Tutorial by Examples: re

Embedded Lua Interpreter with Custom API and Lua Customization

Demonstrate how to embed a lua interpreter in C code, expose a C-defined function to Lua script, evaluate a Lua script, call a C-defined function from Lua, and call a Lua-defined function from C (the host). In this example, we want the mood to be set by a Lua script. Here is mood.lua: -- Get versi...

Lua • Introduction to Lua C API

Create a dispatch queue

You can create your own queue using dispatch_queue_create Objective-C dispatch_queue_t queue = dispatch_queue_create("com.example.myqueue", DISPATCH_QUEUE_SERIAL); Swift // Before Swift 3 let queue = dispatch_queue_create("com.example.myqueue", DISPATCH_QUEUE_SERIAL) // ...

iOS • GCD (Grand Central Dispatch)

Creating a Xposed Module

Xposed is a framework that allows you to hook method calls of other apps. When you do a modification by decompiling an APK, you can insert/change commands directly wherever you want. However, you will need to recompile/sign the APK afterwards and you can only distribute the whole package. With Xpose...

Android • Xposed

Prevent binding on PostModel

Considering a (post)model: public class User { public string FirstName { get; set; } public bool IsAdmin { get; set; } } With a view like so: @using (Html.BeginForm()) { @Html.EditorFor(model => model.FirstName) <input type="submit" value="Save" /...

asp.net-mvc • Model binding

How do foldFree and iterM work?

There are some functions to help tear down Free computations by interpreting them into another monad m: iterM :: (Functor f, Monad m) => (f (m a) -> m a) -> (Free f a -> m a) and foldFree :: Monad m => (forall x. f x -> m x) -> (Free f a -> m a). What are they doing? First l...

Haskell Language • Free Monads

Ajax Abort a Call or Request

var xhr = $.ajax({ type: "POST", url: "some.php", data: "name=John&location=Boston", success: function(msg){ alert( "Data Saved: " + msg ); } }); //kill the request xhr.abort()

jQuery • Ajax

Including LaTeX Preample Commands

There are two possible ways of including LaTeX preamble commands (e.g. \usepackage) in a RMarkdown document. 1. Using the YAML option header-includes: --- title: "Including LaTeX Preample Commands in RMarkdown" header-includes: - \renewcommand{\familydefault}{cmss} - \usepacka...

R Language • Creating reports with RMarkdown

A simple authentication POST request with Jsoup

A simple POST request with authentication data is demonstrated below, note that the username and password field will vary depending on the website: final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36"; ...

Jsoup • Logging into websites with Jsoup

A more comprehensive authentication POST request with Jsoup

Most websites require a much more complicated process than the one demonstrated above. Common steps for logging into a website are: Get the unique cookie from the initial login form. Inspect the login form to see what the destination url is for the authentication request Parse the login form t...

Jsoup • Logging into websites with Jsoup

Structure of a Simple ASP Page

<%@ Language="VBScript" CodePage = 65001 %> <% Option Explicit Response.Charset = "UTF-8" Response.CodePage = 65001 %> <!doctype html> <html> <head> <title>My First Classic ASP Page</title> </head> <body&gt...

asp-classic • Getting started with asp-classic

Enable streaming from flask

Flask has that feature which lets you stream data from a view by using generators. Let's change the app.py file add from flask import Response add from datetime import datetime add from time import sleep create a new view: @app.route("/time/") def time(): def streamer(): ...

Flask • Deploying Flask application using uWSGI web server with Nginx

Pitfall: using == to compare strings

A common mistake for Java beginners is to use the == operator to test if two strings are equal. For example: public class Hello { public static void main(String[] args) { if (args.length > 0) { if (args[0] == "hello") { System.out.println(&q...

Java Language • Common Java Pitfalls

Creating zip archive from directory

System.IO.Compression.ZipFile.CreateFromDirectory("myfolder", "archive.zip") Create archive.zip file containing files which are in myfolder. In example paths are relative to program working directory. You can specify absolute paths.

Visual Basic .NET Language • File/Folder Compression

Extracting zip archive to directory

System.IO.Compression.ZipFile.ExtractToDirectory("archive.zip", "myfolder") Extracts archive.zip to myfolder directory. In example paths are relative to program working directory. You can specify absolute paths.

Visual Basic .NET Language • File/Folder Compression

Create zip archive dynamicaly

' Create filestream to file Using fileStream = New IO.FileStream("archive.zip", IO.FileMode.Create) ' open zip archive from stream Using archive = New System.IO.Compression.ZipArchive(fileStream, IO.Compression.ZipArchiveMode.Create) ' create file_in_archive.txt in arch...

Visual Basic .NET Language • File/Folder Compression

Reads file (/etc/passwd) line by line and field by field

#!/bin/bash FILENAME="/etc/passwd" while IFS=: read -r username password userid groupid comment homedir cmdshell do echo "$username, $userid, $comment $homedir" done < $FILENAME In unix password file, user information is stored line by line, each line consisting of i...

Bash • Read a file (data stream, variable) line-by-line (and/or field-by-field)?

Adding a UIRefreshControl to a TableView

Assumptions: TableView - reference to the TableView DataSource - is a class which inherits UITableViewSource DataSource.Objects - is a public List< object >(), accessible to the UIViewController private UIRefreshControl refreshControl; public override void ViewDidLoad() { base.V...

Xamarin.iOS • Adding UIRefreshControl to a table view

Dictionaries are unordered

You might expect a Python dictionary to be sorted by keys like, for example, a C++ std::map, but this is not the case: myDict = {'first': 1, 'second': 2, 'third': 3} print(myDict) # Out: {'first': 1, 'second': 2, 'third': 3} print([k for k in myDict]) # Out: ['second', 'third', 'first'] Py...

Python Language • Common Pitfalls

RecordWildCards

See RecordWildCards

Haskell Language • Common GHC Language Extensions

POSIX Timer with SIGEV_THREAD notification

This example demonstrates POSIX Timer usage with CLOCK_REALTIME clock and SIGEV_THREAD notification method. #include <stdio.h> /* for puts() */ #include <string.h> /* for memset() */ #include <unistd.h> /* for sleep() */ #include <stdlib.h> /* for EXIT_SUCCESS */ #inc...

POSIX • Timers