Programs & Examples On #Freebase

Freebase was a large, Google owned, community-edited, general knowledge semantic database that could previously be accessed via a RESTful API. It was shut down in 2016.

Dataset - Vehicle make/model/year (free)

Apparently there is not much out there. And a lot of doubt that someone would be willing to provide such a repository. So I solved the problem myself, and am sharing my dataset with anyone else who finds themselves facing the same problem.

Get JSON data from external URL and display it in a div as plain text

If you want to use plain javascript, but avoid promises, you can use Rami Sarieddine's solution, but substitute the promise with a callback function like this:

var getJSON = function(url, callback) {
    var xhr = new XMLHttpRequest();'get', url, true);
    xhr.responseType = 'json';
    xhr.onload = function() {
      var status = xhr.status;
      if (status == 200) {
        callback(null, xhr.response);
      } else {

And you would call it like this:

getJSON('', function(err, data) {
  if (err != null) {
    alert('Something went wrong: ' + err);
  } else {
    alert('Your Json result is:  ' + data.result);
    result.innerText = data.result;

How do I open the "front camera" on the Android platform?


 dependencies {
       compile ''

Set View

CameraSourcePreview mPreview = (CameraSourcePreview) findViewById(;

GraphicOverlay mGraphicOverlay = (GraphicOverlay) findViewById(;

CameraSource mCameraSource = new CameraSource.Builder(context, detector)
                            .setRequestedPreviewSize(640, 480)

           mPreview.start(mCameraSource, mGraphicOverlay);

How to check the multiple permission at single request in Android M?

First initialize permission request code

public  static final int PERMISSIONS_MULTIPLE_REQUEST = 123;

Check android version

 private void checkAndroidVersion() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

    } else {
        // write your logic here


check multiple permission code

 private void checkPermission() {
    if (ContextCompat.checkSelfPermission(getActivity(),
            Manifest.permission.READ_EXTERNAL_STORAGE) + ContextCompat
            != PackageManager.PERMISSION_GRANTED) {

        if (ActivityCompat.shouldShowRequestPermissionRationale
                (getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE) ||
                        (getActivity(), Manifest.permission.CAMERA)) {

                    "Please Grant Permissions to upload profile photo",
                    new View.OnClickListener() {
                        public void onClick(View v) {
                                    new String[]{Manifest.permission
                                            .READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA},
        } else {
                    new String[]{Manifest.permission
                            .READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA},
    } else {
        // write your logic code if permission already granted

call back method after grant permission by user

public void onRequestPermissionsResult(int requestCode,
                                       @NonNull String[] permissions, @NonNull int[] grantResults) {

    switch (requestCode) {
            if (grantResults.length > 0) {
               boolean cameraPermission = grantResults[1] == PackageManager.PERMISSION_GRANTED;
               boolean readExternalFile = grantResults[0] == PackageManager.PERMISSION_GRANTED;

                if(cameraPermission && readExternalFile)
                    // write your logic here 
                } else {
                        "Please Grant Permissions to upload profile photo",
                        new View.OnClickListener() {
                            public void onClick(View v) {
                                        new String[]{Manifest.permission
                                                .READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA},

Could pandas use column as index?

Yes, with set_index you can make Locality your row index.

data.set_index('Locality', inplace=True)

If inplace=True is not provided, set_index returns the modified dataframe as a result.


> import pandas as pd
> df = pd.DataFrame([['ABBOTSFORD', 427000, 448000],
                     ['ABERFELDIE', 534000, 600000]],
                    columns=['Locality', 2005, 2006])

> df
     Locality    2005    2006
0  ABBOTSFORD  427000  448000
1  ABERFELDIE  534000  600000

> df.set_index('Locality', inplace=True)
> df
              2005    2006
ABBOTSFORD  427000  448000
ABERFELDIE  534000  600000

> df.loc['ABBOTSFORD']
2005    427000
2006    448000
Name: ABBOTSFORD, dtype: int64

> df.loc['ABBOTSFORD'][2005]

> df.loc['ABBOTSFORD'].values
array([427000, 448000])

> df.loc['ABBOTSFORD'].tolist()
[427000, 448000]

How do you push just a single Git branch (and no other branches)?

Minor update on top of Karthik Bose's answer - you can configure git globally, to affect all of your workspaces to behave that way:

git config --global push.default upstream

Time calculation in php (add 10 hours)?

You can simply make use of the DateTime class , OOP Style.

$date = new DateTime('1:00:00');
$date->add(new DateInterval('PT10H'));
echo $date->format('H:i:s a'); //"prints" 11:00:00 a.m

A failure occurred while executing

Clean Project -> Invalidate caches/restart. My problem resolved with this.

Django {% with %} tags within {% if %} {% else %} tags?

if you want to stay DRY, use an include.

{% if foo %}
  {% with a as b %}
    {% include "snipet.html" %}
  {% endwith %} 
{% else %}
  {% with bar as b %}
    {% include "snipet.html" %}
  {% endwith %} 
{% endif %}

or, even better would be to write a method on the model that encapsulates the core logic:

def Patient(models.Model):
    def get_legally_responsible_party(self):
       if self.age > 18:
          return self
          return self.parent

Then in the template:

{% with patient.get_legally_responsible_party as p %}
  Do html stuff
{% endwith %} 

Then in the future, if the logic for who is legally responsible changes you have a single place to change the logic -- far more DRY than having to change if statements in a dozen templates.

How to show text in combobox when no item selected?

    private void comboBox1_TextChanged(object sender, EventArgs e)
        if (comboBox1.Text == "")
            comboBox1.Text = "Select one of the answers"; 

should do the trick at startup this line is present, when selected an item on combobox, this items text will appear. when deleling the text this text will appear again

powershell 2.0 try catch how to access the exception

Try something like this:

try {
    $w = New-Object net.WebClient
    $d = $w.downloadString('http://foo')
catch [Net.WebException] {
    Write-Host $_.Exception.ToString()

The exception is in the $_ variable. You might explore $_ like this:

try {
    $w = New-Object net.WebClient
    $d = $w.downloadString('http://foo')
catch [Net.WebException] {
    $_ | fl * -Force

I think it will give you all the info you need.

My rule: if there is some data that is not displayed, try to use -force.

how to clear the screen in python

If you mean the screen where you have that interpreter prompt >>> you can do CTRL+L on Bash shell can help. Windows does not have equivalent. You can do

import os
os.system('cls')  # on windows


os.system('clear')  # on linux / os x

How do you determine what SQL Tables have an identity column programmatically

sys.columns.is_identity = 1


from sys.objects o inner join sys.columns c on o.object_id = c.object_id
where c.is_identity = 1

How to stop text from taking up more than 1 line?

Using ellipsis will add the ... at the last.

   <style type="text/css">
    div {
      white-space: nowrap;
      overflow: hidden;
text-overflow: ellipsis;

Error after upgrading pip: cannot import name 'main'

For Python version 2.7 @Anthony solution works perfect, by changing python3 to python as follows:

sudo python -m pip uninstall pip && sudo apt install python-pip --reinstall

Saving awk output to variable

variable=$(ps -ef | awk '/[p]ort 10/ {print $12}')

The [p] is a neat trick to remove the search from showing from ps

@Jeremy If you post the output of ps -ef | grep "port 10", and what you need from the line, it would be more easy to help you getting correct syntax

How to call a php script/function on a html button click

Of course AJAX is the solution,

To perform an AJAX request (for easiness we can use jQuery library).


Include jQuery library in your web page

a. you can download jQuery library from and keep it locally.

b. or simply paste the following code,

<script src=""></script>

Step 2.

Call a javascript function on button click

<button type="button" onclick="foo()">Click Me</button>

Step 3.

and finally the function

 function foo () {
        url:"test.php", //the page containing php script
        type: "POST", //request type

it will make an AJAX request to test.php when ever you clicks the button and alert the response.

For example your code in test.php is,

<?php echo 'hello'; ?>

then it will alert "hello" when ever you clicks the button.

Getting value of selected item in list box as string

You can Use This One To get the selected ListItme Name ::

String selectedItem = ((ListBoxItem)ListBox.SelectedItem).Name.ToString();

Make sure that Your each ListBoxItem have a Name property

Can the "IN" operator use LIKE-wildcards (%) in Oracle?

Select * from myTable m
where m.status not like 'Done%' 
and m.status not like 'Finished except%'
and m.status not like 'In Progress%'

How to read a list of files from a folder using PHP?

If you have problems with accessing to the path, maybe you need to put this:

$path = "/cv/"; 

// Open the folder
 $dir_handle = @opendir($root . $path) or die("Unable to open $path");

Origin is not allowed by Access-Control-Allow-Origin

if you're under apache, just add an .htaccess file to your directory with this content:

Header set Access-Control-Allow-Origin: *

Header set Access-Control-Allow-Headers: content-type

Header set Access-Control-Allow-Methods: *

Run JavaScript code on window close or page refresh?

The documentation here encourages listening to the onbeforeunload event and/or adding an event listener on window.

window.addEventListener('beforeunload', function(event) {
  //do something here
}, false);

You can also just populate the .onunload or .onbeforeunload properties of window with a function or a function reference.

Though behaviour is not standardized across browsers, the function may return a value that the browser will display when confirming whether to leave the page.

Google Maps JavaScript API RefererNotAllowedMapError

According the google docs this happened because the url on which you are using the Google Maps API, it not registered in list of allowed referrers


From Google Docs

All subdomains of a specified domain are also authorized.

If is authorized, then is also authorized. The reverse is not true: if is authorized, is not necessarily authorized

So,Please configure domain, then your will start work.

Change border-bottom color using jquery?

to modify more css property values, you may use css object. such as:

hilight_css = {"border-bottom-color":"red", 

but if the modification code is bloated. you should consider the approach March suggested. do it this way:

first, in your css file:

.hilight { border-bottom-color:red; background-color:#000; }
.msg { /* something to make it notifiable */ }

second, in your js code:

// to bring message block to normal

if ie 6 is not an issue, you can chain these classes to have more specific selectors.

Initialise numpy array of unknown length

a = np.empty(0)
for x in y:
    a = np.append(a, x)

In bash, how to store a return value in a variable?

The return value (aka exit code) is a value in the range 0 to 255 inclusive. It's used to indicate success or failure, not to return information. Any value outside this range will be wrapped.

To return information, like your number, use

echo "$value"

To print additional information that you don't want captured, use

echo "my irrelevant info" >&2 

Finally, to capture it, use what you did:


In other words:

echo "enter: "
        read input

        first=`echo $last_two| sed -e 's/\(.\)/\1 /g'|awk '{print $2}'`
        second=`echo $last_two| sed -e 's/\(.\)/\1 /g'|awk '{print $1}'`
        let sum=$first+$second
        echo $second >&2
        echo $sum >&2

        if [ $sum -gt 9 ]

        echo $value
echo "The value is $result"

How to efficiently concatenate strings in go

This is the fastest solution that does not require you to know or calculate the overall buffer size first:

var data []byte
for i := 0; i < 1000; i++ {
    data = append(data, getShortStringFromSomewhere()...)
return string(data)

By my benchmark, it's 20% slower than the copy solution (8.1ns per append rather than 6.72ns) but still 55% faster than using bytes.Buffer.

Need a good hex editor for Linux

wxHexEditor is the only GUI disk editor for linux. to google "wxhexeditor" and download the .deb file to install

How to change the JDK for a Jenkins job?

For those who couldn't find this option. Install JDK Parameter Plugin

Change the default base url for axios

Putting my two cents here. I wanted to do the same without hardcoding the URL for my specific request. So i came up with this solution.

To append 'api' to my baseURL, I have my default baseURL set as,

axios.defaults.baseURL = '/api/';

Then in my specific request, after explicitly setting the method and url, i set the baseURL to '/'

    baseURL: '/',
   .then(response => {
   .catch(error => {

AngularJS view not updating on model change

As Ajay beniwal mentioned above you need to use Apply to start digestion.

var app = angular.module('test', []);

app.controller('TestCtrl', function ($scope) {
   $scope.testValue = 0;

    setInterval(function() {
    }, 500);

How to turn on line numbers in IDLE?

As @StahlRat already answered. I would like to add another method for it. There is extension pack for Python Default idle editor Python Extensions Package.

Control the dashed border stroke length and distance between strokes

Css render is browser specific and I don't know any fine tuning on it, you should work with images as recommended by Ham. Reference:

How can I generate a self-signed certificate with SubjectAltName using OpenSSL?

Can someone help me with the exact syntax?

It's a three-step process, and it involves modifying the openssl.cnf file. You might be able to do it with only command line options, but I don't do it that way.

Find your openssl.cnf file. It is likely located in /usr/lib/ssl/openssl.cnf:

$ find /usr/lib -name openssl.cnf

On my Debian system, /usr/lib/ssl/openssl.cnf is used by the built-in openssl program. On recent Debian systems it is located at /etc/ssl/openssl.cnf

You can determine which openssl.cnf is being used by adding a spurious XXX to the file and see if openssl chokes.

First, modify the req parameters. Add an alternate_names section to openssl.cnf with the names you want to use. There are no existing alternate_names sections, so it does not matter where you add it.

[ alternate_names ]

DNS.1        =
DNS.2        =
DNS.3        =
DNS.4        =

Next, add the following to the existing [ v3_ca ] section. Search for the exact string [ v3_ca ]:

subjectAltName      = @alternate_names

You might change keyUsage to the following under [ v3_ca ]:

keyUsage = digitalSignature, keyEncipherment

digitalSignature and keyEncipherment are standard fare for a server certificate. Don't worry about nonRepudiation. It's a useless bit thought up by computer science guys/gals who wanted to be lawyers. It means nothing in the legal world.

In the end, the IETF (RFC 5280), browsers and CAs run fast and loose, so it probably does not matter what key usage you provide.

Second, modify the signing parameters. Find this line under the CA_default section:

# Extension copying option: use with caution.
# copy_extensions = copy

And change it to:

# Extension copying option: use with caution.
copy_extensions = copy

This ensures the SANs are copied into the certificate. The other ways to copy the DNS names are broken.

Third, generate your self-signed certificate:

$ openssl genrsa -out private.key 3072
$ openssl req -new -x509 -key private.key -sha256 -out certificate.pem -days 730
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.

Finally, examine the certificate:

$ openssl x509 -in certificate.pem -text -noout
        Version: 3 (0x2)
        Serial Number: 9647297427330319047 (0x85e215e5869042c7)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, ST=MD, L=Baltimore, O=Test CA, Limited, CN=Test CA/[email protected]
            Not Before: Feb  1 05:23:05 2014 GMT
            Not After : Feb  1 05:23:05 2016 GMT
        Subject: C=US, ST=MD, L=Baltimore, O=Test CA, Limited, CN=Test CA/[email protected]
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (3072 bit)
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Subject Key Identifier:
            X509v3 Authority Key Identifier:

            X509v3 Basic Constraints: critical
            X509v3 Key Usage:
                Digital Signature, Non Repudiation, Key Encipherment, Certificate Sign
            X509v3 Subject Alternative Name:
    Signature Algorithm: sha256WithRSAEncryption

How to debug a stored procedure in Toad?

Basic Steps to Debug a Procedure in Toad

  1. Load your Procedure in Toad Editor.
  2. Put debug point on the line where you want to debug.See the first screenshot.
  3. Right click on the editor Execute->Execute PLSQL(Debugger).See the second screeshot.
  4. A window opens up,you need to select the procedure from the left side and pass parameters for that procedure and then click Execute.See the third screenshot.
  5. Now start your debugging check Debug-->Step Over...Add Watch etc.

Reference:Toad Debugger


Execute In Debug


Can Keras with Tensorflow backend be forced to use CPU or GPU at will?

As per keras tutorial, you can simply use the same tf.device scope as in regular tensorflow:

with tf.device('/gpu:0'):
    x = tf.placeholder(tf.float32, shape=(None, 20, 64))
    y = LSTM(32)(x)  # all ops in the LSTM layer will live on GPU:0

with tf.device('/cpu:0'):
    x = tf.placeholder(tf.float32, shape=(None, 20, 64))
    y = LSTM(32)(x)  # all ops in the LSTM layer will live on CPU:0

Advantage of switch over if-else statement

switch is definitely preferred. It's easier to look at a switch's list of cases & know for sure what it is doing than to read the long if condition.

The duplication in the if condition is hard on the eyes. Suppose one of the == was written !=; would you notice? Or if one instance of 'numError' was written 'nmuError', which just happened to compile?

I'd generally prefer to use polymorphism instead of the switch, but without more details of the context, it's hard to say.

As for performance, your best bet is to use a profiler to measure the performance of your application in conditions that are similar to what you expect in the wild. Otherwise, you're probably optimizing in the wrong place and in the wrong way.

Prevent nginx 504 Gateway timeout using PHP set_time_limit()

Using set_time_limit(0) is useless when using php-fpm or similar process manager.

Bottomline is not to use set_time_limit when using php-fpm, to increase your execution timeout, check this tutorial.

ssh: check if a tunnel is alive


# Check do we have tunnel to server
lsof -i tcp@localhost:6000 > /dev/null

# If exit code wasn't 0 then tunnel doesn't exist.
if [ $? -eq 1 ]
  echo ' > You missing ssh tunnel. Creating one..'
  ssh -L 6000:localhost:5432

echo ' > DO YOUR STUFF < '

Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null

Same error, different situation. I'm posting this here because someone might be in same situation as mine.

I was using context API like below.

export const withDB = Component => props => {
        {db => <Component {...props} db={db} />}

So basically the error message is giving you the answer.

Nothing was returned from render. This usually means a return statement is missing

withDB should return a html block. But it wasn't returning anything. Revising my code to below solved my issue.

export const withDB = Component => props => {
  return (
        {db => <Component {...props} db={db} />}

Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

I am late, hope it will help someone ....This is a known issue with IIS 8.0

The solution is to delete the 3.x module and handler from IIS manager. You could delete them at the application or site level if you want to keep them in applicationHost.config. But I wanted to delete them from applicationHost.config. do the following steps:

In IIS manager, click the machine name node. In “Features View”, double-click “Modules”. Find “ServiceModel” and remove it. Image 1 for Solve IIS 8 Error: Could not load type ‘System.ServiceModel.Activation.HttpModule’

Go back to the machine name node’s “Features View”, double-click “Handler Mappings”. Find “svc-Integrated” and remove it. Image 2 for Solve IIS 8 Error: Could not load type ‘System.ServiceModel.Activation.HttpModule’

How to get Real IP from Visitor?

Yes, $_SERVER["HTTP_X_FORWARDED_FOR"] is how I see my ip when under a proxy on my nginx server.

But your best bet is to run phpinfo() on a page requested from under a proxy so you can look at all the availabe variables and see what is the one that carries your real ip.

INSERT statement conflicted with the FOREIGN KEY constraint - SQL Server

It means exactly what it says. You're trying to insert a value into a column that has a FK constraint on it that doesn't match any values in the lookup table.

How to change Navigation Bar color in iOS 7?

//You could place this code into viewDidLoad
- (void)viewDidLoad
    [super viewDidLoad];
    self.navigationController.navigationBar.tintColor = [UIColor redColor];
    //change the nav bar colour
    self.navigationController.view.backgroundColor = [UIColor redColor];
    //change the background colour
    self.navigationController.navigationBar.translucent = NO;
//Or you can place it into viewDidAppear
- (void)viewDidAppear:(BOOL)animated
    [super viewDidAppear:(BOOL)animated];
    self.navigationController.navigationBar.tintColor = [UIColor redColor];
    //change the nav bar colour
    self.navigationController.view.backgroundColor = [UIColor redColor];
    //change the background colour
    self.navigationController.navigationBar.translucent = NO;

How to select last child element in jQuery?

By using the :last-child selector?

Do you have a specific scenario in mind you need assistance with?

Mail multipart/alternative vs multipart/mixed

I hit this challenge today and I found these answers useful but not quite explicit enough for me.

Edit: Just found the Apache Commons Email that wraps this up nicely, meaning you don't need to know below.

If your requirement is an email with:

  1. text and html versions
  2. html version has embedded (inline) images
  3. attachments

The only structure I found that works with Gmail/Outlook/iPad is:

  • mixed
    • alternative
      • text
      • related
        • html
        • inline image
        • inline image
    • attachment
    • attachment

And the code is:

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.URLDataSource;
import javax.mail.BodyPart;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMultipart;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

 * Created by StrongMan on 25/05/14.
public class MailContentBuilder {

    private static final Pattern COMPILED_PATTERN_SRC_URL_SINGLE = Pattern.compile("src='([^']*)'",  Pattern.CASE_INSENSITIVE);
    private static final Pattern COMPILED_PATTERN_SRC_URL_DOUBLE = Pattern.compile("src=\"([^\"]*)\"",  Pattern.CASE_INSENSITIVE);

     * Build an email message.
     * The HTML may reference the embedded image (messageHtmlInline) using the filename. Any path portion is ignored to make my life easier
     * e.g. If you pass in the image C:\Temp\dog.jpg you can use <img src="dog.jpg"/> or <img src="C:\Temp\dog.jpg"/> and both will work
     * @param messageText
     * @param messageHtml
     * @param messageHtmlInline
     * @param attachments
     * @return
     * @throws MessagingException
    public Multipart build(String messageText, String messageHtml, List<URL> messageHtmlInline, List<URL> attachments) throws MessagingException {
        final Multipart mpMixed = new MimeMultipart("mixed");
            // alternative
            final Multipart mpMixedAlternative = newChild(mpMixed, "alternative");
                // Note: MUST RENDER HTML LAST otherwise iPad mail client only renders the last image and no email
                addHtmlVersion(mpMixedAlternative,messageHtml, messageHtmlInline);
            // attachments

        //msg.setText(message, "utf-8");
        //msg.setContent(message,"text/html; charset=utf-8");
        return mpMixed;

    private Multipart newChild(Multipart parent, String alternative) throws MessagingException {
        MimeMultipart child =  new MimeMultipart(alternative);
        final MimeBodyPart mbp = new MimeBodyPart();
        return child;

    private void addTextVersion(Multipart mpRelatedAlternative, String messageText) throws MessagingException {
        final MimeBodyPart textPart = new MimeBodyPart();
        textPart.setContent(messageText, "text/plain");

    private void addHtmlVersion(Multipart parent, String messageHtml, List<URL> embeded) throws MessagingException {
        // HTML version
        final Multipart mpRelated = newChild(parent,"related");

        // Html
        final MimeBodyPart htmlPart = new MimeBodyPart();
        HashMap<String,String> cids = new HashMap<String, String>();
        htmlPart.setContent(replaceUrlWithCids(messageHtml,cids), "text/html");

        // Inline images
        addImagesInline(mpRelated, embeded, cids);

    private void addImagesInline(Multipart parent, List<URL> embeded, HashMap<String,String> cids) throws MessagingException {
        if (embeded != null)
            for (URL img : embeded)
                final MimeBodyPart htmlPartImg = new MimeBodyPart();
                DataSource htmlPartImgDs = new URLDataSource(img);
                htmlPartImg.setDataHandler(new DataHandler(htmlPartImgDs));
                String fileName = img.getFile();
                fileName = getFileName(fileName);
                String newFileName = cids.get(fileName);
                boolean imageNotReferencedInHtml = newFileName == null;
                if (imageNotReferencedInHtml) continue;
                // Gmail requires the cid have <> around it
                htmlPartImg.setHeader("Content-ID", "<"+newFileName+">");

    private void addAttachments(Multipart parent, List<URL> attachments) throws MessagingException {
        if (attachments != null)
            for (URL attachment : attachments)
                final MimeBodyPart mbpAttachment = new MimeBodyPart();
                DataSource htmlPartImgDs = new URLDataSource(attachment);
                mbpAttachment.setDataHandler(new DataHandler(htmlPartImgDs));
                String fileName = attachment.getFile();
                fileName = getFileName(fileName);

    public String replaceUrlWithCids(String html, HashMap<String,String> cids)
        html = replaceUrlWithCids(html, COMPILED_PATTERN_SRC_URL_SINGLE, "src='cid:@cid'", cids);
        html = replaceUrlWithCids(html, COMPILED_PATTERN_SRC_URL_DOUBLE, "src=\"cid:@cid\"", cids);
        return html;

    private String replaceUrlWithCids(String html, Pattern pattern, String replacement, HashMap<String,String> cids) {
        Matcher matcherCssUrl = pattern.matcher(html);
        StringBuffer sb = new StringBuffer();
        while (matcherCssUrl.find())
            String fileName =;
            // Disregarding file path, so don't clash your filenames!
            fileName = getFileName(fileName);
            // A cid must start with @ and be globally unique
            String cid = "@" + UUID.randomUUID().toString() + "_" + fileName;
            if (cids.containsKey(fileName))
                cid = cids.get(fileName);
        html = sb.toString();
        return html;

    private String getFileName(String fileName) {
        if (fileName.contains("/"))
            fileName = fileName.substring(fileName.lastIndexOf("/")+1);
        return fileName;

And an example of using it with from Gmail

 * Created by StrongMan on 25/05/14.
import com.sun.mail.smtp.SMTPTransport;

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.URLDataSource;
import javax.mail.*;
import javax.mail.internet.*;

 * @author doraemon
public class GoogleMail {

    private GoogleMail() {

     * Send email using GMail SMTP server.
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param title title of the message
     * @param messageText message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
    public static void Send(final String username, final String password, String recipientEmail, String title, String messageText, String messageHtml, List<URL> messageHtmlInline, List<URL> attachments) throws AddressException, MessagingException {
        GoogleMail.Send(username, password, recipientEmail, "", title, messageText, messageHtml, messageHtmlInline,attachments);

     * Send email using GMail SMTP server.
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param ccEmail CC recipient. Can be empty if there is no CC recipient
     * @param title title of the message
     * @param messageText message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
    public static void Send(final String username, final String password, String recipientEmail, String ccEmail, String title, String messageText, String messageHtml, List<URL> messageHtmlInline, List<URL> attachments) throws AddressException, MessagingException {
        final String SSL_FACTORY = "";

        // Get a Properties object
        Properties props = System.getProperties();
        props.setProperty("", "");
        props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
        props.setProperty("mail.smtp.socketFactory.fallback", "false");
        props.setProperty("mail.smtp.port", "465");
        props.setProperty("mail.smtp.socketFactory.port", "465");
        props.setProperty("mail.smtps.auth", "true");

        If set to false, the QUIT command is sent and the connection is immediately closed. If set
        to true (the default), causes the transport to wait for the response to the QUIT command.

        ref :
       - demo program from javamail
        props.put("mail.smtps.quitwait", "false");

        Session session = Session.getInstance(props, null);

        // -- Create a new message --
        final MimeMessage msg = new MimeMessage(session);

        // -- Set the FROM and TO fields --
        msg.setFrom(new InternetAddress(username + ""));
        msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail, false));

        if (ccEmail.length() > 0) {
            msg.setRecipients(Message.RecipientType.CC, InternetAddress.parse(ccEmail, false));


        // mixed
        MailContentBuilder mailContentBuilder = new MailContentBuilder();
        final Multipart mpMixed =, messageHtml, messageHtmlInline, attachments);
        msg.setSentDate(new Date());

        SMTPTransport t = (SMTPTransport)session.getTransport("smtps");

        t.connect("", username, password);
        t.sendMessage(msg, msg.getAllRecipients());


Using Javamail to connect to Gmail smtp server ignores specified port and tries to use 25

For anyone looking for a full solution, I got this working with the following code based on maximdim's answer:

import javax.mail.*
import javax.mail.internet.*

private class SMTPAuthenticator extends Authenticator
    public PasswordAuthentication getPasswordAuthentication()
        return new PasswordAuthentication('[email protected]', 'test1234');

def  d_email = "[email protected]",
        d_uname = "email",
        d_password = "password",
        d_host = "",
        d_port  = "465", //465,587
        m_to = "[email protected]",
        m_subject = "Testing",
        m_text = "Hey, this is the testing email."

def props = new Properties()
props.put("mail.smtp.user", d_email)
props.put("", d_host)
props.put("mail.smtp.port", d_port)
props.put("mail.smtp.debug", "true");
props.put("mail.smtp.auth", "true")
props.put("mail.smtp.socketFactory.port", d_port)
props.put("mail.smtp.socketFactory.class", "")
props.put("mail.smtp.socketFactory.fallback", "false")

def auth = new SMTPAuthenticator()
def session = Session.getInstance(props, auth)

def msg = new MimeMessage(session)
msg.setFrom(new InternetAddress(d_email))
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(m_to))

Transport transport = session.getTransport("smtps");
transport.connect(d_host, 465, d_uname, d_password);
transport.sendMessage(msg, msg.getAllRecipients());

SQL Server error on update command - "A severe error occurred on the current command"

in my case, the method: context.Database.CreateIfNotExists(); called up multiple times before create database and crashed an error A severe error occurred on the current command. The results, if any, should be discarded.

This project references NuGet package(s) that are missing on this computer

Removed below lines in .csproj file

<Import Project="$(SolutionDir)\.nuget\NuGet.targets" 
Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
 <ErrorText>This project references NuGet package(s) that are missing on this computer. 
 Enable NuGet Package Restore to download them.  For more information, see The missing file is {0}.</ErrorText>
<Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')" 
'$(SolutionDir)\.nuget\NuGet.targets'))" />

regular expression to validate datetime format (MM/DD/YYYY)

you can look into this link and I hope this may be of great help as its was for me.

If you are using the regex given in the above link in Java code then use the following regex

"^(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\\d\\d$"

As I noticed in your example you are using js function then this use regex

"^(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\d\d$"

This will match a date in mm/dd/yyyy format from between 1900-01-01 and 2099-12-31, with a choice of four separators. and not to forget the

return regex.test(testdate);

Atom menu is missing. How do I re-enable

Same happened to me, I had to go into Packages and re-enable Tabs and Tree-View (both part of core).

How to convert a String into an array of Strings containing one character each

Use toCharArray() method. It splits the string into an array of characters:

String str = "aabbab";
char[] chs = str.toCharArray();

UITableViewCell Selected Background Color on Multiple Selection

For Swift 3,4 and 5 you can do this in two ways.

1) class: UITableViewCell

override func awakeFromNib() {
    //Costumize cell

    selectionStyle = .none


2) tableView cellForRowAt

    cell.selectionStyle = .none

If you want to set selection color for specific cell, check this answer:

Difference between mkdir() and mkdirs() in java for

mkdirs() will create the specified directory path in its entirety where mkdir() will only create the bottom most directory, failing if it can't find the parent directory of the directory it is trying to create.

In other words mkdir() is like mkdir and mkdirs() is like mkdir -p.

For example, imagine we have an empty /tmp directory. The following code

new File("/tmp/one/two/three").mkdirs();

would create the following directories:

  • /tmp/one
  • /tmp/one/two
  • /tmp/one/two/three

Where this code:

new File("/tmp/one/two/three").mkdir();

would not create any directories - as it wouldn't find /tmp/one/two - and would return false.

How to get the list of files in a directory in a shell script?

Just enter this simple command:

ls -d */

How to Find App Pool Recycles in Event Log

As it seems impossible to filter the XPath message data (it isn't in the XML to filter), you can also use powershell to search:

Get-WinEvent -LogName System | Where-Object {$_.Message -like "*recycle*"}

From this, I can see that the event Id for recycling seems to be 5074, so you can filter on this as well. I hope this helps someone as this information seemed to take a lot longer than expected to work out.

This along with @BlackHawkDesign comment should help you find what you need.

I had the same issue. Maybe interesting to mention is that you have to configure in which cases the app pool recycle event is logged. By default it's in a couple of cases, not all of them. You can do that in IIS > app pools > select the app pool > advanced settings > expand generate recycle event log entry – BlackHawkDesign Jan 14 '15 at 10:00

How can I list all the deleted files in a Git repository?

git log --diff-filter=D --summary

See Find and restore a deleted file in a Git repository

If you don't want all the information about which commit they were removed in, you can just add a grep delete in there.

git log --diff-filter=D --summary | grep delete

How to convert a string to a date in sybase

Use the convert function, for example:

select * from data 
where dateVal < convert(datetime, '01/01/2008', 103)

Where the convert style (103) determines the date format to use.

How to mark a method as obsolete or deprecated?

The shortest way is by adding the ObsoleteAttribute as an attribute to the method. Make sure to include an appropriate explanation:

[Obsolete("Method1 is deprecated, please use Method2 instead.")]
public void Method1()
{ … }

You can also cause the compilation to fail, treating the usage of the method as an error instead of warning, if the method is called from somewhere in code like this:

[Obsolete("Method1 is deprecated, please use Method2 instead.", true)]

MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near

You have to change delimiter before using triggers, stored procedures and so on.

delimiter //
create procedure ProG() 
SELECT * FROM hs_hr_employee_leave_quota;
delimiter ;

How to split a long array into smaller arrays, with JavaScript

var size = 10; var arrayOfArrays = [];
for (var i=0; i<bigarray.length; i+=size) {

Unlike splice(), slice() is non-destructive to the original array.

How to parse a month name (string) to an integer for comparison in C#?

You don't have to create a DateTime instance to do this. It's as simple as this:

public static class Month
    public static int ToInt(this string month)
        return Array.IndexOf(
            + 1;

I'm running on the da-DK culture, so this unit test passes:

[InlineData("Januar", 1)]
[InlineData("Februar", 2)]
[InlineData("Marts", 3)]
[InlineData("April", 4)]
[InlineData("Maj", 5)]
[InlineData("Juni", 6)]
[InlineData("Juli", 7)]
[InlineData("August", 8)]
[InlineData("September", 9)]
[InlineData("Oktober", 10)]
[InlineData("November", 11)]
[InlineData("December", 12)]
public void Test(string monthName, int expected)
    var actual = monthName.ToInt();
    Assert.Equal(expected, actual);

I'll leave it as an exercise to the reader to create an overload where you can pass in an explicit CultureInfo.

SQL Server Express 2008 Install Side-by-side w/ SQL 2005 Express Fails

Although you should have no problem running a 2005 instance of the database engine beside a 2008 instance, The tools are installed into a shared directory, so you can't have two versions of the tools installed. Fortunately, the 2008 tools are backwards-compatible. As we speak, I'm using SSMS 2008 and Profiler 2008 to manage my 2005 Express instances. Works great.

Before installing the 2008 tools, you need to remove any and all "shared" components from 2005. Try going to your Add/Remove programs control panel, find Microsoft SQL Server 2005, and click "Change." Then choose "Workstation Components" and remove everything there (this will not remove your database engine).

I believe the 2008 installer also has an option to upgrade shared components only. You might try that. Good luck!

Replacing &nbsp; from javascript dom text node

i used this, and it worked:

var cleanText = text.replace(/&amp;nbsp;/g,"");

Ionic 2: Cordova is not available. Make sure to include cordova.js or run in a device/simulator (running in emulator)

The livereload plugin fails to serve cordova.js file and serves // mock cordova file during development.

FIX: You need go to node_modules/@ionic/app-scripts/dist/dev-server/serve-config.js

and replace

exports.ANDROID_PLATFORM_PATH = path.join('platforms', 'android', 'assets', 'www');


exports.ANDROID_PLATFORM_PATH = path.join('platforms', 'android', 'app', 'src', 'main', 'assets', 'www');

How to increase space between dotted border dots

I made a javascript function to create dots with an svg. You can adjust dot spacing and size in the javascript code.

var make_dotted_borders = function() {_x000D_
    var spacing = 8;_x000D_
    var dot_width = 2;_x000D_
    var dot_height = 2;_x000D_
    var dotteds = document.getElementsByClassName("dotted");_x000D_
    for (var i = 0; i < dotteds.length; i++) {_x000D_
        var width = dotteds[i].clientWidth + 1.5;_x000D_
        var height = dotteds[i].clientHeight;_x000D_
        var horizontal_count = Math.floor(width / spacing);_x000D_
        var h_spacing_percent = 100 / horizontal_count;_x000D_
        var h_subtraction_percent = ((dot_width / 2) / width) * 100;_x000D_
        var vertical_count = Math.floor(height / spacing);_x000D_
        var v_spacing_percent = 100 / vertical_count;_x000D_
        var v_subtraction_percent = ((dot_height / 2) / height) * 100;_x000D_
        var dot_container = document.createElement("div");_x000D_
        dot_container.classList.add("dot_container");_x000D_ = getComputedStyle(dotteds[i], null).display;_x000D_
        var clone = dotteds[i].cloneNode(true);_x000D_
        dotteds[i].parentElement.replaceChild(dot_container, dotteds[i]);_x000D_
        for (var x = 0; x < horizontal_count; x++) {_x000D_
            // The Top Dots_x000D_
            var dot = document.createElement("div");_x000D_
   = dot_width + "px";_x000D_
   = dot_height + "px";_x000D_
            var left_percent = (h_spacing_percent * x) - h_subtraction_percent;_x000D_
   = left_percent + "%";_x000D_
   = (-dot_height / 2) + "px";_x000D_
            // The Bottom Dots_x000D_
            var dot = document.createElement("div");_x000D_
   = dot_width + "px";_x000D_
   = dot_height + "px";_x000D_
   = (h_spacing_percent * x) - h_subtraction_percent + "%";_x000D_
   = height - (dot_height / 2) + "px";_x000D_
        for (var y = 1; y < vertical_count; y++) {_x000D_
            // The Left Dots:_x000D_
            var dot = document.createElement("div");_x000D_
   = dot_width + "px";_x000D_
   = dot_height + "px";_x000D_
   = (-dot_width / 2) + "px";_x000D_
   = (v_spacing_percent * y) - v_subtraction_percent + "%";_x000D_
        for (var y = 0; y < vertical_count + 1; y++) {_x000D_
            // The Right Dots:_x000D_
            var dot = document.createElement("div");_x000D_
   = dot_width + "px";_x000D_
   = dot_height + "px";_x000D_
   = width - (dot_width / 2) + "px";_x000D_
            if (y < vertical_count) {_x000D_
       = (v_spacing_percent * y) - v_subtraction_percent + "%";_x000D_
            else {_x000D_
       = height - (dot_height / 2) + "px";_x000D_
div.dotted {_x000D_
    display: inline-block;_x000D_
    padding: 0.5em;_x000D_
div.dot_container {_x000D_
    position: relative;_x000D_
    margin-left: 0.25em;_x000D_
    margin-right: 0.25em;_x000D_
_x000D_ {_x000D_
    position: absolute;_x000D_
    content: url('data:image/svg+xml;utf8,<svg xmlns="" height="100" width="100"><circle cx="50" cy="50" r="50" fill="black" /></svg>');_x000D_
<div class="dotted">Lorem Ipsum</div>

How to move all HTML element children to another parent using JavaScript?

If you not use - in id's names then you can do this

#newParent { color: red }
<div id="oldParent">_x000D_
    Hello World_x000D_
<div id="newParent"></div>

White space showing up on right side of page when background image should extend full length of page

I was experiencing the white line to the right on my iPad as well in horizontal position only. I was using a fixed-position div with a background set to 960px wide and z-index of -999. This particular div only shows up on an iPad due to a media query. Content was then placed into a 960px wide div wrapper. The answers provided on this page were not helping in my case. To fix the white stripe issue I changed the width of the content wrapper to 958px. Voilá. No more white right white stripe on the iPad in horizontal position.

Undefined reference to `sin`

I have the problem anyway with -lm added

gcc -Wall -lm mtest.c -o mtest.o
mtest.c: In function 'f1':
mtest.c:6:12: warning: unused variable 'res' [-Wunused-variable]
/tmp/cc925Nmf.o: In function `f1':
mtest.c:(.text+0x19): undefined reference to `sin'
collect2: ld returned 1 exit status

I discovered recently that it does not work if you first specify -lm. The order matters:

gcc mtest.c -o mtest.o -lm

Just link without problems

So you must specify the libraries after.

Updating a date in Oracle SQL table

Just to add to Alex Poole's answer, here is how you do the date and time:

    TO_DATE('31/DEC/2017 12:59:59', 'dd/mm/yyyy hh24:mi:ss')

The pipe ' ' could not be found angular2 custom pipe

You need to include your pipe in module declaration:

declarations: [ UsersPipe ],
providers: [UsersPipe]

PHP is not recognized as an internal or external command in command prompt

You just need to a add the path of your PHP file. In case you are using wamp or have not installed it on the C drive.

The picture shows how to find the path

What are the ways to make an html link open a folder

A bit late to the party, but I had to solve this for myself recently, though slightly different, it might still help someone with similar circumstances to my own.

I'm using xampp on a laptop to run a purely local website app on windows. (A very specific environment I know). In this instance, I use a html link to a php file and run:

shell_exec('cd C:\path\to\file');
shell_exec('start .');

This opens a local Windows explorer window.

Setting the character encoding in form submit for Internet Explorer

It seems that this can't be done, not at least with current versions of IE (6 and 7).

IE supports form attribute accept-charset, but only if its value is 'utf-8'.

The solution is to modify server A to produce encoding 'ISO-8859-1' for page that contains the form.

javascript multiple OR conditions in IF statement

This is an example:

false && true || true   // returns true
false && (true || true) // returns false
(true || true || true)  // returns true
false || true           // returns true
true || false           // returns true

Convert a JSON string to object in Java ME?

Like many stated already, A pretty simple way to do this using JSON.simple as below

import org.json.JSONObject;

String someJsonString = "{name:"MyNode", width:200, height:100}";
JSONObject jsonObj = new JSONObject(someJsonString);

And then use jsonObj to deal with JSON Object. e.g jsonObj.get("name");

As per the below link, JSON.simple is showing constant efficiency for both small and large JSON files

GitHub: invalid username or password

That problem happens sometimes due to wrong password. Please check if you are linked with AD password (Active Directory Password) and you recently changed you AD password but still trying git command with old password or not.

Update old AD password

Control Panel > Credential Manager > Windows Credential > change github password with my new AD password

Print series of prime numbers in python

Here is the simplest logic for beginners to get prime numbers:

for n in range(2,50):
    for k in range(2,50):
        if n%k ==0 and n !=k:
            for t in p:
                if  n%t ==0:

print p

Sharing a variable between multiple different threads

In addition to the other suggestions - you can also wrap the flag in a control class and make a final instance of it in your parent class:

public class Test {
  class Control {
    public volatile boolean flag = false;
  final Control control = new Control();

  class T1 implements Runnable {
    public void run() {
      while ( !control.flag ) {


  class T2 implements Runnable {
    public void run() {
      while ( !control.flag ) {


  private void test() {
    T1 main = new T1();
    T2 help = new T2();

    new Thread(main).start();
    new Thread(help).start();

  public static void main(String[] args) throws InterruptedException {
    try {
      Test test = new Test();
    } catch (Exception e) {

jquery .live('click') vs .click()

remember that the use of "live" is for "jQuery 1.3" or higher

in version "jQuery 1.4.3" or higher is used "delegate"

and version "jQuery 1.7 +" or higher is used "on"

$( selector ).live( events, data, handler ); // jQuery 1.3+
$( document ).delegate( selector, events, data, handler ); // jQuery 1.4.3+
$( document ).on( events, selector, data, handler ); // jQuery 1.7+

As of jQuery 1.7, the .live() method is deprecated.


Regards, Fernando

Move SQL data from one table to another

Should be possible using two statements within one transaction, an insert and a delete:

INSERT INTO Table2 (<columns>)
SELECT <columns>
FROM Table1
WHERE <condition>;

WHERE <condition>;


This is the simplest form. If you have to worry about new matching records being inserted into table1 between the two statements, you can add an and exists <in table2>.

Passing parameters in Javascript onClick event

Try this:

<div id="div"></div>

<script language="javascript" type="text/javascript">
   var div = document.getElementById('div');

   for (var i = 0; i < 10; i++) {
       var f = function() {
           var link = document.createElement('a');
           var j = i; // this j is scoped to our anonymous function
                      // while i is scoped outside the anonymous function,
                      //  getting incremented by the for loop
           link.setAttribute('href', '#');
           link.innerHTML = j + '';
           link.onclick=  function() { onClickLink(j+'');};
           div.appendChild(document.createElement('br')); // lower case BR, please!
       }(); // call the function immediately

   function onClickLink(text) {
       alert('Link ' + text + ' clicked');
       return false;

What's the best way to iterate an Android Cursor?

The simplest way is this:

while (cursor.moveToNext()) {

The cursor starts before the first result row, so on the first iteration this moves to the first result if it exists. If the cursor is empty, or the last row has already been processed, then the loop exits neatly.

Of course, don't forget to close the cursor once you're done with it, preferably in a finally clause.

Cursor cursor = db.rawQuery(...);
try {
    while (cursor.moveToNext()) {
} finally {

If you target API 19+, you can use try-with-resources.

try (Cursor cursor = db.rawQuery(...)) {
    while (cursor.moveToNext()) {

Html.ActionLink as a button or an image, not a link

Just found this extension to do it - simple and effective.

How to fluently build JSON in Java?

Underscore-java library has json builder.

String json = U.objectBuilder()
  .add("key1", "value1")
  .add("key2", "value2")
  .add("key3", U.objectBuilder()
    .add("innerKey1", "value3"))

Troubleshooting BadImageFormatException

It can typically occur when you changed the target framework of .csproj and reverted it back to what you started with.

Make sure 1 if supportedRuntime version="a different runtime from cs project target" under startup tag in app.config.

Make sure 2 That also means checking other autogenerated or other files in may be properties folder to see if there is no more runtime mismatch between these files and one that is defined in .csproj file.

These might just save you lot of time before you start trying different things with project properties to overcome the error.

How to compile for Windows on Linux with gcc/g++?

Suggested method gave me error on Ubuntu 16.04: E: Unable to locate package mingw32


To install this package on Ubuntu please use following:

sudo apt-get install mingw-w64

After install you can use it:


Please note!

For 64-bit use: x86_64-w64-mingw32-g++

For 32-bit use: i686-w64-mingw32-g++

whitespaces in the path of windows filepath

(WINDOWS - AWS solution)
Solved for windows by putting tripple quotes around files and paths.
1) Prevents excludes that quietly were getting ignored.
2) Files/folders with spaces in them, will no longer kick errors.

    aws_command = 'aws s3 sync """D:/""" """s3://mybucket/my folder/"  --exclude """*RECYCLE.BIN/*""" --exclude """*.cab""" --exclude """System Volume Information/*""" '

    r ="powershell.exe {aws_command}", shell=True, capture_output=True, text=True)

Android Camera : data intent returns null

Kotlin code that works for me:

 private fun takePhotoFromCamera() {
          val intent = Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE)
        startActivityForResult(intent, PERMISSIONS_REQUEST_TAKE_PICTURE_CAMERA)

And get Result :

 override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
         if (resultCode == Activity.RESULT_OK) {
           val photo: Bitmap? =  MediaStore.Images.Media.getBitmap(this.contentResolver, Uri.parse( data!!.dataString)   )
            // Do something here : set image to an ImageView or save it ..   
              imgV_pic.imageBitmap = photo 
        } else if (resultCode == Activity.RESULT_CANCELED) {
            Log.i(TAG, "Camera  , RESULT_CANCELED ")



and don't forget to declare request code:

companion object {

What is use of c_str function In c++

Most OLD c++ and c functions, when deal with strings, use const char*.
With STL and std::string, string.c_str() is introduced to be able to convert from std::string to const char*.

That means that if you promise not to change the buffer, you'll be able to use read only string contents. PROMISE = const char*

SQL Data Reader - handling Null column values

There are a lot of answers here with useful info (and some wrong info) spread about, I'd like to bring it all together.

The short answer to the question is to check for DBNull - almost everyone agrees on this bit :)

Rather than using a helper method to read nullable values per SQL data type a generic method allows us to address this with a lot less code. However, you can't have a single generic method for both nullable value types and reference types, this is discussed at length in Nullable type as a generic parameter possible? and C# generic type constraint for everything nullable.

So, following on from the answers from @ZXX and @getpsyched we end up with this, 2 methods for getting nullable values and I've added a 3rd for non-null values (it completes the set based on method naming).

public static T? GetNullableValueType<T>(this SqlDataReader sqlDataReader, string columnName) where T : struct
    int columnOrdinal = sqlDataReader.GetOrdinal(columnName);
    return sqlDataReader.IsDBNull(columnOrdinal) ? (T?)null : sqlDataReader.GetFieldValue<T>(columnOrdinal);

public static T GetNullableReferenceType<T>(this SqlDataReader sqlDataReader, string columnName) where T : class
    int columnOrdinal = sqlDataReader.GetOrdinal(columnName);
    return sqlDataReader.IsDBNull(columnOrdinal) ? null : sqlDataReader.GetFieldValue<T>(columnOrdinal);

public static T GetNonNullValue<T>(this SqlDataReader sqlDataReader, string columnName)
    int columnOrdinal = sqlDataReader.GetOrdinal(columnName);
    return sqlDataReader.GetFieldValue<T>(columnOrdinal);

I usually use column names, alter these if you use column indexes. Based on these method names I can tell whether I'm expecting the data to be nullable or not, quite useful when looking at code written a long time ago.


  • Not having nullable columns in the database avoids this issue. If you have control over the database then columns should be non-null by default and only nullable where necessary.
  • Don't cast database values with the C# 'as' operator because if the cast is wrong it will silently return null.
  • Using a default value expression will change database nulls to non-null values for value types like int, datetime, bit etc.

Lastly, whilst testing the above methods across all SQL Server data types I discovered you can't directly get a char[] from a SqlDataReader, if you want a char[] you will have to get a string and use ToCharArray().

How to use Visual Studio C++ Compiler?

You may be forgetting something. Before #include <iostream>, write #include <stdafx.h> and maybe that will help. Then, when you are done writing, click test, than click output from build, then when it is done processing/compiling, press Ctrl+F5 to open the Command Prompt and it should have the output and "press any key to continue."

Check if an element contains a class in JavaScript?

The easy and effective solution is trying .contains method.


postgresql COUNT(DISTINCT ...) very slow

If your count(distinct(x)) is significantly slower than count(x) then you can speed up this query by maintaining x value counts in different table, for example table_name_x_counts (x integer not null, x_count int not null), using triggers. But your write performance will suffer and if you update multiple x values in single transaction then you'd need to do this in some explicit order to avoid possible deadlock.

How should I call 3 functions in order to execute them one after the other?

your functions should take a callback function, that gets called when it finishes.

function fone(callback){ something...


function ftwo(callback){ something...

then usage would be like:

   ..ftwo done...

How to create two columns on a web page?

Basically you need 3 divs. First as wrapper, second as left and third as right.

.wrapper {

.left {

.right {

Example how to make 2 columns

CSS Cheat Sheet for reference

Dynamically set value of a file input

I am working on an angular js app, andhavecome across a similar issue. What i did was display the image from the db, then created a button to remove or keep the current image. If the user decided to keep the current image, i changed the ng-submit attribute to another function whihc doesnt require image validation, and updated the record in the db without touching the original image path name. The remove image function also changed the ng-submit attribute value back to a function that submits the form and includes image validation and upload. Also a bit of javascript to slide the into view to upload a new image.

how to get vlc logs?

Or you can use the more obvious solution, right in the GUI: Tools -> Messages (set verbosity to 2)...

Printing object properties in Powershell

The below worked really good for me. I patched together all the above answers plus read about displaying object properties in the following link and came up with the below short read about printing objects

add the following text to a file named print_object.ps1:

$date = New-Object System.DateTime
Write-Output $date | Get-Member
Write-Output $date | Select-Object -Property *

open powershell command prompt, go to the directory where that file exists and type the following:

powershell -ExecutionPolicy ByPass -File is_port_in_use.ps1 -Elevated

Just substitute 'System.DateTime' with whatever object you wanted to print. If the object is null, nothing will print out.

How to use confirm using sweet alert?

document.querySelector('#from1').onsubmit = function(e){

    title: "Are you sure?",
    text: "You will not be able to recover this imaginary file!",
    type: "warning",
    showCancelButton: true,
    confirmButtonColor: '#DD6B55',
    confirmButtonText: 'Yes, I am sure!',
    cancelButtonText: "No, cancel it!",
    closeOnConfirm: false,
    closeOnCancel: false

   if (isConfirm){
     swal("Shortlisted!", "Candidates are successfully shortlisted!", "success");

    } else {
      swal("Cancelled", "Your imaginary file is safe :)", "error");

Fit cell width to content

For me, this is the best autofit and autoresize for table and its columns (use css !important ... only if you can't without)

.myclass table {
    table-layout: auto !important;

.myclass th, .myclass td, .myclass thead th, .myclass tbody td, .myclass tfoot td, .myclass tfoot th {
    width: auto !important;

Don't specify css width for table or for table columns. If table content is larger it will go over screen size to.

Getting "java.nio.file.AccessDeniedException" when trying to write to a folder

Ok it turns out I was doing something stupid. I hadn't appended the new file name to the path.

I had

rootDirectory = "C:\\safesite_documents"

but it should have been

rootDirectory = "C:\\safesite_documents\\newFile.jpg" 

Sorry it was a stupid mistake as always.

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

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

ASP.NET MVC Custom Error Handling Application_Error Global.asax?

Use Following code for redirecting on route page. Use exception.Message instide of exception. Coz exception query string gives error if it extends the querystring length.

routeData.Values.Add("error", exception.Message);
// clear error on server

Select default option value from typescript angular 6

In addition to what mentioned before, you can use [attr.selected] directive to select a specific option, as follows:

    <option *ngFor="let program of programs" [attr.selected]="(member.programID ==">
        {{ }}

How does strtok() split the string into tokens in C?

strtok() stores the pointer in static variable where did you last time left off , so on its 2nd call , when we pass the null , strtok() gets the pointer from the static variable .

If you provide the same string name , it again starts from beginning.

Moreover strtok() is destructive i.e. it make changes to the orignal string. so make sure you always have a copy of orignal one.

One more problem of using strtok() is that as it stores the address in static variables , in multithreaded programming calling strtok() more than once will cause an error. For this use strtok_r().

javascript object max size limit

Step 1 is always to first determine where the problem lies. Your title and most of your question seem to suggest that you're running into quite a low length limit on the length of a string in JavaScript / on browsers, an improbably low limit. You're not. Consider:

var str;

document.getElementById('theButton').onclick = function() {
  var build, counter;

  if (!str) {
    str = "0123456789";
    build = [];
    for (counter = 0; counter < 900; ++counter) {
    str = build.join("");
  else {
    str += str;
  display("str.length = " + str.length);

Live copy

Repeatedly clicking the relevant button keeps making the string longer. With Chrome, Firefox, Opera, Safari, and IE, I've had no trouble with strings more than a million characters long:

str.length = 9000
str.length = 18000
str.length = 36000
str.length = 72000
str.length = 144000
str.length = 288000
str.length = 576000
str.length = 1152000
str.length = 2304000
str.length = 4608000
str.length = 9216000
str.length = 18432000

...and I'm quite sure I could got a lot higher than that.

So it's nothing to do with a length limit in JavaScript. You haven't show your code for sending the data to the server, but most likely you're using GET which means you're running into the length limit of a GET request, because GET parameters are put in the query string. Details here.

You need to switch to using POST instead. In a POST request, the data is in the body of the request rather than in the URL, and can be very, very large indeed.

What is the difference between a web API and a web service?

Well, TMK may be right in the Microsoft world, but in world of all software including Java/Python/etc, I believe that there is no difference. They're the same thing.

Is it better to use NOT or <> when comparing values?

The second example would be the one to go with, not just for readability, but because of the fact that in the first example, If NOT value1 would return a boolean value to be compared against value2. IOW, you need to rewrite that example as

If NOT (value1 = value2)

which just makes the use of the NOT keyword pointless.

How can I write variables inside the tasks file in ansible

Whenever you have a module followed by a variable on the same line in ansible the parser will treat the reference variable as the beginning of an in-line dictionary. For example:

- name: some example
  command: {{ myapp }} -a foo

The default here is to parse the first part of {{ myapp }} -a foo as a dictionary instead of a string and you will get an error.

So you must quote the argument like so:

- name: some example
  command: "{{ myapp }} -a foo"

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

I was using pgAdmin to create my tables and while I was not using reserved words, the generated table had a quote in the name and a couple of columns had quotes in them. Here is an example of the generated SQL.

CREATE TABLE public."Test"
    id serial NOT NULL,
    data text NOT NULL,
    updater character varying(50) NOT NULL,
    "updateDt" time with time zone NOT NULL,

TABLESPACE pg_default;

ALTER TABLE public."Test"
    OWNER to svc_newnews_app;

All of these quotes were inserted at "random". I just needed to drop and re-create the table again without the quotes.

Tested on pgAdmin 4.26

Spring Boot: Is it possible to use external files in arbitrary directories with a fat jar?

It's all explained here in the docs:

Which explains that this is the order of precedence:

  • A /config subdir of the current directory.
  • The current directory
  • A classpath /config package
  • The classpath root

It also points out that you can define additional properties files for overrides like so:

java -jar myproject.jar 

If you use spring.config.location, then all the default locations for are also included. This means that you can set up default values in and override as required for a particular environment.

Convert IEnumerable to DataTable

So, 10 years later this is still a thing :)

I've tried every answer on this page (ATOW)
and also some ILGenerator powered solutions (FastMember and Fast.Reflection).
But a compiled Lambda Expression seems to be the fastest.
At least for my use cases (on .Net Core 2.2).

This is what I am using for now:

public static class EnumerableExtensions {

    internal static Func<TClass, object> CompileGetter<TClass>(string propertyName) {
        var param = Expression.Parameter(typeof(TClass));
        var body = Expression.Convert(Expression.Property(param, propertyName), typeof(object));
        return Expression.Lambda<Func<TClass, object>>(body,param).Compile();

    public static DataTable ToDataTable<T>(this IEnumerable<T> collection) {
        var dataTable = new DataTable();
        var properties = typeof(T)
                        .GetProperties(BindingFlags.Public | BindingFlags.Instance)
                        .Where(p => p.CanRead)

        if (properties.Length < 1) return null;
        var getters = new Func<T, object>[properties.Length];

        for (var i = 0; i < properties.Length; i++) {
            var columnType = Nullable.GetUnderlyingType(properties[i].PropertyType) ?? properties[i].PropertyType;
            dataTable.Columns.Add(properties[i].Name, columnType);
            getters[i] = CompileGetter<T>(properties[i].Name);

        foreach (var row in collection) {
            var dtRow = new object[properties.Length];
            for (var i = 0; i < properties.Length; i++) {
                dtRow[i] = getters[i].Invoke(row) ?? DBNull.Value;

        return dataTable;

Only works with properties (not fields) but it works on Anonymous Types.

Reading input files by line using read command in shell scripting skips last line

read reads until it finds a newline character or the end of file, and returns a non-zero exit code if it encounters an end-of-file. So it's quite possible for it to both read a line and return a non-zero exit code.

Consequently, the following code is not safe if the input might not be terminated by a newline:

while read LINE; do
  # do something with LINE

because the body of the while won't be executed on the last line.

Technically speaking, a file not terminated with a newline is not a text file, and text tools may fail in odd ways on such a file. However, I'm always reluctant to fall back on that explanation.

One way to solve the problem is to test if what was read is non-empty (-n):

while read -r LINE || [[ -n $LINE ]]; do
  # do something with LINE

Other solutions include using mapfile to read the file into an array, piping the file through some utility which is guaranteed to terminate the last line properly (grep ., for example, if you don't want to deal with blank lines), or doing the iterative processing with a tool like awk (which is usually my preference).

Note that -r is almost certainly needed in the read builtin; it causes read to not reinterpret \-sequences in the input.

Return multiple values from a function in swift


func getTime() -> (hour: Int, minute: Int,second: Int) {
    let hour = 1
    let minute = 2
    let second = 3
    return ( hour, minute, second)

Then it's invoked as:

let time = getTime()
print("hour: \(time.hour), minute: \(time.minute), second: \(time.second)")

This is the standard way how to use it in the book The Swift Programming Language written by Apple.

or just like:

let time = getTime()
print("hour: \(time.0), minute: \(time.1), second: \(time.2)")

it's the same but less clearly.

Composer Update Laravel

this is command for composer update please try this...

composer self-update

How to compare the contents of two string objects in PowerShell

You want to do $arrayOfString[0].Title -eq $myPbiject.item(0).Title

-match is for regex matching ( the second argument is a regex )

Getting the name of the currently executing method

What's wrong with this approach:

class Example {
    FileOutputStream fileOutputStream;

    public Example() {

        debug("Example.Example()",false); // toggle

        try {
            fileOutputStream = new FileOutputStream("debug.txt");
        } catch (Exception exception) {
             debug(exception + Calendar.getInstance().getTime());

    private boolean was911AnInsideJob() {
        return true;

    public boolean shouldGWBushBeImpeached(){
        return true;

    public void setPunishment(int yearsInJail){
        debug("Server.setPunishment(int yearsInJail=" + yearsInJail + ")",true);

And before people go crazy about using System.out.println(...) you could always, and should, create some method so that output can be redirected, e.g:

    private void debug (Object object) {

    private void dedub(Object object, boolean debug) {
        if (debug) {

            // you can also write to a file but make sure the output stream
            // ISN'T opened every time debug(Object object) is called


How do I change the text of a span element using JavaScript?

(function ($) {
    $("#myspan").text("This is span");
<script src=""></script>
<span id="myspan"> hereismytext </span>

user text() to change span text.

How to sum data.frame column values?

When you have 'NA' values in the column, then

sum(as.numeric(JuneData1$Account.Balance), na.rm = TRUE)

How to create a Rectangle object in Java using g.fillRect method

Try this:

public void paint (Graphics g) {    
    Rectangle r = new Rectangle(xPos,yPos,width,height);
    g.fillRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());  


// With explicit casting
public void paint (Graphics g) {    
        Rectangle r = new Rectangle(xPos, yPos, width, height);

CSS Equivalent of the "if" statement

I would argue that you can use if statements in CSS. Although they aren't worded as such. In the example below, I've said that if the check-box is checked I want the background changed to white. If you want to see a working example check out I built this for a client. Re size your window so that the mobile navigation takes over and click the nav button. All CSS. I think it's safe to say this concept could be used for many things.

     #sidebartoggler:checked + .page-wrap .hamb {
        background: #fff;

// example set as if statement sudo code.

if (sidebaretoggler is checked == true) {
set the background color of .hamb to white;

Location of sqlite database on the device

well this might be late but it will help. You can access the database without rooting your device through adb

start the adb using cmd and type the following commands

-run-as com.your.package  
-shell@android:/data/data/com.your.package $ ls  

Now you can open from here on.

Is there a way to add a gif to a Markdown file?

If you can provide your image in SVG format and if it is an icon and not a photo so it can be animated with SMIL animations, then it would be definitely the superior alternative to gif images (or even other formats).

SVG images, like other image files, could be used with either standard markup or HTML <img> element:

![image description](the_path_to/image.svg)
<img src="the_path_to/image.svg" width="128"/>

Oracle DateTime in Where Clause?

This is because a DATE column in Oracle also contains a time part. The result of the to_date() function is a date with the time set to 00:00:00 and thus it probably doesn't match any rows in the table.

You should use:

WHERE trunc(TIME_CREATED) = TO_DATE('26/JAN/2011','dd/mon/yyyy')

What version of Java is running in Eclipse?

There are various options are available to test which java version is using your eclipse. The best way is to find first java installed in your machine.

run java -version command on terminal

then to check whether your eclipse pointing to the right version or not.

For that go to

Eclipse >> Preferences >>Java >>Installed JREs

How can I put a database under git (version control)?

I'm starting to think of a really simple solution, don't know why I didn't think of it before!!

  • Duplicate the database, (both the schema and the data).
  • In the branch for the new-major-changes, simply change the project configuration to use the new duplicate database.

This way I can switch branches without worrying about database schema changes.


By duplicate, I mean create another database with a different name (like my_db_2); not doing a dump or anything like that.

HTML form with side by side input fields

I would go with Larry K's solution, but you can also set the display to inline-block if you want the benefits of both block and inline elements.

You can do this in the div tag by inserting:


Or in a CSS stylesheet with this method:

div { display:inline-block; }

Hope it helps, but as earlier mentioned, I would personally go for Larry K's solution ;-)

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

Why do symbols like apostrophes and hyphens get replaced with black diamonds on my website?

Look at your actual html code and check that the weird symbols are not originating there. This issue came up when I started coding in Notepad++ halfway after coding in Notepad. It seems to me that the older version of Notepad I was using may have used different encoding to Notepad's++ UTF-8 encoding. After I transferred my code from Notepad to Notepad++, the apostrophes got replaced with weird symbols, so I simply had to remove the symbols from my Notepad++ code.

AngularJS - Find Element with attribute

You haven't stated where you're looking for the element. If it's within the scope of a controller, it is possible, despite the chorus you'll hear about it not being the 'Angular Way'. The chorus is right, but sometimes, in the real world, it's unavoidable. (If you disagree, get in touch—I have a challenge for you.)

If you pass $element into a controller, like you would $scope, you can use its find() function. Note that, in the jQueryLite included in Angular, find() will only locate tags by name, not attribute. However, if you include the full-blown jQuery in your project, all the functionality of find() can be used, including finding by attribute.

So, for this HTML:

<div ng-controller='MyCtrl'>
        <div name='foo' class='myElementClass'>this one</div>

This AngularJS code should work:

angular.module('MyClient').controller('MyCtrl', [
    function ($scope, $element, $log) {

        // Find the element by its class attribute, within your controller's scope
        var myElements = $element.find('.myElementClass');

        // myElements is now an array of jQuery DOM elements

        if (myElements.length == 0) {
            // Not found. Are you sure you've included the full jQuery?
        } else {
            // There should only be one, and it will be element 0
            $log.debug(myElements[0].name); // "foo"


how to display data values on Chart.js

Following this good answer, I'd use these options for a bar chart:

var chartOptions = {
    animation: false,
    responsive : true,
    tooltipTemplate: "<%= value %>",
    tooltipFillColor: "rgba(0,0,0,0)",
    tooltipFontColor: "#444",
    tooltipEvents: [],
    tooltipCaretSize: 0,
    onAnimationComplete: function()
        this.showTooltip(this.datasets[0].bars, true);

window.myBar = new Chart(ctx1).Bar(chartData, chartOptions);

Bar Chart

This still uses the tooltip system and his advantages (automatic positionning, templating, ...) but hiding the decorations (background color, caret, ...)

Python Binomial Coefficient

This question is old but as it comes up high on search results I will point out that scipy has two functions for computing the binomial coefficients:

  1. scipy.special.binom()
  2. scipy.special.comb()

    import scipy.special
    # the two give the same results 
    scipy.special.binom(10, 5)
    # 252.0
    scipy.special.comb(10, 5)
    # 252.0
    scipy.special.binom(300, 150)
    # 9.375970277281882e+88
    scipy.special.comb(300, 150)
    # 9.375970277281882e+88
    # ...but with `exact == True`
    scipy.special.comb(10, 5, exact=True)
    # 252
    scipy.special.comb(300, 150, exact=True)
    # 393759702772827452793193754439064084879232655700081358920472352712975170021839591675861424

Note that scipy.special.comb(exact=True) uses Python integers, and therefore it can handle arbitrarily large results!

Speed-wise, the three versions give somewhat different results:

num = 300

%timeit [[scipy.special.binom(n, k) for k in range(n + 1)] for n in range(num)]
# 52.9 ms ± 107 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

%timeit [[scipy.special.comb(n, k) for k in range(n + 1)] for n in range(num)]
# 183 ms ± 814 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)each)

%timeit [[scipy.special.comb(n, k, exact=True) for k in range(n + 1)] for n in range(num)]
# 180 ms ± 649 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

(and for n = 300, the binomial coefficients are too large to be represented correctly using float64 numbers, as shown above).

HttpClient.GetAsync(...) never returns when using await/async

You are misusing the API.

Here's the situation: in ASP.NET, only one thread can handle a request at a time. You can do some parallel processing if necessary (borrowing additional threads from the thread pool), but only one thread would have the request context (the additional threads do not have the request context).

This is managed by the ASP.NET SynchronizationContext.

By default, when you await a Task, the method resumes on a captured SynchronizationContext (or a captured TaskScheduler, if there is no SynchronizationContext). Normally, this is just what you want: an asynchronous controller action will await something, and when it resumes, it resumes with the request context.

So, here's why test5 fails:

  • Test5Controller.Get executes AsyncAwait_GetSomeDataAsync (within the ASP.NET request context).
  • AsyncAwait_GetSomeDataAsync executes HttpClient.GetAsync (within the ASP.NET request context).
  • The HTTP request is sent out, and HttpClient.GetAsync returns an uncompleted Task.
  • AsyncAwait_GetSomeDataAsync awaits the Task; since it is not complete, AsyncAwait_GetSomeDataAsync returns an uncompleted Task.
  • Test5Controller.Get blocks the current thread until that Task completes.
  • The HTTP response comes in, and the Task returned by HttpClient.GetAsync is completed.
  • AsyncAwait_GetSomeDataAsync attempts to resume within the ASP.NET request context. However, there is already a thread in that context: the thread blocked in Test5Controller.Get.
  • Deadlock.

Here's why the other ones work:

  • (test1, test2, and test3): Continuations_GetSomeDataAsync schedules the continuation to the thread pool, outside the ASP.NET request context. This allows the Task returned by Continuations_GetSomeDataAsync to complete without having to re-enter the request context.
  • (test4 and test6): Since the Task is awaited, the ASP.NET request thread is not blocked. This allows AsyncAwait_GetSomeDataAsync to use the ASP.NET request context when it is ready to continue.

And here's the best practices:

  1. In your "library" async methods, use ConfigureAwait(false) whenever possible. In your case, this would change AsyncAwait_GetSomeDataAsync to be var result = await httpClient.GetAsync("", HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false);
  2. Don't block on Tasks; it's async all the way down. In other words, use await instead of GetResult (Task.Result and Task.Wait should also be replaced with await).

That way, you get both benefits: the continuation (the remainder of the AsyncAwait_GetSomeDataAsync method) is run on a basic thread pool thread that doesn't have to enter the ASP.NET request context; and the controller itself is async (which doesn't block a request thread).

More information:

Update 2012-07-13: Incorporated this answer into a blog post.

Specified cast is not valid?

Try this:

public void LoadData()
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=Stocks;Integrated Security=True;Pooling=False");
            SqlDataAdapter sda = new SqlDataAdapter("Select * From [Stocks].[dbo].[product]", con);
            DataTable dt = new DataTable();

        foreach (DataRow item in dt.Rows)
            int n = DataGridView1.Rows.Add();
            DataGridView1.Rows[n].Cells[0].Value = item["ProductCode"].ToString();
            DataGridView1.Rows[n].Cells[1].Value = item["Productname"].ToString();
            DataGridView1.Rows[n].Cells[2].Value = item["qty"].ToString();                
            if ((bool)item["productstatus"])
                DataGridView1.Rows[n].Cells[3].Value = "Active";
                DataGridView1.Rows[n].Cells[3].Value = "Deactive";

Do C# Timers elapse on a separate thread?

If the elapsed event takes longer then the interval, it will create another thread to raise the elapsed event. But there is a workaround for this

static void timer_Elapsed(object sender, ElapsedEventArgs e)    

grep a file, but show several surrounding lines?

Grep has an option called Context Line Control, you can use the --context in that, simply,

| grep -C 5


| grep -5

Should do the trick

Convert sqlalchemy row object to python dict

With python 3.8+, we can do this with dataclass, and the asdict method that comes with it:

from dataclasses import dataclass, asdict

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy import Column, String, Integer, create_engine

Base = declarative_base()
engine = create_engine('sqlite:///:memory:', echo=False)

class User(Base):
    __tablename__ = 'users'

    id: int = Column(Integer, primary_key=True)
    name: str = Column(String)
    email = Column(String)

    def __init__(self, name): = name = '[email protected]'


SessionMaker = sessionmaker(bind=engine)
session = SessionMaker()

user1 = User("anurag")

query_result = session.query(User).one()  # type: User
print(f'{}, {}, {}')
#,, [email protected]

query_result_dict = asdict(query_result)
# {'id': 1, 'name': 'anurag'}

The key is to use the @dataclass decorator, and annotate each column with its type (the : str part of the name: str = Column(String) line).

Also note that since the email is not annotated, it is not included in query_result_dict.

how to check the jdk version used to compile a .class file

You can try jclasslib:

It's nice that it can associate itself with *.class extension.

How to create a <style> tag with Javascript?

This object variable will append style tag to the head tag with type attribute and one simple transition rule inside that matches every single id/class/element. Feel free to modify content property and inject as many rules as you need. Just make sure that css rules inside content remain in one line (or 'escape' each new line, if You prefer so).

var script = {

  type: 'text/css', style: document.createElement('style'), 
  content: "* { transition: all 220ms cubic-bezier(0.390, 0.575, 0.565, 1.000); }",
  append: function() { = this.type;;

}}; script.append();

Is there a way to get version from package.json in nodejs code?

Why don't use the require resolve...

const packageJson = path.dirname(require.resolve('package-name')) + '/package.json';
const { version } = require(packageJson);
console.log('version', version)

With this approach work for all sub paths :)

What are the differences between the different saving methods in Hibernate?

You should prefer the JPA methods most of the time, and the update for batch processing tasks.

A JPA or Hibernate entity can be in one of the following four states:

  • Transient (New)
  • Managed (Persistent)
  • Detached
  • Removed (Deleted)

The transition from one state to the other is done via the EntityManager or Session methods.

For instance, the JPA EntityManager provides the following entity state transition methods.

JPA entity state transitions

The Hibernate Session implements all the JPA EntityManager methods and provides some additional entity state transition methods like save, saveOrUpdate and update.

Hibernate entity state transitions


To change the state of an entity from Transient (New) to Managed (Persisted), we can use the persist method offered by the JPA EntityManager which is also inherited by the Hibernate Session.

The persist method triggers a PersistEvent which is handled by the DefaultPersistEventListener Hibernate event listener.

Therefore, when executing the following test case:

doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");

        "Persisting the Book entity with the id: {}", 

Hibernate generates the following SQL statements:

CALL NEXT VALUE FOR hibernate_sequence

-- Persisting the Book entity with the id: 1

    'Vlad Mihalcea', 
    'High-Performance Java Persistence', 

Notice that the id is assigned prior to attaching the Book entity to the current Persistence Context. This is needed because the managed entities are stored in a Map structure where the key is formed by the entity type and its identifier and the value is the entity reference. This is the reason why the JPA EntityManager and the Hibernate Session are known as the First-Level Cache.

When calling persist, the entity is only attached to the currently running Persistence Context, and the INSERT can be postponed until the flush is called.

The only exception is the IDENTITY which triggers the INSERT right away since that's the only way it can get the entity identifier. For this reason, Hibernate cannot batch inserts for entities using the IDENTITY generator.


The Hibernate-specific save method predates JPA and it's been available since the beginning of the Hibernate project.

The save method triggers a SaveOrUpdateEvent which is handled by the DefaultSaveOrUpdateEventListener Hibernate event listener. Therefore, the save method is equivalent to the update and saveOrUpdate methods.

To see how the save method works, consider the following test case:

doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");

    Session session = entityManager.unwrap(Session.class);

    Long id = (Long);
        "Saving the Book entity with the id: {}", 

When running the test case above, Hibernate generates the following SQL statements:

CALL NEXT VALUE FOR hibernate_sequence

-- Saving the Book entity with the id: 1

    'Vlad Mihalcea', 
    'High-Performance Java Persistence', 

As you can see, the outcome is identical to the persist method call. However, unlike persist, the save method returns the entity identifier.


The Hibernate-specific update method is meant to bypass the dirty checking mechanism and force an entity update at the flush time.

The update method triggers a SaveOrUpdateEvent which is handled by the DefaultSaveOrUpdateEventListener Hibernate event listener. Therefore, the update method is equivalent to the save and saveOrUpdate methods.

To see how the update method works consider the following example which persists a Book entity in one transaction, then it modifies it while the entity is in the detached state, and it forces the SQL UPDATE using the update method call.

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");


    return book;
});"Modifying the Book entity");

    "High-Performance Java Persistence, 2nd edition"

doInJPA(entityManager -> {
    Session session = entityManager.unwrap(Session.class);

    session.update(_book);"Updating the Book entity");

When executing the test case above, Hibernate generates the following SQL statements:

CALL NEXT VALUE FOR hibernate_sequence

    'Vlad Mihalcea', 
    'High-Performance Java Persistence', 

-- Modifying the Book entity
-- Updating the Book entity

    author = 'Vlad Mihalcea', 
    isbn = '978-9730228236', 
    title = 'High-Performance Java Persistence, 2nd edition'
    id = 1

Notice that the UPDATE is executed during the Persistence Context flush, right before commit, and that's why the Updating the Book entity message is logged first.

Using @SelectBeforeUpdate to avoid unnecessary updates

Now, the UPDATE is always going to be executed even if the entity was not changed while in the detached state. To prevent this, you can use the @SelectBeforeUpdate Hibernate annotation which will trigger a SELECT statement that fetched loaded state which is then used by the dirty checking mechanism.

So, if we annotate the Book entity with the @SelectBeforeUpdate annotation:

@Entity(name = "Book")
@Table(name = "book")
public class Book {

    //Code omitted for brevity

And execute the following test case:

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");


    return book;

doInJPA(entityManager -> {
    Session session = entityManager.unwrap(Session.class);


Hibernate executes the following SQL statements:

    'Vlad Mihalcea', 
    'High-Performance Java Persistence', 

SELECT, AS author2_0_,
    b.isbn AS isbn3_0_,
    b.title AS title4_0_
    book b

Notice that, this time, there is no UPDATE executed since the Hibernate dirty checking mechanism has detected that the entity was not modified.


The Hibernate-specific saveOrUpdate method is just an alias for save and update.

The saveOrUpdate method triggers a SaveOrUpdateEvent which is handled by the DefaultSaveOrUpdateEventListener Hibernate event listener. Therefore, the update method is equivalent to the save and saveOrUpdate methods.

Now, you can use saveOrUpdate when you want to persist an entity or to force an UPDATE as illustrated by the following example.

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");

    Session session = entityManager.unwrap(Session.class);

    return book;

_book.setTitle("High-Performance Java Persistence, 2nd edition");

doInJPA(entityManager -> {
    Session session = entityManager.unwrap(Session.class);

Beware of the NonUniqueObjectException

One problem that can occur with save, update, and saveOrUpdate is if the Persistence Context already contains an entity reference with the same id and of the same type as in the following example:

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");

    Session session = entityManager.unwrap(Session.class);

    return book;

    "High-Performance Java Persistence, 2nd edition"

try {
    doInJPA(entityManager -> {
        Book book = entityManager.find(

        Session session = entityManager.unwrap(Session.class);
} catch (NonUniqueObjectException e) {
        "The Persistence Context cannot hold " +
        "two representations of the same entity", 

Now, when executing the test case above, Hibernate is going to throw a NonUniqueObjectException because the second EntityManager already contains a Book entity with the same identifier as the one we pass to update, and the Persistence Context cannot hold two representations of the same entity.

    A different object with the same identifier value was already associated with the session : []
    at org.hibernate.engine.internal.StatefulPersistenceContext.checkUniqueness(
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performUpdate(
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsDetached(
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(
    at org.hibernate.internal.SessionImpl.fireSaveOrUpdate(
    at org.hibernate.internal.SessionImpl.saveOrUpdate(


To avoid the NonUniqueObjectException, you need to use the merge method offered by the JPA EntityManager and inherited by the Hibernate Session as well.

The merge fetches a new entity snapshot from the database if there is no entity reference found in the Persistence Context, and it copies the state of the detached entity passed to the merge method.

The merge method triggers a MergeEvent which is handled by the DefaultMergeEventListener Hibernate event listener.

To see how the merge method works consider the following example which persists a Book entity in one transaction, then it modifies it while the entity is in the detached state, and passes the detached entity to merge in a subsequence Persistence Context.

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");


    return book;
});"Modifying the Book entity");

    "High-Performance Java Persistence, 2nd edition"

doInJPA(entityManager -> {
    Book book = entityManager.merge(_book);"Merging the Book entity");

    assertFalse(book == _book);

When running the test case above, Hibernate executed the following SQL statements:

    'Vlad Mihalcea', 
    'High-Performance Java Persistence', 

-- Modifying the Book entity

SELECT, AS author2_0_,
    b.isbn AS isbn3_0_,
    b.title AS title4_0_
    book b

-- Merging the Book entity

    author = 'Vlad Mihalcea', 
    isbn = '978-9730228236', 
    title = 'High-Performance Java Persistence, 2nd edition'
    id = 1

Notice that the entity reference returned by merge is different than the detached one we passed to the merge method.

Now, although you should prefer using JPA merge when copying the detached entity state, the extra SELECT can be problematic when executing a batch processing task.

For this reason, you should prefer using update when you are sure that there is no entity reference already attached to the currently running Persistence Context and that the detached entity has been modified.


To persist an entity, you should use the JPA persist method. To copy the detached entity state, merge should be preferred. The update method is useful for batch processing tasks only. The save and saveOrUpdate are just aliases to update and you should not probably use them at all.

Some developers call save even when the entity is already managed, but this is a mistake and triggers a redundant event since, for managed entities, the UPDATE is automatically handled at the Persistence context flush time.

Is there an equivalent of lsusb for OS X

I typically run this command to list USB devices on Mac OS X, along with details about them:

ioreg -p IOUSB -l -w 0

How to right-align and justify-align in Markdown?

If you want to right-align in a form, you can try:

| Option | Description |
| ------:| -----------:|
| data   | path to data files to supply the data that will be passed into templates. |
| engine | engine to be used for processing templates. Handlebars is the default. |
| ext    | extension to be used for dest files. |

HTTP URL Address Encoding in Java

If you have a URL, you can pass url.toString() into this method. First decode, to avoid double encoding (for example, encoding a space results in %20 and encoding a percent sign results in %25, so double encoding will turn a space into %2520). Then, use the URI as explained above, adding in all the parts of the URL (so that you don't drop the query parameters).

public URL convertToURLEscapingIllegalCharacters(String string){
    try {
        String decodedURL = URLDecoder.decode(string, "UTF-8");
        URL url = new URL(decodedURL);
        URI uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef()); 
        return uri.toURL(); 
    } catch (Exception ex) {
        return null;

Psql could not connect to server: No such file or directory, 5432 error?

I was able to solve the issue by running:

sudo systemctl start [email protected]

How to list files and folder in a dir (PHP)


// open this directory 
$myDirectory = opendir(".");
// get each entry
while($entryName = readdir($myDirectory)) {
    $dirArray[] = $entryName;
// close directory
//  count elements in array
$indexCount = count($dirArray);
Print ("$indexCount files<br>\n");
// sort 'em
// print 'em
print("<TABLE border=1 cellpadding=5 cellspacing=0 class=whitelinks>\n");
// loop through the array of files and print them all
for($index=0; $index < $indexCount; $index++) {
        if (substr("$dirArray[$index]", 0, 1) != "."){ // don't list hidden files
        print("<TR><TD><a href=\"$dirArray[$index]\">$dirArray[$index]</a></td>");
        print("<td>");  print(filetype($dirArray[$index])); print("</td>");
        print("<td>");  print(filesize($dirArray[$index])); print("</td>");

2 solution

# The current directory
$directory = dir("./");

# If you want to turn on Extension Filter, then uncomment this:
### $allowed_ext = array(".sample", ".png", ".jpg", ".jpeg", ".txt", ".doc", ".xls"); 

## Description of the soft: list_dir_files.php  
## Major credits: phpDIRList 2.0 -(c)2005 Ulrich S. Kapp :: Systemberatung ::

$do_link = TRUE; 
$sort_what = 0; //0- by name; 1 - by size; 2 - by date
$sort_how = 0; //0 - ASCENDING; 1 - DESCENDING

# # #
function dir_list($dir){ 
    $dl = array(); 
    if ($hd = opendir($dir))    { 
        while ($sz = readdir($hd)) {  
            if (preg_match("/^\./",$sz)==0) $dl[] = $sz;$i.=1;  
    return $dl; 
if ($sort_how == 0) { 
    function compare0($x, $y) {  
        if ( $x[0] == $y[0] ) return 0;  
        else if ( $x[0] < $y[0] ) return -1;  
        else return 1;  
    function compare1($x, $y) {  
        if ( $x[1] == $y[1] ) return 0;  
        else if ( $x[1] < $y[1] ) return -1;  
        else return 1;  
    function compare2($x, $y) {  
        if ( $x[2] == $y[2] ) return 0;  
        else if ( $x[2] < $y[2] ) return -1;  
        else return 1;  
    function compare0($x, $y) {  
        if ( $x[0] == $y[0] ) return 0;  
        else if ( $x[0] < $y[0] ) return 1;  
        else return -1;  
    function compare1($x, $y) {  
        if ( $x[1] == $y[1] ) return 0;  
        else if ( $x[1] < $y[1] ) return 1;  
        else return -1;  
    function compare2($x, $y) {  
        if ( $x[2] == $y[2] ) return 0;  
        else if ( $x[2] < $y[2] ) return 1;  
        else return -1;  


#    We get the information here 

$i = 0; 
while($file=$directory->read()) { 
    $file = strtolower($file);
    $ext = strrchr($file, '.');
    if (isset($allowed_ext) && (!in_array($ext,$allowed_ext)))
            // dump 
    else { 
        $temp_info = stat($file); 
        $new_array[$i][0] = $file; 
        $new_array[$i][1] = $temp_info[7]; 
        $new_array[$i][2] = $temp_info[9]; 
        $new_array[$i][3] = date("F d, Y", $new_array[$i][2]); 
        $i = $i + 1; 

# We sort the information here 

switch ($sort_what) { 
    case 0: 
            usort($new_array, "compare0"); 
    case 1: 
            usort($new_array, "compare1"); 
    case 2: 
            usort($new_array, "compare2"); 

#    We display the infomation here 

$i2 = count($new_array); 
$i = 0; 
echo "<table border=1> 
                    <td width=150> File name</td> 
                    <td width=100> File Size</td> 
                    <td width=100>Last Modified</td> 
for ($i=0;$i<$i2;$i++) { 
    if (!$do_link) { 
        $line = "<tr><td align=right>" .  
                        $new_array[$i][0] .  
                        "</td><td align=right>" .  
                        number_format(($new_array[$i][1]/1024)) .  
        $line = $line  . "</td><td align=right>" . $new_array[$i][3] . "</td></tr>"; 
        $line = '<tr><td align=right><A HREF="' .   
                        $new_array[$i][0] . '">' .  
                        $new_array[$i][0] .  
                        "</A></td><td align=right>"; 
        $line = $line . number_format(($new_array[$i][1]/1024)) .  
                        "k"  . "</td><td align=right>" .  
                        $new_array[$i][3] . "</td></tr>"; 
    echo $line; 
echo "</table>"; 


What is the right way to debug in iPython notebook?

The %pdb magic command is good to use as well. Just say %pdb on and subsequently the pdb debugger will run on all exceptions, no matter how deep in the call stack. Very handy.

If you have a particular line that you want to debug, just raise an exception there (often you already are!) or use the %debug magic command that other folks have been suggesting.

How can I hide the Android keyboard using JavaScript?

Here's what I do (from

 * Hide the on-screen keyboard on touch devices like iOS and Android.
 * It's useful to do this after a form submission that doesn't navigate away from the
 * current page but does update some part of the current page (e.g. dynamically updated
 * search results). If you weren't to do this the user might not be shown any feedback
 * in response to their action (form submission), because it is obscured by the keyboard.
 * To hide the keyboard we temporarily set the active input or textarea to readonly and
 * disabled. To avoid a flash of readonly/disabled styles (often a gray background) you
 * can hook into the [data-oaf-keyboard-hack] html attribute. For example:
 * ```
 *  // Readonly/disabled styles shouldn't be applied when this attribute is present.
 *  [data-oaf-keyboard-hack] {
 *    background-color: $input-bg !important;
 *  }
 * ```
 * Note that lots of people simply `blur()` the focused input to achieve this result
 * but doing that is hostile to keyboard users and users of other AT.
 * Do you need to use this?
 * 1. If your form submission triggers a full page reload, you don't need this.
 * 2. If your form submission explicitly moves focus to some other element, you
 * don't need this. For example you might move focus to some new content that
 * was loaded as a result of the form submission or to a loading message.
 * 3. If your form submission leaves focus where it is, you probably want this.
export const hideOnscreenKeyboard = (): Promise<void> => {
  // TODO: use inputmode="none"?

  // eslint-disable-next-line no-restricted-globals
  const activeElement = document.activeElement;
  const inputType =
    activeElement instanceof HTMLInputElement
      ? activeElement.getAttribute("type")
      : undefined;

  if (
    activeElement !== null &&
    activeElement instanceof HTMLElement &&
    // Don't bother with input types that we know don't trigger an OSK.
    inputType !== "checkbox" &&
    inputType !== "radio" &&
    inputType !== "submit" &&
    inputType !== "reset" &&
    inputType !== "button"
  ) {
    // Blur the active element to dismiss the on-screen keyboard.

    // Set an attribute that allows users to override readonly/disabled styles via CSS.
    // This input will be readonly/disabled for only a fraction of a second and we
    // want to avoid the flash of readonly/disabled styles.
    activeElement.setAttribute("data-oaf-keyboard-hack", "true");

    // Some older Android browsers need extra encouragement.
    // See
    const originalReadonly = activeElement.getAttribute("readonly");
    const originalDisabled = activeElement.getAttribute("disabled");

    // eslint-disable-next-line functional/immutable-data
    activeElement.setAttribute("readonly", "true");
    if (activeElement instanceof HTMLTextAreaElement) {
      // eslint-disable-next-line functional/immutable-data
      activeElement.setAttribute("disabled", "true");

    return new Promise((resolve) => {
      setTimeout(() => {
        // Put things back the way we found them.
        originalReadonly !== null
          ? activeElement.setAttribute("readonly", originalReadonly)
          : activeElement.removeAttribute("readonly");

        if (activeElement instanceof HTMLTextAreaElement) {
          originalDisabled !== null
            ? activeElement.setAttribute("disabled", originalDisabled)
            : activeElement.removeAttribute("disabled");


        // Restore focus back to where it was. Lots of people forget to do this.
        // Note that programmatically calling focus() will not trigger the
        // on-screen keyboard to reemerge.

  } else {
    return Promise.resolve();

Can't import javax.servlet.annotation.WebServlet

If you are using IBM RAD, then ensure the to remove any j2ee.jar in your projects build path -> libraries tab, and then click on "add external jar" and select the j2ee.jar that is shipped with RAD.

How should a model be structured in MVC?

More oftenly most of the applications will have data,display and processing part and we just put all those in the letters M,V and C.

Model(M)-->Has the attributes that holds state of application and it dont know any thing about V and C.

View(V)-->Has displaying format for the application and and only knows about how-to-digest model on it and does not bother about C.

Controller(C)---->Has processing part of application and acts as wiring between M and V and it depends on both M,V unlike M and V.

Altogether there is separation of concern between each. In future any change or enhancements can be added very easily.

Tokenizing Error: java.util.regex.PatternSyntaxException, dangling metacharacter '*'

The first answer covers it.

Im guessing that somewhere down the line you may decide to store your info in a different class/structure. In that case you probably wouldn't want the results going in to an array from the split() method.

You didn't ask for it, but I'm bored, so here is an example, hope it's helpful.

This might be the class you write to represent a single person:

class Person {
            public String firstName;
            public String lastName;
            public int id;
            public int age;

      public Person(String firstName, String lastName, int id, int age) {
         this.firstName = firstName;
         this.lastName = lastName; = id;
         this.age = age;
      // Add 'get' and 'set' method if you want to make the attributes private rather than public.

Then, the version of the parsing code you originally posted would look something like this: (This stores them in a LinkedList, you could use something else like a Hashtable, etc..)

    String ruta="";
    BufferedReader reader = new BufferedReader(new FileReader(ruta));

    LinkedList<Person> list = new LinkedList<Person>();

    String line = null;         
    while ((line=reader.readLine())!=null)
        if (!(line.equals("%")))
            StringTokenizer st = new StringTokenizer(line, "*");
            if (st.countTokens() == 4)          
                list.add(new Person(st.nextToken(), st.nextToken(), Integer.parseInt(st.nextToken()), Integer.parseInt(st.nextToken)));         
                // whatever you want to do to account for an invalid entry
                  // in your file. (not 4 '*' delimiters on a line). Or you
                  // could write the 'if' clause differently to account for it          

Should import statements always be at the top of a module?


In addition to startup performance, there is a readability argument to be made for localizing import statements. For example take python line numbers 1283 through 1296 in my current first python project:

listdata.append(['tk font version', font_version])
listdata.append(['Gtk version', str(Gtk.get_major_version())+"."+

import xml.etree.ElementTree as ET

xmltree = ET.parse('/usr/share/gnome/gnome-version.xml')
xmlroot = xmltree.getroot()
result = []
for child in xmlroot:
listdata.append(['Gnome version', result[0]+"."+result[1]+"."+
                 result[2]+" "+result[3]])

If the import statement was at the top of file I would have to scroll up a long way, or press Home, to find out what ET was. Then I would have to navigate back to line 1283 to continue reading code.

Indeed even if the import statement was at the top of the function (or class) as many would place it, paging up and back down would be required.

Displaying the Gnome version number will rarely be done so the import at top of file introduces unnecessary startup lag.

callback to handle completion of pipe

Streams are EventEmitters so you can listen to certain events. As you said there is a finish event for request (previously end).

 var stream = request(...).pipe(...);
 stream.on('finish', function () { ... });

For more information about which events are available you can check the stream documentation page.

Generic deep diff between two objects

I just use ramda, for resolve the same problem, i need to know what is changed in new object. So here my design.

const oldState = {id:'170',name:'Ivab',secondName:'Ivanov',weight:45};
const newState = {id:'170',name:'Ivanko',secondName:'Ivanov',age:29};

const keysObj1 = R.keys(newState)

const filterFunc = key => {
  const value = R.eqProps(key,oldState,newState)
  return {[key]:value}

const result =, keysObj1)

result is, name of property and it's status.

[{"id":true}, {"name":false}, {"secondName":true}, {"age":false}]

Error occurred during initialization of VM (java/lang/NoClassDefFoundError: java/lang/Object)

Go to Eclipse folder, locate eclipse.ini file, add following entry (before -vmargs if present):

C:\Program Files\Java\jdk1.7.0_10\bin\javaw.exe

Save file and execute eclipse.exe.

Increment a Integer's int value?

Maybe you can try:

final AtomicInteger i = new AtomicInteger(0);

What special characters must be escaped in regular expressions?

Unfortunately there really isn't a set set of escape codes since it varies based on the language you are using.

However, keeping a page like the Regular Expression Tools Page or this Regular Expression Cheatsheet can go a long way to help you quickly filter things out.

Vertically align text next to an image?

Another thing you can do is set the text's line-height to the size of the images within the <div>. Then set the images to vertical-align: middle;

That's seriously the easiest way.

javascript password generator

here is a simply smart code :

function generate(l) {
    if (typeof l==='undefined'){var l=8;}
    /* c : alphanumeric character string */
    var c='abcdefghijknopqrstuvwxyzACDEFGHJKLMNPQRSTUVWXYZ12345679',
    /* p : special character string */
    /* s : determinate the position of the special character */
    s=Math.floor(Math.random() * (p.length-1));

    for(var i=0; i<l; ++i){
        if(s == i){
            /* special charact insertion (random position s) */
            r += p.charAt(Math.floor(Math.random() * o));
            /* alphanumeric insertion */
            r += c.charAt(Math.floor(Math.random() * n));
    return r;

Simply call generate(), and it do key containing one special character (!@#$+-*&_) for security.

Possible results : WJGUk$Ey, gaV7#fF7, ty_T55DD, YtrQMWveZqYyYKo_

There is more details and example in my website :

Get connection string from App.config

1) Create a new form and add this:

Imports System.Configuration
Imports Operaciones.My.MySettings

Public NotInheritable Class frmconexion

    Private Shared _cnx As String
    Public Shared Property ConexionMySQL() As String
            Return My.MySettings.Default.conexionbd
        End Get
        Private Set(ByVal value As String)
            _cnx = value
        End Set
    End Property

End Class

then when you want to use the connection do this in ur form:

 Private Sub frmInsert_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim cn As New MySqlConnection(frmconexion.ConexionMySQL)

and thats it. You will be connected to the DB and can do stuff.

This is for but the logic is the same.

How prevent CPU usage 100% because of worker process in iis

I recently had this problem myself, and once I determined which AppPool was causing the problem, the only way to resolve the issue was remove that app pool completly and create a new one for the site to use.

Bootstrap trying to load map file. How to disable it? Do I need to do it?

If you don't have the correct .map file and you don't want to edit lines in bootstrap.css you can create a dummy .map file.

In my case I was seeing the error:

GET / not found.

So I created an empty in the /public directory and the error stopped.

Can I add extension methods to an existing static class?

I tried to do this with System.Environment back when I was learning extension methods and was not successful. The reason is, as others mention, because extension methods require an instance of the class.

Is there a way to create multiline comments in Python?

You can use triple-quoted strings. When they're not a docstring (the first thing in a class/function/module), they are ignored.

This is a multiline

(Make sure to indent the leading ''' appropriately to avoid an IndentationError.)

Guido van Rossum (creator of Python) tweeted this as a "pro tip".

However, Python's style guide, PEP8, favors using consecutive single-line comments, like this:

# This is a multiline
# comment.

...and this is also what you'll find in many projects. Text editors usually have a shortcut to do this easily.

equals vs Arrays.equals in Java

Arrays inherit equals() from Object and hence compare only returns true if comparing an array against itself.

On the other hand, Arrays.equals compares the elements of the arrays.

This snippet elucidates the difference:

Object o1 = new Object();
Object o2 = new Object();
Object[] a1 = { o1, o2 };
Object[] a2 = { o1, o2 };
System.out.println(a1.equals(a2)); // prints false
System.out.println(Arrays.equals(a1, a2)); // prints true

See also Arrays.equals(). Another static method there may also be of interest: Arrays.deepEquals().

How to get Current Directory?

An easy way to do this is:

int main(int argc, char * argv[]){
    std::cout << argv[0]; 

argv[] is pretty much an array containing arguments you ran the .exe with, but the first one is always a path to the executable. If I build this the console shows: C:\Users\Ulisse\source\repos\altcmd\Debug\currentdir.exe

iReport not starting using JRE 8

iReport does not work with java 8.

  • if not yet installed, download and install java 7
  • find the install dir of your iReport and open the file: ireport.conf

(you will find it here: iReport-x.x.x\etc\ )

change this line:


to this (if not this is your java 7 install dir then replace the parameter value between ""s with your installed java 7's path):

jdkhome="C:\Program Files\Java\jdk1.7.0_67"

Sort ArrayList of custom Objects by property

JAVA 8 lambda expression

Collections.sort(studList, (Student s1, Student s2) ->{
        return s1.getFirstName().compareToIgnoreCase(s2.getFirstName());


Comparator<Student> c = (s1, s2) -> s1.firstName.compareTo(s2.firstName);

IPython/Jupyter Problems saving notebook as PDF

2015-4-22: It looks like an IPython update means that --to pdf should be used instead of --to latex --post PDF. There is a related Github issue.

How can I create an array/list of dictionaries in python?


weightMatrix = []
for k in range(motifWidth):

What is the Difference Between Mercurial and Git?

Sometime last year I evaluated both git and hg for my own use, and decided to go with hg. I felt it looked like a cleaner solution, and worked better on more platforms at the time. It was mostly a toss-up, though.

More recently, I started using git because of git-svn and the ability to act as a Subversion client. This won me over and I've now switched completely to git. I think it's got a slightly higher learning curve (especially if you need to poke around the insides), but it really is a great system. I'm going to go read those two comparison articles that John posted now.

How do I convert an existing callback API to promises?

From the future

A simple generic function I normally use.

const promisify = (fn, ...args) => {
  return new Promise((resolve, reject) => {
    fn(...args, (err, data) => {
      if (err) {
        return reject(err);

How to use it

   promisify(fn, arg1, arg2)

You are probably not looking to this answer, but this will help understand the inner workings of the available utils

JavaScript get child element

ULs don't have a name attribute, but you can reference the ul by tag name.

Try replacing line 3 in your script with this:

var sub = cat.getElementsByTagName("UL");

How to fill Matrix with zeros in OpenCV?

use cv::mat::setto


Call angularjs function using jquery/javascript

One doesn't need to give id for the controller. It can simply called as following


Here HeaderCtrl is the controller name defined in your JS

Center form submit buttons HTML / CSS

I see a few answers here, most of them complicated or with some cons (additional divs, text-align doesn't work because of display: inline-block). I think this is the simplest and problem-free solution:


    <!-- Rows -->
        <td><input name="email" type="email" /></td>
        <td><input type="submit" value="Register!" /></td>


table input[type="submit"] {
    display: block;
    margin: 0 auto;

How to add bootstrap in angular 6 project?

using command

npm install bootstrap --save

open .angular.json old (.angular-cli.json ) file find the "styles" add the bootstrap css file

"styles": [

Sublime Text 3 how to change the font size of the file sidebar?

Navigate to Sublime Text>Preferences>Browse Packages. You should see a file tree.

In the Packages folder, you should see

Theme - Default > Default.sublime-theme (substitute Default for your theme name)

Open that file and find the "class": "sidebar_label: entry and add "font.size".


        "class": "sidebar_label",
        "color": [0, 0, 0],
        "font.bold": false,
        "font.size": 14

How to get the stream key for

This may be an old thread but I came across it and figured that I would give a final answer.

The twitch api is json based and to recieve your stream key you need to authorize your app for use with the api. You do so under the connections tab within your profile on itself.. Down the bottom of said tab there is "register your app" or something similar. Register it and you'll get a client-id header for your get requests.

Now you need to attach your Oauthv2 key to your headers or as a param during the query to the following get request.

curl -H 'Accept: application/vnd.twitchtv.v3+json' -H 'Authorization: OAuth ' \ -X GET

documentataion here

As you can see in the documentation above, if you've done these two things, your stream key will be made available to you.

As I said - Sorry for the bump but some people do find it hard to read the twitch* api.

Hope that helps somebody in the future.

npm - "Can't find Python executable "python", you can set the PYTHON env variable."


Install all the required tools and configurations using Microsoft's windows-build-tools by running npm install -g windows-build-tools from an elevated PowerShell (run as Administrator).

What are allowed characters in cookies?

Years ago MSIE 5 or 5.5 (and probably both) had some serious issue with a "-" in the HTML block if you can believe it. Alhough it's not directly related, ever since we've stored an MD5 hash (containing letters and numbers only) in the cookie to look up everything else in server-side database.

How to make a back-to-top button using CSS and HTML only?

Utilize the <a> tag.

At the top of your website, put an anchor with specified name.

<a name="top"></a>

Then your "back to top" link points to it.

<a href="#top">back to top</a>

Sorting dictionary keys in python

I like this one:

sorted(d, key=d.get)

How to change the foreign key referential action? (behavior)

You can do this in one query if you're willing to change its name:

ALTER TABLE table_name
  DROP FOREIGN KEY `fk_name`,
  ADD CONSTRAINT `fk_name2` FOREIGN KEY (`remote_id`)
    REFERENCES `other_table` (`id`)

This is useful to minimize downtime if you have a large table.

Using module 'subprocess' with timeout

if you are using python 2, give it a try

import subprocess32

    output = subprocess32.check_output(command, shell=True, timeout=3)
except subprocess32.TimeoutExpired as e:
    print e

How to use operator '-replace' in PowerShell to replace strings of texts with special characters and replace successfully

'-replace' does a regex search and you have special characters in that last one (like +) So you might use the non-regex replace version like this:

$c = $c.replace('AccountKey=eKkij32jGEIYIEqAR5RjkKgf4OTiMO6SAyF68HsR/Zd/KXoKvSdjlUiiWyVV2+OUFOrVsd7jrzhldJPmfBBpQA==','DdOegAhDmLdsou6Ms6nPtP37bdw6EcXucuT47lf9kfClA6PjGTe3CfN+WVBJNWzqcQpWtZf10tgFhKrnN48lXA==')

Insert Data Into Temp Table with Query

INTO #Temp

     (CASE WHEN application LIKE '%STUFF%' THEN 'MORESTUFF' END) AS application
     Recieved = 1 AND
     application = 'MORESTUFF'
     CASE WHEN application LIKE '%STUFF%' THEN 'MORESTUFF' END) data
  application LIKE

Run "mvn clean install" in Eclipse

Right click on pom.xml, Run As, you should see the list of m2 options if you have Maven installed, you can select Maven Clean from there

Getting the text from a drop-down box

Based on your example HTML code, here's one way to get the displayed text of the currently selected option:

var skillsSelect = document.getElementById("newSkill");
var selectedText = skillsSelect.options[skillsSelect.selectedIndex].text;

UnicodeDecodeError: 'ascii' codec can't decode byte 0xd1 in position 2: ordinal not in range(128)

Or when you deal with text in Python if it is a Unicode text, make a note it is Unicode.

Set text=u'unicode text' instead just text='unicode text'.

This worked in my case.

How to parse a JSON Input stream

I would suggest you have to use a Reader to convert your InputStream in.

BufferedReader streamReader = new BufferedReader(new InputStreamReader(in, "UTF-8")); 
StringBuilder responseStrBuilder = new StringBuilder();

String inputStr;
while ((inputStr = streamReader.readLine()) != null)
new JSONObject(responseStrBuilder.toString());

I tried in.toString() but it returns:

getClass().getName() + '@' + Integer.toHexString(hashCode())

(like documentation says it derives to toString from Object)

Excel 2010 VBA Referencing Specific Cells in other worksheets

I am going to give you a simplistic answer that hopefully will help you with VBA in general. The easiest way to learn how VBA works and how to reference and access elements is to record your macro then edit it in the VBA editor. This is how I learned VBA. It is based on visual basic so all the programming conventions of VB apply. Recording the macro lets you see how to access and do things.

you could use something like this:

var result = 0
result = Range("A1").Value * Range("B1").Value
Range("D1").Value = result

Alternatively you can also reference a cell using Cells(1,1).Value This way you can set variables and increment them as you wish. I think I am just not clear on exactly what you are trying to do but i hope this helps.

Multiple FROMs - what it means

As of May 2017, multiple FROMs can be used in a single Dockerfile.
See "Builder pattern vs. Multi-stage builds in Docker" (by Alex Ellis) and PR 31257 by Tõnis Tiigi.

The general syntax involves adding FROM additional times within your Dockerfile - whichever is the last FROM statement is the final base image. To copy artifacts and outputs from intermediate images use COPY --from=<base_image_number>.

FROM golang:1.7.3 as builder
WORKDIR /go/src/
RUN go get -d -v  
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/    .
CMD ["./app"]  

The result would be two images, one for building, one with just the resulting app (much, much smaller)

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

multi               latest              bcbbf69a9b59        6 minutes ago       10.3MB  
golang              1.7.3               ef15416724f6        4 months ago        672MB  

what is a base image?

A set of files, plus EXPOSE'd ports, ENTRYPOINT and CMD.
You can add files and build a new image based on that base image, with a new Dockerfile starting with a FROM directive: the image mentioned after FROM is "the base image" for your new image.

does it mean that if I declare neo4j/neo4j in a FROM directive, that when my image is run the neo database will automatically run and be available within the container on port 7474?

Only if you don't overwrite CMD and ENTRYPOINT.
But the image in itself is enough: you would use a FROM neo4j/neo4j if you had to add files related to neo4j for your particular usage of neo4j.

Angular 1.6.0: "Possibly unhandled rejection" error

To avoid having to type additional .catch(function () {}) in your code in multiple places, you could add a decorator to the $exceptionHandler.

This is a more verbose option than the others but you only have to make the change in one place.


configDecorators.$inject = ["$provide"];
function configDecorators($provide) {

    $provide.decorator("$exceptionHandler", exceptionHandler);

    exceptionHandler.$inject = ['$delegate', '$injector'];
    function exceptionHandler($delegate, $injector) {
        return function (exception, cause) {

            if ((exception.toString().toLowerCase()).includes("Possibly unhandled rejection".toLowerCase())) {
                console.log(exception); /* optional to log the "Possibly unhandled rejection" */
            $delegate(exception, cause);