Programs & Examples On #Jquery ui draggable

The jQuery UI Draggable plugin makes selected elements draggable with mouse movement.

Draw a connecting line between two elements

jsPlumb is an option available that supports drag and drop, as seen by its numerous demos, including the Flowchart demo.

It is available in a free Community edition, and a paid Toolkit edition.

The Toolkit edition wraps the Community edition with a comprehensive data binding layer, as well as several UI widgets for building applications and integrations for popular libraries, and is commercially licensed.

How to select lines between two marker patterns which may occur multiple times with awk/sed

This might work for you (GNU sed):

sed '/^abc$/,/^mno$/{//!b};d' file

Delete all lines except for those between lines starting abc and mno

Are iframes considered 'bad practice'?

The original frameset model (Frameset and Frame-elements) were very bad from a usability standpoint. IFrame vas a later invention which didn't have as many problems as the original frameset model, but it does have its drawback.

If you allow the user to navigate inside the IFrame, then links and bookmarks will not work as expected (because you bookmark the URL of the outer page, but not the URL of the iframe).

How do you fix a bad merge, and replay your good commits onto a fixed merge?

Rewriting Git history demands changing all the affected commit ids, and so everyone who's working on the project will need to delete their old copies of the repo, and do a fresh clone after you've cleaned the history. The more people it inconveniences, the more you need a good reason to do it - your superfluous file isn't really causing a problem, but if only you are working on the project, you might as well clean up the Git history if you want to!

To make it as easy as possible, I'd recommend using the BFG Repo-Cleaner, a simpler, faster alternative to git-filter-branch specifically designed for removing files from Git history. One way in which it makes your life easier here is that it actually handles all refs by default (all tags, branches, etc) but it's also 10 - 50x faster.

You should carefully follow the steps here: - but the core bit is just this: download the BFG jar (requires Java 6 or above) and run this command:

$ java -jar bfg.jar --delete-files filename.orig my-repo.git

Your entire repository history will be scanned, and any file named filename.orig (that's not in your latest commit) will be removed. This is considerably easier than using git-filter-branch to do the same thing!

Full disclosure: I'm the author of the BFG Repo-Cleaner.

Evaluate a string with a switch in C++

what about just have the option number:

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

int main()
    string s;
    int op;

    cin >> s >> op;
    switch (op) {
    case 1: break;
    case 2: break;

    return 0;

ps command doesn't work in docker container

Firstly, run the command below:

apt-get update && apt-get install procps

and then run:

ps -ef

Assign a login to a user created without login (SQL Server)

You have an orphaned user and this can't be remapped with ALTER USER (yet) becauses there is no login to map to. So, you need run CREATE LOGIN first.

If the database level user is

  • a Windows Login, the mapping will be fixed automatcially via the AD SID
  • a SQL Login, use "sid" from sys.database_principals for the SID option for the login


Edit, after comments and updates

The sid from sys.database_principals is for a Windows login.

So trying to create and re-map to a SQL Login will fail

Run this to get the Windows login

SELECT SUSER_SNAME(0x0105000000000009030000001139F53436663A4CA5B9D5D067A02390)

INSERT and UPDATE a record using cursors in oracle

This is a highly inefficient way of doing it. You can use the merge statement and then there's no need for cursors, looping or (if you can do without) PL/SQL.

MERGE INTO studLoad l
USING ( SELECT studId, studName FROM student ) s
ON (l.studId = s.studId)
  UPDATE SET l.studName = s.studName
   WHERE l.studName != s.studName
INSERT (l.studID, l.studName)
VALUES (s.studId, s.studName)

Make sure you commit, once completed, in order to be able to see this in the database.

To actually answer your question I would do it something like as follows. This has the benefit of doing most of the work in SQL and only updating based on the rowid, a unique address in the table.

It declares a type, which you place the data within in bulk, 10,000 rows at a time. Then processes these rows individually.

However, as I say this will not be as efficient as merge.


   cursor c_data is
    select b.rowid as rid, a.studId, a.studName
      from student a
      left outer join studLoad b
        on a.studId = b.studId
       and a.studName <> b.studName

   type t__data is table of c_data%rowtype index by binary_integer;
   t_data t__data;


   open c_data;
      fetch c_data bulk collect into t_data limit 10000;

      exit when t_data.count = 0;

      for idx in t_data.first .. t_data.last loop
         if t_data(idx).rid is null then
            insert into studLoad (studId, studName)
            values (t_data(idx).studId, t_data(idx).studName);
            update studLoad
               set studName = t_data(idx).studName
             where rowid = t_data(idx).rid
         end if;
      end loop;

   end loop;
   close c_data;


What does 'useLegacyV2RuntimeActivationPolicy' do in the .NET 4 config?

After a bit of time (and more searching), I found this blog entry by Jomo Fisher.

One of the recent problems we’ve seen is that, because of the support for side-by-side runtimes, .NET 4.0 has changed the way that it binds to older mixed-mode assemblies. These assemblies are, for example, those that are compiled from C++\CLI. Currently available DirectX assemblies are mixed mode. If you see a message like this then you know you have run into the issue:

Mixed mode assembly is built against version 'v1.1.4322' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.


The good news for applications is that you have the option of falling back to .NET 2.0 era binding for these assemblies by setting an app.config flag like so:

<startup useLegacyV2RuntimeActivationPolicy="true">
  <supportedRuntime version="v4.0"/>

So it looks like the way the runtime loads mixed-mode assemblies has changed. I can't find any details about this change, or why it was done. But the useLegacyV2RuntimeActivationPolicy attribute reverts back to CLR 2.0 loading.

Connecting to TCP Socket from browser using javascript

This will be possible via the navigator interface as shown below:

navigator.tcpPermission.requestPermission({remoteAddress:"", remotePort:6789}).then(
  () => {
    // Permission was granted
    // Create a new TCP client socket and connect to remote host
    var mySocket = new TCPSocket("", 6789);

    // Send data to server
    mySocket.writeable.write("Hello World").then(
        () => {

            // Data sent sucessfully, wait for response
            console.log("Data has been sent to server");
                ({ value, done }) => {
                    if (!done) {
                        // Response received, log it:
                        console.log("Data received from server:" + value);

                    // Close the TCP connection
        e => console.error("Sending error: ", e)

More details are outlined in the tcp-udp-sockets documentation.

Another alternative is to use Chrome Sockets

Creating connections

chrome.sockets.tcp.create({}, function(createInfo) {
    IP, PORT, onConnectedCallback);

Sending data

chrome.sockets.tcp.send(socketId, arrayBuffer, onSentCallback);

Receiving data

chrome.sockets.tcp.onReceive.addListener(function(info) {
  if (info.socketId != socketId)
  // is an arrayBuffer.

You can use also attempt to use HTML5 Web Sockets (Although this is not direct TCP communication):

var connection = new WebSocket('ws://IPAddress:Port');

connection.onopen = function () {
  connection.send('Ping'); // Send the message 'Ping' to the server

Your server must also be listening with a WebSocket server such as pywebsocket, alternatively you can write your own as outlined at Mozilla

How do you implement a Stack and a Queue in JavaScript?

The stack implementation is trivial as explained in the other answers.

However, I didn't find any satisfactory answers in this thread for implementing a queue in javascript, so I made my own.

There are three types of solutions in this thread:

  • Arrays - The worst solution, using array.shift() on a large array is very inefficient.
  • Linked lists - It's O(1) but using an object for each element is a bit excessive, especially if there are a lot of them and they are small, like storing numbers.
  • Delayed shift arrays - It consists of associating an index with the array. When an element is dequeued, the index moves forward. When the index reaches the middle of the array, the array is sliced in two to remove the first half.

Delayed shift arrays are the most satisfactory solution in my mind, but they still store everything in one large contiguous array which can be problematic, and the application will stagger when the array is sliced.

I made an implementation using linked lists of small arrays (1000 elements max each). The arrays behave like delayed shift arrays, except they are never sliced: when every element in the array is removed, the array is simply discarded.

The package is on npm with basic FIFO functionality, I just pushed it recently. The code is split into two parts.

Here is the first part

/** Queue contains a linked list of Subqueue */
class Subqueue <T> {
  public full() {
    return this.array.length >= 1000;

  public get size() {
    return this.array.length - this.index;

  public peek(): T {
    return this.array[this.index];

  public last(): T {
    return this.array[this.array.length-1];

  public dequeue(): T {
    return this.array[this.index++];

  public enqueue(elem: T) {

  private index: number = 0;
  private array: T [] = [];

  public next: Subqueue<T> = null;

And here is the main Queue class:

class Queue<T> {
  get length() {
    return this._size;

  public push(...elems: T[]) {
    for (let elem of elems) {
      if (this.bottom.full()) {
        this.bottom = = new Subqueue<T>();

    this._size += elems.length;

  public shift(): T {
    if (this._size === 0) {
      return undefined;

    const val =;
    if (this._size > 0 && === 0 && {
      // Discard current subqueue and point top to the one after =;
    return val;

  public peek(): T {

  public last(): T {
    return this.bottom.last();

  public clear() {
    this.bottom = = new Subqueue();
    this._size = 0;

  private top: Subqueue<T> = new Subqueue();
  private bottom: Subqueue<T> =;
  private _size: number = 0;

Type annotations (: X) can easily be removed to obtain ES6 javascript code.

How to execute command stored in a variable?

$cmd would just replace the variable with it's value to be executed on command line. eval "$cmd" does variable expansion & command substitution before executing the resulting value on command line

The 2nd method is helpful when you wanna run commands that aren't flexible eg.
for i in {$a..$b}
format loop won't work because it doesn't allow variables.
In this case, a pipe to bash or eval is a workaround.

Tested on Mac OSX 10.6.8, Bash 3.2.48

jQuery Mobile: Stick footer to bottom of page

Fixed basics

To enable this behavior on a header or footer, add the data-position="fixed" attribute to a jQuery Mobile header or footer element.

<div data-role="footer" data-position="fixed">
    <h1>Fixed Footer!</h1>

how to calculate binary search complexity

Let's say the iteration in Binary Search terminates after k iterations. At each iteration, the array is divided by half. So let’s say the length of the array at any iteration is n At Iteration 1,

Length of array = n

At Iteration 2,

Length of array = n/2

At Iteration 3,

Length of array = (n/2)/2 = n/22

Therefore, after Iteration k,

Length of array = n/2k

Also, we know that after After k divisions, the length of the array becomes 1 Therefore

Length of array = n/2k = 1
=> n = 2k

Applying log function on both sides:

=> log2 (n) = log2 (2k)
=> log2 (n) = k log2 (2)
As (loga (a) = 1)


As (loga (a) = 1)
k = log2 (n)

Hence the time complexity of Binary Search is

log2 (n)

Div Size Automatically size of content

If you are coming here, there is high chance width: min-content or width: max-content can fix your problem. This can force an element to use the smallest or largest space the browser could choose…

This is the modern solution. Here is a small tutorial for that.

There is also fit-content, which often works like min-content, but is more flexible. (But also has worse browser support.)

This is a quite new feature and some browsers do not support it yet, but browser support is growing. See the current browser status here.

How do you make strings "XML safe"?

1) You can wrap your text as CDATA like this:

    <![CDATA[Your text goes here. Btw: 5<6 and 6>5]]>


2) As already someone said: Escape those chars. E.g. like so:

5&lt;6 and 6&gt;5

How to change icon on Google map marker

var marker = new google.maps.Marker({
  position: myLatLng,
  map: map,
  icon: 'your-icon.png'

How can I declare optional function parameters in JavaScript?


With ES6, this is possible in exactly the manner you have described; a detailed description can be found in the documentation.

Old answer

Default parameters in JavaScript can be implemented in mainly two ways:

function myfunc(a, b)
    // use this if you specifically want to know if b was passed
    if (b === undefined) {
        // b was not passed
    // use this if you know that a truthy value comparison will be enough
    if (b) {
        // b was passed and has truthy value
    } else {
        // b was not passed or has falsy value
    // use this to set b to a default value (using truthy comparison)
    b = b || "default value";

The expression b || "default value" evaluates the value AND existence of b and returns the value of "default value" if b either doesn't exist or is falsy.

Alternative declaration:

function myfunc(a)
    var b;

    // use this to determine whether b was passed or not
    if (arguments.length == 1) {
        // b was not passed
    } else {
        b = arguments[1]; // take second argument

The special "array" arguments is available inside the function; it contains all the arguments, starting from index 0 to N - 1 (where N is the number of arguments passed).

This is typically used to support an unknown number of optional parameters (of the same type); however, stating the expected arguments is preferred!

Further considerations

Although undefined is not writable since ES5, some browsers are known to not enforce this. There are two alternatives you could use if you're worried about this:

b === void 0;
typeof b === 'undefined'; // also works for undeclared variables

Java: Convert a String (representing an IP) to InetAddress

From the documentation of InetAddress.getByName(String host):

The host name can either be a machine name, such as "", or a textual representation of its IP address. If a literal IP address is supplied, only the validity of the address format is checked.

So you can use it.

Maximum filename length in NTFS (Windows XP and Windows Vista)?

255 chars, though the complete path should not be longer than that as well. There is a nice table over at Wikipedia about this:

How to: Install Plugin in Android Studio

if you are on Linux (Ubuntu)... the go to File-> Settings-> Plugin and select plugin from respective location.

If you are on Mac OS... the go to File-> Preferences-> Plugin and select plugin from respective location.

How can I compile a Java program in Eclipse without running it?

Go to the project explorer block ... right click on project name select "Build Path"-----------> "Configuration Build Path"

then the pop up window will get open.

in this pop up window you will find 4 tabs. 1)source 2) project 3)Library 4)order and export

Click on 1) Source

select the project (under which that file is present which you want to compile)

and then click on ok....

Go to the workspace location of the project open a bin folder and search that class file ...

you will get that java file compiled...

just to cross verify check the changed timing.

hope this will help.


How do you check "if not null" with Eloquent?

If you wanted to use the DB facade:


Should a function have only one return statement?

Are there good reasons why it's a better practice to have only one return statement in a function?

Yes, there are:

  • The single exit point gives an excellent place to assert your post-conditions.
  • Being able to put a debugger breakpoint on the one return at the end of the function is often useful.
  • Fewer returns means less complexity. Linear code is generally simpler to understand.
  • If trying to simplify a function to a single return causes complexity, then that's incentive to refactor to smaller, more general, easier-to-understand functions.
  • If you're in a language without destructors or if you don't use RAII, then a single return reduces the number of places you have to clean up.
  • Some languages require a single exit point (e.g., Pascal and Eiffel).

The question is often posed as a false dichotomy between multiple returns or deeply nested if statements. There's almost always a third solution which is very linear (no deep nesting) with only a single exit point.

Update: Apparently MISRA guidelines promote single exit, too.

To be clear, I'm not saying it's always wrong to have multiple returns. But given otherwise equivalent solutions, there are lots of good reasons to prefer the one with a single return.

How to debug stored procedures with print statements?

If you're using MSSQL Server management studio print statements will print out under the messages tab not under the Results tab.

enter image description here

Print statements will appear there.

Cannot use mkdir in home directory: permission denied (Linux Lubuntu)

As @kirbyfan64sos notes in a comment, /home is NOT your home directory (a.k.a. home folder):

The fact that /home is an absolute, literal path that has no user-specific component provides a clue.

While /home happens to be the parent directory of all user-specific home directories on Linux-based systems, you shouldn't even rely on that, given that this differs across platforms: for instance, the equivalent directory on macOS is /Users.

What all Unix platforms DO have in common are the following ways to navigate to / refer to your home directory:

  • Using cd with NO argument changes to your home dir., i.e., makes your home dir. the working directory.
    • e.g.: cd # changes to home dir; e.g., '/home/jdoe'
  • Unquoted ~ by itself / unquoted ~/ at the start of a path string represents your home dir. / a path starting at your home dir.; this is referred to as tilde expansion (see man bash)
    • e.g.: echo ~ # outputs, e.g., '/home/jdoe'
  • $HOME - as part of either unquoted or preferably a double-quoted string - refers to your home dir. HOME is a predefined, user-specific environment variable:
    • e.g.: cd "$HOME/tmp" # changes to your personal folder for temp. files

Thus, to create the desired folder, you could use:

mkdir "$HOME/bin"  # same as: mkdir ~/bin

Note that most locations outside your home dir. require superuser (root user) privileges in order to create files or directories - that's why you ran into the Permission denied error.

Finding last index of a string in Oracle

Use -1 as the start position:

INSTR('JD-EQ-0001', '-', -1)

Why doesn't JavaScript have a last method?

Came here looking for an answer to this question myself. The slice answer is probably best, but I went ahead and created a "last" function just to practice extending prototypes, so I thought I would go ahead and share it. It has the added benefit over some other ones of letting you optionally count backwards through the array, and pull out, say, the second to last or third to last item. If you don't specify a count it just defaults to 1 and pulls out the last item.

Array.prototype.last = Array.prototype.last || function(count) {
    count = count || 1;
    var length = this.length;
    if (count <= length) {
        return this[length - count];
    } else {
        return null;

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
arr.last(); // returns 9
arr.last(4); // returns 6
arr.last(9); // returns 1
arr.last(10); // returns null

Capturing browser logs with Selenium WebDriver using Java

I assume it is something in the lines of:

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.logging.LogEntries;
import org.openqa.selenium.logging.LogEntry;
import org.openqa.selenium.logging.LogType;
import org.openqa.selenium.logging.LoggingPreferences;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class ChromeConsoleLogging {
    private WebDriver driver;

    public void setUp() {
        System.setProperty("", "c:\\path\\to\\chromedriver.exe");        
        DesiredCapabilities caps =;
        LoggingPreferences logPrefs = new LoggingPreferences();
        logPrefs.enable(LogType.BROWSER, Level.ALL);
        caps.setCapability(CapabilityType.LOGGING_PREFS, logPrefs);
        driver = new ChromeDriver(caps);

    public void tearDown() {

    public void analyzeLog() {
        LogEntries logEntries = driver.manage().logs().get(LogType.BROWSER);
        for (LogEntry entry : logEntries) {
            System.out.println(new Date(entry.getTimestamp()) + " " + entry.getLevel() + " " + entry.getMessage());
            //do something useful with the data

    public void testMethod() {
        //do something on page

Source : Get chrome's console log

How to redirect in a servlet filter?

If you also want to keep hash and get parameter, you can do something like this (fill redirectMap at filter init):

String uri = request.getRequestURI();

String[] uriParts = uri.split("[#?]");
String path = uriParts[0];
String rest = uri.substring(uriParts[0].length());

if(redirectMap.containsKey(path)) {
    response.sendRedirect(redirectMap.get(path) + rest);
} else {
    chain.doFilter(request, response);

How to check type of files without extensions in python?

also you can use this code (pure python by 3 byte of header file):

full_path = os.path.join(MEDIA_ROOT, pathfile)

    image_data = open(full_path, "rb").read()
except IOError:
    return "Incorrect Request :( !!!"

header_byte = image_data[0:3].encode("hex").lower()

if header_byte == '474946':
    return "image/gif"
elif header_byte == '89504e':
    return "image/png"
elif header_byte == 'ffd8ff':
    return "image/jpeg"
    return "binary file"

without any package install [and update version]

Make absolute positioned div expand parent div height

This question was asked in 2012 before flexbox. The correct way to solve this problem using modern CSS is with a media query and a flex column reversal for mobile devices. No absolute positioning is needed.


<div class="parent">
  <div style="background-color:lightgrey;">
      I stay on top on desktop and I'm on bottom on mobile
  <div style="background-color:grey;">
      I stay on bottom on desktop and I'm on top on mobile


.parent {
  display: flex;
  flex-direction: column;

@media (max-width: 768px) {
  .parent {
    flex-direction: column-reverse;

How do I use Maven through a proxy?

if you are new to proxy setup for Maven In my case first go and check your Home Folder weather there is .m2 folder and in it there should be a file named settings.xml if not create it , and paste this and change host and port,then if needed change the nonProxyHosts

Home Folder - C:\Users\ {UserName}



If any case this does not success go and do the changes in this location of Home Folder


I am using Eclipse as my IDE
Hope this will help !!

Note: To remove the proxy just move settings.xml to some where else

How to write new line character to a file in Java


File file = new File("F:/ABC.TXT");
FileWriter fileWriter = new FileWriter(file,true);

Deserialize JSON string to c# object

I think the JavaScriptSerializer does not create a dynamic object.

So you should define the class first:

class MyObj {
    public int arg1 {get;set;}
    public int arg2 {get;set;}

And deserialize that instead of object:


Not testet, please try.

Where to get this Java.exe file for a SQL Developer installation

Hhere is what what I did to fix it:


  • Make sure JDK is installed (Not JRE).
  • Make sure Oracle is installed


  1. Open the file ..\sqldeveloper\sqldeveloper\bin\sqldevloper.conf and add the following line to set jdk path:

    SetJavaHome C:\Program Files\Oracle\11g\product\11.1.0\client_1\jdk

    If it dont allow you to save the file, copy whole sqldeveloper folder to a different location where you have write access to modify this file.

  2. Run sqldeveloper.exe (from the new place if you moved the folder out from oracle folders) as administrator and enter the jdk path that comes with your oracle installation: e.g. C:\Program Files\Oracle\11g\product\11.1.0\client_1\jdk\bin

lists and arrays in VBA

You will have to change some of your data types but the basics of what you just posted could be converted to something similar to this given the data types I used may not be accurate.

Dim DateToday As String: DateToday = Format(Date, "yyyy/MM/dd")
Dim Computers As New Collection
Dim disabledList As New Collection
Dim compArray(1 To 1) As String

'Assign data to first item in array
compArray(1) = "asdf"

'Format = Item, Key
Computers.Add "ErrorState", "Computer Name"

'Prints "ErrorState"
Debug.Print Computers("Computer Name")

Collections cannot be sorted so if you need to sort data you will probably want to use an array.

Here is a link to the outlook developer reference.

Another great site to help you get started is

Moving everything over to VBA from VB.Net is not going to be simple since not all the data types are the same and you do not have the .Net framework. If you get stuck just post the code you're stuck converting and you will surely get some help!


Sub ArrayExample()
    Dim subject As String
    Dim TestArray() As String
    Dim counter As Long

    subject = "Example"
    counter = Len(subject)

    ReDim TestArray(1 To counter) As String

    For counter = 1 To Len(subject)
        TestArray(counter) = Right(Left(subject, counter), 1)
End Sub

How to build an android library with Android Studio and gradle?

Note: This answer is a pure Gradle answer, I use this in IntelliJ on a regular basis but I don't know how the integration is with Android Studio. I am a believer in knowing what is going on for me, so this is how I use Gradle and Android.

TL;DR Full Example -

Disclaimer: This is a project I am/was working on.

Gradle has a defined structure ( that you can change, link at the bottom tells you how ) that is very similar to Maven if you have ever used it.

Project Root
+-- src
|   +-- main (your project)
|   |   +-- java (where your java code goes)
|   |   +-- res  (where your res go)
|   |   +-- assets (where your assets go)
|   |   \-- AndroidManifest.xml
|   \-- instrumentTest (test project)
|       \-- java (where your java code goes)
+-- build.gradle
\-- settings.gradle

If you only have the one project, the settings.gradle file isn't needed. However you want to add more projects, so we need it.

Now let's take a peek at that build.gradle file. You are going to need this in it (to add the android tools)


buildscript {
    repositories {
    dependencies {
        classpath ''

Now we need to tell Gradle about some of the Android parts. It's pretty simple. A basic one (that works in most of my cases) looks like the following. I have a comment in this block, it will allow me to specify the version name and code when generating the APK.


apply plugin: "android"
android {
        compileSdkVersion 17
        defaultConfig {
            versionCode = 1
            versionName = "0.0.0"

Something we are going to want to add, to help out anyone that hasn't seen the light of Gradle yet, a way for them to use the project without installing it.


task wrapper(type: org.gradle.api.tasks.wrapper.Wrapper) {
    gradleVersion = '1.4'

So now we have one project to build. Now we are going to add the others. I put them in a directory, maybe call it deps, or subProjects. It doesn't really matter, but you will need to know where you put it. To tell Gradle where the projects are you are going to need to add them to the settings.gradle.

Directory Structure:

Project Root
+-- src (see above)
+-- subProjects (where projects are held)
|   +-- reallyCoolProject1 (your first included project)
|       \-- See project structure for a normal app
|   \-- reallyCoolProject2 (your second included project)
|       \-- See project structure for a normal app
+-- build.gradle
\-- settings.gradle


include ':subProjects:reallyCoolProject1'
include ':subProjects:reallyCoolProject2'

The last thing you should make sure of is the subProjects/reallyCoolProject1/build.gradle has apply plugin: "android-library" instead of apply plugin: "android".

Like every Gradle project (and Maven) we now need to tell the root project about it's dependency. This can also include any normal Java dependencies that you want.


    compile 'com.fasterxml.jackson.core:jackson-core:2.1.4'
    compile 'com.fasterxml.jackson.core:jackson-databind:2.1.4'
    compile project(":subProjects:reallyCoolProject1")
    compile project(':subProjects:reallyCoolProject2')

I know this seems like a lot of steps, but they are pretty easy once you do it once or twice. This way will also allow you to build on a CI server assuming you have the Android SDK installed there.

NDK Side Note: If you are going to use the NDK you are going to need something like below. Example build.gradle file can be found here:


task copyNativeLibs(type: Copy) {
    from fileTree(dir: 'libs', include: '**/*.so' )  into  'build/native-libs'
tasks.withType(Compile) { compileTask -> compileTask.dependsOn copyNativeLibs }

clean.dependsOn 'cleanCopyNativeLibs'

tasks.withType( { pkgTask ->
  pkgTask.jniDir new File('build/native-libs')



How often does python flush to a file?

For file operations, Python uses the operating system's default buffering unless you configure it do otherwise. You can specify a buffer size, unbuffered, or line buffered.

For example, the open function takes a buffer size argument.

"The optional buffering argument specifies the file’s desired buffer size:"

  • 0 means unbuffered,
  • 1 means line buffered,
  • any other positive value means use a buffer of (approximately) that size.
  • A negative buffering means to use the system default, which is usually line buffered for tty devices and fully buffered for other files.
  • If omitted, the system default is used.


bufsize = 0
f = open('file.txt', 'w', buffering=bufsize)

Executing a stored procedure within a stored procedure

T-SQL is not asynchronous, so you really have no choice but to wait until SP2 ends. Luckily, that's what you want.

   PRINT 'Done'

Creating a select box with a search option

Full option searchable select box

This also supports Control buttons keyboards such as ArrowDown ArrowUp and Enter keys

function filterFunction(that, event) {_x000D_
    let container, input, filter, li, input_val;_x000D_
    container = $(that).closest(".searchable");_x000D_
    input_val = container.find("input").val().toUpperCase();_x000D_
    if (["ArrowDown", "ArrowUp", "Enter"].indexOf(event.key) != -1) {_x000D_
        keyControl(event, container)_x000D_
    } else {_x000D_
        li = container.find("ul li");_x000D_
        li.each(function (i, obj) {_x000D_
            if ($(this).text().toUpperCase().indexOf(input_val) > -1) {_x000D_
            } else {_x000D_
        container.find("ul li").removeClass("selected");_x000D_
        setTimeout(function () {_x000D_
            container.find("ul li:visible").first().addClass("selected");_x000D_
        }, 100)_x000D_
function keyControl(e, container) {_x000D_
    if (e.key == "ArrowDown") {_x000D_
        if (container.find("ul li").hasClass("selected")) {_x000D_
            if (container.find("ul li:visible").index(container.find("ul li.selected")) + 1 < container.find("ul li:visible").length) {_x000D_
                container.find("ul li.selected").removeClass("selected").nextAll().not('[style*="display: none"]').first().addClass("selected");_x000D_
        } else {_x000D_
            container.find("ul li:first-child").addClass("selected");_x000D_
    } else if (e.key == "ArrowUp") {_x000D_
        if (container.find("ul li:visible").index(container.find("ul li.selected")) > 0) {_x000D_
            container.find("ul li.selected").removeClass("selected").prevAll().not('[style*="display: none"]').first().addClass("selected");_x000D_
    } else if (e.key == "Enter") {_x000D_
        container.find("input").val(container.find("ul li.selected").text()).blur();_x000D_
        onSelect(container.find("ul li.selected").text())_x000D_
    container.find("ul li.selected")[0].scrollIntoView({_x000D_
        behavior: "smooth",_x000D_
function onSelect(val) {_x000D_
$(".searchable input").focus(function () {_x000D_
    $(this).closest(".searchable").find("ul li").show();_x000D_
$(".searchable input").blur(function () {_x000D_
    let that = this;_x000D_
    setTimeout(function () {_x000D_
    }, 300);_x000D_
$(document).on('click', '.searchable ul li', function () {_x000D_
$(".searchable ul li").hover(function () {_x000D_
    $(this).closest(".searchable").find("ul li.selected").removeClass("selected");_x000D_
div.searchable {_x000D_
    width: 300px;_x000D_
    float: left;_x000D_
    margin: 0 15px;_x000D_
.searchable input {_x000D_
    width: 100%;_x000D_
    height: 50px;_x000D_
    font-size: 18px;_x000D_
    padding: 10px;_x000D_
    -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */_x000D_
    -moz-box-sizing: border-box; /* Firefox, other Gecko */_x000D_
    box-sizing: border-box; /* Opera/IE 8+ */_x000D_
    display: block;_x000D_
    font-weight: 400;_x000D_
    line-height: 1.6;_x000D_
    color: #495057;_x000D_
    background-color: #fff;_x000D_
    background-clip: padding-box;_x000D_
    border: 1px solid #ced4da;_x000D_
    border-radius: .25rem;_x000D_
    transition: border-color .15s ease-in-out, box-shadow .15s ease-in-out;_x000D_
    background: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='' viewBox='0 0 4 5'%3E%3Cpath fill='%23343a40' d='M2 0L0 2h4zm0 5L0 3h4z'/%3E%3C/svg%3E") no-repeat right .75rem center/8px 10px;_x000D_
.searchable ul {_x000D_
    display: none;_x000D_
    list-style-type: none;_x000D_
    background-color: #fff;_x000D_
    border-radius: 0 0 5px 5px;_x000D_
    border: 1px solid #add8e6;_x000D_
    border-top: none;_x000D_
    max-height: 180px;_x000D_
    margin: 0;_x000D_
    overflow-y: scroll;_x000D_
    overflow-x: hidden;_x000D_
    padding: 0;_x000D_
.searchable ul li {_x000D_
    padding: 7px 9px;_x000D_
    border-bottom: 1px solid #e1e1e1;_x000D_
    cursor: pointer;_x000D_
    color: #6e6e6e;_x000D_
.searchable ul li.selected {_x000D_
    background-color: #e8e8e8;_x000D_
    color: #333;_x000D_
<script src=""></script>_x000D_
<div class="searchable">_x000D_
    <input type="text" placeholder="search countries" onkeyup="filterFunction(this,event)">_x000D_
        <li>Iran (Islamic Republic of)</li>_x000D_
        <li>Lao People's Democratic Republic</li>_x000D_
        <li>Micronesia (Federated States of)</li>_x000D_

How to start new activity on button click

Create an intent to a ViewPerson activity and pass the PersonID (for a database lookup, for example).

Intent i = new Intent(getBaseContext(), ViewPerson.class);                      
i.putExtra("PersonID", personID);

Then in ViewPerson Activity, you can get the bundle of extra data, make sure it isn't null (in case if you sometimes don't pass data), then get the data.

Bundle extras = getIntent().getExtras();
if(extras !=null)
     personID = extras.getString("PersonID");

Now if you need to share data between two Activities, you can also have a Global Singleton.

public class YourApplication extends Application 
     public SomeDataClass data = new SomeDataClass();

Then call it in any activity by:

YourApplication appState = ((YourApplication)this.getApplication());; // Do whatever you need to with data here.  Could be setter/getter or some other type of logic

Python unittest passing arguments

Another method for those who really want to do this in spite of the correct remarks that you shouldn't:

import unittest

class MyTest(unittest.TestCase):

    def __init__(self, testName, extraArg):
        super(MyTest, self).__init__(testName)  # calling the super class init varies for different python versions.  This works for 2.7
        self.myExtraArg = extraArg

    def test_something(self):

# call your test
suite = unittest.TestSuite()
suite.addTest(MyTest('test_something', extraArg))

$("#form1").validate is not a function

Probably the browser first downloaded the validade script and then jQuery. If the validade script be downloaded before loading jQuery you'll get an error. You can see this using a tool like firebug.

Try this:

<script src=""></script>
    function LoadValidade() {
        var a = false;
        try {
            var teste = $('*');
            if(teste == null)
                throw 1;
        } catch (e) { 
            a = true; 

        if (a){ 
            setTimeout(LoadValidade, 300);

        var validadeScript = document.createElement("script");
        validadeScript.src = "../common/jquery.validate.js";
    setTimeout(LoadValidade, 300);

No Application Encryption Key Has Been Specified

In my case, while cloning the project from git there was no .env

file. So I copy the .env file from the source project and paste in my current project and change its configuration of database and it run successfully.

How can I count the number of elements with same class?


The document.getElementsByClassName("classstringhere") method returns an array of all the elements with that class name, so .length gives you the amount of them.

XAMPP PORT 80 is Busy / EasyPHP error in Apache configuration file:

I've found that the biggest culprit for taking up port 80 on newer Windows installs is the BranchCache Service (#3) in this list...

  1. SQL Server Reporting Services

  2. Web Deployment Agent Service

  3. BranchCache

  4. World Wide Web Publishing Service

These 4 service probably cover 90% of the native Windows Services that take up port 80.

The other 10% is the hidden HTTP.sys service/driver which takes port 80 when another service requests it. Run this to disable it, and reboot.

sc config http start= disabled

Aside from Skype, TeamViewer is also very commonly installed software, and will take port 80 if not configured otherwise.

List taken from: Opening Up Port 80 For Apache to Use On Windows

Are arrays in PHP copied as value or as reference to new variables, and when passed to functions?

To extend one of the answers, also subarrays of multidimensional arrays are passed by value unless passed explicitely by reference.

$foo = array( array(1,2,3), 22, 33);

function hello($fooarg) {
  $fooarg[0][0] = 99;

function world(&$fooarg) {
  $fooarg[0][0] = 66;

var_dump($foo); // (original array not modified) array passed-by-value

var_dump($foo); // (original array modified) array passed-by-reference

The result is:

array(3) {
  array(3) {
array(3) {
  array(3) {

Inner join with 3 tables in mysql

The correct statement should be :

FROM grade
  INNER JOIN student
    ON student.studentId = grade.fk_studentId
    ON exam.examId = grade.fk_examId

A table is refered to other on the basis of the foreign key relationship defined. You should refer the ids properly if you wish the data to show as queried. So you should refer the id's to the proper foreign keys in the table rather than just on the id which doesn't define a proper relation

Count number of vector values in range with R

Use which:

 x <- sample(10, 50, replace = TRUE)
 length(which(x > 3 & x < 5))
 # [1]  6

Passing HTML to template using Flask/Jinja2

the ideal way is to

{{ something|safe }}

than completely turning off auto escaping.

Get GMT Time in Java

The following code will get the date minus timezone offset:

protected Date toGmt0(ZonedDateTime time) {
    ZonedDateTime gmt0 = time.minusSeconds(time.getOffset().getTotalSeconds());
    return Date.from(gmt0.toInstant());

public void test() {

    ZonedDateTime now =;
    Date dateAtSystemZone = Date.from(now.toInstant());
    Date dateAtGmt0 = toGmt0(now);

    SimpleDateFormat sdfWithoutZone = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
    SimpleDateFormat sdfWithZoneGmt0 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS", Locale.ITALIAN);

            + "\ndateAtSystemZone          = " + dateAtSystemZone
            + "\ndateAtGmt0                = " + dateAtGmt0
            + "\ndiffInMillis              = " + (dateAtSystemZone.getTime() - dateAtGmt0.getTime())
            + "\n"
            + "\ndateWithSystemZone.format = " + sdfWithoutZone.format(dateAtSystemZone)
            + "\ndateAtGmt0.format         = " + sdfWithoutZone.format(dateAtGmt0)
            + "\n"
            + "\ndateFormatWithGmt0        = " + sdfWithZoneGmt0.format(dateAtSystemZone)

output :

dateAtSystemZone          = Thu Apr 23 14:03:36 CST 2020
dateAtGmt0                = Thu Apr 23 06:03:36 CST 2020
diffInMillis              = 28800000

dateWithSystemZone.format = 2020-04-23 14:03:36.140
dateAtGmt0.format         = 2020-04-23 06:03:36.140

dateFormatWithGmt0        = 2020-04-23 06:03:36.140

My system is at GMT+8, so diffInMillis = 28800000 = 8 * 60 * 60 * 1000?

Creating object with dynamic keys

You can't define an object literal with a dynamic key. Do this :

var o = {};
o[key] = value;
return o;

There's no shortcut (edit: there's one now, with ES6, see the other answer).

Keyboard shortcuts in WPF

I had a similar problem and found @aliwa's answer to be the most helpful and most elegant solution; however, I needed a specific key combination, Ctrl + 1. Unfortunately I got the following error:

'1' cannot be used as a value for 'Key'. Numbers are not valid enumeration values.

With a bit of further search, I modified @aliwa's answer to the following:

    <KeyBinding Gesture="Ctrl+1" Command="{Binding MyCommand}"/>

I found this to work great for pretty well any combination I needed.

Adding 30 minutes to time formatted as H:i in PHP

Just to expand on previous answers, a function to do this could work like this (changing the time and interval formats however you like them according to this for, and this for DateInterval):

// Return adjusted start and end times as an array.

function expandTimeByMinutes( $time, $beforeMinutes, $afterMinutes ) {

    $time = DateTime::createFromFormat( 'H:i', $time );
    $time->sub( new DateInterval( 'PT' . ( (integer) $beforeMinutes ) . 'M' ) );
    $startTime = $time->format( 'H:i' );
    $time->add( new DateInterval( 'PT' . ( (integer) $beforeMinutes + (integer) $afterMinutes ) . 'M' ) );
    $endTime = $time->format( 'H:i' );

    return [
        'startTime' => $startTime,
        'endTime'   => $endTime,

$adjustedStartEndTime = expandTimeByMinutes( '10:00', 30, 30 );

echo '<h1>Adjusted Start Time: ' . $adjustedStartEndTime['startTime'] . '</h1>' . PHP_EOL . PHP_EOL;
echo '<h1>Adjusted End Time: '   . $adjustedStartEndTime['endTime']   . '</h1>' . PHP_EOL . PHP_EOL;

How to export data from Excel spreadsheet to Sql Server 2008 table

From your SQL Server Management Studio, you open Object Explorer, go to your database where you want to load the data into, right click, then pick Tasks > Import Data.

This opens the Import Data Wizard, which typically works pretty well for importing from Excel. You can pick an Excel file, pick what worksheet to import data from, you can choose what table to store it into, and what the columns are going to be. Pretty flexible indeed.

You can run this as a one-off, or you can store it as a SQL Server Integration Services (SSIS) package into your file system, or into SQL Server itself, and execute it over and over again (even scheduled to run at a given time, using SQL Agent).

Update: yes, yes, yes, you can do all those things you keep asking - have you even tried at least once to run that wizard??

OK, here it comes - step by step:

Step 1: pick your Excel source

enter image description here

Step 2: pick your SQL Server target database

enter image description here

Step 3: pick your source worksheet (from Excel) and your target table in your SQL Server database; see the "Edit Mappings" button!

enter image description here

Step 4: check (and change, if needed) your mappings of Excel columns to SQL Server columns in the table:

enter image description here

Step 5: if you want to use it later on, save your SSIS package to SQL Server:

enter image description here

Step 6: - success! This is on a 64-bit machine, works like a charm - just do it!!

set the width of select2 input (through Angular-ui directive)

This is an old question but new info is still worth posting...

Starting with Select2 version 3.4.0 there is an attribute dropdownAutoWidth which solves the problem and handles all the odd cases. Note it is not on by default. It resizes dynamically as the user makes selections, it adds width for allowClear if that attribute is used, and it handles placeholder text properly too.

    dropdownAutoWidth : true

How do you divide each element in a list by an int?

myList=[tmpList/myInt for tmpList in range(10,100,10)]

UILabel with text of two different colors

Here you go

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:lblTemp.text];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];
lblTemp.attributedText = string;

SQL: Select columns with NULL values only

You might need to clarify a bit. What are you really trying to accomplish? If you really want to find out the column names that only contain null values, then you will have to loop through the scheama and do a dynamic query based on that.

I don't know which DBMS you are using, so I'll put some pseudo-code here.

for each col
  @cmd = 'if not exists (select * from tablename where ' + col + ' is not null begin print ' + col + ' end'

How do I access Configuration in any class in ASP.NET Core?

In 8-2017 Microsoft came out with System.Configuration for .NET CORE v4.4. Currently v4.5 and v4.6 preview.

For those of us, who works on transformation from .Net Framework to CORE, this is essential. It allows to keep and use current app.config files, which can be accessed from any assembly. It is probably even can be an alternative to appsettings.json, since Microsoft realized the need for it. It works same as before in FW. There is one difference:

In the web applications, [e.g. ASP.NET CORE WEB API] you need to use app.config and not web.config for your appSettings or configurationSection. You might need to use web.config but only if you deploying your site via IIS. You place IIS-specific settings into web.config

I've tested it with netstandard20 DLL and Core Web Api and it is all working.

How to solve error: "Clock skew detected"?

please try to do

make clean

(instead of make), then



Sort an ArrayList based on an object field

You can use the Bean Comparator to sort on any property in your custom class.

What does request.getParameter return?

Both if (one.length() > 0) {} and if (!"".equals(one)) {} will check against an empty foo parameter, and an empty parameter is what you'd get if the the form is submitted with no value in the foo text field.

If there's any chance you can use the Expression Language to handle the parameter, you could access it with empty in an expression.

<c:if test='${not empty}'>
    This page code gets rendered.

Why is using "" for array iteration a bad idea?

The problem with for ... in ... — and this only becomes a problem when a programmer doesn't really understand the language; it's not really a bug or anything — is that it iterates over all members of an object (well, all enumerable members, but that's a detail for now). When you want to iterate over just the indexed properties of an array, the only guaranteed way to keep things semantically consistent is to use an integer index (that is, a for (var i = 0; i < array.length; ++i) style loop).

Any object can have arbitrary properties associated with it. There would be nothing terrible about loading additional properties onto an array instance, in particular. Code that wants to see only indexed array-like properties therefore must stick to an integer index. Code that is fully aware of what for ... in does and really need to see all properties, well then that's ok too.

Replace part of a string with another string

With C++11 you can use std::regex like so:

#include <regex>
std::string string("hello $name");
string = std::regex_replace(string, std::regex("\\$name"), "Somename");

The double backslash is required for escaping an escape character.

How do I simulate a hover with a touch in touch enabled browsers?

Easyest solution I found: I had some < span > tags with :hover css rules in them. I switched for < a href="javascript:void(0)" > and voilà. The hover styles in iOS started working.

Moving all files from one directory to another using Python

For example, if I wanted to move all .txt files from one location to another ( on a Windows OS for instance ) I would do it something like this:

import shutil
import os,glob

inpath = 'R:/demo/in' 
outpath = 'R:/demo/out'

for file in glob.glob("*.txt"):


How to directly move camera to current location in Google Maps Android API v2?

Just change moveCamera to animateCamera like below

Googlemap.animateCamera(CameraUpdateFactory.newLatLngZoom(locate, 16F))

'^M' character at end of lines

To replace ^M characters in vi editor use below

open the text file say t1.txt

vi t1.txt

Enter command mode by pressing shift + :

then press keys as mentioned %s/^M/\r/g

in above ^M is not (shift + 6)M instead it is (ctrl + V)(ctrl + M)

How to create loading dialogs in Android?

It's a ProgressDialog, with setIndeterminate(true).


ProgressDialog dialog =, "", 
                    "Loading. Please wait...", true);

An indeterminate progress bar doesn't actually show a bar, it shows a spinning activity circle thing. I'm sure you know what I mean :)

How to overwrite styling in Twitter Bootstrap

All these tips will work, but a simpler way might be to include your stylesheet after the Bootstrap styles.

If you include your css (site-specific.css) after Bootstrap's (bootstrap.css), you can override rules by redefining them.

For example, if this is how you include CSS in your <head>

<link rel="stylesheet" href="css/bootstrap.css" />
<link rel="stylesheet" href="css/site-specific.css" />

You can simply move the sidebar to the right by writing (in your site-specific.css file):

.sidebar {
    float: right;

Forgive the lack of HAML and SASS, I do not know them well enough to write tutorials in them.

What is a simple C or C++ TCP server and client example?

Here are some examples for:

1) Simple
2) Fork
3) Threads

based server:

Get month name from Date

Another way to format date

new Date().toLocaleString('en-us',{month:'long', year:'numeric', day:'numeric'}) //output: "May 21, 2019"

Grant Select on all Tables Owned By Specific User

Well, it's not a single statement, but it's about as close as you can get with oracle:

   FOR R IN (SELECT owner, table_name FROM all_tables WHERE owner='TheOwner') LOOP
      EXECUTE IMMEDIATE 'grant select on '||R.owner||'.'||R.table_name||' to TheUser';

What is the default maximum heap size for Sun's JVM from Java SE 6?

With JDK, You can also use jinfo to connect to the JVM for the <PROCESS_ID> in question and get the value for MaxHeapSize:

jinfo -flag MaxHeapSize <PROCESS_ID>

What’s the best way to check if a file exists in C++? (cross platform)

How about access?

#include <io.h>

if (_access(filename, 0) == -1)
    // File does not exist

Get the generated SQL statement from a SqlCommand object?

Profiler is hands-down your best option.

You might need to copy a set of statements from profiler due to the prepare + execute steps involved.

cocoapods - 'pod install' takes forever

Updated answer for 2019 - the cocoa pods team moved to using their own CDN which solves this issue, which was due to GitHub rate limiting, as described here:

TL;DR You need to change the source line in your Podfile to this:

source ''

how to get the host url using javascript from the current page

let path = window.location.protocol + '//' + window.location.hostname + ':' + window.location.port;

Position absolute but relative to parent

#father {
   position: relative;

#son1 {
   position: absolute;
   top: 0;

#son2 {
   position: absolute;
   bottom: 0;

This works because position: absolute means something like "use top, right, bottom, left to position yourself in relation to the nearest ancestor who has position: absolute or position: relative."

So we make #father have position: relative, and the children have position: absolute, then use top and bottom to position the children.

Maven Java EE Configuration Marker with Java Server Faces 1.2

Eclipse is buggy on factes screen and at times doesn't update the config files in workspace. There are two options one can try :

  1. Go to org.eclipse.wst.common.project.facet.core.xml file located inside .settings folder of eclipse project. Go and manually delete the JSF facet entry. you can also update other facets as well.

  2. Right click project and go to properties->Maven-->Java EE Integeration. choose options : enable project specific settings, Enable Java EE configuration, Maven archiver generates files under the build directory

How can I use grep to find a word inside a folder?

grep -nr 'yourString*' .

The dot at the end searches the current directory. Meaning for each parameter:

-n            Show relative line number in the file
'yourString*' String for search, followed by a wildcard character
-r            Recursively search subdirectories listed
.             Directory for search (current directory)

grep -nr 'MobileAppSer*' . (Would find or MobileAppServlet.class or MobileAppServlet.txt; 'MobileAppASer*.*' is another way to do the same thing.)

To check more parameters use man grep command.

Create an Android GPS tracking application

The source code for the Android mobile application open-gpstracker which you appreciated is available here.

You can checkout the code using SVN client application or via Git:

Debugging the source code will surely help you.

Why is ZoneOffset.UTC != ZoneId.of("UTC")?

The answer comes from the javadoc of ZoneId (emphasis mine) ...

A ZoneId is used to identify the rules used to convert between an Instant and a LocalDateTime. There are two distinct types of ID:

  • Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses the same offset for all local date-times
  • Geographical regions - an area where a specific set of rules for finding the offset from UTC/Greenwich apply

Most fixed offsets are represented by ZoneOffset. Calling normalized() on any ZoneId will ensure that a fixed offset ID will be represented as a ZoneOffset.

... and from the javadoc of ZoneId#of (emphasis mine):

This method parses the ID producing a ZoneId or ZoneOffset. A ZoneOffset is returned if the ID is 'Z', or starts with '+' or '-'.

The argument id is specified as "UTC", therefore it will return a ZoneId with an offset, which also presented in the string form:




As you use the equals method for comparison, you check for object equivalence. Because of the described difference, the result of the evaluation is false.

When the normalized() method is used as proposed in the documentation, the comparison using equals will return true, as normalized() will return the corresponding ZoneOffset:

Normalizes the time-zone ID, returning a ZoneOffset where possible.

    .equals(now.withZoneSameInstant(ZoneId.of("UTC").normalized())); // true

As the documentation states, if you use "Z" or "+0" as input id, of will return the ZoneOffset directly and there is no need to call normalized():

now.withZoneSameInstant(ZoneOffset.UTC).equals(now.withZoneSameInstant(ZoneId.of("Z"))); //true
now.withZoneSameInstant(ZoneOffset.UTC).equals(now.withZoneSameInstant(ZoneId.of("+0"))); //true

To check if they store the same date time, you can use the isEqual method instead:

    .isEqual(now.withZoneSameInstant(ZoneId.of("UTC"))); // true


System.out.println("equals - ZoneId.of(\"UTC\"): " + nowZoneOffset
System.out.println("equals - ZoneId.of(\"UTC\").normalized(): " + nowZoneOffset
System.out.println("equals - ZoneId.of(\"Z\"): " + nowZoneOffset
System.out.println("equals - ZoneId.of(\"+0\"): " + nowZoneOffset
System.out.println("isEqual - ZoneId.of(\"UTC\"): "+ nowZoneOffset


equals - ZoneId.of("UTC"): false
equals - ZoneId.of("UTC").normalized(): true
equals - ZoneId.of("Z"): true
equals - ZoneId.of("+0"): true
isEqual - ZoneId.of("UTC"): true

Convert text into number in MySQL query

cast(REGEXP_REPLACE(NameNumber, '[^0-9]', '') as UNSIGNED)

"End of script output before headers" error in Apache

Had the same error on raspberry-pi. I fixed it by adding -w to the shebang

#!/usr/bin/perl -w

How to implement a ViewPager with different Fragments / Layouts

This is also fine:

public class MainActivity extends FragmentActivity {
    public void onCreate(Bundle savedInstanceState) {

        ViewPager pager = (ViewPager) findViewById(;
        pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));


public class FragmentTab1 extends Fragment {
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragmenttab1, container, false);
        return rootView;

class MyPagerAdapter extends FragmentPagerAdapter{

    public MyPagerAdapter(FragmentManager fragmentManager){

    public getItem(int position) {
            case 0:
                FragmentTab1 fm =   new FragmentTab1();
                return fm;
            case 1: return new FragmentTab2();
            case 2: return new FragmentTab3();
        return null;

    public int getCount() {
        return 3;
<RelativeLayout xmlns:android=""
    android:layout_height="match_parent" >

        android:text="@string/Fragment1" />


How do I make Git use the editor of my choice for commits?

Mvim as your git editor

Like all the other GUI applications, you have to launch mvim with the wait flag.

git config --global core.editor "mvim --remote-wait"

Get and Set Screen Resolution

in Winforms, there is a Screen class you can use to get data about screen dimensions and color depth for all displays connected to the computer. Here's the docs page:

CHANGING the screen resolution is trickier. There is a Resolution third party class that wraps the native code you'd otherwise hook into. Use its CResolution nested class to set the screen resolution to a new height and width; but understand that doing this will only work for height/width combinations the display actually supports (800x600, 1024x768, etc, not 817x435).

image.onload event and browser cache

As you're generating the image dynamically, set the onload property before the src.

var img = new Image();
img.onload = function () {
   alert("image is loaded");
img.src = "img.jpg";

Fiddle - tested on latest Firefox and Chrome releases.

You can also use the answer in this post, which I adapted for a single dynamically generated image:

var img = new Image();
// 'load' event
$(img).on('load', function() {
  alert("image is loaded");
img.src = "img.jpg";


How should I pass multiple parameters to an ASP.Net Web API GET?

Just add a new route to the WebApiConfig entries.

For instance, to call:

public IEnumerable<SampleObject> Get(int pageNumber, int pageSize) { ..


    name: "GetPagedData",
    routeTemplate: "api/{controller}/{pageNumber}/{pageSize}"

Then add the parameters to the HTTP call:

GET //<service address>/Api/Data/2/10 

Checking character length in ruby

You could take any of the answers above that use the string.length method and replace it with string.size.

They both work the same way.

if string.size <= 25
  puts "No problem here!"
  puts "Sorry too long!"

Set a default parameter value for a JavaScript function

that solution is work for me in js:

function read_file(file, delete_after) {
    delete_after = delete_after || false;
    // Code

How do I edit a file after I shell to a Docker container?

An easy way to edit a few lines would be:

echo "deb stretch main" > sources.list

T-SQL loop over query results


FROM   table


    FROM @getid INTO @id, @name

    EXEC stored_proc @varName=@id, @otherVarName='test', @varForName=@name


CLOSE @getid

Deleting all pending tasks in celery / rabbitmq

From the docs:

$ celery -A proj purge


from proj.celery import app

(EDIT: Updated with current method.)

How to install pip3 on Windows?

On Windows pip3 should be in the Scripts path of your Python installation:



where python

to find out where your Python executable(s) is/are located. The result should look like this:




You can check if pip3 works with this absolute path:


if yes, add C:\path\to\python\Scripts to your environmental variable PATH .

How to change the Title of the window in Qt?

For new Qt users this is a little more confusing than it seems if you are using QT Designer and .ui files.

Initially I tried to use ui->setWindowTitle, but that doesn't exist. ui is not a QDialog or a QMainWindow.

The owner of the ui is the QDialog or QMainWindow, the .ui just describes how to lay it out. In that case, you would use:

this->setWindowTitle("New Title");

I hope this helps someone else.

C# "No suitable method found to override." -- but there is one

Ext needs to inherit the base, so in your definition it should say:

public class Ext : Base { //...

Unable to Connect to For Cloning

I had the same error because I was using proxy. As the answer is given but in case you are using proxy then please set your proxy first using these commands:

git config --global http.proxy http://proxy_username:proxy_password@proxy_ip:port
git config --global https.proxy https://proxy_username:proxy_password@proxy_ip:port

Difference between del, remove, and pop on lists

Already answered quite well by others. This one from my end :)

remove vs pop vs del

Evidently, pop is the only one which returns the value, and remove is the only one which searches the object, while del limits itself to a simple deletion.

javax.servlet.ServletException cannot be resolved to a type in spring web app

import javax.servlet


Go to properties of your project ( with Alt+Enter or righ-click )


check on Apache Tomcat v7.0 under Targeted Runtime and it works.


Reading and writing value from a textfile by using vbscript code

This script will read lines from large file and write to new small files. Will duplicate the header of the first line (Header) to all child files

Dim strLine
lCounter = 1
fCounter = 1
cPosition = 1
MaxLine = 1000
splitAt = MaxLine
Dim fHeader
sFile = "inputFile.txt"
dFile = LEFT(sFile, (LEN(sFile)-4))& "_0" & fCounter & ".txt"
Set objFileToRead = CreateObject("Scripting.FileSystemObject").OpenTextFile(sFile,1)
Set objFileToWrite = CreateObject("Scripting.FileSystemObject").OpenTextFile(dFile,2,true)
do while not objFileToRead.AtEndOfStream
        strLine = objFileToRead.ReadLine()
        If cPosition = 1 Then
            fHeader = strLine
        End If
        If cPosition = splitAt Then
            fCounter = fCounter + 1
            splitAt = splitAt + MaxLine
            Set objFileToWrite = Nothing
            If fCounter < 10 Then
                dFile=LEFT(dFile, (LEN(dFile)-5))& fCounter & ".txt"
                Set objFileToWrite = CreateObject("Scripting.FileSystemObject").OpenTextFile(dFile,2,true)
            ElseIf fCounter <100 Or fCounter = 100 Then
                dFile=LEFT(dFile, (LEN(dFile)-6))& fCounter & ".txt"
                Set objFileToWrite = CreateObject("Scripting.FileSystemObject").OpenTextFile(dFile,2,true)
                dFile=LEFT(dFile, (LEN(dFile)-7)) & fCounter & ".txt"
                Set objFileToWrite = CreateObject("Scripting.FileSystemObject").OpenTextFile(dFile,2,true)
            End If
        End If
        lCounter=lCounter + 1
        cPosition=cPosition + 1
Set objFileToWrite = Nothing
Set objFileToRead = Nothing

"The specified Android SDK Build Tools version (26.0.0) is ignored..."

Set the buildToolsVersion '26.0.2' then change classpath ''.

Make sure you set compileSdkVersion to 26 whiles targetSdkVersion is also set 26.

It is also appropriate to sent set compile ''.

How to use CSS to surround a number with a circle?

For circle sizes varying based on the content this should work:

<span class="numberCircle"><span>30</span></span>
<span class="numberCircle"><span>1</span></span>
<span class="numberCircle"><span>5435</span></span>
<span class="numberCircle"><span>2</span></span>
<span class="numberCircle"><span>100</span></span>

.numberCircle {

  border:2px solid;


.numberCircle span {



It relies on the width of the content plus the margin-'s to determine the radius, then extends the height to match using the padding-'s. The margin-'s would need to be adjusted based on the font-size.

Update to remove inner element:

<span class="numberCircle">30</span>
<span class="numberCircle">1</span>
<span class="numberCircle">5435</span>
<span class="numberCircle">2</span>
<span class="numberCircle">100</span>

<style type="text/css">
.numberCircle {

    border:2px solid;


.numberCircle:after {


.numberCircle:before {
.numberCircle:after {

Uses pseudo-elements to force the height. Need the zero width space for vertical alignment. Moved the line-height:0px from the outer to the pseudo so that it is at least visible when degrading for IE8.

How can I bind to the change event of a textarea in jQuery?

This question needed a more up-to-date answer, with sources. This is what actually works (though you don't have to take my word for it):

// Storing this jQuery object outside of the event callback 
// prevents jQuery from having to search the DOM for it again
// every time an event is fired.
var $myButton = $("#buttonID")

// input           :: for all modern browsers [1]
// selectionchange :: for IE9 [2]
// propertychange  :: for <IE9 [3]
$('#textareaID').on('input selectionchange propertychange', function() {

  // This is the correct way to enable/disabled a button in jQuery [4]
  $myButton.prop('disabled', this.value.length === 0)


2: oninput in IE9 doesn't fire when we hit BACKSPACE / DEL / do CUT

BUT, for a more global solution that you can use throughout your project, I recommend using the textchange jQuery plugin to gain a new, cross-browser compatible textchange event. It was developed by the same person who implemented the equivalent onChange event for Facebook's ReactJS, which they use for nearly their entire website. And I think it's safe to say, if it's a robust enough solution for Facebook, it's probably robust enough for you. :-)

UPDATE: If you happen to need features like drag and drop support in Internet Explorer, you may instead want to check out pandell's more recently updated fork of jquery-splendid-textchange.

What is the correct way to restore a deleted file from SVN?

You should be able to just check out the one file you want to restore. Try something like svn co svn://your_repos/path/to/file/you/want/to/restore@rev where rev is the last revision at which the file existed.

I had to do exactly this a little while ago and if I remember correctly, using the -r option to svn didn't work; I had to use the :rev syntax. (Although I might have remembered it backwards...)

Apache: "AuthType not set!" 500 Error

I think that you have a version 2.4.x of Apache.

Have you sure that you load this 2 modules ? - mod_authn_core - mod_authz_core

LoadModule authn_core_module modules/
LoadModule authz_core_module modules/

PS : My recommendation for authorization and rights is (by default) :

LoadModule authn_file_module modules/
LoadModule authn_core_module modules/
LoadModule authz_host_module modules/
LoadModule authz_groupfile_module modules/
LoadModule authz_user_module modules/
LoadModule authz_core_module modules/
LoadModule auth_basic_module modules/
LoadModule auth_digest_module modules/

Numpy isnan() fails on an array of floats (from pandas dataframe apply)

A great substitute for np.isnan() and pd.isnull() is

for i in range(0,a.shape[0]):
       //do something here
       //a[i] is nan

since only nan is not equal to itself.

How to let an ASMX file output JSON

From WebService returns XML even when ResponseFormat set to JSON:

Make sure that the request is a POST request, not a GET. Scott Guthrie has a post explaining why.

Though it's written specifically for jQuery, this may also be useful to you:
Using jQuery to Consume ASP.NET JSON Web Services

Is there a simple way to remove unused dependencies from a maven pom.xml?

You can use dependency:analyze -DignoreNonCompile

This will print a list of used undeclared and unused declared dependencies (while ignoring runtime/provided/test/system scopes for unused dependency analysis.)

** Be careful while using this, some libraries used at runtime are considered as unused **

For more details refer this link

Graphviz's executables are not found (Python 3.4)

Please note that I am using windows 10. some of the following may or may not applicable for other versions of windows or operating systems:

** Note 2: **
"the Graphviz bin file address on your system" can be C:\Program Files (x86)\Graphviz2.38\bin or any other path you installed Graphviz there.

We have problem not only with Graphviz but also with other external EXE files we want to use in Jupyter.
The reason is when jupyter wants to import a package it looks in working directory to find it and when it fails to find the package it returns such errors.
What we can do is tackle this is as follows:
1) check if the Graphviz is installed on your system and if not you can download and install it from:
and then install it. When you installing Graphviz, keep in mind where (in which folder) you are installing it. If you see the above error when you use

import graphviz

then you have several options:

2) you can call the .exe file in the ipynb via

import os
os.environ["PATH"] += os.pathsep + r'the Graphviz bin file address on your system'

It is my experience that it is only works for the same ipynb that I am working with and every time that I open the notebook I need to call this lines of code.

3) If you want the Jupyter where to find the exe file, you need to set environmenal path.
In windows 10 you can do this going to:
Control Panel > System and Security > System > Advanced System Settings > Environment Variables > Path > Edit > New
and then add the "the Graphviz bin file address on your system" In windows 8 or lower go to :
Control Panel > System and Security > System > Advanced System Settings > Environment Variables
and then add the ;(semicolon) + "the Graphviz bin file address on your system" to the end of path string
Note: remember to restart your machine.

4) and even this does not work, define a variable going to:
Control Panel > System and Security > System > Advanced System Settings > Environment Variables and then:

Start to define an environmental variable

Then define a variable as this: Remember to name the variable Graphviz

Remember to name the variable Graphviz. At last restart your PC and hope it works.

How to do date/time comparison

Recent protocols prefer usage of RFC3339 per golang time package documentation.

In general RFC1123Z should be used instead of RFC1123 for servers that insist on that format, and RFC3339 should be preferred for new protocols. RFC822, RFC822Z, RFC1123, and RFC1123Z are useful for formatting; when used with time.Parse they do not accept all the time formats permitted by the RFCs.

cutOffTime, _ := time.Parse(time.RFC3339, "2017-08-30T13:35:00Z")
// POSTDATE is a date time field in DB (datastore)
query := datastore.NewQuery("db").Filter("POSTDATE >=", cutOffTime).

Cannot GET / Nodejs Error

I think you're missing your routes, you need to define at least one route for example '/' to index.


app.get('/', function (req, res) {
  res.render('index', {});

Calculate business days

function AddWorkDays(){
$i = 0;
$d = 5; // Number of days to add

    while($i <= $d) {
        if(date('N', mktime(0, 0, 0, date(m), date(d)+$i, date(Y))) < 5) {
    return date(Y).','.date(m).','.(date(d)+$d);

How is the java memory pool divided?

The new keyword allocates memory on the Java heap. The heap is the main pool of memory, accessible to the whole of the application. If there is not enough memory available to allocate for that object, the JVM attempts to reclaim some memory from the heap with a garbage collection. If it still cannot obtain enough memory, an OutOfMemoryError is thrown, and the JVM exits.

The heap is split into several different sections, called generations. As objects survive more garbage collections, they are promoted into different generations. The older generations are not garbage collected as often. Because these objects have already proven to be longer lived, they are less likely to be garbage collected.

When objects are first constructed, they are allocated in the Eden Space. If they survive a garbage collection, they are promoted to Survivor Space, and should they live long enough there, they are allocated to the Tenured Generation. This generation is garbage collected much less frequently.

There is also a fourth generation, called the Permanent Generation, or PermGen. The objects that reside here are not eligible to be garbage collected, and usually contain an immutable state necessary for the JVM to run, such as class definitions and the String constant pool. Note that the PermGen space is planned to be removed from Java 8, and will be replaced with a new space called Metaspace, which will be held in native memory. reference:

Diagram of Java memory for several threads Diagram of Java memory distribution

Multiple radio button groups in one form

To create a group of inputs you can create a custom html element

window.customElements.define('radio-group', RadioGroup);

to keep selected option in each group, you need to add name attribute to inputs in group, if you not add it then all is one group.

Git commit in terminal opens VIM, but can't get back to terminal

This is in answer to your question...

I'd also like to know how to make it open up in Sublime Text 2 instead

For Windows:

git config --global core.editor "'C:/Program Files/Sublime Text 2/sublime_text.exe'"

Check that the path for sublime_text.exe is correct and adjust if needed.

For Mac/Linux:

git config --global core.editor "subl -n -w"

If you get an error message such as:

error: There was a problem with the editor 'subl -n -w'.

Create the alias for subl

sudo ln -s /Applications/Sublime\ /usr/local/bin/subl

Again check that the path matches for your machine.

For Sublime Text simply save cmd S and close the window cmd W to return to git.

How to run stored procedures in Entity Framework Core?

Stored procedure support is not yet (as of 7.0.0-beta3) implemented in EF7. You can track the progress of this feature using issue #245.

For now, you can do it the old fashioned way using ADO.NET.

var connection = (SqlConnection)context.Database.AsSqlServer().Connection.DbConnection;

var command = connection.CreateCommand();
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "MySproc";
command.Parameters.AddWithValue("@MyParameter", 42);


scp with port number specified

for use another port on scp command use capital P like this

scp -P port-number source-file/directory user@domain:/destination

ya ali

Hunk #1 FAILED at 1. What's that mean?

In some cases, there is no difference in file versions, but only in indentation, spacing, line ending or line numbers.

To patch despite those differences, it's possible to use the following two arguments :

--ignore-whitespace : It ignores whitespace differences (indentation, etc).

--fuzz 3 : the "--fuzz X" option sets the maximum fuzz factor to lines. This option only applies to context and unified diffs; it ignores up to X lines while looking for the place to install a hunk. Note that a larger fuzz factor increases the odds of making a faulty patch. The default fuzz factor is 2; there is no point to setting it to more than the number of lines of context in the diff, ordinarily 3.

Don't forget to user "--dry-run" : It'll try the patch without applying it.

Example :

patch --verbose --dry-run --ignore-whitespace --fuzz 3 < /path/to/patch.patch

More informations about Fuzz :

Numeric for loop in Django templates

If the number is coming from a model, I found this to be a nice patch to the model:

def iterableQuantity(self):
    return range(self.quantity)

Does Hive have a String split function?

There does exist a split function based on regular expressions. It's not listed in the tutorial, but it is listed on the language manual on the wiki:

split(string str, string pat)
   Split str around pat (pat is a regular expression) 

In your case, the delimiter "|" has a special meaning as a regular expression, so it should be referred to as "\\|".

How to resolve "Input string was not in a correct format." error?

If using TextBox2.Text as the source for a numeric value, it must first be checked to see if a value exists, and then converted to integer.

If the text box is blank when Convert.ToInt32 is called, you will receive the System.FormatException. Suggest trying:

protected void SetImageWidth()
      Image1.Width = Convert.ToInt32(TextBox1.Text);
      Image1.Width = 100; // or other default value as appropriate in context.

How to assert greater than using JUnit Assert?

assertTrue("your message", previousTokenValues[1].compareTo(currentTokenValues[1]) > 0)

this passes for previous > current values

How do I load the contents of a text file into a javascript variable?

If your input was structured as XML, you could use the importXML function. (More info here at quirksmode).

If it isn't XML, and there isn't an equivalent function for importing plain text, then you could open it in a hidden iframe and then read the contents from there.

Multiplication on command line terminal

I have a simple script I use for this:

me@mycomputer:~$ cat /usr/local/bin/c


echo "$*" | sed 's/x/\*/g' | bc -l

It changes x to * since * is a special character in the shell. Use it as follows:

  • c 5x5
  • c 5-4.2 + 1
  • c '(5 + 5) * 30' (you still have to use quotes if the expression contains any parentheses).

Angular 2 execute script after template render

ngAfterViewInit() of AppComponent is a lifecycle callback Angular calls after the root component and it's children have been rendered and it should fit for your purpose.

See also

Set opacity of background image without affecting child elements

If you have to set the opacity only to the bullet, why don't you set the alpha channel directly into the image? By the way I don't think there is a way to set the opacity to a background image via css without changing the opacity of the whole element (and its children too).

Regular Expression: Allow letters, numbers, and spaces (with at least one letter or number)

This will validate against special characters and leading and trailing spaces:

var strString = "Your String";

strString.match(/^[A-Za-z0-9][A-Za-z0-9 ]\*[A-Za-z0-9]\*$/)

How can I edit javascript in my browser like I can use Firebug to edit CSS/HTML?

The problem with editing JavaScript like you can CSS and HTML is that there is no clean way to propagate the changes. JavaScript can modify the DOM, send Ajax requests, and dynamically modify existing objects and functions at runtime. So, once you have loaded a page with JavaScript, it might be completely different after the JavaScript has run. The browser would have to keep track of every modification your JavaScript code performs so that when you edit the JS, it rolls back the changes to a clean page.

But, you can modify JavaScript dynamically a few other ways:

  • JavaScript injections in the URL bar: javascript: alert (1);
  • Via a JavaScript console (there's one built into Firefox, Chrome, and newer versions of IE
  • If you want to modify the JavaScript files as they are served to your browser (i.e. grabbing them in transit and modifying them), then I can't offer much help. I would suggest using a debugging proxy:

The first two options are great because you can modify any JavaScript variables and functions currently in scope. However, you won't be able to modify the code and run it with a "just-served" page like you can with the third option.

Other than that, as far as I know, there is no edit-and-run JavaScript editor in the browser. Hope this helps,

MySQL Stored procedure variables from SELECT statements

Corrected a few things and added an alternative select - delete as appropriate.


IN p_cityID INT -- should this be int unsigned ?

DECLARE cityLat FLOAT; -- should these be decimals ?

    -- method 1
    SELECT lat,lng into cityLat, cityLng FROM cities WHERE cities.cityID = p_cityID;

     HAVERSINE(cityLat,cityLng,, b.lng) AS dist 
     cities b 
    LIMIT 10;

    -- method 2
      HAVERSINE(, a.lng,, b.lng) AS dist
      cities AS a
    JOIN cities AS b on a.cityID = p_cityID
    LIMIT 10;


delimiter ;

align an image and some text on the same line without using div width?

I was working on a different project when I saw this question, this is the solution I used and it seems to work.

#[image id] , p {
        vertical-align: middle;
        display: inline-block;

if it doesn't, just try :



or display: inline instead of inline-block

This worked for me, hope this helped!

405 method not allowed Web API

Make sure your controller inherits from Controller class.

It might even be crazier that stuff would work locally even without that.

How to find index of an object by key and value in an javascript array

Not a direct answer to your question, though I thing it's worth mentioning it, because your question seems like fitting in the general case of "getting things by name in a key-value storage".

If you are not tight to the way "peoples" is implemented, a more JavaScript-ish way of getting the right guy might be :

var peoples = {
  "bob":  { "dinner": "pizza" },
  "john": { "dinner": "sushi" },
  "larry" { "dinner": "hummus" }

// If people is implemented this way, then
// you can get values from their name, like :
var theGuy = peoples["john"];

// You can event get directly to the values
var thatGuysPrefferedDinner = peoples["john"].dinner;

Hope if this is not the answer you wanted, it might help people interested in that "key/value" question.

SQL Query Where Date = Today Minus 7 Days

Use the built in functions:

FROM ExternalHits

Laravel 5.4 Specific Table Migration

You need to put the file(s) into a new directory (ex:selected) and then apply

php artisan migrate  --path=/database/migrations/selected

if you need rollback:

php artisan migrate:rollback  --path=/database/migrations/selected


php artisan migrate:refresh

this will rollback and then migrate all the migrations files in the default directory (/database/migrations)

Writing a list to a file with Python

This logic will first convert the items in list to string(str). Sometimes the list contains a tuple like

alist = [(i12,tiger), 

This logic will write to file each tuple in a new line. We can later use eval while loading each tuple when reading the file:

outfile = open('outfile.txt', 'w') # open a file in write mode
for item in list_to_persistence:    # iterate over the list items
   outfile.write(str(item) + '\n') # write to the file
outfile.close()   # close the file 

How many concurrent requests does a single Flask process receive?

Flask will process one request per thread at the same time. If you have 2 processes with 4 threads each, that's 8 concurrent requests.

Flask doesn't spawn or manage threads or processes. That's the responsability of the WSGI gateway (eg. gunicorn).

How to stop console from closing on exit?

You can simply press Ctrl+F5 instead of F5 to run the built code. Then it will prompt you to press any key to continue. Or you can use this line -> system("pause"); at the end of the code to make it wait until you press any key.

However, if you use the above line, system("pause"); and press Ctrl+F5 to run, it will prompt you twice!

How can I pad an int with leading zeros when using cout << operator?

Another example to output date and time using zero as a fill character on instances of single digit values: 2017-06-04 18:13:02

#include "stdafx.h"
#include <iostream>
#include <iomanip>
#include <ctime>
using namespace std;

int main()
    time_t t = time(0);   // Get time now
    struct tm * now = localtime(&t);
    cout << (now->tm_year + 1900) << '-'
        << setw(2) << (now->tm_mon + 1) << '-'
        << setw(2) << now->tm_mday << ' '
        << setw(2) << now->tm_hour << ':'
        << setw(2) << now->tm_min << ':'
        << setw(2) << now->tm_sec
        << endl;
    return 0;

Early exit from function?

Using a little different approach, you can use try catch, with throw statement.

function name() {
    try {

        //get out of here
        if (a == 'stop')
            throw "exit";

    } catch (e) {
        // TODO: handle exception

Command not found when using sudo

  1. Check that you have execute permission on the script. i.e. chmod +x
  2. Check that the first line of that script is #!/bin/sh or some such.
  3. For sudo you are in the wrong directory. check with sudo pwd

How to call a Parent Class's method from Child Class in Python?

class a(object):
    def my_hello(self):
        print "hello ravi"

class b(a):
    def my_hello(self):
    print "hi"

obj = b()

Shift column in pandas dataframe up by one?

df.gdp = df.gdp.shift(-1) ## shift up
df.gdp.drop(df.gdp.shape[0] - 1,inplace = True) ## removing the last row

Get folder name of the file in Python

You could get the full path as a string then split it into a list using your operating system's separator character. Then you get the program name, folder name etc by accessing the elements from the end of the list using negative indices.

Like this:

import os
strPath = os.path.realpath(__file__)
print( f"Full Path    :{strPath}" )
nmFolders = strPath.split( os.path.sep )
print( "List of Folders:", nmFolders )
print( f"Program Name :{nmFolders[-1]}" )
print( f"Folder Name  :{nmFolders[-2]}" )
print( f"Folder Parent:{nmFolders[-3]}" )

The output of the above was this:

Full Path    :C:\Users\terry\Documents\apps\environments\dev\app_02\
List of Folders: ['C:', 'Users', 'terry', 'Documents', 'apps', 'environments', 'dev', 'app_02', '']
Program Name
Folder Name  :app_02
Folder Parent:dev

C# Wait until condition is true

Ended up writing this today and seems to be ok. Your usage could be:

await TaskEx.WaitUntil(isExcelInteractive);

code (including the inverse operation)

public static class TaskEx
    /// <summary>
    /// Blocks while condition is true or timeout occurs.
    /// </summary>
    /// <param name="condition">The condition that will perpetuate the block.</param>
    /// <param name="frequency">The frequency at which the condition will be check, in milliseconds.</param>
    /// <param name="timeout">Timeout in milliseconds.</param>
    /// <exception cref="TimeoutException"></exception>
    /// <returns></returns>
    public static async Task WaitWhile(Func<bool> condition, int frequency = 25, int timeout = -1)
        var waitTask = Task.Run(async () =>
            while (condition()) await Task.Delay(frequency);

        if(waitTask != await Task.WhenAny(waitTask, Task.Delay(timeout)))
            throw new TimeoutException();

    /// <summary>
    /// Blocks until condition is true or timeout occurs.
    /// </summary>
    /// <param name="condition">The break condition.</param>
    /// <param name="frequency">The frequency at which the condition will be checked.</param>
    /// <param name="timeout">The timeout in milliseconds.</param>
    /// <returns></returns>
    public static async Task WaitUntil(Func<bool> condition, int frequency = 25, int timeout = -1)
        var waitTask = Task.Run(async () =>
            while (!condition()) await Task.Delay(frequency);

        if (waitTask != await Task.WhenAny(waitTask, 
            throw new TimeoutException();

Example usage:

Call Jquery function

Try this code:

        if() { //your condition
                title:'My Title',  
                msg:'The message content',  

How to insert a line break <br> in markdown

Try adding 2 spaces (or a backslash \) after the first line:

[Name of link](url)
My line of text\


[Name of link](url)<space><space>
My line of text\


<p><a href="url">Name of link</a><br>
My line of text<br></p>

Converting java.util.Properties to HashMap<String,String>

When I see Spring framework source code,I find this way

Properties props = getPropertiesFromSomeWhere();
 // change properties to map
Map<String,String> map = new HashMap(props)

Disable back button in react navigation

We can fix it by setting headerLeft to null

static navigationOptions =({navigation}) => {
    return {
        title: 'Rechercher une ville',
        headerLeft: null,

How to read the RGB value of a given pixel in Python?

You could use the Tkinter module, which is the standard Python interface to the Tk GUI toolkit and you don't need extra download. See

(For Python 3, Tkinter is renamed to tkinter)

Here is how to set RGB values:

from Tkinter import *

root = Tk()

def pixel(image, pos, color):
    """Place pixel at pos=(x,y) on image, with color=(r,g,b)."""
    r,g,b = color
    x,y = pos
    image.put("#%02x%02x%02x" % (r,g,b), (y, x))

photo = PhotoImage(width=32, height=32)

pixel(photo, (16,16), (255,0,0))  # One lone pixel in the middle...

label = Label(root, image=photo)

And get RGB:

def getRGB(image, x, y):
    value = image.get(x, y)
    return tuple(map(int, value.split(" ")))

How to exclude property from Json Serialization

If you are using System.Text.Json then you can use [JsonIgnore].
FQ: System.Text.Json.Serialization.JsonIgnoreAttribute

Official Microsoft Docs: JsonIgnoreAttribute

As stated here:

The library is built-in as part of the .NET Core 3.0 shared framework.
For other target frameworks, install the System.Text.Json NuGet package. The package supports:

  • .NET Standard 2.0 and later versions
  • .NET Framework 4.6.1 and later versions
  • .NET Core 2.0, 2.1, and 2.2

plot is not defined

If you want to use a function form a package or module in python you have to import and reference them. For example normally you do the following to draw 5 points( [1,5],[2,4],[3,3],[4,2],[5,1]) in the space:

import matplotlib.pyplot

In your solution

from matplotlib import*

This imports the package matplotlib and "plot is not defined" means there is no plot function in matplotlib you can access directly, but instead if you import as

from matplotlib.pyplot import *

Now you can use any function in matplotlib.pyplot without referencing them with matplotlib.pyplot.

I would recommend you to name imports you have, in this case you can prevent disambiguation and future problems with the same function names. The last and clean version of above example looks like:

import matplotlib.pyplot as plt

Ant is using wrong java version

In Eclipse:

  • Right click on your build.xml

  • click "Run As", click on "External Tool Configurations..."

  • Select tab JRE. Select the JRE you are using.

Re-run the task, it should be fine now.

Excel VBA For Each Worksheet Loop

Instead of adding "ws." before every Range, as suggested above, you can add "ws.activate" before Call instead.

This will get you into the worksheet you want to work on.

Python unittest - opposite of assertRaises?

I am the original poster and I accepted the above answer by DGH without having first used it in the code.

Once I did use I realised that it needed a little tweaking to actually do what I needed it to do (to be fair to DGH he/she did say "or something similar" !).

I thought it was worth posting the tweak here for the benefit of others:

        a = Application("abcdef", "")
    except pySourceAidExceptions.PathIsNotAValidOne:

What I was attempting to do here was to ensure that if an attempt was made to instantiate an Application object with a second argument of spaces the pySourceAidExceptions.PathIsNotAValidOne would be raised.

I believe that using the above code (based heavily on DGH's answer) will do that.

How to change the decimal separator of DecimalFormat from comma to dot/point?

BigDecimal does not seem to respect Locale settings.

Locale.getDefault(); //returns sl_SI

Slovenian locale should have a decimal comma. Guess I had strange misconceptions regarding numbers.

a = new BigDecimal("1,2") //throws exception
a = new BigDecimal("1.2") //is ok

a.toPlainString() // returns "1.2" always

I have edited a part of my message that made no sense since it proved to be due the human error (forgot to commit data and was looking at the wrong thing).

Same as BigDecimal can be said for any Java .toString() functions. I guess that is good in some ways. Serialization for example or debugging. There is an unique string representation.

Also as others mentioned using formatters works OK. Just use formatters, same for the JSF frontend, formatters do the job properly and are aware of the locale.

What is the best way to measure execution time of a function?

I would definitely advise you to have a look at System.Diagnostics.Stopwatch

And when I looked around for more about Stopwatch I found this site;

Beware of the stopwatch

There mentioned another possibility


error NG6002: Appears in the NgModule.imports of AppModule, but could not be resolved to an NgModule class

Restart your server , means stop ng serve and start again like ( ng serve ), your problem will be solved.

when make any changes in your package.json then you need to restart your ng server

Map and Reduce in .NET

Linq equivalents of Map and Reduce: If you’re lucky enough to have linq then you don’t need to write your own map and reduce functions. C# 3.5 and Linq already has it albeit under different names.

  • Map is Select:

    Enumerable.Range(1, 10).Select(x => x + 2);
  • Reduce is Aggregate:

    Enumerable.Range(1, 10).Aggregate(0, (acc, x) => acc + x);
  • Filter is Where:

    Enumerable.Range(1, 10).Where(x => x % 2 == 0);

'any' vs 'Object'

Bit old, but doesn't hurt to add some notes.

When you write something like this

let a: any;
let b: Object;
let c: {};
  • a has no interface, it can be anything, the compiler knows nothing about its members so no type checking is performed when accessing/assigning both to it and its members. Basically, you're telling the compiler to "back off, I know what I'm doing, so just trust me";
  • b has the Object interface, so ONLY the members defined in that interface are available for b. It's still JavaScript, so everything extends Object;
  • c extends Object, like anything else in TypeScript, but adds no members. Since type compatibility in TypeScript is based on structural subtyping, not nominal subtyping, c ends up being the same as b because they have the same interface: the Object interface.

And that's why

a.doSomething(); // Ok: the compiler trusts you on that
b.doSomething(); // Error: Object has no doSomething member
c.doSomething(); // Error: c neither has doSomething nor inherits it from Object

and why

a.toString(); // Ok: whatever, dude, have it your way
b.toString(); // Ok: toString is defined in Object
c.toString(); // Ok: c inherits toString from Object

So Object and {} are equivalents in TypeScript.

If you declare functions like these

function fa(param: any): void {}
function fb(param: Object): void {}

with the intention of accepting anything for param (maybe you're going to check types at run-time to decide what to do with it), remember that

  • inside fa, the compiler will let you do whatever you want with param;
  • inside fb, the compiler will only let you reference Object's members.

It is worth noting, though, that if param is supposed to accept multiple known types, a better approach is to declare it using union types, as in

function fc(param: string|number): void {}

Obviously, OO inheritance rules still apply, so if you want to accept instances of derived classes and treat them based on their base type, as in

interface IPerson {
    gender: string;

class Person implements IPerson {
    gender: string;

class Teacher extends Person {}

function func(person: IPerson): void {

func(new Person());     // Ok
func(new Teacher());    // Ok
func({gender: 'male'}); // Ok
func({name: 'male'});   // Error: no gender..

the base type is the way to do it, not any. But that's OO, out of scope, I just wanted to clarify that any should only be used when you don't know whats coming, and for anything else you should annotate the correct type.


Typescript 2.2 added an object type, which specifies that a value is a non-primitive: (i.e. not a number, string, boolean, symbol, undefined, or null).

Consider functions defined as:

function b(x: Object) {}
function c(x: {}) {}
function d(x: object) {}

x will have the same available properties within all of these functions, but it's a type error to call d with a primitive:

b("foo"); //Okay
c("foo"); //Okay
d("foo"); //Error: "foo" is a primitive

Javascript - How to detect if document has loaded (IE 7/Firefox 3)

if(document.readyState === 'complete') {
} else {
    if (window.addEventListener) {  
        window.addEventListener('load', DoStuffFunction, false);
    } else {
        window.attachEvent('onload', DoStuffFunction);

Circle line-segment collision detection algorithm?

If the line's coordinates are A.x, A.y and B.x, B.y and the circles center is C.x, C.y then the lines formulae are:

x = A.x * t + B.x * (1 - t)

y = A.y * t + B.y * (1 - t)

where 0<=t<=1

and the circle is

(C.x - x)^2 + (C.y - y)^2 = R^2

if you substitute x and y formulae of the line into the circles formula you get a second order equation of t and its solutions are the intersection points (if there are any). If you get a t which is smaller than 0 or greater than 1 then its not a solution but it shows that the line is 'pointing' to the direction of the circle.

Chrome refuses to execute an AJAX script due to wrong MIME type

In my case, I use

$.getJSON(url, function(json) { ... });

to make the request (to Flickr's API), and I got the same MIME error. Like the answer above suggested, adding the following code:

$.ajaxSetup({ dataType: "jsonp" });

Fixed the issue and I no longer see the MIME type error in Chrome's console.

Array slices in C#

static byte[] SliceMe(byte[] source, int length)
    byte[] destfoo = new byte[length];
    Array.Copy(source, 0, destfoo, 0, length);
    return destfoo;


var myslice = SliceMe(sourcearray,41);

MySQL Trigger - Storing a SELECT in a variable

`CREATE TRIGGER `category_before_ins_tr` BEFORE INSERT ON `category`
    **SET @tableId= (SELECT id FROM dummy LIMIT 1);**


How to solve PHP error 'Notice: Array to string conversion in...'

When you have many HTML inputs named C[] what you get in the POST array on the other end is an array of these values in $_POST['C']. So when you echo that, you are trying to print an array, so all it does is print Array and a notice.

To print properly an array, you either loop through it and echo each element, or you can use print_r.

Alternatively, if you don't know if it's an array or a string or whatever, you can use var_dump($var) which will tell you what type it is and what it's content is. Use that for debugging purposes only.

Redirect output of mongo query to a csv file

Just weighing in here with a nice solution I have been using. This is similar to Lucky Soni's solution above in that it supports aggregation, but doesn't require hard coding of the field names.

cursor = db.<collection_name>.<my_query_with_aggregation>;

headerPrinted = false;
while (cursor.hasNext()) {
    item =;
    if (!headerPrinted) {
        headerPrinted = true;

    line = Object
        .map(function(prop) {
            return '"' + item[prop] + '"';

Save this as a .js file, in this case we'll call it example.js and run it with the mongo command line like so:

mongo <database_name> example.js --quiet > example.csv

HorizontalScrollView within ScrollView Touch Handling

It wasn't working well for me. I changed it and now it works smoothly. If anyone interested.

public class ScrollViewForNesting extends ScrollView {
    private final int DIRECTION_VERTICAL = 0;
    private final int DIRECTION_HORIZONTAL = 1;
    private final int DIRECTION_NO_VALUE = -1;

    private final int mTouchSlop;
    private int mGestureDirection;

    private float mDistanceX;
    private float mDistanceY;
    private float mLastX;
    private float mLastY;

    public ScrollViewForNesting(Context context, AttributeSet attrs,
            int defStyle) {
        super(context, attrs, defStyle);

        final ViewConfiguration configuration = ViewConfiguration.get(context);
        mTouchSlop = configuration.getScaledTouchSlop();

    public ScrollViewForNesting(Context context, AttributeSet attrs) {
        this(context, attrs,0);

    public ScrollViewForNesting(Context context) {

    public boolean onInterceptTouchEvent(MotionEvent ev) {      
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDistanceY = mDistanceX = 0f;
                mLastX = ev.getX();
                mLastY = ev.getY();
                mGestureDirection = DIRECTION_NO_VALUE;
            case MotionEvent.ACTION_MOVE:
                final float curX = ev.getX();
                final float curY = ev.getY();
                mDistanceX += Math.abs(curX - mLastX);
                mDistanceY += Math.abs(curY - mLastY);
                mLastX = curX;
                mLastY = curY;

        return super.onInterceptTouchEvent(ev) && shouldIntercept();

    private boolean shouldIntercept(){
        if((mDistanceY > mTouchSlop || mDistanceX > mTouchSlop) && mGestureDirection == DIRECTION_NO_VALUE){
            if(Math.abs(mDistanceY) > Math.abs(mDistanceX)){
                mGestureDirection = DIRECTION_VERTICAL;
                mGestureDirection = DIRECTION_HORIZONTAL;

        if(mGestureDirection == DIRECTION_VERTICAL){
            return true;
            return false;

SQL Server - calculate elapsed time between two datetime stamps in HH:MM:SS format

Use the DATEDIFF to return value in milliseconds, seconds, minutes, hours, ...

DATEDIFF(interval, date1, date2)

interval REQUIRED - The time/date part to return. Can be one of the following values:

year, yyyy, yy = Year
quarter, qq, q = Quarter
month, mm, m = month
dayofyear = Day of the year
day, dy, y = Day
week, ww, wk = Week
weekday, dw, w = Weekday
hour, hh = hour
minute, mi, n = Minute
second, ss, s = Second
millisecond, ms = Millisecond

date1, date2 REQUIRED - The two dates to calculate the difference between

How to update a pull request from forked repo?

If using GitHub on Windows:

  1. Make changes locally.
  2. Open GitHub, switch to local repositories, double click repository.
  3. Switch the branch(near top of window) to the branch that you created the pull request from(i.e. the branch on your fork side of the compare)
  4. Should see option to enter commit comment on right and commit changes to your local repo.
  5. Click sync on top, which among other things, pushes your commit from local to your remote fork on GitHub.
  6. The pull request will be updated automatically with the additional commits. This is because the pulled request represents a diff with your fork's branch. If you go to the pull request page(the one where you and others can comment on your pull request) then the Commits tab should have your additional commit(s).

This is why, before you start making changes of your own, that you should create a branch for each set of changes you plan to put into a pull request. That way, once you make the pull request, you can then make another branch and continue work on some other task/feature/bugfix without affecting the previous pull request.

Multiple select statements in Single query

You can certainly us the a Select Agregation statement as Postulated by Ben James, However This will result in a view with as many columns as you have tables. An alternate method may be as follows:

SELECT COUNT( AS TableCount,'user_table' AS TableSource FROM user_table
UNION SELECT COUNT( AS TableCount,'cat_table' AS TableSource FROM cat_table
UNION SELECT COUNT( AS TableCount, 'course_table' AS TableSource From course_table;

The Nice thing about an approch like this is that you can explicitly write the Union statements and generate a view or create a temp table to hold values that are added consecutively from a Proc cals using variables in place of your table names. I tend to go more with the latter, but it really depends on personal preference and application. If you are sure the tables will never change, you want the data in a single row format, and you will not be adding tables. stick with Ben James' solution. Otherwise I'd advise flexibility, you can always hack a cross tab struc.

There is an error in XML document (1, 41)

I had the same thing. All came down to a "d" instead of a "D" in a tag name in the schema.

moving changed files to another branch for check-in

If you haven't already committed your changes, just use git checkout to move to the new branch and then commit them normally - changes to files are not tied to a particular branch until you commit them.

If you have already committed your changes:

  1. Type git log and remember the SHA of the commit you want to move.
  2. Check out the branch you want to move the commit to.
  3. Type git cherry-pick SHA substituting the SHA from above.
  4. Switch back to your original branch.
  5. Use git reset HEAD~1 to reset back before your wrong-branch commit.

cherry-pick takes a given commit and applies it to the currently checked-out head, thus allowing you to copy the commit over to a new branch.

Batch file to move files to another directory

Suppose there's a file test.txt in Root Folder, and want to move it to \TxtFolder,

You can try

move %~dp0\test.txt %~dp0\TxtFolder


reference answer: relative path in BAT script

How can I convert a Word document to PDF?

Docx4j is open source and the best API for convert Docx to pdf without any alignment or font issue.

Maven Dependencies:




import org.docx4j.Docx4J;
import org.docx4j.openpackaging.packages.WordprocessingMLPackage;

public class DocToPDF {

    public static void main(String[] args) {
        try {
            InputStream templateInputStream = new FileInputStream("D:\\\\Workspace\\\\New\\\\Sample.docx");
            WordprocessingMLPackage wordMLPackage = WordprocessingMLPackage.load(templateInputStream);
            MainDocumentPart documentPart = wordMLPackage.getMainDocumentPart();

            String outputfilepath = "D:\\\\Workspace\\\\New\\\\Sample.pdf";
            FileOutputStream os = new FileOutputStream(outputfilepath);
        } catch (Throwable e) {



How to get the width of a react element

This could be handled perhaps in a simpler way by using callback refs.

React allows you to pass a function into a ref, which returns the underlying DOM element or component node. See:

const MyComponent = () => {
    const myRef = node => console.log(node ? node.innerText : 'NULL!');
    return <div ref={myRef}>Hello World</div>;

This function gets fired whenever the underlying node is changed. It will be null in-between updates, so we need to check for this. Example:

const MyComponent = () => {
    const [time, setTime] = React.useState(123);
    const myRef = node => console.log(node ? node.innerText : 'NULL!');
    setTimeout(() => setTime(time+1), 1000);
    return <div ref={myRef}>Hello World {time}</div>;
/*** Console output: 
 Hello World 123
 Hello World 124

While this does't handle resizing as such (we would still need a resize listener to handle the user resizing the window) I'm not sure that is what the OP was asking for. And this version will handle the node resizing due to an update.

So here is a custom hook based on this idea:

export const useClientRect = () => {
    const [rect, setRect] = useState({width:0, height:0});
    const ref = useCallback(node => {
        if (node !== null) {
            const { width, height } = node.getBoundingClientRect();
            setRect({ width, height });
    }, []);
    return [rect, ref];

The above is based on

Note the hook returns a ref callback, instead of being passed a ref. And we employ useCallback to avoid re-creating a new ref function each time; not vital, but considered good practice.

Usage is like this (based on Marco Antônio's example):

const MyComponent = ({children}) => {
  const [rect, myRef] = useClientRect();
  const { width, height } = rect;

  return (
    <div ref={myRef}>
      <p>width: {width}px</p>
      <p>height: {height}px</p>

How to open a folder in Windows Explorer from VBA?

You can use command prompt to open explorer with path.

here example with batch or command prompt:

start "" explorer.exe (path)

so In VBA ms.access you can write with:

Dim Path
shell "cmd /c start """" explorer.exe " & Path ,vbHide

How can I display a messagebox in ASP.NET?

This code will help you add a MsgBox in your file. You can change the function definition to your requirements. Hope this helps!

protected void Addstaff_Click(object sender, EventArgs e)    
 if (intClassCapcity < intCurrentstaffNumber)     
            MsgBox("Record cannot be added because max seats available for the " + (string)Session["course_name"] + " training has been reached");    

private void MsgBox(string sMessage)    
        string msg = "<script language=\"javascript\">";    
        msg += "alert('" + sMessage + "');";    
        msg += "</script>";    

Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<AnonymousType#1>' to 'System.Collections.Generic.List<string>

If you have source as a string like "abcd" and want to produce a list like this:

{ "a.a" },
{ "b.b" },
{ "c.c" },
{ "d.d" }

then call:

List<string> list = source.Select(c => String.Concat(c, ".", c)).ToList();

How to add text to JFrame?

To create a label for text:

JLabel label1 = new JLabel("Test");

To change the text in the label:

label1.setText("Label Text");

And finally to clear the label:


And all you have to do is place the label in your layout, or whatever layout system you are using, and then just add it to the JFrame...

JQuery to load Javascript file dynamically

Yes, use getScript instead of document.write - it will even allow for a callback once the file loads.

You might want to check if TinyMCE is defined, though, before including it (for subsequent calls to 'Add Comment') so the code might look something like this:

$('#add_comment').click(function() {
    if(typeof TinyMCE == "undefined") {
        $.getScript('tinymce.js', function() {

Assuming you only have to call init on it once, that is. If not, you can figure it out from here :)

How to start Apache and MySQL automatically when Windows 8 comes up

  1. Window + R
  2. Type services.msc
  3. Search for your WAMP Apache and go to property and select Auto.
  4. Restart your computer.

As a service

You can set this one by:

Going first to your installation directory (in my case it’s c:\xampplite). It could be somewhere else depending on your installation. Have also my full version in c:\x2\xampp. Once your in the installation directory, find xampp-control.exe and click/double-click to launch it.

You should first stop all running instances of your apache2 and mysqld/mysql processes to do this.

Click the checkmark next to Apache and MySQL with the header name service. It will warn you that it’s installing as a service which of course is what we like it to do. Click Yes.

Also do step 5 with MySQL. We’re almost done.

Click Start ? Run

Type services.msc (it can also be done in the control panel under administrative tools which is a way lot of click than this one). Find the Apache 2 and MySQL services.

Double click each one and set the startup type to Automatic (you will be presented with three options: Automatic, Manual, and Disabled):

  • Automatic – will start it automatically at startup
  • Manual – users will have to start it up manually i.e. by issuing a command like net start apache2
  • Disabled – will disable it.

Be warned though that any change in the services just like the registry can cause your system to stall.

Click the start button to manually start it (just for the session though). At the next restart it’ll be automated.

Do the same with MySQL.

As a startup program

Find xampp_start.exe from your installation directory.

Press Ctrl + C to copy it or right-click the file and hit copy.

Go to C:\Documents and Settings\Administrator\Start Menu\Programs\Startup and right click on it and hit Paste Shortcut.

When you restart it’ll be starting also and you’ll see something like this:

You can stop it by issuing the xampp_stop.exe command in your installation directory.

Also worth mentioning is that if you right click again on the shortcut and hit properties, try to change the run option to minimized. This way the shortcut will be on your taskbar once started.

In php, is 0 treated as empty?

From manual: Returns FALSE if var has a non-empty and non-zero value.

The following things are considered to be empty:

  • "" (an empty string)
  • 0 (0 as an integer)
  • "0" (0 as a string) NULL
  • FALSE array() (an empty array) var
  • $var; (a variable declared, but without a value in a class)


Refused to execute script, strict MIME type checking is enabled?

I accidentally named the js file .min instead of .min.js ...

Renaming column names of a DataFrame in Spark Scala

def aliasAllColumns(t: DataFrame, p: String = "", s: String = ""): DataFrame =
{ { c => t.col(c).as( p + c + s) } : _* )

In case is isn't obvious, this adds a prefix and a suffix to each of the current column names. This can be useful when you have two tables with one or more columns having the same name, and you wish to join them but still be able to disambiguate the columns in the resultant table. It sure would be nice if there were a similar way to do this in "normal" SQL.

How to view the contents of an Android APK file?

Depending on your reason for wanting to extract the APK, APK Analyzer might be sufficient. It shows you directories, and file sizes. It also shows method counts grouped by package that you can drill down into.

APK Analyzer is built into Android Studio. You can access it from the top menu, Build -> Analyze APK.

How to add property to a class dynamically?

Here is the simple example to create property object programmatically.


class Counter:
    def __init__(self):
        cls = self.__class__
        self._count = 0
        cls.count = self.count_ref()

    def count_get(self):
        print(f'count_get: {self._count}')
        return self._count

    def count_set(self, value):
        self._count = value
        print(f'count_set: {self._count}')

    def count_del(self):
        print(f'count_del: {self._count}')

    def count_ref(self):
        cls = self.__class__
        return property(fget=cls.count_get, fset=cls.count_set, fdel=cls.count_del)

counter = Counter()

for i in range(5):
    counter.count = i
del counter.count

count_get: 0
count_set: 0
count_set: 1
count_set: 2
count_set: 3
count_set: 4
count_del: 4

How to export a mysql database using Command Prompt?

First check if your command line recognizes mysql command. If not go to command & type in:

set path=c:\wamp\bin\mysql\mysql5.1.36\bin

Then use this command to export your database:

mysqldump -u YourUser -p YourDatabaseName > wantedsqlfile.sql

You will then be prompted for the database password.

This exports the database to the path you are currently in, while executing this command

Note: Here are some detailed instructions regarding both import and export

How to detect when WIFI Connection has been established in Android?

You can register a BroadcastReceiver to be notified when a WiFi connection is established (or if the connection changed).

Register the BroadcastReceiver:

IntentFilter intentFilter = new IntentFilter();
registerReceiver(broadcastReceiver, intentFilter);

And then in your BroadcastReceiver do something like this:

public void onReceive(Context context, Intent intent) {
    final String action = intent.getAction();
    if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION)) {
        if (intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false)) {
            //do stuff
        } else {
            // wifi connection was lost

For more info, see the documentation for BroadcastReceiver and WifiManager

Of course you should check whether the device is already connected to WiFi before this.

EDIT: Thanks to ban-geoengineering, here's a method to check whether the device is already connected:

private boolean isConnectedViaWifi() {
     ConnectivityManager connectivityManager = (ConnectivityManager) appObj.getSystemService(Context.CONNECTIVITY_SERVICE);
     NetworkInfo mWifi = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);     
     return mWifi.isConnected();

Show "Open File" Dialog

I agree John M has best answer to OP's question. Thought not explictly stated, the apparent purpose is to get a selected file name, whereas other answers return either counts or lists. I would add, however, that the msofiledialogfilepicker might be a better option in this case. ie:

Dim f As object
Set f = Application.FileDialog(msoFileDialogFilePicker)
dim varfile as variant
with f
    .allowmultiselect = false
     for each varfile in .selecteditems
        msgbox varfile
     next varfile
end with

Note: the value of varfile will remain the same since multiselect is false (only one item is ever selected). I used its value outside the loop with equal success. It's probably better practice to do it as John M did, however. Also, the folder picker can be used to get a selected folder. I always prefer late binding, but I think the object is native to the default access library, so it may not be necessary here

How can I use a local image as the base image with a dockerfile?

Remember to put not only the tag but also the repository in which that tag is, this way:

docker images
REPOSITORY                                TAG                       IMAGE ID            CREATED             SIZE
elixir                                    1.7-centos7_3             e15e6bf57262        20 hours ago        925MB

You should reference it this way:


The executable gets signed with invalid entitlements in Xcode

I was able to fix this by toggling on/off "Game Center" entitlement in Xcode 5 :-)

How to remove a directory from git repository?

You can delete the folder locally and then push, as follow:

git rm -r folder_name
git commit -m "your commit"
git push origin master

How to log as much information as possible for a Java Exception?

What's wrong with the printStacktrace() method provided by Throwable (and thus every exception)? It shows all the info you requested, including the type, message, and stack trace of the root exception and all (nested) causes. In Java 7, it even shows you the information about "supressed" exceptions that might occur in a try-with-resources statement.

Of course you wouldn't want to write to System.err, which the no-argument version of the method does, so instead use one of the available overloads.

In particular, if you just want to get a String:

  Exception e = ...
  StringWriter sw = new StringWriter();
  e.printStackTrace(new PrintWriter(sw));
  String exceptionDetails = sw.toString();

If you happen to use the great Guava library, it provides a utility method doing this:

Excel how to fill all selected blank cells with text

Here's a tricky way to do this - select the cells that you want to replace and in Excel 2010 select F5 to bring up the "goto" box. Hit the "special" button. Select "blanks" - this should select all the cells that are blank. Enter NULL or whatever you want in the formula box and hit ctrl + enter to apply to all selected cells. Easy!