Programs & Examples On #Beyondcompare

Beyond Compare is a tool used to compare files and directories.

Git Diff with Beyond Compare

For MAC after doing lot of research it worked for me..! 1. Install the beyond compare and this will be installed in below location


Please follow these steps to make bc as diff/merge tool in git

How to configure Visual Studio to use Beyond Compare

In Visual Studio, go to the Tools menu, select Options, expand Source Control, (In a TFS environment, click Visual Studio Team Foundation Server), and click on the Configure User Tools button.

image to show location of the Configure User Tools button

Click the Add button.

Enter/select the following options for Compare:

  • Extension: .*
  • Operation: Compare
  • Command: C:\Program Files\Beyond Compare 3\BComp.exe (replace with the proper path for your machine, including version number)
  • Arguments: %1 %2 /title1=%6 /title2=%7

If using Beyond Compare Professional (3-way Merge):

  • Extension: .*
  • Operation: Merge
  • Command: C:\Program Files\Beyond Compare 3\BComp.exe (replace with the proper path for your machine, including version number)
  • Arguments: %1 %2 %3 %4 /title1=%6 /title2=%7 /title3=%8 /title4=%9

If using Beyond Compare v3/v4 Standard or Beyond Compare v2 (2-way Merge):

  • Extension: .*
  • Operation: Merge
  • Command: C:\Program Files\Beyond Compare 3\BComp.exe (replace with the proper path for your machine, including version number)
  • Arguments: %1 %2 /savetarget=%4 /title1=%6 /title2=%7

If you use tabs in Beyond Compare

If you run Beyond Compare in tabbed mode, it can get confused when you diff or merge more than one set of files at a time from Visual Studio. To fix this, you can add the argument /solo to the end of the arguments; this ensures each comparison opens in a new window, working around the issue with tabs.

How to update Git clone

git pull origin master

this will sync your master to the central repo and if new branches are pushed to the central repo it will also update your clone copy.

Stopping an Android app from console

pkill NAMEofAPP

Non rooted marshmallow, termux & terminal emulator.

Selected value for JSP drop down using JSTL

In HTML, the selected option is represented by the presence of the selected attribute on the <option> element like so:

<option ... selected>...</option>

Or if you're HTML/XHTML strict:

<option ... selected="selected">...</option>

Thus, you just have to let JSP/EL print it conditionally. Provided that you've prepared the selected department as follows:

request.setAttribute("selectedDept", selectedDept);

then this should do:

<select name="department">
    <c:forEach var="item" items="${dept}">
        <option value="${item.key}" ${item.key == selectedDept ? 'selected="selected"' : ''}>${item.value}</option>

See also:

SQL Inner Join On Null Values

This article has a good discussion on this issue. You can use

                       SELECT y.QID);

Changing :hover to touch/click for mobile devices

You can add onclick="" to hovered element. Hover will work after that.

Edit: But you really shouldn't add anything style related to your markup, just posted it as an alternative.

How to verify if a file exists in a batch file?

Here is a good example on how to do a command if a file does or does not exist:

if exist C:\myprogram\sync\data.handler echo Now Exiting && Exit
if not exist C:\myprogram\html\data.sql Exit

We will take those three files and put it in a temporary place. After deleting the folder, it will restore those three files.

xcopy "test" "C:\temp"
xcopy "test2" "C:\temp"
del C:\myprogram\sync\
xcopy "C:\temp" "test"
xcopy "C:\temp" "test2"
del "c:\temp"

Use the XCOPY command:

xcopy "C:\myprogram\html\data.sql"  /c /d /h /e /i /y  "C:\myprogram\sync\"

I will explain what the /c /d /h /e /i /y means:

  /C           Continues copying even if errors occur.
  /D:m-d-y     Copies files changed on or after the specified date.
               If no date is given, copies only those files whose
               source time is newer than the destination time.
  /H           Copies hidden and system files also.
  /E           Copies directories and subdirectories, including empty ones.
               Same as /S /E. May be used to modify /T.
  /T           Creates directory structure, but does not copy files. Does not
               include empty directories or subdirectories. /T /E includes
  /I           If destination does not exist and copying more than one file,
               assumes that destination must be a directory.
  /Y           Suppresses prompting to confirm you want to overwrite an
               existing destination file.

`To see all the commands type`xcopy /? in cmd

Call other batch file with option sync.bat myprogram.ini.

I am not sure what you mean by this, but if you just want to open both of these files you just put the path of the file like


If it was in the Bash environment it was easy for me, but I do not know how to test if a file or folder exists and if it is a file or folder.

You are using a batch file. You mentioned earlier you have to create a .bat file to use this:

I have to create a .BAT file that does this:

How do I call REST API from an android app?

  1. If you want to integrate Retrofit (all steps defined here):

Goto my blog : retrofit with kotlin

  1. Please use android-async-http library.

the link below explains everything step by step.

Here are sample apps:



Create a class :

public class HttpUtils {
  private static final String BASE_URL = "";
  private static AsyncHttpClient client = new AsyncHttpClient();

  public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(getAbsoluteUrl(url), params, responseHandler);

  public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {, params, responseHandler);
  public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(url, params, responseHandler);

  public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {, params, responseHandler);

  private static String getAbsoluteUrl(String relativeUrl) {
      return BASE_URL + relativeUrl;

Call Method :

    RequestParams rp = new RequestParams();
    rp.add("username", "aaa"); rp.add("password", "aaa@123");
               , rp, new JsonHttpResponseHandler() {
        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
            // If the response is JSONObject instead of expected JSONArray
            Log.d("asd", "---------------- this is response : " + response);
            try {
                JSONObject serverResp = new JSONObject(response.toString());                                                
            } catch (JSONException e) {
                // TODO Auto-generated catch block
        public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {
            // Pull out the first event on the public timeline

Please grant internet permission in your manifest file.

 <uses-permission android:name="android.permission.INTERNET" />

you can add compile '' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.

FormData.append("key", "value") is not working

If you are in Chrome you can check the Post Data

Here is How to check the Post data

  1. Go to Network Tab
  2. Look for the Link to which you are sending Post Data
  3. Click on it
  4. In the Headers, you can check Request Payload to check the post data

Chrome's DevTools

What is the correct way to restore a deleted file from SVN?

With Tortoise SVN:

If you haven't committed your changes yet, you can do a revert on the parent folder where you deleted the file or directory.

If you have already committed the deleted file, then you can use the repository browser, change to the revision where the file still existed and then use the command Copy to... from the context menu. Enter the path to your working copy as the target and the deleted file will be copied from the repository to your working copy.

Create a custom callback in JavaScript

function loadData(callback) {

    //execute other requirement

    if(callback && typeof callback == "function"){


   //execute callback


Making an array of integers in iOS

You can use a plain old C array:

NSInteger myIntegers[40];

for (NSInteger i = 0; i < 40; i++)
    myIntegers[i] = i;

// to get one of them
NSLog (@"The 4th integer is: %d", myIntegers[3]);

Or, you can use an NSArray or NSMutableArray, but here you will need to wrap up each integer inside an NSNumber instance (because NSArray objects are designed to hold class instances).

NSMutableArray *myIntegers = [NSMutableArray array];

for (NSInteger i = 0; i < 40; i++)
    [myIntegers addObject:[NSNumber numberWithInteger:i]];

// to get one of them
NSLog (@"The 4th integer is: %@", [myIntegers objectAtIndex:3]);

// or
NSLog (@"The 4th integer is: %d", [[myIntegers objectAtIndex:3] integerValue]);

grabbing first row in a mysql query only

To return only one row use LIMIT 1:

FROM tbl_foo
WHERE name = 'sarmen'

It doesn't make sense to say 'first row' or 'last row' unless you have an ORDER BY clause. Assuming you add an ORDER BY clause then you can use LIMIT in the following ways:

  • To get the first row use LIMIT 1.
  • To get the 2nd row you can use limit with an offset: LIMIT 1, 1.
  • To get the last row invert the order (change ASC to DESC or vice versa) then use LIMIT 1.

Curl setting Content-Type incorrectly

I think you want to specify

-H "Content-Type:text/xml"

with a colon, not an equals.

Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

I found a faster way of embedding:

  • Just copy the link.
  • Paste the link and remove the "?s=19" part and add "/video/1"
  • That's it.

How do I resolve a HTTP 414 "Request URI too long" error?

Based on John's answer, I changed the GET request to a POST request. It works, without having to change the server configuration. So I went looking how to implement this. The following pages were helpful:

jQuery Ajax POST example with PHP (Note the sanitize posted data remark) and

Basically, the difference is that the GET request has the url and parameters in one string and then sends null:"GET", url+"?"+params, true);

whereas the POST request sends the url and the parameters in separate commands:"POST", url, true);

Here is a working example:


<script type="text/javascript">
    function ajaxPOSTTest() {
        try {
            // Opera 8.0+, Firefox, Safari
            ajaxPOSTTestRequest = new XMLHttpRequest();
        } catch (e) {
            // Internet Explorer Browsers
            try {
                ajaxPOSTTestRequest = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    ajaxPOSTTestRequest = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {
                    // Something went wrong
                    alert("Your browser broke!");
                    return false;

        ajaxPOSTTestRequest.onreadystatechange = ajaxCalled_POSTTest;
        var url = "ajaxPOST.php";
        var params = "lorem=ipsum&name=binny";"POST", url, true);
        ajaxPOSTTestRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    //Create a function that will receive data sent from the server
    function ajaxCalled_POSTTest() {
        if (ajaxPOSTTestRequest.readyState == 4) {
            document.getElementById("output").innerHTML = ajaxPOSTTestRequest.responseText;

    <button onclick="ajaxPOSTTest()">ajax POST Test</button>
    <div id="output"></div>



print $lorem.'<br>';


I just sent over 12,000 characters without any problems.

What is the most effective way for float and double comparison?

Unfortunately, even your "wasteful" code is incorrect. EPSILON is the smallest value that could be added to 1.0 and change its value. The value 1.0 is very important โ€” larger numbers do not change when added to EPSILON. Now, you can scale this value to the numbers you are comparing to tell whether they are different or not. The correct expression for comparing two doubles is:

if (fabs(a - b) <= DBL_EPSILON * fmax(fabs(a), fabs(b)))
    // ...

This is at a minimum. In general, though, you would want to account for noise in your calculations and ignore a few of the least significant bits, so a more realistic comparison would look like:

if (fabs(a - b) <= 16 * DBL_EPSILON * fmax(fabs(a), fabs(b)))
    // ...

If comparison performance is very important to you and you know the range of your values, then you should use fixed-point numbers instead.

Django return redirect() with parameters

Firstly, your URL definition does not accept any parameters at all. If you want parameters to be passed from the URL into the view, you need to define them in the urlconf.

Secondly, it's not at all clear what you are expecting to happen to the cleaned_data dictionary. Don't forget you can't redirect to a POST - this is a limitation of HTTP, not Django - so your cleaned_data either needs to be a URL parameter (horrible) or, slightly better, a series of GET parameters - so the URL would be in the form:


and so on. In this case, field1, field2 and field3 are not included in the URLconf definition - they are available in the view via request.GET.

So your urlconf would be:

url(r'^link/(?P<backend>\w+?)/$', my_function)

and the view would look like:

def my_function(request, backend):
   data = request.GET

and the reverse would be (after importing urllib):

return "%s?%s" % (redirect('my_function', args=(backend,)),

Edited after comment

The whole point of using redirect and reverse, as you have been doing, is that you go to the URL - it returns an Http code that causes the browser to redirect to the new URL, and call that.

If you simply want to call the view from within your code, just do it directly - no need to use reverse at all.

That said, if all you want to do is store the data, then just put it in the session:

request.session['temp_data'] = form.cleaned_data

How can I recognize touch events using jQuery in Safari for iPad? Is it possible?

jQuery Core doesn't have anything special, but you can read on jQuery Mobile Events page about different touch events, which also work on other than iOS devices as well.

They are:

  • tap
  • taphold
  • swipe
  • swipeleft
  • swiperight

Notice also, that during scroll events (based on touch on mobile devices) iOS devices freezes DOM manipulation while scrolling.

How do I set the background color of my main screen in Flutter?

you should return Scaffold widget and add your widget inside Scaffold

suck as this code :

import 'package:flutter/material.dart';

void main() {
  runApp(new MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  Widget build(BuildContext context) {
    return Scaffold(
          backgroundColor: Colors.white,
          body: Center(child: new Text("Hello, World!"));

Python base64 data decode

(I know this is old but I wanted to post this for people like me who stumble upon it in the future) I personally just use this python code to decode base64 strings:

print open("FILE-WITH-STRING", "rb").read().decode("base64")

So you can run it in a bash script like this:

python -c 'print open("FILE-WITH-STRING", "rb").read().decode("base64")' > outputfile
file -i outputfile

twneale has also pointed out an even simpler solution: base64 -d So you can use it like this:

#Or You Can Do This
echo "STRING" | base64 -d > OUTPUTFILE

That will save the decoded string to outputfile and then attempt to identify file-type using either the file tool or you can try TrID. The following command will decode the string into a file and then use TrID to automatically identify the file's type and add the extension.

echo "STRING" | base64 -d > OUTPUTFILE; trid -ce OUTPUTFILE

How can I create objects while adding them into a vector?

Question 1:


This is problematic because you cannot directly push a class name into a vector. You can either push an object of class into the vector or push reference or pointer to class type into the vector. For example:

vectorOfGamers.push_back(Player(name, id)) 
  //^^assuming name and id are parameters to the vector, call Player constructor
  //^^In other words, push `instance`  of Player class into vector

Question 2:

These 3 classes derives from Gamer. Can I create vector to hold objects of Dealer, Bot and Player at the same time? How do I do that?

Yes you can. You can create a vector of pointers that points to the base class Gamer. A good choice is to use a vector of smart_pointer, therefore, you do not need to manage pointer memory by yourself. Since the other three classes are derived from Gamer, based on polymorphism, you can assign derived class objects to base class pointers. You may find more information from this post: std::vector of objects / pointers / smart pointers to pass objects (buss error: 10)?

Find index of last occurrence of a substring in a string

Try this:

s = 'hello plombier pantin'
print (s.find('p'))
print (s.index('p'))
print (s.rindex('p'))
print (s.rfind('p'))

How to use unicode characters in Windows command line?

As I haven't seen any full answers for Python 2.7, I'll outline the two important steps and an optional step that is quite useful.

  1. You need a font with Unicode support. Windows comes with Lucida Console which may be selected by right-clicking the title bar of command prompt and clicking the Defaults option. This also gives access to colours. Note that you can also change settings for command windows invoked in certain ways (e.g, open here, Visual Studio) by choosing Properties instead.
  2. You need to set the code page to cp65001, which appears to be Microsoft's attempt to offer UTF-7 and UTF-8 support to command prompt. Do this by running chcp 65001 in command prompt. Once set, it remains this way until the window is closed. You'll need to redo this every time you launch cmd.exe.

For a more permanent solution, refer to this answer on Super User. In short, create a REG_SZ (String) entry using regedit at HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor and name it AutoRun. Change the value of it to chcp 65001. If you don't want to see the output message from the command, use @chcp 65001>nul instead.

Some programs have trouble interacting with this encoding, MinGW being a notable one that fails while compiling with a nonsensical error message. Nonetheless, this works very well and doesn't cause bugs with the majority of programs.

Pandas: ValueError: cannot convert float NaN to integer

if you have null value then in doing mathematical operation you will get this error to resolve it use df[~df['x'].isnull()]df[['x']].astype(int) if you want your dataset to be unchangeable.

How to print React component on click of a button?

You'll have to style your printout with @media print {} in the CSS but the simple code is:

export default class Component extends Component {


  render() {

  <span className="print"


Hope that's helpful!

How to make Git "forget" about a file that was tracked but is now in .gitignore?

Do the following steps for file/folder:

Remove File:

  1. need to add that file to .gitignore.
  2. need to remove that file using the command (git rm --cached file name).
  3. need to run (git add .).
  4. need to (commit -m) "file removed".
  5. and finally, (git push).

For example:

I want to delete test.txt file. I accidentally pushed to GitHub want to remove commands will be followed as:

1st add test.txt in .gitignore

git rm --cached test.txt
git add .
git commit -m "test.txt removed"
git push

Remove Folder:

  1. need to add that folder to .gitignore.
  2. need to remove that folder using the command (git rm -r --cached folder name).
  3. need to run (git add .).
  4. need to (commit -m) "folder removed".
  5. and finally, (git push).

For example:

I want to delete the .idea folder/dir. I accidentally pushed to GitHub want to remove commands will be followed as:

1st add .idea in .gitignore

git rm -r --cached .idea
git add .
git commit -m ".idea removed"
git push

Why do we not have a virtual constructor in C++?

Semantic reasons aside, there is no vtable until after the object is constructed, thus making a virtual designation useless.

How to save as a new file and keep working on the original one in Vim?

Thanks for the answers. Now I know that there are two ways of "SAVE AS" in Vim.

Assumed that I'm editing hello.txt.

  • :w world.txt will write hello.txt's content to the file world.txt while keeping hello.txt as the opened buffer in vim.
  • :sav world.txt will first write hello.txt's content to the file world.txt, then close buffer hello.txt, finally open world.txt as the current buffer.

How do I use tools:overrideLibrary in a build.gradle file?

use this code in manifest.xml


How to get the element clicked (for the whole document)?

$(document).click(function (e) {

How to get all privileges back to the root user in MySQL?

Log in as root, then run the following MySQL commands:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost';

How do I send a cross-domain POST request via JavaScript?

If you have access to the cross domain server and don't want to make any code changes on server side, you can use a library called - 'xdomain'.

How it works:

Step 1: server 1: include the xdomain library and configure the cross domain as a slave:

<script src="js/xdomain.min.js" slave="https://crossdomain_server/proxy.html"></script>

Step 2: on cross domain server, create a proxy.html file and include server 1 as a master:

<script src="js/xdomain.min.js"></script>
    "https://server1" : '*'

Step 3:

Now, you can make an AJAX call to the proxy.html as endpoint from server1. This is bypass the CORS request. The library internally uses iframe solution which works with Credentials and all possible methods: GET, POST etc.

Query ajax code:

        url: 'https://crossdomain_server/proxy.html',
        type: "POST",
        data: JSON.stringify(_data),
        dataType: "json",
        contentType: "application/json; charset=utf-8"

store return json value in input hidden field

You can store it in a hidden field, OR store it in a javascript object (my preference) as the likely access will be via javascript.

NOTE: since you have an array, this would then be accessed as myvariable[0] for the first element (as you have it).

EDIT show example:

            success: function(msg)

var myvariable ="";

function LoadProviders(jdata)
  myvariable = jdata;
alert(myvariable[0].id);// shows "15aea3fa" in the alert

EDIT: Created this page: to demonstrate the above. This example makes the assumption that you have already properly returned your named string values in the array and simply need to store it per OP question. In the example, I also put the values of the first array returned (per OP example) into a div as text.

I am not sure why this has been viewed as "complex" as I see no simpler way to handle these strings in this array.

How do I extract specific 'n' bits of a 32-bit unsigned integer in C?

If you need the X last bits of your integer, use a binary mask :

unsigned last8bitsvalue=(32 bit integer) & 0xFF
unsigned last16bitsvalue=(32 bit integer) & 0xFFFF

Descending order by date filter in AngularJs

see w3schools samples:

then add the "reverse" flag:

<!DOCTYPE html>
<script src=""></script>

<p>Click the table headers to change the sorting order:</p>

<div ng-app="myApp" ng-controller="namesCtrl">

<table border="1" width="100%">
<th ng-click="orderByMe('name')">Name</th>
<th ng-click="orderByMe('country')">Country</th>
<tr ng-repeat="x in names | orderBy:myOrderBy:reverse">


angular.module('myApp', []).controller('namesCtrl', function($scope) {
    $scope.names = [

    $scope.orderByMe = function(x) {

        if($scope.myOrderBy == x) {
        $scope.myOrderBy = x;


Visual Studio: LINK : fatal error LNK1181: cannot open input file

I had the same error when running lib.exe from cmd on Windows with a long argument list. apparently cmd.exe has max line length of about 8K characters, which resulted that the filenames at the end of this threshold got changed, thus resulting in bad filename error. my solution was to trim the line. I removed all paths from filenames and added single path using /LIBPATH option. for example:

/LIBPATH:absolute_path /OUT:outfilename filename1.obj filename2.obj ... filenameN.obj

Laravel 4 Eloquent Query Using WHERE with OR AND OR?

You can also use query scopes to make things a bit tidier, so you can do something like:

Invoice::where('account', 27)->notPaidAt($date)->get();

Then in your model

public function scopeNotPaidAt($query, $asAt)
    $query = $query->where(function ($query) use ($asAt) { 
        $query->where('paid', '=', '0000-00-00')->orWhere('paid', '>=', $asAt); 
    return $query;    

How to directly move camera to current location in Google Maps Android API v2?

I am explaining, How to get current location and Directly move to the camera to current location with assuming that you have implemented map-v2. For more details, You can refer official doc.

Add location service in gradle

implementation ""

Add location permission in manifest file

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

Make sure you ask for RunTimePermission. I am using Ask-Permission for that. Its easy to use.

Now refer below code to get the current location and display it on a map.

private FusedLocationProviderClient mFusedLocationProviderClient;

public void onCreate(@Nullable Bundle savedInstanceState) {
        mFusedLocationProviderClient = LocationServices


private void getDeviceLocation() {
        try {
            if (mLocationPermissionGranted) {
                Task<Location> locationResult = mFusedLocationProviderClient.getLastLocation();
                locationResult.addOnCompleteListener(new OnCompleteListener<Location>() {
                    public void onComplete(@NonNull Task<Location> task) {
                        if (task.isSuccessful()) {
                            // Set the map's camera position to the current location of the device.
                            Location location = task.getResult();
                            LatLng currentLatLng = new LatLng(location.getLatitude(),
                            CameraUpdate update = CameraUpdateFactory.newLatLngZoom(currentLatLng,
        } catch (SecurityException e) {
            Log.e("Exception: %s", e.getMessage());

When user granted location permission call above getDeviceLocation() method

private void updateLocationUI() {
        if (googleMap == null) {
        try {
            if (mLocationPermissionGranted) {
            } else {
        } catch (SecurityException e) {
            Log.e("Exception: %s", e.getMessage());

How to order events bound with jQuery

function bindFirst(owner, event, handler) {
    owner.unbind(event, handler);
    owner.bind(event, handler);

    var events ='events')[event];
    events.unshift(events.pop());'events')[event] = events;

How to match hyphens with Regular Expression?

Escape the hyphen.

[a-zA-Z0-9!$* \t\r\n\-]

Never mind this answer - you can add the hyphen to the group but you don't have to escape it. See Konrad Rudolph's answer instead which does a much better job of answering and explains why.

Android Layout Animations from bottom to top and top to bottom on ImageView click

Below Kotlin code will help

Bottom to Top or Slide to Up

private fun slideUp() {
    isMapInfoShown = true
    val animate = TranslateAnimation(
        0f,  // fromXDelta
        0f,  // toXDelta
        views!!.layoutMapInfo.height.toFloat(),  // fromYDelta
        0f  // toYDelta

    animate.duration = 500
    animate.fillAfter = true

Top to Bottom or Slide to Down

private fun slideDown() {
    if (isMapInfoShown) {
        isMapInfoShown = false
        val animate = TranslateAnimation(
            0f,  // fromXDelta
            0f,  // toXDelta
            0f,  // fromYDelta
            views!!.layoutMapInfo.height.toFloat()  // toYDelta

        animate.duration = 500
        animate.fillAfter = true

Kotlin Extensions for Visible and Gone

fun View.visible() {
    this.visibility = View.VISIBLE

fun View.gone() {
    this.visibility = View.GONE

Create a day-of-week column in a Pandas dataframe using Python

In version 0.18.1 is added dt.weekday_name:

print df
    my_dates  myvals
0 2015-01-01       1
1 2015-01-02       2
2 2015-01-03       3

print df.dtypes
my_dates    datetime64[ns]
myvals               int64
dtype: object

df['day_of_week'] = df['my_dates'].dt.weekday_name
print df
    my_dates  myvals day_of_week
0 2015-01-01       1    Thursday
1 2015-01-02       2      Friday
2 2015-01-03       3    Saturday

Another solution with assign:

print df.assign(day_of_week = df['my_dates'].dt.weekday_name)
    my_dates  myvals day_of_week
0 2015-01-01       1    Thursday
1 2015-01-02       2      Friday
2 2015-01-03       3    Saturday

Pure CSS to make font-size responsive based on dynamic amount of characters

This solution might also help :

$(document).ready(function () {
    $(window).resize(function() {
        if ($(window).width() < 600) {
            $('body').css('font-size', '2.8vw' );
        } else if ($(window).width() >= 600 && $(window).width() < 750) {
            $('body').css('font-size', '2.4vw');
         // and so on... (according to our needs)
        } else if ($(window).width() >= 1200) {
            $('body').css('font-size', '1.2vw');

It worked for me well !

Rethrowing exceptions in Java without losing the stack trace

You can also wrap the exception in another one AND keep the original stack trace by passing in the Exception as a Throwable as the cause parameter:

catch (Exception e)
     throw new YourOwnException(e);

CSS selector for text input fields?

The attribute selectors are often used for inputs. This is the list of attribute selectors:

[title] All elements with the title attribute are selected.

[title=banana] All elements which have the 'banana' value of the title attribute.

[title~=banana] All elements which contain 'banana' in the value of the title attribute.

[title|=banana] All elements which value of the title attribute starts with 'banana'.

[title^=banana] All elements which value of the title attribute begins with 'banana'.

[title$=banana] All elements which value of the title attribute ends with 'banana'.

[title*=banana] All elements which value of the title attribute contains the substring 'banana'.


PHP is_numeric or preg_match 0-9 validation

According to, is_numeric alows something like "+0123.45e6" or "0xFF". I think this not what you expect.

preg_match can be slow, and you can have something like 0000 or 0051.

I prefer using ctype_digit (works only with strings, it's ok with $_GET).

  $id = $_GET['id'];
  if (ctype_digit($id)) {
      echo 'ok';
  } else {
      echo 'nok';

How to detect reliably Mac OS X, iOS, Linux, Windows in C preprocessor?

As Jake points out, TARGET_IPHONE_SIMULATOR is a subset of TARGET_OS_IPHONE.

Also, TARGET_OS_IPHONE is a subset of TARGET_OS_MAC.

So a better approach might be:

#ifdef _WIN64
   //define something for Windows (64-bit)
#elif _WIN32
   //define something for Windows (32-bit)
#elif __APPLE__
    #include "TargetConditionals.h"
        // define something for simulator   
        // define something for iphone  
        #define TARGET_OS_OSX 1
        // define something for OSX
#elif __linux
    // linux
#elif __unix // all unices not caught above
    // Unix
#elif __posix
    // POSIX

Running Command Line in Java

what about

public class CmdExec {

public static Scanner s = null;

public static void main(String[] args) throws InterruptedException, IOException {
    s = new Scanner(;
    System.out.print("$ ");
    String cmd = s.nextLine();
    final Process p = Runtime.getRuntime().exec(cmd);

    new Thread(new Runnable() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null; 

            try {
                while ((line = input.readLine()) != null) {
            } catch (IOException e) {



How to check if one DateTime is greater than the other in C#

if (StartDate>=EndDate)
    throw new InvalidOperationException("Ack!  StartDate is not before EndDate!");

Reading file from Workspace in Jenkins with Groovy script

Based on your comments, you would be better off with Text-finder plugin.

It allows to search file(s), as well as console, for a regular expression and then set the build either unstable or failed if found.

As for the Groovy, you can use the following to access ${WORKSPACE} environment variable:
def workspace =["WORKSPACE"]

Split page vertically using CSS

There can also be a solution by having both float to left.

Try this out:

Working Demo

P.S. This is just an improvement of Ankit's Answer

What is the behavior difference between return-path, reply-to and from?

Let's start with a simple example. Let's say you have an email list, that is going to send out the following RFC2822 content.

From: <[email protected]>
To: <[email protected]>
Subject: Super simple email
Reply-To: <[email protected]>

This is a very simple body.

Now, let's say you are going to send it from a mailing list, that implements VERP (or some other bounce tracking mechanism that uses a different return-path). Lets say it will have a return-path of [email protected]. The SMTP session might look like:

{S}220 workstation1 Microsoft ESMTP MAIL Service
{C}HELO workstation1
{S}250 workstation1 Hello []
{C}MAIL FROM:<[email protected]>
{S}250 2.1.0 [email protected] OK
{C}RCPT TO:<[email protected]>
{S}250 2.1.5 [email protected] 
{S}354 Start mail input; end with <CRLF>.<CRLF>
{C}From: <[email protected]>
To: <[email protected]>
Subject: Super simple email
Reply-To: <[email protected]>

This is a very simple body.

{S}250 Queued mail for delivery
{S}221 Service closing transmission channel

Where {C} and {S} represent Client and Server commands, respectively.

The recipient's mail would look like:

Return-Path: [email protected]
From: <[email protected]>
To: <[email protected]>
Subject: Super simple email
Reply-To: <[email protected]>

This is a very simple body.

Now, let's describe the different "FROM"s.

  1. The return path (sometimes called the reverse path, envelope sender, or envelope from โ€” all of these terms can be used interchangeably) is the value used in the SMTP session in the MAIL FROM command. As you can see, this does not need to be the same value that is found in the message headers. Only the recipient's mail server is supposed to add a Return-Path header to the top of the email. This records the actual Return-Path sender during the SMTP session. If a Return-Path header already exists in the message, then that header is removed and replaced by the recipient's mail server.

All bounces that occur during the SMTP session should go back to the Return-Path address. Some servers may accept all email, and then queue it locally, until it has a free thread to deliver it to the recipient's mailbox. If the recipient doesn't exist, it should bounce it back to the recorded Return-Path value.

Note, not all mail servers obey this rule; Some mail servers will bounce it back to the FROM address.

  1. The FROM address is the value found in the FROM header. This is supposed to be who the message is FROM. This is what you see as the "FROM" in most mail clients. If an email does not have a Reply-To header, then all human (mail client) replies should go back to the FROM address.

  2. The Reply-To header is added by the sender (or the sender's software). It is where all human replies should be addressed too. Basically, when the user clicks "reply", the Reply-To value should be the value used as the recipient of the newly composed email. The Reply-To value should not be used by any server. It is meant for client-side (MUA) use only.

However, as you can tell, not all mail servers obey the RFC standards or recommendations.

Hopefully this should help clear things up. However, if I missed anything, let me know, and I'll try to answer.

Compare two Timestamp in java

There are after and before methods for Timestamp which will do the trick

Align button at the bottom of div using CSS

Goes to the right and can be used the same way for the left

   float: right;
   bottom: 0;

forward declaration of a struct in C?

A struct (without a typedef) often needs to (or should) be with the keyword struct when used.

struct A;                      // forward declaration
void function( struct A *a );  // using the 'incomplete' type only as pointer

If you typedef your struct you can leave out the struct keyword.

typedef struct A A;          // forward declaration *and* typedef
void function( A *a );

Note that it is legal to reuse the struct name

Try changing the forward declaration to this in your code:

typedef struct context context;

It might be more readable to do add a suffix to indicate struct name and type name:

typedef struct context_s context_t;

How do I hide certain files from the sidebar in Visual Studio Code?

Sometimes you just want to hide certain file types for a specific project. In that case, you can create a folder in your project folder called .vscode and create the settings.json file in there, (i.e. .vscode/settings.json). All settings within that file will affect your current workspace only.

For example, in a TypeScript project, this is what I have used:

// Workspace settings
    // The following will hide the js and map files in the editor
    "files.exclude": {
        "**/*.js": true,
        "**/*.map": true

Is true == 1 and false == 0 in JavaScript?

In JavaScript, == is pronounced "Probably Equals".

What I mean by that is that JavaScript will automatically convert the Boolean into an integer and then attempt to compare the two sides.

For real equality, use the === operator.

python capitalize first letter only

If the first character is an integer, it will not capitalize the first letter.

>>> '2s'.capitalize()

If you want the functionality, strip off the digits, you can use '2'.isdigit() to check for each character.

>>> s = '123sa'
>>> for i, c in enumerate(s):
...     if not c.isdigit():
...         break
>>> s[:i] + s[i:].capitalize()

Upgrade version of Pandas


pip3 install --upgrade pandas

How to compare dates in Java?

Date has before and after methods and can be compared to each other as follows:

if(todayDate.after(historyDate) && todayDate.before(futureDate)) {
    // In between

For an inclusive comparison:

if(!historyDate.after(todayDate) && !futureDate.before(todayDate)) {
    /* historyDate <= todayDate <= futureDate */ 

You could also give Joda-Time a go, but note that:

Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).

Back-ports are available for Java 6 and 7 as well as Android.

Converting Epoch time into the datetime

First a bit of info in epoch from man gmtime

The ctime(), gmtime() and localtime() functions all take an argument of data type time_t which represents calendar  time.   When  inter-
       preted  as  an absolute time value, it represents the number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal
       Time (UTC).

to understand how epoch should be.

>>> time.time()
>>> time.gmtime(time.time())
(2012, 9, 13, 6, 19, 34, 3, 257, 0)

just ensure the arg you are passing to time.gmtime() is integer.

Insert a new row into DataTable

// get the data table
DataTable dt = ...;

// generate the data you want to insert
DataRow toInsert = dt.NewRow();

// insert in the desired place
dt.Rows.InsertAt(toInsert, index);

How can I issue a single command from the command line through sql plus?

sqlplus user/password@sid < sqlfile.sql

This will also work from the DOS command line. In this case the file sqlfile.sql contains the SQL you wish to execute.

In Python, how do I iterate over a dictionary in sorted key order?

You can now use OrderedDict in Python 2.7 as well:

>>> from collections import OrderedDict
>>> d = OrderedDict([('first', 1),
...                  ('second', 2),
...                  ('third', 3)])
>>> d.items()
[('first', 1), ('second', 2), ('third', 3)]

Here you have the what's new page for 2.7 version and the OrderedDict API.

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '...' is therefore not allowed access

you have to put the headers keys/values in options method response. for example if you have resource at then, in your server code you write

//response handler
void handleRequest(Request request, Response response) {
    if(request.method == "OPTIONS") {
       response.setHeader("Access-Control-Allow-Methods", "GET,POST,PUT,DELETE,OPTIONS");
       response.setHeader("Access-Control-Allow-Headers", "Content-Type");


Select Tag Helper in ASP.NET Core MVC

In Get:

public IActionResult Create()
    ViewData["Tags"] = new SelectList(_context.Tags, "Id", "Name");
    return View();

In Post:

var selectedIds= Request.Form["Tags"];

In View :

<select  asp-for="Tags"  id="Tags" name="Tags" class="form-control" asp-items="ViewBag.Tags" multiple></select>

When should I use a table variable vs temporary table in sql server?

Use a table variable if for a very small quantity of data (thousands of bytes)

Use a temporary table for a lot of data

Another way to think about it: if you think you might benefit from an index, automated statistics, or any SQL optimizer goodness, then your data set is probably too large for a table variable.

In my example, I just wanted to put about 20 rows into a format and modify them as a group, before using them to UPDATE / INSERT a permanent table. So a table variable is perfect.

But I am also running SQL to back-fill thousands of rows at a time, and I can definitely say that the temporary tables perform much better than table variables.

This is not unlike how CTE's are a concern for a similar size reason - if the data in the CTE is very small, I find a CTE performs as good as or better than what the optimizer comes up with, but if it is quite large then it hurts you bad.

My understanding is mostly based on, which has a lot more detail.

How Long Does it Take to Learn Java for a Complete Newbie?

You can definitely get a good understanding of Java in 10 weeks, but as mentioned before, practice makes perfect (or at least better...). A couple of starting places:

The Java API will be your friend:

Java has a lot of built-in functionality so try not to duplicate it (String functions and whatnot).

Also, an IDE might make some things a little more complicated, but it'll also help you find your way around the API. Eclipse is a good place to start (and it's free)

Hope that helps a little..

There has been an error processing your request, Error log record number

When magento mode is default it showws such error Change magento mode to developer with

php bin/magento deploy:mode:set developer

then check your error on your browser and resolve that

CSS Grid Layout not working in IE11 even with prefixes

IE11 uses an older version of the Grid specification.

The properties you are using don't exist in the older grid spec. Using prefixes makes no difference.

Here are three problems I see right off the bat.


The repeat() function doesn't exist in the older spec, so it isn't supported by IE11.

You need to use the correct syntax, which is covered in another answer to this post, or declare all row and column lengths.

Instead of:

.grid {
  display: -ms-grid;
  display: grid;
  -ms-grid-columns: repeat( 4, 1fr );
      grid-template-columns: repeat( 4, 1fr );
  -ms-grid-rows: repeat( 4, 270px );
      grid-template-rows: repeat( 4, 270px );
  grid-gap: 30px;


.grid {
  display: -ms-grid;
  display: grid;
  -ms-grid-columns: 1fr 1fr 1fr 1fr;             /* adjusted */
      grid-template-columns:  repeat( 4, 1fr );
  -ms-grid-rows: 270px 270px 270px 270px;        /* adjusted */
      grid-template-rows: repeat( 4, 270px );
  grid-gap: 30px;

Older spec reference:


The span keyword doesn't exist in the older spec, so it isn't supported by IE11. You'll have to use the equivalent properties for these browsers.

Instead of:

.grid .grid-item.height-2x {
  -ms-grid-row: span 2;
      grid-row: span 2;
.grid .grid-item.width-2x {
  -ms-grid-column: span 2;
      grid-column: span 2;


.grid .grid-item.height-2x {
  -ms-grid-row-span: 2;          /* adjusted */
      grid-row: span 2;
.grid .grid-item.width-2x {
  -ms-grid-column-span: 2;       /* adjusted */
      grid-column: span 2;

Older spec reference:


The grid-gap property, as well as its long-hand forms grid-column-gap and grid-row-gap, don't exist in the older spec, so they aren't supported by IE11. You'll have to find another way to separate the boxes. I haven't read the entire older spec, so there may be a method. Otherwise, try margins.

grid item auto placement

There was some discussion in the old spec about grid item auto placement, but the feature was never implemented in IE11. (Auto placement of grid items is now standard in current browsers).

So unless you specifically define the placement of grid items, they will stack in cell 1,1.

Use the -ms-grid-row and -ms-grid-column properties.

Is CSS Turing complete?

The fundamental issue here is that any machine written in HTML+CSS cannot evaluate infinitely many steps (i.e there can be no "real" recursion) unless the code is infinitely long. And the question will this machine reach configuration H in n steps or less is always answerable if n is finite.

Create whole path automatically when writing to a new file

Since Java 1.7 you can use Files.createFile:

Path pathToFile = Paths.get("/home/joe/foo/bar/myFile.txt");

How to remove border of drop down list : CSS

The most you can get is:

select#xyz {

You cannot style it completely, but you can try something like

select#xyz {
  -webkit-appearance: button;
  -webkit-border-radius: 2px;
  -webkit-box-shadow: 0px 1px 3px rgba(0, 0, 0, 0.1);
  -webkit-padding-end: 20px;
  -webkit-padding-start: 2px;
  -webkit-user-select: none;
  background-image: url(../images/select-arrow.png), 
    -webkit-linear-gradient(#FAFAFA, #F4F4F4 40%, #E5E5E5);
  background-position: center right;
  background-repeat: no-repeat;
  border: 1px solid #AAA;
  color: #555;
  font-size: inherit;
  margin: 0;
  overflow: hidden;
  padding-top: 2px;
  padding-bottom: 2px;
  text-overflow: ellipsis;
  white-space: nowrap;

StringLength vs MaxLength attributes ASP.NET MVC with Entity Framework EF Code First

Following are the results when we use both [MaxLength] and [StringLength] attributes, in EF code first. If both are used, [MaxLength] wins the race. See the test result in studentname column in below class

 public class Student
    public Student () {}

    public int StudentKey { get; set; }

    //[MaxLength(50),StringLength(60)]    //studentname column will be nvarchar(50)
    //[StringLength(60)]    //studentname column will be nvarchar(60)
    [MaxLength(50)] //studentname column will be nvarchar(50)
    public string StudentName { get; set; }

    public byte[] RowVersion { get; set; }

Rails without Time

If you're happy to require 'active_support/core_ext', then you can use # => Sat, 19 Nov 2011 00:00:00 -0800

How to use relative paths without including the context root name?

You start tomcat from some directory - which is the $cwd for tomcat. You can specify any path relative to this $cwd.

suppose you have

- tomcat
- cssStore

And suppose you start tomcat from ~/tomcat, using the command "bin/".

~/tomcat becomes the home directory ($cwd) for tomcat

You can access "../cssStore/file.css" from class files in your servlet now

Hope that helps, - M.S.

How to comment lines in rails html.erb files?


The below also happens to answer the Original Poster's question without, the "ugly" conditional code that some commenters have mentioned.


    • This will work in any mixed language Rails View file, e.g, *.html.erb, *.js.erb, *.rhtml, etc.

    • This should also work with STD OUT/printing code, e.g. <%#= f.label :title %>

    • DETAILS:

      Rather than use rails brackets on each line and commenting in front of each starting bracket as we usually do like this:

        <%# if flash[:myErrors] %>
          <%# if flash[:myErrors].any? %>
            <%# if %>
              <%# if @myPost!=-1 %>
                <%# @post = @myPost %>
              <%# else %>
                <%# @post = %>
              <%# end %>
            <%# end %>
          <%# end %>
        <%# end %>

      YOU CAN INSTEAD add only one comment (hashmark/poundsign) to the first open Rails bracket if you write your code as one large block... LIKE THIS:

          if flash[:myErrors] then
            if flash[:myErrors].any? then
              if then
                if @myPost!=-1 then
                  @post = @myPost 
                  @post = 

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

My solution for a cache implementation that stores optional NSAttributedString:

public static var attributedMessageTextCache    = [String: NSAttributedString?]()

    if attributedMessageTextCache.index(forKey: "key") != nil
        if let attributedMessageText = TextChatCache.attributedMessageTextCache["key"]
            return attributedMessageText
        return nil

    TextChatCache.attributedMessageTextCache["key"] = .some(.none)
    return nil

What is size_t in C?

size_t is an unsigned type. So, it cannot represent any negative values(<0). You use it when you are counting something, and are sure that it cannot be negative. For example, strlen() returns a size_t because the length of a string has to be at least 0.

In your example, if your loop index is going to be always greater than 0, it might make sense to use size_t, or any other unsigned data type.

When you use a size_t object, you have to make sure that in all the contexts it is used, including arithmetic, you want non-negative values. For example, let's say you have:

size_t s1 = strlen(str1);
size_t s2 = strlen(str2);

and you want to find the difference of the lengths of str2 and str1. You cannot do:

int diff = s2 - s1; /* bad */

This is because the value assigned to diff is always going to be a positive number, even when s2 < s1, because the calculation is done with unsigned types. In this case, depending upon what your use case is, you might be better off using int (or long long) for s1 and s2.

There are some functions in C/POSIX that could/should use size_t, but don't because of historical reasons. For example, the second parameter to fgets should ideally be size_t, but is int.

How to do integer division in javascript (Getting division answer in int not float)?

var answer = Math.floor(x)

I sincerely hope this will help future searchers when googling for this common question.

How to refresh a page with jQuery by passing a parameter to URL

if window.location.hash is empty, you cant assign to location.href a new value without using a correct function (at least tested in chrome).

try the window.location.replace:

if (!window.location.hash) 
        window.location.replace(window.location.href + "?single")

Cannot connect to the Docker daemon at unix:/var/run/docker.sock. Is the docker daemon running?

You can get this error if docker doesn't shut down cleanly. The following answer is for the docker snap package.

Run snap logs docker and look for the following:

Error starting daemon: pid file found, ensure docker is not running or delete /var/snap/docker/179/run/

Deleting that file and restarting docker worked for me.

rm /var/snap/docker/<your-version-number>/run/
snap stop docker
snap start docker

Make sure to replace ????<your-version-number>? with the appropriate version number.

Adding up BigDecimals using Streams

Use this approach to sum the list of BigDecimal:

List<BigDecimal> values = ... // List of BigDecimal objects
BigDecimal sum =, y) -> x.add(y)).get();

This approach maps each BigDecimal as a BigDecimal only and reduces them by summing them, which is then returned using the get() method.

Here's another simple way to do the same summing:

List<BigDecimal> values = ... // List of BigDecimal objects
BigDecimal sum =;


If I were to write the class and lambda expression in the edited question, I would have written it as follows:

import java.math.BigDecimal;
import java.util.LinkedList;

public class Demo
  public static void main(String[] args)
    LinkedList<Invoice> invoices = new LinkedList<>();
    invoices.add(new Invoice("C1", "I-001", BigDecimal.valueOf(.1), BigDecimal.valueOf(10)));
    invoices.add(new Invoice("C2", "I-002", BigDecimal.valueOf(.7), BigDecimal.valueOf(13)));
    invoices.add(new Invoice("C3", "I-003", BigDecimal.valueOf(2.3), BigDecimal.valueOf(8)));
    invoices.add(new Invoice("C4", "I-004", BigDecimal.valueOf(1.2), BigDecimal.valueOf(7)));

    // Java 8 approach, using Method Reference for mapping purposes.;
    System.out.println("Sum = " +, y) -> x.add(y)).get());

  // This is just my style of writing classes. Yours can differ.
  static class Invoice
    private String company;
    private String number;
    private BigDecimal unitPrice;
    private BigDecimal quantity;

    public Invoice()
      unitPrice = quantity = BigDecimal.ZERO;

    public Invoice(String company, String number, BigDecimal unitPrice, BigDecimal quantity)

    public BigDecimal total()
      return unitPrice.multiply(quantity);

    public String getCompany()
      return company;

    public void setCompany(String company)
    { = company;

    public String getNumber()
      return number;

    public void setNumber(String number)
      this.number = number;

    public BigDecimal getUnitPrice()
      return unitPrice;

    public void setUnitPrice(BigDecimal unitPrice)
      this.unitPrice = unitPrice;

    public BigDecimal getQuantity()
      return quantity;

    public void setQuantity(BigDecimal quantity)
      this.quantity = quantity;

How can I capitalize the first letter of each word in a string?

Why do you complicate your life with joins and for loops when the solution is simple and safe??

Just do this:

string = "the brown fox"

How to hide reference counts in VS2013?

I guess you probably are running the preview of VS2013 Ultimate, because it is not present in my professional preview. But looking online I found that the feature is called Code Information Indicators or CodeLens, and can be located under

Tools ? Options ? Text Editor ? All Languages ? CodeLens

(for RC/final version)


Tools ? Options ? Text Editor ? All Languages ? Code Information Indicators

(for preview version)

That was according to this link. It seems to be pretty well hidden.

In Visual Studio 2013 RTM, you can also get to the CodeLens options by right clicking the indicators themselves in the editor:

editor options

documented in the Q&A section of the msdn CodeLens documentation

Links in <select> dropdown options

... or if you want / need to keep your option 'value' as it was, just add a new attribute:

<select id="my_selection">
<option value="x" href="/link/to/somewhere">value 1</option>
<option value="y" href="/link/to/somewhere/else">value 2</option>

document.getElementById('my_selection').onchange = function() {
    window.location.href = this.children[this.selectedIndex].getAttribute('href');

How to document Python code using Doxygen

The doxypy input filter allows you to use pretty much all of Doxygen's formatting tags in a standard Python docstring format. I use it to document a large mixed C++ and Python game application framework, and it's working well.

Monitoring the Full Disclosure mailinglist

Two generic ways to do the same thing... I'm not aware of any specific open solutions to do this, but it'd be rather trivial to do.

You could write a daily or weekly cron/jenkins job to scrape the previous time period's email from the archive looking for your keyworkds/combinations. Sending a batch digest with what it finds, if anything.

But personally, I'd Setup a specific email account to subscribe to the various security lists you're interested in. Add a simple automated script to parse the new emails for various keywords or combinations of keywords, when it finds a match forward that email on to you/your team. Just be sure to keep the keywords list updated with new products you're using.

You could even do this with a gmail account and custom rules, which is what I currently do, but I have setup an internal inbox in the past with a simple python script to forward emails that were of interest.

JSON.parse unexpected token s

You're asking it to parse the JSON text something (not "something"). That's invalid JSON, strings must be in double quotes.

If you want an equivalent to your first example:

var s = '"something"';
var result = JSON.parse(s);

ConvergenceWarning: Liblinear failed to converge, increase the number of iterations

Explicitly specifying the max_iter resolves the warning as the default max_iter is 100. [For Logistic Regression].

 logreg = LogisticRegression(max_iter=1000)

docker entrypoint running bash script gets "permission denied"

If you still get Permission denied errors when you try to run your script in the docker's entrypoint, just try DO NOT use the shell form of the entrypoint:

Instead of: ENTRYPOINT ./bin/watcher write ENTRYPOINT ["./bin/watcher"]:

enter image description here

SQL Server: Importing database from .mdf?

If you do not have an LDF file then:

1) put the MDF in the C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS\MSSQL\DATA\

2) In ssms, go to Databases -> Attach and add the MDF file. It will not let you add it this way but it will tell you the database name contained within.

3) Make sure the user you are running ssms.exe as has acccess to this MDF file.

4) Now that you know the DbName, run

EXEC sp_attach_single_file_db @dbname = 'DbName', 
@physname = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS\MSSQL\DATA\yourfile.mdf';


I'm trying to use python in powershell

  1. download Nodejs for windows
  2. install node-vxxx.msi
  3. find "Install Additional Tools for Node.js" script
  4. open and install it
  5. reopen a new shell prompt, type "python" >> press "enter" >> it works!!

Add a space (" ") after an element using :after

I needed this instead of using padding because I used inline-block containers to display a series of individual events in a workflow timeline. The last event in the timeline needed no arrow after it.

Ended up with something like:

.transaction-tile:after {
  content: "\f105";

.transaction-tile:last-child:after {
  content: "\00a0";

Used fontawesome for the gt (chevron) character. For whatever reason "content: none;" was producing alignment issues on the last tile.

How to get current time with jQuery

.clock {_x000D_
width: 260px;_x000D_
margin: 0 auto;_x000D_
padding: 30px;_x000D_
color: #FFF;background:#333;_x000D_
.clock ul {_x000D_
width: 250px;_x000D_
margin: 0 auto;_x000D_
padding: 0;_x000D_
list-style: none;_x000D_
text-align: center_x000D_
.clock ul li {_x000D_
display: inline;_x000D_
font-size: 3em;_x000D_
text-align: center;_x000D_
font-family: "Arial", Helvetica, sans-serif;_x000D_
text-shadow: 0 2px 5px #55c6ff, 0 3px 6px #55c6ff, 0 4px 7px #55c6ff_x000D_
#Date { _x000D_
font-family: 'Arial', Helvetica, sans-serif;_x000D_
font-size: 26px;_x000D_
text-align: center;_x000D_
text-shadow: 0 2px 5px #55c6ff, 0 3px 6px #55c6ff;_x000D_
padding-bottom: 40px;_x000D_
#point {_x000D_
position: relative;_x000D_
-moz-animation: mymove 1s ease infinite;_x000D_
-webkit-animation: mymove 1s ease infinite;_x000D_
padding-left: 10px;_x000D_
padding-right: 10px_x000D_
/* Animasi Detik Kedap - Kedip */_x000D_
@-webkit-keyframes mymove _x000D_
0% {opacity:1.0; text-shadow:0 0 20px #00c6ff;}_x000D_
50% {opacity:0; text-shadow:none; }_x000D_
100% {opacity:1.0; text-shadow:0 0 20px #00c6ff; } _x000D_
@-moz-keyframes mymove _x000D_
0% {opacity:1.0; text-shadow:0 0 20px #00c6ff;}_x000D_
50% {opacity:0; text-shadow:none; }_x000D_
100% {opacity:1.0; text-shadow:0 0 20px #00c6ff; } _x000D_
<script src=""></script>_x000D_
<script type="text/javascript" src=""></script>_x000D_
<script type="text/javascript">_x000D_
$(document).ready(function() {_x000D_
// Making 2 variable month and day_x000D_
var monthNames = [ "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ]; _x000D_
var dayNames= ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]_x000D_
// make single object_x000D_
var newDate = new Date();_x000D_
// make current time_x000D_
// setting date and time_x000D_
$('#Date').html(dayNames[newDate.getDay()] + " " + newDate.getDate() + ' ' + monthNames[newDate.getMonth()] + ' ' + newDate.getFullYear());_x000D_
setInterval( function() {_x000D_
// Create a newDate() object and extract the seconds of the current time on the visitor's_x000D_
var seconds = new Date().getSeconds();_x000D_
// Add a leading zero to seconds value_x000D_
$("#sec").html(( seconds < 10 ? "0" : "" ) + seconds);_x000D_
setInterval( function() {_x000D_
// Create a newDate() object and extract the minutes of the current time on the visitor's_x000D_
var minutes = new Date().getMinutes();_x000D_
// Add a leading zero to the minutes value_x000D_
$("#min").html(( minutes < 10 ? "0" : "" ) + minutes);_x000D_
setInterval( function() {_x000D_
// Create a newDate() object and extract the hours of the current time on the visitor's_x000D_
var hours = new Date().getHours();_x000D_
// Add a leading zero to the hours value_x000D_
$("#hours").html(( hours < 10 ? "0" : "" ) + hours);_x000D_
}, 1000); _x000D_
<div class="clock">_x000D_
<div id="Date"></div>_x000D_
<li id="hours"></li>_x000D_
<li id="point">:</li>_x000D_
<li id="min"></li>_x000D_
<li id="point">:</li>_x000D_
<li id="sec"></li>_x000D_

How to include external Python code to use in other files?

You will need to import the other file as a module like this:

import Math

If you don't want to prefix your Calculate function with the module name then do this:

from Math import Calculate

If you want to import all members of a module then do this:

from Math import *

Edit: Here is a good chapter from Dive Into Python that goes a bit more in depth on this topic.

How do I create a Linked List Data Structure in Java?

Java has a LinkedList implementation, that you might wanna check out. You can download the JDK and it's sources at

What is the garbage collector in Java?

To put it in the most simple terms that even a non-programmer can understand, when a program processes data it creates intermediate data and storage space (variables, arrays, certain object metadata etc.) for that data.

When these objects are accessed across functions or over a certain size, they are allocated from a central heap. Then when they are no long needed, they need to be cleaned up.

There are some very good articles online about how this works, so I'll just cover the very basic definition.

The GC is basically the function that does this cleanup. To do this is clears table entries that aren't referenced by any active objects, effectively deleting the objects, than copies and compacts the memory. It's a little more complicated than this, but you get the idea.

The big problem is some parts this process often requires the entire Java VM to require to be stopped temporarily to take place, as well as this entire process being very processor and memory bandwidth intensive. The various options as of GCs and tuning options for each one are designed to balance these various issues with the whole GC process.

How to format a UTC date as a `YYYY-MM-DD hh:mm:ss` string using NodeJS?

new Date(2015,1,3,15,30).toLocaleString()

//=> 2015-02-03 15:30:00

JQUERY: Uncaught Error: Syntax error, unrecognized expression

This can also happen in safari if you try a selector with a missing ], for example


but interestingly, this same jquery selector with a missing bracket will work in chrome.

Appending to an existing string

Here's another way:

fist_segment = "hello,"
second_segment = "world."
complete_string = "#{first_segment} #{second_segment}"

Adding 30 minutes to time formatted as H:i in PHP

What you need is a datetime which is 30 minutes later than your given datetime, and a datetime which is 30 minutes before a given datetime. In other words, you need a future datetime and a past datetime. Hence, classes that achieve that are called Future and Past. What data do they need to calculate what you need? Apparently, they must have a datetime relative to which to count those 30 minutes, and an interval itself -- 30 minutes in your case. Thus, the desired datetime looks like the following:

use Meringue\ISO8601DateTime\FromCustomFormat as DateTimeCreatedFromCustomFormat;

(new Future(
    new DateTimeCreatedFromCustomFormat('H:i', '10:00'),
    new NMinutes(30)

If you want to format it somehow, you can do:

use Meringue\ISO8601DateTime\FromCustomFormat as DateTimeCreatedFromCustomFormat;

(new ISO8601Formatted(
    new Future(
        new DateTimeCreatedFromCustomFormat('H:i', '10:00'),
        new NMinutes(30)

It's more verbose, but I guess it's way less cryptic than built-in php functions.

If you liked this approach, you can learn some more about the meringue library used in this example, and the overall approach.

Android Button Onclick

You need to make the same method name both in layout XML and java code.

If you use android:onClick="setLogin" then you need to make a method with the same name, setLogin:

// Please be noted that you need to add the "View v" parameter
public void setLogin(View v) {


Do not mix layout with code by using android:onClick tag in your XML. Instead, move the click method to your class with OnClickListener method like:

Button button = (Button) findViewById(;
button.setOnClickListener(new OnClickListener() {
  public void onClick(View v) {
    // TODO Auto-generated method stub

Make a layout just for layout and no more. It will save your precious time when you need to refactoring for Supporting Multiple Screens.

Simplest way to do a recursive self-join?

Check following to help the understand the concept of CTE recursion

@startDate DATETIME,

SET @startDate = '11/10/2011'
SET @endDate = '03/25/2012'

        YEAR(@startDate) AS 'yr',
        MONTH(@startDate) AS 'mm',
        DATENAME(mm, @startDate) AS 'mon',
        DATEPART(d,@startDate) AS 'dd',
        @startDate 'new_date'
        YEAR(new_date) AS 'yr',
        MONTH(new_date) AS 'mm',
        DATENAME(mm, new_date) AS 'mon',
        DATEPART(d,@startDate) AS 'dd',
        DATEADD(d,1,new_date) 'new_date'
    WHERE new_date < @endDate
SELECT yr AS 'Year', mon AS 'Month', count(dd) AS 'Days'
GROUP BY mon, yr, mm
ORDER BY yr, mm

Cross Domain Form POSTing

Same origin policy has nothing to do with sending request to another url (different protocol or domain or port).

It is all about restricting access to (reading) response data from another url. So JavaScript code within a page can post to arbitrary domain or submit forms within that page to anywhere (unless the form is in an iframe with different url).

But what makes these POST requests inefficient is that these requests lack antiforgery tokens, so are ignored by the other url. Moreover, if the JavaScript tries to get that security tokens, by sending AJAX request to the victim url, it is prevented to access that data by Same Origin Policy.

A good example: here

And a good documentation from Mozilla: here

How to set input type date's default value to today?

new Date().getFullYear()+"-"+ ((parseInt(new Date().getMonth())+1+100)+"").substring(1)

How to use responsive background image in css3 in bootstrap

Check this out,

body {
    background-color: black;
    background: url(img/bg.jpg) no-repeat center center fixed; 
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;

When do you use Java's @Override annotation and why?

The best practive is to always use it (or have the IDE fill them for you)

@Override usefulness is to detect changes in parent classes which has not been reported down the hierarchy. Without it, you can change a method signature and forget to alter its overrides, with @Override, the compiler will catch it for you.

That kind of safety net is always good to have.

How to inherit constructors?

Yes, you have to copy all 387 constructors. You can do some reuse by redirecting them:

  public Bar(int i): base(i) {}
  public Bar(int i, int j) : base(i, j) {}

but that's the best you can do.

What is a bus error?

A segfault is accessing memory that you're not allowed to access. It's read-only, you don't have permission, etc...

A bus error is trying to access memory that can't possibly be there. You've used an address that's meaningless to the system, or the wrong kind of address for that operation.

Conversion between UTF-8 ArrayBuffer and String

function stringToUint(string) {
    var string = btoa(unescape(encodeURIComponent(string))),
        charList = string.split(''),
        uintArray = [];
    for (var i = 0; i < charList.length; i++) {
    return new Uint8Array(uintArray);

function uintToString(uintArray) {
    var encodedString = String.fromCharCode.apply(null, uintArray),
        decodedString = decodeURIComponent(escape(atob(encodedString)));
    return decodedString;

I have done, with some help from the internet, these little functions, they should solve your problems! Here is the working JSFiddle.


Since the source of the Uint8Array is external and you can't use atob you just need to remove it(working fiddle):

function uintToString(uintArray) {
    var encodedString = String.fromCharCode.apply(null, uintArray),
        decodedString = decodeURIComponent(escape(encodedString));
    return decodedString;

Warning: escape and unescape is removed from web standards. See this.

When to use IList and when to use List

You should try and use the least specific type that suits your purpose.
IEnumerable is less specific than IList.
You use IEnumerable when you want to loop through the items in a collection.

IList implements IEnumerable.
You should use IList when you need access by index to your collection, add and delete elements, etc...

List implements IList.

How to create a regex for accepting only alphanumeric characters?

[a-zA-Z0-9] will only match ASCII characters, it won't match

String target = new String("A" + "\u00ea" + "\u00f1" +
                             "\u00fc" + "C");

If you also want to match unicode characters:

String pat = "^[\\p{L}0-9]*$";

how to query child objects in mongodb

Assuming your "states" collection is like:

{"name" : "Spain", "cities" : [ { "name" : "Madrid" }, { "name" : null } ] }
{"name" : "France" }

The query to find states with null cities would be:

db.states.find({"" : {"$eq" : null, "$exists" : true}});

It is a common mistake to query for nulls as:

db.states.find({"" : null});

because this query will return all documents lacking the key (in our example it will return Spain and France). So, unless you are sure the key is always present you must check that the key exists as in the first query.

What does `dword ptr` mean?

Consider the figure enclosed in this other question. ebp-4 is your first local variable and, seen as a dword pointer, it is the address of a 32 bit integer that has to be cleared. Maybe your source starts with

Object x = null;

Can a JSON value contain a multiline string

I believe it depends on what json interpreter you're using... in plain javascript you could use line terminators

  "testCases" :
    "case.1" :
      "scenario" : "this the case 1.",
      "result" : "this is a very long line which is not easily readble. \
                  so i would like to write it in multiple lines. \
                  but, i do NOT require any new lines in the output."

'router-outlet' is not a known element

If you are doing unit testing and get this error then Import RouterTestingModule into your app.component.spec.ts or inside your featured components' spec.ts:

import { RouterTestingModule } from '@angular/router/testing';

Add RouterTestingModule into your imports: [] like

describe('AppComponent', () => {

  beforeEach(async(() => {    
      imports: [    
      declarations: [    

Measuring Query Performance : "Execution Plan Query Cost" vs "Time Taken"

The results of the execution time directly contradict the results of the Query Cost, but I'm having difficulty determining what "Query Cost" actually means.

Query cost is what optimizer thinks of how long your query will take (relative to total batch time).

The optimizer tries to choose the optimal query plan by looking at your query and statistics of your data, trying several execution plans and selecting the least costly of them.

Here you may read in more detail about how does it try to do this.

As you can see, this may differ significantly of what you actually get.

The only real query perfomance metric is, of course, how long does the query actually take.

Convert Map<String,Object> to Map<String,String>

While you can do this with brute casting and suppressed warnings

Map<String,Object> map = new HashMap<String,Object>();
// Two casts in a row.  Note no "new"!
Map<String,String> newMap = (HashMap<String,String>)(Map)map;  

that's really missing the whole point. :)

An attempt to convert a narrow generic type to a broader generic type means you're using the wrong type in the first place.

As an analogy: Imagine you have a program that does volumous text processing. Imagine that you do first half of the processing using Objects (!!) and then decide to do the second half with correct-typing as a String, so you narrow-cast from Object to String. Fortunately, you can do this is java (easily in this case) - but it's just masking the fact you're using weak-typing in the first half. Bad practice, no argument.

No difference here (just harder to cast). You should always use strong typing. At minimum use some base type - then generics wildcards can be used ("? extends BaseType" or "? super BaseType") to give type-compatability and automatic casting. Even better, use the correct known type. Never use Object unless you have 100% generalised code that can really be used with any type.

Hope that helps! :) :)

Note: The generic strong typing and type-casting will only exist in .java code. After compilation to .class we are left with raw types (Map and HashMap) with no generic type parameters plus automatic type casting of keys and values. But it greatly helps because the .java code itself is strongly-typed and concise.

Convert Json String to C# Object List

using dynamic variable in C# is the simplest.

Newtonsoft.Json.Linq has class JValue that can be used. Below is a sample code which displays Question id and text from the JSON string you have.

        string jsonString = "[{\"Question\":{\"QuestionId\":49,\"QuestionText\":\"Whats your name?\",\"TypeId\":1,\"TypeName\":\"MCQ\",\"Model\":{\"options\":[{\"text\":\"Rahul\",\"selectedMarks\":\"0\"},{\"text\":\"Pratik\",\"selectedMarks\":\"9\"},{\"text\":\"Rohit\",\"selectedMarks\":\"0\"}],\"maxOptions\":10,\"minOptions\":0,\"isAnswerRequired\":true,\"selectedOption\":\"1\",\"answerText\":\"\",\"isRangeType\":false,\"from\":\"\",\"to\":\"\",\"mins\":\"02\",\"secs\":\"04\"}},\"CheckType\":\"\",\"S1\":\"\",\"S2\":\"\",\"S3\":\"\",\"S4\":\"\",\"S5\":\"\",\"S6\":\"\",\"S7\":\"\",\"S8\":\"\",\"S9\":\"Pratik\",\"S10\":\"\",\"ScoreIfNoMatch\":\"2\"},{\"Question\":{\"QuestionId\":51,\"QuestionText\":\"Are you smart?\",\"TypeId\":3,\"TypeName\":\"True-False\",\"Model\":{\"options\":[{\"text\":\"True\",\"selectedMarks\":\"7\"},{\"text\":\"False\",\"selectedMarks\":\"0\"}],\"maxOptions\":10,\"minOptions\":0,\"isAnswerRequired\":false,\"selectedOption\":\"3\",\"answerText\":\"\",\"isRangeType\":false,\"from\":\"\",\"to\":\"\",\"mins\":\"01\",\"secs\":\"04\"}},\"CheckType\":\"\",\"S1\":\"\",\"S2\":\"\",\"S3\":\"\",\"S4\":\"\",\"S5\":\"\",\"S6\":\"\",\"S7\":\"True\",\"S8\":\"\",\"S9\":\"\",\"S10\":\"\",\"ScoreIfNoMatch\":\"2\"}]";
        dynamic myObject = JValue.Parse(jsonString);
        foreach (dynamic questions in myObject)
            Console.WriteLine(questions.Question.QuestionId + "." + questions.Question.QuestionText.ToString());

Output from the code => Output from the code

Installed Ruby 1.9.3 with RVM but command line doesn't show ruby -v

I ran into a similar issue today - my ruby version didn't match my rvm installs.

> ruby -v
ruby 2.0.0p481

> rvm list
rvm rubies
   ruby-2.1.2 [ x86_64 ]
=* ruby-2.2.1 [ x86_64 ]
   ruby-2.2.3 [ x86_64 ]

Also, rvm current failed.

> rvm current
Warning! PATH is not properly set up, '/Users/randallreed/.rvm/gems/ruby-2.2.1/bin' is not at first place...

The error message recommended this useful command, which resolved the issue for me:

> rvm get stable --auto-dotfiles

What is it exactly a BLOB in a DBMS context

A BLOB is a Binary Large OBject. It is used to store large quantities of binary data in a database.

You can use it to store any kind of binary data that you want, includes images, video, or any other kind of binary data that you wish to store.

Different DBMSes treat BLOBs in different ways; you should read the documentation of the databases you are interested in to see how (and if) they handle BLOBs.

How do the likely/unlikely macros in the Linux kernel work and what is their benefit?

They're hints to the compiler to generate the hint prefixes on branches. On x86/x64, they take up one byte, so you'll get at most a one-byte increase for each branch. As for performance, it entirely depends on the application -- in most cases, the branch predictor on the processor will ignore them, these days.

Edit: Forgot about one place they can actually really help with. It can allow the compiler to reorder the control-flow graph to reduce the number of branches taken for the 'likely' path. This can have a marked improvement in loops where you're checking multiple exit cases.

C# nullable string error

string cannot be the parameter to Nullable because string is not a value type. String is a reference type.

string s = null; 

is a very valid statement and there is not need to make it nullable.

private string typeOfContract
      get { return ViewState["typeOfContract"] as string; }
      set { ViewState["typeOfContract"] = value; }

should work because of the as keyword.

Binding to static property

Look at my project CalcBinding, which provides to you writing complex expressions in Path property value, including static properties, source properties, Math and other. So, you can write this:

<TextBox Text="{c:Binding local:VersionManager.FilterString}"/>


How do I use .woff fonts for my website?

You need to declare @font-face like this in your stylesheet

@font-face {
  font-family: 'Awesome-Font';
  font-style: normal;
  font-weight: 400;
  src: local('Awesome-Font'), local('Awesome-Font-Regular'), url(path/Awesome-Font.woff) format('woff');

Now if you want to apply this font to a paragraph simply use it like this..

p {
font-family: 'Awesome-Font', Arial;

More Reference

.NET - How do I retrieve specific items out of a Dataset?

The DataSet object has a Tables array. If you know the table you want, it will have a Row array, each object of which has an ItemArray array. In your case the code would most likely be

int var1 = int.Parse(ds.Tables[0].Rows[0].ItemArray[4].ToString());

and so forth. This would give you the 4th item in the first row. You can also use Columns instead of ItemArray and specify the column name as a string instead of remembering it's index. That approach can be easier to keep up with if the table structure changes. So that would be

int var1 = int.Parse(ds.Tables[0].Rows[0]["MyColumnName"].ToString());

Using the AND and NOT Operator in Python

Use the keyword and, not & because & is a bit operator.

Be careful with this... just so you know, in Java and C++, the & operator is ALSO a bit operator. The correct way to do a boolean comparison in those languages is &&. Similarly | is a bit operator, and || is a boolean operator. In Python and and or are used for boolean comparisons.

Hiding button using jQuery

Try this:

     function ()

For doing everything else you can use something like this one:

     function ()


For hidding any other elements based on their IDs, use this one:

     function ()


How to comment multiple lines with space or indent

Might just be for Visual Studio '15, if you right-click on source code, there's an option for insert comment

This puts summary tags around your comment section, but it does give the indentation that you want.

jQuery AJAX Call to PHP Script with JSON Return

Your datatype is wrong, change datatype for dataType.

How to get the stream key for

You will get it here (change "yourtwitch" by your twitch nickname")

The link simply moved. You can get this link on the main page of, click on your name then "Dashboard".

How can I declare and use Boolean variables in a shell script?

Alternative - use a function

is_ok(){ :;}
is_ok(){ return 1;}
is_ok && echo "It's OK" || echo "Something's wrong"

Defining the function is less intuitive, but checking its return value is very easy.

Set Encoding of File to UTF8 With BOM in Sublime Text 3

By default, Sublime Text set 'UTF8 without BOM', but that wasn't specified.

The only specicified things is 'UTF8 with BOM'.

Hope this help :)

DataTables fixed headers misaligned with columns in wide tables

For bootstrap users, this fixed it for me:


See article here

Using the && operator in an if statement

So to make your expression work, changing && for -a will do the trick.

It is correct like this:

 if [ -f $VAR1 ] && [ -f $VAR2 ] && [ -f $VAR3 ]
 then  ....

or like

 if [[ -f $VAR1 && -f $VAR2 && -f $VAR3 ]]
 then  ....

or even

 if [ -f $VAR1 -a -f $VAR2 -a -f $VAR3 ]
 then  ....

You can find further details in this question bash : Multiple Unary operators in if statement and some references given there like What is the difference between test, [ and [[ ?.

How do I get the current date and time in PHP?

PHP's time() returns a current Unix timestamp. With this, you can use the date() function to format it to your needs.

$date = date('Format String', time());

As Paolo mentioned in the comments, the second argument is redundant. The following snippet is equivalent to the one above:

$date = date('Format String');

Converting SVG to PNG using C#

There is a much easier way using the library (Newer version @GIT, @NuGet). Here is my code

var byteArray = Encoding.ASCII.GetBytes(svgFileContents);
using (var stream = new MemoryStream(byteArray))
    var svgDocument = SvgDocument.Open(stream);
    var bitmap = svgDocument.Draw();
    bitmap.Save(path, ImageFormat.Png);

How do I format a date as ISO 8601 in moment.js?

If you just want the date portion (e.g. 2017-06-27), and you want it to work regardless of time zone and also in Arabic, here is code I wrote:

function isoDate(date) {
    if (!date) {
        return null
    date = moment(date).toDate()

    // don't call toISOString because it takes the time zone into
    // account which we don't want.  Also don't call .format() because it
    // returns Arabic instead of English

    var month = 1 + date.getMonth()
    if (month < 10) {
        month = '0' + month
    var day = date.getDate()
    if (day < 10) {
        day = '0' + day
    return date.getFullYear() + '-' + month + '-' + day

How to convert Map keys to array?

OK, let's go a bit more comprehensive and start with what's Map for those who don't know this feature in JavaScript... MDN says:

The Map object holds key-value pairs and remembers the original insertion order of the keys.
Any value (both objects and primitive values) may be used as either a key or a value.

As you mentioned, you can easily create an instance of Map using new keyword... In your case:

let myMap = new Map().set('a', 1).set('b', 2);

So let's see...

The way you mentioned is an OK way to do it, but yes, there are more concise ways to do that...

Map has many methods which you can use, like set() which you already used to assign the key values...

One of them is keys() which returns all the keys...

In your case, it will return:

MapIterator {"a", "b"}

and you easily convert them to an Array using ES6 ways, like spread operator...

const b = [...myMap.keys()];

Is it possible to import modules from all files in a directory, using a wildcard?

You can use require as well:

const moduleHolder = []

function loadModules(path) {
  let stat = fs.lstatSync(path)
  if (stat.isDirectory()) {
    // we have a directory: do a tree walk
    const files = fs.readdirSync(path)
    let f,
      l = files.length
    for (var i = 0; i < l; i++) {
      f = pathModule.join(path, files[i])
  } else {
    // we have a file: load it
    var controller = require(path)

Then use your moduleHolder with dynamically loaded controllers:

  for (const controller of moduleHolder) {
    controller(app, db)

HTML 5 video or audio playlist

I wasn't satisfied with what was offered, so here's my proposal, using jQuery :

            <div id="playlist">
                <audio id="player" controls preload="metadata" volume="1">
                  <source src="" type="audio/mpeg">
                  Sorry, this browser doesn't support HTML 5.0

                var folder = "audio";
                var playlist = [
                for (var i in playlist) {
                    jQuery('#playlist ul').append('<li>'+playlist[i]+'</li>');

                var player = document.getElementById('player');
                var playing = playlist[0];
                player.src = folder + '/' + playing;

                function display(id) {
                    var list = jQuery('#playlist ul').children();


                player.onended = function(){
                    var ind_next = playlist.indexOf(playing) + 1;

                    if (ind_next !== 0) {
                        player.src = folder + '/' + playlist[ind_next];
                        playing = player.src;

You only have to edit the playlist array, and you're done

Show default value in Spinner in android

I found a solution by extending ArrayAdapter and Overriding the getView method.

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

 * A SpinnerAdapter which does not show the value of the initial selection initially,
 * but an initialText.
 * To use the spinner with initial selection instead call notifyDataSetChanged().
public class SpinnerAdapterWithInitialText<T> extends ArrayAdapter<T> {

    private Context context;
    private int resource;

    private boolean initialTextWasShown = false;
    private String initialText = "Please select";

     * Constructor
     * @param context The current context.
     * @param resource The resource ID for a layout file containing a TextView to use when
     *                 instantiating views.
     * @param objects The objects to represent in the ListView.
    public SpinnerAdapterWithInitialText(@NonNull Context context, int resource, @NonNull T[] objects) {
        super(context, resource, objects);
        this.context = context;
        this.resource = resource;

     * Returns whether the user has selected a spinner item, or if still the initial text is shown.
     * @param spinner The spinner the SpinnerAdapterWithInitialText is assigned to.
     * @return true if the user has selected a spinner item, false if not.
    public boolean selectionMade(Spinner spinner) {
        return !((TextView)spinner.getSelectedView()).getText().toString().equals(initialText);

     * Returns a TextView with the initialText the first time getView is called.
     * So the Spinner has an initialText which does not represent the selected item.
     * To use the spinner with initial selection instead call notifyDataSetChanged(),
     * after assigning the SpinnerAdapterWithInitialText.
    public View getView(int position, View recycle, ViewGroup container) {
        if(initialTextWasShown) {
            return super.getView(position, recycle, container);
        } else {
            initialTextWasShown = true;
            LayoutInflater inflater = LayoutInflater.from(context);
            final View view = inflater.inflate(resource, container, false);

            ((TextView) view).setText(initialText);

            return view;

What Android does when initialising the Spinner, is calling getView for the selected item before calling getView for all items in T[] objects. The SpinnerAdapterWithInitialText returns a TextView with the initialText, the first time it is called. All the other times it calls super.getView which is the getView method of ArrayAdapter which is called if you are using the Spinner normally.

To find out whether the user has selected a spinner item, or if the spinner still displays the initialText, call selectionMade and hand over the spinner the adapter is assigned to.

What is the purpose of backbone.js?

I have to admit that all the "advantages" of MVC have never made my work easier, faster, or better. It just makes the whole codeing experience more abstract and time consuming. Maintenance is a nightmare when trying to debug someone elses conception of what separation means. Don't know how many of you people have ever tried to update a FLEX site that used Cairngorm as the MVC model but what should take 30 seconds to update can often take over 2 hours (hunting/tracing/debugging just to find a single event). MVC was and still is, for me, an "advantage" that you can stuff.

How to use GROUP BY to concatenate strings in SQL Server?

Using the Stuff and for xml path operator to concatenate rows to string :Group By two columns -->

CREATE TABLE #YourTable ([ID] INT, [Name] CHAR(1), [Value] INT)

INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'A',4)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'B',5)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)

-- retrieve each unique id and name columns and concatonate the values into one column
    FROM #YourTable 
    WHERE (ID = Results.ID and Name = results.[name] ) 
    FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
  ,1,2,'') AS NameValues
FROM #YourTable Results

  [ID],[Name] , --these are acting as the group by clause
    FROM #YourTable 
    WHERE (ID = Results.ID and Name = results.[name] ) 
    FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
  ,1,2,'') AS  NameValues
FROM #YourTable Results


How to find all the subclasses of a class given its name?

The simplest solution in general form:

def get_subclasses(cls):
    for subclass in cls.__subclasses__():
        yield from get_subclasses(subclass)
        yield subclass

And a classmethod in case you have a single class where you inherit from:

def get_subclasses(cls):
    for subclass in cls.__subclasses__():
        yield from subclass.get_subclasses()
        yield subclass

How To Get The Current Year Using Vba

Try =Year(Now()) and format the cell as General.

How to send email via Django?

For SendGrid - Django Specifically:

SendGrid Django Docs here

Set these variables in

EMAIL_HOST_USER = 'sendgrid_username'
EMAIL_HOST_PASSWORD = 'sendgrid_password'


from django.core.mail import send_mail
send_mail('Subject here', 'Here is the message.', '[email protected]', ['[email protected]'], fail_silently=False)

Removing object from array in Swift 3

For Swift 3, you can use index(where:) and include a closure that does the comparison of an object in the array ($0) with whatever you are looking for.

var array = ["alpha", "beta", "gamma"]
if let index = array.index(where: {$0 == "beta"}) {
  array.remove(at: index)

Generate C# class from XML

Use below syntax to create schema class from XSD file.

C:\xsd C:\Test\test-Schema.xsd /classes /language:cs /out:C:\Test\

Convert JSON string to dict using Python


import json

d = json.loads(j)
print d['glossary']['title']

How to terminate the script in JavaScript?

JavaScript equivalent for PHP's die. BTW it just calls exit() (thanks splattne):

function exit( status ) {
    // +   original by: Brett Zamir (
    // +      input by: Paul
    // +   bugfixed by: Hyam Singer (
    // +   improved by: Philip Peterson
    // +   bugfixed by: Brett Zamir (
    // %        note 1: Should be considered expirimental. Please comment on this function.
    // *     example 1: exit();
    // *     returns 1: null

    var i;

    if (typeof status === 'string') {

    window.addEventListener('error', function (e) {e.preventDefault();e.stopPropagation();}, false);

    var handlers = [
        'copy', 'cut', 'paste',
        'beforeunload', 'blur', 'change', 'click', 'contextmenu', 'dblclick', 'focus', 'keydown', 'keypress', 'keyup', 'mousedown', 'mousemove', 'mouseout', 'mouseover', 'mouseup', 'resize', 'scroll',
        'DOMNodeInserted', 'DOMNodeRemoved', 'DOMNodeRemovedFromDocument', 'DOMNodeInsertedIntoDocument', 'DOMAttrModified', 'DOMCharacterDataModified', 'DOMElementNameChanged', 'DOMAttributeNameChanged', 'DOMActivate', 'DOMFocusIn', 'DOMFocusOut', 'online', 'offline', 'textInput',
        'abort', 'close', 'dragdrop', 'load', 'paint', 'reset', 'select', 'submit', 'unload'

    function stopPropagation (e) {
        // e.preventDefault(); // Stop for the form controls, etc., too?
    for (i=0; i < handlers.length; i++) {
        window.addEventListener(handlers[i], function (e) {stopPropagation(e);}, true);

    if (window.stop) {

    throw '';

How to test valid UUID/GUID?

I think Gambol's answer is almost perfect, but it misinterprets the RFC 4122 ยง 4.1.1. Variant section a bit.

It covers Variant-1 UUIDs (10xx = 8..b), but does not cover Variant-0 (0xxx = 0..7) and Variant-2 (110x = c..d) variants which are reserved for backward compatibility, so they are technically valid UUIDs. Variant-4 (111x = e..f) is indeed reserved for future use, so they are not valid currently.

Also, 0 type is not valid, that "digit" is only allowed to be 0 if it's a NIL UUID (like mentioned in Evan's answer).

So I think the most accurate regex that complies with current RFC 4122 specification is (including hyphens):

                            ^                ^^^^^^
                    (0 type is not valid)  (only e..f variant digit is invalid currently)

Is it possible to CONTINUE a loop from an exception?

For this example you really should just use an outer join.

  FOR attr_rec IN ( 
    select attr 
    from USER_TABLE u 
    left outer join attribute_table a 
    on ( u.USERTYPE = 'X' and a.user_id = ) 
  ) LOOP
    <process records> 
    <if primary key of attribute_table is null 
     then the attribute does not exist for this user.>

Section vs Article HTML5

My interpretation is: I think of YouTube it has a comment-section, and inside the comment-section there are multiple articles (in this case comments).

So a section is like a div-container that holds articles.

sending email via php mail function goes to spam

If you are sending this through your own mail server you might need to add a "Sender" header which will contain an email address of from your own domain. Gmail will probably be spamming the email because the FROM address is a gmail address but has not been sent from their own server.

MVC4 DataType.Date EditorFor won't display date value in Chrome, fine in Internet Explorer

In MVC5.2, add Date.cshtml to folder ~/Views/Shared/EditorTemplates:

@model DateTime?
    IDictionary<string, object> htmlAttributes;
    object objAttributes;
    if (ViewData.TryGetValue("htmlAttributes", out objAttributes))
        htmlAttributes = objAttributes as IDictionary<string, object> ?? HtmlHelper.AnonymousObjectToHtmlAttributes(objAttributes);
        htmlAttributes = new RouteValueDictionary();
    htmlAttributes.Add("type", "date");
    String format = (Request.UserAgent != null && Request.UserAgent.Contains("Chrome")) ? "{0:yyyy-MM-dd}" : "{0:d}";
    @Html.TextBox("", Model, format, htmlAttributes)

Google MAP API v3: Center & Zoom on displayed markers

Try this works...

$(function() {
        var myOptions = {
            zoom: 10,
            center: latlng,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        var map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
        var latlng_pos=[];
        var j=0;
            latlng_pos[j]=new google.maps.LatLng($(this).find(".latitude").val(),$(this).find(".longitude").val());
            var marker = new google.maps.Marker({
                position: new google.maps.LatLng($(this).find(".latitude").val(),$(this).find(".longitude").val()),
                // position: new google.maps.LatLng(-35.397, 150.640),
                map: map
        // map: an instance of google.maps.Map object
        // latlng: an array of google.maps.LatLng objects
        var latlngbounds = new google.maps.LatLngBounds( );
        for ( var i = 0; i < latlng_pos.length; i++ ) {
            latlngbounds.extend( latlng_pos[ i ] );
        map.fitBounds( latlngbounds );


Python, how to check if a result set is empty?

cursor.rowcount will usually be set to 0.

If, however, you are running a statement that would never return a result set (such as INSERT without RETURNING, or SELECT ... INTO), then you do not need to call .fetchall(); there won't be a result set for such statements. Calling .execute() is enough to run the statement.

Note that database adapters are also allowed to set the rowcount to -1 if the database adapter can't determine the exact affected count. See the PEP 249 Cursor.rowcount specification:

The attribute is -1 in case no .execute*() has been performed on the cursor or the rowcount of the last operation is cannot be determined by the interface.

The sqlite3 library is prone to doing this. In all such cases, if you must know the affected rowcount up front, execute a COUNT() select in the same transaction first.

how to check for null with a ng-if values in a view with angularjs?

You should check for !test, here is a fiddle showing that.

<span ng-if="!test">null</span>

Get User Selected Range

You can loop through the Selection object to see what was selected. Here is a code snippet from Microsoft (

Sub Count_Selection()
    Dim cell As Object
    Dim count As Integer
    count = 0
    For Each cell In Selection
        count = count + 1
    Next cell
    MsgBox count & " item(s) selected"
End Sub

Difference between Constructor and ngOnInit

I will just add one important thing that was skipped in the explanations above and explains when you MUST use ngOnInit.

If you are doing any manipulation of the component's DOM via e.g. ViewChildren, ContentChildren or ElementRef, your native elements will not be available during the constructor phase.

However, since ngOnInit happens once the component has been created and the checks (ngOnChanges) have been called you can access the DOM at this point.

export class App implements OnInit, AfterViewInit, AfterContentInit {
  @Input() myInput: string;
  @ViewChild() myTemplate: TemplateRef<any>;
  @ContentChild(ChildComponent) myComponent: ChildComponent; 

  constructor(private elementRef: ElementRef) {
     // this.elementRef.nativeElement is undefined here
     // this.myInput is undefined here
     // this.myTemplate is undefined here
     // this.myComponent is undefine here

  ngOnInit() {
     // this.elementRef.nativeElement can be used from here on
     // value of this.myInput is passed from parent scope
     // this.myTemplate and this.myComponent are still undefined
  ngAfterContentInit() {
     // this.myComponent now gets projected in and can be accessed
     // this.myTemplate is still undefined

  ngAfterViewInit() {
     // this.myTemplate can be used now as well

Bootstrap: adding gaps between divs

An alternative way to accomplish what you are asking, without having problems on the mobile version of your website, (Remember that the margin attribute will brake your responsive layout on mobile version thus you have to add on your element a supplementary attribute like @media (min-width:768px){ 'your-class'{margin:0}} to override the previous margin)

is to nest your class in your preferred div and then add on your class the margin option you want

like the following example: HTML

<div class="container">
  <div class="col-md-3 col-xs-12">
   <div class="events">
     <img src="..."  class="img-responsive" alt="...."/>
     <div class="figcaption">
       <h2>Event Title</h2>
       <p>Event Description.</p>
  <div class="col-md-3 col-xs-12">
   <div class="events">
    <img src="..."  class="img-responsive" alt="...."/>
    <div class="figcaption">
     <h2>Event Title</h2>
     <p>Event Description. </p>
  <div class="col-md-3 col-xs-12">
   <div class="events">
    <img src="..."  class="img-responsive" alt="...."/>
    <div class="figcaption">
     <h2>Event Title</h2>
     <p>Event Description. </p>

And on your CSS you just add the margin option on your class which in this example is "events" like:

margin: 20px 10px;

By this method you will have all the wanted space between your divs making sure you do not brake anything on your website's mobile and tablet versions.

What is your favorite C programming trick?

I think the use of userdata pointers is pretty neat. A fashion losing ground nowdays. It's not so much a C feature but is pretty easy to use in C.

MVC 4 client side validation not working

There are no data-validation attributes on your input. Make sure you have generated it with a server side helper such as Html.TextBoxFor and that it is inside a form:

@using (Html.BeginForm())
    @Html.TextBoxFor(x => x.AgreementNumber)

Also I don't know what the jquery.validate.inline.js script is but if it somehow depends on the jquery.validate.js plugin make sure that it is referenced after it.

In all cases look at your javascript console in the browser for potential errors or missing scripts.

How to sort a HashSet?

Add all your objects to the TreeSet, you will get a sorted Set. Below is a raw example.

HashSet myHashSet = new HashSet();

TreeSet myTreeSet = new TreeSet();
System.out.println(myTreeSet); // Prints [1, 12, 23, 45]

Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated

Also make sure you just don't have a pending transaction. :)

I was doing some tests around and began a transaction to be safe but never closed it. I wish the error would have been more explicit but oh well!

c# Image resizing to different size while preserving aspect ratio

I found out how to resize AND pad the image by learning from this this CodeProject Article.

static Image FixedSize(Image imgPhoto, int Width, int Height)
        int sourceWidth = imgPhoto.Width;
        int sourceHeight = imgPhoto.Height;
        int sourceX = 0;
        int sourceY = 0;
        int destX = 0;
        int destY = 0;

        float nPercent = 0;
        float nPercentW = 0;
        float nPercentH = 0;

        nPercentW = ((float)Width / (float)sourceWidth);
        nPercentH = ((float)Height / (float)sourceHeight);
        if (nPercentH < nPercentW)
            nPercent = nPercentH;
            destX = System.Convert.ToInt16((Width -
                          (sourceWidth * nPercent)) / 2);
            nPercent = nPercentW;
            destY = System.Convert.ToInt16((Height -
                          (sourceHeight * nPercent)) / 2);

        int destWidth = (int)(sourceWidth * nPercent);
        int destHeight = (int)(sourceHeight * nPercent);

        Bitmap bmPhoto = new Bitmap(Width, Height,

        Graphics grPhoto = Graphics.FromImage(bmPhoto);
        grPhoto.InterpolationMode =

            new Rectangle(destX, destY, destWidth, destHeight),
            new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),

        return bmPhoto;

TypeScript for ... of with index / key?

"Old school javascript" to the rescue (for those who aren't familiar/in love of functional programming)

for (let i = 0; i < someArray.length ; i++) {
  let item = someArray[i];

Execute action when back bar button of UINavigationController is pressed

If you want to have back button with back arrow you can use an image and code below

backArrow.png arrow1 [email protected] arrow2 [email protected] arrow3

override func viewDidLoad() {
    let customBackButton = UIBarButtonItem(image: UIImage(named: "backArrow") , style: .plain, target: self, action: #selector(backAction(sender:)))
    customBackButton.imageInsets = UIEdgeInsets(top: 2, left: -8, bottom: 0, right: 0)
    navigationItem.leftBarButtonItem = customBackButton

func backAction(sender: UIBarButtonItem) {
    // custom actions here
    navigationController?.popViewController(animated: true)

Gcc error: gcc: error trying to exec 'cc1': execvp: No such file or directory

Amazon Linux: fixing GCC issue

Since this comes up as the first result on Google, I just wanted to document my experience with Amazon Linux. Installing gcc-c++.noarch fixed the problem:

sudo yum install gcc-c++.noarch

Some people also reported this alternative as a solution:

sudo yum install gcc72-c++

How do you clear a slice in Go?

It all depends on what is your definition of 'clear'. One of the valid ones certainly is:

slice = slice[:0]

But there's a catch. If slice elements are of type T:

var slice []T

then enforcing len(slice) to be zero, by the above "trick", doesn't make any element of


eligible for garbage collection. This might be the optimal approach in some scenarios. But it might also be a cause of "memory leaks" - memory not used, but potentially reachable (after re-slicing of 'slice') and thus not garbage "collectable".

How to access route, post, get etc. parameters in Zend Framework 2

All the above methods will work fine if your content-type is "application/-www-form-urlencoded". But if your content-type is "application/json" then you will have to do the following:

$params = json_decode(file_get_contents('php://input'), true); print_r($params);

Reason : See #7 in

Is there a performance difference between i++ and ++i in C?

Please don't let the question of "which one is faster" be the deciding factor of which to use. Chances are you're never going to care that much, and besides, programmer reading time is far more expensive than machine time.

Use whichever makes most sense to the human reading the code.

Error in launching AVD with AMD processor

While creating a Virtual Device select the ARM system Image. Others have suggested to install HAXM, but the truth is haxm wont work on amd platform or even if it does as android studio does not supports amd-vt on windows the end result will still be a very very slow emulator to run and operate. My recommendation would be to either use alternative emulator like Genymotion (works like a charm with Gapps installed) or switch to linux as then you will get the benefit of amd-vt and emulator will run a lot faster.

python date of the previous month

For someone who got here and looking to get both the first and last day of the previous month:

from datetime import date, timedelta

last_day_of_prev_month = - timedelta(days=1)

start_day_of_prev_month = - timedelta(

# For printing results
print("First day of prev month:", start_day_of_prev_month)
print("Last day of prev month:", last_day_of_prev_month)


First day of prev month: 2019-02-01
Last day of prev month: 2019-02-28

How to save DataFrame directly to Hive?

You can create an in-memory temporary table and store them in hive table using sqlContext.

Lets say your data frame is myDf. You can create one temporary table using,


Then you can use a simple hive statement to create table and dump the data from your temp table.

sqlContext.sql("create table mytable as select * from mytempTable");

$http get parameters does not work

The 2nd parameter in the get call is a config object. You want something like this:

    .get('accept.php', {
        params: {
            source: link,
            category_id: category
     .success(function (data,status) {
          $scope.info_show = data

See the Arguments section of$http for more detail

Corrupt jar file

As I just came across this topic I wanted to share the reason and solution why I got the message "invalid or corrupt jarfile":

I had updated the version of the "maven-jar-plugin" in my pom.xml from 2.1 to 3.1.2. Everything still went fine and a jar file was built. But somehow it obviously wouldn't run anymore.

As soon as i set the "maven-jar-plugin" version back to 2.1 again, the problem was gone.

PHP errors NOT being displayed in the browser [Ubuntu 10.10]

Try adding log_errors = Off and check the error_reporting setting whether it's set high enough.

Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

ddd is a graphical front-end to gdb that is pretty nice. One of the down sides is a classic X interface, but I seem to recall it being pretty intuitive.

javascript set cookie with expire time

I use a function to store cookies with a custom expire time in days:

// use it like: writeCookie("mycookie", "1", 30)
// this will set a cookie for 30 days since now
function writeCookie(name,value,days) {
  if (days) {
    var date = new Date();
    var expires = "; expires="+date.toGMTString();
  else var expires = "";
  document.cookie = name+"="+value+expires+"; path=/";

How do you properly determine the current script directory?

If you really want to cover the case that a script is called via execfile(...), you can use the inspect module to deduce the filename (including the path). As far as I am aware, this will work for all cases you listed:

filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))

Using Tkinter in python to edit the title bar

Easy method:

root = Tk()
root.title('Hello World')

PowerShell script to return versions of .NET Framework on a machine?

Not pretty. Definitely not pretty:

ls $Env:windir\Microsoft.NET\Framework | ? { $_.PSIsContainer } | select -exp Name -l 1

This may or may not work. But as far as the latest version is concerned this should be pretty reliable, as there are essentially empty folders for old versions (1.0, 1.1) but not newer ones โ€“ those only appear once the appropriate framework is installed.

Still, I suspect there must be a better way.

Convert a string representation of a hex dump to a byte array using Java?

For Me this was the solution, HEX="FF01" then split to FF(255) and 01(01)

private static byte[] BytesEncode(String encoded) {
    byte result[] = new byte[encoded.length() / 2];
    char enc[] = encoded.toUpperCase().toCharArray();
    String curr = "";
    for (int i = 0; i < encoded.length(); i=i+2) {
        curr = encoded.substring(i,i+2);
            result[i]=((byte) Integer.parseInt(curr, 16));
            result[i/2]=((byte) Integer.parseInt(curr, 16));

    return result;

How to validate domain credentials?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security;
using System.DirectoryServices.AccountManagement;

public struct Credentials
    public string Username;
    public string Password;

public class Domain_Authentication
    public Credentials Credentials;
    public string Domain;

    public Domain_Authentication(string Username, string Password, string SDomain)
        Credentials.Username = Username;
        Credentials.Password = Password;
        Domain = SDomain;

    public bool IsValid()
        using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, Domain))
            // validate the credentials
            return pc.ValidateCredentials(Credentials.Username, Credentials.Password);

Dynamically add data to a javascript map

Well any Javascript object functions sort-of like a "map"

randomObject['hello'] = 'world';

Typically people build simple objects for the purpose:

var myMap = {};

// ...

myMap[newKey] = newValue;

edit — well the problem with having an explicit "put" function is that you'd then have to go to pains to avoid having the function itself look like part of the map. It's not really a Javascripty thing to do.

13 Feb 2014 — modern JavaScript has facilities for creating object properties that aren't enumerable, and it's pretty easy to do. However, it's still the case that a "put" property, enumerable or not, would claim the property name "put" and make it unavailable. That is, there's still only one namespace per object.

Make sure that the controller has a parameterless public constructor error

In my case, it was because of exception inside the constructor of my injected dependency (in your example - inside DashboardRepository constructor). The exception was caught somewhere inside MVC infrastructure. I found this after I added logs in relevant places.

handling DATETIME values 0000-00-00 00:00:00 in JDBC

I wrestled with this problem and implemented the 'convertToNull' solutions discussed above. It worked in my local MySql instance. But when I deployed my Play/Scala app to Heroku it no longer would work. Heroku also concatenates several args to the DB URL that they provide users, and this solution, because of Heroku's use concatenation of "?" before their own set of args, will not work. However I found a different solution which seems to work equally well.

SET sql_mode = 'NO_ZERO_DATE';

I put this in my table descriptions and it solved the problem of '0000-00-00 00:00:00' can not be represented as java.sql.Timestamp

rsync: difference between --size-only and --ignore-times

On a Scientific Linux 6.7 system, the man page on rsync says:

--ignore-times          don't skip files that match size and time

I have two files with identical contents, but with different creation dates:

[root@windstorm ~]# ls -ls /tmp/master/usercron /tmp/new/usercron
4 -rwxrwx--- 1 root root 1595 Feb 15 03:45 /tmp/master/usercron
4 -rwxrwx--- 1 root root 1595 Feb 16 04:52 /tmp/new/usercron

[root@windstorm ~]# diff /tmp/master/usercron /tmp/new/usercron
[root@windstorm ~]# md5sum /tmp/master/usercron /tmp/new/usercron
368165347b09204ce25e2fa0f61f3bbd  /tmp/master/usercron
368165347b09204ce25e2fa0f61f3bbd  /tmp/new/usercron

With --size-only, the two files are regarded the same:

[root@windstorm ~]# rsync -v --size-only -n  /tmp/new/usercron /tmp/master/usercron

sent 29 bytes  received 12 bytes  82.00 bytes/sec
total size is 1595  speedup is 38.90 (DRY RUN)

With --ignore-times, the two files are regarded different:

[root@windstorm ~]# rsync -v --ignore-times -n  /tmp/new/usercron /tmp/master/usercron

sent 32 bytes  received 15 bytes  94.00 bytes/sec
total size is 1595  speedup is 33.94 (DRY RUN)

So it does not looks like --ignore-times has any effect at all.

Most Useful Attributes

I consider that is important to mention here that the following attributes are also very important:


Indicates that the COM threading model for an application is single-threaded apartment (STA).

For example this attribute is used in Windows Forms Applications:

static class Program
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
        Application.Run(new Form1());

And also ...


Suppresses reporting of a specific static analysis tool rule violation, allowing multiple suppressions on a single code artifact.

For example:

[SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "isChecked")]
[SuppressMessage("Microsoft.Performance", "CA1804:RemoveUnusedLocals", MessageId = "fileIdentifier")]
static void FileNode(string name, bool isChecked)
    string fileIdentifier = name;
    string fileName = name;
    string version = String.Empty;

Drop-down menu that opens up/upward with pure css

If we are use chosen dropdown list, then we can use below css(No JS/JQuery require)

<select chosen="{width: '100%'}" ng- 
   model="modelName" class="form-control input- 
   options="persons.persons as 
   persons.persons for persons in 
   <option value=""> </option>
.chosen-container .chosen-drop {
    border-bottom: 0;
    border-top: 1px solid #aaa;
    top: auto;
    bottom: 40px;

.chosen-container.chosen-with-drop .chosen-single {
    border-top-left-radius: 0px;
    border-top-right-radius: 0px;

    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;

    background-image: none;

.chosen-container.chosen-with-drop .chosen-drop {
    border-bottom-left-radius: 0px;
    border-bottom-right-radius: 0px;

    border-top-left-radius: 5px;
    border-top-right-radius: 5px;

    box-shadow: none;

    margin-bottom: -16px;

Dynamic variable names in Bash

I want to be able to create a variable name containing the first argument of the command file:

#!/usr/bin/env bash
function grep_search() {
  eval $1=$(ls | tail -1)


$ source
$ grep_search open_box
$ echo $open_box

As per help eval:

Execute arguments as a shell command.

You may also use Bash ${!var} indirect expansion, as already mentioned, however it doesn't support retrieving of array indices.

For further read or examples, check BashFAQ/006 about Indirection.

We are not aware of any trick that can duplicate that functionality in POSIX or Bourne shells without eval, which can be difficult to do securely. So, consider this a use at your own risk hack.

However, you should re-consider using indirection as per the following notes.

Normally, in bash scripting, you won't need indirect references at all. Generally, people look at this for a solution when they don't understand or know about Bash Arrays or haven't fully considered other Bash features such as functions.

Putting variable names or any other bash syntax inside parameters is frequently done incorrectly and in inappropriate situations to solve problems that have better solutions. It violates the separation between code and data, and as such puts you on a slippery slope toward bugs and security issues. Indirection can make your code less transparent and harder to follow.

Object Dump JavaScript

For Chrome/Chromium


or it's equivalent


Location of ini/config files in linux/unix?

For user configuration I've noticed a tendency towards moving away from individual ~/.myprogramrc to a structure below ~/.config. For example, Qt 4 uses ~/.config/<vendor>/<programname> with the default settings of QSettings. The major desktop environments KDE and Gnome use a file structure below a specific folder too (not sure if KDE 4 uses ~/.config, XFCE does use ~/.config).

Entity Framework. Delete all rows in table

Delete all records. Do not reset the primary index like "truncate".

/// <summary>
/// SET - DELETE all record by table - no truncate - return deleted records
/// </summary>
public static int setListDelAllMYTABLE()
    // INIT
    int retObj = 0;
    using (MYDBEntities ctx = new MYDBEntities())
        // GET - all record
        var tempAllRecord = ctx.MYTABLE.ToList();
        // RESET
        // SET - final save
        retObj += ctx.SaveChanges();
    // RET
    return retObj;

Ionic 2: Cordova is not available. Make sure to include cordova.js or run in a device/simulator (running in emulator)

I also had this same problem.

I build .apk file of the project and installed it into mobile(android) and got it working

Remove specific commit

From other answers here, I was kind of confused with how git rebase -i could be used to remove a commit, so I hope it's OK to jot down my test case here (very similar to the OP).

Here is a bash script that you can paste in to create a test repository in the /tmp folder:

set -x

rm -rf /tmp/myrepo*
cd /tmp

mkdir myrepo_git
cd myrepo_git
git init
git config me
git config [email protected]

mkdir folder
echo aaaa >> folder/file.txt
git add folder/file.txt
git commit -m "1st git commit"

echo bbbb >> folder/file.txt
git add folder/file.txt
git commit -m "2nd git commit"

echo cccc >> folder/file.txt
git add folder/file.txt
git commit -m "3rd git commit"

echo dddd >> folder/file.txt
git add folder/file.txt
git commit -m "4th git commit"

echo eeee >> folder/file.txt
git add folder/file.txt
git commit -m "5th git commit"

At this point, we have a file.txt with these contents:


At this point, HEAD is at the 5th commit, HEAD~1 would be the 4th - and HEAD~4 would be the 1st commit (so HEAD~5 wouldn't exist). Let's say we want to remove the 3rd commit - we can issue this command in the myrepo_git directory:

git rebase -i HEAD~4

(Note that git rebase -i HEAD~5 results with "fatal: Needed a single revision; invalid upstream HEAD~5".) A text editor (see screenshot in @Dennis' answer) will open with these contents:

pick 5978582 2nd git commit
pick 448c212 3rd git commit
pick b50213c 4th git commit
pick a9c8fa1 5th git commit

# Rebase b916e7f..a9c8fa1 onto b916e7f
# ...

So we get all commits since (but not including) our requested HEAD~4. Delete the line pick 448c212 3rd git commit and save the file; you'll get this response from git rebase:

error: could not apply b50213c... 4th git commit

When you have resolved this problem run "git rebase --continue".
If you would prefer to skip this patch, instead run "git rebase --skip".
To check out the original branch and stop rebasing run "git rebase --abort".
Could not apply b50213c... 4th git commit

At this point open myrepo_git/folder/file.txt in a text editor; you'll see it has been modified:

<<<<<<< HEAD
>>>>>>> b50213c... 4th git commit

Basically, git sees that when HEAD got to 2nd commit, there was content of aaaa + bbbb; and then it has a patch of added cccc+dddd which it doesn't know how to append to the existing content.

So here git cannot decide for you - it is you who has to make a decision: by removing the 3rd commit, you either keep the changes introduced by it (here, the line cccc) -- or you don't. If you don't, simply remove the extra lines - including the cccc - in folder/file.txt using a text editor, so it looks like this:


... and then save folder/file.txt. Now you can issue the following commands in myrepo_git directory:

$ nano folder/file.txt  # text editor - edit, save
$ git rebase --continue
folder/file.txt: needs merge
You must edit all merge conflicts and then
mark them as resolved using git add

Ah - so in order to mark that we've solved the conflict, we must git add the folder/file.txt, before doing git rebase --continue:

$ git add folder/file.txt
$ git rebase --continue

Here a text editor opens again, showing the line 4th git commit - here we have a chance to change the commit message (which in this case could be meaningfully changed to 4th (and removed 3rd) commit or similar). Let's say you don't want to - so just exit the text editor without saving; once you do that, you'll get:

$ git rebase --continue
[detached HEAD b8275fc] 4th git commit
 1 file changed, 1 insertion(+)
Successfully rebased and updated refs/heads/master.

At this point, now you have a history like this (which you could also inspect with say gitk . or other tools) of the contents of folder/file.txt (with, apparently, unchanged timestamps of the original commits):

1st git commit  |  +aaaa
2nd git commit  |   aaaa
                |  +bbbb
4th git commit  |   aaaa
                |   bbbb
                |  +dddd
5th git commit  |   aaaa
                |   bbbb
                |   dddd
                |  +eeee

And if previously, we decided to keep the line cccc (the contents of the 3rd git commit that we removed), we would have had:

1st git commit  |  +aaaa
2nd git commit  |   aaaa
                |  +bbbb
4th git commit  |   aaaa
                |   bbbb
                |  +cccc
                |  +dddd
5th git commit  |   aaaa
                |   bbbb
                |   cccc
                |   dddd
                |  +eeee

Well, this was the kind of reading I hoped I'd have found, to start grokking how git rebase works in terms of deleting commits/revisions; so hope it might help others too...