Imenu

Posted on 2018-01-04 by jcs

Here’s a useful reminder from Wilfred Hughes:

I say “useful reminder” because—at least for me—it’s easy to forget about it. That’s true even though I have it bound to an easy keystroke, Ctrl+..

I originally set it up to make package configurations in my init.el easy to find but it’s actually handy for navigating in most languages. It gives you a list of functions and top level variables and, if you do such things, classes. When combined with counsel-imenu you get a nice Ivy-like list of candidates that you can successfully refine to narrow in on exactly what you’re looking for.

The reason that I often forget to use it is that swiper is so powerful that it’s my automatic go-to-tool when I’m looking for something in a file. That’s true even if I just want to glance at it and not necessarily move to it. Still, imenu is useful and gives a nice overview of what’s going on in a source file. It’s worth trying to remember to use it.

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Lava Lamps

Posted on 2018-01-03 by jcs

If you’re a geek with an interest in cryptography, you know that one of the hardest problems in practical cryptography is random number generation. A weak PRG (pseudorandom number generator) is one of the surest ways to get a cryptographic protocol compromised. Most PRGs depend on random events such as mouse activity, disk latency, and other such non-deterministic events to seed the PRG with the required randomness.

You may also know that lava lamps, that refuge from the 1960s, can also produce random numbers1 but if you’re like me, you’ve probably always considered that a (geek) cocktail party factoid of no particular use. It turns out I couldn’t have been more wrong. Cloudflare, which handles about 10% of international Internet Web traffic, uses lava lamps to generate their random numbers. They have a wall with over 100 lava lamps that are busily bubbling away. A video camera captures the action and sends it to a computer for conversion into random numbers. This is an elegant and relatively low cost way of producing the large amount of random numbers that an operation like Cloudflare requires.

Oddly, the 53 year old fad remains strong to this day and you can still get a lava lamp. It makes me wonder what the Hippies would have thought of their beloved lava lamps being used as an integral part of computer communications.

Footnotes:

1

If you’re interested in the details, here’s a nice explanation. It’s a lot simpler than you might think.

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Typesetting the TeX and LaTeX Symbols with Org Mode

Posted on 2018-01-02 by jcs

After writing yesterday’s post, I poked around a bit on Higham’s site looking at some of his recent posts. I’m glad I did because I discovered that something I’ve wanted to do is possible. Occasionally I want to typeset the TeX or LaTeX symbol in a blog post. After a bunch of experimentation I discovered that $\LaTeX$ does typeset the symbol as \(\LaTeX\) but it typesets it in Math mode, which gives it an Italic look. I experimented some more but couldn’t get it to set the symbol in Text mode. I concluded that that was just the way it was. (Yes, I know, it’s Emacs; of course it’s possible.)

But looking at this post of Higham’s, I noticed that he was getting it typeset properly as \(\mathrm{\LaTeX}\) and his blogging workflow is very much like mine. One of the things I learned from my Mathematics training is that it’s often true that knowing a problem has a solution makes it easier to find that solution. That’s exactly what happened here: the first thing I tried worked.

So here’s the solution:

  • $\mathrm{\TeX}$ → \(\mathrm{\TeX}\)
  • $\mathrm{\LaTeX}$ → \(\mathrm{\LaTeX}\)

Oddly, I tried a solution like that before but apparently didn’t get the incantation exactly right.

I’ll probably complete the solution by adding a couple of snippets (or maybe an autocompletion) to make it easier to add the markup to my Org files.

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Tweets on Emacs and Org Mode

Posted on 2018-01-01 by jcs

Nick Higham, whom I’ve mentioned before (1, 2), is a Mathematician and Emacs user. He also, apparently, is like me in that he likes collecting odd bits of information and data. One bit of data that he likes to collect are tweets about Emacs and Org mode.

For those of you who also enjoy such things, Higham has a blog post that displays his collection. You’ll probably recognize some of them as they went viral or at least as viral as a tweet about Emacs and Org mode can be said to be. In any event, I enjoyed browsing through his collection. Perhaps you will too.

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König 36: A Third Way of Setting and Tracking Goals

Posted on 2017-12-31 by jcs

Rainer König is back with a followup to his previous video on setting and tracking goals that I wrote about a week ago. This time he approaches the task using hierarchial tags. With hierarchial tags, you give a set of related tags a group name and can then search or filter the tags by the group name. You can even describe the members of a group with a regular expression so you don’t need to know what they are in advance.

That works out perfectly for König’s purpose because he can tag each individual goal with a unique tag that ties together all the tasks related to that goal and can also refer to all goals by using the group name. See the video for the details on how he used it for tracking goals.

I didn’t know about hierarchial tags before but it’s easy to imagine lots of use cases for them. The Org Mode manual page for them is here. If you like using tags to tie things together, you should definitely take a look at hierarchial tags. You can even have sub-groups (and sub- sub-groups, etc.) so the device is very flexible.

The video is just short of 8 minutes so it should be easy to work it in. If you have time, you might also want to rewatch his previous video to refresh the context.

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The Longevity of CDs

Posted on 2017-12-30 by jcs

Just a few years ago, CDs were still ubiquitous and one of the things the Geekier elements worried about was that they would become unreadable over time. That was probably a reasonable concern, especially for CDs that the user burned himself on his computer.

As for professionally manufactured CDs, we still don’t know and as Kontra points out we’re not apt to find out.

Yes, yes, we all still have CDs but when was the last time you used one? My laptop doesn’t even have a built in player, something that was unthinkable just a couple of generations ago. Even for music, I don’t bother anymore. I ripped the CDs at a high bit rate and listen to the result. Some people will tell you that they can hear the difference and I have no reason to doubt them but I’m not one of those people.

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Remember This?

Posted on 2017-12-29 by jcs

Unless you are really young, you probably remember a spate of capacitor failures in electronic devices of all sorts including computer motherboards. This was around the turn of the century. One of my family members practically had a production line going where he unsoldered a broken capacitor and put in a good one that he happened to have around. He wasn’t even all that particular about the farad rating but everything always worked fine afterwards. It was a real pain for a while but then it went away without me—at least—noticing. Here’s a hint at the backstory:

If you follow the link at the bottom of the tweet, you can read the whole story including what was going on. It’s pretty interesting if you’re Geek 30, say, years or older.

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You Can’t Make This Stuff Up

Posted on 2017-12-28 by jcs

I can’t decide if this is a joke or if someone is actually that clueless. It’s not April 1st so I’m reluctantly concluding that it’s for real1. I’m sure Miessler was surprised to learn that he’s maintaining the master password list for “hackers.”

Footnotes:

1

Well, actually, I still can’t decide. On the one hand it’s “too good not to be true” but on the other the guy has enough knowledge to file a GitHub pull request and his GitHub repositories do indicate he’s got some programming chops. And, really, who’s that naive?

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I Am Not Worthy

Posted on 2017-12-27 by jcs

I used to feel pretty snug when I got up to around 100 open buffers in Emacs. Not anymore:

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Org 9.1.5

Posted on 2017-12-26 by jcs

Over the holidays, Bastien Guerry announced a new Org mode version: 9.1.5:

Another nice Christmas gift from the folks in our community.

I just checked and it’s already in Melpa. It’s a bug fix so if you like to keep things clean you can update now.

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