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:
Description/Name
Resolution
Extra Info & Estimated Date
QVGA
320×240
Typically non-smart phones (and Smartphones c.2005)
HVGA
480×320
Typically older smartphones (c.2008)
VGA
640×480
Typically older smartphones (c.2008)
WVGA
800×480
Low-End Smartphones (c.2010 onwards)
SVGA
800×600
Low-End Computers (c.2000) and mid-range tablets
XGA
1024×768
Mid Range Computers (c.2005)
SXGA
1280×1024
Current Computer Screen (c.2010 onwards)
720p HD
1280×720
HD TVs, High-End Smart-Phones/Tablets
WXGA
1280×800
Laptops, Computers and High-End Smartphones/Tablets
WXGA+
1440×900
Typically Laptops and Computers
Key/Odd Resolutions:
ipad & 2
768×1024
Portrait XGA
iPad 3
1536×2048
XGA
Kindle Fire
600×1024
iPhone 1, 2, 3 & 3G
320×480
Portrait HVGA
iPhone 4, 4S
640×960
Portrait DVGA
iPhone 5
640×1136
HTC Sensation
540×690
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.
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…
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!
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.
Code
Reason
Explanation
0
Reserved
Normal working operation
1
Unspecific Reason
We don’t know what’s wrong
2
Previous authentication no longer valid
Client has associated but is not authorised.
3
Deauthenticated because sending STA is leaving (or has left) IBSS or ESS
The access point went offline, deauthenticating the client.
4
Disassociated due to inactivity
Client session timeout exceeded.
5
Disassociated because AP is unable to handle all currently associated STAs
The access point is busy, performing load balancing, for example.
6
Class 2 frame received from nonauthenticated STA
Client attempted to transfer data before it was authenticated.
7
Class 3 frame received from nonassociated STA
Client attempted to transfer data before it was associated.
8
Disassociated because sending STA is leaving (or has left) BSS
Operating System moved the client to another access point using non-aggressive load balancing.
9
STA requesting (re)association is not authenticated with responding STA
Client not authorized yet, still attempting to associate with an access point.
10
Disassociated because the information in the Power Capability element is unacceptable
11
Disassociated because the information in the Supported Channels element is unacceptable
12
Reserved
Not Used or Special Purpose
13
Invalid information element.
14
Message integrity code (MIC) failure
15
4-Way Handshake timeout
16
Group Key Handshake timeout
17
Information element in 4-Way Handshake different from (Re)Association Request/Probe
Response/Beacon frame
18
Invalid group cipher or
Association denied due to requesting STA not supporting all of the data rates in the BSSBasicRateSet parameter
*NEW* The link speed requested by the client or AP is incompatible. (i,e. trying to operate N only speeds on a G AP)
19
Invalid pairwise cipher
20
Invalid AKMP
21
Unsupported RSN information element version
22
Invalid RSN information element capabilities
23
IEEE 802.1X authentication failed
24
Cipher suite rejected because of the security policy
25-31
Reserved
Not Used or Special Purpose
32
Disassociated for unspecified, QoS-related reason
Quality of Service has denied the action.
33
Disassociated because QoS AP lacks sufficient bandwidth for this QoS STA
34
Disassociated because excessive number of frames need to be acknowledged, but are not
acknowledged due to AP transmissions and/or poor channel conditions
35
Disassociated because STA is transmitting outside the limits of its TXOPs
36
Requested from peer STA as the STA is leaving the BSS (or resetting)
37
Requested from peer STA as it does not want to use the mechanism
38
Requested from peer STA as the STA received frames using the mechanism for which a
setup is required
39
Requested from peer STA due to timeout
45
Peer STA does not support the requested cipher suite
45-65
Reserved
Not Used or Special Purpose
99
Typically “No Reason Code” / Unknown State
535
Reserved
Not Used or Special Purpose
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.
I was testing my Belkin USB WiFi dongle today and Debian wouldn’t use it and I was getting errors/issues to do with a faulty firmware.
Even after following a few guides online and installing different packages etc, I still couldn’t get it to work but I finally managed using the following method:
Add Contrib & Non-Free Repo’s:
nano /etc/apt/sources.list
deb http://YOUR.CHOSEN.MIRROR squeeze main non-free contrib
deb-src http://YOUR.CHOSEN.MIRROR squeeze main non-free contrib
apt-get update