Jordan Bach jbgo

Why?

Users were complaining about a feature that would sometimes fail for no apparent reason. After some time investigating the issue, I suspected an unreliable internet connection might be responsible for these failures. In order to test my theory, I wanted to simulate random packet loss on my development machine to see if I then experienced the same failures.

How?

We can use a program called ipfw to simulate packet loss. From the manual, ipfw is an "IP firewall and traffic shaper control program."

It wasn't immediately obvious how to use this program at first, so here is a summary of what I did. Also, the man page tells me it's deprecated, but worked for me today.

I was getting the error E576: viminfo: Missing '>' in line: [file names] about ten times with various file names whenever I opened or saved a buffer in Vim. This happened both in normal vim and with MacVim. This was followed by the line E136: viminfo: Too many errors, skipping rest of file. Other than these obnoxious messages, Vim itself worked fine.

To fix it, I opened ~/.viminfo and deleted everything in the section labeled # History of marks within files (newest to oldest):. I lost all my history of marks within files, but that was acceptable for me since I was starting a new coding session for the day.

So far, I'm not sure how my viminfo got into this state.

This is how I debug SystemStackError when there is no stack trace.

My first attempt was:

begin
  a_method_that_causes_infinite_recursion_in_a_not_obvious_way
rescue SystemStackError
  puts caller
end

TLDR: File.read(a_file).sub("\xEF\xBB\xBF", "").gsub("\r", "")

I tried using combinations of find/awk/sed, but I ended up corrupting my project files including the git index because I don't understand those commands very well. So instead, I turned to my good old friend ruby. This also has the advantage that I can use it in my program that processes these files. They've been ninja-edited (modfied outside of source control) in the past, which makes it likely that someone will come by and ninja edit them again in the future. But instead of convincing people that it's bad to edit files in notepad or outside of source control, we can just silently fix it on the fly and smile and say "Happy Friday!"

Here is the example of what I'm cleaning up. Thankfully, git's diff viewer is brutally honest and shows these characters. Unfortunately, most editors (including the good ones) simply hide these characters and put them back in when you save the file. The byte order marks were causing browsers to skip CSS declarations

Free disk space when `/boot` is full (Ubuntu)

TL;DR

dpkg -l linux-image*
uname -r
sudo apt-get remove linux-image-2.6.32-{21,37,38,39,40,41,42,43,44}-server
sudo apt-get autoremove

Do you have a pre-existing ProBIND installation with thousands of zones and you would like to change the IP address for hundreds of A records?

Here is one way you could do it without spending hours clicking through the GUI. Ok, so I'm circumventing probind for the most part and going straight to MySQL, since probind is basically a CRUD app around a few tables in a databse.

1. Given a list of domains, preview the records you want to update.

For those unfortunate times when you need to use duct tape to support a slick user experience on really old browsers.

frame = $('iframe').get(0)

doc = if frame.contentWindow
  frame.contentWindow.document
else
  frame.contentDocument

tmux config

~/.tmux.conf

send the prefix

Default prefix: ^b

	description "redis server"

	start on runlevel [2345]
	stop on runlevel [016]

	exec sudo -u redis /opt/redis/redis-server /opt/redis/redis.conf

	respawn

	# -- mode: ruby --
	# vi: set ft=ruby :

	VAGRANTFILE_API_VERSION = "2"

	Vagrant.configure(VAGRANTFILE_API_VERSION) do \|config\|
	config.vm.box = "precise64"
	config.vm.box_url = "http://files.vagrantup.com/precise64.box"
	config.vm.network :private_network, ip: "192.168.33.10"
	config.ssh.forward_agent = true