom:
         GRUB_INIT_TUNE="325 900 6 1000 1 900 2 800 2 750 2 800 1 900 2 600
5 0 1 500 1 600 1 800 1 750 2 600 2 675 2 750 4"
         # ^- The Amazing Water (NiGHTS)
         GRUB_INIT_TUNE="1024 600 2 650 2 700 2 950 10 900 20 0 10 600 2 650
2 700 2 950 20 1050 10 1100 5"
         # ^- Batman, the Animated Series.
         GRUB_INIT_TUNE="2048 600 5 0 1 600 5 0 1 575 5 0 1 575 5 0 1 550 5
0 1 550 5 0 1 575 5 0 1 575 5 0 1 600 5 0 1 600 5 0 1 575 5 0 1 575 5 0 1
550 5 0 1 550 5 0 1 575 5 0 1 575 5 0 1 900 8 0 4 900 24"
         # ^- classic Batman.
    B.4. Save the file, and then sudo update-grub && sudo reboot
Musical notes within the 500-1500 Hz range tend to be within 100Hz of each other
(therefore ± 50 Hz for flats & sharps) typically, but act strange around 600 Hz.



GNU/Linux is dandy for computer programming, especially data processing, because
it is now (thanks to Ubuntu) easier to use than ever; but it changes so quickly
that I've barely skimmed over the repository before the next long-term support
version has been finalized. The installer wizard also sometimes makes mistakes.
The software repository is slowly morphing into a dime-store, any software worth
using requires considerable technical expertise cultivated @ your great expense,
and if anything breaks then you have to be the fastest teletype gun in the west.

And, because my comments re: Linux may mislead, I'm thrilled about Windows 10.
Have you played Microsoft Flight Simulator recently? Great game.