Programs & Examples On #Directshow

The Microsoft DirectShow application programming interface (API) is a media-streaming architecture for Microsoft Windows. Using DirectShow, your applications can perform high-quality video and audio playback or capture.

importing external ".txt" file in python

This answer is modified from infrared's answer at Splitting large text file by a delimiter in Python

with open('words.txt') as fp:
    contents =
    for entry in contents:
        # do something with entry  

How to include js and CSS in JSP with spring MVC

you need declare resources in dispatcher servelet file.below is two declarations

<mvc:annotation-driven />
<mvc:resources location="/resources/" mapping="/resources/**" />

disable viewport zooming iOS 10+ safari?

I tried the previous answer about pinch-to-zoom

document.documentElement.addEventListener('touchstart', function (event) {
    if (event.touches.length > 1) {
}, false);

however sometime the screen still zoom when the event.touches.length > 1 I found out the best way is using touchmove event, to avoid any finger moving on the screen. The code will be something like this:

document.documentElement.addEventListener('touchmove', function (event) {
}, false);

Hope it will help.

PHP/regex: How to get the string value of HTML tag?

this might be old but my answer might help someone

You can simply use

$str = '<textformat leading="2"><p align="left"><font size="10">get me</font></p></textformat>';
echo strip_tags($str);

How to turn on front flash light programmatically in Android?

I have implemented this function in my application through fragments using SurfaceView. The link to this stackoverflow question and its answer can be found here

Hope this helps :)

How to retrieve data from sqlite database in android and display it in TextView

on button click, first open the database, fetch the data and close the data base like this

public class cytaty extends Activity {

    protected void onCreate(Bundle savedInstanceState) {

        Button bLosuj = (Button) findViewById(;
        bLosuj.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            myDatabaseHelper = new DatabaseHelper(cytaty.this);

            String text = myDatabaseHelper.getYourData(); //this is the method to query

            // set text to your TextView

and your getYourData() in database class would be like this

public String[] getAppCategoryDetail() {

    final String TABLE_NAME = "name of table";

    String selectQuery = "SELECT  * FROM " + TABLE_NAME;
    SQLiteDatabase db  = this.getReadableDatabase();
    Cursor cursor      = db.rawQuery(selectQuery, null);
    String[] data      = null;

    if (cursor.moveToFirst()) {
        do {
           // get the data into array, or class variable
        } while (cursor.moveToNext());
    return data;

JQuery datepicker not working

If jQuery UI datepicker isn't working but it used to work on similar DOM earlier, try removing all the classes and try binding it to just a simple input with its id. In my case a class was interfering with it and preventing the date picker to appear.

How to get screen dimensions as pixels in Android

This function returns the approximate screen size in inches.

public double getScreenSize()
        DisplayMetrics dm = new DisplayMetrics();
        int width=dm.widthPixels;
        int height=dm.heightPixels;
        int dens=dm.densityDpi;
        double wi=(double)width/(double)dens;
        double hi=(double)height/(double)dens;
        double x = Math.pow(wi,2);
        double y = Math.pow(hi,2);
        double screenInches = Math.sqrt(x+y);
        return screenInches;

How can I kill whatever process is using port 8080 so that I can vagrant up?

sudo lsof -i:8080

By running the above command you can see what are all the jobs running.

kill -9 <PID Number>

Enter the PID (process identification number), so this will terminate/kill the instance.

How to convert a string to JSON object in PHP

To convert a valid JSON string back, you can use the json_decode() method.

To convert it back to an object use this method:

$jObj = json_decode($jsonString);

And to convert it to a associative array, set the second parameter to true:

$jArr = json_decode($jsonString, true);

By the way to convert your mentioned string back to either of those, you should have a valid JSON string. To achieve it, you should do the following:

  1. In the Coords array, remove the two " (double quote marks) from the start and end of the object.
  2. The objects in an array are comma seprated (,), so add commas between the objects in the Coords array..

And you will have a valid JSON String..

Here is your JSON String I converted to a valid one:

React img tag issue with url and class

var Hello = React.createClass({
    render: function() {
      return (
        <div className="divClass">
           <img src={this.props.url} alt={`${this.props.title}'s picture`}  className="img-responsive" />
           <span>Hello {}</span>

Found a swap file by the name

Looks like you have an open git commit or git merge going on, and an editor is still open editing the commit message.

Two choices:

  1. Find the session and finish it (preferable).
  2. Delete the .swp file (if you're sure the other git session has gone away).

Clarification from comments:

  • The session is the editing session.
  • You can see what .swp is being used by entering the command :sw within the editing session, but generally it's a hidden file in the same directory as the file you are using, with a .swp file suffix (i.e. ~/myfile.txt would be ~/.myfile.txt.swp).

How to enable curl in xampp?

First, make sure you have libcurl (see: installed. Then make sure your copy of PHP has been compiled with the --with-curl[=DIR] flag. For more info see:

If XAMPP comes pre-compiled with cURL you may just need to enable the extension in your php.ini file (usually by removing a semicolon at the start of the line which includes the extension).

c++ string array initialization

In C++11 and above, you can also initialize std::vector with an initializer list. For example:

using namespace std; // for example only

for (auto s : vector<string>{"one","two","three"} ) 
    cout << s << endl;

So, your example would become:

void foo(vector<string> strArray){
  // some code

vector<string> s {"hi", "there"}; // Works
foo(s); // Works

foo(vector<string> {"hi", "there"}); // also works

How can I get client information such as OS and browser

You cannot reliably get this information. The basis of several answers provided here is to examine the User-Agent header of the HTTP request. However, there is no way to know if the information in the User-Agent header is truthful. The client sending the request can write anything in that header. So its content can be spoofed, or not sent at all.

How to get a unique device ID in Swift?

if (UIDevice.current.identifierForVendor?.uuidString) != nil
            self.lblDeviceIdValue.text = UIDevice.current.identifierForVendor?.uuidString

C# Test if user has write access to a folder

I agree with Ash, that should be fine. Alternatively you could use declarative CAS and actually prevent the program from running in the first place if they don't have access.

I believe some of the CAS features may not be present in C# 4.0 from what I've heard, not sure if that might be an issue or not.

Bootstrap modal link

A Simple Approach will be to use a normal link and add Bootstrap modal effect to it. Just make use of my Code, hopefully you will get it run.

 <div class="container">
        <div class="row">
            <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="addContact" aria-hidden="true">
                <div class="modal-dialog">
                    <div class="modal-content">
                        <div class="modal-header">
                            <button type="button" class="close" data-dismiss="modal" aria-hidden="true"><b style="color:#fb3600; font-weight:700;">X</b></button><!--&times;-->
                            <h4 class="modal-title text-center" id="addContact">Add Contact</h4>
                        <div class="modal-body">
                            <div class="row">
                                <ul class="nav nav-tabs">
                                    <li class="active">
                                        <a data-toggle="tab" style="background-color:#f5dfbe" href="#contactTab">Contact</a>
                                        <a data-toggle="tab" style="background-color:#a6d2f6" href="#speechTab">Speech</a>
                                <div class="tab-content">
                                    <div id="contactTab" class="tab-pane in active"><partial name="CreateContactTag"></div>
                                    <div id="speechTab" class="tab-pane fade in"><partial name="CreateSpeechTag"></div>

                        <div class="modal-footer">
                            <a class="btn btn-info" data-dismiss="modal">Close</a>

Two color borders

Another way is to use box-shadow:

#mybox {
  0 0 0 1px #CCC,
  0 0 0 2px #888,
  0 0 0 3px #444,
  0 0 0 4px #000;
  0 0 0 1px #CCC,
  0 0 0 2px #888,
  0 0 0 3px #444,
  0 0 0 4px #000;
  0 0 0 1px #CCC,
  0 0 0 2px #888,
  0 0 0 3px #444,
  0 0 0 4px #000;

<div id="mybox">ABC</div>

See example here.

how to get html content from a webview?

In KitKat and above, you could use evaluateJavascript method on webview

        "(function() { return ('<html>'+document.getElementsByTagName('html')[0].innerHTML+'</html>'); })();",
         new ValueCallback<String>() {
            public void onReceiveValue(String html) {
                Log.d("HTML", html); 
                // code here

See this answer for more examples

Get table name by constraint name

ALL_CONSTRAINTS describes constraint definitions on tables accessible to the current user.

DBA_CONSTRAINTS describes all constraint definitions in the database.

USER_CONSTRAINTS describes constraint definitions on tables in the current user's schema


How to use sudo inside a docker container?

If SUDO or apt-get is not accessible inside the Container, You can use, below option in running container.

docker exec -u root -it f83b5c5bf413 ash

"f83b5c5bf413" is my container ID & here is working example from my terminal:

enter image description here

Open window in JavaScript with HTML inserted

I would not recomend you to use document.write as others suggest, because if you will open such window twice your HTML will be duplicated 2 times (or more).

Use innerHTML instead

var win ="", "Title", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=780,height=200,top="+(screen.height-400)+",left="+(screen.width-840));
win.document.body.innerHTML = "HTML";

How to inspect Javascript Objects

var str = "";
for(var k in obj)
    if (obj.hasOwnProperty(k)) //omit this test if you want to see built-in properties
        str += k + " = " + obj[k] + "\n";

How to set the env variable for PHP?

Follow this for Windows operating system with WAMP installed.

System > Advanced System Settings > Environment Variables
Click new

Variable name  : path
Variable value : c:\wamp\bin\php\php5.3.13\

Click ok

Assembly code vs Machine code vs Object code?

Assembly code is discussed here.

"An assembly language is a low-level language for programming computers. It implements a symbolic representation of the numeric machine codes and other constants needed to program a particular CPU architecture."

Machine code is discussed here.

"Machine code or machine language is a system of instructions and data executed directly by a computer's central processing unit."

Basically, assembler code is the language and it is translated to object code (the native code that the CPU runs) by an assembler (analogous to a compiler).

How to specify the actual x axis values to plot as x axis ticks in R

Take a closer look at the ?axis documentation. If you look at the description of the labels argument, you'll see that it is:

"a logical value specifying whether (numerical) annotations are 
to be made at the tickmarks,"

So, just change it to true, and you'll get your tick labels.

x <- seq(10,200,10)
y <- runif(x)
axis(side = 1, at = x,labels = T)
# Since TRUE is the default for labels, you can just use axis(side=1,at=x)

Be careful that if you don't stretch your window width, then R might not be able to write all your labels in. Play with the window width and you'll see what I mean.

It's too bad that you had such trouble finding documentation! What were your search terms? Try typing r axis into Google, and the first link you will get is that Quick R page that I mentioned earlier. Scroll down to "Axes", and you'll get a very nice little guide on how to do it. You should probably check there first for any plotting questions, it will be faster than waiting for a SO reply.

How do I delete specific lines in Notepad++?

Using regex and find&replace, you can delete all the lines containing #region without leaving empty lines. Because for some reason Ray's method didn't work on my machine I searched for (.*#region.*\n)|(\n.*#region.*) and left the replace box empty.

That regex ensures that the if #region is found on the first line, the ending newline is deleted, and if it is found on the last line the preceding newline is deleted.

Still, Ray's solution is the better one if it works for you.

Switch statement fallthrough in C#?

Switch fallthrough is historically one of the major source of bugs in modern softwares. The language designer decided to make it mandatory to jump at the end of the case, unless you are defaulting to the next case directly without processing.

    case 1:// this is still legal
    case 2:

Java decimal formatting using String.format?

java.text.NumberFormat is probably what you want.

How do you use subprocess.check_output() in Python?

The right answer (using Python 2.7 and later, since check_output() was introduced then) is:

py2output = subprocess.check_output(['python','','-i', 'test.txt'])

To demonstrate, here are my two programs:

import sys
print sys.argv

import subprocess
py2output = subprocess.check_output(['python', '', '-i', 'test.txt'])
print('py2 said:', py2output)

Running it:

$ python3
py2 said: b"['', '-i', 'test.txt']\n"

Here's what's wrong with each of your versions:

py2output = subprocess.check_output([str('python '),'-i', 'test.txt'])

First, str('python') is exactly the same thing as 'python'—you're taking a str, and calling str to convert it to an str. This makes the code harder to read, longer, and even slower, without adding any benefit.

More seriously, python can't be a single argument, unless you're actually trying to run a program named, say, /usr/bin/python\ Which you're not; you're trying to run, say, /usr/bin/python with first argument So, you need to make them separate elements in the list.

Your second version fixes that, but you're missing the ' before test.txt'. This should give you a SyntaxError, probably saying EOL while scanning string literal.

Meanwhile, I'm not sure how you found documentation but couldn't find any examples with arguments. The very first example is:

>>> subprocess.check_output(["echo", "Hello World!"])
b'Hello World!\n'

That calls the "echo" command with an additional argument, "Hello World!".


-i is a positional argument for argparse, test.txt is what the -i is

I'm pretty sure -i is not a positional argument, but an optional argument. Otherwise, the second half of the sentence makes no sense.

What does "implements" do on a class?

Implements means that it takes on the designated behavior that the interface specifies. Consider the following interface:

public interface ISpeak
   public String talk();

public class Dog implements ISpeak
   public String talk()
        return "bark!";

public class Cat implements ISpeak
    public String talk()
        return "meow!";

Both the Cat and Dog class implement the ISpeak interface.

What's great about interfaces is that we can now refer to instances of this class through the ISpeak interface. Consider the following example:

  Dog dog = new Dog();
  Cat cat = new Cat();

  List<ISpeak> animalsThatTalk = new ArrayList<ISpeak>();


  for (ISpeak ispeak : animalsThatTalk)

The output for this loop would be:


Interface provide a means to interact with classes in a generic way based upon the things they do without exposing what the implementing classes are.

One of the most common interfaces used in Java, for example, is Comparable. If your object implements this interface, you can write an implementation that consumers can use to sort your objects.

For example:

public class Person implements Comparable<Person>
  private String firstName;
  private String lastName;

  // Getters/Setters

  public int compareTo(Person p)
    return this.lastName.compareTo(p.getLastName());  

Now consider this code:

//  Some code in other class

List<Person> people = getPeopleList();


What this code did was provide a natural ordering to the Person class. Because we implemented the Comparable interface, we were able to leverage the Collections.sort() method to sort our List of Person objects by its natural ordering, in this case, by last name.

Is there a better way to iterate over two lists, getting one element from each list for each iteration?

Good to see lots of love for zip in the answers here.

However it should be noted that if you are using a python version before 3.0, the itertools module in the standard library contains an izip function which returns an iterable, which is more appropriate in this case (especially if your list of latt/longs is quite long).

In python 3 and later zip behaves like izip.

UIView Infinite 360 degree rotation animation?

Create the animation

- (CABasicAnimation *)spinAnimationWithDuration:(CGFloat)duration clockwise:(BOOL)clockwise repeat:(BOOL)repeats
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    anim.toValue = clockwise ? @(M_PI * 2.0) : @(M_PI * -2.0);
    anim.duration = duration;
    anim.cumulative = YES;
    anim.repeatCount = repeats ? CGFLOAT_MAX : 0;
    return anim;

Add it to a view like this

CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES];
[self.spinningView.layer addAnimation:animation forKey:@"rotationAnimation"];

How is this answer different? You will have way cleaner code if most of your functions returns objects instead of just manipulating some objects here and there.

How to check for a Null value in VB.NET

 If Short.TryParse(editTransactionRow.pay_id, New Short) Then editTransactionRow.pay_id.ToString()

Split string into tokens and save them in an array

You can use strtok()

char string[]=  "abc/qwe/jkh";
char *array[10];
int i=0;

array[i] = strtok(string,"/");

   array[++i] = strtok(NULL,"/");

How to pass data from child component to its parent in ReactJS?

You can even avoid the function at the parent updating the state directly

In Parent Component:

 return(<Child sendData={ v => this.setState({item: v}) } />);

In the Child Component:


Calculating time difference in Milliseconds

Since Java 1.5, you can get a more precise time value with System.nanoTime(), which obviously returns nanoseconds instead.

There is probably some caching going on in the instances when you get an immediate result.

phpmyadmin logs out after 1440 secs

You should restart apache or httpd, not mysqld

sudo service httpd restart


sudo /etc/init.d/apache2 restart

matplotlib get ylim values

I put above-mentioned methods together using ax instead of plt

import numpy as np
import matplotlib.pyplot as plt

x = range(100)
y = x

fig, ax = plt.subplots(1, 1, figsize=(7.2, 7.2))
ax.plot(x, y);

# method 1
# method 2

enter image description here

How to ignore HTML element from tabindex?

Just add the attribute disabled to the element (or use jQuery to do it for you). Disabled prevents the input from being focused or selected at all.

Spring @Autowired and @Qualifier

You can use @Qualifier along with @Autowired. In fact spring will ask you explicitly select the bean if ambiguous bean type are found, in which case you should provide the qualifier

For Example in following case it is necessary provide a qualifier

public Staff implements Person {}

public Manager implements Person {}

public Payroll {

    private Person person;

    public Payroll(@Qualifier("employee") Person person){
          this.person = person;



In Lombok 1.18.4 it is finally possible to avoid the boilerplate on constructor injection when you have @Qualifier, so now it is possible to do the following:

public Staff implements Person {}

public Manager implements Person {}

public Payroll {
   @Qualifier("employee") private final Person person;

provided you are using the new lombok.config rule copyableAnnotations (by placing the following in lombok.config in the root of your project):

# Copy the Qualifier annotation from the instance variables to the constructor
# see
lombok.copyableAnnotations += org.springframework.beans.factory.annotation.Qualifier

This was recently introduced in latest lombok 1.18.4.


If you are using field or setter injection then you have to place the @Autowired and @Qualifier on top of the field or setter function like below(any one of them will work)

public Payroll {
   @Autowired @Qualifier("employee") private final Person person;


public Payroll {
   private final Person person;
   public void setPerson(Person person) {
     this.person = person;

If you are using constructor injection then the annotations should be placed on constructor, else the code would not work. Use it like below -

public Payroll {

    private Person person;

    public Payroll(@Qualifier("employee") Person person){
          this.person = person;


Is there any method to get the URL without query string?

Just add these two lines to $(document).ready in JS as follow:

$(document).ready(function () {
 $("div.sidebar nav a").removeClass("active");
        $('nav a[href$="'+ window.location.pathname.split("?")[0] +'"]').addClass('active');

it is better to use the dollar sign ($) (End with)

$('nav a[href$

instead of (^) (Start with)

$('nav a[href^

because, if you use the (^) sign and you have nested URLs in the navigation menu, (e.g "/account" and "/account/roles")

It will active both of them.

Recursive file search using PowerShell

When searching folders where you might get an error based on security (e.g. C:\Users), use the following command:

Get-ChildItem -Path V:\Myfolder -Filter CopyForbuild.bat -Recurse -ErrorAction SilentlyContinue -Force

Reload parent window from child window

this will work


Java 8: How do I work with exception throwing methods in streams?

If all you want is to invoke foo, and you prefer to propagate the exception as is (without wrapping), you can also just use Java's for loop instead (after turning the Stream into an Iterable with some trickery):

for (A a : (Iterable<A>) as::iterator) {;

This is, at least, what I do in my JUnit tests, where I don't want to go through the trouble of wrapping my checked exceptions (and in fact prefer my tests to throw the unwrapped original ones)

This could be due to the service endpoint binding not using the HTTP protocol

I think the best way to solve this is to follow the error advice, hence looking for server logs. To enable logs I added

      <source name="System.ServiceModel" switchValue="Information, ActivityTracing" propagateActivity="true">
          <add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener" initializeData="c:\logs\TracesServ_ce.svclog" />

Then you go to c:\logs\TracesServ_ce.svclog open it with microsoft service trace viewer. And see what the problem really is.

git recover deleted file where no commit was made after the delete

Newer git (mine is 2.27.0) is more friendly and the actual commands are shown during "git status". For example, if you deleted the file tf.c, then

$ git status
Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
      deleted:    tf.c

You would use "git restore tf.c" to get it back, as it saz. No more search!

Convert image from PIL to openCV format

This is the shortest version I could find,saving/hiding an extra conversion:

pil_image ='image.jpg')
opencvImage = cv2.cvtColor(numpy.array(pil_image), cv2.COLOR_RGB2BGR)

If reading a file from a URL:

import cStringIO
import urllib
file = cStringIO.StringIO(urllib.urlopen(r'').read())
pil_image =
opencvImage = cv2.cvtColor(numpy.array(pil_image), cv2.COLOR_RGB2BGR)

What is the difference between UTF-8 and ISO-8859-1?


UTF is a family of multi-byte encoding schemes that can represent Unicode code points which can be representative of up to 2^31 [roughly 2 billion] characters. UTF-8 is a flexible encoding system that uses between 1 and 4 bytes to represent the first 2^21 [roughly 2 million] code points.

Long story short: any character with a code point/ordinal representation below 127, aka 7-bit-safe ASCII is represented by the same 1-byte sequence as most other single-byte encodings. Any character with a code point above 127 is represented by a sequence of two or more bytes, with the particulars of the encoding best explained here.


ISO-8859 is a family of single-byte encoding schemes used to represent alphabets that can be represented within the range of 127 to 255. These various alphabets are defined as "parts" in the format ISO-8859-n, the most familiar of these likely being ISO-8859-1 aka 'Latin-1'. As with UTF-8, 7-bit-safe ASCII remains unaffected regardless of the encoding family used.

The drawback to this encoding scheme is its inability to accommodate languages comprised of more than 128 symbols, or to safely display more than one family of symbols at one time. As well, ISO-8859 encodings have fallen out of favor with the rise of UTF. The ISO "Working Group" in charge of it having disbanded in 2004, leaving maintenance up to its parent subcommittee.

Why are Python lambdas useful?

I doubt lambda will go away. See Guido's post about finally giving up trying to remove it. Also see an outline of the conflict.

You might check out this post for more of a history about the deal behind Python's functional features:

Curiously, the map, filter, and reduce functions that originally motivated the introduction of lambda and other functional features have to a large extent been superseded by list comprehensions and generator expressions. In fact, the reduce function was removed from list of builtin functions in Python 3.0. (However, it's not necessary to send in complaints about the removal of lambda, map or filter: they are staying. :-)

My own two cents: Rarely is lambda worth it as far as clarity goes. Generally there is a more clear solution that doesn't include lambda.

Error message "unreported exception; must be caught or declared to be thrown"

void showfile() throws  <-----

Your showfile() method throws IOException, so whenever you use it you have to either catch that exception or again thorw it. Something like:

try {
catch(IOException e) {

You should learn about exceptions in Java.

"Automatic" vs "Automatic (Delayed start)"

In short, services set to Automatic will start during the boot process, while services set to start as Delayed will start shortly after boot.

Starting your service Delayed improves the boot performance of your server and has security benefits which are outlined in the article Adriano linked to in the comments.

Update: "shortly after boot" is actually 2 minutes after the last "automatic" service has started, by default. This can be configured by a registry key, according to Windows Internals and other sources (3,4).

The registry keys of interest (At least in some versions of windows) are:

  • HKLM\SYSTEM\CurrentControlSet\services\<service name>\DelayedAutostart will have the value 1 if delayed, 0 if not.
  • HKLM\SYSTEM\CurrentControlSet\services\AutoStartDelay or HKLM\SYSTEM\CurrentControlSet\Control\AutoStartDelay (on Windows 10): decimal number of seconds to wait, may need to create this one. Applies globally to all Delayed services.

Is it possible to use vh minus pixels in a CSS calc()?

It does work indeed. Issue was with my less compiler. It was compiled in to:

.container {
  min-height: calc(-51vh);

Fixed with the following code in less file:

.container {
  min-height: calc(~"100vh - 150px");

Thanks to this link: Less Aggressive Compilation with CSS3 calc

How do I set response headers in Flask?

This work for me

from flask import Flask
from flask import Response

app = Flask(__name__)

def home():
    return Response(headers={'Access-Control-Allow-Origin':'*'})

if __name__ == "__main__":

Gradle finds wrong JAVA_HOME even though it's correctly set

Try installing latest version of gradle,

sudo add-apt-repository ppa:cwchien/gradle

sudo apt-get update

sudo apt-get install gradle

If we install from ubuntu repo, it will install the old version , (for me it was gradle 1.4). In older version, it sets java home from gradle as export JAVA_HOME=/usr/lib/jvm/default-java. Latest version don't have this issue.

PHP 7: Missing VCRUNTIME140.dll

I had the same issue, I changed the ports, restarted the services but in vein, only worked for me when I updated the Microsoft Visual c++ filesFrom There yoy can modify MVC

Receiving "fatal: Not a git repository" when attempting to remote add a Git repo

hit git init using terminal/cmd in your desired folder. It'll do the job.

htaccess Access-Control-Allow-Origin

Make sure you don't have a redirect happening. This can happen if you don't include the trailing slash in the URL.

See this answer for more detail –

CSS filter: make color image with transparency white

You can use

filter: brightness(0) invert(1);

html {_x000D_
  background: red;_x000D_
p {_x000D_
  float: left;_x000D_
  max-width: 50%;_x000D_
  text-align: center;_x000D_
img {_x000D_
  display: block;_x000D_
  max-width: 100%;_x000D_
.filter {_x000D_
  -webkit-filter: brightness(0) invert(1);_x000D_
  filter: brightness(0) invert(1);_x000D_
  <img src="" />_x000D_
  <img src="" class="filter" />_x000D_

First, brightness(0) makes all image black, except transparent parts, which remain transparent.

Then, invert(1) makes the black parts white.

Show a popup/message box from a Windows batch file

Try :

Msg * "insert your message here" 

If you are using Windows XP's, this will open a message box.

Opening a new cmd window isn't quite what you were asking for, I gather. You could also use VBScript, and use this with your .bat file. You would open it from the bat file with this command:

cd C:\"location of vbscript"

What this does is change the directory will search for files from, then on the next line:

"insert name of your vbscript here".vbs

Then you create a new Notepad document, type in

<script type="text/vbscript">
    MsgBox "your text here"

You would then save this as a .vbs file (by putting ".vbs" at the end of the filename), save as "All Files" in the drop down box below the file name (so it doesn't save as .txt), then click Save!

Referenced Project gets "lost" at Compile Time

Check your build types of each project under project properties - I bet one or the other will be set to build against .NET XX - Client Profile.

With inconsistent versions, specifically with one being Client Profile and the other not, then it works at design time but fails at compile time. A real gotcha.

There is something funny going on in Visual Studio 2010 for me, which keeps setting projects seemingly randomly to Client Profile, sometimes when I create a project, and sometimes a few days later. Probably some keyboard shortcut I'm accidentally hitting...

What is Dependency Injection?

The popular answers are unhelpful, because they define dependency injection in a way that isn't useful. Let's agree that by "dependency" we mean some pre-existing other object that our object X needs. But we don't say we're doing "dependency injection" when we say

$foo = Foo->new($bar);

We just call that passing parameters into the constructor. We've been doing that regularly ever since constructors were invented.

"Dependency injection" is considered a type of "inversion of control", which means that some logic is taken out of the caller. That isn't the case when the caller passes in parameters, so if that were DI, DI would not imply inversion of control.

DI means there is an intermediate level between the caller and the constructor which manages dependencies. A Makefile is a simple example of dependency injection. The "caller" is the person typing "make bar" on the command line, and the "constructor" is the compiler. The Makefile specifies that bar depends on foo, and it does a

gcc -c foo.cpp; gcc -c bar.cpp

before doing a

gcc foo.o bar.o -o bar

The person typing "make bar" doesn't need to know that bar depends on foo. The dependency was injected between "make bar" and gcc.

The main purpose of the intermediate level is not just to pass in the dependencies to the constructor, but to list all the dependencies in just one place, and to hide them from the coder (not to make the coder provide them).

Usually the intermediate level provides factories for the constructed objects, which must provide a role that each requested object type must satisfy. That's because by having an intermediate level that hides the details of construction, you've already incurred the abstraction penalty imposed by factories, so you might as well use factories.

How can I get the current directory name in Javascript?

For both / and \:

window.location.pathname.replace(/[^\\\/]*$/, '');

To return without the trailing slash, do:

window.location.pathname.replace(/[\\\/][^\\\/]*$/, '');

How to put a UserControl into Visual Studio toolBox

Recompiling did the trick for me!

Function to convert timestamp to human date in javascript

Here are the simple ways to every date format confusions:

for current date:

var current_date=new Date();

to get the Timestamp of current date:

var timestamp=new Date().getTime();

to convert a particular Date into Timestamp:

var timestamp_formation=new Date('mm/dd/yyyy').getTime();

to convert timestamp into Date:

    var timestamp=new Date('02/10/2016').getTime();
    var todate=new Date(timestamp).getDate();
    var tomonth=new Date(timestamp).getMonth()+1;
    var toyear=new Date(timestamp).getFullYear();
    var original_date=tomonth+'/'+todate+'/'+toyear;


spring autowiring with unique beans: Spring expected single matching bean but found 2

For me it was case of having two beans implementing the same interface. One was a fake ban for the sake of unit test which was conflicting with original bean. If we use


, it still references with suggestionService. So I removed @component and only used


which solved the problem

Why use def main()?

Everyone else has already answered it, but I think I still have something else to add.

Reasons to have that if statement calling main() (in no particular order):

  • Other languages (like C and Java) have a main() function that is called when the program is executed. Using this if, we can make Python behave like them, which feels more familiar for many people.

  • Code will be cleaner, easier to read, and better organized. (yeah, I know this is subjective)

  • It will be possible to import that python code as a module without nasty side-effects.

  • This means it will be possible to run tests against that code.

  • This means we can import that code into an interactive python shell and test/debug/run it.

  • Variables inside def main are local, while those outside it are global. This may introduce a few bugs and unexpected behaviors.

But, you are not required to write a main() function and call it inside an if statement.

I myself usually start writing small throwaway scripts without any kind of function. If the script grows big enough, or if I feel putting all that code inside a function will benefit me, then I refactor the code and do it. This also happens when I write bash scripts.

Even if you put code inside the main function, you are not required to write it exactly like that. A neat variation could be:

import sys

def main(argv):
    # My code here

if __name__ == "__main__":

This means you can call main() from other scripts (or interactive shell) passing custom parameters. This might be useful in unit tests, or when batch-processing. But remember that the code above will require parsing of argv, thus maybe it would be better to use a different call that pass parameters already parsed.

In an object-oriented application I've written, the code looked like this:

class MyApplication(something):
    # My code here

if __name__ == "__main__":
    app = MyApplication()

So, feel free to write the code that better suits you. :)

CSS Float: Floating an image to the left of the text

Is this what you're after?

  • I changed your title into a h3 (header) tag, because it's a more semantic choice than using a div.

Live Demo #1
Live Demo #2 (with header at top, not sure if you wanted that)


<div class="post-container">                
    <div class="post-thumb"><img src="" /></div>
    <div class="post-content">
        <h3 class="post-title">Post title</h3>
        <p>post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc </p>


.post-container {
    margin: 20px 20px 0 0;  
    border: 5px solid #333;
    overflow: auto
.post-thumb {
    float: left
.post-thumb img {
    display: block
.post-content {
    margin-left: 210px
.post-title {
    font-weight: bold;
    font-size: 200%

Vue.js—Difference between v-model and v-bind

it is two way data binding, it is used to bind html input element when you change input value then bounded data will be change.

v-model is used only for HTML input elements

ex: <input type="text" v-model="name" > 

it is one way data binding,means you can only bind data to input element but can't change bounded data changing input element. v-bind is used to bind html attribute
<input type="text" v-bind:class="abc" v-bind:value="">

<a v-bind:href="home/abc" > click me </a>

Div Height in Percentage

It doesn't take the 50% of the whole page is because the "whole page" is only how tall your contents are. Change the enclosing html and body to 100% height and it will work.

html, body{
    height: 100%;
    height: 50%;

enter image description here

^ Your document is only 20px high. 50% of 20px is 10px, and it is not what you expected.

enter image description here

^ Now if you change the height of the document to the height of the whole page (150px), 50% of 150px is 75px, then it will work.

Wait until flag=true

using non blocking javascript with EventTarget API

In my example, i need to wait for a callback before to use it. I have no idea when this callback is set. It can be before of after i need to execute it. And i can need to call it several time (everything async)

// bus to pass event_x000D_
const bus = new EventTarget();_x000D_
// it's magic_x000D_
const waitForCallback = new Promise((resolve, reject) => {_x000D_
    bus.addEventListener("initialized", (event) => {_x000D_
// LET'S TEST IT !_x000D_
// launch before callback has been set_x000D_
waitForCallback.then((callback) => {_x000D_
// async init_x000D_
setTimeout(() => {_x000D_
    const callback = (param) => { return `hello ${param.toString()}`; }_x000D_
    bus.dispatchEvent(new CustomEvent("initialized", {detail: callback}));_x000D_
}, 500);_x000D_
// launch after callback has been set_x000D_
setTimeout(() => {_x000D_
    waitForCallback.then((callback) => {_x000D_
        console.log(callback("my little pony"));_x000D_
}, 1000);

How to convert hex to ASCII characters in the Linux shell?

You can make it through echo only and without the other stuff. Don't forget to add "-n" or you will get a linebreak automatically:

echo -n -e "\x5a"

How to convert a const char * to std::string

This is actually trickier than it looks, because you can't call strlen unless the string is actually nul terminated. In fact, without some additional constraints, the problem practically requires inventing a new function, a version of strlen which never goes beyond the a certain length. However:

If the buffer containing the c-style string is guaranteed to be at least max_length char's (although perhaps with a '\0' before the end), then you can use the address-length constructor of std::string, and trim afterwards:

std::string result( c_string, max_length );
result.erase( std::find( result.begin(), result.end(), '\0' ), result.end() );

and if you know that c_string is a nul terminated string (but perhaps longer than max_length, you can use strlen:

std::string result( c_string, std::min( strlen( c_string ), max_length ) );

HTML input textbox with a width of 100% overflows table cells

Take out the "" from the DOCTYPE declaration and it fix your problem.

Cheers! :)

How do I prevent an Android device from going to sleep programmatically?

If you are a Xamarin user, this is the solution:

   protected override void OnCreate(Bundle bundle)
        base.OnCreate(bundle); //always call superclass first


        LoadApplication(new App());

HTML5 Canvas Rotate Image

@Steve Farthing's answer is absolutely right.

But if you rotate more than 4 times then the image will get cropped from both the side. For that you need to do like this.

    angleInDegrees+=90 % 360;
    if(angleInDegrees == 360){  // add this lines
        angleInDegrees = 0

Then you will get the desired result. Thanks. Hope this will help someone :)

C++ deprecated conversion from string constant to 'char*'

For what its worth, I find this simple wrapper class to be helpful for converting C++ strings to char *:

class StringWrapper {
    std::vector<char> vec;
    StringWrapper(const std::string &str) : vec(str.begin(), str.end()) {

    char *getChars() {
        return &vec[0];

google chrome extension :: console.log() from background page?

Try this, if you want to log to the active page's console:

    code: 'console.log("addd")'

How to set Spinner default value to null?

Merge this:

private long previousItemId = 0;

public long getItemId(int position) {
    long nextItemId = random.nextInt(Integer.MAX_VALUE);
    while(previousItemId == nextItemId) {
        nextItemId = random.nextInt(Integer.MAX_VALUE);
    previousItemId = nextItemId;
    return nextItemId;

With this answer:

public class SpinnerInteractionListener
        implements AdapterView.OnItemSelectedListener, View.OnTouchListener {

    private AdapterView.OnItemSelectedListener onItemSelectedListener;

    public SpinnerInteractionListener(AdapterView.OnItemSelectedListener selectedListener) {
        this.onItemSelectedListener = selectedListener;

    boolean userSelect = false;

    public boolean onTouch(View v, MotionEvent event) {
        userSelect = true;
        return false;

    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        if(userSelect) {
            onItemSelectedListener.onItemSelected(parent, view, pos, id);
            userSelect = false;

    public void onNothingSelected(AdapterView<?> parent) {
        if(userSelect) {
            userSelect = false;

Synchronization vs Lock

I would like to add some more things on top of Bert F answer.

Locks support various methods for finer grained lock control, which are more expressive than implicit monitors (synchronized locks)

A Lock provides exclusive access to a shared resource: only one thread at a time can acquire the lock and all access to the shared resource requires that the lock be acquired first. However, some locks may allow concurrent access to a shared resource, such as the read lock of a ReadWriteLock.

Advantages of Lock over Synchronization from documentation page

  1. The use of synchronized methods or statements provides access to the implicit monitor lock associated with every object, but forces all lock acquisition and release to occur in a block-structured way

  2. Lock implementations provide additional functionality over the use of synchronized methods and statements by providing a non-blocking attempt to acquire a lock (tryLock()), an attempt to acquire the lock that can be interrupted (lockInterruptibly(), and an attempt to acquire the lock that can timeout (tryLock(long, TimeUnit)).

  3. A Lock class can also provide behavior and semantics that is quite different from that of the implicit monitor lock, such as guaranteed ordering, non-reentrant usage, or deadlock detection

ReentrantLock: In simple terms as per my understanding, ReentrantLock allows an object to re-enter from one critical section to other critical section . Since you already have lock to enter one critical section, you can other critical section on same object by using current lock.

ReentrantLock key features as per this article

  1. Ability to lock interruptibly.
  2. Ability to timeout while waiting for lock.
  3. Power to create fair lock.
  4. API to get list of waiting thread for lock.
  5. Flexibility to try for lock without blocking.

You can use ReentrantReadWriteLock.ReadLock, ReentrantReadWriteLock.WriteLock to further acquire control on granular locking on read and write operations.

Apart from these three ReentrantLocks, java 8 provides one more Lock


Java 8 ships with a new kind of lock called StampedLock which also support read and write locks just like in the example above. In contrast to ReadWriteLock the locking methods of a StampedLock return a stamp represented by a long value.

You can use these stamps to either release a lock or to check if the lock is still valid. Additionally stamped locks support another lock mode called optimistic locking.

Have a look at this article on usage of different type of ReentrantLock and StampedLock locks.

Set focus on textbox in WPF

Try this : MyTextBox.Focus ( );

How can I remove or replace SVG content?

You should use append("svg:svg"), not append("svg") so that D3 makes the element with the correct 'namespace' if you're using xhtml.

Switching to a TabBar tab view programmatically?

You can simply just set the selectedIndex property on the UITabBarController to the appropriate index and the view will be changed just like the user tapped the tab button.

Writing to a file in a for loop

That is because you are opening , writing and closing the file 10 times inside your for loop

myfile = open('xyz.txt', 'w')

You should open and close your file outside for loop.

myfile = open('xyz.txt', 'w')
for line in lines:
    var1, var2 = line.split(",");
    myfile.write("%s\n" % var1)


You should also notice to use write and not writelines.

writelines writes a list of lines to your file.

Also you should check out the answers posted by folks here that uses with statement. That is the elegant way to do file read/write operations in Python

How to destroy JWT Tokens on logout?

You cannot manually expire a token after it has been created. Thus, you cannot log out with JWT on the server-side as you do with sessions.

JWT is stateless, meaning that you should store everything you need in the payload and skip performing a DB query on every request. But if you plan to have a strict log out functionality, that cannot wait for the token auto-expiration, even though you have cleaned the token from the client-side, then you might need to neglect the stateless logic and do some queries. so what's a solution?

  • Set a reasonable expiration time on tokens

  • Delete the stored token from client-side upon log out

  • Query provided token against The Blacklist on every authorized request


“Blacklist” of all the tokens that are valid no more and have not expired yet. You can use a DB that has a TTL option on documents which would be set to the amount of time left until the token is expired.


Redis is a good option for blacklist, which will allow fast in-memory access to the list. Then, in the middleware of some kind that runs on every authorized request, you should check if the provided token is in The Blacklist. If it is you should throw an unauthorized error. And if it is not, let it go and the JWT verification will handle it and identify if it is expired or still active.

For more information, see How to log out when using JWT. by Arpy Vanyan

How to recover corrupted Eclipse workspace?

This thread may be a bit older, but since this still is a problem nowadays, I thought I’d propose a new solution for backing up Eclipse.

  • At you can download the Yatta Eclipse Launcher. You can use it to save your Eclipse and workspace setup.

  • After installation, the Launcher will discover your existing Eclipse installations and workspaces.

  • Click the Upload & Share button (the blue one) on the right of the entry you want to back up.

(You won’t actually “share” your Eclipse or workspace with anyone. You’ll just upload a setup file with your metadata that only you have access to yourself . You could share this later, but you can also just use it as a backup).

If you do that, you’ll be able to re-setup your IDE really fast if you ever have a fragged workspace or Eclipse installation.

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

Easy way to compare two json string in javascript

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

var flag=true;

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

Failed to locate the winutils binary in the hadoop binary path

winutils.exe are required for hadoop to perform hadoop related commands. please download hadoop-common-2.2.0 zip file. winutils.exe can be found in bin folder. Extract the zip file and copy it in the local hadoop/bin folder.

Easiest way to detect Internet connection on iOS?

Seeing as this thread is the top google result for this type of question, I figured I would provide the solution that worked for me. I was already using AFNetworking, but searching didn't reveal how to accomplish this task with AFNetworking until midway through my project.

What you want is the AFNetworkingReachabilityManager.

// -- Start monitoring network reachability (globally available) -- //
[[AFNetworkReachabilityManager sharedManager] startMonitoring];

[[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {

    NSLog(@"Reachability changed: %@", AFStringFromNetworkReachabilityStatus(status));

    switch (status) {
        case AFNetworkReachabilityStatusReachableViaWWAN:
        case AFNetworkReachabilityStatusReachableViaWiFi:
            // -- Reachable -- //
        case AFNetworkReachabilityStatusNotReachable:
            // -- Not reachable -- //
            NSLog(@"Not Reachable");


You can also use the following to test reachability synchronously (once monitoring has started):

-(BOOL) isInternetReachable
    return [AFNetworkReachabilityManager sharedManager].reachable;

SQL query for today's date minus two months

TSQL, Alternative using variable declaration. (it might improve Query's readability)

DECLARE @gapPeriod DATETIME = DATEADD(MONTH,-2,GETDATE()); --Period:Last 2 months.

        FB as A
        A.Dte <= @gapPeriod;                               --only older records.

Git copy changes from one branch to another

Copy content of BranchA into BranchB

git checkout BranchA
git pull origin BranchB
git push -u origin BranchA

VBA Runtime Error 1004 "Application-defined or Object-defined error" when Selecting Range

I had a similar issue when trying to loop on each sheet of a workbook. To resolve it I did something like this

dim mySheet as sheet

for each mysheet in myWorkbook.sheets


    with Selection
    'any wanted operations here
    end with


And it worked just fine

I hope you can adapt it in your situation

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

As mentioned by Dan Abramov

Do it right inside render

We actually use that approach with memoise one for any kind of proxying props to state calculations.

Our code looks this way

// ./decorators/memoized.js  
import memoizeOne from 'memoize-one';

export function memoized(target, key, descriptor) {
  descriptor.value = memoizeOne(descriptor.value);
  return descriptor;

// ./components/exampleComponent.js
import React from 'react';
import { memoized } from 'src/decorators';

class ExampleComponent extends React.Component {
  buildValuesFromProps() {
    const {
    } = this.props
    return {
      value1: buildValue1(watchedProp1, watchedProp2),
      value2: buildValue2(watchedProp1, watchedProp3, watchedProp5),
      value3: buildValue3(watchedProp3, watchedProp4, watchedProp5),

  buildValue1(watchedProp1, watchedProp2) {
    return ...;

  buildValue2(watchedProp1, watchedProp3, watchedProp5) {
    return ...;

  buildValue3(watchedProp3, watchedProp4, watchedProp5) {
    return ...;

  render() {
    const {
    } = this.buildValuesFromProps();

    return (
        <Component1 value={value1}>
        <Component2 value={value2}>
        <Component3 value={value3}>

The benefits of it are that you don't need to code tons of comparison boilerplate inside getDerivedStateFromProps or componentWillReceiveProps and you can skip copy-paste initialization inside a constructor.


This approach is used only for proxying the props to state, in case you have some inner state logic it still needs to be handled in component lifecycles.

How do I import the javax.servlet API in my Eclipse project?

I know this is an old post. However, I observed another instance where in the project already has Tomcat added but we still get this error. Did this to resolve that:
Alt + Enter
Project Facets
On the right, next to details, is another tab "Runtimes". The installed tomcat server will be listed there. Select it.
Save the configuration and DONE!

Hope this helps someone.

AngularJS ng-style with a conditional expression

On a generic note, you can use a combination of ng-if and ng-style incorporate conditional changes with change in background image.

<span ng-if=""
              ng-style="{'background-image':'url(../images/'+'{{}}'+'_active.png)','background-size':'52px 57px','padding-top':'70px','background-repeat':'no-repeat','background-position': 'center'}"></span>
        <span ng-if="selectedItem!"
              ng-style="{'background-image':'url(../images/'+'{{}}'+'_deactivated.png)','background-size':'52px 57px','padding-top':'70px','background-repeat':'no-repeat','background-position': 'center'}"></span>

Angular 2 Date Input not binding to date value

In .ts :

today: Date;

constructor() { =new Date();


<input type="date"  
       [ngModel]="today | date:'yyyy-MM-dd'"  
       (ngModelChange)="today = $event"    
       class="form-control form-control-rounded" #searchDate 

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

The singular form dtype is used to check the data type for a single column. And the plural form dtypes is for data frame which returns data types for all columns. Essentially:

For a single column:


For all columns:



import pandas as pd
df = pd.DataFrame({'A': [1,2,3], 'B': [True, False, False], 'C': ['a', 'b', 'c']})

# dtype('int64')
# dtype('bool')
# dtype('O')

#A     int64
#B      bool
#C    object
#dtype: object

Python, how to read bytes from file and save it?

Use the open function to open the file. The open function returns a file object, which you can use the read and write to files:

file_input = open('input.txt') #opens a file in reading mode
file_output = open('output.txt') #opens a file in writing mode

data = #read 1024 bytes from the input file
file_output.write(data) #write the data to the output file

Passing parameter to controller action from a Html.ActionLink

You are using incorrect overload. You should use this overload

public static MvcHtmlString ActionLink(
    this HtmlHelper htmlHelper,
    string linkText,
    string actionName,
    string controllerName,
    Object routeValues,
    Object htmlAttributes

And the correct code would be

<%= Html.ActionLink("Create New Part", "CreateParts", "PartList", new { parentPartId = 0 }, null)%>

Note that extra parameter at the end. For the other overloads, visit LinkExtensions.ActionLink Method. As you can see there is no string, string, string, object overload that you are trying to use.

How can I return two values from a function in Python?

I would like to return two values from a function in two separate variables.

What would you expect it to look like on the calling end? You can't write a = select_choice(); b = select_choice() because that would call the function twice.

Values aren't returned "in variables"; that's not how Python works. A function returns values (objects). A variable is just a name for a value in a given context. When you call a function and assign the return value somewhere, what you're doing is giving the received value a name in the calling context. The function doesn't put the value "into a variable" for you, the assignment does (never mind that the variable isn't "storage" for the value, but again, just a name).

When i tried to to use return i, card, it returns a tuple and this is not what i want.

Actually, it's exactly what you want. All you have to do is take the tuple apart again.

And i want to be able to use these values separately.

So just grab the values out of the tuple.

The easiest way to do this is by unpacking:

a, b = select_choice()

Submitting a form by pressing enter without a submit button

For anyone looking at this answer in future, HTML5 implements a new attribute for form elements, hidden, which will automatically apply display:none to your element.


<input type="submit" hidden />

How to enumerate an enum

I think its help you try it.

public class Program

    public static List<T> GetEnamList<T>()
        var enums = Enum.GetValues(typeof(T)).Cast<T>().Select(v => v).ToList();
        return enums;
    private void LoadEnumList()
        List<DayofWeek> dayofweeks = GetEnamList<DayofWeek>();

        foreach (var item in dayofweeks)

    public enum DayofWeek

What does %~d0 mean in a Windows batch file?

Some gotchas to watch out for:

If you double-click the batch file %0 will be surrounded by quotes. For example, if you save this file as c:\test.bat:

@echo %0

Double-clicking it will open a new command prompt with output:


But if you first open a command prompt and call it directly from that command prompt, %0 will refer to whatever you've typed. If you type test.batEnter, the output of %0 will have no quotes because you typed no quotes:


If you type testEnter, the output of %0 will have no extension too, because you typed no extension:


Same for tEsTEnter:


If you type "test"Enter, the output of %0 will have quotes (since you typed them) but no extension:


Lastly, if you type "C:\test.bat", the output would be exactly as though you've double clicked it:


Note that these are not all the possible values %0 can be because you can call the script from other folders:


All the examples shown above will also affect %~0, because the output of %~0 is simply the output of %0 minus quotes (if any).

Linq Syntax - Selecting multiple columns

You can use anonymous types for example:

  var empData = from res in _db.EMPLOYEEs
                where res.EMAIL == givenInfo || res.USER_NAME == givenInfo
                select new { res.EMAIL, res.USER_NAME };

add string to String array

As many of the answer suggesting better solution is to use ArrayList. ArrayList size is not fixed and it is easily manageable.

It is resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list.

Each ArrayList instance has a capacity. The capacity is the size of the array used to store the elements in the list. It is always at least as large as the list size. As elements are added to an ArrayList, its capacity grows automatically.

Note that this implementation is not synchronized.

ArrayList<String> scripts = new ArrayList<String>();

Error 0x80005000 and DirectoryServices

In the context of Ektron, this issue is resolved by installing the "IIS6 Metabase compatibility" feature in Windows:

Check 'Windows features' or 'Role Services' for IIS6 Metabase compatibility, add if missing:

enter image description here


Why use prefixes on member variables in C++ classes

Lately I have been tending to prefer m_ prefix instead of having no prefix at all, the reasons isn't so much that its important to flag member variables, but that it avoids ambiguity, say you have code like:

void set_foo(int foo) { foo = foo; }

That of cause doesn't work, only one foo allowed. So your options are:

  • this->foo = foo;

    I don't like it, as it causes parameter shadowing, you no longer can use g++ -Wshadow warnings, its also longer to type then m_. You also still run into naming conflicts between variables and functions when you have a int foo; and a int foo();.

  • foo = foo_; or foo = arg_foo;

    Been using that for a while, but it makes the argument lists ugly, documentation shouldn't have do deal with name disambiguity in the implementation. Naming conflicts between variables and functions also exist here.

  • m_foo = foo;

    API Documentation stays clean, you don't get ambiguity between member functions and variables and its shorter to type then this->. Only disadvantage is that it makes POD structures ugly, but as POD structures don't suffer from the name ambiguity in the first place, one doesn't need to use it with them. Having a unique prefix also makes a few search&replace operations easier.

  • foo_ = foo;

    Most of the advantages of m_ apply, but I reject it for aesthetic reasons, a trailing or leading underscore just makes the variable look incomplete and unbalanced. m_ just looks better. Using m_ is also more extendable, as you can use g_ for globals and s_ for statics.

PS: The reason why you don't see m_ in Python or Ruby is because both languages enforce the their own prefix, Ruby uses @ for member variables and Python requires self..

Angular : Manual redirect to route

Redirect to another page using function on component.ts file


import {Router} from '@angular/router';
constructor(private router: Router) {}



<div class="col-3">                  
<button (click)="OnClickFunction()" class="btn btn-secondary btn-custom mr-3">Button Name</button>

LDAP filter for blank (empty) attribute

The schema definition for an attribute determines whether an attribute must have a value. If the manager attribute in the example given is the attribute defined in RFC4524 with OID 0.9.2342.19200300.100.1.10, then that attribute has DN syntax. DN syntax is a sequence of relative distinguished names and must not be empty. The filter given in the example is used to cause the LDAP directory server to return only entries that do not have a manager attribute to the LDAP client in the search result.

Python find min max and average of a list (array)

Only a teacher would ask you to do something silly like this. You could provide an expected answer. Or a unique solution, while the rest of the class will be (yawn) the same...

from operator import lt, gt
def ultimate (l,op,c=1,u=0):
        if op(l[c],l[u]): 
            u = c
        c += 1
        return ultimate(l,op,c,u)
    except IndexError:
        return l[u]
def minimum (l):
    return ultimate(l,lt)
def maximum (l):
    return ultimate(l,gt)

The solution is simple. Use this to set yourself apart from obvious choices.

How do I determine the size of an object in Python?

Here is a quick script I wrote based on the previous answers to list sizes of all variables

for i in dir():
    print (i, sys.getsizeof(eval(i)) )

how to insert a new line character in a string to PrintStream then use a scanner to re-read the file

The linefeed character \n is not the line separator in certain operating systems (such as windows, where it's "\r\n") - my suggestion is that you use \r\n instead, then it'll both see the line-break with only \n and \r\n, I've never had any problems using it.

Also, you should look into using a StringBuilder instead of concatenating the String in the while-loop at BookCatalog.toString(), it is a lot more effective. For instance:

public String toString() {
        BookNode current = front;
        StringBuilder sb = new StringBuilder();
        while (current!=null){
            sb.append(current.getData().toString()+"\r\n ");
            current = current.getNext();
        return sb.toString();

How can I change the class of an element with jQuery>

      $('button').attr('class','btn btn-primary');
}); </script>

Difference between Pragma and Cache-Control headers?

There is no difference, except that Pragma is only defined as applicable to the requests by the client, whereas Cache-Control may be used by both the requests of the clients and the replies of the servers.

So, as far as standards go, they can only be compared from the perspective of the client making a requests and the server receiving a request from the client. The defines the scenario as follows:

HTTP/1.1 caches SHOULD treat "Pragma: no-cache" as if the client had sent "Cache-Control: no-cache". No new Pragma directives will be defined in HTTP.

  Note: because the meaning of "Pragma: no-cache as a response
  header field is not actually specified, it does not provide a
  reliable replacement for "Cache-Control: no-cache" in a response

The way I would read the above:

  • if you're writing a client and need no-cache:

    • just use Pragma: no-cache in your requests, since you may not know if Cache-Control is supported by the server;
    • but in replies, to decide on whether to cache, check for Cache-Control
  • if you're writing a server:

    • in parsing requests from the clients, check for Cache-Control; if not found, check for Pragma: no-cache, and execute the Cache-Control: no-cache logic;
    • in replies, provide Cache-Control.

Of course, reality might be different from what's written or implied in the RFC!

Move entire line up and down in Vim

For me, ddkkp did it (instead of ddkP with an uppercase P, which would work too).

Anaconda site-packages

I encountered this issue in my conda environment. The reason is that packages have been installed into two different folders, only one of which is recognised by the Python executable.

~/anaconda2/envs/[my_env]/site-packages ~/anaconda2/envs/[my_env]/lib/python2.7/site-packages

A proved solution is to add both folders to python path, using the following steps in command line (Please replace [my_env] with your own environment):

  1. conda activate [my_env].
  2. conda-develop ~/anaconda2/envs/[my_env]/site-packages
  3. conda-develop ~/anaconda2/envs/[my_env]/lib/python2.7/site-packages (conda-develop is to add a .pth file to the folder so that the Python executable knows of this folder when searching for packages.)

To ensure this works, try to activate Python in this environment, and import the package that was not found.

jQuery Array of all selected checkboxes (by class)

You can use the :checkbox and :checked pseudo-selectors and the .class selector, with that you will make sure that you are getting the right elements, only checked checkboxes with the class you specify.

Then you can easily use the Traversing/map method to get an array of values:

var values = $('input:checkbox:checked.group1').map(function () {
  return this.value;
}).get(); // ["18", "55", "10"]

sudo service mongodb restart gives "unrecognized service error" in ubuntu 14.0.4

Try this:

Write mongodb instead of mongod

sudo service mongodb status

MongoDB or CouchDB - fit for production?

Adobe is using MongoDB for their upcoming release of Adobe Experience Manager (formerly Day CQ) as the core DB engine.

Several client's at the agency I work at are using CouchDB on projects for large clients.

Both are great and viable DBs, in my opinion. :)

What's better at freeing memory with PHP: unset() or $var = null

I still doubt about this, but I've tried it at my script and I'm using xdebug to know how it will affect my app memory usage. The script is set on my function like this :

function gen_table_data($serv, $coorp, $type, $showSql = FALSE, $table = 'ireg_idnts') {
    $sql = "SELECT COUNT(`operator`) `operator` FROM $table WHERE $serv = '$coorp'";
    if($showSql === FALSE) {
        $sql = mysql_query($sql) or die(mysql_error());
        $data = mysql_fetch_array($sql);
        return $data[0];
    } else echo $sql;

And I add unset just before the return code and it give me : 160200 then I try to change it with $sql = NULL and it give me : 160224 :)

But there is something unique on this comparative when I am not using unset() or NULL, xdebug give me 160144 as memory usage

So, I think giving line to use unset() or NULL will add process to your application and it will be better to stay origin with your code and decrease the variable that you are using as effective as you can .

Correct me if I'm wrong, thanks

Web link to specific whatsapp contact

For what its worth, as of this writing (Nov. 29, 2018), the updated API that seems to work on my end is using this link:<phone number here>


Just replace the placeholder <phone number here> with the intended phone number that you want to use INCLUDING the country code, this means I had to add +60 then the rest of the remaining number.

It doesn't work on my end without one (using Android and iOS at least). It doesn't work means an error message that says along the lines of "you don't have this number".


How to copy a folder via cmd?

xcopy  "C:\Documents and Settings\user\Desktop\?????????" "D:\Backup" /s /e /y /i

Probably the problem is the space.Try with quotes.

Setting background images in JFrame

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

class BackgroundImageJFrame extends JFrame

    JButton b1;
    JLabel l1;

    public BackgroundImageJFrame() {


        setLayout(new BorderLayout());

        JLabel background=new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful_design.png"));


        background.setLayout(new FlowLayout());

        l1=new JLabel("Here is a button");
        b1=new JButton("I am a button");


    public static void main(String args[]) 
        new BackgroundImageJFrame();

check out the below link

Laravel 5 PDOException Could Not Find Driver

Same thing happend to me after upgrading distro.

Running sudo apt-get install php7.0-mysql fixed it for me.

Switch statement equivalent in Windows batch file

I ended up using label names containing the values for the case expressions as suggested by AjV Jsy. Anyway, I use CALL instead of GOTO to jump into the correct case block and GOTO :EOF to jump back. The following sample code is a complete batch script illustrating the idea.


SET /P COLOR="Choose a background color (type red, blue or black): "

2>NUL CALL :CASE_%COLOR% # jump to :CASE_red, :CASE_blue, etc.
IF ERRORLEVEL 1 CALL :DEFAULT_CASE # If label doesn't exist

ECHO Done.

  ECHO Unknown color "%COLOR%"
  GOTO :EOF # return from CALL

How to enable scrolling on website that disabled scrolling?

You can paste the following code to the console to scroll up/down using the a/z keyboard keys. If you want to set your own keys you can visit this page to get the keycodes

function KeyPress(e) {
  var evtobj = window.event? event : e
  if (evtobj.keyCode == 90) {
    window.scrollBy(0, 100) 
  if (evtobj.keyCode == 65) {
    window.scrollBy(0, -100) 

document.onkeydown = KeyPress;

Programmatically close aspx page from code behind

You can just simply use this.. short and easy.


Hope this helps.

How Can I Remove “public/index.php” in the URL Generated Laravel?

Laravel ships with a pretty URL .htaccess already... you should be good to go out of the box...

Make sure mod_rewrite is enabled and that your home path is set to the public directory of your application.

How to set Oracle's Java as the default Java in Ubuntu?

See this; run

sudo  update-java-alternatives --list

to list off all the Java installations on a machine by name and directory, and then run

sudo  update-java-alternatives --set [JDK/JRE name e.g. java-8-oracle]

to choose which JRE/JDK to use.

If you want to use different JDKs/JREs for each Java task, you can run update-alternatives to configure one java executable at a time; you can run

sudo  update-alternatives --config java[Tab]

to see the Java commands that can be configured (java, javac, javah, javaws, etc). And then

sudo  update-alternatives --config [javac|java|javadoc|etc.]

will associate that Java task/command to a particular JDK/JRE.

You may also need to set JAVA_HOME for some applications: from this answer you can use

export JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:bin/java::")

for JREs, or

export JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:jre/bin/java::")

for JDKs.

Getting cursor position in Python

You will not find such function in standard Python libraries, while this function is Windows specific. However if you use ActiveState Python, or just install win32api module to standard Python Windows installation you can use:

x, y = win32api.GetCursorPos()

Fixing Segmentation faults in C++

Before the problem arises, try to avoid it as much as possible:

  • Compile and run your code as often as you can. It will be easier to locate the faulty part.
  • Try to encapsulate low-level / error prone routines so that you rarely have to work directly with memory (pay attention to the modelization of your program)
  • Maintain a test-suite. Having an overview of what is currently working, what is no more working etc, will help you to figure out where the problem is (Boost test is a possible solution, I don't use it myself but the documentation can help to understand what kind of information must be displayed).

Use appropriate tools for debugging. On Unix:

  • GDB can tell you where you program crash and will let you see in what context.
  • Valgrind will help you to detect many memory-related errors.
  • With GCC you can also use mudflap With GCC, Clang and since October experimentally MSVC you can use Address/Memory Sanitizer. It can detect some errors that Valgrind doesn't and the performance loss is lighter. It is used by compiling with the-fsanitize=address flag.

Finally I would recommend the usual things. The more your program is readable, maintainable, clear and neat, the easiest it will be to debug.

Check if an element is present in a Bash array

You could do:

if [[ " ${arr[*]} " == *" d "* ]]; then
    echo "arr contains d"

This will give false positives for example if you look for "a b" -- that substring is in the joined string but not as an array element. This dilemma will occur for whatever delimiter you choose.

The safest way is to loop over the array until you find the element:

array_contains () {
    local seeking=$1; shift
    local in=1
    for element; do
        if [[ $element == "$seeking" ]]; then
    return $in

arr=(a b c "d e" f g)
array_contains "a b" "${arr[@]}" && echo yes || echo no    # no
array_contains "d e" "${arr[@]}" && echo yes || echo no    # yes

Here's a "cleaner" version where you just pass the array name, not all its elements

array_contains2 () { 
    local array="$1[@]"
    local seeking=$2
    local in=1
    for element in "${!array}"; do
        if [[ $element == "$seeking" ]]; then
    return $in

array_contains2 arr "a b"  && echo yes || echo no    # no
array_contains2 arr "d e"  && echo yes || echo no    # yes

For associative arrays, there's a very tidy way to test if the array contains a given key: The -v operator

$ declare -A arr=( [foo]=bar [baz]=qux )
$ [[ -v arr[foo] ]] && echo yes || echo no
$ [[ -v arr[bar] ]] && echo yes || echo no

See 6.4 Bash Conditional Expressions in the manual.

Python - abs vs fabs

Edit: as @aix suggested, a better (more fair) way to compare the speed difference:

In [1]: %timeit abs(5)
10000000 loops, best of 3: 86.5 ns per loop

In [2]: from math import fabs

In [3]: %timeit fabs(5)
10000000 loops, best of 3: 115 ns per loop

In [4]: %timeit abs(-5)
10000000 loops, best of 3: 88.3 ns per loop

In [5]: %timeit fabs(-5)
10000000 loops, best of 3: 114 ns per loop

In [6]: %timeit abs(5.0)
10000000 loops, best of 3: 92.5 ns per loop

In [7]: %timeit fabs(5.0)
10000000 loops, best of 3: 93.2 ns per loop

In [8]: %timeit abs(-5.0)
10000000 loops, best of 3: 91.8 ns per loop

In [9]: %timeit fabs(-5.0)
10000000 loops, best of 3: 91 ns per loop

So it seems abs() only has slight speed advantage over fabs() for integers. For floats, abs() and fabs() demonstrate similar speed.

In addition to what @aix has said, one more thing to consider is the speed difference:

In [1]: %timeit abs(-5)
10000000 loops, best of 3: 102 ns per loop

In [2]: import math

In [3]: %timeit math.fabs(-5)
10000000 loops, best of 3: 194 ns per loop

So abs() is faster than math.fabs().

SQLSTATE[42S22]: Column not found: 1054 Unknown column - Laravel

You don't have a field named user_email in the members table ... as for why, I'm not sure as the code "looks" like it should try to join on different fields

Does the Auth::attempt method perform a join of the schema? Run grep -Rl 'class Auth' /path/to/framework and find where the attempt method is and what it does.

How to set the size of a column in a Bootstrap responsive table

Bootstrap 4.0

Be aware of all migration changes from Bootstrap 3 to 4. On the table you now need to enable flex box by adding the class d-flex, and drop the xs to allow bootstrap to automatically detect the viewport.

<div class="container-fluid">
    <table id="productSizes" class="table">
            <tr class="d-flex">
                <th class="col-1">Size</th>
                <th class="col-3">Bust</th>
                <th class="col-3">Waist</th>
                <th class="col-5">Hips</th>
            <tr class="d-flex">
                <td class="col-1">6</td>
                <td class="col-3">79 - 81</td>
                <td class="col-3">61 - 63</td>
                <td class="col-5">89 - 91</td>
            <tr class="d-flex">
                <td class="col-1">8</td>
                <td class="col-3">84 - 86</td>
                <td class="col-3">66 - 68</td>
                <td class="col-5">94 - 96</td>


Bootstrap 3.2

Table column width use the same layout as grids do; using col-[viewport]-[size]. Remember the column sizes should total 12; 1 + 3 + 3 + 5 = 12 in this example.

                <th class="col-xs-1">Size</th>
                <th class="col-xs-3">Bust</th>
                <th class="col-xs-3">Waist</th>
                <th class="col-xs-5">Hips</th>

Remember to set the <th> elements rather than the <td> elements so it sets the whole column. Here is a working BOOTPLY.

Thanks to @Dan for reminding me to always work mobile view (col-xs-*) first.

How can I check if a View exists in a Database?

You can check the availability of the view in various ways


use sys.objects

   FROM   sys.objects
   WHERE  OBJECT_ID = OBJECT_ID('[schemaName].[ViewName]')
          AND Type_Desc = 'VIEW'
    PRINT 'View Exists'

use sysobjects

   FROM   sysobjects
   WHERE  NAME = '[schemaName].[ViewName]'
          AND xtype = 'V'
    PRINT 'View Exists'

use sys.views

   FROM sys.views
   WHERE OBJECT_ID = OBJECT_ID(N'[schemaName].[ViewName]')
    PRINT 'View Exists'


   WHERE  table_name = 'ViewName'
          AND table_schema = 'schemaName'
    PRINT 'View Exists'


   SELECT OBJECT_ID('ViewName', 'V')
    PRINT 'View Exists'

use sys.sql_modules

   FROM   sys.sql_modules
   WHERE  OBJECT_ID = OBJECT_ID('[schemaName].[ViewName]')
   PRINT 'View Exists'

Get div to take up 100% body height, minus fixed-height header and footer

You can take advatange of the css property Box Sizing.

#content { 
    height: 100%;
    -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
    -moz-box-sizing: border-box;    /* Firefox, other Gecko */
    box-sizing: border-box;         /* Opera/IE 8+ */
    padding-top: 50px;
    margin-top: -50px;
    padding-bottom: 50px;
    margin-bottom: -50px;

See the JsFiddle.

Word wrap for a label in Windows Forms

From MSDN, Automatically Wrap Text in Label:

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

public class GrowLabel : Label {
    private bool mGrowing;
    public GrowLabel() {
        this.AutoSize = false;
    private void resizeLabel() {
        if (mGrowing) 
        try {
            mGrowing = true;
            Size sz = new Size(this.Width, Int32.MaxValue);
            sz = TextRenderer.MeasureText(this.Text, this.Font, sz, TextFormatFlags.WordBreak);
            this.Height = sz.Height;
        finally {
            mGrowing = false;
    protected override void OnTextChanged(EventArgs e) {
    protected override void OnFontChanged(EventArgs e) {
    protected override void OnSizeChanged(EventArgs e) {

key_load_public: invalid format

As Roland mentioned in their answer, it's a warning that the ssh-agent doesn't understand the format of the public key and even then, the public key will not be used locally.

However, I can also elaborate and answer why the warning is there. It simply boils down to the fact that the PuTTY Key Generator generates two different public key formats depending on what you do in the program.

Note: Throughout my explanation, the key files I will be using/generating will be named id_rsa with their appropriate extensions. Furthermore, for copy-paste convenience, the parent folder of the keys will be assumed to be ~/.ssh/. Adjust these details to suit your needs as desired.

The Formats

Link to the relevant PuTTY documentation


When you save a key using the PuTTY Key Generator using the "Save public key" button, it will be saved in the format defined by RFC 4716.


Comment: "github-example-key"


Contrary to popular belief, this format doesn't get saved by the generator. However it is generated and shown in the text box titled "Public key for pasting into OpenSSH authorized_keys file". To save it as a file, you have to manually copy it from the text box and paste it into a new text file.

For the key shown above, this would be:

ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAQEAhl/CNy9wI1GVdiHAJQV0CkHnMEqW7+Si9WYFi2fSBrsGcmqeb5EwgnhmTcPgtM5ptGBjUZR84nxjZ8SPmnLDiDyHDPIsmwLBHxcppY0fhRSGtWL5fT8DGm9EfXaO1QN8c31VU/IkD8niWA6NmHNE1qEqpph3DznVzIm3oMrongEjGw7sDP48ZTZp2saYVAKEEuGC1YYcQ1g20yESzo7aP70ZeHmQqI9nTyEAip3mL20+qHNsHfW8hJAchaUN8CwNQABJaOozYijiIUgdbtSTMRDYPi7fjhgB3bA9tBjh7cOyuU/c4M4D6o2mAVYdLAWMBkSoLG8Oel6TCcfpO/nElw== github-example-key

The format of the key is simply ssh-rsa <signature> <comment> and can be created by rearranging the SSH-2 formatted file.

Regenerating Public Keys

If you are making use of ssh-agent, you will likely also have access to ssh-keygen.

If you have your OpenSSH Private Key (id_rsa file), you can generate the OpenSSH Public Key File using:

ssh-keygen -f ~/.ssh/id_rsa -y > ~/.ssh/

If you only have the PUTTY Private Key (id_rsa.ppk file), you will need to convert it first.

  1. Open the PuTTY Key Generator
  2. On the menu bar, click "File" > "Load private key"
  3. Select your id_rsa.ppk file
  4. On the menu bar, click "Conversions" > "Export OpenSSH key"
  5. Save the file as id_rsa (without an extension)

Now that you have an OpenSSH Private Key, you can use the ssh-keygen tool as above to perform manipulations on the key.

Bonus: The PKCS#1 PEM-encoded Public Key Format

To be honest, I don't know what this key is used for as I haven't needed it. But I have it in my notes I've collated over the years and I'll include it here for wholesome goodness. The file will look like this:


This file can be generated using an OpenSSH Private Key (as generated in "Regenerating Public Keys" above) using:

ssh-keygen -f ~/.ssh/id_rsa -y -e -m pem > ~/.ssh/id_rsa.pem

Alternatively, you can use an OpenSSH Public Key using:

ssh-keygen -f ~/.ssh/ -e -m pem > ~/.ssh/id_rsa.pem


HTML Display Current date

Use Date::toLocaleDateString.

new Date().toLocaleDateString()
= "9/13/2015"

You don't need to set innerHTML, just by writing

<script> document.write(new Date().toLocaleDateString()); </script>

will work.



new Date().toDateString()
= "Sun Sep 13 2015"

How to Automatically Start a Download in PHP?

A clean example.

    header('Content-Type: application/download');
    header('Content-Disposition: attachment; filename="example.txt"');
    header("Content-Length: " . filesize("example.txt"));

    $fp = fopen("example.txt", "r");

How to add a form load event (currently not working)

Three ways you can do this - from the form designer, select the form, and where you normally see the list of properties, just above it there should be a little lightning symbol - this shows you all the events of the form. Find the form load event in the list, and you should be able to pick ProgramViwer_Load from the dropdown.

A second way to do it is programmatically - somewhere (constructor maybe) you'd need to add it, something like: ProgramViwer.Load += new EventHandler(ProgramViwer_Load);

A third way using the designer (probably the quickest) - when you create a new form, double click on the middle of it on it in design mode. It'll create a Form load event for you, hook it in, and take you to the event handler code. Then you can just add your two lines and you're good to go!

How to search for a string in cell array in MATLAB?

The strcmp and strcmpi functions are the most direct way to do this. They search through arrays.

strs = {'HA' 'KU' 'LA' 'MA' 'TATA'}
ix = find(strcmp(strs, 'KU'))

LINQ: "contains" and a Lambda query

Use Any() instead of Contains():

buildingStatus.Any(item => item.GetCharValue() == v.Status)

How to check for null in a single statement in scala?

Option(getObject) foreach (QueueManager add)

How to get past the login page with Wget?

I had the same problem. My solution was to do the login via Chrome and save the cookies data to a text file. This is easily done with this Chrome extension: Chrome cookie.txt export extension.

When you get the cookies data, there is also an example on how to use them with wget. A simple copy-paste command line is provided to you.

C# how to convert File.ReadLines into string array?

Change string[] lines = File.ReadLines("c:\\file.txt"); to IEnumerable<string> lines = File.ReadLines("c:\\file.txt"); The rest of your code should work fine.

Combine two tables for one output

You'll need to use UNION to combine the results of two queries. In your case:

SELECT ChargeNum, CategoryID, SUM(Hours)
FROM KnownHours
GROUP BY ChargeNum, CategoryID
SELECT ChargeNum, 'Unknown' AS CategoryID, SUM(Hours)
FROM UnknownHours
GROUP BY ChargeNum

Note - If you use UNION ALL as in above, it's no slower than running the two queries separately as it does no duplicate-checking.

creating a random number using MYSQL

these both are working nicely:

select round(<maxNumber>*rand())

FLOOR(RAND() * (<max> - <min> + 1)) + <min> // generates a number
between <min> and <max> inclusive.

XAMPP - Error: MySQL shutdown unexpectedly

There may be MySQL server installed previously in your computer try to uninstall that and start MySQL at the XAMPP This solved mine

Escape sequence \f - form feed - what exactly is it?

It's go to newline then add spaces to start second line at end of first line



How do you configure HttpOnly cookies in tomcat / java webapps?

For cookies that I am explicitly setting, I switched to use SimpleCookie provided by Apache Shiro. It does not inherit from javax.servlet.http.Cookie so it takes a bit more juggling to get everything to work correctly however it does provide a property set HttpOnly and it works with Servlet 2.5.

For setting a cookie on a response, rather than doing response.addCookie(cookie) you need to do cookie.saveTo(request, response).

Java Programming: call an exe from Java and passing parameters

import java.lang.ProcessBuilder;

public class handlingexe {
    public static void main(String[] args) throws IOException {
        ProcessBuilder p = new ProcessBuilder();
        System.out.println("Started EXE");

        System.out.println("Started EXE"); 

Uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

In case you can't upgrade to Ruby on Rails 2.3.11 (and to expand on douglasr's answer), thread must be required at the top of boot.rb. For example:

require 'thread'

# Don't change this file!
# Configure your app in config/environment.rb and config/environments/*.rb

How can I split a delimited string into an array in PHP?

The Best choice is to use the function "explode()".

$content = "dad,fger,fgferf,fewf";
$delimiters =",";
$explodes = explode($delimiters, $content);

foreach($exploade as $explode) {
    echo "This is a exploded String: ". $explode;

If you want a faster approach you can use a delimiter tool like There are many websites like this. But I prefer a simple PHP code.

Has been compiled by a more recent version of the Java Runtime (class file version 57.0)

This is a setting in IntelliJ IDEA ($JAVA_HOME and language level were set to 1.8):

File > Settings > Build, Execution, Deployment > Gradle > Gradle JVM

Select eg. Project SDK (corretto-1.8) (or any other compatible version).

Then delete the build directory and restart the IDE.

How do I upload a file to an SFTP server in C# (.NET)?

There is no solution for this within the .net framework. outlines a list of un-free options.

your best free bet is to extend SSH using Granados.

Install Application programmatically on Android

try this

String filePath = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
String title = filePath.substring( filePath.lastIndexOf('/')+1, filePath.length() );
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(filePath)), "application/");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // without this flag android returned a intent error!

read complete file without using loop in java

If the file is small, you can read the whole data once:

File file = new File("a.txt");
FileInputStream fis = new FileInputStream(file);
byte[] data = new byte[(int) file.length()];;

String str = new String(data, "UTF-8");

Eloquent - where not equal to

While this seems to work

    ->where('to_be_used_by_user_id', '!=' , 2)

you should not use it for big tables, because as a general rule "or" in your where clause is stopping query to use index. You are going from "Key lookup" to "full table scan"

enter image description here enter image description here

Instead, try Union

$first = Code::whereNull('to_be_used_by_user_id');

$code = Code::where('to_be_used_by_user_id', '!=' , 2)

How do I switch between command and insert mode in Vim?

Pressing ESC quits from insert mode to normal mode, where you can press : to type in a command. Press i again to back to insert mode, and you are good to go.

I'm not a Vim guru, so someone else can be more experienced and give you other options.

How To limit the number of characters in JTextField?

import java.awt.KeyboardFocusManager;
import javax.swing.InputVerifier;
import javax.swing.JTextField;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
import javax.swing.text.DocumentFilter.FilterBypass;

 * @author Igor
public class CustomLengthTextField extends JTextField {

    protected boolean upper = false;
    protected int maxlength = 0;

    public CustomLengthTextField() {

    public CustomLengthTextField(int length, boolean upper) {
        this(length, upper, null);

    public CustomLengthTextField(int length, InputVerifier inpVer) {
        this(length, false, inpVer);

     * @param length - maksimalan length
     * @param upper - turn it to upercase
     * @param inpVer - InputVerifier
    public CustomLengthTextField(int length, boolean upper, InputVerifier inpVer) {
        this.maxlength = length;
        this.upper = upper;
        if (length > 0) {
            AbstractDocument doc = (AbstractDocument) getDocument();
            doc.setDocumentFilter(new DocumentSizeFilter());

    public CustomLengthTextField(int length) {
        this(length, false);

    public void setMaxLength(int length) {
        this.maxlength = length;

    class DocumentSizeFilter extends DocumentFilter {

        public void insertString(FilterBypass fb, int offs, String str, AttributeSet a)
                throws BadLocationException {

            //This rejects the entire insertion if it would make
            //the contents too long. Another option would be
            //to truncate the inserted string so the contents
            //would be exactly maxCharacters in length.
            if ((fb.getDocument().getLength() + str.length()) <= maxlength) {
                super.insertString(fb, offs, str, a);

        public void replace(FilterBypass fb, int offs,
                int length,
                String str, AttributeSet a)
                throws BadLocationException {

            if (upper) {
                str = str.toUpperCase();

            //This rejects the entire replacement if it would make
            //the contents too long. Another option would be
            //to truncate the replacement string so the contents
            //would be exactly maxCharacters in length.
            int charLength = fb.getDocument().getLength() + str.length() - length;

            if (charLength <= maxlength) {
                super.replace(fb, offs, length, str, a);
                if (charLength == maxlength) {
            } else {

        private void focusNextComponent() {
            if (CustomLengthTextField.this == KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner()) {

How to ignore a particular directory or file for tslint?

In addition to Michael's answer, consider a second way: adding linterOptions.exclude to tslint.json

For example, you may have tslint.json with following lines:

  "linterOptions": {
    "exclude": [

await is only valid in async function

The error is not refering to myfunction but to start.

async function start() {

   const result = await helper.myfunction('test', 'test');

// My function_x000D_
const myfunction = async function(x, y) {_x000D_
  return [_x000D_
// Start function_x000D_
const start = async function(a, b) {_x000D_
  const result = await myfunction('test', 'test');_x000D_
// Call start_x000D_

I use the opportunity of this question to advise you about an known anti pattern using await which is : return await.


async function myfunction() {_x000D_
  console.log('Inside of myfunction');_x000D_
// Here we wait for the myfunction to finish_x000D_
// and then returns a promise that'll be waited for aswell_x000D_
// It's useless to wait the myfunction to finish before to return_x000D_
// we can simply returns a promise that will be resolved later_x000D_
// useless async here_x000D_
async function start() {_x000D_
  // useless await here_x000D_
  return await myfunction();_x000D_
// Call start_x000D_
(async() => {_x000D_
  console.log('before start');_x000D_
  await start();_x000D_
  console.log('after start');_x000D_


async function myfunction() {_x000D_
  console.log('Inside of myfunction');_x000D_
// Here we wait for the myfunction to finish_x000D_
// and then returns a promise that'll be waited for aswell_x000D_
// It's useless to wait the myfunction to finish before to return_x000D_
// we can simply returns a promise that will be resolved later_x000D_
// Also point that we don't use async keyword on the function because_x000D_
// we can simply returns the promise returned by myfunction_x000D_
function start() {_x000D_
  return myfunction();_x000D_
// Call start_x000D_
(async() => {_x000D_
  console.log('before start');_x000D_
  await start();_x000D_
  console.log('after start');_x000D_

Also, know that there is a special case where return await is correct and important : (using try/catch)

Are there performance concerns with `return await`?

Change the Arrow buttons in Slick slider

its very easy. Use the bellow code, Its works for me. Here I have used fontawesome icon but you can use anything as image or any other Icon's code.

            arrows: true,
            prevArrow:"<button type='button' class='slick-prev pull-left'><i class='fa fa-angle-left' aria-hidden='true'></i></button>",
            nextArrow:"<button type='button' class='slick-next pull-right'><i class='fa fa-angle-right' aria-hidden='true'></i></button>"

How do I avoid the specification of the username and password at every git push?

You have to setup a SSH private key, you can review this page, how to do the setup on Mac, if you are on linux the guide should be almost the same, on Windows you would need tool like MSYS.

Will Google Android ever support .NET?

.NET compact framework has been ported to Symbian OS ( If .NET as a 'closed' platform can be ported to this platform, I can't see any reason why it cannot be done for Android.

How to define a List bean in Spring?

You just remove id out of beans inside <list> tag. Like this:

<property name="listStaff">
    <bean class="com.test.entity.Staff">
        <constructor-arg name="name" value = "Jonh"/>
        <constructor-arg name="age" value = "30"/>
    <bean class="com.test.entity.Staff">
        <constructor-arg name="name" value = "Jam"/>
        <constructor-arg name="age" value = "21"/>

How to switch Python versions in Terminal?

Here is a nice and simple way to do it (but on CENTOS), without braking the operating system.

yum install scl-utils


yum install centos-release-scl-rh

And lastly you install the version that you want, lets say python3.5

yum install rh-python35

And lastly:

scl enable rh-python35 bash

Since MAC-OS is a unix operating system, the way to do it it should be quite similar.

How to read file contents into a variable in a batch file?

To get all the lines of the file loaded into the variable, Delayed Expansion is needed, so do the following:

SETLOCAL EnableDelayedExpansion

for /f "Tokens=* Delims=" %%x in (version.txt) do set Build=!Build!%%x

There is a problem with some special characters, though especially ;, % and !

Regex expressions in Java, \\s vs. \\s+

First of all you need to understand that final output of both the statements will be same i.e. to remove all the spaces from given string.

However x.replaceAll("\\s+", ""); will be more efficient way of trimming spaces (if string can have multiple contiguous spaces) because of potentially less no of replacements due the to fact that regex \\s+ matches 1 or more spaces at once and replaces them with empty string.

So even though you get the same output from both it is better to use:

x.replaceAll("\\s+", "");

How to fix org.hibernate.LazyInitializationException - could not initialize proxy - no Session

If you are using Grail's Framework, it's simple to resolve lazy initialization exception by using Lazy keyword on specific field in Domain Class.


class Book {
    static belongsTo = [author: Author]
    static mapping = {
        author lazy: false

Find further information here

De-obfuscate Javascript code to make it readable again

Here's a new automated tool, JSNice, to try to deobfuscate/deminify it. The tool even tries to guess the variable names, which is unbelievably cool. (It mines Javascript on github for this purpose.)

Liquibase lock - reasons?

Sometimes truncating or dropping the table DATABASECHANGELOGLOCK doesn't work. I use PostgreSQL database and came across this issue a lot of times. What I do for solving is to rollback the prepared statements running in background for that database. Try to rollback all the prepared statements and try the liquibase changes again.


SELECT gid FROM pg_prepared_xacts WHERE database='database_name';

If above statement returns any record, then rollback that prepared statement with following SQL statement.

ROLLBACK PREPARED 'gid_obtained_from_above_SQL';

Font size relative to the user's screen resolution?

Not using media queries is nice because it allows scaling the font size gradually.

Using vw units will adjust the font size relative to the view port size.

Directly converting vw units to font size will make it difficult to hit to the sweet spot for both mobile resolutions and desktop.

I recommend trying something like:

body {
    font-size: calc(0.5em + 1vw);

Credit: CSS In Depth

Mask output of `The following objects are masked from....:` after calling attach() function

You actually don't need to use the attach at all. I had the same problem and it was resolved by removing the attach statement.

ActionBar text color

This is the solution I used after checking all answers

<!-- Base application theme. -->
<style name="AppTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorAccent">@color/Button_color</item>
    <item name="android:editTextStyle">@style/EditTextStyle</item>
    <item name="android:typeface">monospace</item>
    <item name="android:windowActionBar">true</item>
    <item name="colorPrimary">@color/Title_Bar_Color</item>
    <item name="android:actionBarStyle">@style/Widget.Styled.ActionBar</item>
    <item name="actionBarStyle">@style/Widget.Styled.ActionBar</item>


<style name="EditTextStyle" parent="Widget.AppCompat.EditText"/>

<style name="Widget.Styled.ActionBar" parent="@style/Widget.AppCompat.Light.ActionBar">
    <item name="titleTextStyle">@style/ActionBarTitleText</item>
    <item name="android:background">@color/Title_Bar_Color</item>
    <item name="background">@color/Title_Bar_Color</item>
    <item name="subtitleTextStyle">@style/ActionBarSubTitleText</item>

<style name="ActionBarTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
    <item name="android:textColor">@color/solid_white</item>
    <item name="android:textSize">12sp</item>

<style name="ActionBarSubTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Subtitle">
    <item name="android:textColor">@color/solid_white</item>
    <item name="android:textSize">12sp</item>

Change the required colors it will work

Using Axios GET with Authorization Header in React-Native App

For anyone else that comes across this post and might find it useful... There is actually nothing wrong with my code. I made the mistake of requesting client_credentials type access code instead of password access code (#facepalms). FYI I am using urlencoded post hence the use of querystring.. So for those that may be looking for some example code.. here is my full request

Big thanks to @swapnil for trying to help me debug this.

   const data = {
      grant_type: USER_GRANT_TYPE,
      client_id: CLIENT_ID,
      client_secret: CLIENT_SECRET,
      scope: SCOPE_INT,
      username: DEMO_EMAIL,
      password: DEMO_PASSWORD
    };, Querystring.stringify(data))   
   .then(response => {
      USER_TOKEN =;
      console.log('userresponse ' +; 
   .catch((error) => {
      console.log('error ' + error);   

const AuthStr = 'Bearer '.concat(USER_TOKEN); 
axios.get(URL, { headers: { Authorization: AuthStr } })
 .then(response => {
     // If request is good...
 .catch((error) => {
     console.log('error ' + error);

What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time?

I'd suggest you use the TimeSpan class for this.

public static void Main(string[] args)
    TimeSpan t = TimeSpan.FromSeconds(80);

    t = TimeSpan.FromSeconds(868693412);



nginx showing blank PHP pages

If you getting a blank screen, that may be because of 2 reasons:

  1. Browser blocking the Frames from being displayed. In some browsers the frames are considered as unsafe. To overcome this you can launch the frameless version of phpPgAdmin by


  2. You have enabled a security feature in Nginx for X-Frame-Options try disabling it.

How to center icon and text in a android button with width set to "fill parent"

As suggested by Rodja, prior to 4.0 there isn't a direct way to center the text with the drawable. And indeed setting a padding_left value does move the drawable away from the border. Therefore my suggestion is that on runtime you calculate exactly how many pixels from the left border your drawable needs to be and then pass it using setPadding Your calculation may be something like

int paddingLeft = (button.getWidth() - drawableWidth - textWidth) / 2;

The width of your drawable's is fixed and you can look it up and you can also calculate or guess the text width.

Finally, you would need to multiple the padding value by the screen density, which you can do using DisplayMetrics

paint() and repaint() in Java

The paint() method supports painting via a Graphics object.

The repaint() method is used to cause paint() to be invoked by the AWT painting thread.

Sort Pandas Dataframe by Date

@JAB's answer is fast and concise. But it changes the DataFrame you are trying to sort, which you may or may not want.

(Note: You almost certainly will want it, because your date columns should be dates, not strings!)

In the unlikely event that you don't want to change the dates into dates, you can also do it a different way.

First, get the index from your sorted Date column:

In [25]: pd.to_datetime(df.Date).order().index
Out[25]: Int64Index([0, 2, 1], dtype='int64')

Then use it to index your original DataFrame, leaving it untouched:

In [26]: df.ix[pd.to_datetime(df.Date).order().index]
        Date Symbol
0 2015-02-20      A
2 2015-08-21      A
1 2016-01-15      A


Note: for Pandas versions 0.20.0 and later, use loc instead of ix, which is now deprecated.

How to open a folder in Windows Explorer from VBA?

You can use command prompt to open explorer with path.

here example with batch or command prompt:

start "" explorer.exe (path)

so In VBA ms.access you can write with:

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


You'll need to join twice:

SELECT home.*, away.*,, g.date_start 
FROM game AS g
INNER JOIN team AS home
  ON home.importid = g.home
INNER JOIN team AS away
  ON away.importid = g.away
ORDER BY g.date_start DESC 

How to check if android checkbox is checked within its onClick method (declared in XML)?

try this one :

public void itemClicked(View v) {
  //code to check if this checkbox is checked!
  CheckBox checkBox = (CheckBox)v;


Store images in a MongoDB database

There is a Mongoose plugin available on NPM called mongoose-file. It lets you add a file field to a Mongoose Schema for file upload. I have never used it but it might prove useful. If the images are very small you could Base64 encode them and save the string to the database.

Storing some small (under 1MB) files with MongoDB in NodeJS WITHOUT GridFS

How to change workspace and build record Root Directory on Jenkins?

I would suggest editing the /etc/default/jenkins

vi /etc/default/jenkins

And changing the $JENKINS_HOME variable (around line 23) to


Then restart the Jenkins with usual

/etc/init.d/jenkins start


Outline radius?

As far as I know, the Outline radius is only supported by Firefox and Firefox for android.

-moz-outline-radius: 1em;

enter image description here

Can I target all <H> tags with a single selector?

You can also use PostCSS and the custom selectors plugin

@custom-selector :--headings h1, h2, h3, h4, h5, h6;

article :--headings {
  margin-top: 0;


article h1,
article h2,
article h3,
article h4,
article h5,
article h6 {
  margin-top: 0;

Get a resource using getResource()

  • leading slash to denote the root of the classpath
  • slashes instead of dots in the path
  • you can call getResource() directly on the class.

How to add dll in c# project

Have you added the dll into your project references list? If not right click on the project "References" folder and selecet "Add Reference" then use browse to locate your science.dll, select it and click ok.


I can't see the image of your VS instance that some people are referring to and I note that you now say that it works in Net4.0 and VS2010.

VS2008 projects support NET 3.5 by default. I expect that is the problem as your DLL may be NET 4.0 compliant but not NET 3.5.

Should I use typescript? or I can just use ES6?

Decision tree between ES5, ES6 and TypeScript

Do you mind having a build step?

  • Yes - Use ES5
  • No - keep going

Do you want to use types?

  • Yes - Use TypeScript
  • No - Use ES6

More Details

ES5 is the JavaScript you know and use in the browser today it is what it is and does not require a build step to transform it into something that will run in today's browsers

ES6 (also called ES2015) is the next iteration of JavaScript, but it does not run in today's browsers. There are quite a few transpilers that will export ES5 for running in browsers. It is still a dynamic (read: untyped) language.

TypeScript provides an optional typing system while pulling in features from future versions of JavaScript (ES6 and ES7).

Note: a lot of the transpilers out there (i.e. babel, TypeScript) will allow you to use features from future versions of JavaScript today and exporting code that will still run in today's browsers.

How to efficiently count the number of keys/properties of an object in JavaScript?

To do this in any ES5-compatible environment, such as Node, Chrome, IE 9+, Firefox 4+, or Safari 5+:


How are VST Plugins made?

I know this is 3 years old, but for everyone reading this now: Don't stick to VST, AU or any vendor's format. Steinberg has stopped supporting VST2, and people are in trouble porting their code to newer formats, because it's too tied to VST2.

These tutorials cover creating plugins that run on Win/Mac, 32/64, all plugin formats from the same code base.

How do you get the list of targets in a makefile?

If you have bash completion for make installed, the completion script will define a function _make_target_extract_script. This function is meant to create a sed script which can be used to obtain the targets as a list.

Use it like this:

# Make sure bash completion is enabled
source /etc/bash_completion 

# List targets from Makefile
sed -nrf <(_make_target_extract_script --) Makefile

What is the correct way to check for string equality in JavaScript?

If you know they are strings, then there's no need to check for type.

"a" == "b"

However, note that string objects will not be equal.

new String("a") == new String("a")

will return false.

Call the valueOf() method to convert it to a primitive for String objects,

new String("a").valueOf() == new String("a").valueOf()

will return true