Programs & Examples On #Wmain Received fatal alert: handshake_failure

Issue resolved.!!! Below are the solutions.

For Java 6: Add below jars into {JAVA_HOME}/jre/lib/ext. 1. bcprov-ext-jdk15on-154.jar 2. bcprov-jdk15on-154.jar

Add property into {JAVA_HOME}/jre/lib/security/ security.provider.1=org.bouncycastle.jce.provider.BouncyCastleProvider

Java 7:download jar from below link and add to {JAVA_HOME}/jre/lib/security

Java 8:download jar from below link and add to {JAVA_HOME}/jre/lib/security

Issue is that it is failed to decrypt 256 bits of encryption.

How can I hide/show a div when a button is clicked?

This can't be done with just HTML/CSS. You need to use javascript here. In jQuery it would be:

    e.preventDefault(); //to prevent standard click event

How can I close a login form and show the main form without my application closing?

public void ShowMain()
       if(auth()) // a method that returns true when the user exists.
         var main = new Main();
              MessageBox.Show("Invalid login details.");

Unknown URL content://downloads/my_downloads

The exception is caused by disabled Download Manager. And there is no way to activate/deactivate Download Manager directly, since it's system application and we don't have access to it.

Only alternative way is redirect user to settings of Download Manager Application.

try {
     //Open the specific App Info page:
     Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
     intent.setData(Uri.parse("package:" + ""));

} catch ( ActivityNotFoundException e ) {

     //Open the generic Apps page:
     Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_APPLICATIONS_SETTINGS);

Convert Rows to columns using 'Pivot' in SQL Server

select * from (select name, ID from Empoyee) Visits
    pivot(sum(ID) for name
    in ([Emp1],
    ) ) as pivottable;

Android Closing Activity Programmatically

you can use this.finish() if you want to close current activity.


ImageView in circular through xml

Best Solution courtesy the width and height of the card view determine the size of the images it contains set up is as follows:

  1. Add Dependency to Gradle(Module)
  2. Add the xml code to activity.xml or fragment.xml file
    implementation 'androidx.cardview:cardview:1.0.0'




How can I check if a string is null or empty in PowerShell?

# cases
$x = null
$x = ''
$x = ' '

# test
if ($x -and $x.trim()) {'not empty'} else {'empty'}
if ([string]::IsNullOrWhiteSpace($x)) {'empty'} else {'not empty'}

Reading from stdin

From the man read:

#include <unistd.h>
ssize_t read(int fd, void *buf, size_t count);

Input parameters:

  • int fd file descriptor is an integer and not a file pointer. The file descriptor for stdin is 0

  • void *buf pointer to buffer to store characters read by the read function

  • size_t count maximum number of characters to read

So you can read character by character with the following code:

char buf[1];

while(read(0, buf, sizeof(buf))>0) {
   // read() here read from stdin charachter by character
   // the buf[0] contains the character got by read()

jQuery - trapping tab select event

From what I can tell, per the documentation here:, it seems as though you're not quite initializing it right. The demos state that you need a main wrapped <div> element, with a <ul> or possibly <ol> element representing the tabs, and then an element for each tab page (presumable a <div> or <p>, possibly a <section> if we're using HTML5). Then you call $().tabs() on the main <div>, not the <ul> element.

After that, you can bind to the tabsselect event no problem. Check out this fiddle for basic, basic example:

relative path to CSS file

You have to move the css folder into your web folder. It seems that your web folder on the hard drive equals the /ServletApp folder as seen from the www. Other content than inside your web folder cannot be accessed from the browsers.

The url of the CSS link is then

 <link rel="stylesheet" type="text/css" href="/ServletApp/css/styles.css"/>

Getting absolute URLs using ASP.NET Core

After RC2 and 1.0 you no longer need to inject an IHttpContextAccessor to you extension class. It is immediately available in the IUrlHelper through the urlhelper.ActionContext.HttpContext.Request. You would then create an extension class following the same idea, but simpler since there will be no injection involved.

public static string AbsoluteAction(
    this IUrlHelper url,
    string actionName, 
    string controllerName, 
    object routeValues = null)
    string scheme = url.ActionContext.HttpContext.Request.Scheme;
    return url.Action(actionName, controllerName, routeValues, scheme);

Leaving the details on how to build it injecting the accesor in case they are useful to someone. You might also just be interested in the absolute url of the current request, in which case take a look at the end of the answer.

You could modify your extension class to use the IHttpContextAccessor interface to get the HttpContext. Once you have the context, then you can get the HttpRequest instance from HttpContext.Request and use its properties Scheme, Host, Protocol etc as in:

string scheme = HttpContextAccessor.HttpContext.Request.Scheme;

For example, you could require your class to be configured with an HttpContextAccessor:

public static class UrlHelperExtensions
    private static IHttpContextAccessor HttpContextAccessor;
    public static void Configure(IHttpContextAccessor httpContextAccessor)
        HttpContextAccessor = httpContextAccessor;  

    public static string AbsoluteAction(
        this IUrlHelper url,
        string actionName, 
        string controllerName, 
        object routeValues = null)
        string scheme = HttpContextAccessor.HttpContext.Request.Scheme;
        return url.Action(actionName, controllerName, routeValues, scheme);


Which is something you can do on your Startup class (Startup.cs file):

public void Configure(IApplicationBuilder app)

    var httpContextAccessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();


You could probably come up with different ways of getting the IHttpContextAccessor in your extension class, but if you want to keep your methods as extension methods in the end you will need to inject the IHttpContextAccessor into your static class. (Otherwise you will need the IHttpContext as an argument on each call)

Just getting the absoluteUri of the current request

If you just want to get the absolute uri of the current request, you can use the extension methods GetDisplayUrl or GetEncodedUrl from the UriHelper class. (Which is different from the UrLHelper)

GetDisplayUrl. Returns the combined components of the request URL in a fully un-escaped form (except for the QueryString) suitable only for display. This format should not be used in HTTP headers or other HTTP operations.

GetEncodedUrl. Returns the combined components of the request URL in a fully escaped form suitable for use in HTTP headers and other HTTP operations.

In order to use them:

  • Include the namespace Microsoft.AspNet.Http.Extensions.
  • Get the HttpContext instance. It is already available in some classes (like razor views), but in others you might need to inject an IHttpContextAccessor as explained above.
  • Then just use them as in this.Context.Request.GetDisplayUrl()

An alternative to those methods would be manually crafting yourself the absolute uri using the values in the HttpContext.Request object (Similar to what the RequireHttpsAttribute does):

var absoluteUri = string.Concat(

Get last 30 day records from today date in SQL Server

Add one more condition in where clause

SELECT * FROM  product 
WHERE pdate >= DATEADD(day,-30,GETDATE()) 
and   pdate <= getdate()

Or use DateDiff

SELECT * FROM  product 
WHERE DATEDIFF(day,pdate,GETDATE()) between 0 and 30 

Google Forms file upload complete example

As of October 2016, Google has added a file upload question type in native Google Forms, no Google Apps Script needed. See documentation.

Embed YouTube Video with No Ads

Whether ads are shown on a video is up to the content owner of that video. It's not something that the embedder can control.

If you had permission from the content owners of the videos to upload copies in your own account, and then ensured that your account was set up with monetization turned off, then that would prevent ads from showing during playback. It's up to you to work out that arrangement/permission with the original videos' owners, of course.

(It's also worth pointing out that if your goal is to help non-profits raise money, then allowing them to monetize their video playbacks is in line with that goal...)

Batch File; List files in directory, only filenames?

The full command is:

dir /b /a-d

Let me break it up;

Basically the /b is what you look for.

/a-d will exclude the directory names.

For more information see dir /? for other arguments that you can use with the dir command.

Adobe Acrobat Pro make all pages the same dimension

  • Open the PDF in MacOS´ Preview App
  • Chose File menu –> Export as PDF
  • In the export dialog klick the Details button an select your page size
  • Click save

All pages of the resulting document will be scaled to that size. The resulting file size is nearly identical to the original PDF, so I conclude, that image resolutions/compressions are not changed.


  1. I am not sure whether the "Export as PDF" menu item is available by default or only if Adobe Acrobat is installed.

  2. My first trial was to use Preview App and print (!) into a new PDF, but this leads to additional margins around the page content.

Generate a random letter in Python

You can use

map(lambda a : chr(a),  np.random.randint(low=65, high=90, size=4))

How to position a table at the center of div horizontally & vertically

You can center a box both vertically and horizontally, using the following technique :

The outher container :

  • should have display: table;

The inner container :

  • should have display: table-cell;
  • should have vertical-align: middle;
  • should have text-align: center;

The content box :

  • should have display: inline-block;

If you use this technique, just add your table (along with any other content you want to go with it) to the content box.

Demo :

body {_x000D_
    margin : 0;_x000D_
.outer-container {_x000D_
    position : absolute;_x000D_
    display: table;_x000D_
    width: 100%;_x000D_
    height: 100%;_x000D_
    background: #ccc;_x000D_
.inner-container {_x000D_
    display: table-cell;_x000D_
    vertical-align: middle;_x000D_
    text-align: center;_x000D_
.centered-content {_x000D_
    display: inline-block;_x000D_
    background: #fff;_x000D_
    padding : 20px;_x000D_
    border : 1px solid #000;_x000D_
<div class="outer-container">_x000D_
   <div class="inner-container">_x000D_
     <div class="centered-content">_x000D_
        <em>Data :</em>_x000D_

See also this Fiddle!

In Django, how do I check if a user is in a certain group?

I did it like this. For group named Editor.

def index(request):
    current_user_groups = request.user.groups.values_list("name", flat=True)
    context = {
        "is_editor": "Editor" in current_user_groups,
    return render(request, "index.html", context)


# index.html
{% if is_editor %}
  <h1>Editor tools</h1>
{% endif %}

How can you program if you're blind?

I can't recall the source, but I've heard/read about a form of audible syntax "colouring" - so that instead of a string assignment being read as

foo equals quote this is a string quote

the string part would be read with a different pitch or voice to make the separation of elements clearer.

Resizing an image in an HTML5 canvas

So something interesting that I found a while ago while working with canvas that might be helpful:

To resize the canvas control on its own, you need to use the height="" and width="" attributes (or canvas.width/canvas.height elements). If you use CSS to resize the canvas, it will actually stretch (i.e.: resize) the content of the canvas to fit the full canvas (rather than simply increasing or decreasing the area of the canvas.

It'd be worth a shot to try drawing the image into a canvas control with the height and width attributes set to the size of the image and then using CSS to resize the canvas to the size you're looking for. Perhaps this would use a different resizing algorithm.

It should also be noted that canvas has different effects in different browsers (and even different versions of different browsers). The algorithms and techniques used in the browsers is likely to change over time (especially with Firefox 4 and Chrome 6 coming out so soon, which will place heavy emphasis on canvas rendering performance).

In addition, you may want to give SVG a shot, too, as it likely uses a different algorithm as well.

Best of luck!

Nginx location priority

From the HTTP core module docs:

  1. Directives with the "=" prefix that match the query exactly. If found, searching stops.
  2. All remaining directives with conventional strings. If this match used the "^~" prefix, searching stops.
  3. Regular expressions, in the order they are defined in the configuration file.
  4. If #3 yielded a match, that result is used. Otherwise, the match from #2 is used.

Example from the documentation:

location  = / {
  # matches the query / only.
  [ configuration A ] 
location  / {
  # matches any query, since all queries begin with /, but regular
  # expressions and any longer conventional blocks will be
  # matched first.
  [ configuration B ] 
location /documents/ {
  # matches any query beginning with /documents/ and continues searching,
  # so regular expressions will be checked. This will be matched only if
  # regular expressions don't find a match.
  [ configuration C ] 
location ^~ /images/ {
  # matches any query beginning with /images/ and halts searching,
  # so regular expressions will not be checked.
  [ configuration D ] 
location ~* \.(gif|jpg|jpeg)$ {
  # matches any request ending in gif, jpg, or jpeg. However, all
  # requests to the /images/ directory will be handled by
  # Configuration D.   
  [ configuration E ] 

If it's still confusing, here's a longer explanation.

How to check if Location Services are enabled?

You can use the below code to check whether gps provider and network providers are enabled or not.

LocationManager lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
boolean gps_enabled = false;
boolean network_enabled = false;

try {
    gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch(Exception ex) {}

try {
    network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch(Exception ex) {}

if(!gps_enabled && !network_enabled) {
    // notify user
    new AlertDialog.Builder(context)
        .setPositiveButton(R.string.open_location_settings, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface paramDialogInterface, int paramInt) {
                context.startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));

And in the manifest file, you will need to add the following permissions

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

Referencing a string in a string array resource with xml

Another way of doing it is defining a resources array in strings.xml like below.

<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE resources [
    <!ENTITY supportDefaultSelection "Choose your issue">
    <!ENTITY issueOption1 "Support">
    <!ENTITY issueOption2 "Feedback">
    <!ENTITY issueOption3 "Help">

and then defining a string array using the above resources

<string-array name="support_issues_array">

You could refer the same string into other xmls too keeping DRY intact. The advantage I see is, with a single value change it would effect all the references in the code.

querySelector and querySelectorAll vs getElementsByClassName and getElementById in JavaScript

querySelector is of w3c Selector API

getElementBy is of w3c DOM API

IMO the most notable difference is that the return type of querySelectorAll is a static node list and for getElementsBy it's a live node list. Therefore the looping in demo 2 never ends because lis is live and updates itself during each iteration.

// Demo 1 correct
var ul = document.querySelectorAll('ul')[0],
    lis = ul.querySelectorAll("li");
for(var i = 0; i < lis.length ; i++){

// Demo 2 wrong
var ul = document.getElementsByTagName('ul')[0], 
    lis = ul.getElementsByTagName("li"); 
for(var i = 0; i < lis.length ; i++){

How to get Exception Error Code in C#

Another method would be to get the error code from the exception class directly. For example:

catch (Exception ex)
    if (ex.InnerException is ServiceResponseException)
        ServiceResponseException srex = ex.InnerException as ServiceResponseException;
        string ErrorCode = srex.ErrorCode.ToString();

How to make primary key as autoincrement for Room Persistence lib

For example, if you have a users entity you want to store, with fields (firstname, lastname , email) and you want autogenerated id, you do this.

@Entity(tableName = "users")
data class Users(
   @PrimaryKey(autoGenerate = true)
   val id: Long,
   val firstname: String,
   val lastname: String,
   val email: String

Room will then autogenerate and auto-increment the id field.

package javax.servlet.http does not exist

If you are working with maven project, then add following dependency to your pom.xml


write() versus writelines() and concatenated strings

Actually, I think the problem is that your variable "lines" is bad. You defined lines as a tuple, but I believe that write() requires a string. All you have to change is your commas into pluses (+).

nl = "\n"
lines = line1+nl+line2+nl+line3+nl

should work.

Add all files to a commit except a single file?

1) To start ignoring changes to a single already versioned file

git update-index --assume-unchanged "main/dontcheckmein.txt"

and to undo that git update-index --no-assume-unchanged "main/dontcheckmein.txt"

github docs to ignore files

2) To completely ignore a specific single file preventing it from being created at repository

First, look at this stackoverflow post: Git global ignore not working

In .gitignore, add the relative path to the file without leading ./.

So, if your file is at MyProject/MyFolder/myfile.txt, (where .git is also in the MyProject folder), add MyFolder/myfile.txt to your at .gitignore file.

You can confirm what rules are associated with ignore via git check-ignore "MyFolder/myfile.txt"

About global ignore

That link talks about ~/.gitignore_global, but the file is related to your project. So, if you put the exclude pattern MyFolder/myfile.txt in ~/.gitignore_global, it will work but will not make much sense...

On the other hand, if you setup your project with git config core.excludesfile .gitignore where .gitignore is in MyProject, the local file will override ~/.gitignore_global, which can have very useful rules...

So, for now, I think it's best to make some script to mix your .gitignore with ~/.gitignore_global at .gitignore.

One last warning
If the file you want to ignore is already in the repository, this method will not work unless you do this: git rm "MyFolder/myfile.txt", but back it up first, as it will be removed locally also! You can copy it back later...

How do I exit from the text window in Git?

Since you are learning Git, know that this has little to do with git but with the text editor configured for use. In vim, you can press i to start entering text and save by pressing esc and :wq and enter, this will commit with the message you typed. In your current state, to just come out without committing, you can do :q instead of the :wq as mentioned above.

Alternatively, you can just do git commit -m '<message>' instead of having git open the editor to type the message.

Note that you can also change the editor and use something you are comfortable with ( like notepad) - How can I set up an editor to work with Git on Windows?

Parsing huge logfiles in Node.js - read in line-by-line

I had the same problem yet. After comparing several modules that seem to have this feature, I decided to do it myself, it's simpler than I thought.


var fetchBlock = lineByline(filepath, onEnd);
fetchBlock(function(lines, start){ ... });  //lines{array} start{int} lines[0] No.

It cover the file opened in a closure, that fetchBlock() returned will fetch a block from the file, end split to array (will deal the segment from last fetch).

I've set the block size to 1024 for each read operation. This may have bugs, but code logic is obvious, try it yourself.

Convert an image to grayscale

To summarize a few items here: There are some pixel-by-pixel options that, while being simple just aren't fast.

@Luis' comment linking to: (archived) is superb.

He runs through three different options and includes timings for each.

How to post pictures to instagram using API

I tried using IFTTT and many other services but all were doing things or post from Instagram to another platform not to Instagram. I read more to found Instagram does not provide any such API as of now.

Using blue stack is again involving heavy installation and doing things manually only.

However, you can use your Google Chrome on the desktop version to make a post on Instagram. It needs a bit tweak.

  1. Open your chrome and browse
  2. Go to inspect element by right clicking on chrome.
  3. From top right corener menu drop down on developer tools, select more tool.
  4. Further select network conditions.
  5. In the network selection section, see the second section there named user agent.
  6. Uncheck select automatically, and select chrome for Android from the list of given user agent.
  7. Refresh your page.

You will notice a change in UI and the option to make a post on Instagram. Your life is now easy. Let me know an easier way if you can find any.

enter image description here

I wrote on about it.

Working Screenshot

enter image description here

Background Image for Select (dropdown) does not work in Chrome

you can use the below css styles for all browsers except Firefox 30

select {
  background: url(dropdown_arw.png) no-repeat right center;
  appearance: none;
  -moz-appearance: none;
  -webkit-appearance: none;
  width: 90px;
  text-indent: 0.01px;
  text-overflow: "";

demo page -


here is solution for Firefox 30. little trick for custom select elements in firefox :-moz-any() css pseudo class.

In MVC, how do I return a string result?

There Are 2 ways to return a string from the controller to the view:


You could return only the string, but it will not be included in your .cshtml file. it will be just a string appearing in your browser.


You could return a string as the Model object of View Result.

Here is the code sample to do this:

public class HomeController : Controller
    // GET: Home
    // this will return just a string, not html
    public string index()
        return "URL to show";

    public ViewResult AutoProperty()
        string s = "this is a string ";
        // name of view , object you will pass
        return View("Result", s);


In the view file to run AutoProperty, It will redirect you to the Result view and will send s
code to the view

<!--this will make this file accept string as it's model-->
@model string

    Layout = null;

<!DOCTYPE html>

    <meta name="viewport" content="width=device-width" />
    <!--this will represent the string -->

I run this at http://localhost:60227/Home/AutoProperty.

What's NSLocalizedString equivalent in Swift?

I've created my own genstrings sort of tool for extracting strings using a custom translation function

extension String {

    func localizedWith(comment:String) -> String {
        return NSLocalizedString(self, tableName: nil, bundle: Bundle.main, value: "", comment: comment)


It will parse all your swift files and exports the strings and comments in your code to a .strings file.

Probably not the easiest way to do it, but it is possible.

installing python packages without internet and using source code as .tar.gz and .whl

We have a similar situation at work, where the production machines have no access to the Internet; therefore everything has to be managed offline and off-host.

Here is what I tried with varied amounts of success:

  1. basket which is a small utility that you run on your internet-connected host. Instead of trying to install a package, it will instead download it, and everything else it requires to be installed into a directory. You then move this directory onto your target machine. Pros: very easy and simple to use, no server headaches; no ports to configure. Cons: there aren't any real showstoppers, but the biggest one is that it doesn't respect any version pinning you may have; it will always download the latest version of a package.

  2. Run a local pypi server. Used pypiserver and devpi. pypiserver is super simple to install and setup; devpi takes a bit more finagling. They both do the same thing - act as a proxy/cache for the real pypi and as a local pypi server for any home-grown packages. localshop is a new one that wasn't around when I was looking, it also has the same idea. So how it works is your internet-restricted machine will connect to these servers, they are then connected to the Internet so that they can cache and proxy the actual repository.

The problem with the second approach is that although you get maximum compatibility and access to the entire repository of Python packages, you still need to make sure any/all dependencies are installed on your target machines (for example, any headers for database drivers and a build toolchain). Further, these solutions do not cater for non-pypi repositories (for example, packages that are hosted on github).

We got very far with the second option though, so I would definitely recommend it.

Eventually, getting tired of having to deal with compatibility issues and libraries, we migrated the entire circus of servers to commercially supported docker containers.

This means that we ship everything pre-configured, nothing actually needs to be installed on the production machines and it has been the most headache-free solution for us.

We replaced the pypi repositories with a local docker image server.

How to change already compiled .class file without decompile?

Sometime we need to compile one single file out of thousand files to fix the problem. In such a case, One can create same folder structure like class path, decompile the file into java or copy java file from source code. Make required changes, compile one particular file into class with all dependency/classes in place and finally replace the class file. Finally restart the container. Once war is exploded file will not be replaced.

text box input height

If you want to increase the height of the input field, you can specify line-height css property for the input field.

input {
    line-height: 2em; // 2em is (2 * default line height)

how to generate web service out of wsdl

This may be very late in answering. But might be helpful to needy: How to convert WSDL to SVC :

  1. Assuming you are having .wsdl file at location "E:\" for ease in access further.
  2. Prepare the command for each .wsdl file as: E:\YourServiceFileName.wsdl
  3. Permissions: Assuming you are having the Administrative rights to perform permissions. Open directory : C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin
  4. Right click to amd64 => Security => Edit => Add User => Everyone Or Current User => Allow all permissions => OK.
  5. Prepare the Commands for each file in text editor as: wsdl.exe E:\YourServiceFileName.wsdl /l:CS /server.
  6. Now open Visual studio command prompt from : C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\Tools\Shortcuts\VS2013 x64 Native Tools Command Prompt.
  7. Execute above command.
  8. Go to directory : C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\amd64, Where respective .CS file should be generated.

    9.Move generated CS file to appropriate location.

What is Android's file system?

Johan is close - it depends on the hardware manufacturer. For example, Samsung Galaxy S phones uses Samsung RFS (proprietary). However, the Nexus S (also made by Samsung) with Android 2.3 uses Ext4 (presumably because Google told them to - the Nexus S is the current Google experience phone). Many community developers have also started moving to Ext4 because of this shift.

How to check for DLL dependency?

The safest thing is have some clean virtual machine, on which you can test your program. On every version you'd like to test, restore the VM to its initial clean value. Then install your program using its setup, and see if it works.

Dll problems have different faces. If you use Visual Studio and dynamically link to the CRT, you have to distribute the CRT DLLs. Update your VS, and you have to distribute another version of the CRT. Just checking dependencies is not enough, as you might miss those. Doing a full install on a clean machine is the only safe solution, IMO.

If you don't want to setup a full-blown test environment and have Windows 7, you can use XP-Mode as the initial clean machine, and XP-More to duplicate the VM.

Spring cron expression for every day 1:01:am

Something missing from gipinani's answer

@Scheduled(cron = "0 1 1,13 * * ?", zone = "CST")

This will execute at 1.01 and 13.01. It can be used when you need to run the job without a pattern multiple times a day.

And the zone attribute is very useful, when you do deployments in remote servers. This was introduced with spring 4.

Could not resolve in Android Studio new project

This issue seems to like the following.

How to resolve repository certificate error in Gradle build

Below steps may help:

1. Add certificate to keystore-

Import some certifications into Android Studio JDK cacerts from Android Studio’s cacerts.

Android Studio’s cacerts may be located in


I used the following import command.

$ keytool -importkeystore -v -srckeystore {src cacerts} -destkeystore {dest cacerts}

2. Add modified cacert path to{your-android-studio-directory}\\jre\\jre\\lib\\security\\cacerts

Ref :

How to Read from a Text File, Character by Character in C++

You could try something like:

char ch;
fstream fin("file", fstream::in);
while (fin >> noskipws >> ch) {
    cout << ch; // Or whatever

Angular - Use pipes in services and components

If you don't want do 'new myPipe()' because you're injecting dependencies to pipe, you can inject in component like provider and use without new.


    // In your component...

    import { Component, OnInit } from '@angular/core';
    import { myPipe} from './pipes';

      selector: 'my-component',
      template: '{{ data }}',
      providers: [ myPipe ]
    export class MyComponent() implements OnInit {
      data = 'some data';
      constructor(private myPipe: myPipe) {}

      ngOnInit() { = this.myPipe.transform(;

Table with 100% width with equal size columns

If you don't know how many columns you are going to have, the declaration

table-layout: fixed

along with not setting any column widths, would imply that browsers divide the total width evenly - no matter what.

That can also be the problem with this approach, if you use this, you should also consider how overflow is to be handled.

C - function inside struct

It can't be done directly, but you can emulate the same thing using function pointers and explicitly passing the "this" parameter:

typedef struct client_t client_t, *pno;
struct client_t
        pid_t pid;
        char password[TAM_MAX]; // -> 50 chars
        pno next;

        pno (*AddClient)(client_t *);    

pno client_t_AddClient(client_t *self) { /* code */ }

int main()

    client_t client;
    client.AddClient = client_t_AddClient; // probably really done in some init fn

    //code ..



It turns out that doing this, however, doesn't really buy you an awful lot. As such, you won't see many C APIs implemented in this style, since you may as well just call your external function and pass the instance.

How do you disable viewport zooming on Mobile Safari?

In order to comply with WAI WCAG 2.0 AA accessibility requirements you must never disable pinch zoom. (WCAG 2.0: SC 1.4.4 Resize text Level AA). You can read more about it here: Mobile Accessibility: How WCAG 2.0 and Other W3C/WAI Guidelines Apply to Mobile, 2.2 Zoom/Magnification

How to give a pandas/matplotlib bar graph custom colors

You can specify the color option as a list directly to the plot function.

from matplotlib import pyplot as plt
from itertools import cycle, islice
import pandas, numpy as np  # I find np.random.randint to be better

# Make the data
x = [{i:np.random.randint(1,5)} for i in range(10)]
df = pandas.DataFrame(x)

# Make a list by cycling through the colors you care about
# to match the length of your data.
my_colors = list(islice(cycle(['b', 'r', 'g', 'y', 'k']), None, len(df)))

# Specify this list of colors as the `color` option to `plot`.
df.plot(kind='bar', stacked=True, color=my_colors)

To define your own custom list, you can do a few of the following, or just look up the Matplotlib techniques for defining a color item by its RGB values, etc. You can get as complicated as you want with this.

my_colors = ['g', 'b']*5 # <-- this concatenates the list to itself 5 times.
my_colors = [(0.5,0.4,0.5), (0.75, 0.75, 0.25)]*5 # <-- make two custom RGBs and repeat/alternate them over all the bar elements.
my_colors = [(x/10.0, x/20.0, 0.75) for x in range(len(df))] # <-- Quick gradient example along the Red/Green dimensions.

The last example yields the follow simple gradient of colors for me:

enter image description here

I didn't play with it long enough to figure out how to force the legend to pick up the defined colors, but I'm sure you can do it.

In general, though, a big piece of advice is to just use the functions from Matplotlib directly. Calling them from Pandas is OK, but I find you get better options and performance calling them straight from Matplotlib.

How to convert any date format to yyyy-MM-dd

You will need to parse the input to a DateTime object and then convert it to any text format you want.

If you are not sure what format you will get, you can restrict the user to a fixed format by using validation or datetimePicker, or some other component.

How to convert between bytes and strings in Python 3?





Here 'StringVariable' represented as a string. 'ByteVariable' represent as Byte. Its not relevent to question Variables..

Change One Cell's Data in mysql

My answer is repeating what others have said before, but I thought I'd add an example, using MySQL, only because the previous answers were a little bit cryptic to me.

The general form of the command you need to use to update a single row's column:

UPDATE my_table SET my_column='new value' WHERE something='some value';

And here's an example.


mysql> select aet,port from ae;
| aet        | port  |
| DCM4CHEE01 | 11112 | 
| CDRECORD   | 10104 | 
2 rows in set (0.00 sec)


mysql> update ae set port='10105' where aet='CDRECORD';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0


mysql> select aet,port from ae;
| aet        | port  |
| DCM4CHEE01 | 11112 | 
| CDRECORD   | 10105 | 
2 rows in set (0.00 sec)

How can I convert a Word document to PDF?

Spire.Doc for Java, it is a professional Java API that enables Java applications to create, convert, manipulate and print Word documents without using Microsoft Office.You can easily convert Word to PDF with several lines of codes as follows.

import com.spire.doc.Document;
import com.spire.doc.FileFormat;
import com.spire.doc.ToPdfParameterList;

public class WordToPDF {
public static void main(String[] args)  {

    //Create Document object
    Document doc = new Document();

    //Load the file from disk.

    //create an instance of ToPdfParameterList.
    ToPdfParameterList ppl=new ToPdfParameterList();

    //embeds full fonts by default when IsEmbeddedAllFonts is set to true.

    //set setDisableLink to true to remove the hyperlink effect for the result PDF page.
    //set setDisableLink to false to preserve the hyperlink effect for the result PDF page.

    //Set the output image quality as 40% of the original image. 80% is the default setting.

    //Save to file.

After running the code snippets above, all formats of the original Word document can be copied into PDF perfectly.

How to get detailed list of connections to database in sql server 2005?

There is also who is active?:

Who is Active? is a comprehensive server activity stored procedure based on the SQL Server 2005 and 2008 dynamic management views (DMVs). Think of it as sp_who2 on a hefty dose of anabolic steroids

How to install gdb (debugger) in Mac OSX El Capitan?

Once you get the macports version of gdb installed you will need to disable SIP in order to make the proper edits to /System/Library/LaunchDaemons/ To disable SIP, you need to restart in recovery mode and execute the following command:

csrutil disable

Then restart. Then you will need to edit the bottom part of like this:


Then you will have to restart to have the changes take effect. Then you should reenable SIP. The gdb command for the macports install is actually ggdb. You will need to code sign ggdb following the instructions here:

The only way I have been able to get the code signing to work is by running ggdb with sudo. Good luck!

Iterate a list with indexes in Python

Yep, that would be the enumerate function! Or more to the point, you need to do:


[(0, 3), (1, 7), (2, 19)]

How do you allow spaces to be entered using scanf?

You may use scanf for this purpose with a little trick. Actually, you should allow user input until user hits Enter (\n). This will consider every character, including space. Here is example:

int main()
  char string[100], c;
  int i;
  printf("Enter the string: ");
  scanf("%s", string);
  i = strlen(string);      // length of user input till first space
    scanf("%c", &c);
    string[i++] = c;       // reading characters after first space (including it)
  } while (c != '\n');     // until user hits Enter
  string[i - 1] = 0;       // string terminating
return 0;

How this works? When user inputs characters from standard input, they will be stored in string variable until first blank space. After that, rest of entry will remain in input stream, and wait for next scanf. Next, we have a for loop that takes char by char from input stream (till \n) and apends them to end of string variable, thus forming a complete string same as user input from keyboard.

Hope this will help someone!

Adding a new array element to a JSON object

In my case, my JSON object didn't have any existing Array in it, so I had to create array element first and then had to push the element.

  elementToPush = [1, 2, 3]
  if (!obj.arr) this.$set(obj, "arr", [])

(This answer may not be relevant to this particular question, but may help someone else)

initialize a numpy array

For your first array example use,

a = numpy.arange(5)

To initialize big_array, use

big_array = numpy.zeros((10,4))

This assumes you want to initialize with zeros, which is pretty typical, but there are many other ways to initialize an array in numpy.

Edit: If you don't know the size of big_array in advance, it's generally best to first build a Python list using append, and when you have everything collected in the list, convert this list to a numpy array using numpy.array(mylist). The reason for this is that lists are meant to grow very efficiently and quickly, whereas numpy.concatenate would be very inefficient since numpy arrays don't change size easily. But once everything is collected in a list, and you know the final array size, a numpy array can be efficiently constructed.

PHP: get the value of TEXTBOX then pass it to a VARIABLE

In testing2.php use the following code to get the name:

if ( ! empty($_POST['name'])){
    $name = $_POST['name']);

When you create the next page, use the value of $name to prefill the form field:

Name: <input type="text" name="name" id="name" value="<?php echo $name; ?>"><br/>

However, before doing that, be sure to use regular expressions to verify that the $name only contains valid characters, such as:

$pattern =  '/^[0-9A-Za-zÁ-Úá-úàÀÜü]+$/';//integers & letters
if (preg_match($pattern, $name) == 1){
} else {
    //reload form with error message

'mat-form-field' is not a known element - Angular 5 & Material2

When using the 'mat-form-field' MatInputModule needs to be imported also

import { 
    MatListModule ,
} from '@angular/material';

Find a commit on GitHub given the commit hash

View single commit:<user>/<project>/commit/<hash>

View log:<user>/<project>/commits/<hash>

View full repo:<user>/<project>/tree/<hash>

<hash> can be any length as long as it is unique.

How to create python bytes object from long hex string?

You can do this with the hex codec. ie:

>>> s='000000000000484240FA063DE5D0B744ADBED63A81FAEA390000C8428640A43D5005BD44'
>>> s.decode('hex')

SQLDataReader Row Count

This will get you the row count, but will leave the data reader at the end.


Can I use tcpdump to get HTTP requests, response header and response body?

I would recommend using Wireshark, which has a "Follow TCP Stream" option that makes it very easy to see the full requests and responses for a particular TCP connection. If you would prefer to use the command line, you can try tcpflow, a tool dedicated to capturing and reconstructing the contents of TCP streams.

Other options would be using an HTTP debugging proxy, like Charles or Fiddler as EricLaw suggests. These have the advantage of having specific support for HTTP to make it easier to deal with various sorts of encodings, and other features like saving requests to replay them or editing requests.

You could also use a tool like Firebug (Firefox), Web Inspector (Safari, Chrome, and other WebKit-based browsers), or Opera Dragonfly, all of which provide some ability to view the request and response headers and bodies (though most of them don't allow you to see the exact byte stream, but instead how the browsers parsed the requests).

And finally, you can always construct requests by hand, using something like telnet, netcat, or socat to connect to port 80 and type the request in manually, or a tool like htty to help easily construct a request and inspect the response.

Difference between a script and a program?

There are really two dimensions to the scripting vs program reality:

  1. Is the language powerful enough, particularly with string operations, to compete with a macro processor like the posix shell and particularly bash? If it isn't better than bash for running some function there isn't much point in using it.

  2. Is the language convenient and quickly started? Java, Scala, JRuby, Closure and Groovy are all powerful languages, but Java requires a lot of boilerplate and the JVM they all require just takes too long to start up.

OTOH, Perl, Python, and Ruby all start up quickly and have powerful string handling (and pretty much everything-else-handling) operations, so they tend to occupy the sometimes-disparaged-but-not-easily-encroached-upon "scripting" world. It turns out they do well at running entire traditional programs as well.

Left in limbo are languages like Javascript, which aren't used for scripting but potentially could be. Update: since this was written node.js was released on multiple platforms. In other news, the question was closed. "Oh well."

How can one see content of stack with GDB?

You need to use gdb's memory-display commands. The basic one is x, for examine. There's an example on the linked-to page that uses

gdb> x/4xw $sp

to print "four words (w ) of memory above the stack pointer (here, $sp) in hexadecimal (x)". The quotation is slightly paraphrased.

Click events on Pie Charts in Chart.js

I was facing the same issues since several days, Today i have found the solution. I have shown the complete file which is ready to execute.

<head><script type="text/javascript" src="">
<canvas id="myChart" width="200" height="200"></canvas>
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
    labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
    datasets: [{
        label: '# of Votes',
        data: [12, 19, 3, 5, 2, 3],
        backgroundColor: [
            'rgba(255, 99, 132, 0.2)',
            'rgba(54, 162, 235, 0.2)',
            'rgba(255, 206, 86, 0.2)',
            'rgba(75, 192, 192, 0.2)',
            'rgba(153, 102, 255, 0.2)',
            'rgba(255, 159, 64, 0.2)'
        borderColor: [
            'rgba(54, 162, 235, 1)',
            'rgba(255, 206, 86, 1)',
            'rgba(75, 192, 192, 1)',
            'rgba(153, 102, 255, 1)',
            'rgba(255, 159, 64, 1)'
        borderWidth: 1
options: {
    scales: {
        yAxes: [{
            ticks: {
    var activePoints = myChart.getElementsAtEvent(e);
    var selectedIndex = activePoints[0]._index;


How to create a data file for gnuplot?

I was having the exact same issue. The problem that I was having is that I hadn't saved the .plt file that I was typing into yet. The fix: I saved the .plt file in the same directory as the data that I was trying to plot and suddenly it worked! If they are in the same directory, you don't even need to specify a path, you can just put in the file name.

Below is exactly what was happening to me, and how I fixed it. The first line shows the problem we were both having. I saved in the second line, and the third line worked!

gnuplot> plot 'c:/Documents and Settings/User/Desktop/data.dat'
         warning: Skipping unreadable file c:/Documents and Settings/User/Desktop/data.dat
         No data in plot

gnuplot> save 'c:/Documents and Settings/User/Desktop/myfile.plt'

gnuplot> plot 'c:/Documents and Settings/User/Desktop/data.dat'

Replacing spaces with underscores in JavaScript?

Try .replace(/ /g,"_");

Edit: or .split(' ').join('_') if you have an aversion to REs

Edit: John Resig said:

If you're searching and replacing through a string with a static search and a static replace it's faster to perform the action with .split("match").join("replace") - which seems counter-intuitive but it manages to work that way in most modern browsers. (There are changes going in place to grossly improve the performance of .replace(/match/g, "replace") in the next version of Firefox - so the previous statement won't be the case for long.)

How to get body of a POST in php?

A possible reason for an empty $_POST is that the request is not POST, or not POST anymore... It may have started out as post, but encountered a 301 or 302 redirect somewhere, which is switched to GET!

Inspect $_SERVER['REQUEST_METHOD'] to check if this is the case.

See for a good discussion of why this should not happen but still does.

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'

The designated data directory /usr/local/var/mysql/ is unusable. You can remove all files that the server added to it.

$brew services stop mysql
$brew services list
$brew uninstall  mysql

$brew install mysql
$brew postinstall mysql

If Any error found then run those cmd
$sudo rm -rf /usr/local/var/mysql
$sudo rm /usr/local/etc/my.cnf
$brew postinstall mysql

$brew services start mysql
_x000D_ enter image description here Completed All process of secure installation then run

$mysql -u root -p

Congratulations you’ve just set up mysql!

How to change the Text color of Menu item in Android?

Simply add this to your theme

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:itemTextAppearance">@style/AppTheme.ItemTextStyle</item>

<style name="AppTheme.ItemTextStyle" parent="@android:style/TextAppearance.Widget.IconMenu.Item">
        <item name="android:textColor">@color/orange_500</item>

Tested on API 21

How can I put the current running linux process in background?

Suspend the process with CTRL+Z then use the command bg to resume it in background. For example:

sleep 60
^Z  #Suspend character shown after hitting CTRL+Z
[1]+  Stopped  sleep 60  #Message showing stopped process info
bg  #Resume current job (last job stopped)

More about job control and bg usage in bash manual page:

Typing the suspend character (typically ^Z, Control-Z) while a process is running causes that process to be stopped and returns control to bash. [...] The user may then manipulate the state of this job, using the bg command to continue it in the background, [...]. A ^Z takes effect immediately, and has the additional side effect of causing pending output and typeahead to be discarded.

bg [jobspec ...]
Resume each suspended job jobspec in the background, as if it had been started with &. If jobspec is not present, the shell's notion of the current job is used.


To start a process where you can even kill the terminal and it still carries on running

nohup [command] [-args] > [filename] 2>&1 &


nohup /home/edheal/myprog -arg1 -arg2 > /home/edheal/output.txt 2>&1 &

To just ignore the output (not very wise) change the filename to /dev/null

To get the error message set to a different file change the &1 to a filename.

In addition: You can use the jobs command to see an indexed list of those backgrounded processes. And you can kill a backgrounded process by running kill %1 or kill %2 with the number being the index of the process.

Put spacing between divs in a horizontal row?

Another idea: Compensate for your margin on the opposite side of the div.

For the side with the spacing you are looking to achieve as an example: 10px, and for the opposing side, compensate with a -10px. It works for me. This likely won't work in all scenarios, but depending on your layout and spacing of other elements, it might work great.

Force flex item to span full row width

When you want a flex item to occupy an entire row, set it to width: 100% or flex-basis: 100%, and enable wrap on the container.

The item now consumes all available space. Siblings are forced on to other rows.

.parent {
  display: flex;
  flex-wrap: wrap;

#range, #text {
  flex: 1;

.error {
  flex: 0 0 100%; /* flex-grow, flex-shrink, flex-basis */
  border: 1px dashed black;
<div class="parent">
  <input type="range" id="range">
  <input type="text" id="text">
  <label class="error">Error message (takes full width)</label>

More info: The initial value of the flex-wrap property is nowrap, which means that all items will line up in a row. MDN

Angular - Set headers for every request

In Angular 2.1.2 I approached this by extending the angular Http:

import {Injectable} from "@angular/core";
import {Http, Headers, RequestOptionsArgs, Request, Response, ConnectionBackend, RequestOptions} from "@angular/http";
import {Observable} from 'rxjs/Observable';

export class HttpClient extends Http {

  constructor(protected _backend: ConnectionBackend, protected _defaultOptions: RequestOptions) {

    super(_backend, _defaultOptions);

  _setCustomHeaders(options?: RequestOptionsArgs):RequestOptionsArgs{
    if(!options) {
      options = new RequestOptions({});
    if(localStorage.getItem("id_token")) {

      if (!options.headers) {

        options.headers = new Headers();

      options.headers.set("Authorization", localStorage.getItem("id_token"))
    return options;

  request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
    options = this._setCustomHeaders(options);
    return super.request(url, options)

then in my App Providers I was able to use a custom Factory to provide 'Http'

import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';
import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';//above snippet

function httpClientFactory(xhrBackend: XHRBackend, requestOptions: RequestOptions): Http {
  return new HttpClient(xhrBackend, requestOptions);

  declarations: APP_DECLARATIONS,
     { provide: Http, useFactory: httpClientFactory, deps: [XHRBackend, RequestOptions]}
export class AppModule {


now I don't need to declare every Http method and can use http as normal throughout my application.

"NOT IN" clause in LINQ to Entities


from p in db.Products
where !theBadCategories.Contains(p.Category)
select p;

What's the SQL query you want to translate into a Linq query?

React ignores 'for' attribute of the label element

That is htmlFor in JSX and class is className in JSX

Check if checkbox is checked with jQuery

IDs must be unique in your document, meaning that you shouldn't do this:

<input type="checkbox" name="chk[]" id="chk[]" value="Apples" />
<input type="checkbox" name="chk[]" id="chk[]" value="Bananas" />

Instead, drop the ID, and then select them by name, or by a containing element:

<fieldset id="checkArray">
    <input type="checkbox" name="chk[]" value="Apples" />

    <input type="checkbox" name="chk[]" value="Bananas" />

And now the jQuery:

var atLeastOneIsChecked = $('#checkArray:checkbox:checked').length > 0;
//there should be no space between identifier and selector

// or, without the container:

var atLeastOneIsChecked = $('input[name="chk[]"]:checked').length > 0;

How do I copy a 2 Dimensional array in Java?

 * Clones the provided array
 * @param src
 * @return a new clone of the provided array
public static int[][] cloneArray(int[][] src) {
    int length = src.length;
    int[][] target = new int[length][src[0].length];
    for (int i = 0; i < length; i++) {
        System.arraycopy(src[i], 0, target[i], 0, src[i].length);
    return target;

Is it possible to modify this code to support n-dimensional arrays of Objects?

You would need to support arbitrary lengths of arrays and check if the src and destination have the same dimensions, and you would also need to copy each element of each array recursively, in case the Object was also an array.

It's been a while since I posted this, but I found a nice example of one way to create an n-dimensional array class. The class takes zero or more integers in the constructor, specifying the respective size of each dimension. The class uses an underlying flat array Object[] and calculates the index of each element using the dimensions and an array of multipliers. (This is how arrays are done in the C programming language.)

Copying an instance of NDimensionalArray would be as easy as copying any other 2D array, though you need to assert that each NDimensionalArray object has equal dimensions. This is probably the easiest way to do it, since there is no recursion, and this makes representation and access much simpler.

Spring Maven clean error - The requested profile "pom.xml" could not be activated because it does not exist

Goto Properties -> maven Remove the pom.xml from the activate profiles and follow the below steps.

Steps :

  1. Delete the .m2 repository
  2. Restart the Eclipse IDE
  3. Refresh and Rebuild it

What does "./" (dot slash) refer to in terms of an HTML file path location?

.  = This location
.. = Up a directory

So, ./foo.html is just foo.html. And it is optional, but may have relevance if a script generated the path (relevance to the script that is, not how the reference works).

Remove a parameter to the URL with JavaScript

Try this. Just pass in the param you want to remove from the URL and the original URL value, and the function will strip it out for you.

function removeParam(key, sourceURL) {
    var rtn = sourceURL.split("?")[0],
        params_arr = [],
        queryString = (sourceURL.indexOf("?") !== -1) ? sourceURL.split("?")[1] : "";
    if (queryString !== "") {
        params_arr = queryString.split("&");
        for (var i = params_arr.length - 1; i >= 0; i -= 1) {
            param = params_arr[i].split("=")[0];
            if (param === key) {
                params_arr.splice(i, 1);
        if (params_arr.length) rtn = rtn + "?" + params_arr.join("&");
    return rtn;

To use it, simply do something like this:

var originalURL = "";
var alteredURL = removeParam("color_id", originalURL);

The var alteredURL will be the output you desire.

Hope it helps!

Angular 2 - Checking for server errors from subscribe

As stated in the relevant RxJS documentation, the .subscribe() method can take a third argument that is called on completion if there are no errors.

For reference:

  1. [onNext] (Function): Function to invoke for each element in the observable sequence.
  2. [onError] (Function): Function to invoke upon exceptional termination of the observable sequence.
  3. [onCompleted] (Function): Function to invoke upon graceful termination of the observable sequence.

Therefore you can handle your routing logic in the onCompleted callback since it will be called upon graceful termination (which implies that there won't be any errors when it is called).

      result => {
        // Handle result
      error => {
        this.errors = error;
      () => {
        // 'onCompleted' callback.
        // No errors, route to new page here

As a side note, there is also a .finally() method which is called on completion regardless of the success/failure of the call. This may be helpful in scenarios where you always want to execute certain logic after an HTTP request regardless of the result (i.e., for logging purposes or for some UI interaction such as showing a modal).


Invokes a specified action after the source observable sequence terminates gracefully or exceptionally.

For instance, here is a basic example:

import { Observable } from 'rxjs/Rx';
import 'rxjs/add/operator/finally';

// ...

    .finally(() => {
      // Execute after graceful or exceptionally termination
      console.log('Handle logging logic...');
    .subscribe (
      result => {
        // Handle result
      error => {
        this.errors = error;
      () => {
        // No errors, route to new page

EPPlus - Read Excel Table

I have got an error on the first answer so I have changed some code line.

Please try my new code, it's working for me.

using OfficeOpenXml;
using OfficeOpenXml.Table;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

public static class ImportExcelReader
    public static List<T> ImportExcelToList<T>(this ExcelWorksheet worksheet) where T : new()
        //DateTime Conversion
        Func<double, DateTime> convertDateTime = new Func<double, DateTime>(excelDate =>
            if (excelDate < 1)
                throw new ArgumentException("Excel dates cannot be smaller than 0.");

            DateTime dateOfReference = new DateTime(1900, 1, 1);

            if (excelDate > 60d)
                excelDate = excelDate - 2;
                excelDate = excelDate - 1;

            return dateOfReference.AddDays(excelDate);

        ExcelTable table = null;

        if (worksheet.Tables.Any())
            table = worksheet.Tables.FirstOrDefault();
            table = worksheet.Tables.Add(worksheet.Dimension, "tbl" + ShortGuid.NewGuid().ToString());

            ExcelAddressBase newaddy = new ExcelAddressBase(table.Address.Start.Row, table.Address.Start.Column, table.Address.End.Row + 1, table.Address.End.Column);

            //Edit the raw XML by searching for all references to the old address
            table.TableXml.InnerXml = table.TableXml.InnerXml.Replace(table.Address.ToString(), newaddy.ToString());

        //Get the cells based on the table address
        List<IGrouping<int, ExcelRangeBase>> groups = table.WorkSheet.Cells[table.Address.Start.Row, table.Address.Start.Column, table.Address.End.Row, table.Address.End.Column]
            .GroupBy(cell => cell.Start.Row)

        //Assume the second row represents column data types (big assumption!)
        List<Type> types = groups.Skip(1).FirstOrDefault().Select(rcell => rcell.Value.GetType()).ToList();

        //Get the properties of T
        List<PropertyInfo> modelProperties = new T().GetType().GetProperties().ToList();

        //Assume first row has the column names
        var colnames = groups.FirstOrDefault()
            .Select((hcell, idx) => new
                Name = hcell.Value.ToString(),
                index = idx
            .Where(o => modelProperties.Select(p => p.Name).Contains(o.Name))

        //Everything after the header is data
        List<List<object>> rowvalues = groups
            .Skip(1) //Exclude header
            .Select(cg => cg.Select(c => c.Value).ToList()).ToList();

        //Create the collection container
        List<T> collection = new List<T>();
        foreach (List<object> row in rowvalues)
            T tnew = new T();
            foreach (var colname in colnames)
                //This is the real wrinkle to using reflection - Excel stores all numbers as double including int
                object val = row[colname.index];
                Type type = types[colname.index];
                PropertyInfo prop = modelProperties.FirstOrDefault(p => p.Name == colname.Name);

                //If it is numeric it is a double since that is how excel stores all numbers
                if (type == typeof(double))
                    //Unbox it
                    double unboxedVal = (double)val;

                    //FAR FROM A COMPLETE LIST!!!
                    if (prop.PropertyType == typeof(int))
                        prop.SetValue(tnew, (int)unboxedVal);
                    else if (prop.PropertyType == typeof(double))
                        prop.SetValue(tnew, unboxedVal);
                    else if (prop.PropertyType == typeof(DateTime))
                        prop.SetValue(tnew, convertDateTime(unboxedVal));
                    else if (prop.PropertyType == typeof(string))
                        prop.SetValue(tnew, val.ToString());
                        throw new NotImplementedException(string.Format("Type '{0}' not implemented yet!", prop.PropertyType.Name));
                    //Its a string
                    prop.SetValue(tnew, val);

        return collection;

How to call this function? please view below code;

private List<FundraiserStudentListModel> GetStudentsFromExcel(HttpPostedFileBase file)
        List<FundraiserStudentListModel> list = new List<FundraiserStudentListModel>();
        if (file != null)
                using (ExcelPackage package = new ExcelPackage(file.InputStream))
                    ExcelWorkbook workbook = package.Workbook;
                    if (workbook != null)
                        ExcelWorksheet worksheet = workbook.Worksheets.FirstOrDefault();
                        if (worksheet != null)
                            list = worksheet.ImportExcelToList<FundraiserStudentListModel>();
            catch (Exception err)
                //save error log
        return list;

FundraiserStudentListModel here:

 public class FundraiserStudentListModel
    public string Name { get; set; }
    public string Email { get; set; }
    public string Phone { get; set; }

Getting first and last day of the current month

Try this code it is already built in c#

int lastDay = DateTime.DaysInMonth (2014, 2);

and the first day is always 1.

Good Luck!

Solving Quadratic Equation

give input through your keyboard

a=float(input("enter the 1st number : "))
b=float(input("enter the 2nd number : "))
c=float(input("enter the 3rd number : "))

calculate the discriminant

d = (b**2) - (4*a*c)

possible solution are

sol_1 = (-b-(0.5**d))/(2*a)
sol_2 = (-b+(0.5**d))/(2*a)

print the result

print('The solution are  %0.f,%0.f'%(sol_1,sol_2))

How do I check if an object has a key in JavaScript?

You should use hasOwnProperty. For example:


Note: If you are using ESLint, the above may give you an error for violating the no-prototype-builtins rule, in that case the workaround is as below:, 'myKey');

Python convert object to float

  • You can use pandas.Series.astype
  • You can do something like this :

    weather["Temp"] = weather.Temp.astype(float)
  • You can also use pd.to_numeric that will convert the column from object to float

  • For details on how to use it checkout this link :
  • Example :

    s = pd.Series(['apple', '1.0', '2', -3])
    print(pd.to_numeric(s, errors='ignore'))
    print(pd.to_numeric(s, errors='coerce'))
  • Output:

    0    apple
    1      1.0
    2        2
    3       -3
    dtype: object
    0    NaN
    1    1.0
    2    2.0
    3   -3.0
    dtype: float64
  • In your case you can do something like this:

    weather["Temp"] = pd.to_numeric(weather.Temp, errors='coerce')
  • Other option is to use convert_objects
  • Example is as follows

    >> pd.Series([1,2,3,4,'.']).convert_objects(convert_numeric=True)
    0     1
    1     2
    2     3
    3     4
    4   NaN
    dtype: float64
  • You can use this as follows:

    weather["Temp"] = weather.Temp.convert_objects(convert_numeric=True)
  • I have showed you examples because if any of your column won't have a number then it will be converted to NaN... so be careful while using it.

NumPy array initialization (fill with identical values)

Updated for Numpy 1.7.0:(Hat-tip to @Rolf Bartstra.)

a=np.empty(n); a.fill(5) is fastest.

In descending speed order:

%timeit a=np.empty(1e4); a.fill(5)
100000 loops, best of 3: 5.85 us per loop

%timeit a=np.empty(1e4); a[:]=5 
100000 loops, best of 3: 7.15 us per loop

%timeit a=np.ones(1e4)*5
10000 loops, best of 3: 22.9 us per loop

%timeit a=np.repeat(5,(1e4))
10000 loops, best of 3: 81.7 us per loop

%timeit a=np.tile(5,[1e4])
10000 loops, best of 3: 82.9 us per loop

Pythonic way of checking if a condition holds for any element of a list


if any(t < 0 for t in x):
    # do something

Also, if you're going to use "True in ...", make it a generator expression so it doesn't take O(n) memory:

if True in (t < 0 for t in x):

Check if space is in a string

You can say word.strip(" ") to remove any leading/trailing spaces from the string - you should do that before your if statement. That way if someone enters input such as " test " your program will still work.

That said, if " " in word: will determine if a string contains any spaces. If that does not working, can you please provide more information?

Using command line arguments in VBscript

Set args = Wscript.Arguments

For Each arg In args
  Wscript.Echo arg

From a command prompt, run the script like this:

CSCRIPT MyScript.vbs 1 2 A B "Arg with spaces"

Will give results like this:

Arg with spaces

Why would someone use WHERE 1=1 AND <conditions> in a SQL clause?

Seems like a lazy way to always know that your WHERE clause is already defined and allow you to keep adding conditions without having to check if it is the first one.

Git Pull vs Git Rebase

In a nutshell :

-> Git Merge: It will simply merge your local changes and remote changes, and that will create another commit history record

-> Git Rebase: It will put your changes above all new remote changes, and rewrite commit history, so your commit history will be much cleaner than git merge. Rebase is a destructive operation. That means, if you do not apply it correctly, you could lose committed work and/or break the consistency of other developer's repositories.

How to iterate over columns of pandas dataframe to run regression

I landed on this question as I was looking for a clean iterator of columns only (Series, no names).

Unless I am mistaken, there is no such thing, which, if true, is a bit annoying. In particular, one would sometimes like to assign a few individual columns (Series) to variables, e.g.:

x, y = df[['x', 'y']]  # does not work

There is df.items() that gets close, but it gives an iterator of tuples (column_name, column_series). Interestingly, there is a corresponding df.keys() which returns df.columns, i.e. the column names as an Index, so a, b = df[['x', 'y']].keys() assigns properly a='x' and b='y'. But there is no corresponding df.values(), and for good reason, as df.values is a property and returns the underlying numpy array.

One (inelegant) way is to do:

x, y = (v for _, v in df[['x', 'y']].items())

but it's less pythonic than I'd like.

Java array reflection: isArray vs. instanceof

If obj is of type int[] say, then that will have an array Class but not be an instance of Object[]. So what do you want to do with obj. If you are going to cast it, go with instanceof. If you are going to use reflection, then use .getClass().isArray().

How to delete all records from table in sqlite with Android?

try this code to delete all data from a table..

String selectQuery = "DELETE FROM table_name ";
Cursor cursor = data1.getReadableDatabase().rawQuery(selectQuery, null);

How can I enter latitude and longitude in Google Maps?

First is latitude, second longitude. Different than many constructors in mapbox.

Here are examples of formats that work:

  • Degrees, minutes, and seconds (DMS): 41°24'12.2"N 2°10'26.5"E
  • Degrees and decimal minutes (DMM): 41 24.2028, 2 10.4418
  • Decimal degrees (DD): 41.40338, 2.17403

Tips for formatting your coordinates

  • Use the degree symbol instead of “d”.
  • Use periods as decimals, not commas.
    • Incorrect: 41,40338, 2,17403.
    • Correct: 41.40338, 2.17403.
  • List your latitude coordinates before longitude coordinates.
  • Check that the first number in your latitude coordinate is between -90 and 90 and the first number in your longitude coordinate is between -180 and 180.

How does lock work exactly?

No, they are not queued, they are sleeping

A lock statement of the form

lock (x) ... 

where x is an expression of a reference-type, is precisely equivalent to

var temp = x;
try { ... } 
finally { System.Threading.Monitor.Exit(temp); }

You just need to know that they are waiting to each other, and only one thread will enter to lock block, the others will wait...

Monitor is written fully in .net so it is enough fast, also look at class Monitor with reflector for more details

Create a Date with a set timezone without using a string representation

This is BEST solution


// TO ALL dates
Date.timezoneOffset(-240) // +4 UTC

// Override offset only for THIS date
new Date().timezoneOffset(-180) // +3 UTC


Date.prototype.timezoneOffset = new Date().getTimezoneOffset();

Date.setTimezoneOffset = function(timezoneOffset) {
  return this.prototype.timezoneOffset = timezoneOffset;

Date.getTimezoneOffset = function() {
  return this.prototype.timezoneOffset;

Date.prototype.setTimezoneOffset = function(timezoneOffset) {
  return this.timezoneOffset = timezoneOffset;

Date.prototype.getTimezoneOffset = function() {
  return this.timezoneOffset;

Date.prototype.toString = function() {
  var offsetDate, offsetTime;
  offsetTime = this.timezoneOffset * 60 * 1000;
  offsetDate = new Date(this.getTime() - offsetTime);
  return offsetDate.toUTCString();

['Milliseconds', 'Seconds', 'Minutes', 'Hours', 'Date', 'Month', 'FullYear', 'Year', 'Day'].forEach((function(_this) {
  return function(key) {
    Date.prototype["get" + key] = function() {
      var offsetDate, offsetTime;
      offsetTime = this.timezoneOffset * 60 * 1000;
      offsetDate = new Date(this.getTime() - offsetTime);
      return offsetDate["getUTC" + key]();
    return Date.prototype["set" + key] = function(value) {
      var offsetDate, offsetTime, time;
      offsetTime = this.timezoneOffset * 60 * 1000;
      offsetDate = new Date(this.getTime() - offsetTime);
      offsetDate["setUTC" + key](value);
      time = offsetDate.getTime() + offsetTime;
      return time;

Coffee version:

Date.prototype.timezoneOffset = new Date().getTimezoneOffset()

Date.setTimezoneOffset = (timezoneOffset)->
    return @prototype.timezoneOffset = timezoneOffset

Date.getTimezoneOffset = ->
    return @prototype.timezoneOffset

Date.prototype.setTimezoneOffset = (timezoneOffset)->
    return @timezoneOffset = timezoneOffset

Date.prototype.getTimezoneOffset = ->
    return @timezoneOffset

Date.prototype.toString = ->
    offsetTime = @timezoneOffset * 60 * 1000
    offsetDate = new Date(@getTime() - offsetTime)
    return offsetDate.toUTCString()

    'Milliseconds', 'Seconds', 'Minutes', 'Hours',
    'Date', 'Month', 'FullYear', 'Year', 'Day'
.forEach (key)=>
    Date.prototype["get#{key}"] = ->
        offsetTime = @timezoneOffset * 60 * 1000
        offsetDate = new Date(@getTime() - offsetTime)
        return offsetDate["getUTC#{key}"]()

    Date.prototype["set#{key}"] = (value)->
        offsetTime = @timezoneOffset * 60 * 1000
        offsetDate = new Date(@getTime() - offsetTime)
        time = offsetDate.getTime() + offsetTime
        return time

Warning - Build path specifies execution environment J2SE-1.4

In eclipse preferences, go to Java->Installed JREs->Execution Environment and set up a JRE Execution Environment for J2SE-1.4

'printf' vs. 'cout' in C++

I'm not a programmer, but I have been a human factors engineer. I feel a programming language should be easy to learn, understand and use, and this requires that it have a simple and consistent linguistic structure. Although all the languages is symbolic and thus, at its core, arbitrary, there are conventions and following them makes the language easier to learn and use.

There are a vast number of functions in C++ and other languages written as function(parameter), a syntax that was originally used for functional relationships in mathematics in the pre-computer era. printf() follows this syntax and if the writers of C++ wanted to create any logically different method for reading and writing files they could have simply created a different function using a similar syntax.

In Python we of course can print using the also fairly standard object.method syntax, i.e. variablename.print, since variables are objects, but in C++ they are not.

I'm not fond of the cout syntax because the << operator does not follow any rules. It is a method or function, i.e. it takes a parameter and does something to it. However it is written as though it were a mathematical comparison operator. This is a poor approach from a human factors standpoint.

CSS selector last row from main table

Your tables should have as immediate children just tbody and thead elements, with the rows within*. So, amend the HTML to be:

<table border="1" width="100%" id="test">
      <table border="1" width="100%">
            <td>table 2</td>
    <tr><td>table 1</td></tr>
    <tr><td>table 1</td></tr>
    <tr><td>table 1</td></tr>

Then amend your selector slightly to this:

#test > tbody > tr:last-child { background:#ff0000; }

See it in action here. That makes use of the child selector, which:

...separates two selectors and matches only those elements matched by the second selector that are direct children of elements matched by the first.

So, you are targeting only direct children of tbody elements that are themselves direct children of your #test table.

Alternative solution

The above is the neatest solution, as you don't need to over-ride any styles. The alternative would be to stick with your current set-up, and over-ride the background style for the inner table, like this:

#test tr:last-child { background:#ff0000; }
#test table tr:last-child { background:transparent; }

* It's not mandatory but most (all?) browsers will add these in, so it's best to make it explicit. As @BoltClock states in the comments:'s now set in stone in HTML5, so for a browser to be compliant it basically must behave this way.

alternatives to REPLACE on a text or ntext datatype

IF your data won't overflow 4000 characters AND you're on SQL Server 2000 or compatibility level of 8 or SQL Server 2000:

UPDATE [CMS_DB_test].[dbo].[cms_HtmlText] 
SET Content = CAST(REPLACE(CAST(Content as NVarchar(4000)),'ABC','DEF') AS NText)
WHERE Content LIKE '%ABC%' 

For SQL Server 2005+:

UPDATE [CMS_DB_test].[dbo].[cms_HtmlText] 
SET Content = CAST(REPLACE(CAST(Content as NVarchar(MAX)),'ABC','DEF') AS NText)
WHERE Content LIKE '%ABC%' 

Android webview & localStorage

The following was missing:


How to launch jQuery Fancybox on page load?

Alex's answer is great. but It is importanting to note that that calls the default fancybox style. If you have your own custom rules, you should just call .trigger click on that specific anchor

$(document).ready(function() {
    'padding':          0,
    'cyclic':       true,
    'width':        625,
    'height':       350,
    'padding':      0, 
    'margin':      0, 
    'speedIn':      300,
    'speedOut':     300,
    'transitionIn': 'elastic',
    'transitionOut': 'elastic',
    'easingIn':     'swing',
    'easingOut':    'swing',
    'titleShow' : false

How to convert a negative number to positive?

In [6]: x = -2
In [7]: x
Out[7]: -2

In [8]: abs(x)
Out[8]: 2

Actually abs will return the absolute value of any number. Absolute value is always a non-negative number.

Find out how much memory is being used by an object in Python

There's no easy way to find out the memory size of a python object. One of the problems you may find is that Python objects - like lists and dicts - may have references to other python objects (in this case, what would your size be? The size containing the size of each object or not?). There are some pointers overhead and internal structures related to object types and garbage collection. Finally, some python objects have non-obvious behaviors. For instance, lists reserve space for more objects than they have, most of the time; dicts are even more complicated since they can operate in different ways (they have a different implementation for small number of keys and sometimes they over allocate entries).

There is a big chunk of code (and an updated big chunk of code) out there to try to best approximate the size of a python object in memory.

You may also want to check some old description about PyObject (the internal C struct that represents virtually all python objects).

Pass C# ASP.NET array to Javascript array

Prepare an array (in my case it is 2d array):

        // prepare a 2d array in c#
        ArrayList header = new ArrayList { "Task Name", "Hours"};
        ArrayList data1 = new ArrayList {"Work", 2};
        ArrayList data2 = new ArrayList { "Eat", 2 };
        ArrayList data3 = new ArrayList { "Sleep", 2 };
        ArrayList data = new ArrayList {header, data1, data2, data3};
        // convert it in json
        string dataStr = JsonConvert.SerializeObject(data, Formatting.None);
        // store it in viewdata/ viewbag
        ViewBag.Data = new HtmlString(dataStr);   

Parse it in the view.

    var data = JSON.parse('@ViewBag.Data');

In your case you can directly use variable name instead of ViewBag.Data.

How to set a Timer in Java?

Use this

long startTime = System.currentTimeMillis();
long elapsedTime = 0L.

while (elapsedTime < 2*60*1000) {
    //perform db poll/check
    elapsedTime = (new Date()).getTime() - startTime;

//Throw your exception

Rank function in MySQL

If you want to rank just one person you can do the following:

WHERE(Age < age_to_rank)

This ranking corresponds to the oracle RANK function (Where if you have people with the same age they get the same rank, and the ranking after that is non-consecutive).

It's a little bit faster than using one of the above solutions in a subquery and selecting from that to get the ranking of one person.

This can be used to rank everyone but it's slower than the above solutions.

  Age AS age_var,
  FROM Person
  WHERE (Age < age_var)
 ) AS rank
 FROM Person

"date(): It is not safe to rely on the system's timezone settings..."

You probably need to put the timezone in a configuration line in your php.ini file. You should have a block like this in your php.ini file:

; Defines the default timezone used by the date functions
date.timezone = America/New_York

If not, add it (replacing the timezone by yours). After configuring, make sure to restart httpd (service httpd restart).

Here is the list of supported timezones.

rsync copy over only certain types of files using include option

Here's the important part from the man page:

As the list of files/directories to transfer is built, rsync checks each name to be transferred against the list of include/exclude patterns in turn, and the first matching pattern is acted on: if it is an exclude pattern, then that file is skipped; if it is an include pattern then that filename is not skipped; if no matching pattern is found, then the filename is not skipped.

To summarize:

  • Not matching any pattern means a file will be copied!
  • The algorithm quits once any pattern matches

Also, something ending with a slash is matching directories (like find -type d would).

Let's pull apart this answer from above.

rsync -zarv  --prune-empty-dirs --include "*/"  --include="*.sh" --exclude="*" "$from" "$to"
  1. Don't skip any directories
  2. Don't skip any .sh files
  3. Skip everything
  4. (Implicitly, don't skip anything, but the rule above prevents the default rule from ever happening.)

Finally, the --prune-empty-directories keeps the first rule from making empty directories all over the place.

HttpServletRequest to complete URL

The HttpServletRequest has the following methods:

  • getRequestURL() - returns the part of the full URL before query string separator character ?
  • getQueryString() - returns the part of the full URL after query string separator character ?

So, to get the full URL, just do:

public static String getFullURL(HttpServletRequest request) {
    StringBuilder requestURL = new StringBuilder(request.getRequestURL().toString());
    String queryString = request.getQueryString();

    if (queryString == null) {
        return requestURL.toString();
    } else {
        return requestURL.append('?').append(queryString).toString();

How to close a Java Swing application from the code

The following program includes code that will terminate a program lacking extraneous threads without explicitly calling System.exit(). In order to apply this example to applications using threads/listeners/timers/etc, one need only insert cleanup code requesting (and, if applicable, awaiting) their termination before the WindowEvent is manually initiated within actionPerformed().

For those who wish to copy/paste code capable of running exactly as shown, a slightly-ugly but otherwise irrelevant main method is included at the end.

public class CloseExample extends JFrame implements ActionListener {

    private JButton turnOffButton;

    private void addStuff() {
        turnOffButton = new JButton("Exit");

    public void actionPerformed(ActionEvent quitEvent) {
        /* Iterate through and close all timers, threads, etc here */
                new WindowEvent(
                      this, WindowEvent.WINDOW_CLOSING));

    public CloseExample() {
        super("Close Me!");

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                CloseExample cTW = new CloseExample();
                cTW.setSize(200, 100);

Is it possible to ignore one single specific line with Pylint?

Pylint message control is documented in the Pylint manual:

Is it possible to locally disable a particular message?

Yes, this feature has been added in Pylint 0.11. This may be done by adding # pylint: disable=some-message,another-one at the desired block level or at the end of the desired line of code.

You can use the message code or the symbolic names.

For example,

def test():
    # Disable all the no-member violations in this function
    # pylint: disable=no-member
global VAR # pylint: disable=global-statement

The manual also has further examples.

There is a wiki that documents all Pylint messages and their codes.

T-SQL: Looping through an array of known values

What I do in this scenario is create a table variable to hold the Ids.

  Declare @Ids Table (id integer primary Key not null)
  Insert @Ids(id) values (4),(7),(12),(22),(19)

-- (or call another table valued function to generate this table)

Then loop based on the rows in this table

  Declare @Id Integer
  While exists (Select * From @Ids)
      Select @Id = Min(id) from @Ids
      exec p_MyInnerProcedure @Id 
      Delete from @Ids Where id = @Id


  Declare @Id Integer = 0 -- assuming all Ids are > 0
  While exists (Select * From @Ids
                where id > @Id)
      Select @Id = Min(id) 
      from @Ids Where id > @Id
      exec p_MyInnerProcedure @Id 

Either of above approaches is much faster than a cursor (declared against regular User Table(s)). Table-valued variables have a bad rep because when used improperly, (for very wide tables with large number of rows) they are not performant. But if you are using them only to hold a key value or a 4 byte integer, with a index (as in this case) they are extremely fast.

Sorting dictionary keys in python

I like this one:

sorted(d, key=d.get)

What is Hive: Return Code 2 from org.apache.hadoop.hive.ql.exec.MapRedTask

Even I faced the same issue - when checked on dashboard I found following Error. As the data was coming through Flume and had interrupted in between due to which may be there was inconsistency in few files.

Caused by: org.apache.hadoop.hive.serde2.SerDeException: org.codehaus.jackson.JsonParseException: Unexpected end-of-input within/between OBJECT entries

Running on fewer files it worked. Format consistency was the reason in my case.

How can I add a variable to console.log?

You can use another console method:

let name = prompt("what is your name?");
console.log(`story ${name} story`);

Open an html page in default browser with VBA?

You can even say:

FollowHyperlink ""

If you get Automation Error then use http://:


How to hide Table Row Overflow?

Here´s something I tried. Basically, I put the "flexible" content (the td which contains lines that are too long) in a div container that´s one line high, with hidden overflow. Then I let the text wrap into the invisible. You get breaks at wordbreaks though, not just a smooth cut-off.

table {
    width: 100%;

.hideend {
    white-space: normal;
    overflow: hidden;
    max-height: 1.2em;
    min-width: 50px;
.showall {

        <td><div class="showall">Show all</div></td>
            <div class="hideend">Be a bit flexible about hiding stuff in a long sentence</div>
            <div class="showall">Show all this too</div>

Where's the IE7/8/9/10-emulator in IE11 dev tools?

I posted an answer to this already when someone else asked the same question (see How to bring back "Browser mode" in IE11?).

Read my answer there for a fuller explaination, but in short:

  • They removed it deliberately, because compat mode is not actually really very good for testing compatibility.

  • If you really want to test for compatibility with any given version of IE, you need to test in a real copy of that IE version. MS provide free VMs on for you to use for this purpose.

  • The only way to get compat mode in IE11 is to set the X-UA-Compatible header. When you have this and the site defaults to compat mode, you will be able to set the mode in dev tools, but only between edge or the specified compat mode; other modes will still not be available.

How do you determine what technology a website is built on?

Some people might even deliberately obscure the technology they use. After all, it wouldn't take me long to tweak apache so that ".asp" actually ran perl scripts and put "powered by Microsoft IIS" into my footer despite the fact I used MySQL.

That way you'd spend all your time trying to hack my site using vulnerabilities it doesn't actually have.

Group a list of objects by an attribute

You can use the following:

Map<String, List<Student>> groupedStudents = new HashMap<String, List<Student>>();
for (Student student: studlist) {
    String key = student.stud_location;
    if (groupedStudents.get(key) == null) {
        groupedStudents.put(key, new ArrayList<Student>());


Set<String> groupedStudentsKeySet = groupedCustomer.keySet();
for (String location: groupedStudentsKeySet) {
   List<Student> stdnts = groupedStudents.get(location);
   for (Student student : stdnts) {
        System.out.println("ID : "+student.stud_id+"\t"+"Name : "+student.stud_name+"\t"+"Location : "+student.stud_location);

Fastest Way of Inserting in Entity Framework

I agree with Adam Rackis. SqlBulkCopy is the fastest way of transferring bulk records from one data source to another. I used this to copy 20K records and it took less than 3 seconds. Have a look at the example below.

public static void InsertIntoMembers(DataTable dataTable)
    using (var connection = new SqlConnection(@"data source=;persist security info=True;user id=;password=;initial catalog=;MultipleActiveResultSets=True;App=EntityFramework"))
        SqlTransaction transaction = null;
            transaction = connection.BeginTransaction();
            using (var sqlBulkCopy = new SqlBulkCopy(connection, SqlBulkCopyOptions.TableLock, transaction))
                sqlBulkCopy.DestinationTableName = "Members";
                sqlBulkCopy.ColumnMappings.Add("Firstname", "Firstname");
                sqlBulkCopy.ColumnMappings.Add("Lastname", "Lastname");
                sqlBulkCopy.ColumnMappings.Add("DOB", "DOB");
                sqlBulkCopy.ColumnMappings.Add("Gender", "Gender");
                sqlBulkCopy.ColumnMappings.Add("Email", "Email");

                sqlBulkCopy.ColumnMappings.Add("Address1", "Address1");
                sqlBulkCopy.ColumnMappings.Add("Address2", "Address2");
                sqlBulkCopy.ColumnMappings.Add("Address3", "Address3");
                sqlBulkCopy.ColumnMappings.Add("Address4", "Address4");
                sqlBulkCopy.ColumnMappings.Add("Postcode", "Postcode");

                sqlBulkCopy.ColumnMappings.Add("MobileNumber", "MobileNumber");
                sqlBulkCopy.ColumnMappings.Add("TelephoneNumber", "TelephoneNumber");

                sqlBulkCopy.ColumnMappings.Add("Deleted", "Deleted");

        catch (Exception)


Can we have functions inside functions in C++?

No, it's not allowed. Neither C nor C++ support this feature by default, however TonyK points out (in the comments) that there are extensions to the GNU C compiler that enable this behavior in C.

Convert JS date time to MySQL datetime

Solution built on the basis of other answers, while maintaining the timezone and leading zeros:

var d = new Date;

var date = [
    ('00' + d.getMonth() + 1).slice(-2),
    ('00' + d.getDate() + 1).slice(-2)

var time = [
    ('00' + d.getHours()).slice(-2),
    ('00' + d.getMinutes()).slice(-2),
    ('00' + d.getSeconds()).slice(-2)

var dateTime = date + ' ' + time;
console.log(dateTime) // 2021-01-41 13:06:01

What does `set -x` do?

set -x

Prints a trace of simple commands, for commands, case commands, select commands, and arithmetic for commands and their arguments or associated word lists after they are expanded and before they are executed. The value of the PS4 variable is expanded and the resultant value is printed before the command and its expanded arguments.



set -x
echo `expr 10 + 20 `
+ expr 10 + 20
+ echo 30

set +x
echo `expr 10 + 20 `

Above example illustrates the usage of set -x. When it is used, above arithmetic expression has been expanded. We could see how a singe line has been evaluated step by step.

  • First step expr has been evaluated.
  • Second step echo has been evaluated.

To know more about set ? visit this link

when it comes to your shell script,

[ "$DEBUG" == 'true' ] && set -x

Your script might have been printing some additional lines of information when the execution mode selected as DEBUG. Traditionally people used to enable debug mode when a script called with optional argument such as -d

How to remove all characters after a specific character in python?

import re
test = "This is a test...we should not be able to see this"
res = re.sub(r'\.\.\..*',"",test)

Output: "This is a test"

Configuring user and password with Git Bash

If you are a Mac user and have keychain enabled, you to need to remove the authorization information that is stored in the keychain:

- Open up Keychain access
- Click "All items" under category in the left-hand column
- Search for git
- Delete all git entries.

Then you should change your username and email from the terminal using git config:

$ git config --global "Bob"

$ git config --global "[email protected]"

Now if you try to push to the repository you will be asked for a username and password. Enter the login credentials you are trying to switch to. This problem normally pops up if you signed into GitHub on a browser using a different username and password or previously switched accounts on your terminal.

Found shared references to a collection org.hibernate.HibernateException

I faced similar exception in my application. After looking into the stacktrace it was clear that exception was thrown within a FlushEntityEventListener class.

In Hibernate 4.3.7 the MSLocalSessionFactory bean no longer supports the eventListeners property. Hence, one has to explicitly fetch the service registry from individual Hibernate session beans and then set the required custom event listeners.

In the process of adding custom event listeners we need to make sure the corresponding default event listeners are removed from the respective Hibernate session.

If the default event listener is not removed then the case arises of two event listeners registered against same event. In this case while iterating over these listeners, against first listeners any collections in the session will be flagged as reached and while processing the same collection against second listener would throw this Hibernate exception.

So, make sure that when registering custom listeners corresponding default listeners are removed from registry.

How to set up fixed width for <td>?

Try this -

 table { table-layout: fixed; }
 table th, table td { overflow: hidden; }

Python Timezone conversion

For Python timezone conversions, I use the handy table from the PyCon 2012 presentation by Taavi Burns.

Is it possible to declare two variables of different types in a for loop?

Also you could use like below in C++.

int j=3;
int i=2;
for (; i<n && j<n ; j=j+2, i=i+2){
  // your code

Hide particular div onload and then show div after click

$(document).ready(function() {
    $('#preview').on('click', function() {
        $('#div1').hide(300, function() { // first hide div1
            // then show div2

You missed # before div2

Working Sample

How to list only the file names that changed between two commits?

This will show the changes in files:

git diff --word-diff SHA1 SHA2

Check if EditText is empty.

use TextUtils.isEmpty("Text here"); for single line code

C# Connecting Through Proxy

This one-liner works for me:

WebRequest.DefaultWebProxy.Credentials = CredentialCache.DefaultNetworkCredentials;

CredentialCache.DefaultNetWorkCredentials is the proxy settings set in Internet Explorer.

WebRequest.DefaultWebProxy.Credentials is used for all internet connectivity in the application.

Including a .js file within a .js file

A popular method to tackle the problem of reducing JavaScript references from HTML files is by using a concatenation tool like Sprockets, which preprocesses and concatenates JavaScript source files together.

Apart from reducing the number of references from the HTML files, this will also reduce the number of hits to the server.

You may then want to run the resulting concatenation through a minification tool like jsmin to have it minified.

Python logging not outputting anything

Many years later there seems to still be a usability problem with the Python logger. Here's some explanations with examples:

import logging
# This sets the root logger to write to stdout (your console).
# Your script/app needs to call this somewhere at least once.

# By default the root logger is set to WARNING and all loggers you define
# inherit that value. Here we set the root logger to NOTSET. This logging
# level is automatically inherited by all existing and new sub-loggers
# that do not set a less verbose level.

# The following line sets the root logger level as well.
# It's equivalent to both previous statements combined:

# You can either share the `logger` object between all your files or the
# name handle (here `my-app`) and call `logging.getLogger` with it.
# The result is the same.
handle = "my-app"
logger1 = logging.getLogger(handle)
logger2 = logging.getLogger(handle)
# logger1 and logger2 point to the same object:
# (logger1 is logger2) == True

# Convenient methods in order of verbosity from highest to lowest
logger.debug("this will get printed")"this will get printed")
logger.warning("this will get printed")
logger.error("this will get printed")
logger.critical("this will get printed")

# In large applications where you would like more control over the logging,
# create sub-loggers from your main application logger.
component_logger = logger.getChild("component-a")"this will get printed with the prefix `my-app.component-a`")

# If you wish to control the logging levels, you can set the level anywhere 
# in the hierarchy:
# - root
#   - my-app
#     - component-a

# Example for development:

# If that prints too much, enable debug printing only for your component:

# For production you rather want:

A common source of confusion comes from a badly initialised root logger. Consider this:

import logging
log = logging.getLogger("myapp")



Depending on your runtime environment and logging levels, the first log line (before basic config) might not show up anywhere.

Are multiple `.gitignore`s frowned on?

Pro single

  • Easy to find.

  • Hunting down exclusion rules can be quite difficult if I have multiple gitignore, at several levels in the repo.

  • With multiple files, you also typically wind up with a fair bit of duplication.

Pro multiple

  • Scopes "knowledge" to the part of the file tree where it is needed.

  • Since Git only tracks files, an empty .gitignore is the only way to commit an "empty" directory.

    (And before Git 1.8, the only way to exclude a pattern like my/**.example was to create my/.gitignore in with the pattern **.foo. This reason doesn't apply now, as you can do /my/**/*.example.)

I much prefer a single file, where I can find all the exclusions. I've never missed per-directory .svn, and I won't miss per-directory .gitignore either.

That said, multiple gitignores are quite common. If you do use them, at least be consistent in their use to make them reasonable to work with. For example, you may put them in directories only one level from the root.

An App ID with Identifier '' is not available. Please enter a different string

Same issue happened with me, it might be that Xcode automatically selected another team name, its solved by choosing my correct team name. Good luck !

Hex transparency in colors

enter image description here

This might be very late answer. But this chart kills it.

All percentage values are mapped to the hexadecimal values.

How to filter multiple values (OR operation) in angularJS

If you want to filter on Array of Objects then you can give

filter:({genres: 'Action', key :value }.

Individual property will be filtered by particular filter given for that property.

But if you wanted to something like filter by individual Property and filter globally for all properties then you can do something like this.

<tr ng-repeat="supp in $data | filter : filterObject |  filter : search">
_x000D_ Where "filterObject" is an object for searching an individual property and "Search" will search in every property globally.


How do I reverse a C++ vector?

There's a function std::reverse in the algorithm header for this purpose.

#include <vector>
#include <algorithm>

int main() {
  std::vector<int> a;
  std::reverse(a.begin(), a.end());
  return 0;

Conditional WHERE clause in SQL Server

This seemed easier to think about where either of two parameters could be passed into a stored procedure. It seems to work:

AND ((@pol IS NOT NULL AND x.PolicyNo = @pol) OR (@st IS NOT NULL AND x.State = @st))

Calculate age given the birth date in the format YYYYMMDD

Here's the simplest, most accurate solution I could come up with:

Date.prototype.getAge = function (date) {
    if (!date) date = new Date();
    return ~~((date.getFullYear() + date.getMonth() / 100
    + date.getDate() / 10000) - (this.getFullYear() + 
    this.getMonth() / 100 + this.getDate() / 10000));

And here is a sample that will consider Feb 29 -> Feb 28 a year.

Date.prototype.getAge = function (date) {
    if (!date) date = new Date();
    var feb = (date.getMonth() == 1 || this.getMonth() == 1);
    return ~~((date.getFullYear() + date.getMonth() / 100 + 
        (feb && date.getDate() == 29 ? 28 : date.getDate())
        / 10000) - (this.getFullYear() + this.getMonth() / 100 + 
        (feb && this.getDate() == 29 ? 28 : this.getDate()) 
        / 10000));

It even works with negative age!

Plotting a 3d cube, a sphere and a vector in Matplotlib

For drawing just the arrow, there is an easier method:-

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.gca(projection='3d')

#draw the arrow

quiver can actually be used to plot multiple vectors at one go. The usage is as follows:- [ from]

quiver(X, Y, Z, U, V, W, **kwargs)


X, Y, Z: The x, y and z coordinates of the arrow locations

U, V, W: The x, y and z components of the arrow vectors

The arguments could be array-like or scalars.

Keyword arguments:

length: [1.0 | float] The length of each quiver, default to 1.0, the unit is the same with the axes

arrow_length_ratio: [0.3 | float] The ratio of the arrow head with respect to the quiver, default to 0.3

pivot: [ ‘tail’ | ‘middle’ | ‘tip’ ] The part of the arrow that is at the grid point; the arrow rotates about this point, hence the name pivot. Default is ‘tail’

normalize: [False | True] When True, all of the arrows will be the same length. This defaults to False, where the arrows will be different lengths depending on the values of u,v,w.

What does asterisk * mean in Python?

A single star means that the variable 'a' will be a tuple of extra parameters that were supplied to the function. The double star means the variable 'kw' will be a variable-size dictionary of extra parameters that were supplied with keywords.

Although the actual behavior is spec'd out, it still sometimes can be very non-intuitive. Writing some sample functions and calling them with various parameter styles may help you understand what is allowed and what the results are.

def f0(a)
def f1(*a)
def f2(**a)
def f3(*a, **b)

What is the difference between "SMS Push" and "WAP Push"?

SMS Push uses SMS as a carrier, WAP uses download via WAP.

How do you get centered content using Twitter Bootstrap?

<div class="container">
  <div class="col-md-12 centered">
    <div class="row">
      <div class="col-md-1"></div>
       <div class="col-md-10">
      <div class="col-md-1"></div>

Do not use container-fluid in the main.

Generate class from database table

I tried to use the suggestions above and in the process improved upon the solutions in this thread.

Let us say you use a base class (ObservableObject in this case) that implements the PropertyChanged Event, you would do something like this. I will probably write a blog post one day in my blog

Please do substitute the values for the first three variables:

    --These three things have to be substituted (when called from Powershell, they are replaced before execution)
DECLARE @Schema VARCHAR(MAX) = N'&Schema'
DECLARE @TableName VARCHAR(MAX) = N'&TableName'
DECLARE @Namespace VARCHAR(MAX) = N'&Namespace'

DECLARE @result VARCHAR(max) = ' '

DECLARE @PrivateProp VARCHAR(100) = @CRLF + 
                CHAR(9) + CHAR(9) + 'private <ColumnType> _<ColumnName>;';
DECLARE @PublicProp VARCHAR(255) = @CRLF + 
                CHAR(9) + CHAR(9) + 'public <ColumnType> <ColumnName> '  + @CRLF +
                CHAR(9) + CHAR(9) + '{ ' + @CRLF +
                CHAR(9) + CHAR(9) + '   get { return _<ColumnName>; } ' + @CRLF +
                CHAR(9) + CHAR(9) + '   set ' + @CRLF +
                CHAR(9) + CHAR(9) + '   { ' + @CRLF +
                CHAR(9) + CHAR(9) + '       _<ColumnName> = value;' + @CRLF +
                CHAR(9) + CHAR(9) + '       base.RaisePropertyChanged();' + @CRLF +
                CHAR(9) + CHAR(9) + '   } ' + @CRLF +
                CHAR(9) + CHAR(9) + '}' + @CRLF;

                CHAR(9) + CHAR(9) + 'public event PropertyChangedEventHandler PropertyChanged; ' + @CRLF +
                CHAR(9) + CHAR(9) + 'private void RaisePropertyChanged( ' + @CRLF +
                CHAR(9) + CHAR(9) + '       [CallerMemberName] string caller = "" ) ' + @CRLF +
                CHAR(9) + CHAR(9) + '{  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   if (PropertyChanged != null)  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   { ' + @CRLF +
                CHAR(9) + CHAR(9) + '       PropertyChanged( this, new PropertyChangedEventArgs( caller ) );  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   } ' + @CRLF +
                CHAR(9) + CHAR(9) + '}';

DECLARE @PropChanged VARCHAR(200) =  @CRLF +            
                CHAR(9) + CHAR(9) + 'protected override void AfterPropertyChanged(string propertyName) ' + @CRLF +
                CHAR(9) + CHAR(9) + '{ ' + @CRLF +
                CHAR(9) + CHAR(9) + '   System.Diagnostics.Debug.WriteLine("' + @TableName + ' property changed: " + propertyName); ' + @CRLF +
                CHAR(9) + CHAR(9) + '}';

SET @result = 'using System;' + @CRLF + @CRLF +
                'using MyCompany.Business;' + @CRLF + @CRLF +
                'namespace ' + @Namespace  + @CRLF + '{' + @CRLF +
                '   public class ' + @TableName + ' : ObservableObject' + @CRLF + 
                '   {' + @CRLF +
                '   #region Instance Properties' + @CRLF 

SELECT @result = @result
                            , '<ColumnName>', ColumnName)
                        , '<ColumnType>', ColumnType)
                            , '<ColumnName>', ColumnName)
                        , '<ColumnType>', ColumnType)                   
    SELECT  c.COLUMN_NAME   AS ColumnName 
        , CASE c.DATA_TYPE   
            WHEN 'bigint' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int64?' ELSE 'Int64' END
            WHEN 'binary' THEN 'Byte[]'
            WHEN 'bit' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Boolean?' ELSE 'Boolean' END            
            WHEN 'char' THEN 'String'
            WHEN 'date' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetime' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetime2' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetimeoffset' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTimeOffset?' ELSE 'DateTimeOffset' END                                    
            WHEN 'decimal' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                    
            WHEN 'float' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Single?' ELSE 'Single' END                                    
            WHEN 'image' THEN 'Byte[]'
            WHEN 'int' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int32?' ELSE 'Int32' END
            WHEN 'money' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                
            WHEN 'nchar' THEN 'String'
            WHEN 'ntext' THEN 'String'
            WHEN 'numeric' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                            
            WHEN 'nvarchar' THEN 'String'
            WHEN 'real' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Double?' ELSE 'Double' END                                                                        
            WHEN 'smalldatetime' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                                    
            WHEN 'smallint' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int16?' ELSE 'Int16'END            
            WHEN 'smallmoney' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                                        
            WHEN 'text' THEN 'String'
            WHEN 'time' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'TimeSpan?' ELSE 'TimeSpan' END                                                                                    
            WHEN 'timestamp' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                                    
            WHEN 'tinyint' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Byte?' ELSE 'Byte' END                                                
            WHEN 'uniqueidentifier' THEN 'Guid'
            WHEN 'varbinary' THEN 'Byte[]'
            WHEN 'varchar' THEN 'String'
            ELSE 'Object'
        END AS ColumnType
WHERE   c.TABLE_NAME = @TableName 
) t

SELECT @result = @result + @CRLF + 
                CHAR(9) + '#endregion Instance Properties' + @CRLF +
                --CHAR(9) + @RPCProc + @CRLF +
                CHAR(9) + @PropChanged + @CRLF +
                CHAR(9) + '}' + @CRLF +
                @CRLF + '}' 
--SELECT @result
PRINT @result

The base class is based on Josh Smith's article here From

I did rename the class to be called ObservableObject and also took advantage of a c# 5 feature using the CallerMemberName attribute

//Jana's change: Used c# 5 feature to bypass passing in the property name using [CallerMemberName] 
//  protected void RaisePropertyChanged([CallerMemberName] string propertyName = "")

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.CompilerServices;

namespace MyCompany.Business

    /// <summary>
    /// Implements the INotifyPropertyChanged interface and 
    /// exposes a RaisePropertyChanged method for derived 
    /// classes to raise the PropertyChange event.  The event 
    /// arguments created by this class are cached to prevent 
    /// managed heap fragmentation.
    /// </summary>
    public abstract class ObservableObject : INotifyPropertyChanged
        #region Data

        private static readonly Dictionary<string, PropertyChangedEventArgs> eventArgCache;
        private const string ERROR_MSG = "{0} is not a public property of {1}";

        #endregion // Data

        #region Constructors

        static ObservableObject()
            eventArgCache = new Dictionary<string, PropertyChangedEventArgs>();

        protected ObservableObject()

        #endregion // Constructors

        #region Public Members

        /// <summary>
        /// Raised when a public property of this object is set.
        /// </summary>
        [field: NonSerialized]
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        /// Returns an instance of PropertyChangedEventArgs for 
        /// the specified property name.
        /// </summary>
        /// <param name="propertyName">
        /// The name of the property to create event args for.
        /// </param>        
        public static PropertyChangedEventArgs
            GetPropertyChangedEventArgs(string propertyName)
            if (String.IsNullOrEmpty(propertyName))
                throw new ArgumentException(
                    "propertyName cannot be null or empty.");

            PropertyChangedEventArgs args;

            // Get the event args from the cache, creating them
            // and adding to the cache if necessary.
            lock (typeof(ObservableObject))
                bool isCached = eventArgCache.ContainsKey(propertyName);
                if (!isCached)
                        new PropertyChangedEventArgs(propertyName));

                args = eventArgCache[propertyName];

            return args;

        #endregion // Public Members

        #region Protected Members

        /// <summary>
        /// Derived classes can override this method to
        /// execute logic after a property is set. The 
        /// base implementation does nothing.
        /// </summary>
        /// <param name="propertyName">
        /// The property which was changed.
        /// </param>
        protected virtual void AfterPropertyChanged(string propertyName)

        /// <summary>
        /// Attempts to raise the PropertyChanged event, and 
        /// invokes the virtual AfterPropertyChanged method, 
        /// regardless of whether the event was raised or not.
        /// </summary>
        /// <param name="propertyName">
        /// The property which was changed.
        /// </param>
        protected void RaisePropertyChanged([CallerMemberName] string propertyName = "")

            PropertyChangedEventHandler handler = this.PropertyChanged;
            if (handler != null)
                // Get the cached event args.
                PropertyChangedEventArgs args =

                // Raise the PropertyChanged event.
                handler(this, args);


        #endregion // Protected Members

        #region Private Helpers

        private void VerifyProperty(string propertyName)
            Type type = this.GetType();

            // Look for a public property with the specified name.
            PropertyInfo propInfo = type.GetProperty(propertyName);

            if (propInfo == null)
                // The property could not be found,
                // so alert the developer of the problem.

                string msg = string.Format(


        #endregion // Private Helpers

Here is the part that you guys are going to like some more. I built a Powershell script to generate for all the tables in a SQL database. It is based on a Powershell guru named Chad Miller's Invoke-SQLCmd2 cmdlet which can be downloaded from here:

Once you have that cmdlet, the Powershell script to generate for all tables becomes simple (do substitute the variables with your specific values).

. C:\MyScripts\Invoke-Sqlcmd2.ps1

$serverInstance = "MySQLInstance"
$databaseName = "MyDb"
$generatorSQLFile = "C:\MyScripts\ModelGen.sql" 
$tableListSQL = "SELECT name FROM $databaseName.sys.tables"
$outputFolder = "C:\MyScripts\Output\"
$namespace = "MyCompany.Business"

$placeHolderSchema = "&Schema"
$placeHolderTableName = "&TableName"
$placeHolderNamespace = "&Namespace"

#Get the list of tables in the database to generate c# models for
$tables = Invoke-Sqlcmd2 -ServerInstance $serverInstance -Database $databaseName -Query $tableListSQL -As DataRow -Verbose

foreach ($table in $tables)
    $table1 = $table[0]
    $outputFile = "$outputFolder\$table1.cs"

    #Replace variables with values (returns an array that we convert to a string to use as query)
    $generatorSQLFileWSubstitutions = (Get-Content $generatorSQLFile).
                                            Replace($placeHolderTableName, $table1).
                                            Replace($placeHolderNamespace, $namespace) | Out-String

    "Ouputing for $table1 to $outputFile"

    #The command generates .cs file content for model using "PRINT" statements which then gets written to verbose output (stream 4)
    # ...capture the verbose output and redirect to a file
    (Invoke-Sqlcmd2 -ServerInstance $serverInstance -Database $databaseName -Query $generatorSQLFileWSubstitutions -Verbose) 4> $outputFile


Can't get Gulp to run: cannot find module 'gulp-util'

Same issue here and whatever I tried after searching around, did not work. Until I saw a remark somewhere about global or local installs. Looking in:


I indeed found an outdated version. So I reinstalled gulp with:

npm install gulp --global

That magically solved my problem.

How do I get the current GPS location programmatically in Android?

Here is additional information for other answers.

Since Android has


you can register to both and start fetch events from onLocationChanged(Location location) from two at the same time. So far so good. Now the question do we need two results or we should take the best. As I know GPS_PROVIDER results have better accuracy than NETWORK_PROVIDER.

Let's define Location field:

private Location currentBestLocation = null;

Before we start listen on Location change we will implement the following method. This method returns the last known location, between the GPS and the network one. For this method newer is best.

 * @return the last know best location
private Location getLastBestLocation() {
    Location locationGPS = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
    Location locationNet = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

    long GPSLocationTime = 0;
    if (null != locationGPS) { GPSLocationTime = locationGPS.getTime(); }

    long NetLocationTime = 0;

    if (null != locationNet) {
        NetLocationTime = locationNet.getTime();

    if ( 0 < GPSLocationTime - NetLocationTime ) {
        return locationGPS;
    else {
        return locationNet;

Each time when we retrieve a new location we will compare it with our previous result.

static final int TWO_MINUTES = 1000 * 60 * 2;

I add a new method to onLocationChanged:

public void onLocationChanged(Location location) {


    if(currentBestLocation == null){
        currentBestLocation = location;


 * This method modify the last know good location according to the arguments.
 * @param location The possible new location.
void makeUseOfNewLocation(Location location) {
    if ( isBetterLocation(location, currentBestLocation) ) {
        currentBestLocation = location;


/** Determines whether one location reading is better than the current location fix
 * @param location  The new location that you want to evaluate
 * @param currentBestLocation  The current location fix, to which you want to compare the new one.
protected boolean isBetterLocation(Location location, Location currentBestLocation) {
    if (currentBestLocation == null) {
        // A new location is always better than no location
        return true;

    // Check whether the new location fix is newer or older
    long timeDelta = location.getTime() - currentBestLocation.getTime();
    boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
    boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
    boolean isNewer = timeDelta > 0;

    // If it's been more than two minutes since the current location, use the new location,
    // because the user has likely moved.
    if (isSignificantlyNewer) {
        return true;
        // If the new location is more than two minutes older, it must be worse.
    } else if (isSignificantlyOlder) {
        return false;

    // Check whether the new location fix is more or less accurate
    int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
    boolean isLessAccurate = accuracyDelta > 0;
    boolean isMoreAccurate = accuracyDelta < 0;
    boolean isSignificantlyLessAccurate = accuracyDelta > 200;

    // Check if the old and new location are from the same provider
    boolean isFromSameProvider = isSameProvider(location.getProvider(),

    // Determine location quality using a combination of timeliness and accuracy
    if (isMoreAccurate) {
        return true;
    } else if (isNewer && !isLessAccurate) {
        return true;
    } else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
        return true;
    return false;

// Checks whether two providers are the same
private boolean isSameProvider(String provider1, String provider2) {
    if (provider1 == null) {
        return provider2 == null;
    return provider1.equals(provider2);


How do you round a floating point number in Perl?

You can either use a module like Math::Round:

use Math::Round;
my $rounded = round( $float );

Or you can do it the crude way:

my $rounded = sprintf "%.0f", $float;

Download file from an ASP.NET Web API method using AngularJS

I have gone through array of solutions and this is what I found to have worked great for me.

In my case I needed to send a post request with some credentials. Small overhead was to add jquery inside the script. But was worth it.

var printPDF = function () {
        //prevent double sending
        var sendz = {};
        sendz.action = "Print";
        sendz.url = "api/Print";
        jQuery('<form action="' + sendz.url + '" method="POST">' +
            '<input type="hidden" name="action" value="Print" />'+
            '<input type="hidden" name="userID" value="'+$scope.user.userID+'" />'+
            '<input type="hidden" name="ApiKey" value="' + $scope.user.ApiKey+'" />'+


UITableView Cell selected Color?

1- Add a view to the content view of your cell.
2- Right click your cell.
3- Make the added view as "selectedBackgroundView".

enter image description here

In Subversion can I be a user other than my login name?

I believe you can set the SVN_USER environment variable to change your SVN username.

Add image to layout in ruby on rails

Anything in the public folder is accessible at the root path (/) so change your img tag to read:

<img src="/images/rss.jpg" alt="rss feed" />

If you wanted to use a rails tag, use this:

<%= image_tag("rss.jpg", :alt => "rss feed") %>

How can I debug a .BAT script?

rem out the @ECHO OFF and call your batch file redirectin ALL output to a log file..

c:> yourbatch.bat (optional parameters) > yourlogfile.txt 2>&1

found at

IT WORKS!! don't forget the 2>&1...


jQuery UI: Datepicker set year range dropdown to 100 years

You can set the year range using this option in jQuery UI datepicker:

yearRange: "c-100:c+0", // last hundred years and current years

yearRange: "c-100:c+100", // last hundred years and future hundred years

yearRange: "c-10:c+10", // last ten years and future ten years

What is setBounds and how do I use it?

setBounds is used to define the bounding rectangle of a component. This includes it's position and size.

The is used in a number of places within the framework.

  • It is used by the layout manager's to define the position and size of a component within it's parent container.
  • It is used by the paint sub system to define clipping bounds when painting the component.

For the most part, you should never call it. Instead, you should use appropriate layout managers and let them determine the best way to provide information to this method.

PHP "php://input" vs $_POST

If post data is malformed, $_POST will not contain anything. Yet, php://input will have the malformed string.

For example there is some ajax applications, that do not form correct post key-value sequence for uploading a file, and just dump all the file as post data, without variable names or anything. $_POST will be empty, $_FILES empty also, and php://input will contain exact file, written as a string.

How to display a content in two-column layout in LaTeX?

You can import a csv file to this website( and click copy to clipboard.

Java 32-bit vs 64-bit compatibility

The 32-bit vs 64-bit difference does become more important when you are interfacing with native libraries. 64-bit Java will not be able to interface with a 32-bit non-Java dll (via JNI)

How to make a <div> appear in front of regular text/tables

You can use the stacking index of the div to make it appear on top of anything else. Make it a larger value that other elements and it well be on top of others.

use z-index property. See Specifying the stack level: the 'z-index' property and

Elaborate description of Stacking Contexts

Something like

#divOnTop { z-index: 1000; }

<div id="divOnTop">I am on top</div>

What you have to look out for will be IE6. In IE 6 some elements like <select> will be placed on top of an element with z-index value higher than the <select>. You can have a workaround for this by placing an <iframe> behind the div.

See this Internet Explorer z-index bug?

Python executable not finding libpython shared library

This worked for me...

$ sudo apt-get install python2.7-dev

'this' vs $scope in AngularJS controllers

I just read a pretty interesting explanation on the difference between the two, and a growing preference to attach models to the controller and alias the controller to bind models to the view. is the article.

NOTE: The original link still exists, but changes in formatting have made it hard to read. It's easier to view in the original.

He doesn't mention it but when defining directives, if you need to share something between multiple directives and don't want a service (there are legitimate cases where services are a hassle) then attach the data to the parent directive's controller.

The $scope service provides plenty of useful things, $watch being the most obvious, but if all you need to bind data to the view, using the plain controller and 'controller as' in the template is fine and arguably preferable.

How do I insert a JPEG image into a python Tkinter window?

import tkinter as tk
from tkinter import ttk
from PIL import Image,  ImageTk
win = tk. Tk()
image1 = Image. open("Aoran. jpg")
image2 =  ImageTk. PhotoImage(image1)
image_label = ttk. Label(win , image =.image2) = 0 , y = 0)

Excel VBA calling sub from another sub with multiple inputs, outputs of different sizes

VBA subs are no macros. A VBA sub can be a macro, but it is not a must.

The term "macro" is only used for recorded user actions. from these actions a code is generated and stored in a sub. This code is simple and do not provide powerful structures like loops, for example Do .. until, for .. next, while.. do, and others.

The more elegant way is, to design and write your own VBA code without using the macro features!

VBA is a object based and event oriented language. Subs, or bette call it "sub routines", are started by dedicated events. The event can be the pressing of a button or the opening of a workbook and many many other very specific events.

If you focus to VB6 and not to VBA, then you can state, that there is always a main-window or main form. This form is started if you start the compiled executable "xxxx.exe".

In VBA you have nothing like this, but you have a XLSM file wich is started by Excel. You can attach some code to the Workbook_Open event. This event is generated, if you open your desired excel file which is called a workbook. Inside the workbook you have worksheets.

It is useful to get more familiar with the so called object model of excel. The workbook has several events and methods. Also the worksheet has several events and methods.

In the object based model you have objects, that have events and methods. methods are action you can do with a object. events are things that can happen to an object. An objects can contain another objects, and so on. You can create new objects, like sheets or charts.

Getting DOM element value using pure JavaScript

The second function should have:

var value = document.getElementById(id).value;

Then they are basically the same function.

Execute external program


public class Code {
  public static void main(String[] args) throws Exception {
    ProcessBuilder builder = new ProcessBuilder("ls", "-ltr");
    Process process = builder.start();

    StringBuilder out = new StringBuilder();
    try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
        String line = null;
      while ((line = reader.readLine()) != null) {

Try online

Best way to check if a drop down list contains a value?

What about this:

ListItem match = ddlCustomerNumber.Items.FindByText(
if (match == null)
    ddlCustomerNumber.SelectedIndex = 0;
//    match.Selected = true; // you'll probably select that cookie value

[Vue warn]: Property or method is not defined on the instance but referenced during render

I had two methods: in the <script>, goes to show, that you can spend hours looking for something that was such a simple mistake.

Should you use rgba(0, 0, 0, 0) or rgba(255, 255, 255, 0) for transparency in CSS?

There are two ways of storing a color with alpha. The first is exactly as you see it, with each component as-is. The second is to use pre-multiplied alpha, where the color values are multiplied by the alpha after converting it to the range 0.0-1.0; this is done to make compositing easier. Ordinarily you shouldn't notice or care which way is implemented by any particular engine, but there are corner cases where you might, for example if you tried to increase the opacity of the color. If you use rgba(0, 0, 0, 0) you are less likely to to see a difference between the two approaches.

mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in

That query is failing and returning false.

Put this after mysqli_query() to see what's going on.

if (!$check1_res) {
    printf("Error: %s\n", mysqli_error($con));

For more information:

How to vertically center an image inside of a div element in HTML using CSS?

As I too am constantly being let down by cross-browser CSS, I'd like to offer a JQuery solution here. This takes the height of each image's parent div, divide it by two and set it as a top margin between the image and the div:

$('div img').each(function() {
 m = Math.floor(($(this).parent('div').height() - $(this).height())/2);
 mp = m+"px";

How to set scope property with ng-init?


<body ng-app="App">
    <div ng-controller="testController" >
        <input type="hidden" id="testInput" ng-model="testInput" ng-init="testInput=123" />
    {{ testInput }}


angular.module('App', []);

testController = function ($scope) {
    $scope.$watch('testInput', testShow, true);
    function testShow() {


Nodejs cannot find installed module on Windows

if you are using windows , it takes some steps , 1) create a file called package.json

  "name": "hello"
, "version": "0.0.1"
, "dependencies": {
    "express": "*"

where hello is the name of the package and * means the latest version of your dependency

2) code to you project directory and run the following command

npm install

It installs the dependencies

Escape quote in web.config connection string

Use &quot; That should work.

Convert string to date in bash

We can use date -d option

1) Change format to "%Y-%m-%d" format i.e 20121212 to 2012-12-12

date -d '20121212' +'%Y-%m-%d'

2)Get next or last day from a given date=20121212. Like get a date 7 days in past with specific format

date -d '20121212 -7 days' +'%Y-%m-%d'

3) If we are getting date in some variable say dat

dat2=$(date -d "$dat -1 days" +'%Y%m%d')

Select element based on multiple classes

You can use these solutions :

CSS rules applies to all tags that have following two classes :

.left.ui-class-selector {
    /*style here*/

CSS rules applies to all tags that have <li> with following two classes :

li.left.ui-class-selector {
   /*style here*/

jQuery solution :

$("li.left.ui-class-selector").css("color", "red");

Javascript solution :

document.querySelector("li.left.ui-class-selector").style.color = "red";

How can I get the DateTime for the start of the week?

Did it for Monday but similar logic for Sunday.

public static DateTime GetStartOfWeekDate()
    // Get today's date
    DateTime today = DateTime.Today;
    // Get the value for today. DayOfWeek is an enum with 0 being Sunday, 1 Monday, etc
    var todayDayOfWeek = (int)today.DayOfWeek;

    var dateStartOfWeek = today;
    // If today is not Monday, then get the date for Monday
    if (todayDayOfWeek != 1)
        // How many days to get back to Monday from today
        var daysToStartOfWeek = (todayDayOfWeek - 1);
        // Subtract from today's date the number of days to get to Monday
        dateStartOfWeek = today.AddDays(-daysToStartOfWeek);

    return dateStartOfWeek;


ActionBarActivity is deprecated

According to this video of Android Developers you should only make two changes

enter image description here

Remove trailing zeros from decimal in SQL Server

I had a similar problem, needed to trim trailing zeros from numbers like xx0000,x00000,xxx000

I used:

select LEFT(code,LEN(code)+1 - PATINDEX('%[1-Z]%',REVERSE(code))) from Tablename

Code is the name of the field with the number to be trimmed. Hope this helps someone else.

Add spaces between the characters of a string in Java?

Blow up your String into array of chars, loop over the char array and create a new string by succeeding a char by a space.

Differences between Microsoft .NET 4.0 full Framework and Client Profile

A list of assemblies is available at Assemblies in the .NET Framework Client Profile on MSDN (the list is too long to include here).

If you're more interested in features, .NET Framework Client Profile on MSDN lists the following as being included:

  • common language runtime (CLR)
  • ClickOnce
  • Windows Forms
  • Windows Presentation Foundation (WPF)
  • Windows Communication Foundation (WCF)
  • Entity Framework
  • Windows Workflow Foundation
  • Speech
  • XSLT support
  • LINQ to SQL
  • Runtime design libraries for Entity Framework and WCF Data Services
  • Managed Extensibility Framework (MEF)
  • Dynamic types
  • Parallel-programming features, such as Task Parallel Library (TPL), Parallel LINQ (PLINQ), and Coordination Data Structures (CDS)
  • Debugging client applications

And the following as not being included:

  • Advanced Windows Communication Foundation (WCF) functionality
  • .NET Framework Data Provider for Oracle
  • MSBuild for compiling

android.os.NetworkOnMainThreadException with android 4.2

Please make sure that you don't do any network access on UI Thread, instead do it in Async Task

The reason why your application crashes on Android versions 3.0 and above, but works fine on Android 2.x is because since HoneyComb are much stricter about abuse against the UI Thread. For example, when an Android device running HoneyComb or above detects a network access on the UI thread, a NetworkOnMainThreadException will be thrown.

See this

Getting IP address of client

I use the following static helper method to retrieve the IP of a client:

public static String getClientIpAddr(HttpServletRequest request) {  
    String ip = request.getHeader("X-Forwarded-For");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("Proxy-Client-IP");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("WL-Proxy-Client-IP");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_CLIENT_IP");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED_FOR");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_VIA");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("REMOTE_ADDR");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getRemoteAddr();  
    return ip;  

Variable length (Dynamic) Arrays in Java

I disagree with the previous answers suggesting ArrayList, because ArrayList is not a Dynamic Array but a List backed by an array. The difference is that you cannot do the following:

ArrayList list = new ArrayList(4);

It will give you an IndexOutOfBoundsException because there is no element at this position yet even though the backing array would permit such an addition. So you need to use a custom extendable Array implementation like suggested by @randy-lance

C# guid and SQL uniqueidentifier

SQL is expecting the GUID as a string. The following in C# returns a string Sql is expecting.

"'" + Guid.NewGuid().ToString() + "'"

Something like

INSERT INTO TABLE (GuidID) VALUE ('4b5e95a7-745a-462f-ae53-709a8583700a')

is what it should look like in SQL.