Programs & Examples On #Alien

jQuery - Sticky header that shrinks when scrolling down

Here a CSS animation fork of jezzipin's Solution, to seperate code from styling.


$(window).on("scroll touchmove", function () {
  $('#header_nav').toggleClass('tiny', $(document).scrollTop() > 0);


.header {
  background: #26b;
  color: #fff;
  transition: height 500ms, background 500ms;
.header.tiny {
  background: #aaa;

On scroll/touchmove the css class "tiny" is set to "#header_nav" if "$(document).scrollTop()" is greater than 0.

CSS transition attribute animates the "height" and "background" attribute nicely.

Does Arduino use C or C++?

Both are supported. To quote the Arduino homepage,

The core libraries are written in C and C++ and compiled using avr-gcc

Note that C++ is a superset of C (well, almost), and thus can often look very similar. I am not an expert, but I guess that most of what you will program for the Arduino in your first year on that platform will not need anything but plain C.

Adjust UILabel height depending on the text

This method will work for both iOS 6 and 7

- (float)heightForLabelSize:(CGSize)maximumLabelSize  Font:(UIFont *)font String:(NSString*)string {

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {
    NSDictionary *stringAttributes = [NSDictionary dictionaryWithObject:font forKey: NSFontAttributeName];

    CGSize adjustedLabelSize = [string maximumLabelSize
                                                               attributes:stringAttributes context:nil].size;
    return adjustedLabelSize.height;
else {
    CGSize adjustedLabelSize = [string sizeWithFont:font constrainedToSize:maximumLabelSize lineBreakMode:NSLineBreakByWordWrapping];

    return adjustedLabelSize.height;


What is the correct way to do a CSS Wrapper?

The best way to do it depends on your specific use-case.

However, if we speak for the general best practices for implementing a CSS Wrapper, here is my proposal: introduce an additional <div> element with the following class:

 * 1. Center the content. Yes, that's a bit opinionated.
 * 2. Use `max-width` instead `width`
 * 3. Add padding on the sides.
.wrapper {
    margin-right: auto; /* 1 */
    margin-left:  auto; /* 1 */

    max-width: 960px; /* 2 */

    padding-right: 10px; /* 3 */
    padding-left:  10px; /* 3 */

... for those of you, who want to understand why, here are the 4 big reasons I see:

1. Use max-width instead width

In the answer currently accepted Aron says width. I disagree and I propose max-width instead.

Setting the width of a block-level element will prevent it from stretching out to the edges of its container. Therefore, the Wrapper element will take up the specified width. The problem occurs when the browser window is smaller than the width of the element. The browser then adds a horizontal scrollbar to the page.

Using max-width instead, in this situation, will improve the browser's handling of small windows. This is important when making a site usable on small devices. Here’s a good example showcasing the problem:

 * The problem with this one occurs_x000D_
 * when the browser window is smaller than 960px._x000D_
 * The browser then adds a horizontal scrollbar to the page._x000D_
.width {_x000D_
    width: 960px;_x000D_
    margin-left: auto;_x000D_
    margin-right: auto;_x000D_
    border: 3px solid #73AD21;_x000D_
 * Using max-width instead, in this situation,_x000D_
 * will improve the browser's handling of small windows._x000D_
 * This is important when making a site usable on small devices._x000D_
.max-width {_x000D_
    max-width: 960px;_x000D_
    margin-left: auto;_x000D_
    margin-right: auto;_x000D_
    border: 3px solid #73AD21;_x000D_
 * Credits for the tip: W3Schools_x000D_
<div class="width">This div element has width: 960px;</div>_x000D_
<br />_x000D_
<div class="max-width">This div element has max-width: 960px;</div>

So in terms of Responsiveness, is seems like max-width is the better choice!-

2. Add Padding on the Sides

I’ve seen a lot of developers still forget one edge case. Let’s say we have a Wrapper with max-width set to 980px. The edge case appears when the user’s device screen width is exactly 980px. The content then will exactly glue to the edges of the screen with not any breathing space left.

Generally, we’d want to have a bit of padding on the sides. That’s why if I need to implement a Wrapper with a total width of 980px, I’d do it like so:

.wrapper {
   max-width: 960px; /** 20px smaller, to fit the paddings on the sides */

   padding-right: 10px;
   padding-left:  10px;

   /** ... omitted for brevity */

Therefore, that’s why adding padding-left and padding-right to your Wrapper might be a good idea, especially on mobile.

3. Use a <div> Instead of a <section>

By definition, the Wrapper has no semantic meaning. It simply holds all visual elements and content on the page. It’s just a generic container. Therefore, in terms of semantics, <div> is the best choice.

One might wonder if maybe a <section> element could fit this purpose. However, here’s what the W3C spec says:

The element is not a generic container element. When an element is needed only for styling purposes or as a convenience for scripting, authors are encouraged to use the div element instead. A general rule is that the section element is appropriate only if the element's contents would be listed explicitly in the document's outline.

The <section> element carries it’s own semantics. It represents a thematic grouping of content. The theme of each section should be identified, typically by including a heading (h1-h6 element) as a child of the section element.

Examples of sections would be chapters, the various tabbed pages in a tabbed dialog box, or the numbered sections of a thesis. A Web site's home page could be split into sections for an introduction, news items, and contact information.

It might not seem very obvious at first sight, but yes! The plain old <div> fits best for a Wrapper!

4. Using the <body> Tag vs. Using an Additional <div>

Here's a related question. Yes, there are some instances where you could simply use the <body> element as a wrapper. However, I wouldn’t recommend you to do so, simply due to flexibility and resilience to changes.

Here's an use-case that illustrates a possible issue: Imagine if on a later stage of the project you need to enforce a footer to "stick" to the end of the document (bottom of the viewport when the document is short). Even if you can use the most modern way to do it - with Flexbox, I guess you need an additional Wrapper <div>.

I would conclude it is still best practice to have an additional <div> for implementing a CSS Wrapper. This way if spec requirements change later on you don't have to add the Wrapper later and deal with moving the styles around a lot. After all, we're only talking about 1 extra DOM element.

PHP function overloading

What about this:

function($arg = NULL) {

    if ($arg != NULL) {

Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference

To state the obvious, the cup represents outerScopeVar.

Asynchronous functions be like...

asynchronous call for coffee

Lua String replace


name = "^aH^ai"
name = name:gsub("%^a", "")

See also:

Parameterize an SQL IN clause

I'd approach this by default with passing a table valued function (that returns a table from a string) to the IN condition.

Here is the code for the UDF (I got it from Stack Overflow somewhere, i can't find the source right now)

CREATE FUNCTION [dbo].[Split] (@sep char(1), @s varchar(8000))
    WITH Pieces(pn, start, stop) AS (
      SELECT 1, 1, CHARINDEX(@sep, @s)
      SELECT pn + 1, stop + 1, CHARINDEX(@sep, @s, stop + 1)
      FROM Pieces
      WHERE stop > 0
      SUBSTRING(@s, start, CASE WHEN stop > 0 THEN stop-start ELSE 512 END) AS s
    FROM Pieces

Once you got this your code would be as simple as this:

select * from Tags 
where Name in (select s from dbo.split(';','ruby;rails;scruffy;rubyonrails'))
order by Count desc

Unless you have a ridiculously long string, this should work well with the table index.

If needed you can insert it into a temp table, index it, then run a join...

Quickly getting to YYYY-mm-dd HH:MM:SS in Perl

Why not use the DateTime module to do the dirty work for you? It's easy to write and remember!

use strict;
use warnings;
use DateTime;

my $dt   = DateTime->now;   # Stores current date and time as datetime object
my $date = $dt->ymd;   # Retrieves date as a string in 'yyyy-mm-dd' format
my $time = $dt->hms;   # Retrieves time as a string in 'hh:mm:ss' format

my $wanted = "$date $time";   # creates 'yyyy-mm-dd hh:mm:ss' string
print $wanted;

Once you know what's going on, you can get rid of the temps and save a few lines of code:

use strict;
use warnings;
use DateTime;

my $dt = DateTime->now;
print join ' ', $dt->ymd, $dt->hms;

Check string length in PHP

An XPath solution is to use:


where $k should be substituted by a number.

This evaluates to the string length of the $k-th (in document order) div in the XML document that has a class attribute with value 'contest'.

jQuery Call to WebService returns "No Transport" error

i solve it by using dataType='jsonp' at the place of dataType='json'

How can I store and retrieve images from a MySQL database using PHP?

Instead of storing images in database store them in a folder in your disk and store their location in your data base.

Swing vs JavaFx for desktop applications

I'd look around to find some (3rd party?) components that do what you want. I've had to create custom Swing components for an agenda view where you can book multiple resources, as well as an Excel-like grid that works well with keyboard navigation and so on. I had a terrible time getting them to work nicely because I needed to delve into many of Swing's many intricacies whenever I came upon a problem. Mouse and focus behaviour and a lot of other things can be very difficult to get right, especially for a casual Swing user. I would hope that JavaFX is a bit more future-orientated and smooth out of the box.

Obtain smallest value from array in Javascript?

var array =[2,3,1,9,8];
var minvalue = array[0]; 
for (var i = 0; i < array.length; i++) {
        minvalue = array[i];


How to use Fiddler to monitor WCF service

I just tried the first answer from Brad Rem and came to this setting in the web.config under BasicHttpBinding:

        <binding bypassProxyOnLocal="False" useDefaultWebProxy="false" proxyAddress="" ...

Hope this helps someone.

Two Divs next to each other, that then stack with responsive change

You can use CSS3 media query for this. Write like this:


.wrapper { 
  border : 2px solid #000; 

.wrapper div {
   min-height: 200px;
   padding: 10px;
#one {
  background-color: gray;
  border-right:2px solid #000;
#two { 
  background-color: white;
  border:2px dashed #ccc;

@media screen and (max-width: 400px) {
   #one { 
    float: none;
    border-bottom:2px solid #000;    


<div class="wrapper">
    <div id="one">one</div>
    <div id="two">two</div>

Check this for more

Ternary operator in AngularJS templates

Update: Angular 1.1.5 added a ternary operator, so now we can simply write

<li ng-class="$first ? 'firstRow' : 'nonFirstRow'">

If you are using an earlier version of Angular, your two choices are:

  1. (condition && result_if_true || !condition && result_if_false)
  2. {true: 'result_if_true', false: 'result_if_false'}[condition]

item 2. above creates an object with two properties. The array syntax is used to select either the property with name true or the property with name false, and return the associated value.


<li class="{{{true: 'myClass1 myClass2', false: ''}[$first]}}">...</li>
<li ng-class="{true: 'myClass1 myClass2', false: ''}[$first]">...</li>

$first is set to true inside an ng-repeat for the first element, so the above would apply class 'myClass1' and 'myClass2' only the first time through the loop.

With ng-class there is an easier way though: ng-class takes an expression that must evaluate to one of the following:

  1. a string of space-delimited class names
  2. an array of class names
  3. a map/object of class names to boolean values.

An example of 1) was given above. Here is an example of 3, which I think reads much better:

 <li ng-class="{myClass: $first, anotherClass: $index == 2}">...</li>

The first time through an ng-repeat loop, class myClass is added. The 3rd time through ($index starts at 0), class anotherClass is added.

ng-style takes an expression that must evaluate to a map/object of CSS style names to CSS values. E.g.,

 <li ng-style="{true: {color: 'red'}, false: {}}[$first]">...</li>

Uncaught ReferenceError: function is not defined with onclick

I was receiving the error (I'm using Vue) and I switched my onclick="someFunction()" to @click="someFunction" and now they are working.

Stream file using ASP.NET MVC FileContentResult in a browser with a name?

Actually, the absolutely easiest way is to do the following...

byte[] content = your_byte[];

FileContentResult result = new FileContentResult(content, "application/octet-stream") 
  FileDownloadName = "your_file_name"

return result;

Determining if Swift dictionary contains key and obtaining any of its values

Here is what works for me on Swift 3

let _ = (dict[key].map { $0 as? String } ?? "")

Execute action when back bar button of UINavigationController is pressed

I was able to achieve this with the following :

Swift 3

override func didMoveToParentViewController(parent: UIViewController?) {

   if parent == nil {
      println("Back Button pressed.")

Swift 4

override func didMove(toParent parent: UIViewController?) {
    super.didMove(toParent: parent)

    if parent == nil {
        debugPrint("Back Button pressed.")

No need of custom back button.

How to install CocoaPods?

Pod Installation giving error on OS X El Capitan 10.11.2

ERROR: Error installing cocoapods: activesupport requires Ruby version >= 2.2.2.

enter image description here

After getting this error tried this command and install again its work for me.

sudo gem install activesupport -v 4.2.6

Now try same pod installation command

sudo gem install -n /usr/local/bin cocoapods

Hope it'll help to all of us.

What is the single most influential book every programmer should read?

Peter Norton's Assembly Language Book for the IBM PC

alt text

I had spent countless nights in front of the pc (DOS), exploring unknown worlds :-D

MySQL vs MySQLi when using PHP

I have abandoned using mysqli. It is simply too unstable. I've had queries that crash PHP using mysqli but work just fine with the mysql package. Also mysqli crashes on LONGTEXT columns. This bug has been raised in various forms since at least 2005 and remains broken. I'd honestly like to use prepared statements but mysqli just isn't reliable enough (and noone seems to bother fixing it). If you really want prepared statements go with PDO.

Count number of columns in a table row

<table id="table1">
  <td colspan=4><input type="text" value="" /></td>

  <td><input type="text" value="" /></td>
  <td><input type="text" value="" /></td>
  <td><input type="text" value="" /></td>
  <td><input type="text" value="" /></td>

    var row=document.getElementById('table1').rows.length;
    console.log('Row '+parseFloat(i+1)+' : '+document.getElementById('table1').rows[i].cells.length +' column');


Row 1 : 1 column
Row 2 : 4 column

When & why to use delegates?

Say you want to write a procedure to integrate some real-valued function f (x) over some interval [a, b]. Say we want to use the 3-Point Gaussian method to do this (any will do, of course).

Ideally we want some function that looks like:

// 'f' is the integrand we want to integrate over [a, b] with 'n' subintervals.
static double Gauss3(Integrand f, double a, double b, int n) {
  double res = 0;

  // compute result
  // ...

  return res;

So we can pass in any Integrand, f, and get its definite integral over the closed interval.

Just what type should Integrand be?

Without Delegates

Well, without delegates, we'd need some sort of interface with a single method, say eval declared as follows:

// Interface describing real-valued functions of one variable.
interface Integrand {
  double eval(double x);

Then we'd need to create a whole bunch of classes implementing this interface, as follows:

// Some function
class MyFunc1 : Integrand {
  public double eval(double x) {
    return /* some_result */ ;

// Some other function
class MyFunc2 : Integrand {
  public double eval(double x) {
    return /* some_result */ ;

// etc

Then to use them in our Gauss3 method, we need to invoke it as follows:

double res1 = Gauss3(new MyFunc1(), -1, 1, 16);
double res2 = Gauss3(new MyFunc2(), 0, Math.PI, 16);

And Gauss3 needs to do the look like the following:

static double Gauss3(Integrand f, double a, double b, int n) {
  // Use the integrand passed in:

So we need to do all that just to use our arbitrary functions in Guass3.

With Delegates

public delegate double Integrand(double x);

Now we can define some static (or not) functions adhering to that prototype:

class Program {
   public delegate double Integrand(double x);   
   // Define implementations to above delegate 
   // with similar input and output types
   static double MyFunc1(double x) { /* ... */ }
   static double MyFunc2(double x) { /* ... */ }
   // ... etc ...

   public static double Gauss3(Integrand f, ...) { 
      // Now just call the function naturally, no f.eval() stuff.
      double a = f(x); 
      // ...

   // Let's use it
   static void Main() {
     // Just pass the function in naturally (well, its reference).
     double res = Gauss3(MyFunc1, a, b, n);
     double res = Gauss3(MyFunc2, a, b, n);    

No interfaces, no clunky .eval stuff, no object instantiation, just simple function-pointer like usage, for a simple task.

Of course, delegates are more than just function pointers under the hood, but that's a separate issue (function chaining and events).

What is the connection string for localdb for version 11

This is for others who would have struggled like me to get this working....I wasted more than half a day on a seemingly trivial thing...

If you want to use SQL Express 2012 LocalDB from VS2010 you must have this patch installed

Just like mentioned in the comments above I too had Microsoft .NET Framework Version 4.0.30319 SP1Rel and since its mentioned everywhere that you need "Framework 4.0.2 or Above" I thought I am good to go...

However, when I explicitly downloaded that 4.0.2 patch and installed it I got it working....

How to avoid precompiled headers

You can create an empty project by selecting the "Empty Project" from the "General" group of Visual C++ projects (maybe that project template isn't included in Express?).

To fix the problem in the project you already have, open the project properties and navigate to:

Configuration Properties | C/C++ | Precompiled Headers

And choose "Not using Precompiled Headers" for the "Precompiled Header" option.

Append to the end of a file in C

Following the documentation of fopen:

``a'' Open for writing. The file is created if it does not exist. The stream is positioned at the end of the file. Subsequent writes to the file will always end up at the then cur- rent end of file, irrespective of any intervening fseek(3) or similar.

So if you pFile2=fopen("myfile2.txt", "a"); the stream is positioned at the end to append automatically. just do:

FILE *pFile;
FILE *pFile2;
char buffer[256];

pFile=fopen("myfile.txt", "r");
pFile2=fopen("myfile2.txt", "a");
if(pFile==NULL) {
    perror("Error opening file.");
else {
    while(fgets(buffer, sizeof(buffer), pFile)) {
        fprintf(pFile2, "%s", buffer);

how to use the Box-Cox power transformation in R

Box and Cox (1964) suggested a family of transformations designed to reduce nonnormality of the errors in a linear model. In turns out that in doing this, it often reduces non-linearity as well.

Here is a nice summary of the original work and all the work that's been done since:

You will notice, however, that the log-likelihood function governing the selection of the lambda power transform is dependent on the residual sum of squares of an underlying model (no LaTeX on SO -- see the reference), so no transformation can be applied without a model.

A typical application is as follows:


# generate some data
n <- 100
x <- runif(n, 1, 5)
y <- x^3 + rnorm(n)

# run a linear model
m <- lm(y ~ x)

# run the box-cox transformation
bc <- boxcox(y ~ x)

enter image description here

(lambda <- bc$x[which.max(bc$y)])
[1] 0.4242424

powerTransform <- function(y, lambda1, lambda2 = NULL, method = "boxcox") {

  boxcoxTrans <- function(x, lam1, lam2 = NULL) {

    # if we set lambda2 to zero, it becomes the one parameter transformation
    lam2 <- ifelse(is.null(lam2), 0, lam2)

    if (lam1 == 0L) {
      log(y + lam2)
    } else {
      (((y + lam2)^lam1) - 1) / lam1

         , boxcox = boxcoxTrans(y, lambda1, lambda2)
         , tukey = y^lambda1

# re-run with transformation
mnew <- lm(powerTransform(y, lambda) ~ x)

# QQ-plot
op <- par(pty = "s", mfrow = c(1, 2))
qqnorm(m$residuals); qqline(m$residuals)
qqnorm(mnew$residuals); qqline(mnew$residuals)

enter image description here

As you can see this is no magic bullet -- only some data can be effectively transformed (usually a lambda less than -2 or greater than 2 is a sign you should not be using the method). As with any statistical method, use with caution before implementing.

To use the two parameter Box-Cox transformation, use the geoR package to find the lambdas:

bc2 <- boxcoxfit(x, y, lambda2 = TRUE)

lambda1 <- bc2$lambda[1]
lambda2 <- bc2$lambda[2]

EDITS: Conflation of Tukey and Box-Cox implementation as pointed out by @Yui-Shiuan fixed.

How to list all functions in a Python module?

You can use dir(module) to see all available methods/attributes. Also check out PyDocs.

Using ConfigurationManager to load config from an arbitrary location

Try this:

System.Configuration.ConfigurationFileMap fileMap = new ConfigurationFileMap(strConfigPath); //Path to your config file
System.Configuration.Configuration configuration = System.Configuration.ConfigurationManager.OpenMappedMachineConfiguration(fileMap);

MySQL GROUP BY two columns

First, let's make some test data:

create table client (client_id integer not null primary key auto_increment,
                     name varchar(64));
create table portfolio (portfolio_id integer not null primary key auto_increment,
                        client_id integer references,
                        cash decimal(10,2),
                        stocks decimal(10,2));
insert into client (name) values ('John Doe'), ('Jane Doe');
insert into portfolio (client_id, cash, stocks) values (1, 11.11, 22.22),
                                                       (1, 10.11, 23.22),
                                                       (2, 30.30, 40.40),
                                                       (2, 40.40, 50.50);

If you didn't need the portfolio ID, it would be easy:

select client_id, name, max(cash + stocks)
from client join portfolio using (client_id)
group by client_id

| client_id | name     | max(cash + stocks) |
|         1 | John Doe |              33.33 | 
|         2 | Jane Doe |              90.90 | 

Since you need the portfolio ID, things get more complicated. Let's do it in steps. First, we'll write a subquery that returns the maximal portfolio value for each client:

select client_id, max(cash + stocks) as maxtotal
from portfolio
group by client_id

| client_id | maxtotal |
|         1 |    33.33 | 
|         2 |    90.90 | 

Then we'll query the portfolio table, but use a join to the previous subquery in order to keep only those portfolios the total value of which is the maximal for the client:

 select portfolio_id, cash + stocks from portfolio 
 join (select client_id, max(cash + stocks) as maxtotal 
       from portfolio
       group by client_id) as maxima
 using (client_id)
 where cash + stocks = maxtotal

| portfolio_id | cash + stocks |
|            5 |         33.33 | 
|            6 |         33.33 | 
|            8 |         90.90 | 

Finally, we can join to the client table (as you did) in order to include the name of each client:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal

| client_id | name     | portfolio_id | cash + stocks |
|         1 | John Doe |            5 |         33.33 | 
|         1 | John Doe |            6 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 

Note that this returns two rows for John Doe because he has two portfolios with the exact same total value. To avoid this and pick an arbitrary top portfolio, tag on a GROUP BY clause:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal
group by client_id, cash + stocks

| client_id | name     | portfolio_id | cash + stocks |
|         1 | John Doe |            5 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 

send/post xml file using curl command line

If you have multiple headers then you might want to use the following:

curl -X POST --header "Content-Type:application/json" --header "X-Auth:AuthKey" --data @hello.json Your_url

What is the difference between Tomcat, JBoss and Glassfish?

Tomcat is just a servlet container, i.e. it implements only the servlets and JSP specification. Glassfish and JBoss are full Java EE servers (including stuff like EJB, JMS, ...), with Glassfish being the reference implementation of the latest Java EE 6 stack, but JBoss in 2010 was not fully supporting it yet.

How do I set up Vim autoindentation properly for editing Python files?

Ensure you are editing the correct configuration file for VIM. Especially if you are using windows, where the file could be named _vimrc instead of .vimrc as on other platforms.

In vim type

:help vimrc

and check your path to the _vimrc/.vimrc file with

:echo $HOME

:echo $VIM

Make sure you are only using one file. If you want to split your configuration into smaller chunks you can source other files from inside your _vimrc file.

:help source

Change the Textbox height?

All you have to do is enable the multiline in the properties window, put the size you want in that same window and then in your .cs after the InitializeComponent put txtexample.Multiline = false; and so the multiline is not enabled but the size of the txt is as you put it.

txtEmail.Multiline = false;
txtPassword.Multiline = false;

enter image description here

enter image description here

enter image description here

How do I change the language of moment.js?

end 2017 / 2018: the anothers answers have too much old code to edit, so here my alternative clean answer:

with require

let moment = require('moment');
// or if you want to include all locales:

with imports

import moment from 'moment';
import 'moment/locale/fr';
// or if you want to include all locales:


moment().format('D MMM YY');  // Correct, set default global format 
// moment.locale('fr').format('D MMM YY') //Wrong old versions for global default format

with timezone




import 'moment-range';
import 'moment-timezone';

use zones:

const newYork    ="2014-06-01 12:00", "America/New_York");
const losAngeles = newYork.clone().tz("America/Los_Angeles");
const london     = newYork.clone().tz("Europe/London");

function to format date

const ISOtoDate = function (dateString, format='') {

 // if date is not string use conversion:
 // value.toLocaleDateString() +' '+ value.toLocaleTimeString();

  if ( !dateString ) {
    return '';

  if (format ) {
    return moment(dateString).format(format);
  } else  {
    return moment(dateString);  // It will use default global format

How to remove all leading zeroes in a string

Similar to another suggestion, except will not obliterate actual zero:

if (ltrim($str, '0') != '') {
    $str = ltrim($str, '0');
} else {
    $str = '0';

Or as was suggested (as of PHP 5.3), shorthand ternary operator can be used:

$str = ltrim($str, '0') ?: '0'; 

Use jquery click to handle anchor onClick()

Lets take an anchor tag with an onclick event, that calls a Javascript function.

<a href="#" onClick="showDiv(1);">1</a>

Now in javascript write the below code

function showDiv(pageid)

This will show you an alert of "1"....

Can't find bundle for base name

java.util.MissingResourceException: Can't find bundle for base name
    org.jfree.chart.LocalizationBundle, locale en_US

To the point, the exception message tells in detail that you need to have either of the following files in the classpath:






Also see the official Java tutorial about resourcebundles for more information.

But as this is actually a 3rd party managed properties file, you shouldn't create one yourself. It should be already available in the JFreeChart JAR file. So ensure that you have it available in the classpath during runtime. Also ensure that you're using the right version, the location of the propertiesfile inside the package tree might have changed per JFreeChart version.

When executing a JAR file, you can use the -cp argument to specify the classpath. E.g.:

java -jar -cp c:/path/to/jfreechart.jar yourfile.jar

Alternatively you can specify the classpath as class-path entry in the JAR's manifest file. You can use in there relative paths which are relative to the JAR file itself. Do not use the %CLASSPATH% environment variable, it's ignored by JAR's and everything else which aren't executed with java.exe without -cp, -classpath and -jar arguments.

Remove a prefix from a string

regex solution (The best way is the solution by @Elazar this is just for fun)

import re
def remove_prefix(text, prefix):
    return re.sub(r'^{0}'.format(re.escape(prefix)), '', text)

>>> print remove_prefix('template.extensions', 'template.')

How to solve “Microsoft Visual Studio (VS)” error “Unable to connect to the configured development Web server”

I just encountered and resolved this in VS2013 on Windows 7. It is a Web Application Project that doesn't use SSL. But when I examined the Properties Window (F4), SSL was enabled. Setting SSL to false resolved the issue.

However, when verifying before posting this answer, turning it back on did not cause a recurrence of the problem. So it might be that anything that writes to that preferences resolves the problem, rather than the details of what was written.

SQLite Reset Primary Key Field

You can reset by update sequence after deleted rows in your-table


Group a list of objects by an attribute

you can use guava's Multimaps

class Persion {
     String name
     Integer age
List<Persion> list = [
   new Persion("qianzi", 100),
   new Persion("qianzi", 99),
   new Persion("zhijia", 99)
println Multimaps.index(list, { Persion p -> return })

it print:

[qianzi:[com.ctcf.message.Persion(qianzi, 100),com.ctcf.message.Persion(qianzi, 88)],zhijia:[com.ctcf.message.Persion(zhijia, 99)]]

Avoid browser popup blockers

In addition Swiss Mister post, in my case the was launched inside a promise, which turned the popup blocker on, my solution was: in angular:

$scope.gotClick = function(){

  var myNewTab = browserService.openNewTab();
        browserService.updateTabLocation(res.url, myNewTab);



this.openNewTab = function(){
     var newTabWindow = $;
     return newTabWindow;

this.updateTabLocation = function(tabLocation, tab) {
     tab.location.href = tabLocation;

this is how you can open a new tab using the promise response and not invoking the popup blocker.

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

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

sysctl -a

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

fatal: ambiguous argument 'origin': unknown revision or path not in the working tree

If origin points to a bare repository on disk, this error can happen if that directory has been moved (even if you update the working copy's remotes). For example

$ mv /path/to/origin /somewhere/else
$ git remote set-url origin /somewhere/else
$ git diff origin/master
fatal: ambiguous argument 'origin': unknown revision or path not in the working tree.

Pulling once from the new origin solves the problem:

$ git stash
$ git pull origin master
$ git stash pop

java.lang.Exception: No runnable methods exception in running JUnits

In Eclipse, I had to use New > Other > JUnit > Junit Test. A Java class created with the exact same text gave me the error, perhaps because it was using JUnit 3.x.

export html table to csv

You don't need PHP script on server side. Do that in the client side only, in browsers that accept Data URIs:


The Data URI will be something like:


You can call this URI by:

  • using
  • or setting the window.location
  • or by the href of an anchor
  • by adding the download attribute it will work in chrome, still have to test in IE.

To test, simply copy the URIs above and paste in your browser address bar. Or test the anchor below in a HTML page:

<a download="somedata.csv" href="data:application/csv;charset=utf-8,Col1%2CCol2%2CCol3%0AVal1%2CVal2%2CVal3%0AVal11%2CVal22%2CVal33%0AVal111%2CVal222%2CVal333">Example</a>

To create the content, getting the values from the table, you can use table2CSV mentioned by MelanciaUK and do:

var csv = $table.table2CSV({delivery:'value'});
window.location.href = 'data:application/csv;charset=UTF-8,' + encodeURIComponent(csv);

Get value of a string after last slash in JavaScript

light weigh



start = Required. The position where to start the extraction. First character is at index 0`.

end = Optional. The position (up to, but not including) where to end the extraction. If omitted, it extracts the rest of the string.

    var string = "var1/var2/var3";

    start   = string.lastIndexOf('/');  //console.log(start); o/p:- 9
    end     = string.length;            //console.log(end);   o/p:- 14

    var string_before_last_slash = string.substring(0, start);
    console.log(string_before_last_slash);//o/p:- var1/var2

    var string_after_last_slash = string.substring(start+1, end);
    console.log(string_after_last_slash);//o/p:- var3


    var string_after_last_slash = string.substring(start+1);
    console.log(string_after_last_slash);//o/p:- var3

The application has stopped unexpectedly: How to Debug?

If you use the Logcat display inside the 'debug' perspective in Eclipse the lines are colour-coded. It's pretty easy to find what made your app crash because it's usually in red.

The Java (or Dalvik) virtual machine should never crash, but if your program throws an exception and does not catch it the VM will terminate your program, which is the 'crash' you are seeing.

How to view transaction logs in SQL Server 2008

You can't read the transaction log file easily because that's not properly documented. There are basically two ways to do this. Using undocumented or semi-documented database functions or using third-party tools.

Note: This only makes sense if your database is in full recovery mode.

SQL Functions:

DBCC LOG and fn_dblog - more details here and here.

Third-party tools:

Toad for SQL Server and ApexSQL Log.

You can also check out several other topics where this was discussed:

Difference in Months between two dates in JavaScript

Consider each date in terms of months, then subtract to find the difference.

var past_date = new Date('11/1/2014');
var current_date = new Date();

var difference = (current_date.getFullYear()*12 + current_date.getMonth()) - (past_date.getFullYear()*12 + past_date.getMonth());

This will get you the difference of months between the two dates, ignoring the days.

Colouring plot by factor in R

plot(data$Sepal.Length, data$Sepal.Width, col=data$Species)

should do it for you. But I prefer ggplot2 and would suggest that for better graphics in R.

Eclipse error, "The selection cannot be launched, and there are no recent launches"

Follow these steps to run your application on the device connected. 1. Change directories to the root of your Android project and execute: ant debug 2. Make sure the Android SDK platform-tools/ directory is included in your PATH environment variable, then execute: adb install bin/<*your app name*>-debug.apk On your device, locate <*your app name*> and open it.

Refer Running App

Cannot catch toolbar home button click event

I changed the DrawerLayout a bit to get the events and be able to consume and event, such as if you want to use the actionToggle as back if you are in detail view:

public class ListenableDrawerLayout extends DrawerLayout {

    private OnToggleButtonClickedListener mOnToggleButtonClickedListener;
    private boolean mManualCall;

    public ListenableDrawerLayout(Context context) {

    public ListenableDrawerLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

    public ListenableDrawerLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

     * Sets the listener for the toggle button
     * @param mOnToggleButtonClickedListener
    public void setOnToggleButtonClickedListener(OnToggleButtonClickedListener mOnToggleButtonClickedListener) {
        this.mOnToggleButtonClickedListener = mOnToggleButtonClickedListener;

     * Opens the navigation drawer manually from code<br>
     * <b>NOTE: </b>Use this function instead of the normal openDrawer method
     * @param drawerView
    public void openDrawerManual(View drawerView) {
        mManualCall = true;

     * Closes the navigation drawer manually from code<br>
     * <b>NOTE: </b>Use this function instead of the normal closeDrawer method
     * @param drawerView
    public void closeDrawerManual(View drawerView) {
        mManualCall = true;

    public void openDrawer(View drawerView) {

        // Check for listener and for not manual open
        if (!mManualCall && mOnToggleButtonClickedListener != null) {

            // Notify the listener and behave on its reaction
            if (mOnToggleButtonClickedListener.toggleOpenDrawer()) {

        // Manual call done
        mManualCall = false;

        // Let the drawer layout to its stuff

    public void closeDrawer(View drawerView) {

        // Check for listener and for not manual close
        if (!mManualCall && mOnToggleButtonClickedListener != null) {

            // Notify the listener and behave on its reaction
            if (mOnToggleButtonClickedListener.toggleCloseDrawer()) {

        // Manual call done
        mManualCall = false;

        // Let the drawer layout to its stuff

     * Interface for toggle button callbacks
    public static interface OnToggleButtonClickedListener {

         * The ActionBarDrawerToggle has been pressed in order to open the drawer
         * @return true if we want to consume the event, false if we want the normal behaviour
        public boolean toggleOpenDrawer();

         * The ActionBarDrawerToggle has been pressed in order to close the drawer
         * @return true if we want to consume the event, false if we want the normal behaviour
        public boolean toggleCloseDrawer();


How to pass data to all views in Laravel 5?

You have two options:

1. Share via ?Boot function in App\Providers\AppServiceProvider:

public function boot()
  view()->share('key', 'value');

And access $key variable in any view file.

Note: Remember that you can't access current Session, Auth, Route data here. This option is good only if you want to share static data. Suppose you want to share some data based on the current user , route, or any custom session variable you won't be able to do with this.

2. Use of a helper class:

Create a helper class anywhere in your application and register it in Alias array in app.php file in config folder.

 'aliases' => [ 
  'Helper' => App\HelperClass\Helper::class,

and create Helper.php in HelperClass folder within App folder:

namespace App\HelperClass;
class Helper
    public static function Sample()
        //Your Code Here

and access it anywhere like Helper::Sample().

You will not be restricted here to use Auth, Route, Session, or any other classes.

How to access host port from docker container

When running Docker natively on Linux, you can access host services using the IP address of the docker0 interface. From inside the container, this will be your default route.

For example, on my system:

$ ip addr show docker0
7: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
    inet brd scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::f4d2:49ff:fedd:28a0/64 scope link 
       valid_lft forever preferred_lft forever

And inside a container:

# ip route show
default via dev eth0 dev eth0  src 

It's fairly easy to extract this IP address using a simple shell script:


hostip=$(ip route show | awk '/default/ {print $3}')
echo $hostip

You may need to modify the iptables rules on your host to permit connections from Docker containers. Something like this will do the trick:

# iptables -A INPUT -i docker0 -j ACCEPT

This would permit access to any ports on the host from Docker containers. Note that:

  • iptables rules are ordered, and this rule may or may not do the right thing depending on what other rules come before it.

  • you will only be able to access host services that are either (a) listening on INADDR_ANY (aka or that are explicitly listening on the docker0 interface.

If you are using Docker on MacOS or Windows 18.03+, you can connect connect to the magic hostname host.docker.internal.

Lastly, under Linux you can run your container in the host network namespace by setting --net=host; in this case localhost on your host is the same as localhost inside the container, so containerized service will act like non-containerized services and will be accessible without any additional configuration.

Remove the legend on a matplotlib figure

According to the information from @naitsirhc, I wanted to find the official API documentation. Here are my finding and some sample code.

  1. I created a matplotlib.Axes object by seaborn.scatterplot().
  2. The ax.get_legend() will return a matplotlib.legned.Legend instance.
  3. Finally, you call .remove() function to remove the legend from your plot.
ax = sns.scatterplot(......)
_lg = ax.get_legend()

If you check the matplotlib.legned.Legend API document, you won't see the .remove() function.

The reason is that the matplotlib.legned.Legend inherited the matplotlib.artist.Artist. Therefore, when you call ax.get_legend().remove() that basically call matplotlib.artist.Artist.remove().

In the end, you could even simplify the code into two lines.

ax = sns.scatterplot(......)

Combining two expressions (Expression<Func<T, bool>>)

Well, you can use Expression.AndAlso / OrElse etc to combine logical expressions, but the problem is the parameters; are you working with the same ParameterExpression in expr1 and expr2? If so, it is easier:

var body = Expression.AndAlso(expr1.Body, expr2.Body);
var lambda = Expression.Lambda<Func<T,bool>>(body, expr1.Parameters[0]);

This also works well to negate a single operation:

static Expression<Func<T, bool>> Not<T>(
    this Expression<Func<T, bool>> expr)
    return Expression.Lambda<Func<T, bool>>(
        Expression.Not(expr.Body), expr.Parameters[0]);

Otherwise, depending on the LINQ provider, you might be able to combine them with Invoke:

// OrElse is very similar...
static Expression<Func<T, bool>> AndAlso<T>(
    this Expression<Func<T, bool>> left,
    Expression<Func<T, bool>> right)
    var param = Expression.Parameter(typeof(T), "x");
    var body = Expression.AndAlso(
            Expression.Invoke(left, param),
            Expression.Invoke(right, param)
    var lambda = Expression.Lambda<Func<T, bool>>(body, param);
    return lambda;

Somewhere, I have got some code that re-writes an expression-tree replacing nodes to remove the need for Invoke, but it is quite lengthy (and I can't remember where I left it...)

Generalized version that picks the simplest route:

static Expression<Func<T, bool>> AndAlso<T>(
    this Expression<Func<T, bool>> expr1,
    Expression<Func<T, bool>> expr2)
    // need to detect whether they use the same
    // parameter instance; if not, they need fixing
    ParameterExpression param = expr1.Parameters[0];
    if (ReferenceEquals(param, expr2.Parameters[0]))
        // simple version
        return Expression.Lambda<Func<T, bool>>(
            Expression.AndAlso(expr1.Body, expr2.Body), param);
    // otherwise, keep expr1 "as is" and invoke expr2
    return Expression.Lambda<Func<T, bool>>(
            Expression.Invoke(expr2, param)), param);

Starting from .NET 4.0, there is the ExpressionVisitor class which allows you to build expressions that are EF safe.

    public static Expression<Func<T, bool>> AndAlso<T>(
        this Expression<Func<T, bool>> expr1,
        Expression<Func<T, bool>> expr2)
        var parameter = Expression.Parameter(typeof (T));

        var leftVisitor = new ReplaceExpressionVisitor(expr1.Parameters[0], parameter);
        var left = leftVisitor.Visit(expr1.Body);

        var rightVisitor = new ReplaceExpressionVisitor(expr2.Parameters[0], parameter);
        var right = rightVisitor.Visit(expr2.Body);

        return Expression.Lambda<Func<T, bool>>(
            Expression.AndAlso(left, right), parameter);

    private class ReplaceExpressionVisitor
        : ExpressionVisitor
        private readonly Expression _oldValue;
        private readonly Expression _newValue;

        public ReplaceExpressionVisitor(Expression oldValue, Expression newValue)
            _oldValue = oldValue;
            _newValue = newValue;

        public override Expression Visit(Expression node)
            if (node == _oldValue)
                return _newValue;
            return base.Visit(node);

How to unzip a file using the command line?

7-Zip, it's open source, free and supports a wide range of formats.

7z.exe x

JavaScript hashmap equivalent

Here is an easy and convenient way of using something similar to the Java map:

var map = {
              'map_name_1': map_value_1,
              'map_name_2': map_value_2,
              'map_name_3': map_value_3,
              'map_name_4': map_value_4

And to get the value:

alert(map['map_name_1']);    // Gives the value of map_value_1

... etc. ...

Send POST data using XMLHttpRequest

Short & modern

You can catch form input values using FormData and send them by fetch

fetch(form.action, {method:'post', body: new FormData(form)});

function send() {
  let form = document.forms['inputform'];
  fetch(form.action, {method:'post', body: new FormData(form)});
<form name="inputform" action="somewhere" method="post">
  <input               value="person" name="user">
  <input type="hidden" value="password" name="pwd">
  <input               value="place" name="organization">
  <input type="hidden" value="key" name="requiredkey">

<!-- I remove type="hidden" for some inputs above only for show them --><br>
Look: chrome console>network and click <button onclick="send()">send</button>

latex tabular width the same as the textwidth

The tabularx package gives you

  1. the total width as a first parameter, and
  2. a new column type X, all X columns will grow to fill up the total width.

For your example:

% ...    
% ...

Input & Output& Action return \\
DNF &  simulation & jsp\\

Spring boot - configure EntityManager

With Spring Boot its not necessary to have any config file like persistence.xml. You can configure with annotations Just configure your DB config for JPA in the



Then you can use CrudRepository provided by Spring where you have standard CRUD transaction methods. There you can also implement your own SQL's like JPQL.

public interface ObjectRepository extends CrudRepository<Object, Long> {

And if you still need to use the Entity Manager you can create another class.

public class ObjectRepositoryImpl implements ObjectCustomMethods{

    private EntityManager em;


This should be in your pom.xml



Multiline strings in VB.NET

To me that is the most annoying thing about VB as a language. Seriously, i once wrote the string in a file and wrote code something along the lines of:

Dim s as String = file_get_contents("filename.txt")

just so i could test the query directly on SQL server if i need to.

My current method is to use a stored procedure on the SQL Server and just call that so i can pass in parameters to the query, etc

ERROR: Error 1005: Can't create table (errno: 121)

If you have a foreign key definition in some table and the name of the foreign key is used elsewhere as another foreign key you will have this error.

How to install a specific JDK on Mac OS X?

As a rule you cannot install other versions of Java on a Mac than those provided by Apple through Software Update. If you need Java 6 you must have a 64-bit Intel computer. You should always have Java 5 and 1.4 and perhaps 1.3 installed if you have at least OS X 10.4.

If you have VERY much elbow grease and is willing to work with beta software you can install the OpenJDK under OS X, but I don't think you want to go there.

Does Spring Data JPA have any way to count entites using method name resolving?

private UserRepository userRepository;

private Long getNumberOfUsers(){
    return userRepository.count();

Circle button css

An round button with box-shadow

.btn {
  height: 50px;
  width: 50px;
  line-height: 50px;
  font-size: 2em;
  border-radius: 50%;
  background-color: red;
  color: white;
  text-align: center;
  border: none;
  cursor: pointer;
  position: fixed;
  z-index: 1;
  bottom: 10%;
  right: 4%;
  box-shadow: 0 3px 5px -1px rgba(0, 0, 0, 0.2), 0 6px 10px 0 rgba(0, 0, 0, 0.14), 0 1px 18px 0 rgba(0, 0, 0, 0.12);
<div class="btn">+</div>

Printing 2D array in matrix format

You can do it like this (with a slightly modified array to show it works for non-square arrays):

        long[,] arr = new long[5, 4] { { 1, 2, 3, 4 }, { 1, 1, 1, 1 }, { 2, 2, 2, 2 }, { 3, 3, 3, 3 }, { 4, 4, 4, 4 } };

        int rowLength = arr.GetLength(0);
        int colLength = arr.GetLength(1);

        for (int i = 0; i < rowLength; i++)
            for (int j = 0; j < colLength; j++)
                Console.Write(string.Format("{0} ", arr[i, j]));
            Console.Write(Environment.NewLine + Environment.NewLine);

How do you rename a MongoDB database?

From version 4.2, the copyDatabase is deprecated. From now on we should use: mongodump and mongorestore.

Let's say we have a database named: old_name and we want to rename it to new_name.

First we have to dump the database:

mongodump --archive="old_name_dump.db" --db=old_name

If you have to authenticate as a user then use:

mongodump -u username --authenticationDatabase admin \
          --archive="old_name_dump.db" --db=old_name

Now we have our db dumped as a file named: old_name_dump.db.

To restore with a new name:

mongorestore --archive="old_name_dump.db" --nsFrom="old_name.*" --nsTo="new_name.*"

Again, if you need to be authenticated add this parameters to the command:

-u username --authenticationDatabase admin 


Selenium and xPath - locating a link by containing text

@FindBy(xpath = "//span[@class='y2' and contains(text(), 'Your Text')] ") 
private WebElementFacade emailLinkToVerifyAccount;

This approach will work for you, hopefully.

Angular: How to update queryParams without changing route

First, we need to import the router module from angular router and declare its alias name

import { Router } from '@angular/router'; ---> import
class AbcComponent implements OnInit(){
    private router: Router ---> decalre alias name
  ) { }

1. You can change query params by using "router.navigate" function and pass the query parameters

this.router.navigate([], { queryParams: {_id: "abc", day: "1", name: "dfd"} 

It will update query params in the current i.e activated route

  1. The below will redirect to abc page with _id, day and name as query params

    this.router.navigate(['/abc'], { queryParams: {_id: "abc", day: "1", name: "dfd"} });

    It will update query params in the "abc" route along with three query paramters

For fetching query params:-

    import { ActivatedRoute } from '@angular/router'; //import activated routed

    export class ABC implements OnInit {

        private route: ActivatedRoute //declare its alias name
      ) {}

       console.log(this.route.snapshot.queryParamMap.get('_id')); //this will fetch the query params

Blurring an image via CSS?

img {
  filter: blur(var(--blur));

Android Writing Logs to text File

I solved this problem with following piece of code in command line way:

File outputFile = new File("pathToFile"); 
Runtime.getRuntime().exec("logcat -c");
Runtime.getRuntime().exec("logcat -v time -f " + outputFile.getAbsolutePath())

Where "time" option adds metadata field details for date, invocation time, priority/tag, and PID of the process issuing the message.

Then in your code just do something similar to this (using android.util.Log):

Log.d("yourappname", "Your message");

Moq, SetupGet, Mocking a property

ColumnNames is a property of type List<String> so when you are setting up you need to pass a List<String> in the Returns call as an argument (or a func which return a List<String>)

But with this line you are trying to return just a string

input.SetupGet(x => x.ColumnNames).Returns(temp[0]);

which is causing the exception.

Change it to return whole list:

input.SetupGet(x => x.ColumnNames).Returns(temp);

Eclipse: Error ".. overlaps the location of another project.." when trying to create new project

In my case checking the check-box

"Copy project into workspace"

did the trick.

What is a raw type and why shouldn't we use it?

Raw types are fine when they express what you want to express.

For example, a deserialisation function might return a List, but it doesn't know the list's element type. So List is the appropriate return type here.

How to set at runtime?

You can use System.setProperty("" , "true");

This is equivalent to passing it in the command line via

Difference between Xms and Xmx and XX:MaxPermSize

Java objects reside in an area called the heap, while metadata such as class objects and method objects reside in the permanent generation or Perm Gen area. The permanent generation is not part of the heap.

The heap is created when the JVM starts up and may increase or decrease in size while the application runs. When the heap becomes full, garbage is collected. During the garbage collection objects that are no longer used are cleared, thus making space for new objects.

-Xmssize Specifies the initial heap size.

-Xmxsize Specifies the maximum heap size.

-XX:MaxPermSize=size Sets the maximum permanent generation space size. This option was deprecated in JDK 8, and superseded by the -XX:MaxMetaspaceSize option.

Sizes are expressed in bytes. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, g or G to indicate gigabytes.


How is the java memory pool divided?

What is perm space?

Java (JVM) Memory Model – Memory Management in Java

Java 7 SE Command Line Options

Java 7 HotSpot VM Options

What is the difference between a candidate key and a primary key?

Think of a table of vehicles with an integer Primary Key.

The registration number would be a candidate key.

In the real world registration numbers are subject change so it depends somewhat on the circumstances what might qualify as a candidate key.

Bulk Insert Correctly Quoted CSV File in SQL Server

Been stung by the same :)

I wrapped this logic into a function to clean up data that had been was already imported

DECLARE @quote_identifier NVARCHAR(MAX);

SET @quote_identifier = N'"';

SET @str = N'"quoted stuff"';

           LEFT(@str, 1) = @quote_identifier
           AND RIGHT(@str, 1) = @quote_identifier,
           SUBSTRING(@str, DATALENGTH(@quote_identifier), LEN(@str) - DATALENGTH(@quote_identifier)),

Find all elements with a certain attribute value in jquery

You can use partial value of an attribute to detect a DOM element using (^) sign. For example you have divs like this:

<div id="abc_1"></div>
<div id="abc_2"></div>
<div id="xyz_3"></div>
<div id="xyz_4"></div>...

You can use the code:

var abc = $('div[id^=abc]')

This will return a DOM array of divs which have id starting with abc:

<div id="abc_1"></div>
<div id="abc_2"></div>

Here is the demo:

"Expected an indented block" error?

I also experienced that for example:

This code doesnt work and get the intended block error.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
return self.title

However, when i press tab before typing return self.title statement, the code works.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
    return self.title

Hope, this will help others.

Impersonate tag in Web.Config

You had the identity node as a child of authentication node. That was the issue. As in the example above, authentication and identity nodes must be children of the system.web node

Use and meaning of "in" in an if statement?

Here raw_input is string, so if you wanted to check, if var>3 then you should convert next to double, ie float(next) and do as you would do if float(next)>3:, but in most cases

Google Play Services GCM 9.2.0 asks to "update" back to 9.0.0

Do you have the line

apply plugin: '' 

line at the bottom of your app's build.gradle file?

I saw some errors when it was on the top and as it's written here, it should be at the bottom.

How to ssh connect through python Paramiko with ppk public key

Ok @Adam and @Kimvais were right, paramiko cannot parse .ppk files.

So the way to go (thanks to @JimB too) is to convert .ppk file to openssh private key format; this can be achieved using Puttygen as described here.

Then it's very simple getting connected with it:

import paramiko
ssh = paramiko.SSHClient()


ssh.connect('<hostname>', username='<username>', password='<password>', key_filename='<path/to/openssh-private-key-file>')

stdin, stdout, stderr = ssh.exec_command('ls')
print stdout.readlines()

filemtime "warning stat failed for"

I think the problem is the realpath of the file. For example your script is working on './', your file is inside the directory './xml'. So better check if the file exists or not, before you get filemtime or unlink it:

  function deleteOldFiles(){
    if ($handle = opendir('./xml')) {
        while (false !== ($file = readdir($handle))) { 

            if(preg_match("/^.*\.(xml|xsl)$/i", $file)){
              $fpath = 'xml/'.$file;
              if (file_exists($fpath)) {
                $filelastmodified = filemtime($fpath);

                if ( (time() - $filelastmodified ) > 24*3600){

XAMPP keeps showing Dashboard/Welcome Page instead of the Configuration Page

Here is the solutions that worked for me:

  1. open index.php from the htdocs folder
  2. inside replace the word dashboard with your database name.
  3. restart the server

This should resolve the issue :-)

How to add bootstrap to an angular-cli project

Install bootstrap using npm i --save bootstrap@version.Now,go to nodemodules folder and from bootstrap folder copy the path of 'bootstrap.min.css.js' and paste the full path(like nodemodules/bootstrap/css/bootstrap.min.css.js) in angular.json under script tag file and re-run the server and to check whether the installation is successful run the program in any browser you like and press F12 you'll find a part of the window gets opened,now go to elements tab open head tag and if you see bootstrap in style tag,then your installation is successful.

Use JSTL forEach loop's varStatus as an ID

you'd use any of these:

JSTL c:forEach varStatus properties

Property Getter Description

  • current getCurrent() The item (from the collection) for the current round of iteration.

  • index getIndex() The zero-based index for the current round of iteration.

  • count getCount() The one-based count for the current round of iteration

  • first isFirst() Flag indicating whether the current round is the first pass through the iteration
  • last isLast() Flag indicating whether the current round is the last pass through the iteration

  • begin getBegin() The value of the begin attribute

  • end getEnd() The value of the end attribute

  • step getStep() The value of the step attribute

When to use window.opener / window.parent /

  • window.opener refers to the window that called ... ) to open the window from which it's called
  • window.parent refers to the parent of a window in a <frame> or <iframe>
  • refers to the top-most window from a window nested in one or more layers of <iframe> sub-windows

Those will be null (or maybe undefined) when they're not relevant to the referring window's situation. ("Referring window" means the window in whose context the JavaScript code is run.)

Twitter Bootstrap vs jQuery UI?

You can use both with relatively few issues. Twitter Bootstrap uses jQuery 1.7.1 (as of this writing), and I can't think of any reasons why you cannot integrate additional Jquery UI components into your HTML templates.

I've been using a combination of HTML5 Boilerplate & Twitter Bootstrap built at This combines two awesome starter templates into one great starter project. Check out the details at and Or to get started right away, go to, click the "Bootstrap 2" button, and click "Download It". This will give you all the js and css you need to get started.

And don't be scared off by HTML5 and CSS3. Initializr and HTML5 Boilerplate include polyfills and IE specific code that will allow all features to work in IE 6, 7 8, and 9.

The use of LESS in Twitter Bootstrap is also optional. They use LESS to compile all the CSS that is used by Bootstrap, but if you just want to override or add your own styles, they provide an empty css file for that purpose.

There is also a blank js file (script.js) for you to add custom code. This is where you would add your handlers or selectors for additional jQueryUI components.

Default value in Doctrine

Be careful when setting default values on property definition! Do it in constructor instead, to keep it problem-free. If you define it on property definition, then persist the object to the database, then make a partial load, then not loaded properties will again have the default value. That is dangerous if you want to persist the object again.

What's an Aggregate Root?

From a broken link:

Within an Aggregate there is an Aggregate Root. The Aggregate Root is the parent Entity to all other Entities and Value Objects within the Aggregate.

A Repository operates upon an Aggregate Root.

More info can also be found here.

Trim leading and trailing spaces from a string in awk

remove leading and trailing white space in 2nd column

awk 'BEGIN{FS=OFS=","}{gsub(/^[ \t]+/,"",$2);gsub(/[ \t]+$/,"",$2)}1' input.txt

another way by one gsub:

awk 'BEGIN{FS=OFS=","} {gsub(/^[ \t]+|[ \t]+$/, "", $2)}1' infile

Setting the User-Agent header for a WebClient request

const string ua = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)";
Request.Headers["User-Agent"] = ua;
var httpWorkerRequestField = Request.GetType().GetField("_wr", BindingFlags.Instance | BindingFlags.NonPublic);
if (httpWorkerRequestField != null)
    var httpWorkerRequest = httpWorkerRequestField.GetValue(Request);
    var knownRequestHeadersField = httpWorkerRequest.GetType().GetField("_knownRequestHeaders", BindingFlags.Instance | BindingFlags.NonPublic);
    if (knownRequestHeadersField != null)
        string[] knownRequestHeaders = (string[])knownRequestHeadersField.GetValue(httpWorkerRequest);
                    knownRequestHeaders[39] = ua;

Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

Well, you should think about one more thing.

If you have a really big dataset, like 1,000,000 examples, split 80/10/10 may be unnecessary, because 10% = 100,000 examples may be just too much for just saying that model works fine.

Maybe 99/0.5/0.5 is enough because 5,000 examples can represent most of the variance in your data and you can easily tell that model works good based on these 5,000 examples in test and dev.

Don't use 80/20 just because you've heard it's ok. Think about the purpose of the test set.

Round integers to the nearest 10

round() can take ints and negative numbers for places, which round to the left of the decimal. The return value is still a float, but a simple cast fixes that:

>>> int(round(5678,-1))
>>> int(round(5678,-2))
>>> int(round(5678,-3))

What does 'git remote add upstream' help achieve?

This is useful when you have your own origin which is not upstream. In other words, you might have your own origin repo that you do development and local changes in and then occasionally merge upstream changes. The difference between your example and the highlighted text is that your example assumes you're working with a clone of the upstream repo directly. The highlighted text assumes you're working on a clone of your own repo that was, presumably, originally a clone of upstream.

How can I load the contents of a text file into a batch file variable?

Use for, something along the lines of:

set content=
for /f "delims=" %%i in ('filename') do set content=%content% %%i

Maybe you’ll have to do setlocal enabledelayedexpansion and/or use !content! rather than %content%. I can’t test, as I don’t have any MS Windows nearby (and I wish you the same :-).

The best batch-file-black-magic-reference I know of is at If you don’t know Russian, you still could make some use of the code snippets provided.

Hide Button After Click (With Existing Form on Page)

This is my solution. I Hide and then confirm check

onclick="return ConfirmSubmit(this);" />

function ConfirmSubmit(sender)
        sender.disabled = true;
        var displayValue = = 'none'

        if (confirm('Seguro que desea entregar los paquetes?')) {
            sender.disabled = false
            return true;

        sender.disabled = false; = displayValue;
        return false;

Understanding the map function

Simplifying a bit, you can imagine map() doing something like this:

def mymap(func, lst):
    result = []
    for e in lst:
    return result

As you can see, it takes a function and a list, and returns a new list with the result of applying the function to each of the elements in the input list. I said "simplifying a bit" because in reality map() can process more than one iterable:

If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel. If one iterable is shorter than another it is assumed to be extended with None items.

For the second part in the question: What role does this play in making a Cartesian product? well, map() could be used for generating the cartesian product of a list like this:

lst = [1, 2, 3, 4, 5]

from operator import add
reduce(add, map(lambda i: map(lambda j: (i, j), lst), lst))

... But to tell the truth, using product() is a much simpler and natural way to solve the problem:

from itertools import product
list(product(lst, lst))

Either way, the result is the cartesian product of lst as defined above:

[(1, 1), (1, 2), (1, 3), (1, 4), (1, 5),
 (2, 1), (2, 2), (2, 3), (2, 4), (2, 5),
 (3, 1), (3, 2), (3, 3), (3, 4), (3, 5),
 (4, 1), (4, 2), (4, 3), (4, 4), (4, 5),
 (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)]

What are the best PHP input sanitizing functions?


You're making a mistake here. Oh, no, you've picked the right PHP functions to make your data a bit safer. That's fine. Your mistake is in the order of operations, and how and where to use these functions.

It's important to understand the difference between sanitizing and validating user data, escaping data for storage, and escaping data for presentation.

Sanitizing and Validating User Data

When users submit data, you need to make sure that they've provided something you expect.

Sanitization and Filtering

For example, if you expect a number, make sure the submitted data is a number. You can also cast user data into other types. Everything submitted is initially treated like a string, so forcing known-numeric data into being an integer or float makes sanitization fast and painless.

What about free-form text fields and textareas? You need to make sure that there's nothing unexpected in those fields. Mainly, you need to make sure that fields that should not have any HTML content do not actually contain HTML. There are two ways you can deal with this problem.

First, you can try escaping HTML input with htmlspecialchars. You should not use htmlentities to neutralize HTML, as it will also perform encoding of accented and other characters that it thinks also need to be encoded.

Second, you can try removing any possible HTML. strip_tags is quick and easy, but also sloppy. HTML Purifier does a much more thorough job of both stripping out all HTML and also allowing a selective whitelist of tags and attributes through.

Modern PHP versions ship with the filter extension, which provides a comprehensive way to sanitize user input.


Making sure that submitted data is free from unexpected content is only half of the job. You also need to try and make sure that the data submitted contains values you can actually work with.

If you're expecting a number between 1 and 10, you need to check that value. If you're using one of those new fancy HTML5-era numeric inputs with a spinner and steps, make sure that the submitted data is in line with the step.

If that data came from what should be a drop-down menu, make sure that the submitted value is one that appeared in the menu.

What about text inputs that fulfill other needs? For example, date inputs should be validated through strtotime or the DateTime class. The given date should be between the ranges you expect. What about email addresses? The previously mentioned filter extension can check that an address is well-formed, though I'm a fan of the is_email library.

The same is true for all other form controls. Have radio buttons? Validate against the list. Have checkboxes? Validate against the list. Have a file upload? Make sure the file is of an expected type, and treat the filename like unfiltered user data.

Every modern browser comes with a complete set of developer tools built right in, which makes it trivial for anyone to manipulate your form. Your code should assume that the user has completely removed all client-side restrictions on form content!

Escaping Data for Storage

Now that you've made sure that your data is in the expected format and contains only expected values, you need to worry about persisting that data to storage.

Every single data storage mechanism has a specific way to make sure data is properly escaped and encoded. If you're building SQL, then the accepted way to pass data in queries is through prepared statements with placeholders.

One of the better ways to work with most SQL databases in PHP is the PDO extension. It follows the common pattern of preparing a statement, binding variables to the statement, then sending the statement and variables to the server. If you haven't worked with PDO before here's a pretty good MySQL-oriented tutorial.

Some SQL databases have their own specialty extensions in PHP, including SQL Server, PostgreSQL and SQLite 3. Each of those extensions has prepared statement support that operates in the same prepare-bind-execute fashion as PDO. Sometimes you may need to use these extensions instead of PDO to support non-standard features or behavior.

MySQL also has its own PHP extensions. Two of them, in fact. You only want to ever use the one called mysqli. The old "mysql" extension has been deprecated and is not safe or sane to use in the modern era.

I'm personally not a fan of mysqli. The way it performs variable binding on prepared statements is inflexible and can be a pain to use. When in doubt, use PDO instead.

If you are not using an SQL database to store your data, check the documentation for the database interface you're using to determine how to safely pass data through it.

When possible, make sure that your database stores your data in an appropriate format. Store numbers in numeric fields. Store dates in date fields. Store money in a decimal field, not a floating point field. Review the documentation provided by your database on how to properly store different data types.

Escaping Data for Presentation

Every time you show data to users, you must make sure that the data is safely escaped, unless you know that it shouldn't be escaped.

When emitting HTML, you should almost always pass any data that was originally user-supplied through htmlspecialchars. In fact, the only time you shouldn't do this is when you know that the user provided HTML, and that you know that it's already been sanitized it using a whitelist.

Sometimes you need to generate some Javascript using PHP. Javascript does not have the same escaping rules as HTML! A safe way to provide user-supplied values to Javascript via PHP is through json_encode.

And More

There are many more nuances to data validation.

For example, character set encoding can be a huge trap. Your application should follow the practices outlined in "UTF-8 all the way through". There are hypothetical attacks that can occur when you treat string data as the wrong character set.

Earlier I mentioned browser debug tools. These tools can also be used to manipulate cookie data. Cookies should be treated as untrusted user input.

Data validation and escaping are only one aspect of web application security. You should make yourself aware of web application attack methodologies so that you can build defenses against them.

How do you deploy Angular apps?

Simple answer. Use the Angular CLI and issue the

ng build 

command in the root directory of your project. The site will be created in the dist directory and you can deploy that to any web server.

This will build for test, if you have production settings in your app you should use

ng build --prod

This will build the project in the dist directory and this can be pushed to the server.

Much has happened since I first posted this answer. The CLI is finally at a 1.0.0 so following this guide go upgrade your project should happen before you try to build.

Defining a percentage width for a LinearLayout?

I solved a similar issue applying some padding to the LinearLayout like this:

<LinearLayout xmlns:android=""



This probably won't give you an exact percentage but can be easily graduated and avoid extra unnecessary layout elements.

"continue" in cursor.forEach()

Here is a solution using for of and continue instead of forEach:

let elementsCollection = SomeElements.find();

for (let el of elementsCollection) {

    // continue will exit out of the current 
    // iteration and continue on to the next
    if (!el.shouldBeProcessed){



This may be a bit more useful if you need to use asynchronous functions inside your loop which do not work inside forEach. For example:

(async fuction(){

for (let el of elementsCollection) {

    if (!el.shouldBeProcessed){

    let res;

    try {
        res = await doSomeLengthyAsyncOperation();
    } catch (err) {
        return Promise.reject(err)



Python JSON dump / append to .txt with each variable on new line

Your question is a little unclear. If you're generating hostDict in a loop:

with open('data.txt', 'a') as outfile:
    for hostDict in ....:
        json.dump(hostDict, outfile)

If you mean you want each variable within hostDict to be on a new line:

with open('data.txt', 'a') as outfile:
    json.dump(hostDict, outfile, indent=2)

When the indent keyword argument is set it automatically adds newlines.

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Instead of

return new ResponseEntity<JSONObject>(entities, HttpStatus.OK);


return new ResponseEntity<List<JSONObject>>(entities, HttpStatus.OK);

Error : Index was outside the bounds of the array.

You have declared an array that can store 8 elements not 9.

this.posStatus = new int[8]; 

It means postStatus will contain 8 elements from index 0 to 7.

Loop structure inside gnuplot?

There sure is (in gnuplot 4.4+):

plot for [i=1:1000] 'data'.i.'.txt' using 1:2 title 'Flow '.i

The variable i can be interpreted as a variable or a string, so you could do something like

plot for [i=1:1000] 'data'.i.'.txt' using 1:($2+i) title 'Flow '.i

if you want to have lines offset from each other.

Type help iteration at the gnuplot command line for more info.

Also be sure to see @DarioP's answer about the do for syntax; that gives you something closer to a traditional for loop.

How to find the privileges and roles granted to a user in Oracle?

select * 
where role in (
    select granted_role
    from dba_role_privs 
    where granted_role in ('ROLE1','ROLE2')

Jquery check if element is visible in viewport

According to the documentation for that plugin, .visible() returns a boolean indicating if the element is visible. So you'd use it like this:

if ($('#element').visible(true)) {
    // The element is visible, do something
} else {
    // The element is NOT visible, do something else

Lollipop : draw behind statusBar with its color set to transparent

I had the same problem so i create ImageView that draw behind status bar API 19+

Set custom image behind Status Bar

public static void setTransparent(Activity activity, int imageRes) {
    // set flags
    } else {

    // get root content of system window
    //ViewGroup rootView = (ViewGroup) ((ViewGroup) activity.findViewById(;
    // rootView.setFitsSystemWindows(true);
    // rootView.setClipToPadding(true);

    ViewGroup contentView = (ViewGroup) activity.findViewById(;
    if (contentView.getChildCount() > 1) {

    // get status bar height
    int res = activity.getResources().getIdentifier("status_bar_height", "dimen", "android");
    int height = 0;
    if (res != 0)
        height = activity.getResources().getDimensionPixelSize(res);

    // create new imageview and set resource id
    ImageView image = new ImageView(activity);
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, height);

    // add image view to content view
    // rootView.setFitsSystemWindows(true);


Is there any use for unique_ptr with array?

There are tradeoffs, and you pick the solution which matches what you want. Off the top of my head:

Initial size

  • vector and unique_ptr<T[]> allow the size to be specified at run-time
  • array only allows the size to be specified at compile time


  • array and unique_ptr<T[]> do not allow resizing
  • vector does


  • vector and unique_ptr<T[]> store the data outside the object (typically on the heap)
  • array stores the data directly in the object


  • array and vector allow copying
  • unique_ptr<T[]> does not allow copying


  • vector and unique_ptr<T[]> have O(1) time swap and move operations
  • array has O(n) time swap and move operations, where n is the number of elements in the array

Pointer/reference/iterator invalidation

  • array ensures pointers, references and iterators will never be invalidated while the object is live, even on swap()
  • unique_ptr<T[]> has no iterators; pointers and references are only invalidated by swap() while the object is live. (After swapping, pointers point into to the array that you swapped with, so they're still "valid" in that sense.)
  • vector may invalidate pointers, references and iterators on any reallocation (and provides some guarantees that reallocation can only happen on certain operations).

Compatibility with concepts and algorithms

  • array and vector are both Containers
  • unique_ptr<T[]> is not a Container

I do have to admit, this looks like an opportunity for some refactoring with policy-based design.

How to use auto-layout to move other views when a view is hidden?

My project uses a custom @IBDesignable subclass of UILabel (to ensure consistency in colour, font, insets etc.) and I have implemented something like the following:

override func intrinsicContentSize() -> CGSize {
    if hidden {
        return CGSizeZero
    } else {
        return super.intrinsicContentSize()

This allows the label subclass to take part in Auto Layout, but take no space when hidden.

AJAX reload page with POST

By using jquery ajax you can reload your page

    type: "POST",
    url: "packtypeAdd.php",
    data: infoPO,
    success: function() {   

MySQL Error: #1142 - SELECT command denied to user

You should have to just clear sessions data thats it everything will work

git: updates were rejected because the remote contains work that you do not have locally

Well actually github is much simpler than we think and absolutely it happens whenever we try to push even after we explicitly inserted some files in our git repository so, in order to fix the issue simply try..

: git pull

and then..

: git push

Note: if you accidently stuck in vim editor after pulling your repository than don't worry just close vim editor and try push :)

How to style components using makeStyles and still have lifecycle methods in Material UI?

Hi instead of using hook API, you should use Higher-order component API as mentioned here

I'll modify the example in the documentation to suit your need for class component

import React from 'react';
import PropTypes from 'prop-types';
import { withStyles } from '@material-ui/styles';
import Button from '@material-ui/core/Button';

const styles = theme => ({
  root: {
    background: 'linear-gradient(45deg, #FE6B8B 30%, #FF8E53 90%)',
    border: 0,
    borderRadius: 3,
    boxShadow: '0 3px 5px 2px rgba(255, 105, 135, .3)',
    color: 'white',
    height: 48,
    padding: '0 30px',

class HigherOrderComponentUsageExample extends React.Component {
    const { classes } = this.props;
    return (
      <Button className={classes.root}>This component is passed to an HOC</Button>

HigherOrderComponentUsageExample.propTypes = {
  classes: PropTypes.object.isRequired,

export default withStyles(styles)(HigherOrderComponentUsageExample);

How to pass data in the ajax DELETE request other than headers

I was able to successfully pass through the data attribute in the ajax method. Here is my code

     url: "/api/Gigs/Cancel",
     type: "DELETE",
     data: {
             "GigId": link.attr('data-gig-id')


The link.attr method simply returned the value of 'data-gig-id' .

How do I check if an element is really visible with JavaScript?

As jkl pointed out, checking the element's visibility or display is not enough. You do have to check its ancestors. Selenium does this when it verifies visibility on an element.

Check out the method Selenium.prototype.isVisible in the selenium-api.js file.

How to check if the user can go back in browser history or not

var fallbackUrl = "home.php";
if(history.back() === undefined)
    window.location.href = fallbackUrl;

Update MySQL using HTML Form and PHP

You have already executed your query here

$sql = mysql_query("UPDATE anstalld SET mandag = '$mandag', tisdag = '$tisdag', onsdag = '$onsdag', torsdag = '$torsdag', fredag = '$fredag' WHERE namn = '$namn'");

So this line has the problem

$retval = mysql_query( $sql, $conn ); //$sql is not a query its a result set here

Try something like this:

$sql = "UPDATE anstalld SET mandag = '$mandag', tisdag = '$tisdag', onsdag = '$onsdag', torsdag = '$torsdag', fredag = '$fredag' WHERE namn = '$namn'";    
$retval = mysql_query( $sql, $conn ); //execute your query

As a sidenote: MySQL_* extension is deprecated use MySQLi_* or PDO instead.

How to get current user in core

I got my solution

var claim = HttpContext.User.CurrentUserID();

public static class XYZ
    public static int CurrentUserID(this ClaimsPrincipal claim)
        var userID = claimsPrincipal.Claims.ToList().Find(r => r.Type == 
        return Convert.ToInt32(userID);
    public static string CurrentUserRole(this ClaimsPrincipal claim)
        var role = claimsPrincipal.Claims.ToList().Find(r => r.Type == 
        return role;

Excel VBA - How to Redim a 2D array?

Here is how I do this.

Dim TAV() As Variant
Dim ArrayToPreserve() as Variant

TAV = ArrayToPreserve
ReDim ArrayToPreserve(nDim1, nDim2)
For i = 0 To UBound(TAV, 1)
    For j = 0 To UBound(TAV, 2)
        ArrayToPreserve(i, j) = TAV(i, j)
    Next j
Next i

How to use Apple's new .p8 certificate for APNs in firebase console

I was able to do this by selecting "All" located under the "Keys" header from the left column

enter image description here

Then I clicked the plus button in the top right corner to add a new key

enter image description here

Enter a name for your key and check "APNs"

enter image description here

Then scroll down and select Continue. You will then be brought to a screen presenting you with the option to download your .p8 now or later. In my case, I was presented with a warning that it could only be downloaded once so keep the file safe.

How can I declare dynamic String array in Java

Maybe you are looking for Vector. It's capacity is automatically expanded if needed. It's not the best choice but will do in simple situations. It's worth your time to read up on ArrayList instead.

How can I make a list of lists in R?

The example creates a list of named lists in a loop.

  MyList <- list()
  for (aName in c("name1", "name2")){
    MyList[[aName]] <- list(aName)

To add another list named "name3" do write:

  MyList$name3 <- list(1, 2, 3)

How do you set the EditText keyboard to only consist of numbers on Android?

android:inputType="number" or android:inputType="phone". You can keep this. You will get the keyboard containing numbers. For further details on different types of keyboard, check this link.

I think it is possible only if you create your own soft keyboard. Or try this android:inputType="number|textVisiblePassword. But it still shows other characters. Besides you can keep android:digits="0123456789" to allow only numbers in your edittext. Or if you still want the same as in image, try combining two or more features with | separator and check your luck, but as per my knowledge you have to create your own keypad to get exactly like that..

In git, what is the difference between merge --squash and rebase?

Merge commits: retains all of the commits in your branch and interleaves them with commits on the base branchenter image description here

Merge Squash: retains the changes but omits the individual commits from history enter image description here

Rebase: This moves the entire feature branch to begin on the tip of the master branch, effectively incorporating all of the new commits in master

enter image description here

More on here

AngularJs directive not updating another directive's scope

Just wondering why you are using 2 directives?

It seems like, in this case it would be more straightforward to have a controller as the parent - handle adding the data from your service to its $scope, and pass the model you need from there into your warrantyDirective.

Or for that matter, you could use 0 directives to achieve the same result. (ie. move all functionality out of the separate directives and into a single controller).

It doesn't look like you're doing any explicit DOM transformation here, so in this case, perhaps using 2 directives is overcomplicating things.

Alternatively, have a look at the Angular documentation for directives: The very last example at the bottom of the page explains how to wire up dependent directives.

Looping through JSON with node.js

If you want to avoid blocking, which is only necessary for very large loops, then wrap the contents of your loop in a function called like this: process.nextTick(function(){<contents of loop>}), which will defer execution until the next tick, giving an opportunity for pending calls from other asynchronous functions to be processed.

Change an image with onclick()

This script helps to change the image on click the text:

    var imgpath = $(this).attr('dir');
    $('#image').html('<img src='+imgpath+'>');
    $('#thumbs').fadeOut(500,function (){

<div class="sandiv">
<h1 style="text-align:center;">The  Human  Body  Parts :</h1>
<div id="thumbs">
<div class="sanl">
<li dir="5.png">Human-body-organ-diag-1</li>
<li dir="4.png">Human-body-organ-diag-2</li>
<li dir="3.png">Human-body-organ-diag-3</li>
<li dir="2.png">Human-body-organ-diag-4</li>
<li dir="1.png">Human-body-organ-diag-5</li>
<div class="man">
<div id="image">
<img src="2.png" width="348" height="375"></div>
<div id="thumbs">
<div class="sanr" >
<li dir="5.png">Human-body-organ-diag-6</li>
<li dir="4.png">Human-body-organ-diag-7</li>
<li dir="3.png">Human-body-organ-diag-8</li>
<li dir="2.png">Human-body-organ-diag-9</li>
<li dir="1.png">Human-body-organ-diag-10</li>
<h2><a style="color:#333;" href=""></a></h2>

see the demo here

history.replaceState() example?

I really wanted to respond to @Sev's answer.

Sev is right, there is a bug inside the window.history.replaceState

To fix this simply rewrite the constructor to set the title manually.

var replaceState_tmp = window.history.replaceState.constructor;
window.history.replaceState.constructor = function(obj, title, url){
    var title_ = document.getElementsByTagName('title')[0];
    if(title_ != undefined){
        title_.innerHTML = title;
        var title__ = document.createElement('title');
        title__.innerHTML = title;
        var head_ = document.getElementsByTagName('head')[0];
        if(head_ != undefined){
            var head__ = document.createElement('head');
    replaceState_tmp(obj,title, url);

AngularJS: How to clear query parameters in the URL?

To clear an item delete it and call $$compose

    if ($location.$$search.yourKey) {
        delete $location.$$search.yourKey;

derived from angularjs source :

How to get max value of a column using Entity Framework?

Selected answer throws exceptions, and the answer from Carlos Toledo applies filtering after retrieving all values from the database.

The following one runs a single round-trip and reads a single value, using any possible indexes, without an exception.

int maxAge = _dbContext.Persons
  .OrderByDescending(p => p.Age)
  .Select(p => p.Age)

Angular: Cannot Get /

For me it also was problem with path, but I had percentage sign in the root folder.

After I replaced %20 with space, it started to work :)

failed to lazily initialize a collection of role

as suggested here solving the famous LazyInitializationException is one of the following methods:

(1) Use Hibernate.initialize



You can use the JOIN FETCH syntax in your JPQL to explicitly fetch the child collection out. This is somehow like EAGER fetching.

(3) Use OpenSessionInViewFilter

LazyInitializationException often occurs in the view layer. If you use Spring framework, you can use OpenSessionInViewFilter. However, I do not suggest you to do so. It may leads to a performance issue if not used correctly.

Twitter bootstrap collapse: change display of toggle button

You do like this. the function return the old text.

            return old=='Read More' ?  'Read Less' : 'Read More';

How to generate .env file for laravel?

In windows OS, you can open command prompt, change directory to your project directory.
My project directory


You can type into your Command prompt like this (hit enter each line):


cd xampp\htdocs\my_project

Then you can type,

copy .env.example .env

If you are using Linux, you can type cp, instead of copy

What's a .sh file?

sh files are unix (linux) shell executables files, they are the equivalent (but much more powerful) of bat files on windows.

So you need to run it from a linux console, just typing its name the same you do with bat files on windows.

Declare a variable in DB2 SQL

I imagine this forum posting, which I quote fully below, should answer the question.

Inside a procedure, function, or trigger definition, or in a dynamic SQL statement (embedded in a host program):

 DECLARE example VARCHAR(15) ;
 SET example = 'welcome' ;
 FROM   tablename
 WHERE  column1 = example ;

or (in any environment):

WITH t(example) AS (VALUES('welcome'))
FROM   tablename, t
WHERE  column1 = example

or (although this is probably not what you want, since the variable needs to be created just once, but can be used thereafter by everybody although its content will be private on a per-user basis):

SET example = 'welcome' ;
FROM   tablename
WHERE  column1 = example ;

SQL 'like' vs '=' performance

A personal example using mysql 5.5: I had an inner join between 2 tables, one of 3 million rows and one of 10 thousand rows.

When using a like on an index as below(no wildcards), it took about 30 seconds:

where login like '12345678'

using 'explain' I get:

enter image description here

When using an '=' on the same query, it took about 0.1 seconds:

where login ='600009'

Using 'explain' I get:

enter image description here

As you can see, the like completely cancelled the index seek, so query took 300 times more time.

Jackson and generic type reference

'JavaType' works !! I was trying to unmarshall (deserialize) a List in json String to ArrayList java Objects and was struggling to find a solution since days.
Below is the code that finally gave me solution. Code:

JsonMarshallerUnmarshaller<T> {
    T targetClass;

    public ArrayList<T> unmarshal(String jsonString) {
        ObjectMapper mapper = new ObjectMapper();

        AnnotationIntrospector introspector = new JacksonAnnotationIntrospector();

        JavaType type = mapper.getTypeFactory().

        try {
            Class c1 = this.targetclass.getClass();
            Class c2 = this.targetclass1.getClass();
            ArrayList<T> temp = (ArrayList<T>) 
                mapper.readValue(jsonString,  type);
            return temp ;
        } catch (JsonParseException e) {
        } catch (JsonMappingException e) {
        } catch (IOException e) {

        return null ;

semaphore implementation

Vary the consumer-rate and the producer-rate (using sleep), to better understand the operation of code. The code below is the consumer-producer simulation (over a max-limit on container).

Code for your reference:

#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>

sem_t semP, semC;
int stock_count = 0;
const int stock_max_limit=5;

void *producer(void *arg) {
    int i, sum=0;
    for (i = 0; i < 10; i++) {

        while(stock_max_limit == stock_count){
            printf("stock overflow, production on wait..\n");
            printf("production operation continues..\n");

        sleep(1);   //production decided here
        printf("P::stock-count : %d\n",stock_count);
        printf("P::post signal..\n");

void *consumer(void *arg) {
    int i, sum=0;
    for (i = 0; i < 10; i++) {

        while(0 == stock_count){
            printf("stock empty, consumer on wait..\n");
            printf("consumer operation continues..\n");

        sleep(2);   //consumer rate decided here
        printf("C::stock-count : %d\n", stock_count);
        printf("C::post signal..\n");

int main(void) {

    pthread_t tid0,tid1;
    sem_init(&semP, 0, 0);
    sem_init(&semC, 0, 0);

        pthread_create(&tid0, NULL, consumer, NULL);
        pthread_create(&tid1, NULL, producer, NULL);
        pthread_join(tid0, NULL);
        pthread_join(tid1, NULL);


    return 0;

How to get $(this) selected option in jQuery?

var cur_value = $('option:selected',this).text();

Proper use of mutexes in Python

I don't know why you're using the Window's Mutex instead of Python's. Using the Python methods, this is pretty simple:

from threading import Thread, Lock

mutex = Lock()

def processData(data):
        print('Do some stuff')

while True:
    t = Thread(target = processData, args = (some_data,))

But note, because of the architecture of CPython (namely the Global Interpreter Lock) you'll effectively only have one thread running at a time anyway--this is fine if a number of them are I/O bound, although you'll want to release the lock as much as possible so the I/O bound thread doesn't block other threads from running.

An alternative, for Python 2.6 and later, is to use Python's multiprocessing package. It mirrors the threading package, but will create entirely new processes which can run simultaneously. It's trivial to update your example:

from multiprocessing import Process, Lock

mutex = Lock()

def processData(data):
    with mutex:
        print('Do some stuff')

if __name__ == '__main__':
    while True:
        p = Process(target = processData, args = (some_data,))

open_basedir restriction in effect. File(/) is not within the allowed path(s):

If you are running a PHP IIS stack and have this error, it is usually a quick permission fix.

If you administer the windows server yourself and have access, try this FIRST:

Navigate to the folder that is giving you grief on writing to and right click it > open properties > security.

See what users have access to the folder, which ones have read only and which have full. Do you have a group that is blocking write?

The fix will be specific to your IIS setup, are you using Anonymous Authentication with specific user IUSR or with the Application Pool identity?

At any rate, you are going to end up adding a new full write permission for one of IUSR, IIS_IUSRS, or your application pool identity - like I said, this is going to vary depending on your setup and how you want to do it, you can go down the google rabbit hole on this one (one such post - IIS_IUSRS and IUSR permissions in IIS8) For me, i use anon with my app pool identity so i can get away with MACHINE_NAME\IIS_IUSRS with full read/write on any temp or upload folders.

I do not need to add anything extra to my open_basedir = in the php.ini.

Is there a numpy builtin to reject outliers from a list

if you want to get the index position of the outliers idx_list will return it.

def reject_outliers(data, m = 2.):
        d = np.abs(data - np.median(data))
        mdev = np.median(d)
        s = d/mdev if mdev else 0.
        data_range = np.arange(len(data))
        idx_list = data_range[s>=m]
        return data[s<m], idx_list

data_points = np.array([8, 10, 35, 17, 73, 77])  

after rejection: [ 8 10 35 17], index positions of outliers: [4 5]

Border for an Image view in Android?

You can use 9 patch in Android Studio to make borders!

I was looking for a solution but I did not find any so I skipped that part.

Then I went to the Google images of Firebase assets and I accidentally discovered that they use 9patch.

9patch in action

Here's the link:

You just need to drag where the edges are.

It's just like border edge in Unity.

"ImportError: no module named 'requests'" after installing with pip

Run in command prompt.

pip list

Check what version you have installed on your system if you have an old version.

Try to uninstall the package...

pip uninstall requests

Try after to install it:

pip install requests

You can also test if pip does not do the job.

easy_install requests

How do I read and parse an XML file in C#?

Here's an application I wrote for reading xml sitemaps:

using System;
using System.Collections.Generic;
using System.Windows.Forms; 
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Data;
using System.Xml;

namespace SiteMapReader
    class Program
        static void Main(string[] args)
            Console.WriteLine("Please Enter the Location of the file");

            // get the location we want to get the sitemaps from 
            string dirLoc = Console.ReadLine();

            // get all the sitemaps 
            string[] sitemaps = Directory.GetFiles(dirLoc);
            StreamWriter sw = new StreamWriter(Application.StartupPath + @"\locs.txt", true);

            // loop through each file 
            foreach (string sitemap in sitemaps)
                    // new xdoc instance 
                    XmlDocument xDoc = new XmlDocument();

                    //load up the xml from the location 

                    // cycle through each child noed 
                    foreach (XmlNode node in xDoc.DocumentElement.ChildNodes)
                        // first node is the url ... have to go to nexted loc node 
                        foreach (XmlNode locNode in node)
                            // thereare a couple child nodes here so only take data from node named loc 
                            if (locNode.Name == "loc")
                                // get the content of the loc node 
                                string loc = locNode.InnerText;

                                // write it to the console so you can see its working 
                                Console.WriteLine(loc + Environment.NewLine);

                                // write it to the file 
                                sw.Write(loc + Environment.NewLine);
                catch { }
            Console.WriteLine("All Done :-)"); 

        static void readSitemap()

Code on Paste Bin

How to remove a package from Laravel using composer?

  1. Remove package folder from vendor folder (Manual delete)
  2. remove it from 'composer.json' & 'composer.lock' files
  3. remove it from 'config/app.php' & 'bootstrap/cache/config.php' files
  4. composer remove package-name
  5. php artisan cache:clear & php artisan config:clear

How large is a DWORD with 32- and 64-bit code?

It is defined as:

typedef unsigned long       DWORD;

However, according to the MSDN:

On 32-bit platforms, long is synonymous with int.

Therefore, DWORD is 32bit on a 32bit operating system. There is a separate define for a 64bit DWORD:

typdef unsigned _int64 DWORD64;

Hope that helps.

Proper MIME media type for PDF files

This is a convention defined in RFC 2045 - Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies.

  1. Private [subtype] values (starting with "X-") may be defined bilaterally between two cooperating agents without outside registration or standardization. Such values cannot be registered or standardized.

  2. New standard values should be registered with IANA as described in RFC 2048.

A similar restriction applies to the top-level type. From the same source,

If another top-level type is to be used for any reason, it must be given a name starting with "X-" to indicate its non-standard status and to avoid a potential conflict with a future official name.

(Note that per RFC 2045, "[m]atching of media type and subtype is ALWAYS case-insensitive", so there's no difference between the interpretation of 'X-' and 'x-'.)

So it's fair to guess that "application/x-foo" was used before the IANA defined "application/foo". And it still might be used by folks who aren't aware of the IANA token assignment.

As Chris Hanson said MIME types are controlled by the IANA. This is detailed in RFC 2048 - Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures. According to RFC 3778, which is cited by the IANA as the definition for "application/pdf",

The application/pdf media type was first registered in 1993 by Paul Lindner for use by the gopher protocol; the registration was subsequently updated in 1994 by Steve Zilles.

The type "application/pdf" has been around for well over a decade. So it seems to me that wherever "application/x-pdf" has been used in new apps, the decision may not have been deliberate.

cannot find zip-align when publishing app

I've fixed this issue by doing this:

Open Android Studio > Preferences > SDK Tools and check "Android SDK Build-Tools"

printf format specifiers for uint32_t and size_t

If you don't want to use the PRI* macros, another approach for printing ANY integer type is to cast to intmax_t or uintmax_t and use "%jd" or %ju, respectively. This is especially useful for POSIX (or other OS) types that don't have PRI* macros defined, for instance off_t.

How to group time by hour or by 10 minutes

select from_unixtime( 600 * ( unix_timestamp( [Date] ) % 600 ) ) AS RecT, avg(Value)
from [FRIIB].[dbo].[ArchiveAnalog]
group by RecT
order by RecT;

replace the two 600 by any number of seconds you want to group.

If you need this often and the table doesn't change, as the name Archive suggests, it would probably be a bit faster to convert and store the date (& time) as a unixtime in the table.

C# DateTime to "YYYYMMDDHHMMSS" format

An easy Method, Full control over 'from type' and 'to type', and only need to remember this code for future castings

DateTime.ParseExact(InputDate, "dd/MM/yyyy", CultureInfo.InvariantCulture).ToString("yyyy/MM/dd"));

Python FileNotFound

try block should be around open. Not around prompt.

while True:
    prompt = input("\n Hello to Sudoku valitator,"
    "\n \n Please type in the path to your file and press 'Enter': ")
        sudoku = open(prompt, 'r').readlines()
    except FileNotFoundError:
        print("Wrong file or file path")

How to Set user name and Password of phpmyadmin

You can simply open the phpmyadmin page from your browser, then open any existing database -> go to Privileges tab, click on your root user and then a popup window will appear, you can set your password there.. Hope this Helps.

Which Python memory profiler is recommended?

My module memory_profiler is capable of printing a line-by-line report of memory usage and works on Unix and Windows (needs psutil on this last one). Output is not very detailed but the goal is to give you an overview of where the code is consuming more memory, not an exhaustive analysis on allocated objects.

After decorating your function with @profile and running your code with the -m memory_profiler flag it will print a line-by-line report like this:

Line #    Mem usage  Increment   Line Contents
     3                           @profile
     4      5.97 MB    0.00 MB   def my_func():
     5     13.61 MB    7.64 MB       a = [1] * (10 ** 6)
     6    166.20 MB  152.59 MB       b = [2] * (2 * 10 ** 7)
     7     13.61 MB -152.59 MB       del b
     8     13.61 MB    0.00 MB       return a

How to use basic authorization in PHP curl

Can you try this,

 $ch = curl_init($url);
 curl_setopt($ch, CURLOPT_USERPWD, $username . ":" . $password);  


How to get the innerHTML of selectable jquery element?

The parameter ui has a property called selected which is a reference to the selected dom element, you can call innerHTML on that element.

Your code $('.ui-selected').innerHTML tries to return the innerHTML property of a jQuery wrapper element for a dom element with class ui-selected

$(function () {
        selected: function (event, ui) {
            var $variable = ui.selected.innerHTML; // or $(ui.selected).html()

Demo: Fiddle

extracting days from a numpy.timedelta64 value

You can convert it to a timedelta with a day precision. To extract the integer value of days you divide it with a timedelta of one day.

>>> x = np.timedelta64(2069211000000000, 'ns')
>>> days = x.astype('timedelta64[D]')
>>> days / np.timedelta64(1, 'D')

Or, as @PhillipCloud suggested, just days.astype(int) since the timedelta is just a 64bit integer that is interpreted in various ways depending on the second parameter you passed in ('D', 'ns', ...).

You can find more about it here.

getContext is not a function

Your value:

this.element = $(id);

is a jQuery object, not a pure Canvas element.

To turn it back so you can call getContext(), call this.element.get(0), or better yet store the real element and not the jQuery object:

function canvasLayer(location, id) {

    this.width = $(window).width();
    this.height = $(window).height();
    this.element = document.createElement('canvas');

       .attr('id', id)
       .text('unsupported browser')
       .attr('width', this.width)       // for pixels
       .attr('height', this.height)
       .width(this.width)               // for CSS scaling

    this.context = this.element.getContext("2d");

See running code at, ideally using the Chrome Javascript Console so you can see the resulting object in the debug output.

In C#, how to check if a TCP port is available?

Be aware the time window between you make check and the moment you try to make connection some process may take the port - classical TOCTOU. Why don't you just try to connect? If it fails then you know the port is not available.

How can I exclude all "permission denied" messages from "find"?

Simple answer:

find . > files_and_folders 2>&-

2>&- closes (-) the standard error file descriptor (2) so all error messages are silenced.

  • Exit code will still be 1 if any 'Permission denied' errors would otherwise be printed

Robust answer for GNU find:

find . -type d \! \( -readable -executable \) -prune -print -o -print > files_and_folders

Pass extra options to find that -prune (prevent descending into) but still -print any directory (-typed) that does not (\!) have both -readable and -executable permissions, or (-o) -print any other file.

  • -readable and -executable options are GNU extensions, not part of the POSIX standard
  • May still return 'Permission denied' on abnormal/corrupt files (e.g., see bug report affecting container-mounted filesystems using lxcfs < v2.0.5)

Robust answer that works with any POSIX-compatible find (GNU, OSX/BSD, etc)

{ LC_ALL=C find . 3>&2 2>&1 1>&3 > files_and_folders | grep -v 'Permission denied'; [ $? = 1 ]; } 3>&2 2>&1

Use a pipeline to pass the standard error stream to grep, removing all lines containing the 'Permission denied' string.

LC_ALL=C sets the POSIX locale using an environment variable, 3>&2 2>&1 1>&3 and 3>&2 2>&1 duplicate file descriptors to pipe the standard-error stream to grep, and [ $? = 1 ] uses [] to invert the error code returned by grep to approximate the original behavior of find.

  • Will also filter any 'Permission denied' errors due to output redirection (e.g., if the files_and_folders file itself is not writable)

Hour from DateTime? in 24 hours format

date.ToString("HH:mm:ss"); // for 24hr format
date.ToString("hh:mm:ss"); // for 12hr format, it shows AM/PM

Refer this link for other Formatters in DateTime.

Are querystring parameters secure in HTTPS (HTTP + SSL)?

Yes. The querystring is also encrypted with SSL. Nevertheless, as this article shows, it isn't a good idea to put sensitive information in the URL. For example:

URLs are stored in web server logs - typically the whole URL of each request is stored in a server log. This means that any sensitive data in the URL (e.g. a password) is being saved in clear text on the server

HTTP vs HTTPS performance

December 2014 Update

You can easily test the difference between HTTP and HTTPS performance in your own browser using the HTTP vs HTTPS Test website by AnthumChris: “This page measures its load time over unsecure HTTP and encrypted HTTPS connections. Both pages load 360 unique, non-cached images (2.04 MB total).”

The results may surprise you.

It's important to have an up to date knowledge about the HTTPS performance because the Let’s Encrypt Certificate Authority will start issuing free, automated, and open SSL certificates in Summer 2015, thanks to Mozilla, Akamai, Cisco, Electronic Frontier Foundation and IdenTrust.

June 2015 Update

Updates on Let’s Encrypt - Arriving September 2015:

More info on Twitter: @letsencrypt

For more info on HTTPS and SSL/TLS performance see:

For more info on the importance of using HTTPS see:

To sum it up, let me quote Ilya Grigorik: "TLS has exactly one performance problem: it is not used widely enough. Everything else can be optimized."

Thanks to Chris - author of the HTTP vs HTTPS Test benchmark - for his comments below.

How to detect the swipe left or Right in Android?

You should be extend a class from View.OnTouchListener and handle the onTouch method by overriding it.

interface SwipeListener {
    fun onSwipeLeft()
    fun onSwipeRight()

class SwipeGestureListener internal constructor(
    private val listener: SwipeListener,
    private val minDistance: Int = DEFAULT_SWIPE_MIN_DISTANCE
) : View.OnTouchListener {
    companion object {
        const val DEFAULT_SWIPE_MIN_DISTANCE = 200

    private var anchorX = 0F

    override fun onTouch(view: View, event: MotionEvent): Boolean {
        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                anchorX = event.x
                return true
            MotionEvent.ACTION_UP -> {
                if (abs(event.x - anchorX) > minDistance) {
                    if (event.x > anchorX) {
                    } else {
                return true
        return view.performClick()

You can just easily implement it like this in your Activity or Fragment.

class MainActivity : AppCompatActivity(), SwipeListener {
    override fun onCreate(savedInstanceState: Bundle?) {

    override fun onSwipeLeft() {
        Toast.makeText(this, "Swipe Left", Toast.LENGTH_SHORT).show()

    override fun onSwipeRight() {
        Toast.makeText(this, "Swipe Right", Toast.LENGTH_SHORT).show()

How to get the week day name from a date?

SQL> SELECT TO_CHAR(date '1982-03-09', 'DAY') day FROM dual;


SQL> SELECT TO_CHAR(date '1982-03-09', 'DY') day FROM dual;


SQL> SELECT TO_CHAR(date '1982-03-09', 'Dy') day FROM dual;


(Note that the queries use ANSI date literals, which follow the ISO-8601 date standard and avoid date format ambiguity.)

What does this mean? "Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM"

The error is down to an "inappropriate use" of the double colon operator:

return $cnf::getConfig($key);

as by using the :: you're attempting to call a static method of the class itself. In your example you want to call a non-static method on an instantiated object.

I think what you want is:

return $cnf->getConfig($key);

Difference between os.getenv and os.environ.get

In Python 2.7 with iPython:

>>> import os
>>> os.getenv??
Signature: os.getenv(key, default=None)
def getenv(key, default=None):
    """Get an environment variable, return None if it doesn't exist.
    The optional second argument can specify an alternate default."""
    return environ.get(key, default)
File:      ~/venv/lib/python2.7/
Type:      function

So we can conclude os.getenv is just a simple wrapper around os.environ.get.

How to align content of a div to the bottom

Use CSS positioning:

/* Creates a new stacking context on the header */
#header {
  position: relative;

/* Positions header-content at the bottom of header's context */
#header-content {
  position: absolute;
  bottom: 0;

As cletus noted, you need identify the header-content to make this work.

<span id="header-content">some header content</span>

<div style="height:100%; position:relative;">
    <div style="height:10%; position:absolute; bottom:0px;">bottom</div>

How to handle static content in Spring MVC?

Place static contents like css ,js in following path


How to loop through a directory recursively to delete files with certain extensions

The following will loop through the given directory recursively and list all the contents :

for d in /home/ubuntu/*; do echo "listing contents of dir: $d"; ls -l $d/; done

Convert named list to vector with values only

Use unlist with use.names = FALSE argument.

unlist(myList, use.names=FALSE)

No server in windows>preferences

I had the same issue. I was using eclipse platform and server was missing in my show view. To fix this go:

  • help>install new software

  • in work with : select : "Indigo Update Site -" , once selected, all available software will be displayed in the section under type filter text

  • Expand “Web, XML, and Java EE Development” and select "JST Server adapters extensions"

  • then click next and finish. The server should be displayed in show view

How can I get the index from a JSON object with value?

Traverse through the array and find the index of the element which contains a key name and has the value as the passed param.

var data = [{_x000D_
  "name": "placeHolder",_x000D_
  "section": "right"_x000D_
}, {_x000D_
  "name": "Overview",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "ByFunction",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "Time",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "allFit",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "allbMatches",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "allOffers",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "allInterests",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "allResponses",_x000D_
  "section": "left"_x000D_
}, {_x000D_
  "name": "divChanged",_x000D_
  "section": "right"_x000D_
Array.prototype.getIndexOf = function(el) {_x000D_
  var arr = this;_x000D_
  for (var i=0; i<arr.length; i++){_x000D_
       return i;_x000D_
  return -1;_x000D_

Generics in C#, using type of a variable as parameter

One way to get around this is to use implicit casting:

bool DoesEntityExist<T>(T entity, Guid guid, ITransaction transaction) where T : IGloballyIdentifiable;

calling it like so:

DoesEntityExist(entity, entityGuid, transaction);

Going a step further, you can turn it into an extension method (it will need to be declared in a static class):

static bool DoesEntityExist<T>(this T entity, Guid guid, ITransaction transaction) where T : IGloballyIdentifiable;

calling as so:

entity.DoesEntityExist(entityGuid, transaction);

How do I create directory if it doesn't exist to create a file?

var filePath = context.Server.MapPath(Convert.ToString(ConfigurationManager.AppSettings["ErrorLogFile"]));

var file = new FileInfo(filePath);

file.Directory.Create(); If the directory already exists, this method does nothing.

var sw = new StreamWriter(filePath, true);

sw.WriteLine(Enter your message here);


How to monitor the memory usage of Node.js?

The original memwatch is essentially dead. Try memwatch-next instead, which seems to be working well on modern versions of Node.

Positioning the colorbar

The best way to get good control over the colorbar position is to give it its own axis. Like so:

# What I imagine your plotting looks like so far
fig = plt.figure()
ax1 = fig.add_subplot(111)

# Now adding the colorbar
cbaxes = fig.add_axes([0.8, 0.1, 0.03, 0.8]) 
cb = plt.colorbar(ax1, cax = cbaxes)  

The numbers in the square brackets of add_axes refer to [left, bottom, width, height], where the coordinates are just fractions that go from 0 to 1 of the plotting area.

Error: Expression must have integral or unscoped enum type

Your variable size is declared as: float size;

You can't use a floating point variable as the size of an array - it needs to be an integer value.

You could cast it to convert to an integer:

float *temp = new float[(int)size];

Your other problem is likely because you're writing outside of the bounds of the array:

   float *temp = new float[size];

    //Getting input from the user
    for (int x = 1; x <= size; x++){
        cout << "Enter temperature " << x << ": ";

        // cin >> temp[x];
        // This should be:
        cin >> temp[x - 1];

Arrays are zero based in C++, so this is going to write beyond the end and never write the first element in your original code.

How to insert an item into a key/value pair object?

Hashtables are not inherently sorted, your best bet is to use another structure such as a SortedList or an ArrayList

How to create/read/write JSON files in Qt5

An example on how to use that would be great. There is a couple of examples at the Qt forum, but you're right that the official documentation should be expanded.

QJsonDocument on its own indeed doesn't produce anything, you will have to add the data to it. That's done through the QJsonObject, QJsonArray and QJsonValue classes. The top-level item needs to be either an array or an object (because 1 is not a valid json document, while {foo: 1} is.)

Convert list of ASCII codes to string (byte array) in Python

key = "".join( chr( val ) for val in myList )

symfony2 : failed to write cache directory

i executed:

ps aux | grep apache

and got something like that:

root     28147  0.0  5.4 326336 27024 ?        Ss   20:06   0:00 /usr/sbin/apache2 -k start
www-data 28150  0.0  1.3 326368  6852 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
www-data 28151  0.0  4.4 329016 22124 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
www-data 28152  0.1  6.0 331252 30092 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
www-data 28153  0.0  1.3 326368  6852 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
www-data 28154  0.0  1.3 326368  6852 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
www-data 28157  0.0  1.3 326368  6852 ?        S    20:06   0:00 /usr/sbin/apache2 -k start
user     28297  0.0  0.1  15736   924 pts/4    S+   20:12   0:00 grep --color=auto apache

so my user with no access turned out to be www-data thus i executed commands:

sudo chown -R www-data app/cache
sudo chown -R www-data app/logs

and it solved access errors.

Never-ever use unsecure 777 for solving specific access probles:

sudo chmod -R 777 app/cache
sudo chmod -R 777 app/logs

Example: Communication between Activity and Service using Messaging

Seems to me you could've saved some memory by declaring your activity with "implements Handler.Callback"

How to detect a remote side socket close?

The isConnected method won't help, it will return true even if the remote side has closed the socket. Try this:

public class MyServer {
    public static final int PORT = 12345;
    public static void main(String[] args) throws IOException, InterruptedException {
        ServerSocket ss = ServerSocketFactory.getDefault().createServerSocket(PORT);
        Socket s = ss.accept();

public class MyClient {
    public static void main(String[] args) throws IOException, InterruptedException {
        Socket s = SocketFactory.getDefault().createSocket("localhost", MyServer.PORT);
        System.out.println(" connected: " + s.isConnected());
        System.out.println(" connected: " + s.isConnected());

Start the server, start the client. You'll see that it prints "connected: true" twice, even though the socket is closed the second time.

The only way to really find out is by reading (you'll get -1 as return value) or writing (an IOException (broken pipe) will be thrown) on the associated Input/OutputStreams.

Append text to file from command line without using io redirection

If you don't mind using sed then,

$ cat test 
this is line 1
$ sed -i '$ a\this is line 2 without redirection' test 
$ cat test 
this is line 1
this is line 2 without redirection

As the documentation may be a bit long to go through, some explanations :

  • -i means an inplace transformation, so all changes will occur in the file you specify
  • $ is used to specify the last line
  • a means append a line after
  • \ is simply used as a delimiter

How can you search Google Programmatically Java API

Just an alternative. Searching google and parsing the results can also be done in a generic way using any HTML Parser such as Jsoup in Java. Following is the link to the mentioned example.

Update: Link no longer works. Please look for any other example.