Tutorial by Examples: re

Semaphores are used to synchronize operations between two or more processes. POSIX defines two different sets of semaphore functions: 'System V IPC' — semctl(), semop(), semget(). 'POSIX Semaphores' — sem_close(), sem_destroy(), sem_getvalue(), sem_init(), sem_open(), sem_post(), sem_try...

The most effective way to resolve curl to a different server is to use the --resolve option. This option will insert the address into curl's DNS cache, so it will effectively make curl believe that's the address it got when it resolved the name. Like so: curl --resolve eaxmple.com:80:1.2.3.4 http:...

val a = arrayOf(1, 2, 3) // creates an Array<Int> of size 3 containing [1, 2, 3].

val a = Array(3) { i -> i * 2 } // creates an Array<Int> of size 3 containing [0, 2, 4]

val a = arrayOfNulls<Int>(3) // creates an Array<Int?> of [null, null, null] The returned array will always have a nullable type. Arrays of non-nullable items can't be created uninitialized.

If you are unsure which rules to list in your .gitattributes file, or you just want to add generally accepted attributes to your project, you can shoose or generate a .gitattributes file at: https://gitattributes.io/ https://github.com/alexkaratarakis/gitattributes

The window resize events can fire in response to the movement of the user's input device. When you resize a canvas it is automatically cleared and you are forced to re-render the content. For animations you do this every frame via the main loop function called by requestAnimationFrame which does its...

class User(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(80)) email = db.Column(db.String(120), unique=True) posts = db.relationship('Post', backref='user') class Post(db.Model): id = db.Column(db.Integer,...

A typical example of the implementation of a Looper thread given by the official documentation uses Looper.prepare() and Looper.loop() and associates a Handler with the loop between these calls. class LooperThread extends Thread { public Handler mHandler; public void run() { Lo...

A HandlerThread can be used to start a thread with a Looper. This looper then can be used to create a Handler for communications with it. HandlerThread thread = new HandlerThread("thread-name"); thread.start(); Handler handler = new Handler(thread.getLooper());

In this example, we will plot a sine curve and a hyperbolic sine curve in the same plot with a common x-axis having different y-axis. This is accomplished by the use of twinx() command. # Plotting tutorials in Python # Adding Multiple plots by twin x axis # Good for plots having different y axis ...

In this example, a plot with curves having common y-axis but different x-axis is demonstrated using twiny() method. Also, some additional features such as the title, legend, labels, grids, axis ticks and colours are added to the plot. # Plotting tutorials in Python # Adding Multiple plots by twin ...

Java StringWriter class is a character stream that collects output from string buffer, which can be used to construct a string. The StringWriter class extends the Writer class. In StringWriter class, system resources like network sockets and files are not used, therefore closing the StringWriter i...

It was most frequent question that can a same thread can be run twice. The answer for this is know one thread can run only once . if you try to run the same thread twice it will execute for the first time but will give error for second time and the error will be IllegalThreadStateException . exam...

A simple HTTP Request for the resource /index.html. The host www.example.com is specified in the HTTP Host header. GET /index.html HTTP/1.1 Host: www.example.com

A possible response to the request above. The response contains the HTTP headers Date, Content-Type, Content-Encoding and Content-Length. HTTP/1.1 200 OK Date: Wed, 21 Jun 2017 10:58:03 GMT Content-Type: text/html; charset=UTF-8 Content-Encoding: UTF-8 Content-Length: 150 <response body&g...

package com.streams; import java.io.*; public class DataStreamDemo { public static void main(String[] args) throws IOException { InputStream input = new FileInputStream("D:\\datastreamdemo.txt"); DataInputStream inst = new DataInputStream(input); int count...

Valgrind provides you with the lines at which the error occurred at the end of each line in the format (file.c:line_no). Errors in valgrind are summarised in the following way: ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) The most common errors include: Illegal read/write er...

Usually, the routes in a controller have the same prefix connected somehow with functionality of this controller. For example: public class ProductsController : ApiController { [Route("api/products")] public IEnumerable<Product> GetProducts() { ... } [Route("a...

First of all you need to create AVAssetWriter NSError *error = nil; NSURL *outputURL = <#NSURL object representing the URL where you want to save the video#>; AVAssetWriter *assetWriter = [AVAssetWriter assetWriterWithURL:outputURL fileType:AVFileTypeQuickTimeMovie error:&error]; if (!...