My Diary.
to Share my Life Events

How to know if iPhone is new or refurbised or replacement iphone.


It is very simple to check if your iphone is new or refurbised. Follow the next step.

1. Go to setting

1. Click General. 

2. Click About. 



If the model first letter start with M then = New

If the mode first letter start wifh F = refurbished  then its is a refurbised device.


Refurbished are repair device or replacement iphone.


Tips: you can check the physical iphone and check your serial number at apple website.

Admin Admin Author

Installing Oracle XE on CENTOS 7.5



Setup CENTOS 7.5 on cloud and install basic tools.

yum install nano -y

yum install unzip -y

yum install bc -y

yum install wget -y


Oracle XE required SWAP files for setup


First you need to check current swap file.

swapon -s

Next check available space.


# Create 2GB swap file

dd if=/dev/zero of=/swapfile bs=1024 count=2048kmkswap /swapfileswapon /swapfile


echo "/swapfile swap swap defaults 0 0" >> /etc/fstab

hown root:root /swapfile chmod 0600 /swapfileset


Next Download 

Oracle XE express

rpm -ivh oracle-xe-11.2.0-1.0.x86_64.rpm

Next run the configuration script#

/etc/init.d/oracle-xe configure



To prevent TNS error during OCI_CONNECT.

sebool -P httpd_can_network_connect 1 

Admin Admin Author

The best stock market simulation apps



The best stock market simulation web apps to learn and practise reading technical chart. . 

Admin Admin Author

Mac Show hidden folder

Mac show hidden folder

Go to the terminal. Type the following command



 defaults write AppleShowAllFiles YES


Then press Option/Alt key and right click on the finder and cick relaunch to see all hidden folder.

to disable.


 defaults write AppleShowAllFiles NO


Admin Admin Author

root does not have permission to access the dev dir

sudo npm install --unsafe-perm --verbose -g sails

Admin Admin Author

React Native Admob plugin error






Javascript error..Invariant Violation: View config not found for name RNGADBannerView
This error is located at:    in RNGADBannerView (at RNAdMobBanner.js:51)    in AdMobBanner (at App.js:33)    in RCTView (at View.js:60)    in View (at App.js:23)    in codetrAdmob (at registerRootComponent.js:35)    in RootErrorBoundary (at registerRootComponent.js:34)    in ExpoRootComponent (at renderApplication.js:33)    in RCTView (at View.js:60)    in View (at AppContainer.js:102)    in RCTView (at View.js:60)    in View (at AppContainer.js:122)    in AppContainer (at renderApplication.js:32)

Admin Admin Author

Try your react native apps with expo


Your app is now running at URL: exp://


View your app with live reloading:


  Android device:

    -> Point the Expo app to the QR code above.

       (You'll find the QR scanner on the Projects tab of the app.)

  iOS device:

    -> Press s to email/text the app URL to your phone.


    -> Press a (Android) or i (iOS) to start an emulator.


Your phone will need to be on the same local network as this computer.

For links to install the Expo app, please visit


Logs from serving your app will appear here. Press Ctrl+C at any time to stop.

or to run on device type

react-native run-iosreact-native run-ios

Admin Admin Author

Upgrade node.js and npm


If you got the following error..

mERR! Failed at the mytest@0.1.0 start script 'react-native-scripts start'.

npmERR! Make sure you have the latest version of node.js and npm installed.

npmERR! If you do, this is most likely a problem with the mytest package,

npmERR! not with npm itself.

NPM error while start the react native apps.

brew update
brew upgrade node
npm install -g npm

Or download the latest version here

You can also nstall watchman or type in the following code:
sudo sysctl -w kern.maxfiles=5242880sudo sysctl -w kern.maxfilesperproc=524288

Admin Admin Author

Create first react native app from command line



1. npm install -g create-react-native-app

2. create-react-native-app my-app

3. cd my-app/

4. npm start

Admin Admin Author

Updating sites with new tutorials


Hi guys, I am going to share you with my Oracle PL/SQL tutorial at my new sites. Its still under construction. I hope you like the contents and give me the feedback so that we can share knowledge together.



Admin Admin Author