Category Archives: tech geak

http-server in Ubuntu

http-server in Ubuntu

For ubuntu users, just install node.js and npm ( node.js package manager). Node.js is available in universe so no need to add any repo.

sudo apt-get install nodejs npm

After that install http-server globally

sudo npm install http-server -g

To start http-server of yours, just type


in your terminal.

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Posted by on January 24, 2017 in tech geak, Ubuntu


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Android Studio : Upgrading Gradle and Its Plugin

Android Studio : Upgrading Gradle and Its Plugin


Hey there, you might have caught in error message in Android Studio. Here, it says

Plugin is too old, please update to a more recent version, or set ANDROID_DAILY_OVERRIDE environment variable to “XXXX”

Here, it also stops working. This starts giving pain and delays your work. Tackling this is simple if you know how to do it. So, here we are ->

1. Upgrading Gradle

Go to and change


Refer this link always before changing to get latest or which version you need. The change you need to perform is change underlined part only by the new one. So, this update may also need new plugin.

After this you must clean and rebuild the project.

2. Upgrading Gradle Plugin

Go to build.gradle and perform a change in

classpath ‘

Refer this link to find out newest versions of Gradle plugin. Now change the underlined part as  you need them. After this you must clean and rebuild the project.

3. Solving the error without updating gradle and its plugin

You may need set an environment variable with the specified value. On OSX this looks as follows:

launchctl setenv ANDROID_DAILY_OVERRIDE <your-value-on-error-message>

Afterwards, clean the project, restart AS, and build again.


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Posted by on March 26, 2016 in Android, tech geak


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How do I Create a Self-Signed Certificate for an Android App?

How do I Create a Self-Signed Certificate for an Android App?


The Android release system requires that all applications installed on user devices are digitally signed with certificates whose private keys are held by the developer of the applications. The certificates allow the Android system to identify the author of an application and establish trust relationships between developers and their applications. The certificates are not used to control which applications the user can and cannot install.

Locating Keytool

Keytool is a key generation application that is made available through your Java SDK installation. You should be able to access the tool using a Terminal on your Mac or through the Command Prompt on your Windows machine.

The location of keytool is included in the directory search path on standard Mac installations but may have to be configured on Windows machines.

You can typically find the keytool application in the following or similar location under windows: C:\Program Files\Java\jdk1.6.0_24\bin\, if you followed the default installation process. You can either run keytool.exe from this location or add the relevant path to your search paths.

To add the path to your existing search paths, open your Control Panel and navigate to System and Security -> System -> Advanced system settings. This opens the System Properties window with the Advanced tab. Select Environment Variables… to open the Environment Variables window. Then select Path from the System variables panel and selectEdit… . This opens the Edit System Variable dialog in which you can add the new path to the existing list of search paths. Make sure that you separate each new path with a semicolon, as is shown in the figure of this step.

Creating the Key


Open your Terminal or Command Prompt and execute the command keytool. If the application is found, it is executed and a list of the available command line options is returned. This provides you with information on how you can configure the key generation process. The following example should allow you to generate an appropriate key:

keytool.exe -genkey -v -keystore release.keystore -alias TicTacToe -keyalg RSA -keysize 2048 -validity 10000

The application is interactive and command line driven, requesting that you enter a number of parameters. Do not worry if you make mistakes when entering parameters, you can enter them again.

Once you have created your key, it is stored in a .keystore file with its location shown at the end of the output, generated by the keytool. You should make a copy of your .keystore and keep it and the passwords in a safe place.

Note: -alias TicTacToe is specific to an application that is being signed to your application. You may want to change this to something that is more meaningful to the application you are working on.

Note: The Android website: has a lot of information and recommendations on how to create your private key. It is strongly recommended that you review that information in addition to what is covered in this lesson.


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Posted by on March 2, 2016 in Android, tech geak


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RAM a working table for all apps

RAM a working table for all apps

Think of the file system and its files as a big cabinet with lots of physical folders in an office of bureaucrats. The sheets in the folders are arranged in fixed ways such that every bureaucrat knows exactly where to expect which information before taking the folder out of the cabinet.



Not let us assume that a bureaucrat (a program) performs a certain operation on a folder/file. It will take the folder to the desk, spread the sheets on the desk, cut certain things out, glue them together, paint marking son certain sheets, translates the text of a sheet to a new one, discards sheets entirely, add sheets, and do all kinds of crazy stuff on the data on the desk in the way that the bureaucrat wants it to do. After all that, the bureaucrat puts the relevant sheets nicely back into the folder such that everything is orderly, puts the folder back into the cabinet and then throw everything that is left on the desk back into the trash bin.

Note that the bureaucrat’s desk is the RAM in this analogy. Now how are things stored on the desk? Well, that depends on what precise step the bureaucrat performs at a time instant. Even more, different bureaucrats doing essentially the same task may do things in a different order. So we can’t really say anything about the organization of a bureaucrat’s/program’s desk/RAM other than whatever is put back into the cabinet/file system is put there orderly. In between, it is up to the bureaucrat how things are stored and in which encoding.

For most data in the RAM, the question how it is encoded does however make sense. However, this encoding can change frequently. For example, when a web browser receives text from a server, it may change the encoding multiple times before the data is actually displayed.

I hope that this analogy helps clearing things up. It has its limits, though, as in a computer, folders are not taken out of the cabinet, but they are rather copied and later overwritten, as this is cheaper in a computer than it is in real life. Also, because the memory sizes of the processes in a computer are not fixed, there is memory management going on, and one can say something about where memory allocation information is stored and how that information is encoded.

After knowing this  a new question arises about what is format of processing data in ram?

The format is whatever the program you are currently executing deems to be appropriate. Your question is like asking how things are arranged on a kitchen table – at every point in time, there is some kind of order, but how things are arranged depends so strongly on what someone is doing are doing at the moment and who is doing that so that no universal answer can be given.


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Posted by on December 27, 2015 in tech geak, Uncategorized


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Troubleshot for all problems during installing CUSTOM rom in Samsung Galaxy Core GT – i8262

Troubleshot for all problems during installing CUSTOM rom in Samsung Galaxy Core GT – i8262

Q. Have you got in cwm recovery loop i.e. when you reboot your phone it goes in recovery mode?

ANS. No probs. Just remove your battery and  open download mode manually by pressing Power button+Home+volume down key. If you do like this only then download mode will support your odin otherwise it won’t supprt. After this just flash your cwm recovery again.

Q. Stuck on boot animation?

ANS. Just download adb (android debug bridge) minimum requirements. Sideload  your rom . It may seem to you that you got stuck there but don’t panic, wait atleast 5 minutes. After that remove your battery and press (Power+Home+volume up) upto it shows samsung screen and then release. Then just install your rom from recovery mode. ENJOY…………………….

Suggestion : If you want to be super user of your mobile then firstly root your device and and be sure by checking it using some apps like root checker etc.

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Posted by on March 30, 2015 in tech geak


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