The modern web is an amazing place. You can do almost anything in a browser that you can do in native code. Including processing audio in realtime. In javascript.
Nuts? Probably. Worth it? Definitely.
Ruby on Rails testing goes parallel – a deep dive!
•July 2, 2019 • Leave a CommentIf you ever work on large software projects, you’re bound to spend a LOT of time compiling code, running unit tests, and lots of other non-code stuff.
Since programming is really thought-intensive, any focus breaks are really disruptive. Even a ten second test suite is enough to break a train of thought. What can we do to improve that? Parallelize it of course!
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Diagnosing Ruby require_relative issues with DTrace on OSX
•June 20, 2019 • Leave a CommentRuby, like many programming languages, has a C-like mechanism for using code defined in other files. It’s critical for the development of any serious program, but it’s also prone to weird errors when files aren’t included in the proper order, or not included at all. It’s usually pretty obvious which file you’re not require_relativeing, but there are times when the only way to make sense of things is to trace the system calls.
On Windows, Process Monitor is by far the best way to diagnose this sort of problem. It gives a useful trace of just about everything a process does. I’ve used it many times before to diagnose file loading issues, and weird compiler errors. Similarly, strace on Linux traces every system call.
But what about OSX?
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Extreme Heat Event in Northern Siberia and the coastal Arctic Ocean This Week
•July 6, 2018 • Leave a CommentThis global warming stuff is getting to be really quite scary. đŤ
Monday’s eclipse & The Fight of The Century
•August 19, 2017 • Leave a CommentOn Monday March 8, 1971, Joe Frazier fought Muhammad Ali in “The Fight of The Century”. It was an event that was so popular that The Citizen’s Commission to Investigate the FBI used it to break into an FBI office and steal every file.
On Monday, a solar eclipse will cross the United States, with the zone of totality crossing from Washington to South Carolina. With millions of Americans stopping what they’re doing to look up at the sun for a few minutes – not quite as long as a boxing match – who knows what people will do?
Wheelbarrows of Money
•May 9, 2016 • Leave a CommentThe idea of just “printing money” to pay off the US Federal government debt is back in the news. Here’s a reminder of what that entails.
After reading my post about the âDepression Pocketbook,â my husband asked if I actually had any verifiable proof that anyone in Germany (or anywhere else) bought bread (or anything else) with a wheelbarrow full of money. Itâs something weâve both heard people say, but I must admit, I couldnât quote a source.
Is it an urban legend? Is it something historians have invented because it sounds good? God knows when I was in school, I was told medieval people believed the world was flat. Not only was that never true (and thereâs evidence from their maps and writings to prove it), but the idea can actually be traced back to a writer (I believe it was Nathaniel Hawthorne) who first used it in his popular biography of Christopher Columbus. It was taken for truth and repeated until it became reality and the truth became lost.
Is that whatâŚ
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Popping shell in a hospital
•March 22, 2016 • Leave a Comment…ok, it’s almost popping shell.
A few months ago, a family member was in the hospital for surgery. The hospital, New York Presbyterian, had courteously set up a computer for family members to use. However, it was running Windows XP, which is a no-longer-supported security nightmare.
Curious, I decided to investigate.
They’d disabled nearly everything. No “run” box, no explorer, nothing except an outdated copy of IE, and Office 2003. In the “Open” dialog, nearly every folder was empty. All modifications are dumped at logoff.
So, all the easiest ways to pop shell on this security nightmare are blocked off. They at least made some effort to secure things. It’s time to look into the wonderful rabbit hole that is Excel.
The wonderful thing about Excel is that it’s extremely flexible: Even an ancient version of Office (2003, which is what they had) can embed ActiveX controls, it can run Visual Basic, it can attach any of the Windows common controls as inputs to individual cells, and many other things.
The dangerous thing about Excel is (also) that it’s extremely flexible: Every single feature increases the attack surface, and exponentially complicates security.
In this case, the ability to embed a hyperlink is the most useful feature for me. Because of the way Windows Explorer/Windows Shell works, we can point a hyperlink at a local file, and the shell will execute the action associated with that file. If the file is an html file, Windows will open it in IE; if it’s a txt file, Windows will open it in Notepad; if it’s an exe file, Windows will execute it. I think you can see where I’m going with this.
When I attempted to “customize” the link, excel popped a version of the Common File Dialog… but all accessible folders were empty!
The “My Documents” folder, like every other browsable location, is devoid of clickable items.
So they’ve clearly tried to shrink the attack surface by hiding every clickable file, which has some value.
But again, Windows Shell link/path handling features are here to help me sneak past their security.
If you type the full path to a file in the “Address” field (or, more generally, the “Name” field), and then click OK (or, “Open”/”Save”), Windows accepts the (valid) path, and closes the dialog.
Opening the link then executes cmd.exe:
Tada! Command prompt opened… kinda
They (thankfully) have “disabled” the command prompt, which means I can’t easily use it to do any harm. There’s probably a way around it, but I was satisfied with getting CMD.exe to execute at all, and so I went on my way.
1984… 1993… 2016.
•February 19, 2016 • Leave a CommentYesterday on Bloomberg West, Nico Sell said: “I believe that Tim Cook is saving [more] lives” [than the FBI, in rejecting the court order]
I remember seeing the Apple commercial back in the day when it came out that depicted 1984 as the catchy advertising plot point for the Mac computer at the time. If only Woz and Jobs has known just how prophetic those images would be today. I remember too back in 1993 when the idea was floated and a governmental movement began to have a back door (aka a clipper chip) inserted into systems to allow access by the government *cough NSA cough* to be able to see the âevil doersâ and stop them. I also remember the sane stopped that from happening. Well, that was then and this is now, well past 9/11 and nigh on 16 years later, we are faced with not only a government toying with the idea again but a federal body demanding through writ of law that a company break the system they have createdâŚ
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Why Does Hot Water Freeze Faster Than Cold?
•December 16, 2015 • Leave a Comment
Many years ago I had to take a day off School to travel down to Cambridge in order to be interviewed for a place on the Natural Sciences Tripos at Magdalene College. One of the questions I was asked was the following:
If you put a bucket of hot water and a bucket of cold water outside on a freezing cold day, which would freeze first?
I think I gave the right answer, which is that itâs not obvious..
My main argument was that evaporation would increase the rate of cooling of the hot water and also mean that when it did get down to freezing point there would be less of it to freeze. I attempted to work something out based on the heat capacity of liquid water versus the latent heat of freezing, but didnât get very far with that as I couldnât remember any numbers. I doâŚ
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