Programs & Examples On #Working set

Options for embedding Chromium instead of IE WebBrowser control with WPF/C#

We had exactly the same challenge some time ago. We wanted to go with CEF3 open source library which is WPF-based and supports .NET 3.5.

Firstly, the author of CEF himself listed binding for different languages here.

Secondly, we went ahead with open source .NET CEF3 binding which is called Xilium.CefGlue and had a good success with it. In cases where something is not working as you'd expect, author usually very responsive to the issues opened in build-in bitbucket tracker

So far it has served us well. Author updates his library to support latest CEF3 releases and bug fixes on regular bases.

What is a PDB file?

I had originally asked myself the question "Do I need a PDB file deployed to my customer's machine?", and after reading this post, decided to exclude the file.

Everything worked fine, until today, when I was trying to figure out why a message box containing an Exception.StackTrace was missing the file and line number information - necessary for troubleshooting the exception. I re-read this post and found the key nugget of information: that although the PDB is not necessary for the app to run, it is necessary for the file and line numbers to be present in the StackTrace string. I included the PDB file in the executable folder and now all is fine.

What is the difference between "is None" and "== None"

In this case, they are the same. None is a singleton object (there only ever exists one None).

is checks to see if the object is the same object, while == just checks if they are equivalent.

For example:

p = [1]
q = [1]
p is q # False because they are not the same actual object
p == q # True because they are equivalent

But since there is only one None, they will always be the same, and is will return True.

p = None
q = None
p is q # True because they are both pointing to the same "None"

In JavaScript, why is "0" equal to false, but when tested by 'if' it is not false by itself?

Your quotes around the 0 make it a string, which is evaluated as true.

Remove the quotes and it should work.

if (0) console.log("ha") 

Built in Python hash() function

This is the hash function that Google uses in production for python 2.5:

def c_mul(a, b):
  return eval(hex((long(a) * b) & (2**64 - 1))[:-1])

def py25hash(self):
  if not self:
    return 0 # empty
  value = ord(self[0]) << 7
  for char in self:
    value = c_mul(1000003, value) ^ ord(char)
  value = value ^ len(self)
  if value == -1:
    value = -2
  if value >= 2**63:
    value -= 2**64
  return value

postgresql return 0 if returned value is null

(this answer was added to provide shorter and more generic examples to the question - without including all the case-specific details in the original question).

There are two distinct "problems" here, the first is if a table or subquery has no rows, the second is if there are NULL values in the query.

For all versions I've tested, postgres and mysql will ignore all NULL values when averaging, and it will return NULL if there is nothing to average over. This generally makes sense, as NULL is to be considered "unknown". If you want to override this you can use coalesce (as suggested by Luc M).

$ create table foo (bar int);

$ select avg(bar) from foo;

(1 row)

$ select coalesce(avg(bar), 0) from foo;
(1 row)

$ insert into foo values (3);
$ insert into foo values (9);
$ insert into foo values (NULL);
$ select coalesce(avg(bar), 0) from foo;
(1 row)

of course, "from foo" can be replaced by "from (... any complicated logic here ...) as foo"

Now, should the NULL row in the table be counted as 0? Then coalesce has to be used inside the avg call.

$ select coalesce(avg(coalesce(bar, 0)), 0) from foo;
(1 row)

How to add meta tag in JavaScript

You can add it:

var meta = document.createElement('meta');
meta.httpEquiv = "X-UA-Compatible";
meta.content = "IE=edge";

...but I wouldn't be surprised if by the time that ran, the browser had already made its decisions about how to render the page.

The real answer here has to be to output the correct tag from the server in the first place. (Sadly, you can't just not have the tag if you need to support IE. :-| )

C# delete a folder and all files and folders within that folder



This will recursively delete all files and folders underneath "path" assuming you have the permissions to do so.

Check if decimal value is null

Decimal is a value type, so if you wish to check whether it has a value other than the value it was initialised with (zero) you can use the condition myDecimal != default(decimal).

Otherwise you should possibly consider the use of a nullable (decimal?) type and the use a condition such as myNullableDecimal.HasValue

html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

The fix posted on above link did not work for me. This did:

function isLocalStorageNameSupported() {
  var testKey = 'test', storage = window.localStorage;
  try {
    storage.setItem(testKey, '1');
    return true;
  } catch (error) {
    return false;

Derived from

How can multiple rows be concatenated into one in Oracle without creating a stored procedure?

There are many way to do the string aggregation, but the easiest is a user defined function. Try this for a way that does not require a function. As a note, there is no simple way without the function.

This is the shortest route without a custom function: (it uses the ROW_NUMBER() and SYS_CONNECT_BY_PATH functions )

SELECT questionid,
       KEEP (DENSE_RANK LAST ORDER BY curr),',') AS elements
FROM   (SELECT questionid,
               ROW_NUMBER() OVER (PARTITION BY questionid ORDER BY elementid) AS curr,
               ROW_NUMBER() OVER (PARTITION BY questionid ORDER BY elementid) -1 AS prev
        FROM   emp)
GROUP BY questionid
CONNECT BY prev = PRIOR curr AND questionid = PRIOR questionid
START WITH curr = 1;

iOS / Android cross platform development

My experience with making something very simple in PhoneGap+jQuery Mobile was fine. I was able to do it quickly for iOS. However, it didn't work on my Android phones without making some changes. The project was a very simple app to take pictures and post them to a web site. And at the end of the day it felt "clunky" compared to a true native app.

I don't believe there will ever be easy cross platform development. I think the browser is as close as you will get. By choosing something like PhoneGap I think you are just trading one set of pain points for a different set of pain points.

Google Maps V3 - How to calculate the zoom level for a given bounds

Valerio is almost right with his solution, but there is some logical mistake.

you must firstly check wether angle2 is bigger than angle, before adding 360 at a negative.

otherwise you always have a bigger value than angle

So the correct solution is:

var west = calculateMin(data.longitudes);
var east = calculateMax(data.longitudes);
var angle = east - west;
var north = calculateMax(data.latitudes);
var south = calculateMin(data.latitudes);
var angle2 = north - south;
var zoomfactor;
var delta = 0;
var horizontal = false;

if(angle2 > angle) {
    angle = angle2;
    delta = 3;

if (angle < 0) {
    angle += 360;

zoomfactor = Math.floor(Math.log(960 * 360 / angle / GLOBE_WIDTH) / Math.LN2) - 2 - delta;

Delta is there, because i have a bigger width than height.

Hide element by class in pure Javascript

var appBanners = document.getElementsByClassName('appBanner');

for (var i = 0; i < appBanners.length; i ++) {
    appBanners[i].style.display = 'none';


Public free web services for testing soap client

There is a bunch on here:

Just google for "Free WebService" or "Open WebService" and you'll find tons of open SOAP endpoints.

Remember, you can get a WSDL from any ASMX endpoint by adding ?WSDL to the url.

Function not defined javascript

I just went through the same problem. And found out once you have a syntax or any type of error in you javascript, the whole file don't get loaded so you cannot use any of the other functions at all.

Is there a simple way that I can sort characters in a string in alphabetical order

Yes; copy the string to a char array, sort the char array, then copy that back into a string.

static string SortString(string input)
    char[] characters = input.ToArray();
    return new string(characters);

Paritition array into N chunks with Numpy

How about this? Here you split the array using the length you want to have.

a = np.random.randint(0,10,[4,4])

array([[1, 5, 8, 7],
       [3, 2, 4, 0],
       [7, 7, 6, 2],
       [7, 4, 3, 0]])

array([[1, 5, 8, 7],
       [3, 2, 4, 0]])

array([[7, 7, 6, 2],
       [7, 4, 3, 0]])

Resolve conflicts using remote changes when pulling from Git remote

If you truly want to discard the commits you've made locally, i.e. never have them in the history again, you're not asking how to pull - pull means merge, and you don't need to merge. All you need do is this:

# fetch from the default remote, origin
git fetch
# reset your current branch (master) to origin's master
git reset --hard origin/master

I'd personally recommend creating a backup branch at your current HEAD first, so that if you realize this was a bad idea, you haven't lost track of it.

If on the other hand, you want to keep those commits and make it look as though you merged with origin, and cause the merge to keep the versions from origin only, you can use the ours merge strategy:

# fetch from the default remote, origin
git fetch
# create a branch at your current master
git branch old-master
# reset to origin's master
git reset --hard origin/master
# merge your old master, keeping "our" (origin/master's) content
git merge -s ours old-master

Jquery Smooth Scroll To DIV - Using ID value from Link

Ids are meant to be unique, and never use an id that starts with a number, use data-attributes instead to set the target like so :

<div id="searchbycharacter">
    <a class="searchbychar" href="#" data-target="numeric">0-9 |</a> 
    <a class="searchbychar" href="#" data-target="A"> A |</a> 
    <a class="searchbychar" href="#" data-target="B"> B |</a> 
    <a class="searchbychar" href="#" data-target="C"> C |</a> 
    ... Untill Z

As for the jquery :

$(document).on('click','.searchbychar', function(event) {
    var target = "#" + this.getAttribute('data-target');
    $('html, body').animate({
        scrollTop: $(target).offset().top
    }, 2000);

Query error with ambiguous column name in SQL

it's because some of the fields (specifically InvoiceID on the Invoices table and on the InvoiceLineItems) are present on both table. The way to answer of question is to add an ALIAS on it.

    a.VendorName,  Invoices.InvoiceID, .. -- or use full tableName
FROM Vendors a   -- This is an `ALIAS` of table Vendors
JOIN Invoices ON (Vendors.VendorID = Invoices.VendorID)
JOIN InvoiceLineItems ON (Invoices.InvoiceID = InvoiceLineItems.InvoiceID)
    Invoices.InvoiceID IN
        (SELECT InvoiceSequence 
         FROM InvoiceLineItems
         WHERE InvoiceSequence > 1)
    VendorName, InvoiceID, InvoiceSequence, InvoiceLineItemAmount

What are the options for storing hierarchical data in a relational database?

This is really a square peg, round hole question.

If relational databases and SQL are the only hammer you have or are willing to use, then the answers that have been posted thus far are adequate. However, why not use a tool designed to handle hierarchical data? Graph database are ideal for complex hierarchical data.

The inefficiencies of the relational model along with the complexities of any code/query solution to map a graph/hierarchical model onto a relational model is just not worth the effort when compared to the ease with which a graph database solution can solve the same problem.

Consider a Bill of Materials as a common hierarchical data structure.

class Component extends Vertex {
    long assetId;
    long partNumber;
    long material;
    long amount;

class PartOf extends Edge {

class AdjacentTo extends Edge {

Shortest path between two sub-assemblies: Simple graph traversal algorithm. Acceptable paths can be qualified based on criteria.

Similarity: What is the degree of similarity between two assemblies? Perform a traversal on both sub-trees computing the intersection and union of the two sub-trees. The percent similar is the intersection divided by the union.

Transitive Closure: Walk the sub-tree and sum up the field(s) of interest, e.g. "How much aluminum is in a sub-assembly?"

Yes, you can solve the problem with SQL and a relational database. However, there are much better approaches if you are willing to use the right tool for the job.

base64 encode in MySQL

If you need this for < 5.6, I tripped across this UDF which seems to work fine:

How to get the error message from the error code returned by GetLastError()?

Since c++11, you can use the standard library instead of FormatMessage:

#include <system_error>

std::string GetLastErrorAsString(){
    DWORD errorMessageID = ::GetLastError();
    if (errorMessageID == 0) {
        return std::string(); //No error message has been recorded
    } else {
        return std::system_category().message(errorMessageID);

How do I insert non breaking space character &nbsp; in a JSF page?

You can use primefaces library

 <p:spacer width="10" />

How to output a multiline string in Bash?

Also with indented source code you can use <<- (with a trailing dash) to ignore leading tabs (but not leading spaces).

For example this:

if [ some test ]; then
    cat <<- xx

Outputs indented text without the leading whitespace:


Django: How can I call a view function from template?

you can put the input inside a form like this:-

        $(document).on('click','#send', function(){

<form id="myForm" action="/request_page url/" method="post">
    <input type="hidden" id="hid" name="hid"/>
<div id="send">Send Data</div>

grep regex whitespace behavior

This looks like a behavior difference in the handling of \s between grep 2.5 and newer versions (a bug in old grep?). I confirm your result with grep 2.5.4, but all four of your greps do work when using grep 2.6.3 (Ubuntu 10.10).


GNU grep 2.5.4
echo "foo bar" | grep "\s"
   (doesn't match)


GNU grep 2.6.3
echo "foo bar" | grep "\s"
foo bar

Probably less trouble (as \s is not documented):

Both GNU greps
echo "foo bar" | grep "[[:space:]]"
foo bar

My advice is to avoid using \s ... use [ \t]* or [[:space:]] or something like it instead.

android.os.NetworkOnMainThreadException with android 4.2

Use StrictMode Something like this:-

   if (android.os.Build.VERSION.SDK_INT > 9) {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();


How to select element using XPATH syntax on Selenium for Python?

Check this blog by Martin Thoma. I tested the below code on MacOS Mojave and it worked as specified.

> def get_browser():
>     """Get the browser (a "driver")."""
>     # find the path with 'which chromedriver'
>     path_to_chromedriver = ('/home/moose/GitHub/algorithms/scraping/'
>                             'venv/bin/chromedriver')
>     download_dir = "/home/moose/selenium-download/"
>     print("Is directory: {}".format(os.path.isdir(download_dir)))
>     from import Options
>     chrome_options = Options()
>     chrome_options.add_experimental_option('prefs', {
>         "plugins.plugins_list": [{"enabled": False,
>                                   "name": "Chrome PDF Viewer"}],
>         "download": {
>             "prompt_for_download": False,
>             "default_directory": download_dir
>         }
>     })
>     browser = webdriver.Chrome(path_to_chromedriver,
>                                chrome_options=chrome_options)
>     return browser

Why do we usually use || over |? What is the difference?

1).(expression1 | expression2), | operator will evaluate expression2 irrespective of whether the result of expression1 is true or false.


class Or 
    public static void main(String[] args) 
        boolean b=true;

        if (b | test());

    static boolean test()
        System.out.println("No short circuit!");
        return false;

2).(expression1 || expression2), || operator will not evaluate expression2 if expression1 is true.


class Or 
    public static void main(String[] args) 
        boolean b=true;

        if (b || test())
            System.out.println("short circuit!");

    static boolean test()
        System.out.println("No short circuit!");
        return false;

Parsing a comma-delimited std::string

Input one number at a time, and check whether the following character is ,. If so, discard it.

#include <vector>
#include <string>
#include <sstream>
#include <iostream>

int main()
    std::string str = "1,2,3,4,5,6";
    std::vector<int> vect;

    std::stringstream ss(str);

    for (int i; ss >> i;) {
        if (ss.peek() == ',')

    for (std::size_t i = 0; i < vect.size(); i++)
        std::cout << vect[i] << std::endl;

How to disable manual input for JQuery UI Datepicker field?

When you make the input, set it to be readonly.

<input type="text" name="datepicker" id="datepicker" readonly="readonly" />

Is a new line = \n OR \r\n?

\n is used for Unix systems (including Linux, and OSX).

\r\n is mainly used on Windows.

\r is used on really old Macs.

PHP_EOL constant is used instead of these characters for portability between platforms.

Convert a Unix timestamp to time in JavaScript

If you want to convert Unix time duration to real hours, minutes, and seconds, you could use the following code:

var hours = Math.floor(timestamp / 60 / 60);
var minutes = Math.floor((timestamp - hours * 60 * 60) / 60);
var seconds = Math.floor(timestamp - hours * 60 * 60 - minutes * 60 );
var duration = hours + ':' + minutes + ':' + seconds;

Replace a string in shell script using a variable

I had a similar requirement to this but my replace var contained an ampersand. Escaping the ampersand like this solved my problem:

replace="salt & pepper"
echo "pass the salt" | sed "s/salt/${replace/&/\&}/g"

How to save a dictionary to a file?

file_name = open("data.json", "w")
json.dump(test_response, file_name)

or use context manager, which is better:

with open("data.json", "w") as file_name:
    json.dump(test_response, file_name)

GCD to perform task in main thread

No, you do not need to check whether you’re already on the main thread. By dispatching the block to the main queue, you’re just scheduling the block to be executed serially on the main thread, which happens when the corresponding run loop is run.

If you already are on the main thread, the behaviour is the same: the block is scheduled, and executed when the run loop of the main thread is run.

iTunes Connect: How to choose a good SKU?

You are able to choose one that you like, but it has to be unique.

Every time I have to enter the SKU I use the App identifier (e.g. de.mycompany.myappname) because this is already unique.

Is there a way to detect if a browser window is not currently active?

I would use jQuery because then all you have to do is this:

  //your code here
  //your code

Or at least it worked for me.

Issue with background color and Google Chrome

I had the same thing in both Chrome and Safari aka Webkit browsers. I'm suspecting it's not a bug, but the incorrect use of css which 'breaks' the background.

In the Question above, the body background property is set to:

background: black;

Which is fine, but not entirely correct. There's no image background, thus...

background-color: black;

Add a user control to a wpf window

You need to add a reference inside the window tag. Something like:


(When you add xmlns:controls=" intellisense should kick in to make this bit easier)

Then you can add the control with:

<controls:CustomControlClassName ..... />

How can I get the day of a specific date with PHP

$datetime = DateTime::createFromFormat('Ymd', '20151102');

echo $datetime->format('D');

Adding form action in html in laravel

Your form is also missing '{{csrf_field()}}'

How to store a list in a column of a database table

I was very reluctant to choose the path I finally decide to take because of many answers. While they add more understanding to what is SQL and its principles, I decided to become an outlaw. I was also hesitant to post my findings as for some it's more important to vent frustration to someone breaking the rules rather than understanding that there are very few universal truthes.

I have tested it extensively and, in my specific case, it was way more efficient than both using array type (generously offered by PostgreSQL) or querying another table.

Here is my answer: I have successfully implemented a list into a single field in PostgreSQL, by making use of the fixed length of each item of the list. Let say each item is a color as an ARGB hex value, it means 8 char. So you can create your array of max 10 items by multiplying by the length of each item:

ALTER product ADD color varchar(80)

In case your list items length differ you can always fill the padding with \0

NB: Obviously this is not necessarily the best approach for hex number since a list of integers would consume less storage but this is just for the purpose of illustrating this idea of array by making use of a fixed length allocated to each item.

The reason why: 1/ Very convenient: retrieve item i at substring i*n, (i +1)*n. 2/ No overhead of cross tables queries. 3/ More efficient and cost-saving on the server side. The list is like a mini blob that the client will have to split.

While I respect people following rules, many explanations are very theoretical and often fail to acknowledge that, in some specific cases, especially when aiming for cost optimal with low-latency solutions, some minor tweaks are more than welcome.

"God forbid that it is violating some holy sacred principle of SQL": Adopting a more open-minded and pragmatic approach before reciting the rules is always the way to go. Else you might end up like a candid fanatic reciting the Three Laws of Robotics before being obliterated by Skynet

I don't pretend that this solution is a breakthrough, nor that it is ideal in term of readability and database flexibility, but it can certainly give you an edge when it comes to latency.

Using Tempdata in ASP.NET MVC - Best practice

Just be aware of TempData persistence, it's a bit tricky. For example if you even simply read TempData inside the current request, it would be removed and consequently you don't have it for the next request. Instead, you can use Peek method. I would recommend reading this cool article:

MVC Tempdata , Peek and Keep confusion

Push method in React Hooks (useState)?

To expand a little further, here are some common examples. Starting with:

const [theArray, setTheArray] = useState(initialArray);
const [theObject, setTheObject] = useState(initialObject);

Push element at end of array

setTheArray(prevArray => [...prevArray, newValue])

Push/update element at end of object

setTheObject(prevState => ({ ...prevState, currentOrNewKey: newValue}));

Push/update element at end of array of objects

setTheArray(prevState => [...prevState, {currentOrNewKey: newValue}]);

Push element at end of object of arrays

let specificArrayInObject = theObject.array.slice();
const newObj = { ...theObject, []: specificArrayInObject };

Here are some working examples too.

TypeError: Can't convert 'int' object to str implicitly

You cannot concatenate a string with an int. You would need to convert your int to a string using the str function, or use formatting to format your output.

Change: -

print("Ok. Your balance is now at " + balanceAfterStrength + " skill points.")

to: -

print("Ok. Your balance is now at {} skill points.".format(balanceAfterStrength))

or: -

print("Ok. Your balance is now at " + str(balanceAfterStrength) + " skill points.")

or as per the comment, use , to pass different strings to your print function, rather than concatenating using +: -

print("Ok. Your balance is now at ", balanceAfterStrength, " skill points.")

jQuery $(document).ready and UpdatePanels?

function pageLoad() is very dangerous to use in this situation. You could have events become wired multiple times. I would also stay away from .live() as it attaches to the document element and has to traverse the entire page (slow and crappy).

The best solution I have seen so far is to use jQuery .delegate() function on a wrapper outside the update panel and make use of bubbling. Other then that, you could always wire up the handlers using Microsoft's Ajax library which was designed to work with UpdatePanels.

How to convert these strange characters? (ë, Ã, ì, ù, Ã)

These are utf-8 encoded characters. Use utf8_decode() to convert them to normal ISO-8859-1 characters.

VB.NET - How to move to next item a For Each Loop?

I want to be clear that the following code is not good practice. You can use GOTO Label:

For Each I As Item In Items

    If I = x Then
       'Move to next item
        GOTO Label1
    End If

    ' Do something

Truncate number to two decimal places without rounding

I know there are already few working examples, but I think it's worth to propose my String.toFixed equivalent, some may find it helpful.

That's my toFixed alternative, that don't round numbers, just truncates it or adds zeroes according to given precision. For extra long number it uses JS build-in rounding when precision is to long. Function works for all problematic number I've found on stack.

function toFixedFixed(value, precision = 0) {
    let stringValue = isNaN(+value) ? '0' : String(+value);

    if (stringValue.indexOf('e') > -1 || stringValue === 'Infinity' || stringValue === '-Infinity') {
        throw new Error('To large number to be processed');

    let [ beforePoint, afterPoint ] = stringValue.indexOf('.') > -1 ? stringValue.split('.') : [ stringValue, ''];

    // Force automatic rounding for some long real numbers that ends with 99X, by converting it to string, cutting off last digit, then adding extra nines and casting it on number again
    // e.g. 2.0199999999999996: +('2.019999999999999' + '9999') will give 2.02
    if (stringValue.length >= 17 && afterPoint.length > 2 && +afterPoint.substr(afterPoint.length - 3) > 995) {
        stringValue = String(+(stringValue.substr(0, afterPoint.length - 1) + '9'.repeat(stringValue.split('.').shift().length + 4)));
        [ beforePoint, afterPoint ] = String(stringValue).indexOf('.') > -1 ? stringValue.split('.') : [ stringValue, ''];

    if (precision === 0) {
        return beforePoint;
    } else if (afterPoint.length > precision) {
        return `${beforePoint}.${afterPoint.substr(0, precision)}`;
    } else {
        return `${beforePoint}.${afterPoint}${'0'.repeat(precision - afterPoint.length)}`;

Keep in mind that precision may not be handled properly for numbers of length 18 and greater, e.g. 64-bit Chrome will round it or add "e+" / "e-" to keep number's length at 18.

If you want to perform operations on real numbers it's safer to multiply it by Math.sqrt(10, precision) first, make the calculations, then dive result by multiplier's value.


0.06 + 0.01 is 0.06999999999999999, and every formatting function that's not rounding will truncate it to 0.06 for precision 2.

But if you'll perform same operation with multiplier&divider: (0.06 * 100 + 0.01 * 100) / 100, you'll get 0.07.

That's why it's so important to use such multiplier/divider when dealing with real numbers in javascript, especially when you're calculating money...

Spring MVC Controller redirect using URL parameters instead of in response

You can have processForm() return a View object instead, and have it return the concrete type RedirectView which has a parameter for setExposeModelAttributes().

When you return a view name prefixed with "redirect:", Spring MVC transforms this to a RedirectView object anyway, it just does so with setExposeModelAttributes to true (which I think is an odd value to default to).

How to resolve conflicts in EGit

As it's an issue we face more than often, below are the steps to resolve it.

  1. Open the Git perspective. In the Git Repository view, go to on Branches ? Local ? master and right click ? Merge...

  2. It should auto select Remote Tracking ? *origin/master. Press Merge.

  3. Launch stage view in Eclipse.

  4. Double click the files which initially showed conflict

  5. In the conflict merge view, by selecting the left arrow for all the non-conflict + conflict changes from left to right, you can resolve all the conflicts.

  6. Save the merged file.

  7. Do a Team ? pull from Eclipse again.

You are all set :)

How to embed a PDF?

FlexPaper is probably still the best viewer out there to be used for this kind of stuff. It has a traditional viewer and a more turn page / flip book style viewer both in flash and html5

What does `return` keyword mean inside `forEach` function?

The return exits the current function, but the iterations keeps on, so you get the "next" item that skips the if and alerts the 4...

If you need to stop the looping, you should just use a plain for loop like so:

$('button').click(function () {
   var arr = [1, 2, 3, 4, 5];
   for(var i = 0; i < arr.length; i++) {
     var n = arr[i]; 
     if (n == 3) {

You can read more about js break & continue here:

Abort a Git Merge

If you do "git status" while having a merge conflict, the first thing git shows you is how to abort the merge.

output of git status while having a merge conflict

MySQL remove all whitespaces from the entire column

To replace all spaces :

UPDATE `table` SET `col_name` = REPLACE(`col_name`, ' ', '')

To remove all tabs characters :

UPDATE `table` SET `col_name` = REPLACE(`col_name`, '\t', '' )

To remove all new line characters :

UPDATE `table` SET `col_name` = REPLACE(`col_name`, '\n', '')

To remove first and last space(s) of column :

UPDATE `table` SET `col_name` = TRIM(`col_name`)

Making HTTP Requests using Chrome Developer tools

If you want to edit and reissue a request that you have captured in Chrome Developer Tools' Network tab:

  • Right-click the Name of the request
  • Select Copy > Copy as cURL
  • Paste to the command line (command includes cookies and headers)
  • Edit request as needed and run

enter image description here

FragmentActivity to Fragment

first of all;

a Fragment must be inside a FragmentActivity, that's the first rule,

a FragmentActivity is quite similar to a standart Activity that you already know, besides having some Fragment oriented methods

second thing about Fragments, is that there is one important method you MUST call, wich is onCreateView, where you inflate your layout, think of it as the setContentLayout

here is an example:

    @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     mView       = inflater.inflate(R.layout.fragment_layout, container, false);       return mView; } 

and continu your work based on that mView, so to find a View by id, call mView.findViewById(..);

for the FragmentActivity part:

the xml part "must" have a FrameLayout in order to inflate a fragment in it

        <FrameLayout             android:id="@+id/content_frame"             android:layout_width="match_parent"             android:layout_height="match_parent"  >         </FrameLayout> 

as for the inflation part

getSupportFragmentManager().beginTransaction().replace(, new YOUR_FRAGMENT, "TAG").commit();

begin with these, as there is tons of other stuf you must know about fragments and fragment activities, start of by reading something about it (like life cycle) at the android developer site

SQL How to remove duplicates within select query?

There are multiple rows with the same date, but the time is different. Therefore, DISTINCT start_date will not work. What you need is: cast the start_date to a DATE (so the TIME part is gone), and then do a DISTINCT:


Depending on what database you use, the type name for DATE is different.

How do I link to part of a page? (hash?)

If there is any tag with an id (e.g., <div id="foo">), then you can simply append #foo to the URL. Otherwise, you can't arbitrarily link to portions of a page.

Here's a complete example: <a href="">Jump to #foo on page.html</a>

Linking content on the same page example: <a href="#foo">Jump to #foo on same page</a>

It is called a URI fragment.

TypeScript: Creating an empty typed container array

Please try this which it works for me.

return [] as Criminal[];

Mockito: Inject real objects into private @Autowired fields

Use @Spy annotation

public class DemoTest {
    private SomeService service = new RealServiceImpl();

    private Demo demo;

    /* ... */

Mockito will consider all fields having @Mock or @Spy annotation as potential candidates to be injected into the instance annotated with @InjectMocks annotation. In the above case 'RealServiceImpl' instance will get injected into the 'demo'

For more details refer




C - gettimeofday for computing time?

No. gettimeofday should NEVER be used to measure time.

This is causing bugs all over the place. Please don't add more bugs.

How to view table contents in Mysql Workbench GUI?

You have to open database connection, not workbench file with schema. It looks a bit wierd, but it makes sense when you realize what you are editing.

So, go to home tab, double click database connection (create it if you don't have it yet) and have fun.

SQL Server default character encoding

You can see collation settings for each table like the following code:

SELECT TableName, ColumnName, collation_name  
FROM sys.columns c  
INNER JOIN sys.tables t on c.object_id = t.object_id where = 'name of table';

How to write unit testing for Angular / TypeScript for private methods with Jasmine

I agree with @toskv: I wouldn't recommend to do that:-)

But if you really want to test your private method, you can be aware that the corresponding code for the TypeScript correspond to a method of the constructor function prototype. This means that it can be used at runtime (whereas you will probably have some compilation errors).

For example:

export class FooBar {
  private _status: number;

  constructor( private foo : Bar ) {

  private initFooBar(data){ data );
    this._status =;

will be transpiled into:

(function(System) {(function(__moduleName){System.register([], function(exports_1, context_1) {
  "use strict";
  var __moduleName = context_1 &&;
  var FooBar;
  return {
    execute: function() {
      FooBar = (function () {
        function FooBar(foo) {
 = foo;
        FooBar.prototype.initFooBar = function (data) {
          this._status =;
        return FooBar;
      exports_1("FooBar", FooBar);

See this plunkr:

Python group by

Python's built-in itertools module actually has a groupby function , but for that the elements to be grouped must first be sorted such that the elements to be grouped are contiguous in the list:

from operator import itemgetter
sortkeyfn = itemgetter(1)
input = [('11013331', 'KAT'), ('9085267', 'NOT'), ('5238761', 'ETH'), 
 ('5349618', 'ETH'), ('11788544', 'NOT'), ('962142', 'ETH'), ('7795297', 'ETH'), 
 ('7341464', 'ETH'), ('9843236', 'KAT'), ('5594916', 'ETH'), ('1550003', 'ETH')] 

Now input looks like:

[('5238761', 'ETH'), ('5349618', 'ETH'), ('962142', 'ETH'), ('7795297', 'ETH'),
 ('7341464', 'ETH'), ('5594916', 'ETH'), ('1550003', 'ETH'), ('11013331', 'KAT'),
 ('9843236', 'KAT'), ('9085267', 'NOT'), ('11788544', 'NOT')]

groupby returns a sequence of 2-tuples, of the form (key, values_iterator). What we want is to turn this into a list of dicts where the 'type' is the key, and 'items' is a list of the 0'th elements of the tuples returned by the values_iterator. Like this:

from itertools import groupby
result = []
for key,valuesiter in groupby(input, key=sortkeyfn):
    result.append(dict(type=key, items=list(v[0] for v in valuesiter)))

Now result contains your desired dict, as stated in your question.

You might consider, though, just making a single dict out of this, keyed by type, and each value containing the list of values. In your current form, to find the values for a particular type, you'll have to iterate over the list to find the dict containing the matching 'type' key, and then get the 'items' element from it. If you use a single dict instead of a list of 1-item dicts, you can find the items for a particular type with a single keyed lookup into the master dict. Using groupby, this would look like:

result = {}
for key,valuesiter in groupby(input, key=sortkeyfn):
    result[key] = list(v[0] for v in valuesiter)

result now contains this dict (this is similar to the intermediate res defaultdict in @KennyTM's answer):

{'NOT': ['9085267', '11788544'], 
 'ETH': ['5238761', '5349618', '962142', '7795297', '7341464', '5594916', '1550003'], 
 'KAT': ['11013331', '9843236']}

(If you want to reduce this to a one-liner, you can:

result = dict((key,list(v[0] for v in valuesiter)
              for key,valuesiter in groupby(input, key=sortkeyfn))

or using the newfangled dict-comprehension form:

result = {key:list(v[0] for v in valuesiter)
              for key,valuesiter in groupby(input, key=sortkeyfn)}

Making href (anchor tag) request POST instead of GET?

Using jQuery it is very simple assuming the URL you wish to post to is on the same server or has implemented CORS

$(function() {
  $("#employeeLink").on("click",function(e) {
    e.preventDefault(); // cancel the link itself
    $.post(this.href,function(data) {

If you insist on using frames which I strongly discourage, have a form and submit it with the link

<form action="employee.action" method="post" target="myFrame" id="myForm"></form>

and use (in plain JS)

 window.addEventListener("load",function() {
   document.getElementById("employeeLink").addEventListener("click",function(e) {
     e.preventDefault(); // cancel the link
     document.getElementById("myForm").submit(); // but make sure nothing has name or ID="submit"

Without a form we need to make one

 window.addEventListener("load",function() {
   document.getElementById("employeeLink").addEventListener("click",function(e) {
     e.preventDefault(); // cancel the actual link
     var myForm = document.createElement("form");
     myForm.action=this.href;// the href of the link"myFrame";

Where do I find the bashrc file on Mac?

The .bash_profile for macOS is found in the $HOME directory. You can create the file if it does not exit. Sublime Text 3 can help.

  • If you follow the instruction from OS X Command Line - Sublime Text to launch ST3 with subl then you can just do this

    $ subl ~/.bash_profile
  • An easier method is to use open

    $ open ~/.bash_profile -a "Sublime Text"

Use Command + Shift + . in Finder to view hidden files in your home directory.

Android lollipop change navigation bar color

Here is how to do it programatically:

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {                

Using Compat library:

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    getWindow().setNavigationBarColor(ContextCompat.getColor(this, R.color.primary));

Here is how to do it with xml in the values-v21/style.xml folder:

<item name="android:navigationBarColor">@color/your_color</item>

placeholder for select tag

         <option value="" disabled selected hidden> placeholder</option>
         <option value="op1">op1</option>
         <option value="op2">op2</option>
         <option value="op3">op3</option>
         <option value="op4">op4</option>

Best approach to remove time part of datetime in SQL Server

I, personally, almost always use User Defined functions for this if dealing with SQL Server 2005 (or lower version), however, it should be noted that there are specific drawbacks to using UDF's, especially if applying them to WHERE clauses (see below and the comments on this answer for further details). If using SQL Server 2008 (or higher) - see below.

In fact, for most databases that I create, I add these UDF's in right near the start since I know there's a 99% chance I'm going to need them sooner or later.

I create one for "date only" & "time only" (although the "date only" one is by far the most used of the two).

Here's some links to a variety of date-related UDF's:

Essential SQL Server Date, Time and DateTime Functions
Get Date Only Function

That last link shows no less than 3 different ways to getting the date only part of a datetime field and mentions some pros and cons of each approach.

If using a UDF, it should be noted that you should try to avoid using the UDF as part of a WHERE clause in a query as this will greatly hinder performance of the query. The main reason for this is that using a UDF in a WHERE clause renders that clause as non-sargable, which means that SQL Server can no longer use an index with that clause in order to improve the speed of query execution. With reference to my own usage of UDF's, I'll frequently use the "raw" date column within the WHERE clause, but apply the UDF to the SELECTed column. In this way, the UDF is only applied to the filtered result-set and not every row of the table as part of the filter.

Of course, the absolute best approach for this is to use SQL Server 2008 (or higher) and separate out your dates and times, as the SQL Server database engine is then natively providing the individual date and time components, and can efficiently query these independently without the need for a UDF or other mechanism to extract either the date or time part from a composite datetime type.

How to create number input field in Flutter?

Set the keyboard and a validator

String numberValidator(String value) {
  if(value == null) {
    return null;
  final n = num.tryParse(value);
  if(n == null) {
    return '"$value" is not a valid number';
  return null;

new TextFormField(
    keyboardType: TextInputType.number, 
    validator: numberValidator, 
    textAlign: TextAlign.right

Calling ASP.NET MVC Action Methods from JavaScript

Javascript Function

function AddToCart(id) {
   url: '@Url.Action("AddToCart", "ControllerName")',
   type: 'GET',
   dataType: 'json',
   cache: false,
   data: { 'id': id },
   success: function (results) {
   error: function () {
    alert('Error occured');

Controller Method to call

  public JsonResult AddToCart(string id)
    string newId = id;
     return Json(newId, JsonRequestBehavior.AllowGet);

How to capture Curl output to a file?

For those of you want to copy the cURL output in the clipboard instead of outputting to a file, you can use pbcopy by using the pipe | after the cURL command.

Example: curl | pbcopy. This will copy all the content from the given URL to your clipboard.

Converting a string to a date in a cell

To accomodate both data scenarios you have, you will want to use this:


That will give you the date number representation for a cell that Excel has in date, or in text datatype.

How do I see which checkbox is checked?

I love short hands so:

$isChecked = isset($_POST['myCheckbox']) ? "yes" : "no";

CSS3 :unchecked pseudo-class

I think you are trying to over complicate things. A simple solution is to just style your checkbox by default with the unchecked styles and then add the checked state styles.

input[type="checkbox"] {
  // Unchecked Styles
input[type="checkbox"]:checked {
  // Checked Styles

I apologize for bringing up an old thread but felt like it could have used a better answer.

EDIT (3/3/2016):

W3C Specs state that :not(:checked) as their example for selecting the unchecked state. However, this is explicitly the unchecked state and will only apply those styles to the unchecked state. This is useful for adding styling that is only needed on the unchecked state and would need removed from the checked state if used on the input[type="checkbox"] selector. See example below for clarification.

input[type="checkbox"] {
  /* Base Styles aka unchecked */
  font-weight: 300; // Will be overwritten by :checked
  font-size: 16px; // Base styling
input[type="checkbox"]:not(:checked) {
  /* Explicit Unchecked Styles */
  border: 1px solid #FF0000; // Only apply border to unchecked state
input[type="checkbox"]:checked {
  /* Checked Styles */
  font-weight: 900; // Use a bold font when checked

Without using :not(:checked) in the example above the :checked selector would have needed to use a border: none; to achieve the same affect.

Use the input[type="checkbox"] for base styling to reduce duplication.

Use the input[type="checkbox"]:not(:checked) for explicit unchecked styles that you do not want to apply to the checked state.

How to rename with prefix/suffix?

The easiest way to bulk rename files in directory is:

ls | xargs -I fileName mv fileName fileName.suffix

SQLiteDatabase.query method

Where clause and args work together to form the WHERE statement of the SQL query. So say you looking to express

WHERE Column1 = 'value1' AND Column2 = 'value2'

Then your whereClause and whereArgs will be as follows

String whereClause = "Column1 =? AND Column2 =?";
String[] whereArgs = new String[]{"value1", "value2"};

If you want to select all table columns, i believe a null string passed to tableColumns will suffice.

Can't find/install

Your problem comes from the 32/64 bit version of your JDK/JRE... Your shared lib is searched for a 32 bit version.

Your default JDK is a 32 bit version. Try to install a 64 bit one by default and relaunch your `.sh file.

Combine :after with :hover

Just append :after to your #alertlist li:hover selector the same way you do with your #alertlist li.selected selector:

#alertlist li.selected:after, #alertlist li:hover:after
    top: 0;

    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-left: 10px solid #303030;
    content: "";

Sequelize, convert entity to plain object

As CharlesA notes in his answer, .values() is technically deprecated, though this fact isn't explicitly noted in the docs. If you don't want to use { raw: true } in the query, the preferred approach is to call .get() on the results.

.get(), however, is a method of an instance, not of an array. As noted in the linked issue above, Sequelize returns native arrays of instance objects (and the maintainers don't plan on changing that), so you have to iterate through the array yourself:

    where: {
        nodeid: node.nodeid
}).success((sensors) => {
    const nodeData = => node.get({ plain: true }));

Ship an application with a database

From what I've seen you should be be shipping a database that already has the tables setup and data. However if you want (and depending on the type of application you have) you can allow "upgrade database option". Then what you do is download the latest sqlite version, get the latest Insert/Create statements of a textfile hosted online, execute the statements and do a data transfer from the old db to the new one.

Set the layout weight of a TextView programmatically

You have to use TableLayout.LayoutParams with something like this:

TextView tv = new TextView(v.getContext());
tv.setLayoutParams(new TableLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 1f));

The last parameter is the weight.

Calculate days between two Dates in Java 8

Here you go:

public class DemoDate {
    public static void main(String[] args) {
        LocalDate today =;
        System.out.println("Current date: " + today);

        //add 1 month to the current date
        LocalDate date2 =, ChronoUnit.MONTHS);
        System.out.println("Next month: " + date2);

        // Put latest date 1st and old date 2nd in 'between' method to get -ve date difference
        long daysNegative = ChronoUnit.DAYS.between(date2, today);
        System.out.println("Days : "+daysNegative);

        // Put old date 1st and new date 2nd in 'between' method to get +ve date difference
        long datePositive = ChronoUnit.DAYS.between(today, date2);
        System.out.println("Days : "+datePositive);

How to [recursively] Zip a directory in PHP?

I needed to run this Zip function in Mac OSX

so I would always zip that annoying .DS_Store.

I adapted by including additionalIgnore files.

function zipIt($source, $destination, $include_dir = false, $additionalIgnoreFiles = array())
    // Ignore "." and ".." folders by default
    $defaultIgnoreFiles = array('.', '..');

    // include more files to ignore
    $ignoreFiles = array_merge($defaultIgnoreFiles, $additionalIgnoreFiles);

    if (!extension_loaded('zip') || !file_exists($source)) {
        return false;

    if (file_exists($destination)) {
        unlink ($destination);

    $zip = new ZipArchive();
        if (!$zip->open($destination, ZIPARCHIVE::CREATE)) {
        return false;
    $source = str_replace('\\', '/', realpath($source));

    if (is_dir($source) === true)

        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);

        if ($include_dir) {

            $arr = explode("/",$source);
            $maindir = $arr[count($arr)- 1];

            $source = "";
            for ($i=0; $i < count($arr) - 1; $i++) { 
                $source .= '/' . $arr[$i];

            $source = substr($source, 1);



        foreach ($files as $file)
            $file = str_replace('\\', '/', $file);

            // purposely ignore files that are irrelevant
            if( in_array(substr($file, strrpos($file, '/')+1), $ignoreFiles) )

            $file = realpath($file);

            if (is_dir($file) === true)
                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
            else if (is_file($file) === true)
                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
    else if (is_file($source) === true)
        $zip->addFromString(basename($source), file_get_contents($source));

    return $zip->close();

SO to ignore the .DS_Store from zip, you run

zipIt('/path/to/folder', '/path/to/', false, array('.DS_Store'));

HttpWebRequest-The remote server returned an error: (400) Bad Request

What type of authentication do you use? Send the credentials using the properties Ben said before and setup a cookie handler. You already allow redirection, check your webserver if any redirection occurs (NTLM auth does for sure). If there is a redirection you need to store the session which is mostly stored in a session cookie.

Jquery insert new row into table at a certain index

Adding on to Nick Craver's answer and also considering the point raised by rossisdead, if scenario exists like one has to append to an empty table, or before a certain row, I have done like this:

var arr = []; //array
if (your condition) {
  arr.push(; //push row's id for eg: to the array
  idx = arr.sort().indexOf(;

  if (idx === 0) {   
    if (arr.length === 1) {  //if array size is only 1 (currently pushed item)
    else {       //if array size more than 1, but index still 0, meaning inserted row must be the first row
       $("#tableID tr").eq(idx + 1).before(row);
  else {     //if index is greater than 0, meaning inserted row to be after specified index row
      $("#tableID tr").eq(idx).after(row);

Hope it helps someone.

how to get the last character of a string?

You can use this simple ES6 method

const lastChar = (str) => str.split('').reverse().join(',').replace(',', '')[str.length === str.length + 1 ? 1 : 0];_x000D_
// example_x000D_

This will work in every browsers.

Android global variable

// My Class Global Variables  Save File Global.Java
public class Global {
    public static int myVi; 
    public static String myVs;

// How to used on many Activity

Global.myVi = 12;
Global.myVs = "my number";
int i;
int s;
i = Global.myVi;
s = Global.myVs + " is " + Global.myVi;

How do I right align div elements?

You can use flexbox with flex-grow to push the last element to the right.

<div style="display: flex;">
  <div style="flex-grow: 1;">Left</div>

Android: Difference between onInterceptTouchEvent and dispatchTouchEvent?

The main difference :

•Activity.dispatchTouchEvent(MotionEvent) - This allows your Activity to intercept all touch events before they are dispatched to the window.
•ViewGroup.onInterceptTouchEvent(MotionEvent) - This allows a ViewGroup to watch events as they are dispatched to child Views.

Output single character in C

As mentioned in one of the other answers, you can use putc(int c, FILE *stream), putchar(int c) or fputc(int c, FILE *stream) for this purpose.

What's important to note is that using any of the above functions is from some to signicantly faster than using any of the format-parsing functions like printf.

Using printf is like using a machine gun to fire one bullet.

How to get the children of the $(this) selector?

You could use

    <script src="">

Set size on background image with CSS?

background-size is working in Chrome 4.1, but so far I couldn't make it work in Firefox 3.6.

DIV table colspan: how?

You could always use CSS to simply adjust the width and the height of those elements that you want to do a colspan and rowspan and then simply omit displaying the overlapped DIVs. For example:

<div class = 'td colspan3 rowspan5'> Some data </div>


   display: table-cell;

   width: 300px; /*3 times the standard cell width of 100px - colspan3 */

   height: 500px; /* 5 times the standard height of a cell - rowspan5 */


Importing Excel into a DataTable Quickly

Caling .Value2 is an expensive operation because it's a COM-interop call. I would instead read the entire range into an array and then loop through the array:

object[,] data = Range.Value2;

// Create new Column in DataTable
for (int cCnt = 1; cCnt <= Range.Columns.Count; cCnt++)
    textBox3.Text = cCnt.ToString();

    var Column = new DataColumn();
    Column.DataType = System.Type.GetType("System.String");
    Column.ColumnName = cCnt.ToString();

    // Create row for Data Table
    for (int rCnt = 1; rCnt <= Range.Rows.Count; rCnt++)
        textBox2.Text = rCnt.ToString();

        string CellVal = String.Empty;
            cellVal = (string)(data[rCnt, cCnt]);
        catch (Microsoft.CSharp.RuntimeBinder.RuntimeBinderException)
            ConvertVal = (double)(data[rCnt, cCnt]);
            cellVal = ConvertVal.ToString();

        DataRow Row;

        // Add to the DataTable
        if (cCnt == 1)

            Row = DT.NewRow();
            Row[cCnt.ToString()] = cellVal;

            Row = DT.Rows[rCnt + 1];
            Row[cCnt.ToString()] = cellVal;


Single line if statement with 2 actions

userType = (user.Type == 0) ? "Admin" : (user.type == 1) ? "User" : "Admin";

should do the trick.

Error - is not marked as serializable

You need to add a Serializable attribute to the class which you want to serialize.

public class OrgPermission

how to fix Cannot call sendRedirect() after the response has been committed?

The root cause of IllegalStateException exception is a java servlet is attempting to write to the output stream (response) after the response has been committed.

It is always better to ensure that no content is added to the response after the forward or redirect is done to avoid IllegalStateException. It can be done by including a ‘return’ statement immediately next to the forward or redirect statement.



Is there a JavaScript / jQuery DOM change listener?

Another approach depending on how you are changing the div. If you are using JQuery to change a div's contents with its html() method, you can extend that method and call a registration function each time you put html into a div.

(function( $, oldHtmlMethod ){
    // Override the core html method in the jQuery object.
    $.fn.html = function(){
        // Execute the original HTML method using the
        // augmented arguments collection.

        var results = oldHtmlMethod.apply( this, arguments );
        return results;

})( jQuery, jQuery.fn.html );

We just intercept the calls to html(), call a registration function with this, which in the context refers to the target element getting new content, then we pass on the call to the original jquery.html() function. Remember to return the results of the original html() method, because JQuery expects it for method chaining.

For more info on method overriding and extension, check out, which is where I cribbed the closure function. Also check out the plugins tutorial at JQuery's site.

How to get on scroll events?

for angular 4, the working solution was to do inside the component

@HostListener('window:scroll', ['$event']) onScrollEvent($event){

How do I align a number like this in C?

As far as I can tell from the question, the amount of padding you want will vary according to the data you have. Accordingly, the only solution to this is to scan the data before printing, to figure out the widest datum, and so find a width value you can pass to printf using the asterix operator, e.g.

loop over data - get correct padding, put into width

printf( "%*d\n", width, datum );

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

var userPasswordString = new Buffer(baseAuth, 'base64').toString('ascii');

Change this line from your code to this -

var userPasswordString = Buffer.from(baseAuth, 'base64').toString('ascii');

or in my case, I gave the encoding in reverse order

var userPasswordString = Buffer.from(baseAuth, 'utf-8').toString('base64');

How to destroy an object?

Short answer: Both are needed.

I feel like the right answer was given but minimally. Yeah generally unset() is best for "speed", but if you want to reclaim memory immediately (at the cost of CPU) should want to use null.

Like others mentioned, setting to null doesn't mean everything is reclaimed, you can have shared memory (uncloned) objects that will prevent destruction of the object. Moreover, like others have said, you can't "destroy" the objects explicitly anyway so you shouldn't try to do it anyway.

You will need to figure out which is best for you. Also you can use __destruct() for an object which will be called on unset or null but it should be used carefully and like others said, never be called directly!


What is difference between assigning NULL and unset?

phpMyAdmin Error: The mbstring extension is missing. Please check your PHP configuration

In my case i made a new installation of php7 using xampp, the error was in php.ini at line 699, i just did

include_path= C:\Program Files (x86)\xampp\php\PEAR


include_path= "C:\Program Files (x86)\xampp\php\PEAR"

and it worked for me.

I checked this by running the php.exe it gave me that error and i fixed it.

Creating runnable JAR with Gradle

Here is the solution I tried with Gradle 6.7

Runnable fat Jar (with all dependent libraries copied to the jar)

task fatJar(type: Jar) {
    manifest {
        attributes 'Main-Class': 'com.example.gradle.App'
    from {
        configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
    } with jar

Runnable jar with all dependencies copied to a directory and adding the classpath to the manifest

    def dependsDir = "${buildDir}/libs/dependencies/"
    task copyDependencies(type: Copy) {
        from configurations.compile
        into "${dependsDir}"
    task createJar(dependsOn: copyDependencies, type: Jar) {
        manifest {
            attributes('Main-Class': 'com.example.gradle.App',
                    'Class-Path': configurations.compile.collect { 'dependencies/' + it.getName() }.join(' ')
        with jar

How to use ?

  • Add the above tasks to build.gradle
  • Execute gradle fatJar //create fatJar
  • Execute gradle createJar // create jar with dependencies copied.

More details :

setHintTextColor() in EditText

Simply add this in your layout for the EditText :


How to share my Docker-Image without using the Docker-Hub?

Docker images are stored as filesystem layers. Every command in the Dockerfile creates a layer. You can also create layers by using docker commit from the command line after making some changes (via docker run probably).

These layers are stored by default under /var/lib/docker. While you could (theoretically) cherry pick files from there and install it in a different docker server, is probably a bad idea to play with the internal representation used by Docker.

When you push your image, these layers are sent to the registry (the docker hub registry, by default… unless you tag your image with another registry prefix) and stored there. When pushing, the layer id is used to check if you already have the layer locally or it needs to be downloaded. You can use docker history to peek at which layers (other images) are used (and, to some extent, which command created the layer).

As for options to share an image without pushing to the docker hub registry, your best options are:

  • docker save an image or docker export a container. This will output a tar file to standard output, so you will like to do something like docker save 'dockerizeit/agent' > dk.agent.latest.tar. Then you can use docker load or docker import in a different host.

  • Host your own private registry. - Outdated, see comments See the docker registry image. We have built an s3 backed registry which you can start and stop as needed (all state is kept on the s3 bucket of your choice) which is trivial to setup. This is also an interesting way of watching what happens when pushing to a registry

  • Use another registry like (I haven't personally tried it), although whatever concerns you have with the docker hub will probably apply here too.

Saving binary data as file using JavaScript from a browser

Use FileSaver.js. It supports Chrome, Edge, Firefox, and IE 10+ (and probably IE < 10 with a few "polyfills" - see Note 4). FileSaver.js implements the saveAs() FileSaver interface in browsers that do not natively support it:

Minified version is really small at < 2.5KB, gzipped < 1.2KB.


/* TODO: replace the blob content with your byte[] */
var blob = new Blob([yourBinaryDataAsAnArrayOrAsAString], {type: "application/octet-stream"});
var fileName = "myFileName.myExtension";
saveAs(blob, fileName);

You might need Blob.js in some browsers (see Note 3). Blob.js implements the W3C Blob interface in browsers that do not natively support it. It is a cross-browser implementation:

Consider StreamSaver.js if you have files larger than blob's size limitations.

Complete example:

/* Two options_x000D_
 * 1. Get FileSaver.js from here_x000D_
 * -->_x000D_
 *     <script src="FileSaver.min.js" />_x000D_
 * Or_x000D_
 * 2. If you want to support only modern browsers like Chrome, Edge, Firefox, etc., _x000D_
 *    then a simple implementation of saveAs function can be:_x000D_
function saveAs(blob, fileName) {_x000D_
    var url = window.URL.createObjectURL(blob);_x000D_
    var anchorElem = document.createElement("a");_x000D_ = "display: none";_x000D_
    anchorElem.href = url;_x000D_ = fileName;_x000D_
    // On Edge, revokeObjectURL should be called only after_x000D_
    // has completed, atleast on EdgeHTML 15.15048_x000D_
    setTimeout(function() {_x000D_
    }, 1000);_x000D_
(function() {_x000D_
    // convert base64 string to byte array_x000D_
    var byteCharacters = atob("R0lGODlhkwBYAPcAAAAAAAABGRMAAxUAFQAAJwAANAgwJSUAACQfDzIoFSMoLQIAQAAcQwAEYAAHfAARYwEQfhkPfxwXfQA9aigTezchdABBckAaAFwpAUIZflAre3pGHFpWVFBIf1ZbYWNcXGdnYnl3dAQXhwAXowkgigIllgIxnhkjhxktkRo4mwYzrC0Tgi4tiSQzpwBIkBJIsyxCmylQtDVivglSxBZu0SlYwS9vzDp94EcUg0wziWY0iFROlElcqkxrtW5OjWlKo31kmXp9hG9xrkty0ziG2jqQ42qek3CPqn6Qvk6I2FOZ41qn7mWNz2qZzGaV1nGOzHWY1Gqp3Wy93XOkx3W1x3i33G6z73nD+ZZIHL14KLB4N4FyWOsECesJFu0VCewUGvALCvACEfEcDfAcEusKJuoINuwYIuoXN+4jFPEjCvAgEPM3CfI5GfAxKuoRR+oaYustTus2cPRLE/NFJ/RMO/dfJ/VXNPVkNvFPTu5KcfdmQ/VuVvl5SPd4V/Nub4hVj49ol5RxoqZfl6x0mKp5q8Z+pu5NhuxXiu1YlvBdk/BZpu5pmvBsjfBilvR/jvF3lO5nq+1yre98ufBoqvBrtfB6p/B+uPF2yJiEc9aQMsSKQOibUvqKSPmEWPyfVfiQaOqkSfaqTfyhXvqwU+u7dfykZvqkdv+/bfy1fpGvvbiFnL+fjLGJqqekuYmTx4SqzJ2+2Yy36rGawrSwzpjG3YjB6ojG9YrU/5XI853U75bV/J3l/6PB6aDU76TZ+LHH6LHX7rDd+7Lh3KPl/bTo/bry/MGJm82VqsmkjtSptfWMj/KLsfu0je6vsNW1x/GIxPKXx/KX1ea8w/Wnx/Oo1/a3yPW42/S45fvFiv3IlP/anvzLp/fGu/3Xo/zZt//knP7iqP7qt//xpf/0uMTE3MPd1NXI3MXL5crS6cfe99fV6cXp/cj5/tbq+9j5/vbQy+bY5/bH6vbJ8vfV6ffY+f7px/3n2f/4yP742OPm8ef9//zp5vjn/f775/7+/gAAACwAAAAAkwBYAAAI/wD9CRxIsKDBgwgTKlzIsKHDhxAjSpxIsaLFixgzatzIsaPHjxD7YQrSyp09TCFSrQrxCqTLlzD9bUAAAMADfVkYwCIFoErMn0AvnlpAxR82A+tGWWgnLoCvoFCjOsxEopzRAUYwBFCQgEAvqWDDFgTVQJhRAVI2TUj3LUAusXDB4jsQxZ8WAMNCrW37NK7foN4u1HThD0sBWpoANPnL+GG/OV2gSUT24Yi/eltAcPAAooO+xqAVbkPT5VDo0zGzfemyqLE3a6hhmurSpRLjcGDI0ItdsROXSAn5dCGzTOC+d8j3gbzX5ky8g+BoTzq4706XL1/KzONdEBWXL3AS3v/5YubavU9fuKg/44jfQmbK4hdn+Jj2/ILRv0wv+MnLdezpweEed/i0YcYXkCQkB3h+tPEfgF3AsdtBzLSxGm1ftCHJQqhc54Y8B9UzxheJ8NfFgWakSF6EA57WTDN9kPdFJS+2ONAaKq6Whx88enFgeAYx892FJ66GyEHvvGggeMs0M01B9ajRRYkD1WMgF60JpAx5ZEgGWjZ44MHFdSkeSBsceIAoED5gqFgGbAMxQx4XlxjESRdcnFENcmmcGBlBfuDh4Ikq0kYGHoxUKSWVApmCnRsFCddlaEPSVuaFED7pDz5F5nGQJ9cJWFA/d1hSUCfYlSFQfdgRaqal6UH/epmUjRDUx3VHEtTPHp5SOuYyn5x4xiMv3jEmlgKNI+w1B/WTxhdnwLnQY2ZwEY1AeqgHRzN0/PiiMmh8x8Vu9YjRxX4CjYcgdwhhE6qNn8DBrD/5AXnQeF3ct1Ap1/VakB3YbThQgXEIVG4X1w7UyXUFs2tnvwq5+0XDBy38RZYMKQuejf7Yw4YZXVCjEHwFyQmyyA4TBPAXhiiUDcMJzfaFvwXdgWYbz/jTjxjgTTiQN2qYQca8DxV44KQpC7SyIi7DjJCcExeET7YAplcGNQvC8RxB3qS6XUTacHEgF7mmvHTTUT+Nnb06Ozi2emOWYeEZRAvUdXZfR/SJ2AdS/8zuymUf9HLaFGLnt3DkPTIQqTLSXRDQ2W0tETbYHSgru3eyjLbfJa9dpYEIG6QHdo4T5LHQdUfUjduas9vhxglJzLaJhKtGOEHdhKrm4gB3YapFdlznHLvhiB1tQtqEmpDFFL9umkH3hNGzQTF+8YZjzGi6uBgg58yuHH0nFM67CIH/xfP+OH9Q9LAXRHn3Du1NhuQCgY80dyZ/4caee58xocYSOgg+uOe7gWzDcwaRWMsOQocVLQI5bOBCggzSDzx8wQsTFEg4RnQ8h1nnVdchA8rucZ02+Iwg4xOaly4DOu8tbg4HogRC6uGfVx3oege5FbQ0VQ8Yts9hnxiUpf9qtapntYF+AxFFqE54qwPlYR772Mc2xpAiLqSOIPiwIG3OJC0ooQFAOVrNFbnTj/jEJ3U4MgPK/oUdmumMDUWCm6u6wDGDbMOMylhINli3IjO4MGkLqcMX7rc4B1nRIPboXdVUdLmNvExFGAMkQxZGHAHmYYXQ4xGPogGO1QBHkn/ZhhfIsDuL3IMLbjghKDECj3O40pWrjIk6XvkZj9hDCEKggAh26QAR9IAJsfzILXkpghj0RSPOYAEJdikCEjjTmczURTA3cgxmQlMEJbBFRlixAms+85vL3KUVpomRQOwSnMtUwTos8g4WnBOd8BTBCNxBzooA4p3oFAENKLL/Dx/g85neRCcEblDPifjzm/+UJz0jkgx35tMBSWDFCZqZTxWwo6AQYQVFwzkFh17zChG550YBKoJx9iMHIwVoCY6J0YVUk6K7TII/UEpSJRQNpSkNZy1WRdN8lgAXLWXIOyYKUIv2o5sklWlD7EHUfIrApsbxKDixqc2gJqQfOBipA4qwqRVMdQgNaWdOw2kD00kVodm0akL+MNJdfuYdbRWBUhVy1LGmc6ECEWs8S0AMtR4kGfjcJREEAliEPnUh9uipU1nqD8COVQQqwKtfBWIPXSJUBcEQCFsNO06F3BOe4ZzrQDQKWhHMYLIFEURKRVCDz5w0rlVFiEbtCtla/xLks/B0wBImAo98iJSZIrDBRTPSjqECd5c7hUgzElpSyjb1msNF0j+nCtJRaeCxIoiuQ2YhhF4el5cquIg9kJAD735Xt47RwWqzS9iEhjch/qTtaQ0C18fO1yHvQAFzmflTiwBiohv97n0bstzV3pcQCR0sQlQxXZLGliDVjGdzwxrfADvgBULo60WSEQHm8uAJE8EHUqfaWX8clKSMHViDAfoC2xJksxWVbEKSMWKSOgGvhOCBjlO8kPgi1AEqAMbifqDjsjLkpVNVZ15rvMwWI4SttBXBLQR41muWWCFQnuoLhquOCoNXxggRa1yVuo9Z6PK4okVklZdpZH8YY//MYWZykhFS4Io2JMsIjQE97cED814TstpFkgSY29lk4DTAMZ1xTncJVX+oF60aNgiMS8vVg4h0qiJ4MEJ8jNAX0FPMpR2wQaRRZUYLZBArDueVCXJdn0rzMgmttEHwYddr8riy603zQfBM0uE6o5u0dcCqB/IOyxq2zeasNWTBvNx4OtkfSL4mmE9d6yZPm8EVdfFBZovpRm/qzBJ+tq7WvEvtclvCw540QvepsxOH09u6UqxTdd3V1UZ2IY7FdAy0/drSrtQg7ibpsJsd6oLoNZ+vdsY7d9nmUT/XqcP2RyGYy+NxL9oB1TX4isVZkHxredq4zec8CXJuhI5guCH/L3dCLu3vYtD3rCpfCKoXPQJFl7bh/TC2YendbuwOg9WPZXd9ba2QgNtZ0ohWQaQTYo81L5PdzZI3QBse4XyS4NV/bfAusQ7X0ioVxrvUdEHsIeepQn0gdQ6nqBOCagmLneRah3rTH6sCbeuq7LvMeNUxPU69hn0hBAft0w0ycxEAORYI2YcrWJoBuq8zIdLQeps9PtWG73rRUh6I0aHZ3wqrAKiArzYJ0FsQbjjAASWIRTtkywIH3Hfo+RQ3ksjd5pCDU9gyx/zPN+V0EZiAGM3o5YVXP5Bk1OAgbxa8M3EfEXNUgJltnnk8bWB3i+dztzprfGkzTmfMDzftH8fH/w9igHWBBF8EuzBI8pUvAu43JNnLL7G6EWp5Na8X9GQXvAjKf5DAF3Ug0fZxCPFaIrB7BOF/8fR2COFYMFV3q7IDtFV/Y1dqniYQ3KBs/GcQhXV72OcPtpdn1eeBzBRo/tB1ysd8C+EMELhwIqBg/rAPUjd1IZhXMBdcaKdsCjgQbWdYx7R50KRn28ZM71UQ+6B9+gdvFMRp16RklOV01qYQARhOWLd3AoWEBfFoJCVuPrhM+6aB52SDllZt+pQQswAE3jVVpPeAUZaBBGF0pkUQJuhsCgF714R4mkdbTDhavRROoGcQUThVJQBmrLADZ4hpQzgQ87duCUGH4fRgIuOmfyXAhgLBctDkgHfob+UHf00Wgv1WWpDFC+qADuZwaNiVhwCYarvEY1gFZwURg9fUhV4YV0vnD+bkiS+ADurACoW4dQoBfk71XcFmA9NWD6mWTozVD+oVYBAge9SmfyIgAwbhDINmWEhIeZh2XNckgQVBicrHfrvkBFgmhsW0UC+FaMxIg8qGTZ3FD0r4bgfBVKKnbzM4EP1UjN64Sz1AgmOHU854eoUYTg4gjIqGirx0eoGFTVbYjN0IUMs4bc1yXfFoWIZHA/ngEGRnjxImVwwxWxFpWCPgclfVagtpeC9AfKIPwY3eGAM94JCehZGGFQOzuIj8uJDLhHrgKFRlh2k8xxCz8HwBFU4FaQOzwJIMQQ5mCFzXaHg28AsRUWbA9pNA2UtQ8HgNAQ8QuV6HdxHvkALudFwpAAMtEJMWMQgsAAPAyJVgxU47AANdCVwlAJaSuJEsAGDMBJYGiBH94Ap6uZdEiRGysJd7OY8S8Q6AqZe8kBHOUJiCiVqM2ZiO+ZgxERAAOw==");_x000D_
    var byteNumbers = new Array(byteCharacters.length);_x000D_
    for (var i = 0; i < byteCharacters.length; i++) {_x000D_
        byteNumbers[i] = byteCharacters.charCodeAt(i);_x000D_
    var byteArray = new Uint8Array(byteNumbers);_x000D_
    // now that we have the byte array, construct the blob from it_x000D_
    var blob1 = new Blob([byteArray], {type: "application/octet-stream"});_x000D_
    var fileName1 = "cool.gif";_x000D_
    saveAs(blob1, fileName1);_x000D_
    // saving text file_x000D_
    var blob2 = new Blob(["cool"], {type: "text/plain"});_x000D_
    var fileName2 = "cool.txt";_x000D_
    saveAs(blob2, fileName2);_x000D_

Tested on Chrome, Edge, Firefox, and IE 11 (use FileSaver.js for supporting IE 11).
You can also save from a canvas element. See


Blog post by author of FileSaver.js:

Note 1: Browser support:

Note 2: Failed to execute 'atob' on 'Window'

Note 3: Polyfill for browsers not supporting Blob:

Note 4: IE < 10 support (I've not tested this part):

Downloadify is a Flash-based polyfill for supporting IE6-9: (I don't recommend Flash-based solutions in general, though.)
Demo using Downloadify and FileSaver.js for supporting IE6-9 also:

Note 5: Creating a BLOB from a Base64 string in JavaScript

Note 6: FileSaver.js examples:

Python Remove last 3 characters of a string

>>> foo = "Bs12 3ab"
>>> foo[:-3]
'Bs12 '
>>> foo[:-3].strip()
>>> foo[:-3].strip().replace(" ","")
>>> foo[:-3].strip().replace(" ","").upper()

Git error: src refspec master does not match any

You've created a new repository and added some files to the index, but you haven't created your first commit yet. After you've done:

 git add a_text_file.txt 

... do:

 git commit -m "Initial commit."

... and those errors should go away.

HTTP get with headers using RestTemplate

The RestTemplate getForObject() method does not support setting headers. The solution is to use the exchange() method.

So instead of restTemplate.getForObject(url, String.class, param) (which has no headers), use

HttpHeaders headers = new HttpHeaders();
headers.set("Header", "value");
headers.set("Other-Header", "othervalue");

HttpEntity entity = new HttpEntity(headers);

ResponseEntity<String> response =
    url, HttpMethod.GET, entity, String.class, param);

Finally, use response.getBody() to get your result.

This question is similar to this question.

How do I force a DIV block to extend to the bottom of a page even if it has no content?

The min-height property is not supported by all browsers. If you need your #content to extend it's height on longer pages the height property will cut it short.

It's a bit of a hack but you could add an empty div with a width of 1px and height of e.g. 1000px inside your #content div. That will force the content to be at least 1000px high and still allow longer content to extend the height when needed

How to change bower's default components folder?

I had the same issue on my windows 10. This is what fixed my problem

  1. Delete bower_components in your root folder
  2. Create a .bowerrc file in the root
  3. In the file write this code {"directory" : "public/bower_components"}
  4. Run a bower install

You should see bower_components folder in your public folder now

ImportError: No module named 'MySQL'

May be simple install from cli?

pip3 install mysql-connector-python-rf

Package name differs from import library name

Or my universal variant in code:

import pip

For new version of pip:

from pip._internal import main

It's better - install needed modules in running python installation (if many)

How to support placeholder attribute in IE8 and 9

For others landing here. This is what worked for me:

//jquery polyfill for showing place holders in IE9
$('[placeholder]').focus(function() {
    var input = $(this);
    if (input.val() == input.attr('placeholder')) {
}).blur(function() {
    var input = $(this);
    if (input.val() == '' || input.val() == input.attr('placeholder')) {

$('[placeholder]').parents('form').submit(function() {
    $(this).find('[placeholder]').each(function() {
        var input = $(this);
        if (input.val() == input.attr('placeholder')) {

Just add this in you script.js file. Courtesy of

Bootstrap 3 - How to load content in modal body via AJAX?

I guess you're searching for this custom function. It takes a data-toggle attribute and creates dynamically the necessary div to place the remote content. Just place the data-toggle="ajaxModal" on any link you want to load via AJAX.

The JS part:

              function(e) {
                var $this = $(this)
                  , $remote = $'remote') || $this.attr('href')
                  , $modal = $('<div class="modal" id="ajaxModal"><div class="modal-body"></div></div>');
                $modal.modal({backdrop: 'static', keyboard: false});

Finally, in the remote content, you need to put the entire structure to work.

<div class="modal-dialog">
    <div class="modal-content">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal">&times;</button>
            <h4 class="modal-title"></h4>
        <div class="modal-body">
        <div class="modal-footer">
            <a href="#" class="btn btn-white" data-dismiss="modal">Close</a>
            <a href="#" class="btn btn-primary">Button</a>
            <a href="#" class="btn btn-primary">Another button...</a>
    </div><!-- /.modal-content -->
</div><!-- /.modal-dialog -->

How to replace item in array?

Replacement can be done in one line:

var items = Array(523, 3452, 334, 31, 5346);_x000D_
items[, i) => [i, e]).filter(e => e[1] == 3452)[0][0]] = 1010_x000D_

Or create a function to reuse:

Array.prototype.replace = function(t, v) {_x000D_
    if (this.indexOf(t)!= -1)_x000D_
        this[, i) => [i, e]).filter(e => e[1] == t)[0][0]] = v;_x000D_
var items = Array(523, 3452, 334, 31, 5346);_x000D_
items.replace(3452, 1010);_x000D_

Scroll RecyclerView to show selected item on top

You just need to call recyclerview.scrollToPosition(position). That's fine!

If you want to call it in adapter, just let your adapter has the instance of recyclerview or the activity or fragment which contains recyclerview,than implements the method getRecyclerview() in them.

I hope it can help you.

Android RelativeLayout programmatically Set "centerInParent"

Completely untested, but this should work:

View positiveButton = findViewById(;
RelativeLayout.LayoutParams layoutParams = 
layoutParams.addRule(RelativeLayout.CENTER_IN_PARENT, RelativeLayout.TRUE);

add android:configChanges="orientation|screenSize" inside your activity in your manifest

Set a thin border using .css() in javascript

After a few futile hours battling with a 'SyntaxError: missing : after property id' message I can now expand on this topic:

border-width is a valid css property but it is not included in the jQuery css oject definition, so .css({border-width: '2px'}) will cause an error, but it's quite happy with .css({'border-width': '2px'}), presumably property names in quotes are just passed on as received.

$location / switching between html5 and hashbang mode / link rewriting

The documentation is not very clear about AngularJS routing. It talks about Hashbang and HTML5 mode. In fact, AngularJS routing operates in three modes:

  • Hashbang Mode
  • HTML5 Mode
  • Hashbang in HTML5 Mode

For each mode there is a a respective LocationUrl class (LocationHashbangUrl, LocationUrl and LocationHashbangInHTML5Url).

In order to simulate URL rewriting you must actually set html5mode to true and decorate the $sniffer class as follows:

$provide.decorator('$sniffer', function($delegate) {
  $delegate.history = false;
  return $delegate;

I will now explain this in more detail:

Hashbang Mode


  .when('/path', {
    templateUrl: 'path.html',

This is the case when you need to use URLs with hashes in your HTML files such as in

<a href="index.html#!/path">link</a>

In the Browser you must use the following Link:!/base/path

As you can see in pure Hashbang mode all links in the HTML files must begin with the base such as "index.html#!".

HTML5 Mode


  .when('/path', {
    templateUrl: 'path.html',

You should set the base in HTML-file

    <base href="/">

In this mode you can use links without the # in HTML files

<a href="/path">link</a>

Link in Browser:

Hashbang in HTML5 Mode

This mode is activated when we actually use HTML5 mode but in an incompatible browser. We can simulate this mode in a compatible browser by decorating the $sniffer service and setting history to false.


$provide.decorator('$sniffer', function($delegate) {
  $delegate.history = false;
  return $delegate;
  .when('/path', {
    templateUrl: 'path.html',

Set the base in HTML-file:

    <base href="/">

In this case the links can also be written without the hash in the HTML file

<a href="/path">link</a>

Link in Browser:!/base/path

IntelliJ cannot find any declarations

In my case, I just updated my IntelliJ to Ultimate 2018.2 and all of my projects suddenly cannot find the implementations and the 'src' folders - it turned out IntelliJ removed the type of project (e.g. Maven).

What I did is:

Right click on the root project > Add Framework support... > Look for Maven (in my case) > Wait to re-index again > Then it worked again.


I have always been encountering this when I update IntelliJ (2019.1.1 Ultimate Edition). Just click the refresh button of Maven Tab and it should re-index your current project as Maven Project:
enter image description here

Easy way to test a URL for 404 in PHP?

this is just and slice of code, hope works for you

            $ch = @curl_init();
            @curl_setopt($ch, CURLOPT_URL, '');
            @curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20061204 Firefox/");
            @curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            @curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
            @curl_setopt($ch, CURLOPT_TIMEOUT, 10);

            $response       = @curl_exec($ch);
            $errno          = @curl_errno($ch);
            $error          = @curl_error($ch);

                    $response = $response;
                    $info = @curl_getinfo($ch);
return $info['http_code'];

Call Stored Procedure within Create Trigger in SQL Server

I think you will have to loop over the "inserted" table, which contains all rows that were updated. You can use a WHERE loop, or a WITH statement if your primary key is a GUID. This is the simpler (for me) to write, so here is my example. We use this approach, so I know for a fact it works fine.

ALTER TRIGGER [dbo].[RA2Newsletter] ON [dbo].[Reiseagent]
        -- This is your primary key.  I assume INT, but initialize
        -- to minimum value for the type you are using.
        DECLARE @rAgent_ID INT = 0

        -- Looping variable.
        DECLARE @i INT = 0

        -- Count of rows affected for looping over
        DECLARE @count INT

        -- These are your old variables.
        DECLARE @rAgent_Name NVARCHAR(50)
        DECLARE @rAgent_Email NVARCHAR(50)
        DECLARE @rAgent_IP NVARCHAR(50)
        DECLARE @hotelID INT
        DECLARE @retval INT

        SET NOCOUNT ON ;

        -- Get count of affected rows
        SELECT  @Count = Count(rAgent_ID)
        FROM    inserted

        -- Loop over rows affected
        WHILE @i < @count
                -- Get the next rAgent_ID
                SELECT TOP 1
                        @rAgent_ID = rAgent_ID
                FROM    inserted
                WHERE   rAgent_ID > @rAgent_ID
                ORDER BY rAgent_ID ASC

                -- Populate values for the current row
                SELECT  @rAgent_Name = rAgent_Name,
                        @rAgent_Email = rAgent_Email,
                        @rAgent_IP = rAgent_IP,
                        @hotelID = hotelID
                FROM    Inserted
                WHERE   rAgent_ID = @rAgent_ID

                -- Run your stored procedure
                EXEC insert2Newsletter '', '', @rAgent_Name, @rAgent_Email,
                    @rAgent_IP, @hotelID, 'RA', @retval 

                -- Set up next iteration
                SET @i = @i + 1

I sure hope this helps you out. Cheers!

How do I fix the error 'Named Pipes Provider, error 40 - Could not open a connection to' SQL Server'?

in my case, i had a standalone server, i changed the sql server port default port 1433 in configuration manager to some number and restarted the sql serve service to take effect,i was able to connect to the sql server through management studio if i login to the server. but i was not able to connect from my local machine through sql server, i was getting the error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and

that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 5)

I checked and verified all the below

-Named pipes/TCP is enabled. -Remote connections are allowed. -Windows Firewall is off -Created an exception for portin Windows Firewall( this was not necessary in my case as the server is in same subnet network). -Enabled everything in SQL Server Configuration Manager.

then i chnaged back the port number to default 1433 and restarted the sql server service, and the issue got resolved and i am able to connect the sql server from my local management studio.

Printing object properties in Powershell

My solution to this problem was to use the $() sub-expression block.

Add-Type -Language CSharp @"
public class Thing{
    public string Name;

$x = New-Object Thing

$x.Name = "Bill"

Write-Output "My name is $($x.Name)"
Write-Output "This won't work right: $x.Name"


My name is Bill
This won't work right: Thing.Name

MySQL pivot table query with dynamic columns

I have a slightly different way of doing this than the accepted answer. This way you can avoid using GROUP_CONCAT which has a limit of 1024 characters and will not work if you have a lot of fields.

SET @sql = '';
    @sql := CONCAT(@sql,if(@sql='','',', '),temp.output)
         'MAX(IF(pa.fieldname = ''',
          ''', pa.fieldvalue, NULL)) AS ',
        ) as output
) as temp;

                    , p.description, ', @sql, ' 
                   FROM product p
                   LEFT JOIN product_additional AS pa 
                    ON =
                   GROUP BY');

PREPARE stmt FROM @sql;

Show/Hide Div on Scroll

i have a pretty answer try this code ;)

<div id="DivID">

$("#DivID").scrollview({ direction: 'y' });
$("#DivID > .ui-scrollbar").addClass("ui-scrollbar-visible");


I had the same issue on localhost. I have changed the domain for the app, but in URLs and hosts file there was still the old domain. Updated my browser bookmarks and hosts file to use new domain and now everything works fine.

How to implement a queue using two stacks?

You can even simulate a queue using only one stack. The second (temporary) stack can be simulated by the call stack of recursive calls to the insert method.

The principle stays the same when inserting a new element into the queue:

  • You need to transfer elements from one stack to another temporary stack, to reverse their order.
  • Then push the new element to be inserted, onto the temporary stack
  • Then transfer the elements back to the original stack
  • The new element will be on the bottom of the stack, and the oldest element is on top (first to be popped)

A Queue class using only one Stack, would be as follows:

public class SimulatedQueue<E> {
    private java.util.Stack<E> stack = new java.util.Stack<E>();

    public void insert(E elem) {
        if (!stack.empty()) {
            E topElem = stack.pop();

    public E remove() {
        return stack.pop();

How to check what version of jQuery is loaded?

My preference is:

console.debug("jQuery "+ (jQuery ? $().jquery : "NOT") +" loaded")


jQuery 1.8.0 loaded

RSA: Get exponent and modulus given a public key

Beware the leading 00 that can appear in the modulus when using:

openssl rsa -pubin -inform PEM -text -noout < public.key

The example modulus contains 257 bytes rather than 256 bytes because of that 00, which is included because the 9 in 98 looks like a negative signed number.

How do I get my page title to have an icon?

If you wanna use a URL just you can use this code.

<link rel="shortcut icon" type="image/x-icon" href="https://..." />

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

This might be helpful for whoever else faces this problem. I finally figured out a solution. Turns out, even if we use the inline for "content-disposition" and specify a file name, the browsers still do not use the file name. Instead browsers try and interpret the file name based on the Path/URL.

You can read further on this URL: Securly download file inside browser with correct filename

This gave me an idea, I just created my URL route that would convert the URL and end it with the name of the file I wanted to give the file. So for e.g. my original controller call just consisted of passing the Order Id of the Order being printed. I was expecting the file name to be of the format Order{0}.pdf where {0} is the Order Id. Similarly for quotes, I wanted Quote{0}.pdf.

In my controller, I just went ahead and added an additional parameter to accept the file name. I passed the filename as a parameter in the URL.Action method.

I then created a new route that would map that URL to the format: http://localhost/ShoppingCart/PrintQuote/1054/Quote1054.pdf

routes.MapRoute("", "{controller}/{action}/{orderId}/{fileName}",
                new { controller = "ShoppingCart", action = "PrintQuote" }
                , new string[] { "x.x.x.Controllers" }

This pretty much solved my issue. Hoping this helps someone!

Cheerz, Anup

When and where to use GetType() or typeof()?

You may find it easier to use the is keyword:

if (mycontrol is TextBox)

How to call another components function in angular2

  1. Add injectable decorator to component2(or any component which have the method)
    providedIn: 'root'
  1. Inject into component1 (the component from where component2 method will be called)
constructor(public comp2 : component2) { }
  1. Define method in component1 from where component2 method is called

component 1 and component 2 code below.

import {Component2} from './Component2';

  selector: 'sel-comp1',
  templateUrl: './comp1.html',
  styleUrls: ['./comp1.scss']
export class Component1 implements OnInit {
  show = false;
  constructor(public comp2: Component2) { }

  selector: 'sel-comp2',
  templateUrl: './comp2.html',
  styleUrls: ['./comp2.scss']
export class Component2 implements OnInit {
  alert('called comp2 method from comp1');

CSS z-index not working (position absolute)

I was struggling to figure it out how to put a div over an image like this: z-index working

No matter how I configured z-index in both divs (the image wrapper) and the section I was getting this:

z-index Not working

Turns out I hadn't set up the background of the section to be background: white;

so basically it's like this:

<div class="img-wrp">
  <img src="myimage.svg"/>
 <other content>

  position: relative;
  background: white; /* THIS IS THE IMPORTANT PART NOT TO FORGET */
  position: absolute;
  z-index: -1; /* also worked with 0 but just to be sure */

How to use the toString method in Java?

It may optionally have uses within the context of an application but far more often it is used for debugging purposes. For example, when you hit a breakpoint in an IDE, it's far easier to read a meaningful toString() of objects than it is to inspect their members.

There is no set requirement for what a toString() method should do. By convention, most often it will tell you the name of the class and the value of pertinent data members. More often than not, toString() methods are auto-generated in IDEs.

Relying on particular output from a toString() method or parsing it within a program is a bad idea. Whatever you do, don't go down that route.

Nexus 7 (2013) and Win 7 64 - cannot install USB driver despite checking many forums and online resources

You can do this go to Settings > Storage, clicking on the setting menu icon in the top right hand corner and selecting "USB computer connection". I then changed the storage mode to "Camera (PTP)". Done try re installing the driver from device manager.

How do you add a Dictionary of items into another Dictionary

You can also use reduce to merge them. Try this in the playground

let d1 = ["a":"foo","b":"bar"]
let d2 = ["c":"car","d":"door"]

let d3 = d1.reduce(d2) { (var d, p) in
   d[p.0] = p.1
   return d

Not able to access adb in OS X through Terminal, "command not found"

This worked for me on my MAC - 2020

Go to directory containing adb:

cd ~/Library/Android/sdk/platform-tools/

Run adb command to list all services

./adb shell dumpsys activity services

Pass by Reference / Value in C++

I'm not sure if I understand your question correctly. It is a bit unclear. However, what might be confusing you is the following:

  1. When passing by reference, a reference to the same object is passed to the function being called. Any changes to the object will be reflected in the original object and hence the caller will see it.

  2. When passing by value, the copy constructor will be called. The default copy constructor will only do a shallow copy, hence, if the called function modifies an integer in the object, this will not be seen by the calling function, but if the function changes a data structure pointed to by a pointer within the object, then this will be seen by the caller due to the shallow copy.

I might have mis-understood your question, but I thought I would give it a stab anyway.

PHP cURL, extract an XML response

no, CURL does not have anything with parsing XML, it does not know anything about the content returned. it serves as a proxy to get content. it's up to you what to do with it.

use JSON if possible (and json_decode) - it's easier to work with, if not possible, use any XML library for parsin such as DOMXML:

'npm' is not recognized as internal or external command, operable program or batch file

I ran into this problem the other day on my Windows 7 machine. Problem wasn't my path, but I had to use escaped forward slashes instead of backslashes like this:

"scripts": {
    "script": ".\\bin\\"

Python Requests throwing SSLError

This is just another way you can try to solve the issue.

If you put "", requests shouts at you. If you put "", you get this error. So if you DO NOT NEED https, you can avoid the error by changing "https" to "http". eg. ""

WARNING: Not using HTTPS is generally not a good idea. See Why HTTPS for Everything? Why HTTPS matters

How to list all methods for an object in Ruby?

The following will list the methods that the User class has that the base Object class does not have...

>> User.methods - Object.methods
=> ["field_types", "maximum", "create!", "active_connections", "to_dropdown",
    "content_columns", "su_pw?", "default_timezone", "encode_quoted_value", 
    "reloadable?", "update", "reset_sequence_name", "default_timezone=", 
    "validate_find_options", "find_on_conditions_without_deprecation", 
    "validates_size_of", "execute_simple_calculation", "attr_protected", 
    "reflections", "table_name_prefix", ...

Note that methods is a method for Classes and for Class instances.

Here's the methods that my User class has that are not in the ActiveRecord base class:

>> User.methods - ActiveRecord::Base.methods
=> ["field_types", "su_pw?", "set_login_attr", "create_user_and_conf_user", 
    "original_table_name", "field_type", "authenticate", "set_default_order",
    "id_name?", "id_name_column", "original_locking_column", "default_order",
    "subclass_associations",  ... 
# I ran the statements in the console.

Note that the methods created as a result of the (many) has_many relationships defined in the User class are not in the results of the methods call.

Added Note that :has_many does not add methods directly. Instead, the ActiveRecord machinery uses the Ruby method_missing and responds_to techniques to handle method calls on the fly. As a result, the methods are not listed in the methods method result.

UnsatisfiedDependencyException: Error creating bean with name

I just added the @Repository annotation to Repository interface and @EnableJpaRepositories ("domain.repositroy-package") to the main class. It worked just fine.

How to reduce the space between <p> tags?


margin: 0;
padding: 0;

If this doesn't work, try

line-height: normal;

How to validate phone number in laravel 5.2?

    'phone' => 'numeric|required',
    'body' => 'required',

Hibernate Error: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

I resolved this problem .
Actually this is happening because we forgot implementation of Generator Type of PK property in the bean class. So make it any type like as

private int id;

when we persist the objects of bean ,every object acquired same ID ,so first object is saved ,when another object to be persist then HIB FW through this type of Exception: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session.

How do I pass multiple ints into a vector at once?

You can also use Boost.Assignment:

const list<int> primes = list_of(2)(3)(5)(7)(11);

vector<int> v; 
v += 1,2,3,4,5,6,7,8,9;

How to ignore certain files in Git

If you have already committed the file and you are trying to ignore it by adding to the .gitignore file, Git will not ignore it. For that, you first have to do the below things:

git rm --cached FILENAME

If you are starting the project freshly and you want to add some files to Git ignore, follow the below steps to create a Git ignore file:

  1. Navigate to your Git repository.
  2. Enter "touch .gitignore" which will create a .gitignore file.

Hibernate error: ids for this class must be manually assigned before calling save():

Resolved this problem using a Sequence ID defined in Oracle database.

ORACLE_DB_SEQ_ID is defined as a sequence for the table. Also look at the console to see the Hibernate SQL that is used to verify.

@Column(name = "MY_ID", unique = true, nullable = false)
@GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "id_Sequence")
@SequenceGenerator(name = "id_Sequence", sequenceName = "ORACLE_DB_SEQ_ID")
Long myId;

When does a process get SIGABRT (signal 6)?

abort() sends the calling process the SIGABRT signal, this is how abort() basically works.

abort() is usually called by library functions which detect an internal error or some seriously broken constraint. For example malloc() will call abort() if its internal structures are damaged by a heap overflow.

RestSharp JSON Parameter Posting

You don't have to serialize the body yourself. Just do

request.RequestFormat = DataFormat.Json;
request.AddJsonBody(new { A = "foo", B = "bar" }); // Anonymous type object is converted to Json body

If you just want POST params instead (which would still map to your model and is a lot more efficient since there's no serialization to JSON) do this:

request.AddParameter("A", "foo");
request.AddParameter("B", "bar");

Add MIME mapping in web.config for IIS Express

Putting it in the "web.config" works fine. The problem was that I got the MIME type wrong. Instead of font/x-woff or font/x-font-woff it must be application/font-woff:

    <remove fileExtension=".woff" />
    <mimeMap fileExtension=".woff" mimeType="application/font-woff" />

See also this answer regarding the MIME type:

Update 4/10/2013

Spec is now a recommendation and the MIME type is officially: application/font-woff

What is function overloading and overriding in php?

Overloading: In Real world, overloading means assigning some extra stuff to someone. As as in real world Overloading in PHP means calling extra functions. In other way You can say it have slimier function with different parameter.In PHP you can use overloading with magic functions e.g. __get, __set, __call etc.

Example of Overloading:

class Shape {
   const Pi = 3.142 ;  // constant value
  function __call($functionname, $argument){
    if($functionname == 'area')
        case 0 : return 0 ;
        case 1 : return self::Pi * $argument[0] ; // 3.14 * 5
        case 2 : return $argument[0] * $argument[1];  // 5 * 10


 $circle = new Shape();`enter code here`
 echo "Area of circle:".$circle->area()."</br>"; // display the area of circle Output 0
 echo "Area of circle:".$circle->area(5)."</br>"; // display the area of circle
 $rect = new Shape();
 echo "Area of rectangle:".$rect->area(5,10); // display area of rectangle

Overriding : In object oriented programming overriding is to replace parent method in child class.In overriding you can re-declare parent class method in child class. So, basically the purpose of overriding is to change the behavior of your parent class method.

Example of overriding :

class parent_class

  public function text()    //text() is a parent class method
    echo "Hello!! everyone I am parent class text method"."</br>";
  public function test()   
    echo "Hello!! I am second method of parent class"."</br>";


class child extends parent_class
  public function text()     // Text() parent class method which is override by child 
    echo "Hello!! Everyone i am child class";


 $obj= new parent_class();
 $obj->text();            // display the parent class method echo
 $obj= new parent_class();
 $obj= new child();
 $obj->text(); // display the child class method echo

Swift Alamofire: How to get the HTTP response status code

For Swift 3.x / Swift 4.0 / Swift 5.0 users with Alamofire >= 4.0 / Alamofire >= 5.0


More verbose example:

        .responseString { response in
            print("Success: \(response.result.isSuccess)")
            print("Response String: \(response.result.value)")

            var statusCode = response.response?.statusCode
            if let error = response.result.error as? AFError {  
                statusCode = error._code // statusCode private                 
                switch error {
                case .invalidURL(let url):
                    print("Invalid URL: \(url) - \(error.localizedDescription)")
                case .parameterEncodingFailed(let reason):
                    print("Parameter encoding failed: \(error.localizedDescription)")
                    print("Failure Reason: \(reason)")
                case .multipartEncodingFailed(let reason):
                    print("Multipart encoding failed: \(error.localizedDescription)")
                    print("Failure Reason: \(reason)")
                case .responseValidationFailed(let reason):
                    print("Response validation failed: \(error.localizedDescription)")
                    print("Failure Reason: \(reason)")

                    switch reason {
                    case .dataFileNil, .dataFileReadFailed:
                        print("Downloaded file could not be read")
                    case .missingContentType(let acceptableContentTypes):
                        print("Content Type Missing: \(acceptableContentTypes)")
                    case .unacceptableContentType(let acceptableContentTypes, let responseContentType):
                        print("Response content type: \(responseContentType) was unacceptable: \(acceptableContentTypes)")
                    case .unacceptableStatusCode(let code):
                        print("Response status code was unacceptable: \(code)")
                        statusCode = code
                case .responseSerializationFailed(let reason):
                    print("Response serialization failed: \(error.localizedDescription)")
                    print("Failure Reason: \(reason)")
                    // statusCode = 3840 ???? maybe..

                print("Underlying error: \(error.underlyingError)")
            } else if let error = response.result.error as? URLError {
                print("URLError occurred: \(error)")
            } else {
                print("Unknown error: \(response.result.error)")

            print(statusCode) // the status code

(Alamofire 4 contains a completely new error system, look here for details)

For Swift 2.x users with Alamofire >= 3.0

Alamofire.request(.GET, urlString)
      .responseString { response in
             print("Success: \(response.result.isSuccess)")
             print("Response String: \(response.result.value)")
             if let alamoError = response.result.error {
               let alamoCode = alamoError.code
               let statusCode = (response.response?.statusCode)!
             } else { //no errors
               let statusCode = (response.response?.statusCode)! //example : 200

Add a new item to a dictionary in Python

default_data['item3'] = 3

Easy as py.

Another possible solution:

default_data.update({'item3': 3})

which is nice if you want to insert multiple items at once.

How to query all the GraphQL type fields without writing a long query?

I guess the only way to do this is by utilizing reusable fragments:

fragment UserFragment on Users {

FetchUsers {
    users(id: "2") {

Using CSS to insert text

The answer using jQuery that everyone seems to like has a major flaw, which is it is not scalable (at least as it is written). I think Martin Hansen has the right idea, which is to use HTML5 data-* attributes. And you can even use the apostrophe correctly:


<div class="task" data-task-owner="Joe">mop kitchen</div>
<div class="task" data-task-owner="Charles" data-apos="1">vacuum hallway</div>


div.task:before { content: attr(data-task-owner)"'s task - " ; }
div.task[data-apos]:before { content: attr(data-task-owner)"' task - " ; }


Joe's task - mop kitchen
Charles' task - vacuum hallway

How to compare 2 dataTables

How about merging 2 data tables and then comparing the changes? Not sure if that will fill 100% of your needs but for the quick compare it will do a job.

public DataTable GetTwoDataTablesChanges(DataTable firstDataTable, DataTable secondDataTable)
     return secondDataTable.GetChanges();

You can read more about DataTable.Merge()


Utils to read resource text file to String (Java)

Use Apache commons's FileUtils. It has a method readFileToString

What are the sizes used for the iOS application splash screen?

2018 Update - Please don't use this info !

I'm leaving the below post for reference purposes.

Please read Apple's documentation Human Interface Guidelines - Launch Screens for details on launch screens and recommendations.


July 2012 - As this reply is rather old, but stills seems popular. I've written a blog post based on Apple's doco and placed it on my blog. I hope you guys find it useful.

Yes. In iPhone/iPad development the Default.png file is displayed by the device automatically so you don't have to program it which is really useful. I don't have it with me, but you need different PNGs for the iPad with specific names. I googled iPad default png and got this info from the phunkwerks site:

iPad Launch Image Orientations

To deal with various orientation options, a new naming convention has been created for iPad launch images. The screen size of the iPad is 768×1024, notice in the dimensions that follow the height takes into account a 20 pixel status bar.

Filename Dimensions

  • Default-Portrait.png * — 768w x 1024h
  • Default-PortraitUpsideDown.png — 768w x 1024h
  • Default-Landscape.png ** — 1024w x 748h
  • Default-LandscapeLeft.png — 1024w x 748h
  • Default-LandscapeRight.png — 1024w x 748h
  • iPad-Retina–Portrait.png — 1536w x 2048h
  • iPad-Retina–Landscape.png — 2048w x 1496h
  • Default.png — Not recommended

*—If you have not specified a Default-PortraitUpsideDown.png file, this file will take precedence.

**—If you have not specified a Default-LandscapeLeft.png or Default-LandscapeRight.png image file, this file will take precedence.

This link to "Apple's Developer Library" is useful, too.

Finding first and last index of some value in a list in Python

Perhaps the two most efficient ways to find the last index:

def rindex(lst, value):
    i = lst.index(value)
    return len(lst) - i - 1
def rindex(lst, value):
    return len(lst) - operator.indexOf(reversed(lst), value) - 1

Both take only O(1) extra space and the two in-place reversals of the first solution are much faster than creating a reverse copy. Let's compare it with the other solutions posted previously:

def rindex(lst, value):
    return len(lst) - lst[::-1].index(value) - 1

def rindex(lst, value):
    return len(lst) - next(i for i, val in enumerate(reversed(lst)) if val == value) - 1

Benchmark results, my solutions are the red and green ones: unshuffled, full range

This is for searching a number in a list of a million numbers. The x-axis is for the location of the searched element: 0% means it's at the start of the list, 100% means it's at the end of the list. All solutions are fastest at location 100%, with the two reversed solutions taking pretty much no time for that, the double-reverse solution taking a little time, and the reverse-copy taking a lot of time.

A closer look at the right end: unshuffled, tail part

At location 100%, the reverse-copy solution and the double-reverse solution spend all their time on the reversals (index() is instant), so we see that the two in-place reversals are about seven times as fast as creating the reverse copy.

The above was with lst = list(range(1_000_000, 2_000_001)), which pretty much creates the int objects sequentially in memory, which is extremely cache-friendly. Let's do it again after shuffling the list with random.shuffle(lst) (probably less realistic, but interesting):

shuffled list, full range

shuffled list, tail part

All got a lot slower, as expected. The reverse-copy solution suffers the most, at 100% it now takes about 32 times (!) as long as the double-reverse solution. And the enumerate-solution is now second-fastest only after location 98%.

Overall I like the operator.indexOf solution best, as it's the fastest one for the last half or quarter of all locations, which are perhaps the more interesting locations if you're actually doing rindex for something. And it's only a bit slower than the double-reverse solution in earlier locations.

All benchmarks done with CPython 3.9.0 64-bit on Windows 10 Pro 1903 64-bit.

How to return JSON data from spring Controller using @ResponseBody

Considering @Arpit answer, for me it worked only when I add two jackson dependencies:


and configured, of cause, web.xml <mvc:annotation-driven/>.

Original answer that helped me is here:

I can't understand why this JAXB IllegalAnnotationException is thrown

for me this error was actually caused by a field falsely declared as public instead of private.

How to convert HTML to PDF using iTextSharp

First, HTML and PDF are not related although they were created around the same time. HTML is intended to convey higher level information such as paragraphs and tables. Although there are methods to control it, it is ultimately up to the browser to draw these higher level concepts. PDF is intended to convey documents and the documents must "look" the same wherever they are rendered.

In an HTML document you might have a paragraph that's 100% wide and depending on the width of your monitor it might take 2 lines or 10 lines and when you print it it might be 7 lines and when you look at it on your phone it might take 20 lines. A PDF file, however, must be independent of the rendering device, so regardless of your screen size it must always render exactly the same.

Because of the musts above, PDF doesn't support abstract things like "tables" or "paragraphs". There are three basic things that PDF supports: text, lines/shapes and images. (There are other things like annotations and movies but I'm trying to keep it simple here.) In a PDF you don't say "here's a paragraph, browser do your thing!". Instead you say, "draw this text at this exact X,Y location using this exact font and don't worry, I've previously calculated the width of the text so I know it will all fit on this line". You also don't say "here's a table" but instead you say "draw this text at this exact location and then draw a rectangle at this other exact location that I've previously calculated so I know it will appear to be around the text".

Second, iText and iTextSharp parse HTML and CSS. That's it. ASP.Net, MVC, Razor, Struts, Spring, etc, are all HTML frameworks but iText/iTextSharp is 100% unaware of them. Same with DataGridViews, Repeaters, Templates, Views, etc. which are all framework-specific abstractions. It is your responsibility to get the HTML from your choice of framework, iText won't help you. If you get an exception saying The document has no pages or you think that "iText isn't parsing my HTML" it is almost definite that you don't actually have HTML, you only think you do.

Third, the built-in class that's been around for years is the HTMLWorker however this has been replaced with XMLWorker (Java / .Net). Zero work is being done on HTMLWorker which doesn't support CSS files and has only limited support for the most basic CSS properties and actually breaks on certain tags. If you do not see the HTML attribute or CSS property and value in this file then it probably isn't supported by HTMLWorker. XMLWorker can be more complicated sometimes but those complications also make it more extensible.

Below is C# code that shows how to parse HTML tags into iText abstractions that get automatically added to the document that you are working on. C# and Java are very similar so it should be relatively easy to convert this. Example #1 uses the built-in HTMLWorker to parse the HTML string. Since only inline styles are supported the class="headline" gets ignored but everything else should actually work. Example #2 is the same as the first except it uses XMLWorker instead. Example #3 also parses the simple CSS example.

//Create a byte array that will eventually hold our final PDF
Byte[] bytes;

//Boilerplate iTextSharp setup here
//Create a stream that we can write to, in this case a MemoryStream
using (var ms = new MemoryStream()) {

    //Create an iTextSharp Document which is an abstraction of a PDF but **NOT** a PDF
    using (var doc = new Document()) {

        //Create a writer that's bound to our PDF abstraction and our stream
        using (var writer = PdfWriter.GetInstance(doc, ms)) {

            //Open the document for writing

            //Our sample HTML and CSS
            var example_html = @"<p>This <em>is </em><span class=""headline"" style=""text-decoration: underline;"">some</span> <strong>sample <em> text</em></strong><span style=""color: red;"">!!!</span></p>";
            var example_css = @".headline{font-size:200%}";

             * Example #1                                     *
             *                                                *
             * Use the built-in HTMLWorker to parse the HTML. *
             * Only inline CSS is supported.                  *
             * ************************************************/

            //Create a new HTMLWorker bound to our document
            using (var htmlWorker = new iTextSharp.text.html.simpleparser.HTMLWorker(doc)) {

                //HTMLWorker doesn't read a string directly but instead needs a TextReader (which StringReader subclasses)
                using (var sr = new StringReader(example_html)) {

                    //Parse the HTML

             * Example #2                                     *
             *                                                *
             * Use the XMLWorker to parse the HTML.           *
             * Only inline CSS and absolutely linked          *
             * CSS is supported                               *
             * ************************************************/

            //XMLWorker also reads from a TextReader and not directly from a string
            using (var srHtml = new StringReader(example_html)) {

                //Parse the HTML
                iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer, doc, srHtml);

             * Example #3                                     *
             *                                                *
             * Use the XMLWorker to parse HTML and CSS        *
             * ************************************************/

            //In order to read CSS as a string we need to switch to a different constructor
            //that takes Streams instead of TextReaders.
            //Below we convert the strings into UTF8 byte array and wrap those in MemoryStreams
            using (var msCss = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_css))) {
                using (var msHtml = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_html))) {

                    //Parse the HTML
                    iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer, doc, msHtml, msCss);


    //After all of the PDF "stuff" above is done and closed but **before** we
    //close the MemoryStream, grab all of the active bytes from the stream
    bytes = ms.ToArray();

//Now we just need to do something with those bytes.
//Here I'm writing them to disk but if you were in ASP.Net you might Response.BinaryWrite() them.
//You could also write the bytes to a database in a varbinary() column (but please don't) or you
//could pass them to another function for further PDF processing.
var testFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "test.pdf");
System.IO.File.WriteAllBytes(testFile, bytes);

2017's update

There are good news for HTML-to-PDF demands. As this answer showed, the W3C standard css-break-3 will solve the problem... It is a Candidate Recommendation with plan to turn into definitive Recommendation this year, after tests.

As not-so-standard there are solutions, with plugins for C#, as showed by

Response Content type as CSV

For C# MVC 4.5 you need to do like this:

Response.ContentType = "application/CSV";
Response.AddHeader("content-disposition", "attachment; filename=\"" + fileName + ".csv\"");
return new EmptyResult();  //this line is important else it will not work.

groovy.lang.MissingPropertyException: No such property: jenkins for class: groovy.lang.Binding

in my case I have used - (Hyphen) in my script name in case of Jenkinsfile Library. Got resolved after replacing Hyphen(-) with Underscore(_)

How do I convert a float number to a whole number in JavaScript?

I just want to point out that monetarily you want to round, and not trunc. Being off by a penny is much less likely, since 4.999452 * 100 rounded will give you 5, a more representative answer.

And on top of that, don't forget about banker's rounding, which is a way to counter the slightly positive bias that straight rounding gives -- your financial application may require it.

Gaussian/banker's rounding in JavaScript

The opposite of Intersect()

/// <summary>
/// Given two list, compare and extract differences
/// </summary>
public class CompareList
    /// <summary>
    /// Returns list of items that are in initial but not in final list.
    /// </summary>
    /// <param name="listA"></param>
    /// <param name="listB"></param>
    /// <returns></returns>
    public static IEnumerable<string> NonIntersect(
        List<string> initial, List<string> final)
        //subtracts the content of initial from final
        //assumes that final.length < initial.length
        return initial.Except(final);

    /// <summary>
    /// Returns the symmetric difference between the two list.
    /// </summary>
    /// <param name="initial"></param>
    /// <param name="final"></param>
    /// <returns></returns>
    public static IEnumerable<string> SymmetricDifference(
        List<string> initial, List<string> final)
        IEnumerable<string> setA = NonIntersect(final, initial);
        IEnumerable<string> setB = NonIntersect(initial, final);
        // sum and return the two set.
        return setA.Concat(setB);

@viewChild not working - cannot read property nativeElement of undefined

it just simple :import this directory

import {Component, Directive, Input, ViewChild} from '@angular/core';

Work with a time span in Javascript

You can use momentjs duration object


const diff = moment.duration( - new Date(2010, 1, 1))
console.log(`${diff.years()} years ${diff.months()} months ${diff.days()} days ${diff.hours()} hours ${diff.minutes()} minutes and ${diff.seconds()} seconds`)

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

I think, here, right click is not mentioned, @Jishnu V S.

document.onkeydown = function(e) {
    if(e.keyCode == 123) {
     return false;
    if(e.ctrlKey && e.shiftKey && e.keyCode == 'I'.charCodeAt(0)){
     return false;
    if(e.ctrlKey && e.shiftKey && e.keyCode == 'J'.charCodeAt(0)){
     return false;
    if(e.ctrlKey && e.keyCode == 'U'.charCodeAt(0)){
     return false;

    if(e.ctrlKey && e.shiftKey && e.keyCode == 'C'.charCodeAt(0)){
     return false;

Nuget connection attempt failed "Unable to load the service index for source"

I couldn't resolve the problem itself, but found a way to install packages.

Just specify as a source directly in Package Manager Console.

Update-Package -reinstall -Source

Setting focus to a textbox control

create a textbox:

 <TextBox Name="tb">

focus() ---> it is used to set input focus to the textbox control


What would be the best method to code heading/title for <ul> or <ol>, Like we have <caption> in <table>?

Though this is old, I'm updating it for others who might find this question when searching later.

@Matt Kelliher:

Using the css :before and a data-* attribute for the list is a great idea, but can be modified slightly to be more handicap accessible as well:


<ul aria-label="Vehicle Models Available:"> 
    <li>Dodge Shadow</li>
    <li>Ford Focus</li>
    <li>Chevy Lumina</li>



This will make a list with the "header" pseudo element above it with text set to the value in the aria-label attribute. You can then easily style it to your needs.

The benefit of this over using a data-* attribute is that aria-label will be read off by screen readers as a "label" for the list, which is semantically correct for your intended use of this data.

Note: IE8 supports :before attributes, but must use the single colon version (and must have a valid doctype defined). IE7 does not support :before, but Modernizer or Selectivizr should fix that issue for you. All modern browsers support the older :before syntax, but prefer that the ::before syntax be used. Generally the best way to handle this is to have an external stylesheet for IE7/8 that uses the old format and a general stylesheet using the new format, but in practice, most just use the old single colon format since it is still 100% cross browser, even if not technically valid for CSS3.

Java 8 stream reverse order

You could define your own collector that collects the elements in reverse order:

public static <T> Collector<T, List<T>, List<T>> inReverse() {
    return Collector.of(
        (l, t) -> l.add(t),
        (l, r) -> {l.addAll(r); return l;},

And use it like:

stream.collect(inReverse()).forEach(t -> ...)

I use an ArrayList in forward order to efficiently insert collect the items (at the end of the list), and Guava Lists.reverse to efficiently give a reversed view of the list without making another copy of it.

Here are some test cases for the custom collector:

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.*;

import java.util.ArrayList;
import java.util.List;
import java.util.function.BiConsumer;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;

import org.hamcrest.Matchers;
import org.junit.Test;


public class TestReverseCollector {
    private final Object t1 = new Object();
    private final Object t2 = new Object();
    private final Object t3 = new Object();
    private final Object t4 = new Object();

    private final Collector<Object, List<Object>, List<Object>> inReverse = inReverse();
    private final Supplier<List<Object>> supplier = inReverse.supplier();
    private final BiConsumer<List<Object>, Object> accumulator = inReverse.accumulator();
    private final Function<List<Object>, List<Object>> finisher = inReverse.finisher();
    private final BinaryOperator<List<Object>> combiner = inReverse.combiner();

    @Test public void associative() {
        final List<Object> a1 = supplier.get();
        accumulator.accept(a1, t1);
        accumulator.accept(a1, t2);
        final List<Object> r1 = finisher.apply(a1);

        final List<Object> a2 = supplier.get();
        accumulator.accept(a2, t1);
        final List<Object> a3 = supplier.get();
        accumulator.accept(a3, t2);
        final List<Object> r2 = finisher.apply(combiner.apply(a2, a3));

        assertThat(r1, Matchers.equalTo(r2));

    @Test public void identity() {
        final List<Object> a1 = supplier.get();
        accumulator.accept(a1, t1);
        accumulator.accept(a1, t2);
        final List<Object> r1 = finisher.apply(a1);

        final List<Object> a2 = supplier.get();
        accumulator.accept(a2, t1);
        accumulator.accept(a2, t2);
        final List<Object> r2 = finisher.apply(combiner.apply(a2, supplier.get()));

        assertThat(r1, equalTo(r2));

    @Test public void reversing() throws Exception {
        final List<Object> a2 = supplier.get();
        accumulator.accept(a2, t1);
        accumulator.accept(a2, t2);

        final List<Object> a3 = supplier.get();
        accumulator.accept(a3, t3);
        accumulator.accept(a3, t4);

        final List<Object> r2 = finisher.apply(combiner.apply(a2, a3));

        assertThat(r2, contains(t4, t3, t2, t1));

    public static <T> Collector<T, List<T>, List<T>> inReverse() {
        return Collector.of(
            (l, t) -> l.add(t),
            (l, r) -> {l.addAll(r); return l;},

JFrame background image

I used a very similar method to @bott, but I modified it a little bit to make there be no need to resize the image:

BufferedImage img = null;
try {
    img = File("image.jpg"));
} catch (IOException e) {
Image dimg = img.getScaledInstance(800, 508, Image.SCALE_SMOOTH);
ImageIcon imageIcon = new ImageIcon(dimg);
setContentPane(new JLabel(imageIcon));

Works every time. You can also get the width and height of the jFrame and use that in place of the 800 and 508 respectively.

Find Locked Table in SQL Server

You can use sp_lock (and sp_lock2), but in SQL Server 2005 onwards this is being deprecated in favour of querying sys.dm_tran_locks:

    object_name(p.object_id) as TableName, 
    resource_type, resource_description
    sys.dm_tran_locks l
    join sys.partitions p on l.resource_associated_entity_id = p.hobt_id

await vs Task.Wait - Deadlock?

Some important facts were not given in other answers:

"async await" is more complex at CIL level and thus costs memory and CPU time.

Any task can be canceled if the waiting time is unacceptable.

In the case "async await" we do not have a handler for such a task to cancel it or monitoring it.

Using Task is more flexible then "async await".

Any sync functionality can by wrapped by async.

public async Task<ActionResult> DoAsync(long id) 
    return await Task.Run(() => { return DoSync(id); } ); 

"async await" generate many problems. We do not now is await statement will be reached without runtime and context debugging. If first await not reached everything is blocked. Some times even await seems to be reached still everything is blocked:

I do not see why I'm must live with the code duplication for sync and async method or using hacks.

Conclusion: Create Task manually and control them is much better. Handler to Task give more control. We can monitor Tasks and manage them:

Sorry for my english.

How do you automatically resize columns in a DataGridView control AND allow the user to resize the columns on that same grid?

This autofits all columns according to their content, fills the remaining empty space by stretching a specified column and prevents the 'jumping' behaviour by setting the last column to fill for any future resizing.

// autosize all columns according to their content
// make column 1 (or whatever) fill the empty space
dgv.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;
// remove column 1 autosizing to prevent 'jumping' behaviour
dgv.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.None;
// let the last column fill the empty space when the grid or any column is resized (more natural/expected behaviour) 
dgv.Columns.GetLastColumn(DataGridViewElementStates.None, DataGridViewElementStates.None).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;

Multiple glibc libraries on a single host

Setup 1: compile your own glibc without dedicated GCC and use it

This setup might work and is quick as it does not recompile the whole GCC toolchain, just glibc.

But it is not reliable as it uses host C runtime objects such as crt1.o, crti.o, and crtn.o provided by glibc. This is mentioned at: Those objects do early setup that glibc relies on, so I wouldn't be surprised if things crashed in wonderful and awesomely subtle ways.

For a more reliable setup, see Setup 2 below.

Build glibc and install locally:

export glibc_install="$(pwd)/glibc/build/install"

git clone git://
cd glibc
git checkout glibc-2.28
mkdir build
cd build
../configure --prefix "$glibc_install"
make -j `nproc`
make install -j `nproc`

Setup 1: verify the build


#define _GNU_SOURCE
#include <assert.h>
#include <gnu/libc-version.h>
#include <stdatomic.h>
#include <stdio.h>
#include <threads.h>

atomic_int acnt;
int cnt;

int f(void* thr_data) {
    for(int n = 0; n < 1000; ++n) {
    return 0;

int main(int argc, char **argv) {
    /* Basic library version check. */
    printf("gnu_get_libc_version() = %s\n", gnu_get_libc_version());

    /* Exercise thrd_create from -pthread,
     * which is not present in glibc 2.27 in Ubuntu 18.04.
     * */
    thrd_t thr[10];
    for(int n = 0; n < 10; ++n)
        thrd_create(&thr[n], f, NULL);
    for(int n = 0; n < 10; ++n)
        thrd_join(thr[n], NULL);
    printf("The atomic counter is %u\n", acnt);
    printf("The non-atomic counter is %u\n", cnt);

Compile and run with

#!/usr/bin/env bash
set -eux
gcc \
  -L "${glibc_install}/lib" \
  -I "${glibc_install}/include" \
  -Wl,--rpath="${glibc_install}/lib" \
  -Wl,--dynamic-linker="${glibc_install}/lib/" \
  -std=c11 \
  -o test_glibc.out \
  -v \
  test_glibc.c \
  -pthread \
ldd ./test_glibc.out

The program outputs the expected:

gnu_get_libc_version() = 2.28
The atomic counter is 10000
The non-atomic counter is 8674

Command adapted from but --sysroot made it fail with:

cannot find /home/ciro/glibc/build/install/lib/ inside /home/ciro/glibc/build/install

so I removed it.

ldd output confirms that the ldd and libraries that we've just built are actually being used as expected:

+ ldd test_glibc.out (0x00007ffe4bfd3000) => /home/ciro/glibc/build/install/lib/ (0x00007fc12ed92000) => /home/ciro/glibc/build/install/lib/ (0x00007fc12e9dc000)
        /home/ciro/glibc/build/install/lib/ => /lib64/ (0x00007fc12f1b3000)

The gcc compilation debug output shows that my host runtime objects were used, which is bad as mentioned previously, but I don't know how to work around it, e.g. it contains:


Setup 1: modify glibc

Now let's modify glibc with:

diff --git a/nptl/thrd_create.c b/nptl/thrd_create.c
index 113ba0d93e..b00f088abb 100644
--- a/nptl/thrd_create.c
+++ b/nptl/thrd_create.c
@@ -16,11 +16,14 @@
    License along with the GNU C Library; if not, see
    <>.  */

+#include <stdio.h>
 #include "thrd_priv.h"

 thrd_create (thrd_t *thr, thrd_start_t func, void *arg)
+  puts("hacked");
   _Static_assert (sizeof (thr) == sizeof (pthread_t),
                   "sizeof (thr) != sizeof (pthread_t)");

Then recompile and re-install glibc, and recompile and re-run our program:

cd glibc/build
make -j `nproc`
make -j `nproc` install

and we see hacked printed a few times as expected.

This further confirms that we actually used the glibc that we compiled and not the host one.

Tested on Ubuntu 18.04.

Setup 2: crosstool-NG pristine setup

This is an alternative to setup 1, and it is the most correct setup I've achieved far: everything is correct as far as I can observe, including the C runtime objects such as crt1.o, crti.o, and crtn.o.

In this setup, we will compile a full dedicated GCC toolchain that uses the glibc that we want.

The only downside to this method is that the build will take longer. But I wouldn't risk a production setup with anything less.

crosstool-NG is a set of scripts that downloads and compiles everything from source for us, including GCC, glibc and binutils.

Yes the GCC build system is so bad that we need a separate project for that.

This setup is only not perfect because crosstool-NG does not support building the executables without extra -Wl flags, which feels weird since we've built GCC itself. But everything seems to work, so this is only an inconvenience.

Get crosstool-NG, configure and build it:

git clone
cd crosstool-ng
git checkout a6580b8e8b55345a5a342b5bd96e42c83e640ac5
export CT_PREFIX="$(pwd)/.build/install"
export PATH="/usr/lib/ccache:${PATH}"
./configure --enable-local
make -j `nproc`
./ct-ng x86_64-unknown-linux-gnu
./ct-ng menuconfig
env -u LD_LIBRARY_PATH time ./ct-ng build CT_JOBS=`nproc`

The build takes about thirty minutes to two hours.

The only mandatory configuration option that I can see, is making it match your host kernel version to use the correct kernel headers. Find your host kernel version with:

uname -a

which shows me:


so in menuconfig I do:

  • Operating System
    • Version of linux

so I select:


which is the first equal or older version. It has to be older since the kernel is backwards compatible.

Setup 2: optional configurations

The .config that we generated with ./ct-ng x86_64-unknown-linux-gnu has:


To change that, in menuconfig do:

  • C-library
  • Version of glibc

save the .config, and continue with the build.

Or, if you want to use your own glibc source, e.g. to use glibc from the latest git, proceed like this:

  • Paths and misc options
    • Try features marked as EXPERIMENTAL: set to true
  • C-library
    • Source of glibc
      • Custom location: say yes
      • Custom location
        • Custom source location: point to a directory containing your glibc source

where glibc was cloned as:

git clone git://
cd glibc
git checkout glibc-2.28

Setup 2: test it out

Once you have built he toolchain that you want, test it out with:

#!/usr/bin/env bash
set -eux
PATH="${PATH}:${install_dir}/bin" \
  x86_64-unknown-linux-gnu-gcc \
  -Wl,--dynamic-linker="${install_dir}/x86_64-unknown-linux-gnu/sysroot/lib/" \
  -Wl,--rpath="${install_dir}/x86_64-unknown-linux-gnu/sysroot/lib" \
  -v \
  -o test_glibc.out \
  test_glibc.c \
  -pthread \
ldd test_glibc.out

Everything seems to work as in Setup 1, except that now the correct runtime objects were used:


Setup 2: failed efficient glibc recompilation attempt

It does not seem possible with crosstool-NG, as explained below.

If you just re-build;

env -u LD_LIBRARY_PATH time ./ct-ng build CT_JOBS=`nproc`

then your changes to the custom glibc source location are taken into account, but it builds everything from scratch, making it unusable for iterative development.

If we do:

./ct-ng list-steps

it gives a nice overview of the build steps:

Available build steps, in order:
  - companion_tools_for_build
  - companion_libs_for_build
  - binutils_for_build
  - companion_tools_for_host
  - companion_libs_for_host
  - binutils_for_host
  - cc_core_pass_1
  - kernel_headers
  - libc_start_files
  - cc_core_pass_2
  - libc
  - cc_for_build
  - cc_for_host
  - libc_post_cc
  - companion_libs_for_target
  - binutils_for_target
  - debug
  - test_suite
  - finish
Use "<step>" as action to execute only that step.
Use "+<step>" as action to execute up to that step.
Use "<step>+" as action to execute from that step onward.

therefore, we see that there are glibc steps intertwined with several GCC steps, most notably libc_start_files comes before cc_core_pass_2, which is likely the most expensive step together with cc_core_pass_1.

In order to build just one step, you must first set the "Save intermediate steps" in .config option for the intial build:

  • Paths and misc options
    • Debug crosstool-NG
      • Save intermediate steps

and then you can try:

env -u LD_LIBRARY_PATH time ./ct-ng libc+ -j`nproc`

but unfortunately, the + required as mentioned at:

Note however that restarting at an intermediate step resets the installation directory to the state it had during that step. I.e., you will have a rebuilt libc - but no final compiler built with this libc (and hence, no compiler libraries like libstdc++ either).

and basically still makes the rebuild too slow to be feasible for development, and I don't see how to overcome this without patching crosstool-NG.

Furthermore, starting from the libc step didn't seem to copy over the source again from Custom source location, further making this method unusable.

Bonus: stdlibc++

A bonus if you're also interested in the C++ standard library: How to edit and re-build the GCC libstdc++ C++ standard library source?

"Bitmap too large to be uploaded into a texture"

BitmapRegionDecoder does the trick.

You can override onDraw(Canvas canvas), start a new Thread and decode the area visible to the user.

Getting multiple keys of specified value of a generic Dictionary?

revised: okay to have some kind of find you would need something other than dictionary, since if you think about it dictionary are one way keys. that is, the values might not be unique

that said it looks like you're using c#3.0 so you might not have to resort to looping and could use something like:

var key = (from k in yourDictionary where string.Compare(k.Value, "yourValue", true)  == 0 select k.Key).FirstOrDefault();

Plot yerr/xerr as shaded region rather than error bars

This is basically the same answer provided by Evert, but extended to show-off some cool options of fill_between

enter image description here

from matplotlib import pyplot as pl
import numpy as np


x = np.linspace(0, 30, 100)
y = np.sin(x) * 0.5
pl.plot(x, y, '-k')

x = np.linspace(0, 30, 30)
y = np.sin(x/6*np.pi)
error = np.random.normal(0.1, 0.02, size=y.shape) +.1
y += np.random.normal(0, 0.1, size=y.shape)

pl.plot(x, y, 'k', color='#CC4F1B')
pl.fill_between(x, y-error, y+error,
    alpha=0.5, edgecolor='#CC4F1B', facecolor='#FF9848')

y = np.cos(x/6*np.pi)    
error = np.random.rand(len(y)) * 0.5
y += np.random.normal(0, 0.1, size=y.shape)
pl.plot(x, y, 'k', color='#1B2ACC')
pl.fill_between(x, y-error, y+error,
    alpha=0.2, edgecolor='#1B2ACC', facecolor='#089FFF',
    linewidth=4, linestyle='dashdot', antialiased=True)

y = np.cos(x/6*np.pi)  + np.sin(x/3*np.pi)  
error = np.random.rand(len(y)) * 0.5
y += np.random.normal(0, 0.1, size=y.shape)
pl.plot(x, y, 'k', color='#3F7F4C')
pl.fill_between(x, y-error, y+error,
    alpha=1, edgecolor='#3F7F4C', facecolor='#7EFF99',

How to upload image in CodeIgniter?

//this is the code you have to use in you controller 

        $config['upload_path'] = './uploads/';  

// directory (http://localhost/codeigniter/index.php/your directory)

        $config['allowed_types'] = 'gif|jpg|png|jpeg';  
//Image type  

        $config['max_size'] = 0;    

 // I have chosen max size no limit 
        $new_name = time() . '-' . $_FILES["txt_file"]['name']; 

//Added time function in image name for no duplicate image 

        $config['file_name'] = $new_name;

//Stored the new name into $config['file_name']

        $this->load->library('upload', $config);

        if (!$this->upload->do_upload() && !empty($_FILES['txt_file']['name'])) {
            $error = array('error' => $this->upload->display_errors());
            $this->load->view('production/create_images', $error);
        } else {
            $upload_data = $this->upload->data();   

How to replace url parameter with javascript/jquery?

How about something like this:

function changeQueryVariable(keyString, replaceString) {
    var query =;
    var vars = query.split("&");
    var replaced = false;
    for (var i = 0; i < vars.length; i++) {
        var pair = vars[i].split("=");
        if (pair[0] == keyString) {
            vars[i] = pair[0] + "="+ replaceString;
            replaced = true;
    if (!replaced) vars.push(keyString + "=" + replaceString);
    return vars.join("&");

SQL Server 100% CPU Utilization - One database shows high CPU usage than others

You can see some reports in SSMS:

Right-click the instance name / reports / standard / top sessions

You can see top CPU consuming sessions. This may shed some light on what SQL processes are using resources. There are a few other CPU related reports if you look around. I was going to point to some more DMVs but if you've looked into that already I'll skip it.

You can use sp_BlitzCache to find the top CPU consuming queries. You can also sort by IO and other things as well. This is using DMV info which accumulates between restarts.

This article looks promising.

Some stackoverflow goodness from Mr. Ozar.

edit: A little more advice... A query running for 'only' 5 seconds can be a problem. It could be using all your cores and really running 8 cores times 5 seconds - 40 seconds of 'virtual' time. I like to use some DMVs to see how many executions have happened for that code to see what that 5 seconds adds up to.

Android Completely transparent Status Bar?

in my case, i dont call at all "onCreate" (its a react native app and this can be fixes also by using the react-native StatusBar component) one can also use this:

override fun onStart() {
        window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
        window.statusBarColor = Color.TRANSPARENT

jQuery UI Sortable, then write order into a database

Try with this solution: where new order is saved in some HMTL element. Then you submit the form with this data to some PHP script, and iterate trough it with for loop.

Note: I had to add another db field of type INT(11) which is updated(timestamp'ed) on each iteration - it serves for script to know which row is recenty updated, or else you end up with scrambled results.

Give column name when read csv file pandas

we can do it with a single line of code.

 user1 = pd.read_csv('dataset/1.csv', names=['TIME', 'X', 'Y', 'Z'], header=None)