Programs & Examples On #Nssplitview

An NSSplitView object stacks several subviews within one view so that the user can change their relative sizes. By default, the split bars between the views are horizontal, so the views are one on top of the other.

How do I stretch a background image to cover the entire HTML element?

If you have a large landscape image, this example here resizes the background in portrait mode, so that it displays on top, leaving blank on the bottom:

html, body {
    margin: 0;
    padding: 0;
    min-height: 100%;

body {
    background-image: url('myimage.jpg');
    background-position-x: center;
    background-position-y: bottom;
    background-repeat: no-repeat;
    background-attachment: scroll;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;

@media screen and (orientation:portrait) {
    body {
        background-position-y: top;
        -webkit-background-size: contain;
        -moz-background-size: contain;
        -o-background-size: contain;
        background-size: contain;

Skipping Incompatible Libraries at compile

Normally, that is not an error per se; it is a warning that the first file it found that matches the -lPI-Http argument to the compiler/linker is not valid. The error occurs when no other library can be found with the right content.

So, you need to look to see whether /dvlpmnt/libPI-Http.a is a library of 32-bit object files or of 64-bit object files - it will likely be 64-bit if you are compiling with the -m32 option. Then you need to establish whether there is an alternative libPI-Http.a or file somewhere else that is 32-bit. If so, ensure that the directory that contains it is listed in a -L/some/where argument to the linker. If not, then you will need to obtain or build a 32-bit version of the library from somewhere.

To establish what is in that library, you may need to do:

mkdir junk
cd junk
ar x /dvlpmnt/libPI-Http.a
file *.o
cd ..
rm -fr junk

The 'file' step tells you what type of object files are in the archive. The rest just makes sure you don't make a mess that can't be easily cleaned up.

php Replacing multiple spaces with a single space

Use preg_replace() and instead of [ \t\n\r] use \s:

$output = preg_replace('!\s+!', ' ', $input);

From Regular Expression Basic Syntax Reference:

\d, \w and \s

Shorthand character classes matching digits, word characters (letters, digits, and underscores), and whitespace (spaces, tabs, and line breaks). Can be used inside and outside character classes.

Facebook page automatic "like" URL (for QR Code)

For a hyperlink just use ID++/like


To make it work with here's what you do:

Open the Facebook page you're looking for then change the URL to the mobile URL ( which is ).

Now you should see a big version of the mobile Facebook page. Copy the target URL of the like button.

Pop that URL into the QR generator to make a "scan to like" barcode. This will open the m.Facebook page in the browser of most mobiles directly from the QR reader. If they are not logged into Facebook then they will be prompted to log in and then click 'like'. If logged in, it will auto like.

Hope this helps!

Also, definitely include something with a "click here/scan here to like us on Facebook"

Removing spaces from string

String res =" Application " res=res.trim();

o/p: Application

Note: White space ,blank space are trim or removed

PHP $_FILES['file']['tmp_name']: How to preserve filename and extension?

If you wanna get the uploaded file name, use $_FILES["file"]["name"]

But If you wanna read the uploaded file you should use $_FILES["file"]["tmp_name"], because tmp_name is a temporary copy of your uploaded file and it's easier than using

$_FILES["file"]["name"] // This name includes a file path, which makes file read process more complex

Deleting an object in java?

You can remove the reference using null.

Let's say You have class A:

A a = new A();

last statement will remove the reference of the object a and that object will be "garbage collected" by JVM. It is one of the easiest ways to do this.

Spring Security with roles and permissions

The basic steps are:

  1. Use a custom authentication provider

    <bean id="myAuthenticationProvider" class="myProviderImplementation" scope="singleton">

  2. Make your custom provider return a custom UserDetails implementation. This UserDetailsImpl will have a getAuthorities() like this:

    public Collection<GrantedAuthority> getAuthorities() {
        List<GrantedAuthority> permissions = new ArrayList<GrantedAuthority>();
        for (GrantedAuthority role: roles) {
        return permissions;

Of course from here you could apply a lot of optimizations/customizations for your specific requirements.

Get Maven artifact version at runtime

I spent some time on the two main approaches here and they didn't work-out for me. I am using Netbeans for the builds, may be there's more going on there. I had some errors and warnings from Maven 3 with some constructs, but I think those were easy to correct. No biggie.

I did find an answer that looks maintainable and simple to implement in this article on DZone:

I already have a resources/config sub-folder, and I named my file:, to better reflect the kind of stuff we may keep there (like a support URL, etc.).

The only caveat is that Netbeans gives a warning that the IDE needs filtering off. Not sure where/how. It has no effect at this point. Perhaps there's a work around for that if I need to cross that bridge. Best of luck.

How to run a task when variable is undefined in ansible?

From the ansible docs: If a required variable has not been set, you can skip or fail using Jinja2’s defined test. For example:


- shell: echo "I've got '{{ foo }}' and am not afraid to use it!"
  when: foo is defined

- fail: msg="Bailing out. this play requires 'bar'"
  when: bar is not defined

So in your case, when: deployed_revision is not defined should work

vagrant primary box defined but commands still run against all boxes

The primary flag seems to only work for vagrant ssh for me.

In the past I have used the following method to hack around the issue.

# stage box intended for configuration closely matching production if ARGV[1] == 'stage'     config.vm.define "stage" do |stage|         box_setup stage, \         "", "deploy/playbook_full_stack.yml", "deploy/hosts/vagrant_stage.yml"     end end 

Eclipse: Set maximum line length for auto formatting?

For HTML / PHP / JSP / JSPF: Web -> HTML Files -> Editor -> Line width


In my case I was using a third party library (i.e. vendor) and the library comes with a sample app which I already had install on my device. So that sample app was now conflicting each time I try to install my own app implementing the library. So I just uninstalled the vendor's sample app and it works afterwards.

fatal: The current branch master has no upstream branch

Well, I was having the same trouble while uploading and I resolved it by doing the same thing which it says to do: Earlier I was trying to push through terminal to my repository in linux by https like

git push

But was not getting any result and hence I went down deeper and tried:

git push --set-upstream master

And it worked. Thus then you will get prompted with username and password. I also generated a token and instead of Password I pasted the token and thus, being done successfully.

  1. To generate a token go to your Github account and in Developer Settings and then create another token.
  2. After getting that, copy that token and paste in the password prompt when it's been asked.

How to reset a timer in C#?

All the timers have the equivalent of Start() and Stop() methods, except System.Threading.Timer.

So an extension method such as...

public static void Reset(this Timer timer)
} one way to go about it.

Simple timeout in java

Nowadays you can use

try {
    String s = CompletableFuture.supplyAsync(() -> br.readLine())
                                .get(1, TimeUnit.SECONDS);
} catch (TimeoutException e) {
    System.out.println("Time out has occurred");
} catch (InterruptedException | ExecutionException e) {
    // Handle

Finding the number of days between two dates

$early_start_date = date2sql($_POST['early_leave_date']);

$date = new DateTime($early_start_date);
$date->modify('+1 day');

$date_a = new DateTime($early_start_date . ' ' . $_POST['start_hr'] . ':' . $_POST['start_mm']);
$date_b = new DateTime($date->format('Y-m-d') . ' ' . $_POST['end_hr'] . ':' . $_POST['end_mm']);

$interval = date_diff($date_a, $date_b);

$time = $interval->format('%h:%i');
$parsed = date_parse($time);
$seconds = $parsed['hour'] * 3600 + $parsed['minute'] * 60;
//        display_error($seconds);

$second3 = $employee_information['shift'] * 60 * 60;

if ($second3 < $seconds)
    display_error(_('Leave time can not be greater than shift time.Please try again........'));
    return FALSE;

javascript window.location in new tab

I don't think there's a way to do this, unless you're writing a browser extension. You could try using and hoping that the user has their browser set to open new windows in new tabs.

Create a batch file to copy and rename file

type C:\temp\test.bat>C:\temp\test.log

"starting Tomcat server 7 at localhost has encountered a prob"

to overcome this kind of problem follow the steps below:

  • open command prompt.
  • c:\Users\CGITS_04> netstat -o -n -a | findstr 0.0:80
  • then you can see a list of process that is currently using port 80.
  • open task manager->search the process-> select and end process.
  • Now open eclipse and start tomcat.
  • happy coding!

Understanding Linux /proc/id/maps

Please check:

address           perms offset  dev   inode       pathname
00400000-00452000 r-xp 00000000 08:02 173521      /usr/bin/dbus-daemon

The address field is the address space in the process that the mapping occupies.

The perms field is a set of permissions:

 r = read
 w = write
 x = execute
 s = shared
 p = private (copy on write)

The offset field is the offset into the file/whatever;

dev is the device (major:minor);

inode is the inode on that device.0 indicates that no inode is associated with the memoryregion, as would be the case with BSS (uninitialized data).

The pathname field will usually be the file that is backing the mapping. For ELF files, you can easily coordinate with the offset field by looking at the Offset field in the ELF program headers (readelf -l).

Under Linux 2.0, there is no field giving pathname.


Here's a simple rule:

PUT to a URL should be used to update or create the resource that can be located at that URL.

POST to a URL should be used to update or create a resource which is located at some other ("subordinate") URL, or is not locatable via HTTP.

How to Get True Size of MySQL Database?

If you use phpMyAdmin, it can tell you this information.

Just go to "Databases" (menu on top) and click "Enable Statistics".

You will see something like this:

phpMyAdmin screenshot

This will probably lose some accuracy as the sizes go up, but it should be accurate enough for your purposes.

Extract digits from a string in Java

Use regular expression to match your requirement.

String num,num1,num2;
String str = "123-456-789";
String regex ="(\\d+)";
Matcher matcher = Pattern.compile( regex ).matcher( str);
while (matcher.find( ))
num =;     

Is there an equivalent to CTRL+C in IPython Notebook in Firefox to break cells that are running?

UPDATE: Turned my solution into a stand-alone python script.

This solution has saved me more than once. Hopefully others find it useful. This python script will find any jupyter kernel using more than cpu_threshold CPU and prompts the user to send a SIGINT to the kernel (KeyboardInterrupt). It will keep sending SIGINT until the kernel's cpu usage goes below cpu_threshold. If there are multiple misbehaving kernels it will prompt the user to interrupt each of them (ordered by highest CPU usage to lowest). A big thanks goes to gcbeltramini for writing code to find the name of a jupyter kernel using the jupyter api. This script was tested on MACOS with python3 and requires jupyter notebook, requests, json and psutil.

Put the script in your home directory and then usage looks like:

python ~/
Interrupt kernel chews cpu.ipynb; PID: 57588; CPU: 2.3%? (y/n) y

Script code below:

from os import getpid, kill
from time import sleep
import re
import signal

from notebook.notebookapp import list_running_servers
from requests import get
from requests.compat import urljoin
import ipykernel
import json
import psutil

def get_active_kernels(cpu_threshold):
    """Get a list of active jupyter kernels."""
    active_kernels = []
    pids = psutil.pids()
    my_pid = getpid()

    for pid in pids:
        if pid == my_pid:
            p = psutil.Process(pid)
            cmd = p.cmdline()
            for arg in cmd:
                if arg.count('ipykernel'):
                    cpu = p.cpu_percent(interval=0.1)
                    if cpu > cpu_threshold:
                        active_kernels.append((cpu, pid, cmd))
        except psutil.AccessDenied:
    return active_kernels

def interrupt_bad_notebooks(cpu_threshold=0.2):
    """Interrupt active jupyter kernels. Prompts the user for each kernel."""

    active_kernels = sorted(get_active_kernels(cpu_threshold), reverse=True)

    servers = list_running_servers()
    for ss in servers:
        response = get(urljoin(ss['url'].replace('localhost', ''), 'api/sessions'),
                       params={'token': ss.get('token', '')})
        for nn in json.loads(response.text):
            for kernel in active_kernels:
                for arg in kernel[-1]:
                    if arg.count(nn['kernel']['id']):
                        pid = kernel[1]
                        cpu = kernel[0]
                        interrupt = input(
                            'Interrupt kernel {}; PID: {}; CPU: {}%? (y/n) '.format(nn['notebook']['path'], pid, cpu))
                        if interrupt.lower() == 'y':
                            p = psutil.Process(pid)
                            while p.cpu_percent(interval=0.1) > cpu_threshold:
                                kill(pid, signal.SIGINT)

if __name__ == '__main__':

Http post and get request in angular 6

You can do a post/get using a library which allows you to use HttpClient with strongly-typed callbacks.

The data and the error are available directly via these callbacks.

The library is called angular-extended-http-client.

angular-extended-http-client library on GitHub

angular-extended-http-client library on NPM

Very easy to use.

Traditional approach

In the traditional approach you return Observable<HttpResponse<T>> from Service API. This is tied to HttpResponse.

With this approach you have to use .subscribe(x => ...) in the rest of your code.

This creates a tight coupling between the http layer and the rest of your code.

Strongly-typed callback approach

You only deal with your Models in these strongly-typed callbacks.

Hence, The rest of your code only knows about your Models.

Sample usage

The strongly-typed callbacks are


  • IObservable<T>
  • IObservableHttpResponse
  • IObservableHttpCustomResponse<T>


  • IObservableError<TError>
  • IObservableHttpError
  • IObservableHttpCustomError<TError>

Add package to your project and in your app module

import { HttpClientExtModule } from 'angular-extended-http-client';

and in the @NgModule imports

  imports: [

Your Models

export class SearchModel {
    code: string;

//Normal response returned by the API.
export class RacingResponse {
    result: RacingItem[];

//Custom exception thrown by the API.
export class APIException {
    className: string;

Your Service

In your Service, you just create params with these callback types.

Then, pass them on to the HttpClientExt's get method.

import { Injectable, Inject } from '@angular/core'
import { SearchModel, RacingResponse, APIException } from '../models/models'
import { HttpClientExt, IObservable, IObservableError, ResponseType, ErrorType } from 'angular-extended-http-client';

export class RacingService {

    //Inject HttpClientExt component.
    constructor(private client: HttpClientExt, @Inject(APP_CONFIG) private config: AppConfig) {


    //Declare params of type IObservable<T> and IObservableError<TError>.
    //These are the success and failure callbacks.
    //The success callback will return the response objects returned by the underlying HttpClient call.
    //The failure callback will return the error objects returned by the underlying HttpClient call.
    searchRaceInfo(model: SearchModel, success: IObservable<RacingResponse>, failure?: IObservableError<APIException>) {
        let url = this.config.apiEndpoint;<SearchModel, RacingResponse>(url, model, 
                                                      ResponseType.IObservable, success, 
                                                      ErrorType.IObservableError, failure);

Your Component

In your Component, your Service is injected and the searchRaceInfo API called as shown below.

  search() {    

    this.service.searchRaceInfo(this.searchModel, response => this.result = response.result,
                                                  error => this.errorMsg = error.className);


Both, response and error returned in the callbacks are strongly typed. Eg. response is type RacingResponse and error is APIException.

How can I specify working directory for popen

subprocess.Popen takes a cwd argument to set the Current Working Directory; you'll also want to escape your backslashes ('d:\\test\\local'), or use r'd:\test\local' so that the backslashes aren't interpreted as escape sequences by Python. The way you have it written, the \t part will be translated to a tab.

So, your new line should look like:

subprocess.Popen(r'c:\mytool\tool.exe', cwd=r'd:\test\local')

To use your Python script path as cwd, import os and define cwd using this:


How to extract the file name from URI returned from Intent.ACTION_GET_CONTENT?

I'm using something like this:

String scheme = uri.getScheme();
if (scheme.equals("file")) {
    fileName = uri.getLastPathSegment();
else if (scheme.equals("content")) {
    String[] proj = { MediaStore.Images.Media.TITLE };
    Cursor cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
    if (cursor != null && cursor.getCount() != 0) {
        int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.TITLE);
        fileName = cursor.getString(columnIndex);
    if (cursor != null) {

JQuery get all elements by class name

With the code in the question, you're only dealing interacting with the first of the four entries returned by that selector.

Code below as a fiddle:

I want to be overly clear that you have four items that matched that selector, so you need to deal with each explicitly. Using eq() is a little more explicit making this point than the answers using map, though map or each is what you'd probably use "in real life" (jquery docs for eq here).

        <script src="//" ></script>

        <div class="mbox">Block One</div>
        <div class="mbox">Block Two</div>
        <div class="mbox">Block Three</div>
        <div class="mbox">Block Four</div>

        <div id="outige"></div>
            // using the $ prefix to use the "jQuery wrapped var" convention
            var i, $mvar = $('.mbox');

            // convenience method to display unprocessed html on the same page
            function logit( string )
                var text = document.createTextNode( string );


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


Output from logit calls (after the initial four div's display):

Block One
Block Two
Block Three
Block Four

Python: Maximum recursion depth exceeded

You can increment the stack depth allowed - with this, deeper recursive calls will be possible, like this:

import sys
sys.setrecursionlimit(10000) # 10000 is an example, try with different values

... But I'd advise you to first try to optimize your code, for instance, using iteration instead of recursion.

In Git, how do I figure out what my current revision is?

What do you mean by "version number"? It is quite common to tag a commit with a version number and then use

$ git describe --tags

to identify the current HEAD w.r.t. any tags. If you mean you want to know the hash of the current HEAD, you probably want:

$ git rev-parse HEAD

or for the short revision hash:

$ git rev-parse --short HEAD

It is often sufficient to do:

$ cat .git/refs/heads/${branch-master}

but this is not reliable as the ref may be packed.

How do I kill a VMware virtual machine that won't die?

Similar, but using WMIC command line to obtain the process ID and path:

WMIC /OUTPUT:C:\ProcessList.txt PROCESS get Caption,Commandline,Processid

This will create a text file with each process and its parameters. You can search in the file for your VM File Path, and get the correct Process ID to end task with.

Thanks to for the correct command line parameters.

Reporting Services export to Excel with Multiple Worksheets

The solution from Edward worked for me.

If you want the whole tablix on one sheet with a constant name, specify the PageName in the tablix's Properties. If you set the PageName in the tablix's Properties, you can not use data from the tablix's dataset in your expression.

If you want rows from the tablix grouped into sheets (or you want one sheet with a name based on the data), specify the PageName in the Group Header.

Conversion from 12 hours time to 24 hours time in java

We can solve this by using String Buffer String s;

static String timeConversion(String s) {
   StringBuffer st=new StringBuffer(s);
   for(int i=0;i<=st.length();i++){

       if(st.charAt(0)=='0' && st.charAt(1)=='1' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '3');
       }else if(st.charAt(0)=='0' && st.charAt(1)=='2' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '4');
        }else if(st.charAt(0)=='0' && st.charAt(1)=='3' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '5');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='4' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '6');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='5' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '7');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='6' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '8');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='7' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '1');
                st.setCharAt(1, '9');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='8' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '2');
                st.setCharAt(1, '0');
         }else if(st.charAt(0)=='0' && st.charAt(1)=='9' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '2');
                st.setCharAt(1, '1');
         }else if(st.charAt(0)=='1' && st.charAt(1)=='0' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '2');
                st.setCharAt(1, '2');
         }else if(st.charAt(0)=='1' && st.charAt(1)=='1' &&st.charAt(8)=='P' ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '2');
                st.setCharAt(1, '3');
         }else if(st.charAt(0)=='1' && st.charAt(1)=='2' &&st.charAt(8)=='A'  ){
        //    if(st.charAt(2)=='1'){
               // st.replace(1,2,"13");
                st.setCharAt(0, '0');
                st.setCharAt(1, '0');
         }else if(st.charAt(0)=='1' && st.charAt(1)=='2' &&st.charAt(8)=='P'  ){
                st.setCharAt(0, '1');
                st.setCharAt(1, '2');
             st.setCharAt(8,' ');

         }else if(st.charAt(8)== 'A'){
             st.setCharAt(8,' ');
             st.setCharAt(9,' ');
   String result=st.toString();
   return result;

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

I just spent some time figure it out. Thoma's answer is not complete. Say your program is, you want to use gpu0 to run this program, and keep other gpus free.

You should write CUDA_VISIBLE_DEVICES=0 python

Notice it's DEVICES not DEVICE

Dismissing a Presented View Controller

Quote from View Controller Programming Guide, "How View Controllers Present Other View Controllers".

Each view controller in a chain of presented view controllers has pointers to the other objects surrounding it in the chain. In other words, a presented view controller that presents another view controller has valid objects in both its presentingViewController and presentedViewController properties. You can use these relationships to trace through the chain of view controllers as needed. For example, if the user cancels the current operation, you can remove all objects in the chain by dismissing the first presented view controller. Dismissing a view controller dismisses not only that view controller but also any view controllers it presented.

So on one hand it makes for a nice balanced design, good de-coupling, etc... But on the other hand it's very practical, because you can quickly get back to a certain point in navigation.

Although, I personally would rather use unwinding segues than try to traverse backwards the presenting view controllers tree, which is what Apple talks about in this chapter where the quote is from.

PHP add elements to multidimensional array with array_push

I know the topic is old, but I just fell on it after a google search so... here is another solution:

$array_merged = array_merge($array_going_first, $array_going_second);

This one seems pretty clean to me, it works just fine!

jQuery Ajax error handling, show custom exception messages

In my case, I just removed HTTP VERB from controller.

    **//[HttpPost]**   ---- just removed this verb
    public JsonResult CascadeDpGetProduct(long categoryId)
        List<ProductModel> list = new List<ProductModel>();
        list = dp.DpProductBasedOnCategoryandQty(categoryId);
        return Json(new SelectList(list, "Value", "Text", JsonRequestBehavior.AllowGet));

clearInterval() not working

You're using clearInterval incorrectly.

This is the proper use:

Set the timer with

var_name = setInterval(fontChange, 500);

and then


Send POST data via raw json with postman

meda's answer is completely legit, but when I copied the code I got an error!

Somewhere in the "php://input" there's an invalid character (maybe one of the quotes?).

When I typed the "php://input" code manually, it worked. Took me a while to figure out!

Declaring abstract method in TypeScript

The name property is marked as protected. This was added in TypeScript 1.3 and is now firmly established.

The makeSound method is marked as abstract, as is the class. You cannot directly instantiate an Animal now, because it is abstract. This is part of TypeScript 1.6, which is now officially live.

abstract class Animal {
    constructor(protected name: string) { }

    abstract makeSound(input : string) : string;

    move(meters) {
        alert( + " moved " + meters + "m.");

class Snake extends Animal {
    constructor(name: string) { super(name); }

    makeSound(input : string) : string {
        return "sssss"+input;

    move() {

The old way of mimicking an abstract method was to throw an error if anyone used it. You shouldn't need to do this any more once TypeScript 1.6 lands in your project:

class Animal {
    constructor(public name) { }
    makeSound(input : string) : string {
        throw new Error('This method is abstract');
    move(meters) {
        alert( + " moved " + meters + "m.");

class Snake extends Animal {
    constructor(name) { super(name); }
    makeSound(input : string) : string {
        return "sssss"+input;
    move() {

Build Error - missing required architecture i386 in file

If your app is meant to run on the device, make sure you are not trying to run in it on the simulator. May sound obvious, but check anyway.

What does a "Cannot find symbol" or "Cannot resolve symbol" error mean?

In my case - I had to perform below operations:

  1. Move context.xml file from src/java/package to the resource directory (IntelliJ IDE)
  2. Clean target directory.

Checking if an object is null in C#

You can try like below

public List<Object> dataList;
public  bool AddData(ref Object data)
bool success = false;
    if (data != null)
       success = doOtherStuff(data);
catch (Exception e)
    throw new Exception(e.ToString());
return success;


Adding 'serial' to existing column in Postgres


Here's a version where you don't need a human to read a value and type it out themselves.

SELECT setval('foo_a_seq', coalesce(max(a), 0) + 1, false) FROM foo;
ALTER TABLE foo ALTER COLUMN a SET DEFAULT nextval('foo_a_seq'); 

Another option would be to employ the reusable Function shared at the end of this answer.

A non-interactive solution

Just adding to the other two answers, for those of us who need to have these Sequences created by a non-interactive script, while patching a live-ish DB for instance.

That is, when you don't wanna SELECT the value manually and type it yourself into a subsequent CREATE statement.

In short, you can not do:

    START WITH ( SELECT max(a) + 1 FROM foo );

... since the START [WITH] clause in CREATE SEQUENCE expects a value, not a subquery.

Note: As a rule of thumb, that applies to all non-CRUD (i.e.: anything other than INSERT, SELECT, UPDATE, DELETE) statements in pgSQL AFAIK.

However, setval() does! Thus, the following is absolutely fine:

SELECT setval('foo_a_seq', max(a)) FROM foo;

If there's no data and you don't (want to) know about it, use coalesce() to set the default value:

SELECT setval('foo_a_seq', coalesce(max(a), 0)) FROM foo;
--                         ^      ^         ^
--                       defaults to:       0

However, having the current sequence value set to 0 is clumsy, if not illegal.
Using the three-parameter form of setval would be more appropriate:

--                                             vvv
SELECT setval('foo_a_seq', coalesce(max(a), 0) + 1, false) FROM foo;
--                                                  ^   ^
--                                                is_called

Setting the optional third parameter of setval to false will prevent the next nextval from advancing the sequence before returning a value, and thus:

the next nextval will return exactly the specified value, and sequence advancement commences with the following nextval.

— from this entry in the documentation

On an unrelated note, you also can specify the column owning the Sequence directly with CREATE, you don't have to alter it later:


In summary:

SELECT setval('foo_a_seq', coalesce(max(a), 0) + 1, false) FROM foo;
ALTER TABLE foo ALTER COLUMN a SET DEFAULT nextval('foo_a_seq'); 

Using a Function

Alternatively, if you're planning on doing this for multiple columns, you could opt for using an actual Function.

CREATE OR REPLACE FUNCTION make_into_serial(table_name TEXT, column_name TEXT) RETURNS INTEGER AS $$
    start_with INTEGER;
    sequence_name TEXT;
    sequence_name := table_name || '_' || column_name || '_seq';
    EXECUTE 'SELECT coalesce(max(' || column_name || '), 0) + 1 FROM ' || table_name
            INTO start_with;
    EXECUTE 'CREATE SEQUENCE ' || sequence_name ||
            ' START WITH ' || start_with ||
            ' OWNED BY ' || table_name || '.' || column_name;
    EXECUTE 'ALTER TABLE ' || table_name || ' ALTER COLUMN ' || column_name ||
            ' SET DEFAULT nextVal(''' || sequence_name || ''')';
    RETURN start_with;

Use it like so:

INSERT INTO foo (data) VALUES ('asdf');
-- ERROR: null value in column "a" violates not-null constraint

SELECT make_into_serial('foo', 'a');
INSERT INTO foo (data) VALUES ('asdf');
-- OK: 1 row(s) affected

How to replace NaNs by preceding values in pandas DataFrame?

In my case, we have time series from different devices but some devices could not send any value during some period. So we should create NA values for every device and time period and after that do fillna.

df = pd.DataFrame([["device1", 1, 'first val of device1'], ["device2", 2, 'first val of device2'], ["device3", 3, 'first val of device3']])
df.pivot(index=1, columns=0, values=2).fillna(method='ffill').unstack().reset_index(name='value')


        0   1   value
0   device1     1   first val of device1
1   device1     2   first val of device1
2   device1     3   first val of device1
3   device2     1   None
4   device2     2   first val of device2
5   device2     3   first val of device2
6   device3     1   None
7   device3     2   None
8   device3     3   first val of device3

Join a list of items with different types as string in Python

For example:

lst_points = [[313, 262, 470, 482], [551, 254, 697, 449]]

lst_s_points = [" ".join(map(str, lst)) for lst in lst_points]
print lst_s_points
# ['313 262 470 482', '551 254 697 449']

As to me, I want to add a str before each str list:

# here o means class, other four points means coordinate
print ['0 ' + " ".join(map(str, lst)) for lst in lst_points]
# ['0 313 262 470 482', '0 551 254 697 449']

Or single list:

lst = [313, 262, 470, 482]
lst_str = [str(i) for i in lst]
print lst_str, ", ".join(lst_str)
# ['313', '262', '470', '482'], 313, 262, 470, 482

lst_str = map(str, lst)
print lst_str, ", ".join(lst_str)
# ['313', '262', '470', '482'], 313, 262, 470, 482

How do I find out where login scripts live?

In addition from the command prompt run SET.

This displayed the "LOGONSERVER" value which indicates the specific domain controller you are using (there can be more than one).

Then you got to that server's NetBios Share \Servername\SYSVOL\domain.local\scripts.

In Perl, how can I read an entire file into a string?

With File::Slurp:

use File::Slurp;
my $text = read_file('index.html');

Yes, even you can use CPAN.

Efficient SQL test query or validation query that will work across all (or most) databases

I use


for hsqldb 1.8.0

Passing arguments to JavaScript function from code-behind

include script manager

code behind function

ScriptManager.RegisterStartupScript(this, this.GetType(), "HideConfirmBox", "javascript:HideAAConfirmBox(); ", true);

find first sequence item that matches a criterion

If you don't have any other indexes or sorted information for your objects, then you will have to iterate until such an object is found:

next(obj for obj in objs if obj.val == 5)

This is however faster than a complete list comprehension. Compare these two:

[i for i in xrange(100000) if i == 1000][0]

next(i for i in xrange(100000) if i == 1000)

The first one needs 5.75ms, the second one 58.3µs (100 times faster because the loop 100 times shorter).

How should strace be used?

strace lists all system calls done by the process it's applied to. If you don't know what system calls mean, you won't be able to get much mileage from it.

Nevertheless, if your problem involves files or paths or environment values, running strace on the problematic program and redirecting the output to a file and then grepping that file for your path/file/env string may help you see what your program is actually attempting to do, as distinct from what you expected it to.

Check if a string is a palindrome

The various provided answers are wrong for numerous reasons, primarily from misunderstanding what a palindrome is. The majority only properly identify a subset of palindromes.

From Merriam-Webster

A word, verse, or sentence (such as "Able was I ere I saw Elba")

And from Wordnik

A word, phrase, verse, or sentence that reads the same backward or forward. For example: A man, a plan, a canal, Panama!

Consider non-trivial palindromes such as "Malayalam" (it's a proper language, so naming rules apply, and it should be capitalized), or palindromic sentences such as "Was it a car or a cat I saw?" or "No 'X' in Nixon".

These are recognized palindromes in any literature.

I'm lifting the thorough solution from a library providing this kind of stuff that I'm the primary author of, so the solution works for both String and ReadOnlySpan<Char> because that's a requirement I've imposed on the library. The solution for purely String will be easy to determine from this, however.

public static Boolean IsPalindrome(this String @string) =>
    !(@string is null) && @string.AsSpan().IsPalindrome();

public static Boolean IsPalindrome(this ReadOnlySpan<Char> span) {
    // First we need to build the string without any punctuation or whitespace or any other
    // unrelated-to-reading characters.
    StringBuilder builder = new StringBuilder(span.Length);
    foreach (Char s in span) {
        if (!(s.IsControl()
            || s.IsPunctuation()
            || s.IsSeparator()
            || s.IsWhiteSpace()) {
            _ = builder.Append(s);
    String prepped = builder.ToString();
    String reversed = prepped.Reverse().Join();
    // Now actually check it's a palindrome
    return String.Equals(prepped, reversed, StringComparison.CurrentCultureIgnoreCase);

You're going to want variants of this that accept a CultureInfo parameter as well, when you're testing a specific language rather than your own language, by instead calling .ToUpper(cultureInfo) on prepped.

And here's proof from the projects unit tests that it works.

unit test results

Change color and appearance of drop down arrow

You can acheive this with CSS but you are not techinically changing the arrow itself.

In this example I am actually hiding the default arrow and displaying my own arrow instead.

.styleSelect select {_x000D_
  background: transparent;_x000D_
  width: 168px;_x000D_
  padding: 5px;_x000D_
  font-size: 16px;_x000D_
  line-height: 1;_x000D_
  border: 0;_x000D_
  border-radius: 0;_x000D_
  height: 34px;_x000D_
  -webkit-appearance: none;_x000D_
  -moz-appearance: none;_x000D_
  appearance: none;_x000D_
  color: #000;_x000D_
.styleSelect {_x000D_
  width: 140px;_x000D_
  height: 34px;_x000D_
  overflow: hidden;_x000D_
  background: url("images/downArrow.png") no-repeat right #fff;_x000D_
  border: 2px solid #000;_x000D_
<div class="styleSelect">_x000D_
  <select class="units">_x000D_
    <option value="Metres">Metres</option>_x000D_
    <option value="Feet">Feet</option>_x000D_
    <option value="Fathoms">Fathoms</option>_x000D_

Extract time from moment js object

This is the good way using formats:

const now = moment()
now.format("hh:mm:ss K") // 1:00:00 PM
now.format("HH:mm:ss") // 13:00:00

Red more about moment sring format

Capture the Screen into a Bitmap

If using the .NET 2.0 (or later) framework you can use the CopyFromScreen() method detailed here:

//Create a new bitmap.
var bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width,

// Create a graphics object from the bitmap.
var gfxScreenshot = Graphics.FromImage(bmpScreenshot);

// Take the screenshot from the upper left corner to the right bottom corner.

// Save the screenshot to the specified path that the user has chosen.
bmpScreenshot.Save("Screenshot.png", ImageFormat.Png);

Convert RGB to Black & White in OpenCV

I do something similar in one of my blog postings. A simple C++ example is shown.

The aim was to use the open source cvBlobsLib library for the detection of spot samples printed to microarray slides, but the images have to be converted from colour -> grayscale -> black + white as you mentioned, in order to achieve this.

How to create an HTTPS server in Node.js?

I found following example.

This works for node v0.1.94 - v0.3.1. server.setSecure() is removed in newer versions of node.

Directly from that source:

const crypto = require('crypto'),
  fs = require("fs"),
  http = require("http");

var privateKey = fs.readFileSync('privatekey.pem').toString();
var certificate = fs.readFileSync('certificate.pem').toString();

var credentials = crypto.createCredentials({key: privateKey, cert: certificate});

var handler = function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World\n');

var server = http.createServer();
server.addListener("request", handler);

The project type is not supported by this installation

Had the same issue with "The project type is not supported by this installation" for web projects in VS 2010 Premium.

devenv /ResetSkipPkgs

and GUIDs magic did not help.

Same projects were working fine on a neighbor box with VS 2010 Premium.

As it turned out the only difference was that my VS installation was missing the following installed products (can be found in VS About dialog):

  • Microsoft Office Developer Tools
  • Microsoft Visual Studio 2010 SharePoint Developer Tools

Add/Remove programs -> VS 2010 -> Customize -> Check the above products - and the problem was solved.

How to find out the username and password for mysql database

There are two easy ways:

  1. In your cpanel Go to cpanel/ softaculous/ wordpress, under the current installation, you will see the websites you have installed with the wordpress. Click the "edit detail" of the particular website and you will see your SQL database username and password.

  2. In your server Access your FTP and view the wp-config.php

C# : Converting Base Class to Child Class

You can copy value of Parent Class to a Child class. For instance, you could use reflection if that is the case.

How can query string parameters be forwarded through a proxy_pass with nginx?

From the proxy_pass documentation:

A special case is using variables in the proxy_pass statement: The requested URL is not used and you are fully responsible to construct the target URL yourself.

Since you're using $1 in the target, nginx relies on you to tell it exactly what to pass. You can fix this in two ways. First, stripping the beginning of the uri with a proxy_pass is trivial:

location /service/ {
  # Note the trailing slash on the proxy_pass.
  # It tells nginx to replace /service/ with / when passing the request.
  proxy_pass http://apache/;

Or if you want to use the regex location, just include the args:

location ~* ^/service/(.*) {
  proxy_pass http://apache/$1$is_args$args;

is there a css hack for safari only NOT chrome?

This hack 100% work only for safari 5.1-6.0. I've just tested it with success.

@media only screen and (-webkit-min-device-pixel-ratio: 1) {
     ::i-block-chrome, .yourcssrule {
        your css property

Is background-color:none valid CSS?

write this:

.class {

Checking if a folder exists using a .bat file

I think the answer is here (possibly duplicate):

How to test if a file is a directory in a batch script?

IF EXIST %VAR%\NUL ECHO It's a directory

Replace %VAR% with your directory. Please read the original answer because includes details about handling white spaces in the folder name.

As foxidrive said, this might not be reliable on NT class windows. It works for me, but I know it has some limitations (which you can find in the referenced question)

if exist "c:\folder\" echo folder exists 

should be enough for modern windows.

error: invalid type argument of ‘unary *’ (have ‘int’)

Barebones C program to produce the above error:

#include <iostream>
using namespace std;
int main(){
    char *p;
    *p = 'c';

    cout << *p[0];  
    //error: invalid type argument of `unary *'
    //peeking too deeply into p, that's a paddlin.

    cout << **p;    
    //error: invalid type argument of `unary *'
    //peeking too deeply into p, you better believe that's a paddlin.


The master puts a shiny round stone inside a small box and gives it to a student. The master says: "Open the box and remove the stone". The student does so.

Then the master says: "Now open the stone and remove the stone". The student said: "I can't open a stone".

The student was then enlightened.

Convert a list to a data frame

assume your list is called L,

data.frame(Reduce(rbind, L))

Retrieve last 100 lines logs

I know this is very old, but, for whoever it may helps.

less +F my_log_file.log

that's just basic, with less you can do lot more powerful things. once you start seeing logs you can do search, go to line number, search for pattern, much more plus it is faster for large files.

its like vim for logs[totally my opinion]

original less's documentation :

less cheatsheet :

Could not load file or assembly 'xxx' or one of its dependencies. An attempt was made to load a program with an incorrect format

It's definitely an issue with some of the projects being built for x86 compatibility instead of any CPU. If I had to guess I would say that some of the references between your projects are probably referencing the dll's in some of the bin\debug folders instead of being project references.

When a project is compiled for x86 instead of 'Any CPU' the dll's go into the bin\x86\debug folder instead of bin\debug (which is probably where your references are looking).

But in any case, you should be using project references between your projects.

Bootstrap 3 select input form inline

I think I've accidentally found a solution. The only thing to do is inserting an empty <span class="input-group-addon"></span> between the <input> and the <select>.

Additionally you can make it "invisible" by reducing its width, horizontal padding and borders:

<link href="" rel="stylesheet"/>_x000D_
<div class="input-group">_x000D_
    <span class="input-group-addon" title="* Price" id="priceLabel">Price</span>_x000D_
    <input type="number" id="searchbygenerals_priceFrom" name="searchbygenerals[priceFrom]" required="required" class="form-control" value="0">_x000D_
    <span class="input-group-addon">-</span>_x000D_
    <input type="number" id="searchbygenerals_priceTo" name="searchbygenerals[priceTo]" required="required" class="form-control" value="0">_x000D_
    <!-- insert this line -->_x000D_
    <span class="input-group-addon" style="width:0px; padding-left:0px; padding-right:0px; border:none;"></span>_x000D_
    <select id="searchbygenerals_currency" name="searchbygenerals[currency]" class="form-control">_x000D_
        <option value="1">HUF</option>_x000D_
        <option value="2">EUR</option>_x000D_

Tested on Chrome and FireFox.

Creation timestamp and last update timestamp with Hibernate and MySQL

As data type in JAVA I strongly recommend to use java.util.Date. I ran into pretty nasty timezone problems when using Calendar. See this Thread.

For setting the timestamps I would recommend using either an AOP approach or you could simply use Triggers on the table (actually this is the only thing that I ever find the use of triggers acceptable).

Display A Popup Only Once Per User

The best solution is to save a Boolean value in the database and then obtain that value and validate whether or not the modal was opened for that user, this value could be in the user table for example.

How to get difference between two rows for a column field?

Query to Find the date difference between 2 rows of a single column

Column name,
(SELECT MAX(date) FROM table name WHERE Column name < b. Column name),
Column name) AS days_since_last
FROM table name AS b

How to get the <td> in HTML tables to fit content, and let a specific <td> fill in the rest

Setting CSS width to 1% or 100% of an element according to all specs I could find out is related to the parent. Although Blink Rendering Engine (Chrome) and Gecko (Firefox) at the moment of writing seems to handle that 1% or 100% (make a columns shrink or a column to fill available space) well, it is not guaranteed according to all CSS specifications I could find to render it properly.

One option is to replace table with CSS4 flex divs:

That works in new browsers i.e. IE11+ see table at the bottom of the article.

Detect Safari browser

I observed that only one word distinguishes Safari - "Version". So this regex will work perfect:


How can I include a YAML file inside another?

Includes are not directly supported in YAML as far as I know, you will have to provide a mechanism yourself however, this is generally easy to do.

I have used YAML as a configuration language in my python apps, and in this case often define a convention like this:

>>> main.yml <<<
includes: [ wibble.yml, wobble.yml]

Then in my (python) code I do:

import yaml
cfg = yaml.load(open("main.yml"))
for inc in cfg.get("includes", []):

The only down side is that variables in the includes will always override the variables in main, and there is no way to change that precedence by changing where the "includes: statement appears in the main.yml file.

On a slightly different point, YAML doesn't support includes as its not really designed as as exclusively as a file based mark up. What would an include mean if you got it in a response to an AJAX request?

How do I delete multiple rows in Entity Framework (without foreach)

You can execute sql queries directly as follows :

    private int DeleteData()
    using (var ctx = new MyEntities(this.ConnectionString))
        if (ctx != null)

            //Delete command
            return ctx.ExecuteStoreCommand("DELETE FROM ALARM WHERE AlarmID > 100");

    return 0;

For select we may use

using (var context = new MyContext()) 
    var blogs = context.MyTable.SqlQuery("SELECT * FROM dbo.MyTable").ToList(); 

Converting Long to Date in Java returns 1970

The Date constructor (click the link!) accepts the time as long in milliseconds, not seconds. You need to multiply it by 1000 and make sure that you supply it as long.

Date d = new Date(1220227200L * 1000);

This shows here

Sun Aug 31 20:00:00 GMT-04:00 2008

Unzip files (7-zip) via cmd command

Regarding Phil Street's post:

It may actually be installed in your 32-bit program folder instead of your default x64, if you're running 64-bit OS. Check to see where 7-zip is installed, and if it is in Program Files (x86) then try using this instead:

PATH=%PATH%;C:\Program Files (x86)\7-Zip

npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]

This still appears to be an issue, causing package installations to be aborted with warnings about optional packages no being installed because of "Unsupported platform".

The problem relates to the "shrinkwrap" or package-lock.json which gets persisted after every package manager execution. Subsequent attempts keep failing as this file is referenced instead of package.json.

Adding these options to the npm install command should allow packages to install again.

   --no-optional argument will prevent optional dependencies from being installed.

   --no-shrinkwrap argument, which will ignore an available package lock or
                   shrinkwrap file and use the package.json instead.

   --no-package-lock argument will prevent npm from creating a package-lock.json file.

The complete command looks like this:

    npm install --no-optional --no-shrinkwrap --no-package-lock


Limit the size of a file upload (html input element)

<script type="text/javascript">
    $(document).ready(function () {

        var uploadField = document.getElementById("file");

        uploadField.onchange = function () {
            if (this.files[0].size > 300000) {
                this.value = "";
                    title: 'File is larger than 300 KB !!',
                    text: 'Please Select a file smaller than 300 KB',
                    type: 'error',
                    timer: 4000,
                    onOpen: () => {
                        timerInterval = setInterval(() => {
                                .textContent = swal.getTimerLeft()
                        }, 100)
                    onClose: () => {

                }).then((result) => {
                    if (
                        // Read more about handling dismissals
                        result.dismiss === swal.DismissReason.timer

                    ) {

                        console.log('I was closed by the timer')



Django - filtering on foreign key properties

This has been possible since the queryset-refactor branch landed pre-1.0. Ticket 4088 exposed the problem. This should work:


The Django Many-to-one documentation has this and other examples of following Foreign Keys using the Model API.

how to calculate binary search complexity

The time complexity of the binary search algorithm belongs to the O(log n) class. This is called big O notation. The way you should interpret this is that the asymptotic growth of the time the function takes to execute given an input set of size n will not exceed log n.

This is just formal mathematical lingo in order to be able to prove statements, etc. It has a very straightforward explanation. When n grows very large, the log n function will out-grow the time it takes to execute the function. The size of the "input set", n, is just the length of the list.

Simply put, the reason binary search is in O(log n) is that it halves the input set in each iteration. It's easier to think about it in the reverse situation. On x iterations, how long list can the binary search algorithm at max examine? The answer is 2^x. From this we can see that the reverse is that on average the binary search algorithm needs log2 n iterations for a list of length n.

If why it is O(log n) and not O(log2 n), it's because simply put again - Using the big O notation constants don't count.

Html table tr inside td

Put another table inside the td element like this.


An unhandled exception of type 'System.TypeInitializationException' occurred in EntityFramework.dll

In static class, if you are getting information from xml or reg, class tries to initialize all properties. therefore, you should control if the config variable is there otherwise properties will not initialize so the class.

Check xml referance variable is there, Check reg referance variable is is there, Make sure you handle if they are not there.

How to retrieve available RAM from Windows command line?

Here is a pure Java solution actually:

public static long getFreePhysicalMemory()
{ bean =
    return bean.getFreePhysicalMemorySize();

"Rate This App"-link in Google Play store app on the phone

Another approach that may work for you is Linkify. If I have a TextView that is asking the user to rate the app, I can linkify a couple of words in the text so they are highlighted and when the user touches them, the play store opens up, ready for their review:

class playTransformFilter implements TransformFilter {
   public String transformUrl(Matcher match, String url) {
        return "market://details?id=com.qwertyasd.yourapp";

class playMatchFilter implements MatchFilter {
    public boolean acceptMatch(CharSequence s, int start, int end) {
        return true;
text1 = (TextView) findViewById(;
text1.setText("Please rate it.");
final Pattern playMatcher = Pattern.compile("rate it");
Linkify.addLinks(text1, playMatcher, "", 
                   new playMatchFilter(), new playTransformFilter());

String literals and escape characters in postgresql

Really stupid question: Are you sure the string is being truncated, and not just broken at the linebreak you specify (and possibly not showing in your interface)? Ie, do you expect the field to show as

This will be inserted \n This will not be


This will be inserted

This will not be

Also, what interface are you using? Is it possible that something along the way is eating your backslashes?

How do I SET the GOPATH environment variable on Ubuntu? What file must I edit?


If you don’t set a GOPATH, the default will be used.

You have to add $GOPATH/bin to your PATH to execute any binary installed in $GOPATH/bin, or you need to type $GOPATH/bin/the-command. Add this to your ~/.bash_profile

export PATH=$GOPATH/bin:$PATH

Current GOPATH command:

go env GOPATH

Changing the GOPATH command:

export GOPATH=$HOME/your-desired-path

Can you use Microsoft Entity Framework with Oracle?

DevArt's OraDirect provider now supports entity framework. See

How do I pull my project from github?

First, you'll need to tell git about yourself. Get your username and token together from your settings page.

Then run:

git config --global github.user YOUR_USERNAME
git config --global github.token YOURTOKEN

You will need to generate a new key if you don't have a back-up of your key.

Then you should be able to run:

git clone [email protected]:YOUR_USERNAME/YOUR_PROJECT.git

Difference of keywords 'typename' and 'class' in templates?

There is no difference between using OR ; i.e. it is a convention used by C++ programmers. I myself prefer as it more clearly describes it use; i.e. defining a template with a specific type :)

Note: There is one exception where you do have to use class (and not typename) when declaring a template template parameter:

template <template class T> class C { }; // valid!

template <template typename T> class C { }; // invalid!

In most cases, you will not be defining a nested template definition, so either definition will work -- just be consistent in your use...

how to loop through json array in jquery?

var data=[{'com':'something'},{'com':'some other thing'}];
$.each(data, function() {
  $.each(this, function(key, val){
    alert(val);//here data 
      alert (key); //here key


Defining static const integer members in class definition

Another way to do this, for integer types anyway, is to define constants as enums in the class:

class test
    enum { N = 10 };

How can I fetch all items from a DynamoDB table without specifying the primary key?

Amazon DynamoDB provides the Scan operation for this purpose, which returns one or more items and its attributes by performing a full scan of a table. Please be aware of the following two constraints:

  • Depending on your table size, you may need to use pagination to retrieve the entire result set:

    If the total number of scanned items exceeds the 1MB limit, the scan stops and results are returned to the user with a LastEvaluatedKey to continue the scan in a subsequent operation. The results also include the number of items exceeding the limit. A scan can result in no table data meeting the filter criteria.

    The result set is eventually consistent.

  • The Scan operation is potentially costly regarding both performance and consumed capacity units (i.e. price), see section Scan and Query Performance in Query and Scan in Amazon DynamoDB:

    [...] Also, as a table grows, the scan operation slows. The scan operation examines every item for the requested values, and can use up the provisioned throughput for a large table in a single operation. For quicker response times, design your tables in a way that can use the Query, Get, or BatchGetItem APIs, instead. Or, design your application to use scan operations in a way that minimizes the impact on your table's request rate. For more information, see Provisioned Throughput Guidelines in Amazon DynamoDB. [emphasis mine]

You can find more details about this operation and some example snippets in Scanning Tables Using the AWS SDK for PHP Low-Level API for Amazon DynamoDB, with the most simple example illustrating the operation being:

$dynamodb = new AmazonDynamoDB();

$scan_response = $dynamodb->scan(array(
    'TableName' => 'ProductCatalog' 

foreach ($scan_response->body->Items as $item)
    echo "<p><strong>Item Number:</strong>"
         . (string) $item->Id->{AmazonDynamoDB::TYPE_NUMBER};
    echo "<br><strong>Item Name: </strong>"
         . (string) $item->Title->{AmazonDynamoDB::TYPE_STRING} ."</p>";

When should I use uuid.uuid1() vs. uuid.uuid4() in python?

Perhaps something that's not been mentioned is that of locality.

A MAC address or time-based ordering (UUID1) can afford increased database performance, since it's less work to sort numbers closer-together than those distributed randomly (UUID4) (see here).

A second related issue, is that using UUID1 can be useful in debugging, even if origin data is lost or not explicitly stored (this is obviously in conflict with the privacy issue mentioned by the OP).

Why is my power operator (^) not working?

Well, first off, the ^ operator in C/C++ is the bit-wise XOR. It has nothing to do with powers.

Now, regarding your problem with using the pow() function, some googling shows that casting one of the arguments to double helps:

result = (int) pow((double) a,i);

Note that I also cast the result to int as all pow() overloads return double, not int. I don't have a MS compiler available so I couldn't check the code above, though.

Since C99, there are also float and long double functions called powf and powl respectively, if that is of any help.

Dataframe to Excel sheet

I tested the previous answers found here: Assuming that we want the other four sheets to remain, the previous answers here did not work, because the other four sheets were deleted. In case we want them to remain use xlwings:

import xlwings as xw
import pandas as pd

filename = "test.xlsx"

df = pd.DataFrame([
    ("a", 1, 8, 3),
    ("b", 1, 2, 5),
    ("c", 3, 4, 6),
    ], columns=['one', 'two', 'three', "four"])

app = xw.App(visible=False)
wb = xw.Book(filename)
ws = wb.sheets["Sheet5"]

ws["A1"].options(pd.DataFrame, header=1, index=False, expand='table').value = df

# If formatting of column names and index is needed as xlsxwriter does it, 
# the following lines will do it (if the dataframe is not multiindex).
ws["A1"].expand("right").api.Font.Bold = True
ws["A1"].expand("down").api.Font.Bold = True
ws["A1"].expand("right").api.Borders.Weight = 2
ws["A1"].expand("down").api.Borders.Weight = 2

How to get back Lost phpMyAdmin Password, XAMPP

You want to edit this file: "\xampp\phpMyAdmin\"

change this line:

$cfg['Servers'][$i]['password'] = 'WhateverPassword';

to whatever your password is. If you don't remember your password, then run this command in the Shell:

mysqladmin.exe -u root password WhateverPassword

where 'WhateverPassword' is your new password.

Arithmetic overflow error converting numeric to data type numeric

check your value which you want to store in integer column. I think this is greater then range of integer. if you want to store value greater then integer range. you should use bigint datatype

How to launch multiple Internet Explorer windows/tabs from batch file?

Try this so you allow enough time for the first process to start.. else it will spawn 2 processes because the first one is not still running when you run the second one... This can happen if your computer is too fast..

@echo off
start /d iexplore.exe
PING -n 1 -w 2000 >NUL
START /d iexplore.exe blablabla

replace blablabla with another address

Detect element content changes with jQuery

Often a simple and effective way to achieve this is to keep track of when and where you are modifying the DOM.

You can do this by creating one central function that is always responsible for modifying the DOM. You then do whatever cleanup you need on the modified element from within this function.

In a recent application, I didn't need immediate action so I used a callback for the handly load() function, to add a class to any modified elements and then updated all modified elements every few seconds with a setInterval timer.

$($location).load("my URL", "", $location.addClass("dommodified"));

Then you can handle it however you want - e.g.

setInterval("handlemodifiedstuff();", 3000); 
function handlemodifiedstuff()
    $(".dommodified").each(function(){/* Do stuff with $(this) */});

php $_GET and undefined index

The real answer to this is to put a @ At symbol before the variable which will suppress the error


It will work some slower, but will keep the code clean.

When something saves time for the programmer, and costs time for the website users (or requires more hardware), it depends on how much people will use it.

Waiting for HOME ('android.process.acore') to be launched

Following steps worked for me: 1. Goto Project -> Clean. 2. Delete your previous AVD and create a new one.

How to check if a variable is a dictionary in Python?

You could use if type(ele) is dict or use isinstance(ele, dict) which would work if you had subclassed dict:

d = {'abc': 'abc', 'def': {'ghi': 'ghi', 'jkl': 'jkl'}}
for element in d.values():
    if isinstance(element, dict):
       for k, v in element.items():
           print(k,' ',v)

Is it possible to have a HTML SELECT/OPTION value as NULL using PHP?

All you need is a check on the post side of things.

if(empty($_REQUEST['type_id']) && $_REQUEST['type_id'] != 0)
    $_REQUEST['type_id'] = null;

how to call service method from ng-change of select in angularjs?

You have at least two issues in your code:

  • ng-change="getScoreData(Score)

    Angular doesn't see getScoreData method that refers to defined service

  • getScoreData: function (Score, callback)

    We don't need to use callback since GET returns promise. Use then instead.

Here is a working example (I used random address only for simulation):


<select ng-model="score"
        ng-options="score as for score in  scores"></select>


var fessmodule = angular.module('myModule', ['ngResource']);

fessmodule.controller('fessCntrl', function($scope, ScoreDataService) {

    $scope.scores = [{
        name: 'Bukit Batok Street 1',
        URL: ', SG, Singapore, 153 Bukit Batok Street 1&sensor=true'
    }, {
        name: 'London 8',
        URL: ', SG, Singapore, London 8&sensor=true'

    $scope.getScoreData = function(score) {
        ScoreDataService.getScoreData(score).then(function(result) {
            $scope.ScoreData = result;
        }, function(result) {
            alert("Error: No data returned");


fessmodule.$inject = ['$scope', 'ScoreDataService'];

fessmodule.factory('ScoreDataService', ['$http', '$q', function($http) {

    var factory = {
        getScoreData: function(score) {
            var data = $http({
                method: 'GET',
                url: score.URL

            return data;
    return factory;

Demo Fiddle

Sending a mail from a linux shell script

Generally, you'd want to use mail command to send your message using local MTA (that will either deliver it using SMTP to the destination or just forward it into some more powerful SMTP server, for example, at your ISP). If you don't have a local MTA (although it's a bit unusual for a UNIX-like system to omit one), you can either use some minimalistic MTA like ssmtp.

ssmtp is quite easy to configure. Basically, you'll just need to specify where your provider's SMTP server is:

# The place where the mail goes. The actual machine name is required
# no MX records are consulted. Commonly mailhosts are named
# The example will fit if you are in and you mailhub is so named.

Another option is to use one of myriads scripts that just connect to SMTP server directly and try to post a message there, such as Smtp-Auth-Email-Script, smtp-cli, SendEmail, etc.

How to get all possible combinations of a list’s elements?

Combination from itertools

import itertools
col_names = ["aa","bb", "cc", "dd"]
all_combinations = itertools.chain(*[itertools.combinations(col_names,i+1) for i,_ in enumerate(col_names)])

How to remove frame from matplotlib (pyplot.figure vs matplotlib.figure ) (frameon=False Problematic in matplotlib)

ax.axis('off'), will as Joe Kington pointed out, remove everything except the plotted line.

For those wanting to only remove the frame (border), and keep labels, tickers etc, one can do that by accessing the spines object on the axis. Given an axis object ax, the following should remove borders on all four sides:


And, in case of removing x and y ticks from the plot:


"No such file or directory" but it exists

I got this error “No such file or directory” but it exists because my file was created in Windows and I tried to run it on Ubuntu and the file contained invalid 15\r where ever a new line was there. I just created a new file truncating unwanted stuff

sleep: invalid time interval ‘15\r’
Try 'sleep --help' for more information. 5: /opt/ag/cont: not found 6: /opt/ag/cont: not found
root@Ubuntu14:/home/abc12/Desktop# vi 
root@Ubuntu14:/home/abc12/Desktop# od -c 
0000000   #   !   /   u   s   r   /   b   i   n   /   e   n   v       b
0000020   a   s   h  \r  \n   w   g   e   t       h   t   t   p   :   /

0000400   :   4   1   2   0   /  \r  \n
root@Ubuntu14:/home/abc12/Desktop# tr -d \\015 < >
root@Ubuntu14:/home/abc12/Desktop# od -c 
0000000   #   !   /   u   s   r   /   b   i   n   /   e   n   v       b
0000020   a   s   h  \n   w   g   e   t       h   t   t   p   :   /   /

0000400   /  \n
root@Ubuntu14:/home/abc12/Desktop# sh -x 

Node.js ES6 classes with require

The ES6 way of require is import. You can export your class and import it somewhere else using import { ClassName } from 'path/to/ClassName'syntax.

import fs from 'fs';
export default class Animal {

  constructor(name){ = name ;

    console.log('Name is :'+;

import Animal from 'path/to/Animal.js';

Using sed, Insert a line above or below the pattern?

The following adds one line after SearchPattern.

sed -i '/SearchPattern/aNew Text' SomeFile.txt

It inserts New Text one line below each line that contains SearchPattern.

To add two lines, you can use a \ and enter a newline while typing New Text.

POSIX sed requires a \ and a newline after the a sed function. [1] Specifying the text to append without the newline is a GNU sed extension (as documented in the sed info page), so its usage is not as portable.


CSS performance relative to translateZ(0)

On mobile devices sending everything to the GPU will cause a memory overload and crash the application. I encountered this on an iPad app in Cordova. Best to only send the required items to the GPU, the divs that you're specifically moving around.

Better yet, use the 3d transitions transforms to do the animations like translateX(50px) as opposed to left:50px;

How to get the caller's method name in the called method?

I found a way if you're going across classes and want the class the method belongs to AND the method. It takes a bit of extraction work but it makes its point. This works in Python 2.7.13.

import inspect, os

class ClassOne:
    def method1(self):

class ClassTwo:
    def method2(self):
        curframe = inspect.currentframe()
        calframe = inspect.getouterframes(curframe, 4)
        print '\nI was called from', calframe[1][3], \
        'in', calframe[1][4][0][6: -2]

# create objects to access class methods
classoneObj = ClassOne()
classtwoObj = ClassTwo()

# start the program

Using ffmpeg to change framerate

With re-encoding:

ffmpeg -y -i seeing_noaudio.mp4 -vf "setpts=1.25*PTS" -r 24 seeing.mp4

Without re-encoding:

First step - extract video to raw bitstream

ffmpeg -y -i seeing_noaudio.mp4 -c copy -f h264 seeing_noaudio.h264

Remux with new framerate

ffmpeg -y -r 24 -i seeing_noaudio.h264 -c copy seeing.mp4

Authentication failed to bitbucket

After fighting with this for a long time, it looks like I found something that seems to work. I was optimizing the urls to not include the username (keep it as generic as possible), but the authentication dialog kept popping up:

enter image description here

I tried everything that came into mind, such as:

  1. Enable and disable MFA (Multi Factor Authentication)
  2. Create app passwords (again, with and without MFA enabled)

No matter what tools I used (including SourceTree), nothing worked. The server kept returning: "Create an app password"

Basically you must

  1. Use the url including the username (e.g. https://[email protected]/...)
  2. Use an app password created in bitbucket

Would be so nice if the server would have returned this in the response instead of suggesting to use an app password...

How to checkout a specific Subversion revision from the command line?

You could try

TortoiseProc.exe /command:checkout /rev:1234

to get revision 1234.

I'm not 100% sure the /rev option is compatible with checkout, but I got the idea from some TortoiseProc documentation.

Which programming language for cloud computing?

Your question is a bit vague about what you are actually thinking about doing. "Cloud computing" can mean almost anything. If you're looking for languages with specific cloud computing advantages, Java has several because it's a compiled language that compiles to operating-system independent byte code.

I also chime in with the others about C++ being a low-level language. Yes, it is. But you're always going to have more than just the C++ language. If you separate both Java and C++ from the classes that come with them, Java and C++ are extremely similar. You have to adopt some rigid criterion like "pointers = low-level, garbage collection = high-level" to make the distinction stick. (And, of course, you can make pointers smart and invisible in C++ and you can use garbage collection in C++ too if you want to.)

How to redirect page after click on Ok button on sweet alert?

I think this will help. It's same as given by Mr. Barmer. But I have enclosed this within php tags.

Here it goes....

    <?php if(!empty($_GET['submitted'])):?>
        setTimeout(function() {
                title: "Congratulaions!",
                text: "Signed up successfully, now verify your mail",
                type: "success",
                confirmButtonText: "Ok"
            }, function() {
                window.location = "index.php";
            }, 1000);
    <?php endif;?>

.htaccess File Options -Indexes on Subdirectories

htaccess files affect the directory they are placed in and all sub-directories, that is an htaccess file located in your root directory ( would affect,, etc.

How do you receive a url parameter with a spring controller mapping

You should be using @RequestParam instead of @ModelAttribute, e.g.

public @ResponseBody int getAttr(@PathVariable(value="someID") String id, 
                                 @RequestParam String someAttr) {

You can even omit @RequestParam altogether if you choose, and Spring will assume that's what it is:

public @ResponseBody int getAttr(@PathVariable(value="someID") String id, 
                                 String someAttr) {

Correct modification of state arrays in React.js

The simplest way with ES6:

this.setState(prevState => ({
    array: [...prevState.array, newElement]

Running the new Intel emulator for Android

You might need to turn on virtualization in your BIOS, most manufacturers disable it by default. Intel HAX requires CPU virtualization to be enabled.

Set a default parameter value for a JavaScript function

From ES6/ES2015, default parameters are in the language specification.

function read_file(file, delete_after = false) {
  // Code

just works.

Reference: Default Parameters - MDN

Default function parameters allow formal parameters to be initialized with default values if no value or undefined is passed.

You can also simulate default named parameters via destructuring:

// the `= {}` below lets you call the function without any parameters
function myFor({ start = 5, end = 1, step = -1 } = {}) { // (A)
    // Use the variables `start`, `end` and `step` here

Pre ES2015,

There are a lot of ways, but this is my preferred method — it lets you pass in anything you want, including false or null. (typeof null == "object")

function foo(a, b) {
  a = typeof a !== 'undefined' ? a : 42;
  b = typeof b !== 'undefined' ? b : 'default_b';

Perform curl request in javascript?

Yes, use getJSONP. It's the only way to make cross domain/server async calls. (*Or it will be in the near future). Something like

$.getJSON('your-api-url/validate.php?'+$(this).serialize+'callback=?', function(data){

The callback parameter will be filled in automatically by the browser, so don't worry.

On the server side ('validate.php') you would have something like this

//if condition is met
echo $_GET['callback'] . '(' . "{'message' : 'success', 'userID':'69', 'serial' : 'XYZ99UAUGDVD&orwhatever'}". ')';
else echo json_encode(array('error'=>'failed'));

Cannot create PoolableConnectionFactory



It worked for me after adding colon before port number instead of a comma

How can I let a user download multiple files when a button is clicked?

    <!DOCTYPE html>
    <html ng-app='app'>
            <link rel="stylesheet" href="">
            <link rel="stylesheet" href="style.css">
        <body ng-cloack>        
            <div class="container" ng-controller='FirstCtrl'>           
              <table class="table table-bordered table-downloads">
                    <th>File name</th>
                  <tr ng-repeat = 'tableData in tableDatas'>
                        <div class="checkbox">
                          <input type="checkbox" name="{{}}" id="{{}}" value="{{}}" ng-model= 'tableData.checked' ng-change="selected()">
                        <a target="_self" id="download-{{}}" ng-href="{{tableData.filePath}}" class="btn btn-success pull-right downloadable" download>download</a>
                <a class="btn btn-success pull-right" ng-click='downloadAll()'>download selected</a>

            <script src=""></script>
            <script src=""></script>
            <script src="script.js"></script>


var app = angular.module('app', []);            
app.controller('FirstCtrl', ['$scope','$http', '$filter', function($scope, $http, $filter){

$scope.tableDatas = [
    {name: 'value1', fileName:'file1', filePath: 'data/file1.txt', selected: true},
    {name: 'value2', fileName:'file2', filePath: 'data/file2.txt', selected: true},
    {name: 'value3', fileName:'file3', filePath: 'data/file3.txt', selected: false},
    {name: 'value4', fileName:'file4', filePath: 'data/file4.txt', selected: true},
    {name: 'value5', fileName:'file5', filePath: 'data/file5.txt', selected: true},
    {name: 'value6', fileName:'file6', filePath: 'data/file6.txt', selected: false},
$scope.application = [];   

$scope.selected = function() {
    $scope.application = $filter('filter')($scope.tableDatas, {
      checked: true

$scope.downloadAll = function(){
    $scope.selectedone = [];     
       $ =;        


plunker example:

Get just the filename from a path in a Bash script

Most UNIX-like operating systems have a basename executable for a very similar purpose (and dirname for the path):

pax> a=/tmp/file.txt
pax> b=$(basename $a)
pax> echo $b

That unfortunately just gives you the file name, including the extension, so you'd need to find a way to strip that off as well.

So, given you have to do that anyway, you may as well find a method that can strip off the path and the extension.

One way to do that (and this is a bash-only solution, needing no other executables):

pax> a=/tmp/xx/file.tar.gz
pax> xpath=${a%/*} 
pax> xbase=${a##*/}
pax> xfext=${xbase##*.}
pax> xpref=${xbase%.*}
pax> echo;echo path=${xpath};echo pref=${xpref};echo ext=${xfext}


That little snippet sets xpath (the file path), xpref (the file prefix, what you were specifically asking for) and xfext (the file extension).

How to enable Google Play App Signing

I had to do following:

  1. Create an app in google play console enter image description here

2.Go to App releases -> Manage production -> Create release

3.Click continue on Google Play App Signing enter image description here

4.Create upload certificate by running "keytool -genkey -v -keystore c:\path\to\cert.keystore -alias uploadKey -keyalg RSA -keysize 2048 -validity 10000"

5.Sign your apk with generated certificate (c:\path\to\cert.keystore)

6.Upload signed apk in App releases -> Manage production -> Edit release

7.By uploading apk, certificate generated in step 4 has been added to App Signing certificates and became your signing cert for all future builds.

Django: OperationalError No Such Table

The issue may be solved by running migrations.

  1. python makemigrations
  2. python migrate

perform the operations above whenever you make changes in

Addition for BigDecimal

BigInteger is immutable, you need to do this,

  BigInteger sum = test.add(new BigInteger(30));  

Change Name of Import in Java, or import two classes with the same name

There is no import aliasing mechanism in Java. You cannot import two classes with the same name and use both of them unqualified.

Import one class and use the fully qualified name for the other one, i.e.

import com.text.Formatter;

private Formatter textFormatter;
private com.json.Formatter jsonFormatter;

C Programming: How to read the whole file contents into a buffer

Here is what I would recommend.

It should conform to C89, and be completely portable. In particular, it works also on pipes and sockets on POSIXy systems.

The idea is that we read the input in large-ish chunks (READALL_CHUNK), dynamically reallocating the buffer as we need it. We only use realloc(), fread(), ferror(), and free():

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

/* Size of each input chunk to be
   read and allocate for. */
#define  READALL_CHUNK  262144

#define  READALL_OK          0  /* Success */
#define  READALL_INVALID    -1  /* Invalid parameters */
#define  READALL_ERROR      -2  /* Stream error */
#define  READALL_TOOMUCH    -3  /* Too much input */
#define  READALL_NOMEM      -4  /* Out of memory */

/* This function returns one of the READALL_ constants above.
   If the return value is zero == READALL_OK, then:
     (*dataptr) points to a dynamically allocated buffer, with
     (*sizeptr) chars read from the file.
     The buffer is allocated for one extra char, which is NUL,
     and automatically appended after the data.
   Initial values of (*dataptr) and (*sizeptr) are ignored.
int readall(FILE *in, char **dataptr, size_t *sizeptr)
    char  *data = NULL, *temp;
    size_t size = 0;
    size_t used = 0;
    size_t n;

    /* None of the parameters can be NULL. */
    if (in == NULL || dataptr == NULL || sizeptr == NULL)
        return READALL_INVALID;

    /* A read error already occurred? */
    if (ferror(in))
        return READALL_ERROR;

    while (1) {

        if (used + READALL_CHUNK + 1 > size) {
            size = used + READALL_CHUNK + 1;

            /* Overflow check. Some ANSI C compilers
               may optimize this away, though. */
            if (size <= used) {
                return READALL_TOOMUCH;

            temp = realloc(data, size);
            if (temp == NULL) {
                return READALL_NOMEM;
            data = temp;

        n = fread(data + used, 1, READALL_CHUNK, in);
        if (n == 0)

        used += n;

    if (ferror(in)) {
        return READALL_ERROR;

    temp = realloc(data, used + 1);
    if (temp == NULL) {
        return READALL_NOMEM;
    data = temp;
    data[used] = '\0';

    *dataptr = data;
    *sizeptr = used;

    return READALL_OK;

Above, I've used a constant chunk size, READALL_CHUNK == 262144 (256*1024). This means that in the worst case, up to 262145 chars are wasted (allocated but not used), but only temporarily. At the end, the function reallocates the buffer to the optimal size. Also, this means that we do four reallocations per megabyte of data read.

The 262144-byte default in the code above is a conservative value; it works well for even old minilaptops and Raspberry Pis and most embedded devices with at least a few megabytes of RAM available for the process. Yet, it is not so small that it slows down the operation (due to many read calls, and many buffer reallocations) on most systems.

For desktop machines at this time (2017), I recommend a much larger READALL_CHUNK, perhaps #define READALL_CHUNK 2097152 (2 MiB).

Because the definition of READALL_CHUNK is guarded (i.e., it is defined only if it is at that point in the code still undefined), you can override the default value at compile time, by using (in most C compilers) -DREADALL_CHUNK=2097152 command-line option -- but do check your compiler options for defining a preprocessor macro using command-line options.

Test if string is URL encoded in PHP

You'll never know for sure if a string is URL-encoded or if it was supposed to have the sequence %2B in it. Instead, it probably depends on where the string came from, i.e. if it was hand-crafted or from some application.

Is it better to search the string for characters which would be encoded, which aren't, and if any exist then its not encoded.

I think this is a better approach, since it would take care of things that have been done programmatically (assuming the application would not have left a non-encoded character behind).

One thing that will be confusing here... Technically, the % "should be" encoded if it will be present in the final value, since it is a special character. You might have to combine your approaches to look for should-be-encoded characters as well as validating that the string decodes successfully if none are found.

How can I determine the current CPU utilization from the shell?

You need to sample the load average for several seconds and calculate the CPU utilization from that. If unsure what to you, get the sources of "top" and read it.

How do I test a private function or a class that has private methods, fields or inner classes?

In C# you could have used System.Reflection, though in Java I don't know. Though I feel the urge to answer this anyway since if you "feel you need to unit test private methods" my guess is that there is something else which is wrong...

I would seriously consider looking at my architecture again with fresh eyes...

How do I select and store columns greater than a number in pandas?

Sample DF:

In [79]: df = pd.DataFrame(np.random.randint(5, 15, (10, 3)), columns=list('abc'))

In [80]: df
    a   b   c
0   6  11  11
1  14   7   8
2  13   5  11
3  13   7  11
4  13   5   9
5   5  11   9
6   9   8   6
7   5  11  10
8   8  10  14
9   7  14  13

present only those rows where b > 10

In [81]: df[df.b > 10]
   a   b   c
0  6  11  11
5  5  11   9
7  5  11  10
9  7  14  13

Minimums (for all columns) for the rows satisfying b > 10 condition

In [82]: df[df.b > 10].min()
a     5
b    11
c     9
dtype: int32

Minimum (for the b column) for the rows satisfying b > 10 condition

In [84]: df.loc[df.b > 10, 'b'].min()
Out[84]: 11

UPDATE: starting from Pandas 0.20.1 the .ix indexer is deprecated, in favor of the more strict .iloc and .loc indexers.

error C2065: 'cout' : undeclared identifier

write this code, it works perfectly..

#include "stdafx.h"
#include <iostream>

using namespace std;

int main()
 cout<<"Hello World!";
  return 0;

Spring,Request method 'POST' not supported

I had csrf enabled in my sprint security xml file, so I just added one line in the form:

<input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}" /> 

This way I was able to submit the form having the model attribute.

How to check if a column exists before adding it to an existing table in PL/SQL?

All the metadata about the columns in Oracle Database is accessible using one of the following views.

user_tab_cols; -- For all tables owned by the user

all_tab_cols ; -- For all tables accessible to the user

dba_tab_cols; -- For all tables in the Database.

So, if you are looking for a column like ADD_TMS in SCOTT.EMP Table and add the column only if it does not exist, the PL/SQL Code would be along these lines..

  v_column_exists number := 0;  
  Select count(*) into v_column_exists
    from user_tab_cols
    where upper(column_name) = 'ADD_TMS'
      and upper(table_name) = 'EMP';
      --and owner = 'SCOTT --*might be required if you are using all/dba views

  if (v_column_exists = 0) then
      execute immediate 'alter table emp add (ADD_TMS date)';
  end if;

If you are planning to run this as a script (not part of a procedure), the easiest way would be to include the alter command in the script and see the errors at the end of the script, assuming you have no Begin-End for the script..

If you have file1.sql

alter table t1 add col1 date;
alter table t1 add col2 date;
alter table t1 add col3 date;

And col2 is present,when the script is run, the other two columns would be added to the table and the log would show the error saying "col2" already exists, so you should be ok.

How to align content of a div to the bottom

The site I just did for a client requested that the footer text was a high box, with the text at the bottom I achieved this with simple padding, should work for all browsers.

<div id="footer">
  some text here
#footer {
  padding: 0 30px;
  padding-top: 60px;
  padding-bottom: 8px;

Are there any Open Source alternatives to Crystal Reports?

Report Manager has been around for quite a few years. It's written in Delphi (at least it was originally) and has components that can be used in Delphi, but is usable via ActiveX or dll from just about any language. Now has a native .NET library too. Has a nifty report-serving webserver you can set up too. The designer gui looks and feels a little rough around the edges but it works.

Twitter Bootstrap add active class to li

Here is complete Twitter bootstrap example and applied active class based on query string.

Few steps to follow to achieve correct solution:

1) Include latest jquery.js and bootstrap.js javascript file.

2) Include latest bootstrap.css file

3) Include querystring-0.9.0.js for getting query string variable value in js.

4) HTML:

<div class="navbar">
  <div class="navbar-inner">
    <div class="container">
      <ul class="nav">
        <li class="active">
          <a href="#?page=0">
          <a href="#?page=1">
          <a href="#?page=2">
          <a href="#?page=3">
          <a href="#?page=4">
          <a href="#?page=5">

JQuery in Script Tag:

$(function() {
    $(".nav li").click(function() {
        $(".nav li").removeClass('active');
        setTimeout(function() {
            var page = $.QueryString("page");
            $(".nav li:eq(" + page + ")").addClass("active");
        }, 300);


I have done complete bin, so please click here

Node.js Web Application examples/tutorials

The Node Knockout competition wrapped up recently, and many of the submissions are available on github. The competition site doesn't appear to be working right now, but I'm sure you could Google up a few entries to check out.

How to discard local commits in Git?

What I do is I try to reset hard to HEAD. This will wipe out all the local commits:

git reset --hard HEAD^

ERROR Source option 1.5 is no longer supported. Use 1.6 or later

You need to set JDK 1.5 to your project and also all dependent project or jar file should also compiled with JDK 1.5

SyntaxError: missing ; before statement

too many ) parenthesis remove one of them.

Uint8Array to string in Javascript

Here's what I use:

var str = String.fromCharCode.apply(null, uint8Arr);

Add button to a layout programmatically

This line:

layout = (LinearLayout) findViewById(;

Looks for the "statsviewlayout" id in your current 'contentview'. Now you've set that here:

setContentView(new GraphTemperature(getApplicationContext()));

And i'm guessing that new "graphTemperature" does not set anything with that id.

It's a common mistake to think you can just find any view with findViewById. You can only find a view that is in the XML (or appointed by code and given an id).

The nullpointer will be thrown because the layout you're looking for isn't found, so


Throws that exception.

addition: Now if you want to get that view from an XML, you should use an inflater:

layout = (LinearLayout) View.inflate(this, R.layout.yourXMLYouWantToLoad, null);

assuming that you have your linearlayout in a file called "yourXMLYouWantToLoad.xml"

Python check if website exists

from urllib2 import Request, urlopen, HTTPError, URLError

user_agent = 'Mozilla/20.0.1 (compatible; MSIE 5.5; Windows NT)'
headers = { 'User-Agent':user_agent }
link = ""
req = Request(link, headers = headers)
        page_open = urlopen(req)
except HTTPError, e:
        print e.code
except URLError, e:
        print e.reason
        print 'ok'

To answer the comment of unutbu:

Because the default handlers handle redirects (codes in the 300 range), and codes in the 100-299 range indicate success, you will usually only see error codes in the 400-599 range. Source

jQuery slide left and show

Don't forget the padding and margins...

jQuery.fn.slideLeftHide = function(speed, callback) { 
    width: "hide", 
    paddingLeft: "hide", 
    paddingRight: "hide", 
    marginLeft: "hide", 
    marginRight: "hide" 
  }, speed, callback);

jQuery.fn.slideLeftShow = function(speed, callback) { 
    width: "show", 
    paddingLeft: "show", 
    paddingRight: "show", 
    marginLeft: "show", 
    marginRight: "show" 
  }, speed, callback);

With the speed/callback arguments added, it's a complete drop-in replacement for slideUp() and slideDown().

How can I pass an Integer class correctly by reference?

I think it is the autoboxing that is throwing you off.

This part of your code:

   public static Integer inc(Integer i) {
        i = i+1;    // I think that this must be **sneakally** creating a new integer...  
        System.out.println("Inc: "+i);
        return i;

Really boils down to code that looks like:

  public static Integer inc(Integer i) {
        i = new Integer(i) + new Integer(1);      
        System.out.println("Inc: "+i);
        return i;

Which of course.. will not changes the reference passed in.

You could fix it with something like this

  public static void main(String[] args) {
        Integer integer = new Integer(0);
        for (int i =0; i<10; i++){
            integer = inc(integer);
            System.out.println("main: "+integer);

INSTALL_FAILED_USER_RESTRICTED : android studio using redmi 4 device

It's common problem and solution is pretty simple. Just follow the below steps:

Open Mobile Settings

Scroll Down & Go to Additional Settings

Open Developer options

(Note: if Developer Option is not visible, click 7 times on Build Number)


Turn off "MIUI optimization" & Restart it.

Make sure USB Debugging is ON & Install via USB is enabled.

Set USB Configuration to Charging (Optional)

Looping from 1 to infinity in Python

If you're doing that in C, then your judgement there is as cloudy as it would be in Python :-)

For a loop that exits on a simple condition check at the start of each iteration, it's more usual (and clearer, in my opinion) to just do that in the looping construct itself. In other words, something like (if you need i after loop end):

int i = 0;
while (! thereIsAReasonToBreak(i)) {
    // do something

or (if i can be scoped to just the loop):

for (int i = 0; ! thereIsAReasonToBreak(i); ++i) {
    // do something

That would translate to the Python equivalent:

i = 0
while not there_is_a_reason_to_break(i):
    # do something
    i += 1

Only if you need to exit in the middle of the loop somewhere (or if your condition is complex enough that it would render your looping statement far less readable) would you need to worry about breaking.

When your potential exit is a simple one at the start of the loop (as it appears to be here), it's usually better to encode the exit into the loop itself.

How do I connect to a Websphere Datasource with a given JNDI name?

For those like me, only needing information on how to connect to a (DB2) WAS Data Source from Java using JNDI lookup (Used IBM Websphere 8.5.5 & DB2 Universal JDBC Driver Provider with implementation class:

public DataSource getJndiDataSource() throws NamingException {
    DataSource datasource = null;
    InitialContext context = new InitialContext();
    // Tomcat/Possibly others: java:comp/env/jdbc/myDatasourceJndiName
    datasource = (DataSource) context.lookup("jdbc/myDatasourceJndiName");
    return datasource;

How to append one DataTable to another DataTable

Consider a solution that will neatly handle arbitrarily many tables.

//ASSUMPTION: All tables must have the same columns
var tables = new List<DataTable>();
//Or in the real world, you might be getting a collection of tables from some abstracted data source.

//behold, a table too great and terrible to imagine
var theOneTable = tables.SelectMany(dt => dt.AsEnumerable()).CopyToDataTable();

Encapsulated into a helper for future reuse:

public static DataTable CombineDataTables(params DataTable[] args)
    return args.SelectMany(dt => dt.AsEnumerable()).CopyToDataTable();

Just have a few tables declared in code?

var combined = CombineDataTables(dt1,dt2,dt3);

Want to combine into one of the existing tables instead of creating a new one?

dt1 = CombineDataTables(dt1,dt2,dt3);

Already have a collection of tables, instead of declared one by one?

//Pretend variable tables already exists
var tables = new[] { dt1, dt2, dt3 };
var combined = CombineDataTables(tables);

How can I get the current time in C#?

try this:

 string.Format("{0:HH:mm:ss tt}", DateTime.Now);

for further details you can check it out : How do you get the current time of day?

The result of a query cannot be enumerated more than once

Try replacing this

var query = context.Search(id, searchText);


var query = context.Search(id, searchText).tolist();

and everything will work well.

pip3: command not found

I had this issue and I fixed it using the following steps You need to completely uninstall python3-p using:

sudo apt-get --purge autoremove python3-pip

Then resintall the package with:

 sudo apt install python3-pip

To confirm that everything works, run:

 pip3 -V

After this you can now use pip3 to manage any python package of your interest. Eg

pip3 install NumPy

Adding value labels on a matplotlib bar chart

Based on a feature mentioned in this answer to another question I have found a very generally applicable solution for placing labels on a bar chart.

Other solutions unfortunately do not work in many cases, because the spacing between label and bar is either given in absolute units of the bars or is scaled by the height of the bar. The former only works for a narrow range of values and the latter gives inconsistent spacing within one plot. Neither works well with logarithmic axes.

The solution I propose works independent of scale (i.e. for small and large numbers) and even correctly places labels for negative values and with logarithmic scales because it uses the visual unit points for offsets.

I have added a negative number to showcase the correct placement of labels in such a case.

The value of the height of each bar is used as a label for it. Other labels can easily be used with Simon's for rect, label in zip(rects, labels) snippet.

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

# Bring some raw data.
frequencies = [6, -16, 75, 160, 244, 260, 145, 73, 16, 4, 1]

# In my original code I create a series and run on that,
# so for consistency I create a series from the list.
freq_series = pd.Series.from_array(frequencies)

x_labels = [108300.0, 110540.0, 112780.0, 115020.0, 117260.0, 119500.0,
            121740.0, 123980.0, 126220.0, 128460.0, 130700.0]

# Plot the figure.
plt.figure(figsize=(12, 8))
ax = freq_series.plot(kind='bar')
ax.set_title('Amount Frequency')
ax.set_xlabel('Amount ($)')

def add_value_labels(ax, spacing=5):
    """Add labels to the end of each bar in a bar chart.

        ax (matplotlib.axes.Axes): The matplotlib object containing the axes
            of the plot to annotate.
        spacing (int): The distance between the labels and the bars.

    # For each bar: Place a label
    for rect in ax.patches:
        # Get X and Y placement of label from rect.
        y_value = rect.get_height()
        x_value = rect.get_x() + rect.get_width() / 2

        # Number of points between bar and label. Change to your liking.
        space = spacing
        # Vertical alignment for positive values
        va = 'bottom'

        # If value of bar is negative: Place label below bar
        if y_value < 0:
            # Invert space to place label below
            space *= -1
            # Vertically align label at top
            va = 'top'

        # Use Y value as label and format number with one decimal place
        label = "{:.1f}".format(y_value)

        # Create annotation
            label,                      # Use `label` as label
            (x_value, y_value),         # Place label at end of the bar
            xytext=(0, space),          # Vertically shift label by `space`
            textcoords="offset points", # Interpret `xytext` as offset in points
            ha='center',                # Horizontally center label
            va=va)                      # Vertically align label differently for
                                        # positive and negative values.

# Call the function above. All the magic happens there.


Edit: I have extracted the relevant functionality in a function, as suggested by barnhillec.

This produces the following output:

Bar chart with automatically placed labels on each bar

And with logarithmic scale (and some adjustment to the input data to showcase logarithmic scaling), this is the result:

Bar chart with logarithmic scale with automatically placed labels on each bar

Java HTML Parsing

You might be interested by TagSoup, a Java HTML parser able to handle malformed HTML. XML parsers would work only on well formed XHTML.

Converting String to Double in Android

    cost=(TextView )findViewById(;

            btn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) { cst =  Double.valueOf(kw.getText().toString());
            cst = cst*0.551;

Any reason to prefer getClass() over instanceof when generating .equals()?

If you want to ensure only that class will match then use getClass() ==. If you want to match subclasses then instanceof is needed.

Also, instanceof will not match against a null but is safe to compare against a null. So you don't have to null check it.

if ( ! (obj instanceof MyClass) ) { return false; }

SHA512 vs. Blowfish and Bcrypt

I agree with erickson's answer, with one caveat: for password authentication purposes, bcrypt is far better than a single iteration of SHA-512 - simply because it is far slower. If you don't get why slowness is an advantage in this particular game, read the article you linked to again (scroll down to "Speed is exactly what you don’t want in a password hash function.").

You can of course build a secure password hashing algorithm around SHA-512 by iterating it thousands of times, just like the way PHK's MD5 algorithm works. Ulrich Drepper did exactly this, for glibc's crypt(). There's no particular reason to do this, though, if you already have a tested bcrypt implementation available.

Better way to get type of a Javascript variable?

typeof condition is used to check variable type, if you are check variable type in if-else condition e.g.

if(typeof Varaible_Name "undefined")


How to set a default value for an existing column

First drop constraints

DECLARE @ConstraintName nvarchar(200)
AND PARENT_COLUMN_ID = (SELECT column_id FROM sys.columns
                        WHERE NAME = N'__ColumnName__'
                        AND object_id = OBJECT_ID(N'__TableName__'))
IF @ConstraintName IS NOT NULL
EXEC('ALTER TABLE __TableName__ DROP CONSTRAINT ' + @ConstraintName)

Second create default value

ALTER TABLE [table name] ADD DEFAULT [default value] FOR [column name]

sqlplus statement from command line

I'm able to execute your exact query by just making sure there is a semicolon at the end of my select statement. (Output is actual, connection params removed.)

echo "select 1 from dual;" | sqlplus -s username/password@host:1521/service 



Note that is should matter but this is running on Mac OS X Snow Leopard and Oracle 11g.

How can I resize an image dynamically with CSS as the browser width/height changes?

window.onresize = function(){
    var img = document.getElementById('fullsize'); = "100%";

In IE onresize event gets fired on every pixel change (width or height) so there could be performance issue. Delay image resizing for few milliseconds by using javascript's window.setTimeout().

How to avoid Number Format Exception in java?

I suggest to do 2 things:

  • validate the input on client side before passing it to the Servlet
  • catch the exception and show an error message within the user frontend as Tobiask mentioned. This case should normally not happen, but never trust your clients. ;-)

Error importing Seaborn module in Python

I would definitely recommend that you install Anaconda and then use the "pip install seaborn" command from the Lab Jupyter IDE. It should work. It seems that the package is already pre-installed on Lab Jupyter.

Associative arrays in Shell scripts

Adding another option, if jq is available:

export NAMES="{
export NAME=David
echo $NAMES | jq --arg v "$NAME" '.[$v]' | tr -d '"' 

Multiple Errors Installing Visual Studio 2015 Community Edition

This was killing me as well, I must have re-installed visual studios a thousand times before Stack Overflow helped me! First is began with a Windows update problem While installing Visual Studio 2015 the Update flagged me that it needed - the update KB2919355. Went to the Windows update and saw several failed updates. No matter how I tried did not work. The Error code that were cited was 80070543 did some research found nothing worked until I encountered this advice Having followed those instructions did the Windows update again and it worked. Went back to to do the Visual Studios update got the same error again! So I decided to research KB2919355 and was frustrated until I found this site

followed the instruction precisely about loading other updates and they worked. KB2919355 was finally updated so I tried again and a different error came up involving language packs. “Fatal Installation error”. After going through a series of frustrating reinstallations, uninstallations light broke through of the advice of that came this (the above) Stack Overflow entry “repairing the C++ Redistributables” which involves: Going to Start -> Control Panel -> Programs and Features Right mouse-clicks on each the redistributables (from the bottom up) and click repair for all. If any ask for a “Restart” do it immediately right then and there! Then I did the Visual Studio installations….finally after days and days of trying….it worked.

Regular expression to find URLs within a string

Short and simple. I have not tested in javascript code yet but It looks it will work:


Code on

Code preview

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '''')' at line 2

There is a single quote in $submitsubject or $submit_message

Why is this a problem?

The single quote char terminates the string in MySQL and everything past that is treated as a sql command. You REALLY don't want to write your sql like that. At best, your application will break intermittently (as you're observing) and at worst, you have just introduced a huge security vulnerability.

Imagine if someone submitted '); DROP TABLE private_messages; in submit message.

Your SQL Command would be:

INSERT INTO private_messages (to_id, from_id, time_sent, subject, message) 
        VALUES('sender_id', 'id', now(),'subjet','');

DROP TABLE private_messages;

Instead you need to properly sanitize your values.

AT A MINIMUM you must run each value through mysql_real_escape_string() but you should really be using prepared statements.

If you were using mysql_real_escape_string() your code would look like this:


    $submit_subject="(no subject)";
$sender_id = mysql_real_escape_string($_POST['sender_id']);

Here is a great article on prepared statements and PDO.

How to implement a Keyword Search in MySQL?

I will explain the method i usally prefer:

First of all you need to take into consideration that for this method you will sacrifice memory with the aim of gaining computation speed. Second you need to have a the right to edit the table structure.

1) Add a field (i usually call it "digest") where you store all the data from the table.

The field will look like:

"n-n1-n2-n3-n4-n5-n6-n7-n8-n9" etc.. where n is a single word

I achieve this using a regular expression thar replaces " " with "-". This field is the result of all the table data "digested" in one sigle string.

2) Use the LIKE statement %keyword% on the digest field:

SELECT * FROM table WHERE digest LIKE %keyword%

you can even build a qUery with a little loop so you can search for multiple keywords at the same time looking like:

 digest LIKE %keyword1% AND 
 digest LIKE %keyword2% AND 
 digest LIKE %keyword3% ... 

Using in my project (Eclipse)

You need to add this in your build.gradle:

dependencies {
    compile ''

And then Sync Project with Gradle Files. Finally, you can use CardView as it's described here.

Can I change the height of an image in CSS :before/:after pseudo-elements?

Here is another (working) solution : just resize your images to the size you want :)

.pdflink:after {
    display: block;
    width: 20px;
    height: 10px;

you need pdf.png to be 20px * 10px for this to work. The 20px/10px in the css are here to give the size of the block so that the elements that come after the block are not all messed up with the image

Don't forget to keep a copy of the raw image in its original size

Fast check for NaN in NumPy

I think np.isnan(np.min(X)) should do what you want.

What is the difference between Session.Abandon() and Session.Clear()

Clear - Removes all keys and values from the session-state collection.

Abandon - removes all the objects stored in a Session. If you do not call the Abandon method explicitly, the server removes these objects and destroys the session when the session times out.
It also raises events like Session_End.

Session.Clear can be compared to removing all books from the shelf, while Session.Abandon is more like throwing away the whole shelf.

You say:

When I test Session, it doesn't makes any change when I Abandon the session.

This is correct while you are doing it within one request only.
On the next request the session will be different. But the session ID can be reused so that the id will remain the same.

If you will use Session.Clear you will have the same session in many requests.

Generally, in most cases you need to use Session.Clear.
You can use Session.Abandon if you are sure the user is going to leave your site.

So back to the differences:

  1. Abandon raises Session_End request.
  2. Clear removes items immidiately, Abandon does not.
  3. Abandon releases the SessionState object and its items so it can ba garbage collected to free the resources. Clear keeps SessionState and resources associated with it.

How to capture Curl output to a file?

use --trace-asci output.txt can output the curl details to the output.txt

how to check if string contains '+' character

[+]is simpler

    String s = "ddjdjdj+kfkfkf";

    if(s.contains ("+"))
        String parts[] = s.split("[+]");
        s =  parts[0]; // i want to strip part after  +

Swift extract regex matches

update @Mike Chirico's to Swift 5

extension String{

  func regex(pattern: String) -> [String]?{
    do {
        let regex = try NSRegularExpression(pattern: pattern, options: NSRegularExpression.Options(rawValue: 0))
        let all = NSRange(location: 0, length: count)
        var matches = [String]()
        regex.enumerateMatches(in: self, options: NSRegularExpression.MatchingOptions(rawValue: 0), range: all) {
            (result : NSTextCheckingResult?, _, _) in
              if let r = result {
                    let nsstr = self as NSString
                    let result = nsstr.substring(with: r.range) as String
        return matches
    } catch {
        return nil

How to use GROUP_CONCAT in a CONCAT in MySQL

select id, group_concat(`Name` separator ',') as `ColumnName`
    concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
  from mytbl
  group by 
) tbl
group by id;

You can see it implemented here : Sql Fiddle Demo. Exactly what you need.

Update Splitting in two steps. First we get a table having all values(comma separated) against a unique[Name,id]. Then from obtained table we get all names and values as a single value against each unique id See this explained here SQL Fiddle Demo (scroll down as it has two result sets)

Edit There was a mistake in reading question, I had grouped only by id. But two group_contacts are needed if (Values are to be concatenated grouped by Name and id and then over all by id). Previous answer was

id,group_concat(concat(`name`,':',`value`) separator ',')
as Result from mytbl group by id

You can see it implemented here : SQL Fiddle Demo

Pointer vs. Reference

Consider C#'s out keyword. The compiler requires the caller of a method to apply the out keyword to any out args, even though it knows already if they are. This is intended to enhance readability. Although with modern IDEs I'm inclined to think that this is a job for syntax (or semantic) highlighting.

Seeing the underlying SQL in the Spring JdbcTemplate?

Parameter values seem to be printed on TRACE level. This worked for me: plate=DEBUG, file, file

Console output:

02:40:56,519 TRACE http-bio-8080-exec-13 core.StatementCreatorUtils:206 - Setting SQL statement parameter value: column index 1, parameter value [Tue May 31 14:00:00 CEST 2005], value class [java.util.Date], SQL type unknown
02:40:56,528 TRACE http-bio-8080-exec-13 core.StatementCreatorUtils:206 - Setting SQL statement parameter value: column index 2, parameter value [61], value class [java.lang.Integer], SQL type unknown
02:40:56,528 TRACE http-bio-8080-exec-13 core.StatementCreatorUtils:206 - Setting SQL statement parameter value: column index 3, parameter value [80], value class [java.lang.Integer], SQL type unknown

What does java:comp/env/ do?

There is also a property resourceRef of JndiObjectFactoryBean that is, when set to true, used to automatically prepend the string java:comp/env/ if it is not already present.

<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
  <property name="jndiName" value="jdbc/loc"/>
  <property name="resourceRef" value="true"/>

How to save password when using Subversion from the console

Try clearing your .subversion folder in your home directory and try to commit again. It should prompt you for your password and then ask you if you would like to save the password.

Fatal Error :1:1: Content is not allowed in prolog

Looks like you forgot adding correct headers to your get request (ask the REST API developer or you specific API description):

HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.header("Accept", "application/xml")


connection.header("Accept", "application/xml;version=1")

Move layouts up when soft keyboard is shown?

Use Scroll View as a Parent and use this Tag in Scroll View


Can someone explain how to append an element to an array in C programming?

int arr[10] = {0, 5, 3, 64};
arr[4] = 5;

EDIT: So I was asked to explain what's happening when you do:

int arr[10] = {0, 5, 3, 64};

you create an array with 10 elements and you allocate values for the first 4 elements of the array.

Also keep in mind that arr starts at index arr[0] and ends at index arr[9] - 10 elements

arr[0] has value 0;
arr[1] has value 5;
arr[2] has value 3;
arr[3] has value 64;

after that the array contains garbage values / zeroes because you didn't allocated any other values

But you could still allocate 6 more values so when you do

arr[4] = 5;

you allocate the value 5 to the fifth element of the array.

You could do this until you allocate values for the last index of the arr that is arr[9];

Sorry if my explanation is choppy, but I have never been good at explaining things.

Use async await with

If you map to an array of Promises, you can then resolve them all to an array of numbers. See Promise.all.

jQuery UI " $("#datepicker").datepicker is not a function"

I know that this post is quite old, but for reference I fixed this issue by updating the version of datepicker

It is worth trying that too to avoid hours of debugging.

LINQ's Distinct() on a particular property

You can do it (albeit not lightning-quickly) like so:

people.Where(p => !people.Any(q => (p != q && p.Id == q.Id)));

That is, "select all people where there isn't another different person in the list with the same ID."

Mind you, in your example, that would just select person 3. I'm not sure how to tell which you want, out of the previous two.

How to display default text "--Select Team --" in combo box on pageload in WPF?

Set IsEditable="True" on the ComboBox element. This will display the Text property of the ComboBox.

Cheap way to search a large text file for a string

If there is no way to tell where the string will be (first half, second half, etc) then there is really no optimized way to do the search other than the builtin "find" function. You could reduce the I/O time and memory consumption by not reading the file all in one shot, but at 4kb blocks (which is usually the size of an hard disk block). This will not make the search faster, unless the string is in the first part of the file, but in all case will reduce memory consumption which might be a good idea if the file is huge.