Code for Concinnity

Several months ago I started using the Google Contacts add-on for Thunderbird and it’s been hanging periodically ever since. I just thought it’s Thunderbird and tried all those compacting folder, resetting the cache thing.

Today it hang again and I was frustrated, so I did dtruss (strace) on it and found that it seemed to be stuck in an infinite loop trying to access my Google contact feed.

I replaced it with the gContactSync add-on and it’s working smoothly now.

Probably Homebrew has changed much since then, with Superenv and stuff. If you are stuck at an old R version and need to install it using Homebrew, you need to add depends_on 11 to /usr/local/Library/Formula/r.rb, like so:

While managing server clusters I often want to open SSH session to a dozen of machines and have them run the same set of commands, interactively. So I wrote tmux-sync to do this:

The above command drops you into a tmux session like below. Your input will be sent to all the panes in tmux:

The source code:

This is cleaner than the official method IMO, because it involves zero / minimal model object modification. The wizard logic clearly belongs to the controller only.

The basic ideas are:

• Derive from the ActiveRecord
• Override save to make Wicked behave. You can do arbitrarily complex thing there without wrangling with validation conditions.

Here’s the code:

Here is another version using a partial flag to persist the partial object in database:

Didn’t have the time to do a very serious benchmark but in case this is useful:

Another run using a Mac with some SSD hard disk. CoreStorage vs. TrueCrypt vs BoxCryptor:

So I was using Windows EFS the other day to encrypt some files. This is surprisingly easy to use and beats TrueCrypt and Mac’s disk encryption in the usability department:

I encrypted AppData, which is a good thing to do since many applications leave its trace there. When I rebooted and logged in, I got lsass 100% CPU and a black desktop.

TL;DR If you changed your password via MMC, you need to re-import your EFS key

The way that EFS works is by protecting your EFS certificate with your login password. That implies some work needs to be done when you change your password. MMC’s “Set Password” doesn’t do it (it warns specifically against this, but this is the first time I actually read what it says ).

It turns out that EFS spends quite a lot of CPU cycles for the wrong password case. Because I encrypted AppData lsass would just spin itself with the obsolete password, trying in vain to decrypt the EFS cert.

So the way out was to remove the EFS key from certmgr.msc, and then reimport it. You may need to refresh the credential cache by

If it worked, you should be able to display some encrypted text files transparently:

Tip: Use another account to runas /user:Victim cmd to do the above.

It’s been reported that the 100% CPU usage be related to the large number of SID files in AppData\Microsoft\Protect. I suspect it’s another consequence of this cause.

(The correct way to change password is to select Change Password in Ctrl+Alt+Del. I don’t know of a command line way to do it :/ Feel free to post in the comments)

This technique is based on Jeff Verkoeyen’s method. I find that modifying .xcodeproj files to be rather inconvenient so I whipped up a Rakefile that can be easily copied and pasted into new projects:

After two years of using Mac, I just discovered the wonder of the Help menu item.

⌘ + /

If you are like me and regard yourself as a “pro” user you’d probably discard Help as something you’ll never need. But the fact is that you can access every menu item from the search field:

I have always thought that Windows does a better job at serving “pro” users due to menu access shortcuts (Alt + something). This thing from Mac is arguably more hacker friendly.

Finally @JugglerShu stepped up and wrote the wonderful XVim. I just have the spread the word and personally report that it worked right out of the box. Thanks JugglerShu!

A clean and hack-less way to do it.

If you got the Undefined symbols for architecture x86_64: "_pcre_free_study", this is for you: