Great demo videos -- looks like lots of strong design decisions! Will definitely try this in a future project.

... actually, given you already have a Golang SDK, I may try this very soon!

Maybe check out https://pipedream.com if you are interested in exploring other low-code, automation solutions?

You can get a lot done on the free tier (full disclosure: I'm one of the co-founders; please let me know if you have any questions)

Do you not need to specify optimization flags when compiling?

The -O3 optimization is just an optimization. It made a 1% difference in performance. It's just something I had in the Makefile I copied.

I'm actually worried about security here...

I don't know much about magnetic strip card technology, so I'm curious to know whether a malicious user could capture the signal and replay it.

Yes, it can

It's still not clear to me how the card data goes to the POS equipment, is it NFC or something else?

Take something like the free the Square magstripe-to-audio converter, record a swipe. Clean it up and/or amplify it, connect the Square reader as headphone output, and blast the recording as loud as necessary to induce the read in a nearby swipe reader. Security-wise, "the magnetic field will generally fall off as the cube of the distance from the magnet".

http://www.instructables.com/id/Read-any-magnetic-strip-card...

http://van.physics.illinois.edu/qa/listing.php?id=419

In the video they mention that they 'broadcast' it, I suspect that means they are actually pushing out a straight magnetic signal which seems to the reader that a card has been swiped.

I don't think it could be NFC, as most merchant readers wouldn't have NFC built in.

It also explains why they need the special case or dongle, it doesn't appear that it can work with just your phone alone.

It's a pretty innovative hack, but on the security issue, if you card is broadcasting it's data, then I assume anybody can pick it up, but they would need to be REALLY close.

They mention in their video or kickstarter site that you have to be within 4" of the mag reader.

That seems to be their secret sauce. It's not NFC as that would not be compatible with existing mag-stripe readers. It has to be some method of emitting magnetic fluctuation.

I'd assume NFC, but I really don't know.

I'm surprised they mention so many people tried and failed... this approach seems fairly intuitive.

This can already be done by anyone with a magstripe or RFID reader

Nice job with your first vim script!

That said, VIM patch 7.3.787 provides a 'better' solution by replacing the current line's number with the absolute number (because seeing 0 on the current line provides nothing meaningful) IMHO:

  with 'relativenumber' can't see the absolute line number

ftp://ftp.vim.org/pub/vim/patches/7.3/7.3.787

I use select2 (http://ivaynberg.github.com/select2/) for all my 'improved' dropdown needs. Any reason I should consider SelectBoxIt?

There are a bunch of reasons SelectBoxIt is a better choice for single option select boxes than Chosen or Select2:

1. Mobile and Tablet Support - The native "wheel" interface is presented on the popular mobile and tablet devices. SelectBoxIt also allows you the flexibility to write your own mobile detection script in case you only want to target certain devices.

2. Theming support - SelectBoxIt currently supports theming your drop down's using Twitter Bootstrap, jQueryUI, or jQuery Mobile stylesheets. More popular CSS frameworks are in the roadmap.

3. More intuitive search algorithm - Instead of appearing as a combo box, SelectBoxIt does not present a "Not Found" result. If a search result is not found, then SelectBoxIt will look for the next best option.

4. Better event support - SelectBoxIt triggers over 24 native and custom events on the original select box that your code can listen to.

5. Better method API - SelectBoxIt supports over 14 methods, including methods that neither Chosen nor Select2 support (disable single options, refresh, etc)

6. Custom Builds - SelectBoxIt offers you the ability to create custom builds via a UI interface: http://gregfranko.com/jquery.selectBoxIt.js/customDownload.h...

That's awesome. Consider putting a little comparison chart towards the bottom? Thanks for replyin'!