The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Monday, April 01, 2024

Notes on an overheard conversion while eating dinner at The Cracker Barrel

“Oh no. This is bad.”

“Wow! Are you sure there are no more moves you can make?”

“Nope. See?”

“How many pegs is that?”

“10.”

“Wow! You are really bad at that!”

[If you add up all the possible ways leaving just one peg in the Peg Game, including rotations, reflections and reflected rotations, you have 438,984 ways of solving the Peg Game. If you add up all the possible ways of leaving 10 pegs, including rotations, reflections and reflected rotations, you have just six solutions. It is a much harder problem leaving 10 pegs than leaving one. I'm just saying … —Editor]

Tuesday, April 02, 2024

It only took 25 years for my idea to catch on

I was exchanging emails with Christian about online document structure when I mentioned The Electric King James Bible and it's rather unique addressing scheme. I came up with that 25 years ago [Good Lord! Has it been that long? —Sean] [Yes. —Editor] [Yikes! —Sean] to precisely pull up Bible verses—anywhere from one verse to an entire book. Of all the Bible sites across the Intarwebs I've come across since have never used such an elegant, and to me, obvious, way of referencing the Bible online. Usually they use a URL format like <https://bible.example.org/?bible=kj&book=Genesis&chapter=1&start_verse=1&end_verse=1>.

But Christian mentioned Sefaria as using my method, and true enough, it does! <https://www.sefaria.org/Genesis.6:9-9:17> does indeed go to the Noah's Ark story. I think that's neat! I don't know if they were inspired by my site (unlikely, but not completely out of the relms of possibility) or just came up with it on their own, but it's nice to see someone else is using an easy to hack URL form for Bible references.

There are differences though—my site only brings up the requested material, whereas Sefaria implements a bidirectional “Scroll Of Doom” where additional material appears when you go up or down. I can't say I'm a fan of that, but it apparently works for them.

Dear LinkedIn, why are you still asking me these questions?

LinkedIn is still asking me to participate as an expert answering questions—this time, “You're a system architect. How do you decide which programming languages to learn?” And just below that is “Powered by AI and the LinkedIn community.”

Sigh. Eu tu, LinkedIn?

I'm still tempted to answer, but no. I can't just bear to answer this how I would want to answer it. Besides, if you know where to look, you might find my answers anyway.

Wednesday, April 03, 2024

An excessive number of packaging layers

I ordered an item from Amazon the other day. The expected arrival time was Friday, but instead, it arrived today. On the front porch was an Amazon box, measuring 6″ × 9″ × 5″ (16cm × 23cm × 13cm for the more civilized amongst you). Inside was another box, 3″ × 4½″ × ⅜″ (7cm × 11cm × 1cm). Inside that was a slightly smaller anti-static bag. Inside that was a smaller plastic bad, and finally, inside that was the item I had purchased—a replacement battery for my old-school flip phone.

Seriously? Four layers of packaging? Sigh.

“Because this kind of battery is encrypted …”

So I'm reading the “Battery Replacement Installation Manual” for the battery I just bought and as translated instructions go, it's not that bad. But there are some choice bits though …

Why does the phone echo?

The echo of the phone may be due to the installation problem. Can you see if there are any loose parts, because the battery will not affect the quality of the phone's call unless there is no power and cause the phone shut down.

“The echo of the phone?”

Feedback? Hearing my own voice echoed back to me? Maybe?

Anyway, carrying on …

Why did I receive a swollen battery?

Because this kind of battery is encrypted …

I have no clue here. It states that swelling may occur if the temperature exceeds 158°F (70°C), and enter sleep mode if the temperature is too low, although it doesn't state what “too low” means. Fortunately, the battery I received isn't swollen, so I guess it's not encrypted?

4. Please carefully check whether there is any debris or screws falling into the battery area. If there is, please clean it up before proceeding to the next step, otherwise the sundries may pierce the battery and cause a short circuit and cause spontaneous combustion.

“Sundries.” Love it!

Thursday, April 04, 2024

Tracking down a bug

I've spent the past two days tracking down a bug, and I think it's a library issue.

So I have this program I wrote some time ago that uses Xlib and for reasons, I needed to store a 64-bit value that's related to a window. This is easy enough with setting a window property. The code for that is easy enough:

void svalue(Display *display,Window window,unsigned long long int value)
{
  assert(display != NULL);
  assert(window  != None);

  XChangeProperty(
    display,
    window,
    CALC_VALUE,
    XA_INTEGER,
    32,	/* format */
    PropModeReplace,
    (unsigned char *)&value,
    sizeof(value) / 4 /* number of 'format' units */
  );
}

CALC_VALUE is the “variable” (for lack of a better term) and XA_INTEGER is (again, for lack of a better term) the base type. Yes, this is just wrapping a single function call in a function, but it's an abstraction to make things simpler as it's called from multiple locations in the codebase.

To query the value:

unsigned long long int qvalue(Display *display,Window window)
{
  assert(display != NULL);
  assert(window  != None);
  
  unsigned long long int  value;
  Atom                    atom_got;
  unsigned char          *plong;
  int                     rc = XGetWindowProperty(
                                  display,
                                  window,
                                  CALC_VALUE,
                                  0,
                                  sizeof(unsigned long long int) / 4,
                                  False,
                                  XA_INTEGER,
                                  &atom_got,
                                  &(int){0}, /* this is don't care */
                                  &(unsigned long int){0}, /* another don't care */
                                  &(unsigned long int){0}, /* another don't care */
                                  &plong
                                );
                     
  if ((rc == Success) && (atom_got == XA_INTEGER))
  {
    memcpy(&value,plong,sizeof(unsigned long long int));
    XFree(plong);
  }
  else
    value = 0;
    
  return value;
}

Again, nothing too horrible or tricky.

The code was originally written on a 32-bit system (just after I left The Enterprise), and it worked. I then wanted to get the program working on a 64-bit system (beacuse I want to both release it and talk about it). It worked, but only for values of 31-bits or less. As soon as the value hit 32-bits, the upper 32-bits were all 1s.

I added code to dump the value just before the call to XChangeProperty() and code to dump the value just after the call to XGetWindowProperty() and somewhere, once the value was 0x00000000FFFFFFFF going into XChangeProperty(), it was 0xFFFFFFFFFFFFFFFF coming out of XGetWindowProperty().

32-bit version? No issues. 64-bit version? Issues.

I tried a different compiler, on the off chance that I might be hitting some weird compiler bug, and no go, GCC or Clang, both on the 64-bit system had the same issue. I tried using a different X server and the same results—32 bit client, fine; 64-bit client, not fine. So I think it's due to the client side on the 64-bit system where the issue lies. Also, if I change the call to XChangeProperty() to:

void svalue(Display *display,Window window,unsigned long long int value)
{
  assert(display != NULL);
  assert(window  != None);

  XChangeProperty(
    display,
    window,
    CALC_VALUE,
    XA_INTEGER,
    8, /* format, this time 8! */
    PropModeReplace,
    (unsigned char *)&value,
    sizeof(value) /* still number of 'format' units */
  );
}

That is, a format of 8 fixed the issue. Even a format of 16 worked. It's just that when I try to use a format of 32, on the 64-bit system, does it fail.

And using a format of 8 on the 32-bit system works as well, so at least I have a workaround for it. Still, it's annoying.

I love it when abstractions are too abstract to be useful

I recently found an annoying aspect of Xlib—it's hard to find documentation about what keys affect the state field of the keyboard event. It's obvious that the shift keys on the keyboard will set ShiftMask, the control key will set ControlMask, and the CapsLock key will set LockMask (when I would expect it to set ShiftMask since it's just locking the shift keys to “on”), but there's little to say what keys set the Mod1Mask, Mod2Mask, Mod3Mask, Mod4Mask and Mod5Mask.

This is problematic, because I do need to check for keyboard events and this threw me for a loop—why are none of the keys working? Well, that's because my virtual Linux server on the Mac sets the NumLock key, which causes the X server to then set the Mod2Mask for all keyboard events and I wasn't expecting that.

Sigh.

Friday, April 05, 2024

Matchbox cars seem to have gotten bigger in recent years

Bunny and I went to a local Toyota dealership to fix an issue with her car (it turns out it was a very unusual, but very minor, issue) and while there, we saw this on the display floor:

[A very small electric car for one] That's not a car! That's an oversized roller skate!

Turns out, this is not a large Matchbox car, but a small electric car straight from a factory in Japan (the informational flying under the windsheid is all in Japanese). A five year old would barely fit in this thing, much less an adult. There doesn't appear to be any storage space of any significant size, and sans doors, I'm not sure this is even road legal. And the the staff there don't even know if it's for sale. Weird.

Obligatory Picture

[The future's so bright, I gotta wear shades]

Obligatory Contact Info

Obligatory Feeds

Obligatory Links

Obligatory Miscellaneous

You have my permission to link freely to any entry here. Go ahead, I won't bite. I promise.

The dates are the permanent links to that day's entries (or entry, if there is only one entry). The titles are the permanent links to that entry only. The format for the links are simple: Start with the base link for this site: https://boston.conman.org/, then add the date you are interested in, say 2000/08/01, so that would make the final URL:

https://boston.conman.org/2000/08/01

You can also specify the entire month by leaving off the day portion. You can even select an arbitrary portion of time.

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