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ldir update

It’s been nearly a year since any update to ldir; mainly because it’s working quite well without any bugs etc but this update is only minor.

Here’s the Change Log

Version 1.7.8

• Added better support for styling – Removed inline width CSS & Added CSS styles for each column
• Removed some linebreaks.
• Removed/Condensed some code (upto 7% smaller)
• Custom UserAgent in CURL Opts.

So in simple terms, I’ve made it tell dropbox (the icon host) that it’s a web app, removed clutter around the code, condensed a few lines and added selectors rather than inline css so styling it (and making it responsive) should be much easier.

Responsive Web Design?

If you’re writing a new responsive website which seems to be the way to go for a single maintained site that is accessable via mobiles, tablets and phones then here’s some key screen resolutions to be targeting:

This is just a small list of resolutions that’s in use out int he wild so to speak. The varying resolutions does make it slightly harder to get a consistant experience throughout but as long as your site looks good in the first list then you will have hit the majority of devices (as long as you remember to test portrait and landscape!).

As you can also see, Apple has recently decided to use strange resolutions in their devices where as most newer smart phones are 800×1280.

If you’re creating a responsive layout then there’s lots of resources out there to create a fluid grid to reflow the content when the screen size changes. I personally recommend Zurb’s Foundation but the latest version doesn’t support IE7; although IE7 usage is shrinking.

Batch Scripts and Sixty Four Bits of Architecture

I was recently writing a batch script to auto-install service packs onto windows, detecting the OS version was relatively simple and there’s plenty of scripts on the internets to do this; on the otherhand, detecting between 32 and 64bit architectures is much more complicated.

Microsoft has a KB artictle with batch script code to do this which is great apart from it doesn’t work under a standard user account and might not even work on an admin account (it didn’t work on my domain admin account), so if MS can’t supply code that works is there even a detection method?

Some people suggest that you should be searching for the %programfiles(x86)% variable which is only on 64bit systems, this is great apart from it didn’t work either.

I then stumbled by chance on a great solution which is to check the %PROCESSOR_ARCHITECTURE% variable. This worked great! I have been told that if the machine has WMI disabled then this wouldn’t work but most systems have WMI enabled.

If "%PROCESSOR_ARCHITECTURE%"=="AMD64" (
     echo x64
     "X:\Windows 7 x64 SP1.exe" /passive /norestart
 ) ELSE (
     echo x86
     "X:\Windows 7 x86 SP1.exe" /passive /norestart
)

That’s the code that I’m now using to detect the architecture of the systema nd install the correct SP, although it will attempt to install the 32bit Service pack onto 64Itinium machines; an extra check can be included to test for that but I’m unlikely to stumble upon an Itinium based system in my 20 PC office…

Hope this is useful to others.

Migrating MySQL to a Different System the Easy Way

Well this week I’ve replaced my personal home server and reinstalled my work’s development server; both these systems have a MySQL server running which contain databases (duh) that would be either too large to import/export or too complex to rebuild from scratch.

So I decided to find a way of copying the database files directly between systems and it’s actually dead easy and strangely not very well documented! So here’s the steps to do it fairly painlessly.

This guide assumes you have a root account and root database access.

Step 1:

Log into MySQL and lock the databases from being edited by typing the following:

FLUSH TABLES WITH READ LOCK

Step 2:

In your favorite shell copy the databases like so:

cp -R /var/lib/mysql /mnt/mounted

Step 3:

On your new system copy the databases into the correct location:

cp -R /mnt/mounted/mysql /var/lib

Step 4:

Fix the permissions on the databases

chmod -R 700 /var/lib/mysql

chown -R mysql:mysql /var/lib/mysql

Step 5:

Reboot MySQL server

service mysql restart

or

/etc/init.d/mysql restart

Step 6:

Unlock the databases by typing this into MySQL

UNLOCK TABLES;

All your databases and previous permissions should now be copied accross and working!

Linux WiFi: Deauthenticated Reason Codes

So I’ve been having a fiddle with Linux and WiFi this evening in an attempt to make a wifi bridge (Windows can do it so why can’t Linux?)…

Anyway the long and short of it is that I was getting disconnected and de-authenticated from the access point. Having a quick look at dmesg said I was disconnected for “Reason 2” and “Reason 6”; these on their own are not very helpful and so in a quest to find out what these codes meant, I found that there isn’t a list that’s published anywhere easy to find (a single forum post and in an IEEE pdf). The codes in italics are the most common.

The first few reason codes where helpful while debugging my wifi related issues.

Edit:
I’ve added a few more codes and descriptions; they conflict with a previous list from IEEE but this one is from Cisco and was discovered after an N wifi card refused to connect to an N router at N speeds.