Programs & Examples On #Scalatra

Scalatra is a tiny Scala web framework, inspired by Sinatra.

How to copy folders to docker image from Dockerfile?

Suppose you want to copy the contents from a folder where you have docker file into your container. Use ADD:

RUN mkdir /temp
ADD folder /temp/Newfolder  

it will add to your container with temp/newfolder

folder is the folder/directory where you have the dockerfile, more concretely, where you put your content and want to copy that.

Now can you check your copied/added folder by runining container and see the content using ls

Get current index from foreach loop

You can't, because IEnumerable doesn't have an index at all... if you are sure your enumerable has less than int.MaxValue elements (or long.MaxValue if you use a long index), you can:

  1. Don't use foreach, and use a for loop, converting your IEnumerable to a generic enumerable first:

    var genericList = list.Cast<object>();
    for(int i = 0; i < genericList.Count(); ++i)
       var row = genericList.ElementAt(i);
       /* .... */
  2. Have an external index:

    int i = 0;
    foreach(var row in list)
       /* .... */
  3. Get the index via Linq:

    foreach(var rowObject in list.Cast<object>().Select((r, i) => new {Row=r, Index=i}))
      var row = rowObject.Row;
      var i = rowObject.Index;
      /* .... */    

In your case, since your IEnumerable is not a generic one, I'd rather use the foreach with external index (second method)... otherwise, you may want to make the Cast<object> outside your loop to convert it to an IEnumerable<object>.

Your datatype is not clear from the question, but I'm assuming object since it's an items source (it could be DataGridRow)... you may want to check if it's directly convertible to a generic IEnumerable<object> without having to call Cast<object>(), but I'll make no such assumptions.

All this said:

The concept of an "index" is foreign to an IEnumerable. An IEnumerable can be potentially infinite. In your example, you are using the ItemsSource of a DataGrid, so more likely your IEnumerable is just a list of objects (or DataRows), with a finite (and hopefully less than int.MaxValue) number of members, but IEnumerable can represent anything that can be enumerated (and an enumeration can potentially never end).

Take this example:

public static IEnumerable InfiniteEnumerable()
  var rnd = new Random();
    yield return rnd.Next();

So if you do:

foreach(var row in InfiniteEnumerable())
  /* ... */

Your foreach will be infinite: if you used an int (or long) index, you'll eventually overflow it (and unless you use an unchecked context, it'll throw an exception if you keep adding to it: even if you used unchecked, the index would be meaningless also... at some point -when it overflows- the index will be the same for two different values).

So, while the examples given work for a typical usage, I'd rather not use an index at all if you can avoid it.

SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: YES) Symfony2

Ok, so this might not fix your issue but it definitely worked for me.

So you've created your Mysql user I take it? Go to user privileges on PhpMyAdmin and click edit next to the user your using for Symfony. Scroll down to near the bottom and where it says which host you want to use make sure you've selected LocalHost not % Any.

Then in your config file swap for localhost. Hopefully that will work for you. Just worked for me as I was having the same issue.

How to make a flex item not fill the height of the flex container?

When you create a flex container various default flex rules come into play.

Two of these default rules are flex-direction: row and align-items: stretch. This means that flex items will automatically align in a single row, and each item will fill the height of the container.

If you don't want flex items to stretch – i.e., like you wrote:

make its height the minimum required for holding its content

... then simply override the default with align-items: flex-start.

#a {_x000D_
  display: flex;_x000D_
  align-items: flex-start; /* NEW */_x000D_
#a > div {_x000D_
  background-color: red;_x000D_
  padding: 5px;_x000D_
  margin: 2px;_x000D_
#b {_x000D_
  height: auto;_x000D_
<div id="a">_x000D_
  <div id="b">left</div>_x000D_

Here's an illustration from the flexbox spec that highlights the five values for align-items and how they position flex items within the container. As mentioned before, stretch is the default value.

enter image description here Source: W3C

Get int value from enum in C#

I have recently converted away from using enums in my code in favour of instead using classes with protected constructors and predefined static instances (thanks to Roelof - C# Ensure Valid Enum Values - Futureproof Method).

In light of that, below's how I'd now approach this issue (including implicit conversion to/from int).

public class Question
    // Attributes
    protected int index;
    protected string name;
    // Go with a dictionary to enforce unique index
    //protected static readonly ICollection<Question> values = new Collection<Question>();
    protected static readonly IDictionary<int,Question> values = new Dictionary<int,Question>();

    // Define the "enum" values
    public static readonly Question Role = new Question(2,"Role");
    public static readonly Question ProjectFunding = new Question(3, "Project Funding");
    public static readonly Question TotalEmployee = new Question(4, "Total Employee");
    public static readonly Question NumberOfServers = new Question(5, "Number of Servers");
    public static readonly Question TopBusinessConcern = new Question(6, "Top Business Concern");

    // Constructors
    protected Question(int index, string name)
        this.index = index; = name;
        values.Add(index, this);

    // Easy int conversion
    public static implicit operator int(Question question) =>
        question.index; //nb: if question is null this will return a null pointer exception

    public static implicit operator Question(int index) =>        
        values.TryGetValue(index, out var question) ? question : null;

    // Easy string conversion (also update ToString for the same effect)
    public override string ToString() =>;

    public static implicit operator string(Question question) =>

    public static implicit operator Question(string name) =>
        name == null ? null : values.Values.FirstOrDefault(item => name.Equals(, StringComparison.CurrentCultureIgnoreCase));

    // If you specifically want a Get(int x) function (though not required given the implicit converstion)
    public Question Get(int foo) =>
        foo; //(implicit conversion will take care of the conversion for you)

The advantage of this approach is you get everything you would have from the enum, but your code's now much more flexible, so should you need to perform different actions based on the value of Question, you can put logic into Question itself (i.e. in the preferred OO fashion) as opposed to putting lots of case statements throughout your code to tackle each scenario.

NB: Answer updated 2018-04-27 to make use of C# 6 features; i.e. declaration expressions and lambda expression body definitions. See revision history for original code. This has the benefit of making the definition a little less verbose; which had been one of the main complaints about this answer's approach.

How to format a date using ng-model?

In Angular2+ for anyone interested:

<input type="text" placeholder="My Date" [ngModel]="myDate | date: 'longDate'">

with type of filters in DatePipe Angular.

What is the difference between String and string in C#?

declare a string variable with string but use the String class when accessing one of its static members:



string name = "";

Where to download visual studio express 2005?

For somebody like me who lands onto this page from Google ages after this question had been posted, you can find VS2005 here:

EDIT: In case that blog dies, here are the links from the blog.

All the bellow files are more them 400MB.

Visual Web Developer 2005 Express Edition
449,848 KB
.IMG File | .ISO File

Visual Basic 2005 Express Edition
445,282 KB
.IMG File | .ISO File

Visual C# 2005 Express Edition
445,282 KB
.IMG File | .ISO File

Visual C++ 2005 Express Edition
474,686 KB
.IMG File | .ISO File

Visual J# 2005 Express Edition
448,702 KB
.IMG File | .ISO File

How do I test a website using XAMPP?

Just make a new folder inside C:\xampp\htdocs like C:\xampp\htdocs\test and place your index.php or whatever file in it. Access it by browsing localhost/test/

Good luck!

Raw SQL Query without DbSet - Entity Framework Core

You can use this (from ) :

public static class SqlQueryExtensions
    public static IList<T> SqlQuery<T>(this DbContext db, string sql, params object[] parameters) where T : class
        using (var db2 = new ContextForQueryType<T>(db.Database.GetDbConnection()))
            return db2.Query<T>().FromSql(sql, parameters).ToList();

    private class ContextForQueryType<T> : DbContext where T : class
        private readonly DbConnection connection;

        public ContextForQueryType(DbConnection connection)
            this.connection = connection;

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
            // switch on the connection type name to enable support multiple providers
            // var name = con.GetType().Name;
            optionsBuilder.UseSqlServer(connection, options => options.EnableRetryOnFailure());


        protected override void OnModelCreating(ModelBuilder modelBuilder)

And the usage:

    using (var db = new Db())
        var results = db.SqlQuery<ArbitraryType>("select 1 id, 'joe' name");
        //or with an anonymous type like this
        var results2 = db.SqlQuery(() => new { id =1, name=""},"select 1 id, 'joe' name");

What exactly is the difference between Web API and REST API in MVC?

ASP.NET Web API is a framework that makes it easy to build HTTP services that reach a broad range of clients, including browsers and mobile devices. ASP.NET Web API is an ideal platform for building RESTful applications on the .NET Framework.


RESTs sweet spot is when you are exposing a public API over the internet to handle CRUD operations on data. REST is focused on accessing named resources through a single consistent interface.


SOAP brings it’s own protocol and focuses on exposing pieces of application logic (not data) as services. SOAP exposes operations. SOAP is focused on accessing named operations, each implement some business logic through different interfaces.

Though SOAP is commonly referred to as “web services” this is a misnomer. SOAP has very little if anything to do with the Web. REST provides true “Web services” based on URIs and HTTP.


And finally: What they could be referring to is REST vs. RPC See this:

Injecting Mockito mocks into a Spring bean

If you're using Spring Boot 1.4, it has an awesome way of doing this. Just use new brand @SpringBootTest on your class and @MockBean on the field and Spring Boot will create a mock of this type and it will inject it into the context (instead of injecting the original one):

public class MyTests {

    private RemoteService remoteService;

    private Reverser reverser;

    public void exampleTest() {
        // RemoteService has been injected into the reverser bean
        String reverse = reverser.reverseSomeCall();


On the other hand, if you're not using Spring Boot or are you using a previous version, you'll have to do a bit more work:

Create a @Configuration bean that injects your mocks into Spring context:

public class MockConfigurer {

    public MyBean myBeanSpy() {
        return mock(MyBean.class);

Using @Primary annotation you're telling spring that this bean has priority if no qualifier are specified.

Make sure you annotate the class with @Profile("useMocks") in order to control which classes will use the mock and which ones will use the real bean.

Finally, in your test, activate userMocks profile:

@SpringApplicationConfiguration(classes = {Application.class})
public class YourIntegrationTestIT {

    private MyBean myBean; //It will be the mock!

    public void test() {

If you don't want to use the mock but the real bean, just don't activate useMocks profile:

@SpringApplicationConfiguration(classes = {Application.class})
public class AnotherIntegrationTestIT {

    private MyBean myBean; //It will be the real implementation!

    public void test() {

How does Tomcat locate the webapps directory?

It can be changed in the $CATALINA_BASE/conf/server.xml in the <Host />. See the Tomcat documentation, specifically the section in regards to the Host container:

Tomcat 6 Configuration

Tomcat 7 Configuration

The default is webapps relative to the $CATALINA_BASE. An absolute pathname can be used.

Hope that helps.

convert '1' to '0001' in JavaScript

This is a clever little trick (that I think I've seen on SO before):

var str = "" + 1
var pad = "0000"
var ans = pad.substring(0, pad.length - str.length) + str

JavaScript is more forgiving than some languages if the second argument to substring is negative so it will "overflow correctly" (or incorrectly depending on how it's viewed):

That is, with the above:

  • 1 -> "0001"
  • 12345 -> "12345"

Supporting negative numbers is left as an exercise ;-)

Happy coding.

How to change the height of a div dynamically based on another div using css?

The simplest way to get equal height columns, without the ugly side effects that come along with absolute positioning, is to use the display: table properties:

.div1 {
  height: auto;
  background-color: grey;  
  border:1px solid;
  display: table;

.div2, .div3 {
  display: table-cell;
.div2 {
  background-color: #F4A460;  

.div3 {
  background-color: #FFFFE0;  

Now, if your goal is to have .div2 so that it is only as tall as it needs to be to contain its content while .div3 is at least as tall as .div2 but still able to expand if its content makes it taller than .div2, then you need to use flexbox. Flexbox support isn't quite there yet (IE10, Opera, Chrome. Firefox follows an old spec, but is following the current spec soon).

.div1 {
  height: auto;
  background-color: grey;  
  border:1px solid;
  display: flex;
  align-items: flex-start;

.div2 {
  background-color: #F4A460;

.div3 {
  background-color: #FFFFE0;
  align-self: stretch;

List All Google Map Marker Images

var pinIcon = new google.maps.MarkerImage(
    null, /* size is determined at runtime */
    null, /* origin is 0,0 */
    null, /* anchor is bottom center of the scaled image */
    new google.maps.Size(12, 18)

The import javax.servlet can't be resolved

Had the same problem in Eclipse. For some reason I didn't have the servlet.jar file in my build path. What I wound up doing was copying a "lib" folder from another project of mine to the project I was working on, then manually going into that folder and adding the servlet.jar file to the build path (option shows up when you right-click on the file in the project explorer).

How can I delete a newline if it is the last character in a file?

Assuming Unix file type and you only want the last newline this works.

sed -e '${/^$/d}'

It will not work on multiple newlines...

* Works only if the last line is a blank line.

Allow only numbers to be typed in a textbox

With HTML5 you can do

<input type="number">

You can also use a regex pattern to limit the input text.

<input type="text" pattern="^[0-9]*$" />

How to convert Json array to list of objects in c#

Json Convert To C# Class =

after the schema comes out

        WebClient client = new WebClient();

        client.Encoding = Encoding.UTF8;

        string myJSON = client.DownloadString("http://xxx/xx/xx.json");

        var valueSet = JsonConvert.DeserializeObject<Root>(myJSON);

The biggest one of our mistakes is that we can't match the class structure with json.

This connection will do the process automatically. You will code it later ;) =

that's it.

Custom exception type

You could implement your own exceptions and their handling for example like here:

// define exceptions "classes" 
function NotNumberException() {}
function NotPositiveNumberException() {}

// try some code
try {
    // some function/code that can throw
    if (isNaN(value))
        throw new NotNumberException();
    if (value < 0)
        throw new NotPositiveNumberException();
catch (e) {
    if (e instanceof NotNumberException) {
        alert("not a number");
    if (e instanceof NotPositiveNumberException) {
        alert("not a positive number");

There is another syntax for catching a typed exception, although this won't work in every browser (for example not in IE):

// define exceptions "classes" 
function NotNumberException() {}
function NotPositiveNumberException() {}

// try some code
try {
    // some function/code that can throw
    if (isNaN(value))
        throw new NotNumberException();
    if (value < 0)
        throw new NotPositiveNumberException();
catch (e if e instanceof NotNumberException) {
    alert("not a number");
catch (e if e instanceof NotPositiveNumberException) {
    alert("not a positive number");

Check a radio button with javascript

Do not mix CSS/JQuery syntax (# for identifier) with native JS.

Native JS solution:

document.getElementById("_1234").checked = true;

JQuery solution:

$("#_1234").prop("checked", true);

Find length (size) of an array in jquery

       var mode = [];
                $("input[name='mode[]']:checked").each(function(i) {
 if(mode.length == 0)
                   alert('Please select mode!')

How to declare a inline object with inline variables without a parent class

You can also do this:

var x = new object[] {
    new { firstName = "john", lastName = "walter" },
    new { brand = "BMW" }

And if they are the same anonymous type (firstName and lastName), you won't need to cast as object.

var y = new [] {
    new { firstName = "john", lastName = "walter" },
    new { firstName = "jill", lastName = "white" }

Convert bytes to bits in python

To binary:


How can I capitalize the first letter of each word in a string?

Capitalize string with non-uniform spaces

I would like to add to @Amit Gupta's point of non-uniform spaces:

From the original question, we would like to capitalize every word in the string s = 'the brown fox'. What if the string was s = 'the brown fox' with non-uniform spaces.

def solve(s):
    # If you want to maintain the spaces in the string, s = 'the brown      fox'
    # Use s.split(' ') instead of s.split().
    # s.split() returns ['the', 'brown', 'fox']
    # while s.split(' ') returns ['the', 'brown', '', '', '', '', '', 'fox']
    capitalized_word_list = [word.capitalize() for word in s.split(' ')]
    return ' '.join(capitalized_word_list)

Google Maps Api v3 - find nearest markers

I'd like to expand on Leor's suggestion for anyone confused on how to compute the nearest location and actually provide a working solution:

I'm using markers in a markers array e.g. var markers = [];.

Then let's have our position as something like var location = new google.maps.LatLng(51.99, -0.74);

Then we simply reduce our markers against the location we have like so:

markers.reduce(function (prev, curr) {

    var cpos = google.maps.geometry.spherical.computeDistanceBetween(location.position, curr.position);
    var ppos = google.maps.geometry.spherical.computeDistanceBetween(location.position, prev.position);

    return cpos < ppos ? curr : prev;


What pops out is your closest marker LatLng object.

Adding custom radio buttons in android

Simple way try this

  1. Create a new layout in drawable folder and name it custom_radiobutton (You can rename also)

     <?xml version="1.0" encoding="utf-8"?>
      <selector xmlns:android="" >
     <item android:state_checked="false" 
    android:drawable="@drawable/your_radio_off_image_name" />
     <item android:state_checked="true" 
    android:drawable="@drawable/your_radio_on_image_name" />
  2. Use this in your layout activity


How to extract the first two characters of a string in shell scripting?

If you want to use shell scripting and not rely on non-posix extensions (such as so-called bashisms), you can use techniques that do not require forking external tools such as grep, sed, cut, awk, etc., which then make your script less efficient. Maybe efficiency and posix portability is not important in your use case. But in case it is (or just as a good habit), you can use the following parameter expansion option method to extract the first two characters of a shell variable:

$ sh -c 'var=abcde; echo "${var%${var#??}}"'

This uses "smallest prefix" parameter expansion to remove the first two characters (this is the ${var#??} part), then "smallest suffix" parameter expansion (the ${var% part) to remove that all-but-the-first-two-characters string from the original value.

This method was previously described in this answer to the "Shell = Check if variable begins with #" question. That answer also describes a couple similar parameter expansion methods that can be used in a slightly different context that the one that applies to the original question here.

C convert floating point to int

Use in C

int C = var_in_float;

They will convert implicit

NSOperation vs Grand Central Dispatch

GCD is indeed lower-level than NSOperationQueue, its major advantage is that its implementation is very light-weight and focused on lock-free algorithms and performance.

NSOperationQueue does provide facilities that are not available in GCD, but they come at non-trivial cost, the implementation of NSOperationQueue is complex and heavy-weight, involves a lot of locking, and uses GCD internally only in a very minimal fashion.

If you need the facilities provided by NSOperationQueue by all means use it, but if GCD is sufficient for your needs, I would recommend using it directly for better performance, significantly lower CPU and power cost and more flexibility.

.htaccess file to allow access to images folder to view pictures?

Create a .htaccess file in the images folder and add this

<IfModule mod_rewrite.c>
RewriteEngine On
# directory browsing
Options All +Indexes

you can put this Options All -Indexes in the project file .htaccess ,file to deny direct access to other folders.

This does what you want

How to synchronize a static variable among threads running different instances of a class in Java?

There are several ways to synchronize access to a static variable.

  1. Use a synchronized static method. This synchronizes on the class object.

    public class Test {
        private static int count = 0;
        public static synchronized void incrementCount() {
  2. Explicitly synchronize on the class object.

    public class Test {
        private static int count = 0;
        public void incrementCount() {
            synchronized (Test.class) {
  3. Synchronize on some other static object.

    public class Test {
        private static int count = 0;
        private static final Object countLock = new Object();
        public void incrementCount() {
            synchronized (countLock) {

Method 3 is the best in many cases because the lock object is not exposed outside of your class.

foreach loop in angularjs

you have to use nested angular.forEach loops for JSON as shown below:

 var values = [

        angular.forEach(value,function(v1,k1){//this is nested angular.forEach loop

How do I create a file at a specific path?

The file path "c:\Test\blah" will have a tab character for the `\T'. You need to use either:




How to update values using pymongo?

With my pymongo version: 3.2.2 I had do the following

from bson.objectid import ObjectId
import pymongo

client = pymongo.MongoClient("localhost", 27017)
db = client.mydbname

  '_id': ObjectId(p['_id']['$oid'])
  '$set': {
    'd.a': existing + 1
}, upsert=False)

Difference between two DateTimes C#?

var theDiff24 = (b-a).Hours

How to vertically align text with icon font?

To expand on Marian Udrea's answer: In my scenario, I was trying to align the text with a material icon. There's something weird about material icons that prevented it from being aligned. None of the answers were working, until I added the vertical-align to the icon element, instead of the parent element.

So, if the icon is 24px in height:

.parent {
    line-height: 24px; // Same as icon height

    i.material-icons {  // Only if you're using material icons
      display: inline-flex;
      vertical-align: top;

How to create a file in a directory in java?

A better and simpler way to do that :

File f = new File("C:/a/b/test.txt");


Windows-1252 to UTF-8 encoding

There's no general way to tell if a file is encoded with a specific encoding. Remember that an encoding is nothing more but an "agreement" how the bits in a file should be mapped to characters.

If you don't know which of your files are actually already encoded in UTF-8 and which ones are encoded in windows-1252, you will have to inspect all files and find out yourself. In the worst case that could mean that you have to open every single one of them with either of the two encodings and see whether they "look" correct -- i.e., all characters are displayed correctly. Of course, you may use tool support in order to do that, for instance, if you know for sure that certain characters are contained in the files that have a different mapping in windows-1252 vs. UTF-8, you could grep for them after running the files through 'iconv' as mentioned by Seva Akekseyev.

Another lucky case for you would be, if you know that the files actually contain only characters that are encoded identically in both UTF-8 and windows-1252. In that case, of course, you're done already.

Simple and fast method to compare images for similarity

If you want to get an index about the similarity of the two pictures, I suggest you from the metrics the SSIM index. It is more consistent with the human eye. Here is an article about it: Structural Similarity Index

It is implemented in OpenCV too, and it can be accelerated with GPU: OpenCV SSIM with GPU

how to create Socket connection in Android?

Here, in this post you will find the detailed code for establishing socket between devices or between two application in the same mobile.

You have to create two application to test below code.

In both application's manifest file, add below permission

<uses-permission android:name="android.permission.INTERNET" />

1st App code: Client Socket


<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android=""


            android:hint="Enter message"
            android:inputType="text" />

            android:text="Send" />


            android:orientation="vertical" />

import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


 * Created by Girish Bhalerao on 5/4/2017.
public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private TextView mTextViewReplyFromServer;
    private EditText mEditTextSendMessage;

    protected void onCreate(Bundle savedInstanceState) {

        Button buttonSend = (Button) findViewById(;

        mEditTextSendMessage = (EditText) findViewById(;
        mTextViewReplyFromServer = (TextView) findViewById(;


    public void onClick(View v) {

        switch (v.getId()) {


    private void sendMessage(final String msg) {

        final Handler handler = new Handler();
        Thread thread = new Thread(new Runnable() {
            public void run() {

                try {
                    //Replace below IP with the IP of that device in which server socket open.
                    //If you change port then change the port number in the server side code also.
                    Socket s = new Socket("", 9002);

                    OutputStream out = s.getOutputStream();

                    PrintWriter output = new PrintWriter(out);

                    BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
                    final String st = input.readLine();

           Runnable() {
                        public void run() {

                            String s = mTextViewReplyFromServer.getText().toString();
                            if (st.trim().length() != 0)
                                mTextViewReplyFromServer.setText(s + "\nFrom Server : " + st);

                } catch (IOException e) {


2nd App Code - Server Socket


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android=""

        android:text="STOP Receiving data"
        android:layout_marginTop="89dp" />


            android:orientation="vertical" />

        android:text="START Receiving data"
        android:layout_marginTop="14dp" />

import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


 * Created by Girish Bhalerao on 5/4/2017.
public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    final Handler handler = new Handler();

    private Button buttonStartReceiving;
    private Button buttonStopReceiving;
    private TextView textViewDataFromClient;
    private boolean end = false;

    protected void onCreate(Bundle savedInstanceState) {

        buttonStartReceiving = (Button) findViewById(;
        buttonStopReceiving = (Button) findViewById(;
        textViewDataFromClient = (TextView) findViewById(;



    private void startServerSocket() {

        Thread thread = new Thread(new Runnable() {

            private String stringData = null;

            public void run() {

                try {

                    ServerSocket ss = new ServerSocket(9002);

                    while (!end) {
                        //Server is waiting for client here, if needed
                        Socket s = ss.accept();
                        BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
                        PrintWriter output = new PrintWriter(s.getOutputStream());

                        stringData = input.readLine();
                        output.println("FROM SERVER - " + stringData.toUpperCase());

                        try {
                        } catch (InterruptedException e) {
                        if (stringData.equalsIgnoreCase("STOP")) {
                            end = true;

                } catch (IOException e) {


    private void updateUI(final String stringData) { Runnable() {
            public void run() {

                String s = textViewDataFromClient.getText().toString();
                if (stringData.trim().length() != 0)
                    textViewDataFromClient.setText(s + "\n" + "From Client : " + stringData);

    public void onClick(View v) {

        switch (v.getId()) {



                //stopping server socket logic you can add yourself

Manage toolbar's navigation and back button from fragment in android

First you add the Navigation back button


Then, add the Method in your HostActivity.

public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId()
        Toast.makeText(this, "OnBAckPressed Works", Toast.LENGTH_SHORT).show();

    return super.onOptionsItemSelected(item);

Try this, definitely work.

how to get current location in google map android

Location locaton;

private GoogleMap mMap;

protected void onCreate(Bundle savedInstanceState) {
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()

public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {


    mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
        public void onMyLocationChange(Location location) {

            CameraUpdate center = CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude()));
            CameraUpdate zoom = CameraUpdateFactory.zoomTo(11);

            MarkerOptions mp = new MarkerOptions();

            mp.position(new LatLng(location.getLatitude(), location.getLongitude()));

            mp.title("my position");



Check if table exists and if it doesn't exist, create it in SQL Server 2008

Something like this

IF  NOT EXISTS (SELECT * FROM sys.objects 
WHERE object_id = OBJECT_ID(N'[dbo].[YourTable]') AND type in (N'U'))

CREATE TABLE [dbo].[YourTable](


NodeJS w/Express Error: Cannot GET /

I had the same problem, so here's what I came up with. This is what my folder structure looked like when I ran node server.js


After printing out the __dirname path, I realized that the __dirname path was where my server was running (app/).

So, the answer to your question is this:

If your server.js file is in the same folder as the files you are trying to render, then

app.use(express.static(__dirname + '/default.htm'));

should actually be


The only time you would want to use the original syntax that you had would be if you had a folder tree like so:


where index.html is in the app/ directory, whereas server.js is in the root directory (i.e. the same level as the app/ directory).

Overall, your code could look like:

var express = require('express');

var app = express();



Decreasing for loops in Python impossible?

0 is conditional value when this condition is true, loop will keep executing.10 is the initial value. 1 is the modifier where may be simple decrement.

for number in reversed(range(0,10,1)):
print number;

Rails: Get Client IP address

request.remote_ip is an interpretation of all the available IP address information and it will make a best-guess. If you access the variables directly you assume responsibility for testing them in the correct precedence order. Proxies introduce a number of headers that create environment variables with different names.

WebDriver: check if an element exists?

you can do an assertion.

see the example

driver.asserts().assertElementFound("Page was not loaded",

you can use this this is native :

public static void waitForElementToAppear(Driver driver, By selector, long timeOutInSeconds, String timeOutMessage) {
    try {
      WebDriverWait wait = new WebDriverWait(driver, timeOutInSeconds);
    } catch (TimeoutException e) {
      throw new IllegalStateException(timeOutMessage);

Why does Eclipse complain about @Override on interface methods?

Even after changing the compiler compliance setting to 1.6 or 1.7 from windows tab, then prefernces, then java, then compiler and setting the compiler compliance, I was still having this issue. The idea is that we need to go the the project folder, right click, Java and set compiler compliance to 1.6 or higer. This worked for me.

Git status shows files as changed even though contents are the same

Update: as per the comment on this question, the problem has been solved:

That is easy: the first file has CRLF line-ends (windows), the second LF (Unix). The file util (available in git\usr\bin) will show you that (file a b will reply something like a: ASCII text, with CRLF line terminators b: ASCII text)

Original answer below:

The diff you show does not show a single different line. Can you post .git/config (or better git config -l).

You might have some whitespace ignores activated

You should try to disable core.whitespace=fix,-indent-with-non-tab,trailing-space,cr-at-eol;


git show HEAD:myfile|md5sum
md5sum myfile

could be used to verify that the files are in fact different. Using external diff could work as well

git show HEAD:myfile > /tmp/myfile.HEAD

diff -u myfile /tmp/myfile.HEAD

# or if you prefer an interactive tool like e.g.:
vim -d myfile /tmp/myfile.HEAD

Uncaught syntaxerror: unexpected identifier?

There are errors here :

var formTag = document.getElementsByTagName("form"), // form tag is an array
selectListItem = $('select'),
makeSelect = document.createElement('select'),
makeSelect.setAttribute("id", "groups");

The code must change to:

var formTag = document.getElementsByTagName("form");
var selectListItem = $('select');
var makeSelect = document.createElement('select');
makeSelect.setAttribute("id", "groups");

By the way, there is another error at line 129 :

var createLi.appendChild(createSubList);

Replace it with:


Pipe to/from the clipboard in Bash script

xsel on Debian/Ubuntu/Mint

# append to clipboard:
cat 'the file with content' | xsel -ib

# or type in the happy face :) and ...
echo 'the happy face :) and content' | xsel -ib

# show clipboard
xsel -b

# Get more info:
man xsel


sudo apt-get install xsel

Javascript Confirm popup Yes, No button instead of OK and Cancel

1) You can download and upload below files on your site

<link href="/Style%20Library/css/smoothness/jquery.alerts.css" type="text/css" rel="stylesheet"/> 

2) after that you can directly use below code

$.alerts.okButton = "yes"; $.alerts.cancelButton = "no";

in document.ready function.

Please try it will work.


How to deserialize JS date using Jackson?

@JsonFormat only work for standard format supported by the jackson version that you are using.

Ex :- compatible with any of standard forms ("yyyy-MM-dd'T'HH:mm:ss.SSSZ", "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", "EEE, dd MMM yyyy HH:mm:ss zzz", "yyyy-MM-dd")) for jackson 2.8.6

Java: Local variable mi defined in an enclosing scope must be final or effectively final

As I can see the array is of String only.For each loop can be used to get individual element of the array and put them in local inner class for use.

Below is the code snippet for it :

    for (String color : colors ){

String pos = Character.toUpperCase(color.charAt(0)) + color.substring(1);
JMenuItem Jmi =new JMenuItem(pos);
Jmi.setIcon(new IconA(color));

Jmi.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            JMenuItem item = (JMenuItem) e.getSource();
            IconA icon = (IconA) item.getIcon();
            // HERE YOU USE THE String color variable and no errors!!!
            Color kolorIkony = getColour(color); 



Upload files with HTTPWebrequest (multipart/form-data)

I had to deal with this recently - another way to approach it is to use the fact that WebClient is inheritable, and change the underlying WebRequest from there:

I prefer C#, but if you're stuck with VB the results will look something like this:

Public Class BigWebClient
    Inherits WebClient
    Protected Overrides Function GetWebRequest(ByVal address As System.Uri) As System.Net.WebRequest
        Dim x As WebRequest = MyBase.GetWebRequest(address)
        x.Timeout = 60 * 60 * 1000
        Return x
    End Function
End Class

'Use BigWebClient here instead of WebClient

Matplotlib color according to class labels

A simple solution is to assign color for each class. This way, we can control how each color is for each class. For example:

arr1 = [1, 2, 3, 4, 5]
arr2 = [2, 3, 3, 4, 4]
labl = [0, 1, 1, 0, 0]
color= ['red' if l == 0 else 'green' for l in labl]
plt.scatter(arr1, arr2, color=color)

How to get MAC address of client using PHP?


    $findme = "Physical";
    $pmac = strpos($mycom, $findme); 

    echo $mac;

This prints the mac address of client machine

How to use ESLint with Jest

I solved the problem REF


# For Yarn
yarn add eslint-plugin-jest -D

# For NPM
npm i eslint-plugin-jest -D

And then add in your .eslintrc file

    "extends": ["airbnb","plugin:jest/recommended"],

If '<selector>' is an Angular component, then verify that it is part of this module

In my case I had a component in a Shared module.

The component was loading and worked well but typescript was highlighting the html tag with red line and showed this error message.

Inside this component, I noticed I didn't import a rxjs operator.

import {map} from 'rxjs/operators';

When I added this import the error message disappeared.

Check all imports inside the component.

Hope it helps someone.

ASP.NET Identity DbContext confusion

There is a lot of confusion about IdentityDbContext, a quick search in Stackoverflow and you'll find these questions:
" Why is Asp.Net Identity IdentityDbContext a Black-Box?
How can I change the table names when using Visual Studio 2013 AspNet Identity?
Merge MyDbContext with IdentityDbContext"

To answer to all of these questions we need to understand that IdentityDbContext is just a class inherited from DbContext.
Let's take a look at IdentityDbContext source:

/// <summary>
/// Base class for the Entity Framework database context used for identity.
/// </summary>
/// <typeparam name="TUser">The type of user objects.</typeparam>
/// <typeparam name="TRole">The type of role objects.</typeparam>
/// <typeparam name="TKey">The type of the primary key for users and roles.</typeparam>
/// <typeparam name="TUserClaim">The type of the user claim object.</typeparam>
/// <typeparam name="TUserRole">The type of the user role object.</typeparam>
/// <typeparam name="TUserLogin">The type of the user login object.</typeparam>
/// <typeparam name="TRoleClaim">The type of the role claim object.</typeparam>
/// <typeparam name="TUserToken">The type of the user token object.</typeparam>
public abstract class IdentityDbContext<TUser, TRole, TKey, TUserClaim, TUserRole, TUserLogin, TRoleClaim, TUserToken> : DbContext
    where TUser : IdentityUser<TKey, TUserClaim, TUserRole, TUserLogin>
    where TRole : IdentityRole<TKey, TUserRole, TRoleClaim>
    where TKey : IEquatable<TKey>
    where TUserClaim : IdentityUserClaim<TKey>
    where TUserRole : IdentityUserRole<TKey>
    where TUserLogin : IdentityUserLogin<TKey>
    where TRoleClaim : IdentityRoleClaim<TKey>
    where TUserToken : IdentityUserToken<TKey>
    /// <summary>
    /// Initializes a new instance of <see cref="IdentityDbContext"/>.
    /// </summary>
    /// <param name="options">The options to be used by a <see cref="DbContext"/>.</param>
    public IdentityDbContext(DbContextOptions options) : base(options)
    { }

    /// <summary>
    /// Initializes a new instance of the <see cref="IdentityDbContext" /> class.
    /// </summary>
    protected IdentityDbContext()
    { }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of Users.
    /// </summary>
    public DbSet<TUser> Users { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of User claims.
    /// </summary>
    public DbSet<TUserClaim> UserClaims { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of User logins.
    /// </summary>
    public DbSet<TUserLogin> UserLogins { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of User roles.
    /// </summary>
    public DbSet<TUserRole> UserRoles { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of User tokens.
    /// </summary>
    public DbSet<TUserToken> UserTokens { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of roles.
    /// </summary>
    public DbSet<TRole> Roles { get; set; }

    /// <summary>
    /// Gets or sets the <see cref="DbSet{TEntity}"/> of role claims.
    /// </summary>
    public DbSet<TRoleClaim> RoleClaims { get; set; }

    /// <summary>
    /// Configures the schema needed for the identity framework.
    /// </summary>
    /// <param name="builder">
    /// The builder being used to construct the model for this context.
    /// </param>
    protected override void OnModelCreating(ModelBuilder builder)
        builder.Entity<TUser>(b =>
            b.HasKey(u => u.Id);
            b.HasIndex(u => u.NormalizedUserName).HasName("UserNameIndex").IsUnique();
            b.HasIndex(u => u.NormalizedEmail).HasName("EmailIndex");
            b.Property(u => u.ConcurrencyStamp).IsConcurrencyToken();

            b.Property(u => u.UserName).HasMaxLength(256);
            b.Property(u => u.NormalizedUserName).HasMaxLength(256);
            b.Property(u => u.Email).HasMaxLength(256);
            b.Property(u => u.NormalizedEmail).HasMaxLength(256);
            b.HasMany(u => u.Claims).WithOne().HasForeignKey(uc => uc.UserId).IsRequired();
            b.HasMany(u => u.Logins).WithOne().HasForeignKey(ul => ul.UserId).IsRequired();
            b.HasMany(u => u.Roles).WithOne().HasForeignKey(ur => ur.UserId).IsRequired();

        builder.Entity<TRole>(b =>
            b.HasKey(r => r.Id);
            b.HasIndex(r => r.NormalizedName).HasName("RoleNameIndex");
            b.Property(r => r.ConcurrencyStamp).IsConcurrencyToken();

            b.Property(u => u.Name).HasMaxLength(256);
            b.Property(u => u.NormalizedName).HasMaxLength(256);

            b.HasMany(r => r.Users).WithOne().HasForeignKey(ur => ur.RoleId).IsRequired();
            b.HasMany(r => r.Claims).WithOne().HasForeignKey(rc => rc.RoleId).IsRequired();

        builder.Entity<TUserClaim>(b => 
            b.HasKey(uc => uc.Id);

        builder.Entity<TRoleClaim>(b => 
            b.HasKey(rc => rc.Id);

        builder.Entity<TUserRole>(b => 
            b.HasKey(r => new { r.UserId, r.RoleId });

        builder.Entity<TUserLogin>(b =>
            b.HasKey(l => new { l.LoginProvider, l.ProviderKey });

        builder.Entity<TUserToken>(b => 
            b.HasKey(l => new { l.UserId, l.LoginProvider, l.Name });

Based on the source code if we want to merge IdentityDbContext with our DbContext we have two options:

First Option:
Create a DbContext which inherits from IdentityDbContext and have access to the classes.

   public class ApplicationDbContext 
    : IdentityDbContext
    public ApplicationDbContext()
        : base("DefaultConnection")

    static ApplicationDbContext()
        Database.SetInitializer<ApplicationDbContext>(new ApplicationDbInitializer());

    public static ApplicationDbContext Create()
        return new ApplicationDbContext();

    // Add additional items here as needed

Extra Notes:

1) We can also change Identity default table names with the following solution:

    public class ApplicationDbContext : IdentityDbContext
        public ApplicationDbContext(): base("DefaultConnection")

        protected override void OnModelCreating(System.Data.Entity.DbModelBuilder modelBuilder)


2) Furthermore we can extend each class and add any property to classes like 'IdentityUser', 'IdentityRole', ...

    public class ApplicationRole : IdentityRole<string, ApplicationUserRole>
    public ApplicationRole() 
        this.Id = Guid.NewGuid().ToString();

    public ApplicationRole(string name)
        : this()
        this.Name = name;

    // Add any custom Role properties/code here

// Must be expressed in terms of our custom types:
public class ApplicationDbContext 
    : IdentityDbContext<ApplicationUser, ApplicationRole, 
    string, ApplicationUserLogin, ApplicationUserRole, ApplicationUserClaim>
    public ApplicationDbContext()
        : base("DefaultConnection")

    static ApplicationDbContext()
        Database.SetInitializer<ApplicationDbContext>(new ApplicationDbInitializer());

    public static ApplicationDbContext Create()
        return new ApplicationDbContext();

    // Add additional items here as needed

To save time we can use AspNet Identity 2.0 Extensible Project Template to extend all the classes.

Second Option:(Not recommended)
We actually don't have to inherit from IdentityDbContext if we write all the code ourselves.
So basically we can just inherit from DbContext and implement our customized version of "OnModelCreating(ModelBuilder builder)" from the IdentityDbContext source code

display HTML page after loading complete

you can also go for this.... this will only show the HTML section once javascript has loaded.

<!-- Adds the hidden style and removes it when javascript has loaded -->
<style type="text/css">
    .hideAll  {

<script type="text/javascript">
    $(window).load(function () {

<div id="tabs" class="hideAll">

How to prevent sticky hover effects for buttons on touch devices

I went through the similar problem, my application was compatible for all screen sizes had a hell lot of hover effects in the desktop-screen-size / mouse based devices , and later on I realised that touch based devices were causing a condition known as sticky-hover and it was an hurdle for the app to work properly for touch based device users.

We were making use of SCSS in our app. and I defined a mixin to take care of touch based device.

@mixin hover-support {
  @media not all and (pointer: coarse) {
    &:hover {

and then I placed all my css classes under the below-mentioned snippet.

   @include hover-support() {
    // Your css-classes or css that you want to apply on those devices that support hover.

For instance we had a class for animating an icon, and which used to trigger once we hover over icon as you can see it from css, but in touch based device it was getting affected by sticky hover-effect and then I placed it inside @include hover-support() in order to ensure that hover only applies to those devices that support hover.

@include hover-support() {
  .animate-icon {
    -webkit-transition: all 0.2s;
    transition: all 0.2s;
    &:hover {
      transform: scale(1.3);
      filter: brightness(85%);
      cursor: pointer;

What USB driver should we use for the Nexus 5?

I just wanted to bring a small contribution, because I have been able to debug on my Nexus 5 device on Windows 8, without doing all of this.

When I plugged it, there wasn't any yellow exclamation mark within Device Manager. So for me, the drivers were OK. But the device was not listed within my Eclipse DDMS. After a little bit of searching, it was just an option to change in the device settings. By default, the Nexus 5 USB computer connection is in MTP mode (Media Device).

What you have to do is:

  • Unplug the device from the computer
  • Go to Settings -> Storage.
  • In the ActionBar, click the option menu and choose "USB computer connection".
  • Check "Camera (PTP)" connection.
  • Plug the device and you should have a popup on the device allowing you to accept the computer's incoming connection, or something like that.
  • Finally, you should see it now in the DDMS and voilà.

I hope this will help!

How do I find which transaction is causing a "Waiting for table metadata lock" state?

mysql 5.7 exposes metadata lock information through the performance_schema.metadata_locks table.

Documentation here

Is it possible to run a .NET 4.5 app on XP?

Try mono:

This download works on all versions of Windows XP, 2003, Vista and Windows 7.

What's the easiest way to escape HTML in Python?

For legacy code in Python 2.7, can do it via BeautifulSoup4:

>>> bs4.dammit import EntitySubstitution
>>> esub = EntitySubstitution()
>>> esub.substitute_html("r&d")

How to create a new figure in MATLAB?

The other thing to be careful about, is to use the clf (clear figure) command when you are starting a fresh plot. Otherwise you may be plotting on a pre-existing figure (not possible with the figure command by itself, but if you do figure(2) there may already be a figure #2), with more than one axis, or an axis that is placed kinda funny. Use clf to ensure that you're starting from scratch:


How to access the elements of a 2D array?

Look carefully how many brackets does your array have. I met an example when function returned answer with extra bracket, like that:

array([[[1192,  391]],
       [[1191,  409]],
       [[1209,  438]],
       [[1191,  409]]])

And this didn't work

>>> approx[1,1]
IndexError: index 1 is out of bounds for axis 1 with size 1

This could open the brackets:

>>> approx[:,0]
array([[1192,  391],
       [1191,  409],
       [1209,  438],
       [1191,  409]])

Now it is possible to use an ordinary element access notation:

>>> approx[:,0][1,1]

Get Android .apk file VersionName or VersionCode WITHOUT installing apk

Using apkanalyzer that is now part of cmdline-tools:

$ apkanalyzer manifest version-code my_app.apk
$ apkanalyzer manifest version-name my_app.apk

Run "mvn clean install" in Eclipse

You can create external command Run -> External Tools -> External Tools Configuration...

It will be available under Run -> External Tools and can be run using shortcuts.

mysql stored-procedure: out parameter

try changing OUT to INOUT for your out_number parameter definition.

CREATE PROCEDURE my_sqrt(input_number INT, INOUT out_number FLOAT)

INOUT means that the input variable for out_number (@out_value in your case.) will also serve as the output variable from which you can select the value from.

Virtual/pure virtual explained

  • Virtual functions must have a definition in base class and also in derived class but not necessary, for example ToString() or toString() function is a Virtual so you can provide your own implementation by overriding it in user-defined class(es).

  • Virtual functions are declared and defined in normal class.

  • Pure virtual function must be declared ending with "= 0" and it can only be declared in abstract class.

  • An abstract class having a pure virtual function(s) cannot have a definition(s) of that pure virtual functions, so it implies that implementation must be provided in class(es) that derived from that abstract class.

Date format in the json output using spring boot

If you want to change the format for all dates you can add a builder customizer. Here is an example of a bean that converts dates to ISO 8601:

public Jackson2ObjectMapperBuilderCustomizer jsonCustomizer() {
    return new Jackson2ObjectMapperBuilderCustomizer() {
        public void customize(Jackson2ObjectMapperBuilder builder) {
            builder.dateFormat(new ISO8601DateFormat());        

Google Map API - Removing Markers

Following code might be useful if someone is using React and has a different component of Marker and want to remove marker from map.

export default function useGoogleMapMarker(props) {
  const [marker, setMarker] = useState();

  useEffect(() => {
    // ...code
    const marker = new maps.Marker({ position, map, title, icon });
    // ...code
    return () => marker.setMap(null); // to remove markers when unmounts
  }, []);

  return marker;

How to catch segmentation fault in Linux?

Here's an example of how to do it in C.

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void segfault_sigaction(int signal, siginfo_t *si, void *arg)
    printf("Caught segfault at address %p\n", si->si_addr);

int main(void)
    int *foo = NULL;
    struct sigaction sa;

    memset(&sa, 0, sizeof(struct sigaction));
    sa.sa_sigaction = segfault_sigaction;
    sa.sa_flags   = SA_SIGINFO;

    sigaction(SIGSEGV, &sa, NULL);

    /* Cause a seg fault */
    *foo = 1;

    return 0;

iOS Simulator to test website on Mac

You could also download Xcode to your mac and use iPhone simulator.

Difference between a Seq and a List in Scala

In Scala, a List inherits from Seq, but implements Product; here is the proper definition of List :

sealed abstract class List[+A] extends AbstractSeq[A] with Product with ...

[Note: the actual definition is a tad bit more complex, in order to fit in with and make use of Scala's very powerful collection framework.]

Undo a particular commit in Git that's been pushed to remote repos

If the commit you want to revert is a merged commit (has been merged already), then you should either -m 1 or -m 2 option as shown below. This will let git know which parent commit of the merged commit to use. More details can be found HERE.

  • git revert <commit> -m 1
  • git revert <commit> -m 2

Selenium: WebDriverException:Chrome failed to start: crashed as google-chrome is no longer running so ChromeDriver is assuming that Chrome has crashed

This error message...

selenium.common.exceptions.WebDriverException: Message: unknown error: Chrome failed to start: crashed
  (unknown error: DevToolsActivePort file doesn't exist)
  (The process started from chrome location /opt/google/chrome/google-chrome is no longer running, so ChromeDriver is assuming that Chrome has crashed.)

...implies that the ChromeDriver was unable to initiate/spawn a new WebBrowser i.e. Chrome Browser session.

Your main issue is the Chrome browser is not installed at the default location within your system.

The server i.e. ChromeDriver expects you to have Chrome installed in the default location for each system as per the image below:


1For Linux systems, the ChromeDriver expects /usr/bin/google-chrome to be a symlink to the actual Chrome binary.


In case you are using a Chrome executable in a non-standard location you have to override the Chrome binary location as follows:

  • Python Solution:

    from selenium import webdriver
    from import Options
    options = Options()
    options.binary_location = "C:\\path\\to\\chrome.exe"    #chrome binary location specified here
    options.add_argument("--start-maximized") #open Browser in maximized mode
    options.add_argument("--no-sandbox") #bypass OS security model
    options.add_argument("--disable-dev-shm-usage") #overcome limited resource problems
    options.add_experimental_option("excludeSwitches", ["enable-automation"])
    options.add_experimental_option('useAutomationExtension', False)
    driver = webdriver.Chrome(options=options, executable_path=r'C:\path\to\chromedriver.exe')
  • Java Solution:

    System.setProperty("", "C:\\Utility\\BrowserDrivers\\chromedriver.exe");
    ChromeOptions opt = new ChromeOptions();
    opt.setBinary("C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe");  //chrome binary location specified here
    options.setExperimentalOption("excludeSwitches", Collections.singletonList("enable-automation"));
    options.setExperimentalOption("useAutomationExtension", false);
    WebDriver driver = new ChromeDriver(opt);

What is IPV6 for localhost and

For use in a /etc/hosts file as a simple ad blocking technique to cause a domain to fail to resolve, the address has been widely used because it causes the request to immediately fail without even trying, because it's not a valid or routable address. This is in comparison to using in that place, where it will at least check to see if your own computer is listening on the requested port 80 before failing with 'connection refused.' Either of those addresses being used in the hosts file for the domain will stop any requests from being attempted over the actual network, but has gained favor because it's more 'optimal' for the above reason. "127" IPs will attempt to hit your own computer, and any other IP will cause a request to be sent to the router to try to route it, but for there's nowhere to even send a request to.

All that being said, having any IP listed in your hosts file for the domain to be blocked is sufficient, and you wouldn't need or want to also put an ipv6 address in your hosts file unless -- possibly -- you don't have ipv4 enabled at all. I'd be really surprised if that was the case, though. And still though, I think having the host appear in /etc/hosts with a bad ipv4 address when you don't have ipv4 enabled would still give you the result you are looking for which is for it to fail, instead of looking up the real DNS of say, and getting back either a v4 or v6 IP.

In Mongoose, how do I sort by date? (node.js)

You can also sort by the _id field. For example, to get the most recent record, you can do,

const mostRecentRecord = await db.collection.findOne().sort({ _id: -1 });

It's much quicker too, because I'm more than willing to bet that your date field is not indexed.

How does GPS in a mobile phone work exactly?

GPS, the Global Positioning System run by the United States Military, is free for civilian use, though the reality is that we're paying for it with tax dollars.

However, GPS on cell phones is a bit more murky. In general, it won't cost you anything to turn on the GPS in your cell phone, but when you get a location it usually involves the cell phone company in order to get it quickly with little signal, as well as get a location when the satellites aren't visible (since the gov't requires a fix even if the satellites aren't visible for emergency 911 purposes). It uses up some cellular bandwidth. This also means that for phones without a regular GPS receiver, you cannot use the GPS at all if you don't have cell phone service.

For this reason most cell phone companies have the GPS in the phone turned off except for emergency calls and for services they sell you (such as directions).

This particular kind of GPS is called assisted GPS (AGPS), and there are several levels of assistance used.


A normal GPS receiver listens to a particular frequency for radio signals. Satellites send time coded messages at this frequency. Each satellite has an atomic clock, and sends the current exact time as well.

The GPS receiver figures out which satellites it can hear, and then starts gathering those messages. The messages include time, current satellite positions, and a few other bits of information. The message stream is slow - this is to save power, and also because all the satellites transmit on the same frequency and they're easier to pick out if they go slow. Because of this, and the amount of information needed to operate well, it can take 30-60 seconds to get a location on a regular GPS.

When it knows the position and time code of at least 3 satellites, a GPS receiver can assume it's on the earth's surface and get a good reading. 4 satellites are needed if you aren't on the ground and you want altitude as well.


As you saw above, it can take a long time to get a position fix with a normal GPS. There are ways to speed this up, but unless you're carrying an atomic clock with you all the time, or leave the GPS on all the time, then there's always going to be a delay of between 5-60 seconds before you get a location.

In order to save cost, most cell phones share the GPS receiver components with the cellular components, and you can't get a fix and talk at the same time. People don't like that (especially when there's an emergency) so the lowest form of GPS does the following:

  1. Get some information from the cell phone company to feed to the GPS receiver - some of this is gross positioning information based on what cellular towers can 'hear' your phone, so by this time they already phone your location to within a city block or so.
  2. Switch from cellular to GPS receiver for 0.1 second (or some small, practically unoticable period of time) and collect the raw GPS data (no processing on the phone).
  3. Switch back to the phone mode, and send the raw data to the phone company
  4. The phone company processes that data (acts as an offline GPS receiver) and send the location back to your phone.

This saves a lot of money on the phone design, but it has a heavy load on cellular bandwidth, and with a lot of requests coming it requires a lot of fast servers. Still, overall it can be cheaper and faster to implement. They are reluctant, however, to release GPS based features on these phones due to this load - so you won't see turn by turn navigation here.

More recent designs include a full GPS chip. They still get data from the phone company - such as current location based on tower positioning, and current satellite locations - this provides sub 1 second fix times. This information is only needed once, and the GPS can keep track of everything after that with very little power. If the cellular network is unavailable, then they can still get a fix after awhile. If the GPS satellites aren't visible to the receiver, then they can still get a rough fix from the cellular towers.

But to completely answer your question - it's as free as the phone company lets it be, and so far they do not charge for it at all. I doubt that's going to change in the future. In the higher end phones with a full GPS receiver you may even be able to load your own software and access it, such as with mologogo on a motorola iDen phone - the J2ME development kit is free, and the phone is only $40 (prepaid phone with $5 credit). Unlimited internet is about $10 a month, so for $40 to start and $10 a month you can get an internet tracking system. (Prices circa August 2008)

It's only going to get cheaper and more full featured from here on out...

Re: Google maps and such

Yes, Google maps and all other cell phone mapping systems require a data connection of some sort at varying times during usage. When you move far enough in one direction, for instance, it'll request new tiles from its server. Your average phone doesn't have enough storage to hold a map of the US, nor the processor power to render it nicely. iPhone would be able to if you wanted to use the storage space up with maps, but given that most iPhones have a full time unlimited data plan most users would rather use that space for other things.

Defining a HTML template to append using JQuery

Very good answer from DevWL about using the native HTML5 template element. To contribute to this good question from the OP I would like to add on how to use this template element using jQuery, for example:

$($('template').html()).insertAfter( $('#somewhere_else') );

The content of the template is not html, but just treated as data, so you need to wrap the content into a jQuery object to then access jQuery's methods.

jQuery selector to get form by name

You have no combinator (space, >, +...) so no children will get involved, ever.

However, you could avoid the need for jQuery by using an ID and getElementById, or you could use the old getElementsByName("frmSave")[0] or the even older document.forms['frmSave']. jQuery is unnecessary here.

Remove a marker from a GoogleMap

If you use Kotlin language you just add this code:

Create global variables of GoogleMap and Marker types.

I use variable marker to make variable marker value can change directly

private lateinit var map: GoogleMap
private lateinit var marker: Marker

And I use this function/method to add the marker on my map:

private fun placeMarkerOnMap(location: LatLng) {
    val markerOptions = MarkerOptions().position(location)
    val titleStr = getAddress(location)
    marker = map.addMarker(markerOptions)

After I create the function I place this code on the onMapReady() to remove the marker and create a new one:

map.setOnMapClickListener { location ->

It's bonus if you want to display the address location when you click the marker add this code to hide and show the marker address but you need a method to get the address location. I got the code from this post: How to get complete address from latitude and longitude?

map.setOnMarkerClickListener {marker ->
        if (marker.isInfoWindowShown){

How to validate an OAuth 2.0 access token for a resource server?

An update on @Scott T.'s answer: the interface between Resource Server and Authorization Server for token validation was standardized in IETF RFC 7662 in October 2015, see: A sample validation call would look like:

POST /introspect HTTP/1.1
Accept: application/json
Content-Type: application/x-www-form-urlencoded
Authorization: Bearer 23410913-abewfq.123483


and a sample response:

HTTP/1.1 200 OK
Content-Type: application/json

  "active": true,
  "client_id": "l238j323ds-23ij4",
  "username": "jdoe",
  "scope": "read write dolphin",
  "sub": "Z5O3upPC88QrAjx00dis",
  "aud": "",
  "iss": "",
  "exp": 1419356238,
  "iat": 1419350238,
  "extension_field": "twenty-seven"

Of course adoption by vendors and products will have to happen over time.

What does template <unsigned int N> mean?

Yes, it is a non-type parameter. You can have several kinds of template parameters

  • Type Parameters.
    • Types
    • Templates (only classes and alias templates, no functions or variable templates)
  • Non-type Parameters
    • Pointers
    • References
    • Integral constant expressions

What you have there is of the last kind. It's a compile time constant (so-called constant expression) and is of type integer or enumeration. After looking it up in the standard, i had to move class templates up into the types section - even though templates are not types. But they are called type-parameters for the purpose of describing those kinds nonetheless. You can have pointers (and also member pointers) and references to objects/functions that have external linkage (those that can be linked to from other object files and whose address is unique in the entire program). Examples:

Template type parameter:

template<typename T>
struct Container {
    T t;

// pass type "long" as argument.
Container<long> test;

Template integer parameter:

template<unsigned int S>
struct Vector {
    unsigned char bytes[S];

// pass 3 as argument.
Vector<3> test;

Template pointer parameter (passing a pointer to a function)

template<void (*F)()>
struct FunctionWrapper {
    static void call_it() { F(); }

// pass address of function do_it as argument.
void do_it() { }
FunctionWrapper<&do_it> test;

Template reference parameter (passing an integer)

template<int &A>
struct SillyExample {
    static void do_it() { A = 10; }

// pass flag as argument
int flag;
SillyExample<flag> test;

Template template parameter.

template<template<typename T> class AllocatePolicy>
struct Pool {
    void allocate(size_t n) {
        int *p = AllocatePolicy<int>::allocate(n);

// pass the template "allocator" as argument. 
template<typename T>
struct allocator { static T * allocate(size_t n) { return 0; } };
Pool<allocator> test;

A template without any parameters is not possible. But a template without any explicit argument is possible - it has default arguments:

template<unsigned int SIZE = 3>
struct Vector {
    unsigned char buffer[SIZE];

Vector<> test;

Syntactically, template<> is reserved to mark an explicit template specialization, instead of a template without parameters:

struct Vector<3> {
    // alternative definition for SIZE == 3

Why is document.write considered a "bad practice"?

I think the biggest problem is that any elements written via document.write are added to the end of the page's elements. That's rarely the desired effect with modern page layouts and AJAX. (you have to keep in mind that the elements in the DOM are temporal, and when the script runs may affect its behavior).

It's much better to set a placeholder element on the page, and then manipulate it's innerHTML.

Can I pass an array as arguments to a method with variable arguments in Java?

I was having same issue.

String[] arr= new String[] { "A", "B", "C" };
Object obj = arr;

And then passed the obj as varargs argument. It worked.

Could not resolve placeholder in string value

I´m frequently running into this issue on some custom properties that could not be found using IntelliJ IDEA - likely after changing branches.

What helpes in my case is

File -> Invalidate Caches / Restart

I had the assumption that it is more likely a Gradle caching issue than an IDE issue, but ./gradle clean did not help

How to convert comma-delimited string to list in Python?

#splits string according to delimeters 
Let's make a function that can split a string
into list according the given delimeters. 
example data: cat;dog:greff,snake/
example delimeters: ,;- /|:
def string_to_splitted_array(data,delimeters):
    #result list
    res = []
    # we will add chars into sub_str until
    # reach a delimeter
    sub_str = ''
    for c in data: #iterate over data char by char
        # if we reached a delimeter, we store the result 
        if c in delimeters: 
            # avoid empty strings
            if len(sub_str)>0:
                # looks like a valid string.
                # reset sub_str to start over
                sub_str = ''
            # c is not a deilmeter. then it is 
            # part of the string.
            sub_str += c
    # there may not be delimeter at end of data. 
    # if sub_str is not empty, we should att it to list. 
    if len(sub_str)>0:
    # result is in res 
    return res

# test the function. 
delimeters = ',;- /|:'
# read the csv data from console. 
csv_string = input('csv string:')
#lets check if working. 
splitted_array = string_to_splitted_array(csv_string,delimeters)

MySQL > Table doesn't exist. But it does (or it should)

Go to :xampp\mysql\data\dbname
inside dbname have tablename.frm and tablename.ibd file.
remove it and restart mysql and try again.

Download file inside WebView

Have you tried?

mWebView.setDownloadListener(new DownloadListener() {
    public void onDownloadStart(String url, String userAgent,
                String contentDisposition, String mimetype,
                long contentLength) {
        Intent i = new Intent(Intent.ACTION_VIEW);

Example Link: Webview File Download - Thanks @c49

How to get row data by clicking a button in a row in an ASP.NET gridview

Is there any specific reason you would want your buttons in an item template.You can alternatively do it the following way , there by giving you the full power of the grid row editing event.You are also given a bonus of wiring easily the cancel and delete functionality.

Mark up

<asp:TemplateField HeaderText="Edit">
   <asp:ImageButton ID="EditImageButton" runat="server" CommandName="Edit"
    ImageUrl="~/images/Edit.png" Style="height: 16px" ToolTip="Edit" 
    CausesValidation="False"  />



                    <asp:LinkButton ID="btnUpdate" runat="server" CommandName="Update" 
                        Text="Update"  Visible="true" ImageUrl="~/images/saveHS.png" 
                   <asp:LinkButton ID="btnCancel" runat="server" CommandName="Cancel"   
                        ImageUrl="~/images/Edit_UndoHS.png"  />

                 <asp:LinkButton ID="btnDelete" runat="server" CommandName="Delete"   
                        ImageUrl="~/images/delete.png"  />


        <ControlStyle BackColor="Transparent" BorderStyle="None" />
               <FooterStyle HorizontalAlign="Center" />
           <ItemStyle HorizontalAlign="Center" />

Code behind

 protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)

    GridView1.EditIndex = e.NewEditIndex;

TextBox txtledName =   (TextBox) GridView1.Rows[e.NewEditIndex].FindControl("txtAccountName");

 //then do something with the retrieved textbox's text.


Entity Framework Join 3 Tables

This is untested, but I believe the syntax should work for a lambda query. As you join more tables with this syntax you have to drill further down into the new objects to reach the values you want to manipulate.

var fullEntries = dbContext.tbl_EntryPoint
        entryPoint => entryPoint.EID,
        entry => entry.EID,
        (entryPoint, entry) => new { entryPoint, entry }
        combinedEntry => combinedEntry.entry.TID,
        title => title.TID,
        (combinedEntry, title) => new 
            UID = combinedEntry.entry.OwnerUID,
            TID = combinedEntry.entry.TID,
            EID = combinedEntry.entryPoint.EID,
            Title = title.Title
    .Where(fullEntry => fullEntry.UID == user.UID)

Call two functions from same onclick

put a semicolon between the two functions as statement terminator.

Authentication plugin 'caching_sha2_password' is not supported

I had the same problem and passing auth_plugin='mysql_native_password' did not work, because I accidentally installed mysql-connector instead of mysql-connector-python (via pip3). Just leaving this here in case it helps someone.

How to create a showdown.js markdown extension

In your last block you have a comma after 'lang', followed immediately with a function. This is not valid json.


It appears that the readme was incorrect. I had to to pass an array with the string 'twitter'.

var converter = new Showdown.converter({extensions: ['twitter']}); converter.makeHtml('whatever @meandave2020'); // output "<p>whatever <a href="">@meandave2020</a></p>" 

I submitted a pull request to update this.

Getting error: Peer authentication failed for user "postgres", when trying to get pgsql working with rails

pg_config is for compliation information, to help extensions and client programs compile and link against PostgreSQL. It knows nothing about the active PostgreSQL instance(s) on the machine, only the binaries.

pg_hba.conf can appear in many other places depending on how Pg was installed. The standard location is pg_hba.conf within the data_directory of the database (which could be in /home, /var/lib/pgsql, /var/lib/postgresql/[version]/, /opt/postgres/, etc etc etc) but users and packagers can put it wherever they like. Unfortunately.

The only valid ways find pg_hba.conf is to ask a running PostgreSQL instance where it's pg_hba.conf is, or ask the sysadmin where it is. You can't even rely on asking where the datadir is and parsing postgresql.conf because an init script might passed a param like -c hba_file=/some/other/path when starting Pg.

What you want to do is ask PostgreSQL:

SHOW hba_file;

This command must be run on a superuser session, so for shell scripting you might write something like:

psql -t -P format=unaligned -c 'show hba_file';

and set the environment variables PGUSER, PGDATABASE, etc to ensure that the connection is right.

Yes, this is somewhat of a chicken-and-egg problem, in that if the user can't connect (say, after screwing up editing pg_hba.conf) you can't find pg_hba.conf in order to fix it.

Another option is to look at the ps command's output and see if the postmaster data directory argument -D is visible there, e.g.

ps aux  | grep 'postgres *-D'

since pg_hba.conf will be inside the data directory (unless you're on Debian/Ubuntu or some derivative and using their packages).

If you're targeting specifically Ubuntu systems with PostgreSQL installed from Debian/Ubuntu packages it gets a little easier. You don't have to deal with hand-compiled-from-source Pg that someone's initdb'd a datadir for in their home dir, or an EnterpriseDB Pg install in /opt, etc. You can ask pg_wrapper, the Debian/Ubuntu multi-version Pg manager, where PostgreSQL is using the pg_lsclusters command from pg_wrapper.

If you can't connect (Pg isn't running, or you need to edit pg_hba.conf to connect) you'll have to search the system for pg_hba.conf files. On Mac and Linux something like sudo find / -type f -name pg_hba.conf will do. Then check the PG_VERSION file in the same directory to make sure it's the right PostgreSQL version if you have more than one. (If pg_hba.conf is in /etc/, ignore this, it's the parent directory name instead). If you have more than one data directory for the same PostgreSQL version you'll have to look at database size, check the command line of the running postgres from ps to see if it's data directory -D argument matches where you're editing, etc.

Illegal Character when trying to compile java code

That's a problem related to BOM (Byte Order Mark) character. Byte Order Mark BOM is an Unicode character used for defining a text file byte order and comes in the start of the file. Eclipse doesn't allow this character at the start of your file, so you must delete it. for this purpose, use a rich text editor like Notepad++ and save the file with encoding "UTF-8 without BOM". That should remove the problem.

I have copy pasted the some content from a website to a Notepad++ editor,
it shows the "LS" with black background. Have deleted the "LS" content and 
have copy the same content from notepad++ to java file, it works fine.

BSTR to std::string (std::wstring) and vice versa

BSTR to std::wstring:

// given BSTR bs
assert(bs != nullptr);
std::wstring ws(bs, SysStringLen(bs));

std::wstring to BSTR:

// given std::wstring ws
BSTR bs = SysAllocStringLen(, ws.size());

Doc refs:

  1. std::basic_string<typename CharT>::basic_string(const CharT*, size_type)
  2. std::basic_string<>::empty() const
  3. std::basic_string<>::data() const
  4. std::basic_string<>::size() const
  5. SysStringLen()
  6. SysAllocStringLen()

How to deal with ModalDialog using selenium webdriver?

Try this code, include your object names & variable to work.

Set<String> windowids = driver.getWindowHandles();
Iterator<String> iter= windowids.iterator();
for (int i = 1; i < sh.getRows(); i++)
System.out.println("Main Window ID :";
            windowids = driver.getWindowHandles();
    iter= windowids.iterator();
    System.out.println("Main Window ID :"+main_windowID);
    //switch over to pop-up window
    System.out.println("Pop-up window Title : "+driver.getTitle());

Run a Command Prompt command from Desktop Shortcut

  1. Create new text file on desktop;

  2. Enter desired commands in text file;

  3. Rename extension of text file from ".txt" --> ".bat"

Ruby's gives "No such file or directory - text.txt (Errno::ENOENT)" error

ENOENT means it's not there.

Just update your code to: + '/text.txt').each {|line| puts line}

Is it possible to append Series to rows of DataFrame without making a list first?

DataFrame.append does not modify the DataFrame in place. You need to do df = df.append(...) if you want to reassign it back to the original variable.

Stripping everything but alphanumeric chars from a string in Python

If i understood correctly the easiest way is to use regular expression as it provides you lots of flexibility but the other simple method is to use for loop following is the code with example I also counted the occurrence of word and stored in dictionary..

s = """An... essay is, generally, a piece of writing that gives the author's own 
argument — but the definition is vague, 
overlapping with those of a paper, an article, a pamphlet, and a short story. Essays 
have traditionally been 
sub-classified as formal and informal. Formal essays are characterized by "serious 
purpose, dignity, logical 
organization, length," whereas the informal essay is characterized by "the personal 
element (self-revelation, 
individual tastes and experiences, confidential manner), humor, graceful style, 
rambling structure, unconventionality 
or novelty of theme," etc.[1]"""

d = {}      # creating empty dic      
words = s.split() # spliting string and stroing in list
for word in words:
    new_word = ''
    for c in word:
        if c.isalnum(): # checking if indiviual chr is alphanumeric or not
            new_word = new_word + c
    print(new_word, end=' ')
    # if new_word not in d:
    #     d[new_word] = 1
    # else:
    #     d[new_word] = d[new_word] +1

please rate this if this answer is useful!

Count number of columns in a table row

First off, when you call getElementById, you need to provide an id. o_O

The only item in your dom with an id is the table element. If you can, you could add ids (make sure they are unique) to your tr elements.

Alternatively, you can use getElementsByTagName('tr') to get a list of tr elements in your document, and then get the number of tds.

here is a fiddle that console logs the results...

How do you tell if caps lock is on using JavaScript?

In JQuery. This covers the event handling in Firefox and will check for both unexpected uppercase and lowercase characters. This presupposes an <input id="password" type="password" name="whatever"/>element and a separate element with id 'capsLockWarning' that has the warning we want to show (but is hidden otherwise).

$('#password').keypress(function(e) {
    e = e || window.event;

    // An empty field resets the visibility.
    if (this.value === '') {

    // We need alphabetic characters to make a match.
    var character = String.fromCharCode(e.keyCode || e.which);
    if (character.toUpperCase() === character.toLowerCase()) {

    // SHIFT doesn't usually give us a lowercase character. Check for this
    // and for when we get a lowercase character when SHIFT is enabled. 
    if ((e.shiftKey && character.toLowerCase() === character) ||
        (!e.shiftKey && character.toUpperCase() === character)) {
    } else {

Spring Bean Scopes

According to the documentation of Spring-Cloud-Config there is one extra scope next to the existing five. It is @RefreshScope.

This is the short description of RefreshScope:

When there is a configuration change, a Spring @Bean that is marked as @RefreshScope gets special treatment. This feature addresses the problem of stateful beans that only get their configuration injected when they are initialized. For instance, if a DataSource has open connections when the database URL is changed via the Environment, you probably want the holders of those connections to be able to complete what they are doing. Then, the next time something borrows a connection from the pool, it gets one with the new URL.

Sometimes, it might even be mandatory to apply the @RefreshScope annotation on some beans which can be only initialized once. If a bean is "immutable", you will have to either annotate the bean with @RefreshScope or specify the classname under the property key

Refresh scope beans are lazy proxies that initialize when they are used (that is, when a method is called), and the scope acts as a cache of initialized values. To force a bean to re-initialize on the next method call, you must invalidate its cache entry.

The RefreshScope is a bean in the context and has a public refreshAll() method to refresh all beans in the scope by clearing the target cache. The /refresh endpoint exposes this functionality (over HTTP or JMX). To refresh an individual bean by name, there is also a refresh(String) method.

allowing only alphabets in text box using java script

    <title>allwon only alphabets in textbox using JavaScript</title>
    <script language="Javascript" type="text/javascript">

        function onlyAlphabets(e, t) {
            try {
                if (window.event) {
                    var charCode = window.event.keyCode;
                else if (e) {
                    var charCode = e.which;
                else { return true; }
                if ((charCode > 64 && charCode < 91) || (charCode > 96 && charCode < 123))
                    return true;
                    return false;
            catch (err) {

    <table align="center">
                <input type="text" onkeypress="return onlyAlphabets(event,this);" />

Meaning of "487 Request Terminated"

The 487 Response indicates that the previous request was terminated by user/application action. The most common occurrence is when the CANCEL happens as explained above. But it is also not limited to CANCEL. There are other cases where such responses can be relevant. So it depends on where you are seeing this behavior and whether its a user or application action that caused it.

15.1.2 UAS Behavior==> BYE Handling in RFC 3261

The UAS MUST still respond to any pending requests received for that dialog. It is RECOMMENDED that a 487 (Request Terminated) response be generated to those pending requests.

Convert array values from string to int?

$string = "1,2,3";
$ids = explode(',', $string );

array_walk( $ids, function ( &$id )
    $id = (int) $id;
var_dump( $ids );

How to have jQuery restrict file types on upload?

This code works fine, but the only issue is if the file format is other than specified options, it shows an alert message but it displays the file name while it should be neglecting it.

                function () {
                    var fileExtension = ['jpeg', 'jpg', 'pdf'];
                    if ($.inArray($(this).val().split('.').pop().toLowerCase(), fileExtension) == -1) {
                        alert("Only '.jpeg','.jpg','.pdf' formats are allowed.");
                        return false; }

Getting the current date in visual Basic 2008

If you need exact '/' delimiters, for example: 09/20/2013 rather than 09.20.2013, use escape sequence '/':

Dim regDate As Date = Date.Now()
Dim strDate As String = regDate.ToString("MM\/dd\/yyyy")

How to programmatically set SelectedValue of Dropdownlist when it is bound to XmlDataSource

Have you tried, after calling DataBind on your DropDownList, to do something like ddl.SelectedIndex = 0 ?

How to delete an object by id with entity framework

If you dont want to query for it just create an entity, and then delete it.

Customer customer  = new Customer() {  Id = 1   } ; 
context.AttachTo("Customers", customer);

angular 2 how to return data from subscribe

You just can't return the value directly because it is an async call. An async call means it is running in the background (actually scheduled for later execution) while your code continues to execute.

You also can't have such code in the class directly. It needs to be moved into a method or the constructor.

What you can do is not to subscribe() directly but use an operator like map()

export class DataComponent{
    someMethod() {
      return this.http.get(path).map(res => {
        return res.json();

In addition, you can combine multiple .map with the same Observables as sometimes this improves code clarity and keeps things separate. Example:

validateResponse = (response) => validate(response);

parseJson = (json) => JSON.parse(json);

fetchUnits() {
    return this.http.get(requestUrl).map(this.validateResponse).map(this.parseJson);

This way an observable will be return the caller can subscribe to

export class DataComponent{
    someMethod() {
      return this.http.get(path).map(res => {
        return res.json();

    otherMethod() {
      this.someMethod().subscribe(data => = data);

The caller can also be in another class. Here it's just for brevity.

data => = data


res => return res.json()

are arrow functions. They are similar to normal functions. These functions are passed to subscribe(...) or map(...) to be called from the observable when data arrives from the response. This is why data can't be returned directly, because when someMethod() is completed, the data wasn't received yet.

Print empty line?

You can just do


to get an empty line.

Importing a csv into mysql via command line

You can simply import by

mysqlimport --ignore-lines=1 --lines-terminated-by='\n' --fields-terminated-by=',' --fields-enclosed-by='"' --verbose --local -uroot -proot db_name csv_import.csv

Note: Csv File name and Table name should be same

Redirecting a request using servlets and the "setHeader" method not working

Alternatively, you could try the following,

resp.setHeader("Location", "index.jsp");
resp.setHeader("Connection", "close");

Pass a variable to a PHP script running from the command line

Save this code in file myfile.php and run as php myfile.php type=daily

$a = $argv;
$b = array();
if (count($a) === 1) exit;
foreach ($a as $key => $arg) {
    if ($key > 0) {
        list($x,$y) = explode('=', $arg);
        $b["$x"] = $y;  

If you add var_dump($b); before the ?> tag, you will see that the array $b contains type => daily.

Regular Expressions and negating a whole character group

The regex [^ab] will match for example 'ab ab ab ab' but not 'ab', because it will match on the string ' a' or 'b '.

What language/scenario do you have? Can you subtract results from the original set, and just match ab?

If you are using GNU grep, and are parsing input, use the '-v' flag to invert your results, returning all non-matches. Other regex tools also have a 'return nonmatch' function, too.

If I understand correctly, you want everything except for those items which contain 'ab' anywhere.

How to convert QString to int?

You don't have all digit characters in your string. So you have to split by space

QString Abcd = "123.5 Kb";
Abcd.split(" ")[0].toInt();    //convert the first part to Int
Abcd.split(" ")[0].toDouble(); //convert the first part to double
Abcd.split(" ")[0].toFloat();  //convert the first part to float

Update: I am updating an old answer. That was a straight forward answer to the specific question, with a strict assumption. However as noted by @DomTomCat in comments and @Mikhail in answer, In general one should always check whether the operation is successful or not. So using a boolean flag is necessary.

bool flag;
double v = Abcd.split(" ")[0].toDouble(&flag); 
  // use v

Also if you are taking that string as user input, then you should also be doubtful about whether the string is really splitable with space. If there is a possibility that the assumption may break then a regex verifier is more preferable. A regex like the following will extract the floating point value and the prefix character of 'b'. Then you can safely convert the captured strings to double.


You can have an utility function like the following

QPair<double, QString> split_size_str(const QString& str){
    QRegExp regex("([0-9]*\\.?[0-9]+)\\s+(\\w[bB])");
    int pos = regex.indexIn(str);
    QStringList captures = regex.capturedTexts();
    if(captures.count() > 1){
        double value = captures[1].toDouble(); // should succeed as regex matched
        QString unit = captures[2]; // should succeed as regex matched
        return qMakePair(value, unit);
    return qMakePair(0.0f, QString());

How can I export a GridView.DataSource to a datatable or dataset?

You should convert first DataSource in BindingSource, look example

BindingSource bs = (BindingSource)dgrid.DataSource; // Se convierte el DataSource 
DataTable tCxC = (DataTable) bs.DataSource;

With the data of tCxC you can do anything.

How to make zsh run as a login shell on Mac OS X (in iTerm)?

In iTerm -> Preferences -> Profiles Tab -> General section set Command to: /bin/zsh --login

/bin/zsh --login

How to upload multiple files using PHP, jQuery and AJAX


<form enctype="multipart/form-data" action="upload.php" method="post">
    <input name="file[]" type="file" />
    <button class="add_more">Add More Files</button>
    <input type="button" value="Upload File" id="upload"/>


        $(this).before("<input name='file[]' type='file'/>");

for ajax upload

$('#upload').click(function() {
    var filedata = document.getElementsByName("file"),
            formdata = false;
    if (window.FormData) {
        formdata = new FormData();
    var i = 0, len = filedata.files.length, img, reader, file;

    for (; i < len; i++) {
        file = filedata.files[i];

        if (window.FileReader) {
            reader = new FileReader();
            reader.onloadend = function(e) {
                showUploadedItem(, file.fileName);
        if (formdata) {
            formdata.append("file", file);
    if (formdata) {
            url: "/path to upload/",
            type: "POST",
            data: formdata,
            processData: false,
            contentType: false,
            success: function(res) {

            error: function(res) {



for($i=0; $i<count($_FILES['file']['name']); $i++){
    $target_path = "uploads/";
    $ext = explode('.', basename( $_FILES['file']['name'][$i]));
    $target_path = $target_path . md5(uniqid()) . "." . $ext[count($ext)-1]; 

    if(move_uploaded_file($_FILES['file']['tmp_name'][$i], $target_path)) {
        echo "The file has been uploaded successfully <br />";
    } else{
        echo "There was an error uploading the file, please try again! <br />";

    Edit: $target_path variable need to be reinitialized and should 
    be inside for loop to avoid appending previous file name to new one. 

Please use the script above script for ajax upload. It will work

Retain precision with double in Java

As others have mentioned, you'll probably want to use the BigDecimal class, if you want to have an exact representation of 11.4.

Now, a little explanation into why this is happening:

The float and double primitive types in Java are floating point numbers, where the number is stored as a binary representation of a fraction and a exponent.

More specifically, a double-precision floating point value such as the double type is a 64-bit value, where:

  • 1 bit denotes the sign (positive or negative).
  • 11 bits for the exponent.
  • 52 bits for the significant digits (the fractional part as a binary).

These parts are combined to produce a double representation of a value.

(Source: Wikipedia: Double precision)

For a detailed description of how floating point values are handled in Java, see the Section 4.2.3: Floating-Point Types, Formats, and Values of the Java Language Specification.

The byte, char, int, long types are fixed-point numbers, which are exact representions of numbers. Unlike fixed point numbers, floating point numbers will some times (safe to assume "most of the time") not be able to return an exact representation of a number. This is the reason why you end up with 11.399999999999 as the result of 5.6 + 5.8.

When requiring a value that is exact, such as 1.5 or 150.1005, you'll want to use one of the fixed-point types, which will be able to represent the number exactly.

As has been mentioned several times already, Java has a BigDecimal class which will handle very large numbers and very small numbers.

From the Java API Reference for the BigDecimal class:

Immutable, arbitrary-precision signed decimal numbers. A BigDecimal consists of an arbitrary precision integer unscaled value and a 32-bit integer scale. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. The value of the number represented by the BigDecimal is therefore (unscaledValue × 10^-scale).

There has been many questions on Stack Overflow relating to the matter of floating point numbers and its precision. Here is a list of related questions that may be of interest:

If you really want to get down to the nitty gritty details of floating point numbers, take a look at What Every Computer Scientist Should Know About Floating-Point Arithmetic.

Building a fat jar using maven

An alternative is to use the maven shade plugin to build an uber-jar.

    <version> Your Version Here </version>
            <!-- put your configurations here -->

Could not load file or assembly 'Newtonsoft.Json, Version=, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'

The key point is referencing right version in your config file.


1- look at what is the version of your Newtonsoft.Json.dll in the project reference property what ever the version in your package folder (For example mine is 7.0.1 and the reference Version is

2- look at what the project expect from you in the exception (mine is

3- Add dependent assembly to your config file as it should be..

    <assemblyIdentity name="Newtonsoft.Json"  publicKeyToken="30AD4FE6B2A6AEED" culture="neutral"/>
    <bindingRedirect oldVersion="" newVersion=""/>

Maximum and minimum values in a textbox

It depends on the kind of numbers and what you will allow. Handling numbers with decimals is more difficult than simple integers. Handling situations where multiple cultures are allowed is more complicated again.

The basics are these:

  • Handle the "keypress" event for the text box. When a character which is not allowed has been pressed, cancel further processing of the event so the browser doesn't add it to the textbox.
  • While handling "keypress", it is often useful to simple create the potential new string based on the key that was pressed. If the string is a valid number, allow the kepress. Otherwise, toss the keypress. This can greatly simplify some of the work.
  • Potentially handle the "keydown" event if you're concerned with keys that "keypress" doesn't handle.

Shared folder between MacOSX and Windows on Virtual Box

Yesterday, I am able to share the folders from my host OS Macbook (high Sierra) to Guest OS Windows 10

Original Answer

Because there isn't an official answer yet and I literally just did this for my OS X/WinXP install, here's what I did:

  1. VirtualBox Manager: Open the Shared Folders setting and click the '+' icon to add a new folder. Then, populate the Folder Path (or use the drop-down to navigate) with the folder you want shared and make sure "Auto-Mount" and "Make Permanent" are checked.
  2. Boot Windows
  3. Download the VBoxGuestAdditions_4.0.12.iso from
  4. Go to Devices > Optical drives > choose disk image.. choose the one downloaded in step 3
  5. Inside host guest OS (Windows 10, in my case) I could see: This PC > CD Drive (D:) Virtual Guest Additions

For now, right click on it, select Properties, the Compatibility tab, and select Windows 8 compatibility there. Much easier than using the compatibility troubleshooting I did initially.

enter image description here

  1. reboot the guest OS (Windows 10)
  2. Inside host guest OS, you could see the shared folder This PC> shared folder

It worked for me so I thought of sharing with everyone too.

Imply bit with constant 1 or 0 in SQL Server

No, but you could cast the whole expression rather than the sub-components of that expression. Actually, that probably makes it less readable in this case.

insert password into database in md5 format?

Darren Davies is partially correct in saying that you should use a salt - there are several issues with his claim that MD5 is insecure.

You've said that you have to insert the password using an Md5 hash, but that doesn't really tell us why. Is it because that's the format used when validatinb the password? Do you have control over the code which validates the password?

The thing about using a salt is that it avoids the problem where 2 users have the same password - they'll also have the same hash - not a desirable outcome. By using a diferent salt for each password then this does not arise (with very large volumes of data there is still a risk of collisions arising from 2 different passwords - but we'll ignore that for now).

So you can aither generate a random value for the salt and store that in the record too, or you could use some of the data you already hold - such as the username:

$query="INSERT INTO ptb_users (id,
        email )

(I am assuming that you've properly escaped all those strings earlier in your code)

Pandas: change data type of Series to String

Personally none of the above worked for me. What did:

new_str = [str(x) for x in old_obj][0]

How to stop (and restart) the Rails Server?

Press Ctrl+C

When you start the server it mentions this in the startup text.

How do I set up Vim autoindentation properly for editing Python files?

Ensure you are editing the correct configuration file for VIM. Especially if you are using windows, where the file could be named _vimrc instead of .vimrc as on other platforms.

In vim type

:help vimrc

and check your path to the _vimrc/.vimrc file with

:echo $HOME

:echo $VIM

Make sure you are only using one file. If you want to split your configuration into smaller chunks you can source other files from inside your _vimrc file.

:help source

How do I detect a click outside an element?

First you have to track wether the mouse is inside or outside your element1, using the mouseenter and mouseleave events. Then you can create an element2 which covers the whole screen to detect any clicks, and react accordingly depending on wether you are inside or outside element1.

I strongly recommend to handle both initialization and cleanup, and that the element2 is made as temporary as possible, for obvious reasons.

In the example below, the overlay is an element positionned somewhere, which can be selected by clicking inside, and unselected by clicking outside. The _init and _release methods are called as part of an automatic initialisation/cleanup process. The class inherits from a ClickOverlay which has an inner and outerElement, don't worry about it. I used outerElement.parentNode.appendChild to avoid conflicts.

import ClickOverlay from './ClickOverlay.js'

/* CSS */
// .unselect-helper {
//  position: fixed; left: -100vw; top: -100vh;
//  width: 200vw; height: 200vh;
// }
// .selected {outline: 1px solid black}

export default class ResizeOverlay extends ClickOverlay {
    _init(_opts) {
        this.enterListener = () => this.onEnter()
        this.innerElement.addEventListener('mouseenter', this.enterListener)
        this.leaveListener = () => this.onLeave()
        this.innerElement.addEventListener('mouseleave', this.leaveListener)
        this.selectListener = () => {
            if (this.unselectHelper)
            this.unselectHelper = document.createElement('div')
            this.unselectListener = () => {
                if (this.mouseInside)
                , this.unselectListener)
        this.innerElement.addEventListener('pointerup', this.selectListener)

    _release() {
        this.innerElement.removeEventListener('mouseenter', this.enterListener)
        this.innerElement.removeEventListener('mouseleave', this.leaveListener)
        this.innerElement.removeEventListener('pointerup', this.selectListener)

    clearUnselectHelper() {
        if (!this.unselectHelper)
            , this.unselectListener)
        delete this.unselectListener
        delete this.unselectHelper

    onEnter() {
        this.mouseInside = true

    onLeave() {
        delete this.mouseInside

    onSelect() {

    onUnselect() {

Access denied for user 'homestead'@'localhost' (using password: YES)

if you are using php artisan migrate NOT from vagrant box but from host machine then you must define inside the .env the ip of the box

and obviously set permission to homestead user from your ip something like

grant all privileges on *.* to 'homestead'@% identified by 'secret';

in .env file


How can I install packages using pip according to the requirements.txt file from a local directory?

I had a similar problem. I tried this:

    pip install -U -r requirements.txt

(-U = update if it had already installed)

But the problem continued. I realized that some of generic libraries for development were missed.

    sudo apt-get install libtiff5-dev libjpeg8-dev zlib1g-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk

I don't know if this would help you.

TypeError: Router.use() requires middleware function but got a Object

In my case i wasn't exporting the module. module.exports = router;

Sending a JSON HTTP POST request from Android

Posting parameters Using POST:-

URL url;
URLConnection urlConn;
DataOutputStream printout;
DataInputStream  input;
url = new URL (getCodeBase().toString() + "env.tcgi");
urlConn = url.openConnection();
urlConn.setDoInput (true);
urlConn.setDoOutput (true);
urlConn.setUseCaches (false);
urlConn.setRequestProperty("Host", "");
//Create JSONObject here
JSONObject jsonParam = new JSONObject();
jsonParam.put("ID", "25");
jsonParam.put("description", "Real");
jsonParam.put("enable", "true");

The part which you missed is in the the following... i.e., as follows..

// Send POST output.
printout = new DataOutputStream(urlConn.getOutputStream ());
printout.flush ();
printout.close ();

The rest of the thing you can do it.

Android Studio - local path doesn't exist

I fixed this by adding "Gradle-aware make" before launch in my launch configuration.

enter image description here

Update some specific field of an entity in android Room

If you need to update user information for a specific user ID "x",

  1. you need to create a dbManager class that will initialise the database in its constructor and acts as a mediator between your viewModel and DAO, and also .
  2. The ViewModel will initialize an instance of dbManager to access the database. The code should look like this:

        class User{
        String userId;
        String username;
        Interface UserDao{
        void updateUser(User user)
        Class DbManager{
        //AppDatabase gets the static object o roomDatabase.
        AppDatabase appDatabase;
        UserDao userDao;
        public DbManager(Application application ){
        appDatabase = AppDatabase.getInstance(application);
        //getUserDao is and abstract method of type UserDao declared in AppDatabase //class
        userDao = appDatabase.getUserDao();
        public void updateUser(User user, boolean isUpdate){
        new InsertUpdateUserAsyncTask(userDao,isUpdate).execute(user);
        public static class InsertUpdateUserAsyncTask extends AsyncTask<User, Void, Void> {
         private UserDao userDAO;
         private boolean isInsert;
         public InsertUpdateBrandAsyncTask(BrandDAO userDAO, boolean isInsert) {
           this. userDAO = userDAO;
           this.isInsert = isInsert;
         protected Void doInBackground(User... users) {
           if (isInsert)
        //for update
        //try {
        //  Thread.sleep(1000);
        //} catch (InterruptedException e) {
        //  e.printStackTrace();
           return null;
         Class UserViewModel{
         DbManager dbManager;
         public UserViewModel(Application application){
         dbmanager = new DbMnager(application);
         public void updateUser(User user, boolean isUpdate){
    Now in your activity or fragment initialise your UserViewModel like this:
    UserViewModel userViewModel = ViewModelProviders.of(this).get(UserViewModel.class);

    Then just update your user item this way, suppose your userId is 1122 and userName is "xyz" which has to be changed to "zyx".

    Get an userItem of id 1122 User object

User user = new user();
 if(user.getUserId() == 1122){

This is a raw code, hope it helps you.

Happy coding

Using CSS how to change only the 2nd column of a table

Try this:

.countTable table tr td:first-child + td

You could also reiterate in order to style the others columns:

.countTable table tr td:first-child + td + td {...} /* third column */
.countTable table tr td:first-child + td + td + td {...} /* fourth column */
.countTable table tr td:first-child + td + td + td +td {...} /* fifth column */

ASP.NET Bundles how to disable minification

If you set the following property to false then it will disable both bundling and minification.

In Global.asax.cs file, add the line as mentioned below

protected void Application_Start()
    System.Web.Optimization.BundleTable.EnableOptimizations = false;

How to make a div center align in HTML

<!DOCTYPE html>_x000D_
    <div style="text-align: center;">_x000D_
      <div style="width: 500px; margin: 0 auto; background: #000; color: #fff;">This DIV is centered</div>_x000D_

Tested and worked in IE, Firefox, Chrome, Safari and Opera. I did not test IE6. The outer text-align is needed for IE. Other browsers (and IE9?) will work when you give the DIV margin (left and right) value of auto. Margin "0 auto" is a shorthand for margin "0 auto 0 auto" (top right bottom left).

Note: the text is also centered inside the inner DIV, if you want it to remain on the left side just specify text-align: left; for the inner DIV.

Edit: IE 6, 7, 8 and 9 running on the Standards Mode will work with margins set to auto.

Git mergetool generates unwanted .orig files

I use this to clean up all files ending in ".orig":

function git-clean-orig {
    git status -su | grep -e"\.orig$" | cut -f2 -d" " | xargs rm -r

If you are a scaredy-cat :) you could leave the last part off just to list them (or leave off the -r if you want to approve each delete):

function git-show-orig {
    git status -su | grep -e"\.orig$" | cut -f2 -d" "

Android how to convert int to String?

You called an incorrect method of String class, try:

int tmpInt = 10;
String tmpStr10 = String.valueOf(tmpInt);

You can also do:

int tmpInt = 10;
String tmpStr10 = Integer.toString(tmpInt);

How to dynamically remove items from ListView on a button click?

Have a button on list and let it onclick feature in xml like to get postion first

public void OnClickButton(View V){
  final int postion = listView.getPositionForView(V);
    System.out.println("postion selected is : "+postion);

public void Delete(int position){
    if (adapter.getCount() > 0) {

        //Log.d("largest no is",""+largestitemno);
        //deleting the latest added by subtracting one 1 
        comment = (GenrricStoring) adapter.getItem(position);
        //Log.d("Deleting item is: ",""+comment);
        List<GenrricStoring> values = dbconnection.getAllComments();
        //updating the content on the screen
        this.adapter = new UserItemAdapter(this, android.R.layout.simple_list_item_1, values);
        int duration = Toast.LENGTH_SHORT;
        //for showing nothing is left in the list
        Toast toast = Toast.makeText(getApplicationContext(),"Db is empty", duration);
        toast.setGravity(Gravity.CENTER, 0, 0);;


AsyncTask Android example

Update: March 2020

According to Android developer official documentation, AsyncTask is now deprecated.

It's recommended to use kotlin corourines instead. Simply, it allows you to write asynchronous tasks in a sequential style.

How to move a git repository into another directory and make that directory a git repository?

It's very simple. Git doesn't care about what's the name of its directory. It only cares what's inside. So you can simply do:

# copy the directory into newrepo dir that exists already (else create it)
$ cp -r gitrepo1 newrepo

# remove .git from old repo to delete all history and anything git from it
$ rm -rf gitrepo1/.git

Note that the copy is quite expensive if the repository is large and with a long history. You can avoid it easily too:

# move the directory instead
$ mv gitrepo1 newrepo

# make a copy of the latest version
# Either:
$ mkdir gitrepo1; cp -r newrepo/* gitrepo1/  # doesn't copy .gitignore (and other hidden files)

# Or:
$ git clone --depth 1 newrepo gitrepo1; rm -rf gitrepo1/.git

# Or (look further here:
$ git archive --format=tar --remote=<repository URL> HEAD | tar xf -

Once you create newrepo, the destination to put gitrepo1 could be anywhere, even inside newrepo if you want it. It doesn't change the procedure, just the path you are writing gitrepo1 back.

How to set "style=display:none;" using jQuery's attr method?

Please try below code for it :



Getting ORA-01031: insufficient privileges while querying a table instead of ORA-00942: table or view does not exist

You may get ORA-01031: insufficient privileges instead of ORA-00942: table or view does not exist when you have at least one privilege on the table, but not the necessary privilege.

Create schemas

SQL> create user schemaA identified by schemaA;

User created.

SQL> create user schemaB identified by schemaB;

User created.

SQL> create user test_user identified by test_user;

User created.

SQL> grant connect to test_user;

Grant succeeded.

Create objects and privileges

It is unusual, but possible, to grant a schema a privilege like DELETE without granting SELECT.

SQL> create table schemaA.table1(a number);

Table created.

SQL> create table schemaB.table2(a number);

Table created.

SQL> grant delete on schemaB.table2 to test_user;

Grant succeeded.

Connect as TEST_USER and try to query the tables

This shows that having some privilege on the table changes the error message.

SQL> select * from schemaA.table1;
select * from schemaA.table1
ERROR at line 1:
ORA-00942: table or view does not exist

SQL> select * from schemaB.table2;
select * from schemaB.table2
ERROR at line 1:
ORA-01031: insufficient privileges


How do I use Wget to download all images into a single folder, from a URL?

wget -nd -r -l 2 -A jpg,jpeg,png,gif
  • -nd: no directories (save all files to the current directory; -P directory changes the target directory)
  • -r -l 2: recursive level 2
  • -A: accepted extensions
wget -nd -H -p -A jpg,jpeg,png,gif -e robots=off{1..2}
  • -H: span hosts (wget doesn't download files from different domains or subdomains by default)
  • -p: page requisites (includes resources like images on each page)
  • -e robots=off: execute command robotos=off as if it was part of .wgetrc file. This turns off the robot exclusion which means you ignore robots.txt and the robot meta tags (you should know the implications this comes with, take care).

Example: Get all .jpg files from an exemplary directory listing:

$ wget -nd -r -l 1 -A jpg

Count a list of cells with the same background color

I just created this and it looks easier. You get these 2 functions:

=GetColorIndex(E5)  <- returns color number for the cell

from (cell)

=CountColorIndexInRange(C7:C24,14) <- returns count of cells C7:C24 with color 14

from (range of cells, color number you want to count)

example shows percent of cells with color 14

=ROUND(CountColorIndexInRange(C7:C24,14)/18, 4 )

Create these 2 VBA functions in a Module (hit Alt-F11)

open + folders. double-click on Module1

Just paste this text below in, then close the module window (it must save it then):

Function GetColorIndex(Cell As Range)
  GetColorIndex = Cell.Interior.ColorIndex
End Function

Function CountColorIndexInRange(Rng As Range, TestColor As Long)
  Dim cnt
  Dim cl As Range
  cnt = 0

  For Each cl In Rng
    If GetColorIndex(cl) = TestColor Then
      Rem Debug.Print ">" & TestColor & "<"
      cnt = cnt + 1
    End If

  CountColorIndexInRange = cnt

End Function

Need to combine lots of files in a directory

There is a convenient third party tool named FileMenu Tools, that gives several right-click tools as a windows explorer extension.

One of them is Split file / Join Parts, that does and undoes exactly what you are looking for.

Check it at Of course, it is windows only, as Unixes environments already have lots of tools for that.

How To have Dynamic SQL in MySQL Stored Procedure

I don't believe MySQL supports dynamic sql. You can do "prepared" statements which is similar, but different.

Here is an example:

mysql> PREPARE stmt FROM 
    -> 'select count(*) 
    -> from information_schema.schemata 
    -> where schema_name = ? or schema_name = ?'
Query OK, 0 rows affected (0.00 sec)
Statement prepared
mysql> EXECUTE stmt 
    -> USING @schema1,@schema2
| count(*) |
|        2 |
1 row in set (0.00 sec)

The prepared statements are often used to see an execution plan for a given query. Since they are executed with the execute command and the sql can be assigned to a variable you can approximate the some of the same behavior as dynamic sql.

Here is a good link about this:

Don't forget to deallocate the stmt using the last line!

Good Luck!

How to run binary file in Linux

:-) If not typo, why are you using ./commonRT instead of ./commonKT ??

Repeat each row of data.frame the number of times specified in a column

Another possibility is using tidyr::expand:


df %>% group_by_at(vars(-freq)) %>% expand(temp = 1:freq) %>% select(-temp)
#> # A tibble: 6 x 2
#> # Groups:   var1, var2 [3]
#>   var1  var2 
#>   <fct> <fct>
#> 1 a     d    
#> 2 b     e    
#> 3 b     e    
#> 4 c     f    
#> 5 c     f    
#> 6 c     f

One-liner version of vonjd's answer:


setDT(df)[ ,list(freq=rep(1,freq)),by=c("var1","var2")][ ,freq := NULL][]
#>    var1 var2
#> 1:    a    d
#> 2:    b    e
#> 3:    b    e
#> 4:    c    f
#> 5:    c    f
#> 6:    c    f

Created on 2019-05-21 by the reprex package (v0.2.1)

How to display both icon and title of action inside ActionBar?

Try adding a TextView to the menubar first and using setCompoundDrawables() to place the image on whichever side you want. Bond click activity to the textview in the end.

MenuItem item = menu.add(Menu.NONE,, 10,;
TextView textBtn = getTextButton(btn_title, btn_image);
textBtn.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
           // your selector here   }

You can literally customize everything here:

public TextView getTextButton (String btn_title, Drawable btn_image) {
    TextView textBtn = new TextView(this);
    textBtn.setTypeface(Typeface.create("sans-serif-light", Typeface.BOLD));
    textBtn.setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
    Drawable img = btn_image;
    img.setBounds(0, 0, 30, 30);
    textBtn.setCompoundDrawables(null, null, img, null); 
    // left,top,right,bottom. In this case icon is right to the text

    return textBtn;

Converting a character code to char (VB.NET)

The Chr function in VB.NET converts the integer back to the character:

Dim i As Integer = Asc("x") ' Convert to ASCII integer.
Dim x As Char = Chr(i)      ' Convert ASCII integer to char.

How to convert an integer (time) to HH:MM:SS::00 in SQL Server 2008?

You can use the following time conversion within SQL like this:

--Convert Time to Integer (Minutes)
DECLARE @timeNow datetime = '14:47'
SELECT DATEDIFF(mi,CONVERT(datetime,'00:00',108), CONVERT(datetime, RIGHT(CONVERT(varchar, @timeNow, 100),7),108))

--Convert Minutes to Time
DECLARE @intTime int = (SELECT DATEDIFF(mi,CONVERT(datetime,'00:00',108), CONVERT(datetime, RIGHT(CONVERT(varchar, @timeNow, 100),7),108)))
SELECT DATEADD(minute, @intTime, '')

Result: 887 <- Time in minutes and 1900-01-01 14:47:00.000 <-- Minutes to time

When should an IllegalArgumentException be thrown?

When talking about "bad input", you should consider where the input is coming from.

Is the input entered by a user or another external system you don't control, you should expect the input to be invalid, and always validate it. It's perfectly ok to throw a checked exception in this case. Your application should 'recover' from this exception by providing an error message to the user.

If the input originates from your own system, e.g. your database, or some other parts of your application, you should be able to rely on it to be valid (it should have been validated before it got there). In this case it's perfectly ok to throw an unchecked exception like an IllegalArgumentException, which should not be caught (in general you should never catch unchecked exceptions). It is a programmer's error that the invalid value got there in the first place ;) You need to fix it.

How to get to Model or Viewbag Variables in a Script Tag

try this method

<script type="text/javascript">

    function set(value) {
        return value;

    alert(set(@Html.Raw(Json.Encode(Model.Message)))); // Message set from controller



How to get last 7 days data from current datetime to last 7 days in sql server

Try something like:

 SELECT id, NewsHeadline as news_headline, NewsText as news_text, state CreatedDate as created_on
 FROM News 
 WHERE CreatedDate >= DATEADD(day,-7, GETDATE())

How to use Checkbox inside Select Option

Only add class create div and add class form-control. iam use JSP,boostrap4. Ignore c:foreach.

<div class="multi-select form-control" style="height:107.292px;">
        <div class="checkbox" id="checkbox-expedientes">
            <c:forEach var="item" items="${postulantes}">
                <label class="form-check-label">
                    <input id="options" class="postulantes" type="checkbox" value="1">Option 1</label>

How to blur background images in Android

You can quickly get to blur effect by doing the following.

// Add this to build.gradle app //

Compile ' com.github.jgabrielfreitas:BlurImageView:1.0.1 '

// Add to XML


//Add this to java

Import com.jgabrielfreitas.core.BlueImageView;

// Under public class *activity name * //

BlurImageView myBlurImage;

// Under Oncreate//

myBlurImage = (ImageView) findViewById(

I hope that helps someone

get the selected index value of <select> tag in php

As you said..

$Gender  = isset($_POST["gender"]); ' it returns a empty string 

because, you haven't mention method type either use POST or GET, by default it will use GET method. On the other side, you are trying to retrieve your value by using POST method, but in the form you haven't mentioned POST method. Which means miss-match method will result for empty.

Try this code..

<form name="signup_form"  action="./signup.php" onsubmit="return validateForm()"   method="post">
  <tr> <td> First Name    </td><td> <input type="text" name="fname" size=10/></td></tr>
  <tr> <td> Last Name     </td><td> <input type="text" name="lname" size=10/></td></tr>
  <tr> <td> Your Email    </td><td> <input type="text" name="email" size=10/></td></tr>
  <tr> <td> Re-type Email </td><td> <input type="text" name="remail"size=10/></td></tr>
  <tr> <td> Password      </td><td> <input type="password" name="paswod" size=10/> </td></tr>
  <tr> <td> Gender        </td><td> <select name="gender">
  <option value="select">                Select </option>    
  <option value="male">   Male   </option>
  <option value="female"> Female </option></select></td></tr> 
  <tr> <td> <input type="submit" value="Sign up" id="signup"/> </td> </tr>

and on signup page

$Gender  = $_POST["gender"];

i'm sure.. now, you will get the value..

Limit the output of the TOP command to a specific process name

Suppose .. if we have more than 20 process running on the server with the same name ... this will not help

top -p pgrep oracle | head -n 20 | tr "\\n" "," | sed 's/,$//'

It will try to list and provide real time output of 20 process where we have good chance of missing other prcesses which consumes more resource ....

I am still looking for better option on this

Transform hexadecimal information to binary using a Linux command

As @user786653 suggested, use the xxd(1) program:

xxd -r -p input.txt output.bin

CSV file written with Python has blank lines between each row

Note: It seems this is not the preferred solution because of how the extra line was being added on a Windows system. As stated in the python document:

If csvfile is a file object, it must be opened with the ‘b’ flag on platforms where that makes a difference.

Windows is one such platform where that makes a difference. While changing the line terminator as I described below may have fixed the problem, the problem could be avoided altogether by opening the file in binary mode. One might say this solution is more "elegent". "Fiddling" with the line terminator would have likely resulted in unportable code between systems in this case, where opening a file in binary mode on a unix system results in no effect. ie. it results in cross system compatible code.

From Python Docs:

On Windows, 'b' appended to the mode opens the file in binary mode, so there are also modes like 'rb', 'wb', and 'r+b'. Python on Windows makes a distinction between text and binary files; the end-of-line characters in text files are automatically altered slightly when data is read or written. This behind-the-scenes modification to file data is fine for ASCII text files, but it’ll corrupt binary data like that in JPEG or EXE files. Be very careful to use binary mode when reading and writing such files. On Unix, it doesn’t hurt to append a 'b' to the mode, so you can use it platform-independently for all binary files.


As part of optional paramaters for the csv.writer if you are getting extra blank lines you may have to change the lineterminator (info here). Example below adapated from the python page csv docs. Change it from '\n' to whatever it should be. As this is just a stab in the dark at the problem this may or may not work, but it's my best guess.

>>> import csv
>>> spamWriter = csv.writer(open('eggs.csv', 'w'), lineterminator='\n')
>>> spamWriter.writerow(['Spam'] * 5 + ['Baked Beans'])
>>> spamWriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])

Django values_list vs values

You can get the different values with:

set(Article.objects.values_list('comment_id', flat=True))

Specify JDK for Maven to use

You could also set the JDK for Maven in a file in your home directory ~/.mavenrc:


This environment variable will be checked by the mvn script and used when present:

  if [ -f "$HOME/.mavenrc" ] ; then
    . "$HOME/.mavenrc"

How do I install the yaml package for Python?

pip install PyYAML

If libyaml is not found or compiled PyYAML can do without it on Mavericks.

Char array to hex string C++

You could use std::hex


std::cout << std::hex << packet;

Retrieving values from nested JSON Object

Try this, you can parse nested JSON

public static String getJsonValue(String jsonReq, String key) {
        JSONObject json = new JSONObject(jsonReq);
        boolean exists = json.has(key);
        Iterator<?> keys;
        String nextKeys;
        String val = "";
        if (!exists) {
            keys = json.keys();
            while (keys.hasNext()) {
                nextKeys = (String);
                try {
                    if (json.get(nextKeys) instanceof JSONObject) {
                        return getJsonValue(json.getJSONObject(nextKeys).toString(), key);
                    } else if (json.get(nextKeys) instanceof JSONArray) {
                        JSONArray jsonArray = json.getJSONArray(nextKeys);
                        int i = 0;
                        if (i < jsonArray.length()) do {
                            String jsonArrayString = jsonArray.get(i).toString();
                            JSONObject innerJson = new JSONObject(jsonArrayString);
                            return getJsonValue(innerJson.toString(),key);
                        } while (i < jsonArray.length());
                } catch (Exception e) {
        } else {
            val = json.get(key).toString();
        return val;

GC overhead limit exceeded

From Java SE 6 HotSpot[tm] Virtual Machine Garbage Collection Tuning

the following

Excessive GC Time and OutOfMemoryError

The concurrent collector will throw an OutOfMemoryError if too much time is being spent in garbage collection: if more than 98% of the total time is spent in garbage collection and less than 2% of the heap is recovered, an OutOfMemoryError will be thrown. This feature is designed to prevent applications from running for an extended period of time while making little or no progress because the heap is too small. If necessary, this feature can be disabled by adding the option -XX:-UseGCOverheadLimit to the command line.

The policy is the same as that in the parallel collector, except that time spent performing concurrent collections is not counted toward the 98% time limit. In other words, only collections performed while the application is stopped count toward excessive GC time. Such collections are typically due to a concurrent mode failure or an explicit collection request (e.g., a call to System.gc()).

in conjunction with a passage further down

One of the most commonly encountered uses of explicit garbage collection occurs with RMIs distributed garbage collection (DGC). Applications using RMI refer to objects in other virtual machines. Garbage cannot be collected in these distributed applications without occasionally collection the local heap, so RMI forces full collections periodically. The frequency of these collections can be controlled with properties. For example,

java -Dsun.rmi.dgc.client.gcInterval=3600000

-Dsun.rmi.dgc.server.gcInterval=3600000 specifies explicit collection once per hour instead of the default rate of once per minute. However, this may also cause some objects to take much longer to be reclaimed. These properties can be set as high as Long.MAX_VALUE to make the time between explicit collections effectively infinite, if there is no desire for an upper bound on the timeliness of DGC activity.

Seems to imply that the evaluation period for determining the 98% is one minute long, but it might be configurable on Sun's JVM with the correct define.

Of course, other interpretations are possible.

how to convert a string to date in mysql?

Here's another two examples.

To output the day, month, and year, you can use:

select STR_TO_DATE('14/02/2015', '%d/%m/%Y');

Which produces:


To also output the time, you can use:

select STR_TO_DATE('14/02/2017 23:38:12', '%d/%m/%Y %T');

Which produces:

2017-02-14 23:38:12

Replace String in all files in Eclipse

I have tried the following option in Helios Version of Eclipse. Simply press CTRL+F you will get the "Find/Replace" Window on your screen

enter image description here

How to enter a formula into a cell using VBA?

You aren't building your formula right.

Worksheets("EmployeeCosts").Range("B" & var1a).Formula =  "=SUM(H5:H" & var1a & ")"

This does the same as the following lines do:

Dim myFormula As String
myFormula = "=SUM(H5:H"
myFormula = myFormula & var1a
myformula = myformula & ")"

which is what you are trying to do.

Also, you want to have the = at the beginning of the formala.

Microsoft.Office.Core Reference Missing

Have you actually gone to your references and added a .NET reference to the 'Microsoft.Office.Core' library? If you downloaded the example application, the answer would be yes. If that is the case, follow the advice in the article:

If your system does not have Microsoft Office Outlook 2003 you may have to change the References used by the "OutlookConnector" project. That is to say, if you received a build error described as "The type of namespace name 'Outlook' could not be found", you probably don't have Office 2003. Simply expand the project references, remove the afflicted items, and add the COM Library appropriate for your system. If someone has a dynamic way to handle this, I'd be curious to see you've done.

That should solve your problem. If not, let us know.

How to properly override clone method?

Do you absolutely have to use clone? Most people agree that Java's clone is broken.

Josh Bloch on Design - Copy Constructor versus Cloning

If you've read the item about cloning in my book, especially if you read between the lines, you will know that I think clone is deeply broken. [...] It's a shame that Cloneable is broken, but it happens.

You may read more discussion on the topic in his book Effective Java 2nd Edition, Item 11: Override clone judiciously. He recommends instead to use a copy constructor or copy factory.

He went on to write pages of pages on how, if you feel you must, you should implement clone. But he closed with this:

Is all this complexities really necessary? Rarely. If you extend a class that implements Cloneable, you have little choice but to implement a well-behaved clone method. Otherwise, you are better off providing alternative means of object copying, or simply not providing the capability.

The emphasis was his, not mine.

Since you made it clear that you have little choice but to implement clone, here's what you can do in this case: make sure that MyObject extends java.lang.Object implements java.lang.Cloneable. If that's the case, then you can guarantee that you will NEVER catch a CloneNotSupportedException. Throwing AssertionError as some have suggested seems reasonable, but you can also add a comment that explains why the catch block will never be entered in this particular case.

Alternatively, as others have also suggested, you can perhaps implement clone without calling super.clone.

ASP.Net MVC - Read File from HttpPostedFileBase without save

A slight change to Thangamani Palanisamy answer, which allows the Binary reader to be disposed and corrects the input length issue in his comments.

string result = string.Empty;

using (BinaryReader b = new BinaryReader(file.InputStream))
  byte[] binData = b.ReadBytes(file.ContentLength);
  result = System.Text.Encoding.UTF8.GetString(binData);

Calling a function every 60 seconds

// example:
// checkEach(1000, () => {
//   if(!canIDoWorkNow()) {
//     return true // try again after 1 second
//   }
//   doWork()
// })
export function checkEach(milliseconds, fn) {
  const timer = setInterval(
    () => {
      try {
        const retry = fn()

        if (retry !== true) {
      } catch (e) {

        throw e

How do you clear Apache Maven's cache?

So there are some commands which you can use for cleaning

 1. mvn clean cache   
 2. mvn clean install 
 3. mvn clean install -Pclean-database

also deleting repository folder from .m2 can help.

RegEx for matching "A-Z, a-z, 0-9, _" and "."

regex: /^[a-zA-Z0-9_.]$/i

This works

The operation couldn’t be completed. (com.facebook.sdk error 2.) ios6

This worked for me:

  • Go to the settings app of your iPhone.
  • Open your Facebook Settings
  • Scroll down to your app and make sure your app allows facebook interaction.

This could happen on any device, therefore in your app you will have to make sure to handle this error correctly. I reckon you give the user feedback why Login With Facebook failed and ask the user to check their Facebook settings on their device.

 - (void)facebookSessionStateChanged:(FBSession *)session state:(FBSessionState)state error:(NSError *)error
    switch (state) {
        case FBSessionStateOpen:
            // handle successful login here
        case FBSessionStateClosed:
        case FBSessionStateClosedLoginFailed:
            [FBSession.activeSession closeAndClearTokenInformation];

            if (error) {
                // handle error here, for example by showing an alert to the user
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Could not login with Facebook"
                                                                message:@"Facebook login failed. Please check your Facebook settings on your phone."
                [alert show];

Convert integer value to matching Java Enum

There is no way to elegantly handle integer-based enumerated types. You might think of using a string-based enumeration instead of your solution. Not a preferred way all the times, but it still exists.

public enum Port {
   * The default port for the push server.

   * The alternative port that can be used to bypass firewall checks
   * made to the default <i>HTTPS</i> port.

  private final String portString;

  Port(final String portString) {
    this.portString = portString;

   * Returns the port for given {@link Port} enumeration value.
   * @return The port of the push server host.
  public Integer toInteger() {
    return Integer.parseInt(portString);

AWS ssh access 'Permission denied (publickey)' issue

For Ubuntu instances:

chmod 600 ec2-keypair.pem
ssh -v -i ec2-keypair.pem [email protected]

For other instances, you might have to use ec2-user instead of ubuntu.

Most EC2 Linux images I've used only have the root user created by default.

See also:

Example using Hyperlink in WPF

One of the most beautiful ways in my opinion (since it is now commonly available) is using behaviours.

It requires:

  • nuget dependency: Microsoft.Xaml.Behaviors.Wpf
  • if you already have behaviours built in you might have to follow this guide on Microsofts blog.

xaml code:



<Hyperlink NavigateUri="{Binding Path=Link}">
        <behaviours:HyperlinkOpenBehaviour ConfirmNavigation="True"/>
        <Run Text="{Binding Path=Link}"/>

behaviour code:

using System.Windows;
using System.Windows.Documents;
using System.Windows.Navigation;
using Microsoft.Xaml.Behaviors;

namespace YourNameSpace
    public class HyperlinkOpenBehaviour : Behavior<Hyperlink>
        public static readonly DependencyProperty ConfirmNavigationProperty = DependencyProperty.Register(
            nameof(ConfirmNavigation), typeof(bool), typeof(HyperlinkOpenBehaviour), new PropertyMetadata(default(bool)));

        public bool ConfirmNavigation
            get { return (bool) GetValue(ConfirmNavigationProperty); }
            set { SetValue(ConfirmNavigationProperty, value); }

        /// <inheritdoc />
        protected override void OnAttached()
            this.AssociatedObject.RequestNavigate += NavigationRequested;
            this.AssociatedObject.Unloaded += AssociatedObjectOnUnloaded;

        private void AssociatedObjectOnUnloaded(object sender, RoutedEventArgs e)
            this.AssociatedObject.Unloaded -= AssociatedObjectOnUnloaded;
            this.AssociatedObject.RequestNavigate -= NavigationRequested;

        private void NavigationRequested(object sender, RequestNavigateEventArgs e)
            if (!ConfirmNavigation || MessageBox.Show("Are you sure?", "Question", MessageBoxButton.YesNo, MessageBoxImage.Question) == MessageBoxResult.Yes)

            e.Handled = true;

        private void OpenUrl()
//          Process.Start(new ProcessStartInfo(AssociatedObject.NavigateUri.AbsoluteUri));
            MessageBox.Show($"Opening {AssociatedObject.NavigateUri}");

        /// <inheritdoc />
        protected override void OnDetaching()
            this.AssociatedObject.RequestNavigate -= NavigationRequested;

Calculating sum of repeated elements in AngularJS ng-repeat

This is also working both the filter and normal list. The first thing to create a new filter for the sum of all values from the list, and also given solution for a sum of the total quantity. In details code check it fiddler link.

angular.module("sampleApp", [])
        .filter('sumOfValue', function () {
        return function (data, key) {        
            if (angular.isUndefined(data) || angular.isUndefined(key))
                return 0;        
            var sum = 0;        
                sum = sum + parseInt(value[key], 10);
            return sum;
    }).filter('totalSumPriceQty', function () {
        return function (data, key1, key2) {        
            if (angular.isUndefined(data) || angular.isUndefined(key1)  || angular.isUndefined(key2)) 
                return 0;        
            var sum = 0;
                sum = sum + (parseInt(value[key1], 10) * parseInt(value[key2], 10));
            return sum;
    }).controller("sampleController", function ($scope) {
        $scope.items = [
          {"id": 1,"details": "test11","quantity": 2,"price": 100}, 
          {"id": 2,"details": "test12","quantity": 5,"price": 120}, 
          {"id": 3,"details": "test3","quantity": 6,"price": 170}, 
          {"id": 4,"details": "test4","quantity": 8,"price": 70}

<div ng-app="sampleApp">
  <div ng-controller="sampleController">
    <div class="col-md-12 col-lg-12 col-sm-12 col-xsml-12">
      <input type="text" class="form-control" ng-model="searchFilter" />
    <div class="col-md-12 col-lg-12 col-sm-12 col-xsml-12">
      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2">

      <div class="col-md-4 col-lg-4 col-sm-4 col-xsml-4">

      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">

      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">

      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">

      <div ng-repeat="item in resultValue=(items | filter:{'details':searchFilter})">
        <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2">{{}}</div>
        <div class="col-md-4 col-lg-4 col-sm-4 col-xsml-4">{{item.details}}</div>
        <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">{{item.quantity}}</div>
        <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">{{item.price}}</div>
        <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">{{item.quantity * item.price}}</div>
      <div colspan='3' class="col-md-8 col-lg-8 col-sm-8 col-xsml-8 text-right">
        <h4>{{resultValue | sumOfValue:'quantity'}}</h4>

      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">
        <h4>{{resultValue | sumOfValue:'price'}}</h4>

      <div class="col-md-2 col-lg-2 col-sm-2 col-xsml-2 text-right">
        <h4>{{resultValue | totalSumPriceQty:'quantity':'price'}}</h4>


check this Fiddle Link

How to "pull" from a local branch into another one?

If you are looking for a brand new pull from another branch like from local to master you can follow this.

git commit -m "Initial Commit"
git add .
git pull --rebase git_url
git push origin master

throwing an exception in objective-c/cocoa

I think to be consistant it's nicer to use @throw with your own class that extends NSException. Then you use the same notations for try catch finally:

@try {

Apple explains here how to throw and handle exceptions: Catching Exceptions Throwing Exceptions

How to add native library to "java.library.path" with Eclipse launch (instead of overriding it)

Many of the existing answers assume you want to set this for a particular project, but I needed to set it for Eclipse itself in order to support integrated authentication for the SQL Server JDBC driver.

To do this, I followed these instructions for launching Eclipse from the Java commandline instead of its normal launcher. Then I just modified that script to add my -Djava.library.path argument to the Java commandline.