Programs & Examples On #Culerity

Use of ~ (tilde) in R programming Language

R defines a ~ (tilde) operator for use in formulas. Formulas have all sorts of uses, but perhaps the most common is for regression:

lm( myFormula, data=iris)

help("~") or help("formula") will teach you more.

@Spacedman has covered the basics. Let's discuss how it works.

First, being an operator, note that it is essentially a shortcut to a function (with two arguments):

> `~`(lhs,rhs)
lhs ~ rhs
> lhs ~ rhs
lhs ~ rhs

That can be helpful to know for use in e.g. apply family commands.

Second, you can manipulate the formula as text:

oldform <- as.character(myFormula) # Get components
myFormula <- as.formula( paste( oldform[2], "Sepal.Length", sep="~" ) )

Third, you can manipulate it as a list:


Finally, there are some helpful tricks with formulae (see help("formula") for more):

myFormula <- Species ~ . 

For example, the version above is the same as the original version, since the dot means "all variables not yet used." This looks at the data.frame you use in your eventual model call, sees which variables exist in the data.frame but aren't explicitly mentioned in your formula, and replaces the dot with those missing variables.

JavaScript equivalent to printf/String.Format

Building on the previously suggested solutions:

// First, checks if it isn't implemented yet.
if (!String.prototype.format) {
  String.prototype.format = function() {
    var args = arguments;
    return this.replace(/{(\d+)}/g, function(match, number) { 
      return typeof args[number] != 'undefined'
        ? args[number]
        : match

"{0} is dead, but {1} is alive! {0} {2}".format("ASP", "ASP.NET")


ASP is dead, but ASP.NET is alive! ASP {2}

If you prefer not to modify String's prototype:

if (!String.format) {
  String.format = function(format) {
    var args =, 1);
    return format.replace(/{(\d+)}/g, function(match, number) { 
      return typeof args[number] != 'undefined'
        ? args[number] 
        : match

Gives you the much more familiar:

String.format('{0} is dead, but {1} is alive! {0} {2}', 'ASP', 'ASP.NET');

with the same result:

ASP is dead, but ASP.NET is alive! ASP {2}

Java Refuses to Start - Could not reserve enough space for object heap

Given that none of the other suggestions have worked (including many things I'd have suggested myself), to help troubleshoot further, could you try running:

sysctl -a

On both the SuSE and RedHat machines to see if there are any differences? I'm guessing the default configurations are different between these two distributions that's causing this.

Javascript Src Path

If you have

<base href="/" />

It's will not load file right. Just delete it.

JSON Parse File Path

This solution uses an Asynchronous call. It will likely work better than a synchronous solution.

var request = new XMLHttpRequest();"GET", "../../data/file.json", false);
request.onreadystatechange = function() {
  if ( request.readyState === 4 && request.status === 200 ) {
    var my_JSON_object = JSON.parse(request.responseText);

Webpack.config how to just copy the index.html to the dist folder

I will add an option to VitalyB's answer:

Option 3

Via npm. If you run your commands via npm, then you could add this setup to your package.json (check out also the webpack.config.js there too). For developing run npm start, no need to copy index.html in this case because the web server will be run from the source files directory, and the bundle.js will be available from the same place (the bundle.js will live in memory only but will available as if it was located together with index.html). For production run npm run build and a dist folder will contain your bundle.js and index.html gets copied with good old cp-command, as you can see below:

"scripts": {
    "test": "NODE_ENV=test karma start",
    "start": "node node_modules/.bin/webpack-dev-server --content-base app",
    "build": "NODE_ENV=production node node_modules/.bin/webpack && cp app/index.html dist/index.html"

Update: Option 4

There is a copy-webpack-plugin, as described in this Stackoverflow answer

But generally, except for the very "first" file (like index.html) and larger assets (like large images or video), include the css, html, images and so on directly in your app via require and webpack will include it for you (well, after you set it up correctly with loaders and possibly plugins).

long long in C/C++

It depends in what mode you are compiling. long long is not part of the C++ standard but only (usually) supported as extension. This affects the type of literals. Decimal integer literals without any suffix are always of type int if int is big enough to represent the number, long otherwise. If the number is even too big for long the result is implementation-defined (probably just a number of type long int that has been truncated for backward compatibility). In this case you have to explicitly use the LL suffix to enable the long long extension (on most compilers).

The next C++ version will officially support long long in a way that you won't need any suffix unless you explicitly want the force the literal's type to be at least long long. If the number cannot be represented in long the compiler will automatically try to use long long even without LL suffix. I believe this is the behaviour of C99 as well.

TypeError: only length-1 arrays can be converted to Python scalars while plot showing

Take note of what is printed for x. You are trying to convert an array (basically just a list) into an int. length-1 would be an array of a single number, which I assume numpy just treats as a float. You could do this, but it's not a purely-numpy solution.

EDIT: I was involved in a post a couple of weeks back where numpy was slower an operation than I had expected and I realised I had fallen into a default mindset that numpy was always the way to go for speed. Since my answer was not as clean as ayhan's, I thought I'd use this space to show that this is another such instance to illustrate that vectorize is around 10% slower than building a list in Python. I don't know enough about numpy to explain why this is the case but perhaps someone else does?

import numpy as np
import matplotlib.pyplot as plt
import datetime

time_start =

# My original answer
def f(x):
    rebuilt_to_plot = []
    for num in x:
    return rebuilt_to_plot

for t in range(10000):
    x = np.arange(1, 15.1, 0.1)
    plt.plot(x, f(x))

time_end =

# Answer by ayhan
def f_1(x):

for t in range(10000):
    f2 = np.vectorize(f_1)
    x = np.arange(1, 15.1, 0.1)
    plt.plot(x, f2(x))

time_end_2 =

print time_end - time_start
print time_end_2 - time_end

How do you specify a debugger program in Code::Blocks 12.11?

  1. Go to Settings -> Debugger -> Common -> GDB/CDB Debugger -> Default
  2. Click on executable path to find the address to gdb32.exe
  3. Locate where your codeblock is installed
  4. Follow the given path:

CodeBlock -> MinGW -> bin -> gdb32.exe (locate it and double click on it)

  1. Press OK

Write applications in C or C++ for Android?

Normally, you have to:

  1. Install Google Android NDK. It contains libs, headers, makfile examples and gcc toolchain
  2. Build an executable from your C code for ARM, optimize and link it with provided libs if required
  3. Connect to a phone using provided adb interface and test your executable

If you are looking to sell an app:

  1. Build a library from your C code
  2. Create simple Java code which will use this library
  3. Embed this library into application package file
  4. Test your app
  5. Sell it or distribute it for free

Unable to create Genymotion Virtual Device

We had the same issues, it was because we had wrong version of Oracle VM Virtual Box. Make sure you uninstall wrong version and re-install Compatible Oracle VM Virtual Box.

How do I solve this error, "error while trying to deserialize parameter"

This is happening because the web-service relies on using XmlSerializer to convert the wsdl among other things to XML, which doesn't support mixed-mode properties, like these:

public string strThing { get; private set; }


More information:

How to integrate sourcetree for gitlab

Using the SSH URL from GitLab:

Step 1: Generate an SSH Key with default values from GitLab.

GitLab provides the commands to generate it. Just copy them, edit the email, and paste it in the terminal. Using the default values is important. Else SourceTree will not be able to access the SSH key without additional configuration.

STEP 2: Add the SSH key to your keychain using the command ssh-add -K.

Open the terminal and paste the above command in it. This will add the key to your keychain.

STEP 3: Restart SourceTree and clone remote repo using URL.

Restarting SourceTree is needed so that SourceTree picks the new key.

enter image description here

STEP 4: Copy the SSH URL provided by GitLab.

enter image description here

STEP 5: Paste the SSH URL into the Source URL field of SourceTree.

enter image description here

These steps were successfully performed on Mac OS 10.13.2 using SourceTree 2.7.1.

enter image description hereenter image description here

Installing mysql-python on Centos

For centos7 I required: sudo yum install mysql-devel gcc python-pip python-devel sudo pip install mysql-python

So, gcc and mysql-devel (rather than mysql) were important

How to create our own Listener interface in android?

I have done it something like below for sending my model class from the Second Activity to First Activity. I used LiveData to achieve this, with the help of answers from Rupesh and TheCodeFather.

Second Activity

public static MutableLiveData<AudioListModel> getLiveSong() {
        MutableLiveData<AudioListModel> result = new MutableLiveData<>();
        return result;

"liveSong" is AudioListModel declared globally

Call this method in the First Activity

PlayerActivity.getLiveSong().observe(this, new Observer<AudioListModel>() {
            public void onChanged(AudioListModel audioListModel) {
                if (PlayerActivity.mediaPlayer != null && PlayerActivity.mediaPlayer.isPlaying()) {
                    Log.d("LiveSong--->Changes-->", audioListModel.getSongName());

May this help for new explorers like me.

Kill detached screen session

[xxx@devxxx ~]$ screen -ls

There are screens on:
        23487.pts-0.devxxx      (Detached)
        26727.pts-0.devxxx      (Attached)
2 Sockets in /tmp/uscreens/S-xxx.

[xxx@devxxx ~]$ screen -X -S 23487.pts-0.devxxx kill

[xxx@devxxx ~]$ screen -ls
There is a screen on:
        26727.pts-0.devxxx      (Attached)
1 Socket in /tmp/uscreens/S-xxx.

How do I stop a web page from scrolling to the top when a link is clicked that triggers JavaScript?

You might want to check your CSS. In the example here: there's position: absolute; top: -9999px;. This is particularly goofy on Chrome, as onclick="whatever" still jumps to the absolute position of the clicked element.

Removing position: absolute; top: -9999px;, for display: none; might help.

Android Studio: Module won't show up in "Edit Configuration"

The following are methods to help you:

  1. Close and Open Project again
  2. Close and Open Android Studio
  3. Clean Project
  4. Rebuild Project
  5. Instantiate and Restart
  6. Make sure you have included :app
  7. Import the Project

Oracle select most recent date record

you can't use aliases from select list inside the WHERE clause (because of the Order of Evaluation of a SELECT statement)

also you cannot use OVER clause inside WHERE clause - "You can specify analytic functions with this clause in the select list or ORDER BY clause." (citation from

select *
from (select
  staff_id, site_id, pay_level, date, 
  max(date) over (partition by staff_id) max_date
  from owner.table
  where end_enrollment_date is null
where date = max_date

How do I connect to a MySQL Database in Python?

As a db driver, there is also oursql. Some of the reasons listed on that link, which say why oursql is better:

  • oursql has real parameterization, sending the SQL and data to MySQL completely separately.
  • oursql allows text or binary data to be streamed into the database and streamed out of the database, instead of requiring everything to be buffered in the client.
  • oursql can both insert rows lazily and fetch rows lazily.
  • oursql has unicode support on by default.
  • oursql supports python 2.4 through 2.7 without any deprecation warnings on 2.6+ (see PEP 218) and without completely failing on 2.7 (see PEP 328).
  • oursql runs natively on python 3.x.

So how to connect to mysql with oursql?

Very similar to mysqldb:

import oursql

db_connection = oursql.connect(host='',user='foo',passwd='foobar',db='db_name')
cur.execute("SELECT * FROM `tbl_name`")
for row in cur.fetchall():
    print row[0]

The tutorial in the documentation is pretty decent.

And of course for ORM SQLAlchemy is a good choice, as already mentioned in the other answers.

C++ performance vs. Java/C#

One of the most significant JIT optimizations is method inlining. Java can even inline virtual methods if it can guarantee runtime correctness. This kind of optimization usually cannot be performed by standard static compilers because it needs whole-program analysis, which is hard because of separate compilation (in contrast, JIT has all the program available to it). Method inlining improves other optimizations, giving larger code blocks to optimize.

Standard memory allocation in Java/C# is also faster, and deallocation (GC) is not much slower, but only less deterministic.

Rerender view on browser resize with React

For this reason better is if you use this data from CSS or JSON file data, and then with this data setting new state with this.state({width: "some value",height:"some value" }); or writing code who use data of width screen data in self work if you wish responsive show images

How to install SimpleJson Package for Python

If you have Python 2.6 installed then you already have simplejson - just import json; it's the same thing.

Add CSS box shadow around the whole DIV

Just use the below code. It will shadow surround the entire DIV

-webkit-box-shadow: -1px 1px 5px 9px rgba(0,0,0,0.75);
-moz-box-shadow: -1px 1px 5px 9px rgba(0,0,0,0.75);
box-shadow: -1px 1px 5px 9px rgba(0,0,0,0.75);

Hope this will work

what does numpy ndarray shape do?

yourarray.shape or np.shape() or returns the shape of your ndarray as a tuple; And you can get the (number of) dimensions of your array using yourarray.ndim or np.ndim(). (i.e. it gives the n of the ndarray since all arrays in NumPy are just n-dimensional arrays (shortly called as ndarrays))

For a 1D array, the shape would be (n,) where n is the number of elements in your array.

For a 2D array, the shape would be (n,m) where n is the number of rows and m is the number of columns in your array.

Please note that in 1D case, the shape would simply be (n, ) instead of what you said as either (1, n) or (n, 1) for row and column vectors respectively.

This is to follow the convention that:

For 1D array, return a shape tuple with only 1 element   (i.e. (n,))
For 2D array, return a shape tuple with only 2 elements (i.e. (n,m))
For 3D array, return a shape tuple with only 3 elements (i.e. (n,m,k))
For 4D array, return a shape tuple with only 4 elements (i.e. (n,m,k,j))

and so on.

Also, please see the example below to see how np.shape() or behaves with 1D arrays and scalars:

# sample array
In [10]: u = np.arange(10)

# get its shape
In [11]: np.shape(u)    # u.shape
Out[11]: (10,)

# get array dimension using `np.ndim`
In [12]: np.ndim(u)
Out[12]: 1

In [13]: np.shape(np.mean(u))
Out[13]: ()       # empty tuple (to indicate that a scalar is a 0D array).

# check using `numpy.ndim`
In [14]: np.ndim(np.mean(u))
Out[14]: 0

P.S.: So, the shape tuple is consistent with our understanding of dimensions of space, at least mathematically.

VB6 IDE cannot load MSCOMCTL.OCX after update KB 2687323

After hours of effort, system restore, register, unregister cycles and a night's sleep I have managed to pinpoint the problem. It turns out that the project file contains the below line:

Object={831FDD16-0C5C-11D2-A9FC-0000F8754DA1}#2.0#0; MSCOMCTL.OCX

The version information "2.0" it seems was the reason of not loading. Changing it to "2.1" in notepad solved the problem:

Object={831FDD16-0C5C-11D2-A9FC-0000F8754DA1}#2.1#0; MSCOMCTL.OCX

So in a similar "OCX could not be loaded" situation one possible way of resolution is to start a new project. Put the control on one of the forms and check the vbp file with notepad to see what version it is expecting.


(I have added this section after Bob's valuable comment below)

You can open your VBP project file in Notepad and find the nasty line that is preventing VB6 to upgrade the project automatically to 2.1 and remove it:


Python: create dictionary using dict() with integer keys?

There are also these 'ways':

>>> dict.fromkeys(range(1, 4))
{1: None, 2: None, 3: None}
>>> dict(zip(range(1, 4), range(1, 4)))
{1: 1, 2: 2, 3: 3}

How to convert a NumPy array to PIL image applying matplotlib colormap

  • input = numpy_image
  • np.unit8 -> converts to integers
  • convert('RGB') -> converts to RGB
  • Image.fromarray -> returns an image object

    from PIL import Image
    import numpy as np
    PIL_image = Image.fromarray(np.uint8(numpy_image)).convert('RGB')
    PIL_image = Image.fromarray(numpy_image.astype('uint8'), 'RGB')

The iOS Simulator deployment targets is set to 7.0, but the range of supported deployment target version for this platform is 8.0 to 12.1

if anybody is experiencing is issue while updating to the latest react native, try updating your pod file with

  post_install do |installer|
    installer.pods_project.targets.each do |target|
      target.build_configurations.each do |config|
        config.build_settings.delete 'IPHONEOS_DEPLOYMENT_TARGET'

How do I get logs from all pods of a Kubernetes replication controller?

Another solution that I would consider is using K9S which is a great kube administration tool.

After installation, the usage is very straightforward:

 k9s -n my-namespace --context the_context_name_in_kubeconfig

(If kubeconfig is not in the default location add KUBECONFIG=path/to/kubeconfig prefix).

The default view will list all pods as a list:

enter image description here

We can change the view to other Kube controllers like replica set (question asked for replication controllers so notice they are deprecated), deployments, cron jobs, etc' by entering a colon : and start typing the desired controller - as we can see K9S provides autocompletion for us:

enter image description here

And we can see all replica sets in the current namespace:

enter image description here

We can just choose the desired replica set by clicking enter and then we'll see the list of all pods which are related to this replica set - we can then press on 'l' to view logs of each pod.

So, unlike in the case of stern, we still need to go on each pod and view its logs but I think it is very convenient with K9S - we first view all pods of a related controller and then investigate logs of each pod by simply navigating with enter, l and escape.

Could not load file or assembly '' or one of its dependencies

screenshotIn solution explorer right click on project (not solution), in build tab choose Platform target : "Any CPU".

AttributeError: 'str' object has no attribute

The problem is in your playerMovement method. You are creating the string name of your room variables (ID1, ID2, ID3):

letsago = "ID" + str(self.dirDesc.values())

However, what you create is just a str. It is not the variable. Plus, I do not think it is doing what you think its doing:


If you REALLY needed to find the variable this way, you could use the eval function:

>>>foo = 'Hello World!'
'Hello World!'

or the globals function:

class Foo(object):
    def __init__(self):
        super(Foo, self).__init__()
    def test(self, name):

foo = Foo()
bar = 'Hello World!'

However, instead I would strongly recommend you rethink you class(es). Your userInterface class is essentially a Room. It shouldn't handle player movement. This should be within another class, maybe GameManager or something like that.

Formatting "yesterday's" date in python

To expand on the answer given by Chris

if you want to store the date in a variable in a specific format, this is the shortest and most effective way as far as I know

>>> from datetime import date, timedelta                   
>>> yesterday = ( - timedelta(days=1)).strftime('%m%d%y')
>>> yesterday

If you want it as an integer (which can be useful)

>>> yesterday = int(( - timedelta(days=1)).strftime('%m%d%y'))
>>> yesterday

How to decode viewstate

This is somewhat "native" .NET way of converting ViewState from string into StateBag Code is below:

public static StateBag LoadViewState(string viewState)
        System.Web.UI.Page converterPage = new System.Web.UI.Page();
        HiddenFieldPageStatePersister persister = new HiddenFieldPageStatePersister(new Page());
        Type utilClass = typeof(System.Web.UI.BaseParser).Assembly.GetType("System.Web.UI.Util");
        if (utilClass != null && persister != null)
            MethodInfo method = utilClass.GetMethod("DeserializeWithAssert", BindingFlags.NonPublic | BindingFlags.Static);
            if (method != null)
                PropertyInfo formatterProperty = persister.GetType().GetProperty("StateFormatter", BindingFlags.NonPublic | BindingFlags.Instance);
                if (formatterProperty != null)
                    IStateFormatter formatter = (IStateFormatter)formatterProperty.GetValue(persister, null);
                    if (formatter != null)
                        FieldInfo pageField = formatter.GetType().GetField("_page", BindingFlags.NonPublic | BindingFlags.Instance);
                        if (pageField != null)
                            pageField.SetValue(formatter, null);
                                Pair pair = (Pair)method.Invoke(null, new object[] { formatter, viewState });
                                if (pair != null)
                                    MethodInfo loadViewState = converterPage.GetType().GetMethod("LoadViewStateRecursive", BindingFlags.Instance | BindingFlags.NonPublic);
                                    if (loadViewState != null)
                                        FieldInfo postback = converterPage.GetType().GetField("_isCrossPagePostBack", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (postback != null)
                                            postback.SetValue(converterPage, true);
                                        FieldInfo namevalue = converterPage.GetType().GetField("_requestValueCollection", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (namevalue != null)
                                            namevalue.SetValue(converterPage, new NameValueCollection());
                                        loadViewState.Invoke(converterPage, new object[] { ((Pair)((Pair)pair.First).Second) });
                                        FieldInfo viewStateField = typeof(Control).GetField("_viewState", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (viewStateField != null)
                                            return (StateBag)viewStateField.GetValue(converterPage);
                            catch (Exception ex)
                                if (ex != null)

        return null;

Why do we have to normalize the input for an artificial neural network?

It's explained well here.

If the input variables are combined linearly, as in an MLP [multilayer perceptron], then it is rarely strictly necessary to standardize the inputs, at least in theory. The reason is that any rescaling of an input vector can be effectively undone by changing the corresponding weights and biases, leaving you with the exact same outputs as you had before. However, there are a variety of practical reasons why standardizing the inputs can make training faster and reduce the chances of getting stuck in local optima. Also, weight decay and Bayesian estimation can be done more conveniently with standardized inputs.

How do I read text from the clipboard?

you can easily get this done through the built-in module Tkinter which is basically a GUI library. This code creates a blank widget to get the clipboard content from OS.

from tkinter import Tk  # Python 3
#from Tkinter import Tk # for Python 2.x

How to find the largest file in a directory and its subdirectories?

ls -alR|awk '{ if ($5 > max) {max=$5;ff=$9}} END {print max "\t" ff;}'

Global javascript variable inside document.ready

Use window.intro inside of $(document).ready().

How do I import a CSV file in R?

You would use the read.csv function; for example:

dat = read.csv("spam.csv", header = TRUE)

You can also reference this tutorial for more details.

Note: make sure the .csv file to read is in your working directory (using getwd()) or specify the right path to file. If you want, you can set the current directory using setwd.

phpmyadmin "no data received to import" error, how to fix?

Check permissions for you upload directory. You can find its path inside /etc/phpmyadmin/apache.conf file.

In my case (Ubuntu 14.04) it was:

php_admin_value upload_tmp_dir /var/lib/phpmyadmin/tmp

So I checked permissions for /var/lib/phpmyadmin/tmp and it turns out that the directory wasn't writable for my Apache user (which is by default www-data). It could be the case especially if you changed your apache user like I do.

MySQL Query GROUP BY day / month / year

Here's one more approach. This uses [MySQL's LAST_DAY() function][1] to map each timestamp to its month. It also is capable of filtering by year with an efficient range-scan if there's an index on record_date.

  SELECT LAST_DAY(record_date) month_ending, COUNT(*) record_count
    FROM stats
   WHERE record_date >= '2000-01-01'
     AND record_date <  '2000-01-01' + INTERVAL 1 YEAR
   GROUP BY LAST_DAY(record_date) 

If you want your results by day, use DATE(record_date) instead.

If you want your results by calendar quarter, use YEAR(record_date), QUARTER(record_date).

Here's a writeup. [1]:

PHPmailer sending HTML CODE

do like this-paste your html code inside your separate html file using GET method.

    $mail->WordWrap = 70;                                 
    $mail->addAttachment= $_GET['addattachment']; $mail->AltBody   
    =$_GET['AltBody'];  $mail->Subject = $_GET['subject']; $mail->Body = $_GET['body'];

How do I upgrade PHP in Mac OS X?

I think one simple way to do it, is:

1 - Check you where is your current PHP:

$ which php
$ /usr/local/bin/php

You see? Usually, our commands that we run is a link in /usr/local/bin so...

2 - Unlink this current link of PHP

unlink /usr/local/bin/php

If you prefere, before unlink it, check the path and then remove php files (do ls -al /usr/local/bin | grep php and then rm -rf into desired path)

3 - Install PHP 7.1

curl -s | bash -s 7.1

4 - Create new link (using php 7.1 bin that you have installed)

ln /usr/local/php5-7.1.9-20170914-100859/bin/php /usr/local/bin/php

Like I said, its a simple way I think.

MIME types missing in IIS 7 for ASP.NET - 404.17


I chose the "ISAPI & CGI Restrictions" after clicking the server name (not the site name) in IIS Manager, and right clicked the "ASP.NET v4.0.30319" lines and chose "Allow".

After turning on ASP.NET from "Programs and Features > Turn Windows features on or off", you must install ASP.NET from the Windows command prompt. The MIME types don't ever show up, but after doing this command, I noticed these extensions showed up under the IIS web site "Handler Mappings" section of IIS Manager.

C:\>cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>dir aspnet_reg*
 Volume in drive C is Windows
 Volume Serial Number is 8EE6-5DD0

 Directory of C:\Windows\Microsoft.NET\Framework64\v4.0.30319

03/18/2010  08:23 PM            19,296 aspnet_regbrowsers.exe
03/18/2010  08:23 PM            36,696 aspnet_regiis.exe
03/18/2010  08:23 PM           102,232 aspnet_regsql.exe
               3 File(s)        158,224 bytes
               0 Dir(s)  34,836,508,672 bytes free

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis.exe -i
Start installing ASP.NET (4.0.30319).
Finished installing ASP.NET (4.0.30319).


However, I still got this error. But if you do what I mentioned for the "Fix", this will go away.

HTTP Error 404.2 - Not Found
The page you are requesting cannot be served because of the ISAPI and CGI Restriction list settings on the Web server.

How to lock orientation of one view controller to portrait mode only in Swift

As of iOS 10 and 11, iPad supports Slide Over and Split View. To enable an app in Slide Over and Split View, Requires full screen must be unchecked. That means the accepted answer cannot be used if the app wants to support Slide Over and Split View. See more from Apple's Adopting Multitasking Enhancements on iPad here.

I have a solution that allows (1) unchecking Requires full screen, (2) just one function to be implemented in appDelegate (especially if you don't want to / can't modify the target view controllers), and (3) avoid recursive calls. No need of helper class nor extensions.

appDelegate.swift (Swift 4)

func application(_ application: UIApplication,
                 supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
    // Search for the visible view controller
    var vc = window?.rootViewController
    // Dig through tab bar and navigation, regardless their order 
    while (vc is UITabBarController) || (vc is UINavigationController) {
        if let c = vc as? UINavigationController {
            vc = c.topViewController
        } else if let c = vc as? UITabBarController {
            vc = c.selectedViewController
    // Look for model view controller
    while (vc?.presentedViewController) != nil {
        vc = vc!.presentedViewController
    print("vc = " + (vc != nil ? String(describing: type(of: vc!)) : "nil"))
    // Final check if it's our target class.  Also make sure it isn't exiting.
    // Otherwise, system will mistakenly rotate the presentingViewController.
    if (vc is TargetViewController) && !(vc!.isBeingDismissed) {
        return [.portrait]
    return [.all]


@bmjohns pointed out that this function is not called on iPad. I verified and yes it was not called. So, I did a bit more testing and found out some facts:

  1. I unchecked Requires full screen because I want to enable Slide Over and Slide View on iPad. That requires the app to support all 4 orientation for iPad, in Info.plist: Supported interface orientations (iPad).

My app works same way as Facebook: on iPhone, most of the time it is locked to portrait. When viewing image in full screen, allows users to rotate landscape for better view. On iPad, users can rotate to any orientation in any view controllers. So, the app looks nice when iPad is stand on Smart Cover (landscape left).

  1. For iPad to call application(_:supportedInterfaceOrientationsFor), in Info.plist, only keep portrait for iPad. The app will lose Slide Over + Split View ability. But you can lock or unlock the orientation for any view controller, in just one place and no need to modify ViewController class.

  2. Finally, this function get called on view controller's life cycle, when view is displayed/removed. If your app need to lock/unlock/change orientation in other time, it might not work

ERROR 2003 (HY000): Can't connect to MySQL server (111)

I had the same problem trying to connect to a remote mysql db.

I fixed it by opening the firewall on the db server to allow traffic through:

sudo ufw allow mysql

How to show loading spinner in jQuery?

You can insert the animated image into the DOM right before the AJAX call, and do an inline function to remove it...

$("#myDiv").html('<img src="images/spinner.gif" alt="Wait" />');
$('#message').load('index.php?pg=ajaxFlashcard', null, function() {

This will make sure your animation starts at the same frame on subsequent requests (if that matters). Note that old versions of IE might have difficulties with the animation.

Good luck!

Command not found error in Bash variable assignment

When you define any variable then you do not have to put in any extra spaces.


name = "Stack Overflow"  
// it is not valid, you will get an error saying- "Command not found"

So remove spaces:

name="Stack Overflow" 

and it will work fine.

How to check if object property exists with a variable holding the property name?

For own property :

var loan = { amount: 150 };
if(, "amount")) 
   //will execute

Note: using Object.prototype.hasOwnProperty is better than loan.hasOwnProperty(..), in case a custom hasOwnProperty is defined in the prototype chain (which is not the case here), like

var foo = {
      hasOwnProperty: function() {
        return false;
      bar: 'Here be dragons'


To include inherited properties in the finding use the in operator: (but you must place an object at the right side of 'in', primitive values will throw error, e.g. 'length' in 'home' will throw error, but 'length' in new String('home') won't)

const yoshi = { skulk: true };
const hattori = { sneak: true };
const kuma = { creep: true };
if ("skulk" in yoshi) 
    console.log("Yoshi can skulk");

if (!("sneak" in yoshi)) 
    console.log("Yoshi cannot sneak");

if (!("creep" in yoshi)) 
    console.log("Yoshi cannot creep");

Object.setPrototypeOf(yoshi, hattori);

if ("sneak" in yoshi)
    console.log("Yoshi can now sneak");
if (!("creep" in hattori))
    console.log("Hattori cannot creep");

Object.setPrototypeOf(hattori, kuma);

if ("creep" in hattori)
    console.log("Hattori can now creep");
if ("creep" in yoshi)
    console.log("Yoshi can also creep");


Note: One may be tempted to use typeof and [ ] property accessor as the following code which doesn't work always ...

var loan = { amount: 150 };

loan.installment = undefined;

if("installment" in loan) // correct
    // will execute

if(typeof loan["installment"] !== "undefined") // incorrect
    // will not execute

Regex for empty string or white space

Had similar problem, was looking for white spaces in a string, solution:

  • To search for 1 space:

    var regex = /^.+\s.+$/ ;

    example: "user last_name"

  • To search for multiple spaces:

    var regex = /^.+\s.+$/g ;

    example: "user last name"

Replace Default Null Values Returned From Left Outer Join


COALESCE(field, 'default')

For example:

    COALESCE(d.field, 'default')
     test t
     detail d ON = d.item

Also, you can use multiple columns to check their NULL by COALESCE function. For example:

        -> 1
        -> 0
        -> NULL

connecting MySQL server to NetBeans

in my cases, i found my password in glassfish-recources.xml under WEB-INF

How can INSERT INTO a table 300 times within a loop in SQL?

DECLARE @first AS INT = 1
DECLARE @last AS INT = 300

WHILE(@first <= @last)
    INSERT INTO tblFoo VALUES(@first)
    SET @first += 1

How can I bring my application window to the front?

Use Form.Activate() or Form.Focus() methods.

Get elements by attribute when querySelectorAll is not available without using libraries?


//find first element with "someAttr" attribute


//find all elements with "someAttr" attribute

to find elements by attribute. It's now supported in all relevant browsers (even IE8):

Are HTTP headers case-sensitive?

the Headers word are not case sensitive, but on the right like the Content-Type, is good practice to write it this way, because its case sensitve. like my example below

headers = headers.set('Content-Type'

C# Generics and Type Checking

There is no way to use the switch statement for what you want it to do. The switch statement must be supplied with integral types, which does not include complex types such as a "Type" object, or any other object type for that matter.

Which mime type should I use for mp3

Your best bet would be using the RFC defined mime-type audio/mpeg.

Twitter Bootstrap onclick event on buttons-radio

Looking at the example HTML for radio buttons on the Twitter Bootstrap page (, you can see that each input has a unique ID attribute, i.e. optionsRadios1 and optionsRadios2.

The relevant HTML example snippet is included here for completeness:

<div class="controls">
  <label class="radio">
    <input type="radio" checked="" value="option1" id="optionsRadios1" name="optionsRadios">
    Option one is this and that—be sure to include why it's great
  <label class="radio">
    <input type="radio" value="option2" id="optionsRadios2" name="optionsRadios">
    Option two can is something else and selecting it will deselect option one

So you can use a jQuery click event, and then use the this reference to look at the id of the HTML element that was clicked.

  } else {
    //... call some other function

How to set String's font size, style in Java using the Font class?

Look here

JComponent has a setFont() method. You will control the font there, not on the String.

Such as

JButton b = new JButton();

List and kill at jobs on UNIX

To delete a job which has not yet run, you need the atrm command. You can use atq command to get its number in the at list.

To kill a job which has already started to run, you'll need to grep for it using:

ps -eaf | grep <command name>

and then use kill to stop it.

A quicker way to do this on most systems is:

pkill <command name>

What's a good way to extend Error in JavaScript?

To avoid the boilerplate for every different type of error, I combined the wisdom of some of the solutions into a createErrorType function:

function createErrorType(name, init) {
  function E(message) {
    if (!Error.captureStackTrace)
      this.stack = (new Error()).stack;
      Error.captureStackTrace(this, this.constructor);
    this.message = message;
    init && init.apply(this, arguments);
  E.prototype = new Error(); = name;
  E.prototype.constructor = E;
  return E;

Then you can define new error types easily as follows:

var NameError = createErrorType('NameError', function (name, invalidChar) {
  this.message = 'The name ' + name + ' may not contain ' + invalidChar;

var UnboundError = createErrorType('UnboundError', function (variableName) {
  this.message = 'Variable ' + variableName + ' is not bound';

Using HTML5/Canvas/JavaScript to take in-browser screenshots

Get screenshot as Canvas or Jpeg Blob / ArrayBuffer using getDisplayMedia API:

FIX 1: Use the getUserMedia with chromeMediaSource only for Electron.js
FIX 2: Throw error instead return null object
FIX 3: Fix demo to prevent the error: getDisplayMedia must be called from a user gesture handler

// docs:
// see:
// see:

function getDisplayMedia(options) {
    if (navigator.mediaDevices && navigator.mediaDevices.getDisplayMedia) {
        return navigator.mediaDevices.getDisplayMedia(options)
    if (navigator.getDisplayMedia) {
        return navigator.getDisplayMedia(options)
    if (navigator.webkitGetDisplayMedia) {
        return navigator.webkitGetDisplayMedia(options)
    if (navigator.mozGetDisplayMedia) {
        return navigator.mozGetDisplayMedia(options)
    throw new Error('getDisplayMedia is not defined')

function getUserMedia(options) {
    if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
        return navigator.mediaDevices.getUserMedia(options)
    if (navigator.getUserMedia) {
        return navigator.getUserMedia(options)
    if (navigator.webkitGetUserMedia) {
        return navigator.webkitGetUserMedia(options)
    if (navigator.mozGetUserMedia) {
        return navigator.mozGetUserMedia(options)
    throw new Error('getUserMedia is not defined')

async function takeScreenshotStream() {
    // see:
    const width = screen.width * (window.devicePixelRatio || 1)
    const height = screen.height * (window.devicePixelRatio || 1)

    const errors = []
    let stream
    try {
        stream = await getDisplayMedia({
            audio: false,
            // see:
            video: {
                frameRate: 1,
    } catch (ex) {

    // for electron js
    if (navigator.userAgent.indexOf('Electron') >= 0) {
        try {
            stream = await getUserMedia({
                audio: false,
                video: {
                    mandatory: {
                        chromeMediaSource: 'desktop',
                        // chromeMediaSourceId:,
                        minWidth         : width,
                        maxWidth         : width,
                        minHeight        : height,
                        maxHeight        : height,
        } catch (ex) {

    if (errors.length) {
        if (!stream) {
            throw errors[errors.length - 1]

    return stream

async function takeScreenshotCanvas() {
    const stream = await takeScreenshotStream()

    // from:
    const video = document.createElement('video')
    const result = await new Promise((resolve, reject) => {
        video.onloadedmetadata = () => {

            // from:
            const canvas = document.createElement('canvas')
            canvas.width = video.videoWidth
            canvas.height = video.videoHeight
            const context = canvas.getContext('2d')
            // see:
            context.drawImage(video, 0, 0, video.videoWidth, video.videoHeight)
        video.srcObject = stream

    stream.getTracks().forEach(function (track) {
    if (result == null) {
        throw new Error('Cannot take canvas screenshot')

    return result

// from:
function getJpegBlob(canvas) {
    return new Promise((resolve, reject) => {
        // docs:
        canvas.toBlob(blob => resolve(blob), 'image/jpeg', 0.95)

async function getJpegBytes(canvas) {
    const blob = await getJpegBlob(canvas)
    return new Promise((resolve, reject) => {
        const fileReader = new FileReader()

        fileReader.addEventListener('loadend', function () {
            if (this.error) {


async function takeScreenshotJpegBlob() {
    const canvas = await takeScreenshotCanvas()
    return getJpegBlob(canvas)

async function takeScreenshotJpegBytes() {
    const canvas = await takeScreenshotCanvas()
    return getJpegBytes(canvas)

function blobToCanvas(blob, maxWidth, maxHeight) {
    return new Promise((resolve, reject) => {
        const img = new Image()
        img.onload = function () {
            const canvas = document.createElement('canvas')
            const scale = Math.min(
                maxWidth ? maxWidth / img.width : 1,
                maxHeight ? maxHeight / img.height : 1,
            canvas.width = img.width * scale
            canvas.height = img.height * scale
            const ctx = canvas.getContext('2d')
            ctx.drawImage(img, 0, 0, img.width, img.height, 0, 0, canvas.width, canvas.height)
        img.onerror = () => {
            reject(new Error('Error load blob to Image'))
        img.src = URL.createObjectURL(blob)


document.body.onclick = async () => {
    // take the screenshot
    var screenshotJpegBlob = await takeScreenshotJpegBlob()

    // show preview with max size 300 x 300 px
    var previewCanvas = await blobToCanvas(screenshotJpegBlob, 300, 300) = 'fixed'

    // send it to the server
    var formdata = new FormData()
    formdata.append("screenshot", screenshotJpegBlob)
    await fetch('', {
        method: 'POST',
        body: formdata,
        'Content-Type' : "multipart/form-data",

// and click on the page

Getting title and meta tags from external website

get_meta_tags did not work with title.

Only meta tags with name attributes like

<meta name="description" content="the description">

will be parsed.

Volatile vs. Interlocked vs. lock

Interlocked functions do not lock. They are atomic, meaning that they can complete without the possibility of a context switch during increment. So there is no chance of deadlock or wait.

I would say that you should always prefer it to a lock and increment.

Volatile is useful if you need writes in one thread to be read in another, and if you want the optimizer to not reorder operations on a variable (because things are happening in another thread that the optimizer doesn't know about). It's an orthogonal choice to how you increment.

This is a really good article if you want to read more about lock-free code, and the right way to approach writing it

Saving a text file on server using JavaScript

It's not possible to save content to the website using only client-side scripting such as JavaScript and jQuery, but by submitting the data in an AJAX POST request you could perform the other half very easily on the server-side.

However, I would not recommend having raw content such as scripts so easily writeable to your hosting as this could easily be exploited. If you want to learn more about AJAX POST requests, you can read the jQuery API page:

And here are some things you ought to be aware of if you still want to save raw script files on your hosting. You have to be very careful with security if you are handling files like this!

File uploading (most of this applies if sending plain text too if javascript can choose the name of the file)

Remove innerHTML from div


But why are you clearing, divToUpdate.html(data); will completely replace the old HTML.

How can I get the source directory of a Bash script from within the script itself?

Look at the test at bottom with weird directory names.

To change the working directory to the one where the Bash script is located, you should try this simple, tested and verified with shellcheck solution:

#!/bin/bash --
cd "$(dirname "${0}")"/. || exit 2

The test:

$ ls 
$ mkdir "$(printf "\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37\40\41\42\43\44\45\46\47testdir" "")"
$ mv application *testdir
$ ln -s *testdir "$(printf "\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37\40\41\42\43\44\45\46\47symlink" "")"
$ ls -lb
total 4
lrwxrwxrwx 1 jay stacko   46 Mar 30 20:44 \001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037\ !"#$%&'symlink -> \001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037\ !"#$%&'testdir
drwxr-xr-x 2 jay stacko 4096 Mar 30 20:44 \001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037\ !"#$%&'testdir
$ *testdir/application && printf "SUCCESS\n" ""
$ *symlink/application && printf "SUCCESS\n" ""

More Pythonic Way to Run a Process X Times

If you are after the side effects that happen within the loop, I'd personally go for the range() approach.

If you care about the result of whatever functions you call within the loop, I'd go for a list comprehension or map approach. Something like this:

def f(n):
    return n * n

results = [f(i) for i in range(50)]
# or using map:
results = map(f, range(50))

Errno 13 Permission denied Python

The problem here is your user doesn't have proper rights/permissions to open the file this means that you'd need to grant some administrative privileges to your python ide before you run that command.

As you are a windows user you just need to right click on python ide => select option 'Run as Administrator' and then run your command.

And if you are using the command line to run the codes, do the same open the command prompt with admin rights. Hope it helps

C++ Double Address Operator? (&&)

&& is new in C++11, and it signifies that the function accepts an RValue-Reference -- that is, a reference to an argument that is about to be destroyed.

Convert SQL Server result set into string

Assign a value when declaring the variable.

DECLARE @result VARCHAR(1000) ='';

SELECT @result = CAST(StudentId AS VARCHAR) + ',' FROM Student WHERE condition = xyz

A transport-level error has occurred when receiving results from the server

You get this message when your script make SQL Service stopped for some reasons. so if you start SQL Service again perhaps your problem will be resolved.

Image height and width not working?

You must write

<img src="theSource" style="width:30px;height:30px;" />

Inline styling will always take precedence over CSS styling. The width and height attributes are being overridden by your stylesheet, so you need to switch to this format.

IsNull function in DB2 SQL?

COALESCE function same ISNULL function Note. you must use COALESCE function with same data type of column that you check is null.

No provider for HttpClient

In my case I found once I rebuild the app it worked.

I had imported the HttpClientModule as specified in the previous posts but I was still getting the error. I stopped the server, rebuilt the app (ng serve) and it worked.

Array formula on Excel for Mac

This doesn't seem to work in Mac Excel 2016. After a bit of digging, it looks like the key combination for entering the array formula has changed from ?+RETURN to CTRL+SHIFT+RETURN.

Call a Class From another class

Simply create an instance of Class2 and call the desired method.

Suggested reading:

MySQL - DATE_ADD month interval

Well, for me this is the expected result; adding six months to Jan. 1st July.

mysql> SELECT DATE_ADD( '2011-01-01', INTERVAL 6 month );
| DATE_ADD( '2011-01-01', INTERVAL 6 month ) |
| 2011-07-01                                 | 

Testing web application on Mac/Safari when I don't own a Mac

For my case (a small, personal project) was very helpful. Free tier allows for 6 sessions per month.

How can I assign the output of a function to a variable using bash?

I think init_js should use declare instead of local!

function scan3() {
    declare -n outvar=$1    # -n makes it a nameref.
    local nl=$'\x0a'
    outvar="output${nl}${nl}"  # two total. quotes preserve newlines

Responsive Images with CSS

Use max-width:100%;, height: auto; and display:block; as follow:

image {
    height: auto;

while installing vc_redist.x64.exe, getting error "Failed to configure per-machine MSU package."

In my case and while installing VS 2015 on Windows7 64x SP1, I experienced the same so tried to cancel and download/install the KBKB2999226 separately and for some reason the standalone update installer also get stuck searching for updates.

enter image description here

Here what I did:

  1. When the VS installer stuck at the KB2999226 update I clicked cancel.
  2. Installer took me back to confirm cancellation, waited for a while then opened the windows task manager and ended the process of wuse.exe (windows standalone update installer)
  3. On the VS installer clicked "No" to return to installation process. The process was completed without errors.

How to get string objects instead of Unicode from JSON?

Mike Brennan's answer is close, but there is no reason to re-traverse the entire structure. If you use the object_hook_pairs (Python 2.7+) parameter:

object_pairs_hook is an optional function that will be called with the result of any object literal decoded with an ordered list of pairs. The return value of object_pairs_hook will be used instead of the dict. This feature can be used to implement custom decoders that rely on the order that the key and value pairs are decoded (for example, collections.OrderedDict will remember the order of insertion). If object_hook is also defined, the object_pairs_hook takes priority.

With it, you get each JSON object handed to you, so you can do the decoding with no need for recursion:

def deunicodify_hook(pairs):
    new_pairs = []
    for key, value in pairs:
        if isinstance(value, unicode):
            value = value.encode('utf-8')
        if isinstance(key, unicode):
            key = key.encode('utf-8')
        new_pairs.append((key, value))
    return dict(new_pairs)

In [52]: open('test.json').read()
Out[52]: '{"1": "hello", "abc": [1, 2, 3], "def": {"hi": "mom"}, "boo": [1, "hi", "moo", {"5": "some"}]}'                                        

In [53]: json.load(open('test.json'))
{u'1': u'hello',
 u'abc': [1, 2, 3],
 u'boo': [1, u'hi', u'moo', {u'5': u'some'}],
 u'def': {u'hi': u'mom'}}

In [54]: json.load(open('test.json'), object_pairs_hook=deunicodify_hook)
{'1': 'hello',
 'abc': [1, 2, 3],
 'boo': [1, 'hi', 'moo', {'5': 'some'}],
 'def': {'hi': 'mom'}}

Notice that I never have to call the hook recursively since every object will get handed to the hook when you use the object_pairs_hook. You do have to care about lists, but as you can see, an object within a list will be properly converted, and you don't have to recurse to make it happen.

EDIT: A coworker pointed out that Python2.6 doesn't have object_hook_pairs. You can still use this will Python2.6 by making a very small change. In the hook above, change:

for key, value in pairs:


for key, value in pairs.iteritems():

Then use object_hook instead of object_pairs_hook:

In [66]: json.load(open('test.json'), object_hook=deunicodify_hook)
{'1': 'hello',
 'abc': [1, 2, 3],
 'boo': [1, 'hi', 'moo', {'5': 'some'}],
 'def': {'hi': 'mom'}}

Using object_pairs_hook results in one less dictionary being instantiated for each object in the JSON object, which, if you were parsing a huge document, might be worth while.

What is the size of column of int(11) in mysql in bytes?

I think max value of int(11) is 4294967295

How do you set your pythonpath in an already-created virtualenv?

The comment by @s29 should be an answer:

One way to add a directory to the virtual environment is to install virtualenvwrapper (which is useful for many things) and then do

mkvirtualenv myenv
workon myenv
add2virtualenv . #for current directory
add2virtualenv ~/my/path

If you want to remove these path edit the file myenvhomedir/lib/python2.7/site-packages/_virtualenv_path_extensions.pth

Documentation on virtualenvwrapper can be found at

Specific documentation on this feature can be found at

Getting URL parameter in java and extract a specific text from that URL

I have something like this:

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URIBuilder;

private String getParamValue(String link, String paramName) throws URISyntaxException {
        List<NameValuePair> queryParams = new URIBuilder(link).getQueryParams();
                .filter(param -> param.getName().equalsIgnoreCase(paramName))

Scaling an image to fit on canvas

You made the error, for the second call, to set the size of source to the size of the target.
Anyway i bet that you want the same aspect ratio for the scaled image, so you need to compute it :

var hRatio = canvas.width / img.width    ;
var vRatio = canvas.height / img.height  ;
var ratio  = Math.min ( hRatio, vRatio );
ctx.drawImage(img, 0,0, img.width, img.height, 0,0,img.width*ratio, img.height*ratio);

i also suppose you want to center the image, so the code would be :

function drawImageScaled(img, ctx) {
   var canvas = ctx.canvas ;
   var hRatio = canvas.width  / img.width    ;
   var vRatio =  canvas.height / img.height  ;
   var ratio  = Math.min ( hRatio, vRatio );
   var centerShift_x = ( canvas.width - img.width*ratio ) / 2;
   var centerShift_y = ( canvas.height - img.height*ratio ) / 2;  
   ctx.clearRect(0,0,canvas.width, canvas.height);
   ctx.drawImage(img, 0,0, img.width, img.height,
                      centerShift_x,centerShift_y,img.width*ratio, img.height*ratio);  

you can see it in a jsbin here :,output

Select multiple rows with the same value(s)

This may work for you:

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

How to write a confusion matrix in Python?

Scikit-learn (which I recommend using anyways) has it included in the metrics module:

>>> from sklearn.metrics import confusion_matrix
>>> y_true = [0, 1, 2, 0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 0, 0, 0, 1, 1, 0, 2, 2]
>>> confusion_matrix(y_true, y_pred)
array([[3, 0, 0],
       [1, 1, 1],
       [1, 1, 1]])

Nesting await in Parallel.ForEach

After introducing a bunch of helper methods, you will be able run parallel queries with this simple syntax:

const int DegreeOfParallelism = 10;
IEnumerable<double> result = await Enumerable.Range(0, 1000000)
    .SelectManyAsync(async i => await CalculateAsync(i).ConfigureAwait(false))

What happens here is: we split source collection into 10 chunks (.Split(DegreeOfParallelism)), then run 10 tasks each processing its items one by one (.SelectManyAsync(...)) and merge those back into a single list.

Worth mentioning there is a simpler approach:

double[] result2 = await Enumerable.Range(0, 1000000)
    .Select(async i => await CalculateAsync(i).ConfigureAwait(false))

But it needs a precaution: if you have a source collection that is too big, it will schedule a Task for every item right away, which may cause significant performance hits.

Extension methods used in examples above look as follows:

public static class CollectionExtensions
    /// <summary>
    /// Splits collection into number of collections of nearly equal size.
    /// </summary>
    public static IEnumerable<List<T>> Split<T>(this IEnumerable<T> src, int slicesCount)
        if (slicesCount <= 0) throw new ArgumentOutOfRangeException(nameof(slicesCount));

        List<T> source = src.ToList();
        var sourceIndex = 0;
        for (var targetIndex = 0; targetIndex < slicesCount; targetIndex++)
            var list = new List<T>();
            int itemsLeft = source.Count - targetIndex;
            while (slicesCount * list.Count < itemsLeft)

            yield return list;

    /// <summary>
    /// Takes collection of collections, projects those in parallel and merges results.
    /// </summary>
    public static async Task<IEnumerable<TResult>> SelectManyAsync<T, TResult>(
        this IEnumerable<IEnumerable<T>> source,
        Func<T, Task<TResult>> func)
        List<TResult>[] slices = await source
            .Select(async slice => await slice.SelectListAsync(func).ConfigureAwait(false))
        return slices.SelectMany(s => s);

    /// <summary>Runs selector and awaits results.</summary>
    public static async Task<List<TResult>> SelectListAsync<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, Task<TResult>> selector)
        List<TResult> result = new List<TResult>();
        foreach (TSource source1 in source)
            TResult result1 = await selector(source1).ConfigureAwait(false);
        return result;

    /// <summary>Wraps tasks with Task.WhenAll.</summary>
    public static Task<TResult[]> WhenAll<TResult>(this IEnumerable<Task<TResult>> source)
        return Task.WhenAll<TResult>(source);

How do I check if a SQL Server text column is empty?

To get only empty values (and not null values):

SELECT * FROM myTable WHERE myColumn = ''

To get both null and empty values:

SELECT * FROM myTable WHERE myColumn IS NULL OR myColumn = ''

To get only null values:


To get values other than null and empty:

SELECT * FROM myTable WHERE myColumn <> ''

And remember use LIKE phrases only when necessary because they will degrade performance compared to other types of searches.

Fit background image to div

You can use this attributes:

background-size: contain;
background-repeat: no-repeat;

and you code is then like this:

 <div style="text-align:center;background-image: url(/media/img_1_bg.jpg); background-size: contain;
background-repeat: no-repeat;" id="mainpage">

Could not find a declaration file for module 'module-name'. '/path/to/module-name.js' implicitly has an 'any' type

For anyone else reading this, try renaming your .js file to .ts

Edit: You can also add "allowJs": true to your tsconfig file.

What does cv::normalize(_src, dst, 0, 255, NORM_MINMAX, CV_8UC1);

When the normType is NORM_MINMAX, cv::normalize normalizes _src in such a way that the min value of dst is alpha and max value of dst is beta. cv::normalize does its magic using only scales and shifts (i.e. adding constants and multiplying by constants).

CV_8UC1 says how many channels dst has.

The documentation here is pretty clear:

MySQL connection not working: 2002 No such file or directory

On a Mac, before doing all the hard work, simply check your settings in System Preferences > MySQL. More often than not, I've experienced the team running into this problem since The MySQL Server Instance is stopped.

Click the Start MySQL Server button, and magic will happen.

Convert php array to Javascript

I'm going to assume that the two arrays you've given for PHP and JS are not related, and they're just examples of how arrays look in the two languages. Clearly you're not going to be able to convert those sequences of letters and numbers into those city names.

PHP provides a function to convert PHP arrays into Javascript code: json_encode(). (technically, it's JSON format; JSON stands for JavaScript Object Notation)

Use it like this:

<script type='text/javascript'>
$php_array = array('abc','def','ghi');
$js_array = json_encode($php_array);
echo "var javascript_array = ". $js_array . ";\n";

See also the manual page I linked above for more information.

Note that json_encode() is only available in PHP 5.2 and up, so if you're using an older version, you'll need to use an existing one -- the PHP manual page also includes comments with functions written by people who needed it. (but that said, if you're using anything older than PHP 5.2 you should upgrade ASAP)

Bootstrap full responsive navbar with logo or brand name text

Just set the height and width where you are adding that logo. I tried and its working fine

How to call a method in MainActivity from another class?

public class MainActivity extends AppCompatActivity {

    private static MainActivity instance;

    protected void onCreate(Bundle savedInstanceState) {
        instance = this;

    public static MainActivity getInstance() {
        return instance;

    public void myMethod() {
       // do something...

public Class AnotherClass() {
     // call this method

Check if an array contains any element of another array in JavaScript

You could use lodash and do:

_.intersection(originalTarget, arrayToCheck).length > 0

Set intersection is done on both collections producing an array of identical elements.

Sending data through POST request from a node.js server to a node.js server

Posting data is a matter of sending a query string (just like the way you would send it with an URL after the ?) as the request body.

This requires Content-Type and Content-Length headers, so the receiving server knows how to interpret the incoming data. (*)

var querystring = require('querystring');
var http = require('http');

var data = querystring.stringify({
      username: yourUsernameValue,
      password: yourPasswordValue

var options = {
    host: 'my.url',
    port: 80,
    path: '/login',
    method: 'POST',
    headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Content-Length': Buffer.byteLength(data)

var req = http.request(options, function(res) {
    res.on('data', function (chunk) {
        console.log("body: " + chunk);


(*) Sending data requires the Content-Type header to be set correctly, i.e. application/x-www-form-urlencoded for the traditional format that a standard HTML form would use.

It's easy to send JSON (application/json) in exactly the same manner; just JSON.stringify() the data beforehand.

URL-encoded data supports one level of structure (i.e. key and value). JSON is useful when it comes to exchanging data that has a nested structure.

The bottom line is: The server must be able to interpret the content type in question. It could be text/plain or anything else; there is no need to convert data if the receiving server understands it as it is.

Add a charset parameter (e.g. application/json; charset=Windows-1252) if your data is in an unusual character set, i.e. not UTF-8. This can be necessary if you read it from a file, for example.

How to update Ruby Version 2.0.0 to the latest version in Mac OSX Yosemite?

Simplest way is definitely to enter the following command in the terminal:

sudo gem update --system

You can add the flag --no-document if you do not want to download the documentation. Here is sample output after running the command:

sudo gem update --system
Updating rubygems-update
Fetching: rubygems-update-2.6.8.gem (100%)
Successfully installed rubygems-update-2.6.8
Parsing documentation for rubygems-update-2.6.8
Installing ri documentation for rubygems-update-2.6.8
Installing darkfish documentation for rubygems-update-2.6.8
Installing RubyGems 2.6.8
RubyGems 2.6.8 installed
Parsing documentation for rubygems-2.6.8
Installing ri documentation for rubygems-2.6.8


RubyGems installed the following executables:

Ruby Interactive (ri) documentation was installed. ri is kind of like man 
pages for ruby libraries. You may access it like this:
  ri Classname
  ri Classname.class_method
  ri Classname#instance_method

How do I shut down a python simpleHTTPserver?

kill -9 `ps -ef |grep SimpleHTTPServer |grep $MYPORT |awk '{print $2}'`

That is it!

Explain command line :

  • ps -ef : list all process.

  • grep SimpleHTTPServer : filter process which belong to "SimpleHTTPServer"

  • grep $MYPORT : filter again process belong to "SimpleHTTPServer" where port is MYPORT (.i.e: MYPORT=8888)

  • awk '{print $2}' : print second column of result which is the PID (Process ID)

  • kill -9 <PID> : Force Kill process with the appropriate PID.

Base 64 encode and decode example code

To anyone else who ended up here while searching for info on how to decode a string encoded with Base64.encodeBytes(), here was my solution:

// encode
String ps = "techPass";
String tmp = Base64.encodeBytes(ps.getBytes());

// decode
String ps2 = "dGVjaFBhC3M=";
byte[] tmp2 = Base64.decode(ps2); 
String val2 = new String(tmp2, "UTF-8"); 

Also, I'm supporting older versions of Android so I'm using Robert Harder's Base64 library from

How to make Python speak

There may not be anything 'Python specific', but the KDE and GNOME desktops offer text-to-speech as a part of their accessibility support, and also offer python library bindings. It may be possible to use the python bindings to control the desktop libraries for text to speech.

If using the Jython implementation of Python on the JVM, the FreeTTS system may be usable.

Finally, OSX and Windows have native APIs for text to speech. It may be possible to use these from python via ctypes or other mechanisms such as COM.

How do I get the base URL with PHP?

$modifyUrl = parse_url($url);

Its just simple to use
Output :

    [scheme] => http
    [host] =>
    [path] => /

When should I use curly braces for ES6 import?

I would say there is also a starred notation for the import ES6 keyword worth to mention.

enter image description here

If you try to console log Mix:

import * as Mix from "./A";

You will get:

enter image description here

When should I use curly braces for ES6 import?

The brackets are golden when you need only specific components from the module, which makes smaller footprints for bundlers like webpack.

Remove lines that contain certain string

Regex is a little quicker than the accepted answer (for my 23 MB test file) that I used. But there isn't a lot in it.

import re

bad_words = ['bad', 'naughty']

regex = f"^.*(:{'|'.join(bad_words)}).*\n"
subst = ""

with open('oldfile.txt') as oldfile:
    lines =

result = re.sub(regex, subst, lines, re.MULTILINE) 

with open('newfile.txt', 'w') as newfile:

enter image description here

The type initializer for 'MyClass' threw an exception

I wrapped my line that was crashing in a try-catch block, printed out the exception, and breaked immediately after it was printed. The exception information shown had a stack trace which pointed me to the file and line of code causing the fault to occur.

enter image description here

System.TypeInitializationException: The type initializer for 'Blah.blah.blah' threw an exception. 
---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Some.Faulty.Software..cctor() in C:\Projects\My.Faulty.File.cs:line 56
   --- End of inner exception stack trace ---
   at Blah.blah.blah(Blah.blah.blah)
   at TestApplication.Program.Main(String[] args) 
   in C:\Projects\Blah.blah.blah\Program.cs:line 29 Exception caught.

How can I change eclipse's Internal Browser from IE to Firefox on Windows XP?

I like the Aptana Browser Preview windo for this.

You can get it from their update site:

After you install the Aptana plugin, open an Aptana project and there should be an option under help to install aptana features. under other you will find a Firefox/XUL browser. There may be a more direct way to install the XUL plugin, but the above procedure works.

In java how to get substring from a string till a character c?

The accepted answer is correct but it doesn't tell you how to use it. This is how you use indexOf and substring functions together.

String filename = "abc.def.ghi";     // full file name
int iend = filename.indexOf("."); //this finds the first occurrence of "." 
//in string thus giving you the index of where it is in the string

// Now iend can be -1, if lets say the string had no "." at all in it i.e. no "." is found. 
//So check and account for it.

String subString;
if (iend != -1) 
    subString= filename.substring(0 , iend); //this will give abc

Ruby on Rails: Clear a cached page

More esoteric ways:


For Redis:{ |key| Rails.cache.delete(key) }

Another git process seems to be running in this repository

Solved it by going into the .git folder and manually deleting the HEAD.lock file

How do I add all new files to SVN

This add all unversioned files even if it contains spaces

svn status | awk '{$1=""; print $0}' | xargs -i svn add "{}"

Warning:No JDK specified for module 'Myproject'.when run my project in Android studio

I was able to fix it using the answer here: But I have 150 modules. So I would have had to perform this step 150 times.

So I needed to do it a different way.

So first close the existing project, then Import it again, In the first step of the wizard choose "Gradle" project. Then the next step of the wizard has the Gradle project properties. Here it's going to ask you for, among other things, the Java SDK to use. The default will be "Project SDK". Do not use this default, instead hand pick your Java SDK from the list. Then finish the import.

Now the problem should go away.

How to hide html source & disable right click and text copy?

View source is not disabled in my browser (Chrome).

But they have added a lot of blank lines to the source, so you have to scroll down to view it. Try to scroll down and you will see.

the disabled right click is possible with javascript, but dont do it. Its very irritating for the user.

Delete empty lines using sed

Another option without sed, awk, perl, etc

strings $file > $output

strings - print the strings of printable characters in files.

.Contains() on a list of custom class objects

Implement override Equals() and GetHashCode()

public class CartProduct
    public Int32 ID;

    public CartProduct(Int32 ID, ...)
        this.ID = ID;

    public override int GetHashCode()
        return ID;

    public override bool Equals(Object obj)
            if (obj == null || !(obj is CartProduct))
                return false;
                return GetHashCode() == ((CartProduct)obj).GetHashCode();



if (CartProducts.Contains(p))

lvalue required as left operand of assignment

You cannot assign an rvalue to an rvalue.

if (strcmp("hello", "hello") = 0)

is wrong. Suggestions:

if (strcmp("hello", "hello") == 0)

= is the assign operator.
== is the equal to operator.
I know many new programmers are confused with this fact.

How to get just the responsive grid from Bootstrap 3?

Go to and toggle just what you want from the BS3 framework and then click "Compile and Download" and you'll get the CSS and JS that you chose.

Bootstrap Customizer

Open up the CSS and remove all but the grid. They include some normalize stuff too. And you'll need to adjust all the styles on your site to box-sizing: border-box -

Hibernate Auto Increment ID

If you have a numeric column that you want to auto-increment, it might be an option to set columnDefinition directly. This has the advantage, that the schema auto-generates the value even if it is used without hibernate. This might make your code db-specific though:

import javax.persistence.Column;
@Column(columnDefinition = "serial") // postgresql

How to create a link to another PHP page

You can also used like this

<a href="<?php echo 'index.php'; ?>">Index Page</a>
<a href="<?php echo 'page2.php'; ?>">Page 2</a>

Application_Start not firing?

I hade the same problem, couldn't catch Application_Start. And the reason was that it was not firing do to a missmatch in the markup file. The markup file Global.asax was inheriting another class...

How to force Laravel Project to use HTTPS for all routes?

Place this in the AppServiceProvider in the boot() method

if($this->app->environment('production')) {

How to push a new folder (containing other folders and files) to an existing git repo?

You can directly go to Web IDE and upload your folder there.


  1. Go to Web IDE(Mostly located below the clone option).
  2. Create new directory at your path
  3. Upload your files and folders

In some cases you may not be able to directly upload entire folder containing folders, In such cases, you will have to create directory structure yourself.

Simple calculations for working with lat/lon and km distance?

Why not use properly formulated geospatial queries???

Here is the SQL server reference page on the STContains geospatial function:

or if you do not waant to use box and radian conversion , you cna always use the distance function to find the points that you need:

DECLARE @CurrentLocation geography; 
SET @CurrentLocation  = geography::Point(12.822222, 80.222222, 4326)

SELECT * , Round (GeoLocation.STDistance(@CurrentLocation ),0) AS Distance FROM [Landmark]
WHERE GeoLocation.STDistance(@CurrentLocation )<= 2000 -- 2 Km

There should be similar functionality for almost any database out there.

If you have implemented geospatial indexing correctly your searches would be way faster than the approach you are using

Installing tkinter on ubuntu 14.04

First, make sure you have Tkinter module installed.

sudo apt-get install python-tk

In python 2 the package name is Tkinter not tkinter.

from Tkinter import *


How do I get some variable from another class in Java?

Your example is perfect: the field is private and it has a getter. This is the normal way to access a field. If you need a direct access to an object field, use reflection. Using reflection to get a field's value is a hack and should be used in extreme cases such as using a library whose code you cannot change.

parseInt with jQuery

var test = parseInt($("#testid").val());

Php, wait 5 seconds before executing an action

before starting your actions, use


Using logging in multiple modules

I always do it as below.

Use a single python file to config my log as singleton pattern which named ''


import logging.config

def singleton(cls):
    instances = {}
    def get_instance():
        if cls not in instances:
            instances[cls] = cls()
        return instances[cls]
    return get_instance()

class Logger():
    def __init__(self):
        self.logr = logging.getLogger('root')

In another module, just import the config.

from log_conf import Logger"Hello World")

This is a singleton pattern to log, simply and efficiently.

Date Comparison using Java

Use java.util.Calendar if you have extensive date related processing.

Date has before(), after() methods. you could use them as well.

How to run mysql command on bash?

This one worked, double quotes when $user and $password are outside single quotes. Single quotes when inside a single quote statement.

mysql --user="$user" --password="$password" --database="$user" --execute='DROP DATABASE '$user'; CREATE DATABASE '$user';'

Random record from MongoDB

My PHP/MongoDB sort/order by RANDOM solution. Hope this helps anyone.

Note: I have numeric ID's within my MongoDB collection that refer to a MySQL database record.

First I create an array with 10 randomly generated numbers

    $randomNumbers = [];
    for($i = 0; $i < 10; $i++){
        $randomNumbers[] = rand(0,1000);

In my aggregation I use the $addField pipeline operator combined with $arrayElemAt and $mod (modulus). The modulus operator will give me a number from 0 - 9 which I then use to pick a number from the array with random generated numbers.

    $aggregate[] = [
        '$addFields' => [
            'random_sort' => [ '$arrayElemAt' => [ $randomNumbers, [ '$mod' => [ '$my_numeric_mysql_id', 10 ] ] ] ],

After that you can use the sort Pipeline.

    $aggregate[] = [
        '$sort' => [
            'random_sort' => 1

Django ChoiceField

Better Way to Provide Choice inside a django Model :

from django.db import models

class Student(models.Model):
    JUNIOR = 'JR'
    SENIOR = 'SR'
        (FRESHMAN, 'Freshman'),
        (SOPHOMORE, 'Sophomore'),
        (JUNIOR, 'Junior'),
        (SENIOR, 'Senior'),
        (GRADUATE, 'Graduate'),
    year_in_school = models.CharField(

Get parent directory of running script

As of PHP 5.3.0 you can use __DIR__ for this purpose.

The directory of the file. If used inside an include, the directory of the included file is returned. This is equivalent to dirname(__ FILE__).

See PHP Magic constants.

C:\www>php --version
PHP 5.5.6 (cli) (built: Nov 12 2013 11:33:44)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies

C:\www>php -r "echo __DIR__;"

How can I clear the SQL Server query cache?

EXEC sys.sp_configure N'max server memory (MB)', N'2147483646'

What value you specify for the server memory is not important, as long as it differs from the current one.

Btw, the thing that causes the speedup is not the query cache, but the data cache.

Update multiple rows in same query using PostgreSQL

In addition to other answers, comments and documentation, the datatype cast can be placed on usage. This allows an easier copypasting:

update test as t set
    column_a = c.column_a::number
from (values
    ('123', 1),
    ('345', 2)  
) as c(column_b, column_a) 
where t.column_b = c.column_b::text;

Going from MM/DD/YYYY to DD-MMM-YYYY in java

Below should work.

SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
Date oldDate = df.parse(df.format(date)); //this date is your old date object

angular.service vs angular.factory

app.factory('fn', fn) vs. app.service('fn',fn)


With factories, Angular will invoke the function to get the result. It is the result that is cached and injected.

 var obj = fn();
 return obj;

With services, Angular will invoke the constructor function by calling new. The constructed function is cached and injected.

  var obj = new fn();
  return obj;


Factories typically return an object literal because the return value is what's injected into controllers, run blocks, directives, etc

  app.factory('fn', function(){
         var foo = 0;
         var bar = 0;
         function setFoo(val) {
               foo = val;
         function setBar (val){
               bar = val;
         return {
                setFoo: setFoo,
                serBar: setBar

Service functions typically do not return anything. Instead, they perform initialization and expose functions. Functions can also reference 'this' since it was constructed using 'new'.

app.service('fn', function () {
         var foo = 0;
         var bar = 0;
         this.setFoo = function (val) {
               foo = val;
         this.setBar = function (val){
               bar = val;


When it comes to using factories or services they are both very similar. They are injected into a controllers, directives, run block, etc, and used in client code in pretty much the same way. They are also both singletons - meaning the same instance is shared between all places where the service/factory is injected.

So which should you prefer? Either one - they are so similar that the differences are trivial. If you do choose one over the other, just be aware how they are constructed, so that you can implement them properly.

Select Pandas rows based on list index

There are many ways of solving this problem, and the ones listed above are the most commonly used ways of achieving the solution. I want to add two more ways, just in case someone is looking for an alternative.

index_list = [1,3]



df.query('index in @index_list')

Why is there no multiple inheritance in Java, but implementing multiple interfaces is allowed?

Take for example the case where Class A has a getSomething method and class B has a getSomething method and class C extends A and B. What would happen if someone called C.getSomething? There is no way to determine which method to call.

Interfaces basically just specify what methods a implementing class needs to contain. A class that implements multiple interfaces just means that class has to implement the methods from all those interfaces. Whci would not lead to any issues as described above.

Length of a JavaScript object

@palmsey: In fairness to the OP, the JavaScript documentation actually explicitly refer to using variables of type Object in this manner as "associative arrays".

And in fairness to @palmsey he was quite correct. They aren't associative arrays; they're definitely objects :) - doing the job of an associative array. But as regards to the wider point, you definitely seem to have the right of it according to this rather fine article I found:

JavaScript “Associative Arrays” Considered Harmful

But according to all this, the accepted answer itself is bad practice?

Specify a prototype size() function for Object

If anything else has been added to Object .prototype, then the suggested code will fail:

<script type="text/javascript">
Object.prototype.size = function () {
  var len = this.length ? --this.length : -1;
    for (var k in this)
  return len;
Object.prototype.size2 = function () {
  var len = this.length ? --this.length : -1;
    for (var k in this)
  return len;
var myArray = new Object();
myArray["firstname"] = "Gareth";
myArray["lastname"] = "Simpson";
myArray["age"] = 21;
alert("age is " + myArray["age"]);
alert("length is " + myArray.size());

I don't think that answer should be the accepted one as it can't be trusted to work if you have any other code running in the same execution context. To do it in a robust fashion, surely you would need to define the size method within myArray and check for the type of the members as you iterate through them.

Pinging an IP address using PHP and echoing the result

this works fine for me..

$output=shell_exec('ping -n 1 '.$host);

echo "<pre>$output</pre>"; //for viewing the ping result, if not need it just remove it

if (strpos($output, 'out') !== false) {
    echo "Dead";
    elseif(strpos($output, 'expired') !== false)
    echo "Network Error";
    elseif(strpos($output, 'data') !== false)
    echo "Alive";
    echo "Unknown Error";

How do I get a list of files in a directory in C++?

Here's an example in C on Linux. That's if, you're on Linux and don't mind doing this small bit in ANSI C.

#include <dirent.h>

DIR *dpdf;
struct dirent *epdf;

dpdf = opendir("./");
if (dpdf != NULL){
   while (epdf = readdir(dpdf)){
      printf("Filename: %s",epdf->d_name);
      // std::cout << epdf->d_name << std::endl;

How to sort by Date with DataTables jquery plugin?

As of 2015, the most convenient way according to me to sort Date column in a DataTable, is using the required sort plugin. Since the date format in my case was dd/mm/yyyy hh:mm:ss, I ended up using the date-euro plugin. All one needs to do is:

Step 1: Include the sorting plugin JavaScript file or code and;

Step 2: Add columnDefs as shown below to target appropriate column(s).

$('#example').dataTable( {
    columnDefs: [
       { type: 'date-euro', targets: 0 }

jQuery scroll() detect when user stops scrolling

function scrolled() {
    //do by scroll start
        //do by scroll end
    }, 500)

very small Version with start and end ability

Get month name from number

import datetime

monthinteger = 4

month =, monthinteger, 1).strftime('%B')

print month


How to unzip gz file using Python

It is very simple.. Here you go !!

import gzip


ip = sample.gzip

#output file to be filled

op = open("output_file","w") 

with,"rb") as ip_byte:

How can I parse a local JSON file from assets folder into a ListView?

As Faizan describes in their answer here:

First of all read the Json File from your assests file using below code.

and then you can simply read this string return by this function as

public String loadJSONFromAsset() {
    String json = null;
    try {
        InputStream is = getActivity().getAssets().open("yourfilename.json");
        int size = is.available();
        byte[] buffer = new byte[size];;
        json = new String(buffer, "UTF-8");
    } catch (IOException ex) {
        return null;
    return json;

and use this method like that

    try {
        JSONObject obj = new JSONObject(loadJSONFromAsset());
        JSONArray m_jArry = obj.getJSONArray("formules");
        ArrayList<HashMap<String, String>> formList = new ArrayList<HashMap<String, String>>();
        HashMap<String, String> m_li;

        for (int i = 0; i < m_jArry.length(); i++) {
            JSONObject jo_inside = m_jArry.getJSONObject(i);
            Log.d("Details-->", jo_inside.getString("formule"));
            String formula_value = jo_inside.getString("formule");
            String url_value = jo_inside.getString("url");

            //Add your values in your `ArrayList` as below:
            m_li = new HashMap<String, String>();
            m_li.put("formule", formula_value);
            m_li.put("url", url_value);

    } catch (JSONException e) {

For further details regarding JSON Read HERE

How can I convert a PFX certificate file for use with Apache on a linux server?

Took some tooling around but this is what I ended up with.

Generated and installed a certificate on IIS7. Exported as PFX from IIS

Convert to pkcs12

openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes

NOTE: While converting PFX to PEM format, openssl will put all the Certificates and Private Key into a single file. You will need to open the file in Text editor and copy each Certificate & Private key(including the BEGIN/END statements) to its own individual text file and save them as certificate.cer, CAcert.cer, privateKey.key respectively.

Saved as certificate.key

Saved as certificate.crt

Added to apache vhost w/ Webmin.

Sort a two dimensional array based on one column

Arrays.sort(yourarray, new Comparator() {
    public int compare(Object o1, Object o2) {
        String[] elt1 = (String[])o1;
        String[] elt2 = (String[])o2;
        return elt1[0].compareTo(elt2[0]);

How to run a specific Android app using Terminal?

I keep this build-and-run script handy, whenever I am working from command line:

#!/usr/bin/env bash

echo "Package: $PACKAGE"

echo "Building the project with tasks: $TASKS"
./gradlew $TASKS

echo "Uninstalling $PACKAGE"
adb uninstall $PACKAGE

echo "Installing $APK_LOCATION"
adb install $APK_LOCATION

echo "Starting $ACTIVITY"
adb shell am start -n $PACKAGE/$ACTIVITY

Function to close the window in Tkinter

class App():
    def __init__(self):
        self.root = Tkinter.Tk()
        button = Tkinter.Button(self.root, text = 'root quit', command=self.quit)

    def quit(self):

app = App()

matching query does not exist Error in Django

In case anybody is here and the other two solutions do not make the trick, check that what you are using to filter is what you expect:

user = UniversityDetails.objects.get(email=email)

is email a str, or a None? or an int?

How do you unit test private methods?

I use PrivateObject class. But as mentioned previously better to avoid testing private methods.

Class target = new Class();
PrivateObject obj = new PrivateObject(target);
var retVal = obj.Invoke("PrivateMethod");


In Eclipse,

Run -- > Debug Configurations --> Select "target", and select a preferred emulator target to launch.

Then Below that "additional emulator command line options," add this:

-partition-size 1024

Then CLOSE the emulator and click the debug icon, which will launch the preferred emulator you selected.

enter image description here

Hope it Helps...!

How to add a line break within echo in PHP?

You have to use br when using echo , like this :

echo "Thanks for your email" ."<br>". "Your orders details are below:"

and it will work properly

How do I get a file extension in PHP?

The simplest way to get file extension in PHP is to use PHP's built-in function pathinfo.

$file_ext = pathinfo('your_file_name_here', PATHINFO_EXTENSION);
echo ($file_ext); // The output should be the extension of the file e.g., png, gif, or html

Gradient of n colors ranging from color 1 and color 2

Just to expand on the previous answer colorRampPalettecan handle more than two colors.

So for a more expanded "heat map" type look you can....

plot(rep(1,50),col=(colfunc(50)), pch=19,cex=2)

The resulting image:

enter image description here

JPA CriteriaBuilder - How to use "IN" comparison operator

If I understand well, you want to Join ScheduleRequest with User and apply the in clause to the userName property of the entity User.

I'd need to work a bit on this schema. But you can try with this trick, that is much more readable than the code you posted, and avoids the Join part (because it handles the Join logic outside the Criteria Query).

List<String> myList = new ArrayList<String> ();
for (User u : usersList) {
Expression<String> exp = scheduleRequest.get("createdBy");
Predicate predicate =;

In order to write more type-safe code you could also use Metamodel by replacing this line:

Expression<String> exp = scheduleRequest.get("createdBy");

with this:

Expression<String> exp = scheduleRequest.get(ScheduleRequest_.createdBy);

If it works, then you may try to add the Join logic into the Criteria Query. But right now I can't test it, so I prefer to see if somebody else wants to try.

Not a perfect answer though may be code snippets might help.

public <T> List<T> findListWhereInCondition(Class<T> clazz,
            String conditionColumnName, Serializable... conditionColumnValues) {
        QueryBuilder<T> queryBuilder = new QueryBuilder<T>(clazz);
        addWhereInClause(queryBuilder, conditionColumnName,
        return queryBuilder.getResultList();


private <T> void addWhereInClause(QueryBuilder<T> queryBuilder,
            String conditionColumnName, Serializable... conditionColumnValues) {

        Path<Object> path = queryBuilder.root.get(conditionColumnName);
        In<Object> in =;
        for (Serializable conditionColumnValue : conditionColumnValues) {


What is the "assert" function?

assert will terminate the program (usually with a message quoting the assert statement) if its argument turns out to be false. It's commonly used during debugging to make the program fail more obviously if an unexpected condition occurs.

For example:

assert(length >= 0);  // die if length is negative.

You can also add a more informative message to be displayed if it fails like so:

assert(length >= 0 && "Whoops, length can't possibly be negative! (didn't we just check 10 lines ago?) Tell jsmith");

Or else like this:

assert(("Length can't possibly be negative! Tell jsmith", length >= 0));

When you're doing a release (non-debug) build, you can also remove the overhead of evaluating assert statements by defining the NDEBUG macro, usually with a compiler switch. The corollary of this is that your program should never rely on the assert macro running.

// BAD


// Watch out! Depends on the function:

// Here's a safer way:
int ret = foo();

From the combination of the program calling abort() and not being guaranteed to do anything, asserts should only be used to test things that the developer has assumed rather than, for example, the user entering a number rather than a letter (which should be handled by other means).

How do I format XML in Notepad++?

Here are most of plugins you can use in Notepad++ to format your XML code.

  • UniversalIndentGUI
    (I recommend this one)

Enable 'text auto update' in plugin manager-> UniversalIndentGUI

  • TextFX
    (this is the tool that most of the users use)


  • XML Tools
    (customized plugin for XML)


Clear contents of cells in VBA using column reference

For anyone like me who came across this and needs a solution that doesn't clear headers, here is the one liner that works for me:

ActiveSheet.Range("A3:A" & Range("A3").End(xlDown).Row).ClearContents

Starts on the third row - change to your liking.

Why use String.Format?

I can see a number of reasons:


string s = string.Format("Hey, {0} it is the {1}st day of {2}.  I feel {3}!", _name, _day, _month, _feeling);


string s = "Hey," + _name + " it is the " + _day + "st day of " + _month + ".  I feel " + feeling + "!";

Format Specifiers (and this includes the fact you can write custom formatters)

string s = string.Format("Invoice number: {0:0000}", _invoiceNum);


string s = "Invoice Number = " + ("0000" + _invoiceNum).Substr(..... /*can't even be bothered to type it*/)

String Template Persistence

What if I want to store string templates in the database? With string formatting:

_id         _translation
  1         Welcome {0} to {1}.  Today is {2}.
  2         You have {0} products in your basket.
  3         Thank-you for your order.  Your {0} will arrive in {1} working days.


_id         _translation
  1         Welcome
  2         to
  3         .  Today is
  4         . 
  5         You have
  6         products in your basket.
  7         Someone
  8         just shoot
  9         the developer.

Dynamically add data to a javascript map

Javascript now has a specific built in object called Map, you can call as follows :

   var myMap = new Map()

You can update it with .set :


This has the advantage of methods you can use to handle look ups, like the boolean .has

  myMap.has("key1"); // evaluates to false 

You can use this before calling .get on your Map object to handle looking up non-existent keys

How to Initialize char array from a string

Another option is to use sprintf.

For example,

char buffer[50];
sprintf( buffer, "My String" );

Good luck.

Best practices for Storyboard login screen, handling clearing of data upon logout

I use this to check for first launch:

- (NSInteger) checkForFirstLaunch
    NSInteger result = 0; //no first launch

    // Get current version ("Bundle Version") from the default Info.plist file
    NSString *currentVersion = (NSString*)[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"];
    NSArray *prevStartupVersions = [[NSUserDefaults standardUserDefaults] arrayForKey:@"prevStartupVersions"];
    if (prevStartupVersions == nil)
        // Starting up for first time with NO pre-existing installs (e.g., fresh
        // install of some version)
        [[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:currentVersion] forKey:@"prevStartupVersions"];
        result = 1; //first launch of the app
    } else {
        if (![prevStartupVersions containsObject:currentVersion])
            // Starting up for first time with this version of the app. This
            // means a different version of the app was alread installed once
            // and started.
            NSMutableArray *updatedPrevStartVersions = [NSMutableArray arrayWithArray:prevStartupVersions];
            [updatedPrevStartVersions addObject:currentVersion];
            [[NSUserDefaults standardUserDefaults] setObject:updatedPrevStartVersions forKey:@"prevStartupVersions"];
            result = 2; //first launch of this version of the app

    // Save changes to disk
    [[NSUserDefaults standardUserDefaults] synchronize];

    return result;

(if the user deletes the app and re-installs it, it counts like a first launch)

In the AppDelegate I check for first launch and create a navigation-controller with the login screens (login and register), which I put on top of the current main window:

[self.window makeKeyAndVisible];

if (firstLaunch == 1) {
    UINavigationController *_login = [[UINavigationController alloc] initWithRootViewController:loginController];
    [self.window.rootViewController presentViewController:_login animated:NO completion:nil];

As this is on top of the regular view controller it's independent from the rest of your app and you can just dismiss the view controller, if you don't need it anymore. And you can also present the view this way, if the user presses a button manually.

BTW: I save the login-data from my users like this:

KeychainItemWrapper *keychainItem = [[KeychainItemWrapper alloc] initWithIdentifier:@"com.youridentifier" accessGroup:nil];
[keychainItem setObject:password forKey:(__bridge id)(kSecValueData)];
[keychainItem setObject:email forKey:(__bridge id)(kSecAttrAccount)];

For the logout: I switched away from CoreData (too slow) and use NSArrays and NSDictionaries to manage my data now. Logout just means to empty those arrays and dictionaries. Plus I make sure to set my data in viewWillAppear.

That's it.

TypeScript: Property does not exist on type '{}'

Access the field with array notation to avoid strict type checking on single field:

data['propertyName']; //will work even if data has not declared propertyName

Alternative way is (un)cast the variable for single access:

(<any>data).propertyName;//access propertyName like if data has no type

The first is shorter, the second is more explicit about type (un)casting

You can also totally disable type checking on all variable fields:

let untypedVariable:any= <any>{}; //disable type checking while declaring the variable
untypedVariable.propertyName = anyValue; //any field in untypedVariable is assignable and readable without type checking

Note: This would be more dangerous than avoid type checking just for a single field access, since all consecutive accesses on all fields are untyped

How to make audio autoplay on chrome

Use the Autoplay attribute in HTML to autoplay the audio or video.

<audio id="player" autoplay controls><source src="0.mp3" type="audio/mp3"></audio>

How do I set the driver's python version in spark?

In case you only want to change the python version for current task, you can use following pyspark start command:

    PYSPARK_DRIVER_PYTHON=/home/user1/anaconda2/bin/python PYSPARK_PYTHON=/usr/local/anaconda2/bin/python pyspark --master ..

ImportError: No module named sqlalchemy

first install the library

pip install flask_sqlalchemy 

after that

from flask_sqlalchemy import SQLAlchemy

put this in file to get the access of database through SQLAlchemy

Converting String to Double in Android

I would do it this way:

try {
  txtProt = (EditText) findViewById(; // Same
  p = txtProt.getText().toString(); // Same
  protein = Double.parseDouble(p); // Make use of autoboxing.  It's also easier to read.
} catch (NumberFormatException e) {
  // p did not contain a valid double

EDIT: "the program force closes immediately without leaving any info in the logcat"

I don't know bout not leaving information in the logcat output, but a force-close generally means there's an uncaught exception - like a NumberFormatException.

Disable submit button when form invalid with AngularJS

To add to this answer. I just found out that it will also break down if you use a hyphen in your form name (Angular 1.3):

So this will not work:

<form name="my-form">
    <input name="myText" type="text" ng-model="mytext" required />
    <button ng-disabled="my-form.$invalid">Save</button>

Fill remaining vertical space with CSS using display:flex

The example below includes scrolling behaviour if the content of the expanded centre component extends past its bounds. Also the centre component takes 100% of remaining space in the viewport.

jsfiddle here

html, body, .r_flex_container{
    height: 100%;
    display: flex;
    flex-direction: column;
    background: red;
    margin: 0;
.r_flex_container {
    flex-flow: column nowrap;

.r_flex_fixed_child {

.r_flex_expand_child {

Example of html that can be used to demonstrate this behaviour

    <div class="r_flex_container">
      <div class="r_flex_fixed_child">
        <p> This is the fixed 'header' child of the flex container </p>
      <div class="r_flex_expand_child">
            <article>this child container expands to use all of the space given to it -  but could be shared with other expanding childs in which case they would get equal space after the fixed container space is allocated. 
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,
      <div class="r_flex_fixed_child">
        this is the fixed footer child of the flex container
        <p> another line</p>


NGINX - No input file specified. - php Fast/CGI

I had the same Error and my Problem was, that I had my php-file in my encrypted home-directory. And I run my fpm with the www-data user and this user can't read the php-files even if the permissions on the file were right. The solutioin was that I run fpm with the user who owns the home-directory. This can be changed in folowing file:


hope this will help you :)

Differences in string compare methods in C#

In the forms you listed here, there's not much difference between the two. CompareTo ends up calling a CompareInfo method that does a comparison using the current culture; Equals is called by the == operator.

If you consider overloads, then things get different. Compare and == can only use the current culture to compare a string. Equals and String.Compare can take a StringComparison enumeration argument that let you specify culture-insensitive or case-insensitive comparisons. Only String.Compare allows you to specify a CultureInfo and perform comparisons using a culture other than the default culture.

Because of its versatility, I find I use String.Compare more than any other comparison method; it lets me specify exactly what I want.

How do I connect to an MDF database file?

string sqlCon = @"Data Source=.\SQLEXPRESS;" +
                Integrated Security=True;
                Connect Timeout=30;
                User Instance=True";
SqlConnection Con = new SqlConnection(sqlCon);

The filepath should have |DataDirectory| which actually links to "current project directory\App_Data\" or "current project directory" and get the .mdf file.....Place the .mdf in either of these places and should work in visual studio 2010.And when you use the standalone application on production system, then the current path where the executable file is, should have the .mdf file.

Alternate table with new not null Column in existing table in SQL

You will either have to specify a DEFAULT, or add the column with NULLs allowed, update all the values, and then change the column to NOT NULL.

ALTER TABLE <YourTable> 
ADD <NewColumn> <NewColumnType> NOT NULL DEFAULT <DefaultValue>

How to get a variable from a file to another file in Node.js

You need module.exports:


An object which is shared between all instances of the current module and made accessible through require(). exports is the same as the module.exports object. See src/node.js for more information. exports isn't actually a global but rather local to each module.

For example, if you would like to expose variableName with value "variableValue" on sourceFile.js then you can either set the entire exports as such:

module.exports = { variableName: "variableValue" };

Or you can set the individual value with:

module.exports.variableName = "variableValue";

To consume that value in another file, you need to require(...) it first (with relative pathing):

const sourceFile = require('./sourceFile');

Alternatively, you can deconstruct it.

const { variableName } = require('./sourceFile');
//            current directory --^
// ../     would be one directory down
// ../../  is two directories down

If all you want out of the file is variableName then


const variableName = 'variableValue'
module.exports = variableName


const variableName = require('./sourceFile')

Edit (2020):

Since Node.js version 8.9.0, you can also use ECMAScript Modules with varying levels of support. The documentation.

  • For Node v13.9.0 and beyond, experimental modules are enabled by default
  • For versions of Node less than version 13.9.0, use --experimental-modules

Node.js will treat the following as ES modules when passed to node as the initial input, or when referenced by import statements within ES module code:

  • Files ending in .mjs.
  • Files ending in .js when the nearest parent package.json file contains a top-level field "type" with a value of "module".
  • Strings passed in as an argument to --eval or --print, or piped to node via STDIN, with the flag --input-type=module.

Once you have it setup, you can use import and export.

Using the example above, there are two approaches you can take


// This is a named export of variableName
export const variableName = 'variableValue'
// Alternatively, you could have exported it as a default. 
// For sake of explanation, I'm wrapping the variable in an object
// but it is not necessary. 
// You can actually omit declaring what variableName is here. 
// { variableName } is equivalent to { variableName: variableName } in this case. 
export default { variableName: variableName } 


// There are three ways of importing. 
// If you need access to a non-default export, then 
// you use { nameOfExportedVariable } 
import { variableName } from './sourceFile'
console.log(variableName) // 'variableValue'

// Otherwise, you simply provide a local variable name 
// for what was exported as default.
import sourceFile from './sourceFile'
console.log(sourceFile.variableName) // 'variableValue'


// The third way of importing is for situations where there
// isn't a default export but you want to warehouse everything
// under a single variable. Say you have:
export const a = 'A'
export const b = 'B'


// Then you can import all exports under a single variable
// with the usage of * as:
import * as sourceFileWithoutDefault from './sourceFileWithoutDefault'

console.log(sourceFileWithoutDefault.a) // 'A'
console.log(sourceFileWithoutDefault.b) // 'B'

// You can use this approach even if there is a default export:
import * as sourceFile from './sourceFile'

// Default exports are under the variable default:
console.log(sourceFile.default) // { variableName: 'variableValue' }

// As well as named exports:
console.log(sourceFile.variableName) // 'variableValue

Printing Even and Odd using two Threads in Java

The other question was closed as a duplicate of this one. I think we can safely get rid of "even or odd" problem and use the wait/notify construct as follows:

public class WaitNotifyDemoEvenOddThreads {
     * A transfer object, only use with proper client side locking!
    static final class LastNumber {
        int num;
        final int limit;

        LastNumber(int num, int limit) {
            this.num = num;
            this.limit = limit;

    static final class NumberPrinter implements Runnable {
        private final LastNumber last;
        private final int init;

        NumberPrinter(LastNumber last, int init) {
            this.last = last;
            this.init = init;

        public void run() {
            int i = init;
            synchronized (last) {
                while (i <= last.limit) {
                    while (last.num != i) {
                        try {
                        } catch (InterruptedException e) {
                    System.out.println(Thread.currentThread().getName() + " prints: " + i);
                    last.num = i + 1;
                    i += 2;

    public static void main(String[] args) {
        LastNumber last = new LastNumber(0, 10); // or 0, 1000
        NumberPrinter odd = new NumberPrinter(last, 1);
        NumberPrinter even = new NumberPrinter(last, 0);
        new Thread(odd, "o").start();
        new Thread(even, "e").start();

VBA Excel Provide current Date in Text box

I know this is extremely old post, but I've used this before

You can always adjust to activate. Now method is another way. Just an option

Private Sub UserForm_Initialize()

Textbox1.Text = Format(Now(), "mmddyyyhhmmss")

End Sub

What is the <leader> in a .vimrc file?

In my system its the \ key. it's used for commands so that you can combine it with other chars.

How to change the default docker registry from to my private registry?

There is the use case of a mirror of Docker Hub (such as Artifactory or a custom one), which I haven't seen mentioned here. This is one of the most valid cases where changing the default registry is needed.

Luckily, Docker (at least version 19.03.3) allows you to set a mirror (tested in Docker CE). I don't know if this will work with additional images pushed to that mirror that aren't on Docker Hub, but I do know it will use the mirror instead. Docker documentation:

Essentially, you need to add "registry-mirrors": [] to the /etc/docker/daemon.json configuration file. So if you have a mirror hosted at, your /etc/docker/daemon.json should contain:

  "registry-mirrors": [""]

Afterwards, restart the Docker daemon. Now if you do a docker pull postgres:12, Docker should fetch the image from the mirror instead of directly from Docker Hub. This is much better than prepending all images with

Appending HTML string to the DOM

Use insertAdjacentHTML if it's available, otherwise use some sort of fallback. insertAdjacentHTML is supported in all current browsers.

div.insertAdjacentHTML( 'beforeend', str );

Live demo:

UITextField text change event

Swift 3 Version

yourTextField.addTarget(self, action: #selector(YourControllerName.textChanges(_:)), for: UIControlEvents.editingChanged)

And get the changes in here

func textChanges(_ textField: UITextField) {
    let text = textField.text! // your desired text here
    // Now do whatever you want.

Hope it helps.

How to parse dates in multiple formats using SimpleDateFormat

If working in Java 1.8 you can leverage the DateTimeFormatterBuilder

public static boolean isTimeStampValid(String inputString)
    DateTimeFormatterBuilder dateTimeFormatterBuilder = new DateTimeFormatterBuilder()
            .append(DateTimeFormatter.ofPattern("" + "[yyyy-MM-dd'T'HH:mm:ss.SSSZ]" + "[yyyy-MM-dd]"));

    DateTimeFormatter dateTimeFormatter = dateTimeFormatterBuilder.toFormatter();

    try {
        return true;
    } catch (DateTimeParseException e) {
        return false;

See post: Java 8 Date equivalent to Joda's DateTimeFormatterBuilder with multiple parser formats?

'Connect-MsolService' is not recognized as the name of a cmdlet

I had to do this in that order:

Install-Module MSOnline
Install-Module AzureAD
Import-Module AzureAD

PHP create key => value pairs within a foreach

In PHP >= 5.3 it can be done like this:

$offerArray = array_map(function($value) {
    return $value[4];
}, $offer);

Android Respond To URL in Intent

I did it! Using <intent-filter>. Put the following into your manifest file:

  <action android:name="android.intent.action.VIEW" />
  <category android:name="android.intent.category.DEFAULT" />
  <category android:name="android.intent.category.BROWSABLE" />
  <data android:host="" android:scheme="http" />

This works perfectly!

How can I get an HTTP response body as a string?

The Answer by McDowell is correct one. However if you try other suggestion in few of the posts above.

HttpEntity responseEntity = httpResponse.getEntity();
if(responseEntity!=null) {
   response = EntityUtils.toString(responseEntity);
   S.O.P (response);

Then it will give you illegalStateException stating that content is already consumed.

Before and After Suite execution hook in jUnit 4.x

Provided that all your tests may extend a "technical" class and are in the same package, you can do a little trick :

public class AbstractTest {
  private static int nbTests = listClassesIn(<package>).size();
  private static int curTest = 0;

  public static void incCurTest() { curTest++; }

  public static void closeTestSuite() {
      if (curTest == nbTests) { /*cleaning*/ }             

public class Test1 extends AbstractTest {
   public void check() {}
public class Test2 extends AbstractTest {
   public void check() {}

Be aware that this solution has a lot of drawbacks :

  • must execute all tests of the package
  • must subclass a "techincal" class
  • you can not use @BeforeClass and @AfterClass inside subclasses
  • if you execute only one test in the package, cleaning is not done
  • ...

For information: listClassesIn() => How do you find all subclasses of a given class in Java?

How to count check-boxes using jQuery?

Assume that you have a tr row with multiple checkboxes in it, and you want to count only if the first checkbox is checked.

You can do that by giving a class to the first checkbox

For example class='mycxk' and you can count that using the filter, like this


Why does the Visual Studio editor show dots in blank spaces?

In Visual Studio 2012
Go to
Edit -> Advanced -> View White Spaces
Press Ctrl+R, Ctrl+W

How to print jquery object/array

Your result is currently in string format, you need to parse it as json.

var obj = $.parseJSON(result);

Additionally, if you set the dataType of the ajax call you are making to json, you can skip the $.parseJSON() step.

List of strings to one string

I would go with option A:

String.Join(String.Empty, los.ToArray());

My reasoning is because the Join method was written for that purpose. In fact if you look at Reflector, you'll see that unsafe code was used to really optimize it. The other two also WORK, but I think the Join function was written for this purpose, and I would guess, the most efficient. I could be wrong though...

As per @Nuri YILMAZ without .ToArray(), but this is .NET 4+:

String.Join(String.Empty, los);

How can I save a screenshot directly to a file in Windows?

This will do it in Delphi. Note the use of the BitBlt function, which is a Windows API call, not something specific to Delphi.

Edit: Added example usage

function TForm1.GetScreenShot(OnlyActiveWindow: boolean) : TBitmap;
  w,h : integer;
  DC : HDC;
  hWin : Cardinal;
  r : TRect;
  //take a screenshot and return it as a TBitmap.
  //if they specify "OnlyActiveWindow", then restrict the screenshot to the
  //currently focused window (same as alt-prtscrn)
  //Otherwise, get a normal screenshot (same as prtscrn)
  Result := TBitmap.Create;
  if OnlyActiveWindow then begin
    hWin := GetForegroundWindow;
    dc := GetWindowDC(hWin);
    w := r.Right - r.Left;
    h := r.Bottom - r.Top;
  end  //if active window only
  else begin
    hWin := GetDesktopWindow;
    dc := GetDC(hWin);
    w := GetDeviceCaps(DC,HORZRES);
    h := GetDeviceCaps(DC,VERTRES);
  end;  //else entire desktop

    Result.Width := w;
    Result.Height := h;
    ReleaseDC(hWin, DC) ;
  end;  //try-finally

procedure TForm1.btnSaveScreenshotClick(Sender: TObject);
  bmp : TBitmap;
  savdlg : TSaveDialog;
  //take a screenshot, prompt for where to save it
  savdlg := TSaveDialog.Create(Self);
  bmp := GetScreenshot(False);
    if savdlg.Execute then begin
  end;  //try-finally