Brain Lint

I noticed this morning that google finance has a new stock screener feature that lets you choose stocks with features in a certain range by way of an interactive sparkline. These are miniature graphs that go inline with text. In this case the graph is a histogram that indicates how much of the stock market falls into each part of the range - this will give one a quick preview how inclusive their search parameters are.

I’m really lax about updating my wordpress install. Turns out I got burned this time, and inadvertently hosted a bunch of links to various flavors of porn site.

I was on an ancient (and security hole ridden) version of Wordpress, and I wouldn’t even have noticed if the hack didn’t also break posting new entries. I was attempting to post my previous entry on Ruby programming, and the post wasn’t working. So I figured it wasn’t working because of the programming language syntax being rejected somehow, so I would update to a more modern version. Which I did, and that still didn’t work so I started poking around the log files. Lo and behold, my access log is full of requests for html files in a subdirectory of the site. They shouldn’t be there I thought!

So I’d been hacked- someone got remote access to my account using this hack in a file “ro8kfbsmag.txt” (more info). All cleaned up now (I think) but not how I’d meant to spend my afternoon.

I found out (by introducing a bug into the application I’ve been working on) that “or” and “||” do not have equal precedence in Ruby.

More importantly, the assignment operator “=” has higher precedence than “or” so that means that while the expression


>> foo = nil || 2
=> 2
>> foo
=> 2


results in foo being assigned the value 2 as you might expect, the following expression leaves foo assigned the value nil.


>> foo = nil or 2
=> 2
>> foo
=> nil


This is well covered ground online (see this post) but I was surprised that this oddity didn’t warrant an explicit mention in the operator precedence section of the Pickaxe book.