Android tips** Sign an update.zip to run in recovery mode

Its been a while that i have been away from my blogs. Today i finally did something after a long timw worth onwriting and hence.. I have been meddling around with my android fone for some time now.. checking out new ROMs and other applications, until i came up with Titanium backup pro. Its such a wonderful took to take backup of your applications along with the data and settings. You can even remove apps which were preinstalled with the phone, freeze it or take backup. There is a feature in Titanium backup where you can create an update.zip so that you can directly install Titanium from recovery mode (this helps a lot of time installing every application you flash the ROM).

However what Titanium backup creates is an "unsigned" file. Basically every APK files are to be signed so that the OS can validate if its from a valid creator or not. Since the file is not signed the installation from recovery mode will fail. I have just ran through a tutorial to sign the file. Follow the steps below

Disclaimerr: I am not responsible if you brick your phone.Please test at your own risk and expense

Application Please note that this is applicable only if you are flashing a ROM and you need to delete all data using factory reset and start from scratch.

Prerequisites
1) Ensure that you have taken backup of all the current applications using Titanium backup
2) Take backup of the following files/folders on your laptop
- TitaniumBackup (include backups of all apps and data)
- Other important files (music, personal records etc)
3) Create an update.zip file on /mnt/sdcard using TitaniumBackup
4) Plug the phone onto laptop and copy the update.zip on the laptop, remove the connection
5) Ensure that you have Android SDK installed on your laptop
6) Set the correct classpath in the environment variable
- Right click on My computer> Properties> Advanced system settings> Environment variables
- Select Tem, and under System variables select CLASSPATH
- Add semi-colon and C:\program files\Android\android-sdk\ after the end ie ;C:\program files\Android\android-sdk\

Signing the update.zip
1) Download testsign.zip and copy it in your /tools folder. Extract it here. It should create a sign subfolder with a testsign.jar file in it.
2) Go to command promt (Windows button+R, then type cmd and enter)
3) Go to the path where you have the copy of update.zip file in command mode
4) Type the following command

java -classpath /tools/sign/testsign.jar" testsign update.zip update-signed.zip

5) Once done, you will see a new file on the path update-signed.zip

Thats it, you have signed the file. Now you can go and flash your new ROM. Post installation, when you need to install the older apps go through the below steps

1) Reboot into recovery mode. 

2) Select the option Install from sdcard

3) Select update-signed.zip

4) Select reboot the system

5) Once phone is up, connect it to laptop and copy all the data (step 2 of prequisites list above) back to SDCARD

6) Disconnect the phone from the laptop

7) Open TitaniumBackup (installed in sept 3 above)

8) Ensure that the phone is rooted. Restore all application backups

Bingo !! you will be up and running in a matter of minutes..

Do let me know in case you have any issues




Credits: RobMcGhee.com

Creating virtual interfaces on a router

Have you ever wondered how a wi-fi hotspot in a coffee restaurant nearby works or is created? The second question is at what cost? We will come to that later on, first lets explore the possibility of creating a wi-fi access point for public use. It would be practically stupid of someone to take a broadband connection just for public consumption at your own expense, not practical even if you give it on chargeable basis. What can be done is creation of two networks - private (encrypted and password protected) and public (open network). You might have encountered virtual office, virtual server, cloud computing.. but might have less heard about a virtual interface ! Though virtual servers have virtual interfaces, you can just create such an interface using DD-WRT firmware for routers. Then you can use the virtual access point for public use , which can be an open network (without password). You may think why would you provide free internet to others when you are paying the bill? We will come to that later too..

Creating virtual interface
First you need a broadband connection with a router that supports DD-WRT firmware.
With DD-WRT, you can create two or more virtual interfaces to create multiple Access Points (AP). Its simple, goto the router settings accessible at http://192.168.1.1 and go to Wireless tab. Under the basic settings, you have an option to create a virtual interface. Click Add, name the SSID and keep AP isolation disabled.
Save your settings, now you are done, as simple as that.

You can choose to password protect it or keep it as an open network via the "Wireless Security" tab .

Now if you go to the network connection are, you can see the SSID being broadcasted.

Why provide free internet for public?
Now coming to the point of why free internet to public! There are many service providers who provide free wi-fi hotspots around the world to its members, and can earn money by letting non-members use the services. One of them is FON.  Its a beautiful concept of creating a network of wi-fi access sharing members across the world , of the same community. Since its a network of members across the world, wherever you go, all you need to do is login with your membership and use free internet.
The bandwidth you share is negligible and wont hardly affect your work. For more details visit the site

Image courtesy: FON (C)

Lend your bandwidth
What happens in a coffee shop is such networks, which are made available to non-members for a nominal price. DD-WRT has done a great job by integrating it with a service provider called Sputnik. It can be found in your router settings at Services >> Hotspot.

Here basically, you have a variety of choices. You can provide free internet, broadcast your product over wi-fi (as you normally see at Cafe Coffee day etc) , offer/ lend your bandwidth for a nominal price. You can broadcast your services to let other wi-fi enabled devices know about your services too.

Image courtesy: Sputnik (C)

Whatever be the reason you took a broadband connection, i believe that unless you share it with the society.. its a waste. Be it for earning some income, as a social service or ads campaign. The choice however is entirely yours.

To know more on how to create a free internet service , read here
If you dont want your file to be shared in your public network, learn how to create a private network here

Added a new feature

Upon much persuasion, I have added another interface of a hovering search bar which one can use to search words or post across the blog easily. Not only that, you can search of the word in the blogsite by just selecting and highlighting the text  . Try it out !!

Note: Recent update is that, it seems to be working on chrome but not on firefox. Checking out the reason why

Search bar follows as you scroll

Searches text and show results instantly