Programs & Examples On #Wiimote

The Wii Remote, also known as the Wiimote, is the primary controller for Nintendo's Wii console.

What SOAP client libraries exist for Python, and where is the documentation for them?

As I suggested here I recommend you roll your own. It's actually not that difficult and I suspect that's the reason there aren't better Python SOAP libraries out there.

MySQL Join Where Not Exists

There are three possible ways to do that.

  1. Option

    SELECT  lt.* FROM    table_left lt
        table_right rt
    ON      rt.value = lt.value
    WHERE   rt.value IS NULL
  2. Option

    SELECT  lt.* FROM    table_left lt
    WHERE   lt.value NOT IN
    SELECT  value
    FROM    table_right rt
  3. Option

    SELECT  lt.* FROM    table_left lt
    FROM    table_right rt
    WHERE   rt.value = lt.value

Virtual/pure virtual explained

I'd like to comment on Wikipedia's definition of virtual, as repeated by several here. [At the time this answer was written,] Wikipedia defined a virtual method as one that can be overridden in subclasses. [Fortunately, Wikipedia has been edited since, and it now explains this correctly.] That is incorrect: any method, not just virtual ones, can be overridden in subclasses. What virtual does is to give you polymorphism, that is, the ability to select at run-time the most-derived override of a method.

Consider the following code:

#include <iostream>
using namespace std;

class Base {
    void NonVirtual() {
        cout << "Base NonVirtual called.\n";
    virtual void Virtual() {
        cout << "Base Virtual called.\n";
class Derived : public Base {
    void NonVirtual() {
        cout << "Derived NonVirtual called.\n";
    void Virtual() {
        cout << "Derived Virtual called.\n";

int main() {
    Base* bBase = new Base();
    Base* bDerived = new Derived();


What is the output of this program?

Base NonVirtual called.
Base Virtual called.
Base NonVirtual called.
Derived Virtual called.

Derived overrides every method of Base: not just the virtual one, but also the non-virtual.

We see that when you have a Base-pointer-to-Derived (bDerived), calling NonVirtual calls the Base class implementation. This is resolved at compile-time: the compiler sees that bDerived is a Base*, that NonVirtual is not virtual, so it does the resolution on class Base.

However, calling Virtual calls the Derived class implementation. Because of the keyword virtual, the selection of the method happens at run-time, not compile-time. What happens here at compile-time is that the compiler sees that this is a Base*, and that it's calling a virtual method, so it insert a call to the vtable instead of class Base. This vtable is instantiated at run-time, hence the run-time resolution to the most-derived override.

I hope this wasn't too confusing. In short, any method can be overridden, but only virtual methods give you polymorphism, that is, run-time selection of the most derived override. In practice, however, overriding a non-virtual method is considered bad practice and rarely used, so many people (including whoever wrote that Wikipedia article) think that only virtual methods can be overridden.

How to Maximize a firefox browser window using Selenium WebDriver with node.js

As of 2020, the correct answer is :


How to get the jQuery $.ajax error response text?

If you want to get Syntax Error with line number, use this

error: function(xhr, status, error) {

How to write subquery inside the OUTER JOIN Statement

I think you don't have to use sub query in this scenario.You can directly left outer join the DEPRMNT table .

While using Left Outer Join ,don't use columns in the RHS table of the join in the where condition, you ll get wrong output

Asynchronous Process inside a javascript for loop

var i = 0;_x000D_
var length = 10;_x000D_
function for1() {_x000D_
function for2() {_x000D_
  if (i == length) {_x000D_
    return false;_x000D_
  setTimeout(function() {_x000D_
  }, 500);_x000D_

Here is a sample functional approach to what is expected here.

How do you make websites with Java?

I'd suggest OOWeb to act as an HTTP server and a templating engine like Velocity to generate HTML. I also second Esko's suggestion of Wicket. Both solutions are considerably simpler than the average setup.

How to create an integer-for-loop in Ruby?

x.times do |i|

how to automatically scroll down a html page?

You can use two different techniques to achieve this.

The first one is with javascript: set the scrollTop property of the scrollable element (e.g. document.body.scrollTop = 1000;).

The second is setting the link to point to a specific id in the page e.g.

<a href="mypage.html#sectionOne">section one</a>

Then if in your target page you'll have that ID the page will be scrolled automatically.

Only detect click event on pseudo-element

Actually, it is possible. You can check if the clicked position was outside of the element, since this will only happen if ::before or ::after was clicked.

This example only checks the element to the right but that should work in your case.

span = document.querySelector('span');_x000D_
span.addEventListener('click', function (e) {_x000D_
    if (e.offsetX > span.offsetWidth) {_x000D_
        span.className = 'c2';_x000D_
    } else {_x000D_
        span.className = 'c1';_x000D_
div { margin: 20px; }_x000D_
span:after { content: 'AFTER'; position: absolute; }_x000D_
span.c1 { background: yellow; }_x000D_
span.c2:after { background: yellow; }


How to resolve "local edit, incoming delete upon update" message

If you haven't made any changes inside the conflicted directory, you can also rm -rf conflicts_in_here/ and then svn up. This worked for me at least.

Using Mockito's generic "any()" method

Since Java 8 you can use the argument-less any method and the type argument will get inferred by the compiler:



The new thing in Java 8 is that the target type of an expression will be used to infer type parameters of its sub-expressions. Before Java 8 only arguments to methods where used for type parameter inference (most of the time).

In this case the parameter type of doStuff will be the target type for any(), and the return value type of any() will get chosen to match that argument type.

This mechanism was added in Java 8 mainly to be able to compile lambda expressions, but it improves type inferences generally.

Primitive types

This doesn't work with primitive types, unfortunately:

public interface IBar {
    void doPrimitiveStuff(int i);

verify(bar).doPrimitiveStuff(any()); // Compiles but throws NullPointerException
verify(bar).doPrimitiveStuff(anyInt()); // This is what you have to do instead

The problem is that the compiler will infer Integer as the return value type of any(). Mockito will not be aware of this (due to type erasure) and return the default value for reference types, which is null. The runtime will try to unbox the return value by calling the intValue method on it before passing it to doStuff, and the exception gets thrown.

Start an Activity with a parameter

Put an int which is your id into the new Intent.

Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
Bundle b = new Bundle();
b.putInt("key", 1); //Your id
intent.putExtras(b); //Put your id to your next Intent

Then grab the id in your new Activity:

Bundle b = getIntent().getExtras();
int value = -1; // or other values
if(b != null)
    value = b.getInt("key");

Using ping in c#

private void button26_Click(object sender, EventArgs e)
    System.Diagnostics.ProcessStartInfo proc = new System.Diagnostics.ProcessStartInfo();
    proc.FileName = @"C:\windows\system32\cmd.exe";
    proc.Arguments = "/c ping -t " + tx1.Text + " ";

private void button27_Click(object sender, EventArgs e)
    System.Diagnostics.ProcessStartInfo proc = new System.Diagnostics.ProcessStartInfo();
    proc.FileName = @"C:\windows\system32\cmd.exe";
    proc.Arguments = "/c ping  " + tx2.Text + " ";

phpMyAdmin on MySQL 8.0

As @kgr mentioned, MySQL 8.0.11 made some changes to the authentication method.

I've opened a phpMyAdmin bug report about this:

MySQL 8.0.4-rc was working fine for me, and I kind of think it's ridiculous for MySQL to make such a change in a patch level release.

How can I remove the outline around hyperlinks images?

I hope this is useful to some of you, it can be used to remove outline from links, images and flash and from MSIE 9:

    a, a:hover, a:active, a:focus, a img, object, embed {
    outline: none;
    ie-dummy: expression(this.hideFocus=true); /* MSIE - Microsoft Internet Explorer 9 remove outline */

The code below is able to hide image border:

    img {
    border: 0;

If you would like to support Firefox 3.6.8 but not Firefox 4... Clicking down on an input type=image can produce a dotted outline as well, to remove it in the old versions of firefox the following will do the trick:

   input::-moz-focus-inner { 
   border: 0; 

IE 9 doesn't allow in some cases to remove the dotted outline around links unless you include this meta tag between and in your pages:

     <meta http-equiv="X-UA-Compatible" content="IE=9" />

How to set margin of ImageView using code, not xml

Using a method similar to this might save you some headaches in some situations. If you have two passes of programmatical tinkering with margins it is safer to check if there are already some layoutParams set. If there are some margins already one should increase them and not replace them:

public void addMargins(View v, int left, int top, int right, int bottom) {
    LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) v.getLayoutParams();
    if (params == null)
        params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
    int oldLeft = params.leftMargin;
    int oldTop = params.topMargin;
    int oldRight = params.rightMargin;
    int oldBottom = params.bottomMargin;
    params.setMargins(oldLeft + left, oldTop + top, oldRight + right, oldBottom + bottom);

SQL Server stored procedure creating temp table and inserting value

A SELECT INTO statement creates the table for you. There is no need for the CREATE TABLE statement before hand.

What is happening is that you create #ivmy_cash_temp1 in your CREATE statement, then the DB tries to create it for you when you do a SELECT INTO. This causes an error as it is trying to create a table that you have already created.

Either eliminate the CREATE TABLE statement or alter your query that fills it to use INSERT INTO SELECT format.

If you need a unique ID added to your new row then it's best to use SELECT INTO... since IDENTITY() only works with this syntax.

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference

it sometimes occurs when we use a custom adapter in any activity of fragment . and we return null object i.e null view so the activity gets confused which view to load , so that is why this exception occurs

shows the position where to change the view

How do I break out of nested loops in Java?

Another one solution, mentioned without example (it actually works in prod code).

try {
    for (Type type : types) {
        for (Type t : types2) {
            if (some condition #1) {
                // Do something and break the loop.
                throw new BreakLoopException();
catch (BreakLoopException e) {
    // Do something on look breaking.

Of course BreakLoopException should be internal, private and accelerated with no-stack-trace:

private static class BreakLoopException extends Exception {
    public StackTraceElement[] getStackTrace() {
        return new StackTraceElement[0];

What's the CMake syntax to set and use variables?

Here are a couple basic examples to get started quick and dirty.

One item variable

Set variable:


Use variable:


Multi-item variable (ie. list)

Set variable:


Use variable:

add_executable(program "${PROGRAM_SRCS}")

CMake docs on variables

Import pfx file into particular certificate store from command line

To anyone else looking for this, I wasn't able to use certutil -importpfx into a specific store, and I didn't want to download the importpfx tool supplied by jaspernygaard's answer in order to avoid the requirement of copying the file to a large number of servers. I ended up finding my answer in a powershell script shown here.

The code uses System.Security.Cryptography.X509Certificates to import the certificate and then moves it into the desired store:

function Import-PfxCertificate { 

    param([String]$certPath,[String]$certRootStore = “localmachine”,[String]$certStore = “My”,$pfxPass = $null) 
    $pfx = new-object System.Security.Cryptography.X509Certificates.X509Certificate2 

    if ($pfxPass -eq $null) 
        $pfxPass = read-host "Password" -assecurestring


    $store = new-object System.Security.Cryptography.X509Certificates.X509Store($certStore,$certRootStore) 

Displaying a message in iOS which has the same functionality as Toast in Android

If you want one with iOS Style, download this framework from Github

iOS Toast Alert View Framework

This examples work on you UIViewController, once you imported the Framework.

Example 1:

let tav = ToastAlertView()
tav.message = "Hey!"
tav.image = UIImage(named: "img1")!
//tav.dismiss() to Hide

Example 2:

//Toast Alert View with Time Dissmis Only
self.showToastAlert("5 Seconds",
                image: UIImage(named: "img1")!,
                hideWithTap: false,
                hideWithTime: true,
                hideTime: 5.0)


Toast Alert View Image Example

Using Mysql in the command line in osx - command not found?

So there are few places where terminal looks for commands. This places are stored in your $PATH variable. Think of it as a global variable where terminal iterates over to look up for any command. This are usually binaries look how /bin folder is usually referenced.

/bin folder has lots of executable files inside it. Turns out this are command. This different folder locations are stored inside one Global variable i.e. $PATH separated by :

Now usually programs upon installation takes care of updating PATH & telling your terminal that hey i can be all commands inside my bin folder.

Turns out MySql doesn't do it upon install so we manually have to do it.

We do it by following command,

export PATH=$PATH:/usr/local/mysql/bin

If you break it down, export is self explanatory. Think of it as an assignment. So export a variable PATH with value old $PATH concat with new bin i.e. /usr/local/mysql/bin

This way after executing it all the commands inside /usr/local/mysql/bin are available to us.

There is a small catch here. Think of one terminal window as one instance of program and maybe something like $PATH is class variable ( maybe ). Note this is pure assumption. So upon close we lose the new assignment. And if we reopen terminal we won't have access to our command again because last when we exported, it was stored in primary memory which is volatile.

Now we need to have our mysql binaries exported every-time we use terminal. So we have to persist concat in our path.

You might be aware that our terminal using something called dotfiles to load configuration on terminal initialisation. I like to think of it's as sets of thing passed to constructer every-time a new instance of terminal is created ( Again an assumption but close to what it might be doing ). So yes by now you get the point what we are going todo.

.bash_profile is one of the primary known dotfile.

So in following command,

echo 'export PATH=$PATH:/usr/local/mysql/bin' >> ~/.bash_profile

What we are doing is saving result of echo i.e. output string to ~/.bash_profile

So now as we noted above every-time we open terminal or instance of terminal our dotfiles are loaded. So .bash_profile is loaded respectively and export that we appended above is run & thus a our global $PATH gets updated and we get all the commands inside /usr/local/mysql/bin.


if you are not running first command export directly but just running second in order to persist it? Than for current running instance of terminal you have to,

source ~/.bash_profile

This tells our terminal to reload that particular file.

What does it mean when Statement.executeUpdate() returns -1?

For executeUpdate statements against a DB2 for z/OS server, the value that is returned depends on the type of SQL statement that is being executed:

For an SQL statement that can have an update count, such as an INSERT, UPDATE, or DELETE statement, the returned value is the number of affected rows. It can be:

A positive number, if a positive number of rows are affected by the operation, and the operation is not a mass delete on a segmented table space.

0, if no rows are affected by the operation.

-1, if the operation is a mass delete on a segmented table space.

For a DB2 CALL statement, a value of -1 is returned, because the DB2 database server cannot determine the number of affected rows. Calls to getUpdateCount or getMoreResults for a CALL statement also return -1. For any other SQL statement, a value of -1 is returned.

How to enable PHP's openssl extension to install Composer?

For WAMP server, comment given by "Enrique" solved my problem.

wamp is using this php.ini:


But composer is using PHP from CLI, and hence it's reading this file:

c:\wamp\bin\php\php5.4.12\php.ini (so you need to enable openssl there)

For composer you will have to enable extension in






How to do a regular expression replace in MySQL?

With MySQL 8.0+ you could use natively REGEXP_REPLACE function.

12.5.2 Regular Expressions:

REGEXP_REPLACE(expr, pat, repl[, pos[, occurrence[, match_type]]])

Replaces occurrences in the string expr that match the regular expression specified by the pattern pat with the replacement string repl, and returns the resulting string. If expr, pat, or repl is NULL, the return value is NULL.

and Regular expression support:

Previously, MySQL used the Henry Spencer regular expression library to support regular expression operators (REGEXP, RLIKE).

Regular expression support has been reimplemented using International Components for Unicode (ICU), which provides full Unicode support and is multibyte safe. The REGEXP_LIKE() function performs regular expression matching in the manner of the REGEXP and RLIKE operators, which now are synonyms for that function. In addition, the REGEXP_INSTR(), REGEXP_REPLACE(), and REGEXP_SUBSTR() functions are available to find match positions and perform substring substitution and extraction, respectively.

SELECT REGEXP_REPLACE('Stackoverflow','[A-Zf]','-',1,0,'c'); 
-- Output:

DBFiddle Demo

How to start and stop/pause setInterval?

As you've tagged this jQuery ...

First, put IDs on your input buttons and remove the inline handlers:

<input type="number" id="input" />
<input type="button" id="stop" value="stop"/>
<input type="button" id="start" value="start"/>

Then keep all of your state and functions encapsulated in a closure:

EDIT updated for a cleaner implementation, that also addresses @Esailija's concerns about use of setInterval().

$(function() {
    var timer = null;
    var input = document.getElementById('input');

    function tick() {
        start();        // restart the timer

    function start() {  // use a one-off timer
        timer = setTimeout(tick, 1000);

    function stop() {

    $('#start').bind("click", start); // use .on in jQuery 1.7+
    $('#stop').bind("click", stop);

    start();  // if you want it to auto-start

This ensures that none of your variables leak into global scope, and can't be modified from outside.

(Updated) working demo at

gpg: no valid OpenPGP data found

i got this problem "gpg-no-valid-openpgp-data-found" and solve it with the following first i open browser and paste then i download the key in Downloads folder then cd /Downloads/ then sudo apt-key add if Appear "OK" then you success to add the key :)

How to improve performance of ngRepeat over a huge dataset (angular.js)?

Virtual scrolling is another way to improve scrolling performance when dealing with huge lists and large dataset.

One way to implement this is by using Angular Material md-virtual-repeat as it is demonstrated on this Demo with 50,000 items

Taken straight from the documentation of virtual repeat:

Virtual repeat is a limited substitute for ng-repeat that renders only enough dom nodes to fill the container and recycling them as the user scrolls.

Why doesn't Java offer operator overloading?

I think that people making decisions simply forgot about complex values, matrix algebra, set theory and other cases when overloading would allow to use the standard notation without building everything into the language. Anyway, only mathematically oriented software really benefits from such features. A generic customer application almost never needs them.

They arguments about the unnecessary obfuscation are obviously valid when a programmer defines some program-specific operator where it could be the function instead. A name of the function, when clearly visible, provides the hint that it does. Operator is a function without the readable name.

Java is generally designed about philosophy that some extra verbosity is not bad as it makes the code more readable. Constructs that do the same just have less code to type in used to be called a "syntax sugar" in the past. This is very different from the Python philosophy, for instance, where shorter is near always seen as better, even if providing less context for the second reader.

Passing a local variable from one function to another

You can very easily use this to re-use the value of the variable in another function.

// Use this in source window.var1= oEvent.getSource().getBindingContext();

// Get value of var1 in destination var var2= window.var1;

Git clone particular version of remote repository

Probably git reset solves your problem.

git reset --hard -#commit hash-

How to stop creating .DS_Store on Mac?

Its is possible by using mach_inject. Take a look at Death to .DS_Store

I found that overriding HFSPlusPropertyStore::FlushChanges() with a function that simply did nothing, successfully prevented the creation of .DS_Store files on both Snow Leopard and Lion.

DeathToDSStore source code

NOTE: On 10.11 you can not inject code into system apps.

Find records from one table which don't exist in another

There's several different ways of doing this, with varying efficiency, depending on how good your query optimiser is, and the relative size of your two tables:

This is the shortest statement, and may be quickest if your phone book is very short:

FROM    Call
WHERE   phone_number NOT IN (SELECT phone_number FROM Phone_book)

alternatively (thanks to Alterlife)

FROM   Call
   FROM   Phone_book
   WHERE  Phone_book.phone_number = Call.phone_number)

or (thanks to WOPR)

FROM   Call
  ON (Call.phone_number = Phone_book.phone_number)
  WHERE Phone_book.phone_number IS NULL

(ignoring that, as others have said, it's normally best to select just the columns you want, not '*')

Volatile vs. Interlocked vs. lock

EDIT: As noted in comments, these days I'm happy to use Interlocked for the cases of a single variable where it's obviously okay. When it gets more complicated, I'll still revert to locking...

Using volatile won't help when you need to increment - because the read and the write are separate instructions. Another thread could change the value after you've read but before you write back.

Personally I almost always just lock - it's easier to get right in a way which is obviously right than either volatility or Interlocked.Increment. As far as I'm concerned, lock-free multi-threading is for real threading experts, of which I'm not one. If Joe Duffy and his team build nice libraries which will parallelise things without as much locking as something I'd build, that's fabulous, and I'll use it in a heartbeat - but when I'm doing the threading myself, I try to keep it simple.

Android : Capturing HTTP Requests with non-rooted android device

SandroProxy seems to be better than Drony (by the same developer): You can (but do not have to) conveniently view and analyze the traffic in your PC's browser.

Should work in emulators as well.

Single huge .css file vs. multiple smaller specific .css files?

Maybe take a look at compass, which is an open source CSS authoring framework. It's based on Sass so it supports cool things like variables, nesting, mixins and imports. Especially imports are useful if you want to keep seperate smaller CSS files but have them combined into 1 automatically (avoiding multiple slow HTTP calls). Compass adds to this a big set of pre-defined mixins that are easy for handling cross-browser stuff. It's written in Ruby but it can easily be used with any system....

With ng-bind-html-unsafe removed, how do I inject HTML?

You indicated that you're using Angular 1.2.0... as one of the other comments indicated, ng-bind-html-unsafe has been deprecated.

Instead, you'll want to do something like this:

<div ng-bind-html="preview_data.preview.embed.htmlSafe"></div>

In your controller, inject the $sce service, and mark the HTML as "trusted":

myApp.controller('myCtrl', ['$scope', '$sce', function($scope, $sce) {
  // ...
  $scope.preview_data.preview.embed.htmlSafe = 

Note that you'll want to be using 1.2.0-rc3 or newer. (They fixed a bug in rc3 that prevented "watchers" from working properly on trusted HTML.)

Why does the 260 character path length limit exist in Windows?

It does, and it is a default for some reason, but you could easily override it with this registry key:



How to get the url parameters using AngularJS

While routing is indeed a good solution for application-level URL parsing, you may want to use the more low-level $location service, as injected in your own service or controller:

var paramValue = $; 

This simple syntax will work for However, only if you configured the $locationProvider in the HTML 5 mode before:


Otherwise have a look at the!/path?myParam=someValue "Hashbang" syntax which is a bit more complicated, but have the benefit of working on old browsers (non-HTML 5 compatible) as well.


I'm not sure why you think the documentation is vague.

It simply goes through all the parameters one by one, and returns the first that is NOT NULL.

=> 1

COALESCE(1, 2, 3, 4, 5, NULL)
=> 1

=> 3

COALESCE(6, 5, 4, 3, 2, NULL)
=> 6


It accepts pretty much any number of parameters, but they should be the same data-type. (If they're not the same data-type, they get implicitly cast to an appropriate data-type using data-type order of precedence.)

It's like ISNULL() but for multiple parameters, rather than just two.

It's also ANSI-SQL, where-as ISNULL() isn't.

Normal arguments vs. keyword arguments

There is one last language feature where the distinction is important. Consider the following function:

def foo(*positional, **keywords):
    print "Positional:", positional
    print "Keywords:", keywords

The *positional argument will store all of the positional arguments passed to foo(), with no limit to how many you can provide.

>>> foo('one', 'two', 'three')
Positional: ('one', 'two', 'three')
Keywords: {}

The **keywords argument will store any keyword arguments:

>>> foo(a='one', b='two', c='three')
Positional: ()
Keywords: {'a': 'one', 'c': 'three', 'b': 'two'}

And of course, you can use both at the same time:

>>> foo('one','two',c='three',d='four')
Positional: ('one', 'two')
Keywords: {'c': 'three', 'd': 'four'}

These features are rarely used, but occasionally they are very useful, and it's important to know which arguments are positional or keywords.

Make REST API call in Swift

swift 4

USE ALAMOFIRE in our App plz install pod file

pod 'Alamofire', '~> 4.0'

We can Use API for Json Data -

Then We can create A networking class for Our project- networkingService.swift

import Foundation
import Alamofire
typealias JSON = [String:Any]
class networkingService{
     static let shared = networkingService()
    private init() {}
    func getPeople(success successblock: @escaping (GetPeopleResponse) -> Void)
    Alamofire.request("").responseJSON { response in
        guard let json = response.result.value as? JSON else {return}
       // print(json)
        do {
                let getPeopleResponse = try GetPeopleResponse(json: json)
    func getHomeWorld(homeWorldLink:String,completion: @escaping(String) ->Void){
        Alamofire.request(homeWorldLink).responseJSON {(response) in
            guard let json = response.result.value as? JSON,
            let name = json["name"] as? String

Then Create NetworkingError.swift class

import Foundation
enum networkingError : Error{
    case badNetworkigStuff


Then create Person.swift class

import Foundation
struct Person {
    private let homeWorldLink : String
    let birthyear : String
    let gender : String
    let haircolor : String
    let eyecolor : String
    let height : String
    let mass : String
    let name : String
    let skincolor : String
    init?(json : JSON) {
        guard let birthyear = json["birth_year"] as? String,
        let eyecolor = json["eye_color"] as? String,
        let gender = json["gender"] as? String,
        let haircolor = json["hair_color"] as? String,
        let height = json["height"] as? String,
        let homeWorldLink = json["homeworld"] as? String,
        let mass = json["mass"] as? String,
        let name = json["name"] as? String,
        let skincolor = json["skin_color"] as? String
        else { return nil }
        self.homeWorldLink = homeWorldLink
        self.birthyear = birthyear
        self.gender = gender
        self.haircolor = haircolor
        self.eyecolor = eyecolor
        self.height = height
        self.mass = mass = name
        self.skincolor = skincolor
    func homeWorld(_ completion: @escaping (String) -> Void)  {
        networkingService.shared.getHomeWorld(homeWorldLink: homeWorldLink){ (homeWorld) in

Then create DetailVC.swift

import UIKit
class DetailVC: UIViewController {
    var person :Person!
    @IBOutlet var name: UILabel!
    @IBOutlet var birthyear: UILabel!
    @IBOutlet var homeworld: UILabel!
    @IBOutlet var eyeColor: UILabel!
    @IBOutlet var skinColor: UILabel!
    @IBOutlet var gender: UILabel!
    @IBOutlet var hairColor: UILabel!
    @IBOutlet var mass: UILabel!
    @IBOutlet var height: UILabel!
    override func viewDidLoad() {
        name.text =
        birthyear.text = person.birthyear
        eyeColor.text = person.eyecolor
        gender.text = person.gender
        hairColor.text = person.haircolor
        mass.text = person.mass
        height.text = person.height
        skinColor.text = person.skincolor
        person.homeWorld{(homeWorld) in
            self.homeworld.text = homeWorld

Then Create GetPeopleResponse.swift class

import Foundation
struct GetPeopleResponse {
    let people : [Person]
    init(json :JSON) throws {
        guard let results = json["results"] as? [JSON] else { throw networkingError.badNetworkigStuff}
        let people ={Person(json: $0)}.flatMap{ $0 }
        self.people = people

Then Our View controller class

import UIKit

class ViewController: UIViewController {

    @IBOutlet var tableVieww: UITableView!
    var people = [Person]()

    @IBAction func getAction(_ sender: Any)
        networkingService.shared.getPeople{ response in
            self.people = response.people
    override func prepare(for segue: UIStoryboardSegue, sender: Any?)
        guard segue.identifier == "peopleToDetails",
        let detailVC = segue.destination as? DetailVC,
        let person = sender as AnyObject as? Person
        else {return}
        detailVC.person = person
    extension ViewController:UITableViewDataSource{
        func numberOfSections(in tableView: UITableView) -> Int {
            return 1
        func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            return people.count
        func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         let cell = UITableViewCell()
            cell.textLabel?.text = people[indexPath.row].name

            return cell

extension ViewController:UITableViewDelegate{
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        performSegue(withIdentifier: "peopleToDetails", sender: people[indexPath.row])

In our StoryBoard

plz Connect with our View with another one using segue with identifier -peopleToDetails

  • Use UITableView In our First View

  • Use UIButton For get the Data

  • Use 9 Labels in our DetailVc

?: operator (the 'Elvis operator') in PHP

Be careful with arrays. We must write a checking variable after ?, because:

  $params = ['param1' => 'value1',
             'param2' => 'value2',
             'param3' => 'value3',];

  $param1 = isset($params['param1'])?:null;
  $param2 = !empty($params['param2'])?:null;
  $param3 = $params['param3']?:null; // get E_NOTICE, if $params['param3'] eq false

  true // would like to expect `value1`
  true // would like to expect `value2`
  param3 // properly, but problem above


From RFC. In PHP 7 the operator Null Coalesce Operator will do it, for example:

$param1 = $params['param1'] ?? null;
// Equivalent to:  $param1 = isset($params['param1']) ? $params['param1'] : null;

How to check if any flags of a flag combination are set?

Sorry, but i will show it in VB :)

   <Flags()> Public Enum Cnt As Integer
        None = 0
        One = 1
        Two = 2
        Three = 4
        Four = 8    
    End Enum

    Sub Test()
    Dim CntValue As New Cnt
    CntValue += Cnt.One
    CntValue += Cnt.Three
    End Sub

CntValue = 5 So the enum contains 1 + 4

Email address validation in C# MVC 4 application: with or without using Regex


Use a regex for a quick sanity check, something like .@.., but almost all langauges / frameworks have better methods for checking an e-mail address. Use that.

It is possible to validate an e-mail address with a regex, but it is a long regex. Very long.
And in the end you will be none the wiser. You'll only know that the format is valid, but you still don't know if it's an active e-mail address. The only way to find out, is by sending a confirmation e-mail.

Python logging: use milliseconds in time format

tl;dr for folks looking here for an ISO formatted date:

instead of using something like '%Y-%m-%d %H:%M:%S.%03d%z', create your own class as @unutbu indicated. Here's one for iso date format:

import logging
from time import gmtime, strftime

class ISOFormatter(logging.Formatter):
    def formatTime(self, record, datefmt=None):
        t = strftime("%Y-%m-%dT%H:%M:%S", gmtime(record.created))
        z = strftime("%z",gmtime(record.created))
        s = "%s.%03d%s" % (t, record.msecs,z)        
        return s

logger = logging.getLogger(__name__)

console = logging.StreamHandler()

formatter = ISOFormatter(fmt='%(asctime)s - %(module)s - %(levelname)s - %(message)s')

logger.debug('Jackdaws love my big sphinx of quartz.')
#2020-10-23T17:25:48.310-0800 - <stdin> - DEBUG - Jackdaws love my big sphinx of quartz.

How to install Android SDK Build Tools on the command line?

The "android" command is deprecated.

For command-line tools, use tools/bin/sdkmanager and tools/bin/avdmanager

If you do not need Android Studio, you can download the basic Android command line tools from in section Command line tools only.

from CLI it should be somfing like:

curl --output


wget --output-document

After that just unpack the archive to the target folder


And now we can install everything you need...

./tools/bin/sdkmanager --install 'build-tools;29.0.2' 'platform-tools' 'platforms;android-29' 'tools'

You can get a complete list of packages using the command ./tools/bin/sdkmanager --list

Some packages require acceptance of the license agreement. you can accept it interactively or just pass "y" to the input stream, like this(two agreements in case):

echo -ne "y\ny" | ./tools/bin/sdkmanager --install 'system-images;android-29;default;x86_64'

And of course, for your convenience, you can export variables such as ANDROID_HOME or ANDROID_SDK_ROOT (including doing it in ~/.profile or ~/.bash_profile) or patch the PATH variable - all this is at your discretion.

Script example:

mkdir /opt/android-sdk
cd /opt/android-sdk
curl --output
echo -ne "y" | ./tools/bin/sdkmanager --install 'build-tools;29.0.2' 'platform-tools' 'platforms;android-29' 'tools'

Requirements: curl(or wget) and unzip


if you see Warning: Could not create settings, you need to have the tools directory inside the cmdline-tools directory inside the ANDROID_HOME (create it if needed with this exact name) see Android Command line tools sdkmanager always shows: Warning: Could not create settings

Connect to Active Directory via LDAP

If your email address is '[email protected]', try changing the createDirectoryEntry() as below.

XYZ is an optional parameter if it exists in mydomain directory

static DirectoryEntry createDirectoryEntry()
    // create and return new LDAP connection with desired settings
    DirectoryEntry ldapConnection = new DirectoryEntry("");
    ldapConnection.Path = "LDAP://OU=Users, OU=XYZ,DC=mydomain,DC=com";
    ldapConnection.AuthenticationType = AuthenticationTypes.Secure;
    return ldapConnection;

This will basically check for com -> mydomain -> XYZ -> Users -> abcd

The main function looks as below:

    username = "Firstname LastName"
    DirectoryEntry myLdapConnection = createDirectoryEntry();
    DirectorySearcher search = new DirectorySearcher(myLdapConnection);
    search.Filter = "(cn=" + username + ")";

How to monitor the memory usage of Node.js?

On Linux/Unix (note: Mac OS is a Unix) use top and press M (Shift+M) to sort processes by memory usage.

On Windows use the Task Manager.

Jetty: HTTP ERROR: 503/ Service Unavailable

Remove/Delete the project from workspace. and Reimport the project to the workspace. This method worked for me.

Add property to an array of objects

You can use the forEach method to execute a provided function once for each element in the array. In this provided function you can add the Active property to the element.

Results.forEach(function (element) {
  element.Active = "false";

where to place CASE WHEN column IS NULL in this query

Thanks for all your help! @Svetoslav Tsolov had it very close, but I was still getting an error, until I figured out the closing parenthesis was in the wrong place. Here's the final query that works:

SELECT dbo.AdminID.CountryID, dbo.AdminID.CountryName, dbo.AdminID.RegionID, 
dbo.AdminID.[Region name], dbo.AdminID.DistrictID, dbo.AdminID.DistrictName,
dbo.AdminID.ADMIN3_ID, dbo.AdminID.ADMIN3,
FROM dbo.AdminID 

ON dbo.AdminID.DistrictID = dbo.EU_Admin2.DistrictID

ON dbo.AdminID.ADMIN3_ID = dbo.EU_Admin3.ADMIN3_ID

Get img src with PHP

Use a HTML parser like DOMDocument and then evaluate the value you're looking for with DOMXpath:

$html = '<img id="12" border="0" src="/images/image.jpg"
         alt="Image" width="100" height="100" />';

$doc = new DOMDocument();
$xpath = new DOMXPath($doc);
$src = $xpath->evaluate("string(//img/@src)"); # "/images/image.jpg"

Or for those who really need to save space:

$xpath = new DOMXPath(@DOMDocument::loadHTML($html));
$src = $xpath->evaluate("string(//img/@src)");

And for the one-liners out there:

$src = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($html))->xpath("//img/@src"));

How to store NULL values in datetime fields in MySQL?

I just tested in MySQL v5.0.6 and the datetime column accepted null without issue.

XPath query to get nth instance of an element

This is a FAQ:


means "Find every node selected by //somexpression that is the $Nth child of its parent".

What you want is:


Remember: The [] operator has higher precedence (priority) than the // abbreviation.

Converting HTML element to string in JavaScript / JQuery

you can just wrap it into another element and call html after that:

$('<div><iframe width="854" height="480" src="" frameborder="0" allowfullscreen></iframe></div>').html();

note that outerHTML doesn't exist on older browsers but innerHTML still does (it doesn't exist for example in ff < 11 while it's still used on many older computers)

How can I import data into mysql database via mysql workbench?

  • Under Server Administration on the Home window select the server instance you want to restore database to (Create New Server Instance if doing it first time).
  • Click on Manage Import/Export
  • Click on Data Import/Restore on the left side of the screen.
  • Select Import from Self-Contained File radio button (right side of screen)
  • Select the path of .sql
  • Click Start Import button at the right bottom corner of window.

Hope it helps.

---Edited answer---

Regarding selection of the schema. MySQL Workbench (5.2.47 CE Rev1039) does not yet support exporting to the user defined schema. It will create only the schema for which you exported the .sql... In 5.2.47 we see "New" target schema. But it does not work. I use MySQL Administrator (the old pre-Oracle MySQL Admin beauty) for my work for backup/restore. You can still download it from Googled trustable sources (search MySQL Administrator 1.2.17).

Fastest way to flatten / un-flatten nested JSON objects

Here's a recursive solution for flatten I put together in PowerShell:

#---helper function for ConvertTo-JhcUtilJsonTable
function getNodes {
    param (

    $t = $job.GetType()
    $ct = 0
    $h = @{}

    if ($t.Name -eq 'PSCustomObject') {
        foreach ($m in Get-Member -InputObject $job -MemberType NoteProperty) {
            getNodes -job $job.($m.Name) -path ($path + '.' + $m.Name)
    elseif ($t.Name -eq 'Object[]') {
        foreach ($o in $job) {
            getNodes -job $o -path ($path + "[$ct]")
    else {
        $h[$path] = $job

#---flattens a JSON document object into a key value table where keys are proper JSON paths corresponding to their value
function ConvertTo-JhcUtilJsonTable {
    param (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]

    begin {
        $rootNode = 'root'    
    process {
        foreach ($o in $jsonObj) {
            $table = getNodes -job $o -path $rootNode

            # $h = @{}
            $a = @()
            $pat = '^' + $rootNode
            foreach ($i in $table) {
                foreach ($k in $i.keys) {
                    # $h[$k -replace $pat, ''] = $i[$k]
                    $a += New-Object -TypeName psobject -Property @{'Key' = $($k -replace $pat, ''); 'Value' = $i[$k]}
                    # $h[$k -replace $pat, ''] = $i[$k]
            # $h



'{"name": "John","Address": {"house": "1234", "Street": "Boogie Ave"}, "pets": [{"Type": "Dog", "Age": 4, "Toys": ["rubberBall", "rope"]},{"Type": "Cat", "Age": 7, "Toys": ["catNip"]}]}' | ConvertFrom-Json | ConvertTo-JhcUtilJsonTable
Key              Value
---              -----   1234
.Address.Street  Boogie Ave
.name            John
.pets[0].Age     4
.pets[0].Toys[0] rubberBall
.pets[0].Toys[1] rope
.pets[0].Type    Dog
.pets[1].Age     7
.pets[1].Toys[0] catNip
.pets[1].Type    Cat

In SQL Server, how do I generate a CREATE TABLE statement for a given table?

Support for schemas:

This is an updated version that amends the great answer from David, et al. Added is support for named schemas. It should be noted this may break if there's actually tables of the same name present within various schemas. Another improvement is the use of the official QuoteName() function.

    'create table '+QuoteName(t.TABLE_SCHEMA)+'.' + QuoteName( + ' (' + LEFT(o.List, Len(o.List)-1) + ');  ' 
        + CASE WHEN tc.Constraint_Name IS NULL THEN '' 
            'ALTER TABLE ' + QuoteName(t.TABLE_SCHEMA)+'.' + QuoteName( 
            + ' ADD CONSTRAINT ' + tc.Constraint_Name  + ' PRIMARY KEY ' + ' (' + LEFT(j.List, Len(j.List)-1) + ');  ' 
          END as 'SQL_CREATE_TABLE'
FROM sysobjects so

          '  ['+column_name+'] ' 
          +  data_type 
          + case data_type
                when 'sql_variant' then ''
                when 'text' then ''
                when 'ntext' then ''
                when 'decimal' then '(' + cast(numeric_precision as varchar) + ', ' + cast(numeric_scale as varchar) + ')'
                '('+ case when character_maximum_length = -1 
                    then 'MAX' 
                    else cast(character_maximum_length as varchar) end 
                + ')','') 
        + ' ' 
        + case when exists ( 
            SELECT id 
            FROM syscolumns
                object_name(id) =
                and name = column_name
                and columnproperty(id,name,'IsIdentity') = 1 
          ) then
            'IDENTITY(' + 
            cast(ident_seed( as varchar) + ',' + 
            cast(ident_incr( as varchar) + ')'
          else ''
        + ' ' 
        + (case when IS_NULLABLE = 'No' then 'NOT ' else '' end) 
        + 'NULL ' 
        + case when information_schema.columns.COLUMN_DEFAULT IS NOT NULL THEN 'DEFAULT '+ information_schema.columns.COLUMN_DEFAULT 
          ELSE '' 
        + ','  -- can't have a field name or we'll end up with XML

    FROM information_schema.columns 
    WHERE table_name =
    ORDER BY ordinal_position
    FOR XML PATH('')
) o (list)

LEFT JOIN information_schema.table_constraints tc on  
    tc.Table_name = so.Name
    AND tc.Constraint_Type  = 'PRIMARY KEY'

LEFT JOIN information_schema.tables t on  
    t.Table_name = so.Name

    SELECT QuoteName(Column_Name) + ', '
    FROM information_schema.key_column_usage kcu
    WHERE kcu.Constraint_Name = tc.Constraint_Name
    FOR XML PATH('')
) j (list)

    xtype = 'U'
    AND name NOT IN ('dtproperties')
    -- AND = 'ASPStateTempSessions'


For use in Management Studio:

One detractor to the sql code above is if you test it using SSMS, long statements aren't easy to read. So, as per this helpful post, here's another version that's somewhat modified to be easier on the eyes after clicking the link of a cell in the grid. The results are more readily identifiable as nicely formatted CREATE TABLE statements for each table in the db.

-- settings
SET @CRLF = Nchar(13) + NChar(10)

-- the main query
            'create table ' + QuoteName(t.TABLE_SCHEMA) + '.' + QuoteName( + ' (' + @CRLF 
            + LEFT(o.List, Len(o.List) - (LEN(@PLACEHOLDER)+2)) + @CRLF + ');' + @CRLF
            + CASE WHEN tc.Constraint_Name IS NULL THEN '' 
                'ALTER TABLE ' + QuoteName(t.TABLE_SCHEMA) + '.' + QuoteName(so.Name) 
                + ' ADD CONSTRAINT ' + tc.Constraint_Name  + ' PRIMARY KEY (' + LEFT(j.List, Len(j.List) - 1) + ');' + @CRLF
FROM sysobjects so

          '   '
          + '['+column_name+'] ' 
          +  data_type 
          + case data_type
                when 'sql_variant' then ''
                when 'text' then ''
                when 'ntext' then ''
                when 'decimal' then '(' + cast(numeric_precision as varchar) + ', ' + cast(numeric_scale as varchar) + ')'
                '('+ case when character_maximum_length = -1 
                    then 'MAX' 
                    else cast(character_maximum_length as varchar) end 
                + ')','') 
        + ' ' 
        + case when exists ( 
            SELECT id 
            FROM syscolumns
                object_name(id) =
                and name = column_name
                and columnproperty(id,name,'IsIdentity') = 1 
          ) then
            'IDENTITY(' + 
            cast(ident_seed( as varchar) + ',' + 
            cast(ident_incr( as varchar) + ')'
          else ''
        + ' ' 
        + (case when IS_NULLABLE = 'No' then 'NOT ' else '' end) 
        + 'NULL ' 
        + case when information_schema.columns.COLUMN_DEFAULT IS NOT NULL THEN 'DEFAULT '+ information_schema.columns.COLUMN_DEFAULT 
          ELSE '' 
        + ', ' 
        + @PLACEHOLDER  -- note, can't have a field name or we'll end up with XML

    FROM information_schema.columns where table_name =
    ORDER BY ordinal_position
    FOR XML PATH('')
) o (list)

LEFT JOIN information_schema.table_constraints tc on  
    tc.Table_name = so.Name
    AND tc.Constraint_Type  = 'PRIMARY KEY'

LEFT JOIN information_schema.tables t on  
    t.Table_name = so.Name

    SELECT QUOTENAME(Column_Name) + ', '
    FROM information_schema.key_column_usage kcu
    WHERE kcu.Constraint_Name = tc.Constraint_Name
    FOR XML PATH('')
) j (list)

    xtype = 'U'
    AND name NOT IN ('dtproperties')
    -- AND = 'ASPStateTempSessions'

Not to belabor the point, but here's the functionally equivalent example outputs for comparison:

-- 1 (scripting version)
create table [dbo].[ASPStateTempApplications] (  [AppId] int  NOT NULL ,  [AppName] char(280)  NOT NULL );  ALTER TABLE [dbo].[ASPStateTempApplications] ADD CONSTRAINT PK__ASPState__8E2CF7F908EA5793 PRIMARY KEY  ([AppId]);  

-- 2 (SSMS version)
create table [dbo].[ASPStateTempSessions] (
   [SessionId] nvarchar(88)  NOT NULL , 
   [Created] datetime  NOT NULL DEFAULT (getutcdate()), 
   [Expires] datetime  NOT NULL , 
   [LockDate] datetime  NOT NULL , 
   [LockDateLocal] datetime  NOT NULL , 
   [LockCookie] int  NOT NULL , 
   [Timeout] int  NOT NULL , 
   [Locked] bit  NOT NULL , 
   [SessionItemShort] varbinary(7000)  NULL , 
   [SessionItemLong] image(2147483647)  NULL , 
   [Flags] int  NOT NULL DEFAULT ((0))
ALTER TABLE [dbo].[ASPStateTempSessions] ADD CONSTRAINT PK__ASPState__C9F4929003317E3D PRIMARY KEY ([SessionId]);


Detracting factors:

It should be noted that I remain relatively unhappy with this due to the lack of support for indeces other than a primary key. It remains suitable for use as a mechanism for simple data export or replication.

Java HTML Parsing

Several years ago I used JTidy for the same purpose:

"JTidy is a Java port of HTML Tidy, a HTML syntax checker and pretty printer. Like its non-Java cousin, JTidy can be used as a tool for cleaning up malformed and faulty HTML. In addition, JTidy provides a DOM interface to the document that is being processed, which effectively makes you able to use JTidy as a DOM parser for real-world HTML.

JTidy was written by Andy Quick, who later stepped down from the maintainer position. Now JTidy is maintained by a group of volunteers.

More information on JTidy can be found on the JTidy SourceForge project page ."

Nginx reverse proxy causing 504 Gateway Timeout

You can also face this situation if your upstream server uses a domain name, and its IP address changes (e.g.: your upstream points to an AWS Elastic Load Balancer)

The problem is that nginx will resolve the IP address once, and keep it cached for subsequent requests until the configuration is reloaded.

You can tell nginx to use a name server to re-resolve the domain once the cached entry expires:

location /mylocation {
    # use google dns to resolve host after IP cached expires
    set $upstream_endpoint http://your.backend.server/;
    proxy_pass $upstream_endpoint;

The docs on proxy_pass explain why this trick works:

Parameter value can contain variables. In this case, if an address is specified as a domain name, the name is searched among the described server groups, and, if not found, is determined using a resolver.

Kudos to "Nginx with dynamic upstreams" ( for the detailed explanation, which also contains some relevant information on a caveat of this approach regarding forwarded URIs.

How to install psycopg2 with "pip" on Python?

The answers so far are too much like magic recipes. The error that you received tells you that pip cannot find a needed part of the PostgreSQL Query library. Possibly this is because you have it installed in a non-standard place for your OS which is why the message suggests using the --pg-config option.

But a more common reason is that you don't have libpq installed at all. This commonly happens on machines where you do NOT have PostgreSQL server installed because you only want to run client apps, not the server itself. Each OS/distro is different, for instance on Debian/Ubuntu you need to install libpq-dev. This allows you to compile and link code against the PostgreSQL Query library.

Most of the answers also suggest installing a Python dev library. Be careful. If you are only using the default Python installed by your distro, that will work, but if you have a newer version, it could cause problems. If you have built Python on this machine then you already have the dev libraries needed for compiling C/C++ libraries to interface with Python. As long as you are using the correct pip version, the one installed in the same bin folder as the python binary, then you are all set. No need to install the old version.

Are there any SHA-256 javascript implementations that are generally considered trustworthy?

On I found this snippet that uses internal js module:

async function sha256(message) {
    // encode as UTF-8
    const msgBuffer = new TextEncoder().encode(message);                    

    // hash the message
    const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer);

    // convert ArrayBuffer to Array
    const hashArray = Array.from(new Uint8Array(hashBuffer));

    // convert bytes to hex string                  
    const hashHex = => ('00' + b.toString(16)).slice(-2)).join('');
    return hashHex;

Note that crypto.subtle in only available on https or localhost - for example for your local development with python3 -m http.server you need to add this line to your /etc/hosts: localhost

Reboot - and you can open localhost:8000 with working crypto.subtle.

What do the crossed style properties in Google Chrome devtools mean?

On a side note. If you are using @media queries (such as @media screen (max-width:500px)) pay particular attention to applying @media query AFTER you are done with normal styles. Because @media query will be crossed out (even though it is more specific) if followed by css that manipulates the same elements. Example:

@media (max-width:750px){
#buy-box {width: 300px;}


** width will be 500px and 300px will be crossed out in Developer Tools. **


@media (max-width:750px){
#buy-box {width: 300px;}

** width will be 300px and 500px will be crossed out **

Change One Cell's Data in mysql

try this.

UPDATE `database_name`.`table_name` SET `column_name`='value' WHERE `id`='1';

How to remove blank lines from a Unix file

with awk

awk 'NF > 0' filename

AngularJS - Binding radio buttons to models with boolean values

That's an odd approach with isUserAnswer. Are you really going to send all three choices back to the server where it will loop through each one checking for isUserAnswer == true? If so, you can try this:


<input type="radio" name="response" value="true" ng-click="setChoiceForQuestion(question1, choice)"/>


$scope.setChoiceForQuestion = function (q, c) {
    angular.forEach(q.choices, function (c) {
        c.isUserAnswer = false;

    c.isUserAnswer = true;

Alternatively, I'd recommend changing your tack:

<input type="radio" name="response" value="{{}}" ng-model="question1.userChoiceId"/>

That way you can just send {{question1.userChoiceId}} back to the server.

Why does jQuery or a DOM method such as getElementById not find the element?

the problem is that the dom element 'speclist' is not created at the time the javascript code is getting executed. So I put the javascript code inside a function and called that function on body onload event.

function do_this_first(){
   //appending code

<body onload="do_this_first()">

What is the C# equivalent of NaN or IsNumeric?

In addition to the previous correct answers it is probably worth pointing out that "Not a Number" (NaN) in its general usage is not equivalent to a string that cannot be evaluated as a numeric value. NaN is usually understood as a numeric value used to represent the result of an "impossible" calculation - where the result is undefined. In this respect I would say the Javascript usage is slightly misleading. In C# NaN is defined as a property of the single and double numeric types and is used to refer explicitly to the result of diving zero by zero. Other languages use it to represent different "impossible" values.

Java collections maintaining insertion order

some Collection are not maintain the order because of, they calculate the hashCode of content and store it accordingly in the appropriate bucket.

glm rotate usage in Opengl

You need to multiply your Model matrix. Because that is where model position, scaling and rotation should be (that's why it's called the model matrix).

All you need to do is (see here)

Model = glm::rotate(Model, angle_in_radians, glm::vec3(x, y, z)); // where x, y, z is axis of rotation (e.g. 0 1 0)

Note that to convert from degrees to radians, use glm::radians(degrees)

That takes the Model matrix and applies rotation on top of all the operations that are already in there. The other functions translate and scale do the same. That way it's possible to combine many transformations in a single matrix.

note: earlier versions accepted angles in degrees. This is deprecated since 0.9.6

Model = glm::rotate(Model, angle_in_degrees, glm::vec3(x, y, z)); // where x, y, z is axis of rotation (e.g. 0 1 0)

Why doesn't the height of a container element increase if it contains floated elements?

Its because of the float of the div. Add overflow: hidden on the outside element.

<div style="overflow:hidden; margin:0 auto;width: 960px; min-height: 100px; background-color:orange;">
    <div style="width:500px; height:200px; background-color:black; float:right">


Jar mismatch! Fix your dependencies

Use a Library Project just for the Support Library

As of ADT 22, using Eclipse Juno

I don't think any of the above are really the best answers. I also don't think it is recommended to use the external jar function in Eclipse anymore (AFAIK).

Rather, what worked for me is to create a separate empty library project.

Then use Android tools > Add Support Library to get the latest version you need or want.

Then remove the support lib jar from all other projects.

Finally, for every project that requires it, add a reference to your new Library project

(project properties) > Android > (Library box) > Add...

Then all your projects will have a single source to use and update the support library. This also makes javadocs easier to get working.

For info on how to setup the javadocs see:

How to attach javadoc or sources to jars in libs folder?

How to use localization in C#

  • Add a Resource file to your project (you can call it "strings.resx") by doing the following:
    Right-click Properties in the project, select Add -> New Item... in the context menu, then in the list of Visual C# Items pick "Resources file" and name it strings.resx.
  • Add a string resouce in the resx file and give it a good name (example: name it "Hello" with and give it the value "Hello")
  • Save the resource file (note: this will be the default resource file, since it does not have a two-letter language code)
  • Add references to your program: System.Threading and System.Globalization

Run this code:


It should print "Hello".

Now, add a new resource file, named "" (note the "fr" part; this one will contain resources in French). Add a string resource with the same name as in strings.resx, but with the value in French (Name="Hello", Value="Salut"). Now, if you run the following code, it should print Salut:

Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("fr-FR");

What happens is that the system will look for a resource for "fr-FR". It will not find one (since we specified "fr" in your file"). It will then fall back to checking for "fr", which it finds (and uses).

The following code, will print "Hello":

Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("en-US");

That is because it does not find any "en-US" resource, and also no "en" resource, so it will fall back to the default, which is the one that we added from the start.

You can create files with more specific resources if needed (for instance and for French in France and Canada respectively). In each such file you will need to add the resources for those strings that differ from the resource that it would fall back to. So if a text is the same in France and Canada, you can put it in, while strings that are different in Canadian french could go into

How to use setprecision in C++

Replace These Headers

#include <iomanip.h>
#include <iomanip>

With These.

#include <iostream>
#include <iomanip>
using namespace std;

Thats it...!!!

How ViewBag in ASP.NET MVC works

ViewBag is of type dynamic but, is internally an System.Dynamic.ExpandoObject()

It is declared like this:

dynamic ViewBag = new System.Dynamic.ExpandoObject();

which is why you can do :

ViewBag.Foo = "Bar";

A Sample Expander Object Code:

public class ExpanderObject : DynamicObject, IDynamicMetaObjectProvider
    public Dictionary<string, object> objectDictionary;

    public ExpanderObject()
        objectDictionary = new Dictionary<string, object>();
    public override bool TryGetMember(GetMemberBinder binder, out object result)
        object val;
        if (objectDictionary.TryGetValue(binder.Name, out val))
            result = val;
            return true;
        result = null;
        return false;

    public override bool TrySetMember(SetMemberBinder binder, object value)
            objectDictionary[binder.Name] = value;
            return true;
        catch (Exception ex)
            return false;

Is there a max size for POST parameter content?

Yes there is 2MB max and it can be increased by configuration change like this. If your POST body is not in form of multipart file then you might need to add the max-http-post configuration for tomcat in the application yml configuration file.

Increase max size of each multipart file to 10MB and total payload size of 100MB max

      multipart:max-file-size: 10MB
      multipart:max-request-size: 100MB

Setting max size of post requests which might just be the formdata in string format to ~10 MB

        max-http-post-size: 100000000 # max-http-form-post-size: 10MB for new version

You might need to add this for the latest sprintboot version ->

server: tomcat: max-http-form-post-size: 10MB

Correct MIME Type for favicon.ico?

I have noticed that when using type="image/", the favicon fails to appear when the browser is not connected to the internet. But type="image/x-icon" works whether the browser can connect to the internet, or not. When developing, at times I am not connected to the internet.

How to get current date time in milliseconds in android

I think leverage this functionality using Java

long time= System.currentTimeMillis();

this will return current time in milliseconds mode . this will surely work

long time= System.currentTimeMillis();
android.util.Log.i("Time Class ", " Time value in millisecinds "+time);

Here is my logcat using the above function

05-13 14:38:03.149: INFO/Time Class(301): Time value in millisecinds 1368436083157

If you got any doubt with millisecond value .Check Here

EDIT : Time Zone I used to demo the code IST(+05:30) ,So if you check milliseconds that mentioned in log to match with time in log you might get a different value based your system timezone

EDIT: This is easy approach .but if you need time zone or any other details I think this won't be enough Also See this approach using android api support

ERROR 2003 (HY000): Can't connect to MySQL server (111)

Please check your listenning ports with :

netstat -nat |grep :3306

If it show

 tcp        0      0  *               LISTEN 

Thats is ok for your remote connection.

But in this case i think you have

tcp        0  *               LISTEN 

Thats is ok for your remote connection. You should also check your firewall (iptables if you centos/redhat)

services iptables stop

for testing or use :

iptables -A input -p tcp -i eth0 --dport 3306 -m state NEW,ESTABLISHED -j ACCEPT
iptables -A output -p tcp -i eth0 --sport 3306 -m state NEW,ESTABLISHED -j ACCEPT

And another thing to check your grant permission for remote connection :

GRANT ALL ON *.* TO remoteUser@'remoteIpadress' IDENTIFIED BY 'my_password';

How to completely uninstall python 2.7.13 on Ubuntu 16.04

try following to see all instances of python

whereis python
which python

Then remove all instances using:

sudo apt autoremove python

repeat sudo apt autoremove python(for all versions) that should do it, then install Anaconda and manage Pythons however you like if you need to reinstall it.

'uint32_t' identifier not found error

You can #include <cstdint>. It's part of C++-standard since 2011.

check if file exists in php

for me also the file_exists() function is not working properly. So I got this alternative solution. Hope this one help someone

$path = 'http://localhost/admin/public/upload/video_thumbnail/thumbnail_1564385519_0.png';

    if (@GetImageSize($path)) {
        echo 'File exits';
    } else {
        echo "File doesn't exits";

How to embed image or picture in jupyter notebook, either from a local machine or from a web resource?

If you want to use the Jupyter Notebook API (and not the IPython one anymore), I find the ipywidgets Jupyter's sub-project. You have an Image widget. Docstring specifies that you have a value parameter which is a bytes. So you can do:

import requests
from ipywidgets import Image


I agree, it's simpler to use the Markdown style. But it shows you the Image display Notebook API. You can also resize the image with the width and height parameters.

How to generate a Dockerfile from an image?

docker pull chenzj/dfimage

alias dfimage="docker run -v /var/run/docker.sock:/var/run/docker.sock --rm chenzj/dfimage"

dfimage image_id

Below is ouput of dfimage command:

$ dfimage 0f1947a021ce

FROM node:8
WORKDIR /usr/src/app

COPY file:e76d2e84545dedbe901b7b7b0c8d2c9733baa07cc821054efec48f623e29218c in ./
RUN /bin/sh -c npm install
COPY dir:a89a4894689a38cbf3895fdc0870878272bb9e09268149a87a6974a274b2184a in .

CMD ["npm" "start"]

Is #pragma once a safe include guard?

#pragma once does have one drawback (other than being non-standard) and that is if you have the same file in different locations (we have this because our build system copies files around) then the compiler will think these are different files.

How to format a QString?

You can use QString.arg like this

QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", "Jane");
// You get "~/Tom-Jane.txt"

This method is preferred over sprintf because:

Changing the position of the string without having to change the ordering of substitution, e.g.

// To get "~/Jane-Tom.txt"
QString my_formatted_string = QString("%1/%3-%2.txt").arg("~", "Tom", "Jane");

Or, changing the type of the arguments doesn't require changing the format string, e.g.

// To get "~/Tom-1.txt"
QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", QString::number(1));

As you can see, the change is minimal. Of course, you generally do not need to care about the type that is passed into QString::arg() since most types are correctly overloaded.

One drawback though: QString::arg() doesn't handle std::string. You will need to call: QString::fromStdString() on your std::string to make it into a QString before passing it to QString::arg(). Try to separate the classes that use QString from the classes that use std::string. Or if you can, switch to QString altogether.

UPDATE: Examples are updated thanks to Frank Osterfeld.

UPDATE: Examples are updated thanks to alexisdm.

What does template <unsigned int N> mean?

You templatize your class based on an 'unsigned int'.


template <unsigned int N>
class MyArray
        double    data[N]; // Use N as the size of the array

int main()
    MyArray<2>     a1;
    MyArray<2>     a2;

    MyArray<4>     b1;

    a1 = a2;  // OK The arrays are the same size.
    a1 = b1;  // FAIL because the size of the array is part of the
              //      template and thus the type, a1 and b1 are different types.
              //      Thus this is a COMPILE time failure.

How do I install TensorFlow's tensorboard?

you may have installed tensorflow to virtualenv. activate it and tensorboard command will become available.

Closing WebSocket correctly (HTML5, Javascript)

As mentioned by theoobe, some browsers do not close the websockets automatically. Don't try to handle any "close browser window" events client-side. There is currently no reliable way to do it, if you consider support of major desktop AND mobile browsers (e.g. onbeforeunload will not work in Mobile Safari). I had good experience with handling this problem server-side. E.g. if you use Java EE, take a look at javax.websocket.Endpoint, depending on the browser either the OnClose method or the OnError method will be called if you close/reload the browser window.

PHP Function Comments

That's phpDoc syntax.

Read more here: phpDocumentor

Changing website favicon dynamically

Why not?

var link = document.querySelector("link[rel~='icon']");
if (!link) {
    link = document.createElement('link');
    link.rel = 'icon';
link.href = '';

Return positions of a regex match() in Javascript?

From docs on the String .match() method:

The returned Array has an extra input property, which contains the original string that was parsed. In addition, it has an index property, which represents the zero-based index of the match in the string.

When dealing with a non-global regex (i.e., no g flag on your regex), the value returned by .match() has an index property...all you have to do is access it.

var index = str.match(/regex/).index;

Here is an example showing it working as well:

var str = 'my string here';_x000D_
var index = str.match(/here/).index;_x000D_
alert(index); // <- 10

I have successfully tested this all the way back to IE5.

Removing duplicate rows from table in Oracle

From Ask Tom

delete from t
 where rowid IN ( select rid
                    from (select rowid rid, 
                                 row_number() over (partition by 
                         companyid, agentid, class , status, terminationdate
                                   order by rowid) rn
                            from t)
                   where rn <> 1);

(fixed the missing parenthesis)

How to change JAVA.HOME for Eclipse/ANT

Under Windows you need to follow:

Start -> Control Panel -> System -> Advanced -> Environment Variables.

... and you need to set JAVA_HOME (which is distinct from the PATH variable you mention) to reference the JDK home directory, not the bin sub-directory; e.g. "C:\program files\java\jdk".

How to post data to specific URL using WebClient in C#

I just found the solution and yea it was easier than I thought :)

so here is the solution:

string URI = "";
string myParameters = "param1=value1&param2=value2&param3=value3";

using (WebClient wc = new WebClient())
    wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
    string HtmlResult = wc.UploadString(URI, myParameters);

it works like charm :)

Generate a UUID on iOS from Swift

For Swift 4;

let uuid = NSUUID().uuidString.lowercased()

How can I print a circular structure in a JSON-like format?

Use JSON.stringify with a custom replacer. For example:

// Demo: Circular reference
var circ = {};
circ.circ = circ;

// Note: cache should not be re-used by repeated calls to JSON.stringify.
var cache = [];
JSON.stringify(circ, (key, value) => {
  if (typeof value === 'object' && value !== null) {
    // Duplicate reference found, discard key
    if (cache.includes(value)) return;

    // Store value in our collection
  return value;
cache = null; // Enable garbage collection

The replacer in this example is not 100% correct (depending on your definition of "duplicate"). In the following case, a value is discarded:

var a = {b:1}
var o = {}; = a;
o.two = a;
// one and two point to the same object, but two is discarded:
JSON.stringify(o, ...);

But the concept stands: Use a custom replacer, and keep track of the parsed object values.

As a utility function written in es6:

// safely handles circular references
JSON.safeStringify = (obj, indent = 2) => {
  let cache = [];
  const retVal = JSON.stringify(
    (key, value) =>
      typeof value === "object" && value !== null
        ? cache.includes(value)
          ? undefined // Duplicate reference found, discard key
          : cache.push(value) && value // Store value in our collection
        : value,
  cache = null;
  return retVal;

// Example:
console.log('options', JSON.safeStringify(options))

Rename Excel Sheet with VBA Macro

The "no frills" options are as follows:

ActiveSheet.Name = "New Name"


Sheets("Sheet2").Name = "New Name"

You can also check out recording macros and seeing what code it gives you, it's a great way to start learning some of the more vanilla functions.

Is there a simple way to use button to navigate page as a link does in angularjs

For me, best solution is to use Angular router native directives with ui-sref like:

<button ui-sref="">Go!!</button>

To understand that directive and get more options visit ui-router docs at:

: )

How to change background color of cell in table using java script

document.getElementById('id1').bgColor = '#00FF00';

seems to work. I don't think .style.backgroundColor does.

How to import a single table in to mysql database using command line

If you're in the pwd of an SQL dump and you need a table from that, do this:

sed -n '/-- Table structure for table `'TableNameTo_GrabHere'`/,/-- Table/{ /^--.*$/d;p }' dump_file_to_extract_from.sql > table_name_here.sql

Then just import the table you extracted from the above into the needed database

Getting Date or Time only from a DateTime Object

You can use Instance.ToShortDateString() for the date,
and Instance.ToShortTimeString() for the time to get date and time from the same instance.

How to compare two JSON have the same properties without order?

Easy way to compare two json string in javascript

var obj1 = {"name":"Sam","class":"MCA"};
var obj2 = {"class":"MCA","name":"Sam"};

var flag=true;

    for(key in obj1) { 
        if(obj1[key] == obj2[key]) {
        else {
else {
console.log("is object equal"+flag);

How to emulate a BEFORE INSERT trigger in T-SQL / SQL Server for super/subtype (Inheritance) entities?

While Andriy's proposal will work well for INSERTs of a small number of records, full table scans will be done on the final join as both 'enumerated' and '@new_super' are not indexed, resulting in poor performance for large inserts.

This can be resolved by specifying a primary key on the @new_super table, as follows:

DECLARE @new_super TABLE (
  super_id   int

This will result in the SQL optimizer scanning through the 'enumerated' table but doing an indexed join on @new_super to get the new key.

How to implement class constructor in Visual Basic?

A class with a field:

Public Class MyStudent
   Public StudentId As Integer

The constructor:

    Public Sub New(newStudentId As Integer)
        StudentId = newStudentId
    End Sub
End Class

How can I display an image from a file in Jupyter Notebook?

This will import and display a .jpg image in Jupyter (tested with Python 2.7 in Anaconda environment)

from IPython.display import display
from PIL import Image


You may need to install PIL

in Anaconda this is done by typing

conda install pillow

Generate sha256 with OpenSSL and C++

A more "C++"ish version

#include <iostream>
#include <sstream>

#include "openssl/sha.h"

using namespace std;

string to_hex(unsigned char s) {
    stringstream ss;
    ss << hex << (int) s;
    return ss.str();

string sha256(string line) {    
    unsigned char hash[SHA256_DIGEST_LENGTH];
    SHA256_CTX sha256;
    SHA256_Update(&sha256, line.c_str(), line.length());
    SHA256_Final(hash, &sha256);

    string output = "";    
    for(int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
        output += to_hex(hash[i]);
    return output;

int main() {
    cout << sha256("hello, world") << endl;

    return 0;

Add JavaScript object to JavaScript object

var jsonIssues = []; // new Array
jsonIssues.push( { ID:1, "Name":"whatever" } );
// "push" some more here

How to Update Date and Time of Raspberry Pi With out Internet

Thanks for the replies.
What I did was,
1. I install meinberg ntp software application on windows 7 pc. (softros ntp server is also possible.)
2. change raspberry pi ntp.conf file (for auto update date and time)

server iburst
server iburst
server iburst
server iburst

3. If you want to make sure that date and time update at startup run this python script in rpi,

import os

    client = ntplib.NTPClient()
    response = client.request('', version=4)
    print "===================================="
    print "Offset : "+str(response.offset)
    print "Version : "+str(response.version)
    print "Date Time : "+str(ctime(response.tx_time))
    print "Leap : "+str(ntplib.leap_to_text(response.leap))
    print "Root Delay : "+str(response.root_delay)
    print "Ref Id : "+str(ntplib.ref_id_to_text(response.ref_id))
    os.system("sudo date -s '"+str(ctime(response.tx_time))+"'")
    print "===================================="
    os.system("sudo date")
    print "NTP Server Down Date Time NOT Set At The Startup"

I found more info in raspberry pi forum.

php exec command (or similar) to not wait for result

This uses wget to notify a URL of something without waiting.

$command = 'wget -qO-';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);

This uses ls to update a log without waiting.

$command = 'ls -la > content.log';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);

onClick function of an input type="button" not working

you could also try creating a button, this will work if you put it outside of the form;

<button onClick="moreFields(); return false;">Give me more fields!</button>

GCC dump preprocessor defines

The simple approach (gcc -dM -E - < /dev/null) works fine for gcc but fails for g++. Recently I required a test for a C++11/C++14 feature. Recommendations for their corresponding macro names are published at But:

g++ -dM -E - < /dev/null | fgrep __cpp_alias_templates

always fails, because it silently invokes the C-drivers (as if invoked by gcc). You can see this by comparing its output against that of gcc or by adding a g++-specific command line option like (-std=c++11) which emits the error message cc1: warning: command line option ‘-std=c++11’ is valid for C++/ObjC++ but not for C.

Because (the non C++) gcc will never support "Templates Aliases" (see you must add the -x c++ option to force the invocation of the C++ compiler (Credits for using the -x c++ options instead of an empty dummy file go to yuyichao, see below):

g++ -dM -E -x c++ /dev/null | fgrep __cpp_alias_templates

There will be no output because g++ (revision 4.9.1, defaults to -std=gnu++98) does not enable C++11-features by default. To do so, use

g++ -dM -E -x c++ -std=c++11 /dev/null | fgrep __cpp_alias_templates

which finally yields

#define __cpp_alias_templates 200704

noting that g++ 4.9.1 does support "Templates Aliases" when invoked with -std=c++11.

What is the difference between signed and unsigned int

In practice, there are two differences:

  1. printing (eg with cout in C++ or printf in C): unsigned integer bit representation is interpreted as a nonnegative integer by print functions.
  2. ordering: the ordering depends on signed or unsigned specifications.

this code can identify the integer using ordering criterion:

char a = 0;
if (0 < a)

char is considered signed in some compilers and unsigned in other compilers. The code above determines which one is considered in a compiler, using the ordering criterion. If a is unsigned, after a--, it will be greater than 0, but if it is signed it will be less than zero. But in both cases, the bit representation of a is the same. That is, in both cases a-- does the same change to the bit representation.

How to get Map data using JDBCTemplate.queryForMap

queryForMap is appropriate if you want to get a single row. You are selecting without a where clause, so you probably want to queryForList. The error is probably indicative of the fact that queryForMap wants one row, but you query is retrieving many rows.

Check out the docs. There is a queryForList that takes just sql; the return type is a


So once you have the results, you can do what you are doing. I would do something like

List results = template.queryForList(sql);

for (Map m : results){

I'll let you fill in the details, but I would not iterate over keys in this case. I like to explicit about what I am expecting.

If you have a User object, and you actually want to load User instances, you can use the queryForList that takes sql and a class type

queryForList(String sql, Class<T> elementType)

(wow Spring has changed a lot since I left Javaland.)

jQuery ID starts with

Here you go:

$('td[id^="' + value +'"]')

so if the value is for instance 'foo', then the selector will be 'td[id^="foo"]'.

Note that the quotes are mandatory: [id^="...."].


How can I decrease the size of Ratingbar?

In RatingBar give attribute:


Get values from other sheet using VBA

Sub TEST()
Dim value1 As String
Dim value2 As String
value1 = ThisWorkbook.Sheets(1).Range("A1").Value 'value from sheet1
value2 = ThisWorkbook.Sheets(2).Range("A1").Value 'value from sheet2
If value1 = value2 Then ThisWorkbook.Sheets(2).Range("L1").Value = value1 'or 2
End Sub

This will compare two sheets cells values and if they match place the value on sheet 2 in column L.

Routing HTTP Error 404.0 0x80070002

The problem for me was a new server that System.Web.Routing was of version 3.5 while web.config requested version The resolution was

%WINDIR%\Framework\v4.0.30319\aspnet_regiis -i

%WINDIR%\Framework64\v4.0.30319\aspnet_regiis -i

Why do you create a View in a database?

The one major advantage of a view over a stored procedure is that you can use a view just like you use a table. Namely, a view can be referred to directly in the FROM clause of a query. E.g., SELECT * FROM dbo.name_of_view.

In just about every other way, stored procedures are more powerful. You can pass in parameters, including out parameters that allow you effectively to return several values at once, you can do SELECT, INSERT, UPDATE, and DELETE operations, etc. etc.

If you want a View's ability to query from within the FROM clause, but you also want to be able to pass in parameters, there's a way to do that too. It's called a table-valued function.

Here's a pretty useful article on the topic:

EDIT: By the way, this sort of raises the question, what advantage does a view have over a table-valued function? I don't have a really good answer to that, but I will note that the T-SQL syntax for creating a view is simpler than for a table-valued function, and users of your database may be more familiar with views.

How to completely uninstall Android Studio from windows(v10)?

First go to android studio folder on location that you installed it ( It’s usually in this path by default ; C:\Program Files\Android\Android Studio, unless you change it when you install Android Studio). Find and run uninstall.exe file.

Wait until uninstallation complete successfully, just few minutes, and after click the close.

To delete any remains of Android Studio setting files, in File Explorer, go to C:\Users\%username%, and delete .android, .AndroidStudio(#version-number) and also .gradle, AndroidStudioProjects if they exist. If you want remain your projects, you’d like to keep AndroidStudioProjects folder.

Then, go to C:\Users\%username%\AppData\Roaming and delete the JetBrains directory.

Note that AppData folder is hidden by default, to make visible it go to view tab and check hidden items in windows8 and10 ( in windows7 Select Folder Options, then select the View tab. Under Advanced settings, select Show hidden files, folders, and drives, and then select OK.

Done, you can remove Android Studio successfully, if you plan to delete SDK tools too, it is enough to remove SDK folder completely.

Converting a String to a List of Words?

Try this:

import re

mystr = 'This is a string, with words!'
wordList = re.sub("[^\w]", " ",  mystr).split()

How it works:

From the docs :

re.sub(pattern, repl, string, count=0, flags=0)

Return the string obtained by replacing the leftmost non-overlapping occurrences of pattern in string by the replacement repl. If the pattern isn’t found, string is returned unchanged. repl can be a string or a function.

so in our case :

pattern is any non-alphanumeric character.

[\w] means any alphanumeric character and is equal to the character set [a-zA-Z0-9_]

a to z, A to Z , 0 to 9 and underscore.

so we match any non-alphanumeric character and replace it with a space .

and then we split() it which splits string by space and converts it to a list

so 'hello-world'

becomes 'hello world'

with re.sub

and then ['hello' , 'world']

after split()

let me know if any doubts come up.

Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute' from assembly 'mscorlib

In my case, it was Blend SDK missed out on TeamCity machine. This caused the error due incorrect way of assembly resolving then.

Using Java with Nvidia GPUs (CUDA)

From the research I have done, if you are targeting Nvidia GPUs and have decided to use CUDA over OpenCL, I found three ways to use the CUDA API in java.

  1. JCuda (or alternative)- This seems like the best solution for the problems I am working on. Many of libraries such as CUBLAS are available in JCuda. Kernels are still written in C though.
  2. JNI - JNI interfaces are not my favorite to write, but are very powerful and would allow you to do anything CUDA can do.
  3. JavaCPP - This basically lets you make a JNI interface in Java without writing C code directly. There is an example here: What is the easiest way to run working CUDA code in Java? of how to use this with CUDA thrust. To me, this seems like you might as well just write a JNI interface.

All of these answers basically are just ways of using C/C++ code in Java. You should ask yourself why you need to use Java and if you can't do it in C/C++ instead.

If you like Java and know how to use it and don't want to work with all the pointer management and what-not that comes with C/C++ then JCuda is probably the answer. On the other hand, the CUDA Thrust library and other libraries like it can be used to do a lot of the pointer management in C/C++ and maybe you should look at that.

If you like C/C++ and don't mind pointer management, but there are other constraints forcing you to use Java, then JNI might be the best approach. Though, if your JNI methods are just going be wrappers for kernel commands you might as well just use JCuda.

There are a few alternatives to JCuda such as Cuda4J and Root Beer, but those do not seem to be maintained. Whereas at the time of writing this JCuda supports CUDA 10.1. which is the most up-to-date CUDA SDK.

Additionally there are a few java libraries that use CUDA, such as deeplearning4j and Hadoop, that may be able to do what you are looking for without requiring you to write kernel code directly. I have not looked into them too much though.

Change default global installation directory for node.js modules in Windows?

trying to install global packages into C:\Program Files (x86)\nodejs\ gave me Run as Administrator issues, because npm was trying to install into
C:\Program Files (x86)\nodejs\node_modules\

to resolve this, change global install directory to C:\Users\{username}\AppData\Roaming\npm:

in C:\Users\{username}\, create .npmrc file with contents:

prefix = "C:\\Users\\{username}\\AppData\\Roaming\\npm"


nodejs x86 installer into C:\Program Files (x86)\nodejs\ on Windows 7 Ultimate N 64-bit SP1
node --version : v0.10.28
npm --version : 1.4.10

Adding multiple class using ng-class

With multiple conditions

<div ng-class="{'class1' : con1 || can2, 'class2' : con3 && con4}">
Hello World!

"Too many values to unpack" Exception

This problem looked familiar so I thought I'd see if I could replicate from the limited amount of information.

A quick search turned up an entry in James Bennett's blog here which mentions that when working with the UserProfile to extend the User model a common mistake in can cause Django to throw this error.

To quote the blog entry:

The value of the setting is not "appname.models.modelname", it's just "appname.modelname". The reason is that Django is not using this to do a direct import; instead, it's using an internal model-loading function which only wants the name of the app and the name of the model. Trying to do things like "appname.models.modelname" or "projectname.appname.models.modelname" in the AUTH_PROFILE_MODULE setting will cause Django to blow up with the dreaded "too many values to unpack" error, so make sure you've put "appname.modelname", and nothing else, in the value of AUTH_PROFILE_MODULE.

If the OP had copied more of the traceback I would expect to see something like the one below which I was able to duplicate by adding "models" to my AUTH_PROFILE_MODULE setting.

TemplateSyntaxError at /

Caught an exception while rendering: too many values to unpack

Original Traceback (most recent call last):
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/", line 71, in render_node
    result = node.render(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/", line 87, in render
    output = force_unicode(self.filter_expression.resolve(context))
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/", line 535, in resolve
    obj = self.var.resolve(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/", line 676, in resolve
    value = self._resolve_lookup(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/", line 711, in _resolve_lookup
    current = current()
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/contrib/auth/", line 291, in get_profile
    app_label, model_name = settings.AUTH_PROFILE_MODULE.split('.')
ValueError: too many values to unpack

This I think is one of the few cases where Django still has a bit of import magic that tends to cause confusion when a small error doesn't throw the expected exception.

You can see at the end of the traceback that I posted how using anything other than the form "appname.modelname" for the AUTH_PROFILE_MODULE would cause the line "app_label, model_name = settings.AUTH_PROFILE_MODULE.split('.')" to throw the "too many values to unpack" error.

I'm 99% sure that this was the original problem encountered here.

Max size of an iOS application

As of July 2016:

Short Answer:

  1. If your game is released for iOS 9.0 or newer, you can have maximum app size of 400 MB for the size of the Mach-O binary file (for example,

  2. Your app’s total uncompressed size must be less than 4 Gb.

Long Answer:

Your app’s total uncompressed size must be less than 4 billion bytes. Each Mach-O executable file (for example, must not exceed these limits:

For apps whose MinimumOSVersion is less than 7.0: maximum of 80 MB for the total of all __TEXT sections in the binary.

For apps whose MinimumOSVersion is 7.x through 8.x: maximum of 60 MB per slice for the __TEXT section of each architecture slice in the binary.

For apps whose MinimumOSVersion is 9.0 or greater: maximum of 400 MB for the size of the Mach-O binary file.

However, consider download times when determining your app’s size. Minimize the file’s size as much as possible, keeping in mind that there is a 100 MB limit for over-the-air downloads. Abnormally large build files are usually the result of storing data, such as images, inside the compiled binary itself instead of as a resource inside your app bundle. If you are compiling an image or large dataset into your binary, it would be best to split this data out into a resource that is loaded dynamically by your app.

Here is the link to Apple Developer Guide that contains the info I posted above:

You can go to the section "Submitting the App for App Review" on the link above to read more on the info I posted above.

Jquery Ajax Posting json to webservice

You mentioned using json2.js to stringify your data, but the POSTed data appears to be URLEncoded JSON You may have already seen it, but this post about the invalid JSON primitive covers why the JSON is being URLEncoded.

I'd advise against passing a raw, manually-serialized JSON string into your method. ASP.NET is going to automatically JSON deserialize the request's POST data, so if you're manually serializing and sending a JSON string to ASP.NET, you'll actually end up having to JSON serialize your JSON serialized string.

I'd suggest something more along these lines:

var markers = [{ "position": "128.3657142857143", "markerPosition": "7" },
               { "position": "235.1944023323615", "markerPosition": "19" },
               { "position": "42.5978231292517", "markerPosition": "-3" }];

    type: "POST",
    url: "/webservices/PodcastService.asmx/CreateMarkers",
    // The key needs to match your method's input parameter (case-sensitive).
    data: JSON.stringify({ Markers: markers }),
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function(data){alert(data);},
    error: function(errMsg) {

The key to avoiding the invalid JSON primitive issue is to pass jQuery a JSON string for the data parameter, not a JavaScript object, so that jQuery doesn't attempt to URLEncode your data.

On the server-side, match your method's input parameters to the shape of the data you're passing in:

public class Marker
  public decimal position { get; set; }
  public int markerPosition { get; set; }

public string CreateMarkers(List<Marker> Markers)
  return "Received " + Markers.Count + " markers.";

You can also accept an array, like Marker[] Markers, if you prefer. The deserializer that ASMX ScriptServices uses (JavaScriptSerializer) is pretty flexible, and will do what it can to convert your input data into the server-side type you specify.

How do I wait until Task is finished in C#?

A clean example that answers the Title

string output = "Error";
Task task = Task.Factory.StartNew(() =>
    output = "Complete";


Differences between .NET 4.0 and .NET 4.5 in High level in .NET

.NET Framework 4

Microsoft announced the intention to ship .NET Framework 4 on 29 September 2008. The Public Beta was released on 20 May 2009.

  • Parallel Extensions to improve support for parallel computing, which target multi-core or distributed systems. To this end, technologies like PLINQ (Parallel LINQ), a parallel implementation of the LINQ engine, and Task Parallel Library, which exposes parallel constructs via method calls., are included.
  • New Visual Basic .NET and C# language features, such as implicit line continuations, dynamic dispatch, named parameters, and optional parameters.
  • Support for Code Contracts.
  • Inclusion of new types to work with arbitrary-precision arithmetic (System.Numerics.BigInteger) and complex numbers (System.Numerics.Complex).
  • Introduce Common Language Runtime (CLR) 4.0.

After the release of the .NET Framework 4, Microsoft released a set of enhancements, named Windows Server AppFabric, for application server capabilities in the form of AppFabric Hosting and in-memory distributed caching support.

.NET Framework 4.5

.NET Framework 4.5 was released on 15 August 2012., a set of new or improved features were added into this version. The .NET Framework 4.5 is only supported on Windows Vista or later. The .NET Framework 4.5 uses Common Language Runtime 4.0, with some additional runtime features.

1. .NET for Metro style apps

Metro-style apps are designed for specific form factors and leverage the power of the Windows operating system. A subset of the .NET Framework is available for building Metro style apps for Windows 8 using C# or Visual Basic. This subset is called .NET APIs for apps. The version of .NET Framework, runtime and libraries, used for Metro style apps is a part of the new Windows Runtime, which is the new platform and application model for Metro style apps. It is an ecosystem that houses many platforms and languages, including .NET Framework, C++ and HTML5/JavaScript.

2. Core Features

  • Ability to limit how long the regular expression engine will attempt to resolve a regular expression before it times out.
  • Ability to define the culture for an application domain.
  • Console support for Unicode (UTF-16) encoding.
  • Support for versioning of cultural string ordering and comparison data.
  • Better performance when retrieving resources.
  • Zip compression improvements to reduce the size of a compressed file.
  • Ability to customize a reflection context to override default reflection behavior through the CustomReflectionContext class.

3. Managed Extensibility Framework (MEF)

  • Support for generic types.
  • Convention-based programming model that enables you to create parts based on naming conventions rather than attributes.
  • Multiple scopes.

4. Asynchronous operations

In the .NET Framework 4.5, new asynchronous features were added to the C# and Visual Basic languages. These features add a task-based model for performing asynchronous operations.


  • Support for new HTML5 form types.
  • Support for model binders in Web Forms. These let you bind data controls directly to data-access methods, and automatically convert user input to and from .NET Framework data types.
  • Support for unobtrusive JavaScript in client-side validation scripts.
  • Improved handling of client script through bundling and minification for improved page performance.
  • Integrated encoding routines from the AntiXSS library (previously an external library) to protect from cross-site scripting attacks.
  • Support for WebSocket protocol.
  • Support for reading and writing HTTP requests and responses asynchronously.
  • Support for asynchronous modules and handlers.
  • Support for content distribution network (CDN) fallback in the ScriptManager control.

6. Networking

  • Provides a new programming interface for HTTP applications: System.Net.Http namespace and System.Net.Http.Headers namespaces are added.
  • Other improvements: Improved internationalization and IPv6 support. RFC-compliant URI support. Support for Internationalized Domain Name (IDN) parsing. Support for Email Address Internationalization (EAI).

7. Windows Presentation Foundation (WPF)

  • The new Ribbon control, which enables you to implement a ribbon user interface that hosts a Quick Access Toolbar, Application Menu, and tabs.
  • The new INotifyDataErrorInfo interface, which supports synchronous and asynchronous data validation.
  • New features for the VirtualizingPanel and Dispatcher classes.
  • Improved performance when displaying large sets of grouped data, and by accessing collections on non-UI threads.
  • Data binding to static properties, data binding to custom types that implement the ICustomTypeProvider interface and retrieval of data binding information from a binding expression.
  • Repositioning of data as the values change (live shaping).
  • Better integration between WPF and Win32 user interface components.
  • Ability to check whether the data context for an item container is disconnected.
  • Ability to set the amount of time that should elapse between property changes and data source updates.
  • Improved support for implementing weak event patterns. Also, events can now accept markup extensions.

8. Windows Communication Foundation (WCF)

In the .NET Framework 4.5, the following features have been added to make it simpler to write and maintain Windows Communication Foundation (WCF) applications:

  • Simplification of generated configuration files.
  • Support for contract-first development.
  • Ability to configure ASP.NET compatibility mode more easily.
  • Changes in default transport property values to reduce the likelihood that you will have to set them.
  • Updates to the XmlDictionaryReaderQuotas class to reduce the likelihood that you will have to manually configure quotas for XML dictionary readers.
  • Validation of WCF configuration files by Visual Studio as part of the build process, so you can detect configuration errors before you run your application.
  • New asynchronous streaming support.
  • New HTTPS protocol mapping to make it easier to expose an endpoint over HTTPS with Internet Information Services (IIS).
  • Ability to generate metadata in a single WSDL document by appending ?singleWSDL to the service URL.
  • Websockets support to enable true bidirectional communication over ports 80 and 443 with performance characteristics similar to the TCP transport.
  • Support for configuring services in code.
  • XML Editor tooltips.
  • ChannelFactory caching support.
  • Binary encoder compression support.
  • Support for a UDP transport that enables developers to write services that use "fire and forget" messaging. A client sends a message to a service and expects no response from the service.
  • Ability to support multiple authentication modes on a single WCF endpoint when using the HTTP transport and transport security.
  • Support for WCF services that use internationalized domain names (IDNs).

9. Tools

  • Resource File Generator (Resgen.exe) enables you to create a .resw file for use in Windows Store apps from a .resources file embedded in a .NET Framework assembly.
  • Managed Profile Guided Optimization (Mpgo.exe) enables you to improve application startup time, memory utilization (working set size), and throughput by optimizing native image assemblies. The command-line tool generates profile data for native image application assemblies.

For more information and access to reference links, please visit:

===========.Net 4.5 Poster=========

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How do I sort a list of dictionaries by a value of the dictionary?

It may look cleaner using a key instead a cmp:

newlist = sorted(list_to_be_sorted, key=lambda k: k['name']) 

or as J.F.Sebastian and others suggested,

from operator import itemgetter
newlist = sorted(list_to_be_sorted, key=itemgetter('name')) 

For completeness (as pointed out in comments by fitzgeraldsteele), add reverse=True to sort descending

newlist = sorted(l, key=itemgetter('name'), reverse=True)

update package.json version automatically

With Husky:

  "name": "demo-project",
  "version": "0.0.3",
  "husky": {
    "hooks": {
      "pre-commit": "npm --no-git-tag-version version patch && git add ."

Assign variable in if condition statement, good practice or not?

you could do something like so:

if (value = /* sic */ some_function()){

How can I get Eclipse to show .* files?

Preferences -> Remote Systems -> Files -> Show hidden files

(make sure this is checked)

How to set NODE_ENV to production/development in OS X

In order to have multiple environments you need all of the answers before (NODE_ENV parameter and export it), but I use a very simple approach without the need of installing anything. In your package.json just put a script for each env you need, like this:

"scripts": {
    "start-dev": "export NODE_ENV=dev && ts-node-dev --respawn --transpileOnly ./src/app.ts",
    "start-prod": "export NODE_ENV=prod && ts-node-dev --respawn --transpileOnly ./src/app.ts"

Then, to start the app instead of using npm start use npm run script-prod.

In the code you can access the current environment with process.env.NODE_ENV.


Activity <App Name> has leaked ServiceConnection <ServiceConnection Name>@438030a8 that was originally bound here

Try using unbindService() in OnUserLeaveHint(). It prevents the the ServiceConnection leaked scenario and other exceptions.
I used it in my code and works fine.

Getting the index of the returned max or min item using max()/min() on a list

Assuming you have a following list my_list = [1,2,3,4,5,6,7,8,9,10] and we know that if we do max(my_list) it will return 10 and min(my_list) will return 1. Now we want to get the index of the maximum or minimum element we can do the following.

my_list = [1,2,3,4,5,6,7,8,9,10]

max_value = max(my_list) # returns 10
max_value_index = my_list.index(max_value) # retuns 9

#to get an index of minimum value

min_value = min(my_list) # returns 1
min_value_index = my_list.index(min_value) # retuns 0

Can I export a variable to the environment from a bash script without sourcing it?

Maybe you can write a function in ~/.zshrc, ~/.bashrc .

# set my env
[ -s ~/.env ] && export MYENV=`cat ~/.env`
function myenv() { [[ -s ~/.env ]] && echo $argv > ~/.env && export MYENV=$argv }

Beacause of use variable outside, you can avoid write script file.

Currency Formatting in JavaScript

You can use standard JS toFixed method

var num = 5.56789;
var n=num.toFixed(2);


In order to add commas (to separate 1000's) you can add regexp as follows (where num is a number):

num.toString().replace(/(\d)(?=(\d\d\d)+(?!\d))/g, "$1,")

//100000 => 100,000
//8000 => 8,000
//1000000 => 1,000,000

Complete example:

var value = 1250.223;
var num = '$' + value.toFixed(2).replace(/(\d)(?=(\d\d\d)+(?!\d))/g, "$1,");

//document.write(num) would write value as follows: $1,250.22

Separation character depends on country and locale. For some countries it may need to be .

How do I update the password for Git?

For Mac

If you have multiple remote repositories (Github, Bitbucket, Job, etc.)

1) run in the project directory

git config --unset user.password

2) run remote git command (ie. git push or git pull)

Git will prompt you to reenter your and user.password for this repository

Or you can do it globally if you have only one remote repository

git config --global --unset user.password

What is the use of adding a null key or value to a HashMap in Java?

Another example : I use it to group Data by date. But some data don't have date. I can group it with the header "NoDate"

How to serve all existing static files directly with NGINX, but proxy the rest to a backend server.

If you use mod_rewrite to hide the extension of your scripts, or if you just like pretty URLs that end in /, then you might want to approach this from the other direction. Tell nginx to let anything with a non-static extension to go through to apache. For example:

location ~* ^.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$
    root   /path/to/static-content;

location ~* ^!.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$ {
    if (!-f $request_filename) {
        return 404;
    proxy_set_header X-Real-IP  $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

I found the first part of this snippet over at:

Extract images from PDF without resampling, in python?

As of February 2019, the solution given by @sylvain (at least on my setup) does not work without a small modification: xObject[obj]['/Filter'] is not a value, but a list, thus in order to make the script work, I had to modify the format checking as follows:

import PyPDF2, traceback

from PIL import Image

input1 = PyPDF2.PdfFileReader(open(src, "rb"))
nPages = input1.getNumPages()
print nPages

for i in range(nPages) :
    print i
    page0 = input1.getPage(i)
    try :
        xObject = page0['/Resources']['/XObject'].getObject()
    except : xObject = []

    for obj in xObject:
        if xObject[obj]['/Subtype'] == '/Image':
            size = (xObject[obj]['/Width'], xObject[obj]['/Height'])
            data = xObject[obj].getData()
            try :
                if xObject[obj]['/ColorSpace'] == '/DeviceRGB':
                    mode = "RGB"
                elif xObject[obj]['/ColorSpace'] == '/DeviceCMYK':
                    mode = "CMYK"
                    # will cause errors when saving
                    mode = "P"

                fn = 'p%03d-%s' % (i + 1, obj[1:])
                print '\t', fn
                if '/FlateDecode' in xObject[obj]['/Filter'] :
                    img = Image.frombytes(mode, size, data)
           + ".png")
                elif '/DCTDecode' in xObject[obj]['/Filter']:
                    img = open(fn + ".jpg", "wb")
                elif '/JPXDecode' in xObject[obj]['/Filter'] :
                    img = open(fn + ".jp2", "wb")
                elif '/LZWDecode' in xObject[obj]['/Filter'] :
                    img = open(fn + ".tif", "wb")
                else :
                    print 'Unknown format:', xObject[obj]['/Filter']
            except :

Combine multiple results in a subquery into a single comma-separated value

        FROM   TABLEB t1 
        WHERE  t1.F_ID = T.TABLEA.ID) 

This will work for selecting from different table using sub query.

ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean

As for me, I removed the provided scope in tomcat dependency.

  <scope>provided</scope> // remove this scope

SDK Manager.exe doesn't work

Step #1: Open up a command prompt.

Step #2: Use the cd command to move to wherever you installed your Android SDK.

Step #3: Run tools\android.

If that does not work, you should have information dumped to the command prompt that will help you diagnose your setup problem.

C++ Returning reference to local variable

A local variable is memory on the stack, that memory is not automatically invalidated when you go out of scope. From a Function deeper nested (higher on the stack in memory), its perfectly safe to access this memory.

Once the Function returns and ends though, things get dangerous. Usually the memory is not deleted or overwritten when you return, meaning the memory at that adresss is still containing your data - the pointer seems valid.

Until another function builds up the stack and overwrites it. This is why this can work for a while - and then suddenly cease to function after one particularly deeply nested set of functions, or a function with really huge sized or many local objects, reaches that stack-memory again.

It even can happen that you reach the same program part again, and overwrite your old local function variable with the new function variable. All this is very dangerous and should be heavily discouraged. Do not use pointers to local objects!

Calculate percentage saved between two numbers?

I see that this is a very old question, but this is how I calculate the percentage difference between 2 numbers:

(1 - (oldNumber / newNumber)) * 100

So, the percentage difference from 30 to 40 is:

(1 - (30/40)) * 100 = +25% (meaning, increase by 25%)

The percentage difference from 40 to 30 is:

(1 - (40/30)) * 100 = -33.33% (meaning, decrease by 33%)

In php, I use a function like this:

function calculatePercentage($oldFigure, $newFigure) {
        if (($oldFigure != 0) && ($newFigure != 0)) {
            $percentChange = (1 - $oldFigure / $newFigure) * 100;
        else {
            $percentChange = null;
        return $percentChange;

How can I enter latitude and longitude in Google Maps?

It's actually fairly easy, just enter it as a latitude,longitude pair, ie 46.38S,115.36E (which is in the middle of the ocean). You'll want to convert it to decimal though (divide the minutes portion by 60 and add it to the degrees [I've done that with your example]).

Print the data in ResultSet along with column names

For those who wanted more better version of the resultset printing as util class This was really helpful for printing resultset and does many things from a single util... thanks to Hami Torun!

In this class printResultSet uses ResultSetMetaData in a generic way have a look at it..

import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.StringJoiner;

public final class DBTablePrinter {

     * Column type category for CHAR, VARCHAR
     * and similar text columns.
    public static final int CATEGORY_STRING = 1;
     * Column type category for TINYINT, SMALLINT,
     * INT and BIGINT columns.
    public static final int CATEGORY_INTEGER = 2;
     * Column type category for REAL, DOUBLE,
     * and DECIMAL columns.
    public static final int CATEGORY_DOUBLE = 3;
     * Column type category for date and time related columns like
    public static final int CATEGORY_DATETIME = 4;
     * Column type category for BOOLEAN columns.
    public static final int CATEGORY_BOOLEAN = 5;
     * Column type category for types for which the type name
     * will be printed instead of the content, like BLOB,
     * BINARY, ARRAY etc.
    public static final int CATEGORY_OTHER = 0;
     * Default maximum number of rows to query and print.
    private static final int DEFAULT_MAX_ROWS = 10;
     * Default maximum width for text columns
     * (like a VARCHAR) column.
    private static final int DEFAULT_MAX_TEXT_COL_WIDTH = 150;

     * Overloaded method that prints rows from table tableName
     * to standard out using the given database connection
     * conn. Total number of rows will be limited to
     * {@link #DEFAULT_MAX_ROWS} and
     * {@link #DEFAULT_MAX_TEXT_COL_WIDTH} will be used to limit
     * the width of text columns (like a VARCHAR column).
     * @param conn      Database connection object (java.sql.Connection)
     * @param tableName Name of the database table
    public static void printTable(Connection conn, String tableName) {
        printTable(conn, tableName, DEFAULT_MAX_ROWS, DEFAULT_MAX_TEXT_COL_WIDTH);

     * Overloaded method that prints rows from table tableName
     * to standard out using the given database connection
     * conn. Total number of rows will be limited to
     * maxRows and
     * {@link #DEFAULT_MAX_TEXT_COL_WIDTH} will be used to limit
     * the width of text columns (like a VARCHAR column).
     * @param conn      Database connection object (java.sql.Connection)
     * @param tableName Name of the database table
     * @param maxRows   Number of max. rows to query and print
    public static void printTable(Connection conn, String tableName, int maxRows) {
        printTable(conn, tableName, maxRows, DEFAULT_MAX_TEXT_COL_WIDTH);

     * Overloaded method that prints rows from table tableName
     * to standard out using the given database connection
     * conn. Total number of rows will be limited to
     * maxRows and
     * maxStringColWidth will be used to limit
     * the width of text columns (like a VARCHAR column).
     * @param conn              Database connection object (java.sql.Connection)
     * @param tableName         Name of the database table
     * @param maxRows           Number of max. rows to query and print
     * @param maxStringColWidth Max. width of text columns
    public static void printTable(Connection conn, String tableName, int maxRows, int maxStringColWidth) {
        if (conn == null) {
            System.err.println("DBTablePrinter Error: No connection to database (Connection is null)!");
        if (tableName == null) {
            System.err.println("DBTablePrinter Error: No table name (tableName is null)!");
        if (tableName.length() == 0) {
            System.err.println("DBTablePrinter Error: Empty table name!");
        if (maxRows 
     * ResultSet to standard out using {@link #DEFAULT_MAX_TEXT_COL_WIDTH}
     * to limit the width of text columns.
     * @param rs The ResultSet to print
    public static void printResultSet(ResultSet rs) {
        printResultSet(rs, DEFAULT_MAX_TEXT_COL_WIDTH);

     * Overloaded method to print rows of a 
     * ResultSet to standard out using maxStringColWidth
     * to limit the width of text columns.
     * @param rs                The ResultSet to print
     * @param maxStringColWidth Max. width of text columns
    public static void printResultSet(ResultSet rs, int maxStringColWidth) {
        try {
            if (rs == null) {
                System.err.println("DBTablePrinter Error: Result set is null!");
            if (rs.isClosed()) {
                System.err.println("DBTablePrinter Error: Result Set is closed!");
            if (maxStringColWidth  columns = new ArrayList(columnCount);

            // List of table names. Can be more than one if it is a joined
            // table query
            List tableNames = new ArrayList(columnCount);

            // Get the columns and their meta data.
            // NOTE: columnIndex for rsmd.getXXX methods STARTS AT 1 NOT 0
            for (int i = 1; i  maxStringColWidth) {
                                value = value.substring(0, maxStringColWidth - 3) + "...";

                    // Adjust the column width
                    c.setWidth(value.length() > c.getWidth() ? value.length() : c.getWidth());
                } // END of for loop columnCount

            } // END of while (

            At this point we have gone through meta data, get the
            columns and created all Column objects, iterated over the
            ResultSet rows, populated the column values and adjusted
            the column widths.
            We cannot start printing just yet because we have to prepare
            a row separator String.

            // For the fun of it, I will use StringBuilder
            StringBuilder strToPrint = new StringBuilder();
            StringBuilder rowSeparator = new StringBuilder();

            Prepare column labels to print as well as the row separator.
            It should look something like this:
            +--------+------------+------------+-----------+  (row separator)
            | EMP_NO | BIRTH_DATE | FIRST_NAME | LAST_NAME |  (labels row)
            +--------+------------+------------+-----------+  (row separator)

            // Iterate over columns
            for (Column c : columns) {
                int width = c.getWidth();

                // Center the column label
                String toPrint;
                String name = c.getLabel();
                int diff = width - name.length();

                if ((diff % 2) == 1) {
                    // diff is not divisible by 2, add 1 to width (and diff)
                    // so that we can have equal padding to the left and right
                    // of the column label.

                int paddingSize = diff / 2; // InteliJ says casting to int is redundant.

                // Cool String repeater code thanks to user102008 at

                String padding = new String(new char[paddingSize]).replace("\0", " ");

                toPrint = "| " + padding + name + padding + " ";
                // END centering the column label


                rowSeparator.append(new String(new char[width + 2]).replace("\0", "-"));

            String lineSeparator = System.getProperty("line.separator");

            // Is this really necessary ??
            lineSeparator = lineSeparator == null ? "\n" : lineSeparator;


            strToPrint.insert(0, rowSeparator);

            StringJoiner sj = new StringJoiner(", ");
            for (String name : tableNames) {

            String info = "Printing " + rowCount;
            info += rowCount > 1 ? " rows from " : " row from ";
            info += tableNames.size() > 1 ? "tables " : "table ";
            info += sj.toString();


            // Print out the formatted column labels

            String format;

            // Print out the rows
            for (int i = 0; i 
     * Integers should not be truncated so column widths should
     * be adjusted without a column width limit. Text columns should be
     * left justified and can be truncated to a max. column width etc...


* See also: * java.sql.Types * * @param type Generic SQL type * @return The category this type belongs to */ private static int whichCategory(int type) { switch (type) { case Types.BIGINT: case Types.TINYINT: case Types.SMALLINT: case Types.INTEGER: return CATEGORY_INTEGER; case Types.REAL: case Types.DOUBLE: case Types.DECIMAL: return CATEGORY_DOUBLE; case Types.DATE: case Types.TIME: case Types.TIME_WITH_TIMEZONE: case Types.TIMESTAMP: case Types.TIMESTAMP_WITH_TIMEZONE: return CATEGORY_DATETIME; case Types.BOOLEAN: return CATEGORY_BOOLEAN; case Types.VARCHAR: case Types.NVARCHAR: case Types.LONGVARCHAR: case Types.LONGNVARCHAR: case Types.CHAR: case Types.NCHAR: return CATEGORY_STRING; default: return CATEGORY_OTHER; } } /** * Represents a database table column. */ private static class Column { /** * Column label. */ private String label; /** * Generic SQL type of the column as defined in * * java.sql.Types * . */ private int type; /** * Generic SQL type name of the column as defined in * * java.sql.Types * . */ private String typeName; /** * Width of the column that will be adjusted according to column label * and values to be printed. */ private int width = 0; /** * Column values from each row of a ResultSet. */ private List values = new ArrayList(); /** * Flag for text justification using String.format. * Empty string ("") to justify right, * dash (-) to justify left. * * @see #justifyLeft() */ private String justifyFlag = ""; /** * Column type category. The columns will be categorised according * to their column types and specific needs to print them correctly. */ private int typeCategory = 0; /** * Constructs a new Column with a column label, * generic SQL type and type name (as defined in * * java.sql.Types * ) * * @param label Column label or name * @param type Generic SQL type * @param typeName Generic SQL type name */ public Column(String label, int type, String typeName) { this.label = label; this.type = type; this.typeName = typeName; } /** * Returns the column label * * @return Column label */ public String getLabel() { return label; } /** * Returns the generic SQL type of the column * * @return Generic SQL type */ public int getType() { return type; } /** * Returns the generic SQL type name of the column * * @return Generic SQL type name */ public String getTypeName() { return typeName; } /** * Returns the width of the column * * @return Column width */ public int getWidth() { return width; } /** * Sets the width of the column to width * * @param width Width of the column */ public void setWidth(int width) { this.width = width; } /** * Adds a String representation (value) * of a value to this column object's {@link #values} list. * These values will come from each row of a * * ResultSet * of a database query. * * @param value The column value to add to {@link #values} */ public void addValue(String value) { values.add(value); } /** * Returns the column value at row index i. * Note that the index starts at 0 so that getValue(0) * will get the value for this column from the first row * of a * ResultSet. * * @param i The index of the column value to get * @return The String representation of the value */ public String getValue(int i) { return values.get(i); } /** * Returns the value of the {@link #justifyFlag}. The column * values will be printed using String.format and * this flag will be used to right or left justify the text. * * @return The {@link #justifyFlag} of this column * @see #justifyLeft() */ public String getJustifyFlag() { return justifyFlag; } /** * Sets {@link #justifyFlag} to "-" so that * the column value will be left justified when printed with * String.format. Typically numbers will be right * justified and text will be left justified. */ public void justifyLeft() { this.justifyFlag = "-"; } /** * Returns the generic SQL type category of the column * * @return The {@link #typeCategory} of the column */ public int getTypeCategory() { return typeCategory; } /** * Sets the {@link #typeCategory} of the column * * @param typeCategory The type category */ public void setTypeCategory(int typeCategory) { this.typeCategory = typeCategory; } } }

This is the scala version of doing this... which will print column names and data as well in a generic way...

def printQuery(res: ResultSet): Unit = {
    val rsmd = res.getMetaData
    val columnCount = rsmd.getColumnCount
    var rowCnt = 0
    val s = StringBuilder.newBuilder
    while ( {

      if (rowCnt == 0) {
        s.append("| ")
        for (i <- 1 to columnCount) {
          val name = rsmd.getColumnName(i)
          s.append("| ")
      rowCnt += 1
      s.append("| ")
      for (i <- 1 to columnCount) {
        if (i > 1)
          s.append(" | ")
      s.append(" |")
    System.out.println(s"TOTAL: $rowCnt rows")

How to find which views are using a certain table in SQL Server (2008)?

If you need to find database objects (e.g. tables, columns, triggers) by name - have a look at the FREE Red-Gate tool called SQL Search which does this - it searches your entire database for any kind of string(s).

enter image description here

enter image description here

It's a great must-have tool for any DBA or database developer - did I already mention it's absolutely FREE to use for any kind of use??

There isn't anything to compare. Nothing to compare, branches are entirely different commit histories

I had mine solved by overriding the branch:

My case: I wanted to override whatever code is in the develop with version_2.

  1. delete the local copy of conflicting branch:
git checkout version_2
git branch -D develop
  1. checkout a fresh branch from the version_2 and force push to git:
git checkout -b `develop`
git push origin `develop`

I didn't need to rebase. But in my case, I didn't need to take code from my old code.

Unable to Git-push master to Github - 'origin' does not appear to be a git repository / permission denied

I have the same problem and i think the firewall is blocking the git protocol. So in the end I have to resort to using https:// to fetch and push. However this will always prompt the user to enter the password...

here is the example what working for me (just to share with those cant use git:// protocol :)

git fetch https://[user-name][user-name]/[project].git

if the above works, you can remove the origin and replace with

git remote rm origin  
git remote add origin https://[user-name][user-name]/[project].git

Is there any option to limit mongodb memory usage?

I don't think you can configure how much memory MongoDB uses, but that's OK (read below).

To quote from the official source:

Virtual memory size and resident size will appear to be very large for the mongod process. This is benign: virtual memory space will be just larger than the size of the datafiles open and mapped; resident size will vary depending on the amount of memory not used by other processes on the machine.

In other words, Mongo will let other programs use memory if they ask for it.

What exactly is "exit" in PowerShell?

It's a reserved keyword (like return, filter, function, break).


Also, as per Section 7.6.4 of Bruce Payette's Powershell in Action:

But what happens when you want a script to exit from within a function defined in that script? ... To make this easier, Powershell has the exit keyword.

Of course, as other have pointed out, it's not hard to do what you want by wrapping exit in a function:

PS C:\> function ex{exit}
PS C:\> new-alias ^D ex

What are App Domains in Facebook Apps?

it stands for your website where your app is running on. like you have made an app then you will type this in App domain the site where your app is running on should be secure and valid

ORA-12154 could not resolve the connect identifier specified

I had this error in Visual Studio 2013, with an SSIS project. I set Project, Properties, Debugging, Run64BitRuntime = false and then the SSIS package ran. However, when I deployed the package to the server I had to set the value to true (Server is 64 bit Windows 2012 / Sql 2014 ).

I think the reasoning behind this is that Visual Studio is a 32 bit application.

Angularjs simple file download causes router to redirect

If you need a directive more advanced, I recomend the solution that I implemnted, correctly tested on Internet Explorer 11, Chrome and FireFox.

I hope it, will be helpfull.


<a href="#" class="btn btn-default" file-name="'fileName.extension'"  ng-click="getFile()" file-download="myBlobObject"><i class="fa fa-file-excel-o"></i></a>




            scope.$watch('fileDownload',function(newValue, oldValue){

                if(newValue!=undefined && newValue!=null){
                    console.debug('Downloading a new file'); 
                    var isFirefox = typeof InstallTrigger !== 'undefined';
                    var isSafari ='Constructor') > 0;
                    var isIE = /*@cc_on!@*/false || !!document.documentMode;
                    var isEdge = !isIE && !!window.StyleMedia;
                    var isChrome = !! && !!;
                    var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;
                    var isBlink = (isChrome || isOpera) && !!window.CSS;

                    if(isFirefox || isIE || isChrome){
                            console.log('Manage Google Chrome download');
                            var url = window.URL || window.webkitURL;
                            var fileURL = url.createObjectURL(scope.fileDownload);
                            var downloadLink = angular.element('<a></a>');//create a new  <a> tag element
                            downloadLink[0].click();//call click function
                            url.revokeObjectURL(fileURL);//revoke the object from URL
                            console.log('Manage IE download>10');
                            console.log('Manage Mozilla Firefox download');
                            var url = window.URL || window.webkitURL;
                            var fileURL = url.createObjectURL(scope.fileDownload);
                            var a=elem[0];//recover the <a> tag from directive
                  ;//we call click function

                        alert('SORRY YOUR BROWSER IS NOT COMPATIBLE');



        console.log('download started, you can show a wating animation');
        serviceAsPromise.getStream({param1:'data1',param1:'data2', ...})
        .then(function(data){//is important that the data was returned as Aray Buffer
                console.log('Stream download complete, stop animation!');
                $scope.myBlobObject=new Blob([data],{ type:'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'});
                console.log('Download Error, stop animation and show error message');


function getStream(params){
                 var deferred = $q.defer();

                     method:"PUT",//you can use also GET or POST
                     headers:{'Content-type': 'application/json'},
                     responseType : 'arraybuffer',//THIS IS IMPORTANT
                    .success(function (data) {
                    }).error(function (data) {

                 return deferred.promise;


@RequestMapping(value = "/downloadURL/", method = RequestMethod.PUT)
public void downloadExcel(HttpServletResponse response,
        @RequestBody Map<String,String> spParams
        ) throws IOException {
        OutputStream outStream=null;
outStream = response.getOutputStream();//is important manage the exceptions here
ObjectThatWritesOnOutputStream myWriter= new ObjectThatWritesOnOutputStream();// note that this object doesn exist on JAVA,
ObjectThatWritesOnOutputStream.write(outStream);//you can configure more things here

How to add hours to current date in SQL Server?

The DATEADD() function adds or subtracts a specified time interval from a date.


datepart(interval) can be hour, second, day, year, quarter, week etc; number (increment int); date(expression smalldatetime)

For example if you want to add 30 days to current date you can use something like this

 select dateadd(dd, 30, getdate())

To Substract 30 days from current date

select dateadd(dd, -30, getdate())

Delete all rows in an HTML table

If you do not want to remove th and just want to remove the rows inside, this is working perfectly.

var tb = document.getElementById('tableId');
  while(tb.rows.length > 1) {

How do I print bytes as hexadecimal?

Use C++ streams and restore state afterwards

This is a variation of How do I print bytes as hexadecimal? but:


#include <iomanip>
#include <iostream>

int main() {
    int array[] = {0, 0x8, 0x10, 0x18};
    constexpr size_t size = sizeof(array) / sizeof(array[0]);

    // Sanity check decimal print.
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;

    // Hex print and restore default afterwards.
    std::ios cout_state(nullptr);
    std::cout << std::hex << std::setfill('0') << std::setw(2);
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;

    // Check that cout state was restored.
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;

Compile and run:

g++ -o main.out -std=c++11 main.cpp


0 8 16 24 
00 8 10 18 
0 8 16 24

Tested on Ubuntu 16.04, GCC 6.4.0.

What is the best IDE for C Development / Why use Emacs over an IDE?

I started off by using IDEs, Microsoft or not. Then, while working on QNX some long time ago, I was forced to do with a text editor + compiler/linker. Now I prefer this simple combination––a syntax highlighting editor + C compiler and linker cli + make––to any IDEs, even if environment allows for them.

The reasons are, for me:

  1. it's everywhere. If you program in C, you do have the compiler, and usually you can get yourself an editor. The first thing I do––I get myself nedit on Linux or Notepad++ on Windows. I would go with vi, but GUI editors provide for a better fonts, and that is important when you look at code all day

  2. you can program remotely, via ssh, when you need to. And it does help a lot sometimes to be able to ssh into the target and do some quick things there

  3. it keeps me close to CLI, preferably UNIX/Linux CLI. So all the commands are on my fingertips, and when I need them I don't have to go read a reference book. And UNIX CLI can do things IDEs often can't––because their developers didn't think you'd need them

  4. most importantly, it is very much like seeing the Matrix in raw code. I operate files, so I'm forced to keep them manageable. I'm finding things in my code manually, which makes me keep it simple and organized. I do Config Management explicitly, so I know when I'm synced and how. I know my Makefiles because I write them, and they only do what I tell them to

    (if you wonder if that works in "really big projects"––it does work, and the bigger the project the more performance it gains me)

  5. when people ask me to look at their code, I don't have to learn the IDE they use

Find all files in a directory with extension .txt in Python

A simple method by using for loop :

import os

dir = ["e","x","e"]

p = os.listdir('E:')  #path

for n in range(len(p)):
   name = p[n]
   myfile = [name[-3],name[-2],name[-1]]  #for .txt
   if myfile == dir :

Though this can be made more generalised .

PHP: Calling another class' method

If they are separate classes you can do something like the following:

class A
    private $name;

    public function __construct()
        $this->name = 'Some Name';

    public function getName()
        return $this->name;

class B
    private $a;

    public function __construct(A $a)
        $this->a = $a;

    function getNameOfA()
        return $this->a->getName();

$a = new A();
$b = new B($a);


What I have done in this example is first create a new instance of the A class. And after that I have created a new instance of the B class to which I pass the instance of A into the constructor. Now B can access all the public members of the A class using $this->a.

Also note that I don't instantiate the A class inside the B class because that would mean I tighly couple the two classes. This makes it hard to:

  1. unit test your B class
  2. swap out the A class for another class

Redirect Windows cmd stdout and stderr to a single file

There is, however, no guarantee that the output of SDTOUT and STDERR are interweaved line-by-line in timely order, using the POSIX redirect merge syntax.

If an application uses buffered output, it may happen that the text of one stream is inserted in the other at a buffer boundary, which may appear in the middle of a text line.

A dedicated console output logger (I.e. the "StdOut/StdErr Logger" by 'LoRd MuldeR') may be more reliable for such a task.

See: MuldeR's OpenSource Projects

How to mock static methods in c# using MOQ framework?

Moq (and other DynamicProxy-based mocking frameworks) are unable to mock anything that is not a virtual or abstract method.

Sealed/static classes/methods can only be faked with Profiler API based tools, like Typemock (commercial) or Microsoft Moles (free, known as Fakes in Visual Studio 2012 Ultimate /2013 /2015).

Alternatively, you could refactor your design to abstract calls to static methods, and provide this abstraction to your class via dependency injection. Then you'd not only have a better design, it will be testable with free tools, like Moq.

A common pattern to allow testability can be applied without using any tools altogether. Consider the following method:

public class MyClass
    public string[] GetMyData(string fileName)
        string[] data = FileUtil.ReadDataFromFile(fileName);
        return data;

Instead of trying to mock FileUtil.ReadDataFromFile, you could wrap it in a protected virtual method, like this:

public class MyClass
    public string[] GetMyData(string fileName)
        string[] data = GetDataFromFile(fileName);
        return data;

    protected virtual string[] GetDataFromFile(string fileName)
        return FileUtil.ReadDataFromFile(fileName);

Then, in your unit test, derive from MyClass and call it TestableMyClass. Then you can override the GetDataFromFile method to return your own test data.

Hope that helps.

Visual c++ can't open include file 'iostream'

Make sure you have Desktop Development with C++ installed. I was experiencing the same problem because I only had Universal Windows Platform Development installed.

Android Studio Error: Error:CreateProcess error=216, This version of %1 is not compatible with the version of Windows you're running

I had the same issue, but I have resolved it the next:

1) Install jdk1.8...

2) In AndroidStudio File->Project Structure->SDK Location, select your directory where the JDK is located, by default Studio uses embedded JDK but for some reason it produces error=216.

3) Click Ok.

How to convert HTML file to word?

Try using pandoc

pandoc -f html -t docx -o output.docx input.html

If the input or output format is not specified explicitly, pandoc will attempt to guess it from the extensions of the input and output filenames.
— pandoc manual

So you can even use

pandoc -o output.docx input.html

Java split string to array

This behavior is explicitly documented in String.split(String regex) (emphasis mine):

This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.

If you want those trailing empty strings included, you need to use String.split(String regex, int limit) with a negative value for the second parameter (limit):

String[] array = values.split("\\|", -1);

Using git to get just the latest revision

Use git clone with the --depth option set to 1 to create a shallow clone with a history truncated to the latest commit.

For example:

git clone --depth 1

To also initialize and update any nested submodules, also pass --recurse-submodules and to clone them shallowly, also pass --shallow-submodules.

For example:

git clone --depth 1 --recurse-submodules --shallow-submodules

String.Format not work in TypeScript

If you are using NodeJS, you can use the build-in util function:

import * as util from "util";
util.format('My string: %s', 'foo');

Document can be found here:

How to start/stop/restart a thread in Java?

It is impossible to terminate a thread unless the code running in that thread checks for and allows termination.

You said: "Sadly I must kill/restart it ... I don't have complete control over the contents of the thread and for my situation it requires a restart"

If the contents of the thread does not allow for termination of its exectuion then you can not terminate that thread.

In your post you said: "My first attempt was with ExecutorService but I can't seem to find a way for it restart a task. When I use .shutdownnow()..."

If you look at the source of "shutdownnow" it just runs through and interrupts the currently running threads. This will not stop their execution unless the code in those threads checks to see if it has been ineterrupted and, if so, stops execution itself. So shutdownnow is probably not doing what you think.

Let me illustrate what I mean when I say that the contents of the thread must allow for that thread to be terminated:

myExecutor.execute(new Runnable() {
 public void run() {
  while (true) {

That thread will continue to run forever, even though shutdownnow was called, because it never checks to see if it has been terminated or not. This thread, however, will shut down:

myExecutor.execute(new Runnable() {
 public void run() {
  while (!Thread.interrupted()) {

Since this thread checks to see whether or not it has been interrupted / shut down / terminated.

So if you want a thread that you can shut down, you need to make sure it checks to see if it has been interrupted. If you want a thread that you can "shut down" and "restart" you can make a runnable that can take new tasks as was mentioned before.

Why can you not shut down a running thread? Well I actually lied, you can call "yourThread.stop()" but why is this a bad idea? The thread could be in a synchronized (or other critical section, but we will limit ourselves to setions guarded by the syncrhonized key word here) section of code when you stop it. synch blocks are supposed to be executed in their entirity and only by one thread before being accessed by some other thread. If you stop a thread in the middle of a synch block, the protection put into place by the synch block is invalidated and your program will get into an unknown state. Developers make put stuff in synch blocks to keep things in synch, if you use threadInstance.stop() you destroy the meaning of synchronize, what the developer of that code was trying to accomplish and how the developer of that code expected his synchronized blocks to behave.

How do I duplicate a line or selection within Visual Studio Code?

For those migrating from WebStorm/PhpStorm,

You could install IntelliJ IDEA Keybindings to keep using almost all the keyboard shortcuts as you did in Webstorm/Phpstorm.


  • Duplicate lines => CTRL + D
  • Move a line/selection of code Up/Down => Ctrl + Shift + UP/DOWN

Also, here is a list of recommended VS Code extensions that will make your transition from WebStorm/Phpstorm much easier.

How to get Java Decompiler / JD / JD-Eclipse running in Eclipse Helios

After testing on Juno, Kepler and Luna, I found JD only works for *.class files on build path.

  1. Adding the jar as a lib of an existing project
  2. Go to Preferences->General->Editors->File Associations, set *.class without source to Class File Editor with a cup icon

std::thread calling method of class

Not so hard:

#include <thread>

void Test::runMultiThread()
    std::thread t1(&Test::calculate, this,  0, 10);
    std::thread t2(&Test::calculate, this, 11, 20);

If the result of the computation is still needed, use a future instead:

#include <future>

void Test::runMultiThread()
     auto f1 = std::async(&Test::calculate, this,  0, 10);
     auto f2 = std::async(&Test::calculate, this, 11, 20);

     auto res1 = f1.get();
     auto res2 = f2.get();

Semi-transparent color layer over background-image?

Another one with an SVG as inline overlay-image (note: if you use # inside the svg-code you have to urlencode that!):

background: url('data:image/svg+xml;utf8,<svg xmlns="" viewBox="0 0 1 1"><path fill="rgba(255, 255, 255, 0.4)" d="M0 0h1v1H0z"/></svg>')
                no-repeat center center/cover, 
            url('overlayed-image.jpg') no-repeat center center/cover;

React-Router: No Not Found Route?

In newer versions of react-router you want to wrap the routes in a Switch which only renders the first matched component. Otherwise you would see multiple components rendered.

For example:

import React from 'react';
import ReactDOM from 'react-dom';
import {
  BrowserRouter as Router,
} from 'react-router-dom';

import App from './app/App';
import Welcome from './app/Welcome';
import NotFound from './app/NotFound';

const Root = () => (
  <Router history={browserHistory}>
      <Route exact path="/" component={App}/>
      <Route path="/welcome" component={Welcome}/>
      <Route component={NotFound}/>


How to initialize a List<T> to a given size (as opposed to capacity)?

Why are you using a List if you want to initialize it with a fixed value ? I can understand that -for the sake of performance- you want to give it an initial capacity, but isn't one of the advantages of a list over a regular array that it can grow when needed ?

When you do this:

List<int> = new List<int>(100);

You create a list whose capacity is 100 integers. This means that your List won't need to 'grow' until you add the 101th item. The underlying array of the list will be initialized with a length of 100.

How to get param from url in angular 4?


export const MyRoutes: Routes = [
    { path: '/items/:id', component: MyComponent }


import { ActivatedRoute } from '@angular/router';
public id: string;

constructor(private route: ActivatedRoute) {}

ngOnInit() { = this.route.snapshot.paramMap.get('id');

How can I make a clickable link in an NSAttributedString?

The heart of my question was that I wanted to be able to create clickable links in text views/fields/labels without having to write custom code to manipulate the text and add the links. I wanted it to be data-driven.

I finally figured out how to do it. The issue is that IB doesn't honor embedded links.

Furthermore, the iOS version of NSAttributedString doesn't let you initialize an attributed string from an RTF file. The OS X version of NSAttributedString does have an initializer that takes an RTF file as input.

NSAttributedString conforms to the NSCoding protocol, so you can convert it to/from NSData

I created an OS X command line tool that takes an RTF file as input and outputs a file with the extension .data that contains the NSData from NSCoding. I then put the .data file into my project and add a couple of lines of code that loads the text into the view. The code looks like this (this project was in Swift) :

If we can load a file called "" from the bundle and convert it to an attributed string,
install it in the dates field. The contents contain clickable links with custom URLS to select
each date.
  let datesPath = NSBundle.mainBundle().pathForResource("Dates", ofType: "data"),
  let datesString = NSKeyedUnarchiver.unarchiveObjectWithFile(datesPath) as? NSAttributedString
  datesField.attributedText = datesString

For apps that use a lot of formatted text, I create a build rule that tells Xcode that all the .rtf files in a given folder are source and the .data files are the output. Once I do that, I simply add .rtf files to the designated directory, (or edit existing files) and the build process figures out that they are new/updated, runs the command line tool, and copies the files into the app bundle. It works beautifully.

I wrote a blog post that links to a sample (Swift) project demonstrating the technique. You can see it here:

Creating clickable URLs in a UITextField that open in your app

Call a function on click event in Angular 2

The line in your controller code, which reads $scope.myFunc={ should be $scope.myFunc = function() { the function() part is important to indicate, it is a function!

The updated controller code would be

    $scope.myFunc = function() {
    console.log("function called");

How do you check what version of SQL Server for a database using TSQL?

Getting only the major SQL Server version in a single select:

SELECT  SUBSTRING(ver, 1, CHARINDEX('.', ver) - 1)
FROM (SELECT CAST(serverproperty('ProductVersion') AS nvarchar) ver) as t

Returns 8 for SQL 2000, 9 for SQL 2005 and so on (tested up to 2012).

The type or namespace name could not be found

check your Project Properties, your Reference Paths should be empty like this:

Project Properties


jQuery: get data attribute

This is what I came up with:

   console.log(this.attributes['data'].nodeValue) _x000D_
<script src=""></script>_x000D_
<div id='external-events'>_x000D_
   <div class='fc-event' data='00:30:00' >30 Mins</div>_x000D_
   <div class='fc-event' data='00:45:00' >45 Mins</div>_x000D_

Changing the size of a column referenced by a schema-bound view in SQL Server

The views are probably created using the WITH SCHEMABINDING option and this means they are explicitly wired up to prevent such changes. Looks like the schemabinding worked and prevented you from breaking those views, lucky day, heh? Contact your database administrator and ask him to do the change, after it asserts the impact on the database.

From MSDN:


Binds the view to the schema of the underlying table or tables. When SCHEMABINDING is specified, the base table or tables cannot be modified in a way that would affect the view definition. The view definition itself must first be modified or dropped to remove dependencies on the table that is to be modified.

Is mongodb running?

Probably because I didn't shut down my dev server properly or a similar reason. To fix it, remove the lock and start the server with: sudo rm /var/lib/mongodb/mongod.lock ; sudo start mongodb

DataAnnotations validation (Regular Expression) in mvc 4 - razor view

What browser are you using? I entered your example and tried in both IE8 and Chrome and it validated fine when I typed in the value Sam's

 public class IndexViewModel
    [RegularExpression("^([a-zA-Z0-9 .&'-]+)$", ErrorMessage = "Invalid First Name")]
    public string Name { get; set; }

When I inspect the DOM using IE Developer toolbar and Chrome Developer mode it does not show any special characters.

Embedding a media player in a website using HTML

You can use plenty of things.

  • If you're a standards junkie, you can use the HTML5 <audio> tag:

Here is the official W3C specification for the audio tag.


<audio controls>
 <source src=""
 <!-- The next two lines are only executed if the browser doesn't support MP4 files -->
 <source src=""
         type='audio/ogg; codecs=vorbis'>
 <!-- The next line will only be executed if the browser doesn't support the <audio> tag-->
 <p>Your user agent does not support the HTML5 Audio element.</p>

jsFiddle here.

Note: I'm not sure which are the best ones, as I have never used one (yet).

UPDATE: As mentioned in another answer's comment, you are using XHTML 1.0 Transitional. You might be able to get <audio> to work with some hack.

UPDATE 2: I just remembered another way to do play audio. This will work in XHTML!!! This is fully standards-compliant.

You use this JavaScript:

var aud = document.createElement("iframe");
aud.setAttribute('src', ""); // replace with actual file path
aud.setAttribute('width', '1px');
aud.setAttribute('height', '1px');
aud.setAttribute('scrolling', 'no'); = "0px";

This is my answer to another question.

UPDATE 3: To customise the controls, you can use something like this.

Struct with template variables in C++

The syntax is wrong. The typedef should be removed.

HSL to RGB color conversion

Here's a fast, super-simple, branchless version in GLSL:

vec3 hsl2rgb( vec3 c ) {
    vec3 rgb = clamp(abs(mod(c.x*6.0 + vec3(0.0, 4.0, 2.0), 6.0)-3.0)-1.0, 0.0, 1.0);
    return c.z + c.y * (rgb-0.5)*(1.0-abs(2.0*c.z-1.0));

Doesn't get much shorter than that ~

Link to the original proof-of-concept:

(Disclaimer: not my code!)

What's the best way to parse a JSON response from the requests library?

You can use json.loads:

import json
import requests

response = requests.get(...)
json_data = json.loads(response.text)

This converts a given string into a dictionary which allows you to access your JSON data easily within your code.

Or you can use @Martijn's helpful suggestion, and the higher voted answer, response.json().

How do you run a .bat file from PHP?

This snippet is from working code.

You can trigger bat file not only from Windows GUI or Task Scheduler, but directly from PHP script when you need it. But in most cases it will have execution for 30-60 sec. depending from your PHP configuration. If job in BAT file is long and you don't want to freeze your PHP scripts, you need to fork BAT job as another process using php.exe and not be dependable from Apache.

This runs in background mode in Windows, seen as separate processes cmd.exe and php.exe from Task Manager not halting your Apache PHP scripts. The messages produced by your script may be stored and retrieved back via log files.

In my case in file_scanner.php I do some heavy calculations in loop for big array of files which may last for few hours with php function sleep() not to overload CPU.

The success poiner result from file $r which you can query via ajax if you want to know success or fauty start. In my case file_scanner.php writes log file with messages somefile.jpg - OK wich you can load to your UI with AJAX every few seconds to show progress.


 * Runs bat file in background mode
 function run_scanner() {

    $c='start /b D:\Web\\tasks\file_scanner.bat'; 
    $r=pclose(popen($c, 'r')); 
    return json_encode(array('result'=>$r));



@echo Off
D:\PHP\php.exe D:\Web\\tasks\file_scanner.php > D:\Web\\tasks\file_scanner.log