Programs & Examples On #Itemcommand

How to properly -filter multiple strings in a PowerShell copy script

Something like this should work (it did for me). The reason for wanting to use -Filter instead of -Include is that include takes a huge performance hit compared to -Filter.

Below just loops each file type and multiple servers/workstations specified in separate files.

##  This script will pull from a list of workstations in a text file and search for the specified string

## Change the file path below to where your list of target workstations reside
## Change the file path below to where your list of filetypes reside

$filetypes = gc 'pathToListOffiletypes.txt'
$servers = gc 'pathToListOfWorkstations.txt'

##Set the scope of the variable so it has visibility
set-variable -Name searchString -Scope 0
$searchString = 'whatYouAreSearchingFor'

foreach ($server in $servers)

    foreach ($filetype in $filetypes)

    ## below creates the search path.  This could be further improved to exclude the windows directory
    $serverString = "\\"+$server+"\c$\Program Files"

    ## Display the server being queried
    write-host “Server:” $server "searching for " $filetype in $serverString

    Get-ChildItem -Path $serverString -Recurse -Filter $filetype |
    #-Include "*.xml","*.ps1","*.cnf","*.odf","*.conf","*.bat","*.cfg","*.ini","*.config","*.info","*.nfo","*.txt" |
    Select-String -pattern $searchstring | group path | select name | out-file f:\DataCentre\String_Results.txt

    $os = gwmi win32_operatingsystem -computer $server
    $sp = $os | % {$_.servicepackmajorversion}
    $a = $os | % {$_.caption}

    ##  Below will list again the server name as well as its OS and SP
    ##  Because the script may not be monitored, this helps confirm the machine has been successfully scanned
        write-host $server “has completed its " $filetype "scan:” “|” “OS:” $a “SP:” “|” $sp


#end script

Creating a folder if it does not exists - "Item already exists"

With New-Item you can add the Force parameter

New-Item -Force -ItemType directory -Path foo

Or the ErrorAction parameter

New-Item -ErrorAction Ignore -ItemType directory -Path foo

Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack

Just encase someone else ran into the issues I did I was using Response.End() an async trigger button

<asp:AsyncPostBackTrigger ControlID="btn_login" />

in an update panel. I switched to regular post back not the best but it worked.

<asp:PostBackTrigger ControlID="btn_login" />. 

Since I was only redirecting on the page this was a viable solution.

WPF Databinding: How do I access the "parent" data context?

This also works in Silverlight 5 (perhaps earlier as well but i haven't tested it). I used the relative source like this and it worked fine.

RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=telerik:RadGridView}"

How to get an isoformat datetime string including the default timezone?

Nine years later. If you know your time zone. I like the T between date and time. And if you don't want microseconds.

Python <= 3.8

pip3 install pytz  # needed!

>>> import datetime
>>> import pytz
>>>'Europe/Berlin')).isoformat('T', 'seconds')

Tested on Ubuntu 18.04 and Python 3.6.9.

Python >= 3.9

pip3 install tzdata  # only on Windows needed!

py -3
>>> import datetime
>>> import zoneinfo
>>>'Europe/Berlin')).isoformat('T', 'seconds')

Tested on Windows 10 and Python 3.9.0.

How to download HTTP directory with all files and sub-directories as they appear on the online files/folders list?

wget is an invaluable resource and something I use myself. However sometimes there are characters in the address that wget identifies as syntax errors. I'm sure there is a fix for that, but as this question did not ask specifically about wget I thought I would offer an alternative for those people who will undoubtedly stumble upon this page looking for a quick fix with no learning curve required.

There are a few browser extensions that can do this, but most require installing download managers, which aren't always free, tend to be an eyesore, and use a lot of resources. Heres one that has none of these drawbacks:

"Download Master" is an extension for Google Chrome that works great for downloading from directories. You can choose to filter which file-types to download, or download the entire directory.

For an up-to-date feature list and other information, visit the project page on the developer's blog:

How to group an array of objects by key

There is absolutely no reason to download a 3rd party library to achieve this simple problem, like the above solutions suggest.

The one line version to group a list of objects by a certain key in es6:

const groupByKey = (list, key) => list.reduce((hash, obj) => ({...hash, [obj[key]]:( hash[obj[key]] || [] ).concat(obj)}), {})

The longer version that filters out the objects without the key:

function groupByKey(array, key) {
   return array
     .reduce((hash, obj) => {
       if(obj[key] === undefined) return hash; 
       return Object.assign(hash, { [obj[key]]:( hash[obj[key]] || [] ).concat(obj)})
     }, {})

var cars = [{'make':'audi','model':'r8','year':'2012'},{'make':'audi','model':'rs5','year':'2013'},{'make':'ford','model':'mustang','year':'2012'},{'make':'ford','model':'fusion','year':'2015'},{'make':'kia','model':'optima','year':'2012'}];

console.log(groupByKey(cars, 'make'))

NOTE: It appear the original question asks how to group cars by make, but omit the make in each group. So the short answer, without 3rd party libraries, would look like this:

const groupByKey = (list, key, {omitKey=false}) => list.reduce((hash, {[key]:value,}) => ({...hash, [value]:( hash[value] || [] ).concat(omitKey ? {} : {[key]:value,})} ), {})

var cars = [{'make':'audi','model':'r8','year':'2012'},{'make':'audi','model':'rs5','year':'2013'},{'make':'ford','model':'mustang','year':'2012'},{'make':'ford','model':'fusion','year':'2015'},{'make':'kia','model':'optima','year':'2012'}];

console.log(groupByKey(cars, 'make', {omitKey:true}))

Difference between variable declaration syntaxes in Javascript (including global variables)?

In global scope there is no semantic difference.

But you really should avoid a=0 since your setting a value to an undeclared variable.

Also use closures to avoid editing global scope at all

(function() {
   // do stuff locally

   // Hoist something to global scope
   window.someGlobal = someLocal

Always use closures and always hoist to global scope when its absolutely neccesary. You should be using asynchronous event handling for most of your communication anyway.

As @AvianMoncellor mentioned there is an IE bug with var a = foo only declaring a global for file scope. This is an issue with IE's notorious broken interpreter. This bug does sound familiar so it's probably true.

So stick to window.globalName = someLocalpointer

How to add buttons dynamically to my form?

Two problems- List is empty. You need to add some buttons to the list first. Second problem: You can't add buttons to "this". "This" is not referencing what you think, I think. Change this to reference a Panel for instance.

//Assume you have on your .aspx page:
<asp:Panel ID="Panel_Controls" runat="server"></asp:Panel>

private void button1_Click(object sender, EventArgs e)
        List<Button> buttons = new List<Button>();

        for (int i = 0; i < buttons.Capacity; i++)

How do I remove files saying "old mode 100755 new mode 100644" from unstaged changes in Git?

Setting core.filemode to false does work, but make sure the settings in ~/.gitconfig aren't being overridden by those in .git/config.

Add bottom line to view in SwiftUI / Swift / Objective-C / Xamarin

What I did was to create an extension to UITextField and added a Designer editable property. Setting this property to any color would change the border (bottom) to that color (setting other borders to none).

Since this also requires to change the place holder text color, I also added that to the extension.

    extension UITextField {

    @IBInspectable var placeHolderColor: UIColor? {
        get {
            return self.placeHolderColor
        set {
            self.attributedPlaceholder = NSAttributedString(string:self.placeholder != nil ? self.placeholder! : "", attributes:[NSForegroundColorAttributeName: newValue!])

    @IBInspectable var bottomBorderColor: UIColor? {
        get {
            return self.bottomBorderColor
        set {
            self.borderStyle = UITextBorderStyle.None;
            let border = CALayer()
            let width = CGFloat(0.5)
            border.borderColor = newValue?.CGColor
            border.frame = CGRect(x: 0, y: self.frame.size.height - width,   width:  self.frame.size.width, height: self.frame.size.height)

            border.borderWidth = width
            self.layer.masksToBounds = true


What characters are allowed in an email address?

Wikipedia has a good article on this, and the official spec is here. From Wikipdia:

The local-part of the e-mail address may use any of these ASCII characters:

  • Uppercase and lowercase English letters (a-z, A-Z)
  • Digits 0 to 9
  • Characters ! # $ % & ' * + - / = ? ^ _ ` { | } ~
  • Character . (dot, period, full stop) provided that it is not the first or last character, and provided also that it does not appear two or more times consecutively.

Additionally, quoted-strings (ie: "John Doe" are permitted, thus allowing characters that would otherwise be prohibited, however they do not appear in common practice. RFC 5321 also warns that "a host that expects to receive mail SHOULD avoid defining mailboxes where the Local-part requires (or uses) the Quoted-string form".

C/C++ line number

You could use a macro with the same behavior as printf(), except that it also includes debug information such as function name, class, and line number:

#include <cstdio>  //needed for printf
#define print(a, args...) printf("%s(%s:%d) " a,  __func__,__FILE__, __LINE__, ##args)
#define println(a, args...) print(a "\n", ##args)

These macros should behave identically to printf(), while including java stacktrace-like information. Here's an example main:

void exampleMethod() {
    println("printf() syntax: string = %s, int = %d", "foobar", 42);

int main(int argc, char** argv) {
    print("Before exampleMethod()...\n");

Which results in the following output:

main(main.cpp:11) Before exampleMethod()...
exampleMethod(main.cpp:7) printf() syntax: string = foobar, int = 42
main(main.cpp:13) Success!

What does character set and collation mean exactly?

From MySQL docs:

A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set. Let's make the distinction clear with an example of an imaginary character set.

Suppose that we have an alphabet with four letters: 'A', 'B', 'a', 'b'. We give each letter a number: 'A' = 0, 'B' = 1, 'a' = 2, 'b' = 3. The letter 'A' is a symbol, the number 0 is the encoding for 'A', and the combination of all four letters and their encodings is a character set.

Now, suppose that we want to compare two string values, 'A' and 'B'. The simplest way to do this is to look at the encodings: 0 for 'A' and 1 for 'B'. Because 0 is less than 1, we say 'A' is less than 'B'. Now, what we've just done is apply a collation to our character set. The collation is a set of rules (only one rule in this case): "compare the encodings." We call this simplest of all possible collations a binary collation.

But what if we want to say that the lowercase and uppercase letters are equivalent? Then we would have at least two rules: (1) treat the lowercase letters 'a' and 'b' as equivalent to 'A' and 'B'; (2) then compare the encodings. We call this a case-insensitive collation. It's a little more complex than a binary collation.

In real life, most character sets have many characters: not just 'A' and 'B' but whole alphabets, sometimes multiple alphabets or eastern writing systems with thousands of characters, along with many special symbols and punctuation marks. Also in real life, most collations have many rules: not just case insensitivity but also accent insensitivity (an "accent" is a mark attached to a character as in German 'ö') and multiple-character mappings (such as the rule that 'ö' = 'OE' in one of the two German collations).

error: expected class-name before ‘{’ token

I got the same error with a different problem,

I used namespaces in my headers and forgot the closing bracket and got this cryptic error instead.

Format decimal for percentage values?

This code may help you:

double d = double.Parse(input_value);
string output= d.ToString("F2", CultureInfo.InvariantCulture) + "%";

How to sort multidimensional array by column?

sorted(list, key=lambda x: x[1])

Note: this works on time variable too.

MySQL - How to select rows where value is in array?

Use the FIND_IN_SET function:

 WHERE FIND_IN_SET(3, t.ids) > 0

Clear the value of bootstrap-datepicker

Actually it is much more useful use the method that came with the library like this $(".datepicker").datepicker("clearDates");

I recommend you to always take a look at the documentation of the library, here is the one I used for this.

bootstrap-datepicker methods documentation

Easy way to build Android UI? try this tool its not for free but offers simple way to create android ui on your phone

How to set timeout in Retrofit library?

public class ApiClient {
    private static Retrofit retrofit = null;
    private static final Object LOCK = new Object();

    public static void clear() {
        synchronized (LOCK) {
            retrofit = null;

    public static Retrofit getClient() {
        synchronized (LOCK) {
            if (retrofit == null) {

                Gson gson = new GsonBuilder()

                OkHttpClient okHttpClient = new OkHttpClient().newBuilder()
                        .connectTimeout(40, TimeUnit.SECONDS)
                        .readTimeout(60, TimeUnit.SECONDS)
                        .writeTimeout(60, TimeUnit.SECONDS)

                // Log.e("jjj", "=" + (MySharedPreference.getmInstance().isEnglish() ? Constant.WEB_SERVICE : Constant.WEB_SERVICE_ARABIC));
                retrofit = new Retrofit.Builder()
            return retrofit;
        }`enter code here`


    public static RequestBody plain(String content) {
        return getRequestBody("text/plain", content);

    public static RequestBody getRequestBody(String type, String content) {
        return RequestBody.create(MediaType.parse(type), content);


    implementation 'com.squareup.retrofit2:retrofit:2.4.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.4.0'

What does "connection reset by peer" mean?

This means that a TCP RST was received and the connection is now closed. This occurs when a packet is sent from your end of the connection but the other end does not recognize the connection; it will send back a packet with the RST bit set in order to forcibly close the connection.

This can happen if the other side crashes and then comes back up or if it calls close() on the socket while there is data from you in transit, and is an indication to you that some of the data that you previously sent may not have been received.

It is up to you whether that is an error; if the information you were sending was only for the benefit of the remote client then it may not matter that any final data may have been lost. However you should close the socket and free up any other resources associated with the connection.

std::enable_if to conditionally compile a member function

One way to solve this problem, specialization of member functions is to put the specialization into another class, then inherit from that class. You may have to change the order of inheritence to get access to all of the other underlying data but this technique does work.

template< class T, bool condition> struct FooImpl;
template<class T> struct FooImpl<T, true> {
T foo() { return 10; }

template<class T> struct FoolImpl<T,false> {
T foo() { return 5; }

template< class T >
class Y : public FooImpl<T, boost::is_integer<T> > // whatever your test is goes here.
    typedef FooImpl<T, boost::is_integer<T> > inherited;

    // you will need to use "inherited::" if you want to name any of the 
    // members of those inherited classes.

The disadvantage of this technique is that if you need to test a lot of different things for different member functions you'll have to make a class for each one, and chain it in the inheritence tree. This is true for accessing common data members.


template<class T, bool condition> class Goo;
// repeat pattern above.

template<class T, bool condition>
class Foo<T, true> : public Goo<T, boost::test<T> > {
    typedef Goo<T, boost::test<T> > inherited:
    // etc. etc.

Is there a standard function to check for null, undefined, or blank variables in JavaScript?

Try Boolean() and isNaN() (for number type) to check a variable has a value or not.

function isEmpty(val) {
  return typeof val === 'number' ? isNaN(val) : !Boolean(val);

var emptyVals = [undefined, null, false, NaN, ''];
emptyVals.forEach(v => console.log(isEmpty(v)));

How do you pull first 100 characters of a string in PHP

You could use substr, I guess:

$string2 = substr($string1, 0, 100);

or mb_substr for multi-byte strings:

$string2 = mb_substr($string1, 0, 100);

You could create a function wich uses this function and appends for instance '...' to indicate that it was shortened. (I guess there's allready a hundred similar replies when this is posted...)

Android Studio doesn't see device

This is what worked for me:

  • windows 10.
  • Android Studio 4.1 .
  • Samsung galaxy a50.

In Android Studio do this: File – settings – languages and frameworks – flutter . Then point to the spot in your computer where you flutter is stored at, like: C:\Desktop\Flutter for example.

Hope it helps. : D

How to split a string and assign it to variables

As a side note, you can include the separators while splitting the string in Go. To do so, use strings.SplitAfter as in the example below.

package main

import (

func main() {
    fmt.Printf("%q\n", strings.SplitAfter("z,o,r,r,o", ","))

Slide div left/right using jQuery

$('#hello').hide('slide', {direction: 'left'}, 1000); requires the jQuery-ui library. See

SQL Insert Query Using C#

I have just wrote a reusable method for that, there is no answer here with reusable method so why not to share...
here is the code from my current project:

public static int ParametersCommand(string query,List<SqlParameter> parameters)
    SqlConnection connection = new SqlConnection(ConnectionString);
        using (SqlCommand cmd = new SqlCommand(query, connection))
        {   // for cases where no parameters needed
            if (parameters != null)

            int result = cmd.ExecuteNonQuery();
            return result;
    catch (Exception ex)
        AddEventToEventLogTable("ERROR in DAL.DataBase.ParametersCommand() method: " + ex.Message, 1);
        return 0;

        CloseConnection(ref connection);

private static void CloseConnection(ref SqlConnection conn)
    if (conn.State != ConnectionState.Closed)

Jquery to change form action

Use jQuery.attr() in your click handler:

$("#myform").attr('action', 'page1.php');

Convenient way to parse incoming multipart/form-data parameters in a Servlet

Not always there's a servlet before of an upload (I could use a filter for example). Or could be that the same controller ( again a filter or also a servelt ) can serve many actions, so I think that rely on that servlet configuration to use the getPart method (only for Servlet API >= 3.0), I don't know, I don't like.

In general, I prefer independent solutions, able to live alone, and in this case is one of that.

List<FileItem> multiparts = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);
    for (FileItem item : multiparts) {
        if (!item.isFormField()) {
            //your operations on file
        } else {
            String name = item.getFieldName();
            String value = item.getString();
            //you operations on paramters

Reset git proxy to default configuration

For me, I had to add:

git config --global --unset http.proxy

Basically, you can run:

git config --global -l 

to get the list of all proxy defined, and then use "--unset" to disable them

Random float number generation

drand48(3) is the POSIX standard way. GLibC also provides a reentrant version, drand48_r(3).

The function was declared obsolete in SVID 3 but no adequate alternative was provided so IEEE Std 1003.1-2013 still includes it and has no notes that it's going anywhere anytime soon.

In Windows, the standard way is CryptGenRandom().

How to import and export components using React + ES6 + webpack?

MDN has really nice documentation for all the new ways to import and export modules is ES 6 Import-MDN . A brief description of it in regards to your question you could've either:

  1. Declared the component you were exporting as the 'default' component that this module was exporting: export default class MyNavbar extends React.Component { , and so when Importing your 'MyNavbar' you DON'T have to put curly braces around it : import MyNavbar from './comp/my-navbar.jsx';. Not putting curly braces around an import though is telling the document that this component was declared as an 'export default'. If it wasn't you'll get an error (as you did).

  2. If you didn't want to declare your 'MyNavbar' as a default export when exporting it : export class MyNavbar extends React.Component { , then you would have to wrap your import of 'MyNavbar in curly braces: import {MyNavbar} from './comp/my-navbar.jsx';

I think that since you only had one component in your './comp/my-navbar.jsx' file it's cool to make it the default export. If you'd had more components like MyNavbar1, MyNavbar2, MyNavbar3 then I wouldn't make either or them a default and to import selected components of a module when the module hasn't declared any one thing a default you can use: import {foo, bar} from "my-module"; where foo and bar are multiple members of your module.

Definitely read the MDN doc it has good examples for the syntax. Hopefully this helps with a little more of an explanation for anyone that's looking to toy with ES 6 and component import/exports in React.

UITableView, Separator color where to set?

If you just want to set the same color to every separator and it is opaque you can use:

 self.tableView.separatorColor = UIColor.redColor()

If you want to use different colors for the separators or clear the separator color or use a color with alpha.

BE CAREFUL: You have to know that there is a backgroundView in the separator that has a default color.

To change it you can use this functions:

    func tableView(tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
            var headerView = view as! UITableViewHeaderFooterView;
            headerView.backgroundView?.backgroundColor = myColor

           //Other colors you can change here
           // headerView.backgroundColor = myColor
           // headerView.contentView.backgroundColor = myColor

    func tableView(tableView: UITableView, willDisplayFooterView view: UIView, forSection section: Int) {
            var footerView = view as! UITableViewHeaderFooterView;
            footerView.backgroundView?.backgroundColor = myColor
           //Other colors you can change here
           //footerView.backgroundColor = myColor
           //footerView.contentView.backgroundColor = myColor

Hope it helps!

SSL handshake fails with - a verisign chain certificate - that contains two CA signed certificates and one self-signed certificate

Root certificates issued by CAs are just self-signed certificates (which may in turn be used to issue intermediate CA certificates). They have not much special about them, except that they've managed to be imported by default in many browsers or OS trust anchors.

While browsers and some tools are configured to look for the trusted CA certificates (some of which may be self-signed) in location by default, as far as I'm aware the openssl command isn't.

As such, any server that presents the full chain of certificate, from its end-entity certificate (the server's certificate) to the root CA certificate (possibly with intermediate CA certificates) will have a self-signed certificate in the chain: the root CA.

openssl s_client -connect -showcerts doesn't have any particular reason to trust Verisign's root CA certificate, and because it's self-signed you'll get "self signed certificate in certificate chain".

If your system has a location with a bundle of certificates trusted by default (I think /etc/pki/tls/certs on RedHat/Fedora and /etc/ssl/certs on Ubuntu/Debian), you can configure OpenSSL to use them as trust anchors, for example like this:

openssl s_client -connect -showcerts -CApath /etc/ssl/certs

PHP - print all properties of an object

<?php var_dump(obj) ?>


<?php print_r(obj) ?>

These are the same things you use for arrays too.

These will show protected and private properties of objects with PHP 5. Static class members will not be shown according to the manual.

If you want to know the member methods you can use get_class_methods():

$class_methods = get_class_methods('myclass');
// or
$class_methods = get_class_methods(new myclass());
foreach ($class_methods as $method_name) 
    echo "$method_name<br/>";

Related stuff:



get_class() <-- for the name of the instance

When is a language considered a scripting language?

It's like porn, you know it when you see it. The only possible definition of a scripting language is:

A language which is described as a scripting language.

A bit circular, isn't it? (By the way, I'm not joking).

Basically, there is nothing that makes a language a scripting language except that it is called such, especially by its creators. The major set of modern scripting languages is PHP, Perl, JavaScript, Python, Ruby and Lua. Tcl is the first major modern scripting language (it wasn't the first scripting language though, I forget what it is, but I was surprised to learn that it predated Tcl).

I describe features of major scripting languages in my paper:

 A Practical Solution for Scripting Language Compilers
 Paul Biggar, Edsko de Vries and David Gregg
 SAC '09: ACM Symposium on Applied Computing (2009), (March 2009)

Most are dynamically typed and interpreted, and most have no defined semantics outside of their reference implementation. However, even if their major implementation becomes compiled or JITed, that doesn't change the "nature" of the language.

They only remaining question is how can you tell if a new language is a scripting language. Well, if it's called a scripting language, it is one. So Factor is a scripting language (or at least was when that was written), but, say, Java is not.

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

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

EDIT: Fails on

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

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

AngularJS : The correct way of binding to a service properties

Late to the party, but for future Googlers - don't use the provided answer.

JavaScript has a mechanism of passing objects by reference, while it only passes a shallow copy for values "numbers, strings etc".

In above example, instead of binding attributes of a service, why don't we expose the service to the scope?

$scope.hello = HelloService;

This simple approach will make angular able to do two-way binding and all the magical things you need. Don't hack your controller with watchers or unneeded markup.

And if you are worried about your view accidentally overwriting your service attributes, use defineProperty to make it readable, enumerable, configurable, or define getters and setters. You can gain lots of control by making your service more solid.

Final tip: if you spend your time working on your controller more than your services then you are doing it wrong :(.

In that particular demo code you supplied I would recommend you do:

 function TimerCtrl1($scope, Timer) {
   $scope.timer = Timer;
///Inside view
{{ timer.time_updated }}
{{ timer.other_property }}


As I mentioned above, you can control the behaviour of your service attributes using defineProperty


// Lets expose a property named "propertyWithSetter" on our service
// and hook a setter function that automatically saves new value to db !
Object.defineProperty(self, 'propertyWithSetter', {
  get: function() { return; },
  set: function(newValue) {  = newValue; 
         // let's update the database too to reflect changes in data-model !
  enumerable: true,
  configurable: true

Now in our controller if we do

$scope.hello = HelloService;
$scope.hello.propertyWithSetter = 'NEW VALUE';

our service will change the value of propertyWithSetter and also post the new value to database somehow!

Or we can take any approach we want.

Refer to the MDN documentation for defineProperty.

How to call jQuery function onclick?

Please have a look at

$("#submit").click(function () {
var url = $(location).attr('href');
$('#spn_url').html('<strong>' + url + '</strong>');

How to get pandas.DataFrame columns containing specific dtype

You can also try to get the column names from panda data frame that returns columnn name as well dtype. here i'll read csv file from but you have define header that contain columns names.

import pandas as pd


df=pd.read_csv(url,header = None)



print df.columns

How to export a Vagrant virtual machine to transfer it

As of 2019 there is a subcommand: vagrant box repackage

vagrant box repackage --help 
Usage: vagrant box repackage <name> <provider> <version>
    -h, --help                       Print this help

You can find name provider and version by running vagrant box list

vagrant box list
macinbox (virtualbox, 10.14.5)

The ouput of vagrant box repackage is a file called which is basically a tgz file which the content can be listed as below:

tar tzf

How to open this .DB file?

You can use a tool like the TrIDNet - File Identifier to look for the Magic Number and other telltales, if the file format is in it's database it may tell you what it is for.

However searching the definitions did not turn up anything for the string "FLDB", but it checks more than magic numbers so it is worth a try.

If you are using Linux File is a command that will do a similar task.

The other thing to try is if you have access to the program that generated this file, there may be DLL's or EXE's from the database software that may contain meta information about the dll's creator which could give you a starting point for looking for software that can read the file outside of the program that originally created the .db file.

My httpd.conf is empty

It seems to me, that it is by design that this file is empty.

A similar question has been asked here:

So, you should have a look for /etc/apache2/apache2.conf

How are ssl certificates verified?

if you're more technically minded, this site is probably what you want:

warning: the rabbit hole goes deep :).

List to array conversion to use ravel() function

If all you want is calling ravel on your (nested, I s'pose?) list, you can do that directly, numpy will do the casting for you:

L = [[1,None,3],["The", "quick", object]]
# array([1, None, 3, 'The', 'quick', <class 'object'>], dtype=object)

Also worth mentioning that you needn't go through numpy at all.

How to set Status Bar Style in Swift 3

swift 3

if View controller-based status bar appearance = YES in Info.plist

then use this extension for all NavigationController

    extension UINavigationController
        override open var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent

if there is no UINavigationController and only have UIViewController then use Below code:

    extension UIViewController
        override open var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent

Sending the bearer token with axios

You can create config once and use it everywhere.

const instance = axios.create({
  baseURL: '',
  timeout: 1000,
  headers: {'Authorization': 'Bearer '+token}

.then(response => {

Getting hold of the outer class object from the inner class object

Within the inner class itself, you can use OuterClass.this. This expression, which allows to refer to any lexically enclosing instance, is described in the JLS as Qualified this.

I don't think there's a way to get the instance from outside the code of the inner class though. Of course, you can always introduce your own property:

public OuterClass getOuter() {
    return OuterClass.this;

EDIT: By experimentation, it looks like the field holding the reference to the outer class has package level access - at least with the JDK I'm using.

EDIT: The name used (this$0) is actually valid in Java, although the JLS discourages its use:

The $ character should be used only in mechanically generated source code or, rarely, to access pre-existing names on legacy systems.

When is it practical to use Depth-First Search (DFS) vs Breadth-First Search (BFS)?

DFS is more space-efficient than BFS, but may go to unnecessary depths.

Their names are revealing: if there's a big breadth (i.e. big branching factor), but very limited depth (e.g. limited number of "moves"), then DFS can be more preferrable to BFS.


It should be mentioned that there's a less-known variant that combines the space efficiency of DFS, but (cummulatively) the level-order visitation of BFS, is the iterative deepening depth-first search. This algorithm revisits some nodes, but it only contributes a constant factor of asymptotic difference.

Get value of div content using jquery

$('#field-function_purpose') will get you the element with ID field-function_purpose, which is your div element. text() returns you the content of the div.

var x = $('#field-function_purpose').text();

Converting Pandas dataframe into Spark dataframe error

In spark version >= 3 you can convert pandas dataframes to pyspark dataframe in one line

use spark.createDataFrame(pandasDF)

dataset = pd.read_csv("data/AS/test_v2.csv")

sparkDf = spark.createDataFrame(dataset);

if you are confused about spark session variable, spark session is as follows

sc = SparkContext.getOrCreate(SparkConf().setMaster("local[*]"))

spark = SparkSession \
    .builder \

How to install crontab on Centos

As seen in Install crontab on CentOS, the crontab package in CentOS is vixie-cron. Hence, do install it with:

yum install vixie-cron

And then start it with:

service crond start

To make it persistent, so that it starts on boot, use:

chkconfig crond on

On CentOS 7 you need to use cronie:

yum install cronie

On CentOS 6 you can install vixie-cron, but the real package is cronie:

yum install vixie-cron


yum install cronie

In both cases you get the same output:

 Package         Arch       Version         Repository      Size
 cronie          x86_64     1.4.4-12.el6    base             73 k
Installing for dependencies:
 cronie-anacron  x86_64     1.4.4-12.el6    base             30 k
 crontabs        noarch     1.10-33.el6     base             10 k
 exim            x86_64     4.72-6.el6      epel            1.2 M

Transaction Summary
Install       4 Package(s)

Remove a folder from git tracking

if file is committed and pushed to github then you should run

git rm --fileName

git ls-files to make sure that the file is removed or untracked

git commit -m "UntrackChanges"

git push

Get value from JToken that may not exist (best practices)

You can simply typecast, and it will do the conversion for you, e.g.

var with = (double?) jToken[key] ?? 100;

It will automatically return null if said key is not present in the object, so there's no need to test for it.

Using Helvetica Neue in a Website

I'd recommend this article on CSS Tricks by Chris Coyier entitled Better Helvetica:

He basically recommends the following declaration for covering all the bases:

body {
    font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif; 
    font-weight: 300;

Remove ALL styling/formatting from hyperlinks

You can just use an a selector in your stylesheet to define all states of an anchor/hyperlink. For example:

a {
    color: blue;

Would override all link styles and make all the states the colour blue.

Adding elements to a collection during iteration

IMHO the safer way would be to create a new collection, to iterate over your given collection, adding each element in the new collection, and adding extra elements as needed in the new collection as well, finally returning the new collection.

I want to get the type of a variable at runtime

I think the question is incomplete. if you meant that you wish to get the type information of some typeclass then below:

If you wish to print as you have specified then:

scala>  def manOf[T: Manifest](t: T): Manifest[T] = manifest[T]
manOf: [T](t: T)(implicit evidence$1: Manifest[T])Manifest[T]

scala> val x = List(1,2,3)
x: List[Int] = List(1, 2, 3)

scala> println(manOf(x))

If you are in repl mode then

scala> :type List(1,2,3)

Or if you just wish to know what the class type then as @monkjack explains "string".getClass might solve the purpose

How to Get a Specific Column Value from a DataTable?

I suggest such way based on extension methods:

IEnumerable<Int32> countryIDs =
    .Where(row => row.Field<String>("CountryName") == countryName)
    .Select(row => row.Field<Int32>("CountryID"));

System.Data.DataSetExtensions.dll needs to be referenced.

How to get indices of a sorted array in Python

We will create another array of indexes from 0 to n-1 Then zip this to the original array and then sort it on the basis of the original values

ar = [1,2,3,4,5]
new_ar = list(zip(ar,[i for i in range(len(ar))]))


Why am I getting Unknown error in line 1 of pom.xml?

whenever you facing this type of error simply change the Release version just like In my case it is showing Error in 2.2.7 I changed to 2.2.6





How is the default max Java heap size determined?


As of Java 8u191 you now have the options:


that can be used to size the heap as a percentage of the usable physical RAM. (which is same as the RAM installed less what the kernel uses).

See Release Notes for Java8 u191 for more information. Note that the options are mentioned under a Docker heading but in fact they apply whether you are in Docker environment or in a traditional environment.

The default value for MaxRAMPercentage is 25%. This is extremely conservative.

My own rule: If your host is more or less dedicated to running the given java application, then you can without problems increase dramatically. If you are on Linux, only running standard daemons and have installed RAM from somewhere around 1 Gb and up then I wouldn't hesitate to use 75% for the JVM's heap. Again, remember that this is 75% of the RAM available, not the RAM installed. What is left is the other user land processes that may be running on the host and the other types of memory that the JVM needs (eg for stack). All together, this will typically fit nicely in the 25% that is left. Obviously, with even more installed RAM the 75% is a safer and safer bet. (I wish the JDK folks had implemented an option where you could specify a ladder)

Setting the MaxRAMPercentage option look like this:

java -XX:MaxRAMPercentage=75.0  ....

Note that these percentage values are of 'double' type and therefore you must specify them with a decimal dot. You get a somewhat odd error if you use "75" instead of "75.0".

remove item from array using its name / value

You can delete by 1 or more properties:

//Delets an json object from array by given object properties. 
//Exp. someJasonCollection.deleteWhereMatches({ l: 1039, v: '3' }); -> 
//removes all items        with property l=1039 and property v='3'.
Array.prototype.deleteWhereMatches = function (matchObj) {
    var indexes = this.findIndexes(matchObj).sort(function (a, b) { return b > a; });
    var deleted = 0;
    for (var i = 0, count = indexes.length; i < count; i++) {
        this.splice(indexes[i], 1);
    return deleted;

How to delete from a table where ID is in a list of IDs?

Your question almost spells the SQL for this:

DELETE FROM table WHERE id IN (1, 4, 6, 7)

Find and Replace text in the entire table using a MySQL query

Put this in a php file and run it and it should do what you want it to do.

// Connect to your MySQL database.
$hostname = "localhost";
$username = "db_username";
$password = "db_password";
$database = "db_name";

mysql_connect($hostname, $username, $password);

// The find and replace strings.
$find = "find_this_text";
$replace = "replace_with_this_text";

$loop = mysql_query("
        concat('UPDATE ',table_schema,'.',table_name, ' SET ',column_name, '=replace(',column_name,', ''{$find}'', ''{$replace}'');') AS s
        table_schema = '{$database}'")
or die ('Cant loop through dbfields: ' . mysql_error());

while ($query = mysql_fetch_assoc($loop))

Print debugging info from stored procedure in MySQL

Quick way to print something is:

select '** Place your mesage here' AS '** DEBUG:';

ArrayList initialization equivalent to array initialization

Arrays.asList can help here:

new ArrayList<Integer>(Arrays.asList(1,2,3,5,8,13,21));

php: Get html source code with cURL

Try the following:

$ch = curl_init("");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
$content = curl_exec($ch);

I would only recommend this for small files. Big files are read as a whole and are likely to produce a memory error.

EDIT: after some discussion in the comments we found out that the problem was that the server couldn't resolve the host name and the page was in addition a HTTPS resource so here comes your temporary solution (until your server admin fixes the name resolving).

what i did is just pinging to see the IP address, replace the host name with the IP address and instead specify the header manually. This however renders the SSL certificate invalid so we have to suppress peer verification.

//$url = "";
$url = "";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Host:'));
$output = curl_exec($ch);

Keep in mind that the IP address might change and this is an error source. you should also do some error handling using curl_error();.

How to randomize two ArrayLists in the same fashion?

This can be done using the shuffle method:

private List<Integer> getJumbledList() {
     List<Integer> myArrayList2 = new ArrayList<Integer>();
        return myArrayList2;

Debugging the error "gcc: error: x86_64-linux-gnu-gcc: No such file or directory"

the error can be due to one of several missing package. Below command will install several packages like g++, gcc, etc.

sudo apt-get install build-essential

Get Context in a Service

  1. Service extends ContextWrapper
  2. ContextWrapper extends Context


Context context = this;

(in Service or Activity Class)

Saving and Reading Bitmaps/Images from Internal memory in Android

// mutiple image retrieve

 File folPath = new File(getIntent().getStringExtra("folder_path"));
 File[] imagep = folPath.listFiles();

 for (int i = 0; i < imagep.length ; i++) {
     imageModelList.add(new ImageModel(imagep[i].getAbsolutePath(), Uri.parse(imagep[i].getAbsolutePath())));

Convert string to Color in C#

 Color red = Color.FromName("Red");   

The MSDN doesn't say one way or another, so there's a good chance that it is case-sensitive. (UPDATE: Apparently, it is not.)

As far as I can tell, ColorTranslator.FromHtml is also.

If Color.FromName cannot find a match, it returns new Color(0,0,0);

If ColorTranslator.FromHtml cannot find a match, it throws an exception.


Since you're using Microsoft.Xna.Framework.Graphics.Color, this gets a bit tricky:

using XColor = Microsoft.Xna.Framework.Graphics.Color;
using CColor = System.Drawing.Color;

 CColor clrColor = CColor.FromName("Red"); 
 XColor xColor = new XColor(clrColor.R, clrColor.G, clrColor.B, clrColor.A);

Construct pandas DataFrame from list of tuples of (row,col,values)

I submit that it is better to leave your data stacked as it is:

df = pandas.DataFrame(data, columns=['R_Number', 'C_Number', 'Avg', 'Std'])

# Possibly also this if these can always be the indexes:
# df = df.set_index(['R_Number', 'C_Number'])

Then it's a bit more intuitive to say

df.set_index(['R_Number', 'C_Number']).Avg.unstack(level=1)

This way it is implicit that you're seeking to reshape the averages, or the standard deviations. Whereas, just using pivot, it's purely based on column convention as to what semantic entity it is that you are reshaping.

How to use "not" in xpath?

you can use not(expression) function


expression != true()

Rename Pandas DataFrame Index

You can also use Index.set_names as follows:

In [25]: x = pd.DataFrame({'year':[1,1,1,1,2,2,2,2],
   ....:                   'country':['A','A','B','B','A','A','B','B'],
   ....:                   'prod':[1,2,1,2,1,2,1,2],
   ....:                   'val':[10,20,15,25,20,30,25,35]})

In [26]: x = x.set_index(['year','country','prod']).squeeze()

In [27]: x
year  country  prod
1     A        1       10
               2       20
      B        1       15
               2       25
2     A        1       20
               2       30
      B        1       25
               2       35
Name: val, dtype: int64
In [28]: x.index = x.index.set_names('foo', level=1)

In [29]: x
year  foo  prod
1     A    1       10
           2       20
      B    1       15
           2       25
2     A    1       20
           2       30
      B    1       25
           2       35
Name: val, dtype: int64

How to check if a string starts with a specified string?

You can check if your string starts with http or https using the small function below.

function has_prefix($string, $prefix) {
   return substr($string, 0, strlen($prefix)) == $prefix;

$url   = '';
echo 'the url ' . (has_prefix($url, 'http://')  ? 'does' : 'does not') . ' start with http://';
echo 'the url ' . (has_prefix($url, 'https://') ? 'does' : 'does not') . ' start with https://';

Reflection generic get field value

You are calling get with the wrong argument.

It should be:

Object value = field.get(object);

Communication between multiple docker-compose projects

I would ensure all containers are docker-compose'd to the same network by composing them together at the same time, using:

docker compose --file ~/front/docker-compose.yml --file ~/api/docker-compose.yml up -d

What is the difference between MVC and MVVM?

MVVM adds the view model into the mix. This is important, as it allows you to use a lot of the binding approach of WPF, without putting all that UI specific pieces in your regular model.

I may be wrong, but I am not sure MVVM really forces the controller into the mix. I find the concept to be more in line with: I think that people choose to combine it with MVC, not that it is built in into the pattern.

log4net hierarchy and logging levels

As others have noted, it is usually preferable to specify a minimum logging level to log that level and any others more severe than it. It seems like you are just thinking about the logging levels backwards.

However, if you want more fine-grained control over logging individual levels, you can tell log4net to log only one or more specific levels using the following syntax:

<filter type="log4net.Filter.LevelMatchFilter">
  <levelToMatch value="WARN"/>

Or to exclude a specific logging level by adding a "deny" node to the filter.

You can stack multiple filters together to specify multiple levels. For instance, if you wanted only WARN and FATAL levels. If the levels you wanted were consecutive, then the LevelRangeFilter is more appropriate.

Reference Doc: log4net.Filter.LevelMatchFilter

If the other answers haven't given you enough information, hopefully this will help you get what you want out of log4net.

Comparing two files in linux terminal

You can also use:

sdiff file1 file2

To display differences side by side within your terminal!

json call with C#

In your code you don't get the HttpResponse, so you won't see what the server side sends you back.

you need to get the Response similar to the way you get (make) the Request. So

public static bool SendAnSMSMessage(string message)
  var httpWebRequest = (HttpWebRequest)WebRequest.Create("");
  httpWebRequest.ContentType = "text/json";
  httpWebRequest.Method = "POST";

  using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
    string json = "{ \"method\": \"send\", " +
                      "  \"params\": [ " +
                      "             \"IPutAGuidHere\", " +
                      "             \"[email protected]\", " +
                      "             \"MyTenDigitNumberWasHere\", " +
                      "             \"" + message + "\" " +
                      "             ] " +

  var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
  using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    var responseText = streamReader.ReadToEnd();
    //Now you have your response.
    //or false depending on information in the response
    return true;        

I also notice in the pennysms documentation that they expect a content type of "text/json" and not "application/json". That may not make a difference, but it's worth trying in case it doesn't work.

Add key value pair to all objects in array

Simply you can add that way. see below the console image

enter image description here

How to remove the border highlight on an input text element

You can try this also

input[type="text"] {
outline-style: none;


.classname input{
outline-style: none;

Looping through a Scripting.Dictionary using index/item number

According to the documentation of the Item property:

Sets or returns an item for a specified key in a Dictionary object.

In your case, you don't have an item whose key is 1 so doing:

s = d.Item(i)

actually creates a new key / value pair in your dictionary, and the value is empty because you have not used the optional newItem argument.

The Dictionary also has the Items method which allows looping over the indices:

a = d.Items
For i = 0 To d.Count - 1
    s = a(i)
Next i

Windows Scheduled task succeeds but returns result 0x1

For Powershell scripts

I have seen this problem multiple times while scheduling Powershell scripts with parameters on multiple Windows servers. The solution has always been to use the -File parameter:

  1. Under "Actions" --> "Program / Script" Type: "Powershell"
  2. Under "Add arguments", instead of just typeing "C:/script/test.ps1" use -File "C:/script/test.ps1"

Happy scheduling!

enter image description here

Protecting cells in Excel but allow these to be modified by VBA script

You can modify a sheet via code by taking these actions

  • Unprotect
  • Modify
  • Protect

In code this would be:

Sub UnProtect_Modify_Protect()

  ThisWorkbook.Worksheets("Sheet1").Unprotect Password:="Password"

  ThisWorkbook.ActiveSheet.Range("A1").FormulaR1C1 = "Changed"

  ThisWorkbook.Worksheets("Sheet1").Protect Password:="Password"

End Sub

The weakness of this method is that if the code is interrupted and error handling does not capture it, the worksheet could be left in an unprotected state.

The code could be improved by taking these actions

  • Re-protect
  • Modify

The code to do this would be:

Sub Re-Protect_Modify()

ThisWorkbook.Worksheets("Sheet1").Protect Password:="Password", _
'Protect, even if already protected

  ThisWorkbook.ActiveSheet.Range("A1").FormulaR1C1 = "Changed"

End Sub

This code renews the protection on the worksheet, but with the ‘UserInterfaceOnly’ set to true. This allows VBA code to modify the worksheet, while keeping the worksheet protected from user input via the UI, even if execution is interrupted.

This setting is lost when the workbook is closed and re-opened. The worksheet protection is still maintained.

So the 'Re-protection' code needs to be included at the start of any procedure that attempts to modify the worksheet or can just be run once when the workbook is opened.

Reading from file using read() function

fgets would work for you. here is very good documentation on this :-

If you don't want to use fgets, following method will work for you :-

int readline(FILE *f, char *buffer, size_t len)
   char c; 
   int i;

   memset(buffer, 0, len);

   for (i = 0; i < len; i++)
      int c = fgetc(f); 

      if (!feof(f)) 
         if (c == '\r')
            buffer[i] = 0;
         else if (c == '\n')
            buffer[i] = 0;

            return i+1;
            buffer[i] = c; 
         //fprintf(stderr, "read_line(): recv returned %d\n", c);
         return -1; 

   return -1; 

How to check if a service is running on Android?

There can be several services with the same class name.

I've just created two apps. The package name of the first app is com.example.mock. I created a subpackage called lorem in the app and a service called Mock2Service. So its fully qualified name is com.example.mock.lorem.Mock2Service.

Then I created the second app and a service called Mock2Service. The package name of the second app is com.example.mock.lorem. The fully qualified name of the service is com.example.mock.lorem.Mock2Service, too.

Here is my logcat output.

03-27 12:02:19.985: D/TAG(32155): Mock-01: com.example.mock.lorem.Mock2Service
03-27 12:02:33.755: D/TAG(32277): Mock-02: com.example.mock.lorem.Mock2Service

A better idea is to compare ComponentName instances because equals() of ComponentName compares both package names and class names. And there can't be two apps with the same package name installed on a device.

The equals() method of ComponentName.

public boolean equals(Object obj) {
    try {
        if (obj != null) {
            ComponentName other = (ComponentName)obj;
            // Note: no null checks, because mPackage and mClass can
            // never be null.
            return mPackage.equals(other.mPackage)
                    && mClass.equals(other.mClass);
    } catch (ClassCastException e) {
    return false;


CSS customized scroll bar in div

This is what Google has used in some of its applications for a long time now. See in the code that, if you apply next classes, they somehow hide the scrollbar in Chrome, but it still works.

The classes are jfk-scrollbar, jfk-scrollbar-borderless, and jfk-scrollbar-dark

.testg{ border:1px solid black;  max-height:150px;  overflow-y: scroll; overflow-x: hidden; width: 250px;}_x000D_
.content{ height: 700px}_x000D_
/* The google css code for scrollbars */_x000D_
::-webkit-scrollbar {_x000D_
    height: 16px;_x000D_
    overflow: visible;_x000D_
    width: 16px_x000D_
::-webkit-scrollbar-button {_x000D_
    height: 0;_x000D_
    width: 0_x000D_
::-webkit-scrollbar-track {_x000D_
    background-clip: padding-box;_x000D_
    border: solid transparent;_x000D_
    border-width: 0 0 0 7px_x000D_
::-webkit-scrollbar-track:horizontal {_x000D_
    border-width: 7px 0 0_x000D_
::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(0, 0, 0, .05);_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .1)_x000D_
::-webkit-scrollbar-track:horizontal:hover {_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .1)_x000D_
::-webkit-scrollbar-track:active {_x000D_
    background-color: rgba(0, 0, 0, .05);_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .14), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
::-webkit-scrollbar-track:horizontal:active {_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .14), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(255, 255, 255, .1);_x000D_
    box-shadow: inset 1px 0 0 rgba(255, 255, 255, .2)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-track:horizontal:hover {_x000D_
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, .2)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-track:active {_x000D_
    background-color: rgba(255, 255, 255, .1);_x000D_
    box-shadow: inset 1px 0 0 rgba(255, 255, 255, .25), inset -1px 0 0 rgba(255, 255, 255, .15)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-track:horizontal:active {_x000D_
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, .25), inset 0 -1px 0 rgba(255, 255, 255, .15)_x000D_
::-webkit-scrollbar-thumb {_x000D_
    background-color: rgba(0, 0, 0, .2);_x000D_
    background-clip: padding-box;_x000D_
    border: solid transparent;_x000D_
    border-width: 0 0 0 7px;_x000D_
    min-height: 28px;_x000D_
    padding: 100px 0 0;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .1), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 7px 0 0;_x000D_
    padding: 0 0 0 100px;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .1), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
::-webkit-scrollbar-thumb:hover {_x000D_
    background-color: rgba(0, 0, 0, .4);_x000D_
    box-shadow: inset 1px 1px 1px rgba(0, 0, 0, .25)_x000D_
::-webkit-scrollbar-thumb:active {_x000D_
    background-color: rgba(0, 0, 0, 0.5);_x000D_
    box-shadow: inset 1px 1px 3px rgba(0, 0, 0, 0.35)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-thumb {_x000D_
    background-color: rgba(255, 255, 255, .3);_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .15), inset 0 -1px 0 rgba(255, 255, 255, .1)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-thumb:horizontal {_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .15), inset -1px 0 0 rgba(255, 255, 255, .1)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-thumb:hover {_x000D_
    background-color: rgba(255, 255, 255, .6);_x000D_
    box-shadow: inset 1px 1px 1px rgba(255, 255, 255, .37)_x000D_
.jfk-scrollbar-dark::-webkit-scrollbar-thumb:active {_x000D_
    background-color: rgba(255, 255, 255, .75);_x000D_
    box-shadow: inset 1px 1px 3px rgba(255, 255, 255, .5)_x000D_
.jfk-scrollbar-borderless::-webkit-scrollbar-track {_x000D_
    border-width: 0 1px 0 6px_x000D_
.jfk-scrollbar-borderless::-webkit-scrollbar-track:horizontal {_x000D_
    border-width: 6px 0 1px_x000D_
.jfk-scrollbar-borderless::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(0, 0, 0, .035);_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .14), inset -1px -1px 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar-dark::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(255, 255, 255, .07);_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .25), inset -1px -1px 0 rgba(255, 255, 255, .15)_x000D_
.jfk-scrollbar-borderless::-webkit-scrollbar-thumb {_x000D_
    border-width: 0 1px 0 6px_x000D_
.jfk-scrollbar-borderless::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 6px 0 1px_x000D_
::-webkit-scrollbar-corner {_x000D_
    background: transparent_x000D_
body::-webkit-scrollbar-track-piece {_x000D_
    background-clip: padding-box;_x000D_
    background-color: #f5f5f5;_x000D_
    border: solid #fff;_x000D_
    border-width: 0 0 0 3px;_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .14), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
body::-webkit-scrollbar-track-piece:horizontal {_x000D_
    border-width: 3px 0 0;_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .14), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
body::-webkit-scrollbar-thumb {_x000D_
    border-width: 1px 1px 1px 5px_x000D_
body::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 5px 1px 1px_x000D_
body::-webkit-scrollbar-corner {_x000D_
    background-clip: padding-box;_x000D_
    background-color: #f5f5f5;_x000D_
    border: solid #fff;_x000D_
    border-width: 3px 0 0 3px;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .14)_x000D_
.jfk-scrollbar::-webkit-scrollbar {_x000D_
    height: 16px;_x000D_
    overflow: visible;_x000D_
    width: 16px_x000D_
.jfk-scrollbar::-webkit-scrollbar-button {_x000D_
    height: 0;_x000D_
    width: 0_x000D_
.jfk-scrollbar::-webkit-scrollbar-track {_x000D_
    background-clip: padding-box;_x000D_
    border: solid transparent;_x000D_
    border-width: 0 0 0 7px_x000D_
.jfk-scrollbar::-webkit-scrollbar-track:horizontal {_x000D_
    border-width: 7px 0 0_x000D_
.jfk-scrollbar::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(0, 0, 0, .05);_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .1)_x000D_
.jfk-scrollbar::-webkit-scrollbar-track:horizontal:hover {_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .1)_x000D_
.jfk-scrollbar::-webkit-scrollbar-track:active {_x000D_
    background-color: rgba(0, 0, 0, .05);_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .14), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar::-webkit-scrollbar-track:horizontal:active {_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .14), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(255, 255, 255, .1);_x000D_
    box-shadow: inset 1px 0 0 rgba(255, 255, 255, .2)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-track:horizontal:hover {_x000D_
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, .2)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-track:active {_x000D_
    background-color: rgba(255, 255, 255, .1);_x000D_
    box-shadow: inset 1px 0 0 rgba(255, 255, 255, .25), inset -1px 0 0 rgba(255, 255, 255, .15)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-track:horizontal:active {_x000D_
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, .25), inset 0 -1px 0 rgba(255, 255, 255, .15)_x000D_
.jfk-scrollbar::-webkit-scrollbar-thumb {_x000D_
    background-color: rgba(0, 0, 0, .2);_x000D_
    background-clip: padding-box;_x000D_
    border: solid transparent;_x000D_
    border-width: 0 0 0 7px;_x000D_
    min-height: 28px;_x000D_
    padding: 100px 0 0;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .1), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 7px 0 0;_x000D_
    padding: 0 0 0 100px;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .1), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar::-webkit-scrollbar-thumb:hover {_x000D_
    background-color: rgba(0, 0, 0, .4);_x000D_
    box-shadow: inset 1px 1px 1px rgba(0, 0, 0, .25)_x000D_
.jfk-scrollbar::-webkit-scrollbar-thumb:active {_x000D_
    background-color: rgba(0, 0, 0, 0.5);_x000D_
    box-shadow: inset 1px 1px 3px rgba(0, 0, 0, 0.35)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-thumb {_x000D_
    background-color: rgba(255, 255, 255, .3);_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .15), inset 0 -1px 0 rgba(255, 255, 255, .1)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-thumb:horizontal {_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .15), inset -1px 0 0 rgba(255, 255, 255, .1)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-thumb:hover {_x000D_
    background-color: rgba(255, 255, 255, .6);_x000D_
    box-shadow: inset 1px 1px 1px rgba(255, 255, 255, .37)_x000D_
.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-thumb:active {_x000D_
    background-color: rgba(255, 255, 255, .75);_x000D_
    box-shadow: inset 1px 1px 3px rgba(255, 255, 255, .5)_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar::-webkit-scrollbar-track {_x000D_
    border-width: 0 1px 0 6px_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar::-webkit-scrollbar-track:horizontal {_x000D_
    border-width: 6px 0 1px_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(0, 0, 0, .035);_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .14), inset -1px -1px 0 rgba(0, 0, 0, .07)_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar-dark.jfk-scrollbar::-webkit-scrollbar-track:hover {_x000D_
    background-color: rgba(255, 255, 255, .07);_x000D_
    box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .25), inset -1px -1px 0 rgba(255, 255, 255, .15)_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar::-webkit-scrollbar-thumb {_x000D_
    border-width: 0 1px 0 6px_x000D_
.jfk-scrollbar-borderless.jfk-scrollbar::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 6px 0 1px_x000D_
.jfk-scrollbar::-webkit-scrollbar-corner {_x000D_
    background: transparent_x000D_
body.jfk-scrollbar::-webkit-scrollbar-track-piece {_x000D_
    background-clip: padding-box;_x000D_
    background-color: #f5f5f5;_x000D_
    border: solid #fff;_x000D_
    border-width: 0 0 0 3px;_x000D_
    box-shadow: inset 1px 0 0 rgba(0, 0, 0, .14), inset -1px 0 0 rgba(0, 0, 0, .07)_x000D_
body.jfk-scrollbar::-webkit-scrollbar-track-piece:horizontal {_x000D_
    border-width: 3px 0 0;_x000D_
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, .14), inset 0 -1px 0 rgba(0, 0, 0, .07)_x000D_
body.jfk-scrollbar::-webkit-scrollbar-thumb {_x000D_
    border-width: 1px 1px 1px 5px_x000D_
body.jfk-scrollbar::-webkit-scrollbar-thumb:horizontal {_x000D_
    border-width: 5px 1px 1px_x000D_
body.jfk-scrollbar::-webkit-scrollbar-corner {_x000D_
    background-clip: padding-box;_x000D_
    background-color: #f5f5f5;_x000D_
    border: solid #fff;_x000D_
    border-width: 3px 0 0 3px;_x000D_
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, .14)_x000D_
<div class="testg">_x000D_
    <div class="content">_x000D_
        Look Ma'  my scrollbars doesn't have arrows <br /><br />_x000D_
        content, content, content <br /> content, content, content <br /> content, content, content s<br />  content, content, content <br/> content, content, content <br/> content, content, content d<br/>  content, content, content <br/> _x000D_
<div class="testg jfk-scrollbar jfk-scrollbar-borderless jfk-scrollbar-dark">_x000D_
    <div class="content">_x000D_
        Look Ma'  my scrollbars dissapear in chrome<br /><br />_x000D_
        content, content, content <br /> content, content, content <br /> content, content, content s<br />  content, content, content <br/> content, content, content <br/> content, content, content d<br/>  content, content, content <br/> _x000D_

I just found it useful to remove the arrows from the scrollbars. As of 2015 it's been used in Google Maps when searching for places in the list of results in its material design UI.

No increment operator (++) in Ruby?

I don't think that notation is available because—unlike say PHP or C—everything in Ruby is an object.

Sure you could use $var=0; $var++ in PHP, but that's because it's a variable and not an object. Therefore, $var = new stdClass(); $var++ would probably throw an error.

I'm not a Ruby or RoR programmer, so I'm sure someone can verify the above or rectify it if it's inaccurate.

javascript return true or return false when and how to use it?

returning true or false indicates that whether execution should continue or stop right there. So just an example

<input type="button" onclick="return func();" />

Now if func() is defined like this

function func()
 // do something
return false;

the click event will never get executed. On the contrary if return true is written then the click event will always be executed.

How can I recover a lost commit in Git?

This happened to me just today, so I am writing what came out as a lifesaver for me. My answer is very similar to @Amber 's answer.

First, I did a git reflog and searched for that particular commit's hash, then just copied that hash and did a git cherry-pick <hash> from that branch. This brought all the change from that lost commit to my current branch, and restored my faith on GIT.

Have a nice day!

How to execute a stored procedure within C# program

Calling Store Procedure in C#

    SqlCommand cmd = new SqlCommand("StoreProcedureName",con);
    int rowAffected=cmd.ExecuteNonQuery();

fatal error LNK1169: one or more multiply defined symbols found in game programming

just add /FORCE as linker flag and you're all set.

for instance, if you're working on CMakeLists.txt. Then add following line:


Is Eclipse the best IDE for Java?

There is no best IDE. You make it as good as you get used using it.

Count number of files within a directory in Linux?

this is one:

ls -l . | egrep -c '^-'


ls -1 | wc -l

Which means: ls: list files in dir

-1: (that's a ONE) only one entry per line. Change it to -1a if you want hidden files too

|: pipe output onto...

wc: "wordcount"

-l: count lines.

JQuery create a form and add elements to it programmatically

The tag is not closed:

$form.append("<input type=button value=button");

Should be:

$form.append('<input type="button" value="button">');

DateTimeFormat in TypeScript

This should work...

var displayDate = new Date().toLocaleDateString();


But I suspect you are trying it on something else, for example:

var displayDate =; // No!


Linux: where are environment variables stored?

That variable isn't stored in some script. It's simply set by the X server scripts. You can check the environment variables currently set using set.

Auto number column in SharePoint list

As stated, all objects in sharepoint contain some sort of unique identifier (often an integer based counter for list items, and GUIDs for lists).

That said, there is also a feature available at called "Unique Column Policy", designed to add an other column with a unique value. A complete writeup is available at!8F5DEA8AEA9E6FBB!293.entry

How can I select from list of values in SQL Server

Select user id from list of user id:

SELECT * FROM my_table WHERE user_id IN (1,3,5,7,9,4);

Why is this program erroneously rejected by three C++ compilers?

You could try different colors for brackets, maybe some green or red would help ? I think your compiler can't rcognize black ink :P

Pass connection string to code-first DbContext

I have a little solution example for that problem.


 public MyDBContext(DBConnectionType ConnectionType) //: base("ConnMain")
         this.Database.Connection.ConnectionString = ConfigurationManager.ConnectionStrings["ConnMain"].ConnectionString;
      else if(ConnectionType==DBConnectionType.BackupConnection)
         this.Database.Connection.ConnectionString = ConfigurationManager.ConnectionStrings["ConnBackup"].ConnectionString;


public enum DBConnectionType


 MyDBContext db = new MyDBContext(DBConnectionType.MainConnection);
//MyDBContext db = new MyDBContext(DBConnectionType.BackupConnection);

How to highlight text using javascript

Since HTML5 you can use the <mark></mark> tags to highlight text. You can use javascript to wrap some text/keyword between these tags. Here is a little example of how to mark and unmark text.


Error message "Unable to install or run the application. The application requires stdole Version 7.0.3300.0 in the GAC"

Check if you're really using EnvDTE reference. If not, remove it and recompile.

Groovy built-in REST/HTTP client?


public class HttpclassgetrRoles {
     static void main(String[] args){
         def baseUrl = new URL('')

         HttpURLConnection connection = (HttpURLConnection) baseUrl.openConnection();
         connection.addRequestProperty("Accept", "application/json")
         connection.with {
           doOutput = true
           requestMethod = 'GET'
           println content.text


How to create a dump with Oracle PL/SQL Developer?

Just to keep this up to date:

The current version of SQLDeveloper has an export tool (Tools > Database Export) that will allow you to dump a schema to a file, with filters for object types, object names, table data etc.

It's a fair amount easier to set-up and use than exp and imp if you're used to working in a GUI environment, but not as versatile if you need to use it for scripting anything.

error: Error parsing XML: not well-formed (invalid token) ...?

I tried everything on my end and ended up with the following.

I had the first line as:


And I was missing two spaces there, and it should be:

<?xml version="1.0" encoding="utf-8"?>

Before the version and before the encoding there should be a space.

Check if list is empty in C#

Why not...

bool isEmpty = !list.Any();
    // error message
    // show grid

The GridView has also an EmptyDataTemplate which is shown if the datasource is empty. This is an approach in ASP.NET:

<emptydatarowstyle backcolor="LightBlue" forecolor="Red"/>


  <asp:image id="NoDataErrorImg"
    imageurl="~/images/NoDataError.jpg" runat="server"/>

    No Data Found!  


laravel 5.4 upload image

In Laravel 5.4, you can use guessClientExtension

Why does C# XmlDocument.LoadXml(string) fail when an XML header is included?

I figured it out. Read the MSDN documentation and it says to use .Load instead of LoadXml when reading from strings. Found out this works 100% of time. Oddly enough using StringReader causes problems. I think the main reason is that this is a Unicode encoded string and that could cause problems because StringReader is UTF-8 only.

MemoryStream stream = new MemoryStream();
            byte[] data = body.PayloadEncoding.GetBytes(body.Payload);
            stream.Write(data, 0, data.Length);
            stream.Seek(0, SeekOrigin.Begin);

            XmlTextReader reader = new XmlTextReader(stream);

            // MSDN reccomends we use Load instead of LoadXml when using in memory XML payloads

D3.js: How to get the computed width and height for an arbitrary element?

.getBoundingClientRect() returns the size of an element and its position relative to the viewport.We can easily get following

  • left, right
  • top, bottom
  • height, width

Example :

var element ='.elementClassName').node();

Issue with virtualenv - cannot activate

I was also facing the same issue in my Windows 10 machine. What steps i tried were:

Go to andconda terminal Step 1

pip3 install -U pip virtualenv

Step 2

virtualenv --system-site-packages -p python ./venv


virtualenv --system-site-packages -p python3 ./venv

Step 3


You can check it via spider tool in anaconda by typing import tensorflow as tf

Cordova app not displaying correctly on iPhone X (Simulator)

I found the solution to the white bars here:

Set viewport-fit=cover on the viewport <meta> tag, i.e.:

<meta name="viewport" content="initial-scale=1, width=device-width, height=device-height, viewport-fit=cover">

The white bars in UIWebView then disappear:

The solution to remove the black areas (provided by @dpogue in a comment below) is to use LaunchStoryboard images with cordova-plugin-splashscreen to replace the legacy launch images, used by Cordova by default. To do so, add the following to the iOS platform in config.xml:

<platform name="ios">    
    <splash src="res/screen/ios/Default@2x~iphone~anyany.png" />
    <splash src="res/screen/ios/Default@2x~iphone~comany.png" />
    <splash src="res/screen/ios/Default@2x~iphone~comcom.png" />
    <splash src="res/screen/ios/Default@3x~iphone~anyany.png" />
    <splash src="res/screen/ios/Default@3x~iphone~anycom.png" />
    <splash src="res/screen/ios/Default@3x~iphone~comany.png" />
    <splash src="res/screen/ios/Default@2x~ipad~anyany.png" />
    <splash src="res/screen/ios/Default@2x~ipad~comany.png" />   

    <!-- more iOS config... -->

Then create the images with the following dimensions in res/screen/ios (remove any existing ones):

Default@2x~iphone~anyany.png - 1334x1334
Default@2x~iphone~comany.png - 750x1334
Default@2x~iphone~comcom.png - 1334x750
Default@3x~iphone~anyany.png - 2208x2208
Default@3x~iphone~anycom.png - 2208x1242
Default@3x~iphone~comany.png - 1242x2208
Default@2x~ipad~anyany.png - 2732x2732
Default@2x~ipad~comany.png - 1278x2732

Once the black bars are removed, there's another thing that's different about the iPhone X to address: The status bar is larger than 20px due to the "notch", which means any content at the far top of your Cordova app will be obscured by it:

Rather than hard-coding a padding in pixels, you can handle this automatically in CSS using the new safe-area-inset-* constants in iOS 11.

Note: in iOS 11.0 the function to handle these constants was called constant() but in iOS 11.2 Apple renamed it to env() (see here), therefore to cover both cases you need to overload the CSS rule with both and rely on the CSS fallback mechanism to apply the appropriate one:

    padding-top: constant(safe-area-inset-top);
    padding-top: env(safe-area-inset-top);

The result is then as desired: the app content covers the full screen, but is not obscured by the "notch":

I've created a Cordova test project which illustrates the above steps:


Footer buttons

  • If your app has footer buttons (as mine does), you will also need to apply safe-area-inset-bottom to avoid them being overlapped by the virtual Home button on iPhone X.
  • In my case, I couldn't apply this to <body> as the footer is absolutely positioned, so I needed to apply it directly to the footer:

    margin-bottom: constant(safe-area-inset-bottom);
    margin-bottom: env(safe-area-inset-bottom);


  • The status bar size has changed on iPhone X, so older versions of cordova-plugin-statusbar display incorrectly on iPhone X
  • Mike Hartington has created this pull request which applies the necessary changes.
  • This was merged into the [email protected] release, so make sure you're using at least this version to apply to safe-area-insets


  • The LaunchScreen storyboard constraints changed on iOS 11/iPhone X, meaning the splashscreen appeared to "jump" on launch when using existing versions of the plugin (see here).
  • This was captured in bug report CB-13505, fixed PR cordova-ios#354 and released in [email protected], so make sure you're using a recent version of the cordova-ios platform.

device orientation

  • When using UIWebView on iOS 11.0, rotating from portrait > landscape > portrait causes the safe-area-inset not to be re-applied, causing the content to be obscured by the notch again (as highlighted by jms in a comment below).
  • Also happens if app is launched in landscape then rotated to portrait
  • This doesn't happen when using WKWebView via cordova-plugin-wkwebview-engine.
  • Radar report:
  • Update: this appears to have been fixed in iOS 11.1

For reference, this is the original Cordova issue I opened which captures this:

How to run Spyder in virtual environment?

I follow one of the advice above and indeed it works. In summary while you download Anaconda on Ubuntu using the advice given above can help you to 'create' environments. The default when you download Spyder in my case is: (base) smith@ubuntu ~$. After you create the environment, i.e. fenics and activate it with $ conda activate fenics the prompt change to (fenics) smith@ubuntu ~$. Then you launch Spyder from this prompt, i.e $ spyder and your system open the Spyder IDE, and you can write fenics code on it. Remember every time you open a terminal your system open the default prompt. You have to activate your environment where your package is and the prompt change to it i.e. (fenics).

XmlDocument - load from string?

XmlDocument doc = new XmlDocument();

Where str is your XML string. See the MSDN article for more info.

Simple pagination in javascript

i am assuming you will display 10 data in every page


<!DOCTYPE html>
    <link rel="stylesheet"  href="pathofcssfile.css">
        <table id="user"></table>
    <script src=""></script>
    <li value="1">1</li>
    <li value="2">2</li>
    <li value="3">3</li>
    <li value="4">4</li>
    <li value="5">5</li>
    <li value="6">6</li>
    <li value="7">7</li>
    <li value="8">8</li>
    <li value="9">9</li>
    <li value="10">10</li>


    <script src="pathnameofjsfile.js" type="text/javascript"></script>


var xhr = new XMLHttpRequest();'GET',"",true);

var udata;

xhr.onload = function() 
    if(this.status == 200) 
        var userdata = JSON.parse(this.responseText);
        udata = userdata;

$("li").click(function ()
var a = $(this).attr("value");
console.log("value li "+ a);

function data(a)
    var output = "";
        output +='<tr>'+
                 '<td>'+ udata[i].userId + '</td>'+
                 '<td>'+ udata[i].id + '</td>'+
                 '<td>'+ udata[i].title + '</td>'+ '<br>'
    document.getElementById('user').innerHTML = output;


display: flex;
padding: 20px;

padding: 20px;

    padding: 10px;

Scanner vs. StringTokenizer vs. String.Split

String.split seems to be much slower than StringTokenizer. The only advantage with split is that you get an array of the tokens. Also you can use any regular expressions in split. org.apache.commons.lang.StringUtils has a split method which works much more faster than any of two viz. StringTokenizer or String.split. But the CPU utilization for all the three is nearly the same. So we also need a method which is less CPU intensive, which I am still not able to find.

How to open the terminal in Atom?

There are a number of Atom packages which give you access to the terminal from within Atom. Try a few out to find the best option for you.

Some recommendations which work in Ubuntu (with their primary keyboard shortcuts):

Open a terminal in Atom:

Edit: recommended plugin changed as terminal-plus is no longer maintained. Thanks for the head's-up, @MorganRodgers.

If you want to open a terminal panel in Atom, try atom-ide-terminal. Use the keyboard shortcut ctrl-` to open a new terminal instance.

Open an external terminal from Atom:

If you just want a shortcut to open your external terminal from within Atom, try atom-terminal (this is what I use). You can use ctrl-shift-t to open your external terminal in the current file's directory, or alt-shift-t to open the terminal in the project's root directory.

How to delete items from a dictionary while iterating over it?

With python3, iterate on dic.keys() will raise the dictionary size error. You can use this alternative way:

Tested with python3, it works fine and the Error "dictionary changed size during iteration" is not raised:

my_dic = { 1:10, 2:20, 3:30 }
# Is important here to cast because ".keys()" method returns a dict_keys object.
key_list = list( my_dic.keys() )

# Iterate on the list:
for k in key_list:
    del( my_dic[k] )

print( my_dic )
# {}

Fragment onResume() & onPause() is not called on backstack

I use in my activity - KOTLIN

supportFragmentManager.addOnBackStackChangedListener {
                val f = supportFragmentManager.findFragmentById(

                if (f?.tag == "MyFragment")

How to get tf.exe (TFS command line client)?

You need to install Team Explorer, it's best to install the version of Team Explorer that matches the version of TFS you are using e.g. if you're using TFS 2010 then install Team Explorer 2010.

2012 version

2013 version

2019 version

You also might be interested in the TFS power tools. They add some extra command line features (using tfpt.exe) and also add some extra IDE features.

CSS: Background image and padding

You can use percent values:

background: yellow url("arrow1.gif") no-repeat 95% 50%;

Not pixel perfect, but…

Android TextView padding between lines

You can use lineSpacingExtra and lineSpacingMultiplier in your XML file.

How do you set EditText to only accept numeric values in Android?

For only digits input use android:inputType="numberPassword" along with editText.setTransformationMethod(null); to remove auto-hiding of the number.



For only digits input, I feel these couple ways are better than android:inputType="number". The limitation of mentioning "number" as inputType is that the keyboard allows to switch over to characters and also lets other special characters be entered. "numberPassword" inputType doesn't have those issues as the keyboard only shows digits. Even "phone" inputType works as the keyboard doesnt allow you to switch over to characters. But you can still enter couple special characters like +, /, N, etc.

android:inputType="numberPassword" with editText.setTransformationMethod(null);






How to exit from the application and show the home screen?

first finish your application using method finish();

and then add below lines in onDestroy for Removing Force close


How do I combine two data-frames based on two columns?

Hope this helps;

df1 = data.frame(CustomerId=c(1:10),
             Hobby = c(rep("sing", 4), rep("pingpong", 3), rep("hiking", 3)),
             Product=c(rep("Toaster",3),rep("Phone", 2), rep("Radio",3), rep("Stereo", 2)))

df2 = data.frame(CustomerId=c(2,4,6, 8, 10),State=c(rep("Alabama",2),rep("Ohio",1),   rep("Cal", 2)),
             like=c("sing", 'hiking', "pingpong", 'hiking', "sing"))

df3 = merge(df1, df2, by.x=c("CustomerId", "Hobby"), by.y=c("CustomerId", "like"))

Assuming df1$Hobby and df2$like mean the same thing.

How do you make a div tag into a link


  • If you want a link, wrap the content in the proper <A>NCHOR</a>.
  • If you want to turn the <DIV> into a link, use "Javascript" to wrap the <DIV> inside an <A>NCHOR</A>
  • If you want to perform some action when clicking the <DIV> use the onclick event handler... and don't call it a "link".

Producer/Consumer threads using a Queue

You are reinventing the wheel.

If you need persistence and other enterprise features use JMS (I'd suggest ActiveMq).

If you need fast in-memory queues use one of the impementations of java's Queue.

If you need to support java 1.4 or earlier, use Doug Lea's excellent concurrent package.

javax.el.PropertyNotFoundException: Property 'foo' not found on type com.example.Bean

javax.el.PropertyNotFoundException: Property 'foo' not found on type com.example.Bean

This literally means that the mentioned class com.example.Bean doesn't have a public (non-static!) getter method for the mentioned property foo. Note that the field itself is irrelevant here!

The public getter method name must start with get, followed by the property name which is capitalized at only the first letter of the property name as in Foo.

public Foo getFoo() {
    return foo;

You thus need to make sure that there is a getter method matching exactly the property name, and that the method is public (non-static) and that the method does not take any arguments and that it returns non-void. If you have one and it still doesn't work, then chances are that you were busy editing code forth and back without firmly cleaning the build, rebuilding the code and redeploying/restarting the application. You need to make sure that you have done so.

For boolean (not Boolean!) properties, the getter method name must start with is instead of get.

public boolean isFoo() {
    return foo;

Regardless of the type, the presence of the foo field itself is thus not relevant. It can have a different name, or be completely absent, or even be static. All of below should still be accessible by ${}.

public Foo getFoo() {
    return bar;
public Foo getFoo() {
    return new Foo("foo");
public Foo getFoo() {
    return FOO_CONSTANT;

You see, the field is not what counts, but the getter method itself. Note that the property name itself should not be capitalized in EL. In other words, ${bean.Foo} won't ever work, it should be ${}.

See also:

Select option padding not working in chrome

You should be targeting select for your CSS instead of select option.

select { 
padding: 10px;
margin: 0;

View this article Styling Select Box with CSS3 for more styling options.

Get folder name of the file in Python

you can use pathlib

from pathlib import Path

The output of the above was this:


How to update a value, given a key in a hashmap?

map.put(key, map.get(key) + 1);

should be fine. It will update the value for the existing mapping. Note that this uses auto-boxing. With the help of map.get(key) we get the value of corresponding key, then you can update with your requirement. Here I am updating to increment value by 1.

Connecting PostgreSQL 9.2.1 with Hibernate

Yes by using spring-boot with hibernate configuration files we can persist the data to the database. keep hibernating .cfg.xml in your src/main/resources folder for reading the configurations related to database.

enter image description here

Auto highlight text in a textbox control

In Windows Forms and WPF:

textbox.SelectionStart = 0;
textbox.SelectionLength = textbox.Text.Length;

How can labels/legends be added for all chart types in chart.js (

You can include a legend template in the chart options:

//legendTemplate takes a template as a string, you can populate the template with values from your dataset 
var options = {
  legendTemplate : '<ul>'
                  +'<% for (var i=0; i<datasets.length; i++) { %>'
                    +'<span style=\"background-color:<%=datasets[i].lineColor%>\"></span>'
                    +'<% if (datasets[i].label) { %><%= datasets[i].label %><% } %>'
                +'<% } %>'

  //don't forget to pass options in when creating new Chart
  var lineChart = new Chart(element).Line(data, options);

  //then you just need to generate the legend
  var legend = lineChart.generateLegend();

  //and append it to your page somewhere

You'll also need to add some basic css to get it looking ok.

How to programmatically disable page scrolling with jQuery

To turn OFF scrolling try this:

var current = $(window).scrollTop();
$(window).scroll(function() {

to reset:


Displaying the build date

it could be Assembly execAssembly = Assembly.GetExecutingAssembly(); var creationTime = new FileInfo(execAssembly.Location).CreationTime; // "2019-09-08T14:29:12.2286642-04:00"

HTML5 placeholder css padding

I found the answer that remedied my frustrations regarding this on John Catterfeld's blog.

... Chrome (v20-30) implements almost all styles but with a major caveat – the placeholder styles do no resize the input box, so stay clear of things like line-height and padding top or bottom.

If you are using line-height or padding you are going to be frustrated with the resulting placeholder. I haven't found a way around that up to this point.

How to delete a folder with files using Java

Here is a simple way to do it :

public void deleteDirectory(String directoryPath)  {
      new Thread(new Runnable() {
          public void run() {
             for(String e: new File(directoryPath).list()) {
                 if(new File(e).isDirectory()) 
                     new File(e).delete();

Specify path to node_modules in package.json

In short: It is not possible, and as it seems won't ever be supported (see here

There are some hacky work-arrounds with using the CLI or ENV-Variables (see the current selected answer), .npmrc-Config-Files or npm link - what they all have in common: They are never just project-specific, but always some kind of global Solutions.

For me, none of those solutions are really clean because contributors to your project always need to create some special configuration or have some special knowledge - they can't just npm install and it works.

So: Either you will have to put your package.json in the same directory where you want your node_modules installed, or live with the fact that they will always be in the root-dir of your project.

How to get root directory of project in core. Directory.GetCurrentDirectory() doesn't seem to work correctly on a mac

In some cases _hostingEnvironment.ContentRootPath and System.IO.Directory.GetCurrentDirectory() targets to source directory. Here is bug about it.

The solution proposed there helped me


Removing unwanted table cell borders with CSS

add some css:

td, th {

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

The main reason for the error is that the default encoding assumed by python is ASCII. Hence, if the string data to be encoded by encode('utf8') contains character that is outside of ASCII range e.g. for a string like 'hgvcj???387', python would throw error because the string is not in the expected encoding format.

If you are using python version earlier than version 3.5, a reliable fix would be to set the default encoding assumed by python to utf8:

import sys
name = school_name.encode('utf8')

This way python would be able to anticipate characters within a string that fall outside of ASCII range.

However, if you are using python version 3.5 or above, reload() function is not available, so you would have to fix it using decode e.g.

name = school_name.decode('utf8').encode('utf8')

File count from a folder

You can use the Directory.GetFiles method

Also see Directory.GetFiles Method (String, String, SearchOption)

You can specify the search option in this overload.

TopDirectoryOnly: Includes only the current directory in a search.

AllDirectories: Includes the current directory and all the subdirectories in a search operation. This option includes reparse points like mounted drives and symbolic links in the search.

// searches the current directory and sub directory
int fCount = Directory.GetFiles(path, "*", SearchOption.AllDirectories).Length;
// searches the current directory
int fCount = Directory.GetFiles(path, "*", SearchOption.TopDirectoryOnly).Length;

How to configure Visual Studio to use Beyond Compare

BComp.exe works in multiple-tabbed scenario as well, so there is no need to add /solo unless you really want separate windows for each file comparison. Tested/verified on Beyond Compare 3 and 4. Moral: use BComp.exe, not BCompare.exe, for VS external compare tool configuration.

Predefined type 'System.ValueTuple´2´ is not defined or imported

I would not advise adding ValueTuple as a package reference to the .net Framework projects. As you know this assembly is available from 4.7 .NET Framework.

There can be certain situations when your project will try to include at all costs ValueTuple from .NET Framework folder instead of package folder and it can cause some assembly not found errors.

We had this problem today in company. We had solution with 2 projects (I oversimplify that) :

  • Lib
  • Web

Lib was including ValueTuple and Web was using Lib. It turned out that by some unknown reason Web when trying to resolve path to ValueTuple was having HintPath into .NET Framework directory and was taking incorrect version. Our application was crashing because of that. ValueTuple was not defined in .csproj of Web nor HintPath for that assembly. The problem was very weird. Normally it would copy the assembly from package folder. This time was not normal.

For me it is always risk to add System.* package references. They are often like time-bomb. They are fine at start and they can explode in your face in the worst moment. My rule of thumb: Do not use System.* Nuget package for .NET Framework if there is no real need for them.

We resolved our problem by adding manually ValueTuple into .csproj file inside Web project.

How to make div fixed after you scroll to that div?

I know this is tagged html/css only, but you can't do that with css only. Easiest way will be using some jQuery.

var fixmeTop = $('.fixme').offset().top;       // get initial position of the element

$(window).scroll(function() {                  // assign scroll event listener

    var currentScroll = $(window).scrollTop(); // get current position

    if (currentScroll >= fixmeTop) {           // apply position: fixed if you
        $('.fixme').css({                      // scroll to that element or below it
            position: 'fixed',
            top: '0',
            left: '0'
    } else {                                   // apply position: static
        $('.fixme').css({                      // if you scroll above it
            position: 'static'


How can I know which radio button is selected via jQuery?

In my case I have two radio buttons in one form and I wanted to know the status of each button. This below worked for me:

// get radio buttons value_x000D_
console.log( "radio1: " +  $('input[id=radio1]:checked', '#toggle-form').val() );_x000D_
console.log( "radio2: " +  $('input[id=radio2]:checked', '#toggle-form').val() );_x000D_
<script src=""></script>_x000D_
<form id="toggle-form">_x000D_
  <div id="radio">_x000D_
    <input type="radio" id="radio1" name="radio" checked="checked" /><label for="radio1">Plot single</label>_x000D_
    <input type="radio" id="radio2" name="radio"/><label for="radio2">Plot all</label>_x000D_

Correct way to push into state array

Here you can not push the object to a state array like this. You can push like your way in normal array. Here you have to set the state,

     myArray: [...this.state.myArray, 'new value'] 

Cannot instantiate the type List<Product>

List can be instantiated by any class implementing the interface.By this way,Java provides us polymorphic behaviour.See the example below:

List<String> list = new ArrayList<String>();

Instead of instantiating an ArrayList directly,I am using a List to refer to ArrayList object so that we are using only the List interface methods and do not care about its actual implementation.

Examples of classes implementing List are ArrayList,LinkedList,Vector.You probably want to create a List depending upon your requirements.

Example:- a LinkedList is more useful when you hve to do a number of inertion or deletions .Arraylist is more performance intensive as it is backed by a fixed size array and array contents have to be changed by moving or regrowing the array.

Again,using a List we can simply change our object instantiation without changing any code further in your programs.

Suppose we are using ArrayList<String> value = new ArrayList<String>();

we may use a specific method of ArrrayList and out code will not be robust

By using List<String> value = new ArrayList<String>();

we are making sure we are using only List interface methods..and if we want to change it to a LinkedList we simply have to change the code :

List<String> value = new ArrayList<String>(); 

------ your code uses List interface methods.....

value = new LinkedList<String>(); 

-----your code still uses List interface methods and we do not have to change anything---- and we dont have to change anything in our code further

By the way a LinkedList also works a Deque which obviously also you cannot instantiate as it is also an interface

Fastest way to find second (third...) highest/lowest value in vector or column

Rfast has a function called nth_element that does exactly what you ask and is faster than all of the implementations discussed above

Also the methods discussed above that are based on partial sort, don't support finding the k smallest values

Disclaimer: An issue appears to occur when dealing with integers which can by bypassed by using as.numeric (e.g. Rfast::nth(as.numeric(1:10), 2)), and will be addressed in the next update of Rfast.

Rfast::nth(x, 5, descending = T)

Will return the 5th largest element of x, while

Rfast::nth(x, 5, descending = F)

Will return the 5th smallest element of x

Benchmarks below against most popular answers.

For 10 thousand numbers:

N = 10000
x = rnorm(N)

maxN <- function(x, N=2){
    len <- length(x)
        warning('N greater than length(x).  Setting N=length(x)')
        N <- length(x)

Rfast = Rfast::nth(x,5,descending = T),
maxn = maxN(x,5),
order = x[order(x, decreasing = T)[5]])

Unit: microseconds
  expr      min       lq      mean   median        uq       max neval
 Rfast  160.364  179.607  202.8024  194.575  210.1830   351.517   100
  maxN  396.419  423.360  559.2707  446.452  487.0775  4949.452   100
 order 1288.466 1343.417 1746.7627 1433.221 1500.7865 13768.148   100

For 1 million numbers:

N = 1e6
x = rnorm(N)

Rfast = Rfast::nth(x,5,descending = T),
maxN = maxN(x,5),
order = x[order(x, decreasing = T)[5]]) 

Unit: milliseconds
  expr      min        lq      mean   median        uq       max neval
 Rfast  89.7722  93.63674  114.9893 104.6325  120.5767  204.8839   100
  maxN 150.2822 207.03922  235.3037 241.7604  259.7476  336.7051   100
 order 930.8924 968.54785 1005.5487 991.7995 1031.0290 1164.9129   100

Visual C++: How to disable specific linker warnings?

You cannot disable linker warning 4099, as said @John Weldon.

You should rebuild library with some project configuration changes. You have several options:

  • Save PDB file with debug information is same folder where you save .lib file. Set value "$(OutDir)$(TargetName).pdb" to Properties->C/C++->Output Files-Program Database File Name
  • Save debug information in .lib file. Set value "C7 compatible (/Z7)" to Properties->C/C++->General->Debug Information Format
  • Disable generation debug information for this library. Remove value from Properties->C/C++->General->Debug Information Format

How to display a list inline using Twitter's Bootstrap

While TheBrent's answer is true in general, it does not answer the question of how to do it in the official bootstrap way. The markup for bootstrap is simple:

<ul class="inline">


Link to the issue number on GitHub within a commit message

If you want to link to a GitHub issue and close the issue, you can provide the following lines in your Git commit message:

Closes #1.
Closes GH-1.
Closes gh-1.

(Any of the three will work.) Note that this will link to the issue and also close it. You can find out more in this blog post (start watching the embedded video at about 1:40).

I'm not sure if a similar syntax will simply link to an issue without closing it.

How to make an image center (vertically & horizontally) inside a bigger div

Typically, I'll set the line-height to be 200px. Usually does the trick.

Keep only date part when using pandas.to_datetime

This is a simple way to extract the date:

import pandas as pd

d='2015-01-08 22:44:09' 

How to put a delay on AngularJS instant search?

For those who uses keyup/keydown in the HTML markup. This doesn't uses watch.


app.controller('SearchCtrl', function ($scope, $http, $timeout) {
  var promise = '';
  $ = function() {
    promise = $timeout(function() {
    //ajax call goes here..


<input type="search" autocomplete="off" ng-model="keywords" ng-keyup="search()" placeholder="Search...">

How to view DLL functions?

For .NET DLLs you can use ildasm

What to put in a python module docstring?

To quote the specifications:

The docstring of a script (a stand-alone program) should be usable as its "usage" message, printed when the script is invoked with incorrect or missing arguments (or perhaps with a "-h" option, for "help"). Such a docstring should document the script's function and command line syntax, environment variables, and files. Usage messages can be fairly elaborate (several screens full) and should be sufficient for a new user to use the command properly, as well as a complete quick reference to all options and arguments for the sophisticated user.

The docstring for a module should generally list the classes, exceptions and functions (and any other objects) that are exported by the module, with a one-line summary of each. (These summaries generally give less detail than the summary line in the object's docstring.) The docstring for a package (i.e., the docstring of the package's module) should also list the modules and subpackages exported by the package.

The docstring for a class should summarize its behavior and list the public methods and instance variables. If the class is intended to be subclassed, and has an additional interface for subclasses, this interface should be listed separately (in the docstring). The class constructor should be documented in the docstring for its __init__ method. Individual methods should be documented by their own docstring.

The docstring of a function or method is a phrase ending in a period. It prescribes the function or method's effect as a command ("Do this", "Return that"), not as a description; e.g. don't write "Returns the pathname ...". A multiline-docstring for a function or method should summarize its behavior and document its arguments, return value(s), side effects, exceptions raised, and restrictions on when it can be called (all if applicable). Optional arguments should be indicated. It should be documented whether keyword arguments are part of the interface.

How to compare two floating point numbers in Bash?

Using bashj ( ), a bash mutant with java support, you just write (and it IS easy to read):


static int doubleCompare(double a,double b) {return((a>b) ? 1 : (a<b) ? -1 : 0);}

if [ $comp == 0 ] ; then echo "Equal" ; fi
if [ $comp == 1 ] ; then echo "$num1 > $num2" ; fi
if [ $comp == -1 ] ; then echo "$num2 > $num1" ; fi

Of course bashj bash/java hybridation offers much more...

How to delete all the rows in a table using Eloquent?

In a similar vein to Travis vignon's answer, I required data from the eloquent model, and if conditions were correct, I needed to either delete or update the model. I wound up getting the minimum and maximum I'd field returned by my query (in case another field was added to the table that would meet my selection criteria) along with the original selection criteria to update the fields via one raw SQL query (as opposed to one eloquent query per object in the collection).

I know the use of raw SQL violates laravels beautiful code philosophy, but itd be hard to stomach possibly hundreds of queries in place of one.

Jquery assiging class to th in a table

You had thead in your selector, but there is no thead in your table. Also you had your selectors backwards. As you mentioned above, you wanted to be adding the tr class to the th, not vice-versa (although your comment seems to contradict what you wrote up above).

$('tr th').each(function(index){     if($('tr td').eq(index).attr('class') != ''){         // get the class of the td         var tdClass = $('tr td').eq(index).attr('class');         // add it to this th         $(this).addClass(tdClass );     } }); 


Returning IEnumerable<T> vs. IQueryable<T>

Yes, both will give you deferred execution.

The difference is that IQueryable<T> is the interface that allows LINQ-to-SQL (LINQ.-to-anything really) to work. So if you further refine your query on an IQueryable<T>, that query will be executed in the database, if possible.

For the IEnumerable<T> case, it will be LINQ-to-object, meaning that all objects matching the original query will have to be loaded into memory from the database.

In code:

IQueryable<Customer> custs = ...;
// Later on...
var goldCustomers = custs.Where(c => c.IsGold);

That code will execute SQL to only select gold customers. The following code, on the other hand, will execute the original query in the database, then filtering out the non-gold customers in the memory:

IEnumerable<Customer> custs = ...;
// Later on...
var goldCustomers = custs.Where(c => c.IsGold);

This is quite an important difference, and working on IQueryable<T> can in many cases save you from returning too many rows from the database. Another prime example is doing paging: If you use Take and Skip on IQueryable, you will only get the number of rows requested; doing that on an IEnumerable<T> will cause all of your rows to be loaded in memory.

Get the real width and height of an image with JavaScript? (in Safari/Chrome)

You can programmatically get the image and check the dimensions using Javascript without having to mess with the DOM at all.

var img = new Image();
img.onload = function() {
  console.log(this.width + 'x' + this.height);
img.src = '';

How to change font size in html?

You can do this by setting a style in your paragraph tag. For example if you wanted to change the font size to 28px.

<p style="font-size: 28px;"> Hello, World! </p>

You can also set the color by setting:

<p style="color: blue;"> Hello, World! </p>

However, if you want to preview font sizes and colors (which I recommend doing) before you add them to your website and use them. I recommend testing them out beforehand so you pick a good font size and color that contrasts well with the background. I recommend using this site if you wish to do so, couldn't find anything else:

How to SUM parts of a column which have same text value in different column in the same row

This can be done by using SUMPRODUCT as well. Update the ranges as you see fit


A2:A7 = First name range

B2:B7 = Last Name Range

C2:C7 = Numbers Range

This will find all the names with the same first and last name and sum the numbers in your numbers column

How can I get the number of days between 2 dates in Oracle 11g?

This will work i have tested myself.
It gives difference between sysdate and date fetched from column admitdate

  "TOTAL" NUMBER(*,0), 
"DUES" NUMBER(*,0), 

select TO_NUMBER(trunc(sysdate) - to_date(to_char(admitdate, 'yyyy-mm-dd'),'yyyy-mm-dd')) from admin.duestesting where total=300

You can't specify target table for update in FROM clause

If you are trying to read fieldA from tableA and save it on fieldB on the same table, when fieldc = fieldd you might want consider this.

UPDATE tableA,
    tableA AS tableA_1 
    tableA.fieldB= tableA_1.filedA
    (((tableA.conditionFild) = 'condition')
        AND ((tableA.fieldc) = tableA_1.fieldd));

Above code copies the value from fieldA to fieldB when condition-field met your condition. this also works in ADO (e.g access )

source: tried myself

Find multiple files and rename them in Linux

small script i wrote to replace all files with .txt extension to .cpp extension under /tmp and sub directories recursively


for file in $(find /tmp -name '*.txt')
  mv $file $(echo "$file" | sed -r 's|.txt|.cpp|g')

How to remove any URL within a string in Python

This solution caters for http, https and the other normal url type special characters :

import re
def remove_urls (vTEXT):
    vTEXT = re.sub(r'(https|http)?:\/\/(\w|\.|\/|\?|\=|\&|\%)*\b', '', vTEXT, flags=re.MULTILINE)

print( remove_urls("this is a test lets see this too end"))

How to get All input of POST in Laravel

its better to use the Dependency than to attache it to the class.

public function add_question(Request $request)
    return Request::all();

or if you prefer using input variable use

public function add_question(Request $input)
    return $input::all();

you can now use the global request method provided by laravel


for example to get the first_name of a form input.

// or

In a Git repository, how to properly rename a directory?

lots of correct answers, but as I landed here to copy & paste a folder rename with history, I found that this

git mv <old name> <new name>

will move the old folder (itself) to nest within the new folder


git mv <old name>/ <new name>

(note the '/') will move the nested content from the old folder to the new folder

both commands didn't copy along the history of nested files. I eventually renamed each nested folder individually ?

git mv <old name>/<nest-folder> <new name>/<nest-folder>

css display table cell requires percentage width

Note also that vertical-align:top; is often necessary for correct table cell appearance.

css table-cell, contents have unnecessary top margin

Binding multiple events to a listener (without JQuery)?


let el = document.getElementById("el");
let handler =()=> console.log("changed");
['change', 'keyup', 'cut'].forEach(event => el.addEventListener(event, handler));

Error 80040154 (Class not registered exception) when initializing VCProjectEngineObject (Microsoft.VisualStudio.VCProjectEngine.dll)

There are not many good reasons this would fail, especially the regsvr32 step. Run dumpbin /exports on that dll. If you don't see DllRegisterServer then you've got a corrupt install. It should have more side-effects, you wouldn't be able to build C/C++ projects anymore.

One standard failure mode is running this on a 64-bit operating system. This is 32-bit unmanaged code, you would indeed get the 'class not registered' exception. Project + Properties, Build tab, change Platform Target to x86.

How to master AngularJS?

Concerning more advanced usage, I find these two pages a must read:

How do I call a JavaScript function on page load?

here's the trick (works everywhere):

alert('DOM Ready!');
function r(f){/in/.test(document.readyState)?setTimeout('r('+f+')',9):f()}

How to store NULL values in datetime fields in MySQL?

For what it is worth: I was experiencing a similar issue trying to update a MySQL table via Perl. The update would fail when an empty string value (translated from a null value from a read from another platform) was passed to the date column ('dtcol' in the code sample below). I was finally successful getting the data updated by using an IF statement embedded in my update statement:

    my $stmnt='update tbl set colA=?,dtcol=if(?="",null,?) where colC=?';
    my $status=$dbh->do($stmt,undef,$iref[1],$iref[2],$iref[2],$ref[0]);

ViewDidAppear is not called when opening app from background

Swift 3.0 ++ version

In your viewDidLoad, register at notification center to listen to this opened from background action

NotificationCenter.default.addObserver(self, selector:#selector(doSomething), name: NSNotification.Name.UIApplicationWillEnterForeground, object: nil)

Then add this function and perform needed action

func doSomething(){

Finally add this function to clean up the notification observer when your view controller is destroyed.

deinit {

Exploitable PHP functions

What about dangerous syntactic elements?

The "variable variable" ($$var) will find a variable in the current scope by the name of $var. If used wrong, the remote user can modify or read any variable in the current scope. Basically a weaker eval.

Ex: you write some code $$uservar = 1;, then the remote user sets $uservar to "admin", causing $admin to be set to 1 in the current scope.

500.21 Bad module "ManagedPipelineHandler" in its module list

Please follow these steps:

1) Run the command prompt as administrator.

2) Type either of the two lines below in the command prompt:

%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i


%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

SQL select only rows with max value on a column

I can't vouch for the performance, but here's a trick inspired by the limitations of Microsoft Excel. It has some good features


  • It should force return of only one "max record" even if there is a tie (sometimes useful)
  • It doesn't require a join


It is a little bit ugly and requires that you know something about the range of valid values of the rev column. Let us assume that we know the rev column is a number between 0.00 and 999 including decimals but that there will only ever be two digits to the right of the decimal point (e.g. 34.17 would be a valid value).

The gist of the thing is that you create a single synthetic column by string concatenating/packing the primary comparison field along with the data you want. In this way, you can force SQL's MAX() aggregate function to return all of the data (because it has been packed into a single column). Then you have to unpack the data.

Here's how it looks with the above example, written in SQL

       CAST(SUBSTRING(max(packed_col) FROM 2 FOR 6) AS float) as max_rev,
       SUBSTRING(max(packed_col) FROM 11) AS content_for_max_rev 
       CAST(1000 + rev + .001 as CHAR) || '---' || CAST(content AS char) AS packed_col
       FROM yourtable

The packing begins by forcing the rev column to be a number of known character length regardless of the value of rev so that for example

  • 3.2 becomes 1003.201
  • 57 becomes 1057.001
  • 923.88 becomes 1923.881

If you do it right, string comparison of two numbers should yield the same "max" as numeric comparison of the two numbers and it's easy to convert back to the original number using the substring function (which is available in one form or another pretty much everywhere).

Python Regex - How to Get Positions and Values of Matches

note that the span & group are indexed for multi capture groups in a regex

for match in re.finditer(regex_with_3_groups, string):
    for idx in range(0, 4):

Aligning two divs side-by-side

This Can be Done by Style Property.

<!DOCTYPE html>
#main {

  display: flex;

#main div {
  flex-grow: 0;
  flex-shrink: 0;
  flex-basis: 40px;

<div id="main">
  <div style="background-color:coral;">Red DIV</div>
  <div style="background-color:lightblue;" id="myBlueDiv">Blue DIV</div>


Its Result will be :

enter image description here

Enjoy... Please Note: This works in Higher version of CSS (>3.0).

Bootstrap 3 hidden-xs makes row narrower

How does it work if you only are using visible-md at Col4 instead? Do you use the -lg at all? If not this might work.

<div class="container">
    <div class="row">
        <div class="col-xs-4 col-sm-2 col-md-1" align="center">
        <div class="col-xs-4 col-sm-2" align="center">
        <div class="hidden-xs col-sm-6 col-md-5" align="center">
        <div class="visible-md col-md-3 " align="center">
        <div class="col-xs-4 col-sm-2 col-md-1" align="center">

Convert MySQL to SQlite

Here is a list of converters. (snapshot at

An alternative method that would work even on windows but is rarely mentioned is: use an ORM class that abstracts specific database differences away for you. e.g. you get these in PHP (RedBean), Python (Django's ORM layer, Storm, SqlAlchemy), Ruby on Rails (ActiveRecord), Cocoa (CoreData) etc.

i.e. you could do this:

  1. Load data from source database using the ORM class.
  2. Store data in memory or serialize to disk.
  3. Store data into destination database using the ORM class.

How do you do a limit query in JPQL or HQL?

You can easily use pagination for this.

    @QueryHints({ @QueryHint(name = "org.hibernate.cacheable", value = "true") })
    @Query("select * from a_table order by a_table_column desc")
    List<String> getStringValue(Pageable pageable);

you have to pass new PageRequest(0, 1)to fetch records and from the list fetch the first record.

mysql: see all open connections to a given database?

In MySql,the following query shall show the total number of open connections:

show status like 'Threads_connected';

Rename package in Android Studio

  1. Press Ctrl + Shift + R

  2. Replace the old package with the new one.

  3. Right click on the package name.

  4. Refactor > Rename and rename to the new one

C#: How to make pressing enter in a text box trigger a button, yet still allow shortcuts such as "Ctrl+A" to get through?

If you add e.SuppressKeyPress = true; as shown in the answer in this link you will suppress the annoying ding sound that occurs.

Remove part of string after "."

You could do:

sub("*\\.[0-9]", "", a)


str_sub(a, start=1, end=-3)

How can I open Java .class files in a human-readable way?

JAD is an excellent option if you want readable Java code as a result. If you really want to dig into the internals of the .class file format though, you're going to want javap. It's bundled with the JDK and allows you to "decompile" the hexadecimal bytecode into readable ASCII. The language it produces is still bytecode (not anything like Java), but it's fairly readable and extremely instructive.

Also, if you really want to, you can open up any .class file in a hex editor and read the bytecode directly. The result is identical to using javap.

How to set thymeleaf th:field value from other variable

The correct approach is to use preprocessing

For example


What is the maximum value for an int32?

You will find in binary the maximum value of an Int32 is 1111111111111111111111111111111 but in ten based you will find it is 2147483647 or 2^31-1 or Int32.MaxValue

Replace tabs with spaces in vim


set expandtab

for soft tabs.

To fix pre-existing tabs:

:%s/\t/  /g

I used two spaces since you already set your tabstop to 2 spaces.