Programs & Examples On #Custom sections

Best practices for copying files with Maven

In order to copy a file use:



In order to copy folder with sub-folders use next configuration:


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

I had the same issue on Windows 7 and I had to install both JDK and JRE and it's a success.

json_encode is returning NULL?

For me, an issue where json_encode would return null encoding of an entity was because my jsonSerialize implementation fetched entire objects for related entities; I solved the issue by making sure that I fetched the ID of the related/associated entity and called ->toArray() when there were more than one entity associated with the object to be json serialized. Note, I'm speaking about cases where one implements JsonSerializable on entities.

Undefined index with $_POST

I know that this is old post but someone can help:

function POST($index, $default=NULL){
                return $_POST[$index];
        return $default;

This code above are my basic POST function what I use anywhere. Here you can put filters, regular expressions, etc. Is faster and clean. My advanced POST function is more complicate to accept and check arrays, string type, default values etc. Let's your imagination work here.

You easy can check username like this:

$username = POST("username");
    echo "{$username} is in the house.";

Also I added $default string that you can define some default value if POST is not active or content not exists.

echo "<h1>".POST("title", "Stack Overflow")."</h1>";

Play with it.

Show/Hide Table Rows using Javascript classes

JQuery 10.1.2 has a nice show and hide functions that encapsulate the behavior you are talking about. This would save you having to write a new function or keep track of css classes.



w3cSchool link to JQuery show and hide

Why use def main()?

if the content of

print __name__
if __name__ == '__main__':
    print 'XXXX'

A file can be used in two ways.

  • imported in another file : import foo

In this case __name__ is foo, the code section does not get executed and does not print XXXX.

  • executed directly : python

When it is executed directly, __name__ is same as __main__ and the code in that section is executed and prints XXXX

One of the use of this functionality to write various kind of unit tests within the same module.

Scroll to a specific Element Using html

You should mention whether you want it to smoothly scroll or simply jump to an element. Jumping is easy & can be done just with HTML or Javascript. The simplest is to use anchor's. The limitation is that every element you want to scroll to has to have an id. A side effect is that #theID will be appended to the URL

<a href="#scroll">Go to Title</a>
  <h1 id="scroll">Title</h1>

You can add CSS effects to the target when the link is clicked with the CSS :target selector.

With some basic JS you can do more, namely the method scrollIntoView(). Your elements don't need an id, though it is still easier, e.g.

function onLinkClick() {
  // will scroll to 4th h3 element

Finally, if you need smooth scrolling, you should have a look at JS Smooth Scroll or this snippet for jQuery. (NB: there are probably many more).

ASP.NET Setting width of DataBound column in GridView

I did a small demo for you. Demonstrating how to display long text.

In this example there is a column Name which may contain very long text. The boundField will display all content in a table cell and therefore the cell will expand as needed (because of the content)

The TemplateField will also be rendered as a cell BUT it contains a div which limits the width of any contet to eg 40px. So this column will have some kind of max-width!

    <asp:GridView ID="gvPersons" runat="server" AutoGenerateColumns="False" Width="100px">
            <asp:BoundField HeaderText="ID" DataField="ID" />
            <asp:BoundField HeaderText="Name (long)" DataField="Name">
                <ItemStyle Width="40px"></ItemStyle>
            <asp:TemplateField HeaderText="Name (short)">
                    <div style="width: 40px; overflow: hidden; white-space: nowrap; text-overflow: ellipsis">
                        <%# Eval("Name") %>

enter image description here

Here is my demo codeBehind

 public partial class gridViewLongText : System.Web.UI.Page
     protected void Page_Load(object sender, EventArgs e)
         #region init and bind data
         List<Person> list = new List<Person>();
         list.Add(new Person(1, "Sam"));
         list.Add(new Person(2, "Max"));
         list.Add(new Person(3, "Dave"));
         list.Add(new Person(4, "TabularasaVeryLongName"));
         gvPersons.DataSource = list;

 public class Person
     public int ID { get; set; }
     public string Name { get; set; }

     public Person(int _ID, string _Name)
         ID = _ID;
         Name = _Name;

How to use the TextWatcher class in Android?

A little bigger perspective of the solution:

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.yourlayout, container, false);
        View tv = v.findViewById(;
        ((TextView) tv).addTextChangedListener(new TextWatcher() {
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                 SpannableString contentText = new SpannableString(((TextView) tv).getText());
                 String contents = Html.toHtml(contentText).toString();

            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

                // TODO Auto-generated method stub

            public void afterTextChanged(Editable s) {

                // TODO Auto-generated method stub
        return v;

This works for me, doing it my first time.

operator << must take exactly one argument

A friend function is not a member function, so the problem is that you declare operator<< as a friend of A:

 friend ostream& operator<<(ostream&, A&);

then try to define it as a member function of the class logic

 ostream& logic::operator<<(ostream& os, A& a)

Are you confused about whether logic is a class or a namespace?

The error is because you've tried to define a member operator<< taking two arguments, which means it takes three arguments including the implicit this parameter. The operator can only take two arguments, so that when you write a << b the two arguments are a and b.

You want to define ostream& operator<<(ostream&, const A&) as a non-member function, definitely not as a member of logic since it has nothing to do with that class!

std::ostream& operator<<(std::ostream& os, const A& a)
  return os << a.number;

How can I create basic timestamps or dates? (Python 3.4)

Ultimately you want to review the datetime documentation and become familiar with the formatting variables, but here are some examples to get you started:

import datetime

print('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(
print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(
print('Date now: %s' %
print('Date today: %s' %

today =
print("Today's date is {:%b, %d %Y}".format(today))

schedule = '{:%b, %d %Y}'.format(today) + ' - 6 PM to 10 PM Pacific'
schedule2 = '{:%B, %d %Y}'.format(today) + ' - 1 PM to 6 PM Central'
print('Maintenance: %s' % schedule)
print('Maintenance: %s' % schedule2)

The output:

Timestamp: 2014-10-18 21:31:12

Timestamp: 2014-Oct-18 21:31:12

Date now: 2014-10-18 21:31:12.318340

Date today: 2014-10-18

Today's date is Oct, 18 2014

Maintenance: Oct, 18 2014 - 6 PM to 10 PM Pacific

Maintenance: October, 18 2014 - 1 PM to 6 PM Central

Reference link:

How to enable assembly bind failure logging (Fusion) in .NET

Set the following registry value:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion!EnableLog] (DWORD) to 1

To disable, set to 0 or delete the value.

[edit ]:Save the following text to a file, e.g FusionEnableLog.reg, in Windows Registry Editor Format:

Windows Registry Editor Version 5.00


Then run the file from windows explorer and ignore the warning about possible damage.

Creating email templates with Django

I have created Django Simple Mail to have a simple, customizable and reusable template for every transactional email you would like to send.

Emails contents and templates can be edited directly from django's admin.

With your example, you would register your email :

from simple_mail.mailer import BaseSimpleMail, simple_mailer

class WelcomeMail(BaseSimpleMail):
    email_key = 'welcome'

    def set_context(self, user_id, welcome_link):
        user = User.objects.get(id=user_id)
        return {
            'user': user,
            'welcome_link': welcome_link


And send it this way :

welcome_mail = WelcomeMail()
welcome_mail.set_context(user_id, welcome_link)
welcome_mail.send(to, from_email=None, bcc=[], connection=None, attachments=[],
                   headers={}, cc=[], reply_to=[], fail_silently=False)

I would love to get any feedback.

Why is textarea filled with mysterious white spaces?

Open (and close!) your PHP tags right after, and before, your textarea tags:

<textarea style="width:350px; height:80px;" cols="42" rows="5" name="sitelink"><?php
  if($siteLink_val) echo $siteLink_val;

vba error handling in loop

The problem is probably that you haven't resumed from the first error. You can't throw an error from within an error handler. You should add in a resume statement, something like the following, so VBA no longer thinks you are inside the error handler:

For Each oSheet In ActiveWorkbook.Sheets
    On Error GoTo NextSheet:
     Set qry = oSheet.ListObjects(1).QueryTable
     oCmbBox.AddItem oSheet.Name
    Resume NextSheet2
Next oSheet

Using Notepad++ to validate XML against an XSD

  1. In Notepad++ go to Plugins > Plugin manager > Show Plugin Manager then find Xml Tools plugin. Tick the box and click Install

    enter image description here

  2. Open XML document you want to validate and click Ctrl+Shift+Alt+M (Or use Menu if this is your preference Plugins > XML Tools > Validate Now).
    Following dialog will open: enter image description here

  3. Click on .... Point to XSD file and I am pretty sure you'll be able to handle things from here.

Hope this saves you some time.

EDIT: Plugin manager was not included in some versions of Notepad++ because many users didn't like commercials that it used to show. If you want to keep an older version, however still want plugin manager, you can get it on github, and install it by extracting the archive and copying contents to plugins and updates folder.
In version 7.7.1 plugin manager is back under a different guise... Plugin Admin so now you can simply update notepad++ and have it back.

enter image description here read stream to byte[]

I am very surprised that nobody here has mentioned the problem of connection and read timeout. It could happen (especially on Android and/or with some crappy network connectivity) that the request will hang and wait forever.

The following code (which also uses Apache IO Commons) takes this into account, and waits max. 5 seconds until it fails:

public static byte[] downloadFile(URL url)
    try {
        URLConnection conn = url.openConnection();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        IOUtils.copy(conn.getInputStream(), baos);

        return baos.toByteArray();
    catch (IOException e)
        // Log error and return null, some default or throw a runtime exception

How to change Java version used by TOMCAT?

test open the termenal or cmd. go to the [tomcat-home]\bin directory. ex: c:\tomcat8\bin write the following command: Tomcat8W //ES//Tomcat8 will open dialog, select the java tap(top tap). change the Java virtual Machine value.

jquery : focus to div is not working

Focus doesn't work on divs by default. But, according to this, you can make it work:

The focus event is sent to an element when it gains focus. This event is implicitly applicable to a limited set of elements, such as form elements (<input>, <select>, etc.) and links (<a href>). In recent browser versions, the event can be extended to include all element types by explicitly setting the element's tabindex property. An element can gain focus via keyboard commands, such as the Tab key, or by mouse clicks on the element.

In Angular, how to redirect with $location.path as $ success callback

Here is the changeLocation example from this article

//be sure to inject $scope and $location
var changeLocation = function(url, forceReload) {
  $scope = $scope || angular.element(document).scope();
  if(forceReload || $scope.$$phase) {
    window.location = url;
  else {
    //only use this if you want to replace the history stack

    //this this if you want to change the URL and add it to the history stack

Android SQLite: Update Statement

It's all in the tutorial how to do that:

    ContentValues args = new ContentValues();
    args.put(columnName, newValue);
    db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null);

Use ContentValues to set the updated columns and than the update() method in which you have to specifiy, the table and a criteria to only update the rows you want to update.

http://localhost:8080/ Access Error: 404 -- Not Found Cannot locate document: /

When I had an error Access Error: 404 -- Not Found I fixed it by doing the following:

  1. Open command prompt and type "netstat -aon" (without the quotes)
  2. Search for port 8080 and look at its PID number/code.
  3. Open Task Manager (CTRL+ALT+DELETE), go to Services tab, and find the service with the exact PID number. Then right click it and stop the process.

Original purpose of <input type="hidden">?

The values of form elements including type='hidden' are submitted to the server when the form is posted. input type="hidden" values are not visible in the page. Maintaining User IDs in hidden fields, for example, is one of the many uses.

SO uses a hidden field for the upvote click.

<input value="16293741" name="postId" type="hidden">

Using this value, the server-side script can store the upvote.

How do I remove a submodule?

In latest git just 4 operation is needed to remove the git submodule.

  • Remove corresponding entry in .gitmodules
  • Stage changes git add .gitmodules
  • Remove the submodule directory git rm --cached <path_to_submodule>
  • Commit it git commit -m "Removed submodule xxx"

How do I show the number keyboard on an EditText in android?


Converting String array to java.util.List

List<String> strings = Arrays.asList(new String[]{"one", "two", "three"});

This is a list view of the array, the list is partly unmodifiable, you can't add or delete elements. But the time complexity is O(1).

If you want a modifiable a List:

List<String> strings = 
     new ArrayList<String>(Arrays.asList(new String[]{"one", "two", "three"}));

This will copy all elements from the source array into a new list (complexity: O(n))

Given two directory trees, how can I find out which files differ by content?

To find diff use this command:

diff -qr dir1/ dir2/

-r will diff all subdirectories too -q tells diff to report only when files differ.

diff  --brief dir1/ dir2/

--brief will show the files that dosent exist in directory.

Or else

we can use Meld which will show in graphical window its easy to find the difference.

meld  dir1/ dir2/

How to create text file and insert data to that file on Android

Check the android documentation. It's in fact not much different than standard java io file handling so you could also check that documentation.

An example from the android documentation:

String FILENAME = "hello_file";
String string = "hello world!";

FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Correct expression is

"source " + (DT_STR,4,1252)DATEPART( "yyyy" , getdate() ) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "mm" , getdate() ), 2) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "dd" , getdate() ), 2) +".CSV"

How to check if a particular service is running on Ubuntu

For Ubuntu (checked with 12.04)

You can get list of all services and select by color one of them with 'grep':

sudo service --status-all | grep postgres

Or you may use another way if you know correct name of service:

sudo service postgresql status

Android: remove notification from notification bar

Please try this,

public void removeNotification(Context context, int notificationId) {      
    NotificationManager nMgr = (NotificationManager) context.getApplicationContext()

How to Logout of an Application Where I Used OAuth2 To Login With Google?

Overview of OAuth: Is the User Who He/She Says He/She is?:

I'm not sure if you used OAuth to login to Stack Overflow, like the "Login with Google" option, but when you use this feature, Stack Overflow is simply asking Google if it knows who you are:

"Yo Google, this Vinesh fella claims that [email protected] is him, is that true?"

If you're logged in already, Google will say YES. If not, Google will say:

"Hang on a sec Stack Overflow, I'll authenticate this fella and if he can enter the right password for his Google account, then it's him".

When you enter your Google password, Google then tells Stack Overflow you are who you say you are, and Stack Overflow logs you in.

When you logout of your app, you're logging out of your app:

Here's where developers new to OAuth sometimes get a little confused... Google and Stack Overflow, Assembla, Vinesh's-very-cool-slick-webapp, are all different entities, and Google knows nothing about your account on Vinesh's cool webapp, and vice versa, aside from what's exposed via the API you're using to access profile information.

When your user logs out, he or she isn't logging out of Google, he/she is logging out of your app, or Stack Overflow, or Assembla, or whatever web application used Google OAuth to authenticate the user.

In fact, I can log out of all of my Google accounts and still be logged into Stack Overflow. Once your app knows who the user is, that person can log out of Google. Google is no longer needed.

With that said, what you're asking to do is log the user out of a service that really doesn't belong to you. Think about it like this: As a user, how annoyed do you think I would be if I logged into 5 different services with my Google account, then the first time I logged out of one of them, I have to login to my Gmail account again because that app developer decided that, when I log out of his application, I should also be logged out of Google? That's going to get old really fast. In short, you really don't want to do this...

Yeh yeh, whatever, I still want to log the user out Of Google, just tell me how do I do this?

With that said, if you still do want to log a user out of Google, and realize that you may very well be disrupting their workflow, you could dynamically build the logout url from one of their Google services logout button, and then invoke that using an img element or a script tag:

<script type="text/javascript" 
    src="" />


<img src="" />


window.location = "";

If you redirect your user to the logout page, or invoke it from an element that isn't cross-domain restricted, the user will be logged out of Google.

Note that this does not necessarily mean the user will be logged out of your application, only Google. :)


What's important for you to keep in mind is that, when you logout of your app, you don't need to make the user re-enter a password. That's the whole point! It authenticates against Google so the user doesn't have to enter his or her password over and over and over again in each web application he or she uses. It takes some getting used to, but know that, as long as the user is logged into Google, your app doesn't need to worry about whether or not the user is who he/she says he/she is.

I have the same implementation in a project as you do, using the Google Profile information with OAuth. I tried the very same thing you're looking to try, and it really started making people angry when they had to login to Google over and over again, so we stopped logging them out of Google. :)

How to send a message to a particular client with

SURE: Simply,

This is what you need :"event", data);

whenever a user joined to the server, socket details will be generated including ID. This is the ID really helps to send a message to particular people.

first we need to store all the socket.ids in array,

var people={};

people[name] =;

here name is the receiver name. Example:


So, now we can get that with the receiver name whenever we are sending message:

for this we need to know the receivername. You need to emit receiver name to the server.

final thing is:

 socket.on('chat message', function(data){[data.receiver]).emit('chat message', data.msg);

Hope this works well for you.

Good Luck!!

How do I get the logfile from an Android device?

Often I get the error "logcat read: Invalid argument". I had to clear the log, before reading from the log.

I do like this:

prompt> cd ~/Desktop
prompt> adb logcat -c
prompt> adb logcat | tee log.txt

sql - insert into multiple tables in one query

I had the same problem. I solve it with a for loop.


If I want to write in 2 identical tables, using a loop

for x = 0 to 1

 if x = 0 then TableToWrite = "Table1"
 if x = 1 then TableToWrite = "Table2"
  Sql = "INSERT INTO " & TableToWrite & " VALUES ('1','2','3')"


ArrTable = ("Table1", "Table2")

for xArrTable = 0 to Ubound(ArrTable)
 Sql = "INSERT INTO " & ArrTable(xArrTable) & " VALUES ('1','2','3')"

If you have a small query I don't know if this is the best solution, but if you your query is very big and it is inside a dynamical script with if/else/case conditions this is a good solution.

how to get param in method post spring mvc?

You should use @RequestParam on those resources with method = RequestMethod.GET

In order to post parameters, you must send them as the request body. A body like JSON or another data representation would depending on your implementation (I mean, consume and produce MediaType).

Typically, multipart/form-data is used to upload files.

MVC which submit button has been pressed

<input name="submit" type="submit" id="submit" value="Save" />
<input name="process" type="submit" id="process" value="Process" />

And in your controller action:

public ActionResult SomeAction(string submit)
    if (!string.IsNullOrEmpty(submit))
        // Save was pressed
        // Process was pressed

Javascript Array of Functions

I think this is what the original poster meant to accomplish:

var array_of_functions = [
    function() { first_function('a string') },
    function() { second_function('a string') },
    function() { third_function('a string') },
    function() { fourth_function('a string') }

for (i = 0; i < array_of_functions.length; i++) {

Hopefully this will help others (like me 20 minutes ago :-) looking for any hint about how to call JS functions in an array.

How to handle the `onKeyPress` event in ReactJS?

var Test = React.createClass({
     add: function(event){
         if(event.key === 'Enter'){
     render: function(){
            <input type="text" id="one" onKeyPress={(event) => this.add(event)}/>    

What __init__ and self do in Python?

A brief illustrative example

In the hope it might help a little, here's a simple example I used to understand the difference between a variable declared inside a class, and a variable declared inside an __init__ function:

class MyClass(object):
    i = 123
    def __init__(self):
        self.i = 345
a = MyClass()



Does Internet Explorer 8 support HTML 5?

Some of the other answers here are about adding HTML5 capabilities to IE8 and other browsers. These are called Polyfills and my favourite place for finding those is here.

Compare and contrast REST and SOAP web services?

SOAP brings it’s own protocol and focuses on exposing pieces of application logic (not data) as services. SOAP exposes operations. SOAP is focused on accessing named operations, each implement some business logic through different interfaces.

Though SOAP is commonly referred to as “web services” this is a misnomer. SOAP has very little if anything to do with the Web. REST provides true “Web services” based on URIs and HTTP.

By way of illustration here are few calls and their appropriate home with commentary.


This is a rest operation as you are accessing a resource (data).

switchCategory(User, OldCategory, NewCategory)

REST permits many different data formats where as SOAP only permits XML. While this may seem like it adds complexity to REST because you need to handle multiple formats, in my experience it has actually been quite beneficial. JSON usually is a better fit for data and parses much faster. REST allows better support for browser clients due to it’s support for JSON.

How to determine a user's IP address in node

If you are using Graphql-Yoga you can use the following function:

const getRequestIpAddress = (request) => {_x000D_
    const requestIpAddress = request.request.headers['X-Forwarded-For'] || request.request.connection.remoteAddress_x000D_
    if (!requestIpAddress) return null_x000D_
    const ipv4 = new RegExp("(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)")_x000D_
    const [ipAddress] = requestIpAddress.match(ipv4)_x000D_
    return ipAddress_x000D_

MySQL the right syntax to use near '' at line 1 error

the problem is because you have got the query over multiple lines using the " " that PHP is actually sending all the white spaces in to MySQL which is causing it to error out.

Either put it on one line or append on each line :o)

Sqlyog must be trimming white spaces on each line which explains why its working.


$qr2="INSERT INTO wp_bp_activity
 (this stuff)component,
     (is)      `type`,
    (a)        `action`,
  (problem)  content,

printing out a 2-D array in Matrix format

public static void printMatrix(double[][] matrix) {
    for (double[] row : matrix) {
        for (double element : row) {
            System.out.printf("%5.1f", element);

Function Call

printMatrix(new double[][]{2,0,0},{0,2,0},{0,0,3}});


  2.0  0.0  0.0
  0.0  2.0  0.0
  0.0  0.0  3.0

In console:

Console Output

how to move elasticsearch data from one server to another

If anyone encounter the same issue, when trying to dump from elasticsearch <2.0 to >2.0 you need to do:

elasticdump --input=http://localhost:9200/$SRC_IND --output=http://$TARGET_IP:9200/$TGT_IND --type=analyzer
elasticdump --input=http://localhost:9200/$SRC_IND --output=http://$TARGET_IP:9200/$TGT_IND --type=mapping
elasticdump --input=http://localhost:9200/$SRC_IND --output=http://$TARGET_IP:9200/$TGT_IND --type=data --transform "delete doc.__source['_id']"

How can I display just a portion of an image in HTML/CSS?

Another alternative is the following, although not the cleanest as it assumes the image to be the only element in a container, such as in this case:

<header class="siteHeader">
  <img src="img" class="siteLogo" />

You can then use the container as a mask with the desired size, and surround the image with a negative margin to move it into the right position:

    width: 50px;
    height: 50px;
    overflow: hidden;

.siteHeader .siteLogo{
    margin: -100px;

Demo can be seen in this JSFiddle.

Only seems to work in IE>9, and probably all significant versions of all other browsers.

URL Encoding using C#

Edit: Note that this answer is now out of date. See Siarhei Kuchuk's answer below for a better fix

UrlEncoding will do what you are suggesting here. With C#, you simply use HttpUtility, as mentioned.

You can also Regex the illegal characters and then replace, but this gets far more complex, as you will have to have some form of state machine (switch ... case, for example) to replace with the correct characters. Since UrlEncode does this up front, it is rather easy.

As for Linux versus windows, there are some characters that are acceptable in Linux that are not in Windows, but I would not worry about that, as the folder name can be returned by decoding the Url string, using UrlDecode, so you can round trip the changes.

How to get a context in a recycler view adapter

If you are using Databinding on layout you can get the context from holder. An exemple below.

public void onBindViewHolder(@NonNull GenericViewHolder holder, int position) {
    View currentView = holder.binding.getRoot().findViewById(;// id of your root layout
    currentView.setBackgroundColor(ContextCompat.getColor(holder.binding.getRoot().getContext(), R.color.light_green));

How to loop an object in React?

const tifOptions = [];

for (const [key, value] of Object.entries(tifs)) {
    tifOptions.push(<option value={key} key={key}>{value}</option>);

return (
   <select id="tif" name="tif" onChange={this.handleChange}>  
      { tifOptions }          

How to align a div inside td element using CSS class

div { margin: auto; }

This will center your div.

Div by itself is a blockelement. Therefor you need to define the style to the div how to behave.

Insert value into a string at a certain position?

If you have a string and you know the index you want to put the two variables in the string you can use:

string temp = temp.Substring(0,index) + textbox1.Text + ":" + textbox2.Text +temp.Substring(index);

But if it is a simple line you can use it this way:

string temp = string.Format("your text goes here {0} rest of the text goes here : {1} , textBox1.Text , textBox2.Text ) ;"

HTML5 Audio Looping

Try using jQuery for the event listener, it will then work in Firefox.

myAudio = new Audio('someSound.ogg');

$(myAudio).bind('ended', function()  {
    myAudio.currentTime = 0;;

Something like that.

How to replace values at specific indexes of a python list?

for index in a:

This will cause index to take on the values of the elements of a, so using them as indices is not what you want. In Python, we iterate over a container by actually iterating over it.

"But wait", you say, "For each of those elements of a, I need to work with the corresponding element of m. How am I supposed to do that without indices?"

Simple. We transform a and m into a list of pairs (element from a, element from m), and iterate over the pairs. Which is easy to do - just use the built-in library function zip, as follows:

for a_element, m_element in zip(a, m):
  s[a_element] = m_element

To make it work the way you were trying to do it, you would have to get a list of indices to iterate over. This is doable: we can use range(len(a)) for example. But don't do that! That's not how we do things in Python. Actually directly iterating over what you want to iterate over is a beautiful, mind-liberating idea.

what about operator.itemgetter

Not really relevant here. The purpose of operator.itemgetter is to turn the act of indexing into something, into a function-like thing (what we call "a callable"), so that it can be used as a callback (for example, a 'key' for sorting or min/max operations). If we used it here, we'd have to re-call it every time through the loop to create a new itemgetter, just so that we could immediately use it once and throw it away. In context, that's just busy-work.

nginx: [emerg] "server" directive is not allowed here

That is not an nginx configuration file. It is part of an nginx configuration file.

The nginx configuration file (usually called nginx.conf) will look like:

events {
http {
    server {

The server block is enclosed within an http block.

Often the configuration is distributed across multiple files, by using the include directives to pull in additional fragments (for example from the sites-enabled directory).

Use sudo nginx -t to test the complete configuration file, which starts at nginx.conf and pulls in additional fragments using the include directive. See this document for more.

What's with the dollar sign ($"string")

String Interpolation

is a concept that languages like Perl have had for quite a while, and now we’ll get this ability in C# as well. In String Interpolation, we simply prefix the string with a $ (much like we use the @ for verbatim strings). Then, we simply surround the expressions we want to interpolate with curly braces (i.e. { and }):

It looks a lot like the String.Format() placeholders, but instead of an index, it is the expression itself inside the curly braces. In fact, it shouldn’t be a surprise that it looks like String.Format() because that’s really all it is – syntactical sugar that the compiler treats like String.Format() behind the scenes.

A great part is, the compiler now maintains the placeholders for you so you don’t have to worry about indexing the right argument because you simply place it right there in the string.

C# string interpolation is a method of concatenating,formatting and manipulating strings. This feature was introduced in C# 6.0. Using string interpolation, we can use objects and expressions as a part of the string interpolation operation.

Syntax of string interpolation starts with a ‘$’ symbol and expressions are defined within a bracket {} using the following syntax.



  • interpolatedExpression - The expression that produces a result to be formatted
  • alignment - The constant expression whose value defines the minimum number of characters in the string representation of the result of the interpolated expression. If positive, the string representation is right-aligned; if negative, it's left-aligned.
  • formatString - A format string that is supported by the type of the expression result.

The following code example concatenates a string where an object, author as a part of the string interpolation.

string author = "Mohit";  
string hello = $"Hello {author} !";  
Console.WriteLine(hello);  // Hello Mohit !

Read more on C#/.NET Little Wonders: String Interpolation in C# 6

Update Rows in SSIS OLEDB Destination

Use Lookupstage to decide whether to insert or update. Check this link for more info -

Steps to do update:

  1. Drag OLEDB Command [instead of oledb destination]
  2. Go to properties window
  3. Under Custom properties select SQLCOMMAND and insert update command ex:

    UPDATE table1 SET col1 = ?, col2 = ? where id = ?

  4. map columns in exact order from source to output as in update command

Disable browser 'Save Password' functionality

Because autocomplete="off" does not work for password fields, one must rely on javascript. Here's a simple solution based on answers found here.

Add the attribute data-password-autocomplete="off" to your password field:

<input type="password" data-password-autocomplete="off">

Include the following JS:

    $('[data-password-autocomplete="off"]').each(function() {
        $(this).prop('type', 'text');
        $('<input type="password"/>').hide().insertBefore(this);
        $(this).focus(function() {
            $(this).prop('type', 'password');

This solution works for both Chrome and FF.

Where is the Docker daemon log?

I was not able to find the logs under Manjaro 20/Arch Linux. Instead i just stopped the docker daemon process and restarted daemon in debug mode with $ sudo dockerd -D to produce logs. It's unfortunate that the official Docker docs don't provide this info for Arch.
This should not only work for Arch, but for other systems in general.

iOS: set font size of UILabel Programmatically

For iOS 8

  static NSString *_myCustomFontName;

 + (NSString *)myCustomFontName:(NSString*)fontName
 if ( !_myCustomFontName )
   NSArray *arr = [UIFont fontNamesForFamilyName:fontName];
    // I know I only have one font in this family
    if ( [arr count] > 0 )
       _myCustomFontName = arr[0];

 return _myCustomFontName;


batch file to check 64bit or 32bit OS

I really do not understand some of the answers given here (sorry for that). The top-voted answer for example does not return the Windows architecture, instead it will give you the processor architecture. While running a 32-bits Windows build on a 64-bits CPU you will get the wrong result (it's a query on hardware being used).

The safest option is to query the BuildLabEx value from the registry.

Determine x86 (intel) or x86-64 (amd)

reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".x86fre."   && set "_ARCH_=x86" || set "_ARCH_=x86-64"

Determine x86 (intel), x86-64 (amd) or arm

set "_ARCH_=unknown"
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".x86fre."   && set "_ARCH_=x86" 
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".amd64fre." && set "_ARCH_=x86-64" 
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".armfre."   && set "_ARCH_=arm" 

An alternative option (mentioned before)

if defined ProgramFiles(x86) ( set "_ARCH_=x86-64" ) else ( set "_ARCH_=x86" )

The problem with the latter is when you mess up your variables, you are not able to use this method. Checking for the folder's existence will cause problems too when there are leftovers from a previous install (or some user purposely created the folder).

How to select option in drop down protractorjs e2e tests

I had a similar problem, and eventually wrote a helper function that selects dropdown values.

I eventually decided that I was fine selecting by option number, and therefore wrote a method that takes an element and the optionNumber, and selects that optionNumber. If the optionNumber is null it selects nothing (leaving the dropdown unselected).

var selectDropdownbyNum = function ( element, optionNum ) {
  if (optionNum){
    var options = element.all(by.tagName('option'))   

I wrote a blog post if you want more detail, it also covers verifying the text of the selected option in a dropdown:

How to show git log history (i.e., all the related commits) for a sub directory of a git repo?

For tracking changes to a folder where the folder was moved, I started using:

git rev-list --all --pretty=oneline -- "*/foo/subfoo/*"

This isn't perfect as it will grab other folders with the same name, but if it is unique, then it seems to work.

TreeMap sort by value

Olof's answer is good, but it needs one more thing before it's perfect. In the comments below his answer, dacwe (correctly) points out that his implementation violates the Compare/Equals contract for Sets. If you try to call contains or remove on an entry that's clearly in the set, the set won't recognize it because of the code that allows entries with equal values to be placed in the set. So, in order to fix this, we need to test for equality between the keys:

static <K,V extends Comparable<? super V>> SortedSet<Map.Entry<K,V>> entriesSortedByValues(Map<K,V> map) {
    SortedSet<Map.Entry<K,V>> sortedEntries = new TreeSet<Map.Entry<K,V>>(
        new Comparator<Map.Entry<K,V>>() {
            @Override public int compare(Map.Entry<K,V> e1, Map.Entry<K,V> e2) {
                int res = e1.getValue().compareTo(e2.getValue());
                if (e1.getKey().equals(e2.getKey())) {
                    return res; // Code will now handle equality properly
                } else {
                    return res != 0 ? res : 1; // While still adding all entries
    return sortedEntries;

"Note that the ordering maintained by a sorted set (whether or not an explicit comparator is provided) must be consistent with equals if the sorted set is to correctly implement the Set interface... the Set interface is defined in terms of the equals operation, but a sorted set performs all element comparisons using its compareTo (or compare) method, so two elements that are deemed equal by this method are, from the standpoint of the sorted set, equal." (

Since we originally overlooked equality in order to force the set to add equal valued entries, now we have to test for equality in the keys in order for the set to actually return the entry you're looking for. This is kinda messy and definitely not how sets were intended to be used - but it works.

What does "Failure [INSTALL_FAILED_OLDER_SDK]" mean in Android Studio?

I fixed this problem.The device system version is older then the sdk minSdkVersion? I just modified the minSdkVersion from android_L to 19 to target my nexus 4.4.4.

buildscript {
    repositories {
    dependencies {
        classpath ''
apply plugin: ''

repositories {

android {
    **compileSdkVersion 'android-L'** modified to 19
    buildToolsVersion "20.0.0"

    defaultConfig {
        applicationId "com.antwei.uiframework.ui"
        minSdkVersion 14
        targetSdkVersion 'L'
        versionCode 1
        versionName "1.0"
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), ''

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    **compile ''** modified to compile ''

how to modified the value by ide. select file->Project Structure -> Facets -> android-gradle and then modified the compile Sdk Version from android_L to 19

sorry I don't have enough reputation to add pictures

Remove final character from string


st =  "abcdefghij"
st = st[:-1]

There is also another way that shows how it is done with steps:

list1 = "abcdefghij"
list2 = list(list1)
list3 = list2[:-1]

This is also a way with user input:

list1 = input ("Enter :")
list2 = list(list1)
list3 = list2[:-1]

To make it take away the last word in a list:

list1 = input("Enter :")
list2 = list1.split()
list3 = list2[:-1]

How to remove all line breaks from a string

How you'd find a line break varies between operating system encodings. Windows would be \r\n, but Linux just uses \n and Apple uses \r.

I found this in JavaScript line breaks:

someText = someText.replace(/(\r\n|\n|\r)/gm, "");

That should remove all kinds of line breaks.

Where is the web server root directory in WAMP?

To check what is your root directory go to httpd.conf file of apache and search for "DocumentRoot".The location following it is your root directory

Excel to CSV with UTF8 encoding

Another one I've found useful: "Numbers" allows encoding-settings when saving as CSV.

best way to create object

Or you can use a data file to put many person objects in to a list or array. You do need to use the System.IO for this. And you need a data file which contains all the information about the objects.

A method for it would look something like this:

static void ReadFile()
    using(StreamWriter writer = new StreamWriter(@"Data.csv"))
        string line = null;
        line = reader.ReadLine();
        while(null!= (line = reader.ReadLine())
                    string[] values = line.Split(',');
                    string name = values[0];
                    int age = int.Parse(values[1]);
        Person person = new Person(name, age);

MySQL delete multiple rows in one query conditions unique to each row

Took a lot of googling but here is what I do in Python for MySql when I want to delete multiple items from a single table using a list of values.

#create some empty list
values = []
#continue to append the values you want to delete to it
#BUT you must ensure instead of a string it's a single value tuple
values.append(([Your Variable],))
#Then once your array is loaded perform an execute many
cursor.executemany("DELETE FROM YourTable WHERE ID = %s", values)

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

Well that is Because of

you are only able to encrypt data in blocks of 128 bits or 16 bytes. That's why you are getting that IllegalBlockSizeException exception. and the one way is to encrypt that data Directly into the String.

look this. Try and u will be able to resolve this

public static String decrypt(String encryptedData) throws Exception {

    Key key = generateKey();
    Cipher c = Cipher.getInstance(ALGO);
    c.init(Cipher.DECRYPT_MODE, key);
    String decordedValue = new BASE64Decoder().decodeBuffer(encryptedData).toString().trim();
    System.out.println("This is Data to be Decrypted" + decordedValue);
    return decordedValue;

hope that will help.

How to require a controller in an angularjs directive

I got lucky and answered this in a comment to the question, but I'm posting a full answer for the sake of completeness and so we can mark this question as "Answered".

It depends on what you want to accomplish by sharing a controller; you can either share the same controller (though have different instances), or you can share the same controller instance.

Share a Controller

Two directives can use the same controller by passing the same method to two directives, like so:

app.controller( 'MyCtrl', function ( $scope ) {
  // do stuff...

app.directive( 'directiveOne', function () {
  return {
    controller: 'MyCtrl'

app.directive( 'directiveTwo', function () {
  return {
    controller: 'MyCtrl'

Each directive will get its own instance of the controller, but this allows you to share the logic between as many components as you want.

Require a Controller

If you want to share the same instance of a controller, then you use require.

require ensures the presence of another directive and then includes its controller as a parameter to the link function. So if you have two directives on one element, your directive can require the presence of the other directive and gain access to its controller methods. A common use case for this is to require ngModel.

^require, with the addition of the caret, checks elements above directive in addition to the current element to try to find the other directive. This allows you to create complex components where "sub-components" can communicate with the parent component through its controller to great effect. Examples could include tabs, where each pane can communicate with the overall tabs to handle switching; an accordion set could ensure only one is open at a time; etc.

In either event, you have to use the two directives together for this to work. require is a way of communicating between components.

Check out the Guide page of directives for more info:

How do I correct this Illegal String Offset?

I get the same error in WP when I use php ver 7.1.6 - just take your php version back to 7.0.20 and the error will disappear.

Convert Enumeration to a Set/List

When using guava (See doc) there is Iterators.forEnumeration. Given an Enumeration x you can do the following:

to get a immutable Set:


to get a immutable List:


to get a hashSet:


Getting the location from an IP address

You need to use an external service... such as if you google search for "geo-ip" you can get more results.

The Host-IP API is HTTP based so you can use it either in PHP or JavaScript depending on your needs.

How do you check if a certain index exists in a table?

A slight deviation from the original question however may prove useful for future people landing here wanting to DROP and CREATE an index, i.e. in a deployment script.

You can bypass the exists check simply by adding the following to your create statement:

ON dbo.TableName

Read more here: CREATE INDEX (Transact-SQL) - DROP_EXISTING Clause

N.B. As mentioned in the comments, the index must already exist for this clause to work without throwing an error.

Android ListView not refreshing after notifyDataSetChanged

In onResume() change this line

items = dbHelper.getItems(); //reload the items from database


items.addAll(dbHelper.getItems()); //reload the items from database

The problem is that you're never telling your adapter about the new items list. If you don't want to pass a new list to your adapter (as it seems you don't), then just use items.addAll after your clear(). This will ensure you are modifying the same list that the adapter has a reference to.

Getting one value from a tuple


Single elements of a tuple a can be accessed -in an indexed array-like fashion-

via a[0], a[1], ... depending on the number of elements in the tuple.


If your tuple is a=(3,"a")

  • a[0] yields 3,
  • a[1] yields "a"

Concrete answer to question

def tup():
  return (3, "hello")

tup() returns a 2-tuple.

In order to "solve"

i = 5 + tup()  # I want to add just the three

you select the 3 by

tup()[0|    #first element

so in total

i = 5 + tup()[0]


Go with namedtuple that allows you to access tuple elements by name (and by index). Details at

>>> import collections
>>> MyTuple=collections.namedtuple("MyTuple", "mynumber, mystring")
>>> m = MyTuple(3, "hello")
>>> m[0]
>>> m.mynumber
>>> m[1]
>>> m.mystring

Eclipse : Failed to connect to remote VM. Connection refused.

when you have Failed to connect to remote VM Connection refused error, restart your eclipse

Error 1022 - Can't write; duplicate key in table

I just spent the last 4 hours with the same issue. What I did was to simply make sure the constraints had unique names.

You can rename the constraints. I appended a number to mine so I could easily trace the number of occurrences.


If a constraint in a table is named boy with a foreign key X The next constraint with the foreign key X can be called boy1

I'm sure you'd figure out better names than I did.

PHP If Statement with Multiple Conditions

You can try this:

    echo (($var=='abc' || $var=='def' || $var=='hij' || $var=='klm' || $var=='nop') ? "true" : "false");

Can I use DIV class and ID together in CSS?

If you want to target a specific class and ID in CSS, then use a format like div.x#y {}.

How to send an email with Gmail as provider using Python?

I ran into a similar problem and stumbled on this question. I got an SMTP Authentication Error but my user name / pass was correct. Here is what fixed it. I read this:

In a nutshell, google is not allowing you to log in via smtplib because it has flagged this sort of login as "less secure", so what you have to do is go to this link while you're logged in to your google account, and allow the access:

Once that is set (see my screenshot below), it should work.

enter image description here

Login now works:

smtpserver = smtplib.SMTP("", 587)
smtpserver.login('[email protected]', 'me_pass')

Response after change:

(235, '2.7.0 Accepted')

Response prior:

smtplib.SMTPAuthenticationError: (535, '5.7.8 Username and Password not accepted. Learn more at\n5.7.8 g66sm2224117qgf.37 - gsmtp')

Still not working? If you still get the SMTPAuthenticationError but now the code is 534, its because the location is unknown. Follow this link:

Click continue and this should give you 10 minutes for registering your new app. So proceed to doing another login attempt now and it should work.

UPDATE: This doesn't seem to work right away you may be stuck for a while getting this error in smptlib:

235 == 'Authentication successful'
503 == 'Error: already authenticated'

The message says to use the browser to sign in:

SMTPAuthenticationError: (534, '5.7.9 Please log in with your web browser and then try again. Learn more at\n5.7.9 qo11sm4014232igb.17 - gsmtp')

After enabling 'lesssecureapps', go for a coffee, come back, and try the 'DisplayUnlockCaptcha' link again. From user experience, it may take up to an hour for the change to kick in. Then try the sign-in process again.


Remove any "Hard Coded" reference of your package name, from your manifest file.

(This is best practice even if you don't using productFlavors)

For example, if your manifest contains:

<uses-permission android:name=""/>
<uses-permission android:name=""/>


Changed it to:

<uses-permission android:name=""/>
<uses-permission android:name="${applicationId}.permission.C2D_MESSAGE"/>


Then, in your module gradle file, set your relevant applicationId:

signingConfigs {
    stage {
        storeFile file('keystore/stage.keystore')
        storePassword 'android'
        keyAlias 'androiddebugkey'
        keyPassword 'android'
    production {
        storeFile file('keystore/playstore.keystore')
        storePassword store_password
        keyAlias key_alias
        keyPassword key_password

productFlavors {
    staging {
        signingConfig signingConfigs.staging
        applicationId defaultConfig.applicationId + ".staging"
        versionName defaultConfig.versionName + "-staging"

    production {
        signingConfig signingConfigs.production

You can follow this tutorial for more info

Difference between two DateTimes C#?

You can do the following:

TimeSpan duration = b - a;

There's plenty of built in methods in the timespan class to do what you need, i.e.


More info can be found here.

Run cmd commands through Java

Here the value adder is use of ampersands to batch commands and correct format for change drive with cd.

public class CmdCommander {

public static void main(String[] args) throws Exception {
    //easyway to start native windows command prompt from Intellij

    Rules are:
    1.baseStart must be dual start
    2.first command must not have &.
    3.subsequent commands must be prepended with & change needs extra &
    5.use quotes at start and end of command batch
    String startQuote = "\"";
    String endQuote = "\"";
    //String baseStart_not_taking_commands = " cmd  /K start ";
    String baseStart = " cmd  /K start cmd /K ";//dual start is must

    String first_command_chcp = " chcp 1251 ";
    String dirList = " &dir ";//& in front of commands after first command means enter
    //change yours
    String changeDir = " &cd &I: ";//extra & makes changing drive happen

    String javaLaunch = " &java ";//just another command
    String javaClass = " Encodes ";//parameter for java needs no &

    String javaCommand = javaLaunch + javaClass;
    //build batch command
    String totalCommand =
            baseStart +
                    startQuote +
                    first_command_chcp +
                    //javaCommand +
                    changeDir +
                    dirList +

    System.out.println(totalCommand);//prints into Intellij terminal
    //Thread t = Thread.currentThread();
    System.out.println("loppu hep");//prints into Intellij terminal


public static void runCmd(String command) throws Exception {

    Runtime rt = Runtime.getRuntime();
    Process proc = rt.exec(command);



No newline after div?

<div style="display: inline">Is this what you meant?</div>

Maximum number of rows in an MS Access database engine table?

It all depends. Theoretically using a single column with 4 byte data type. You could store 300 000 rows. But there is probably alot of overhead in the database even before you do anything. I read some where that you could have 1.000.000 rows but again, it all depends..

You can also link databases together. Limiting yourself to only disk space.

INSERT INTO @TABLE EXEC @query with SQL Server 2000

N.B. - this question and answer relate to the 2000 version of SQL Server. In later versions, the restriction on INSERT INTO @table_variable ... EXEC ... were lifted and so it doesn't apply for those later versions.

You'll have to switch to a temp table:

CREATE TABLE #tmp (code varchar(50), mount money)
DECLARE @q nvarchar(4000)
SET @q = 'SELECT coa_code, amount FROM T_Ledger_detail'

INSERT INTO  #tmp (code, mount)
EXEC sp_executesql (@q)

SELECT * from #tmp

From the documentation:

A table variable behaves like a local variable. It has a well-defined scope, which is the function, stored procedure, or batch in which it is declared.

Within its scope, a table variable may be used like a regular table. It may be applied anywhere a table or table expression is used in SELECT, INSERT, UPDATE, and DELETE statements. However, table may not be used in the following statements:

INSERT INTO table_variable EXEC stored_procedure

SELECT select_list INTO table_variable statements.

Comparing Dates in Oracle SQL

You can use trunc and to_date as follows:

select TO_CHAR (g.FECHA, 'DD-MM-YYYY HH24:MI:SS') fecha_salida, g.NUMERO_GUIA, g.BOD_ORIGEN, g.TIPO_GUIA, dg.DOC_NUMERO, dg.* 
from ils_det_guia dg, ils_guia g
and dg.LAB_CODIGO = 56 
and trunc(g.FECHA) > to_date('01/02/15','DD/MM/YY')
order by g.FECHA;

adding .css file to ejs

app.use(express.static(__dirname + '/public'));
<link href="/css/style.css" rel="stylesheet" type="text/css">

So folder structure should be:


What killed my process and why?

This is the Linux out of memory manager (OOM). Your process was selected due to 'badness' - a combination of recentness, resident size (memory in use, rather than just allocated) and other factors.

sudo journalctl -xb

You'll see a message like:

Jul 20 11:05:00 someapp kernel: Mem-Info:
Jul 20 11:05:00 someapp kernel: Node 0 DMA per-cpu:
Jul 20 11:05:00 someapp kernel: CPU    0: hi:    0, btch:   1 usd:   0
Jul 20 11:05:00 someapp kernel: Node 0 DMA32 per-cpu:
Jul 20 11:05:00 someapp kernel: CPU    0: hi:  186, btch:  31 usd:  30
Jul 20 11:05:00 someapp kernel: active_anon:206043 inactive_anon:6347 isolated_anon:0
                                    active_file:722 inactive_file:4126 isolated_file:0
                                    unevictable:0 dirty:5 writeback:0 unstable:0
                                    free:12202 slab_reclaimable:3849 slab_unreclaimable:14574
                                    mapped:792 shmem:12802 pagetables:1651 bounce:0
Jul 20 11:05:00 someapp kernel: Node 0 DMA free:4576kB min:708kB low:884kB high:1060kB active_anon:10012kB inactive_anon:488kB active_file:4kB inactive_file:4kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present
Jul 20 11:05:00 someapp kernel: lowmem_reserve[]: 0 968 968 968
Jul 20 11:05:00 someapp kernel: Node 0 DMA32 free:44232kB min:44344kB low:55428kB high:66516kB active_anon:814160kB inactive_anon:24900kB active_file:2884kB inactive_file:16500kB unevictable:0kB isolated(anon):0kB isolated
Jul 20 11:05:00 someapp kernel: lowmem_reserve[]: 0 0 0 0
Jul 20 11:05:00 someapp kernel: Node 0 DMA: 17*4kB (UEM) 22*8kB (UEM) 15*16kB (UEM) 12*32kB (UEM) 8*64kB (E) 9*128kB (UEM) 2*256kB (UE) 3*512kB (UM) 0*1024kB 0*2048kB 0*4096kB = 4580kB
Jul 20 11:05:00 someapp kernel: Node 0 DMA32: 216*4kB (UE) 601*8kB (UE) 448*16kB (UE) 311*32kB (UEM) 135*64kB (UEM) 74*128kB (UEM) 5*256kB (EM) 0*512kB 0*1024kB 1*2048kB (R) 0*4096kB = 44232kB
Jul 20 11:05:00 someapp kernel: Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
Jul 20 11:05:00 someapp kernel: 17656 total pagecache pages
Jul 20 11:05:00 someapp kernel: 0 pages in swap cache
Jul 20 11:05:00 someapp kernel: Swap cache stats: add 0, delete 0, find 0/0
Jul 20 11:05:00 someapp kernel: Free swap  = 0kB
Jul 20 11:05:00 someapp kernel: Total swap = 0kB
Jul 20 11:05:00 someapp kernel: 262141 pages RAM
Jul 20 11:05:00 someapp kernel: 7645 pages reserved
Jul 20 11:05:00 someapp kernel: 264073 pages shared
Jul 20 11:05:00 someapp kernel: 240240 pages non-shared
Jul 20 11:05:00 someapp kernel: [ pid ]   uid  tgid total_vm      rss nr_ptes swapents oom_score_adj name
Jul 20 11:05:00 someapp kernel: [  241]     0   241    13581     1610      26        0             0 systemd-journal
Jul 20 11:05:00 someapp kernel: [  246]     0   246    10494      133      22        0         -1000 systemd-udevd
Jul 20 11:05:00 someapp kernel: [  264]     0   264    29174      121      26        0         -1000 auditd
Jul 20 11:05:00 someapp kernel: [  342]     0   342    94449      466      67        0             0 NetworkManager
Jul 20 11:05:00 someapp kernel: [  346]     0   346   137495     3125      88        0             0 tuned
Jul 20 11:05:00 someapp kernel: [  348]     0   348    79595      726      60        0             0 rsyslogd
Jul 20 11:05:00 someapp kernel: [  353]    70   353     6986       72      19        0             0 avahi-daemon
Jul 20 11:05:00 someapp kernel: [  362]    70   362     6986       58      18        0             0 avahi-daemon
Jul 20 11:05:00 someapp kernel: [  378]     0   378     1621       25       8        0             0 iprinit
Jul 20 11:05:00 someapp kernel: [  380]     0   380     1621       26       9        0             0 iprupdate
Jul 20 11:05:00 someapp kernel: [  384]    81   384     6676      142      18        0          -900 dbus-daemon
Jul 20 11:05:00 someapp kernel: [  385]     0   385     8671       83      21        0             0 systemd-logind
Jul 20 11:05:00 someapp kernel: [  386]     0   386    31573      153      15        0             0 crond
Jul 20 11:05:00 someapp kernel: [  391]   999   391   128531     2440      48        0             0 polkitd
Jul 20 11:05:00 someapp kernel: [  400]     0   400     9781       23       8        0             0 iprdump
Jul 20 11:05:00 someapp kernel: [  419]     0   419    27501       32      10        0             0 agetty
Jul 20 11:05:00 someapp kernel: [  855]     0   855    22883      258      43        0             0 master
Jul 20 11:05:00 someapp kernel: [  862]    89   862    22926      254      44        0             0 qmgr
Jul 20 11:05:00 someapp kernel: [23631]     0 23631    20698      211      43        0         -1000 sshd
Jul 20 11:05:00 someapp kernel: [12884]     0 12884    81885     3754      80        0             0 firewalld
Jul 20 11:05:00 someapp kernel: [18130]     0 18130    33359      291      65        0             0 sshd
Jul 20 11:05:00 someapp kernel: [18132]  1000 18132    33791      748      64        0             0 sshd
Jul 20 11:05:00 someapp kernel: [18133]  1000 18133    28867      122      13        0             0 bash
Jul 20 11:05:00 someapp kernel: [18428]    99 18428   208627    42909     151        0             0 node
Jul 20 11:05:00 someapp kernel: [18486]    89 18486    22909      250      46        0             0 pickup
Jul 20 11:05:00 someapp kernel: [18515]  1000 18515   352905   141851     470        0             0 npm
Jul 20 11:05:00 someapp kernel: [18520]     0 18520    33359      291      66        0             0 sshd
Jul 20 11:05:00 someapp kernel: [18522]  1000 18522    33359      294      64        0             0 sshd
Jul 20 11:05:00 someapp kernel: [18523]  1000 18523    28866      115      12        0             0 bash
Jul 20 11:05:00 someapp kernel: Out of memory: Kill process 18515 (npm) score 559 or sacrifice child
Jul 20 11:05:00 someapp kernel: Killed process 18515 (npm) total-vm:1411620kB, anon-rss:567404kB, file-rss:0kB Connection reset

I also had this problem with a Java program trying to send a command on a server via SSH. The problem was with the machine executing the Java code. It didn't have the permission to connect to the remote server. The write() method was doing alright, but the read() method was throwing a Connection reset. I fixed this problem with adding the client SSH key to the remote server known keys.

Remove a HTML tag but keep the innerHtml


This selects all <b> elements, then uses .contents() to target the text content of the <b>, then .unwrap() to remove its parent <b> element.

For the greatest performance, always go native:

var b = document.getElementsByTagName('b');

while(b.length) {
    var parent = b[ 0 ].parentNode;
    while( b[ 0 ].firstChild ) {
        parent.insertBefore(  b[ 0 ].firstChild, b[ 0 ] );
     parent.removeChild( b[ 0 ] );

This will be much faster than any jQuery solution provided here.

Python assigning multiple variables to same value? list behavior

In python, everything is an object, also "simple" variables types (int, float, etc..).

When you changes a variable value, you actually changes it's pointer, and if you compares between two variables it's compares their pointers. (To be clear, pointer is the address in physical computer memory where a variable is stored).

As a result, when you changes an inner variable value, you changes it's value in the memory and it's affects all the variables that point to this address.

For your example, when you do:

a = b =  5 

This means that a and b points to the same address in memory that contains the value 5, but when you do:

a = 6

It's not affect b because a is now points to another memory location that contains 6 and b still points to the memory address that contains 5.

But, when you do:

a = b = [1,2,3]

a and b, again, points to the same location but the difference is that if you change the one of the list values:

a[0] = 2

It's changes the value of the memory that a is points on, but a is still points to the same address as b, and as a result, b changes as well.

Creating a class object in c++

1)What is the difference between both the way of creating class objects.

First one is a pointer to a constructed object in heap (by new). Second one is an object that implicitly constructed. (Default constructor)

2)If i am creating object like Example example; how to use that in an singleton class.

It depends on your goals, easiest is put it as a member in class simply.

A sample of a singleton class which has an object from Example class:

class Sample

    Example example;


    static inline Sample *getInstance()
        if (!uniqeInstance)
            uniqeInstance = new Sample;
        return uniqeInstance;
    virtual ~Sample();
    Sample(const Sample&);
    Sample &operator=(const Sample &);
    static Sample *uniqeInstance;

Is there a way to get a list of all current temporary tables in SQL Server?

You can get list of temp tables by following query :

select left(name, charindex('_',name)-1) 
from tempdb..sysobjects
where charindex('_',name) > 0 and
xtype = 'u' and not object_id('tempdb..'+name) is null

How do I get 'date-1' formatted as mm-dd-yyyy using PowerShell?

    Windows PowerShell
    Copyright (C) 2014 Microsoft Corporation. All rights reserved.

    PS C:\Windows\system32> **$dte = Get-Date**
    PS C:\Windows\system32> **$PastDueDate = $dte.AddDays(-45).Date**
    PS C:\Windows\system32> **$PastDueDate**

    Sunday, March 1, 2020 12:00:00 AM

   PS C:\Windows\system32> **$NewDateFormat = Get-Date $PastDueDate -Format MMddyyyy**
   PS C:\Windows\system32> **$NewDateFormat 03012020**

There're few additional methods available as well e.g.: $dte.AddDays(-45).Day

Controlling fps with requestAnimationFrame?

Update 2016/6

The problem throttling the frame rate is that the screen has a constant update rate, typically 60 FPS.

If we want 24 FPS we will never get the true 24 fps on the screen, we can time it as such but not show it as the monitor can only show synced frames at 15 fps, 30 fps or 60 fps (some monitors also 120 fps).

However, for timing purposes we can calculate and update when possible.

You can build all the logic for controlling the frame-rate by encapsulating calculations and callbacks into an object:

function FpsCtrl(fps, callback) {

    var delay = 1000 / fps,                               // calc. time per frame
        time = null,                                      // start time
        frame = -1,                                       // frame count
        tref;                                             // rAF time reference

    function loop(timestamp) {
        if (time === null) time = timestamp;              // init start time
        var seg = Math.floor((timestamp - time) / delay); // calc frame no.
        if (seg > frame) {                                // moved to next frame?
            frame = seg;                                  // update
            callback({                                    // callback function
                time: timestamp,
                frame: frame
        tref = requestAnimationFrame(loop)

Then add some controller and configuration code:

// play status
this.isPlaying = false;

// set frame-rate
this.frameRate = function(newfps) {
    if (!arguments.length) return fps;
    fps = newfps;
    delay = 1000 / fps;
    frame = -1;
    time = null;

// enable starting/pausing of the object
this.start = function() {
    if (!this.isPlaying) {
        this.isPlaying = true;
        tref = requestAnimationFrame(loop);

this.pause = function() {
    if (this.isPlaying) {
        this.isPlaying = false;
        time = null;
        frame = -1;


It becomes very simple - now, all that we have to do is to create an instance by setting callback function and desired frame rate just like this:

var fc = new FpsCtrl(24, function(e) {
     // render each frame here

Then start (which could be the default behavior if desired):


That's it, all the logic is handled internally.


var ctx = c.getContext("2d"), pTime = 0, mTime = 0, x = 0;_x000D_
ctx.font = "20px sans-serif";_x000D_
// update canvas with some information and animation_x000D_
var fps = new FpsCtrl(12, function(e) {_x000D_
 ctx.clearRect(0, 0, c.width, c.height);_x000D_
 ctx.fillText("FPS: " + fps.frameRate() + _x000D_
                 " Frame: " + e.frame + _x000D_
                 " Time: " + (e.time - pTime).toFixed(1), 4, 30);_x000D_
 pTime = e.time;_x000D_
 var x = (pTime - mTime) * 0.1;_x000D_
 if (x > c.width) mTime = pTime;_x000D_
 ctx.fillRect(x, 50, 10, 10)_x000D_
// start the loop_x000D_
// UI_x000D_
bState.onclick = function() {_x000D_
 fps.isPlaying ? fps.pause() : fps.start();_x000D_
sFPS.onchange = function() {_x000D_
function FpsCtrl(fps, callback) {_x000D_
 var delay = 1000 / fps,_x000D_
  time = null,_x000D_
  frame = -1,_x000D_
 function loop(timestamp) {_x000D_
  if (time === null) time = timestamp;_x000D_
  var seg = Math.floor((timestamp - time) / delay);_x000D_
  if (seg > frame) {_x000D_
   frame = seg;_x000D_
    time: timestamp,_x000D_
    frame: frame_x000D_
  tref = requestAnimationFrame(loop)_x000D_
 this.isPlaying = false;_x000D_
 this.frameRate = function(newfps) {_x000D_
  if (!arguments.length) return fps;_x000D_
  fps = newfps;_x000D_
  delay = 1000 / fps;_x000D_
  frame = -1;_x000D_
  time = null;_x000D_
 this.start = function() {_x000D_
  if (!this.isPlaying) {_x000D_
   this.isPlaying = true;_x000D_
   tref = requestAnimationFrame(loop);_x000D_
 this.pause = function() {_x000D_
  if (this.isPlaying) {_x000D_
   this.isPlaying = false;_x000D_
   time = null;_x000D_
   frame = -1;_x000D_
body {font:16px sans-serif}
<label>Framerate: <select id=sFPS>_x000D_
<canvas id=c height=60></canvas><br>_x000D_
<button id=bState>Start/Stop</button>

Old answer

The main purpose of requestAnimationFrame is to sync updates to the monitor's refresh rate. This will require you to animate at the FPS of the monitor or a factor of it (ie. 60, 30, 15 FPS for a typical refresh rate @ 60 Hz).

If you want a more arbitrary FPS then there is no point using rAF as the frame rate will never match the monitor's update frequency anyways (just a frame here and there) which simply cannot give you a smooth animation (as with all frame re-timings) and you can might as well use setTimeout or setInterval instead.

This is also a well known problem in the professional video industry when you want to playback a video at a different FPS then the device showing it refresh at. Many techniques has been used such as frame blending and complex re-timing re-building intermediate frames based on motion vectors, but with canvas these techniques are not available and the result will always be jerky video.

var FPS = 24;  /// "silver screen"
var isPlaying = true;

function loop() {
    if (isPlaying) setTimeout(loop, 1000 / FPS);

    ... code for frame here

The reason why we place setTimeout first (and why some place rAF first when a poly-fill is used) is that this will be more accurate as the setTimeout will queue an event immediately when the loop starts so that no matter how much time the remaining code will use (provided it doesn't exceed the timeout interval) the next call will be at the interval it represents (for pure rAF this is not essential as rAF will try to jump onto the next frame in any case).

Also worth to note that placing it first will also risk calls stacking up as with setInterval. setInterval may be slightly more accurate for this use.

And you can use setInterval instead outside the loop to do the same.

var FPS = 29.97;   /// NTSC
var rememberMe = setInterval(loop, 1000 / FPS);

function loop() {

    ... code for frame here

And to stop the loop:


In order to reduce frame rate when the tab gets blurred you can add a factor like this:

var isFocus = 1;
var FPS = 25;

function loop() {
    setTimeout(loop, 1000 / (isFocus * FPS)); /// note the change here

    ... code for frame here

window.onblur = function() {
    isFocus = 0.5; /// reduce FPS to half   

window.onfocus = function() {
    isFocus = 1; /// full FPS

This way you can reduce the FPS to 1/4 etc.

How do I convert a PDF document to a preview image in PHP?

You can also try executing the 'convert' utility that comes with imagemagick.

exec("convert pdf_doc.pdf image.jpg");
echo 'image-0.jpg';

What's the best three-way merge tool?

KDiff3 open source, cross platform

Same interface for Linux and Windows, very smart algorithm for solving conflicts, regular expressions for automatically solving conflicts, integrate with ClearCase, SVN, Git, MS Visual Studio, editable merged file, compare directories

Its keyboard-navigation is great: ctrl-arrows to navigate the diffs, ctrl-1, 2, 3 to do the merging.

Also, see

enter image description here

How do I create dynamic variable names inside a loop?

In this dynamicVar, I am creating dynamic variable "ele[i]" in which I will put value/elements of "arr" according to index. ele is blank at initial stage, so we will copy the elements of "arr" in array "ele".

function dynamicVar(){
            var arr = ['a','b','c'];
            var ele = [];
            for (var i = 0; i < arr.length; ++i) {
                ele[i] = arr[i];
 ]               console.log(ele[i]);

How can I get the Windows last reboot reason

Take a look at the Event Log API. Case a) (bluescreen, user cut the power cord or system hang) causes a note ('system did not shutdown correctly' or something like that) to be left in the 'System' event log the next time the system is rebooted properly. You should be able to access it programmatically using the above API (honestly, I've never used it but it should work).

How to create a stopwatch using JavaScript?

Solution by Mosh Hamedani

Creating a StopWatch function constructor.

Define 4 local variables

  1. startTime
  2. endTime
  3. isRunning
  4. duration set to 0

Next create 3 methods

  1. start
  2. stop
  3. reset

start method

  • check if isRunning is true if so throw an error that start cannot be called twice.
  • set isRunning to true
  • assign the current Date object to startTime.

stop method

  • check if isRunning is false if so throw an error that stop cannot be called twice.
  • set isRunning to false
  • assign the current Date object to endTime.
  • calculate the seconds by endTime and startTime Date object
  • increment duration with seconds

reset method:

  • reset all the local variables.

Read-only property

if you want to access the duration local variable you need to define a property using Object.defineProperty. It's useful when you want to create a read-only property.

Object.defineProperty takes 3 parameters

  • the object which to define a property (in this case the current object (this))
  • the name of the property
  • the value of the key property.

  • We want to create a Read-only property so we pass an object as a value. The object contain a get method that return the duration local variable. in this way we cannot change the property only get it.

The trick is to use Date() object to calculate the time.

Reference the code below

function StopWatch() {

let startTime,
    duration = 0;

  this.start = function () {
    if (isRunning) throw new Error("StopWatch has already been started.");

    isRunning = true;

    startTime = new Date();

this.stop = function () {
    if (!isRunning) throw new Error("StopWatch has already been stop.");

    isRunning = false;

    endTime = new Date();

    const seconds = (endTime.getTime() - startTime.getTime()) / 1000;
    duration += seconds;

  this.reset = function () {
    duration = 0;
    startTime = null;
    endTime = null;
    isRunning = false;

  Object.defineProperty(this, "duration", {
    get: function () {
      return duration;

const sw = new StopWatch();

CSS: Creating textured backgrounds

with latest CSS3 technology, it is possible to create textured background. Check this out:

but it still limited on so many aspect. And browser support is also not so ready.

your best bet is using small texture image and make repeat to that background. you could get some nice ready to use texture image here:

What is the simplest way to SSH using Python?

please refer to, its very useful while doing ssh using python.

import paramiko

import time

ssh = paramiko.SSHClient() #SSHClient() is the paramiko object</n>

#Below lines adds the server key automatically to know_hosts file.use anyone one of the below




#Here we are actually connecting to the server.

ssh.connect('', port=22, username='admin', password='')


#I have mentioned time because some servers or endpoint prints there own information after 
#loggin in e.g. the version, model and uptime information, so its better to give some time 
#before executing the command.

#Here we execute the command, stdin for input, stdout for output, stderr for error

stdin, stdout, stderr = ssh.exec_command('xstatus Time')

#Here we are reading the lines from output.

output = stdout.readlines() 


#Below all are the Exception handled by paramiko while ssh. Refer to for more information about exception.

except (BadHostKeyException, AuthenticationException,  
    SSHException, socket.error) as e:           


async await return Task

You need to use the await keyword when use async and your function return type should be generic Here is an example with return value:

public async Task<object> MethodName()
    return await Task.FromResult<object>(null);

Here is an example with no return value:

public async Task MethodName()
    await Task.CompletedTask;

Read these:

TPL: and Tasks:

Async: Await:

How to uninstall Apache with command line

sc delete Apache2.4

Remove service in windows

What is the difference between .*? and .* regular expressions?

Let's say you have:


<(.*)> would match a></a where as <(.*?)> would match a. The latter stops after the first match of >. It checks for one or 0 matches of .* followed by the next expression.

The first expression <(.*)> doesn't stop when matching the first >. It will continue until the last match of >.

Bug? #1146 - Table 'xxx.xxxxx' doesn't exist

run from CMD & %path%=set to mysql/bin

mysql_upgrade -u user -ppassword

iPhone app signing: A valid signing identity matching this profile could not be found in your keychain

What you need:

1) A private and a public key.

They have this symbol in your keychain:

alt text

2) A certificate made from the signing request of those keys

3) A provisioning profile linked to that certificate

Let's say you change computers and want to set up Xcode with provisioning profiles again. How do you do it?

  1. Open Xcode, press ctrl + O to open the Organizer, and delete all provisioning profiles you might have installed already.
  2. Open keychain access, and create a signing request which you save to file (when you create the request, a private and public key is created in your keychain).
  3. Create/Update a certificate in the provisioning portal by sending apple this signing request
  4. Download and install the newly created certificate.
  5. Revoke your provisioning profiles and update them with the new certificate.
  6. Download and install the newly updated provisioning profiles.

SQL multiple column ordering

FROM    mytable
        column1 DESC, column2 ASC

What is object slicing?

"Slicing" is where you assign an object of a derived class to an instance of a base class, thereby losing part of the information - some of it is "sliced" away.

For example,

class A {
   int foo;

class B : public A {
   int bar;

So an object of type B has two data members, foo and bar.

Then if you were to write this:

B b;

A a = b;

Then the information in b about member bar is lost in a.

How to strip comma in Python string

Use replace method of strings not strip:

s = s.replace(',','')

An example:

>>> s = 'Foo, bar'
>>> s.replace(',',' ')
'Foo  bar'
>>> s.replace(',','')
'Foo bar'
>>> s.strip(',') # clears the ','s at the start and end of the string which there are none
'Foo, bar'
>>> s.strip(',') == s

Merge r brings error "'by' must specify uniquely valid columns"

This is what I tried for a right outer join [as per my requirement]:

m1 <- merge(x=companies, y=rounds2, by.x=companies$permalink, 
            by.y=rounds2$company_permalink, all.y=TRUE)
# Error in, x) : 'by' must specify uniquely valid columns
m1 <- merge(x=companies, y=rounds2, by.x=c("permalink"), 
            by.y=c("company_permalink"), all.y=TRUE)

This worked.

Convert file to byte array and vice versa

You can't do this. A File is just an abstract way to refer to a file in the file system. It doesn't contain any of the file contents itself.

If you're trying to create an in-memory file that can be referred to using a File object, you aren't going to be able to do that, either, as explained in this thread, this thread, and many other places..

How do I create a new user in a SQL Azure database?

I found this link very helpful:

It details things like:
- Azure SQL Database subscriber account
- Using Azure Active Directory users to access the database
- Server-level principal accounts (unrestricted access)
- Adding users to the dbmanager database role

I used this and Stuart's answer to do the following:
On the master database (see link as to who has permissions on this):

CREATE LOGIN [MyAdmin] with password='ReallySecurePassword'

And then on the database in question:

ALTER ROLE db_owner ADD MEMBER [MyAdmin]

You can also create users like this, according to the link:


WAMP Server doesn't load localhost

Change the port 80 to port 8080 and restart all services and access like localhost:8080/

It will work fine.

Query Mongodb on month, day, year... of a datetime

You can use MongoDB_DataObject wrapper to perform such query like below:

$model = new MongoDB_DataObject('orders');

$model->whereAdd('MONTH(created) = 4 AND YEAR(created) = 2016');


while ($model->fetch()) {

OR, similarly, using direct query string:

$model = new MongoDB_DataObject();

$model->query('SELECT * FROM orders WHERE MONTH(created) = 4 AND YEAR(created) = 2016');

while ($model->fetch()) {

How do I get the file name from a String containing the Absolute file path?

Alternative using Path (Java 7+):

Path p = Paths.get("C:\\Hello\\AnotherFolder\\The File Name.PDF");
String file = p.getFileName().toString();

Note that splitting the string on \\ is platform dependent as the file separator might vary. Path#getName takes care of that issue for you.

Getting data from Yahoo Finance

Since Yahoo Finances API was disabled, I found Alpha Vantage API

This a stock query sample that I'm using with Excel's Power Query:

What is the difference between ports 465 and 587?

The correct answer to this question has been changed by the publication of RFC 8314. As a result, port 465 and 587 are both valid ports for a mail submission agent (MSA). Port 465 requires negotiation of TLS/SSL at connection setup and port 587 uses STARTTLS if one chooses to negotiate TLS. The IANA registry was updated to allow legitimate use of port 465 for this purpose. For mail relay, only port 25 is used so STARTTLS is the only way to do TLS with mail relay. It's helpful to think of mail relay and mail submission as two very different services (with many behavior differences like requiring auth, different timeouts, different message modification rules, etc.) that happen to use a similar wire protocol.

Removing spaces from string

Try this:

String urle = HOST + url + value;

Then return the values from:

urle.replace(" ", "%20").trim();

check if array is empty (vba excel)

this worked for me:

Private Function arrIsEmpty(arr as variant)
    On Error Resume Next
    arrIsEmpty = False
    arrIsEmpty = IsNumeric(UBound(arr))
End Function

link with target="_blank" does not open in new tab in Chrome

If you use React this should work:

<a href="#" onClick={()=>"https://...")}</a>

How do I change the formatting of numbers on an axis with ggplot?

I'm late to the game here but in-case others want an easy solution, I created a set of functions which can be called like:

 ggplot + scale_x_continuous(labels = human_gbp)

which give you human readable numbers for x or y axes (or any number in general really).

You can find the functions here: Github Repo Just copy the functions in to your script so you can call them.

Disable sorting on last column when using jQuery DataTables

Do this in jQuery. The below code works well even if you columns generated automatically or not sure about the column number.

var table = $('#tbl').DataTable({
        "columnDefs": [{ targets: 'no-sort', orderable: false }]});

and add a class 'no-sort' to whatever headers you want to disable sort like this..

<th class="no-sort">Header n</th>

How to disable a ts rule for a specific line?

You can use /* tslint:disable-next-line */ to locally disable tslint. However, as this is a compiler error disabling tslint might not help.

You can always temporarily cast $ to any:

delete ($ as any).summernote.options.keyMap.pc.TAB

which will allow you to access whatever properties you want.

Edit: As of Typescript 2.6, you can now bypass a compiler error/warning for a specific line:

if (false) {
    // @ts-ignore: Unreachable code error

Note that the official docs "recommend you use [this] very sparingly". It is almost always preferable to cast to any instead as that better expresses intent.

Undefined reference to static class member

The problem comes because of an interesting clash of new C++ features and what you're trying to do. First, let's take a look at the push_back signature:

void push_back(const T&)

It's expecting a reference to an object of type T. Under the old system of initialization, such a member exists. For example, the following code compiles just fine:

#include <vector>

class Foo {
    static const int MEMBER;

const int Foo::MEMBER = 1; 

int main(){
    std::vector<int> v;
    v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'
    v.push_back( (int) Foo::MEMBER ); // OK  
    return 0;

This is because there is an actual object somewhere that has that value stored in it. If, however, you switch to the new method of specifying static const members, like you have above, Foo::MEMBER is no longer an object. It is a constant, somewhat akin to:

#define MEMBER 1

But without the headaches of a preprocessor macro (and with type safety). That means that the vector, which is expecting a reference, can't get one.

Exact difference between CharSequence and String in java

From the Java API of CharSequence:

A CharSequence is a readable sequence of characters. This interface provides uniform, read-only access to many different kinds of character sequences.

This interface is then used by String, CharBuffer and StringBuffer to keep consistency for all method names.

How to force link from iframe to be opened in the parent window

You can use any options

in case of only parent page:

if you want to open all link into parent page or parent iframe, then you use following code in head section of iframe:

<base target="_parent" />


if you want to open a specific link into parent page or parent iframe, then you use following way:

<a target="_parent" href="">specific Link</a>
<a  href="">Normal Link</a>


in case of nested iframe:

If want to open all link into browser window (redirect in browser url), then you use following code in head section of iframe:

<script src=""></script>
<script type="text/javascript">
            return true;


if you want to open a specific link into browser window (redirect in browser url), then you use following way:

<a  href=""   target="_top" >specific Link</a>


<a  href="javascript:top.window.location.href='your_link'">specific Link</a>
<a  href="javascript:top.window.location.href=''">specific Link</a>
<a  href="">Normal Link</a>

Clear the cache in JavaScript

Here's a snippet of what I'm using for my latest project.

From the controller:

if ( IS_DEV ) {
    $this->view->cacheBust = microtime(true);
} else {
    $this->view->cacheBust = file_exists($versionFile) 
        // The version file exists, encode it
        ? urlencode( file_get_contents($versionFile) )
        // Use today's year and week number to still have caching and busting 
        : date("YW");

From the view:

<script type="text/javascript" src="/javascript/somefile.js?v=<?= $this->cacheBust; ?>"></script>
<link rel="stylesheet" type="text/css" href="/css/layout.css?v=<?= $this->cacheBust; ?>">

Our publishing process generates a file with the revision number of the current build. This works by URL encoding that file and using that as a cache buster. As a fail-over, if that file doesn't exist, the year and week number are used so that caching still works, and it will be refreshed at least once a week.

Also, this provides cache busting for every page load while in the development environment so that developers don't have to worry with clearing the cache for any resources (javascript, css, ajax calls, etc).

How to parse float with two decimal places in javascript?

To return a number, add another layer of parentheses. Keeps it clean.

var twoPlacedFloat = parseFloat((10.02745).toFixed(2));

Using Mockito's generic "any()" method

You can use Mockito.isA() for that:

import static org.mockito.Matchers.isA;
import static org.mockito.Mockito.verify;


What does upstream mean in nginx?

If we have a single server we can directly include it in the proxy_pass. But in case if we have many servers we use upstream to maintain the servers. Nginx will load-balance based on the incoming traffic.

What are passive event listeners?

Passive event listeners are an emerging web standard, new feature shipped in Chrome 51 that provide a major potential boost to scroll performance. Chrome Release Notes.

It enables developers to opt-in to better scroll performance by eliminating the need for scrolling to block on touch and wheel event listeners.

Problem: All modern browsers have a threaded scrolling feature to permit scrolling to run smoothly even when expensive JavaScript is running, but this optimization is partially defeated by the need to wait for the results of any touchstart and touchmove handlers, which may prevent the scroll entirely by calling preventDefault() on the event.

Solution: {passive: true}

By marking a touch or wheel listener as passive, the developer is promising the handler won't call preventDefault to disable scrolling. This frees the browser up to respond to scrolling immediately without waiting for JavaScript, thus ensuring a reliably smooth scrolling experience for the user.

document.addEventListener("touchstart", function(e) {
    console.log(e.defaultPrevented);  // will be false
    e.preventDefault();   // does nothing since the listener is passive
    console.log(e.defaultPrevented);  // still false
}, Modernizr.passiveeventlisteners ? {passive: true} : false);

DOM Spec , Demo Video , Explainer Doc

Eclipse: Enable autocomplete / content assist

  1. window->preferences->java->Editor->Contest Assist
  2. Enter in Auto activation triggers for java:
  3. Apply and Close

other method:
type initial letter then ctrl+spacebar for auto-complete options.

Get a list of all functions and procedures in an Oracle database


The column STATUS tells you whether the object is VALID or INVALID. If it is invalid, you have to try a recompile, ORACLE can't tell you if it will work before.

How can I get the session object if I have the entity-manager?

'entityManager.unwrap(Session.class)' is used to get session from EntityManager.

public class EmployeeRepository {

  private EntityManager entityManager;

  public Session getSession() {
    Session session = entityManager.unwrap(Session.class);
    return session;



Demo Application link.

phpMyAdmin mbstring error

I just installed WAMP 3 on Windows 10 and had this issue.

I had to go to C:\wamp64\bin\php\php7.0.0\ and copy the php.ini file to C:\wamp64\bin\apache\apache2.4.17\bin\

Then I restarted WAMP, and was finally able to access my phpMyAdmin file.

Note: this is probably not the correct way to do this because now there are 2 php.ini files. There is probably a setting in an Apache file that points to the php.ini file, but I haven't seen that yet. I will update this if I find it.

Why do multiple-table joins produce duplicate rows?

When you have related tables you often have one-to-many or many-to-many relationships. So when you join to TableB each record in TableA many have multiple records in TableB. This is normal and expected.

Now at times you only need certain columns and those are all the same for all the records, then you would need to do some sort of group by or distinct to remove the duplicates. Let's look at an example:

Id Field1
1  test
2  another test

ID Field2 field3
1  Test1  something
1  test1  More something
2  Test2  Anything

So when you join them and select all the files you get:

select * 
from tableA a 
join tableb b on =

a.Id a.Field1   b.field2  b.field3
1    test            1      Test1     something
1    test            1      Test1     More something
2    another test 2  2      Test2     Anything

These are not duplicates because the values of Field3 are different even though there are repeated values in the earlier fields. Now when you only select certain columns the same number of records are being joined together but since the columns with the different information is not being displayed they look like duplicates.

select a.Id, a.Field1,  b.field2
from tableA a 
join tableb b on =

a.Id a.Field1       b.field2  
1    test           Test1     
1    test           Test1 
2    another test   Test2

This appears to be duplicates but it is not because of the multiple records in TableB.

You normally fix this by using aggregates and group by, by using distinct or by filtering in the where clause to remove duplicates. How you solve this depends on exactly what your business rule is and how your database is designed and what kind of data is in there.

MySQL error: key specification without a key length

You have to change column type to varchar or integer for indexing.

Fill remaining vertical space with CSS using display:flex

A more modern approach would be to use the grid property.

section {_x000D_
  display: grid;_x000D_
  align-items: stretch;_x000D_
  height: 300px;_x000D_
  grid-template-rows: min-content auto 60px;_x000D_
header {_x000D_
  background: tomato;_x000D_
div {_x000D_
  background: gold;_x000D_
  overflow: auto;_x000D_
footer {_x000D_
  background: lightgreen;_x000D_
    header: sized to content_x000D_
    <br>(but is it really?)_x000D_
    main content: fills remaining space<br>_x000D_
    footer: fixed height in px_x000D_

Capture Image from Camera and Display in Activity

You can use this code to onClick listener (you can use ImageView or button)

image.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
                startActivityForResult(takePictureIntent, 1);

To display in your imageView

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
        Bundle extras = data.getExtras();
        bitmap = (Bitmap) extras.get("data");


Note: Insert this to the manifest

<uses-feature android:name="" android:required="true" />

"Prevent saving changes that require the table to be re-created" negative effects

Tools --> Options --> Designers node --> Uncheck " Prevent saving changes that require table recreation ".

Problems with installation of Google App Engine SDK for php in OS X

It's likely that the download was corrupted if you are getting an error with the disk image. Go back to the downloads page at and look at the SHA1 checksum. Then, go to your Terminal app on your mac and run the following:

openssl sha1 [put the full path to the file here without brackets] 

For example:

openssl sha1 /Users/me/Desktop/myFile.dmg 

If you get a different value than the one on the Downloads page, you know your file is not properly downloaded and you should try again.

How can I determine the URL that a local Git repository was originally cloned from?

To summarize, there are at least four ways:

(The following was tried for the official Linux repository)

Least information:

$ git config --get remote.origin.url


$ git ls-remote --get-url

More information:

$ git remote -v
origin (fetch)
origin (push)

Even more information:

$ git remote show origin
* remote origin
  Fetch URL:
  Push  URL:
  HEAD branch: master
  Remote branch:
    master tracked
  Local branch configured for 'git pull':
    master merges with remote master
  Local ref configured for 'git push':
    master pushes to master (up to date)

How can you tell when a layout has been drawn?

When onMeasure is called the view gets its measured width/height. After this, you can call layout.getMeasuredHeight().

Convert a object into JSON in REST service by Spring MVC

The Json conversion should work out-of-the box. In order this to happen you need add some simple configurations:
First add a contentNegotiationManager into your spring config file. It is responsible for negotiating the response type:

<bean id="contentNegotiationManager"
    <property name="favorPathExtension" value="false" />
    <property name="favorParameter" value="true" />
    <property name="ignoreAcceptHeader" value="true" />
    <property name="useJaf" value="false" />
     <property name="defaultContentType" value="application/json" />

      <property name="mediaTypes">
            <entry key="json" value="application/json" />
            <entry key="xml" value="application/xml" />

      content-negotiation-manager="contentNegotiationManager" />

   <context:annotation-config />

Then add Jackson2 jars (jackson-databind and jackson-core) in the service's class path. Jackson is responsible for the data serialization to JSON. Spring will detect these and initialize the MappingJackson2HttpMessageConverter automatically for you. Having only this configured I have my automatic conversion to JSON working. The described config has an additional benefit of giving you the possibility to serialize to XML if you set accept:application/xml header.

how to refresh Select2 dropdown menu after ajax loading different content?

select2 has the placeholder parameter. Use that one

   placeholder: "Choose a Country"

How to kill a nodejs process in Linux?

pkill is the easiest command line utility

pkill -f node


pkill -f nodejs

whatever name the process runs as for your os

Numpy, multiply array with scalar

You can multiply numpy arrays by scalars and it just works.

>>> import numpy as np
>>> np.array([1, 2, 3]) * 2
array([2, 4, 6])
>>> np.array([[1, 2, 3], [4, 5, 6]]) * 2
array([[ 2,  4,  6],
       [ 8, 10, 12]])

This is also a very fast and efficient operation. With your example:

>>> a_1 = np.array([1.0, 2.0, 3.0])
>>> a_2 = np.array([[1., 2.], [3., 4.]])
>>> b = 2.0
>>> a_1 * b
array([2., 4., 6.])
>>> a_2 * b
array([[2., 4.],
       [6., 8.]])

Shared folder between MacOSX and Windows on Virtual Box

You should map your virtual network drive in Windows.

  1. Open command prompt in Windows (VirtualBox)
  2. Execute: net use x: \\vboxsvr\<your_shared_folder_name>
  3. You should see new drive X: in My Computer

In your case execute net use x: \\vboxsvr\win7

Draggable div without jQuery UI

Here is my simple version.
The function draggable takes a jQuery object as argument.

 * @param {jQuery} elem
function draggable(elem){

        var x = parseInt( || 0) - evt.pageX;
        var y = parseInt( || 0) - evt.pageY;

            elem.css('left', x + evt.pageX);
            elem.css('top', y + evt.pageY);


    function off(){"mousemove");

Setting mime type for excel document

Waking up an old thread here I see, but I felt the urge to add the "new" .xlsx format.

According to the extension for .xlsx is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. It might be a good idea to include it when checking for mime types!

How can I make my flexbox layout take 100% vertical space?

You should set height of html, body, .wrapper to 100% (in order to inherit full height) and then just set a flex value greater than 1 to .row3 and not on the others.

.wrapper, html, body {
    height: 100%;
    margin: 0;
.wrapper {
    display: flex;
    flex-direction: column;
#row1 {
    background-color: red;
#row2 {
    background-color: blue;
#row3 {
    background-color: green;
    display: flex;
#col1 {
    background-color: yellow;
    flex: 0 0 240px;
    min-height: 100%;/* chrome needed it a question time , not anymore */
#col2 {
    background-color: orange;
    flex: 1 1;
    min-height: 100%;/* chrome needed it a question time , not anymore */
#col3 {
    background-color: purple;
    flex: 0 0 240px;
    min-height: 100%;/* chrome needed it a question time , not anymore */
<div class="wrapper">
    <div id="row1">this is the header</div>
    <div id="row2">this is the second line</div>
    <div id="row3">
        <div id="col1">col1</div>
        <div id="col2">col2</div>
        <div id="col3">col3</div>


How to set viewport meta for iPhone that handles rotation properly?

Why not just reload the page when the user rotates the screen with javascript

function doOnOrientationChange()

window.addEventListener('orientationchange', doOnOrientationChange);

Git reset single file in feature branch to be the same as in master

you are almost there; you just need to give the reference to master; since you want to get the file from the master branch:

git checkout master -- filename

Note that the differences will be cached; so if you want to see the differences you obtained; use

git diff --cached

How do I get the name of the active user via the command line in OS X?

as 'whoami' has been obsoleted, it's probably more forward compatible to use:

id -un

App.Config file in console application C#

use this


Subtract two variables in Bash

For simple integer arithmetic, you can also use the builtin let command.

 let "THREE = $ONE + $TWO"
 echo $THREE

For more info on let, look here.

Is there any way I can define a variable in LaTeX?

add the following to you preamble:

\newcommand{\newCommandName}{text to insert}

Then you can just use \newCommandName{} in the text

For more info on \newcommand, see e.g. wikibooks





jQuery counter to count up to a target number

Try jCounter, it has a customRange setting where you can specify the start and end number, it can count up as well including the fallback you want at the end.

Getting the last revision number in SVN?

Looks like there is an entry in the official FAQ for this. The source code is in C but the same principle applies, as outlined here in this mailing list post.

SQL Server - calculate elapsed time between two datetime stamps in HH:MM:SS format

Hope this helps you in getting the exact time between two time stamps

Create PROC TimeDurationbetween2times(@iTime as time,@oTime as time) 

DECLARE @Dh int, @Dm int, @Ds int ,@Im int, @Om int, @Is int,@Os int     


SET @Dh=DATEDIFF(hh,@iTime,@oTime)  
SET @Dm = DATEDIFF(mi,@iTime,@oTime)  
SET @Ds = DATEDIFF(ss,@iTime,@oTime)  

DECLARE @HH as int, @MI as int, @SS as int  

SET @Dh=@Dh-1  
SET @Dm=@Dm-1  

SET @HH = @Dh  
SET @MI = @Dm-(60*@HH)  
SET @SS = @Ds-(60*@Dm)  

DECLARE @hrsWkd as varchar(8)         

SET @hrsWkd = cast(@HH as char(2))+':'+cast(@MI as char(2))+':'+cast(@SS as char(2))          

select @hrsWkd as TimeDuration   


Fine control over the font size in Seaborn plots for academic papers

You are right. This is a badly documented issue. But you can change the font size parameter (by opposition to font scale) directly after building the plot. Check the following example:

import seaborn as sns
tips = sns.load_dataset("tips")

b = sns.boxplot(x=tips["total_bill"])
b.set_xlabel("X Label",fontsize=30)
b.set_ylabel("Y Label",fontsize=20)

, which results in this:

Different font sizes for different labels

To make it consistent in between plots I think you just need to make sure the DPI is the same. By the way it' also a possibility to customize a bit the rc dictionaries since "font.size" parameter exists but I'm not too sure how to do that.

NOTE: And also I don't really understand why they changed the name of the font size variables for axis labels and ticks. Seems a bit un-intuitive.

Delete duplicate records from a SQL table without a primary key

           ADD UNIQUE INDEX 'test' ('b'); 

@ here 'b' is column name to uniqueness, @ here 'test' is index name.

How to make several plots on a single page using matplotlib?

This works also:

for i in range(19):

It plots 19 total graphs on one page. The format is 5 down and 4 across..

jQuery.getJSON - Access-Control-Allow-Origin Issue

You may well want to use JSON-P instead (see below). First a quick explanation.

The header you've mentioned is from the Cross Origin Resource Sharing standard. Beware that it is not supported by some browsers people actually use, and on other browsers (Microsoft's, sigh) it requires using a special object (XDomainRequest) rather than the standard XMLHttpRequest that jQuery uses. It also requires that you change server-side resources to explicitly allow the other origin (

To get the JSON data you're requesting, you basically have three options:

  1. If possible, you can be maximally-compatible by correcting the location of the files you're loading so they have the same origin as the document you're loading them into. (I assume you must be loading them via Ajax, hence the Same Origin Policy issue showing up.)

  2. Use JSON-P, which isn't subject to the SOP. jQuery has built-in support for it in its ajax call (just set dataType to "jsonp" and jQuery will do all the client-side work). This requires server side changes, but not very big ones; basically whatever you have that's generating the JSON response just looks for a query string parameter called "callback" and wraps the JSON in JavaScript code that would call that function. E.g., if your current JSON response is:

    {"weather": "Dreary start but soon brightening into a fine summer day."}

    Your script would look for the "callback" query string parameter (let's say that the parameter's value is "jsop123") and wraps that JSON in the syntax for a JavaScript function call:

    jsonp123({"weather": "Dreary start but soon brightening into a fine summer day."});

    That's it. JSON-P is very broadly compatible (because it works via JavaScript script tags). JSON-P is only for GET, though, not POST (again because it works via script tags).

  3. Use CORS (the mechanism related to the header you quoted). Details in the specification linked above, but basically:

    A. The browser will send your server a "preflight" message using the OPTIONS HTTP verb (method). It will contain the various headers it would send with the GET or POST as well as the headers "Origin", "Access-Control-Request-Method" (e.g., GET or POST), and "Access-Control-Request-Headers" (the headers it wants to send).

    B. Your PHP decides, based on that information, whether the request is okay and if so responds with the "Access-Control-Allow-Origin", "Access-Control-Allow-Methods", and "Access-Control-Allow-Headers" headers with the values it will allow. You don't send any body (page) with that response.

    C. The browser will look at your response and see whether it's allowed to send you the actual GET or POST. If so, it will send that request, again with the "Origin" and various "Access-Control-Request-xyz" headers.

    D. Your PHP examines those headers again to make sure they're still okay, and if so responds to the request.

    In pseudo-code (I haven't done much PHP, so I'm not trying to do PHP syntax here):

    // Find out what the request is asking for
    corsOrigin = get_request_header("Origin")
    corsMethod = get_request_header("Access-Control-Request-Method")
    corsHeaders = get_request_header("Access-Control-Request-Headers")
    if corsOrigin is null or "null" {
        // Requests from a `file://` path seem to come through without an
        // origin or with "null" (literally) as the origin.
        // In my case, for testing, I wanted to allow those and so I output
        // "*", but you may want to go another way.
        corsOrigin = "*"
    // Decide whether to accept that request with those headers
    // If so:
    // Respond with headers saying what's allowed (here we're just echoing what they
    // asked for, except we may be using "*" [all] instead of the actual origin for
    // the "Access-Control-Allow-Origin" one)
    set_response_header("Access-Control-Allow-Origin", corsOrigin)
    set_response_header("Access-Control-Allow-Methods", corsMethod)
    set_response_header("Access-Control-Allow-Headers", corsHeaders)
    if the HTTP request method is "OPTIONS" {
        // Done, no body in response to OPTIONS
    // Process the GET or POST here; output the body of the response

    Again stressing that this is pseudo-code.

iOS 7: UITableView shows under status bar

For those like me who would rather not embed their UITableViewController in a UIViewController try this:

A custom UITableViewController subclass can append a mask view to the tableView's superview. Add the mask on viewDidAppear, and remove the mask on viewWillDisappear.

private var statusBarMaskView: UIView!

override func viewDidAppear(_ animated: Bool) {

    if let superview = self.tableView.superview {
        self.statusBarMaskView = UIView(frame:
        superview.insertSubview(self.statusBarMaskView, aboveSubview: self.tableView)
        self.statusBarMaskView.backgroundColor = self.tableView.backgroundColor

        // using a nice constraint layout library to set the frame
        self.statusBarMaskView.pinTop(to: superview)
        self.statusBarMaskView.pinLeft(to: superview)
        self.statusBarMaskView.pinRight(to: superview)
        self.statusBarMaskView.addHeightConstraint(with: 22.0)

override func viewWillDisappear(_ animated: Bool) {

    self.statusBarMaskView = nil

Bootstrap Datepicker - Months and Years Only

For the latest bootstrap-datepicker (1.4.0 at the time of writing), you need to use this:

    format: "mm/yyyy",
    startView: "year", 
    minViewMode: "months"

Source: Bootstrap Datepicker Options

How to call an async method from a getter or setter?

In .NET Core/NetStandard2, you can use Nito.AsyncEx.AsyncContext.Run instead of System.Windows.Threading.Dispatcher.InvokeAsync:

class AsyncPropertyTest

    private static async System.Threading.Tasks.Task<int> GetInt(string text)
        await System.Threading.Tasks.Task.Delay(2000);
        return int.Parse(text);

    public static int MyProperty
            int x = 0;

            Nito.AsyncEx.AsyncContext.Run(async delegate ()
                x = await GetInt("123");

            return x;

    public static void Test()
        System.Console.WriteLine(System.DateTime.Now.ToString("dd.MM.yyyy HH:mm:ss.fff"));
        System.Console.WriteLine(System.DateTime.Now.ToString("dd.MM.yyyy HH:mm:ss.fff"));


If you simply chose System.Threading.Tasks.Task.Run or System.Threading.Tasks.Task<int>.Run, then it wouldn't work.

continuing execution after an exception is thrown in java

If you have a method that you want to throw an error but you want to do some cleanup in your method beforehand you can put the code that will throw the exception inside a try block, then put the cleanup in the catch block, then throw the error.

try {

    //Dangerous code: could throw an error

} catch (Exception e) {

    //Cleanup: make sure that this methods variables and such are in the desired state

    throw e;

This way the try/catch block is not actually handling the error but it gives you time to do stuff before the method terminates and still ensures that the error is passed on to the caller.

An example of this would be if a variable changed in the method then that variable was the cause of an error. It may be desirable to revert the variable.

jQuery animate scroll

I just use:

$('body').animate({ 'scrollTop': '-=-'+<yourValueScroll>+'px' }, 2000);

Java Runtime.getRuntime(): getting output from executing a command line program

Adapted from the previous answer:

public static String execCmdSync(String cmd, CmdExecResult callback) throws, InterruptedException {
    RLog.i(TAG, "Running command:", cmd);

    Runtime rt = Runtime.getRuntime();
    Process proc = rt.exec(cmd);

    //String[] commands = {"system.exe", "-get t"};

    BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));
    BufferedReader stdError = new BufferedReader(new InputStreamReader(proc.getErrorStream()));

    StringBuffer stdOut = new StringBuffer();
    StringBuffer errOut = new StringBuffer();

    // Read the output from the command:
    System.out.println("Here is the standard output of the command:\n");
    String s = null;
    while ((s = stdInput.readLine()) != null) {

    // Read any errors from the attempted command:
    System.out.println("Here is the standard error of the command (if any):\n");
    while ((s = stdError.readLine()) != null) {

    if (callback == null) {
        return stdInput.toString();

    int exitVal = proc.waitFor();
    callback.onComplete(exitVal == 0, exitVal, errOut.toString(), stdOut.toString(), cmd);

    return stdInput.toString();

public interface CmdExecResult{
    void onComplete(boolean success, int exitVal, String error, String output, String originalCmd);

PermissionError: [WinError 5] Access is denied python using moviepy to write gif

I got the same error when an imported library was trying to create a directory at path "./logs/".

It turns out that the library was trying to create it at the wrong location, i.e. inside the folder of my python interpreter instead of the base project directory. I solved the issue by setting the "Working directory" path to my project folder inside the "Run Configurations" menu of PyCharm. If instead you're using the terminal to run your code, maybe you just need to move inside the project folder before running it.

Java: how to import a jar file from command line


java -cp "your_jar.jar:lib/referenced_jar.jar" com.your.main.Main

If you are on windows, you should use ; instead of :

Java reverse an int value without using array

Java solution without the loop. Faster response.

int numberToReverse;//your number 
StringBuilder sb=new StringBuilder();
String intermediateString=sb.toString();
int reversedNumber=Integer.parseInt(intermediateString);

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

The first regex will match one whitespace character. The second regex will reluctantly match one or more whitespace characters. For most purposes, these two regexes are very similar, except in the second case, the regex can match more of the string, if it prevents the regex match from failing.  from

Multiple inputs on one line

Yes, you can.


Because these functions are operator overloading functions, the usual way in which they are called is:

   strm >> variable;

Where strm is the identifier of a istream object and variable is an object of any type supported as right parameter. It is also possible to call a succession of extraction operations as:

   strm >> variable1 >> variable2 >> variable3; //...

which is the same as performing successive extractions from the same object strm.

Just replace strm with cin.

How do you find out the type of an object (in Swift)?

Old question, but this works for my need (Swift 5.x):

print(type(of: myObjectName))

Set the location in iPhone Simulator

Open iOS Simulator application from Debug Menu -> Location ->

  1. None
  2. Custom Location
  3. Apple Stores ...

Getting the text from a drop-down box


Should work

Xcode 9 error: "iPhone has denied the launch request"

I had this issue and I'm running on xCode 10.2.1, I'm not sure what is causing it but the first thing you should try to do is do a hard reset of the device you are trying to build to. That fixed it for me just fine. I bet these other answers have merit but any of the answers that tell you to edit the scheme WILL NOT FIX IT but just mask the issue until you need to debug. Try my fix first and see if it works and if it doesn't look at another one. This doesn't seem to be caused by just a single issue.

Bash function to find newest file matching pattern

There is a much more efficient way of achieving this. Consider the following command:

find . -cmin 1 -name "b2*"

This command finds the latest file produced exactly one minute ago with the wildcard search on "b2*". If you want files from the last two days then you'll be better off using the command below:

find . -mtime 2 -name "b2*"

The "." represents the current directory. Hope this helps.

Is there a simple way to increment a datetime object one month in Python?

>>> now
datetime.datetime(2016, 1, 28, 18, 26, 12, 980861)
>>> later = now.replace(month=now.month+1)
>>> later
datetime.datetime(2016, 2, 28, 18, 26, 12, 980861)

EDIT: Fails on

y =, 1, 31); y.replace(month=2) results in ValueError: day is out of range for month

Ther is no simple way to do it, but you can use your own function like answered below.

How do I set a cookie on HttpClient's HttpRequestMessage

Here's how you could set a custom cookie value for the request:

var baseAddress = new Uri("");
var cookieContainer = new CookieContainer();
using (var handler = new HttpClientHandler() { CookieContainer = cookieContainer })
using (var client = new HttpClient(handler) { BaseAddress = baseAddress })
    var content = new FormUrlEncodedContent(new[]
        new KeyValuePair<string, string>("foo", "bar"),
        new KeyValuePair<string, string>("baz", "bazinga"),
    cookieContainer.Add(baseAddress, new Cookie("CookieName", "cookie_value"));
    var result = await client.PostAsync("/test", content);

Split string into array

ES6 is quite powerful in iterating through objects (strings, Array, Map, Set). Let's use a Spread Operator to solve this.

entry = prompt("Enter your name");
var count = [...entry];

How to handle button clicks using the XML onClick within Fragments

Adding to Blundell's answer,
If you have more fragments, with plenty of onClicks:


Fragment someFragment1 = (Fragment)getFragmentManager().findFragmentByTag("someFragment1 "); 
Fragment someFragment2 = (Fragment)getFragmentManager().findFragmentByTag("someFragment2 "); 
Fragment someFragment3 = (Fragment)getFragmentManager().findFragmentByTag("someFragment3 "); 

...onCreate etc instantiating your fragments

public void myClickMethod(View v){
  if (someFragment1.isVisible()) {
  }else if(someFragment2.isVisible()){
  }else if(someFragment3.isVisible()){


In Your Fragment:

  public void myClickMethod(View v){
       // Just like you were doing

How to install JDK 11 under Ubuntu?

sudo apt-get install openjdk-11-jdk

after this, try

java -version

to make sure java version is 1.11.x, if found old one or different, check below command to see the available jdks,

sudo update-java-alternatives --list

you should see something like below,

java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64

java-1.8.0-openjdk-amd64 1081 /usr/lib/jvm/java-1.8.0-openjdk-amd64

you can see java 1.11 available from above list, use below command to set java 11 to default,

sudo update-alternatives --config java

for above command, you will get something like below and also, will ask for an option to set,

There are 3 choices for the alternative java (providing /usr/bin/java).

Selection Path Priority Status

0 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto mode

1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode

*2 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1081 manual mode

3 /usr/lib/jvm/jdk1.8.0_211/bin/java 0 manual mode

Press to keep the current choice[*], or type selection number:

you can select desired selection number, my case it's 0

for javac,

sudo update-alternatives --config javac

will result something like below,

There are 3 choices for the alternative javac (providing /usr/bin/javac).

Selection Path Priority Status

0 /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 auto mode

1 /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 manual mode

*2 /usr/lib/jvm/java-8-openjdk-amd64/bin/javac 1081 manual mode
3 /usr/lib/jvm/jdk1.8.0_211/bin/javac 0 manual mode

Press to keep the current choice[*], or type selection number:

in my case, it's 0 again

after above steps, try

java -version

it will display something like below,

openjdk version "11.0.4" 2019-07-16

OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3)

OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed > mode, sharing)

How to iterate over array of objects in Handlebars?

Using this and {{this}}. See code below in node.js:

var Handlebars= require("handlebars");
var randomList= ["James Bond", "Dr. No", "Octopussy", "Goldeneye"];
var source= "<ul>{{#each this}}<li>{{this}}</li>{{/each}}</ul>";
var template= Handlebars.compile(source);

Console log output:

<ul><li>James Bond</li><li>Dr. No</li><li>Octopussy</li><li>Goldeneye</li></ul>

Accidentally committed .idea directory files into git

Add .idea directory to the list of ignored files

First, add it to .gitignore, so it is not accidentally committed by you (or someone else) again:


Remove it from repository

Second, remove the directory only from the repository, but do not delete it locally. To achieve that, do what is listed here:

Remove a file from a Git repository without deleting it from the local filesystem

Send the change to others

Third, commit the .gitignore file and the removal of .idea from the repository. After that push it to the remote(s).


The full process would look like this:

$ echo '.idea' >> .gitignore
$ git rm -r --cached .idea
$ git add .gitignore
$ git commit -m '(some message stating you added .idea to ignored entries)'
$ git push

(optionally you can replace last line with git push some_remote, where some_remote is the name of the remote you want to push to)

Python 3 Float Decimal Points/Precision

The comments state the objective is to print to 2 decimal places.

There's a simple answer for Python 3:

>>> num=3.65
>>> "The number is {:.2f}".format(num)
'The number is 3.65'

or equivalently with f-strings (Python 3.6+):

>>> num = 3.65
>>> f"The number is {num:.2f}"
'The number is 3.65'

As always, the float value is an approximation:

>>> "{}".format(num)
>>> "{:.10f}".format(num)
>>> "{:.20f}".format(num)

I think most use cases will want to work with floats and then only print to a specific precision.

Those that want the numbers themselves to be stored to exactly 2 decimal digits of precision, I suggest use the decimal type. More reading on floating point precision for those that are interested.

Any way to declare an array in-line?

m(new String[]{"blah", "hey", "yo"});

Git push rejected after feature branch rebase

The following works for me:

git push -f origin branch_name

and it does not remove any of my code.

But, if you want to avoid this then you can do the following:

git checkout master
git pull --rebase
git checkout -b new_branch_name

then you can cherry-pick all your commits to the new branch. git cherry-pick COMMIT ID and then push your new branch.

Keep only date part when using pandas.to_datetime

Pandas v0.13+: Use to_csv with date_format parameter

Avoid, where possible, converting your datetime64[ns] series to an object dtype series of objects. The latter, often constructed using, is stored as an array of pointers and is inefficient relative to a pure NumPy-based series.

Since your concern is format when writing to CSV, just use the date_format parameter of to_csv. For example:

df.to_csv(filename, date_format='%Y-%m-%d')

See Python's strftime directives for formatting conventions.