NFC technology, contactless payments future

Hope you are watching the advertisement on TV or youtube, in which people paying bills just by hovering their credit card on POS machine. Banks like ICICI in India launched this type of cards where NFC( Near field communication ) technology is used. Lets understand NFC, two devices here one is credit card and other is POS terminal/ Card … Read more

Add new SSH users to AWS EC2

Check existing users : cut -d: -f1 /etc/passwd sudo adduser user_name add newly created to root group sudo usermod -a -G sudo user_name change current user to new user cd to home dir of newly created user run mkdir .ssh secure it by chmod 700 .ssh to create authorized_keys file run touch .ssh/authorized_keys Copy your public key in clipboard cat … Read more

Python virtualenv?

We always use different version of libraries in our projects as per requirement, it means we need project environments supporting local installation of packages and avoid usage of globally installed packages. virtualenv i.e. Virtual Environment, is solutions to above problem as it maintain a separate copy of Python and libs utilized in your python project. … Read more

Gravity Form Date Field Filter

When you use “Gravity form date field” and want a user to select future dates or today’s date only, simply add one Html field and copy paste below code snippet to HTML field. This will be applied to all date fields in gravity form. <script > gform.addFilter( ‘gform_datepicker_options_pre_init’, function( optionsObj, formId, fieldId ) { // do stuff optionsObj.minDate = new … Read more

Installing Composer on OS X

Composer is a cross-platform dependency manager for PHP libraries. Let’s install it on OS X and add an alias/shortcut/command so you can use it from anywhere. Downloading Composer will create a Phar (PHP Archive) file called “composer.phar” From your terminal, run the following command: curl -sS | php // S option to show any errors if … Read more

Setup android environment var on mac os

Whenever you start with new OS installation or with a new machine and leading to android app development, we need to setup PATH environment variables. So maybe you have ‘android SDK’ downloaded or ‘android studio’ running. To add environment variables permanently, need to add those in .bash_profile file, which doesn’t exist, we need to make one by typing … Read more

Firebase Cloud Messaging in ionic apps

People who are used to integarte GCM in ionic apps, its time to migrate to FCM( Firebase Cloud Messaging ) App/Device/Client side steps : Use plugin STEP 1 cordova plugin add cordova-plugin-fcm STEP 2 if(window.cordova) { FCMPlugin.onNotification( function(data){ if(data.wasTapped){ // $state.go(‘message’, {id:data.pageId}); // $location.path(‘app/userList’); alert(‘onNotification tapped true’); } else { alert(“xxxxxxxxxxxx”+data); } }, function(msg){ // … Read more

install redis server on CentOS 7

While implementation,( server clusters case ), simple socket server will not work and you need to use socket with redis server. So how to install redis on centos os, follow steps below. *Sudo user required. yum install redis // install redis server systemctl start redis.service // start redis server systemctl status redis.service // check server status redis-cli … Read more