pathed - munge the Bash PATH

I wrote "pathed", a tool to munge the Bash "PATH" environment variable.

The Bash "PATH" environment variable contains a colon-separated list of paths. pathed - "path editor" - can split the path, append, prepend or remove elements, remove duplicates and reassemble it.

http://marcelgruenauer.com/blog/2013/02/22/pathed/

fresh perlbrew sugar

A fresh new version of perlbrew is out that incorporates some sweet new sugar via arc:

perlbrew install --switch stable

Which expands as:

  • Install the "latest stable" Perl - don't make me think about version numbers ;)
  • When you're done, switch to it

It is just sugar, but it makes a one-liner out of what used to be:

  • Figure out what the latest stable version of Perl is.
    • Think about here: "those outside the echo chamber"
  • perlbrew install perl-5.16.2
  • perlbrew switch perl-5.16.2

More usefully for my (planned) purposes, I can write documentation targetted to outside the echo chamber that ensures both:

  • those reading it will always get the latest stable version of Perl, and
  • I won't have to bump the docs every time a new release is rolled.

Go lazy!

Headless Selenium testing with PhantomJS

As you know, Selenium is a marvelous library for automating a browser. It can be combined with Test::More and PhantomJS to provide a headless test suite.

An example script looks like:

Give your application a shell (and never write any ad-hoc scripts again)

As developers, we sometimes have to help operations going smoothly by fiddling with the data "by hand" because there's no GUI to allow people doing some rare and obscure things. One common way of doing it is by connecting to the DB and writing some SQL. But often, accessing your database is not enough, because you need your application code to be run.

And for that, you need a shell.

Recreated comments for Perl in Catincan, an open source crowd funding proposal

I spent time to create the below message for Brian's post on crowfunding. For whatever reason, he felt the need to delete my post. So I've recreated the gist of what I said previously. I guess next time I'll take a screenshot for posterity.

Brian, Now that is a great contribution! Thank you!

Discoverability issues: On a crowdfunding platform that is generic in nature there is a discoverability problem if you are targeting a specific audience. Brian, does Catincan support creating a Perl channel/filter with permalinking? If so this could then be linked directly from Perl.org. If not, how do we address that issue?

A follow up on three-value logic in Perl

So far the initial response to my three-value logic in Perl post has been great. Due to that response, on Reddit, Perlmonks, here and my RT queue has led to:

  • Made sorting a bit more useful
  • Contemplating removing stringification
  • Plenty of strengthening of the documentation (including making it explicitly clear that the unknown logic is akin to SQL's NULL)

And then there's been some interesting rebuttals.

Swampy.pm6

Last night I reached chapter 4 of Think Python, which is full of good old fashioned turtle graphics stuff.

It’s just - well - there’s a problem. I don’t think there is a port of the swampy library to Perl 6. I could write one, but that would probably require a Tk interface with Perl 6. Even just writing a Perl 5 Tk version of Swampy is beyond my spare time attention span.

I know what I’ll do. I’ll cheat and have perl6 call python.

Perl in Catincan, an open source crowd funding proposal

I've proposed a "Perl" project on Catincan, a new crowd funding site targeted at open source software. They've said that the first 25 projects to be fully funded have their fees waived for life. That is, if a Perl project gets funded, we have a crowd sourcing platform where the developer gets all the money.

That fee waiver is interesting. I've looked at many crowd funding sites. Most at least charge the credit card fees. Fractured Atlas, where I'm a board member, charges 7% for their fiscal sponsorship program. If TPF wanted to set up their own program, not only would they have to charge some fees, even to just cover costs, but they'd have to manage it as well. If there's already someone doing all that work and doing it for us for free, so much the better.

PPI highlighted Mojolicious "quine"

On February 28th I will be presenting an “Introduction to Mojolicious” to the Chicago.pm meeting. If you are in the area I hope you will stop by; it won’t just be an introduction despite the name. If you are interested, here is the Meetup link.

I haven’t decided, but I might try to “self-host” the talk, writing it as a Mojolcious app! To do that I had to resurrect one of my earliest CPAN releases Mojolicious::Plugin::PPI. This module does just what the name should imply, providing syntax highlighting via PPI and PPI::HTML in a handy Mojolicious plugin.

Whether or not I decide to use this for my talk, it still is handy to have around. Here is a cute example, a simple “quine” which you can run:

Thames Valley Perl Mongers

After being dormant for longer than I can remember, the Thames Valley Perl Mongers mail list woke up recently when someone[1] offered to host a meeting.

I've put together a very short survey to work out how many might be interested. If you live in this corner of the UK and/or fancy coming along, please let us know:

http://www.surveymonkey.com/s/QNPF2V8

[1] the offer comes from Opsview, a company based at the University of Reading campus who use Perl in their main product (and might be scouting for employees).

Drop a note to oliver at cpan dot org if you have any questions. Many thanks!

Three-value logic in Perl

Bad news. You've a brand-new CEO and he has a reputation for having a short temper. He knows about his reputation so he's decided to win over the employees by offering all "underpaid" employees a salary increase of $3,000 per year. You've been tasked to write the code. Fortunately, it's fairly straight-forward.

foreach my $employee (@employees) {
    if ( $employee->salary < $threshold ) {
        increase_salary( $employee, 3_000 );
    }
}

Congratulations. You just got fired and have to find a new job. Here's what went wrong and a new way to make sure it doesn't happen again.

About Perl Grants

The following is my view on the subject (and also first, hopefully not last, blog post here), a comment to About the Grants Committee.

Whenever someone is about to submit a grant proposal, that proposal goes through one's "internal review" first. And in that internal review one asks yourself: "Why should I ask to be paid for what countless of others just CONTRIBUTE to Perl community? The Perl itself and tens of thousands of modules are literally millions of hours, hundreds of years of work just contributed. Why should I ask for pay?". This is the perfectly right question to ask. And this makes the one's internal review quite picky, and the result is what we see - no proposals. And, though surprisingly it may sound, this is the right thing.

To be financed with grant there must really be a tangible, important benefit to community at large that cannot be achieved without grant. And this criteria leaves VERY FEW things appropriate to be financed with grant.

Think Python, But Perl 6 - Chapter 3: Functions

On to chapter 3 of Allen B. Downey's Think Python book, as interpreted through Perl 6.

Testing Refactored Webapp Against Current Version With Geest (Ruby Kage port)

I'm currently working on a big, and I mean /BIG/ codebase, like 200K LOC with about 10 years of history behind it.

In this post I'll briefly describe how I'm refactoring code using a little tool called Geest (github), which I completely stole from Ruby's kage.

tl;dr: With Geest you can check differences between new / old code transparently. It's really handy. Please let me know what you think, or file issues if you find any.

Ask JAPH - A Tumblr Experiment

So Tumblr, well known blogging platform, has this feature where you can set up a simple site and then invite people to ask you questions. I thought it would be fun to try out doing this for Perl.

http://askjaph.tumblr.com/

Why?

  • Get the Perl name out there some more
  • Offer yet another place other than Linked In and Stack Overflow for people to ask questions about Perl
  • Teaching a subject is the best way to learn that subject
  • Give me something to do with my abundance of free time (this one is sarcastic...)

Not sure which to be more scared about - getting zero questions or getting lots of questions! But I'm more excited about getting lots of questions.

Whether you're completely new to Perl, or a Perl expert with a random question, you can always Ask JAPH!

Let's see how this goes :-)

Web Scraping with Modern Perl (Part 2 - Speed Edition)

tl;dr

Grab the gist with the complete, working source code. Benchmark it against the one featured on the previous article:

$ \time perl mojo-crawler.pl
23.08user 0.07system 2:11.99elapsed 17%CPU (0avgtext+0avgdata 84064maxresident)k
16inputs+0outputs (0major+6356minor)pagefaults 0swaps

$ \time perl yada-crawler.pl
8.83user 0.30system 0:12.60elapsed 72%CPU (0avgtext+0avgdata 131008maxresident)k
0inputs+0outputs (0major+8607minor)pagefaults 0swaps

How can it be 10x faster while consuming less than a half of CPU resources?!

Think Perl6-ish Variables, Expressions, and Statements

Continuing the Perl 6 adventures with Allen B. Downey's Think Python book.

Red-Black Trees in Perl 6 Explained

I've started digging around with Perl 6 again and I'm quite pleasantly surprised. As you can see, Perl 6 is just about feature-complete. The main obstacle to using it is probably performance. When I previously checked it was 20 times slower than Perl 5, now it's only 4 times slower and catching up rapidly (update: this information was from a conversation at FOSDEM and appears to not be correct. Perl 6 is still much slower. I will try to track down more information). Jonathan Worthington's port to the JVM is going well and Nick Clark mentions that initial tests on one (admittedly small) benchmark show it significantly faster than Perl 5!. With Perl 5 already being the fastest widely used dynamic language, this might be the key to Perl 6 being ready for prime time.

More on video recordings

No idea why the anonymous poster did not approve my long comment for his post, having allowed another three comments after mine, so I copy my reply here.

http://yapc.tv is another great start :-)

Seriously (why did you post anonymously?), every small step in recording conference video is easy. All together it is a pain in ass for the organises.

1. Cameras are cheap indeed. In Riga we had a few HD camera that cost less that 200 €. Transporting cameras with tripods is a hassle (OK, I admit that most organisers really live in the city where the conference takes place, and this is not a problem).

2. You need a dedicated cameramen for each camera (thus, three of four additional persons in the stuff). One of the cameras in Riga was stolen. You'd better pay these cameramen and do not ask the attendees as it is difficult for them to sit the whole day in one room.

YAPC Presentation Recordings

Is there a reason The Perl Foundation does not take charge of a central hosting repository for videos from larger YAPCs? Or an initiative to focus on quality recordings? I'd love to see(and hear) more high quality recordings. Looking over the 2012 YAPC:NA videos it appears they were recorded at 480p resolution making text reading difficult. Audio is often not ideal either relying on the facility's broadcast capabilities.

Could we get some interest or a mechanism(fundraising?) to improve this? I realize there is a fear of losing attendance if the material is readily available but I think the actual number of Perl users able to attend key YAPCs compared to the userbase is significantly insignificant.

Many smartphones can capture video at 720p/1080p. Audio capture can likewise be done with a separate smartphone recording at the podium or close distance to the speaker. Dedicated digital videocams and digital audio recorders are not likely to be that expensive if purposed and shared for the large events.

About blogs.perl.org

blogs.perl.org is a common blogging platform for the Perl community. Written in Perl with a graphic design donated by Six Apart, Ltd.