Tutorial by Examples: v

Dockerfile + supervisord.conf

To run multiple processes e.g. an Apache web server together with an SSH daemon inside the same container you can use supervisord. Create your supervisord.conf configuration file like: [supervisord] nodaemon=true [program:sshd] command=/usr/sbin/sshd -D [program:apache2] command=/bin/bash...

Docker • Multiple processes in one container instance

Sort a dynamic array via generic TArray.Sort

uses System.Generics.Collections, { TArray } System.Generics.Defaults; { TComparer<T> } var StringArray: TArray<string>; { Also works with "array of string" } ... { Sorts the array case insensitive } TArray.Sort<string>(StringArray, TComparer<string>...

Embarcadero Delphi • Generics

Simple MVP Example

To illustrate a simple example usage of the MVP pattern, consider the following code which creates a simple UI with only a button and a label. When the button is clicked, the label updates with the number of times the button has been clicked. We have 5 classes: Model - The POJO to maintain state...

swing • MVP Pattern

Creating a data type with value constructor parameters

Value constructors are functions that return a value of a data type. Because of this, just like any other function, they can take one or more parameters: data Foo = Bar String Int | Biz String Let's check the type of the Bar value constructor. :t Bar prints Bar :: String -> Int -> Foo...

Haskell Language • Creating Custom Data Types

To get old table structure using div

This is the normal HTML table structure <style> table { width: 100%; } </style> <table> <tr> <td> I'm a table </td> </tr> </table> You can do same implementation like this <style> .table-...

CSS • Layout Control

Very basic example demonstrating function use on SetTimer.

;Sends the keystroke for the letter "a" every 3 seconds. #Persistent SetTimer, SendLetterA, 3000 return SendLetterA() { Send, a }

AutoHotkey • Use functions instead of labels

Advanced use of SetTimer: Calling the same function with different parameters

This is an example of something that would have been straight up impossible with labels. If you execute the same label multiple times at the same time and they rely on variables that are being defined within them, they very likely interfere and cause unexpected behavior. Here is how to do it with f...

AutoHotkey • Use functions instead of labels

The Options pattern / Injecting options into services

With ASP.NET Core the Microsoft team also introduced the Options pattern, which allows to have strong typed options and once configured the ability to inject the options into your services. First we start with a strong typed class, which will hold our configuration. public class MySettings { ...

asp.net-core • Dependency Injection

Context. Using a credential cache for elevated execution of code

While server side-code can run with elevated privileges, there is not an equivalent method to elevate privileges in client-side code (for obvious security reasons). As an alternative, you can specify credentials to emulate the access of a specific user or service account. To specify credentials, bu...

sharepoint • Working with Managed Client Side Object Model (CSOM)

Marshaling structs with private fields

As a good developer you have created following struct with both exported and unexported fields: type MyStruct struct { uuid string Name string } Example in Playground: https://play.golang.org/p/Zk94Il2ANZ Now you want to Marshal() this struct into valid JSON for storage in somet...

Go • JSON

Monad as a Subclass of Applicative

As of GHC 7.10, Applicative is a superclass of Monad (i.e., every type which is a Monad must also be an Applicative). All the methods of Applicative (pure, <*>) can be implemented in terms of methods of Monad (return, >>=). It is obvious that pure and return serve equivalent purposes, ...

Haskell Language • Monads

Uninitialized variable

BAD CODE Dim f As System.Windows.Forms.Form f.ShowModal() GOOD CODE Dim f As System.Windows.Forms.Form = New System.Windows.Forms.Form ' Dim f As New System.Windows.Forms.Form ' alternative syntax f.ShowModal() EVEN BETTER CODE (Ensure proper disposal of IDisposable object more info) Us...

Visual Basic .NET Language • NullReferenceException

Width vs Viewport

When we are using "width" with media queries it is important to set the meta tag correctly. Basic meta tag looks like this and it needs to be put inside the <head> tag. <meta name="viewport" content="width=device-width,initial-scale=1"> Why this is impo...

CSS • Media Queries

Download file from FTP server

My.Computer.Network.DownloadFile("ftp://server.my/myfile.txt", "donwloaded_file.txt") This command download myfile.txt file from server named server.my and saves it as donwloaded_file.txt into working directory. You can specify absolute path for downloaded file.

Visual Basic .NET Language • FTP server

Download file from FTP server when login required

My.Computer.Network.DownloadFile("ftp://srv.my/myfile.txt", "donwload.txt", "Peter", "1234") This command download myfile.txt file from server named srv.my and saves it as donwload.txt into working directory. You can specify absolute path for downloaded fil...

Visual Basic .NET Language • FTP server

Upload file to FTP server

My.Computer.Network.UploadFile("example.txt", "ftp://server.my/server_example.txt") This command upload example.txt file from working directory (you could specify absolute path if you want) to server named server.my. File stored on the server will be named server_example.txt. ...

Visual Basic .NET Language • FTP server

Upload file to FTP server when login required

My.Computer.Network.UploadFile("doc.txt", "ftp://server.my/on_server.txt", "Peter", "1234") This command upload doc.txt file from working directory (you could specify absolute path if you want) to server named server.my. File stored on the server will be na...

Visual Basic .NET Language • FTP server

Searching For A Value In A Binary Search Tree With Recursion in C/C++

Structure for Binary Search Tree (BST) nodes: struct node { int data; node * left; node * right; } Search Algorithm // Check if a value exists in the tree bool BSTSearch(node * current, int value) { if (current->data == value) { return true; } e...

Recursion • Getting started with Recursion

Select dataset except where values are in this other dataset

--dataset schemas must be identical SELECT 'Data1' as 'Column' UNION ALL SELECT 'Data2' as 'Column' UNION ALL SELECT 'Data3' as 'Column' UNION ALL SELECT 'Data4' as 'Column' UNION ALL SELECT 'Data5' as 'Column' EXCEPT SELECT 'Data3' as 'Column' --Returns Data1, Data2, Data4, and Data5

SQL • EXCEPT

Viewing information for Bash built-ins

help <command> This will display the Bash help (manual) page for the specified built-in. For example, help unset will show: unset: unset [-f] [-v] [-n] [name ...] Unset values and attributes of shell variables and functions. For each NAME, remove the corresponding variable or ...

Bash • Getting started with Bash