Programs & Examples On #Rrdtool

RRDtool (acronym for round-robin database tool) aims to handle time-series data like network bandwidth, temperatures, CPU load etc.

jQuery slide left and show

And if you want to vary the speed and include callbacks simply add them like this :

            slideRightShow: function(speed,callback) {
                return this.each(function() {
                    $(this).show('slide', {direction: 'right'}, speed, callback);
            slideLeftHide: function(speed,callback) {
                return this.each(function() {
                    $(this).hide('slide', {direction: 'left'}, speed, callback);
            slideRightHide: function(speed,callback) {
                return this.each(function() {  
                    $(this).hide('slide', {direction: 'right'}, speed, callback);
            slideLeftShow: function(speed,callback) {
                return this.each(function() {
                    $(this).show('slide', {direction: 'left'}, speed, callback);

Replace all non Alpha Numeric characters, New Lines, and multiple White Space with one Space

This is an old post of mine, the accepted answers are good for the most part. However i decided to benchmark each solution and another obvious one (just for fun). I wondered if there was a difference between the regex patterns on different browsers with different sized strings.

So basically i used jsPerf on

  • Testing in Chrome 65.0.3325 / Windows 10 0.0.0
  • Testing in Edge 16.16299.0 / Windows 10 0.0.0

The regex patterns i tested were

  • /[\W_]+/g
  • /[^a-z0-9]+/gi
  • /[^a-zA-Z0-9]+/g

I loaded them up with a string length of random characters

  • length 5000
  • length 1000
  • length 200

Example javascript i used var newstr = str.replace(/[\W_]+/g," ");

Each run consisted of 50 or more sample on each regex, and i run them 5 times on each browser.

Lets race our horses!


                                Chrome                  Edge
Chars   Pattern                 Ops/Sec     Deviation   Op/Sec      Deviation
5,000   /[\W_]+/g                19,977.80  1.09         10,820.40  1.32
5,000   /[^a-z0-9]+/gi           19,901.60  1.49         10,902.00  1.20
5,000   /[^a-zA-Z0-9]+/g         19,559.40  1.96         10,916.80  1.13
1,000   /[\W_]+/g                96,239.00  1.65         52,358.80  1.41
1,000   /[^a-z0-9]+/gi           97,584.40  1.18         52,105.00  1.60
1,000   /[^a-zA-Z0-9]+/g         96,965.80  1.10         51,864.60  1.76
  200   /[\W_]+/g               480,318.60  1.70        261,030.40  1.80
  200   /[^a-z0-9]+/gi          476,177.80  2.01        261,751.60  1.96
  200   /[^a-zA-Z0-9]+/g        486,423.00  0.80        258,774.20  2.15

Truth be known, Regex in both browsers (taking into consideration deviation) were nearly indistinguishable, however i think if it run this even more times the results would become a little more clearer (but not by much).

Theoretical scaling for 1 character

                            Chrome                        Edge
Chars   Pattern             Ops/Sec     Scaled            Op/Sec    Scaled
5,000   /[\W_]+/g            19,977.80  99,889,000       10,820.40  54,102,000
5,000   /[^a-z0-9]+/gi       19,901.60  99,508,000       10,902.00  54,510,000
5,000   /[^a-zA-Z0-9]+/g     19,559.40  97,797,000       10,916.80  54,584,000

1,000   /[\W_]+/g            96,239.00  96,239,000       52,358.80  52,358,800
1,000   /[^a-z0-9]+/gi       97,584.40  97,584,400       52,105.00  52,105,000
1,000   /[^a-zA-Z0-9]+/g     96,965.80  96,965,800       51,864.60  51,864,600

  200   /[\W_]+/g           480,318.60  96,063,720      261,030.40  52,206,080
  200   /[^a-z0-9]+/gi      476,177.80  95,235,560      261,751.60  52,350,320
  200   /[^a-zA-Z0-9]+/g    486,423.00  97,284,600      258,774.20  51,754,840

I wouldn't take to much into these results as this is not really a significant differences, all we can really tell is edge is slower :o . Additionally that i was super bored.

Anyway you can run the benchmark for your self.

Jsperf Benchmark here

In python, what is the difference between random.uniform() and random.random()?

In random.random() the output lies between 0 & 1 , and it takes no input parameters

Whereas random.uniform() takes parameters , wherein you can submit the range of the random number. e.g.
import random as ra print ra.random() print ra.uniform(5,10)

0.672485369423 7.9237539416

Setting the JVM via the command line on Windows

If you have 2 installations of the JVM. Place the version upfront. Linux : export PATH=/usr/lib/jvm/java-8-oracle/bin:$PATH

This eliminates the ambiguity.

How do I add a library project to Android Studio?

  1. Press F4 to show Project Structure, click libraries or Global libraries, and click + to add the JAR file.
  2. Click Modules what you want add jar, select the Dependencies tab, click +, and add Library.

How to wait until an element is present in Selenium?

WebDriverWait wait = new WebDriverWait(driver,5)

you can use this as some time before loading whole page code gets executed and throws and error. time is in second

How to clear an ImageView in Android?

For ListView item image you can set ImageView.setVisibility(View.INVISIBLE) or ImageView.setImageBitmap(null) in list adapter for "no image" case.

cleanest way to skip a foreach if array is empty

I wouldn't recommend suppressing the warning output. I would, however, recommend using is_array instead of !empty. If $items happens to be a nonzero scalar, then the foreach will still error out if you use !empty.

Getting the button into the top right corner inside the div box

Just add position:absolute; top:0; right:0; to the CSS for your button.

 #button {
     line-height: 12px;
     width: 18px;
     font-size: 8pt;
     font-family: tahoma;
     margin-top: 1px;
     margin-right: 2px;

jsFiddle example

PHP Function with Optional Parameters

To accomplish what you want, use an array Like Rabbot said (though this can become a pain to document/maintain if used excessively). Or just use the traditional optional args.

//My function with tons of optional params
function my_func($req_a, $req_b, $opt_a = NULL, $opt_b = NULL, $opt_c = NULL)
  //Do stuff
my_func('Hi', 'World', null, null, 'Red');

However, I usually find that when I start writing a function/method with that many arguments - more often than not it is a code smell, and can be re-factored/abstracted into something much cleaner.

//Specialization of my_func - assuming my_func itself cannot be refactored
function my_color_func($reg_a, $reg_b, $opt = 'Red')
  return my_func($reg_a, $reg_b, null, null, $opt);
my_color_func('Hi', 'World');
my_color_func('Hello', 'Universe', 'Green');

To get total number of columns in a table in sql

Select Table_Name, Count(*) As ColumnCount
From Information_Schema.Columns
Group By Table_Name
Order By Table_Name

This code show a list of tables with a number of columns present in that table for a database.

If you want to know the number of column for a particular table in a database then simply use where clause e.g. where Table_Name='name_your_table'

Javascript objects: get parent

A nested object (child) inside another object (parent) cannot get data directly from its parent.

Have a look on this:

var main = {
    name : "main object",
    child : {
        name : "child object"

If you ask the main object what its child name is ( you will get it.
Instead you cannot do it vice versa because the child doesn't know who its parent is.
(You can get but you won't get

By the way, a function could be useful to solve this clue.
Let's extend the code above:

var main = {
    name : "main object",
    child : {
        name : "child object"
    init : function() {
        this.child.parent = this;
        delete this.init;
        return this;

Inside the init function you can get the parent object simply calling this.
So we define the parent property directly inside the child object.
Then (optionally) we can remove the init method.
Finally we give the main object back as output from the init function.

If you try to get now you will get it right.
It is a little bit tricky but it works fine.

How do I dynamically change the content in an iframe using jquery?

If you just want to change where the iframe points to and not the actual content inside the iframe, you would just need to change the src attribute.

 $("#myiframe").attr("src", "newwebpage.html");

Get generic type of class at runtime

Java generics are mostly compile time, this means that the type information is lost at runtime.

class GenericCls<T>
    T t;

will be compiled to something like

class GenericCls
   Object o;

To get the type information at runtime you have to add it as an argument of the ctor.

class GenericCls<T>
     private Class<T> type;
     public GenericCls(Class<T> cls)
        type= cls;
     Class<T> getType(){return type;}


GenericCls<?> instance = new GenericCls<String>(String.class);
assert instance.getType() == String.class;

How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?

You can put the jQuery's Ajax setup in synchronous mode by calling


And then perform your Ajax calls using jQuery.get( ... );

Then just turning it on again once


I guess it works out the same thing as suggested by @Adam, but it might be helpful to someone that does want to reconfigure their jQuery.get() or to the more elaborate jQuery.ajax() syntax.

How do I PHP-unserialize a jQuery-serialized form?

I think you need to separate the form names from its values, one method to do this is to explode (&) so that you will get attribute=value,attribute2=value.

My point here is that you will convert the serialized jQuery string into arrays in PHP.

Here is the steps that you should follow to be more specific.

  1. Passed on the serialized jQuery to a PHP page(e.g ajax.php) where you use $.ajax to submit using post or get.
  2. From your php page, explode the (&) thus separating each attributes. Now you will get attribute1=value, attribute2=value, now you will get a php array variable. e.g$data = array("attribute1=value","attribute2=value")
  3. Do a foreach on $data and explode the (=) so that you can separate the attribute from the value, and be sure to urldecode the value so that it will convert serialized values to the value that you need, and insert the attribute and its value to a new array variable, which stores the attribute and the value of the serialized string.

Let me know if you need more clarifications.

Google Maps API - Get Coordinates of address

What you are looking for is called Geocoding.

Google provides a Geocoding Web Service which should do what you're looking for. You will be able to do geocoding on your server.

JSON Example:,+Mountain+View,+CA

XML Example:,+Mountain+View,+CA


Please note that this is now a deprecated method and you must provide your own Google API key to access this data.

How to create websockets server in PHP

I was in your shoes for a while and finally ended up using node.js, because it can do hybrid solutions like having web and socket server in one. So php backend can submit requests thru http to node web server and then broadcast it with websocket. Very efficiant way to go.

android edittext onchange listener

First, you can see if the user finished editing the text if the EditText loses focus or if the user presses the done button (this depends on your implementation and on what fits the best for you). Second, you can't get an EditText instance within the TextWatcher only if you have declared the EditText as an instance object. Even though you shouldn't edit the EditText within the TextWatcher because it is not safe.


To be able to get the EditText instance into your TextWatcher implementation, you should try something like this:

public class YourClass extends Activity {

    private EditText yourEditText;

    public void onCreate(Bundle savedInstanceState) {

        yourEditText = (EditText) findViewById(;

        yourEditText.addTextChangedListener(new TextWatcher() {

            public void afterTextChanged(Editable s) {

                // you can call or do what you want with your EditText here

                // yourEditText... 

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

            public void onTextChanged(CharSequence s, int start, int before, int count) {}

Note that the above sample might have some errors but I just wanted to show you an example.

How should I validate an e-mail address?

Here is android.util.Patterns.EMAIL_ADDRESS


String will match it if

Start by 1->256 character in (a-z, A-Z, 0-9, +, ., _, %, - , +)  
then 1 '@' character  
then 1 character in (a-z, A-Z, 0-9)  
then 0->64 character in (a-z, A-Z, 0-9, -)  
then **ONE OR MORE** 
         1 '.' character   
    then 1 character in (a-z, A-Z, 0-9)   
    then 0->25 character in (a-z, A-Z, 0-9, -)

Example some special match email

[email protected]
[email protected]
[email protected]

You may modify this pattern for your case then validate by

fun isValidEmail(email: String): Boolean {
    return Patterns.EMAIL_ADDRESS.matcher(email).matches()

What is dtype('O'), in pandas?

'O' stands for object.

#Loading a csv file as a dataframe
import pandas as pd 
train_df = pd.read_csv('train.csv')
col_name = 'Name of Employee'

#Checking the datatype of column name

#Instead try printing the same thing
print train_df[col_name].dtype

The first line returns: dtype('O')

The line with the print statement returns the following: object

JavaScript unit test tools for TDD

We added JUnit integration to our Java to Javascript code generator ST-JS ( The framework generates to corresponding Javascript for both the tested code and the unit tests and sends the code to different browsers.

There is no need for a separate server as the unit test runner opens the needed http port (and closes it once the tests finished). The framework manipulates the Java stacktrace so that the failed asserts are correctly displayed by the JUnit Eclipse plugin. Here is a simple example with jQuery and Mockjax:

@HTMLFixture("<div id='fortune'></div>")

@Scripts({ "classpath://jquery.js",
       "classpath://jquery.mockjax.js", "classpath://json2.js" })
public class MockjaxExampleTest {
  public void myTest() {
    $.ajaxSetup($map("async", false));
    $.mockjax(new MockjaxOptions() {
        url = "/restful/fortune";
        responseText = new Fortune() {
            status = "success";
            fortune = "Are you a turtle?";

    $.getJSON("/restful/fortune", null, new Callback3<Fortune, String, JQueryXHR>() {
      public void $invoke(Fortune response, String p2, JQueryXHR p3) {
        if (response.status.equals("success")) {
          $("#fortune").html("Your fortune is: " + response.fortune);
        } else {
          $("#fortune").html("Things do not look good, no fortune was told");

    assertEquals("Your fortune is: Are you a turtle?", $("#fortune").html());

  private static class Fortune {
    public String status;
    public String fortune;

SQL Insert Query Using C#

static SqlConnection myConnection;

    public Form1()

    private void button1_Click(object sender, EventArgs e)
        myConnection = new SqlConnection("server=localhost;" +
                                                      "Trusted_Connection=true;" +
             "database=zxc; " +
                                                      "connection timeout=30");

            label1.Text = "connect successful";

        catch (SqlException ex)
            label1.Text = "connect fail";

    private void Form1_Load(object sender, EventArgs e)


    private void button2_Click(object sender, EventArgs e)
        String st = "INSERT INTO supplier(supplier_id, supplier_name)VALUES(" + textBox1.Text + ", " + textBox2.Text + ")";
        SqlCommand sqlcom = new SqlCommand(st, myConnection);
            MessageBox.Show("insert successful");
        catch (SqlException ex)

How do I enable MSDTC on SQL Server?

MSDTC must be enabled on both systems, both server and client.
Also, make sure that there isn't a firewall between the systems that blocks RPC.
DTCTest is a nice litt app that helps you to troubleshoot any other problems.

MYSQL order by both Ascending and Descending sorting

I don't understand what the meaning of ordering with the same column ASC and DESC in the same ORDER BY, but this how you can do it: naam DESC, naam ASC like so:

ORDER BY `product_category_id` DESC,`naam` DESC, `naam` ASC

See whether an item appears more than once in a database column

How about:

select salesid from AXDelNotesNoTracking group by salesid having count(*) > 1;

Reading a text file with SQL Server

What does your text file look like?? Each line a record?

You'll have to check out the BULK INSERT statement - that should look something like:

BULK INSERT dbo.YourTableName
FROM 'D:\directory\YourFileName.csv'
  CODEPAGE = '1252',

Here, in my case, I'm importing a CSV file - but you should be able to import a text file just as well.

From the MSDN docs - here's a sample that hopefully works for a text file with one field per row:

BULK INSERT dbo.temp 
   FROM 'c:\temp\file.txt'
         ROWTERMINATOR ='\n'

Seems to work just fine in my test environment :-)

Does GPS require Internet?

There are two issues:

  1. Getting the current coordinates (longitude, latitude, perhaps altitude) based on some external signals received by your device, and
  2. Deriving a human-readable position (address) from the coordinates.

To get the coordinates you don't need the Internet. GPS is satellite-based. But to derive street/city information from the coordinates, you'd need either to implement the map and the corresponding algorithms yourself on the device (a lot of work!) or to rely on proven services, e.g. by Google, in which case you'd need an Internet connection.

As of recently, Google allows for caching the maps, which would at least allow you to show your current position on the map even without a data connection, provided, you had cached the map in advance, when you could access the Internet.

How to set locale in DatePipe in Angular 2?

I was struggling with the same issue and didn't work for me using this

{{dateObj | date:'ydM'}}

So, I've tried a workaround, not the best solution but it worked:

{{dateObj | date:'d'}}/{{dateObj | date:'M'}}/{{dateObj | date:'y'}}

I can always create a custom pipe.

How to add dividers and spaces between items in RecyclerView?

For those who are looking just for spaces between items in the RecyclerView see my approach where you get equal spaces between all items, except in first and last items where I gave a bigger padding. I only apply padding to left/right in horizontal LayoutManager and to top/bottom in vertical LayoutManager.

public class PaddingItemDecoration extends RecyclerView.ItemDecoration {

    private int mPaddingPx;
    private int mPaddingEdgesPx;

    public PaddingItemDecoration(Activity activity) {
        final Resources resources = activity.getResources();
        mPaddingPx = (int) resources.getDimension(R.dimen.paddingItemDecorationDefault);
        mPaddingEdgesPx = (int) resources.getDimension(R.dimen.paddingItemDecorationEdge);

    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);

        final int itemPosition = parent.getChildAdapterPosition(view);
        if (itemPosition == RecyclerView.NO_POSITION) {
        int orientation = getOrientation(parent);
        final int itemCount = state.getItemCount();

        int left = 0;
        int top = 0;
        int right = 0;
        int bottom = 0;

        /** HORIZONTAL */
        if (orientation == LinearLayoutManager.HORIZONTAL) {
            /** all positions */
            left = mPaddingPx;
            right = mPaddingPx;

            /** first position */
            if (itemPosition == 0) {
                left += mPaddingEdgesPx;
            /** last position */
            else if (itemCount > 0 && itemPosition == itemCount - 1) {
                right += mPaddingEdgesPx;
        /** VERTICAL */
        else {
            /** all positions */
            top = mPaddingPx;
            bottom = mPaddingPx;

            /** first position */
            if (itemPosition == 0) {
                top += mPaddingEdgesPx;
            /** last position */
            else if (itemCount > 0 && itemPosition == itemCount - 1) {
                bottom += mPaddingEdgesPx;

        if (!isReverseLayout(parent)) {
            outRect.set(left, top, right, bottom);
        } else {
            outRect.set(right, bottom, left, top);

    private boolean isReverseLayout(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
            return layoutManager.getReverseLayout();
        } else {
            throw new IllegalStateException("PaddingItemDecoration can only be used with a LinearLayoutManager.");

    private int getOrientation(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
            return layoutManager.getOrientation();
        } else {
            throw new IllegalStateException("PaddingItemDecoration can only be used with a LinearLayoutManager.");


    <dimen name="paddingItemDecorationDefault">10dp</dimen>
    <dimen name="paddingItemDecorationEdge">20dp</dimen>


If you connect with the server, then you can get a return code from it, otherwise it will fail and you get a 0. So if you try to connect to "" you will get a return code of 400, if you go directly to, you will get 302 (and then 200 if you forward to the next page... well I do because it forwards to, so you might not get that), and if you go to "googlecom" you will get a 0 (host no found), so with the last one, there is nobody to send a code back.

Tested using the code below.


$html_brand = "";
$ch = curl_init();

$options = array(
    CURLOPT_URL            => $html_brand,
    CURLOPT_HEADER         => true,
    CURLOPT_ENCODING       => "",
    CURLOPT_TIMEOUT        => 120,
    CURLOPT_MAXREDIRS      => 10,
curl_setopt_array( $ch, $options );
$response = curl_exec($ch); 
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

if ( $httpCode != 200 ){
    echo "Return code is {$httpCode} \n"
} else {
    echo "<pre>".htmlspecialchars($response)."</pre>";


Shortcuts in Objective-C to concatenate NSStrings

Try stringWithFormat:

NSString *myString = [NSString stringWithFormat:@"%@ %@ %@ %d", "The", "Answer", "Is", 42];

Reading Excel files from C#

Not free, but with the latest Office there's a very nice automation .Net API. (there has been an API for a long while but was nasty COM) You can do everything you want / need in code all while the Office app remains a hidden background process.

Default property value in React component using TypeScript

Functional Component

Actually, for functional component the best practice is like below, I create a sample Spinner component:

import React from 'react';
import { ActivityIndicator } from 'react-native';
import { colors } from 'helpers/theme';
import type { FC } from 'types';

interface SpinnerProps {
  color?: string;
  size?: 'small' | 'large' | 1 | 0;
  animating?: boolean;
  hidesWhenStopped?: boolean;

const Spinner: FC<SpinnerProps> = ({
}) => (

Spinner.defaultProps = {
  animating: true,
  color: colors.primary,
  hidesWhenStopped: true,
  size: 'small',

export default Spinner;

Variable might not have been initialized error

Set variable "a" to some value like this,


Declaring and initialzing are both different.

Good Luck

invalid types 'int[int]' for array subscript

I think that you had intialized a 3d array but you are trying to access an array with 4 dimension.

Node.js - Find home directory in platform agnostic way

os.homedir() was added by this PR and is part of the public 4.0.0 release of nodejs.

Example usage:

const os = require('os');


ISO time (ISO 8601) in Python

ISO 8601 Time Representation

The international standard ISO 8601 describes a string representation for dates and times. Two simple examples of this format are

2010-12-16 17:22:15

(which both stand for the 16th of December 2010), but the format also allows for sub-second resolution times and to specify time zones. This format is of course not Python-specific, but it is good for storing dates and times in a portable format. Details about this format can be found in the Markus Kuhn entry.

I recommend use of this format to store times in files.

One way to get the current time in this representation is to use strftime from the time module in the Python standard library:

>>> from time import strftime
>>> strftime("%Y-%m-%d %H:%M:%S")
'2010-03-03 21:16:45'

You can use the strptime constructor of the datetime class:

>>> from datetime import datetime
>>> datetime.strptime("2010-06-04 21:08:12", "%Y-%m-%d %H:%M:%S")
datetime.datetime(2010, 6, 4, 21, 8, 12)

The most robust is the Egenix mxDateTime module:

>>> from mx.DateTime.ISO import ParseDateTimeUTC
>>> from datetime import datetime
>>> x = ParseDateTimeUTC("2010-06-04 21:08:12")
>>> datetime.fromtimestamp(x)
datetime.datetime(2010, 3, 6, 21, 8, 12)


When increasing the size of VARCHAR column on a large table could there be any problems?

Changing to Varchar(1200) from Varchar(200) should cause you no issue as it is only a metadata change and as SQL server 2008 truncates excesive blank spaces you should see no performance differences either so in short there should be no issues with making the change.

Some dates recognized as dates, some dates not recognized. Why?

The simplest solution is to put yy,mm,dd into the date() formula by first extracting them with left(), mid() and right(). In this case, assuming your input date is in A1:


Explanation of above:

=right(A1,2) gets the last two digits in the cell (yy). We add 100 because it defaults to 1911 instead 2011 (omit +100 if it doesn't do that on yours)

=left(A1,2) gets the first two digits in the cell (mm).

=mid(A1,4,2) gets 2 digits in the middle of the cell, starting at 4th digit (dd).

Why this happens in the first place:

I come across this problem all the time when I import Canadian bank data into excel. In short, your input date format does not match your regional settings.

Seems your setting mean Excel wants date input as either DD-MM-YY or YY-MM-DD, but your input data is formatted as MM-DD-YY.

So, excel sees your days as months and vice-versa, which means any date with day below 12 will be recognized as a date, BUT THE WRONG DATE (month and day reversed) and any date with day above 12 won't be recognized as a date at all, because Excel sees the day as a 13th+ month.

Unfortunately, you can't just change the formatting, because Excel has already locked those day/month assignments in place, and you just end up moving what Excel THINKS are days and months around visually, not reassigning them.

Frankly, it is surprising to me there is not a date-reverse tool in excel, because I would think this happens all the time. But the formula above does it pretty simply.

NOTE: if your dates don't have leading zeros (i.e. 4/8/11 vs 04/08/12) it gets trickier because you have to extract different amounts of digits depending on the date (i.e. 4/9/11 vs 4/10/11). You then have to build a couple if statements in your formula. Gross.

The data-toggle attributes in Twitter Bootstrap

The presence of this data-attribute tells Bootstrap to switch between visual or a logical states of another element on user interaction.

It is used to show modals, tab content, tooltips and popover menus as well as setting a pressed-state for a toggle-button. It is used in multiple ways without a clear documentation.

How to add a delay for a 2 or 3 seconds

Use a timer with an interval set to 2–3 seconds.

You have three different options to choose from, depending on which type of application you're writing:

  1. System.Timers.Timer
  2. System.Windows.Forms.Timer
  3. System.Threading.Timer

Don't use Thread.Sleep if your application need to process any inputs on that thread at the same time (WinForms, WPF), as Sleep will completely lock up the thread and prevent it from processing other messages. Assuming a single-threaded application (as most are), your entire application will stop responding, rather than just delaying an operation as you probably intended. Note that it may be fine to use Sleep in pure console application as there are no "events" to handle or on separate thread (also Task.Delay is better option).

In addition to timers and Sleep you can use Task.Delay which is asynchronous version of Sleep that does not block thread from processing events (if used properly - don't turn it into infinite sleep with .Wait()).

 public async void ClickHandler(...)
      // whatever you need to do before delay goes here         

      await Task.Delay(2000);

      // whatever you need to do after delay.

The same await Task.Delay(2000) can be used in a Main method of a console application if you use C# 7.1 (Async main on MSDN blogs).

Note: delaying operation with Sleep has benefit of avoiding race conditions that comes from potentially starting multiple operations with timers/Delay. Unfortunately freezing UI-based application is not acceptable so you need to think about what will happen if you start multiple delays (i.e. if it is triggered by a button click) - consider disabling such button, or canceling the timer/task or making sure delayed operation can be done multiple times safely.

How to get all enum values in Java?

One can also use the java.util.EnumSet like this

void test(){
    Enum aEnum =DayOfWeek.MONDAY;

void printAll(Enum value){
    Set allValues = EnumSet.allOf(value.getClass());

linq query to return distinct field values from a list of objects

If just want to user pure Linq, you can use groupby:

List<obj> distinct =
  objs.GroupBy(car => car.typeID).Select(g => g.First()).ToList();

If you want a method to be used all across the app, similar to what MoreLinq does:

public static IEnumerable<TSource> DistinctBy<TSource, TKey>
    (this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
    HashSet<TKey> seenKeys = new HashSet<TKey>();
    foreach (TSource element in source)
        if (!seenKeys.Contains(keySelector(element)))
            yield return element;

Using this method to find the distinct values using just the Id property, you could use:

var query = objs.DistinctBy(p => p.TypeId);

you can use multiple properties:

var query = objs.DistinctBy(p => new { p.TypeId, p.Name });

How to add to the end of lines containing a pattern with sed or awk?

This should work for you

sed -e 's_^all: .*_& anotherthing_'

Using s command (substitute) you can search for a line which satisfies a regular expression. In the command above, & stands for the matched string.

Replacing NULL with 0 in a SQL server query

If you are using Presto, AWS Athena etc, there is no ISNULL() function. Instead, use:

SELECT COALESCE(myColumn, 0 ) FROM myTable

Error: EPERM: operation not permitted, unlink 'D:\Sources\**\node_modules\fsevents\node_modules\abbrev\package.json'

For me it was Docker...

The moment that I closed the app container, I could do an npm install without any proble

P.S My node version is 14.15.5

ASP.NET MVC: What is the correct way to redirect to pages/actions in MVC?

RedirectToAction("actionName", "controllerName");

It has other overloads as well, please check up!

Also, If you are new and you are not using T4MVC, then I would recommend you to use it!

It gives you intellisence for actions,Controllers,views etc (no more magic strings)

What's the difference between JavaScript and JScript?

JScript is Microsoft's implementation of the ECMAScript specification. JavaScript is the Mozilla implementation of the specification.

No suitable driver found for 'jdbc:mysql://localhost:3306/mysql

( If your url is correct and still get that error messege ) Do following steps to setup the Classpath in netbeans,

  1. Create a new folder in your project workspace and add the downloaded .jar file(eg:- mysql-connector-java-5.1.35-bin.jar )
  2. Right click your project > properties > Libraries > ADD jar/Folder Select the jar file in that folder you just make. And click OK.

Now you will see that .jar file will be included under the libraries. Now you will not need to use the line, Class.forName("com.mysql.jdbc.Driver"); also.

If above method did not work, check the mysql-connector version (eg:- 5.1.35) and try a newer or a suitable version for you.

Basic HTTP and Bearer Token Authentication

With nginx you can send both tokens like this (even though it's against the standard):

Authorization: Basic basic-token,Bearer bearer-token

This works as long as the basic token is first - nginx successfully forwards it to the application server.

And then you need to make sure your application can properly extract the Bearer from the above string.

How to remove stop words using nltk or python

from nltk.corpus import stopwords
# ...
filtered_words = [word for word in word_list if word not in stopwords.words('english')]

What does "#pragma comment" mean?

These link in the libraries selected in MSVC++.

Are there any HTTP/HTTPS interception tools like Fiddler for mac OS X?

There's the more general but perhaps not as helpful to you Wireshark.

One of the SO server sites might be better suited for your question. In fact, it's already been asked on SuperUser.

Difference between git checkout --track origin/branch and git checkout -b branch origin/branch

There is no difference at all!

1) git checkout -b branch origin/branch

If there is no --track and no --no-track, --track is assumed as default. The default can be changed with the setting branch.autosetupmerge.

In effect, 1) behaves like git checkout -b branch --track origin/branch.

2) git checkout --track origin/branch

“As a convenience”, --track without -b implies -b and the argument to -b is guessed to be “branch”. The guessing is driven by the configuration variable remote.origin.fetch.

In effect, 2) behaves like git checkout -b branch --track origin/branch.

As you can see: no difference.

But it gets even better:

3) git checkout branch

is also equivalent to git checkout -b branch --track origin/branch if “branch” does not exist yet but “origin/branch” does1.

All three commands set the “upstream” of “branch” to be “origin/branch” (or they fail).

Upstream is used as reference point of argument-less git status, git push, git merge and thus git pull (if configured like that (which is the default or almost the default)).

E.g. git status tells you how far behind or ahead you are of upstream, if one is configured.

git push is configured to push the current branch upstream by default2 since git 2.0.

1 ...and if “origin” is the only remote having “branch”
2 the default (named “simple”) also enforces for both branch names to be equal

Good ways to sort a queryset? - Django

Here's a way that allows for ties for the cut-off score.

author_count = Author.objects.count()
cut_off_score = Author.objects.order_by('-score').values_list('score')[min(30, author_count)]
top_authors = Author.objects.filter(score__gte=cut_off_score).order_by('last_name')

You may get more than 30 authors in top_authors this way and the min(30,author_count) is there incase you have fewer than 30 authors.

How to add external fonts to android application

The easiest way to accomplish this is to package the desired font(s) with your application. To do this, simply create an assets/ folder in the project root, and put your fonts (in TrueType, or TTF, form) in the assets. You might, for example, create assets/fonts/ and put your TTF files in there.

Then, you need to tell your widgets to use that font. Unfortunately, you can no longer use layout XML for this, since the XML does not know about any fonts you may have tucked away as an application asset. Instead, you need to make the change in Java code, by calling Typeface.createFromAsset(getAssets(), “fonts/HandmadeTypewriter.ttf”), then taking the created Typeface object and passing it to your TextView via setTypeface().

For more reference here is the tutorial where I got this:

Stored Procedure parameter default value - is this a constant or a variable

It has to be a constant - the value has to be computable at the time that the procedure is created, and that one computation has to provide the value that will always be used.

Look at the definition of sys.all_parameters:

default_value sql_variant If has_default_value is 1, the value of this column is the value of the default for the parameter; otherwise, NULL.

That is, whatever the default for a parameter is, it has to fit in that column.

As Alex K pointed out in the comments, you can just do:

CREATE PROCEDURE [dbo].[problemParam] 
    @StartDate INT = NULL,
    @EndDate INT = NULL
   SET @StartDate = COALESCE(@StartDate,CONVERT(INT,(CONVERT(CHAR(8),GETDATE()-130,112))))

provided that NULL isn't intended to be a valid value for @StartDate.

As to the blog post you linked to in the comments - that's talking about a very specific context - that, the result of evaluating GETDATE() within the context of a single query is often considered to be constant. I don't know of many people (unlike the blog author) who would consider a separate expression inside a UDF to be part of the same query as the query that calls the UDF.

Java - How to access an ArrayList of another class?

import java.util.ArrayList;
public class numbers {
   private int number1 = 50;
   private int number2 = 100;
   private List<Integer> list;

   public numbers() {
       list = new ArrayList<Integer>();

   public List<Integer> getList() {
       return list;

And the test class:

import java.util.ArrayList;
public class test {
   private numbers number;

   public test() {
     number = new numbers();
     List<Integer> list = number.getList();
     //hurray !

How do I reset a sequence in Oracle?

1) Suppose you create a SEQUENCE like shown below:


2) Now you fetch values from SEQUENCE. Lets say I have fetched four times as shown below.


3) After executing above four commands the value of the SEQUENCE will be 4. Now suppose I have reset the value of the SEQUENCE to 1 again. The follow the following steps. Follow all the steps in the same order as shown below:


copy-item With Alternate Credentials

PowerShell 3.0 now supports for credentials on the FileSystem provider. To use alternate credentials, simply use the Credential parameter on the New-PSDrive cmdlet

PS > New-PSDrive -Name J -PSProvider FileSystem -Root \\server001\sharename -Credential mydomain\travisj -Persist

After this command you can now access the newly created drive and do other operations including copy or move files like normal drive. here is the full solution:

$Source = "C:\Downloads\myfile.txt"
$Dest   = "\\\c$\skumar"
$Username = "administrator"
$Password = ConvertTo-SecureString "Complex_Passw0rd" -AsPlainText -Force
$mycreds = New-Object System.Management.Automation.PSCredential($Username, $Password)

New-PSDrive -Name J -PSProvider FileSystem -Root $Dest -Credential $mycreds -Persist
Copy-Item -Path $Source -Destination "J:\myfile.txt"

Reading/Writing a MS Word file in PHP

phpLiveDocx is a Zend Framework component and can read and write DOC and DOCX files in PHP on Linux, Windows and Mac.

See the project web site at:

How to create a DateTime equal to 15 minutes ago?

from datetime import timedelta - datetime.timedelta(0, 900)

Actually 900 is in seconds. Which is equal to 15 minutes. `15*60 = 900`

Serializing and submitting a form with jQuery and PHP

 $("#contactForm").submit(function() {

    $.post(url, $.param($(this).serializeArray()), function(data) {


GSON throwing "Expected BEGIN_OBJECT but was BEGIN_ARRAY"?

according to GSON User guide, you cannot.

Collections Limitations

Can serialize collection of arbitrary objects but can not deserialize from it. Because there is no way for the user to indicate the type of the resulting object

How can a Jenkins user authentication details be "passed" to a script which uses Jenkins API to create jobs?

This worked for me:

curl -u $username:$api_token -FSubmit=Build 'http://<jenkins-server>/job/<job-name>/buildWithParameters?environment='

API token can be obtained from Jenkins user configuration.

How can I get screen resolution in java?

You can get the screen size with the Toolkit.getScreenSize() method.

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
double width = screenSize.getWidth();
double height = screenSize.getHeight();

On a multi-monitor configuration you should use this :

GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
int width = gd.getDisplayMode().getWidth();
int height = gd.getDisplayMode().getHeight();

If you want to get the screen resolution in DPI you'll have to use the getScreenResolution() method on Toolkit.

Resources :

jQuery Scroll to bottom of page/iframe


I use this code to scroll the chat when new messages arrive.

Set cURL to use local virtual hosts

Actually, curl has an option explicitly for this: --resolve

Instead of curl -H 'Host:'

use curl --resolve ''

What's the difference, you ask?

Among others, this works with HTTPS. Assuming your local server has a certificate for, the first example above will fail because the certificate doesn't match the hostname in the URL.

The second example works correctly with HTTPS.

In essence, passing a "Host" header via -H does hack your Host into the header set, but bypasses all of curl's host-specific intelligence. Using --resolve leverages all of the normal logic that applies, but simply pretends the DNS lookup returned the data in your command-line option. It works just like /etc/hosts should.

Note --resolve takes a port number, so for HTTPS you would use

curl --resolve ''

Move cursor to end of file in vim

If you plan to write the next line, ESCGo will do the carriage return and put you in insert mode on the next line (at the end of the file), saving a couple more keystrokes.

Why do you have to link the math library in C?

I think it's kind of arbitrary. You have to draw a line somewhere (which libraries are default and which need to be specified).

It gives you the opportunity to replace it with a different one that has the same functions, but I don't think it's very common to do so.

EDIT: (from my own comments): I think gcc does this to maintain backwards compatibility with the original cc. My guess for why cc does this is because of build time -- cc was written for machines with far less power than we have now. A lot of programs have no floating-point math and they probably took every library that wasn't commonly used out of the default. I'm guessing that the build time of the UNIX OS and the tools that go along with it were the driving force.

What are these attributes: `aria-labelledby` and `aria-hidden`

ARIA does not change functionality, it only changes the presented roles/properties to screen reader users. WebAIM’s WAVE toolbar identifies ARIA roles on the page.

What do numbers using 0x notation mean?

It's a hexadecimal number.

0x6400 translates to 4*16^2 + 6*16^3 = 25600

How to while loop until the end of a file in Python without checking for empty line?

for line in f

reads all file to a memory, and that can be a problem.

My offer is to change the original source by replacing stripping and checking for empty line. Because if it is not last line - You will receive at least newline character in it ('\n'). And '.strip()' removes it. But in last line of a file You will receive truely empty line, without any characters. So the following loop will not give You false EOF, and You do not waste a memory:

with open("blablabla.txt", "r") as fl_in:
   while True:
      line = fl_in.readline()

        if not line:

      line = line.strip()
      # do what You want

How to fix "could not find a base address that matches schema http"... in WCF

I had to do two things to the IIS configuration of the site/application. My issue had to do with getting net.tcp working in an IIS Web Site App:


  1. Right click on the IIS App name.
  2. Manage Web Site
  3. Advanced Settings
  4. Set Enabled protocols to be "http,net.tcp"


  1. Under the Actions menu on the right side of the Manager, click Bindings...
  2. Click Add
  3. Change type to "net.tcp"
  4. Set binding information to {open port number}:*
  5. OK

Comparing double values in C#

Adding onto Valentin Kuzub's answer above:

we could use a single method that supports providing nth precision number:

public static bool EqualsNthDigitPrecision(this double value, double compareTo, int precisionPoint) =>
    Math.Abs(value - compareTo) < Math.Pow(10, -Math.Abs(precisionPoint));

Note: This method is built for simplicity without added bulk and not with performance in mind.

How to read embedded resource text file

I know it is an old thread, but this is what worked for me :

  1. add the text file to the project resources
  2. set the access modifier to public, as showed above by Andrew Hill
  3. read the text like this :

    textBox1 = new TextBox();
    textBox1.Text = Properties.Resources.SomeText;

The text that I added to the resources: 'SomeText.txt'

Retrieving a List from a in Java 8

There is a new method Stream.toList() in Java 16:

List<Long> targetLongList = sourceLongList
         .filter(l -> l > 100)

How to alert using jQuery

For each works with JQuery as in

$(<selector>).each(function() {
   //this points to item

JQuery also, for a popup, has in the UI library a dialog widget:

Check it out, works really well.


jQuery Multiple ID selectors

If you give each of these instances a class you can use


lodash multi-column sortBy descending

You can always use Array.prototype.reverse()

var data = _.sortBy(array_of_objects, ['type', 'name']).reverse();

Tool for sending multipart/form-data request

UPDATE: I have created a video on sending multipart/form-data requests to explain this better.

Actually, Postman can do this. Here is a screenshot

Newer version : Screenshot captured from postman chrome extension enter image description here

Another version

enter image description here

Older version

enter image description here

Make sure you check the comment from @maxkoryukov

Be careful with explicit Content-Type header. Better - do not set it's value, the Postman is smart enough to fill this header for you. BUT, if you want to set the Content-Type: multipart/form-data - do not forget about boundary field.

Best way to call a JSON WebService from a .NET Console

Although the existing answers are valid approaches , they are antiquated . HttpClient is a modern interface for working with RESTful web services . Check the examples section of the page in the link , it has a very straightforward use case for an asynchronous HTTP GET .

using (var client = new System.Net.Http.HttpClient())
    return await client.GetStringAsync(""); //uri

How to remove the hash from window.location (URL) with JavaScript without page refresh?

<script type="text/javascript">
var uri = window.location.toString();
if (uri.indexOf("?") > 0) {
    var clean_uri = uri.substring(0, uri.indexOf("?"));
    window.history.replaceState({}, document.title, clean_uri);

put this code on head section

How do I rename the extension for a bunch of files?

rename 's/\.html$/\.txt/' *.html

does exactly what you want.

How do I implement charts in Bootstrap?

Github did this using the HTML canvas element.

This specification defines the 2D Context for the HTML canvas element. The 2D Context provides objects, methods, and properties to draw and manipulate graphics on a canvas drawing surface.

If you use a browser inspector, you see inside every list element a div with a canvas element.

<div class="participation-graph">
   <canvas class="bars" data-color-all="#F5F5F5" data-color-owner="#F5F5F5" data-source="/mxcl/homebrew/graphs/owner_participation" height="80" width="640"></canvas>

With CSS (z-index, position...) you can put that canvas in the background of a li element or table, in your case.

Do a search about jquery pluggins that fit your requirement.

Hope this pointers help you to achieve that.

Getting random numbers in Java

int max = 50;
int min = 1;

1. Using Math.random()

double random = Math.random() * 49 + 1;
int random = (int )(Math.random() * 50 + 1);

This will give you value from 1 to 50 in case of int or 1.0 (inclusive) to 50.0 (exclusive) in case of double


random() method returns a random number between 0.0 and 0.9..., you multiply it by 50, so upper limit becomes 0.0 to 49.999... when you add 1, it becomes 1.0 to 50.999..., now when you truncate to int, you get 1 to 50. (thanks to @rup in comments). leepoint's awesome write-up on both the approaches.

2. Using Random class in Java.

Random rand = new Random(); 
int value = rand.nextInt(50); 

This will give value from 0 to 49.

For 1 to 50: rand.nextInt((max - min) + 1) + min;

Source of some Java Random awesomeness.

Writing/outputting HTML strings unescaped

Apart from using @MvcHtmlString.Create(ViewBag.Stuff) as suggested by Dommer, I suggest you to also use AntiXSS library as suggested phill

It encodes almost all the possible XSS attack string.

Where to find the complete definition of off_t type?

Since this answer still gets voted up, I want to point out that you should almost never need to look in the header files. If you want to write reliable code, you're much better served by looking in the standard. A better question than "how is off_t defined on my machine" is "how is off_t defined by the standard?". Following the standard means that your code will work today and tomorrow, on any machine.

In this case, off_t isn't defined by the C standard. It's part of the POSIX standard, which you can browse here.

Unfortunately, off_t isn't very rigorously defined. All I could find to define it is on the page on sys/types.h:

blkcnt_t and off_t shall be signed integer types.

This means that you can't be sure how big it is. If you're using GNU C, you can use the instructions in the answer below to ensure that it's 64 bits. Or better, you can convert to a standards defined size before putting it on the wire. This is how projects like Google's Protocol Buffers work (although that is a C++ project).

So, I think "where do I find the definition in my header files" isn't the best question. But, for completeness here's the answer:

On my machine (and most machines using glibc) you'll find the definition in bits/types.h (as a comment says at the top, never directly include this file), but it's obscured a bit in a bunch of macros. An alternative to trying to unravel them is to look at the preprocessor output:

#include <stdio.h>
#include <sys/types.h>

int main(void) {
  off_t blah;

  return 0;

And then:

$ gcc -E sizes.c  | grep __off_t
typedef long int __off_t;

However, if you want to know the size of something, you can always use the sizeof() operator.

Edit: Just saw the part of your question about the __. This answer has a good discussion. The key point is that names starting with __ are reserved for the implementation (so you shouldn't start your own definitions with __).

What do the return values of Comparable.compareTo mean in Java?

int x = thisObject.compareTo(anotherObject);

The compareTo() method returns an int with the following characteristics:

  • negative If thisObject < anotherObject
  • zero If thisObject == anotherObject
  • positive If thisObject > anotherObject

Assign command output to variable in batch file

This post has a method to achieve this

from (zvrba) You can do it by redirecting the output to a file first. For example:

echo zz > bla.txt
set /p VV=<bla.txt
echo %VV%

LDAP Authentication using Java

// this class will authenticate LDAP UserName or Email

// simply call LdapAuth.authenticateUserAndGetInfo (username,password);

//Note: Configure ldapURI ,requiredAttributes ,ADSearchPaths,accountSuffex 

import java.util.*;

import javax.naming.*;

import java.util.regex.*;


import javax.naming.ldap.InitialLdapContext;

import javax.naming.ldap.LdapContext;

public class LdapAuth {

private final static String ldapURI = "ldap://,DC=local";

private final static String contextFactory = "com.sun.jndi.ldap.LdapCtxFactory";

private  static String[] requiredAttributes = {"cn","givenName","sn","displayName","userPrincipalName","sAMAccountName","objectSid","userAccountControl"};

// see you active directory user OU's hirarchy 

private  static String[] ADSearchPaths = 


    "OU=O365 Synced Accounts,OU=ALL USERS",

    "OU=Users,OU=O365 Synced Accounts,OU=ALL USERS",

    "OU=In-House,OU=Users,OU=O365 Synced Accounts,OU=ALL USERS",

    "OU=Torbram Users,OU=Users,OU=O365 Synced Accounts,OU=ALL USERS",

    "OU=Migrated Users,OU=TES-Users"


private static String accountSuffex = "@corp.local"; // this will be used if user name is just provided

private static void authenticateUserAndGetInfo (String user, String password) throws Exception {

    try {

        Hashtable<String,String> env = new Hashtable <String,String>();

        env.put(Context.INITIAL_CONTEXT_FACTORY, contextFactory);

        env.put(Context.PROVIDER_URL, ldapURI);     

        env.put(Context.SECURITY_AUTHENTICATION, "simple");

        env.put(Context.SECURITY_PRINCIPAL, user);

        env.put(Context.SECURITY_CREDENTIALS, password);

        DirContext ctx = new InitialDirContext(env);

        String filter = "(sAMAccountName="+user+")";  // default for search filter username

        if(user.contains("@"))  // if user name is a email then
            //String parts[] = user.split("\\@");
            //use different filter for email
            filter = "(userPrincipalName="+user+")";

        SearchControls ctrl = new SearchControls();

        NamingEnumeration userInfo = null;

        Integer i = 0;
            userInfo =[i], filter, ctrl);

        } while(!userInfo.hasMore() && i < ADSearchPaths.length );

        if (userInfo.hasMore()) {

            SearchResult UserDetails = (SearchResult);
            Attributes userAttr = UserDetails.getAttributes();System.out.println("adEmail = "+userAttr.get("userPrincipalName").get(0).toString());

            System.out.println("adFirstName = "+userAttr.get("givenName").get(0).toString());

            System.out.println("adLastName = "+userAttr.get("sn").get(0).toString());

            System.out.println("name = "+userAttr.get("cn").get(0).toString());

            System.out.println("AdFullName = "+userAttr.get("cn").get(0).toString());



    catch (javax.naming.AuthenticationException e) {


How to create multiple class objects with a loop in python?

This question is asked every day in some variation. The answer is: keep your data out of your variable names, and this is the obligatory blog post.

In this case, why not make a list of objs?

objs = [MyClass() for i in range(10)]
for obj in objs:


C++, What does the colon after a constructor mean?

As others have said, it's an initialisation list. You can use it for two things:

  1. Calling base class constructors
  2. Initialising member variables before the body of the constructor executes.

For case #1, I assume you understand inheritance (if that's not the case, let me know in the comments). So you are simply calling the constructor of your base class.

For case #2, the question may be asked: "Why not just initialise it in the body of the constructor?" The importance of the initialisation lists is particularly evident for const members. For instance, take a look at this situation, where I want to initialise m_val based on the constructor parameter:

class Demo
    Demo(int& val) 
         m_val = val;
    const int& m_val;

By the C++ specification, this is illegal. We cannot change the value of a const variable in the constructor, because it is marked as const. So you can use the initialisation list:

class Demo
    Demo(int& val) : m_val(val)
    const int& m_val;

That is the only time that you can change a const member variable. And as Michael noted in the comments section, it is also the only way to initialise a reference that is a class member.

Outside of using it to initialise const member variables, it seems to have been generally accepted as "the way" of initialising variables, so it's clear to other programmers reading your code.

How to use jQuery in AngularJS

The best option is create a directive and wrap the slider features there. The secret is use $timeout, the jquery code will be called only when DOM is ready.

    ['$timeout', function($timeout) {
        return {
            scope: true,
            template: '<div id="{{ id }}"></div>',
            link: function($scope) {
                $ = String(Math.random()).substr(2, 8);

                $timeout(function() {

Why does the JFrame setSize() method not set the size correctly?

The top border of frame is of size 30.You can write code for printing the coordinate of any point on the frame using MouseInputAdapter.You will find when the cursor is just below the top border of the frame the y coordinate is not zero , its close to 30.Hence if you give size to frame 300 * 300 , the size available for putting the components on the frame is only 300 * 270.So if you need to have size 300 * 300 ,give 300 * 330 size of the frame.

Artisan migrate could not find driver

whilst sometimes you might have multiple php versions, you might also have a held-back version of php-mysql.. do a sudo dpkg -l | grep mysql | grep php and compare what you get from php -v

Kubernetes service external ip pending

I created a single node k8s cluster using kubeadm. When i tried PortForward and kubectl proxy, it showed external IP as pending.

$ kubectl get svc -n argocd argocd-server
NAME            TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
argocd-server   LoadBalancer   <pending>     80:30047/TCP,443:31307/TCP   110s

In my case I've patched the service like this:

kubectl patch svc <svc-name> -n <namespace> -p '{"spec": {"type": "LoadBalancer", "externalIPs":[""]}}'

After this, it started serving over the public IP

$ kubectl get svc argo-ui -n argo
NAME      TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)        AGE
argo-ui   LoadBalancer   80:30981/TCP   7m50s

How to print a two dimensional array?

public static void printTwoDimensionalArray(int[][] a) {
    for (int i = 0; i < a.length; i++) {
        for (int j = 0; j < a[i].length; j++) {
            System.out.printf("%d ", a[i][j]);

just for int array

jQuery: Load Modal Dialog Contents via Ajax

Check out this blog post from Nemikor, which should do what you want.

Basically, before calling 'open', you 'load' the content from the other page first.

jQuery('#dialog').load('path to my page').dialog('open'); 

Run jar file in command prompt

Try this

java -jar <jar-file-name>.jar

How can you detect the version of a browser?

I wrote this for my needs.

It get info like if is a mobile device or if has a retina display

try it

var nav = {
            return (navigator.userAgent.match(/iPhone|iPad|iPod|Android|BlackBerry|Opera Mini|IEMobile/i) != null);
            return (navigator.userAgent.match(/iPhone|iPad|iPod|Android|BlackBerry|Opera Mini|IEMobile/i) == null);
        isAndroid: function() {
            return navigator.userAgent.match(/Android/i);
        isBlackBerry: function() {
            return navigator.userAgent.match(/BlackBerry/i);
        isIOS: function() {
            return navigator.userAgent.match(/iPhone|iPad|iPod/i);
        isOpera: function() {
            return navigator.userAgent.match(/Opera Mini/i);
        isWindows: function() {
            return navigator.userAgent.match(/IEMobile/i);
            return window.devicePixelRatio && window.devicePixelRatio > 1;
            isIPad = (/ipad/gi).test(navigator.platform);
            return isIPad;
            if(window.innerHeight < window.innerWidth){
                return true;
            return false;
                var OSVersion = navigator.appVersion.match(/OS (\d+_\d+)/i);
                OSVersion = OSVersion[1] ? +OSVersion[1].replace('_', '.') : 0;
                return OSVersion;
                return false;
                return navigator.standalone;
            return false;
            var isChrome = (/Chrome/gi).test(navigator.appVersion);
            var isSafari = (/Safari/gi).test(navigator.appVersion)
            return isChrome && isSafari;
            var isSafari = (/Safari/gi).test(navigator.appVersion)
            var isChrome = (/Chrome/gi).test(navigator.appVersion)
            return !isChrome && isSafari;

How should I use try-with-resources with JDBC?

As others have stated, your code is basically correct though the outer try is unneeded. Here are a few more thoughts.


Other answers here are correct and good, such the accepted Answer by bpgergo. But none of the show the use of DataSource, commonly recommended over use of DriverManager in modern Java.

So for the sake of completeness, here is a complete example that fetches the current date from the database server. The database used here is Postgres. Any other database would work similarly. You would replace the use of org.postgresql.ds.PGSimpleDataSource with an implementation of DataSource appropriate to your database. An implementation is likely provided by your particular driver, or connection pool if you go that route.

A DataSource implementation need not be closed, because it is never “opened”. A DataSource is not a resource, is not connected to the database, so it is not holding networking connections nor resources on the database server. A DataSource is simply information needed when making a connection to the database, with the database server's network name or address, the user name, user password, and various options you want specified when a connection is eventually made. So your DataSource implementation object does not go inside your try-with-resources parentheses.

Nested try-with-resources

Your code makes proper used of nested try-with-resources statements.

Notice in the example code below that we also use the try-with-resources syntax twice, one nested inside the other. The outer try defines two resources: Connection and PreparedStatement. The inner try defines the ResultSet resource. This is a common code structure.

If an exception is thrown from the inner one, and not caught there, the ResultSet resource will automatically be closed (if it exists, is not null). Following that, the PreparedStatement will be closed, and lastly the Connection is closed. Resources are automatically closed in reverse order in which they were declared within the try-with-resource statements.

The example code here is overly simplistic. As written, it could be executed with a single try-with-resources statement. But in a real work you will likely be doing more work between the nested pair of try calls. For example, you may be extracting values from your user-interface or a POJO, and then passing those to fulfill ? placeholders within your SQL via calls to PreparedStatement::set… methods.

Syntax notes

Trailing semicolon

Notice that the semicolon trailing the last resource statement within the parentheses of the try-with-resources is optional. I include it in my own work for two reasons: Consistency and it looks complete, and it makes copy-pasting a mix of lines easier without having to worry about end-of-line semicolons. Your IDE may flag the last semicolon as superfluous, but there is no harm in leaving it.

Java 9 – Use existing vars in try-with-resources

New in Java 9 is an enhancement to try-with-resources syntax. We can now declare and populate the resources outside the parentheses of the try statement. I have not yet found this useful for JDBC resources, but keep it in mind in your own work.

ResultSet should close itself, but may not

In an ideal world the ResultSet would close itself as the documentation promises:

A ResultSet object is automatically closed when the Statement object that generated it is closed, re-executed, or used to retrieve the next result from a sequence of multiple results.

Unfortunately, in the past some JDBC drivers infamously failed to fulfill this promise. As a result, many JDBC programmers learned to explicitly close all their JDBC resources including Connection, PreparedStatement, and ResultSet too. The modern try-with-resources syntax has made doing so easier, and with more compact code. Notice that the Java team went to the bother of marking ResultSet as AutoCloseable, and I suggest we make use of that. Using a try-with-resources around all your JDBC resources makes your code more self-documenting as to your intentions.

Code example

package work.basil.example;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.LocalDate;
import java.util.Objects;

public class App
    public static void main ( String[] args )
        App app = new App();

    private void doIt ( )
        System.out.println( "Hello World!" );

        org.postgresql.ds.PGSimpleDataSource dataSource = new org.postgresql.ds.PGSimpleDataSource();

        dataSource.setServerName( "" );
        dataSource.setPortNumber( 5432 );

        dataSource.setDatabaseName( "example_db_" );
        dataSource.setUser( "scott" );
        dataSource.setPassword( "tiger" );

        dataSource.setApplicationName( "ExampleApp" );

        System.out.println( "INFO - Attempting to connect to database: " );
        if ( Objects.nonNull( dataSource ) )
            String sql = "SELECT CURRENT_DATE ;";
            try (
                    Connection conn = dataSource.getConnection() ;
                    PreparedStatement ps = conn.prepareStatement( sql ) ;
                … make `PreparedStatement::set…` calls here.
                try (
                        ResultSet rs = ps.executeQuery() ;
                    if ( )
                        LocalDate ld = rs.getObject( 1 , LocalDate.class );
                        System.out.println( "INFO - date is " + ld );
            catch ( SQLException e )

        System.out.println( "INFO - all done." );

What is the use of hashCode in Java?

hashCode() is a function that takes an object and outputs a numeric value. The hashcode for an object is always the same if the object doesn't change.

Functions like HashMap, HashTable, HashSet, etc. that need to store objects will use a hashCode modulo the size of their internal array to choose in what "memory position" (i.e. array position) to store the object.

There are some cases where collisions may occur (two objects end up with the same hashcode), and that, of course, needs to be solved carefully.

How to detect window.print() finish

It works for me with $(window).focus().

var w;
var src = 'http://pagetoprint';
if (/chrom(e|ium)/.test(navigator.userAgent.toLowerCase())) {
    w = $('<iframe></iframe>');
    w.attr('src', src);
    w.css('display', 'none');
    w.load(function() {
    $(window).focus(function() {
        console.log('After print');
else {
    w =;
    $(w).unload(function() {
        console.log('After print');

Not equal <> != operator on NULL

NULL has no value, and so cannot be compared using the scalar value operators.

In other words, no value can ever be equal to (or not equal to) NULL because NULL has no value.

Hence, SQL has special IS NULL and IS NOT NULL predicates for dealing with NULL.

PHP get domain name

To answer your question, these should work as long as:

  • Your HTTP server passes these values along to PHP (I don't know any that don't)
  • You're not accessing the script via command line (CLI)

But, if I remember correctly, these values can be faked to an extent, so it's best not to rely on them.

My personal preference is to set the domain name as an environment variable in the apache2 virtual host:

# Virtual host

And read it in PHP:

// PHP
echo getenv(DOMAIN_NAME);

This, however, isn't applicable in all circumstances.

Angular 2 Routing run in new tab

In my use case, I wanted to asynchronously retrieve a url, and then follow that url to an external resource in a new window. A directive seemed overkill because I don't need reusability, so I simply did:

<button (click)="navigateToResource()">Navigate</button>

And in my component.ts

navigateToResource(): void {
  this.service.getUrl((result: any) =>;


Routing to a link indirectly like this will likely trigger the browser's popup blocker.

Can I use GDB to debug a running process?

Yes. You can do:

gdb program_name program_pid

A shortcut would be (assuming only one instance is running):

gdb program_name `pidof program_name`

Insert string at specified position

Try it, it will work for any number of substrings

    $string = 'bcadef abcdef';
    $substr = 'a';
    $attachment = '+++';

    //$position = strpos($string, 'a');

    $newstring = str_replace($substr, $substr.$attachment, $string);

    // bca+++def a+++bcdef

Key Shortcut for Eclipse Imports

Yes. you can't remember all the shortcuts. You will forget many of them for sure. In this way, you can recall it and get the work done quickly.

Press Ctrl+3

And type whatever the hell you want :) It's a shortcut for shortcuts

enter image description here

checking if number entered is a digit in jquery

Forget regular expressions. JavaScript has a builtin function for this: isNaN():

isNaN(123)           // false
isNaN(-1.23)         // false
isNaN(5-2)           // false
isNaN(0)             // false
isNaN("100")         // false
isNaN("Hello")       // true
isNaN("2005/12/12")  // true

Just call it like so:

if (isNaN( $("#whatever").val() )) {
    // It isn't a number
} else {
    // It is a number

Error:java: invalid source release: 8 in Intellij. What does it mean?

As Andreas mentioned all about:

Error:java: invalid source release: 8 in IntelliJ
Error:java: invalid source release: 13 in IntelliJ
Error:java: invalid source release: 14 in IntelliJ...

OR whatever version you are using in Java...

The problem will exist if you do not have it matching inside the below code:


This 1.8 in my case, must be matching on your device through MAVEN project library, settings, preferences, project setting and SDK.

test attribute in JSTL <c:if> tag

You can also use something like

<c:if test="${ testObject.testPropert == "testValue" }">...</c:if>

Install msi with msiexec in a Specific Directory

If you've used Advanced Installer to build your .msi you will want to use APPDIR=

What is the difference between String and StringBuffer in Java?

String is an immutable class. This means that once you instantiate an instance of a string like so:

String str1 = "hello";

The object in memory cannot be altered. Instead you will have to create a new instance, copy the old String and append whatever else as in this example:

String str1 = "hello";
str1 = str1 + " world!";

What is really happening hear is that we are NOT updating the existing str1 object... we are reallocating new memory all together, copying the "hello" data and appending " world!" to the end, then settings the str1 reference to point to this new memory. So it really looks more like this under the hood:

String str1 = "hello";
String str2 = str1 + " world!";
str1 = str2;

So it follows that this "copy + paste and move stuff around in memory" process can be very expensive if done repitively especially recursively.

When you are in that situation of having to do things over and over utilize StringBuilder. It is mutable and can append strings to the end of the current one because it's back by an [growing array] (not 100% if that is the actual data structure, could be a list).

VSCode single to double quote automatic replace

As noted by @attdona the Vetur extension includes prettier.

While you can change the prettier settings, as per the accepted answer, you can also change the formatter for specific regions of a vue component.

Here, for example, I've set Vetur to use the vscode-typescript formatter as it uses single quotes by default:

vscode vetur settings

No content to map due to end-of-input jackson parser

I could fix this error. In my case, the problem was at client side. By mistake I did not close the stream that I was writing to server. I closed stream and it worked fine. Even the error sounds like server was not able to identify the end-of-input.

OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
out.close() ; //This is what I did

Can't connect to local MySQL server through socket '/var/mysql/mysql.sock' (38)

I ran into this issue today. None of these answers provided the fix. I needed to do the following commands (found here for my mysql service to start:

sudo /etc/init.d/mysql stop
cd /var/lib/mysql/
ls ib_logfile*
mv ib_logfile0 ib_logfile0.bak
mv ib_logfile1 ib_logfile1.bak
... etc ...
/etc/init.d/mysql restart

This was partly indicated by the following errors in /var/log/mysql/error.log:

140319 11:58:21 InnoDB: Completed initialization of buffer pool
InnoDB: Error: log file ./ib_logfile0 is of different size 0 50331648 bytes
InnoDB: than specified in the .cnf file 0 5242880 bytes!
140319 11:58:21 [ERROR] Plugin 'InnoDB' init function returned error.
140319 11:58:21 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
140319 11:58:21 [ERROR] Unknown/unsupported storage engine: InnoDB
140319 11:58:21 [ERROR] Aborting

I also saw the disk full error, but only when running commands without sudo. If the permissions check fails, it reports disk full (even when your partition is not even close to full).

App store link for "rate/review this app"

Starting from iOS 10.3 you can attach action=write-review query item to your and URLs. On iOS 10.3 and up it will open Write a review automatically, while on lower iOS releases will fall back to the app's App Store page.

iOS 11 update: Use Apple's linkmaker: and append &action=write-review, seems to be the most safe way to go.

“tag already exists in the remote" error after recreating the git tag

In Windows SourceTree, untick Push all tags to remotes.

enter image description here

How to draw a filled circle in Java?

/***Your Code***/
public void paintComponent(Graphics g){
/***Your Code***/


Remove style attribute from HTML tags

Here you go:


$html = '<p style="border: 1px solid red;">Test</p>';
echo preg_replace('/<p style="(.+?)">(.+?)<\/p>/i', "<p>$2</p>", $html);


By the way, as pointed out by others, regex are not suggested for this.

How to create a thread?

public class ThreadParameter
            public int Port { get; set; }
            public string Path { get; set; }

Thread t = new Thread(new ParameterizedThreadStart(Startup));
t.Start(new ThreadParameter() { Port = port, Path = path});

Create an object with the port and path objects and pass it to the Startup method.

How to debug PDO database queries?

No. PDO queries are not prepared on the client side. PDO simply sends the SQL query and the parameters to the database server. The database is what does the substitution (of the ?'s). You have two options:

  • Use your DB's logging function (but even then it's normally shown as two separate statements (ie, "not final") at least with Postgres)
  • Output the SQL query and the paramaters and piece it together yourself

Difference between List, List<?>, List<T>, List<E>, and List<Object>

You're right: String is a subset of Object. Since String is more "precise" than Object, you should cast it to use it as an argument for System.out.println().

How to add buttons dynamically to my form?

It doesn't work because the list is empty. Try this:

private void button1_Click(object sender, EventArgs e)
    List<Button> buttons = new List<Button>();
    for (int i = 0; i < 10; i++)
        Button newButton = new Button();

How to select records without duplicate on just one field in SQL?

Ignore duplicate rows in SQL. I think this may help you.

    SELECT res2.*
    (select * from [dbo].[tbl_countries])as res1
    )as res2
    WHERE res2.num=1

What is the difference between json.dumps and json.load?

dumps takes an object and produces a string:

>>> a = {'foo': 3}
>>> json.dumps(a)
'{"foo": 3}'

load would take a file-like object, read the data from that object, and use that string to create an object:

with open('file.json') as fh:
    a = json.load(fh)

Note that dump and load convert between files and objects, while dumps and loads convert between strings and objects. You can think of the s-less functions as wrappers around the s functions:

def dump(obj, fh):

def load(fh):
    return loads(

How to delete from select in MySQL?

  FROM posts AS p1 
) AS p2
USING (id)

How to get every first element in 2 dimensional list

Compared the 3 methods

  1. 2D list: 5.323603868484497 seconds
  2. Numpy library : 0.3201274871826172 seconds
  3. Zip (Thanks to Joran Beasley) : 0.12395167350769043 seconds
for i in range(10**5):
    for j in range(10):
        b=[k[j] for k in D2_list]

for i in range(10**5):
    for j in range(10):

D2_trans = list(zip(*D2_list)) 
for i in range(10**5):
    for j in range(10):

print ('2D List:',D2_list_time)
print ('Numpy:',Numpy_time)
print ('Zip:',Zip_time)

The Zip method works best. It was quite useful when I had to do some column wise processes for mapreduce jobs in the cluster servers where numpy was not installed.

What is the difference between prefix and postfix operators?

In fact return (i++) will only return 10.

The ++ and -- operators can be placed before or after the variable, with different effects. If they are before, then they will be processed and returned and essentially treated just like (i-1) or (i+1), but if you place the ++ or -- after the i, then the return is essentailly

return i;
i + 1;

So it will return 10 and never increment it.

Test for multiple cases in a switch, like an OR (||)

You can use fall-through:

switch (pageid)
    case "listing-page":
    case "home-page":
    case "details-page":

Android Google Maps API V2 Zoom to Current Location

youmap.animateCamera(CameraUpdateFactory.newLatLngZoom(currentlocation, 16));

16 is the zoom level

optional parameters in SQL Server stored proc?

You can declare like this

    @Parameter1 INT = 1,
    @Parameter2 VARCHAR (100) = 'StringValue',
    @Parameter3 VARCHAR (100) = NULL

/* check for the NULL / default value (indicating nothing was passed */
if (@Parameter3 IS NULL)
    /* whatever code you desire for a missing parameter*/
    INSERT INTO ........

/* and use it in the query as so*/
FROM Table
WHERE Column = @Parameter

Google OAuth 2 authorization - Error: redirect_uri_mismatch

This answer is same as this Mike's answer, and Jeff's answer, both sets redirect_uri to postmessage on client side. I want to add more about the server side, and also the special circumstance applying to this configuration.

Tech Stack



The "Code" Flow (Specifically for Google OAuth2)

Summary: React --> request social auth "code" --> request jwt token to acquire "login" status in terms of your own backend server/database.

  1. Frontend (React) uses a "Google sign in button" with responseType="code" to get an authorization code. (it's not token, not access token!)
    • The google sign in button is from react-google-login mentioned above.
    • Click on the button will bring up a popup window for user to select account. After user select one and the window closes, you'll get the code from the button's callback function.
  2. Frontend send this to backend server's JWT endpoint.
    • POST request, with { "provider": "google-oauth2", "code": "your retrieved code here", "redirect_uri": "postmessage" }
  3. For my Django server I use Django REST Framework JWT + Django REST Social Auth. Django receives the code from frontend, verify it with Google's service (done for you). Once verified, it'll send the JWT (the token) back to frontend. Frontend can now harvest the token and store it somewhere.
    • All of REST_SOCIAL_OAUTH_ABSOLUTE_REDIRECT_URI, REST_SOCIAL_DOMAIN_FROM_ORIGIN and REST_SOCIAL_OAUTH_REDIRECT_URI in Django's are unnecessary. (They are constants used by Django REST Social Auth) In short, you don't have to setup anything related to redirect url in Django. The "redirect_uri": "postmessage" in React frontend suffice. This makes sense because the social auth work you have to do on your side is all Ajax-style POST request in frontend, not submitting any form whatsoever, so actually no redirection occur by default. That's why the redirect url becomes useless if you're using the code + JWT flow, and the server-side redirect url setting is not taking any effect.
  4. The Django REST Social Auth handles account creation. This means it'll check the google account email/last first name, and see if it match any account in database. If not, it'll create one for you, using the exact email & first last name. But, the username will be something like youremailprefix717e248c5b924d60 if your email is [email protected]. It appends some random string to make a unique username. This is the default behavior, I believe you can customize it and feel free to dig into their documentation.
  5. The frontend stores that token and when it has to perform CRUD to the backend server, especially create/delete/update, if you attach the token in your Authorization header and send request to backend, Django backend will now recognize that as a login, i.e. authenticated user. Of course, if your token expire, you have to refresh it by making another request.

Oh my goodness, I've spent more than 6 hours and finally got this right! I believe this is the 1st time I saw this postmessage thing. Anyone working on a Django + DRF + JWT + Social Auth + React combination will definitely crash into this. I can't believe none of the article out there mentions this except answers here. But I really hope this post can save you tons of time if you're using the Django + React stack.

Clearing an input text field in Angular2

You can just change the reference of input value, as below

    <input type="text" placeholder="Search..." #reference>
    <button (click)="reference.value=''">Clear</button>

How to get the CUDA version?

If you are running on linux:

dpkg -l | grep cuda

How to completely remove borders from HTML table

Using TinyMCE editor, the only way I was able to remove all borders was to use border:hidden in the style like this:

table, tr {border:hidden;}
td, th {border:hidden;}

And in the HTML like this:

<table style="border:hidden;"</table>


Find number of decimal places in decimal value regardless of culture

You can try:

int priceDecimalPlaces =

Sorting std::map using value

A std::map sorted by it's value is in essence a std::set. By far the easiest way is to copy all entries in the map to a set (taken and adapted from here)

template <typename M, typename S> 
void MapToSet( const  M & m, S & s )
    typename M::const_iterator end = m.end();
    for( typename M::const_iterator it = m.begin(); it != end ; ++it )
        s.insert( it->second );

One caveat: if the map contains different keys with the same value, they will not be inserted into the set and be lost.

Insert data into a view (SQL Server)

Inserting 'test' to name will lead to inserting NULL values to other columns of the base table which wont be correct as Id is a PRIMARY KEY and it cannot have NULL value.

onKeyDown event not working on divs in React

You should use tabIndex attribute to be able to listen onKeyDown event on a div in React. Setting tabIndex="0" should fire your handler.


I wrote a (recursive) function to delete any row based on its primary key. I wrote this because I did not want to create my constraints as "on delete cascade". I wanted to be able to delete complex sets of data (as a DBA) but not allow my programmers to be able to cascade delete without thinking through all of the repercussions. I'm still testing out this function, so there may be bugs in it -- but please don't try it if your DB has multi column primary (and thus foreign) keys. Also, the keys all have to be able to be represented in string form, but it could be written in a way that doesn't have that restriction. I use this function VERY SPARINGLY anyway, I value my data too much to enable the cascading constraints on everything. Basically this function is passed in the schema, table name, and primary value (in string form), and it will start by finding any foreign keys on that table and makes sure data doesn't exist-- if it does, it recursively calls itsself on the found data. It uses an array of data already marked for deletion to prevent infinite loops. Please test it out and let me know how it works for you. Note: It's a little slow. I call it like so: select delete_cascade('public','my_table','1');

create or replace function delete_cascade(p_schema varchar, p_table varchar, p_key varchar, p_recursion varchar[] default null)
 returns integer as $$
    rx record;
    rd record;
    v_sql varchar;
    v_recursion_key varchar;
    recnum integer;
    v_primary_key varchar;
    v_rows integer;
    recnum := 0;
    select ccu.column_name into v_primary_key
        information_schema.table_constraints  tc
        join information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name and ccu.constraint_schema=tc.constraint_schema
        and tc.constraint_type='PRIMARY KEY'
        and tc.table_name=p_table
        and tc.table_schema=p_schema;

    for rx in (
        select kcu.table_name as foreign_table_name, 
        kcu.column_name as foreign_column_name, 
        kcu.table_schema foreign_table_schema,
        kcu2.column_name as foreign_table_primary_key
        from information_schema.constraint_column_usage ccu
        join information_schema.table_constraints tc on tc.constraint_name=ccu.constraint_name and tc.constraint_catalog=ccu.constraint_catalog and ccu.constraint_schema=ccu.constraint_schema 
        join information_schema.key_column_usage kcu on kcu.constraint_name=ccu.constraint_name and kcu.constraint_catalog=ccu.constraint_catalog and kcu.constraint_schema=ccu.constraint_schema
        join information_schema.table_constraints tc2 on tc2.table_name=kcu.table_name and tc2.table_schema=kcu.table_schema
        join information_schema.key_column_usage kcu2 on kcu2.constraint_name=tc2.constraint_name and kcu2.constraint_catalog=tc2.constraint_catalog and kcu2.constraint_schema=tc2.constraint_schema
        where ccu.table_name=p_table  and ccu.table_schema=p_schema
        and tc2.constraint_type='PRIMARY KEY'
        v_sql := 'select '||rx.foreign_table_primary_key||' as key from '||rx.foreign_table_schema||'.'||rx.foreign_table_name||'
            where '||rx.foreign_column_name||'='||quote_literal(p_key)||' for update';
        --raise notice '%',v_sql;
        --found a foreign key, now find the primary keys for any data that exists in any of those tables.
        for rd in execute v_sql
            if (v_recursion_key = any (p_recursion)) then
                --raise notice 'Avoiding infinite loop';
                --raise notice 'Recursing to %,%',rx.foreign_table_name, rd.key;
                recnum:= recnum +delete_cascade(rx.foreign_table_schema::varchar, rx.foreign_table_name::varchar, rd.key::varchar, p_recursion||v_recursion_key);
            end if;
        end loop;
    end loop;
    --actually delete original record.
    v_sql := 'delete from '||p_schema||'.'||p_table||' where '||v_primary_key||'='||quote_literal(p_key);
    execute v_sql;
    get diagnostics v_rows= row_count;
    --raise notice 'Deleting %.% %=%',p_schema,p_table,v_primary_key,p_key;
    recnum:= recnum +v_rows;
    exception when others then recnum=0;

    return recnum;
language PLPGSQL;

is there a tool to create SVG paths from an SVG file?

Open the svg using Inkscape.

Inkscape is a svg editor it is a bit like Illustrator but as it is built specifically for svg it handles it way better. It is a free software and it's available @

  • ctrl A (select all)
  • shift ctrl C (=Path/Object to paths)
  • ctrl s (save (choose as plain svg))


all rect/circle have been converted to path

jQuery - Add active class and remove active from other element on click

Use jquery cookie and then you can be sure the class will stay on page refresh.

Stores the id of the clicked element in the cookie and then uses that to add the class on refresh.

        //Get cookie value and set active
        var tab = $.cookie('active');
        $('#' + tab).addClass('active');

        //Set cookie active tab value on click
        //Done this way to preserve after page refresh
        $('.topTab').click(function (event) {
            var clickedTab =;
            $.removeCookie('active', { path: '/' });
            $( '.active' ).removeClass( 'active' );
            $.cookie('active', clickedTab, { path: '/' });

Skipping Incompatible Libraries at compile

That message isn't actually an error - it's just a warning that the file in question isn't of the right architecture (e.g. 32-bit vs 64-bit, wrong CPU architecture). The linker will keep looking for a library of the right type.

Of course, if you're also getting an error along the lines of can't find lPI-Http then you have a problem :-)

It's hard to suggest what the exact remedy will be without knowing the details of your build system and makefiles, but here are a couple of shots in the dark:

  1. Just to check: usually you would add flags to CFLAGS rather than CTAGS - are you sure this is correct? (What you have may be correct - this will depend on your build system!)
  2. Often the flag needs to be passed to the linker too - so you may also need to modify LDFLAGS

If that doesn't help - can you post the full error output, plus the actual command (e.g. gcc foo.c -m32 -Dxxx etc) that was being executed?

Infinity symbol with HTML

According to this page, it's &infin;.

websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:


var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);

// Tell the server this is client 1 (swap for client 2 of course)
  id: "client1"

// Tell the server we want to send something to the other client
  to: "client2",
  data: "foo"


var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[] = client;
  } else {
    // Send data to the client requested

How to pass data from Javascript to PHP and vice versa?

Using cookies is a easy way. You can use jquery and a pluging as jquery.cookie or create your own. Using Jquery + jquery.cookie, by example

   var php_value = '<?php echo $php_variable; ?>';

   var infobar_active = $.cookie('php_value');
   var infobar_alert  = any_process(infobar_active);

    //set a cookie to readit via php
   $.cookie('infobar_alerta', infobar_alerta );



    var js_value = code to read a cookie


I've found this usefull Server-Side and Hybrid Frameworks:

I've been using Ashley's RSJS Script to update values in HTML without any problem for a long time until I met JQuery (ajax, load, etc.)

How to check if a class inherits another class without instantiating it?

Try this


This will tell you whether BarClass(Derived) implements IFoo(SomeType) or not

What is the difference between printf() and puts() in C?

When comparing puts() and printf(), even though their memory consumption is almost the same, puts() takes more time compared to printf().

Array to Collection: Optimized code

Based on the reference of java.util.Collections.addAll(Collection<? super String> c, String... elements) its implementation is similar to your first method, it says

Adds all of the specified elements to the specified collection. Elements to be added may be specified individually or as an array. The behavior of this convenience method is identical to that of c.addAll(Arrays.asList(elements)), but this method is likely to run significantly faster under most implementations.

Its implementation in jdk is (jdk7)

public static <T> boolean addAll(Collection<? super T> c, T... elements) {
    boolean result = false;
    for (T element : elements)
        result |= c.add(element);
    return result;

So among your samples the better approach must be Collections.addAll(list, array);

Since Java 8, we can use Stream api which may perform better


String[] array = {"item1", "item2", "item3"};

Stream<String> stream = Stream.of(array);

//if the array is extremely large 
stream = stream.parallel();

final List<String> list = stream.collect(Collectors.toList());

If the array is very large we can do it as a batch operation in parallel using parallel stream (stream = stream.parallel()) that will utilize all CPUs to finish the task quickly. If the array length is very small parallel stream will take more time than sequential stream.

Angular2: custom pipe could not be found

be sure, that if the declarations for the pipe are done in one module, while you are using the pipe inside another module, you should provide correct imports/declarations at the current module under which is the class where you are using the pipe. In my case that was the reason for the pipe miss

Is it safe to expose Firebase apiKey to the public?

I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.

I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable. Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase. Go to and perfrom a security steup.

Regular Expressions: Is there an AND operator?

You could pipe your output to another regex. Using grep, you could do this:

grep A | grep B

How to use LocalBroadcastManager?

localbroadcastmanager is deprecated, use implementations of the observable pattern instead.

androidx.localbroadcastmanager is being deprecated in version 1.1.0


LocalBroadcastManager is an application-wide event bus and embraces layer violations in your app; any component may listen to events from any other component. It inherits unnecessary use-case limitations of system BroadcastManager; developers have to use Intent even though objects live in only one process and never leave it. For this same reason, it doesn’t follow feature-wise BroadcastManager .

These add up to a confusing developer experience.


You can replace usage of LocalBroadcastManager with other implementations of the observable pattern. Depending on your use case, suitable options may be LiveData or reactive streams.

Advantage of LiveData

You can extend a LiveData object using the singleton pattern to wrap system services so that they can be shared in your app. The LiveData object connects to the system service once, and then any observer that needs the resource can just watch the LiveData object.

 public class MyFragment extends Fragment {
    public void onActivityCreated(Bundle savedInstanceState) {
        LiveData<BigDecimal> myPriceListener = ...;
        myPriceListener.observe(this, price -> {
            // Update the UI.

The observe() method passes the fragment, which is an instance of LifecycleOwner, as the first argument. Doing so denotes that this observer is bound to the Lifecycle object associated with the owner, meaning:

  • If the Lifecycle object is not in an active state, then the observer isn't called even if the value changes.

  • After the Lifecycle object is destroyed, the observer is automatically removed

The fact that LiveData objects are lifecycle-aware means that you can share them between multiple activities, fragments, and services.

Delete a row in DataGridView Control in VB.NET

Assuming you are using Windows forms, you could allow the user to select a row and in the delete key click event. It is recommended that you allow the user to select 1 row only and not a group of rows (myDataGridView.MultiSelect = false)

Private Sub pbtnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click

        If myDataGridView.SelectedRows.Count > 0 Then
            'you may want to add a confirmation message, and if the user confirms delete
            MessageBox.Show("Select 1 row before you hit Delete")
        End If

    End Sub

Note that this will not delete the row form the database until you perform the delete in the database.

How can I have linebreaks in my long LaTeX equations?

Without configuring your math environment to clip, you could force a new line with two backslashes in a sequence like this:

Bla Bla \\ Bla Bla in another line

The problem with this is that you will need to determine where a line is likely to end and force to always have a line break there. With equations, rather than text, I prefer this manual way.

You could also use \\* to prevent a new page from being started.

Android Emulator: Installation error: INSTALL_FAILED_VERSION_DOWNGRADE

In Marshmallow, I got this error,

Please check logcat output for more details.
Launch canceled!

Looking for solution I searched and came here. I deleted the app but still have this problem in Nexus 6. Later found that in,

Settings > Apps > [My app name] have to removed for all user. 

bash script read all the files in directory

To write it with a while loop you can do:

ls -f /var | while read -r file; do cmd $file; done

The primary disadvantage of this is that cmd is run in a subshell, which causes some difficulty if you are trying to set variables. The main advantages are that the shell does not need to load all of the filenames into memory, and there is no globbing. When you have a lot of files in the directory, those advantages are important (that's why I use -f on ls; in a large directory ls itself can take several tens of seconds to run and -f speeds that up appreciably. In such cases 'for file in /var/*' will likely fail with a glob error.)

Passing HTML input value as a JavaScript Function Parameter

1 IDs are meant to be unique

2 You dont need to pass any argument as you can call them in your javascript

  a: <input type="number" name="a" id="a"><br>
  b: <input type="number" name="b" id="b"><br>
  <button onclick="add()">Add</button>
  function add() {
    var a = document.getElementById('a').value;
    var b = document.getElementById('b').value;
    var sum = a + b;

Print a list in reverse order with range()?

You could use range(10)[::-1] which is the same thing as range(9, -1, -1) and arguably more readable (if you're familiar with the common sequence[::-1] Python idiom).

How to set background image of a view?

use this

self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Default"]];

How can I add a box-shadow on one side of an element?

Ok, here is one try more. Using pseudo elements and aplying the shadow-box porperty over them.


<div class="no-relevant-box">
  <div class="div-to-shadow-1"></div>
  <div class="div-to-shadow-2"></div>


.div-to-shadow-1, .div-to-shadow-2
  height: 150px
  width: 150px
  overflow: hidden
  transition: all 0.3s ease-in-out
    display: block
    content: ''
    position: relative
    top: 0
    left: 100%
    height: 100%
    width: 10px
    border: 1px solid mediumeagreen
    box-shadow:  0px 7px 12px rgba(0,0,0,0.3)
    border: 1px solid dodgerblue
    overflow: visible

How is a tag different from a branch in Git? Which should I use, here?

I like to think of branches as where you're going, tags as where you've been.

A tag feels like a bookmark of a particular important point in the past, such as a version release.

Whereas a branch is a particular path the project is going down, and thus the branch marker advances with you. When you're done you merge/delete the branch (i.e. the marker). Of course, at that point you could choose to tag that commit.

What is a web service endpoint?

A endpoint is a URL for web service.And Endpoints also is a distributed API.

The Simple Object Access Protocol (SOAP) endpoint is a URL. It identifies the location on the built-in HTTP service where the web services listener listens for incoming requests.


How do you open a file in C++?

#include <fstream>

ifstream infile;**file path**);

Send a ping to each IP on a subnet

The command line utility nmap can do this too:

nmap -sP 192.168.1.*

How to force garbage collector to run?

System.GC.Collect() forces garbage collector to run. This is not recommended but can be used if situations arise.

How to access at request attributes in JSP?

EL expression:


There are several implicit objects in JSP EL. See Expression Language under the "Implicit Objects" heading.

How to convert URL parameters to a JavaScript object?

I needed to also deal with + in the query part of the URL (decodeURIComponent doesn't), so I adapted Wolfgang's code to become:

var search =;
search = search?JSON.parse('{"' + search.replace(/\+/g, ' ').replace(/&/g, '","').replace(/=/g,'":"') + '"}',
             function(key, value) { return key===""?value:decodeURIComponent(value)}):{};

In my case, I'm using jQuery to get URL-ready form parameters, then this trick to build an object out of it and I can then easily update parameters on the object and rebuild the query URL, e.g.:

var objForm = JSON.parse('{"' + $myForm.serialize().replace(/\+/g, ' ').replace(/&/g, '","').replace(/=/g,'":"') + '"}',
             function(key, value) { return key===""?value:decodeURIComponent(value)});
objForm.anyParam += stringToAddToTheParam;
var serializedForm = $.param(objForm);

How to throw a C++ exception

Just add throw where needed, and try block to the caller that handles the error. By convention you should only throw things that derive from std::exception, so include <stdexcept> first.

int compare(int a, int b) {
    if (a < 0 || b < 0) {
        throw std::invalid_argument("a or b negative");

void foo() {
    try {
        compare(-1, 0);
    } catch (const std::invalid_argument& e) {
        // ...

Also, look into Boost.Exception.

Github permission denied: ssh add agent has no identities

This could cause for any new terminal, the agent id is different. You need to add the Private key for the agent

$ ssh-add <path to your private key>

How to select date from datetime column?

You can use:

DATEDIFF ( day , startdate , enddate ) = 0


DATEPART( day, startdate ) = DATEPART(day, enddate)
DATEPART( month, startdate ) = DATEPART(month, enddate)
DATEPART( year, startdate ) = DATEPART(year, enddate)



Assign null to a SqlParameter

My code, working in real project Look the ternary operator beafore make the sqlparameter this is the best way for me, withou problems:

    public bool Key_AddExisting
          string clave
        , int? idHito_FileServer
        , int? idTipoDocumental_Almacen
        , string tipoExp_CHJ
        , int idTipoExp_Verti2
        , int idMov_Verti2
        List<SqlParameter> pars = new List<SqlParameter>()
              new SqlParameter { ParameterName = "@Clave", Value = clave }
    LOOK -> , idHito_FileServer == null ? new SqlParameter { ParameterName = "@IdHito_FileServer", Value = DBNull.Value } : new SqlParameter { ParameterName = "@IdHito_FileServer", Value = idHito_FileServer }
    LOOK -> , idTipoDocumental_Almacen == null ? new SqlParameter { ParameterName = "@IdTipoDocumental_Almacen", Value = DBNull.Value } : new SqlParameter { ParameterName = "@IdTipoDocumental_Almacen", Value = idTipoDocumental_Almacen }
            , new SqlParameter { ParameterName = "@TipoExp_CHJ", Value = tipoExp_CHJ }
            , new SqlParameter { ParameterName = "@IdTipoExp_Verti2", Value = idTipoExp_Verti2 }
            , new SqlParameter { ParameterName = "@IdMov_Verti2", Value = idMov_Verti2 }

        string sql = "INSERT INTO [dbo].[Enlaces_ClavesCHJ_MovimientosVerti2] " +
            "( " +
            "  [Clave] " +
            ", [IdHito_FileServer] " +
            ", [IdTipoDocumental_Almacen] " +
            ", [TipoExp_CHJ] " +
            ", [IdTipoExp_Verti2] " +
            ", [IdMov_Verti2] " +
            ") " +
            "VALUES" +
            "( " +
            "  @Clave" +
            ", @IdHito_FileServer" +
            ", @IdTipoDocumental_Almacen" +
            ", @TipoExp_CHJ" +
            ", @IdTipoExp_Verti2" +
            ", @IdMov_Verti2" +

        return DbBasic.ExecNonQuery(ref this.conn, sql, pars);

Loop backwards using indices in Python?

You can always do increasing range and subtract from a variable in your case 100 - i where i in range( 0, 101 ).

for i in range( 0, 101 ):
    print 100 - i

Failed to add a service. Service metadata may not be accessible. Make sure your service is running and exposing metadata.`

In case you rename the svc file make sure that your markup is correct. You'll need to modify the default configuration and follow these steps: 1) Go to SVC file right click and select view markup 2) Make sure that that code behind and service pointing to correct the file and class name.

How to remove an app with active device admin enabled on Android?

On Samsung go to "Settings" -> "Lock screen and security" -> "Other security settings" -> "Phone administrators" and deselect the admin which you want to uninstall.

The "security" word was hidden on my display, so it was not obvious that I should click on "Lock screen".

PHP foreach change original array values

Use &:

foreach($arr as &$value) {
    $value = $newVal;

& passes a value of the array as a reference and does not create a new instance of the variable. Thus if you change the reference the original value will change.

PHP documentation for Passing by Reference

Edit 2018

This answer seems to be favored by a lot of people on the internet, which is why I decided to add more information and words of caution.
While pass by reference in foreach (or functions) is a clean and short solution, for many beginners this might be a dangerous pitfall.

  1. Loops in PHP don't have their own scope. - @Mark Amery

    This could be a serious problem when the variables are being reused in the same scope. Another SO question nicely illustrates why that might be a problem.

  2. As foreach relies on the internal array pointer in PHP 5, changing it within the loop may lead to unexpected behavior. - PHP docs for foreach.

    Unsetting a record or changing the hash value (the key) during the iteration on the same loop could lead to potentially unexpected behaviors in PHP < 7. The issue gets even more complicated when the array itself is a reference.

  3. Foreach performance.
    In general, PHP prefers pass by value due to the copy-on-write feature. It means that internally PHP will not create duplicate data unless the copy of it needs to be changed. It is debatable whether pass by reference in foreach would offer a performance improvement. As it is always the case, you need to test your specific scenario and determine which option uses less memory and CPU time. For more information see the SO post linked below by NikiC.

  4. Code readability.
    Creating references in PHP is something that quickly gets out of hand. If you are a novice and don't have full control of what you are doing, it is best to stay away from references. For more information about & operator take a look at this guide: Reference — What does this symbol mean in PHP?
    For those who want to learn more about this part of PHP language: PHP References Explained

A very nice technical explanation by @NikiC of the internal logic of PHP foreach loops:
How does PHP 'foreach' actually work?

PHP isset() with multiple parameters

You just need:

if (!empty($_POST['search_term']) && !empty($_POST['postcode']))

isset && !empty is redundant.

How to add property to a class dynamically?

Not sure if I completely understand the question, but you can modify instance properties at runtime with the built-in __dict__ of your class:

class C(object):
    def __init__(self, ks, vs):
        self.__dict__ = dict(zip(ks, vs))

if __name__ == "__main__":
    ks = ['ab', 'cd']
    vs = [12, 34]
    c = C(ks, vs)
    print(c.ab) # 12

Formatting Phone Numbers in PHP

It's faster than RegEx.

$input = "0987654321"; 

$output = substr($input, -10, -7) . "-" . substr($input, -7, -4) . "-" . substr($input, -4); 
echo $output;

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

I got the same error but then I figured it out its because the Mysql server is not running at that time.

So to change the status of the server

  1. Go to Task Manager
  2. Go to Services
  3. then search for your Mysql server(eg:for my case its MYSQL56)
  4. then you will see under the status column it says its not running
  5. by right clicking and select start

Hope this will help.

html5: display video inside canvas

Here's a solution that uses more modern syntax and is less verbose than the ones already provided:

const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");
const video = document.querySelector("video");

video.addEventListener('play', () => {
  function step() {
    ctx.drawImage(video, 0, 0, canvas.width, canvas.height)

Some useful links:

OpenJDK8 for windows

Go to this link

Download version tar.gz for windows and just extract files to the folder by your needs. On the left pane, you can select which version of openjdk to download

Tutorial: unzip as expected. You need to set system variable PATH to include your directory with openjdk so you can type java -version in console.

JDK vs OpenJDK

Python group by

The following function will quickly (no sorting required) group tuples of any length by a key having any index:

# given a sequence of tuples like [(3,'c',6),(7,'a',2),(88,'c',4),(45,'a',0)],
# returns a dict grouping tuples by idx-th element - with idx=1 we have:
# if merge is True {'c':(3,6,88,4),     'a':(7,2,45,0)}
# if merge is False {'c':((3,6),(88,4)), 'a':((7,2),(45,0))}
def group_by(seqs,idx=0,merge=True):
    d = dict()
    for seq in seqs:
        k = seq[idx]
        v = d.get(k,tuple()) + (seq[:idx]+seq[idx+1:] if merge else (seq[:idx]+seq[idx+1:],))
    return d

In the case of your question, the index of key you want to group by is 1, therefore:



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

which is not exactly the output you asked for, but might as well suit your needs.

How to set image to fit width of the page using jsPDF?

If you want a dynamic sized image to automatically fill the page as much as possible and still keep the image width/height-ratio, you could do as follows:

let width = doc.internal.pageSize.getWidth()
let height = doc.internal.pageSize.getHeight()

let widthRatio = width / canvas.width
let heightRatio = height / canvas.height

let ratio = widthRatio > heightRatio ? heightRatio : widthRatio

  canvas.toDataURL('image/jpeg', 1.0),
  canvas.width * ratio,
  canvas.height * ratio,

How to disable a input in angular2

I presume you meant false instead of 'false'

Also, [disabled] is expecting a Boolean. You should avoid returning a null.

How does the keyword "use" work in PHP and can I import classes with it?

use doesn't include anything. It just imports the specified namespace (or class) to the current scope

If you want the classes to be autoloaded - read about autoloading

What does <? php echo ("<pre>"); ..... echo("</pre>"); ?> mean?

if you put text within an HTML tag, all spaces and line breaks will be preserved.

Otherwise, the default behaviour is to remove multiple spaces and keep only one space, and ignore line breaks (unless you use the

I'd like to say it's from the time before CSS - not necessarily used to make text more legible, only more formatted.

How to try convert a string to a Guid

If all you want is some very basic error checking, you could just check the length of the string.

              string guidStr = "";
              if( guidStr.Length == Guid.Empty.ToString().Length )
                 Guid g = new Guid( guidStr );

The HTTP request is unauthorized with client authentication scheme 'Negotiate'. The authentication header received from the server was 'NTLM'

I have upgraded my older version of WCF to WCF 4 with below changes, hope you can also make the similar changes.

1. Web.config:

          <binding name="Demo_BasicHttp">
            <security mode="TransportCredentialOnly">
              <transport clientCredentialType="InheritedFromHost"/>
        <service name="DemoServices.CalculatorService.ServiceImplementation.CalculatorService" behaviorConfiguration="Demo_ServiceBehavior">
          <endpoint address="" binding="basicHttpBinding"
              bindingConfiguration="Demo_BasicHttp" contract="DemoServices.CalculatorService.ServiceContracts.ICalculatorServiceContract">
              <dns value="localhost"/>
          <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
          <behavior name="Demo_ServiceBehavior">
            <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
            <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
            <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
            <serviceDebug includeExceptionDetailInFaults="false"/>
        <add scheme="http" binding="basicHttpBinding" bindingConfiguration="Demo_BasicHttp"/>
      <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />

2. App.config:

        <binding name="BasicHttpBinding_ICalculatorServiceContract" maxBufferSize="2147483647" maxBufferPoolSize="33554432" maxReceivedMessageSize="2147483647" closeTimeout="00:10:00" sendTimeout="00:10:00" receiveTimeout="00:10:00">
          <readerQuotas maxArrayLength="2147483647" maxBytesPerRead="4096" />
          <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Ntlm" proxyCredentialType="None" realm="" />
      <endpoint address="http://localhost:24357/CalculatorService.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_ICalculatorServiceContract" contract="ICalculatorServiceContract" name="Demo_BasicHttp" />

Bad operand type for unary +: 'str'

You say that if int(splitLine[0]) > int(lastUnix): is causing the trouble, but you don't actually show anything which suggests that. I think this line is the problem instead:

print 'Pulled', + stock

Do you see why this line could cause that error message? You want either

>>> stock = "AAAA"
>>> print 'Pulled', stock
Pulled AAAA


>>> print 'Pulled ' + stock
Pulled AAAA


>>> print 'Pulled', + stock
PulledTraceback (most recent call last):
  File "<ipython-input-5-7c26bb268609>", line 1, in <module>
    print 'Pulled', + stock
TypeError: bad operand type for unary +: 'str'

You're asking Python to apply the + symbol to a string like +23 makes a positive 23, and she's objecting.

How to Identify port number of SQL server

  1. Open Run in your system.

  2. Type %windir%\System32\cliconfg.exe

  3. Click on ok button then check that the "TCP/IP Network Protocol Default Value Setup" pop-up is open.

  4. Highlight TCP/IP under the Enabled protocols window.

  5. Click the Properties button.

  6. Enter the new port number, then click OK.

enter image description here

Executing Javascript code "on the spot" in Chrome?

I'm not sure how far it will get you, but you can execute JavaScript one line at a time from the Developer Tool Console.

How to remove unwanted space between rows and columns in table?

Just adding on top of Jacob's answer, for img in td,

body {line-height: 0;}
img {display: block; vertical-align: bottom;}

This works for most email clients, including Gmail. But not Outlook. For outlook, you need to do two steps more:

table {border-collapse: collapse;}

and set every td elements to have the same height and width as its contained images. For example,

<td width="600" height="80" style="line-height: 80px;">
    <img height="80" src="" width="600" />

Javascript: how to validate dates in format MM-DD-YYYY?

what isn't working about it? here's a tested version:

String.prototype.isValidDate = function()   {

    const match = this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);
    if (!match || match.length !== 4) {
        return false

    const test = new Date(match[3], match[1] - 1, match[2]);

    return (
        (test.getMonth() == match[1] - 1) &&
        (test.getDate() == match[2]) &&
        (test.getFullYear() == match[3])

var date = '12/08/1984'; // Date() is 'Sat Dec 08 1984 00:00:00 GMT-0800 (PST)'
alert(date.isValidDate() ); // true

how to print float value upto 2 decimal place without rounding off

i'd suggest shorter and faster approach:

printf("%.2f", ((signed long)(fVal * 100) * 0.01f));

this way you won't overflow int, plus multiplication by 100 shouldn't influence the significand/mantissa itself, because the only thing that really is changing is exponent.