Programs & Examples On #Dbproviderfactories

An unhandled exception of type 'System.TypeInitializationException' occurred in EntityFramework.dll

Read the message:

Only one <configSections> element allowed per config file and if present must be the first child of the root <configuration> element.

Move the configSections element to the top - just above where is currently.

Unable to find the requested .Net Framework Data Provider. It may not be installed. - when following mvc3 tutorial

I had the same issue. I checked the version of System.Data.SqlServerCe in C:\Windows\assembly. It was So I installed version 4.0.0 from below link (x86) and works fine.

.htaccess rewrite to redirect root URL to subdirectory

Two ways out of possible solutions to achieve this are: 1. Create a .htaccess file in root folder as under (just replace and my_dir with your corresponding values):

<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(www.)?$
RewriteCond %{REQUEST_URI} !^/my_dir/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /my_dir/$1
RewriteCond %{HTTP_HOST} ^(www.)?$
RewriteRule ^(/)?$ my_dir/index.php [L] 
  1. Use RedirectMatch to only redirect the root URL “/” to another folder or URL,

    RedirectMatch ^/$

The remote server returned an error: (407) Proxy Authentication Required

HttpWebRequest webRequest = WebRequest.Create(uirTradeStream) as HttpWebRequest;

webRequest.Proxy = WebRequest.DefaultWebProxy;

webRequest.Credentials = new NetworkCredential("user", "password");

webRequest.Proxy.Credentials = new NetworkCredential("user", "password");

It is successful.

TypeError: $(...).autocomplete is not a function

you missed jquery ui library. Use CDN of Jquery UI or if you want it locally then download the file from Jquery Ui

<link href="" rel="Stylesheet"></link>
<script src="YourJquery source path"></script>
<script src="" ></script>

git: Your branch is ahead by X commits

This worked for me

git reset --hard origin/master

The output must look like

On branch dev HEAD is now at ae1xc41z Last commit message

How to break out of multiple loops?

First, you may also consider making the process of getting and validating the input a function; within that function, you can just return the value if its correct, and keep spinning in the while loop if not. This essentially obviates the problem you solved, and can usually be applied in the more general case (breaking out of multiple loops). If you absolutely must keep this structure in your code, and really don't want to deal with bookkeeping booleans...

You may also use goto in the following way (using an April Fools module from here):

#import the stuff
from goto import goto, label

while True:
    #snip: print out current state
    while True:
        ok = get_input("Is this ok? (y/n)")
        if ok == "y" or ok == "Y": goto .breakall
        if ok == "n" or ok == "N": break
    #do more processing with menus and stuff
label .breakall

I know, I know, "thou shalt not use goto" and all that, but it works well in strange cases like this.

What is a good Hash Function?

What you're saying here is you want to have one that uses has collision resistance. Try using SHA-2. Or try using a (good) block cipher in a one way compression function (never tried that before), like AES in Miyaguchi-Preenel mode. The problem with that is that you need to:

1) have an IV. Try using the first 256 bits of the fractional parts of Khinchin's constant or something like that. 2) have a padding scheme. Easy. Barrow it from a hash like MD5 or SHA-3 (Keccak [pronounced 'ket-chak']). If you don't care about the security (a few others said this), look at FNV or lookup2 by Bob Jenkins (actually I'm the first one who reccomends lookup2) Also try MurmurHash, it's fast (check this: .16 cpb).

ant warning: "'includeantruntime' was not set"

The answer from Daniel works just perfect. Here is a sample snippet that I added to my build.xml:

<target name="compile">
    <mkdir dir="${classes.dir}"/>
    <javac srcdir="${src.dir}" destdir="${classes.dir}" includeantruntime="false">
                                                 <!--   ^^^^^^^^^^^^^^^^^^^^^^^^^  -->
            <path id="application" location="${jar.dir}/${}.jar"/>
            <path id="junit" location="${lib.dir}/junit-4.9b2.jar"/>

What's the fastest algorithm for sorting a linked list?

This is a nice little paper on this topic. His empirical conclusion is that Treesort is best, followed by Quicksort and Mergesort. Sediment sort, bubble sort, selection sort perform very badly.


Check if a given time lies between two times regardless of date

The answer given by @kocko works in only same day.
If start time "23:00:00" and end "02:00:00"[next day] and current time is "01:30:00" then result will false...
I modified the @kocko's answer to work perfectly

public static boolean isTimeBetweenTwoTime(String initialTime, String finalTime, 
    String currentTime) throws ParseException {

    String reg = "^([0-1][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
    if (initialTime.matches(reg) && finalTime.matches(reg) && 
        boolean valid = false;
        //Start Time
        //all times are from java.util.Date
        Date inTime = new SimpleDateFormat("HH:mm:ss").parse(initialTime);
        Calendar calendar1 = Calendar.getInstance();

        //Current Time
        Date checkTime = new SimpleDateFormat("HH:mm:ss").parse(currentTime);
        Calendar calendar3 = Calendar.getInstance();

        //End Time
        Date finTime = new SimpleDateFormat("HH:mm:ss").parse(finalTime);
        Calendar calendar2 = Calendar.getInstance();

        if (finalTime.compareTo(initialTime) < 0) 
            calendar2.add(Calendar.DATE, 1);
            calendar3.add(Calendar.DATE, 1);

        java.util.Date actualTime = calendar3.getTime();
        if ((actualTime.after(calendar1.getTime()) || 
             actualTime.compareTo(calendar1.getTime()) == 0) && 
            valid = true;
            return valid;
        } else {
            throw new IllegalArgumentException("Not a valid time, expecting 
            HH:MM:SS format");


"07:00:00" - "17:30:00" - "15:30:00" [current] - true
"17:00:00" - "21:30:00" - "16:30:00" [current] - false
"23:00:00" - "04:00:00" - "02:00:00" [current] - true
"00:30:00" - "06:00:00" - "06:00:00" [current] - false 

(I have included lower limit value to [upper limit value-1])

HTML5 - mp4 video does not play in IE9

Ended up using to support all browsers.

But to get the video working in IE9 and Chrome I just added html5 doc type and used mp4:

<!DOCTYPE html>
  <video src="video.mp4" width="400" height="300" preload controls>

Sending a mail from a linux shell script

If both exim and ssmtp are running, you may enter into troubles. So if you just want to run a simple MTA, just to have a simple smtp client to send email notifications for insistance, you shall purge the eventually preinstalled MTA like exim or postfix first and reinstall ssmtp.

Then it's quite straight forward, configuring only 2 files (revaliases and ssmtp.conf) - See ssmtp doc - , and usage in your bash or bourne script is like :



[[ -z $1 ]] && SUBJECT="Notification from $SENDER on server $SERVER_NAME"  
[[ -z $2 ]] && RECEIVER="another_configured_email_address"   
[[ -z $3 ]] && TEXT="no text content"  

echo -e $MAIL_TXT | sendmail -t  
exit $?  

Obviously do not forget to open your firewall output to the smtp port (25).

PHP array printing using a loop

Another advanced method is called an ArrayIterator. It’s part of a wider class that exposes many accessible variables and functions. You are more likely to see this as part of PHP classes and heavily object-oriented projects.

$fnames = ["Muhammed", "Ali", "Fatimah", "Hasan", "Hussein"];

$arrObject = new ArrayObject($fnames);
$arrayIterator = $arrObject->getIterator();

while( $arrayIterator->valid() ){
echo $arrayIterator->current() . "<br />";

Call a function from another file?

Inside MathMethod.Py.

def Add(a,b):
   return a+b 

def subtract(a,b):
  return a-b

Inside Main.Py

import MathMethod as MM 


Common xlabel/ylabel for matplotlib subplots

It will look better if you reserve space for the common labels by making invisible labels for the subplot in the bottom left corner. It is also good to pass in the fontsize from rcParams. This way, the common labels will change size with your rc setup, and the axes will also be adjusted to leave space for the common labels.

fig_size = [8, 6]
fig, ax = plt.subplots(5, 2, sharex=True, sharey=True, figsize=fig_size)
# Reserve space for axis labels
ax[-1, 0].set_xlabel('.', color=(0, 0, 0, 0))
ax[-1, 0].set_ylabel('.', color=(0, 0, 0, 0))
# Make common axis labels
fig.text(0.5, 0.04, 'common X', va='center', ha='center', fontsize=rcParams['axes.labelsize'])
fig.text(0.04, 0.5, 'common Y', va='center', ha='center', rotation='vertical', fontsize=rcParams['axes.labelsize'])

enter image description here enter image description here

Why is using a wild card with a Java import statement bad?

Here are the few things that I found regarding this topic.

  • During compilation, the compiler tries to find classes that are used in the code from the .* import and the corresponding byte code will be generated by selecting the used classes from .* import. So the byte code of using .* import or .class names import will be same and the runtime performance will also be the same because of the same byte code.

  • In each compilation, the compiler has to scan all the classes of .* package to match the classes that are actually used in the code. So, code with .* import takes more time during the compilation process as compared to using .class name imports.

  • Using .* import helps to make code more cleaner

  • Using .* import can create ambiguity when we use two classes of the same name from two different packages. Eg, Date is available in both packages.

      import java.util.*;
      import java.sql.*;
      public class DateDemo {
          private Date utilDate;
          private Date sqlDate;

What does android:layout_weight mean?

layout_weight tells Android how to distribute your Views in a LinearLayout. Android then first calculates the total proportion required for all Views that have a weight specified and places each View according to what fraction of the screen it has specified it needs. In the following example, Android sees that the TextViews have a layout_weight of 0 (this is the default) and the EditTexts have a layout_weight of 2 each, while the Button has a weight of 1. So Android allocates 'just enough' space to display tvUsername and tvPassword and then divides the remainder of the screen width into 5 equal parts, two of which are allocated to etUsername, two to etPassword and the last part to bLogin:

<LinearLayout android:orientation="horizontal" ...>

    <TextView android:id="@+id/tvUsername" 
    android:layout_width="wrap_content" ... />

    <EditText android:id="@+id/etUsername"
    android:layout_weight="2" ... />

    <TextView android:id="@+id/tvPassword"
    android:layout_width="wrap_content" />

    <EditText android:id="@+id/etPassword"
    android:layout_weight="2" ... />

    <Button android:id="@+id/bLogin"
    android:text="Login"... />


It looks like:
landscape orientation and
portrait orientation

CSS how to make scrollable list

Another solution would be as below where the list is placed under a drop-down button.

  <button class="btn dropdown-toggle btn-primary btn-sm" data-toggle="dropdown"
    >Markets<span class="caret"></span></button>

    <ul class="dropdown-menu", style="height:40%; overflow:hidden; overflow-y:scroll;">
      {{ }}

Dynamic tabs with user-click chosen components

there is component ready to use (rc5 compatible) ng2-steps which uses Compiler to inject component to step container and service for wiring everything together (data sync)

    import { Directive , Input, OnInit, Compiler , ViewContainerRef } from '@angular/core';

import { StepsService } from './ng2-steps';

export class StepDirective implements OnInit{

  @Input('content') content:any;
  @Input('index') index:string;
  public instance;

    private compiler:Compiler,
    private viewContainerRef:ViewContainerRef,
    private sds:StepsService

      const injector = this.viewContainerRef.injector;
      this.viewContainerRef.createComponent(cmpFactory, 0,  injector);


Execute action when back bar button of UINavigationController is pressed

Try this .

self.navigationItem.leftBarButtonItem?.target = "methodname"
func methodname ( ) {            
  //    enter code here

Try on this too.

override func viewWillAppear(animated: Bool) {
  //empty your array

Installing jdk8 on ubuntu- "unable to locate package" update doesn't fix

Ubuntu defaults to the OpenJDK packages. If you want to install Oracle's JDK, then you need to visit their download page, and grab the package from there.

Once you've installed the Oracle JDK, you also need to update the following (system defaults will point to OpenJDK):

export JAVA_HOME=/my/path/to/oracle/jdk
export PATH=$JAVA_HOME/bin:$PATH

If you want the Oracle JDK to be the default for your system, you will need to remove the OpenJDK packages, and update your profile environment variables.

Docker command can't connect to Docker daemon

Tested in Ubuntu 16.04

# Create the docker group and add your user to the docker group
groupadd docker
usermod -aG docker $USER
newgrp docker

# Configure docker service to be exposed
mkdir -p /etc/systemd/system/docker.service.d
echo -e '[Service]\nExecStart=\nExecStart=/usr/bin/dockerd -H fd:// -H tcp://' >> /etc/systemd/system/docker.service.d/override.conf

# restart service
systemctl daemon-reload
service docker restart

How to dynamic new Anonymous Class?

You can create an ExpandoObject like this:

IDictionary<string,object> expando = new ExpandoObject();
expando["Name"] = value;

And after casting it to dynamic, those values will look like properties:

dynamic d = expando;

However, they are not actual properties and cannot be accessed using Reflection. So the following statement will return a null:


Extracting columns from text file with different delimiters in Linux

If the command should work with both tabs and spaces as the delimiter I would use awk:

awk '{print $100,$101,$102,$103,$104,$105}' myfile > outfile

As long as you just need to specify 5 fields it is imo ok to just type them, for longer ranges you can use a for loop:

awk '{for(i=100;i<=105;i++)print $i}' myfile > outfile

If you want to use cut, you need to use the -f option:

cut -f100-105 myfile > outfile

If the field delimiter is different from TAB you need to specify it using -d:

cut -d' ' -f100-105 myfile > outfile

Check the man page for more info on the cut command.

NSString with \n or line break

NSString *str1 = @"Share Role Play Photo via Facebook, or Twitter for free coins per photo.";
NSString *str2 = @"Like Role Play on facebook for 50 free coins.";
NSString *str3 = @"Check out 'What's Hot' on other ways to receive free coins";

NSString *msg = [NSString stringWithFormat:@"%@\n%@\n%@", str1, str2, str3];

login to remote using "mstsc /admin" with password

Same problem but @Angelo answer didn't work for me, because I'm using same server with different credentials. I used the approach below and tested it on Windows 10.

cmdkey /add:server01 /user:<username> /pass:<password>

Then used mstsc /v:server01 to connect to the server.

The point is to use names instead of ip addresses to avoid conflict between credentials. If you don't have a DNS server locally accessible try c:\windows\system32\drivers\etc\hosts file.

Access-Control-Allow-Origin and Angular.js $http

Try with this:

              type: 'POST',
              url: URL,
              defaultHeaders: {
                  'Content-Type': 'application/json',
                  "Access-Control-Allow-Origin": "*",
                  'Accept': 'application/json'

              data: obj,
              dataType: 'json',
              success: function (response) {
            //    BindTableData();
                console.log("success ");
              error: function (xhr) {
                console.log("error ");

Setting a Sheet and cell as variable

Yes, set the cell as a RANGE object one time and then use that RANGE object in your code:

Sub RangeExample()
Dim MyRNG As Range

Set MyRNG = Sheets("Sheet1").Cells(23, 4)

Debug.Print MyRNG.Value

End Sub

Alternately you can simply store the value of that cell in memory and reference the actual value, if that's all you really need. That variable can be Long or Double or Single if numeric, or String:

Sub ValueExample()
Dim MyVal As String

MyVal = Sheets("Sheet1").Cells(23, 4).Value

Debug.Print MyVal

End Sub

How can I format decimal property to currency?

You can use String.Format, see the code [via How-to Geek]:

decimal moneyvalue = 1921.39m;
string html = String.Format("Order Total: {0:C}", moneyvalue);
// Output: $1,921.39

See also:

How should I edit an Entity Framework connection string?

Open .edmx file any text editor change the Schema="your required schema" and also open the app.config/web.config, change the user id and password from the connection string. you are done.

Stretch Image to Fit 100% of Div Height and Width

will the height attribute stretch the image beyond its native resolution? If I have a image with a height of say 420 pixels, I can't get css to stretch the image beyond the native resolution to fill the height of the viewport.

I am getting pretty close results with:

 .rightdiv img {
        max-width: 25vw;
        min-height: 100vh;

the 100vh is getting pretty close, with just a few pixels left over at the bottom for some reason.

Is it possible to run an .exe or .bat file on 'onclick' in HTML

No, that would be a huge security breach. Imagine if someone could run

format c:

whenever you visted their website.

Changing Jenkins build number

Perhaps a combination of these plugins may come in handy:

Excel - Button to go to a certain sheet

In Excel 2007, goto Insert/Shape and pick a shape. Colour it and enter whatever text you want. Then right click on the shape and insert a hyperlink

enter image description here

enter image description here

A few tips with shapes..

If you want to easily position the shape with cells, hold down Alt when you move the shape and it will lock to the cell. If you don't want the shape to move or resize with rows/columns, right click the shape, select size and properties and choose the setting which works best.

How to check if any Checkbox is checked in Angular

If you have only one checkbox, you can do this easily with just ng-model:

<input type="checkbox" ng-model="checked"/>
<button ng-disabled="!checked"> Next </button>

And initialize $scope.checked in your Controller (default=false). The official doc discourages the use of ng-init in that case.

Correct mime type for .mp4

video/mp4should be used when you have video content in your file. If there is none, but there is audio, you should use audio/mp4. If no audio and no video is used, for instance if the file contains only a subtitle track or a metadata track, the MIME should be application/mp4. Also, as a server, you should try to include the codecs or profiles parameters as defined in RFC6381, as this will help clients determine if they can play the file, prior to downloading it.

ListView with Add and Delete Buttons in each Row in android

public class UserCustomAdapter extends ArrayAdapter<User> {
 Context context;
 int layoutResourceId;
 ArrayList<User> data = new ArrayList<User>();

 public UserCustomAdapter(Context context, int layoutResourceId,
   ArrayList<User> data) {
  super(context, layoutResourceId, data);
  this.layoutResourceId = layoutResourceId;
  this.context = context; = data;

 public View getView(int position, View convertView, ViewGroup parent) {
  View row = convertView;
  UserHolder holder = null;

  if (row == null) {
   LayoutInflater inflater = ((Activity) context).getLayoutInflater();
   row = inflater.inflate(layoutResourceId, parent, false);
   holder = new UserHolder();
   holder.textName = (TextView) row.findViewById(;
   holder.textAddress = (TextView) row.findViewById(;
   holder.textLocation = (TextView) row.findViewById(;
   holder.btnEdit = (Button) row.findViewById(;
   holder.btnDelete = (Button) row.findViewById(;
  } else {
   holder = (UserHolder) row.getTag();
  User user = data.get(position);
  holder.btnEdit.setOnClickListener(new OnClickListener() {

   public void onClick(View v) {
    // TODO Auto-generated method stub
    Log.i("Edit Button Clicked", "**********");
    Toast.makeText(context, "Edit button Clicked",
  holder.btnDelete.setOnClickListener(new OnClickListener() {

   public void onClick(View v) {
    // TODO Auto-generated method stub
    Log.i("Delete Button Clicked", "**********");
    Toast.makeText(context, "Delete button Clicked",
  return row;


 static class UserHolder {
  TextView textName;
  TextView textAddress;
  TextView textLocation;
  Button btnEdit;
  Button btnDelete;

Hey Please have a look here-

I have same answer here on my blog ..

What's the difference between OpenID and OAuth?

Many people still visit this so here's a very simple diagram to explain it


Courtesy Wikipedia

Handling onchange event in HTML.DropDownList Razor MVC


You can use another overload of the DropDownList method. Pick the one you need and pass in a object with your html attributes.


@Html.DropDownList("CategoryID", null, new { @onchange="location = this.value;" })

More Information

XPath OR operator for different nodes

If you want to select only one of two nodes with union operator, you can use this solution: (//bookstore/book/title | //bookstore/city/zipcode/title)[1]

Can git undo a checkout of unstaged files

In VSCODE ctrl+z (undo) worked for me

I did git checkout .instead of git add . and all my file changes were lost.

But Now using command + z in my mac , recovered the changes and saved a tone of work for me.

C# generic list <T> how to get the type of T?

Given an object which I suspect to be some kind of IList<>, how can I determine of what it's an IList<>?

Here's the gutsy solution. It assumes you have the actual object to test (rather than a Type).

public static Type ListOfWhat(Object list)
    return ListOfWhat2((dynamic)list);

private static Type ListOfWhat2<T>(IList<T> list)
    return typeof(T);

Example usage:

object value = new ObservableCollection<DateTime>();



Multiple models in a view

a simple way to do that

we can call all model first

@using project.Models

then send your model with viewbag

// for list
ViewBag.Name = db.YourModel.ToList();

// for one
ViewBag.Name = db.YourModel.Find(id);

and in view

// for list
List<YourModel> Name = (List<YourModel>)ViewBag.Name ;

//for one
YourModel Name = (YourModel)ViewBag.Name ;

then easily use this like Model

Capture the Screen into a Bitmap

Bitmap memoryImage;
//Set full width, height for image
memoryImage = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
Size s = new Size(memoryImage.Width, memoryImage.Height);
Graphics memoryGraphics = Graphics.FromImage(memoryImage);
memoryGraphics.CopyFromScreen(0, 0, 0, 0, s);
string str = "";
    str = string.Format(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) +
          @"\Screenshot.png");//Set folder to save image
catch { };;

View's getWidth() and getHeight() returns 0

This is a little old, but was having trouble with this myself (needing to animate objects in a fragment when it is created). This solution worked for me, I believe it is self explanatory.

class YourFragment: Fragment() {
    var width = 0
    var height = 0

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Inflate the layout for this fragment
    val root = inflater.inflate(R.layout.fragment_winner_splash, container, false)
    container?.width.let {
        if (it != null) {
            width = it
    container?.height.let {
        if (it != null) {
            height = it
    return root

What is the equivalent of Java's final in C#?

It depends on the context.

Link vs compile vs controller

  • compile: used when we need to modify directive template, like add new expression, append another directive inside this directive
  • controller: used when we need to share/reuse $scope data
  • link: it is a function which used when we need to attach event handler or to manipulate DOM.

How to split a line into words separated by one or more spaces in bash?

$ line="these are words"
$ ll=($line)
$ declare -p ll  # dump the array
declare -a ll='([0]="these" [1]="are" [2]="words")'
$ for w in ${ll[@]}; do echo $w; done

How to ignore the first line of data when processing CSV data?

Python 3.X


It was quite frustrating that the csv module could not easily get the header, there is also a bug with the UTF-8 BOM (first char in file). This works for me using only the csv module:

import csv

def read_csv(self, csv_path, delimiter):
    with open(csv_path, newline='', encoding='utf-8') as f:
        # Remove UTF8 BOM.
        txt =[1:]

    # Remove header line.
    header = txt.splitlines()[:1]
    lines = txt.splitlines()[1:]

    # Convert to list.
    csv_rows = list(csv.reader(lines, delimiter=delimiter))

    for row in csv_rows:
        value = row[INDEX_HERE]

How to unmerge a Git merge?

If you haven't committed the merge, then use:

git merge --abort

How to multi-line "Replace in files..." in Notepad++

The workaround is

  1. search and replace \r\n to thisismynewlineword

(this will remove all the new lines and there should be whole one line)

  1. now perform your replacements

  2. search and replace thisismynewlineword to \r\n

(to undo the step 1)

Is this how you define a function in jQuery?

No, you can just write the function as:

$(document).ready(function() {

function MyBlah(blah) {

This calls the function MyBlah on content ready.

Confirm postback OnClientClick button ASP.NET

This is a simple way to do client-side validation BEFORE the confirmation. It makes use of the built in ASP.NET validation javascript.

<script type="text/javascript">
    function validateAndConfirm() {
        Page_ClientValidate("GroupName");  //'GroupName' is the ValidationGroup
        if (Page_IsValid) {
            return confirm("Are you sure?");
        return false;

<asp:TextBox ID="IntegerTextBox" runat="server" Width="100px" MaxLength="6" />
<asp:RequiredFieldValidator ID="reqIntegerTextBox" runat="server" ErrorMessage="Required"
    ValidationGroup="GroupName"  ControlToValidate="IntegerTextBox" />
<asp:RangeValidator ID="rangeTextBox" runat="server" ErrorMessage="Invalid"
    ValidationGroup="GroupName" Type="Integer" ControlToValidate="IntegerTextBox" />
<asp:Button ID="SubmitButton" runat="server" Text="Submit"  ValidationGroup="GroupName"
    OnClick="SubmitButton_OnClick" OnClientClick="return validateAndConfirm();" />

Source: Client Side Validation using ASP.Net Validator Controls from Javascript

How can I get a random number in Kotlin?

Whenever there is a situation where you want to generate key or mac address which is hexadecimal number having digits based on user demand, and that too using android and kotlin, then you my below code helps you:

private fun getRandomHexString(random: SecureRandom, numOfCharsToBePresentInTheHexString: Int): String {
    val sb = StringBuilder()
    while (sb.length < numOfCharsToBePresentInTheHexString) {
        val randomNumber = random.nextInt()
        val number = String.format("%08X", randomNumber)
    return sb.toString()

Why is the Java main method static?

I don't know if the JVM calls the main method before the objects are instantiated... But there is a far more powerful reason why the main() method is static... When JVM calls the main method of the class (say, Person). it invokes it by "Person.main()". You see, the JVM invokes it by the class name. That is why the main() method is supposed to be static and public so that it can be accessed by the JVM.

Hope it helped. If it did, let me know by commenting.

log4j:WARN No appenders could be found for logger in web.xml

You may get this error when your are not present in the classpath.

This means you have to move the into the src folder and set the output to the bin folder so that at run time will read from the bin folder and your error will be resolved easily.

TypeScript error TS1005: ';' expected (II)

I was injecting service like this:

private messageShowService MessageShowService

instead of:

private messageShowService: MessageShowService

and that was the reason of error, despite nothing related with ',' was there.

Where does Chrome store extensions?

For my Mac, extensions were here:

~/Library/Application Support/Google/Chrome/Default/Extensions/

if you go to chrome://extensions you'll find the "ID" of each extension. That is going to be a directory within Extensions directory. It is there you'll find all of the extension's files.

Get UTC time in seconds

You say you're using:


where date_in_seconds_from_bash is presumably the output of date +%s.

The time.localtime function, as the name implies, gives you local time.

If you want UTC, use time.gmtime() rather than time.localtime().

As JamesNoonan33's answer says, the output of date +%s is timezone invariant, so date +%s is exactly equivalent to date -u %s. It prints the number of seconds since the "epoch", which is 1970-01-01 00:00:00 UTC. The output you show in your question is entirely consistent with that:

date -u
Thu Jul 3 07:28:20 UTC 2014

date +%s
1404372514   # 14 seconds after "date -u" command

date -u +%s
1404372515   # 15 seconds after "date -u" command

ssh "permissions are too open" error

provide 400 permission, execute below command

chmod 400 /Users/username/.ssh/id_rsa

enter image description here

Assign output of a program to a variable using a MS batch file

Some macros to set the output of a command to a variable/

For directly in the command prompt

c:\>doskey assign=for /f "tokens=1,2 delims=," %a in ("$*") do @for /f "tokens=* delims=" %# in ('"%a"') do @set "%b=%#"

c:\>assign WHOAMI /LOGONID,my-id

c:\>echo %my-id%

Macro with arguments

As this macro accepts arguments as a function i think it is the neatest macro to be used in a batch file:

@echo off

::::: ---- defining the assign macro ---- ::::::::
setlocal DisableDelayedExpansion
(set LF=^
set ^"\n=^^^%LF%%LF%^%LF%%LF%^^"

::set argv=Empty
set assign=for /L %%n in (1 1 2) do ( %\n%
   if %%n==2 (%\n%
      setlocal enableDelayedExpansion%\n%
      for /F "tokens=1,2 delims=," %%A in ("!argv!") do (%\n%
         for /f "tokens=* delims=" %%# in ('%%~A') do endlocal^&set "%%~B=%%#" %\n%
      ) %\n%
   ) %\n%
) ^& set argv=,

::::: -------- ::::::::

%assign% "WHOAMI /LOGONID",result
echo %result%

FOR /F macro

not so easy to read as the previous macro.

;;set "{{=for /f "tokens=* delims=" %%# in ('" &::
;;set "--=') do @set ""                        &::
;;set "}}==%%#""                               &::

:: --examples

::assigning ver output to %win-ver% variable
%{{% ver %--%win-ver%}}%
echo 3: %win-ver%

::assigning hostname output to %my-host% variable
%{{% hostname %--%my-host%}}%
echo 4: %my-host%

Macro using a temp file

Easier to read , it is not so slow if you have a SSD drive but still it creates a temp file.

@echo off

;;set "[[=>"#" 2>&1&set/p "&set "]]==<# & del /q # >nul 2>&1" &::

chcp %[[%code-page%]]%
echo ~~%code-page%~~

whoami %[[%its-me%]]%
echo ##%its-me%##

What is the method for converting radians to degrees?

In javascript you can do it this way

radians = degrees * (Math.PI/180);

degrees = radians * (180/Math.PI);

How to open in default browser in C#

dotnet core throws an error if we use Process.Start(URL). The following code will work in dotnet core. You can add any browser instead of Chrome.

var processes = Process.GetProcessesByName("Chrome");
var path  = processes.FirstOrDefault()?.MainModule?.FileName;
Process.Start(path,  url);

How to change the status bar color in Android?

This is what worked for me in KitKat and with good results.

public static void setTaskBarColored(Activity context) {
            Window w = context.getWindow();
            w.setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            //status bar height
            int statusBarHeight = Utilities.getStatusBarHeight(context);

            View view = new View(context);
            view.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
            view.getLayoutParams().height = statusBarHeight;
            ((ViewGroup) w.getDecorView()).addView(view);

How to add not null constraint to existing column in MySQL

Try this, you will know the difference between change and modify,

ALTER TABLE table_name CHANGE curr_column_name new_column_name new_column_datatype [constraints]

ALTER TABLE table_name MODIFY column_name new_column_datatype [constraints]
  • You can change name and datatype of the particular column using CHANGE.
  • You can modify the particular column datatype using MODIFY. You cannot change the name of the column using this statement.

Hope, I explained well in detail.

Javascript geocoding from address to latitude and longitude numbers not working

Try using this instead:

var latitude = results[0];
var longitude = results[0].geometry.location.lng();

It's bit hard to navigate Google's api but here is the relevant documentation.

One thing I had trouble finding was how to go in the other direction. From coordinates to an address. Here is the code I neded upp using. Please not that I also use jquery.

$.each(results[0].address_components, function(){
    $("#CreateDialog").find('input[name="'+ this.types+'"]').attr('value', this.long_name);

What I'm doing is to loop through all the returned address_components and test if their types match any input element names I have in a form. And if they do I set the value of the element to the address_components value.
If you're only interrested in the whole formated address then you can follow Google's example

Angular ng-class if else

Just make a rule for each case:

<div id="homePage" ng-class="{ 'center': page.isSelected(1) , 'left': !page.isSelected(1)  }">

Or use the ternary operator:

<div id="homePage" ng-class="page.isSelected(1) ? 'center' : 'left'">

How can I use a reportviewer control in an mvc 3 razor view?

It is possible to get an SSRS report to appear on an MVC page without using iFrames or an aspx page.

The bulk of the work is explained here:

The link explains how to create a web service and MVC action method that will allow you to call the reporting service and render result of the web service as an Excel file. With a small change to the code in the example you can render it as HTML.

All you need to do then is use a button to call a javascript function that makes an AJAX call to your MVC action which returns the HTML of the report. When the AJAX call returns with the HTML just replace a div with this HTML.

We use AngularJS so my example below is in that format, but it could be any javascript function

$scope.getReport = function()
        method: "POST",
        url: "Report/ExportReport",
                    { Name: 'DateFrom', Value: $scope.dateFrom },
                    { Name: 'DateTo', Value: $scope.dateTo },
                    { Name: 'LocationsCSV', Value: $scope.locationCSV }

    .success(function (serverData)


And the Action Method - mainly taken from the above link...

    public FileContentResult ExportReport([FromBody]List<ReportParameterModel> parameters)
         byte[] output;
         string extension, mimeType, encoding;
         string reportName = "/Reports/DummyReport";
         ReportService.Warning[] warnings;
         string[] ids;

            new NetworkCredential("username", "password", "domain"),
            out output,
            out extension,
            out mimeType,
            out encoding,
            out warnings,
            out ids

        // Set HTTP Response Header to show download dialog popup
        Response.AddHeader("content-disposition", string.Format("attachment;filename=GeneratedExcelFile{0:yyyyMMdd}.{1}", DateTime.Today, extension));
        return new FileContentResult(output, mimeType);

So the result is that you get to pass parameters to an SSRS reporting server which returns a report which you render as HTML. Everything appears on the one page. This is the best solution I could find

Is there a way to use SVG as content in a pseudo element :before or :after

<div class="author_">Lord Byron</div>

.author_ {  font-family: 'Playfair Display', serif; font-size: 1.25em; font-weight: 700;letter-spacing: 0.25em; font-style: italic;_x000D_
  margin-top: -0.5em;_x000D_
  color: black;_x000D_
  margin:0 -100% 0 0;_x000D_
  display: inline-block;_x000D_
  height: 10px;_x000D_
  content: url(data:image/svg+xml,;_x000D_
.author_:before {_x000D_
  margin:0 0 0 -100%;_x000D_
  display: inline-block;_x000D_
  height: 10px;_x000D_
  content: url(data:image/svg+xml,;_x000D_
 <div class="author_">Lord Byron</div>

Convenient tool for SVG encoding url-encoder

Jquery bind double click and single click separately

This is a method you can do using the basic JavaScript, which is works for me:

var v_Result;
function OneClick() {
    v_Result = false;
    window.setTimeout(OneClick_Nei, 500)
    function OneClick_Nei() {
        if (v_Result != false) return;
        alert("single click");
function TwoClick() {
    v_Result = true;
    alert("double click");

jQuery - passing value from one input to another

Add ID attributes with same values as name attributes and then you can do this:

$('#first_name').change(function () {

How to include PHP files that require an absolute path?

You could define a constant with the path to the root directory of your project, and then put that at the beginning of the path.

How to read a line from the console in C?

If you are using the GNU C library or another POSIX-compliant library, you can use getline() and pass stdin to it for the file stream.

The matching wildcard is strict, but no declaration can be found for element 'tx:annotation-driven'

Any one can help for me!!!!!!!!!
<?xml  version="1.0" encoding="UTF-8"?>
    <beans xmlns=""
        <context:annotation-config />(ERROR OCCUR)
        <context:component-scan base-package="hiberrSpring" /> (ERROR OCCUR)
        <bean id="jspViewResolver"
            <property name="viewClass"
            <property name="prefix" value="/WEB-INF/"></property>
            <property name="suffix" value=".jsp"></property>
        <bean id="messageSource"
            <property name="basename" value="classpath:messages"></property>
            <property name="defaultEncoding" value="UTF-8"></property>
        <bean id="propertyConfigurer"
        <bean id="dataSource"
            class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"
            p:url="${jdbc:mysql://localhost/}" p:username="${root}"
        <bean id="sessionFactory"
            <property name="dataSource" ref="dataSource"></property>
            <property name="configLocation">
            <property name="configurationClass">
            <property name="hibernateProperties">
                    <prop key="hibernate.dialect">${org.hibernate.dialect.MySQLDialect}</prop>
                    <prop key="hibernate.show_sql">true</prop>
        <bean id="employeeDAO" class="hiberrSpring.EmployeeDaoImpl"></bean>
        <bean id="employeeManager" class="hiberrSpring.EmployeeManagerImpl"></bean>
        <tx:annotation-driven /> (ERROR OCCUR)
        <bean id="transactionManager"
            <property name="sessionFactory" ref="sessionFactory"></property>

Android custom dropdown/popup menu

The Kotlin Way

fun showPopupMenu(view: View) {
    PopupMenu(view.context, view).apply {
                menuInflater.inflate(, menu)
                setOnMenuItemClickListener { item ->
                    Toast.makeText(view.context, "You Clicked : " + item.title, Toast.LENGTH_SHORT).show()

UPDATE: In the above code, the apply function returns this which is not required, so we can use run which don't return anything and to make it even simpler we can also remove the curly braces of showPopupMenu method.

Even Simpler:

fun showPopupMenu(view: View) = PopupMenu(view.context, view).run {
            menuInflater.inflate(, menu)
            setOnMenuItemClickListener { item ->
                Toast.makeText(view.context, "You Clicked : ${item.title}", Toast.LENGTH_SHORT).show()

How to run multiple Python versions on Windows

One easy way for this is that you can use

py -3.8 -m pip install virtualenv here -3.8 goes with your [version number]

After installing the virtualenv, you can create the virtual environment of your application using

py -3.8 -m virtualenv [your env name]

then cd to venv, enter activate

This would activate the python version you like. Just change the version number to use a different python version.

JavaScript file upload size validation

Yes, you can use the File API for this.

Here's a complete example (see comments):

document.getElementById("btnLoad").addEventListener("click", function showFileSize() {
    // (Can't use `typeof FileReader === "function"` because apparently it
    // comes back as "object" on some browsers. So just see if it's there
    // at all.)
    if (!window.FileReader) { // This is VERY unlikely, browser support is near-universal
        console.log("The file API isn't supported on this browser yet.");

    var input = document.getElementById('fileinput');
    if (!input.files) { // This is VERY unlikely, browser support is near-universal
        console.error("This browser doesn't seem to support the `files` property of file inputs.");
    } else if (!input.files[0]) {
        addPara("Please select a file before clicking 'Load'");
    } else {
        var file = input.files[0];
        addPara("File " + + " is " + file.size + " bytes in size");

function addPara(text) {
    var p = document.createElement("p");
    p.textContent = text;
body {
    font-family: sans-serif;
<form action='#' onsubmit="return false;">
<input type='file' id='fileinput'>
<input type='button' id='btnLoad' value='Load'>

Slightly off-topic, but: Note that client-side validation is no substitute for server-side validation. Client-side validation is purely to make it possible to provide a nicer user experience. For instance, if you don't allow uploading a file more than 5MB, you could use client-side validation to check that the file the user has chosen isn't more than 5MB in size and give them a nice friendly message if it is (so they don't spend all that time uploading only to get the result thrown away at the server), but you must also enforce that limit at the server, as all client-side limits (and other validations) can be circumvented.

Class file for not found

Do not mix 12 and 15, use this

implementation ''
implementation ''
implementation ''

How to use boolean 'and' in Python

& is used for bit-wise comparison. use and instead. and btw, you don't need semicolon at the end of print statement.

what is the use of annotations @Id and @GeneratedValue(strategy = GenerationType.IDENTITY)? Why the generationtype is identity?

In a Object Relational Mapping context, every object needs to have a unique identifier. You use the @Id annotation to specify the primary key of an entity.

The @GeneratedValue annotation is used to specify how the primary key should be generated. In your example you are using an Identity strategy which

Indicates that the persistence provider must assign primary keys for the entity using a database identity column.

There are other strategies, you can see more here.

DB query builder toArray() laravel 4

Easiest way is using laravel toArray function itself:

    $result = array_map(function ($value) {
        return $value instanceof Arrayable ? $value->toArray() : $value;
    }, $result);

Adding a collaborator to my free GitHub account?

project link:

you will get a page like this, go to Collaborator and add collaborator Check setting tab

Change the value in app.config file dynamically


Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.AppSettings.Settings.Add("configFilePath", configFilePath);
config.SaveAs(@"C:\Users\USERNAME\Documents\Visual Studio 2010\Projects\ADI2v1.4\ADI2CE2\App.config",ConfigurationSaveMode.Modified, true); 

How to add a WiX custom action that happens only on uninstall (via MSI)?

The biggest problem with a batch script is handling rollback when the user clicks cancel (or something goes wrong during your install). The correct way to handle this scenario is to create a CustomAction that adds temporary rows to the RemoveFiles table. That way the Windows Installer handles the rollback cases for you. It is insanely simpler when you see the solution.

Anyway, to have an action only execute during uninstall add a Condition element with:


the ~= says compare case insensitive (even though I think ALL is always uppercaesd). See the MSI SDK documentation about Conditions Syntax for more information.

PS: There has never been a case where I sat down and thought, "Oh, batch file would be a good solution in an installation package." Actually, finding an installation package that has a batch file in it would only encourage me to return the product for a refund.

difference between css height : 100% vs height : auto

The default is height: auto in browser, but height: X% Defines the height in percentage of the containing block.

Div Height in Percentage

You need to give the body and the html a height too. Otherwise, the body will only be as high as its contents (the single div), and 50% of that will be half the height of this div.

Updated fiddle:

Is it possible to get the index you're sorting over in Underscore.js?

If you'd rather transform your array, then the iterator parameter of underscore's map function is also passed the index as a second argument. So:[1, 4, 2, 66, 444, 9], function(value, index){ return index + ':' + value; });

... returns:

["0:1", "1:4", "2:2", "3:66", "4:444", "5:9"]

allowing only alphabets in text box using java script

just use onkeypress event like below:

<input type="text" name="onlyalphabet" onkeypress="return (event.charCode > 64 && event.charCode < 91) || (event.charCode > 96 && event.charCode < 123)">

jQuery DataTables: control table width

This is my way of doing it..

    processing: true,
    serverSide: true,
    ajax: 'customer/data',
    columns: [
        { data: 'id', name: 'id' , width: '50px', class: 'text-right' },
        { data: 'name', name: 'name' width: '50px', class: 'text-right' }

How to scroll UITableView to specific position

[tableview scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:NO];

This will take your tableview to the first row.

How to enable SOAP on CentOS

After hours of searching I think my problem was that command yum install php-soap installs the latest version of soap for the latest php version.

My php version was 7.027, but latest php version is 7.2 so I had to search for the right soap version and finaly found it HERE!

yum install rh-php70-php-soap

Now php -m | grep -i soap works, Output: soap

Do not forget to restart httpd service.

How do I get the selected element by name and then get the selected value from a dropdown using jQuery?

Your selector is a little off, it's missing the trailing ]

var mySelect = $('select[name=' + name + ']')

you may also need to put quotes around the name, like so:

var mySelect = $('select[name="' + name + '"]')

unix diff side-to-side results?

If your files have inconsistent use of spaces and tabs, you may find it helpful to include the -t argument to expand the tabs:

diff -ty file1 file2

How to automatically update an application without ClickOnce?

A Lay men's way is

on Main() rename the executing assembly file .exe to some thing else check date and time of created. and the updated file date time and copy to the application folder.

//Rename he executing file
System.IO.FileInfo file = new System.IO.FileInfo(System.Reflection.Assembly.GetExecutingAssembly().Location);

System.IO.File.Move(file.FullName, file.DirectoryName + "\\" + file.Name.Replace(file.Extension,"") + "-1" + file.Extension);

then do the logic check and copy the new file to executing folder

SQL Server: combining multiple rows into one row

There's a convenient method for this in MySql called GROUP_CONCAT. An equivalent for SQL Server doesn't exist, but you can write your own using the SQLCLR. Luckily someone already did that for you.

Your query then turns into this (which btw is a much nicer syntax):

FROM Jira.customfieldvalue

But please note that this method is good for at the most 100 rows within a group. Beyond that, you'll have major performance problems. SQLCLR aggregates have to serialize any intermediate results and that quickly piles up to quite a lot of work. Keep this in mind!

Interestingly the FOR XML doesn't suffer from the same problem but instead uses that horrendous syntax.

No resource found that matches the given name '@style/ Theme.Holo.Light.DarkActionBar'

in addition,if you try to use CustomActionBarTheme,make sure there is

<application android:theme="@style/CustomActionBarTheme" ... />

in AndroidManifest.xml


<application android:theme="@android:style/CustomActionBarTheme" ... />

How to consume REST in Java

Apache Http Client APIs are very commonly used for calling HTTP Rest services.

Here is one of example of consuming HTTP GET call.

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.HttpClientBuilder;

public class CallHTTPGetService {

public static void main(String[] args) throws ClientProtocolException, IOException {

    HttpClient client = HttpClientBuilder.create().build();
    HttpUriRequest httpUriRequest = new HttpGet("URL");

    HttpResponse response = client.execute(httpUriRequest);


Use following maven dependency if using Maven project.

    <!-- -->

CSS to set A4 paper size seems to solve all my needs.

Paper CSS for happy printing

Front-end printing solution - previewable and live-reloadable!

Go To Definition: "Cannot navigate to the symbol under the caret."

Close visual studio then remove the hidden file name .vs on that project and open again the visual studio then build the project. Boom! All good!

How can I specify a display?


export DISPLAY=localhost:0.0

Static extension methods

specifically I want to overload Boolean.Parse to allow an int argument.

Would an extension for int work?

public static bool ToBoolean(this int source){
    // do it
    // return it

Then you can call it like this:

int x = 1;

bool y = x.ToBoolean();

Installing OpenCV 2.4.3 in Visual C++ 2010 Express

1. Installing OpenCV 2.4.3

First, get OpenCV 2.4.3 from Its a self-extracting so just double click to start the installation. Install it in a directory, say C:\.

OpenCV self-extractor

Wait until all files get extracted. It will create a new directory C:\opencv which contains OpenCV header files, libraries, code samples, etc.

Now you need to add the directory C:\opencv\build\x86\vc10\bin to your system PATH. This directory contains OpenCV DLLs required for running your code.

Open Control PanelSystemAdvanced system settingsAdvanced Tab → Environment variables...

enter image description here

On the System Variables section, select Path (1), Edit (2), and type C:\opencv\build\x86\vc10\bin; (3), then click Ok.

On some computers, you may need to restart your computer for the system to recognize the environment path variables.

This will completes the OpenCV 2.4.3 installation on your computer.

2. Create a new project and set up Visual C++

Open Visual C++ and select FileNewProject...Visual C++Empty Project. Give a name for your project (e.g: cvtest) and set the project location (e.g: c:\projects).

New project dialog

Click Ok. Visual C++ will create an empty project.

VC++ empty project

Make sure that "Debug" is selected in the solution configuration combobox. Right-click cvtest and select PropertiesVC++ Directories.

Project property dialog

Select Include Directories to add a new entry and type C:\opencv\build\include.

Include directories dialog

Click Ok to close the dialog.

Back to the Property dialog, select Library Directories to add a new entry and type C:\opencv\build\x86\vc10\lib.

Library directories dialog

Click Ok to close the dialog.

Back to the property dialog, select LinkerInputAdditional Dependencies to add new entries. On the popup dialog, type the files below:


Note that the filenames end with "d" (for "debug"). Also note that if you have installed another version of OpenCV (say 2.4.9) these filenames will end with 249d instead of 243d (opencv_core249d.lib..etc).

enter image description here

Click Ok to close the dialog. Click Ok on the project properties dialog to save all settings.


These steps will configure Visual C++ for the "Debug" solution. For "Release" solution (optional), you need to repeat adding the OpenCV directories and in Additional Dependencies section, use:


instead of:


You've done setting up Visual C++, now is the time to write the real code. Right click your project and select AddNew Item...Visual C++C++ File.

Add new source file

Name your file (e.g: loadimg.cpp) and click Ok. Type the code below in the editor:

#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
    Mat im = imread("c:/full/path/to/lena.jpg");
    if (im.empty()) 
        cout << "Cannot load image!" << endl;
        return -1;
    imshow("Image", im);

The code above will load c:\full\path\to\lena.jpg and display the image. You can use any image you like, just make sure the path to the image is correct.

Type F5 to compile the code, and it will display the image in a nice window.

First OpenCV program

And that is your first OpenCV program!

3. Where to go from here?

Now that your OpenCV environment is ready, what's next?

  1. Go to the samples dir → c:\opencv\samples\cpp.
  2. Read and compile some code.
  3. Write your own code.

How to use ternary operator in razor (specifically on HTML attributes)?

You can also use this method:

<input type="text" class="@(@mvccondition ? "true-class" : "false-class")">

Try this .. Good luck Thanks.

Difference between two lists

List<ObjectC> _list_DF_BW_ANB = new List<ObjectC>();    
List<ObjectA> _listA = new List<ObjectA>();
List<ObjectB> _listB = new List<ObjectB>();

foreach (var itemB in _listB )
    var flat = 0;
    foreach(var itemA in _listA )
            flat = 1;
    if (flat == 0)

How to make external HTTP requests with Node.js

NodeJS supports http.request as a standard module:

var http = require('http');

var options = {
  host: '',
  port: 80,
  path: '/foo.html'

http.get(options, function(resp){
  resp.on('data', function(chunk){
    //do something with chunk
}).on("error", function(e){
  console.log("Got error: " + e.message);

Javamail Could not convert socket to TLS GMail

I got similar problem when default SSL protocol for sending emails was set to TLSv1 and smtp server was not supporting this protocol anymore. Trick was to use newer protocol:


What does AND 0xFF do?

if byte1 is an 8-bit integer type then it's pointless - if it is more than 8 bits it will essentially give you the last 8 bits of the value:

    0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
 &  0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
    0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1

exception in initializer error in java when using Netbeans

Wherever there is errors or exceptions in static blocks, this exception will be thrown. To get the cause of this exception simply use Throwable.getCause() to know what is wrong.

Set min-width in HTML table's <td>

<table style="min-width:50px; max-width:150px;">
        <td style="min-width:50px">one</td>
        <td style="min-width:100px">two</td>

This works for me using an email script.

How do I get JSON data from RESTful service using Python?

Well first of all I think rolling out your own solution for this all you need is urllib2 or httplib2 . Anyways in case you do require a generic REST client check this out .

However i think the feature set of the library will not work for most web services because they shall probably using oauth etc .. . Also I don't like the fact that it is written over httplib which is a pain as compared to httplib2 still should work for you if you don't have to handle a lot of redirections etc ..

How do you open a file in C++?

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

int main () {
  ofstream file; ("codebind.txt");
  file << "Please writr this text to a file.\n this text is written using C++\n";
  return 0;

Pandas: Creating DataFrame from Series

Here is how to create a DataFrame where each series is a row.

For a single Series (resulting in a single-row DataFrame):

series = pd.Series([1,2], index=['a','b'])
df = pd.DataFrame([series])

For multiple series with identical indices:

cols = ['a','b']
list_of_series = [pd.Series([1,2],index=cols), pd.Series([3,4],index=cols)]
df = pd.DataFrame(list_of_series, columns=cols)

For multiple series with possibly different indices:

list_of_series = [pd.Series([1,2],index=['a','b']), pd.Series([3,4],index=['a','c'])]
df = pd.concat(list_of_series, axis=1).transpose()

To create a DataFrame where each series is a column, see the answers by others. Alternatively, one can create a DataFrame where each series is a row, as above, and then use df.transpose(). However, the latter approach is inefficient if the columns have different data types.

List of remotes for a Git repository?

None of those methods work the way the questioner is asking for and which I've often had a need for as well. eg:

$ git remote
fatal: Not a git repository (or any of the parent directories): .git
$ git remote user@bserver
fatal: Not a git repository (or any of the parent directories): .git
$ git remote user@server:/home/user
fatal: Not a git repository (or any of the parent directories): .git
$ git ls-remote
fatal: No remote configured to list refs from.
$ git ls-remote user@server:/home/user
fatal: '/home/user' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

The whole point of doing this is that you do not have any information except the remote user and server and want to find out what you have access to.

The majority of the answers assume you are querying from within a git working set. The questioner is assuming you are not.

As a practical example, assume there was a repository foo.git on the server. Someone in their wisdom decides they need to change it to foo2.git. It would really be nice to do a list of a git directory on the server. And yes, I see the problems for git. It would still be nice to have though.

Error : getaddrinfo ENOTFOUND

I have a fresh Windows 10 installed on my PC and tried this on the command line and it works like a charm:

npm config rm https-proxy

How to define hash tables in Bash?

A coworker just mentioned this thread. I've independently implemented hash tables within bash, and it's not dependent on version 4. From a blog post of mine in March 2010 (before some of the answers here...) entitled Hash tables in bash:

I previously used cksum to hash but have since translated Java's string hashCode to native bash/zsh.

# Here's the hashing function
ht() {
  local h=0 i
  for (( i=0; i < ${#1}; i++ )); do
    let "h=( (h<<5) - h ) + $(printf %d \'${1:$i:1})"
    let "h |= h"
  printf "$h"

# Example:

myhash[`ht foo bar`]="a value"
myhash[`ht baz baf`]="b value"

echo ${myhash[`ht baz baf`]} # "b value"
echo ${myhash[@]} # "a value b value" though perhaps reversed
echo ${#myhash[@]} # "2" - there are two values (note, zsh doesn't count right)

It's not bidirectional, and the built-in way is a lot better, but neither should really be used anyway. Bash is for quick one-offs, and such things should quite rarely involve complexity that might require hashes, except perhaps in your ~/.bashrc and friends.

What is the cause for "angular is not defined"

You have not placed the script tags for angular js

you can do so by using cdn or downloading the angularjs for your project and then referencing it

after this you have to add your own java script in your case main.js

that should do

Get decimal portion of a number with JavaScript

How is 0.2999999999999998 an acceptable answer? If I were the asker I would want an answer of .3. What we have here is false precision, and my experiments with floor, %, etc indicate that Javascript is fond of false precision for these operations. So I think the answers that are using conversion to string are on the right track.

I would do this:

var decPart = (n+"").split(".")[1];

Specifically, I was using 100233.1 and I wanted the answer ".1".

Import Error: No module named numpy

Faced with same issue

ImportError: No module named numpy

So, in our case (we are use PIP and python 2.7) the solution was SPLIT pip install commands :


RUN pip install numpy scipy pandas sklearn


RUN pip install numpy scipy
RUN pip install pandas sklearn

Solution found here :, it's related latest update of pandas to v0.24.0

How to convert an ArrayList containing Integers to primitive int array?

Google Guava

Google Guava provides a neat way to do this by calling Ints.toArray.

List<Integer> list = ...;
int[] values = Ints.toArray(list);

How do I create an array of strings in C?

Ack! Constant strings:

const char *strings[] = {"one","two","three"};

If I remember correctly.

Oh, and you want to use strcpy for assignment, not the = operator. strcpy_s is safer, but it's neither in C89 nor in C99 standards.

strcpy(arr[0], "blah");

Update: Thomas says strlcpy is the way to go.

SSL_connect: SSL_ERROR_SYSCALL in connection to

I just turned off VPN and it solved the issue.

How do I jump out of a foreach loop in C#?

how about:


That should do the trick if all you want to do is check for an "ok" and return the answer ...

How to get file name from file path in android

I think you can use substring method to get name of the file from the path string.

String path=":/storage/sdcard0/DCIM/Camera/1414240995236.jpg"; 
// it contains your image path...I'm using a temp string...
String filename=path.substring(path.lastIndexOf("/")+1);

How to allow only one radio button to be checked?

They need to all have the same name.

What exactly is \r in C language?

That is not always true; it only works in Windows.
For interacting with terminal in putty, Linux shell,... it will be used for returning the cursor to the beginning of line. following picture shows the usage of that:

Without '\r':

Data comes without '\r' to the putty terminal, it has just '\n'.
it means that data will be printed just in next line.

enter image description here

With '\r':

Data comes with '\r', i.e. string ends with '\r\n'. So the cursor in putty terminal not only will go to the next line but also at the beginning of line

enter image description here

Debugging Spring configuration

Yes, Spring framework logging is very detailed, You did not mention in your post, if you are already using a logging framework or not. If you are using log4j then just add spring appenders to the log4j config (i.e to log4j.xml or, If you are using log4j xml config you can do some thing like this

<category name="org.springframework.beans">
    <priority value="debug" />


<category name="org.springframework">
    <priority value="debug" />

I would advise you to test this problem in isolation using JUnit test, You can do this by using spring testing module in conjunction with Junit. If you use spring test module it will do the bulk of the work for you it loads context file based on your context config and starts container so you can just focus on testing your business logic. I have a small example here

public class SpringDAOTest 
    private SpringDAO dao;

    private ApplicationContext appContext;

    public void checkConfig()
        AnySpringBean bean =  appContext.getBean(AnySpringBean.class);


I am not advising you to change the way you load logging but try this in your dev environment, Add this snippet to your web.xml file



UPDATE log4j config file

I tested this on my local tomcat and it generated a lot of logging on application start up. I also want to make a correction: use debug not info as @Rayan Stewart mentioned.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

<log4j:configuration xmlns:log4j="" debug="false">
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Threshold" value="debug" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern"
                value="%d{HH:mm:ss} %p [%t]:%c{3}.%M()%L - %m%n" />

    <appender name="springAppender" class="org.apache.log4j.RollingFileAppender"> 
        <param name="file" value="C:/tomcatLogs/webApp/spring-details.log" /> 
        <param name="append" value="true" /> 
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern"
                value="%d{MM/dd/yyyy HH:mm:ss}  [%t]:%c{5}.%M()%L %m%n" />

    <category name="org.springframework">
        <priority value="debug" />

    <category name="org.springframework.beans">
        <priority value="debug" />

    <category name="">
        <priority value="debug" />

        <priority value="debug" />

    <category name="org.springframework.jdbc.core">
        <priority value="debug" />

    <category name="">
        <priority value="debug" />

        <priority value="debug" />
        <appender-ref ref="springAppender" />
        <!-- <appender-ref ref="STDOUT"/>  -->

How to validate Google reCAPTCHA v3 on server side?

Source Tutorial Link

V2 of Google reCAPTCHA.

Step 1 - Go to Google reCAPTCHA

Login then get Site Key and Secret Key

Step 2 - Download PHP code here and upload src folder on your server.

Step 3 - Use below code in your form.php

            <title> Google reCAPTCHA EXAMPLE form</title>
            <script src=''></script>



            $siteKey = '6LegPmIUAAAAADLwDmXXXXXXXyZAJVJXXXjN';
            $secret = '6LegPmIUAAAAAO3ZTXXXXXXXXJwQ66ngJ7AlP';

            $recaptcha = new \ReCaptcha\ReCaptcha($secret);

            $gRecaptchaResponse = $_POST['g-recaptcha-response']; //google captcha post data
            $remoteIp = $_SERVER['REMOTE_ADDR']; //to get user's ip

            $recaptchaErrors = ''; // blank varible to store error

            $resp = $recaptcha->verify($gRecaptchaResponse, $remoteIp); //method to verify captcha
            if ($resp->isSuccess()) {


                Add code to create User here when form submission is successful


            } else {


                // This variable will have error when reCAPTCHA is not entered correctly.


               $recaptchaErrors = $resp->getErrorCodes(); 

                <form autcomplete="off" class="form-createuser" name="create_user_form" action="" method="post">
                    <div class="panel periodic-login">
                        <div class="panel-body text-center">
                            <div class="form-group form-animate-text" style="margin-top:40px !important;">
                                <input type="text" autcomplete="off" class="form-text" name="new_user_name" required="">
                                <span class="bar"></span>
                            <div class="form-group form-animate-text" style="margin-top:40px !important;">
                                <input type="text" autcomplete="off" class="form-text" name="new_phone_number" required="">
                                <span class="bar"></span>
                            <div class="form-group form-animate-text" style="margin-top:40px !important;">
                                <input type="password" autcomplete="off" class="form-text" name="new_user_password" required="">
                                <span class="bar"></span>
                                        print('Error in Submitting Form. Please Enter reCAPTCHA AGAIN');
                            <div class="g-recaptcha" data-sitekey="6LegPmIUAAAAADLwDmmVmXXXXXXXXXXXXXXjN"></div>
                            <input type="submit" class="btn col-md-12" value="Create User">


Rails - controller action name to string

This snippet works for Rails 3

class ReportsController < ApplicationController

  def summary
    logger.debug self.class.to_s + "." + self.action_name


will print

. . .
. . .

How do you get a string from a MemoryStream?

In this case, if you really want to use ReadToEnd method in MemoryStream in an easy way, you can use this Extension Method to achieve this:

public static class SetExtensions
    public static string ReadToEnd(this MemoryStream BASE)
        BASE.Position = 0;
        StreamReader R = new StreamReader(BASE);
        return R.ReadToEnd();

And you can use this method in this way:

using (MemoryStream m = new MemoryStream())
    //for example i want to serialize an object into MemoryStream
    //I want to use XmlSeralizer
    XmlSerializer xs = new XmlSerializer(_yourVariable.GetType());
    xs.Serialize(m, _yourVariable);

    //the easy way to use ReadToEnd method in MemoryStream

How to access a mobile's camera from a web app?

It should be noted that security features have been implemented which require either the app to be ran locally under localhost, or through SSL for GetUserMedia() to work.

I discovered this when trying several of the demos available and was dissapointed when they didn't work! See: New Security Restrictions

Remove last character of a StringBuilder?


StringBuilder result = new StringBuilder();
for(String string : collection) {
return result.substring(0, result.length() - 1) ;

What browsers support HTML5 WebSocket API?

Client side

  • Hixie-75:
    • Chrome 4.0 + 5.0
    • Safari 5.0.0
  • HyBi-00/Hixie-76:
  • HyBi-07+:
  • HyBi-10:
    • Chrome 14.0 + 15.0
    • Firefox 7.0 + 8.0 + 9.0 + 10.0 - prefixed: MozWebSocket
    • IE 10 (from Windows 8 developer preview)
  • HyBi-17/RFC 6455
    • Chrome 16
    • Firefox 11
    • Opera 12.10 / Opera Mobile 12.1

Any browser with Flash can support WebSocket using the web-socket-js shim/polyfill.

See caniuse for the current status of WebSockets support in desktop and mobile browsers.

See the test reports from the WS testsuite included in Autobahn WebSockets for feature/protocol conformance tests.

Server side

It depends on which language you use.

In Java/Java EE:

Some other Java implementations:

In C#:


In Python:

In C:

In Node.js:

  • : also has serverside ports for Python, Java, Google GO, Rack
  • sockjs : sockjs also has serverside ports for Python, Java, Erlang and Lua
  • WebSocket-Node - Pure JavaScript Client & Server implementation of HyBi-10.

Vert.x (also known as Node.x) : A node like polyglot implementation running on a Java 7 JVM and based on Netty with :

  • Support for Ruby(JRuby), Java, Groovy, Javascript(Rhino/Nashorn), Scala, ...
  • True threading. (unlike Node.js)
  • Understands multiple network protocols out of the box including: TCP, SSL, UDP, HTTP, HTTPS, Websockets, SockJS as fallback for WebSockets is a Websocket cloud service accessible through a REST API.

DotCloud cloud platform supports Websockets, and Java (Jetty Servlet Container), NodeJS, Python, Ruby, PHP and Perl programming languages.

Openshift cloud platform supports websockets, and Java (Jboss, Spring, Tomcat & Vertx), PHP (ZendServer & CodeIgniter), Ruby (ROR), Node.js, Python (Django & Flask) plateforms.

For other language implementations, see the Wikipedia article for more information.

The RFC for Websockets : RFC6455

How do you properly determine the current script directory?

If you really want to cover the case that a script is called via execfile(...), you can use the inspect module to deduce the filename (including the path). As far as I am aware, this will work for all cases you listed:

filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))

pandas how to check dtype for all columns in a dataframe?

Suppose df is a pandas DataFrame then to get number of non-null values and data types of all column at once use:

Adding a user on .htpasswd

Exact same thing, just omit the -c option. Apache's docs on it here.

htpasswd /etc/apache2/.htpasswd newuser

Also, htpasswd typically isn't run as root. It's typically owned by either the web server, or the owner of the files being served. If you're using root to edit it instead of logging in as one of those users, that's acceptable (I suppose), but you'll want to be careful to make sure you don't accidentally create a file as root (and thus have root own it and no one else be able to edit it).

Disable Auto Zoom in Input "Text" tag - Safari on iPhone

There's no clean way I could find, but here's a hack...

1) I noticed that the mouseover event happens prior to the zoom, but the zoom happens before mousedown or focus events.

2) You can dynamically change the META viewport tag using javascript (see Enable/disable zoom on iPhone safari with Javascript?)

So, try this (shown in jquery for compactness):

$("input[type=text], textarea").mouseover(zoomDisable).mousedown(zoomEnable);
function zoomDisable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="user-scalable=0" />');
function zoomEnable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="user-scalable=1" />');

This is definitely a hack... there may be situations where mouseover/down don't always catch entries/exits, but it worked well in my tests and is a solid start.

Wait until flag=true

In my example, I log a new counter value every second:

var promises_arr = [];_x000D_
var new_cntr_val = 0;_x000D_
// fill array with promises_x000D_
for (let seconds = 1; seconds < 10; seconds++) {_x000D_
    new_cntr_val = new_cntr_val + 5;    // count to 50_x000D_
    promises_arr.push(new Promise(function (resolve, reject) {_x000D_
        // create two timeouts: one to work and one to resolve the promise_x000D_
        setTimeout(function(cntr) {_x000D_
        }, seconds * 1000, new_cntr_val);    // feed setTimeout the counter parameter_x000D_
        setTimeout(resolve, seconds * 1000);_x000D_
// wait for promises to finish_x000D_
Promise.all(promises_arr).then(function (values) {_x000D_
    console.log("all promises have returned");_x000D_

Why AVD Manager options are not showing in Android Studio

On linux I have same problem - its not listed in tools.

However there is a small icon:

enter image description here

Higlighted in yellow above in the top right corner of studio. It looks like a small phone with the android logo.

How to load property file from classpath?

If you use the static method and load the properties file from the classpath folder so you can use the below code :

//load a properties file from class path, inside static method
Properties prop = new Properties();

How to change title of Activity in Android?

The code helped me change the title.

protected void onCreate(Bundle savedInstanceState) {
    ActivityName.this.setTitle("Your Activity Title");}

In Python, how do I determine if an object is iterable?

I found a nice solution here:

isiterable = lambda obj: isinstance(obj, basestring) \
    or getattr(obj, '__iter__', False)

Pass in an array of Deferreds to $.when()

If you're using angularJS or some variant of the Q promise library, then you have a .all() method that solves this exact problem.

var savePromises = [];
angular.forEach(models, function(model){

  function success(results){...},
  function failed(results){...}

see the full API:$q

How to add multiple font files for the same font?

The solution seems to be to add multiple @font-face rules, for example:

@font-face {
    font-family: "DejaVu Sans";
    src: url("fonts/DejaVuSans.ttf");
@font-face {
    font-family: "DejaVu Sans";
    src: url("fonts/DejaVuSans-Bold.ttf");
    font-weight: bold;
@font-face {
    font-family: "DejaVu Sans";
    src: url("fonts/DejaVuSans-Oblique.ttf");
    font-style: italic, oblique;
@font-face {
    font-family: "DejaVu Sans";
    src: url("fonts/DejaVuSans-BoldOblique.ttf");
    font-weight: bold;
    font-style: italic, oblique;

By the way, it would seem Google Chrome doesn't know about the format("ttf") argument, so you might want to skip that.

(This answer was correct for the CSS 2 specification. CSS3 only allows for one font-style rather than a comma-separated list.)

How to convert String to DOM Document object in java?

you can try

DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader("<root><node1></node1></root>"));

Document doc = db.parse(is);

refer this

file.delete() returns false even though file.exists(), file.canRead(), file.canWrite(), file.canExecute() all return true

I tried this simple thing and it seems to be working.


It works for me.

If this does not work try to run your Java application with sudo if on linux and as administrator when on windows. Just to make sure Java has rights to change the file properties.

How to close an iframe within iframe itself

its kind of hacky but it works well-ish

 function close_frame(){
    }else if(window.should_close==1){
        //or iframe hide or whatever

 <iframe src="iframe_index.php" onload="close_frame()"></iframe>

then inside the frame

        window.location = 'iframe_index.php?close=1';

and if you want to get fancy through a


at the top of your frame page to make that reload unnoticeable

so basically the first time the frame loads it doesnt hide itself but the next time it loads itll call the onload function and the parent will have a the window var causing the frame to close

Get text from DataGridView selected cells

the Best of both worlds.....

Private Sub tsbSendNewsLetter_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsbSendNewsLetter.Click
        Dim tmpstr As String = ""
        Dim cnt As Integer = 0
        Dim virgin As Boolean = True
        For cnt = 0 To (dgvDetails.Rows.Count - 1)
            If Not dgvContacts.Rows(cnt).Cells(9).Value.ToString() Is Nothing Then
                If Not dgvContacts.Rows(cnt).Cells(9).Value.ToString().Length = 0 Then
                    If Not virgin Then
                        tmpstr += ", "
                    End If
                    tmpstr += dgvContacts.Rows(cnt).Cells(9).Value.ToString()
                    virgin = False
                End If
            End If
        Dim email As New qkuantusMailer()
        email.txtMailTo.Text = tmpstr
    End Sub

Get list of Excel files in a folder using VBA

You can use the built-in Dir function or the FileSystemObject.

They each have their own strengths and weaknesses.

Dir Function

The Dir Function is a built-in, lightweight method to get a list of files. The benefits for using it are:

  • Easy to Use
  • Good performance (it's fast)
  • Wildcard support

The trick is to understand the difference between calling it with or without a parameter. Here is a very simple example to demonstrate:

Public Sub ListFilesDir(ByVal sPath As String, Optional ByVal sFilter As String)

    Dim sFile As String

    If Right(sPath, 1) <> "\" Then
        sPath = sPath & "\"
    End If

    If sFilter = "" Then
        sFilter = "*.*"
    End If

    'call with path "initializes" the dir function and returns the first file name
    sFile = Dir(sPath & sFilter)

   'call it again until there are no more files
    Do Until sFile = ""

        Debug.Print sFile

        'subsequent calls without param return next file name
        sFile = Dir


End Sub

If you alter any of the files inside the loop, you will get unpredictable results. It is better to read all the names into an array of strings before doing any operations on the files. Here is an example which builds on the previous one. This is a Function that returns a String Array:

Public Function GetFilesDir(ByVal sPath As String, _
    Optional ByVal sFilter As String) As String()

    'dynamic array for names
    Dim aFileNames() As String
    ReDim aFileNames(0)

    Dim sFile As String
    Dim nCounter As Long

    If Right(sPath, 1) <> "\" Then
        sPath = sPath & "\"
    End If

    If sFilter = "" Then
        sFilter = "*.*"
    End If

    'call with path "initializes" the dir function and returns the first file
    sFile = Dir(sPath & sFilter)

    'call it until there is no filename returned
    Do While sFile <> ""

        'store the file name in the array
        aFileNames(nCounter) = sFile

        'subsequent calls without param return next file
        sFile = Dir

        'make sure your array is large enough for another
        nCounter = nCounter + 1
        If nCounter > UBound(aFileNames) Then
            'preserve the values and grow by reasonable amount for performance
            ReDim Preserve aFileNames(UBound(aFileNames) + 255)
        End If


    'truncate the array to correct size
    If nCounter < UBound(aFileNames) Then
        ReDim Preserve aFileNames(0 To nCounter - 1)
    End If

    'return the array of file names
    GetFilesDir = aFileNames()

End Function

File System Object

The File System Object is a library for IO operations which supports an object-model for manipulating files. Pros for this approach:

  • Intellisense
  • Robust object-model

You can add a reference to to "Windows Script Host Object Model" (or "Windows Scripting Runtime") and declare your objects like so:

Public Sub ListFilesFSO(ByVal sPath As String)

    Dim oFSO As FileSystemObject
    Dim oFolder As Folder
    Dim oFile As File

    Set oFSO = New FileSystemObject
    Set oFolder = oFSO.GetFolder(sPath)
    For Each oFile In oFolder.Files
        Debug.Print oFile.Name
    Next 'oFile

    Set oFile = Nothing
    Set oFolder = Nothing
    Set oFSO = Nothing

End Sub

If you don't want intellisense you can do like so without setting a reference:

Public Sub ListFilesFSO(ByVal sPath As String)

    Dim oFSO As Object
    Dim oFolder As Object
    Dim oFile As Object

    Set oFSO = CreateObject("Scripting.FileSystemObject")
    Set oFolder = oFSO.GetFolder(sPath)
    For Each oFile In oFolder.Files
        Debug.Print oFile.Name
    Next 'oFile

    Set oFile = Nothing
    Set oFolder = Nothing
    Set oFSO = Nothing

End Sub

How to resolve Error : Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation

You can't show dialog box ON SERVER from ASP.NET application, well of course tehnically you can do that but it makes no sense since your user is using browser and it can't see messages raised on server. You have to understand how web sites work, server side code (ASP.NET in your case) produces html, javascript etc on server and then browser loads that content and displays it to the user, so in order to present modal message box to the user you have to use Javascript, for example alert function.

Here is the example for :

Combine two integer arrays

int [] newArray = new int[old1.length+old2.length];
System.arraycopy( old1, 0, newArray, 0, old1.length);
System.arraycopy( old2, 0, newArray, old1.length, old2.length );

Don't use element-by-element copying, it's very slow compared to System.arraycopy()

How to pass multiple parameters in a querystring


(Following is the text of the linked section of the Wikipedia entry.)


A typical URL containing a query string is as follows:


When a server receives a request for such a page, it runs a program (if configured to do so), passing the query_string unchanged to the program. The question mark is used as a separator and is not part of the query string.

A link in a web page may have a URL that contains a query string, however, HTML defines three ways a web browser can generate the query string:

  • a web form via the ... element
  • a server-side image map via the ?ismap? attribute on the element with a construction
  • an indexed search via the now deprecated element

Web forms

The main use of query strings is to contain the content of an HTML form, also known as web form. In particular, when a form containing the fields field1, field2, field3 is submitted, the content of the fields is encoded as a query string as follows:


  • The query string is composed of a series of field-value pairs.
  • Within each pair, the field name and value are separated by an equals sign. The equals sign may be omitted if the value is an empty string.
  • The series of pairs is separated by the ampersand, '&' (or semicolon, ';' for URLs embedded in HTML and not generated by a ...; see below). While there is no definitive standard, most web frameworks allow multiple values to be associated with a single field:


For each field of the form, the query string contains a pair field=value. Web forms may include fields that are not visible to the user; these fields are included in the query string when the form is submitted

This convention is a W3C recommendation. W3C recommends that all web servers support semicolon separators in addition to ampersand separators[6] to allow application/x-www-form-urlencoded query strings in URLs within HTML documents without having to entity escape ampersands.

Technically, the form content is only encoded as a query string when the form submission method is GET. The same encoding is used by default when the submission method is POST, but the result is not sent as a query string, that is, is not added to the action URL of the form. Rather, the string is sent as the body of the HTTP request.

How to remove underline from a link in HTML?

The other answers all mention text-decoration. Sometimes you use a Wordpress theme or someone else's CSS where links are underlined by other methods, so that text-decoration: none won't turn off the underlining.

Border and box-shadow are two other methods I'm aware of for underlining links. To turn these off:

border: none;


box-shadow: none;

Converting unix timestamp string to readable date

There are two parts:

  1. Convert the unix timestamp ("seconds since epoch") to the local time
  2. Display the local time in the desired format.

A portable way to get the local time that works even if the local time zone had a different utc offset in the past and python has no access to the tz database is to use a pytz timezone:

#!/usr/bin/env python
from datetime import datetime
import tzlocal  # $ pip install tzlocal

unix_timestamp = float("1284101485")
local_timezone = tzlocal.get_localzone() # get pytz timezone
local_time = datetime.fromtimestamp(unix_timestamp, local_timezone)

To display it, you could use any time format that is supported by your system e.g.:

print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))
print(local_time.strftime("%B %d %Y"))  # print date in your format

If you do not need a local time, to get a readable UTC time instead:

utc_time = datetime.utcfromtimestamp(unix_timestamp)
print(utc_time.strftime("%Y-%m-%d %H:%M:%S.%f+00:00 (UTC)"))

If you don't care about the timezone issues that might affect what date is returned or if python has access to the tz database on your system:

local_time = datetime.fromtimestamp(unix_timestamp)
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f"))

On Python 3, you could get a timezone-aware datetime using only stdlib (the UTC offset may be wrong if python has no access to the tz database on your system e.g., on Windows):

#!/usr/bin/env python3
from datetime import datetime, timezone

utc_time = datetime.fromtimestamp(unix_timestamp, timezone.utc)
local_time = utc_time.astimezone()
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))

Functions from the time module are thin wrappers around the corresponding C API and therefore they may be less portable than the corresponding datetime methods otherwise you could use them too:

#!/usr/bin/env python
import time

unix_timestamp  = int("1284101485")
utc_time = time.gmtime(unix_timestamp)
local_time = time.localtime(unix_timestamp)
print(time.strftime("%Y-%m-%d %H:%M:%S", local_time)) 
print(time.strftime("%Y-%m-%d %H:%M:%S+00:00 (UTC)", utc_time))  

How to run a javascript function during a mouseover on a div

This is badly formed HTML. You need to either have a single id or space separated classes. Either way if you're new I'd look into jQuery.

<div id="sub1">some text</div>


<div class="sub1 sub2 sub3">some text</div>

If you had the following HTML:

<div id="sub1">some text</div>
<div id="welcome" style="display:none;">Some welcome message</div>


$(document).ready(function() {
      function() { $('#welcome').show(); },
      function() { $('#welcome').hide(); }


you'd probably want to include the events on your html:

<div id="sub1" onmouseover="showWelcome();" onmouseout="hideWelcome();">some text</div>

then your javascript would have these two functions

function showWelcome()
   var welcome = document.getElementById('welcome'); = 'block';

function hideWelcome()
   var welcome = document.getElementById('welcome'); = 'none';

Please note: this javascript doesn't take cross browser issues into consideration. for this you'd need to elaborate on your code, just another reason to use jquery.

Show datalist labels but submit the actual value

When clicking on the button for search you can find it without a loop.
Just add to the option an attribute with the value you need (like id) and search for it specific.

$('#search_wrapper button').on('click', function(){
$('#autocomplete_input').val() +'"]').data('value'));

How to hide element label by element id in CSS?

If you don't care about IE6 users, use the equality attribute selector.

label[for="foo"] { display:none; }

How to apply a CSS class on hover to dynamically generated submit buttons?

The most efficient selector you can use is an attribute selector.

 input[name="btnPage"]:hover {/*your css here*/}

Here's a live demo:

Color picker utility (color pipette) in Ubuntu

You can install the package gcolor2 for this:

sudo apt-get install gcolor2


Applications -> Graphics -> GColor2

error TS2339: Property 'x' does not exist on type 'Y'

The correct fix is to add the property in the type definition as explained by @Nitzan Tomer. But also you can just define property as any, if you want to write code almost as in JavaScript:

arr.filter((item:any) => {
    return item.isSelected == true;

Modify table: How to change 'Allow Nulls' attribute from not null to allow null

Yes you can use ALTER TABLE as follows:

ALTER TABLE [table name] ALTER COLUMN [column name] [data type] NULL

Quoting from the ALTER TABLE documentation:

NULL can be specified in ALTER COLUMN to force a NOT NULL column to allow null values, except for columns in PRIMARY KEY constraints.

NSUserDefaults - How to tell if a key exists

Swift 3 / 4:

Here is a simple extension for Int/Double/Float/Bool key-value types that mimic the Optional-return behavior of the other types accessed through UserDefaults.

(Edit Aug 30 2018: Updated with more efficient syntax from Leo's suggestion.)

extension UserDefaults {
    /// Convenience method to wrap the built-in .integer(forKey:) method in an optional returning nil if the key doesn't exist.
    func integerOptional(forKey: String) -> Int? {
        return self.object(forKey: forKey) as? Int
    /// Convenience method to wrap the built-in .double(forKey:) method in an optional returning nil if the key doesn't exist.
    func doubleOptional(forKey: String) -> Double? {
        return self.object(forKey: forKey) as? Double
    /// Convenience method to wrap the built-in .float(forKey:) method in an optional returning nil if the key doesn't exist.
    func floatOptional(forKey: String) -> Float? {
        return self.object(forKey: forKey) as? Float
    /// Convenience method to wrap the built-in .bool(forKey:) method in an optional returning nil if the key doesn't exist.
    func boolOptional(forKey: String) -> Bool? {
        return self.object(forKey: forKey) as? Bool

They are now more consistent alongside the other built-in get methods (string, data, etc.). Just use the get methods in place of the old ones.

let AppDefaults = UserDefaults.standard

// assuming the key "Test" does not exist...

// old:
print(AppDefaults.integer(forKey: "Test")) // == 0
// new:
print(AppDefaults.integerOptional(forKey: "Test")) // == nil

CheckBox in RecyclerView keeps on checking different items

I've had the same issue. When I was clicking on item's toggle button in my recyclerView checked Toggle button appeared in every 10th item (for example if it was clicked in item with 0 index, items with 9, 18, 27 indexes were getting clicked too). Firstly, my code in onBindViewHolder was:

if (newsItems.get(position).getBookmark() == 1) {

But then I added Else statement

if (newsItems.get(position).getBookmark() == 1) {
//else statement prevents auto toggling
        } else{

And the problem was solved

How can I clear the NuGet package cache using the command line?

Clearing the cache

With dotnet core cli

dotnet nuget locals all --clear

With Visual Studio 2017

  1. Go to menu Tools ? NuGet Package Manager ? Package Manager Settings.
  2. Click Clear All NuGet Cache(s):

visual studio NuGet Package Manager General settings screenshot

With the nuget cli

Download and install the NuGet command line tool.

nuget locals all -clear

With windows command line

del %LOCALAPPDATA%\NuGet\Cache\*.nupkg /q

(can be used in a .bat file)

With PowerShell

rm $env:LOCALAPPDATA\NuGet\Cache\*.nupkg

Or 'quiet' mode (without error messages):

rm $env:LOCALAPPDATA\NuGet\Cache\*.nupkg 2> $null

Cache location





Build server

%windir%/ServiceProfiles/[account under build service runs]\AppData\Local\NuGet\Cache



This answer is a rollup of all the existing answers for your convenience

No connection could be made because the target machine actively refused it?

I faced same error because when your Server and Client run on same machine the Client need server local ip address not Public ip address to communicate with server you need Public ip address only in case when Server and Client run on separate machine so use Local ip address in client program to connect with server Local ip address can be found using this method.

 public static string Getlocalip()
            IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());
            return localIPs[7].ToString();
        catch (Exception)

            return "null";


How to find SQL Server running port?

If you can start the Sql Server Configuration Manager > SQL Server Network Configuration > Your instance > TCP/IP > Properties

enter image description here

What is the actual use of Class.forName("oracle.jdbc.driver.OracleDriver") while connecting to a database?

From the Java JDBC tutorial:

In previous versions of JDBC, to obtain a connection, you first had to initialize your JDBC driver by calling the method Class.forName. Any JDBC 4.0 drivers that are found in your class path are automatically loaded. (However, you must manually load any drivers prior to JDBC 4.0 with the method Class.forName.)

So, if you're using the Oracle 11g (11.1) driver with Java 1.6, you don't need to call Class.forName. Otherwise, you need to call it to initialise the driver.

Why isn't .ico file defined when setting window's icon?

Both codes are working fine with me on python 3.7..... hope will work for u as well

import tkinter as tk
m.title("SALAH Tutorials")

and do not forget to keep "myfavicon.ico" in the same folder where your project script file is present

Another method

from tkinter import *
m.title("SALAH Tutorials")

[*NOTE:- python version-3 works with tkinter and below version-3 i.e version-2 works with Tkinter]

How to get access to HTTP header information in Spring MVC REST controller?

You can use HttpEntity to read both Body and Headers.

   @RequestMapping(value = "/restURL")
   public String serveRest(HttpEntity<String> httpEntity){
                MultiValueMap<String, String> headers = 
                Iterator<Map.Entry<String, List<String>>> s = 
                while(s.hasNext()) {
                    Map.Entry<String, List<String>> obj =;
                    String key = obj.getKey();
                    List<String> value = obj.getValue();
                String body = httpEntity.getBody();


What are invalid characters in XML

The only illegal characters are &, < and > (as well as " or ' in attributes, depending on which character is used to delimit the attribute value: attr="must use &quot; here, ' is allowed" and attr='must use &apos; here, " is allowed').

They're escaped using XML entities, in this case you want &amp; for &.

Really, though, you should use a tool or library that writes XML for you and abstracts this kind of thing away for you so you don't have to worry about it.

Android Error [Attempt to invoke virtual method 'void' on a null object reference]

if u have creat a new toolbar then apply check that u have apply the method setSupportActionBar(); it will defenetly help you

serialize/deserialize java 8 java.time with Jackson JSON mapper

I had a similar problem while using Spring boot. With Spring boot 1.5.1.RELEASE all I had to do is to add dependency:


Node.js: printing to console without a trailing newline?

There seem to be many answers suggesting:


Error logs should be emitted on:


Instead use:


For anyone who is wonder why process.stdout.write('\033[0G'); wasn't doing anything it's because stdout is buffered and you need to wait for drain event (more info).

If write returns false it will fire a drain event.

Copy multiple files from one directory to another from Linux shell

I guess you are looking for brace expansion:

cp /home/ankur/folder/{file1,file2} /home/ankur/dest

take a look here, it would be helpful for you if you want to handle multiple files once :

tab completion with zsh...

enter image description here

Escaping backslash in string - javascript

Add an input id to the element and do something like that:


How do I wait for a promise to finish before returning the variable of a function?

What do I need to do to make this function wait for the result of the promise?

Use async/await (NOT Part of ECMA6, but available for Chrome, Edge, Firefox and Safari since end of 2017, see canIuse)

    async function waitForPromise() {
        // let result = await any Promise, like:
        let result = await Promise.resolve('this is a sample promise');

Added due to comment: An async function always returns a Promise, and in TypeScript it would look like:

    async function waitForPromise(): Promise<string> {
        // let result = await any Promise, like:
        let result = await Promise.resolve('this is a sample promise');

increase the java heap size permanently?

what platform are you running?..
if its unix, maybe adding

alias java='java -Xmx1g'  

to .bashrc (or similar) work

edit: Changing XmX to Xmx

How does autowiring work in Spring?

How does @Autowired work internally?


class EnglishGreeting {
   private Greeting greeting;
   //setter and getter

class Greeting {
   private String message;
   //setter and getter

.xml file it will look alike if not using @Autowired:

<bean id="englishGreeting" class="com.bean.EnglishGreeting">
   <property name="greeting" ref="greeting"/>

<bean id="greeting" class="com.bean.Greeting">
   <property name="message" value="Hello World"/>

If you are using @Autowired then:

class EnglishGreeting {
   @Autowired //so automatically based on the name it will identify the bean and inject.
   private Greeting greeting;
   //setter and getter

.xml file it will look alike if not using @Autowired:

<bean id="englishGreeting" class="com.bean.EnglishGreeting"></bean>

<bean id="greeting" class="com.bean.Greeting">
   <property name="message" value="Hello World"/>

If still have some doubt then go through below live demo

How does @Autowired work internally ?

Dynamic WHERE clause in LINQ

A simple Approach can be if your Columns are of Simple Type like String

public static IEnumerable<MyObject> WhereQuery(IEnumerable<MyObject> source, string columnName, string propertyValue)
   return source.Where(m => { return m.GetType().GetProperty(columnName).GetValue(m, null).ToString().StartsWith(propertyValue); });

Fit image into ImageView, keep aspect ratio and then resize ImageView to image dimensions?

The Below code make the bitmap perfectly with same size of the imageview. Get the bitmap image height and width and then calculate the new height and width with the help of imageview's parameters. That give you required image with best aspect ratio.

int currentBitmapWidth = bitMap.getWidth();
int currentBitmapHeight = bitMap.getHeight();

int ivWidth = imageView.getWidth();
int ivHeight = imageView.getHeight();
int newWidth = ivWidth;

newHeight = (int) Math.floor((double) currentBitmapHeight *( (double) new_width / (double) currentBitmapWidth));

Bitmap newbitMap = Bitmap.createScaledBitmap(bitMap, newWidth, newHeight, true);



C# Change A Button's Background Color

this.button2.BaseColor = System.Drawing.Color.FromArgb(((int)(((byte)(29)))), ((int)(((byte)(190)))), ((int)(((byte)(149)))));

a = open("file", "r"); a.readline() output without \n

That would be:


If you want to strip space from each and every line, you might consider instead:

This will give you a list of lines, without the line end characters.

Read XLSX file in Java

I don't know if it is up to date for Excel 2007, but for earlier versions I use the JExcelAPI

Git submodule update

Git 1.8.2 features a new option ,--remote, that will enable exactly this behavior. Running

git submodule update --rebase --remote

will fetch the latest changes from upstream in each submodule, rebase them, and check out the latest revision of the submodule. As the documentation puts it:


This option is only valid for the update command. Instead of using the superproject’s recorded SHA-1 to update the submodule, use the status of the submodule’s remote-tracking branch.

This is equivalent to running git pull in each submodule, which is generally exactly what you want.

(This was copied from this answer.)

How to determine the longest increasing subsequence using dynamic programming?

Speaking about DP solution, I found it surprising that no one mentioned the fact that LIS can be reduced to LCS. All you need to do is sort the copy of the original sequence, remove all the duplicates and do LCS of them. In pseudocode it is:

def LIS(S):
    T = sort(S)
    T = removeDuplicates(T)
    return LCS(S, T)

And the full implementation written in Go. You do not need to maintain the whole n^2 DP matrix if you do not need to reconstruct the solution.

func lcs(arr1 []int) int {
    arr2 := make([]int, len(arr1))
    for i, v := range arr1 {
        arr2[i] = v
    arr3 := []int{}
    prev := arr1[0] - 1
    for _, v := range arr1 {
        if v != prev {
            prev = v
            arr3 = append(arr3, v)

    n1, n2 := len(arr1), len(arr3)

    M := make([][]int, n2 + 1)
    e := make([]int, (n1 + 1) * (n2 + 1))
    for i := range M {
        M[i] = e[i * (n1 + 1):(i + 1) * (n1 + 1)]

    for i := 1; i <= n2; i++ {
        for j := 1; j <= n1; j++ {
            if arr2[j - 1] == arr3[i - 1] {
                M[i][j] = M[i - 1][j - 1] + 1
            } else if M[i - 1][j] > M[i][j - 1] {
                M[i][j] = M[i - 1][j]
            } else {
                M[i][j] = M[i][j - 1]

    return M[n2][n1]

"Full screen" <iframe>

You can use this piece of code:

  <iframe src="" frameborder="0" style="overflow:hidden;overflow-x:hidden;overflow-y:hidden;height:100%;width:100%;position:absolute;top:0%;left:0px;right:0px;bottom:0px" height="100%" width="100%"></iframe>

How can I change the image displayed in a UIImageView programmatically?

Example in Swift:

import UIKit

class ViewController: UIViewController {

    @IBOutlet var myUIImageView: UIImageView!

    override func viewDidLoad() {

    @IBAction func myAction(sender: UIButton) {
        let newImg: UIImage? = UIImage(named: "profile-picture-name")
        self.myUIImageView.image = newImg

    @IBAction func myAction2(sender: UIButton) {
        self.myUIImageView.image = nil
        self.myUIImageView.image = UIImage(data: NSData(contentsOfURL: NSURL(string: "http://url/image.png")!)!)


Maven plugin not using Eclipse's proxy settings

Eclipse by default does not know about your external Maven installation and uses the embedded one. Therefore in order for Eclipse to use your global settings you need to set it in menu Settings ? Maven ? Installations.

How To Run PHP From Windows Command Line in WAMPServer

If you want to just run a quick code snippet you can use the -r option:

php -r "echo 'hi';"

-r allows to run code without using script tags <?..?>

Select distinct using linq

myList.GroupBy(i => => group.First())

OperationalError: database is locked

try this command:

sudo fuser -k 8000/tcp

Secondary axis with twinx(): how to add to legend?

I'm not sure if this functionality is new, but you can also use the get_legend_handles_labels() method rather than keeping track of lines and labels yourself:

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rc
rc('mathtext', default='regular')

pi = np.pi

# fake data
time = np.linspace (0, 25, 50)
temp = 50 / np.sqrt (2 * pi * 3**2) \
        * np.exp (-((time - 13)**2 / (3**2))**2) + 15
Swdown = 400 / np.sqrt (2 * pi * 3**2) * np.exp (-((time - 13)**2 / (3**2))**2)
Rn = Swdown - 10

fig = plt.figure()
ax = fig.add_subplot(111)

ax.plot(time, Swdown, '-', label = 'Swdown')
ax.plot(time, Rn, '-', label = 'Rn')
ax2 = ax.twinx()
ax2.plot(time, temp, '-r', label = 'temp')

# ask matplotlib for the plotted objects and their labels
lines, labels = ax.get_legend_handles_labels()
lines2, labels2 = ax2.get_legend_handles_labels()
ax2.legend(lines + lines2, labels + labels2, loc=0)

ax.set_xlabel("Time (h)")
ax.set_ylabel(r"Radiation ($MJ\,m^{-2}\,d^{-1}$)")
ax2.set_ylabel(r"Temperature ($^\circ$C)")
ax2.set_ylim(0, 35)

What is the best way to tell if a character is a letter or number in Java without using regexes?

Use the below code


Uploading multiple files using formData()

Here is the Vanilla JavaScript solution for this issue -

First, we'll use Array.prototype.forEach() method, as

document.querySelectorAll('input[type=file]') returns an array like object.

Then we'll use the method to assign each element in the array-like object to the this value in the .forEach method.


<form id="myForm">

    <input type="file" name="myFile" id="myFile_1">
    <input type="file" name="myFile" id="myFile_2">
    <input type="file" name="myFile" id="myFile_3">

    <button type="button" onclick="saveData()">Save</button>



 function saveData(){
     var data = new FormData(document.getElementById("myForm"));
     var inputs = document.querySelectorAll('input[type=file]');[0].files, function(index){
        data.append('files', index);

You can view the working example of the same HERE

How to convert the system date format to dd/mm/yy in SQL Server 2008 R2?

The query below will result in dd-mmm-yy format.

cast(DAY(getdate()) as varchar)+'-'+left(DATEname(m,getdate()),3)+'-'+  

How do include paths work in Visual Studio?

This answer only applies to ancient versions of Visual Studio - see the more recent answers for modern versions.

You can set Visual Studio's global include path here:

Tools / Options / Projects and Solutions / VC++ Directories / Include files

how to use DEXtoJar

If you're looking for the version for windows get it from source forge:

It has the d2j-dex2jar.bat file you need

How to include view/partial specific styling in AngularJS

@sz3, funny enough today I had to do exactly what you were trying to achieve: 'load a specific CSS file only when a user access' a specific page. So I used the solution above.

But I am here to answer your last question: 'where exactly should I put the code. Any ideas?'

You were right including the code into the resolve, but you need to change a bit the format.

Take a look at the code below:

.when('/home', {
  title:'Home - ' + siteName,
  bodyClass: 'home',
  templateUrl: function(params) {
    return 'views/home.html';
  controler: 'homeCtrl',
  resolve: {
    style : function(){
      /* check if already exists first - note ID used on link element*/
      /* could also track within scope object*/
      if( !angular.element('link#mobile').length){
        angular.element('head').append('<link id="home" href="home.css" rel="stylesheet">');

I've just tested and it's working fine, it injects the html and it loads my 'home.css' only when I hit the '/home' route.

Full explanation can be found here, but basically resolve: should get an object in the format

  'key' : string or function()

You can name the 'key' anything you like - in my case I called 'style'.

Then for the value you have two options:

  • If it's a string, then it is an alias for a service.

  • If it's function, then it is injected and the return value is treated as the dependency.

The main point here is that the code inside the function is going to be executed before before the controller is instantiated and the $routeChangeSuccess event is fired.

Hope that helps.

Jquery split function

Try this. It uses the split function which is a core part of javascript, nothing to do with jQuery.

var parts = html.split(":-"),
    i, l
for (i = 0, l = parts.length; i < l; i += 2) {
    $("#" + parts[i]).text(parts[i + 1]);