Print selection only in Chrome

Maybe you already know about "Print selection only" in Chrome.  But it changed my life today.

I wanted to print only a part of a web page.  Usually, I tweak the pages but then it spans pages and it's confusing to get just the pages I want.  Or if I got desperate, I would copy/paste into a text editor and print that instead (after reformatting all the copy/paste noise away).  Instead of all that nonsense, I found a better way.

Here's how to do it:

1. Select the text you want to print (in Chrome)
2. Click Print (or press Ctrl-P or Cmd-P on Mac)
3. Click "More Settings" in the Chrome print dialog
4. Select the "Selection only" box
5. Adjust "Scale" to get it on the right number of pages (1 page usually)

Then print and you can move on with your life.  I love how simple it is.  Hopefully you benefit from this.

Git worktree - clone but not quite

Have you ever wanted another workarea for the current repository you're working in?  Maybe you're running some tests and need the normal workarea to stay unchanged, so you can't rebase or tweak another branch in the meantime.

Options up to now:

• $ git clone [current-repo] [temp-repo]; cd temp-repo  # too heavy-weight, have to push changes back
• $ sleep 120; check email  # interrupts flow

In Git 2.5.0, you can do this easily:

• $ git worktree add ../temp master

This creates a new workarea in ../temp with all the current branches.  It's the same repository!  Any git command you do in the new workarea is applied to (and uses the database of) the original repository: commit, rebase, push, etc.

NOTE: If you leave off the branch name, 'git worktree add' creates a branch named after the new worktree directory.

NOTE: If you want to operate on the same branch as the original repository, it is disallowed by default.  In order to operate on the same branch, you have to say $ git worktree add ../temp master -f'.  Also if you ever move off of the branch and want to switch back when another worktree has the same branch checked out, you have to use an annoyingly-long option: $ git checkout master --ignore-other-worktrees.  You could put that in an alias like so: $ git config --global alias.co "checkout --ignore-other-worktrees".

Rubber Ducking with Git

You've heard of the phenomenon where when you try to explain a hard problem to someone else, you suddenly know the answer, and the other person did nothing but listen to you ramble.

On the C2 wiki, it's called:

• http://c2.com/cgi/wiki?RubberDucking
• http://c2.com/cgi/wiki?CardboardAnalyst

The theory I have about the phenomenon is that in a problem solving situation, the human mind develops a lot of parallel ideas & possible solutions, even ones that you are not aware of.  But when you try to describe the problem and your ideas to someone else, just the act of trying to explain the situation helps you see it more clearly and links the ideas together better in a way that you become aware of more possibilities than you were able to see before.

But I've always had a problem talking to inanimate objects.  Call me less imaginative, I guess.  Or timid, maybe.

Well, I've had the feeling for a while now that using Git with small commits made me more productive.  And I just realized, I'm using my future self as a rubber ducky, and that the act of writing explanatory commit messages to explain things to my future self is a source of ideas for me.

Painless localhost demos

Quick demo?  Easier than heroku?  Look at @ngrok.

I have periodically needed something that lets me painlessly set up a demo from my laptop that I could just email a link to anyone on the internet.

I guess that ngrok.com would be a pretty valuable target to pwn.  Maybe it wouldn't be too hard to install on my own host.

Thanks to @lmonson for retweeting about @ngrok.

Map-reduce-friendly graph traversal

You may be well acquainted with this, but I thought I'd pass it along.

    https://giraph.apache.org/intro.html

It does iterative graph processing.  The cool thing is that it lets you break down your graph traversal into substeps that are distributed.

Here is some sample code:

  public void compute(Iterable<DoubleWritable> messages) {
    double minDist = Double.MAX_VALUE;
    for (DoubleWritable message : messages) {
      minDist = Math.min(minDist, message.get());
    }
    if (minDist < getValue().get()) {
      setValue(new DoubleWritable(minDist));
      for (Edge edge : getEdges()) {
        double distance = minDist + edge.getValue().get();
        sendMessage(edge.getTargetVertexId(), new DoubleWritable(distance));
      }
    }
    voteToHalt();
  }

Anyway, it looks like a very interesting project.

If I can do map reduce over change history, then it would then be possible to do contribution graph processing -- deep inspection of the graph of users and records they edit, possibly overlaid with the graph of users and which records they are connected to by ancestry.

For example, given a defined group of users, it would be interesting to see how their edits overlap with each other.  Another example would be to determine which top 1000 editing users made the most "distant" edits, based on some kind of ancestral distance measure.

Google Fiber in Provo, UT

This makes me want to move to Provo:

https://fiber.google.com/cities/provo/

That's something my wife thought she'd never hear! :)

Subscribing to FamilySearch Updates

Keeping up with all that's going on at FamilySearch is harder than it needs to be, but I finally figured out how.

Most sites give you large categories of feeds to track, but FamilySearch has all of 14 different feeds, some of which overlap or not (the feeds are available by appending '/feed' to the URL).  But I couldn't find any "everything" feed URL.

Because I work for FamilySearch, and because I care about what goes on around me, I want to subscribe to everything, if only just to skim.  The most important announcements get forwarded through internal email, however the additional articles are very useful context, especially for an employee.

Unfortunately, the default "subscribe" link just subscribes you to feeds #2, #3, & #4, or Indexing, Record Search, & Indexing, respectively.  The "Subscribe" link is visible on an individual article's page, but isn't even present on the main blog page.

Here is the feed link you can put in your feed reader to subscribe to everything:

• https://www.familysearch.org/taxonomy/term/1+2+3+4+5+6+7+8+9+10+11+12+13+14/0/feed

When feed/category/blog #15 gets defined, this feed URL will be invalid again.  Maybe there is a better way.  If anyone knows a better way, please let me know.

I want an "everything" subscribe link that I won't have to update in my feed reader, or maybe an "everything but trivia" link.

Missed Tweets Through News.me

I've never really been a twitter nut.  There are already enough sources of distraction for me, I don't need to add another source.  It just seemed really noisy.

However, people have been saying and linking to important things on twitter for a while now.  I'm just not discerning enough and don't have enough time to filter the firehose in a useful way.

The most helpful summary of interesting news I skim regularly is the weekly LinkedIn emails.  In fact, I think it may have been through a link chain from one of those emails that I stumbled on unionfs, as reported in the last post.  If I could have the same thing for twitter, but personalized to the people I follow, that would be really helpful!

Ironically, as part of the effort to make this blog more stuble-upon-able, I was looking for a way to auto-post on twitter and facebook whenever I post on this blog, and I found twitterfeed.com, which does all of that and more.  And it's easy to set up.

After setting that up this morning, I wondered: "What is the company behind twitterfeed.com?", and found betaworks.  They run some very interesting sites/companies, some of which I knew about (bit.ly), some of which were new to me (findings.com, chartbeat.com).  The interesting one for me right now was another site called news.me.

Turns out that news.me is just the kind of thing that has the chance of making twitter useful to me.  If things go well, you'll probably hear more about it.

Intrusion Detection through Stackable Filesystems

I've always wondered what exploit might be running on my system, and never had any time to devise/install a detection system that would have the right balance of useful detection (maximize) and performance impact (minimize).

When I stumbled upon unionfs a couple weeks ago, I thought that was an interesting idea from a change-logging perspective.  It's sometimes useful to be able to keep a filesystem-based diff of what a certain operation does to a system, and then bake it onto the system when I know it did what I wanted to.  The takeaway for me was that unionfs's performance profile had the opportunity to be so low because it was so thin and so baked into the kernel.

This compounded with my recent discovery and fiddling with fusefs (in user-land) and I wondered about what kind of useful logic I could put underneath a filesystem.  The GlusterFS feature set, the recent LessFS GC stuff, the bup-fuse stuff, and the S3FS stuff is all just *really* cool.  I ended up gazing longingly at the big backlog of fuse filsystem suggestions on their wiki, and wandered back into the unionfs space.

So, when I saw the I3FS paper (linked from here) about the modular application of this technique to intrusion detection, this really triggered the Useful *AND* Performant neurons and I got really excited.

Unfortunately, on first glance, the stackable filesystems stuff seemed pretty cryptic to set up in a lightweight, just-works kind of way (think custom mount command-lines complete with arcane stacking options).

It would be soooo awesome to have an easy-to-compose ruby DSL for doing some kind of rack-like filesystem mashup with a kernel-level unionfs layer underneath a user-land fusefs layer, but all expressed in the same DSL.

This would be an awesome tool to put on top of the Arch-derived clone I want to put up for people at work.  There are folks who care about living more on the edge of linux stuff, but that don't care to install from scratch, and also might not care that much about not having a full Gnome stack if things just work.  And if I could give them the same tuned IDS-on-the-desktop solution (or upgrade their developer stack by letting them pull a filesystem delta over), that would be really cool.

The cheap development observation [PDF, linked from] because of modularity is one of attributes valued highly by the Ruby community as well.  It is one the key things that makes Ruby as a community awesome.

These kinds of ideas really matter, and making them so cheap and stable that you don't have to think about them really matters even more.

NOTE: The I3FS paper is really pretty old (2004), and the whole unionfs stack is older than that.  The fuse stack came into the kernel a long time ago too (2005).  So while this is new to me, it's been around for quite a long time.  I'm playing catch-up.

Backwards Names

My family likes to play a fun game called Backwards Names.  This game is played by taking each name piece of a person's name and reversing the characters and trying to pronounce it fluently.

I was just sitting on the couch tonight after a long Saturday and not thinking about backwards names at all.  I had my laptop open to get some work done, but my son sat down next to me, and I wanted to show him some programming.

I started out in irb and just did some simple string substitution with his name, but irb and ruby make it so easy to just mess around that I ended up with an implementation of Backwards Names before I knew it.

Here it is:


It was just really fun to do that with him and see lights start to turn on about what programming was like.

Core Goals of Version Control

After having a couple of years of experience with Git, I was finally able to clearly articulate the core value that version control brings to software development. This article will be written with a bias toward Git, but I've at least tried to express the core value in abstract terms.

The value is expressible in 4 goals.

Core Goals

1. Capture source artifacts
2. Isolate stable codelines from WIP
3. Enable concurrent WIP
4. Make it easy to leave sensible history behind

WIP = Work In Progress

The continuous delivery crowd says that WIP should be basically zero. I think that there is space for a fairly short development pipeline (3-5d) that can free developers up to capture ideas and then wrangle them into shape in a second or third pass.

Capture Source Artifacts

As a developer, I feel happy when I can push a save button when I've taken a small step -- and then never have think about it again. I also feel happy when I can save, even if I'm based on a slightly out-of-date base. I also feel happy when I don't have to worry about binary vs. text -- as long as its a true source file of a reasonable size.

I feel happiest when I don't have to be distracted by superfluous concerns, and can focus on the task at hand and save the results easily.

Main Point: A good version control system makes it easy to capture source artifacts.

Isolate Stable Codelines From WIP

Software is hard to get right, and once things get stable, the only way to keep them there is to avoid making risky changes. But stability is always balanced against the common desire for enhancement and restructuring.

A typical bug fix is one or two isolated commits that fix a specific problem. Most version control systems more or less support cherry-picking a small change over into another codeline.

I feel happy when I'm able to easily take an isolated series of commits from the development codeline into a stable one, even if the fix turns out to be a little larger than a couple commits.

Main Point: A good version control system makes it easy to cherry-pick changes, and even longer patch sequences, from one codeline to another with easy reconciliation of overlapping edits.

Enable Concurrent WIP

For software developed by a team larger than 2-3 people, it is useful to be able to work in parallel with each other, even on the same feature. Sometimes you can arrange your work so as not to overlap at all, but there are real situations where you want to track someone else's development within the fairly short development pipeline (3-5d) before things have gotten stable.

I feel happy when I don't have to catch people up on what I've been doing, and when they don't have to catch me up on what they've been doing, and we can get to the point easily and quickly. I also feel happy when we can leap-frog each other with ideas and real implementation.

Main Point: A good version control system makes it easy to track other team members' work, and easy to tentatively integrate with that work.

Make It Easy To Leave Sensible History Behind

After stepping away from a piece of software, it is easy to lose context and forget the concerns that shaped the development of that software. It doesn't take long. For me, about 2 weeks is enough for me to start forgetting details and motivations.

Of course, it is important to leave a properly structured artifact behind. Proper naming means a lot; proper factoring is important. Once you comprehend the structure, it is possible to change things without introducing big problems.

But often, full comprehension isn't practical, and a flat 2D view of the artifact is insufficient for reasoning about the thing itself. Often, it is often very useful to be able to get a vector on where the software came from, and interpolate from that vector where it was headed.

The creative process is messy, filled with double steps and backtracking. Don't confuse me with all the noise. Give me a history that, given all the knowledge you had when it got stable, at least looks well-reasoned.

I feel happy when I'm able to take an easy editing pass following capture/review that lets me intentionally craft history as an email to the future about the vector of change that is inherent in a certain patch sequence. I also feel very happy to not have to think about this during the creative, messy, focus-draining capture/review pass.

Main Point: A good version control system includes tools to both: 1) enable the developers to easily leave behind meaningful history, and 2) extract focused history for all or part of a piece of software.

Reality Vacuum

A place where people have chosen to ignore a certain part of reality, and where that choice to ignore is embedded in the culture of that place.

I know I've occupied such a space, and even contributed to the vacuum. However, once I realize what's going on, I always want out.

To some degree, each person in the world has to keep up in one way or another. Some just have a better feel for keeping in touch with current reality, and what to do when they're not.

Personally, I want to improve in my ability to close the loop better and faster.

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