Tutorial by Examples: ch

Using search results

The following script shows more advanced split file technique, where FOR function loops through a list of files in a directory, and each file content is piped to FINDSTR that looks for a string containing substring var preceded by undefined number of spaces and superseded by any extra text. Once fou...

batch-file • Search strings in batch

Branching

When we’re first starting our work, we have to decide if this is a separate area of work we’re working on, or is this part of an existing line of work. If it’s existing, we can work off of that branch. If it’s new, we’ll start a new branch. Our workflow then is: hg branch MyNewFeature work wo...

mercurial • Getting started with mercurial

Show git branch name in terminal prompt

You can have functions in the PS1 variable, just make sure to single quote it or use escape for special chars: gitPS1(){ gitps1=$(git branch 2>/dev/null | grep '*') gitps1="${gitps1:+ (${gitps1/#\* /})}" echo "$gitps1" } PS1='\u@\h:\w$(gitPS1)$ ' It will...

Bash • Customizing PS1

Splitting by separator changes

We can just do simple replacement of separators from space to new line, as following example. echo $sentence | tr " " "\n" It'll split the value of the variable sentence and show it line by line respectively.

Bash • Word splitting

Check which process running on specific port

To check which process running on port 8080 lsof -i :8080

Bash • Jobs and Processes

Pie Chart with Demo

<!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(function(){ var canvas = document.getElementById("canvas"); var ctx = canvas.getContext(&...

html5-canvas • Charts & Diagrams

basic channel operations: creating, putting, taking, closing, and buffers.

core.async is about making processes that take values from and put values into channels. (require [clojure.core.async :as a]) Creating channels with chan You create a channel using the chan function: (def chan-0 (a/chan)) ;; unbuffered channel: acts as a rendez-vous point. (def chan-1 (a/chan...

clojure • core.async

Bonus: Simple Search example (Another way to read)

MarkLogic is first and foremost a search engine, so let's use two different methods to search for this document. Using search:search() This gives a peek into using search:search() to develop search applications. This library provides Google-like search results and will likely speed up your develop...

marklogic • Very simple CRUD examples for XML documents

Check if resource exists

/** * Checks if a resource exists by sending a HEAD-Request. * @param url The url of a resource which has to be checked. * @return true if the response code is 200 OK. */ public static final boolean checkIfResourceExists(URL url) throws IOException { HttpURLConnection conn = (HttpURLCo...

Java Language • HttpURLConnection

Adding a URL scheme to your own app

Let's say you're working on an app called MyTasks, and you want to allow inbound URLs to create a new task with a title and a body. The URL you're designing might look something like this: mytasks://create?title=hello&body=world (Of course, the text and body parameters are used to populate our...

iOS • Deep Linking in iOS

Character evaluation

a Character evaluates to true if it's value is not zero, false if zero assert ! new Character((char)0) assert ! new Character('\u0000Hello Zero Char'.charAt(0)) assert new Character('Hello'.charAt(0))

groovy • Groovy Truth (true-ness)

Matcher evaluation

a Matcher evaluates to true if it can find at least one match, false if no match is found // a match is found => true assert 'foo' =~ /[a-z]/ // the regexp does not match fully => no match => false assert !( 'foo' ==~ /[a-z]/ ) // a match is found => true assert 'foo' =~ /o/ // no...

groovy • Groovy Truth (true-ness)

MERGE to make Target match Source

MERGE INTO targetTable t USING sourceTable s ON t.PKID = s.PKID WHEN MATCHED AND NOT EXISTS ( SELECT s.ColumnA, s.ColumnB, s.ColumnC INTERSECT SELECT t.ColumnA, t.ColumnB, s.ColumnC ) THEN UPDATE SET t.Colum...

SQL • MERGE

Checking for nonlinearity with polynomial regression

Sometimes when working with linear regression we need to check for non-linearity in the data. One way to do this is to fit a polynomial model and check whether it fits the data better than a linear model. There are other reasons, such as theoretical, that indicate to fit a quadratic or higher order ...

R Language • Linear Models (Regression)

DropCreateDatabaseIfModelChanges

This implementation of IDatabaseInitializer drops and recreates the database if the model changes automatically. Usage: public class MyContext : DbContext { public MyContext() { Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyContext>()); } }

Entity Framework • Database Initialisers

if()...else Ladder Chaining two or more if () ... else statements

While the if ()... else statement allows to define only one (default) behaviour which occurs when the condition within the if () is not met, chaining two or more if () ... else statements allow to define a couple more behaviours before going to the last else branch acting as a "default", i...

C Language • Selection Statements

Synchronous IPC communication

Create index.js as const {app, BrowserWindow, ipcMain} = require('electron') let win = null app.on('ready', () => { win = new BrowserWindow() win.loadURL(`file://${__dirname}/index.html`) win.webContents.openDevTools() win.on('closed', () => { win = null }) }) ipcM...

electron • Main and renderer process.

Finding all branches with no merged changes

Sometimes you might have branches lying around that have already had their changes merged into master. This finds all branches that are not master that have no unique commits as compared to master. This is very useful for finding branches that were not deleted after the PR was merged into master. ...

Git • Merging

Prime checking

Please note that by definition 1 is not a prime number. To check if a number n is a prime we should try to find a divisor i of n. If we cannot, then n is a prime. We have found a divisor when n % i == 0 evaluates to true. We only need to try odd numbers, since there's only one even prime, namely 2,...

math • prime numbers

implement View.OnLayoutChangeListener in Nativescript

let playerLayoutChangeListener = new android.view.View.OnLayoutChangeListener( { onLayoutChange : function ( v:View, left:number, top:number, right:number, bottom:number, oldLeft:number, oldTop:number, oldRight:number, oldBottom:number):any { if (left != oldLeft || top != oldTop ...

nativescript • implement Interface