Tutorial by Examples: co

Suppose you have a file that looks like this John Smith 31 Robert Jones 27 ... This file has 3 columns separated by spaces. To select only the first column, do the following. cut -d ' ' -f1 filename Here the -d flag, specifies the delimiter, or what separates the records. The -f flag speci...

Sometimes, it's useful to display a range of columns in a file. Suppose you have this file Apple California 2017 1.00 47 Mango Oregon 2015 2.30 33 To select the first 3 columns do cut -d ' ' -f1-3 filename This will display the following output Apple California 2017 Mango Oregon 2015 ...

Internally, Django uses the Python logging system. There is many way to configure the logging of a project. Here is a base: LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'formatters': { 'default': { 'format': "[%(asctime)s] %(levelname)s [%(n...

See Ellie for a working example. This example uses the NoRedInk/elm-decode-pipeline module. Given a list of JSON objects, which themselves contain lists of JSON objects: [ { "id": 0, "name": "Item 1", "transactions": [ { "id&quo...

var foo = new uint8[12]; var bar = foo; assert (foo != bar); In this example, the both foo and bar possess a strong reference, but since uint8[] only support single ownership, a copy is made.

By default STI model class name is stored in a column named type. But its name can be changed by overriding inheritance_column value in a base class. E.g.: class User < ActiveRecord::Base self.inheritance_column = :entity_type # can be string as well end class Admin < User; end Migr...

Having type column in a Rails model without invoking STI can be achieved by assigning :_type_disabled to inheritance_column: class User < ActiveRecord::Base self.inheritance_column = :_type_disabled end

In a basic implementation the task module must define a run/1 function that takes a list of arguments. E.g. def run(args) do ... end defmodule Mix.Tasks.Example_Task do use Mix.Task @shortdoc "Example_Task prints hello + its arguments" def run(args) do IO.puts "Hello ...

namespace Spirograph type MainWindow(app: App, model: Model) as this = inherit MainWindowXaml() let myApp = app let myModel = model let whenLoaded _ = () let whenClosing _ = () let whenClosed _ = () let menuExitHandler _ = System.Wind...

Main Component File: //our root app component import {Component, NgModule, ViewChild, ViewContainerRef, ComponentFactoryResolver, ComponentRef} from '@angular/core' import {BrowserModule} from '@angular/platform-browser' import {ChildComponent} from './childComp.ts' @Component({ selector: ...

Let's say we want to move a given date a numof months. We can define the following function, that uses the mondate package: moveNumOfMonths <- function(date, num) { as.Date(mondate(date) + num) } It moves consistently the month part of the date and adjusting the day, in case the date re...

import sys from PyQt5.QtWidgets import QApplication, QWidget from PyQt5.QtGui import QIcon class Example(QWidget): def __init__(self): super().__init__() self.initUI() def initUI(self): self.setGeometry(300, 30...

The basic setup of hybrid coding is a single, fluid column. Since most email clients support max-width, we can use that to set the <table>'s width to 100% (fluid), but not exceed a max width (660px in this case). Just like on the web. However, Windows Desktop Microsoft doesn't support max-wid...

@Component({ selector: 'zippy', template: ` <div class="zippy"> <div (click)="toggle()">Toggle</div> <div [hidden]="!visible"> <ng-content></ng-content> </div> </div>`}) export class Zippy...

As of Jekyll 3.2, you can use the filter where_exp to filter a collection by any of its properties. Say you have the following collection item in an "albums" collection: --- title: My Amazing Album --- ... You can combine the where_exp and first filters to grab just that one item: ...

Given an 'albums' collection, you can loop through and output each item: {% for album in site.albums %} {{ album.content }} {% endfor %} Any custom front matter variables are also available within the loop. {% for album in site.albums %} {{ album.title }} {{ album.content }} {%...

Given an 'albums' collection, an item can be added by creating a file in the <source>/_albums directory. Note that files not including frontmatter will be ignored. For instance, adding a file called my_album.md to the _albums directory would add it to the collection: --- title: "My Alb...

The code snippet below shows the various ways you can filter on an array of objects using lodash. let lodash = require('lodash'); var countries = [ {"key": "DE", "name": "Deutschland", "active": false}, {"key": "ZA&qu...

Going to its roots, Logstash has the ability to parse and store syslog data. This example shows a basic configuration that gets you to that. input { file { path => [ "/var/log/syslog", "/var/log/auth.log" ] type => "syslog" } }...

After a while, you end up with many configuration items in your config.yml. It can make you configuration easier to read if you split your configuration across multiple files. You can easily include all files from a directory this way: config.yml: imports: - { resource: parameters.yml } ...