Programs & Examples On #Nsimagerep

org.xml.sax.SAXParseException: Premature end of file for *VALID* XML

Please make sure that you are not consuming your inputstream anywhere before parsing. Sample code is following: the respose below is httpresponse(i.e. response) and main content is contain inside StringEntity (i.e. getEntity())in form of inputStream(i.e. getContent()).

InputStream rescontent = response.getEntity().getContent();
tsResponse=(TsResponse) transformer.convertFromXMLToObject(rescontent );

Can I write a CSS selector selecting elements NOT having a certain class or attribute?

You can use :not(.class) selector as mentioned before.

If you care about Internet explorer compatibility I recommend you to use

But remember to run it under apache otherwise you won't see the effect.

How to set commands output as a variable in a batch file

FOR /F "tokens=* USEBACKQ" %%F IN (`command`) DO (
SET var=%%F
ECHO %var%

I always use the USEBACKQ so that if you have a string to insert or a long file name, you can use your double quotes without screwing up the command.

Now if your output will contain multiple lines, you can do this

SET count=1
FOR /F "tokens=* USEBACKQ" %%F IN (`command`) DO (
  SET var!count!=%%F
  SET /a count=!count!+1
ECHO %var1%
ECHO %var2%
ECHO %var3%

How to remove class from all elements jquery

This just removes the highlight class from everything that has the edgetoedge class:


I think you want this:

$(".edgetoedge .highlight").removeClass("highlight");

The .edgetoedge .highlight selector will choose everything that is a child of something with the edgetoedge class and has the highlight class.

Best practice to return errors in ASP.NET Web API

It looks like you're having more trouble with Validation than errors/exceptions so I'll say a bit about both.


Controller actions should generally take Input Models where the validation is declared directly on the model.

public class Customer
    public string Name { get; set; }

Then you can use an ActionFilter that automatically sends validation messages back to the client.

public class ValidationActionFilter : ActionFilterAttribute
    public override void OnActionExecuting(HttpActionContext actionContext)
        var modelState = actionContext.ModelState;

        if (!modelState.IsValid) {
            actionContext.Response = actionContext.Request
                 .CreateErrorResponse(HttpStatusCode.BadRequest, modelState);

For more information about this check out

Error handling

It's best to return a message back to the client that represents the exception that happened (with relevant status code).

Out of the box you have to use Request.CreateErrorResponse(HttpStatusCode, message) if you want to specify a message. However, this ties the code to the Request object, which you shouldn't need to do.

I usually create my own type of "safe" exception that I expect the client would know how to handle and wrap all others with a generic 500 error.

Using an action filter to handle the exceptions would look like this:

public class ApiExceptionFilterAttribute : ExceptionFilterAttribute
    public override void OnException(HttpActionExecutedContext context)
        var exception = context.Exception as ApiException;
        if (exception != null) {
            context.Response = context.Request.CreateErrorResponse(exception.StatusCode, exception.Message);

Then you can register it globally.

GlobalConfiguration.Configuration.Filters.Add(new ApiExceptionFilterAttribute());

This is my custom exception type.

using System;
using System.Net;

namespace WebApi
    public class ApiException : Exception
        private readonly HttpStatusCode statusCode;

        public ApiException (HttpStatusCode statusCode, string message, Exception ex)
            : base(message, ex)
            this.statusCode = statusCode;

        public ApiException (HttpStatusCode statusCode, string message)
            : base(message)
            this.statusCode = statusCode;

        public ApiException (HttpStatusCode statusCode)
            this.statusCode = statusCode;

        public HttpStatusCode StatusCode
            get { return this.statusCode; }

An example exception that my API can throw.

public class NotAuthenticatedException : ApiException
    public NotAuthenticatedException()
        : base(HttpStatusCode.Forbidden)

How to configure Glassfish Server in Eclipse manually

I could fix it using below steps.(GlassFish server3.1.2.2 and eclipse Luna 4.4.1)

  1. Help > Eclipse Marketplace > Search GlassFish > you will see GlassFish Tools > Select appropriate one and install it.
  2. Restart eclipse
  3. Windows > Open Views > Other > Server > Servers > GlassFish 3.1
  4. You will need jdk1.7.0 added to Installed JRE. Close the previous window to take effect of new default jdk1.7.0.

How to read file from res/raw by name

Here are two approaches you can read raw resources using Kotlin.

You can get it by getting the resource id. Or, you can use string identifier in which you can programmatically change the filename with incrementation.

Cheers mate

// R.raw.data_post

this.context.resources.getIdentifier("data_post", "raw", this.context.packageName)

Swift 3: Display Image from URL

The easiest way according to me will be using SDWebImage

Add this to your pod file

  pod 'SDWebImage', '~> 4.0'

Run pod install

Now import SDWebImage

      import SDWebImage

Now for setting image from url

    imageView.sd_setImage(with: URL(string: "http://www.domain/path/to/image.jpg"), placeholderImage: UIImage(named: "placeholder.png"))

It will show placeholder image but when image is downloaded it will show the image from url .Your app will never crash

This are the main feature of SDWebImage

Categories for UIImageView, UIButton, MKAnnotationView adding web image and cache management

An asynchronous image downloader

An asynchronous memory + disk image caching with automatic cache expiration handling

A background image decompression

A guarantee that the same URL won't be downloaded several times

A guarantee that bogus URLs won't be retried again and again

A guarantee that main thread will never be blocked Performances!

Use GCD and ARC

To know more

How can I concatenate a string and a number in Python?

You have to convert the int into a string:

"abc" + str(9)

error: No resource identifier found for attribute 'adSize' in package '' main.xml

I had a similar issue on MonoDroid when building a class library with Drawables and Layouts files that have "android:" attribute in the xml. I get a similar error as the one in the question.

No resource identifier found for attribute 'textCursorDrawable' in package 'android'

I found from that "android: " attribute is only available in Android API Level 12+ and I was trying to build for an older version. Updating my project to build against Android 4.0 fixed the issue for me. Here is where I found the answer.!topic/android-developers/ocxKphM5MWM Just make sure that you are building against the right API level if you get a similar issue, and ensure that the missing identifier exists in that API level that you are build against.

How to access to a child method from the parent in vue.js

To communicate a child component with another child component I've made a method in parent which calls a method in a child with:


And from the another child I've called the root method:


It worked for me.

ImportError: No module named 'encodings'

I had a similar issue. I had both anaconda and python installed on my computer and my python dependencies were from the Anaconda directory. When I uninstalled Anaconda, this error started popping. I added PYTHONPATH but it still didn't go. I checked with python -version and go to know that it was still taking the anaconda path. I had to manually delete Anaconda3 directory and after that python started taking dependencies from PYTHONPATH.
Issue Solved!

How to disable mouse right click on a web page?

You can do so with Javascript and/or an HTML attribute (which is really a Javascript event handler anyway) as described here:

<script language="javascript">
status="Right Click Disabled";
Function disableclick(event)
     return false;    


<body oncontextmenu="return false">

How to get DataGridView cell value in messagebox?

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
           int rowIndex = e.RowIndex; // Get the order of the current row 
            DataGridViewRow row = dataGridView1.Rows[rowIndex];//Store the value of the current row in a variable
            MessageBox.Show(row.Cells[rowIndex].Value.ToString());//show message for current row

VBoxManage: error: Failed to create the host-only adapter

If you are on Linux, simply run: sudo vboxreload

The proxy server received an invalid response from an upstream server

This is not mentioned in you post but I suspect you are initiating an SSL connection from the browser to Apache, where VirtualHosts are configured, and Apache does a revese proxy to your Tomcat.

There is a serious bug in (some versions ?) of IE that sends the 'wrong' host information in an SSL connection (see EDIT below) and confuses the Apache VirtualHosts. In short the server name presented is the one of the reverse DNS resolution of the IP, not the one in the URL.

The workaround is to have one IP address per SSL virtual hosts/server name. Is short, you must end up with something like

1 server name == 1 IP address == 1 certificate == 1 Apache Virtual Host


Though the conclusion is correct, the identification of the problem is better described here

Detecting a redirect in ajax request?

The AJAX request never has the opportunity to NOT follow the redirect (i.e., it must follow the redirect). More information can be found in this answer

Java Generate Random Number Between Two Given Values

You could use e.g. r.nextInt(101)

For a more generic "in between two numbers" use:

Random r = new Random();
int low = 10;
int high = 100;
int result = r.nextInt(high-low) + low;

This gives you a random number in between 10 (inclusive) and 100 (exclusive)

Use Device Login on Smart TV / Console

Implement Login for Devices

Facebook Login for Devices is for devices that directly make HTTP calls over the internet. The following are the API calls and responses your device can make.

1. Enable Login for Devices

Change Settings > Advanced > OAuth Settings > Login from Devices to 'Yes'.

2. Generate a Code which is required for facebook device identification

When the person clicks Log in with Facebook, you device should make an HTTP POST to:

       &amp;scope=<COMMA_SEPARATED_PERMISSION_NAMES> // e.g.public_profile,user_likes

The response comes in this form:

  "code": "92a2b2e351f2b0b3503b2de251132f47",
  "user_code": "A1NWZ9",
  "verification_uri": "",
  "expires_in": 420,
  "interval": 5

This response means:

  • Display the string “A1NWZ9” on your device
  • Tell the person to go to “” and enter this code
  • The code expires in 420 seconds. You should cancel the login flow after that time if you do not receive an access token
  • Your device should poll the Device Login API every 5 seconds to see if the authorization has been successful

3. Display the Code

Your device should display the user_code and tell people to visit the verification_uri such as on their PC or smartphone. See the Design Guidelines.

4. Poll for Authorization

Your device should poll the Device Login API to see if the person successfully authorized your application. You should do this at the interval in the response to your call in Step 1, which is every 5 seconds. Your device should poll to:

       &amp;code=<LONG_CODE_FROM_STEP_1> //e.g."92a2b2e351f2b0b3503b2de251132f47"

You will get 200 HTTP code i.e User has successfully authorized the device. The device can now use the access_token value to make authenticated API calls.

5. Confirm Successful Login

Your device should display their name and if available, a profile picture until they click Continue. To get the person's name and profile picture, your device should make a standard Graph API call:



  "name": "John Doe", 
  "picture": {
    "data": {
      "is_silhouette": false, 
      "url": ""
  "id": "2023462875238472"

6. Store Access Tokens

Your device should persist the access token to make other requests to the Graph API.

Device Login access tokens may be valid for up to 60 days but may be invalided in a number of scenarios. For example when a person changes their Facebook password their access token is invalidated.

If the token is invalid, your device should delete the token from its memory. The person using your device needs to perform the Device Login flow again from Step 1 to retrieve a new, valid token.

Create a date time with month and day only, no year

Well, you can create your own type - but a DateTime always has a full date and time. You can't even have "just a date" using DateTime - the closest you can come is to have a DateTime at midnight.

You could always ignore the year though - or take the current year:

// Consider whether you want DateTime.UtcNow.Year instead
DateTime value = new DateTime(DateTime.Now.Year, month, day);

To create your own type, you could always just embed a DateTime within a struct, and proxy on calls like AddDays etc:

public struct MonthDay : IEquatable<MonthDay>
    private readonly DateTime dateTime;

    public MonthDay(int month, int day)
        dateTime = new DateTime(2000, month, day);

    public MonthDay AddDays(int days)
        DateTime added = dateTime.AddDays(days);
        return new MonthDay(added.Month, added.Day);

    // TODO: Implement interfaces, equality etc

Note that the year you choose affects the behaviour of the type - should Feb 29th be a valid month/day value or not? It depends on the year...

Personally I don't think I would create a type for this - instead I'd have a method to return "the next time the program should be run".

How to use [DllImport("")] in C#?

You can't declare an extern local method inside of a method, or any other method with an attribute. Move your DLL import into the class:

using System.Runtime.InteropServices;

public class WindowHandling
    public static extern int SetForegroundWindow(IntPtr point);

    public void ActivateTargetApplication(string processName, List<string> barcodesList)
        Process p = Process.Start("notepad++.exe");
        IntPtr h = p.MainWindowHandle;
        IntPtr processFoundWindow = p.MainWindowHandle;

Python: Making a beep noise


$ apt-get install beep

$ python
>>> os.system("beep -f 555 -l 460")


$ beep -f 659 -l 460 -n -f 784 -l 340 -n -f 659 -l 230 -n -f 659 -l 110 -n -f 880 -l 230 -n -f 659 -l 230 -n -f 587 -l 230 -n -f 659 -l 460 -n -f 988 -l 340 -n -f 659 -l 230 -n -f 659 -l 110 -n -f 1047-l 230 -n -f 988 -l 230 -n -f 784 -l 230 -n -f 659 -l 230 -n -f 988 -l 230 -n -f 1318 -l 230 -n -f 659 -l 110 -n -f 587 -l 230 -n -f 587 -l 110 -n -f 494 -l 230 -n -f 740 -l 230 -n -f 659 -l 460

How to print like printf in Python3?

Simple Example:

print("foo %d, bar %d" % (1,2))

How can I clear the content of a file?

The simplest way to do this is perhaps deleting the file via your application and creating a new one with the same name... in even simpler way just make your application overwrite it with a new file.

Excel formula to get ranking position

You can use the RANK function in Excel without necessarily sorting the data. Type =RANK(C2,$C$2:$C$7). Excel will find the relative position of the data in C2 and display the answer. Copy the formula through to C7 by dragging the small node at the right end of the cell cursor.

How to use XPath preceding-sibling correctly

I also like to build locators from up to bottom like:

//div[contains(@class,'btn-group')][./button[contains(.,'Arcade Reader')]]/button[@name='settings']

It's pretty simple, as we just search btn-group with button[contains(.,'Arcade Reader')] and get it's button[@name='settings']

That's just another option to build xPath locators

What is the profit of searching wrapper element: you can return it by method (example in java) and just build selenium constructions like:

getGroupByName("Arcade Reader").find("button[name='settings']");
getGroupByName("Arcade Reader").find("button[name='delete']");

or even simplify more

getGroupButton("Arcade Reader", "delete").click();

SyntaxError: unexpected EOF while parsing

elec_and_weather['DEMAND_t-%i'% k] = np.zeros(len(elec_and_weather['DEMAND']))'

The error comes at the end of the line where you have the (') sign; this error always means that you have a syntax error.

Make xargs handle filenames that contain spaces

ls | grep mp3 | sed -n "7p" | xargs -i mplayer {}

Note that in the command above, xargs will call mplayer anew for each file. This may be undesirable for mplayer, but may be okay for other targets.

How to write UTF-8 in a CSV file

For python2 you can use this code before csv_writer.writerows(rows)
This code will NOT convert integers to utf-8 strings

def encode_rows_to_utf8(rows):
    encoded_rows = []
    for row in rows:
        encoded_row = []
        for value in row:
            if isinstance(value, basestring):
                value = unicode(value).encode("utf-8")
    return encoded_rows

Measuring the distance between two coordinates in PHP

It's just addition to @martinstoeckli and @Janith Chinthana answers. For those who curious about which algorithm is fastest i wrote the performance test. Best performance result shows optimized function from

 * Optimized algorithm from
 * @param float $latitudeFrom
 * @param float $longitudeFrom
 * @param float $latitudeTo
 * @param float $longitudeTo
 * @return float [km]
function codexworldGetDistanceOpt($latitudeFrom, $longitudeFrom, $latitudeTo, $longitudeTo)
    $rad = M_PI / 180;
    //Calculate distance from latitude and longitude
    $theta = $longitudeFrom - $longitudeTo;
    $dist = sin($latitudeFrom * $rad) 
        * sin($latitudeTo * $rad) +  cos($latitudeFrom * $rad)
        * cos($latitudeTo * $rad) * cos($theta * $rad);

    return acos($dist) / $rad * 60 *  1.853;

Here is test results:

Test name       Repeats         Result          Performance     
codexworld-opt  10000           0.084952 sec    +0.00%
codexworld      10000           0.104127 sec    -22.57%
custom          10000           0.107419 sec    -26.45%
custom2         10000           0.111576 sec    -31.34%
custom1         10000           0.136691 sec    -60.90%
vincenty        10000           0.165881 sec    -95.26%

How to initialize a vector in C++

You can also do like this:

template <typename T>
class make_vector {
  typedef make_vector<T> my_type;
  my_type& operator<< (const T& val) {
    return *this;
  operator std::vector<T>() const {
    return data_;
  std::vector<T> data_;

And use it like this:

std::vector<int> v = make_vector<int>() << 1 << 2 << 3;

How to convert an Image to base64 string in java?

this did it for me. you can vary the options for the output format to Base64.Default whatsoever.

// encode base64 from image
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] b = baos.toByteArray();
encodedString = Base64.encodeToString(b, Base64.URL_SAFE | Base64.NO_WRAP);

How to convert any Object to String?

"toString()" is Very useful method which returns a string representation of an object. The "toString()" method returns a string reperentation an object.It is recommended that all subclasses override this method.

Declaration: java.lang.Object.toString()

Since, you have not mentioned which object you want to convert, so I am just using any object in sample code.

Integer integerObject = 5;
String convertedStringObject = integerObject .toString();
System.out.println(convertedStringObject );

You can find the complete code here. You can test the code here.

How to call a .NET Webservice from Android using KSOAP2?

Typecast the envelope to SoapPrimitive:

SoapPrimitive result = (SoapPrimitive)envelope.getResponse();
String strRes = result.toString();

and it will work.

Run PHP Task Asynchronously

It's a great idea to use cURL as suggested by rojoca.

Here is an example. You can monitor text.txt while the script is running in background:


function doCurl($begin)
    echo "Do curl<br />\n";
    $url = 'http://'.$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
    $url = preg_replace('/\?.*/', '', $url);
    $url .= '?begin='.$begin;
    echo 'URL: '.$url.'<br>';
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $result = curl_exec($ch);
    echo 'Result: '.$result.'<br>';

if (empty($_GET['begin'])) {
else {
    while (ob_get_level())
    header('Connection: close');
    echo 'Connection Closed';
    $size = ob_get_length();
    header("Content-Length: $size");

    $begin = $_GET['begin'];
    $fp = fopen("text.txt", "w");
    fprintf($fp, "begin: %d\n", $begin);
    for ($i = 0; $i < 15; $i++) {
        fprintf($fp, "i: %d\n", $i);
    if ($begin < 10)
        doCurl($begin + 1);


What is Domain Driven Design?

Here is another good article that you may check out on Domain Driven Design. if your application is anything serious than college assignment. The basic premise is structure everything around your entities and have a strong domain model. Differentiate between services that provide infrastructure related things (like sending email, persisting data) and services that actually do things that are your core business requirments.

Hope that helps.

How do I split a string so I can access item x?

This pattern works fine and you can generalize

                          ^^^^^                                   ^^^^^     ^^^^


Let some table with identifiers like


Then, you can write

SELECT Source         = q.value('(/n[1])', 'varchar(10)'),
       RecordType     = q.value('(/n[2])', 'varchar(20)'),
       RecordNumber   = q.value('(/n[3])', 'int'),
       Status         = q.value('(/n[4])', 'varchar(5)')
FROM   (
         SELECT   q = Convert(xml,'<n>'+Replace(fieldName,'.','</n><n>')+'</n>')
         FROM     some_TABLE
       ) Q

splitting and casting all parts.

Command to get time in milliseconds

date command didnt provide milli seconds on OS X, so used an alias from python

millis(){  python -c "import time; print(int(time.time()*1000))"; }


alias millis='python -c "import time; print(int(time.time()*1000))"'

EDIT: following the comment from @CharlesDuffy. Forking any child process takes extra time.

$ time date +%s%N
date +%s%N  0.00s user 0.00s system 63% cpu 0.006 total

Python is still improving it's VM start time, and it is not as fast as ahead-of-time compiled code (such as date).

On my machine, it took about 30ms - 60ms (that is 5x-10x of 6ms taken by date)

$ time python -c "import time; print(int(time.time()*1000))"
python -c "import time; print(int(time.time()*1000))"  0.03s user 0.01s system 83% cpu 0.053 total

I figured awk is lightweight than python, so awk takes in the range of 6ms to 12ms (i.e. 1x to 2x of date):

$ time awk '@load "time"; BEGIN{print int(1000 * gettimeofday())}'
awk '@load "time"; BEGIN{print int(1000 * gettimeofday())}'  0.00s user 0.00s system 74% cpu 0.010 total

Responding with a JSON object in Node.js (converting object/array to JSON string)

var objToJson = { };
objToJson.response = response;

If you alert(JSON.stringify(objToJson)) you will get {"response":"value"}

How do I give text or an image a transparent background using CSS?

Almost all these answers assume the designer wants a solid color background. If the designer actually wants a photo as the background the only real solution at the moment is JavaScript like the jQuery Transify plugin mentioned elsewhere.

What we need to do is join the CSS working group discussion and make them give us a background-opacity attribute! It should work hand in hand with the multiple-backgrounds feature.

Check if string doesn't contain another string

The answers you got assumed static text to compare against. If you want to compare against another column (say, you're joining two tables, and want to find ones where a column from one table is part of a column from another table), you can do this

WHERE NOT (someColumn LIKE '%' || someOtherColumn || '%')

How to change the status bar color in Android?

Place this is your values-v21/styles.xml, to enable this on Lollipop:

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light">
        <item name="colorPrimary">@color/color_primary</item>
        <item name="colorPrimaryDark">@color/color_secondary</item>
        <item name="colorAccent">@color/color_accent</item>
        <item name="android:statusBarColor">@color/color_primary</item>

Install Android App Bundle on device

Short answer:

Not directly.

Longer answer:

Android App Bundles is a publishing format. Android devices require .apk files to install applications.

The PlayStore or any other source that you're installing from needs to extract apks from the bundle, sign each one and then install them specific to the target device.

The conversion from .aab to .apk is done via bundletool.

You can use Internal App Sharing to upload a debuggable build of your app to the Play Store and share it with testers.

How can I display a tooltip on an HTML "option" tag?

Why use a dropdown at all? The only way the user will see your explanatory text is by blindly hovering over one of the options.

I think it would be preferable to use a radio button group, and next to each item, put a tooltip icon indicating additional information, as well as displaying it after selection (like you currently have it).

I realize this doesn't exactly solve your problem, but I don't see the point in struggling with an html element that's notorious for its inflexibility when you could just use one that's better suited in the first place.

jQuery creating objects

May be you want this (oop in javascript)

function box(color)

var box1=new box('red');    
var box2=new box('white');    


For more information.

How to get the selected row values of DevExpress XtraGrid?

I found the solution as follows:

private void gridView1_RowCellClick(object sender, DevExpress.XtraGrid.Views.Grid.RowCellClickEventArgs e)
    TBGRNo.Text = gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "GRNo").ToString();
    TBSName.Text = gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "SName").ToString();
    TBFName.Text = gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "FName").ToString();            

enter image description here

How do I create a singleton service in Angular 2?

Update (Angular 6 +)

The recommended way to create a singleton service has changed. It is now recommended to specify in the @Injectable decorator on the service that it should be provided in the 'root'. This makes a lot of sense to me and there's no need to list all the provided services in your modules at all anymore. You just import the services when you need them and they register themselves in the proper place. You can also specify a module so it will only be provided if the module is imported.

  providedIn: 'root',
export class ApiService {

Update (Angular 2)

With NgModule, the way to do it now I think is to create a 'CoreModule' with your service class in it, and list the service in the module's providers. Then you import the core module in your main app module which will provide the one instance to any children requesting that class in their constructors:


import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { ApiService } from './api.service';

    imports: [
    exports: [ // components that we want to make available
    declarations: [ // components for use in THIS module
    providers: [ // singleton services
export class CoreModule { }


import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { AppComponent } from './app.component';
import { CoreModule } from './core/core.module';

    declarations: [ AppComponent ],
    imports: [
        CoreModule // will provide ApiService
    providers: [],
    bootstrap: [ AppComponent ]
export class AppModule { }

Original Answer

If you list a provider in bootstrap(), you don't need to list them in your component decorator:

import { ApiService } from '../core/api-service';

    selector: 'main-app',
    templateUrl: '/views/main-app.html',
    // (unless you want a new instance)
    //providers: [ApiService]
export class MainAppComponent {
    constructor(private api: ApiService) {}

In fact listing your class in 'providers' creates a new instance of it, if any parent component already lists it then the children don't need to, and if they do they will get a new instance.

How to insert spaces/tabs in text using HTML/CSS

Types of Spaces in HTML

Creates four spaces between the text- &emsp;

Creates two spaces between the text - &ensp;

Creates a regular space between the text - &nbsp;

creates a narrow space ( similar to regular space but slight difference - "&thinsp";

spacing between sentences - "</br>"

This link might help you. Check out []

Document Root PHP

The Easiest way to do it is to have good site structure and write it as a constant.


Is there a native jQuery function to switch elements?

I used a technique like this before. I use it for the connector list on

// clone element1 and put the clone before element2

// replace the original element1 with element2
// leaving the element1 clone in it's place

How do I find out which process is locking a file using .NET?

It is very complex to invoke Win32 from C#.

You should use the tool Handle.exe.

After that your C# code have to be the following:

string fileName = @"c:\aaa.doc";//Path to locked file

Process tool = new Process();
tool.StartInfo.FileName = "handle.exe";
tool.StartInfo.Arguments = fileName+" /accepteula";
tool.StartInfo.UseShellExecute = false;
tool.StartInfo.RedirectStandardOutput = true;
string outputTool = tool.StandardOutput.ReadToEnd();

string matchPattern = @"(?<=\s+pid:\s+)\b(\d+)\b(?=\s+)";
foreach(Match match in Regex.Matches(outputTool, matchPattern))

Printing out all the objects in array list

Whenever you print any instance of your class, the default toString implementation of Object class is called, which returns the representation that you are getting. It contains two parts: - Type and Hashcode

So, in student.Student@82701e that you get as output ->

  • student.Student is the Type, and
  • 82701e is the HashCode

So, you need to override a toString method in your Student class to get required String representation: -

public String toString() {
    return "Student No: " + this.getStudentNo() + 
           ", Student Name: " + this.getStudentName();

So, when from your main class, you print your ArrayList, it will invoke the toString method for each instance, that you overrided rather than the one in Object class: -

List<Student> students = new ArrayList();

// You can directly print your ArrayList

// Or, iterate through it to print each instance
for(Student student: students) {
    System.out.println(student);  // Will invoke overrided `toString()` method

In both the above cases, the toString method overrided in Student class will be invoked and appropriate representation of each instance will be printed.

How to pass variable from jade template file to a script file?

#{} is for escaped string interpolation which automatically escapes the input and is thus more suitable for plain strings rather than JS objects:

script var data = #{JSON.stringify(data)}
<script>var data = {&quot;foo&quot;:&quot;bar&quot;} </script>

!{} is for unescaped code interpolation, which is more suitable for objects:

script var data = !{JSON.stringify(data)}
<script>var data = {"foo":"bar"} </script>

CAUTION: Unescaped code can be dangerous. You must be sure to sanitize any user inputs to avoid cross-site scripting (XSS).


{ foo: 'bar </script><script> alert("xss") //' }

will become:

<script>var data = {"foo":"bar </script><script> alert("xss") //"}</script>

Possible solution: Use .replace(/<\//g, '<\\/')

script var data = !{JSON.stringify(data).replace(/<\//g, '<\\/')}
<script>var data = {"foo":"bar<\/script><script>alert(\"xss\")//"}</script>

The idea is to prevent the attacker to:

  1. Break out of the variable: JSON.stringify escapes the quotes
  2. Break out of the script tag: if the variable contents (which you might not be able to control if comes from the database for ex.) has a </script> string, the replace statement will take care of it

Server http:/localhost:8080 requires a user name and a password. The server says: XDB

Add username and password in application propreties files.

When adding spring security every http query must be authentified by login and password.

See Screenshot

How is the java memory pool divided?

Heap memory

The heap memory is the runtime data area from which the Java VM allocates memory for all class instances and arrays. The heap may be of a fixed or variable size. The garbage collector is an automatic memory management system that reclaims heap memory for objects.

  • Eden Space: The pool from which memory is initially allocated for most objects.

  • Survivor Space: The pool containing objects that have survived the garbage collection of the Eden space.

  • Tenured Generation or Old Gen: The pool containing objects that have existed for some time in the survivor space.

Non-heap memory

Non-heap memory includes a method area shared among all threads and memory required for the internal processing or optimization for the Java VM. It stores per-class structures such as a runtime constant pool, field and method data, and the code for methods and constructors. The method area is logically part of the heap but, depending on the implementation, a Java VM may not garbage collect or compact it. Like the heap memory, the method area may be of a fixed or variable size. The memory for the method area does not need to be contiguous.

  • Permanent Generation: The pool containing all the reflective data of the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.

  • Code Cache: The HotSpot Java VM also includes a code cache, containing memory that is used for compilation and storage of native code.

Here's some documentation on how to use Jconsole.

ASP.NET Identity DbContext confusion

This is a late entry for folks, but below is my implementation. You will also notice I stubbed-out the ability to change the the KEYs default type: the details about which can be found in the following articles:

It should be noted that you cannot use Guid's for your keys. This is because under the hood they are a Struct, and as such, have no unboxing which would allow their conversion from a generic <TKey> parameter.


public class ApplicationDbContext : IdentityDbContext<ApplicationUser, CustomRole, string, CustomUserLogin, CustomUserRole, CustomUserClaim>
    #region <Constructors>

    public ApplicationDbContext() : base(Settings.ConnectionString.Database.AdministrativeAccess)


    #region <Properties>

    //public DbSet<Case> Case { get; set; }


    #region <Methods>


    protected override void OnModelCreating(DbModelBuilder modelBuilder)

        //modelBuilder.Configurations.Add(new ResourceConfiguration());
        //modelBuilder.Configurations.Add(new OperationsToRolesConfiguration());



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



    public class ApplicationUser : IdentityUser<string, CustomUserLogin, CustomUserRole, CustomUserClaim>
        #region <Constructors>

        public ApplicationUser()


        #region <Properties>

        public string FirstName { get; set; }

        public string LastName { get; set; }


        #region <Methods>

        #region private

        private void Init()
            Id = Guid.Empty.ToString();


        #region public

        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser, string> manager)
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);

            // Add custom user claims here

            return userIdentity;



    public class CustomUserStore : UserStore<ApplicationUser, CustomRole, string, CustomUserLogin, CustomUserRole, CustomUserClaim>
        #region <Constructors>

        public CustomUserStore(ApplicationDbContext context) : base(context)


    public class CustomUserRole : IdentityUserRole<string>

    public class CustomUserLogin : IdentityUserLogin<string>

    public class CustomUserClaim : IdentityUserClaim<string> 

    public class CustomRoleStore : RoleStore<CustomRole, string, CustomUserRole>
        #region <Constructors>

        public CustomRoleStore(ApplicationDbContext context) : base(context)


    public class CustomRole : IdentityRole<string, CustomUserRole>
        #region <Constructors>

        public CustomRole() { }
        public CustomRole(string name) 
            Name = name; 


When to use RSpec let()?

In general, let() is a nicer syntax, and it saves you typing @name symbols all over the place. But, caveat emptor! I have found let() also introduces subtle bugs (or at least head scratching) because the variable doesn't really exist until you try to use it... Tell tale sign: if adding a puts after the let() to see that the variable is correct allows a spec to pass, but without the puts the spec fails -- you have found this subtlety.

I have also found that let() doesn't seem to cache in all circumstances! I wrote it up in my blog:

Maybe it is just me?

How to use SQL Select statement with IF EXISTS sub query?


Permission denied at hdfs

I solved this problem temporary by disabling the dfs permission.By adding below property code to conf/hdfs-site.xml


Assigning default value while creating migration file

I tried t.boolean :active, :default => 1 in migration file for creating entire table. After ran that migration when i checked in db it made as null. Even though i told default as "1". After that slightly i changed migration file like this then it worked for me for setting default value on create table migration file.

t.boolean :active, :null => false,:default =>1. Worked for me.

My Rails framework version is 4.0.0

How to add 30 minutes to a JavaScript Date object?

it is simple as it is;

let initial_date = new Date;
let added30Min = new Date(initial_date.getTime() + (30*60*1000));

Tomcat request timeout

This article talks about setting the timeouts on the server level.

What is causing the application to go into infinite loop? If you are opening connections to other resources, you might want to put timeouts on those connections and sending appropriate response when those time out occurs.

Ruby: What is the easiest way to remove the first element from an array?

This is pretty neat:

head, *tail = [1, 2, 3, 4, 5]
#==> head = 1, tail = [2, 3, 4, 5]

As written in the comments, there's an advantage of not mutating the original list.

Add JavaScript object to JavaScript object

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

Can I access variables from another file?

As Fermin said, a variable in the global scope should be accessible to all scripts loaded after it is declared. You could also use a property of window or (in the global scope) this to get the same effect.

// first.js
var colorCodes = {

  back  : "#fff",
  front : "#888",
  side  : "#369"


... in another file ...

// second.js
alert (colorCodes.back); // alerts `#fff`

... in your html file ...

<script type="text/javascript" src="first.js"></script> 
<script type="text/javascript" src="second.js"></script> 

Ignore Typescript Errors "property does not exist on value of type"

A quick fix where nothing else works:

const a.b = 5 // error

const a['b'] = 5 // error if ts-lint rule no-string-literal is enabled

const B = 'b'
const a[B] = 5 // always works

Not good practice but provides a solution without needing to turn off no-string-literal

Select objects based on value of variable in object using jq

I had a similar related question: What if you wanted the original object format back (with key names, e.g. FOO, BAR)?

Jq provides to_entries and from_entries to convert between objects and key-value pair arrays. That along with map around the select

These functions convert between an object and an array of key-value pairs. If to_entries is passed an object, then for each k: v entry in the input, the output array includes {"key": k, "value": v}.

from_entries does the opposite conversion, and with_entries(foo) is a shorthand for to_entries | map(foo) | from_entries, useful for doing some operation to all keys and values of an object. from_entries accepts key, Key, name, Name, value and Value as keys.

jq15 < json 'to_entries | map(select(.value.location=="Stockholm")) | from_entries'

  "FOO": {
    "name": "Donald",
    "location": "Stockholm"
  "BAR": {
    "name": "Walt",
    "location": "Stockholm"

Using the with_entries shorthand, this becomes:

jq15 < json 'with_entries(select(.value.location=="Stockholm"))'
  "FOO": {
    "name": "Donald",
    "location": "Stockholm"
  "BAR": {
    "name": "Walt",
    "location": "Stockholm"

JBoss AS 7: How to clean up tmp?

Files related for deployment (and others temporary items) are created in standalone/tmp/vfs (Virtual File System). You may add a policy at startup for evicting temporary files :


Replacing last character in a String with java

    if (fieldName.endsWith(",")) {
        fieldName = fieldName.substring(0, fieldName.length()-1) + " ";

Error inflating when extending a class

fwiw, I received this error due to some custom initialization within the constructor attempting to access a null object.

Custom Drawable for ProgressBar/ProgressDialog

Custom progress with scale!

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="" >
    <item android:duration="150">
            android:scaleGravity="center" />
    <item android:duration="150">
            android:scaleGravity="center" />
    <item android:duration="150">
            android:scaleGravity="center" />
    <item android:duration="150">
            android:scaleGravity="center" />


How to escape % in String.Format?

To complement the previous stated solution, use:

str = str.replace("%", "%%");

LaTeX "\indent" creating paragraph indentation / tabbing package requirement?

LaTeX will usually not indent the first paragraph of a section. This is standard typographical practice. However, if you really want to override this default setting, use the package indentfirst available on CTAN.

Best way to do multi-row insert in Oracle?

Cursors may also be used, although it is inefficient. The following stackoverflow post discusses the usage of cursors :

INSERT and UPDATE a record using cursors in oracle

Reset all the items in a form

You can create the form again and dispose the old one.

public partial class Form1 : Form
    public Form1()

    private void btnReset_Click(object sender, EventArgs e)
        Form1 NewForm = new Form1();           

How to sign in kubernetes dashboard?


To get the token in a single oneliner:

kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | awk '/^deployment-controller-token-/{print $1}') | awk '$1=="token:"{print $2}'

This assumes that your ~/.kube/config is present and valid. And also that kubectl config get-contexts indicates that you are using the correct context (cluster and namespace) for the dashboard you are logging into.


I derived this answer from what I learned from @silverfox's answer. That is a very informative write up. Unfortunately it falls short of telling you how to actually put the information into practice. Maybe I've been doing DevOps too long, but I think in shell. It's much more difficult for me to learn or teach in English.

Here is that oneliner with line breaks and indents for readability:

kubectl -n kube-system describe secret $(
  kubectl -n kube-system get secret | \
  awk '/^deployment-controller-token-/{print $1}'
) | \
awk '$1=="token:"{print $2}'

There are 4 distinct commands and they get called in this order:

  • Line 2 - This is the first command from @silverfox's Token section.
  • Line 3 - Print only the first field of the line beginning with deployment-controller-token- (which is the pod name)
  • Line 1 - This is the second command from @silverfox's Token section.
  • Line 5 - Print only the second field of the line whose first field is "token:"

system("pause"); - Why is it wrong?

It's all a matter of style. It's useful for debugging but otherwise it shouldn't be used in the final version of the program. It really doesn't matter on the memory issue because I'm sure that those guys who invented the system("pause") were anticipating that it'd be used often. In another perspective, computers get throttled on their memory for everything else we use on the computer anyways and it doesn't pose a direct threat like dynamic memory allocation, so I'd recommend it for debugging code, but nothing else.

Re-order columns of table in Oracle

I followed the solution above from Jonas and it worked well until I needed to add a second column. What I found is that when making the columns visible again Oracle does not necessarily set them visible in the order listed in the statement.

To demonstrate this follow Jonas' example above. As he showed, once the steps are complete the table is in the order that you'd expect. Things then break down when you add another column as shown below:

Example (continued from Jonas'):

Add another column which is to be inserted before column C.


Use the technique demonstrated above to move the newly added B2 column before column C.




As shown above column C has moved to the end. It seems that the ALTER TABLE statement above processed the columns in the order D, E, C rather than in the order specified in the statement (perhaps in physical table order). To ensure that the column is placed where desired it is necessary to make the columns visible one by one in the desired order.




Setting HTTP headers

If you don't want to override your router (if you don't have your app configured in a way that supports this, or want to configure CORS on a route by route basis), add an OPTIONS handler to handle the pre flight request.

Ie, with Gorilla Mux your routes would look like:

accounts := router.Path("/accounts").Subrouter()

Note above that in addition to our POST handler, we're defining a specific OPTIONS method handler.

And then to actual handle the OPTIONS preflight method, you could define AccountsCreatePreFlight like so:

// Check the origin is valid.
origin := r.Header.Get("Origin")
validOrigin, err := validateOrigin(origin)
if err != nil {
    return err

// If it is, allow CORS.
if validOrigin {
    w.Header().Set("Access-Control-Allow-Origin", origin)
    w.Header().Set("Access-Control-Allow-Methods", "POST")
        "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")

What really made this all click for me (in addition to actually understanding how CORS works) is that the HTTP Method of a preflight request is different from the HTTP Method of the actual request. To initiate CORS, the browser sends a preflight request with HTTP Method OPTIONS, which you have to handle explicitly in your router, and then, if it receives the appropriate response "Access-Control-Allow-Origin": origin (or "*" for all) from your application, it initiates the actual request.

I also believe that you can only do "*" for standard types of requests (ie: GET), but for others you'll have to explicitly set the origin like I do above.

Smooth scrolling with just pure css

You need to use the target selector.

Here is a fiddle with another example:

How to change the scrollbar color using css

Your css will only work in IE browser. And the css suggessted by hayk.mart will olny work in webkit browsers. And by using different css hacks you can't style your browsers scroll bars with a same result.

So, it is better to use a jQuery/Javascript plugin to achieve a cross browser solution with a same result.


By Using jScrollPane a jQuery plugin, you can achieve a cross browser solution

See This Demo

How do I get the width and height of a HTML5 canvas?

Well, all the answers before aren't entirely correct. 2 of major browsers don't support those 2 properties (IE is one of them) or use them differently.

Better solution (supported by most browsers, but I didn't check Safari):

var canvas = document.getElementById('mycanvas');
var width = canvas.scrollWidth;
var height = canvas.scrollHeight;

At least I get correct values with scrollWidth and -Height and MUST set canvas.width and height when it is resized.

How to dynamically add and remove form fields in Angular 2

This is a few months late but I thought I'd provide my solution based on this here tutorial. The gist of it is that it's a lot easier to manage once you change the way you approach forms.

First, use ReactiveFormsModule instead of or in addition to the normal FormsModule. With reactive forms you create your forms in your components/services and then plug them into your page instead of your page generating the form itself. It's a bit more code but it's a lot more testable, a lot more flexible, and as far as I can tell the best way to make a lot of non-trivial forms.

The end result will look a little like this, conceptually:

  • You have one base FormGroup with whatever FormControl instances you need for the entirety of the form. For example, as in the tutorial I linked to, lets say you want a form where a user can input their name once and then any number of addresses. All of the one-time field inputs would be in this base form group.

  • Inside that FormGroup instance there will be one or more FormArray instances. A FormArray is basically a way to group multiple controls together and iterate over them. You can also put multiple FormGroup instances in your array and use those as essentially "mini-forms" nested within your larger form.

  • By nesting multiple FormGroup and/or FormControl instances within a dynamic FormArray, you can control validity and manage the form as one, big, reactive piece made up of several dynamic parts. For example, if you want to check if every single input is valid before allowing the user to submit, the validity of one sub-form will "bubble up" to the top-level form and the entire form becomes invalid, making it easy to manage dynamic inputs.

  • As a FormArray is, essentially, a wrapper around an array interface but for form pieces, you can push, pop, insert, and remove controls at any time without recreating the form or doing complex interactions.

In case the tutorial I linked to goes down, here some sample code you can implement yourself (my examples use TypeScript) that illustrate the basic ideas:

Base Component code:

import { Component, Input, OnInit } from '@angular/core';
import { FormArray, FormBuilder, FormGroup, Validators } from '@angular/forms';

  selector: 'my-form-component',
  templateUrl: './my-form.component.html'
export class MyFormComponent implements OnInit {
    @Input() inputArray: ArrayType[];
    myForm: FormGroup;

    constructor(private fb: FormBuilder) {}
    ngOnInit(): void {
        let newForm ={
            appearsOnce: ['InitialValue', [Validators.required, Validators.maxLength(25)]],
            formArray: this.fb.array([])

        const arrayControl = <FormArray>newForm.controls['formArray'];
        this.inputArray.forEach(item => {
            let newGroup ={
                itemPropertyOne: ['InitialValue', [Validators.required]],
                itemPropertyTwo: ['InitialValue', [Validators.minLength(5), Validators.maxLength(20)]]

        this.myForm = newForm;
    addInput(): void {
        const arrayControl = <FormArray>this.myForm.controls['formArray'];
        let newGroup ={

            /* Fill this in identically to the one in ngOnInit */

    delInput(index: number): void {
        const arrayControl = <FormArray>this.myForm.controls['formArray'];
    onSubmit(): void {
        // Your form value is outputted as a JavaScript object.
        // Parse it as JSON or take the values necessary to use as you like

Sub-Component Code: (one for each new input field, to keep things clean)

import { Component, Input } from '@angular/core';
import { FormGroup } from '@angular/forms';

    selector: 'my-form-sub-component',
    templateUrl: './my-form-sub-component.html'
export class MyFormSubComponent {
    @Input() myForm: FormGroup; // This component is passed a FormGroup from the base component template

Base Component HTML

<form [formGroup]="myForm" (ngSubmit)="onSubmit()" novalidate>
    <label>Appears Once:</label>
    <input type="text" formControlName="appearsOnce" />

    <div formArrayName="formArray">
        <div *ngFor="let control of myForm.controls['formArray'].controls; let i = index">
            <button type="button" (click)="delInput(i)">Delete</button>
            <my-form-sub-component [myForm]="myForm.controls.formArray.controls[i]"></my-form-sub-component>
    <button type="button" (click)="addInput()">Add</button>
    <button type="submit" [disabled]="!myForm.valid">Save</button>

Sub-Component HTML

<div [formGroup]="form">
    <label>Property One: </label>
    <input type="text" formControlName="propertyOne"/>

    <label >Property Two: </label>
    <input type="number" formControlName="propertyTwo"/>

In the above code I basically have a component that represents the base of the form and then each sub-component manages its own FormGroup instance within the FormArray situated inside the base FormGroup. The base template passes along the sub-group to the sub-component and then you can handle validation for the entire form dynamically.

Also, this makes it trivial to re-order component by strategically inserting and removing them from the form. It works with (seemingly) any number of inputs as they don't conflict with names (a big downside of template-driven forms as far as I'm aware) and you still retain pretty much automatic validation. The only "downside" of this approach is, besides writing a little more code, you do have to relearn how forms work. However, this will open up possibilities for much larger and more dynamic forms as you go on.

If you have any questions or want to point out some errors, go ahead. I just typed up the above code based on something I did myself this past week with the names changed and other misc. properties left out, but it should be straightforward. The only major difference between the above code and my own is that I moved all of the form-building to a separate service that's called from the component so it's a bit less messy.

Count the number of occurrences of each letter in string

One simple possibility would be to make an array of 26 ints, each is a count for a letter a-z:

int alphacount[26] = {0}; //[0] = 'a', [1] = 'b', etc

Then loop through the string and increment the count for each letter:

for(int i = 0; i<strlen(mystring); i++)      //for the whole length of the string
        alphacount[tolower(mystring[i])-'a']++;  //make the letter lower case (if it's not)
                                                 //then use it as an offset into the array
                                                 //and increment

It's a simple idea that works for A-Z, a-z. If you want to separate by capitals you just need to make the count 52 instead and subtract the correct ASCII offset

Formatting MM/DD/YYYY dates in textbox in VBA

While I agree with what's mentioned in the answers below, suggesting that this is a very bad design for a Userform unless copious amounts of error checks are included...

to accomplish what you need to do, with minimal changes to your code, there are two approaches.

  1. Use KeyUp() event instead of Change event for the textbox. Here is an example:

    Private Sub TextBox2_KeyUp(ByVal KeyCode As MSForms.ReturnInteger, ByVal Shift As Integer)
        Dim TextStr As String
        TextStr = TextBox2.Text
        If KeyCode <> 8 Then ' i.e. not a backspace
            If (Len(TextStr) = 2 Or Len(TextStr) = 5) Then
                TextStr = TextStr & "/"
            End If
        End If
        TextBox2.Text = TextStr
    End Sub
  2. Alternately, if you need to use the Change() event, use the following code. This alters the behavior so the user keeps entering the numbers, as


while the result as he's typing appears as


But the '/' character appears only once the first character of the DD i.e. 0 of 07 is entered. Not ideal, but will still handle backspaces.

    Private Sub TextBox1_Change()
        Dim TextStr As String

        TextStr = TextBox1.Text

        If (Len(TextStr) = 3 And Mid(TextStr, 3, 1) <> "/") Then
            TextStr = Left(TextStr, 2) & "/" & Right(TextStr, 1)
        ElseIf (Len(TextStr) = 6 And Mid(TextStr, 6, 1) <> "/") Then
            TextStr = Left(TextStr, 5) & "/" & Right(TextStr, 1)
        End If

        TextBox1.Text = TextStr
    End Sub

UITextField border color

If you use a TextField with rounded corners use this code:

    self.TextField.layer.borderColor=[[UIColor redColor]CGColor];
    self.TextField.layer.borderWidth= 1.0f;

To remove the border:

self.TextField.layer.borderColor=[[UIColor clearColor]CGColor];

.NET Console Application Exit Event

As a good example may be worth it to navigate to this project and see how to handle exiting processes grammatically or in this snippet from VM found in here

                ConsoleOutputStream = new ObservableCollection<string>();

                var startInfo = new ProcessStartInfo(FilePath)
                    WorkingDirectory = RootFolderPath,
                    Arguments = StartingArguments,
                    RedirectStandardOutput = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                ConsoleProcess = new Process {StartInfo = startInfo};

                ConsoleProcess.EnableRaisingEvents = true;

                ConsoleProcess.OutputDataReceived += (sender, args) =>
                    App.Current.Dispatcher.Invoke((System.Action) delegate
                        ConsoleOutputStream.Insert(0, args.Data);
                ConsoleProcess.Exited += (sender, args) =>
                    InProgress = false;


    private void RegisterProcessWatcher()
        startWatch = new ManagementEventWatcher(
            new WqlEventQuery($"SELECT * FROM Win32_ProcessStartTrace where ProcessName = '{FileName}'"));
        startWatch.EventArrived += new EventArrivedEventHandler(startProcessWatch_EventArrived);

        stopWatch = new ManagementEventWatcher(
            new WqlEventQuery($"SELECT * FROM Win32_ProcessStopTrace where ProcessName = '{FileName}'"));
        stopWatch.EventArrived += new EventArrivedEventHandler(stopProcessWatch_EventArrived);

    private void stopProcessWatch_EventArrived(object sender, EventArrivedEventArgs e)
        InProgress = false;

    private void startProcessWatch_EventArrived(object sender, EventArrivedEventArgs e)
        InProgress = true;

javascript object max size limit

There is no such limit on the string length. To be certain, I just tested to create a string containing 60 megabyte.

The problem is likely that you are sending the data in a GET request, so it's sent in the URL. Different browsers have different limits for the URL, where IE has the lowest limist of about 2 kB. To be safe, you should never send more data than about a kilobyte in a GET request.

To send that much data, you have to send it in a POST request instead. The browser has no hard limit on the size of a post, but the server has a limit on how large a request can be. IIS for example has a default limit of 4 MB, but it's possible to adjust the limit if you would ever need to send more data than that.

Also, you shouldn't use += to concatenate long strings. For each iteration there is more and more data to move, so it gets slower and slower the more items you have. Put the strings in an array and concatenate all the items at once:

var items = $.map(keys, function(item, i) {
  var value = $("#value" + (i+1)).val().replace(/"/g, "\\\"");
    '{"Key":' + '"' + Encoder.htmlEncode($(this).html()) + '"' + ",'+
    '" + '"Value"' + ':' + '"' + Encoder.htmlEncode(value) + '"}';
var jsonObj =
  '{"code":"' + code + '",'+
  '"defaultfile":"' + defaultfile + '",'+
  '"filename":"' + currentFile + '",'+
  '"lstResDef":[' + items.join(',') + ']}';

Regular Expression to match every new line character (\n) inside a <content> tag

Actually... you can't use a simple regex here, at least not one. You probably need to worry about comments! Someone may write:

<!-- <content> blah </content> -->

You can take two approaches here:

  1. Strip all comments out first. Then use the regex approach.
  2. Do not use regular expressions and use a context sensitive parsing approach that can keep track of whether or not you are nested in a comment.

Be careful.

I am also not so sure you can match all new lines at once. @Quartz suggested this one:


This will match any content tags that have a newline character RIGHT BEFORE the closing tag... but I'm not sure what you mean by matching all newlines. Do you want to be able to access all the matched newline characters? If so, your best bet is to grab all content tags, and then search for all the newline chars that are nested in between. Something more like this:


BUT THERE IS ONE CAVEAT: regexes are greedy, so this regex will match the first opening tag to the last closing one. Instead, you HAVE to suppress the regex so it is not greedy. In languages like python, you can do this with the "?" regex symbol.

I hope with this you can see some of the pitfalls and figure out how you want to proceed. You are probably better off using an XML parsing library, then iterating over all the content tags.

I know I may not be offering the best solution, but at least I hope you will see the difficulty in this and why other answers may not be right...


Let me summarize a bit more and add some more detail to my response. I am going to use python's regex syntax because it is what I am more used to (forgive me ahead of time... you may need to escape some characters... comment on my post and I will correct it):

To strip out comments, use this regex: Notice the "?" suppresses the .* to make it non-greedy.

Similarly, to search for content tags, use: .*?

Also, You may be able to try this out, and access each newline character with the match objects groups():


I know my escaping is off, but it captures the idea. This last example probably won't work, but I think it's your best bet at expressing what you want. My suggestion remains: either grab all the content tags and do it yourself, or use a parsing library.


So here is python code that ought to work. I am still unsure what you mean by "find" all newlines. Do you want the entire lines? Or just to count how many newlines. To get the actual lines, try:


import re

def FindContentNewlines(xml_text):
    # May want to compile these regexes elsewhere, but I do it here for brevity
    comments = re.compile(r"<!--.*?-->", re.DOTALL)
    content = re.compile(r"<content>(.*?)</content>", re.DOTALL)
    newlines = re.compile(r"^(.*?)$", re.MULTILINE|re.DOTALL)

    # strip comments: this actually may not be reliable for "nested comments"
    # How does xml handle <!--  <!-- --> -->. I am not sure. But that COULD
    # be trouble.
    xml_text = re.sub(comments, "", xml_text)

    result = []
    all_contents = re.findall(content, xml_text)
    for c in all_contents:
        result.extend(re.findall(newlines, c))

    return result

if __name__ == "__main__":
    example = """

<!-- This stuff
ought to be omitted

This stuff is good

This is not found
    print FindContentNewlines(example)

This program prints the result:

 ['', '<p>', '  haha!', '</p>', '']

The first and last empty strings come from the newline chars immediately preceeding the first <p> and the one coming right after the </p>. All in all this (for the most part) does the trick. Experiment with this code and refine it for your needs. Print out stuff in the middle so you can see what the regexes are matching and not matching.

Hope this helps :-).

PS - I didn't have much luck trying out my regex from my first update to capture all the newlines... let me know if you do.

Python object deleting itself

In this specific context, your example doesn't make a lot of sense.

When a Being picks up an Item, the item retains an individual existence. It doesn't disappear because it's been picked up. It still exists, but it's (a) in the same location as the Being, and (b) no longer eligible to be picked up. While it's had a state change, it still exists.

There is a two-way association between Being and Item. The Being has the Item in a collection. The Item is associated with a Being.

When an Item is picked up by a Being, two things have to happen.

  • The Being how adds the Item in some set of items. Your bag attribute, for example, could be such a set. [A list is a poor choice -- does order matter in the bag?]

  • The Item's location changes from where it used to be to the Being's location. There are probably two classes os Items - those with an independent sense of location (because they move around by themselves) and items that have to delegate location to the Being or Place where they're sitting.

Under no circumstances does any Python object ever need to get deleted. If an item is "destroyed", then it's not in a Being's bag. It's not in a location.


Is all that's required to let the cat out of the bag. Since the cat is not used anywhere else, it will both exist as "used" memory and not exist because nothing in your program can access it. It will quietly vanish from memory when some quantum event occurs and memory references are garbage collected.

On the other hand,

here.add( cat )

Will put the cat in the current location. The cat continues to exist, and will not be put out with the garbage.

How to check if an object is a certain type

In VB.NET, you need to use the GetType method to retrieve the type of an instance of an object, and the GetType() operator to retrieve the type of another known type.

Once you have the two types, you can simply compare them using the Is operator.

So your code should actually be written like this:

Sub FillCategories(ByVal Obj As Object)
    Dim cmd As New SqlCommand("sp_Resources_Categories", Conn)
    cmd.CommandType = CommandType.StoredProcedure
    Obj.DataSource = cmd.ExecuteReader
    If Obj.GetType() Is GetType(System.Web.UI.WebControls.DropDownList) Then

    End If
End Sub

You can also use the TypeOf operator instead of the GetType method. Note that this tests if your object is compatible with the given type, not that it is the same type. That would look like this:

If TypeOf Obj Is System.Web.UI.WebControls.DropDownList Then

End If

Totally trivial, irrelevant nitpick: Traditionally, the names of parameters are camelCased (which means they always start with a lower-case letter) when writing .NET code (either VB.NET or C#). This makes them easy to distinguish at a glance from classes, types, methods, etc.

Installed Ruby 1.9.3 with RVM but command line doesn't show ruby -v

I ran into a similar issue today - my ruby version didn't match my rvm installs.

> ruby -v
ruby 2.0.0p481

> rvm list
rvm rubies
   ruby-2.1.2 [ x86_64 ]
=* ruby-2.2.1 [ x86_64 ]
   ruby-2.2.3 [ x86_64 ]

Also, rvm current failed.

> rvm current
Warning! PATH is not properly set up, '/Users/randallreed/.rvm/gems/ruby-2.2.1/bin' is not at first place...

The error message recommended this useful command, which resolved the issue for me:

> rvm get stable --auto-dotfiles

MySQL "between" clause not inclusive?

select * from person where DATE(dob) between '2011-01-01' and '2011-01-31'

Surprisingly such conversions are solutions to many problems in MySQL.

What are the nuances of scope prototypal / prototypical inheritance in AngularJS?

I in no way want to compete with Mark's answer, but just wanted to highlight the piece that finally made everything click as someone new to Javascript inheritance and its prototype chain.

Only property reads search the prototype chain, not writes. So when you set

myObject.prop = '123';

It doesn't look up the chain, but when you set

myObject.myThing.prop = '123';

there's a subtle read going on within that write operation that tries to look up myThing before writing to its prop. So that's why writing to from the child gets at the parent's objects.

Where is the Global.asax.cs file?

That's because you created a Web Site instead of a Web Application. The cs/vb files can only be seen in a Web Application, but in a website you can't have a separate cs/vb file.

Edit: In the website you can add a cs file behavior like..

<%@ Application CodeFile="Global.asax.cs" Inherits="ApplicationName.MyApplication" Language="C#" %>


namespace ApplicationName
    public partial class MyApplication : System.Web.HttpApplication
        protected void Application_Start()

How to store Query Result in variable using mysql

Surround that select with parentheses.

SET @v1 := (SELECT COUNT(*) FROM user_rating);

How to import load a .sql or .csv file into SQLite?

if you are using it in windows, be sure to add the path to the db in "" and also to use double slash \ in the path to make sure windows understands it.

Best way to parse RSS/Atom feeds with PHP

The HTML Tidy library is able to fix some malformed XML files. Running your feeds through that before passing them on to the parser may help.

Angular2 @Input to a property with get/set

Updated accepted answer to angular 7.0.1 on stackblitz here:

directives are no more in Component decorator options. So I have provided sub directive to app module.

thank you @thierry-templier!

jquery input select all on focus

You can use simple code:


How do I pass parameters into a PHP script through a webpage?

Presumably you're passing the arguments in on the command line as follows:

php /path/to/wwwpublic/path/to/script.php arg1 arg2

... and then accessing them in the script thusly:

// $argv[0] is '/path/to/wwwpublic/path/to/script.php'
$argument1 = $argv[1];
$argument2 = $argv[2];

What you need to be doing when passing arguments through HTTP (accessing the script over the web) is using the query string and access them through the $_GET superglobal:

Go to

... and access:

$argument1 = $_GET['argument1'];
$argument2 = $_GET['argument2'];

If you want the script to run regardless of where you call it from (command line or from the browser) you'll want something like the following:

EDIT: as pointed out by Cthulhu in the comments, the most direct way to test which environment you're executing in is to use the PHP_SAPI constant. I've updated the code accordingly:

if (PHP_SAPI === 'cli') {
    $argument1 = $argv[1];
    $argument2 = $argv[2];
else {
    $argument1 = $_GET['argument1'];
    $argument2 = $_GET['argument2'];

Select distinct values from a list using LINQ in C#

You can try with this code

var result =  (from  item in List
              select new 
                 EmpLoc = item.empLoc,
                 EmpPL= item.empPL,
                 EmpShift= item.empShift

KeyListener, keyPressed versus keyTyped

You should use keyPressed if you want an immediate effect, and keyReleased if you want the effect after you release the key. You cannot use keyTyped because F5 is not a character. keyTyped is activated only when an character is pressed.

How to plot a function curve in R

Lattice solution with additional settings which I needed:

distribution<-function(x) {2^(-x*2)}
xyplot(distribution(X)~X,type="l", col = rgb(red = 255, green = 90, blue = 0, maxColorValue = 255), cex.lab = 3.5, cex.axis = 3.5, lwd=2 )
  1. If you need your range of values for x plotted in increments different from 1, e.g. 0.00001 you can use:


  1. You can change the colour of your line by defining a rgb value:

col = rgb(red = 255, green = 90, blue = 0, maxColorValue = 255)

  1. You can change the width of the plotted line by setting:

lwd = 2

  1. You can change the size of the labels by scaling them:

cex.lab = 3.5, cex.axis = 3.5

Example plot

Does java have a int.tryparse that doesn't throw an exception for bad data?

Apache Commons has an IntegerValidator class which appears to do what you want. Java provides no in-built method for doing this.

See here for the groupid/artifactid.

Change Name of Import in Java, or import two classes with the same name

Java doesn't allow you to do that. You'll need to refer to one of the classes by its fully qualified name and only import the other one.

Convert pandas dataframe to NumPy array

It seems like df.to_records() will work for you. The exact feature you're looking for was requested and to_records pointed to as an alternative.

I tried this out locally using your example, and that call yields something very similar to the output you were looking for:

rec.array([(1, nan, 0.2, nan), (2, nan, nan, 0.5), (3, nan, 0.2, 0.5),
       (4, 0.1, 0.2, nan), (5, 0.1, 0.2, 0.5), (6, 0.1, nan, 0.5),
       (7, 0.1, nan, nan)],
      dtype=[(u'ID', '<i8'), (u'A', '<f8'), (u'B', '<f8'), (u'C', '<f8')])

Note that this is a recarray rather than an array. You could move the result in to regular numpy array by calling its constructor as np.array(df.to_records()).

How to implement a custom AlertDialog View

The easiest way to do this is by using instead of where public AlertDialog.Builder setView (int layoutResId) can be used below API 21.

new AlertDialog.Builder(getActivity())
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                //Do something
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                //Do something

Error: macro names must be identifiers using #ifdef 0

#ifdef 0

#ifdef expect a macro rather than expression when using constant or expression

#if 0


#if !defined(PP_CHECK) || defined(PP_CHECK_OTHER)

if #ifdef is used the it reports this error

#ifdef !defined(PP_CHECK) || defined(PP_CHECK_OTHER)

Where #ifdef expect a macro rather than macro expresssion

insert echo into the specific html element like div which has an id or class

Well from your code its clear that $row['name'] is the location of the image on the file, try including the div tag like this

echo '<div>' .$row['name']. '</div>' ;

and do the same for others, let me know if it works because you said that one snippet of your code is giving the desired result so try this and if the div has some class specifier then do this

echo '<div class="whatever_it_is">' . $row['name'] . '</div'> ;

If Else If In a Sql Server Function

No one seems to have picked that if (yes=no)>na or (no=na)>yes or (na=yes)>no, you get NULL as the result. Don't believe this is what you are after.

Here's also a more condensed form of the function, which works even if any of yes, no or na_ans is NULL.

USE [***]
/****** Object:  UserDefinedFunction [dbo].[fnActionSq]    Script Date: 02/17/2011 10:21:47 ******/
ALTER FUNCTION [dbo].[fnTally] (@SchoolId nvarchar(50))
RETURNS nvarchar(3)
return (select (
       select top 1 Result from
       (select 'Yes' Result, yes_ans union all
        select 'No', no_ans union all
        select 'N/A', na_ans) [ ]
        order by yes_ans desc, Result desc)
       from dbo.qrc_maintally
       where school_id = @SchoolId)

How to run JUnit tests with Gradle?

If you set up your project with the default gradle package structure, i.e.:


then you won't need to modify sourceSets to run your tests. Gradle will figure out that your test classes and resources are in src/test. You can then run as Oliver says above. One thing to note: Be careful when setting property files and running your test classes with both gradle and you IDE. I use Eclipse, and when running JUnit from it, Eclipse chooses one classpath (the bin directory) whereas gradle chooses another (the build directory). This can lead to confusion if you edit a resource file, and don't see your change reflected at test runtime.


I was also facing the same issue where I was receiving the Transaction_Date as YYYYMMDD in bigint format. So I converted it into Datetime format using below query and saved it in new column with datetime format. I hope this will help you as well.

convert( Datetime, STUFF(STUFF(Transaction_Date, 5, 0, '-'), 8, 0, '-'), 120) As [Transaction_Date_New]
FROM mydb

Run "mvn clean install" in Eclipse

If you want to open command prompt inside your eclipse, this can be a useful approach to link cmd with eclipse.

You can follow this link to get the steps in detail with screenshots. How to use cmd prompt inside Eclipse ?

I'm quoting the steps here:

Step 1: Setup a new External Configuration Tool

In the Eclipse tool go to Run -> External Tools -> External Tools Configurations option.

Step 2: Click New Launch Configuration option in Create, manage and run configuration screen

Step 3: New Configuration screen for configuring the command prompt

Step 4: Provide configuration details of the Command Prompt in the Main tab

Name: Give any name to your configuration (Here it is Command_Prompt)
Location: Location of the CMD.exe in your Windows
Working Directory: Any directory where you want to point the Command prompt

Step 5: Tick the check box Allocate console This will ensure the eclipse console is being used as the command prompt for any input or output.

Step 6: Click Run and you are there!! You will land up in the C: directory as a working directory

How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

Have you seen this one? From

public DataTable Import(String path)
    Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook workBook = app.Workbooks.Open(path, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);

    Microsoft.Office.Interop.Excel.Worksheet workSheet = (Microsoft.Office.Interop.Excel.Worksheet)workBook.ActiveSheet;

    int index = 0;
    object rowIndex = 2;

    DataTable dt = new DataTable();

    DataRow row;

    while (((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2 != null)

        row = dt.NewRow();
        row[0] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2);
        row[1] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 2]).Value2);
        row[2] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 3]).Value2);
        row[3] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 4]).Value2);
        row[4] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 5]).Value2);

        rowIndex = 2 + index;
    return dt;

Access restriction: Is not accessible due to restriction on required library ..\jre\lib\rt.jar

In Eclipse:
Project -> properties -> java Build Path -> libraries

Remove existing JRE System Library, then Add Library -> JRE System library -> next -> ok

Error will be removed.

How do I redirect output to a variable in shell?

read hash < <(genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5)

This technique uses Bash's "process substitution" not to be confused with "command substitution".

Here are a few good references:

How to get a list of programs running with nohup

When I started with $ nohup storm dev-zookeper ,

METHOD1 : using jobs,

prayagupd@prayagupd:/home/vmfest# jobs -l
[1]+ 11129 Running                 nohup ~/bin/storm/bin/storm dev-zookeeper &

METHOD2 : using ps command.

$ ps xw
1031 tty1     Ss+    0:00 /sbin/getty -8 38400 tty1
10582 ?        S      0:01 [kworker/0:0]
10826 ?        Sl     0:18 java -server -Dstorm.options= -Dstorm.home=/root/bin/storm -Djava.library.path=/usr/local/lib:/opt/local/lib:/usr/lib -Dsto
10853 ?        Ss     0:00 sshd: vmfest [priv] 

TTY column with ? => nohup running programs.


  • TTY column = the terminal associated with the process
  • STAT column = state of a process
    • S = interruptible sleep (waiting for an event to complete)
    • l = is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)


$ man ps # then search /PROCESS STATE CODES


If you don't care about the data, you can drop database first and then recreate it:


How can I make a program wait for a variable change in javascript?

JavaScript interpreters are single threaded, so a variable can never change, when the code is waiting in some other code that does not change the variable.

In my opinion it would be the best solution to wrap the variable in some kind of object that has a getter and setter function. You can then register a callback function in the object that is called when the setter function of the object is called. You can then use the getter function in the callback to retrieve the current value:

function Wrapper(callback) {
    var value;
    this.set = function(v) {
        value = v;
    this.get = function() {
        return value;

This could be easily used like this:

<script type="text/javascript" src="wrapper.js"></script>
<script type="text/javascript">
function callback(wrapper) {
    alert("Value is now: " + wrapper.get());

wrapper = new Wrapper(callback);
    <input type="text" onchange="wrapper.set(this.value)"/>

Select multiple rows with the same value(s)

This may work for you:

select t1.*
from table t1
join (select t2.Chromosome, t2.Locus
    from table2
    group by t2.Chromosome, t2.Locus
    having count(*) > 1) u on u.Chromosome = t1.Chromosome and u.Locus = t1.Locus

Table-level backup

I don't know, whether it will match the problem described here. I had to take a table's incremental backup! (Only new inserted data should be copied). I used to design a DTS package where.

  1. I fetch new records (on the basis of a 'status' column) and transferred the data to destination. (Through 'Transform Data Task')

  2. Then I just updated the 'status' column. (Through 'Execute SQL Task')

I had to fix the 'workflow' properly.

How to check if field is null or empty in MySQL?

Try using nullif:

SELECT ifnull(nullif(field1,''),'empty') AS field1
  FROM tablename;

What is the simplest way to swap each pair of adjoining chars in a string with Python?

>>> import ctypes
>>> s = 'abcdef'
>>> mutable = ctypes.create_string_buffer(s)
>>> for i in range(0,len(s),2):
>>>     mutable[i], mutable[i+1] = mutable[i+1], mutable[i]
>>> s = mutable.value
>>> print s

Spaces in URLs?

A URL must not contain a literal space. It must either be encoded using the percent-encoding or a different encoding that uses URL-safe characters (like application/x-www-form-urlencoded that uses + instead of %20 for spaces).

But whether the statement is right or wrong depends on the interpretation: Syntactically, a URI must not contain a literal space and it must be encoded; semantically, a %20 is not a space (obviously) but it represents a space.

how to convert 2d list to 2d numpy array?

Just pass the list to np.array:

a = np.array(a)

You can also take this opportunity to set the dtype if the default is not what you desire.

a = np.array(a, dtype=...)

Android: Getting "Manifest merger failed" error after updating to a new version of gradle

  • Update your support library to last version

  • Open Manifest File , and add it into Manifest File

  • <uses-sdk tools:overrideLibrary=""/>

  • And add for recyclerview in >> build.gradle Module app :

  • compile ''

  • And click : Sync Now

Linux command line howto accept pairing for bluetooth device without pin

Try setting security to none in /etc/bluetooth/hcid.conf

This will probably only work for HCI devices (mouse, keyboard, spaceball, etc.). If you have a different kind of device, there's probably a different but similar setting to change.

How to install Google Play Services in a Genymotion VM (with no drag and drop support)?

I tried almost all of the above options, but was not able to install google play services, however just found from the faq section of genymotion that the only way to access google play services is to use the packages provided by OpenGapps.

I tried and this worked:

  1. Visit
  2. Select x86 as platform
  3. Choose the Android version corresponding to your virtual device
  4. Select nano as variant
  5. Download the zip file
  6. Drag & Drop the zip installer in new Genymotion virtual device (2.7.2 and above only)
  7. Follow the pop-up instructions

java.rmi.ConnectException: Connection refused to host:;

when you want to connect to remote server with RMI you must add a system property same as:

System.setProperty("java.rmi.server.hostname","Ip or DNS of the server");

or add environment variable.

For me I got Connection Refused and solve it by adding this line of code in server side:

 java -jar -Djava.rmi.server.hostname="ip or dns of the server" packageName.jar

Thank to other guy for guide me to solve it.

Convert cells(1,1) into "A1" and vice versa

The Address property of a cell can get this for you:

MsgBox Cells(1, 1).Address(RowAbsolute:=False, ColumnAbsolute:=False)

returns A1.

The other way around can be done with the Row and Column property of Range:

MsgBox Range("A1").Row & ", " & Range("A1").Column

returns 1,1.

What is the easiest way to initialize a std::vector with hardcoded elements?

For vector initialisation -

vector<int> v = {10,20,30}

can be done if you have C++11 compiler.

Else, you can have an array of the data and then use a for loop.

int array[] = {10,20,30}
for(unsigned int i=0; i<sizeof(array)/sizeof(array[0]); i++)

Apart from these, there are various other ways described above using some code. In my opinion, these ways are easy to remember and quick to write.

Postgresql tables exists, but getting "relation does not exist" when querying

I had the same problem that occurred after I restored data from a postgres dumped db.

My dump file had the command below from where things started going south.

    SELECT pg_catalog.set_config('search_path', '', false);


  1. Probably remove it or change that false to be true.
  2. Create a private schema that will be used to access all the tables.

The command above simply deactivates all the publicly accessible schemas.

Check more on the documentation here:

Angular 2 router.navigate

import { ActivatedRoute } from '@angular/router';_x000D_
export class ClassName {_x000D_
  private router = ActivatedRoute;_x000D_
    constructor(r: ActivatedRoute) {_x000D_
        this.router =r;_x000D_
onSuccess() {_x000D_
         {queryParams: {email: loginEmail, code: userCode}});_x000D_
Get this values:_x000D_
ngOnInit() {_x000D_
        .subscribe(params => {_x000D_
            let code = params['code'];_x000D_
            let userEmail = params['email'];_x000D_


socket.error:[errno 99] cannot assign requested address and namespace in python

Stripping things down to basics this is what you would want to test with:

import socket
server = socket.socket() 
server.bind(("", 6677)) 
client_socket, client_address = server.accept()
print(client_address, "has connected")
while 1==1:
    recvieved_data = client_socket.recv(1024)

This works assuming a few things:

  1. Your local IP address (on the server) is (This video shows you how)
  2. No other software is listening on port 6677

Also note the basic concept of IP addresses:

Try the following, open the start menu, in the "search" field type cmd and press enter. Once the black console opens up type ping and this should give you and IP address for google. This address is googles local IP and they bind to that and obviously you can not bind to an IP address owned by google.

With that in mind, you own your own set of IP addresses. First you have the local IP of the server, but then you have the local IP of your house. In the below picture is the local IP of the server which you can bind to. You still own but the problem is that it's owned by the Router and not your server. So even if you visit and that tells you that your IP is that is not the case because it can only see where you're coming from.. and you're accessing your internet from a router.

enter image description here

In order for your friends to access your server (which is bound to you need to forward port 6677 to and this is done in your router. Assuming you are behind one.

If you're in school there's other dilemmas and routers in the way most likely.

linux shell script: split string, put them in an array then loop through them

Here is an example code that you may use:

$ STR="String;1;2;3"
$ for EACH in `echo "$STR" | grep -o -e "[^;]*"`; do
    echo "Found: \"$EACH\"";

grep -o -e "[^;]*" will select anything that is not ';', therefore spliting the string by ';'.

Hope that help.

How to get values of selected items in CheckBoxList with foreach in ASP.NET C#?

If you have a databound checklistbox it does not work to get item(j).Selected, because the control does not have a selected attribute. If you clearSelections i.e. on Load, then apparently it now understands item(j).selected.

Partial Dependency (Databases)

Partial dependency implies is a situation where a non-prime attribute(An attribute that does not form part of the determinant(Primary key/Candidate key)) is functionally dependent to a portion/part of a primary key/Candidate key.

Another Repeated column in mapping for entity error

use this, is work for me:

@Column(name = "candidate_id", nullable=false)
private Long candidate_id;
@JoinColumn(name = "candidate_id", insertable=false, updatable=false)
private Candidate candidate;

How to create javascript delay function

You can create a delay using the following example


Replace 3000 with # of milliseconds

You can place the content of what you want executed inside the function.

How do I get the localhost name in PowerShell?

hostname also works just fine in Powershell

How to list active connections on PostgreSQL?

Following will give you active connections/ queries in postgres DB-

FROM pg_stat_activity
WHERE state = 'active';

You may use 'idle' instead of active to get already executed connections/queries.

How do I vertically center an H1 in a div?

You can achieve this with the display property:

html, body {
#section1 {
    width:100%; /*full width*/
    display:table; /*acts like a table*/
    vertical-align:middle; /*middle centred*/
    display:table-cell; /*acts like a table cell*/


ASP.NET 2.0 - How to use app_offline.htm

Possible Permission Issue

I know this post is fairly old, but I ran into a similar issue and my file was spelled correctly.

I originally created the app_offline.htm file in another location and then moved it to the root of my application. Because of my setup I then had a permissions issue.

The website acted as if it was not there. Creating the file within the root directory instead of moving it, fixed my problem. (Or you could just fix the permission in properties->security)

Hope it helps someone.

How can I restore the MySQL root user’s full privileges?

  1. "sudo cat /etc/mysql/debian.cnf" to use debian-sys-maint user
  2. login by this user throgh "mysql -u saved-username -p;", then enter the saved password.
  3. mysql> UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';
  5. mysql> exit
  6. reboot Thanks

NumPy array is not JSON serializable

use NumpyEncoder it will process json dump successfully.without throwing - NumPy array is not JSON serializable

import numpy as np
import json
from numpyencoder import NumpyEncoder
arr = array([   0,  239,  479,  717,  952, 1192, 1432, 1667], dtype=int64) 

Oracle SQL: Update a table with data from another table

Try this:

MERGE INTO table1 t1
-- For more complicated queries you can use WITH clause here
SELECT * FROM table2
ON( =
t1.desc = t2.desc;

Search and get a line in Python

With regular expressions

import re

    token qwerty

>>> items=re.findall("token.*$",s,re.MULTILINE)
>>> for x in items:
...     print x
token qwerty

How to join multiple collections with $lookup in mongodb

First add the collections and then apply lookup on these collections. Don't use $unwind as unwind will simply separate all the documents of each collections. So apply simple lookup and then use $project for projection. Here is mongoDB query:

        $lookup: {
           from: "userRole",
           localField: "userId",
           foreignField: "userId",
           as: "userRole"
        $lookup: {
            from: "userInfo",
            localField: "userId",
            foreignField: "userId",
            as: "userInfo"
    {$project: {
        } ])

Here is the output:

/* 1 */ {
    "userId" : "AD",
    "phone" : "0000000000",
    "userRole" : [ 
            "userId" : "AD",
            "role" : "admin"
    "userInfo" : [ 
            "userId" : "AD",
            "phone" : "0000000000"
    ] }


Cygwin Make bash command not found

You probably have not installed make. Restart the cygwin installer, search for make, select it and it should be installed. By default the cygwin installer does not install everything for what I remember.

Make HTML5 video poster be same size as video itself

You can resize image size after generating thumb

exec("ffmpeg -i $video_image_dir/out.png -vf scale=320:240 {$video_image_dir}/resize.png",$out2, $return2);

How to find tag with particular text with Beautiful Soup?

You could solve this with some simple gazpacho parsing:

from gazpacho import Soup

soup = Soup(html)
tds = soup.find("td", {"class": "pos"})

Which will output:

text I am looking for

Nginx - Customizing 404 page

The "error_page" parameter makes a redirect, converting the request method to "GET", it is not a custom response page.

The easiest solution is

         root /var/www/html;
         location ~ \.php {
            if (!-f $document_root/$fastcgi_script_name){
                return 404;
            include fastcgi_params.default;
            fastcgi_param  SCRIPT_FILENAME  $document_root/$fastcgi_script_name;

By the way, if you want Nginx to process 404 status returned by PHP scripts, you need to add

[fastcgi_intercept_errors][1] on;


     location ~ \.php {
            error_page  404   404.html;
            fastcgi_intercept_errors on;

Java 8 Lambda function that throws exception?

If you have lombok, you can annotate your method with @SneakyThrows

SneakyThrow does not silently swallow, wrap into RuntimeException, or otherwise modify any exceptions of the listed checked exception types. The JVM does not check for the consistency of the checked exception system; javac does, and this annotation lets you opt out of its mechanism.

UTF-8 all the way through

Unicode support in PHP is still a huge mess. While it's capable of converting an ISO8859 string (which it uses internally) to utf8, it lacks the capability to work with unicode strings natively, which means all the string processing functions will mangle and corrupt your strings. So you have to either use a separate library for proper utf8 support, or rewrite all the string handling functions yourself.

The easy part is just specifying the charset in HTTP headers and in the database and such, but none of that matters if your PHP code doesn't output valid UTF8. That's the hard part, and PHP gives you virtually no help there. (I think PHP6 is supposed to fix the worst of this, but that's still a while away)

"The following SDK components were not installed: sys-img-x86-addon-google_apis-google-22 and addon-google_apis-google-22"



-> Run Android Studio as Administrator (this is only required for first run or when any issues arise due to automatic updates on any run in future).

Though it shows API 23 is or any other updates are not installed (and wouldn't show any 'Retry' button), BUT still the download and installation of rest of the updates would proceed (you can see the download progress incrementing even after seeing the above errors). So, DO NOT ABORT the operation.

-> At the end of installation (after rest of successful updates are installed) it would this time display the "Retry" button to retry installation for API 23 or any other versions which had failed earlier. Then click the "Retry" button, it would work this time.

This would resolve your issue with successful installation.

-> Next time onward no need to run Android studio as Administrator, unless it does any automatic updates and shows similar issues.


-> Alternative approach is to install any updates (which ever failed in earlier attempt) from Android SDK Manager first and then later launch Android Studio (which would not need any check for updates and any additional installations).

To install any features or updates, run Android SDK manager as administrator (run as administrator is not mandatory for this but preferred to avoid any permissions related issues) and check the required options and proceed with the installation without any issues.


-> If still your issue is not resolved, then try the proxy solution as suggested by others or check your internet connectivity if it's working properly or not.

*Any of the above solutions should resolve your issues.

Connecting to SQL Server Express - What is my server name?

If sql server is installed on your machine, you should check

Programs -> Microsoft SQL Server 20XX -> Configuration Tools -> SQL Server Configuration Manager -> SQL Server Services You'll see "SQL Server (MSSQLSERVER)"

Programs -> Microsoft SQL Server 20XX -> Configuration Tools -> SQL Server Configuration Manager -> SQL Server Network Configuration -> Protocols for MSSQLSERVER -> TCP/IP Make sure it's using port number 1433

If you want to see if the port is open and listening try this from your command prompt... telnet 1433

And yes, SQL Express installs use localhost\SQLEXPRESS as the instance name by default.

JQuery confirm dialog

Try this one

  .html('<div><h6>Yes or No?</h6></div>')
      modal: true, title: 'message', zIndex: 10000, autoOpen: true,
      width: 'auto', resizable: false,
      buttons: {
          Yes: function () {
          No: function () {
      close: function (event, ui) {


How can I match multiple occurrences with a regex in JavaScript similar to PHP's preg_match_all()?

To avoid regex hell you could find your first match, chop off a chunk then attempt to find the next one on the substring. In C# this looks something like this, sorry I've not ported it over to JavaScript for you.

        long count = 0;
        var remainder = data;
        Match match = null;
            match = _rgx.Match(remainder);
            if (match.Success)
                remainder = remainder.Substring(match.Index + 1, remainder.Length - (match.Index+1));
        } while (match.Success);
        return count;

SqlDataAdapter vs SqlDataReader

A SqlDataAdapter is typically used to fill a DataSet or DataTable and so you will have access to the data after your connection has been closed (disconnected access).

The SqlDataReader is a fast forward-only and connected cursor which tends to be generally quicker than filling a DataSet/DataTable.

Furthermore, with a SqlDataReader, you deal with your data one record at a time, and don't hold any data in memory. Obviously with a DataTable or DataSet, you do have a memory allocation overhead.

If you don't need to keep your data in memory, so for rendering stuff only, go for the SqlDataReader. If you want to deal with your data in a disconnected fashion choose the DataAdapter to fill either a DataSet or DataTable.

Date only from TextBoxFor()

The DisplayFormat attribute did not work for me in either form upon initial load. I created an EditorTemplate instead:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<System.DateTime>" %>
<%@ Import Namespace="System.Web.Mvc.Html" %>
    Html.TextBox("", Model.ToShortDateString(), new { @class = "date-range" }) %>

Create a button with rounded border

Use StadiumBorder shape

                onPressed: () {},
                child: Text("Follow"),
                borderSide: BorderSide(color:,
                shape: StadiumBorder(),

Bootstrap col-md-offset-* not working

If you are ok with small tweak - we know that bootstrap works with a width of 12

<div class="row">
      <div class="col-md-1">
            Keep it blank it becomes left offset
      <div class="col-md-5">
      <div class="col-md-5">
      <div class="col-md-1">
            Keep it blank it becomes right offset

I am sure there is a better way to do this, but i was in a hurry so used this trick

Responsively change div size keeping aspect ratio

Bumming off Chris's idea, another option is to use pseudo elements so you don't need to use an absolutely positioned internal element.

.square {
    /* width within the parent.
       can be any percentage. */
    width: 100%;
.square:before {
    content: "";
    float: left;

    /* essentially the aspect ratio. 100% means the
       div will remain 100% as tall as it is wide, or
       square in other words.  */
    padding-bottom: 100%;
/* this is a clearfix. you can use whatever
   clearfix you usually use, add
   overflow:hidden to the parent element,
   or simply float the parent container. */
.square:after {
    content: "";
    display: table;
    clear: both;
<div class="square">
  <p>This div will maintain its aspect ratio.</p>

I've put together a demo here:


Now, bumming off of Isaac's idea, it's easier in modern browsers to simply use vw units to force aspect ratio (although I wouldn't also use vh as he does or the aspect ratio will change based on window height).

So, this simplifies things:

.square {
    /* width within the parent (could use vw instead of course) */
    width: 50%;
    /* set aspect ratio */
    height: 50vw;
<div class="square">
  <p>This div will maintain its aspect ratio.</p>

I've put together a modified demo here:

You could also set max-height, max-width, and/or min-height, min-width if you don't want it to grow ridiculously big or small, since it's based on the browser's width now and not the container and will grow/shrink indefinitely.

Note you can also scale the content inside the element if you set the font size to a vw measurement and all the innards to em measurements, and here's a demo for that:

How to write loop in a Makefile?

This answer, just as that of @Vroomfondel aims to circumvent the loop problem in an elegant way.

My take is to let make generate the loop itself as an imported makefile like this:

include > $@

The shell script can the be as advanced as you like but a minimal working example could be

for Target in `seq $NoTargest` ; do
    echo $
    echo $'\t'./ $Target
    LoopTargets="$LoopTargets $File"
echo;echo;echo LoopTargets:=$LoopTargets

which generates the file
    ./ 1
    ./ 2
    ./ 3
    ./ 4
    ./ 5

LoopTargets:= target_1.dat target_2.dat target_3.dat target_4.dat target_5.dat

And advantage there is that make can itself keep track of which files have been generated and which ones need to be (re)generated. As such, this also enables make to use the -j flag for parallelization.

How do I merge changes to a single file, rather than merging commits?

You can checkout the old version of the file to merge, saving it under a different name, then run whatever your merge tool is on the two files.


git show B:src/common/store.ts > /tmp/store.ts (where B is the branch name/commit/tag)

meld src/common/store.ts /tmp/store.ts

Open file with associated application

Just write

System.Diagnostics.Process.Start(@"file path");



And shell will run associated program reading it from the registry, like usual double click does.

How to build a DataTable from a DataGridView?

First convert you datagridview's data to List, then convert List to DataTable

        public static DataTable ToDataTable<T>( this List<T> list) where T : class {
        Type type = typeof(T);
        var ps = type.GetProperties ( );
        var cols = from p in ps
                   select new DataColumn ( p.Name , p.PropertyType );

        DataTable dt = new DataTable();

        list.ForEach ( (l) => {
            List<object> objs = new List<object>();
            objs.AddRange ( ps.Select ( p => p.GetValue ( l , null ) ) );
            dt.Rows.Add ( objs.ToArray ( ) );
        } );

        return dt;

How to download a file from a website in C#

Use WebClient.DownloadFile:

using (WebClient client = new WebClient())

Show/Hide Div on Scroll

Here is my answer when you want to animate it and start fading it out after couple of seconds. I used opacity because first of all i didn't want to fade it out completely, second, it does not go back and force after many scrolls.

$(window).scroll(function () {
    var elem = $('div');
    setTimeout(function() {

Switch with if, else if, else, and loops inside case

If you need the for statement to contain only the if, you need to remove its else, like this:

for(int i=0; i<something_in_the_array.length;i++)

    /*this "else" must go*/

    else if(whatever_value==3)

INSERT INTO from two different server database

You cannot directly copy a table into a destination server database from a different database if source db is not in your linked servers. But one way is possible that, generate scripts (schema with data) of the desired table into one table temporarily in the source server DB, then execute the script in the destination server DB to create a table with your data. Finally use INSERT INTO [DESTINATION_TABLE] select * from [TEMPORARY_SOURCE_TABLE]. After getting the data into your destination table drop the temporary one.

I found this solution when I faced the same situation. Hope this helps you too.

Android Left to Right slide animation

I was not able to find any solution for this type of animation using ViewPropertyAnimator.

Here's an example:




Animate - Right to left and exit view:

final childView = findViewById(;
View containerView = findViewById(;
  .setInterpolator(new AccelerateDecelerateInterpolator())
  .setListener(new AnimatorListenerAdapter() {
    public void onAnimationEnd(Animator animation) {

Animate - Right to left enter view:

final View childView = findViewById(;
View containerView = findViewById(;
    .setInterpolator(new AccelerateDecelerateInterpolator())
    .setListener(new AnimatorListenerAdapter() {
        public void onAnimationStart(Animator animation) {

Check if String / Record exists in DataTable

Something like this

 string find = "item_manuf_id = 'some value'";
 DataRow[] foundRows = table.Select(find);

switch case statement error: case expressions must be constant expression

In a regular Android project, constants in the resource R class are declared like this:

public static final int main=0x7f030004;

However, as of ADT 14, in a library project, they will be declared like this:

public static int main=0x7f030004;

In other words, the constants are not final in a library project. Therefore your code would no longer compile.

The solution for this is simple: Convert the switch statement into an if-else statement.

public void onClick(View src)
    int id = src.getId();
    if (id =={
    } else if (id =={
        Log.d(TAG, "onClick: stopping srvice");
        Playbutton.setVisibility(0); //visible
        Stopbutton.setVisibility(4); //invisible
        stopService(new Intent(RakistaRadio.this,myservice.class));
        Title.setText(" ");
        Artist.setText(" ");
    } else if (id =={

You can quickly convert a switch statement to an if-else statement using the following:

In Eclipse
Move your cursor to the switch keyword and press Ctrl + 1 then select

Convert 'switch' to 'if-else'.

In Android Studio
Move your cursor to the switch keyword and press Alt + Enter then select

Replace 'switch' with 'if'.

could not extract ResultSet in hibernate

For MySql take in mind that it's not a good idea to write camelcase. For example if the schema is like that:

    `teaching_hours` DECIMAL(5,2) DEFAULT NULL,
    `is_validated` BOOLEAN DEFAULT FALSE,

You must be very careful cause isActive column will translate to isactive. So in your Entity class is should be like this:

 @Column(name = "isactive", nullable = true)
 public boolean isActive() {
     return isActive;
 public void setActive(boolean active) {
     isActive = active;

That was my problem at least that got me your error

This has nothing to do with MySql which is case insensitive, but rather is a naming strategy that spring will use to translate your tables. For more refer to this post

Math constant PI value in C

Just define:

#define M_PI acos(-1.0)

It should give you exact PI number that math functions are working with. So if they change PI value they are working with in tangent or cosine or sine, then your program should be always up-to-dated ;)

Working with INTERVAL and CURDATE in MySQL



should work.

REST API Best practices: Where to put parameters?

As a programmer often on the client-end, I prefer the query argument. Also, for me, it separates the URL path from the parameters, adds to clarity, and offers more extensibility. It also allows me to have separate logic between the URL/URI building and the parameter builder.

I do like what manuel aldana said about the other option if there's some sort of tree involved. I can see user-specific parts being treed off like that.

How to configure ChromeDriver to initiate Chrome browser in Headless mode through Selenium?


is not a supported browser


Open Browser    ${event_url}    ${BROWSER}   options=add_argument("--no-sandbox"); add_argument("--ignore-certificate-errors"); add_argument("--disable-dev-shm-usage'")

don't forget to add spaces between ${BROWSER} options

Populating a ComboBox using C#

To make it read-only, the DropDownStyle property to DropDownStyle.DropDownList.

To populate the ComboBox, you will need to have a object like Language or so containing both for instance:

public class Language {
    public string Name { get; set; }
    public string Code { get; set; }

Then, you may bind a IList to your ComboBox.DataSource property like so:

IList<Language> languages = new List<Language>();
languages.Add(new Language("English", "en"));
languages.Add(new Language("French", "fr"));

ComboxBox.DataSource = languages;
ComboBox.DisplayMember = "Name";
ComboBox.ValueMember = "Code";

This will do exactly what you expect.

How to add Date Picker Bootstrap 3 on MVC 5 project using the Razor engine?

This answer uses the jQuery UI Datepicker, which is a separate include. There are other ways to do this without including jQuery UI.

First, you simply need to add the datepicker class to the textbox, in addition to form-control:

<div class="form-group input-group-sm">
    @Html.LabelFor(model => model.DropOffDate)
    @Html.TextBoxFor(model => model.DropOffDate, new { @class = "form-control datepicker", placeholder = "Enter Drop-off date here..." })
    @Html.ValidationMessageFor(model => model.DropOffDate)

Then, to be sure the javascript is triggered after the textbox is rendered, you have to put the datepicker call in the jQuery ready function:

<script type="text/javascript">
    $(function () { // will trigger when the document is ready
       $('.datepicker').datepicker(); //Initialise any date pickers

xcopy file, rename, suppress "Does xxx specify a file name..." message

Since you're not actually changing the filename, you can take out the filename from the destination and there will be no questions.

xcopy bin\development\whee.config.example TestConnectionExternal\bin\Debug\  /Y

This approach works well when the destination directory is guaranteed to exist, and when the source may equally be a file or directory.

cannot download, $GOPATH not set

You can use the "export" solution just like what other guys have suggested. I'd like to provide you with another solution for permanent convenience: you can use any path as GOPATH when running Go commands.

Firstly, you need to download a small tool named gost : . If you use ubuntu, you can download the linux version(

Then you need to run the commands below to unpack it :

$ cd /path/to/your/download/directory 
$ tar -xvf gost_linux_amd64.tar.gz

You would get an executable gost. You can move it to /usr/local/bin for convenient use:

$ sudo mv gost /usr/local/bin

Run the command below to add the path you want to use as GOPATH into the pathspace gost maintains. It is required to give the path a name which you would use later.

$ gost add foo /home/foobar/bar     # 'foo' is the name and '/home/foobar/bar' is the path

Run any Go command you want in the format:

gost goCommand [-p {pathName}] -- [goFlags...] [goArgs...]

For example, you want to run go get with /home/foobar/bar as the GOPATH, just do it as below:

$ gost get -p foo --  # 'foo' is the name you give to the path above.

It would help you to set the GOPATH and run the command. But remember that you have added the path into gost's pathspace. If you are under any level of subdirectories of /home/foobar/bar, you can even just run the command below which would do the same thing for short :

$ gost get --

gost is a Simple Tool of Go which can help you to manage GOPATHs and run Go commands. For more details about how to use it to run other Go commands, you can just run gost help goCmdName. For example you want to know more about install, just type words below in:

$ gost help install

You can also find more details in the README of the project:

ImportError: No module named matplotlib.pyplot

You can install the matplotlib package in python 3 by doing this

python3 -m pip install matplotlib --user

It's working for me.

Iterate a certain number of times without storing the iteration number anywhere

Sorry, but in order to iterate over anything in any language, Python and English included, an index must be stored. Be it in a variable or not. Finding a way to obscure the fact that python is internally tracking the for loop won't change the fact that it is. I'd recommend just leaving it as is.

Pagination response payload from a RESTful API

As someone who has written several libraries for consuming REST services, let me give you the client perspective on why I think wrapping the result in metadata is the way to go:

  • Without the total count, how can the client know that it has not yet received everything there is and should continue paging through the result set? In a UI that didn't perform look ahead to the next page, in the worst case this might be represented as a Next/More link that didn't actually fetch any more data.
  • Including metadata in the response allows the client to track less state. Now I don't have to match up my REST request with the response, as the response contains the metadata necessary to reconstruct the request state (in this case the cursor into the dataset).
  • If the state is part of the response, I can perform multiple requests into the same dataset simultaneously, and I can handle the requests in any order they happen to arrive in which is not necessarily the order I made the requests in.

And a suggestion: Like the Twitter API, you should replace the page_number with a straight index/cursor. The reason is, the API allows the client to set the page size per-request. Is the returned page_number the number of pages the client has requested so far, or the number of the page given the last used page_size (almost certainly the later, but why not avoid such ambiguity altogether)?

Modifying list while iterating

Never alter the container you're looping on, because iterators on that container are not going to be informed of your alterations and, as you've noticed, that's quite likely to produce a very different loop and/or an incorrect one. In normal cases, looping on a copy of the container helps, but in your case it's clear that you don't want that, as the container will be empty after 50 legs of the loop and if you then try popping again you'll get an exception.

What's anything BUT clear is, what behavior are you trying to achieve, if any?! Maybe you can express your desires with a while...?

i = 0
while i < len(some_list):
    print i,                         
    print some_list.pop(0),                  
    print some_list.pop(0)

How to create permanent PowerShell Aliases

UPDATED - January 2021

It's possible to store in a profile.ps1 file any PowerShell code to be executed each time PowerShell starts. There are at least 6 different paths where to store the code depending on which user has to execute it. We will consider only 2 of them: the "all users" and the "only your user" paths (follow the previous link for further options).

To answer your question, you only have to create a profile.ps1 file containing the code you want to be executed, that is:

New-Alias Goto Set-Location

and save it in the proper path:

  • "$Home\Documents" (usually C:\Users<yourname>\Documents): Only your user will execute the code. This is the reccomanded place.
    You can quickly find your profile location by running echo $profile in PowerShell
  • $PsHome (C:\Windows\System32\WindowsPowerShell\v1.0): Every user will execute the code.

IMPORTANT: Remember you need to restart your PowerShell instances to apply the changes.


  • If both paths contain a profile.ps1 file, the all-users one is executed first, then the user-specific one. This means the user-specific commands will overwrite variables in case of duplicates or conflicts.

  • Always put the code in the user-specific profile if there is no need to extend its execution to every user. This is safer because you don't pollute other users' space (usually, you don't want to do that).
    Another advantage is that you don't need administrator rights to add the file to your user-space (you do for anything in C:\Windows\System32).

  • If you really need to execute the profile code for every user, mind that the $PsHome path is different for 32bit and 64bit instances of PowerShell. You should consider both environments if you want to always execute the profile code.
    The paths are:

    • C:\Windows\System32\WindowsPowerShell\v1.0 for the 64bit environment
    • C:\Windows\SysWow64\WindowsPowerShell\v1.0 for the 32bit one (Yeah I know, the folder naming is counterintuitive, but it's correct).

How do you stash an untracked file?

How do you stash an untracked file?

git stash --include-untracked

How can I get the UUID of my Android phone in an application?

As Dave Webb mentions, the Android Developer Blog has an article that covers this. Their preferred solution is to track app installs rather than devices, and that will work well for most use cases. The blog post will show you the necessary code to make that work, and I recommend you check it out.

However, the blog post goes on to discuss solutions if you need a device identifier rather than an app installation identifier. I spoke with someone at Google to get some additional clarification on a few items in the event that you need to do so. Here's what I discovered about device identifiers that's NOT mentioned in the aforementioned blog post:

  • ANDROID_ID is the preferred device identifier. ANDROID_ID is perfectly reliable on versions of Android <=2.1 or >=2.3. Only 2.2 has the problems mentioned in the post.
  • Several devices by several manufacturers are affected by the ANDROID_ID bug in 2.2.
  • As far as I've been able to determine, all affected devices have the same ANDROID_ID, which is 9774d56d682e549c. Which is also the same device id reported by the emulator, btw.
  • Google believes that OEMs have patched the issue for many or most of their devices, but I was able to verify that as of the beginning of April 2011, at least, it's still quite easy to find devices that have the broken ANDROID_ID.
  • When a device has multiple users (available on certain devices running Android 4.2 or higher), each user appears as a completely separate device, so the ANDROID_ID value is unique to each user.

Based on Google's recommendations, I implemented a class that will generate a unique UUID for each device, using ANDROID_ID as the seed where appropriate, falling back on TelephonyManager.getDeviceId() as necessary, and if that fails, resorting to a randomly generated unique UUID that is persisted across app restarts (but not app re-installations).

Note that for devices that have to fallback on the device ID, the unique ID WILL persist across factory resets. This is something to be aware of. If you need to ensure that a factory reset will reset your unique ID, you may want to consider falling back directly to the random UUID instead of the device ID.

Again, this code is for a device ID, not an app installation ID. For most situations, an app installation ID is probably what you're looking for. But if you do need a device ID, then the following code will probably work for you.

import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings.Secure;
import android.telephony.TelephonyManager;

import java.util.UUID;

public class DeviceUuidFactory {
    protected static final String PREFS_FILE = "device_id.xml";
    protected static final String PREFS_DEVICE_ID = "device_id";

    protected static UUID uuid;

    public DeviceUuidFactory(Context context) {

        if( uuid ==null ) {
            synchronized (DeviceUuidFactory.class) {
                if( uuid == null) {
                    final SharedPreferences prefs = context.getSharedPreferences( PREFS_FILE, 0);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null );

                    if (id != null) {
                        // Use the ids previously computed and stored in the prefs file
                        uuid = UUID.fromString(id);

                    } else {

                        final String androidId = Secure.getString(context.getContentResolver(), Secure.ANDROID_ID);

                        // Use the Android ID unless it's broken, in which case fallback on deviceId,
                        // unless it's not available, then fallback on a random number which we store
                        // to a prefs file
                        try {
                            if (!"9774d56d682e549c".equals(androidId)) {
                                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
                            } else {
                                final String deviceId = ((TelephonyManager) context.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();
                                uuid = deviceId!=null ? UUID.nameUUIDFromBytes(deviceId.getBytes("utf8")) : UUID.randomUUID();
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);

                        // Write the value out to the prefs file
                        prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString() ).commit();




     * Returns a unique UUID for the current android device.  As with all UUIDs, this unique ID is "very highly likely"
     * to be unique across all Android devices.  Much more so than ANDROID_ID is.
     * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
     * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
     * on a random UUID that's persisted to SharedPreferences if getDeviceID() does not return a
     * usable value.
     * In some rare circumstances, this ID may change.  In particular, if the device is factory reset a new device ID
     * may be generated.  In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
     * to a newer, non-buggy version of Android, the device ID may change.  Or, if a user uninstalls your app on
     * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
     * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
     * change after a factory reset.  Something to be aware of.
     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
     * @see
     * @return a UUID that may be used to uniquely identify your device for most purposes.
    public UUID getDeviceUuid() {
        return uuid;

Spring - @Transactional - What happens in background?

This is a big topic. The Spring reference doc devotes multiple chapters to it. I recommend reading the ones on Aspect-Oriented Programming and Transactions, as Spring's declarative transaction support uses AOP at its foundation.

But at a very high level, Spring creates proxies for classes that declare @Transactional on the class itself or on members. The proxy is mostly invisible at runtime. It provides a way for Spring to inject behaviors before, after, or around method calls into the object being proxied. Transaction management is just one example of the behaviors that can be hooked in. Security checks are another. And you can provide your own, too, for things like logging. So when you annotate a method with @Transactional, Spring dynamically creates a proxy that implements the same interface(s) as the class you're annotating. And when clients make calls into your object, the calls are intercepted and the behaviors injected via the proxy mechanism.

Transactions in EJB work similarly, by the way.

As you observed, through, the proxy mechanism only works when calls come in from some external object. When you make an internal call within the object, you're really making a call through the "this" reference, which bypasses the proxy. There are ways of working around that problem, however. I explain one approach in this forum post in which I use a BeanFactoryPostProcessor to inject an instance of the proxy into "self-referencing" classes at runtime. I save this reference to a member variable called "me". Then if I need to make internal calls that require a change in the transaction status of the thread, I direct the call through the proxy (e.g. "me.someMethod()".) The forum post explains in more detail. Note that the BeanFactoryPostProcessor code would be a little different now, as it was written back in the Spring 1.x timeframe. But hopefully it gives you an idea. I have an updated version that I could probably make available.

Inserting values to SQLite table in Android

okkk you have take id INTEGER PRIMARY KEY AUTOINCREMENT and still u r passing value... that is the problem :) for more detail see this still getting problem then post code and logcat

What uses are there for "placement new"?

I've seen it used as a slight performance hack for a "dynamic type" pointer (in the section "Under the Hood"):

But here is the tricky trick I used to get fast performance for small types: if the value being held can fit inside of a void*, I don't actually bother allocating a new object, I force it into the pointer itself using placement new.

cocoapods - 'pod install' takes forever

As of 15th August 2016, the repo is a massive 2.39GB file. I opened the Activity Monitor to look at what the terminal was doing. It was downloading this huge file.

How to do SQL Like % in Linq?

System.Data.Linq.SqlClient.SqlMethods.Like("mystring", "%string")

How to get just the parent directory name of a specific file

Use below,

File file = new File("file/path");
String parentPath = file.getAbsoluteFile().getParent();