Tutorial by Examples: nd

&& chains two commands. The second one runs only if the first one exits with success. || chains two commands. But second one runs only if first one exits with failure. [ a = b ] && echo "yes" || echo "no" # if you want to run more commands within a logical c...

A semicolon separates just two commands. echo "i am first" ; echo "i am second" ; echo " i am third"

The | takes the output of the left command and pipes it as input the right command. Mind, that this is done in a subshell. Hence you cannot set values of vars of the calling process wihtin a pipe. find . -type f -a -iname '*.mp3' | \ while read filename; do mute --noise &quot...

Adding a video that will autoplay on a loop and has no controls or sound. Perfect for a video header or background. <video width="1280" height="720" autoplay muted loop poster="video.jpg" id="videobg"> <source src="video.mp4" type="...

BFS can be used to find the connected components of an undirected graph. We can also find if the given graph is connected or not. Our subsequent discussion assumes we are dealing with undirected graphs.The definition of a connected graph is: A graph is connected if there is a path between every p...

Install pip : $ pip install django-cassandra-engine Add Getting Started to INSTALLED_APPS in your settings.py file: INSTALLED_APPS = ['django_cassandra_engine'] Cange DATABASES setting Standart: Standart DATABASES = { 'default': { 'ENGINE': 'django_cassandra_engine', ...

In this example, we use this database: "your-project-name" : { "users" : { "randomUserId1" : { "display-name" : "John Doe", "gender" : "male" } "randomUserId2" :...

Note: You need to know which data referenced by getReference() first before you can completely understand this example. There are three common method to get your data from Firebase Realtime Database: addValueEventListener() addListenerForSingleValueEvent() addChildEventListener() When w...

This example demonstrate how to dynamically insert data into MySQL using Python Scrapy. You do not need to edit pipelines.py file for any project. This example can be used for all your project. Just yield you_data_dictionary from your Spider and inside pipelines.py a query will be created automat...

Event Type- DDL_COMMAND_START DDL_COMMAND_END SQL_DROP This is example for creating an Event Trigger and logging DDL_COMMAND_START events. CREATE TABLE TAB_EVENT_LOGS( DATE_TIME TIMESTAMP, EVENT_NAME TEXT, REMARKS TEXT ); CREATE OR REPLACE FUNCTION FN_LOG_EVENT() RETURNS EVE...

This example shows a very basic example of how to utilize onCommand. I don't suggest processing your commands directly in onCommand, but this does the trick for this simple case. In this example we attempt to set the player's gamemode. The first thing we need to do is make sure that the sender isn...

$rootId = Mage::app()->getStore($storeId)->getRootCategoryId(); $categories = Mage::getModel('catalog/category')->getCollection() ->addAttributeToSelect('*') ->addFieldToFilter('path', array('like'=> "1/$rootId/%")) ->addAttributeToFilter('level', 2...

Since a signal handler will be called by the kernel using the C calling convention, we must tell the compiler to use the C calling convention when compiling the function. volatile sig_atomic_t death_signal = 0; extern "C" void cleanup(int signum) { death_signal = signum; } int mai...

import sys from PyQt4.QtCore import * from PyQt4.QtGui import * def window(): app = QApplication(sys.argv) win = QDialog() b1 = QPushButton(win) b1.setText("Button1") b1.move(50,20) b1.clicked.connect(b1_clicked) b2 = QPushButton(win) b2.setText(&quot...

retrieve all documents in a collection db.collection.find({}); retrieve documents in a collection using a condition ( similar to WHERE in MYSQL ) db.collection.find({key: value}); example db.users.find({email:"[email protected]"}); retrieve documents in a collection using Boole...

db.collection.findOne({}); the querying functionality is similar to find() but this will end execution the moment it finds one document matching its condition , if used with and empty object , it will fetch the first document and return it . findOne() mongodb api documentation

In your activity layout activity_main.xml specify WebView component as following: <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" ...

Install cordova using the following command npm install -g cordova. Use cordova -version to check the cordova version. Set path variables ANDROID_HOME and JAVA_HOME. Example: export ANDROID_HOME = /home/geethu/android-sdk-linux export PATH = $PATH:$ANDROID_HOME/tools:$ANDROID_H...

To create a new project ng new [project-name] which initializes git.Install packages for tooling via npm. It creates the project successfully. cd [project-name] and execute either npm start or ng serve It'll run the server in the given default port. Application will refresh according to the chan...

bindings: { mandatory: '=' optional: '=?', foo: '=?bar' } Optional attributes should be marked with question mark: =? or =?bar. It is protection for ($compile:nonassign) exception.