Programs & Examples On #Mappingexception

Another Repeated column in mapping for entity error

We have resolved the circular dependency(Parent-child Entities) by mapping the child entity instead of parent entity in Grails 4(GORM).


Class Person {
    String name

Class Employee extends Person{
    String empId

//Before my code 
Class Address {
    static belongsTo = [person: Person]

//We changed our Address class to:
Class Address {
    static belongsTo = [person: Employee]

Get response from PHP file using AJAX

in your PHP file, when you echo your data use json_encode (


//plum or data...
$output = array("data","plum");

echo json_encode($output);


in your javascript code, when your ajax completes the json encoded response data can be turned into an js array like this:

                type: "POST",
                url: "process.php",
                data: somedata;
                success function(json_data){
                    var data_array = $.parseJSON(json_data);

                    //access your data like this:
                    var plum_or_whatever = data_array['output'];.
                    //continue from here...

Print array without brackets and commas

Basically, don't use ArrayList.toString() - build the string up for yourself. For example:

StringBuilder builder = new StringBuilder();
for (String value : publicArray) {
String text = builder.toString();

(Personally I wouldn't call the variable publicArray when it's not actually an array, by the way.)

'cout' was not declared in this scope

Use std::cout, since cout is defined within the std namespace. Alternatively, add a using std::cout; directive.

Is there a way to automatically generate getters and setters in Eclipse?

In Eclipse Juno, by default, ALT+SHIFT+S,R opens the getter/setter dialog box. Note you have to press all 4 keys.

How to get last inserted id?

I tried the above but they didn't work, i found this thought, that works a just fine for me.

var ContactID = db.GetLastInsertId();

Its less code and i easy to put in.

Hope this helps someone.

Keyboard shortcuts in WPF

Documenting this answer for others, as there is a much simpler way to do this that is rarely referenced, and doesn't require touching the XAML at all.

To link a keyboard shortcut, in the Window constructor simply add a new KeyBinding to the InputBindings collection. As the command, pass in your arbitrary command class that implements ICommand. For the execute method, simply implement whatever logic you need. In my example below, my WindowCommand class takes a delegate that it will execute whenever invoked. When I construct the new WindowCommand to pass in with my binding, I simply indicate in my initializer, the method that I want the WindowCommand to execute.

You can use this pattern to come up with your own quick keyboard shortcuts.

public YourWindow() //inside any WPF Window constructor
   //add this one statement to bind a new keyboard command shortcut
   InputBindings.Add(new KeyBinding( //add a new key-binding, and pass in your command object instance which contains the Execute method which WPF will execute
      new WindowCommand(this)
         ExecuteDelegate = TogglePause //REPLACE TogglePause with your method delegate
      }, new KeyGesture(Key.P, ModifierKeys.Control)));

Create a simple WindowCommand class which takes an execution delegate to fire off any method set on it.

public class WindowCommand : ICommand
    private MainWindow _window;

    //Set this delegate when you initialize a new object. This is the method the command will execute. You can also change this delegate type if you need to.
    public Action ExecuteDelegate { get; set; }

    //You don't have to add a parameter that takes a constructor. I've just added one in case I need access to the window directly.
    public WindowCommand(MainWindow window)
        _window = window;

    //always called before executing the command, mine just always returns true
    public bool CanExecute(object parameter)
        return true; //mine always returns true, yours can use a new CanExecute delegate, or add custom logic to this method instead.

    public event EventHandler CanExecuteChanged; //i'm not using this, but it's required by the interface

    //the important method that executes the actual command logic
    public void Execute(object parameter)
        if (ExecuteDelegate != null)
            throw new InvalidOperationException();

SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch

SL_CTX_use_PrivateKey("/etc/nginx/ssl/file") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch)

This error can happen, when the certificate private key (ssl_certificate_key, e.g. .key or .pem file) does not match the public certificate file (ssl_certificate) in your Nginx configuration (check nginx.conf or in sites-enabled/). Make sure both files are matching.

Check Nginx error logs for further details (e.g. /var/log/nginx/error.log).

Dynamic tabs with user-click chosen components

I'm not cool enough for comments. I fixed the plunker from the accepted answer to work for rc2. Nothing fancy, links to the CDN were just broken is all.

'@angular/core': {
  main: 'bundles/core.umd.js',
  defaultExtension: 'js'
'@angular/compiler': {
  main: 'bundles/compiler.umd.js',
  defaultExtension: 'js'
'@angular/common': {
  main: 'bundles/common.umd.js',
  defaultExtension: 'js'
'@angular/platform-browser-dynamic': {
  main: 'bundles/platform-browser-dynamic.umd.js',
  defaultExtension: 'js'
'@angular/platform-browser': {
  main: 'bundles/platform-browser.umd.js',
  defaultExtension: 'js'

How to append to the end of an empty list?

You don't need the assignment operator. append returns None.

c#: getter/setter

In C# 6:

It is now possible to declare the auto-properties just as a field:

public string FirstName { get; set; } = "Ropert";

Read-Only Auto-Properties

public string FirstName { get;} = "Ropert";

How do I create a message box with "Yes", "No" choices and a DialogResult?

This simple code worked for me. I grabbed it from MSDN here:

if (System.Windows.Forms.MessageBox.Show
            ("Are you sure you want to add the audit?", "Add",
        // Do stuff after 'YES is clicked'
        // DO stuff after 'NO is clicked'

Composer: file_put_contents(./composer.json): failed to open stream: Permission denied

In my case I used sudo mkdir projectFolder to create folder. It was owned by root user and I was logged in using non root user.

So I changed the folder permission using command sudo chown mynonrootuser:mynonrootuser projectFolder and then it worked fine.

Func vs. Action vs. Predicate

Func - When you want a delegate for a function that may or may not take parameters and returns a value. The most common example would be Select from LINQ:

var result = someCollection.Select( x => new { x.Name, x.Address });

Action - When you want a delegate for a function that may or may not take parameters and does not return a value. I use these often for anonymous event handlers:

button1.Click += (sender, e) => { /* Do Some Work */ }

Predicate - When you want a specialized version of a Func that evaluates a value against a set of criteria and returns a boolean result (true for a match, false otherwise). Again, these are used in LINQ quite frequently for things like Where:

var filteredResults = 
    someCollection.Where(x => x.someCriteriaHolder == someCriteria);

I just double checked and it turns out that LINQ doesn't use Predicates. Not sure why they made that decision...but theoretically it is still a situation where a Predicate would fit.

How to check if an array element exists?

A little anecdote to illustrate the use of array_key_exists.

// A programmer walked through the parking lot in search of his car
// When he neared it, he reached for his pocket to grab his array of keys
$keyChain = array(
    'office-door' => unlockOffice(),
    'home-key' => unlockSmallApartment(),
    'wifes-mercedes' => unusedKeyAfterDivorce(),
    'safety-deposit-box' => uselessKeyForEmptyBox(),
    'rusto-old-car' => unlockOldBarrel(),

// He tried and tried but couldn't find the right key for his car
// And so he wondered if he had the right key with him.
// To determine this he used array_key_exists
if (array_key_exists('rusty-old-car', $keyChain)) {
    print('Its on the chain.');

Resize an Array while keeping current elements in Java?

Standard class java.util.ArrayList is resizable array, growing when new elements added.

error: pathspec 'test-branch' did not match any file(s) known to git

My friend, you need to create those corresponding branches locally first, in order to check-out to those other two branches, using this line of code

git branch test-branch  


git branch change-the-title

then only you will be able to do git checkout to those branches

Also after creating each branch, take latest changes of those particular branches by using git pull origin branch_name as shown in below code

git branch test-branch
git checkout test-branch
git pull origin test-branch

and for other branch named change-the-title run following code =>

git branch change-the-title
git checkout change-the-title
git pull origin change-the-title

Happy programming :)

How to make a Java Generic method static?

the only thing you can do is to change your signature to

public static <E> E[] appendToArray(E[] array, E item)

Important details:

Generic expressions preceding the return value always introduce (declare) a new generic type variable.

Additionally, type variables between types (ArrayUtils) and static methods (appendToArray) never interfere with each other.

So, what does this mean: In my answer <E> would hide the E from ArrayUtils<E> if the method wouldn't be static. AND <E> has nothing to do with the E from ArrayUtils<E>.

To reflect this fact better, a more correct answer would be:

public static <I> I[] appendToArray(I[] array, I item)

A required class was missing while executing org.apache.maven.plugins:maven-war-plugin:2.1.1:war

My solution below is for cases when default maven repositories are not accessible (e.g. due to firewalls).

In case the default repository is not accessible appropriate local <pluginRepository> has to be specified in the settings.xml. If it's the same as your local artifact repository it still needs to be added to the <pluginRepositories> section for plugin jars to be found. Regular <repositories> section is not used to fetch plugin jars.

In my case, however, the issue was caused by the fact that there were multiple plugin repositories defined in that section.

The first repository in the list did not contain the required maven-filtering jar.

I had to change the order of <pluginRepository> definitions to ensure the first one contains maven-filtering.

Changing of repository definitions typically requires to clean ~/.m2/repository and start fresh.

HTTP Error 503. The service is unavailable. App pool stops on accessing website

For anyone coming here with Windows 10 and after updating them to Anniversary update, please check this link, it helped me:

In case link goes down: If your Event log shows that aspnetcore.dll, rewrite.dll (most often, but could be others as well) failed to load, you have to repair the missing items.

Here are two specific issues we've experienced so far and how to fix them, but you may bump into completely different ones:

"C:\WINDOWS\system32\inetsrv\rewrite.dll" (reference)
    Go to "Programs and Features" (Win+X, F) and repair "IIS URL Rewrite Module 2".
"C:\WINDOWS\system32\inetsrv\aspnetcore.dll" (reference)
    Go to "Programs and Features" (Win+X, F) and repair "Microsoft .NET Core 1.0.0 - VS 2015 Tooling ...".

What is the difference between Views and Materialized Views in Oracle?

Adding to Mike McAllister's pretty-thorough answer...

Materialized views can only be set to refresh automatically through the database detecting changes when the view query is considered simple by the compiler. If it's considered too complex, it won't be able to set up what are essentially internal triggers to track changes in the source tables to only update the changed rows in the mview table.

When you create a materialized view, you'll find that Oracle creates both the mview and as a table with the same name, which can make things confusing.

Center image in table td in CSS

Simple way to do it for html5 in css:

td img{
    display: block;
    margin-left: auto;
    margin-right: auto;


Worked for me perfectly.

Python: Random numbers into a list

Fix the indentation of the print statement

import random

for i in range (10):

print (my_randoms)

Android studio doesn't list my phone under "Choose Device"

I've had this problem many times before with my Galaxy Nexus. Despite having the Android SDK's USB drivers installed, it did not seem to suffice.

I've always solved this by installing a program called PdaNet. While I don't know exactly what it is used for and where it gets its drivers - it comes with the drivers that has always fixed the problem for me. You can uninstall the program itself once it has finished.

Apply style ONLY on IE

Welcome BrowserDetect - an awesome function.

    var BrowserDetect;
    BrowserDetect = {...};//  get BrowserDetect Object from the link referenced in this answer
    // On page load, detect browser (with jQuery or vanilla)
    if (BrowserDetect.browser === 'Explorer') {
      // Add 'ie' class on every element on the page.

<style> {
       // do something special for div on IE browser.
    } {
     // do something special for h1 on IE browser.

The Object BrowserDetect also provides version info so we can add specific classes - for ex. $('*').addClass('ie9'); if (BrowserDetect.version == 9).

Good Luck....

Android-java- How to sort a list of objects by a certain value within the object

Model Class:

public class ToDoModel implements Comparable<ToDoModel> {
    private String id;
    private Date taskDate;

    public String getId() {
        return id;

    public void setId(String id) { = id;

    public Date getTaskDate() {
        return taskDate;

    public void setTaskDate(Date taskDate) {
        this.taskDate = taskDate;

    public int compareTo(ToDoModel another) {
        return getTaskDate().compareTo(another.getTaskDate());  

Now set data in ArrayList

for (int i = 0; i < your_array_length; i++) {
    ToDoModel tm = new ToDoModel();

Now Sort ArrayList


Summary: It will sort your data datewise

Github: Can I see the number of downloads for a repo?

To try to make this more clear:
for this github project: stant/mdcsvimporter2015
with releases at

go to http or https: (note added "api." and "/repos")

you will get this json output and you can search for "download_count":

    "download_count": 2,
    "created_at": "2015-02-24T18:20:06Z",
    "updated_at": "2015-02-24T18:20:07Z",
    "browser_download_url": ""

or on command line do:
wget --no-check-certificate

React-router urls don't work when refreshing or writing manually

The router can be called in two different ways, depending on whether the navigation occurs on the client or on the server. You have it configured for client-side operation. The key parameter is the second one to the run method, the location.

When you use the React Router Link component, it blocks browser navigation and calls transitionTo to do a client-side navigation. You are using HistoryLocation, so it uses the HTML5 history API to complete the illusion of navigation by simulating the new URL in the address bar. If you're using older browsers, this won't work. You would need to use the HashLocation component.

When you hit refresh, you bypass all of the React and React Router code. The server gets the request for /joblist and it must return something. On the server you need to pass the path that was requested to the run method in order for it to render the correct view. You can use the same route map, but you'll probably need a different call to As Charles points out, you can use URL rewriting to handle this. Another option is to use a node.js server to handle all requests and pass the path value as the location argument.

In express, for example, it might look like this:

var app = express();

app.get('*', function (req, res) { // This wildcard method handles all requests, req.path, function (Handler, state) {
        var element = React.createElement(Handler);
        var html = React.renderToString(element);
        res.render('main', { content: html });

Note that the request path is being passed to run. To do this, you'll need to have a server-side view engine that you can pass the rendered HTML to. There are a number of other considerations using renderToString and in running React on the server. Once the page is rendered on the server, when your app loads in the client, it will render again, updating the server-side rendered HTML as needed.

Android XXHDPI resources

480 dpi is the standard QUANTIZED resolution for xxhdpi, it can vary something less (i.e.: 440 dpi) or more (i.e.: 520 dpi). Scale factor: 3x (3 * mdpi).

Now there's a higher resolution, xxxhdpi (640 dpi). Scale factor 4x (4 * mdpi).

Here's the source reference.

T-SQL substring - separating first and last name

This will take care of names like "Firstname Z. Lastname" and "First Z Last"

    WHEN CHARINDEX(' ',name) = 0 THEN name
    WHEN CHARINDEX(' ',name) = PATINDEX('% _[., ]%',name) THEN RTRIM(SUBSTRING(name, 1, CHARINDEX(' ',name) + 2)) 
    ELSE SUBSTRING(name,1, CHARINDEX(' ',name))
END [firstname]
    WHEN CHARINDEX(' ',name) = 0 THEN ''
    WHEN CHARINDEX(' ',name) = PATINDEX('% _[., ]%',name) THEN LTRIM(SUBSTRING(name, CHARINDEX(' ',name) + 3,1000)) 
    ELSE SUBSTRING(name,CHARINDEX(' ',name)+1,1000)
END [lastname]
FROM [myTable]

Auto highlight text in a textbox control

You can use this, pithy. :D

TextBox1.Select(0, TextBox1.Text.Length);

Powershell get ipv4 address into a variable

Here is what I ended up using

$ipaddress = $(ipconfig | where {$_ -match 'IPv4.+\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' } | out-null; $Matches[1])

which breaks down as

  • execute ipconfig command - get all the network interface information
  • use powershell's where filter with a regular expression
  • regular expression finds the line with "IPv4" and a set of 4 blocks each with 1-3 digits separated by periods, i.e. a v4 IP address
  • disregard the output by piping it to null
  • finally get the first matched group as defined by the brackets in the regular expression.
  • catch that output in $ipaddress for later use.

How to install OpenSSL for Python

SSL development libraries have to be installed


$ yum install openssl-devel libffi-devel


$ apt-get install libssl-dev libffi-dev

OS X (with Homebrew installed):

$ brew install openssl

Function to calculate distance between two coordinates

Adding this for Node.JS users. You can use the haversine-distance module to do this so you won't need to handle the calculations on your own. See the npm page for more information.

To install:

npm install --save haversine-distance

You can use the module as follows:

var haversine = require("haversine-distance");

//First point in your haversine calculation
var point1 = { lat: 6.1754, lng: 106.8272 }

//Second point in your haversine calculation
var point2 = { lat: 6.1352, lng: 106.8133 }

var haversine_m = haversine(point1, point2); //Results in meters (default)
var haversine_km = haversine_m /1000; //Results in kilometers

console.log("distance (in meters): " + haversine_m + "m");
console.log("distance (in kilometers): " + haversine_km + "km");

Add a column to existing table and uniquely number them on MS SQL Server

for oracle you could do something like below

alter table mytable add (myfield integer);

update mytable set myfield = rownum;

How do files get into the External Dependencies in Visual Studio C++?

To resolve external dependencies within project. below things are important..
1. The compiler should know that where are header '.h' files located in workspace.
2. The linker able to find all specified  all '.lib' files & there names for current project.

So, Developer has to specify external dependencies for Project as below..

1. Select Project in Solution explorer.

2 . Project Properties -> Configuration Properties -> C/C++ -> General
specify all header files in "Additional Include Directories".

3.  Project Properties -> Configuration Properties -> Linker -> General
specify relative path for all lib files in "Additional Library Directories".

enter image description here enter image description here

Eclipse+Maven src/main/java not visible in src folder in Package Explorer

I have solved this issue by below steps:

Right click the Maven Project -> Build Path -> Configure Build Path In Order and Export tab, you can see the message like '2 build path entries are missing' Now select 'JRE System Library' and 'Maven Dependencies' checkbox Click OK Now you can see below in all type of Explorers (Package or Project or Navigator)

How to get my project path?

You can use

string wanted_path = Path.GetDirectoryName(Path.GetDirectoryName(System.IO.Directory.GetCurrentDirectory()));

How can I increase the size of a bootstrap button?

Use block level buttons, those that span the full width of a parent You can achieve this by adding btn-block class your button element.

Documentation here

How do you scroll up/down on the console of a Linux VM

Alternative: you can use the less command.

Type in console:

"your_command" | less   

This will allow you to scroll with the up and down arrow keys.

Basically your output has been piped with the less command.

Can't escape the backslash with regex?

From :

Note that the only special characters or metacharacters inside a character class are the closing bracket (]), the backslash (\\), the caret (^) and the hyphen (-). The usual metacharacters are normal characters inside a character class, and do not need to be escaped by a backslash. To search for a star or plus, use [+*]. Your regex will work fine if you escape the regular metacharacters inside a character class, but doing so significantly reduces readability.

To include a backslash as a character without any special meaning inside a character class, you have to escape it with another backslash. [\\x] matches a backslash or an x. The closing bracket (]), the caret (^) and the hyphen (-) can be included by escaping them with a backslash, or by placing them in a position where they do not take on their special meaning. I recommend the latter method, since it improves readability. To include a caret, place it anywhere except right after the opening bracket. [x^] matches an x or a caret. You can put the closing bracket right after the opening bracket, or the negating caret. []x] matches a closing bracket or an x. [^]x] matches any character that is not a closing bracket or an x. The hyphen can be included right after the opening bracket, or right before the closing bracket, or right after the negating caret. Both [-x] and [x-] match an x or a hyphen.

What language are you writing the regex in?

Using Server.MapPath in external C# Classes in ASP.NET

class test
public static void useServerPath(string path)
   if (File.Exists(path)
 \\...... do whatever you wabt

Now when you call the method from the codebehind

for example :

protected void BtAtualizacao_Click(object sender, EventArgs e)
             string path = Server.MapPath("Folder") + "\\anifile.txt";


in this way your code is to simple and with one method u can use multiple path for each call :)

Android SDK folder taking a lot of disk space. Do we need to keep all of the System Images?

I had 20.8 GB in the C:\Users\ggo\AppData\Local\Android\Sdk\system-images folder (6 android images: - android-10 - android-15 - android-21 - android-23 - android-25 - android-26 ).

I have compressed the C:\Users\ggo\AppData\Local\Android\Sdk\system-images folder.

Now it takes only 4.65 GB.


I did not encountered any problem up to now...

Compression seems to vary from 2/3 to 6, sometimes much more:





Necessary to add link tag for favicon.ico?

We can add for all devices with platform specific size

<link rel="apple-touch-icon" sizes="57x57" href="fav_icons/apple-icon-57x57.png">
<link rel="apple-touch-icon" sizes="60x60" href="fav_icons/apple-icon-60x60.png">
<link rel="apple-touch-icon" sizes="72x72" href="fav_icons/apple-icon-72x72.png">
<link rel="apple-touch-icon" sizes="76x76" href="fav_icons/apple-icon-76x76.png">
<link rel="apple-touch-icon" sizes="114x114" href="fav_icons/apple-icon-114x114.png">
<link rel="apple-touch-icon" sizes="120x120" href="fav_icons/apple-icon-120x120.png">
<link rel="apple-touch-icon" sizes="144x144" href="fav_icons/apple-icon-144x144.png">
<link rel="apple-touch-icon" sizes="152x152" href="fav_icons/apple-icon-152x152.png">
<link rel="apple-touch-icon" sizes="180x180" href="fav_icons/apple-icon-180x180.png">

<link rel="icon" type="image/png" sizes="192x192"  href="fav_icons/">
<link rel="icon" type="image/png" sizes="32x32" href="fav_icons/favicon-32x32.png">
<link rel="icon" type="image/png" sizes="96x96" href="fav_icons/favicon-96x96.png">
<link rel="icon" type="image/png" sizes="16x16" href="fav_icons/favicon-16x16.png">

How to change CSS using jQuery?

You can do either:

$("h1").css("background-color", "yellow");


$("h1").css({backgroundColor: "yellow"});

Check if a variable is between two numbers with Java

<<= is like +=, but for a left shift. x <<= 1 means x = x << 1. That's why 90 >>= angle doesn't parse. And, like others have said, Java doesn't have an elegant syntax for checking if a number is an an interval, so you have to do it the long way. It also can't do if (x == 0 || 1), and you're stuck writing it out the long way.

How to add target="_blank" to JavaScript window.location?

I have created a function that allows me to obtain this feature:

function redirect_blank(url) {
  var a = document.createElement('a');"_blank";

How to write subquery inside the OUTER JOIN Statement

You need the "correlation id" (the "AS SS" thingy) on the sub-select to reference the fields in the "ON" condition. The id's assigned inside the sub select are not usable in the join.

    CUSTMR cs
                    dp.DEPADDRESS = 'TOKYO'
        ) ss
            ON (
                ss.DEPID = cs.CUSID
                AND ss.DEPNAME = cs.CUSTNAME
    cs.CUSID != '' 

How to pass a value to razor variable from javascript variable?

Razor View Server Side variable can be read to Client Side JavaScript using @ While and JavaScript client side variable can read to Razor View using @:

How to retrieve form values from HTTPPOST, dictionary or?

You could have your controller action take an object which would reflect the form input names and the default model binder will automatically create this object for you:

public ActionResult SubmitAction(SomeModel model)
    var value1 = model.SimpleProp1;
    var value2 = model.SimpleProp2;
    var value3 = model.ComplexProp1.SimpleProp1;

    ... return something ...

Another (obviously uglier) way is:

public ActionResult SubmitAction()
    var value1 = Request["SimpleProp1"];
    var value2 = Request["SimpleProp2"];
    var value3 = Request["ComplexProp1.SimpleProp1"];

    ... return something ...

WRONGTYPE Operation against a key holding the wrong kind of value php

Redis supports 5 data types. You need to know what type of value that a key maps to, as for each data type, the command to retrieve it is different.

Here are the commands to retrieve key value:

  • if value is of type string -> GET <key>
  • if value is of type hash -> HGETALL <key>
  • if value is of type lists -> lrange <key> <start> <end>
  • if value is of type sets -> smembers <key>
  • if value is of type sorted sets -> ZRANGEBYSCORE <key> <min> <max>

Use the TYPE command to check the type of value a key is mapping to:

  • type <key>

MVC 3 file upload and model binding

Your form doesn't contain any input tag other than the file so in your controller action you cannot expect to get anything else than the uploaded file (that's all that's being sent to the server). One way to achieve this would be to include a hidden tag containing the id of the model which will allow you to retrieve it from your datastore inside the controller action you are posting to (use this if the user is not supposed to modify the model but simply attach a file):

@using (Html.BeginForm("Uploadfile", "Containers", FormMethod.Post, new { enctype = "multipart/form-data" }))
    @Html.HiddenFor(x => x.Id)
    <input type="file" name="file" id="file" />
    <input type="submit" value="submit" />

and then in your controller action:

public ActionResult Uploadfile(int id, HttpPostedFileBase file)
    Containers containers = Repository.GetContainers(id);

On the other hand if you wanted to allow the user to modify this model then you will need to include the proper input fields for each field of your model that you want to be sent to the server:

@using (Html.BeginForm("Uploadfile", "Containers", FormMethod.Post, new { enctype = "multipart/form-data" }))
    @Html.TextBoxFor(x => x.Prop1)
    @Html.TextBoxFor(x => x.Prop2)
    @Html.TextBoxFor(x => x.Prop3)
    <input type="file" name="file" id="file" />
    <input type="submit" value="submit" />

and then you will have the default model binder reconstruct this model from the request:

public ActionResult Uploadfile(Container containers, HttpPostedFileBase file)

How do I create a WPF Rounded Corner container?

I know that this isn't an answer to the initial question ... but you often want to clip the inner content of that rounded corner border you just created.

Chris Cavanagh has come up with an excellent way to do just this.

I have tried a couple different approaches to this ... and I think this one rocks.

Here is the xaml below:

    <!-- Rounded yellow border -->
            <!-- Rounded mask (stretches to fill Grid) -->

            <!-- Main content container -->
                <!-- Use a VisualBrush of 'mask' as the opacity mask -->
                    <VisualBrush Visual="{Binding ElementName=mask}"/>

                <!-- Any content -->
                <Image Source=""/>

How can I delay a method call for 1 second?

You could also use a block

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
    [object method]; 

Most of time you will want to use dispatch_get_main_queue, although if there is no UI in the method you could use a global queue.


Swift 3 version:

DispatchQueue.main.asyncAfter(deadline: .now() + 1) {

Equally, might also be a good option.

Using generic std::function objects with member functions in one class

A non-static member function must be called with an object. That is, it always implicitly passes "this" pointer as its argument.

Because your std::function signature specifies that your function doesn't take any arguments (<void(void)>), you must bind the first (and the only) argument.

std::function<void(void)> f = std::bind(&Foo::doSomething, this);

If you want to bind a function with parameters, you need to specify placeholders:

using namespace std::placeholders;
std::function<void(int,int)> f = std::bind(&Foo::doSomethingArgs, this, std::placeholders::_1, std::placeholders::_2);

Or, if your compiler supports C++11 lambdas:

std::function<void(int,int)> f = [=](int a, int b) {
    this->doSomethingArgs(a, b);

(I don't have a C++11 capable compiler at hand right now, so I can't check this one.)

Saving excel worksheet to CSV files with filename+worksheet name using VB

The code above works perfectly with one minor flaw; the resulting file is not saved with a .csv extension. – Tensigh 2 days ago

I added the following to code and it saved my file as a csv. Thanks for this bit of code.It all worked as expected.

ActiveWorkbook.SaveAs Filename:=SaveToDirectory & ThisWorkbook.Name & "-" & WS.Name & ".csv", FileFormat:=xlCSV

preferredStatusBarStyle isn't called

UIStatusBarStyle in iOS 7

The status bar in iOS 7 is transparent, the view behind it shows through.

The style of the status bar refers to the appearances of its content. In iOS 7, the status bar content is either dark (UIStatusBarStyleDefault) or light (UIStatusBarStyleLightContent). Both UIStatusBarStyleBlackTranslucent and UIStatusBarStyleBlackOpaque are deprecated in iOS 7.0. Use UIStatusBarStyleLightContent instead.

How to change UIStatusBarStyle

If below the status bar is a navigation bar, the status bar style will be adjusted to match the navigation bar style (UINavigationBar.barStyle):

Specifically, if the navigation bar style is UIBarStyleDefault, the status bar style will be UIStatusBarStyleDefault; if the navigation bar style is UIBarStyleBlack, the status bar style will be UIStatusBarStyleLightContent.

If there is no navigation bar below the status bar, the status bar style can be controlled and changed by an individual view controller while the app runs.

-[UIViewController preferredStatusBarStyle] is a new method added in iOS 7. It can be overridden to return the preferred status bar style:

- (UIStatusBarStyle)preferredStatusBarStyle
      return UIStatusBarStyleLightContent;

If the status bar style should be controlled by a child view controller instead of self, override -[UIViewController childViewControllerForStatusBarStyle] to return that child view controller.

If you prefer to opt out of this behavior and set the status bar style by using the -[UIApplication statusBarStyle] method, add the UIViewControllerBasedStatusBarAppearance key to an app’s Info.plist file and give it the value NO.

How to update record using Entity Framework 6?

Try It....


var book = new Model.Book
    BookNumber =  _book.BookNumber,
    BookName = _book.BookName,
    BookTitle = _book.BookTitle,
using (var db = new MyContextDB())
    var result = db.Books.SingleOrDefault(b => b.BookNumber == bookNumber);
    if (result != null)
            db.Entry(book).State = EntityState.Modified;
        catch (Exception ex)

Is Visual Studio Community a 30 day trial?

For my case the problem was in fact that i broke machine.config and looks like VS couldn't have a connection I've added the following lines to my machine.config

  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="" usesystemdefault="false" />

After replacing the previous section to:

  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="" usesystemdefault="false" />

VS started to work.

How to make child divs always fit inside parent div?

For closure, I think the answer to this question is that there is no solution. The only way to get the behavior I want is with javascript.

SQL query to make all data in a column UPPER CASE?

If you want to only update on rows that are not currently uppercase (instead of all rows), you'd need to identify the difference using COLLATE like this:

SET    MyColumn = UPPER(MyColumn)
WHERE  MyColumn != UPPER(MyColumn) COLLATE Latin1_General_CS_AS 

A Bit About Collation

Cases sensitivity is based on your collation settings, and is typically case insensitive by default.

Collation can be set at the Server, Database, Column, or Query Level:

-- Server
-- Database
SELECT name, collation_name FROM sys.databases
-- Column 

Collation Names specify how a string should be encoded and read, for example:

  • Latin1_General_CI_AS ? Case Insensitive
  • Latin1_General_CS_AS ? Case Sensitive

shell-script headers (#!/bin/sh vs #!/bin/csh)

The #! line tells the kernel (specifically, the implementation of the execve system call) that this program is written in an interpreted language; the absolute pathname that follows identifies the interpreter. Programs compiled to machine code begin with a different byte sequence -- on most modern Unixes, 7f 45 4c 46 (^?ELF) that identifies them as such.

You can put an absolute path to any program you want after the #!, as long as that program is not itself a #! script. The kernel rewrites an invocation of

./script arg1 arg2 arg3 ...

where ./script starts with, say, #! /usr/bin/perl, as if the command line had actually been

/usr/bin/perl ./script arg1 arg2 arg3

Or, as you have seen, you can use #! /bin/sh to write a script intended to be interpreted by sh.

The #! line is only processed if you directly invoke the script (./script on the command line); the file must also be executable (chmod +x script). If you do sh ./script the #! line is not necessary (and will be ignored if present), and the file does not have to be executable. The point of the feature is to allow you to directly invoke interpreted-language programs without having to know what language they are written in. (Do grep '^#!' /usr/bin/* -- you will discover that a great many stock programs are in fact using this feature.)

Here are some rules for using this feature:

  • The #! must be the very first two bytes in the file. In particular, the file must be in an ASCII-compatible encoding (e.g. UTF-8 will work, but UTF-16 won't) and must not start with a "byte order mark", or the kernel will not recognize it as a #! script.
  • The path after #! must be an absolute path (starts with /). It cannot contain space, tab, or newline characters.
  • It is good style, but not required, to put a space between the #! and the /. Do not put more than one space there.
  • You cannot put shell variables on the #! line, they will not be expanded.
  • You can put one command-line argument after the absolute path, separated from it by a single space. Like the absolute path, this argument cannot contain space, tab, or newline characters. Sometimes this is necessary to get things to work (#! /usr/bin/awk -f), sometimes it's just useful (#! /usr/bin/perl -Tw). Unfortunately, you cannot put two or more arguments after the absolute path.
  • Some people will tell you to use #! /usr/bin/env interpreter instead of #! /absolute/path/to/interpreter. This is almost always a mistake. It makes your program's behavior depend on the $PATH variable of the user who invokes the script. And not all systems have env in the first place.
  • Programs that need setuid or setgid privileges can't use #!; they have to be compiled to machine code. (If you don't know what setuid is, don't worry about this.)

Regarding csh, it relates to sh roughly as Nutrimat Advanced Tea Substitute does to tea. It has (or rather had; modern implementations of sh have caught up) a number of advantages over sh for interactive usage, but using it (or its descendant tcsh) for scripting is almost always a mistake. If you're new to shell scripting in general, I strongly recommend you ignore it and focus on sh. If you are using a csh relative as your login shell, switch to bash or zsh, so that the interactive command language will be the same as the scripting language you're learning.

Print in new line, java

System.out.println(" 1  2  3  4  5  6  7  8  9" + "\n" + "----------------------------");

System.out.printf(" 1  2  3  4  5  6  7  8  9" + "\n" + "----------------------------");

System.out.print(" 1  2  3  4  5  6  7  8  9" + "\n" + "----------------------------");

Uncaught Error: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function but got: object

I got this by doing import App from './app/'; expecting it to import ./app/index.js, but it instead imported ./app.json.

Support for "border-radius" in IE

The answer to this question has changed since it was asked a year ago. (This question is currently one of the top results for Googling "border-radius ie".)

IE9 will support border-radius.

There is a platform preview available which supports border-radius. You will need Windows Vista or Windows 7 to run the preview (and IE9 when it is released).

How to remove all the occurrences of a char in c++ string

I guess the method std:remove works but it was giving some compatibility issue with the includes so I ended up writing this little function:

string removeCharsFromString(const string str, char* charsToRemove )
    char c[str.length()+1]; // + terminating char
    const char *p = str.c_str();
    unsigned int z=0, size = str.length();
    unsigned int x;
    bool rem=false;

    for(x=0; x<size; x++)
        rem = false;
        for (unsigned int i = 0; charsToRemove[i] != 0; i++)
            if (charsToRemove[i] == p[x])
                rem = true;
        if (rem == false) c[z++] = p[x];

    c[z] = '\0';
    return string(c);

Just use as

myString = removeCharsFromString(myString, "abc\r");

and it will remove all the occurrence of the given char list.

This might also be a bit more efficient as the loop returns after the first match, so we actually do less comparison.

'Access-Control-Allow-Origin' issue when API call made from React (Isomorphic app)

Because the server don't have CORS header, so you are not allowed to get the response.

This is header from API that I captured from Chrome brower:

Cache-Control:max-age=3600, public
Date:Fri, 06 Jan 2017 02:05:33 GMT
Status:200 OK
Via:1.1 vegur, 1.1 (CloudFront)
X-Cache:Hit from cloudfront
X-Xss-Protection:1; mode=block

No CORS header in response headers.

VBA paste range

I would try

Set Ticker = Range(Cells(2, 1), Cells(65, 1))


Changing the default title of confirm() in JavaScript?

Not possible. You can however use a third party javascript library that emulates a popup window, and it will probably look better as well and be less intrusive.

Regex match one of two words

There are different regex engines but I think most of them will work with this:


How to jump to a particular line in a huge text file?

Do the lines themselves contain any index information? If the content of each line was something like "<line index>:Data", then the seek() approach could be used to do a binary search through the file, even if the amount of Data is variable. You'd seek to the midpoint of the file, read a line, check whether its index is higher or lower than the one you want, etc.

Otherwise, the best you can do is just readlines(). If you don't want to read all 15MB, you can use the sizehint argument to at least replace a lot of readline()s with a smaller number of calls to readlines().

simple Jquery hover enlarge

Well I'm not exactly sure why your code is not working because I usually follow a different approach when trying to accomplish something similar.

But your code is erroring out.. There seems to be an issue with the way you are using scale I got the jQuery to actually execute by changing your code to the following.

    $('img').hover(function() {
        $(this).css("cursor", "pointer");
          effect: "scale",
          percent: "90%"
    }, function() {
           effect: "scale",
           percent: "80%"


But I have always done it by using CSS to setup my scaling and transition..

Here is an example, hopefully it helps.

    $('#content').hover(function() {

    }, function() {

How to disable textbox from editing?

        textBox1.Enabled = false;

"false" property will make the text box disable. and "true" will make it in regular form. Thanks.

ORA-00904: invalid identifier

Are you sure you have a column DEPARTEMENT_CODE on your table PS_TBL_DEPARTMENT_DETAILS

More informations about your ERROR

ORA-00904: string: invalid identifier Cause: The column name entered is either missing or invalid. Action: Enter a valid column name. A valid column name must begin with a letter, be less than or equal to 30 characters, and consist of only alphanumeric characters and the special characters $, _, and #. If it contains other characters, then it must be enclosed in d double quotation marks. It may not be a reserved word.

Can I pass column name as input parameter in SQL stored Procedure

This is not possible. Either use dynamic SQL (dangerous) or a gigantic case expression (slow).

What is the difference between substr and substring?

The difference is second parameter. Their second parameters, while both numbers, are expecting two different things:

When using substring the second parameter is the first index not to include:

var s = "string";
s.substring(1, 3); // would return 'tr'

var s = "another example";
s.substring(3, 7); // would return 'ther'

When using substr the second parameter is the number of characters to include in the substring:

var s = "string";
s.substr(1, 3); // would return 'tri'

var s = "another example";
s.substr(3, 7); // would return 'ther ex'

How to redirect all HTTP requests to HTTPS

take this code to you .htaccess file Redirect HTTP to HTTPS automatically

RewriteEngine On RewriteCond %{HTTPS} off RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Java split string to array

This is expected. Refer to Javadocs for split.

Splits this string around matches of the given regular expression.

This method works as if by invoking the two-argument split(java.lang.String,int) method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.

"PKIX path building failed" and "unable to find valid certification path to requested target"


  1. use https connections
  2. verify SSL chains
  3. do not deal with cacerts
  4. add certificate in runtime
  5. do not lose certificates from cacerts

How to do it:

  1. define own keystore
  2. put certificate into keystore
  3. redefine SSL default context with our custom class
  4. ???
  5. profit

My Keystore wrapper file:

public class CertificateManager {

    private final static Logger logger = Logger.getLogger(CertificateManager.class);

    private String keyStoreLocation;
    private String keyStorePassword;
    private X509TrustManager myTrustManager;
    private static KeyStore myTrustStore;

    public CertificateManager(String keyStoreLocation, String keyStorePassword) throws Exception {
        this.keyStoreLocation = keyStoreLocation;
        this.keyStorePassword = keyStorePassword;
        myTrustStore = createKeyStore(keyStoreLocation, keyStorePassword);

    public void addCustomCertificate(String certFileName, String certificateAlias)
            throws Exception {
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init((KeyStore) null);
        Certificate certificate = myTrustStore.getCertificate(certificateAlias);
        if (certificate == null) {
  "Certificate not exists");
            addCertificate(certFileName, certificateAlias);
        } else {
  "Certificate exists");
        tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        for (TrustManager tm : tmf.getTrustManagers()) {
            if (tm instanceof X509TrustManager) {
                setMytrustManager((X509TrustManager) tm);
      "Trust manager found");

    private InputStream fullStream(String fname) throws IOException {
        ClassLoader classLoader = getClass().getClassLoader();
        InputStream resource = classLoader.getResourceAsStream(fname);
        try {
            if (resource != null) {
                DataInputStream dis = new DataInputStream(resource);
                byte[] bytes = new byte[dis.available()];
                return new ByteArrayInputStream(bytes);
            } else {
      "resource not found");
        } catch (Exception e) {
            logger.error("exception in certificate fetching as resource", e);
        return null;

    public static KeyStore createKeyStore(String keystore, String pass) throws Exception {
        try {
            InputStream in = CertificateManager.class.getClass().getResourceAsStream(keystore);
            KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
            keyStore.load(in, pass.toCharArray());
  "Keystore was created from resource file");
            return keyStore;
        } catch (Exception e) {
  "Fail to create keystore from resource file");

        File file = new File(keystore);
        KeyStore keyStore = KeyStore.getInstance("JKS");
        if (file.exists()) {
            keyStore.load(new FileInputStream(file), pass.toCharArray());
  "Default keystore loaded");
        } else {
            keyStore.load(null, null);
   FileOutputStream(file), pass.toCharArray());
  "New keystore created");
        return keyStore;

    private void addCertificate(String certFileName, String certificateAlias) throws CertificateException,
            IOException, KeyStoreException, NoSuchAlgorithmException {
        CertificateFactory cf = CertificateFactory.getInstance("X.509");
        InputStream certStream = fullStream(certFileName);
        Certificate certs = cf.generateCertificate(certStream);
        myTrustStore.setCertificateEntry(certificateAlias, certs);
        FileOutputStream out = new FileOutputStream(getKeyStoreLocation());, getKeyStorePassword().toCharArray());
        out.close();"Certificate pushed");

    public String getKeyStoreLocation() {
        return keyStoreLocation;

    public String getKeyStorePassword() {
        return keyStorePassword;
    public X509TrustManager getMytrustManager() {
        return myTrustManager;
    public void setMytrustManager(X509TrustManager myTrustManager) {
        this.myTrustManager = myTrustManager;

This class will create keystore if necessary, and will be able to manage certificates inside of it. Now class for SSL context:

public class CustomTrustManager implements X509TrustManager {

    private final static Logger logger = Logger.getLogger(CertificateManager.class);

    private static SSLSocketFactory socketFactory;
    private static CustomTrustManager instance = new CustomTrustManager();
    private static List<CertificateManager> register = new ArrayList<>();

    public static CustomTrustManager getInstance() {
        return instance;

    private X509TrustManager defaultTm;

    public void register(CertificateManager certificateManager) {
        for(CertificateManager manager : register) {
            if(manager == certificateManager) {
      "Certificate manager already registered");
        register.add(certificateManager);"New Certificate manager registered");

    private CustomTrustManager() {
        try {
            String algorithm = TrustManagerFactory.getDefaultAlgorithm();
            TrustManagerFactory tmf = TrustManagerFactory.getInstance(algorithm);

            tmf.init((KeyStore) null);
            boolean found = false;
            for (TrustManager tm : tmf.getTrustManagers()) {
                if (tm instanceof X509TrustManager) {
                    defaultTm = (X509TrustManager) tm;
                    found = true;
            if(found) {
      "Default trust manager found");
            } else {
                logger.warn("Default trust manager was not found");

            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, new TrustManager[]{this}, null);
            socketFactory = sslContext.getSocketFactory();

  "Custom trust manager was set");
        } catch (NoSuchAlgorithmException | KeyManagementException | KeyStoreException e) {
            logger.warn("Custom trust manager can't be set");

    public X509Certificate[] getAcceptedIssuers() {
        List<X509Certificate> out = new ArrayList<>();
        if (defaultTm != null) {
        int defaultCount = out.size();"Default trust manager contain " + defaultCount + " certficates");
        for(CertificateManager manager : register) {
            X509TrustManager customTrustManager = manager.getMytrustManager();
            X509Certificate[] issuers = customTrustManager.getAcceptedIssuers();
        }"Custom trust managers contain " + (out.size() - defaultCount) + " certficates");
        X509Certificate[] arrayOut = new X509Certificate[out.size()];
        return out.toArray(arrayOut);

    public void checkServerTrusted(X509Certificate[] chain,
                                   String authType) throws CertificateException {
        for(CertificateManager certificateManager : register) {
            X509TrustManager customTrustManager = certificateManager.getMytrustManager();
            try {
                customTrustManager.checkServerTrusted(chain, authType);
      "Certificate chain (server) was aproved by custom trust manager");
            } catch (Exception e) {
        if (defaultTm != null) {
            defaultTm.checkServerTrusted(chain, authType);
  "Certificate chain (server) was aproved by default trust manager");
        } else {
  "Certificate chain (server) was rejected");
            throw new CertificateException("Can't check server trusted certificate.");

    public void checkClientTrusted(X509Certificate[] chain,
                                   String authType) throws CertificateException {
        try {
            if (defaultTm != null) {
                defaultTm.checkClientTrusted(chain, authType);
      "Certificate chain (client) was aproved by default trust manager");
            } else {
                throw new NullPointerException();
        } catch (Exception e) {
            for(CertificateManager certificateManager : register) {
                X509TrustManager customTrustManager = certificateManager.getMytrustManager();
                try {
                    customTrustManager.checkClientTrusted(chain, authType);
          "Certificate chain (client) was aproved by custom trust manager");
                } catch (Exception e1) {
  "Certificate chain (client) was rejected");
            throw new CertificateException("Can't check client trusted certificate.");

    public SSLSocketFactory getSocketFactory() {
        return socketFactory;

This class made as singleton, because only one defaultSSL context allowed. So, now usage:

            CertificateManager certificateManager = new CertificateManager("C:\\myapplication\\mykeystore.jks", "changeit");
            String certificatePath = "C:\\myapplication\\public_key_for_your_ssl_service.crt";
            try {
                certificateManager.addCustomCertificate(certificatePath, "alias_for_public_key_for_your_ssl_service");
            } catch (Exception e) {
                log.error("Can't add custom certificate");

Possibly, it will not work with this settings, because I keep certificate file inside of resource folder, so my path is not absolute. But generally, it work perfectly.

How to set Java environment path in Ubuntu

To Set JAVA_HOME / PATH for a single user, Login to your account and open .bash_profile file

$ vi ~/.bash_profile

Set JAVA_HOME as follows using syntax export JAVA_HOME=<path-to-java>. If your path is set to /usr/java/jdk1.5.0_07/bin/java, set it as follows:

export JAVA_HOME=/usr/java/jdk1.5.0_07/bin/java

Set PATH as follows:

export PATH=$PATH:/usr/java/jdk1.5.0_07/bin

Feel free to replace /usr/java/jdk1.5.0_07 as per your setup. Save and close the file. Just logout and login back to see new changes. Alternatively, type the following command to activate the new path settings immediately:

$ source ~/.bash_profile


$ . ~/.bash_profile

Verify new settings:

$ echo $JAVA_HOME
$ echo $PATH

Tip: Use the following command to find out exact path to which java executable under UNIX / Linux:

$ which java

Please note that the file ~/.bashrc is similar, with the exception that ~/.bash_profile runs only for Bash login shells and .bashrc runs for every new Bash shell.

To Set JAVA_HOME / PATH for all user, You need to setup global config in /etc/profile OR /etc/bash.bashrc file for all users:

# vi /etc/profile

Next setup PATH / JAVA_PATH variables as follows:

export PATH=$PATH:/usr/java/jdk1.5.0_07/bin
export PATH=$PATH:/usr/java/jdk1.5.0_07/bin

Save and close the file. Once again you need to type the following command to activate the path settings immediately:

# source /etc/profile


# . /etc/profile

Font scaling based on width of container

Try This is what I use for my sites, and it has worked perfectly.

Android ImageView Animation

How to rotate an image around its center:

ImageView view = ... //Initialize ImageView via FindViewById or programatically

RotateAnimation anim = new RotateAnimation(0.0f, 360.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);

//Setup anim with desired properties
anim.setInterpolator(new LinearInterpolator());
anim.setRepeatCount(Animation.INFINITE); //Repeat animation indefinitely
anim.setDuration(700); //Put desired duration per anim cycle here, in milliseconds

//Start animation
//Later on, use view.setAnimation(null) to stop it.

This will cause the image to rotate around its center (0.5 or 50% of its width/height). I am posting this for future readers who get here from Google, as I have, and who wish to rotate the image around its center without defining said center in absolute pixels.

How do I remove lines between ListViews on Android?

For ListFragment use


after the list has been obtained.

TypeError: 'NoneType' object is not iterable in Python

For me it was a case of having my Groovy hat on instead of the Python 3 one.

Forgot the return keyword at the end of a def function.

Had not been coding Python 3 in earnest for a couple of months. Was thinking last statement evaluated in routine was being returned per the Groovy (or Rust) way.

Took a few iterations, looking at the stack trace, inserting try: ... except TypeError: ... block debugging/stepping thru code to figure out what was wrong.

The solution for the message certainly did not make the error jump out at me.

PHP substring extraction. Get the string before the first '/' or the whole string

why not use:

function getwhatiwant($s)
    return ($x?$x:$s);


   function getwhatiwant($s)
       $t=explode($delimiter, $s);
       return ($t[1]?$t[0]:$s);


They both work the same way, but $_POST should be used as it is cleaner. You can add isset() to it to check it exists.

How to cast Object to its actual type?

This method might not be the most efficient but is simple and does the job.

It performs two operations: firstly it calls .ToString() which is basiclly a serialization, and then the deserialization using Newtonsoft nuget (which you must install).

public T Format<T>(Object obj) =>

How do I find out which process is locking a file using .NET?

This works for DLLs locked by other processes. This routine will not find out for example that a text file is locked by a word process.


using System.Management; 
using System.IO;   

static class Module1 
static internal ArrayList myProcessArray = new ArrayList(); 
private static Process myProcess; 

public static void Main() 

    string strFile = "c:\\windows\\system32\\msi.dll"; 
    ArrayList a = getFileProcesses(strFile); 
    foreach (Process p in a) { 

private static ArrayList getFileProcesses(string strFile) 
    Process[] processes = Process.GetProcesses; 
    int i = 0; 
    for (i = 0; i <= processes.GetUpperBound(0) - 1; i++) { 
        myProcess = processes(i); 
        if (!myProcess.HasExited) { 
            try { 
                ProcessModuleCollection modules = myProcess.Modules; 
                int j = 0; 
                for (j = 0; j <= modules.Count - 1; j++) { 
                    if ((modules.Item(j).FileName.ToLower.CompareTo(strFile.ToLower) == 0)) { 
                        break; // TODO: might not be correct. Was : Exit For 
            catch (Exception exception) { 
            //MsgBox(("Error : " & exception.Message)) 
    return myProcessArray; 


Imports System.Management
Imports System.IO

Module Module1
Friend myProcessArray As New ArrayList
Private myProcess As Process

Sub Main()

    Dim strFile As String = "c:\windows\system32\msi.dll"
    Dim a As ArrayList = getFileProcesses(strFile)
    For Each p As Process In a
End Sub

Private Function getFileProcesses(ByVal strFile As String) As ArrayList
    Dim processes As Process() = Process.GetProcesses
    Dim i As Integer
    For i = 0 To processes.GetUpperBound(0) - 1
        myProcess = processes(i)
        If Not myProcess.HasExited Then
                Dim modules As ProcessModuleCollection = myProcess.Modules
                Dim j As Integer
                For j = 0 To modules.Count - 1
                    If (modules.Item(j).FileName.ToLower.CompareTo(strFile.ToLower) = 0) Then
                        Exit For
                    End If
                Next j
            Catch exception As Exception
                'MsgBox(("Error : " & exception.Message))
            End Try
        End If
    Next i
    Return myProcessArray
End Function
End Module

How can I get all the request headers in Django?

Simply you can use HttpRequest.headers from Django 2.2 onward. Following example is directly taken from the official Django Documentation under Request and response objects section.

>>> request.headers
{'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6', ...}

>>> 'User-Agent' in request.headers
>>> 'user-agent' in request.headers

>>> request.headers['User-Agent']
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
>>> request.headers['user-agent']
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)

>>> request.headers.get('User-Agent')
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
>>> request.headers.get('user-agent')
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)

Replace duplicate spaces with a single space in T-SQL

Method #1

The first method is to replace extra spaces between words with an uncommon symbol combination as a temporary marker. Then you can replace the temporary marker symbols using the replace function rather than a loop.

Here is a code example that replaces text within a String variable.

DECLARE @testString AS VARCHAR(256) = ' Test        text   with  random*        spacing. Please normalize  this spacing!';
SELECT REPLACE(REPLACE(REPLACE(@testString, ' ', '*^'), '^*', ''), '*^', ' ');

Execution Time Test #1: In ten runs of this replacement method, the average wait time on server replies was 1.7 milliseconds and total execution time was 4.6 milliseconds. Execution Time Test #2: The average wait time on server replies was 1.7 milliseconds and total execution time was 3.7 milliseconds.

Method #2

The second method is not quite as elegant as the first, but also gets the job done. This method works by nesting four (or optionally more) replace statements that replace two blank spaces with one blank space.

DECLARE @testString AS VARCHAR(256) = ' Test        text   with  random*        spacing. Please normalize  this spacing!';
SELECT REPLACE(REPLACE(REPLACE(REPLACE(@testString,' ',' '),' ',' '),' ',' '),' ',' ')

Execution Time Test #1: In ten runs of this replacement method, the average wait time on server replies was 1.9 milliseconds and total execution time was 3.8 milliseconds. Execution Time Test #2: The average wait time on server replies was 1.8 milliseconds and total execution time was 4.8 milliseconds.

Method #3

The third method of replacing extra spaces between words is to use a simple loop. You can do a check on extra spaces in a while loop and then use the replace function to reduce the extra spaces with each iteration of the loop.

DECLARE @testString AS VARCHAR(256) = ' Test text with random* spacing. Please normalize this spacing!';
WHILE CHARINDEX(' ',@testString) > 0
SET @testString = REPLACE(@testString, ' ', ' ')
SELECT @testString

Execution Time Test #1: In ten runs of this replacement method, the average wait time on server replies was 1.8 milliseconds and total execution time was 3.4 milliseconds. Execution Time Test #2: The average wait time on server replies was 1.9 milliseconds and total execution time was 2.8 milliseconds.

JavaScript .replace only replaces first Match

For that you neet to use the g flag of regex.... Like this :

var new_string=old_string.replace( / (regex) /g,  replacement_text);

That sh

How to change the text color of first select option

What about this:

  width: 150px;
  height: 30px;
  padding: 5px;
  color: green;
select option { color: black; }
select option:first-child{
  color: green;

Docker expose all ports or range of ports from 7000 to 8000

For anyone facing this issue and ending up on this post...the issue is still open -

Using sed to mass rename files

The sed command

s/\(.\).\(.*\)/mv & \1\2/

means to replace:



mv & \1\2

just like a regular sed command. However, the parentheses, & and \n markers change it a little.

The search string matches (and remembers as pattern 1) the single character at the start, followed by a single character, follwed by the rest of the string (remembered as pattern 2).

In the replacement string, you can refer to these matched patterns to use them as part of the replacement. You can also refer to the whole matched portion as &.

So what that sed command is doing is creating a mv command based on the original file (for the source) and character 1 and 3 onwards, effectively removing character 2 (for the destination). It will give you a series of lines along the following format:

mv F00001-0708-RG-biasliuyda F0001-0708-RG-biasliuyda
mv abcdef acdef

and so on.

What's the difference between '$(this)' and 'this'?

$() is the jQuery constructor function.

this is a reference to the DOM element of invocation.

So basically, in $(this), you are just passing the this in $() as a parameter so that you could call jQuery methods and functions.

Quickest way to clear all sheet contents VBA

Technically, and from Comintern's accepted workaround, I believe you actually want to Delete all the Cells in the Sheet. Which removes Formatting (See footnote for exceptions), etc. as well as the Cells Contents. I.e. Sheets("Zeroes").Cells.Delete

Combined also with UsedRange, ScreenUpdating and Calculation skipping it should be nearly intantaneous:

Sub DeleteCells ()
    Application.Calculation = XlManual
    Application.ScreenUpdating = False
    Application.ScreenUpdating = True
    Application.Calculation = xlAutomatic
End Sub

Or if you prefer to respect the Calculation State Excel is currently in:

Sub DeleteCells ()
    Dim SaveCalcState
    SaveCalcState = Application.Calculation
    Application.Calculation = XlManual
    Application.ScreenUpdating = False
    Application.ScreenUpdating = True
    Application.Calculation = SaveCalcState
End Sub

Footnote: If formatting was applied for an Entire Column, then it is not deleted. This includes Font Colour, Fill Colour and Borders, the Format Category (like General, Date, Text, Etc.) and perhaps other properties too, but

Conditional formatting IS deleted, as is Entire Row formatting.

(Entire Column formatting is quite useful if you are importing raw data repeatedly to a sheet as it will conform to the Formats originally applied if a simple Paste-Values-Only type import is done.)

How to split a string in Ruby and get all items except the first one?

if u want to use them as an array u already knew, else u can use every one of them as a different parameter ... try this :

parameter1,parameter2,parameter3,parameter4,parameter5 = ex.split(",")

regex for zip-code

For the listed three conditions only, these expressions might work also:


Please see this demo for additional explanation.

If we would have had unexpected additional spaces in between 5 and 4 digits or a continuous 9 digits zip code, such as:

12345 1234
12345  1234

this expression for instance would be a secondary option with less constraints:


Please see this demo for additional explanation.

RegEx Circuit visualizes regular expressions:

enter image description here


const regex = /^\d{5}[-\s]?(?:\d{4})?$/gm;_x000D_
const str = `12345_x000D_
12345 1234_x000D_
12345 1234_x000D_
12345  1234_x000D_
let m;_x000D_
while ((m = regex.exec(str)) !== null) {_x000D_
    // This is necessary to avoid infinite loops with zero-width matches_x000D_
    if (m.index === regex.lastIndex) {_x000D_
    // The result can be accessed through the `m`-variable._x000D_
    m.forEach((match, groupIndex) => {_x000D_
        console.log(`Found match, group ${groupIndex}: ${match}`);_x000D_

How to delete history of last 10 commands in shell?

history -c will clear all histories.

What is Python used for?

Why should you learn Python Programming Language?

Python offers a stepping stone into the world of programming. Even though Python Programming Language has been around for 25 years, it is still rising in popularity. Some of the biggest advantage of Python are it's

  • Easy to Read & Easy to Learn
  • Very productive or small as well as big projects
  • Big libraries for many things

enter image description here

What is Python Programming Language used for?

As a general purpose programming language, Python can be used for multiple things. Python can be easily used for small, large, online and offline projects. The best options for utilizing Python are web development, simple scripting and data analysis. Below are a few examples of what Python will let you do:

Web Development:

You can use Python to create web applications on many levels of complexity. There are many excellent Python web frameworks including, Pyramid, Django and Flask, to name a few.

Data Analysis:

Python is the leading language of choice for many data scientists. Python has grown in popularity, within this field, due to its excellent libraries including; NumPy and Pandas and its superb libraries for data visualisation like Matplotlib and Seaborn.

Machine Learning:

What if you could predict customer satisfaction or analyse what factors will affect household pricing or to predict stocks over the next few days, based on previous years data? There are many wonderful libraries implementing machine learning algorithms such as Scikit-Learn, NLTK and TensorFlow.

Computer Vision:

You can do many interesting things such as Face detection, Color detection while using Opencv and Python.

Internet Of Things With Raspberry Pi:

Raspberry Pi is a very tiny and affordable computer which was developed for education and has gained enormous popularity among hobbyists with do-it-yourself hardware and automation. You can even build a robot and automate your entire home. Raspberry Pi can be used as the brain for your robot in order to perform various actions and/or react to the environment. The coding on a Raspberry Pi can be performed using Python. The Possibilities are endless!

Game Development:

Create a video game using module Pygame. Basically, you use Python to write the logic of the game. PyGame applications can run on Android devices.

Web Scraping:

If you need to grab data from a website but the site does not have an API to expose data, use Python to scraping data.

Writing Scripts:

If you're doing something manually and want to automate repetitive stuff, such as emails, it's not difficult to automate once you know the basics of this language.

Browser Automation:

Perform some neat things such as opening a browser and posting a Facebook status, you can do it with Selenium with Python.

GUI Development:

Build a GUI application (desktop app) using Python modules Tkinter, PyQt to support it.

Rapid Prototyping:

Python has libraries for just about everything. Use it to quickly built a (lower-performance, often less powerful) prototype. Python is also great for validating ideas or products for established companies and start-ups alike.

Python can be used in so many different projects. If you're a programmer looking for a new language, you want one that is growing in popularity. As a newcomer to programming, Python is the perfect choice for learning quickly and easily.

List file names based on a filename pattern and file content?

find /folder -type f -mtime -90 | grep -E "(.txt|.php|.inc|.root|.gif)" | xargs ls -l > WWWlastActivity.log

Best HTML5 markup for sidebar

Update 17/07/27: As this is the most-voted answer, I should update this to include current information locally (with links to the references).

From the spec [1]:

The aside element represents a section of a page that consists of content that is tangentially related to the content of the parenting sectioning content, and which could be considered separate from that content. Such sections are often represented as sidebars in printed typography.

Great! Exactly what we're looking for. In addition, it is best to check on <section> as well.

The section element represents a generic section of a document or application. A section, in this context, is a thematic grouping of content. Each section should be identified, typically by including a heading (h1-h6 element) as a child of the section element.


A general rule is that the section element is appropriate only if the element’s contents would be listed explicitly in the document’s outline.

Excellent. Just what we're looking for. As opposed to <article> [2] which is for "self-contained" content, <section> allows for related content that isn't stand-alone, or generic enough for a <div> element.

As such, the spec seems to suggest that using Option 1, <aside> with <section> children is best practice.



What is the equivalent to a JavaScript setInterval/setTimeout in Android/Java?

I was creating a mp3 player for android, I wanted to update the current time every 500ms so I did it like this


private void update() {
    new android.os.Handler().postDelayed(new Runnable() {
        public void run() {
            long cur = player.getCurrentPosition();
            long dur = player.getDuration();
            currentTime = millisecondsToTime(cur);
            if (cur < dur) {

            // update seekbar
            seekBar.setProgress( (int) Math.round((float)cur / (float)dur * 100f));
    }, 500);

which calls the same method recursively

Ruby Array find_first object?

Guess you just missed the find method in the docs:

my_array.find {|e| e.satisfies_condition? }

How do I display a wordpress page content?

Just put this code in your content div

    while ( have_posts() ) : the_post(); ?> <!--Because the_content() works only inside a WP Loop -->
        <div class="entry-content-page">
            <?php the_content(); ?> <!-- Page Content -->
        </div><!-- .entry-content-page -->

endwhile; //resetting the page loop
wp_reset_query(); //resetting the page query

Android LinearLayout Gradient Background

With Kotlin you can do that in just 2 lines

Change color values in the array

                  val gradientDrawable = GradientDrawable(
                    gradientDrawable.cornerRadius = 0f;

                   //Set Gradient


enter image description here

How to downgrade tensorflow, multiple versions possible?

Click to green checkbox on installed tensorflow and choose needed versionscreenshot Anaconda navigator

Comparing strings in Java

Try to use .trim() first, before .equals(), or create a new String var that has these things.

Check if instance is of a type

A little more compact than the other answers if you want to use c as a TForm:

if(c is TForm form){

How to properly export an ES6 class in Node 4?

With ECMAScript 2015 you can export and import multiple classes like this

class Person
        this.type = "Person";

class Animal{
        this.type = "Animal";

module.exports = {

then where you use them:

const { Animal, Person } = require("classes");

const animal = new Animal();
const person = new Person();

In case of name collisions, or you prefer other names you can rename them like this:

const { Animal : OtherAnimal, Person : OtherPerson} = require("./classes");

const animal = new OtherAnimal();
const person = new OtherPerson();

Can I target all <H> tags with a single selector?

No, a comma-separated list is what you want in this case.

How to download a file over HTTP?

import urllib2
mp3file = urllib2.urlopen("")
with open('test.mp3','wb') as output:

The wb in open('test.mp3','wb') opens a file (and erases any existing file) in binary mode so you can save data with it instead of just text.

Excel vba - convert string to number

If, for example, x = 5 and is stored as string, you can also just:

x = x + 0

and the new x would be stored as a numeric value.

How can I find a file/directory that could be anywhere on linux command line?

Below example will help to find the specific folder in the current directory. This example only search current direct and it'll search sub directory available in the current directory


result=$(ls -d operational)

echo $result


if [ "$result" == "$test" ] 
   echo "TRUE"
   echo "FALSE"

How to parse this string in Java?

String.split(String regex) is convenient but if you don't need the regular expression handling then go with the substring(..) example, java.util.StringTokenizer or use Apache commons lang 1. The performance difference when not using regular expressions can be a gain of 1 to 2 orders of magnitude in speed.

Bash Templating: How to build configuration files from templates with Bash?

envsubst was new to me. Fantastic.

For the record, using a heredoc is a great way to template a conf file.

STATUS_URI="/hows-it-goin";  MONITOR_IP="";

cat >/etc/apache2/conf.d/mod_status.conf <<EOF
<Location ${STATUS_URI}>
    SetHandler server-status
    Order deny,allow
    Deny from all
    Allow from ${MONITOR_IP}

How do I add a library (android-support-v7-appcompat) in IntelliJ IDEA

Using Maven

First of all you should install android libraries to your local maven repository using Maven Android SDK Deployer

Then you can add dependency to your pom like this:



How to change the buttons text using javascript

You can toggle filterstatus value like this

filterstatus ^= 1;

So your function looks like

function showFilterItem(objButton) {
if (filterstatus == 0) {
    $find('<%=FileAdminRadGrid.ClientID %>').get_masterTableView().showFilterItem();
    objButton.value = "Hide Filter";
else {
    $find('<%=FileAdminRadGrid.ClientID %>').get_masterTableView().hideFilterItem();
    objButton.value = "Show filter";
  filterstatus ^= 1;    

How to get all elements which name starts with some string?

You can use getElementsByName("input") to get a collection of all the inputs on the page. Then loop through the collection, checking the name on the way. Something like this:

<!DOCTYPE html>
<meta charset=utf-8 />
<title>JS Bin</title>


  <input name="q1_a" type="text" value="1A"/>
  <input name="q1_b" type="text" value="1B"/>
  <input name="q1_c" type="text" value="1C"/>
  <input name="q2_d" type="text" value="2D"/>

  <script type="text/javascript">
  var inputs = document.getElementsByTagName("input");
  for (x = 0 ; x < inputs.length ; x++){
    myname = inputs[x].getAttribute("name");
      // do more stuff here


How can I make PHP display the error instead of giving me 500 Internal Server Error

Use "php -l <filename>" (that's an 'L') from the command line to output the syntax error that could be causing PHP to throw the status 500 error. It'll output something like:

PHP Parse error: syntax error, unexpected '}' in <filename> on line 18

Detecting iOS orientation change instantly

For my case handling UIDeviceOrientationDidChangeNotification was not good solution as it is called more frequent and UIDeviceOrientation is not always equal to UIInterfaceOrientation because of (FaceDown, FaceUp).

I handle it using UIApplicationDidChangeStatusBarOrientationNotification:

//To add the notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didChangeOrientation:)

//to remove the
[[NSNotificationCenter defaultCenter]removeObserver:self name:UIDeviceOrientationDidChangeNotification object:nil];


- (void)didChangeOrientation:(NSNotification *)notification
    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;

    if (UIInterfaceOrientationIsLandscape(orientation)) {
    else {

SQL SELECT WHERE field contains words

DECLARE @SearchStr nvarchar(100)
SET @SearchStr = ' '

CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))


DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')


    SET @ColumnName = ''
    SET @TableName = 
        WHERE         TABLE_TYPE = 'BASE TABLE'
            AND    OBJECTPROPERTY(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)

        SET @ColumnName =
            WHERE         TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND    TABLE_NAME    = PARSENAME(@TableName, 1)
                AND    DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal')
                AND    QUOTENAME(COLUMN_NAME) > @ColumnName

        IF @ColumnName IS NOT NULL

            INSERT INTO #Results
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2

SELECT ColumnName, ColumnValue FROM #Results


Get the size of a 2D array

Expanding on what Mark Elliot said earlier, the easiest way to get the size of a 2D array given that each array in the array of arrays is of the same size is:

array.length * array[0].length

I do not understand how execlp() works in Linux

this prototype:

  int execlp(const char *file, const char *arg, ...);

Says that execlp ìs a variable argument function. It takes 2 const char *. The rest of the arguments, if any, are the additional arguments to hand over to program we want to run - also char * - all these are C strings (and the last argument must be a NULL pointer)

So, the file argument is the path name of an executable file to be executed. arg is the string we want to appear as argv[0] in the executable. By convention, argv[0] is just the file name of the executable, normally it's set to the same as file.

The ... are now the additional arguments to give to the executable.

Say you run this from a commandline/shell:

$ ls

That'd be execlp("ls", "ls", (char *)NULL); Or if you run

$ ls -l /

That'd be execlp("ls", "ls", "-l", "/", (char *)NULL);

So on to execlp("/bin/sh", ..., "ls -l /bin/??", ...);

Here you are going to the shell, /bin/sh , and you're giving the shell a command to execute. That command is "ls -l /bin/??". You can run that manually from a commandline/shell:

 $ ls -l /bin/??

Now, how do you run a shell and tell it to execute a command ? You open up the documentation/man page for your shell and read it.

What you want to run is:

$ /bin/sh -c "ls -l /bin/??"

This becomes

  execlp("/bin/sh","/bin/sh", "-c", "ls -l /bin/??", (char *)NULL);

Side note: The /bin/?? is doing pattern matching, this pattern matching is done by the shell, and it expands to all files under /bin/ with 2 characters. If you simply did

  execlp("ls","ls", "-l", "/bin/??", (char *)NULL);

Probably nothing would happen (unless there's a file actually named /bin/??) as there's no shell that interprets and expands /bin/??

Python: finding lowest integer

It looks like you want to convert the list to a list of numbers

>>> foo = ['-1.2', '0.0', '1']
>>> bar = map(float, foo)
>>> bar
[-1.2, 0.0, 1.0]
>>> min(bar)

or if it really is strings you want, that you want to use min's key argument

>>> foo = ['-1.2', '0.0', '1']
>>> min(foo, key=float)

ORA-01830: date format picture ends before converting entire input string / Select sum where date query

You can use

Select to_date('08/15/2017 12:00:00 AM','MM/DD/YYYY HH:MI:SS AM') from dual;

If you are using it in an SP then your variable datatype should be Varchar2

and also in your code the datatype of your input parameter should be


Basically I had to put a DateFrom and DateTo filter in my SP so I passed dates as String in it.

Note: This is one of the solution which worked for me, there could be more solutions to this problem.

How do I remove blank elements from an array?

When I want to tidy up an array like this I use:

["Kathmandu", "Pokhara", "", "Dharan", "Butwal"] - ["", nil]

This will remove all blank or nil elements.

How to embed new Youtube's live video permanent URL?

Here's how to do it in Squarespace using the embed block classes to create responsiveness.

Put this into a code block:

<div class="sqs-block embed-block sqs-block-embed" data-block-type="22" >
    <div class="sqs-block-content"><div class="intrinsic" style="max-width:100%">
        <div class="embed-block-wrapper embed-block-provider-YouTube" style="padding-bottom:56.20609%;">
            <iframe allow="autoplay; fullscreen" scrolling="no" data-image-dimensions="854x480" allowfullscreen="true" src="" width="854" data-embed="true" frameborder="0" title="YouTube embed" class="embedly-embed" height="480">

Tweak however you'd like!

Make hibernate ignore class variables that are not mapped

JPA will use all properties of the class, unless you specifically mark them with @Transient:

private String agencyName;

The @Column annotation is purely optional, and is there to let you override the auto-generated column name. Furthermore, the length attribute of @Column is only used when auto-generating table definitions, it has no effect on the runtime.

openCV program compile error " cannot open shared object file: No such file or directory" in ubuntu 12.04

Add this link:


The total is:

g++ -o main.out main.cpp -I /usr/local/include -I /usr/local/include/opencv -I /usr/local/include/opencv2 -L /usr/local/lib /usr/local/lib/*.so /usr/local/lib/*.so.*

What is C# analog of C++ std::pair?

The PowerCollections library (formerly available from Wintellect but now hosted on Codeplex @ has a generic Pair structure.

Easiest way to make lua script wait/pause/sleep/block for a few seconds?

I would implement a simple function to wrap the host system's sleep function in C.

How to use concerns in Rails 4

I have been reading about using model concerns to skin-nize fat models as well as DRY up your model codes. Here is an explanation with examples:

1) DRYing up model codes

Consider a Article model, a Event model and a Comment model. An article or an event has many comments. A comment belongs to either Article or Event.

Traditionally, the models may look like this:

Comment Model:

class Comment < ActiveRecord::Base
  belongs_to :commentable, polymorphic: true

Article Model:

class Article < ActiveRecord::Base
  has_many :comments, as: :commentable 

  def find_first_comment
    comments.first(created_at DESC)

  def self.least_commented
   #return the article with least number of comments

Event Model

class Event < ActiveRecord::Base
  has_many :comments, as: :commentable 

  def find_first_comment
    comments.first(created_at DESC)

  def self.least_commented
   #returns the event with least number of comments

As we can notice, there is a significant piece of code common to both Event and Article. Using concerns we can extract this common code in a separate module Commentable.

For this create a commentable.rb file in app/models/concerns.

module Commentable
  extend ActiveSupport::Concern

  included do
    has_many :comments, as: :commentable

  # for the given article/event returns the first comment
  def find_first_comment
    comments.first(created_at DESC)

  module ClassMethods
    def least_commented
      #returns the article/event which has the least number of comments

And now your models look like this :

Comment Model:

class Comment < ActiveRecord::Base
  belongs_to :commentable, polymorphic: true

Article Model:

class Article < ActiveRecord::Base
  include Commentable

Event Model:

class Event < ActiveRecord::Base
  include Commentable

2) Skin-nizing Fat Models.

Consider a Event model. A event has many attenders and comments.

Typically, the event model might look like this

class Event < ActiveRecord::Base   
  has_many :comments
  has_many :attenders

  def find_first_comment
    # for the given article/event returns the first comment

  def find_comments_with_word(word)
    # for the given event returns an array of comments which contain the given word

  def self.least_commented
    # finds the event which has the least number of comments

  def self.most_attended
    # returns the event with most number of attendes

  def has_attendee(attendee_id)
    # returns true if the event has the mentioned attendee

Models with many associations and otherwise have tendency to accumulate more and more code and become unmanageable. Concerns provide a way to skin-nize fat modules making them more modularized and easy to understand.

The above model can be refactored using concerns as below: Create a attendable.rb and commentable.rb file in app/models/concerns/event folder


module Attendable
  extend ActiveSupport::Concern

  included do 
    has_many :attenders

  def has_attender(attender_id)
    # returns true if the event has the mentioned attendee

  module ClassMethods
    def most_attended
      # returns the event with most number of attendes


module Commentable
  extend ActiveSupport::Concern

  included do 
    has_many :comments

  def find_first_comment
    # for the given article/event returns the first comment

  def find_comments_with_word(word)
    # for the given event returns an array of comments which contain the given word

  module ClassMethods
    def least_commented
      # finds the event which has the least number of comments

And now using Concerns, your Event model reduces to

class Event < ActiveRecord::Base
  include Commentable
  include Attendable

* While using concerns its advisable to go for 'domain' based grouping rather than 'technical' grouping. Domain Based grouping is like 'Commentable', 'Photoable', 'Attendable'. Technical grouping will mean 'ValidationMethods', 'FinderMethods' etc

SQL Server Management Studio missing

I know this is an old question, but I've just had the same frustrating issue for a couple of hours and wanted to share my solution. In my case the option "Managements Tools" wasn't available in the installation menu either. It wasn't just greyed out as disabled or already installed, but instead just missing, it wasn't anywhere on the menu.

So what finally worked for me was to use the Web Platform Installer 4.0, and check this for installation: Products > Database > "Sql Server 2008 R2 Management Objects". Once this is done, you can relaunch the installation and "Management Tools" will appear like previous answers stated.

Note there could also be a "Sql Server 2012 Shared Management Objects", but I think this is for different purposes.

Hope this saves someone the couple of hours I wasted into this.

Printing image with PrintDocument. how to adjust the image to fit paper size

The solution provided by BBoy works fine. But in my case I had to use

e.Graphics.DrawImage(memoryImage, e.PageBounds);

This will print only the form. When I use MarginBounds it prints the entire screen even if the form is smaller than the monitor screen. PageBounds solved that issue. Thanks to BBoy!

What's the simplest way to print a Java array?

Always check the standard libraries first.

import java.util.Arrays;

Then try:


or if your array contains other arrays as elements:


Iterating Over Dictionary Key Values Corresponding to List in Python

List comprehension can shorten things...

win_percentages = [m**2.0 / (m**2.0 + n**2.0) * 100 for m, n in [a[i] for i in NL_East]]

What is the difference between a JavaBean and a POJO?

POJO: If the class can be executed with underlying JDK,without any other external third party libraries support then its called POJO

JavaBean: If class only contains attributes with accessors(setters and getters) those are called javabeans.Java beans generally will not contain any bussiness logic rather those are used for holding some data in it.

All Javabeans are POJOs but all POJO are not Javabeans

Chrome doesn't delete session cookies

I just had this issue. I noticed that even after I closed my browser I had many Chrome processes running. Turns out these were each from my Chrome extension.

Under advanced settings I unchecked 'Continue running background apps when Google Chrome is closed' and my session cookies started working as they should.

Still a pain in the rear for all of us developers that have been coding expecting that session cookies would get cleared when the user is done browsing.

Get properties and values from unknown object

    /// get set value field in object to object new (two object  field like ) 

    public static void SetValueObjectToObject (object sourceObj , object resultObj)
        IList<PropertyInfo> props = new List<PropertyInfo>(sourceObj.GetType().GetProperties());
        foreach (PropertyInfo prop in props)
                //get value in sourceObj
                object propValue = prop.GetValue(sourceObj, null);
                //set value in resultObj
                PropertyInfo propResult = resultObj.GetType().GetProperty(prop.Name, BindingFlags.Public | BindingFlags.Instance);
                if (propResult != null && propResult.CanWrite)
                    propResult.SetValue(resultObj, propValue, null);
            catch (Exception ex)
                // do something with Ex

Check if string contains only whitespace

I'm assuming in your scenario, an empty string is a string that is truly empty or one that contains all white space.

    print("string is not empty")
    print("string is empty")

Note this does not check for None

How to increase image size of pandas.DataFrame.plot in jupyter notebook?

Try figsize param in df.plot(figsize=(width,height)):

df = pd.DataFrame({"a":[1,2],"b":[1,2]})

enter image description here

df = pd.DataFrame({"a":[1,2],"b":[1,2]})

enter image description here

The size in figsize=(5,3) is given in inches per (width, height)

Up, Down, Left and Right arrow keys do not trigger KeyDown event

The best way to do, I think, is to handle it like the MSDN said on

But handle it, how you really need it. My way (in the example below) is to catch every KeyDown ;-)

    /// <summary>
    /// onPreviewKeyDown
    /// </summary>
    /// <param name="e"></param>
    protected override void OnPreviewKeyDown(PreviewKeyDownEventArgs e)
        e.IsInputKey = true;

    /// <summary>
    /// onKeyDown
    /// </summary>
    /// <param name="e"></param>
    protected override void OnKeyDown(KeyEventArgs e)
        e.Handled = true;

    /// <summary>
    /// onKeyUp
    /// </summary>
    /// <param name="e"></param>
    protected override void OnKeyUp(KeyEventArgs e)
        e.Handled = true;

Accessing inventory host variable in Ansible playbook

You should be able to use the variable name directly


Or you can go through hostvars without having to specify the host literally by using the magic variable inventory_hostname


Form Submit jQuery does not work

The NUMBER ONE error is having ANYTHING with the reserved word submit as ID or NAME in your form.

If you plan to call .submit() on the form AND the form has submit as id or name on any form element, then you need to rename that form element, since the form’s submit method/handler is shadowed by the name/id attribute.

Several other things:

As mentioned, you need to submit the form using a simpler event than the jQuery one

BUT you also need to cancel the clicks on the links

Why, by the way, do you have two buttons? Since you use jQuery to submit the form, you will never know which of the two buttons were clicked unless you set a hidden field on click.

<form action="deletprofil.php" id="form_id" method="post">
  <div data-role="controlgroup" data-filter="true" data-input="#filterControlgroup-input">
  <button type="submit" value="1" class="ui-btn ui-shadow ui-corner-all ui-icon-delete ui-btn-icon-right" data-icon="delete" aria-disabled="false">Anlegen</button>
  <button type="submit" value="2" class="ui-btn ui-shadow ui-corner-all ui-icon-delete ui-btn-icon-right" data-icon="delete" aria-disabled="false">Bnlegen</button>

    $("#NOlink, #OKlink").on("click", function(e) {
        e.preventDefault(); // cancel default action
        if ("OKlink") { 
          document.getElementById("form_id").submit(); // or $("#form_id")[0].submit();

    $('#form_id').on('submit', function(e){

Judging from your comments, I think you really want to do this:

<form action="deletprofil.php" id="form_id" method="post">
  <input type="hidden" id="whichdelete" name="whichdelete" value="" />
  <div data-role="controlgroup" data-filter="true" data-input="#filterControlgroup-input">
  <button type="button" value="1" class="delete ui-btn ui-shadow ui-corner-all ui-icon-delete ui-btn-icon-right" data-icon="delete" aria-disabled="false">Anlegen</button>
  <button type="button" value="2" class="delete ui-btn ui-shadow ui-corner-all ui-icon-delete ui-btn-icon-right" data-icon="delete" aria-disabled="false">Bnlegen</button>

    $("#NOlink, #OKlink").on("click", function(e) {
        e.preventDefault(); // cancel default action
        if ("OKlink") { 
          // trigger the submit event, not the event handler
          document.getElementById("form_id").submit(); // or $("#form_id")[0].submit();
    $(".delete").on("click", function(e) {
    $('#form_id').on('submit', function(e){

Convert seconds to Hour:Minute:Second

The gmtdate() function didn't work for me as I was tracking hours worked on a project and if it's over 24 hours, you get amount left over after 24 hours is subtracted. In other words 37 hours becomes 13 hours. (all as stated above by Glavic - thanks for your examples!) This one worked well:

Convert seconds to format by 'foot' no limit :
$seconds = 8525;
$H = floor($seconds / 3600);
$i = ($seconds / 60) % 60;
$s = $seconds % 60;
echo sprintf("%02d:%02d:%02d", $H, $i, $s);
# 02:22:05

How do you post data with a link

If you want to pass the data using POST instead of GET, you can do it using a combination of PHP and JavaScript, like this:

function formSubmit(house_number)
  document.forms[0].house_number.value = house_number;

Then in PHP you loop through the house-numbers, and create links to the JavaScript function, like this:

<form action="house.php" method="POST">
<input type="hidden" name="house_number" value="-1">

foreach ($houses as $id => name)
    echo "<a href=\"javascript:formSubmit($id);\">$name</a>\n";

That way you just have one form whose hidden variable(s) get modified according to which link you click on. Then JavasScript submits the form.

Duplicating a MySQL table, indices, and data

After I tried the solution above, I come up with my own way.

My solution a little manual and needs DBMS.

First, export the data.

Second, open the export data.

Third, replace old table name with new table name.

Fourth, change all the trigger name in the data (I use MySQL and it show error when I don't change trigger name).

Fifth, import your edited SQL data to the database.

How to use GNU Make on Windows?

While make itself is available as a standalone executable ( package make), using it in a proper development environment means using msys2.

Git 2.24 (Q4 2019) illustrates that:

See commit 4668931, commit b35304b, commit ab7d854, commit be5d88e, commit 5d65ad1, commit 030a628, commit 61d1d92, commit e4347c9, commit ed712ef, commit 5b8f9e2, commit 41616ef, commit c097b95 (04 Oct 2019), and commit dbcd970 (30 Sep 2019) by Johannes Schindelin (dscho).
(Merged by Junio C Hamano -- gitster -- in commit 6d5291b, 15 Oct 2019)

test-tool run-command: learn to run (parts of) the testsuite

Signed-off-by: Johannes Schindelin

Git for Windows jumps through hoops to provide a development environment that allows to build Git and to run its test suite.

To that end, an entire MSYS2 system, including GNU make and GCC is offered as "the Git for Windows SDK".
It does come at a price: an initial download of said SDK weighs in with several hundreds of megabytes, and the unpacked SDK occupies ~2GB of disk space.

A much more native development environment on Windows is Visual Studio. To help contributors use that environment, we already have a Makefile target vcxproj that generates a commit with project files (and other generated files), and Git for Windows' vs/master branch is continuously re-generated using that target.

The idea is to allow building Git in Visual Studio, and to run individual tests using a Portable Git.

How can I remove specific rules from iptables?

First list all iptables rules with this command:

iptables -S

it lists like:

-A XYZ -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT

Then copy the desired line, and just replace -A with -D to delete that:

iptables -D XYZ -p ...

position fixed header in html

Your #container should be outside of the #header-wrap, then specify a fixed height for #header-wrap, after, specify margin-top for #container equal to the #header-wrap's height. Something like this:

#header-wrap {
    position: fixed;
    height: 200px;
    top: 0;
    width: 100%;
    z-index: 100;
    margin-top: 200px;

Hope this is what you need:

Can anybody tell me details about hs_err_pid.log file generated when Tomcat crashes?

A very very good document regarding this topic is Troubleshooting Guide for Java from (originally) Sun. See the chapter "Troubleshooting System Crashes" for information about hs_err_pid* Files.

See Appendix C - Fatal Error Log

Per the guide, by default the file will be created in the working directory of the process if possible, or in the system temporary directory otherwise. A specific location can be chosen by passing in the -XX:ErrorFile product flag. It says:

If the -XX:ErrorFile= file flag is not specified, the system attempts to create the file in the working directory of the process. In the event that the file cannot be created in the working directory (insufficient space, permission problem, or other issue), the file is created in the temporary directory for the operating system.

How to switch to other branch in Source Tree to commit the code?

  1. Go to the log view (to be able to go here go to View -> log view).
  2. Double click on the line with the branch label stating that branch. Automatically, it will switch branch. (A prompt will dropdown and say switching branch.)
  3. If you have two or more branches on the same line, it will ask you via prompt which branch you want to switch. Choose the specific branch from the dropdown and click ok.

To determine which branch you are now on, look at the side bar, under BRANCHES, you are in the branch that is in BOLD LETTERS.

@RequestParam vs @PathVariable

@PathVariable - must be placed in the endpoint uri and access the query parameter value from the request
@RequestParam - must be passed as method parameter (optional based on the required property)

 @RequestMapping(value=“/call/{callId}", method = RequestMethod.GET)
 public List<Calls> getAgentCallById(
            @PathVariable(“callId") int callId,
            @RequestParam(value = “status", required = false) String callStatus) {



@RequestMapping(value=“/call/{callId}", method = RequestMethod.GET)
public List<Calls> getAgentCallById(
            @PathVariable(“callId") int callId,
            @RequestParam(value = “status", required = true) String callStatus) {


Python: get key of index in dictionary

You could do something like this:

i={'foo':'bar', 'baz':'huh?'}
keys=i.keys()  #in python 3, you'll need `list(i.keys())`
print keys[values.index("bar")]  #'foo'

However, any time you change your dictionary, you'll need to update your keys,values because dictionaries are not ordered in versions of Python prior to 3.7. In these versions, any time you insert a new key/value pair, the order you thought you had goes away and is replaced by a new (more or less random) order. Therefore, asking for the index in a dictionary doesn't make sense.

As of Python 3.6, for the CPython implementation of Python, dictionaries remember the order of items inserted. As of Python 3.7+ dictionaries are ordered by order of insertion.

Also note that what you're asking is probably not what you actually want. There is no guarantee that the inverse mapping in a dictionary is unique. In other words, you could have the following dictionary:

d={'i':1, 'j':1}

In that case, it is impossible to know whether you want i or j and in fact no answer here will be able to tell you which ('i' or 'j') will be picked (again, because dictionaries are unordered). What do you want to happen in that situation? You could get a list of acceptable keys ... but I'm guessing your fundamental understanding of dictionaries isn't quite right.

C# - Multiple generic types in one list

Following leppie's answer, why not make MetaData an interface:

public interface IMetaData { }

public class Metadata<DataType> : IMetaData where DataType : struct
    private DataType mDataType;

Invalid length for a Base-64 char array

    string stringToDecrypt = CypherText.Replace(" ", "+");
    int len = stringToDecrypt.Length;
    byte[] inputByteArray = Convert.FromBase64String(stringToDecrypt); 

@Autowired - No qualifying bean of type found for dependency

Spent much of my time with this! My bad! Later found that the class on which I declared the annotation Service or Component was of type abstract. Had enabled debug logs on Springframework but no hint was received. Please check if the class if of abstract type. If then, the basic rule applied, can't instantiate an abstract class.

High Quality Image Scaling Library

I have some improve for Doctor Jones's answer.

It works for who wanted to how to proportional resize the image. It tested and worked for me.

The methods of class I added:

public static System.Drawing.Bitmap ResizeImage(System.Drawing.Image image, Size size)
    return ResizeImage(image, size.Width, size.Height);

public static Size GetProportionedSize(Image image, int maxWidth, int maxHeight, bool withProportion)
    if (withProportion)
        double sourceWidth = image.Width;
        double sourceHeight = image.Height;

        if (sourceWidth < maxWidth && sourceHeight < maxHeight)
            maxWidth = (int)sourceWidth;
            maxHeight = (int)sourceHeight;
            double aspect = sourceHeight / sourceWidth;

            if (sourceWidth < sourceHeight)
                maxWidth = Convert.ToInt32(Math.Round((maxHeight / aspect), 0));
                maxHeight = Convert.ToInt32(Math.Round((maxWidth * aspect), 0));

    return new Size(maxWidth, maxHeight);

and new available using according to this codes:

using (var resized = ImageUtilities.ResizeImage(image, ImageUtilities.GetProportionedSize(image, 50, 100)))
    ImageUtilities.SaveJpeg(@"C:\myimage.jpeg", resized, 90);

How to split one text file into multiple *.txt files?

Try something like this:

awk -vc=1 'NR%1000000==0{++c}{print $0 > c".txt"}' Datafile.txt

for filename in *.txt; do mv "$filename" "Prefix_$filename"; done;

Android Firebase, simply get one child object's data

You don't directly read a value. You can set it with .setValue(), but there is no .getValue() on the reference object.

You have to use a listener. If you just want to read the value once, you use ref.addListenerForSingleValueEvent().


Firebase ref = new Firebase("YOUR-URL-HERE/PATH/TO/YOUR/STUFF");
ref.addListenerForSingleValueEvent(new ValueEventListener() {
   public void onDataChange(DataSnapshot dataSnapshot) {
       String value = (String) dataSnapshot.getValue();

       // do your stuff here with value


   public void onCancelled(FirebaseError firebaseError) {



initializing a boolean array in java

The main difference is that Boolean is an object and boolean is an primitive.

  • Object default value is null;
  • boolean default value is false;

Why is the parent div height zero when it has floated children

I'm not sure this is a right way but I solved it by adding display: inline-block; to the wrapper div.

    display: inline-block;
    /*border: 1px black solid;*/
    width: 75%;
    min-width: 800px;

    text-align: justify; 
    float: right; 
    width: 90%;

    text-align: justify; 
    float: left; 
    width: 10%;

How to use ClassLoader.getResources() correctly?

This is the simplest wat to get the File object to which a certain URL object is pointing at:

File file=new File(url.toURI());

Now, for your concrete questions:

  • finding all resources in the META-INF "directory":

You can indeed get the File object pointing to this URL

Enumeration<URL> en=getClass().getClassLoader().getResources("META-INF");
if (en.hasMoreElements()) {
    URL metaInf=en.nextElement();
    File fileMetaInf=new File(metaInf.toURI());

    File[] files=fileMetaInf.listFiles();
    String[] filenames=fileMetaInf.list();
  • all resources named bla.xml (recursivly)

In this case, you'll have to do some custom code. Here is a dummy example:

final List<File> foundFiles=new ArrayList<File>();

FileFilter customFilter=new FileFilter() {
    public boolean accept(File pathname) {

        if(pathname.isDirectory()) {
        if(pathname.getName().endsWith("bla.xml")) {
            return true;
        return false;

//rootFolder here represents a File Object pointing the root forlder of your search 

When the code is run, you'll get all the found ocurrences at the foundFiles List.

How to execute a remote command over ssh with arguments?

This is an example that works on the AWS Cloud. The scenario is that some machine that booted from autoscaling needs to perform some action on another server, passing the newly spawned instance DNS via SSH

# Get the public DNS of the current machine (AWS specific)
MY_DNS=`curl -s`

ssh \
    -o StrictHostKeyChecking=no \
    -i ~/.ssh/id_rsa \
    [email protected] \
<< EOF
cd ~/
echo "Hey I was just SSHed by ${MY_DNS}"
# Newline is important before final EOF!


Access a URL and read Data with R

Beside of read.csv(url("...")) you also can use read.table("http://...").


> sample <- read.table("")
> sample
                V1   V2   V3   V4 V5
1        Rochester 19.0 20.6 15.0  E
2         Syracuse 17.0 15.6 20.2  E
43         Atlanta  4.2 70.6 32.6  S

Returning string from C function

You are allocating your string on the stack, and then returning a pointer to it. When your function returns, any stack allocations become invalid; the pointer now points to a region on the stack that is likely to be overwritten the next time a function is called.

In order to do what you're trying to do, you need to do one of the following:

  1. Allocate memory on the heap using malloc or similar, then return that pointer. The caller will then need to call free when it is done with the memory.
  2. Allocate the string on the stack in the calling function (the one that will be using the string), and pass a pointer in to the function to put the string into. During the entire call to the calling function, data on its stack is valid; its only once you return that stack allocated space becomes used by something else.

C# : Out of Memory exception

OutOfMemoryException (on 32-bit machines) is just as often about Fragmentation as actual hard limits on memory - you'll find lots about this, but here's my first google hit briefly discussing it: (@Anthony Pegram is referring to the same problem in his comment above).

That said, there is one other possibility that comes to mind for your code above: As you're using the "IEnumerable" constructor to the List, you may not giving the object any hints as to the size of the collection you're passing to the List constructor. If the object you are passing is is not a collection (does not implement the ICollection interface), then behind-the-scenes the List implementation is going to need to grow several (or many) times, each time leaving behind a too-small array that needs to be garbage collected. The garbage collector probably won't get to those discarded arrays fast enough, and you'll get your error.

The simplest fix for this would be to use the List(int capacity) constructor to tell the framework what backing array size to allocate (even if you're estimating and just guessing "50000" for example), and then use the AddRange(IEnumerable collection) method to actually populate your list.

So, simplest "Fix" if I'm right: replace

List<Vehicle> vList = new List<Vehicle>(selectedVehicles);


List<Vehicle> vList = new List<Vehicle>(50000);  

All the other comments and answers still apply in terms of overall design decisions - but this might be a quick fix.

Note (as @Alex commented below), this is only an issue if selectedVehicles is not an ICollection.

FlutterError: Unable to load asset

  1. you should start image path with assets word:

image: AssetImage('assets/images/pizza0.png')

  1. you must add each sub folder in a new line in pubspec.yaml

Cannot load properties file from resources directory

Right click the Resources folder and select Build Path > Add to Build Path

List and kill at jobs on UNIX

at -l to list jobs, which gives return like this:

age2%> at -l
11      2014-10-21 10:11 a hoppent
10      2014-10-19 13:28 a hoppent

atrm 10 kills job 10

Or so my sysadmin told me, and it

How to grep recursively, but only in files with certain extensions?

ag (the silver searcher) has pretty simple syntax for this

       -G --file-search-regex PATTERN
          Only search files whose names match PATTERN.


ag -G *.h -G *.cpp CP_Image <path>

Lodash .clone and .cloneDeep behaviors

Thanks to Gruff Bunny and Louis' comments, I found the source of the issue.

As I use Backbone.js too, I loaded a special build of Lodash compatible with Backbone and Underscore that disables some features. In this example:

var clone = _.clone(data, true);

data[1].values.d = 'x';

I just replaced the Underscore build with the Normal build in my Backbone application and the application is still working. So I can now use the Lodash .clone with the expected behaviour.

Edit 2018: the Underscore build doesn't seem to exist anymore. If you are reading this in 2018, you could be interested by this documentation (Backbone and Lodash).

Neither user 10102 nor current process has android.permission.READ_PHONE_STATE

I was experiencing this problem on Samsung devices (fine on others). like zyamys suggested in his/her comment, I added the manifest.permission line but in addition to rather than instead of the original line, so:

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

I'm targeting API 22, so don't need to explicitly ask for permissions.

Processing $http response in service

Here is a Plunk that does what you want:

The idea is that you work with promises directly and their "then" functions to manipulate and access the asynchronously returned responses.

app.factory('myService', function($http) {
  var myService = {
    async: function() {
      // $http returns a promise, which has a then function, which also returns a promise
      var promise = $http.get('test.json').then(function (response) {
        // The then function here is an opportunity to modify the response
        // The return value gets picked up by the then in the controller.
      // Return the promise to the controller
      return promise;
  return myService;

app.controller('MainCtrl', function( myService,$scope) {
  // Call the async method and then do stuff with what is returned inside our own then function
  myService.async().then(function(d) {
    $ = d;

Here is a slightly more complicated version that caches the request so you only make it first time (

app.factory('myService', function($http) {
  var promise;
  var myService = {
    async: function() {
      if ( !promise ) {
        // $http returns a promise, which has a then function, which also returns a promise
        promise = $http.get('test.json').then(function (response) {
          // The then function here is an opportunity to modify the response
          // The return value gets picked up by the then in the controller.
      // Return the promise to the controller
      return promise;
  return myService;

app.controller('MainCtrl', function( myService,$scope) {
  $scope.clearData = function() {
    $ = {};
  $scope.getData = function() {
    // Call the async method and then do stuff with what is returned inside our own then function
    myService.async().then(function(d) {
      $ = d;

Flutter - The method was called on null

You should declare your method first in void initState(), so when the first time pages has been loaded, it will init your method first, hope it can help

Pip install - Python 2.7 - Windows 7

For New versions

Older versions of python may not have pip installed and get-pip will throw errors. Please update your python (2.7.15 as of Aug 12, 2018).

All current versions have an option to install pip and add it to the path.


  1. Open Powershell as admin. (win+x then a)
  2. Type python -m pip install <package>.

If python is not in PATH, it'll throw an error saying unrecognized cmd. To fix, simply add it to the path as mentioned below.

[OLD Answer]

Python 2.7 must be having pip pre-installed.

Try installing your package by:

  1. Open cmd as admin. (win+x then a)
  2. Go to scripts folder: C:\Python27\Scripts
  3. Type pip install "package name".

Note: Else reinstall python:

Also note: You must be in C:\Python27\Scripts in order to use pip command, Else add it to your path by typing: [Environment]::SetEnvironmentVariable("Path","$env:Path;C:\Python27\;C:\Python27\Scripts\", "User")

Entity Framework select distinct name

Entity-Framework Select Distinct Name:

Suppose if you are want every first data of particular column of each group ;

 var data = objDb.TableName.GroupBy(dt => dt.ColumnName).Select(dt => new { dt.Key }).ToList();

            foreach (var item in data)
                var data2= objDb.TableName.Where(dt=>dt.ColumnName==item.Key).Select(dt=>new {dt.SelectYourColumn}).Distinct().FirstOrDefault();



An attempt was made to access a socket in a way forbidden by its access permissions

As per, having internet connection sharing enabled for my ethernet adapter ended up causing this problem for me. Disabling the sharing fixed the problem

How do I make a transparent border with CSS?

Use transparent property

border-color : transparent;

How does internationalization work in JavaScript?

Some of it is native, the rest is available through libraries.

For example Datejs is a good international date library.

For the rest, it's just about language translation, and JavaScript is natively Unicode compatible (as well as all major browsers).

Create array of all integers between two numbers, inclusive, in Javascript/jQuery

var values = $(this).val().split('-'),
    i = +values[0],
    l = +values[1],
    range = [];

while (i < l) {
    range[range.length] = i;
    i += 1;

range[range.length] = l;

There's probably a DRYer way to do the loop, but that's the basic idea.

Rails raw SQL example

I know this is old... But I was having the same problem today and found a solution:


If you want to instantiate the results:

  SELECT * FROM clients
  INNER JOIN orders ON = orders.client_id
  ORDER BY clients.created_at desc
# => [<Client id: 1, first_name: "Lucas" >, <Client id: 2, first_name: "Jan">...]


If you just want a hash of values:

Client.connection.select_all("SELECT first_name, created_at FROM clients
   WHERE id = '1'").to_hash
# => [
  {"first_name"=>"Rafael", "created_at"=>"2012-11-10 23:23:45.281189"},
  {"first_name"=>"Eileen", "created_at"=>"2013-12-09 11:22:35.221282"}

Result object:

select_all returns a result object. You can do magic things with it.

result = Post.connection.select_all('SELECT id, title, body FROM posts')
# Get the column names of the result:
# => ["id", "title", "body"]

# Get the record values of the result:
# => [[1, "title_1", "body_1"],
      [2, "title_2", "body_2"],

# Get an array of hashes representing the result (column => value):
# => [{"id" => 1, "title" => "title_1", "body" => "body_1"},
      {"id" => 2, "title" => "title_2", "body" => "body_2"},

# ActiveRecord::Result also includes Enumerable.
result.each do |row|
  puts row['title'] + " " + row['body']


  1. ActiveRecord - Findinig by SQL.
  2. Ruby on Rails - Active Record Result .

Why use @Scripts.Render("~/bundles/jquery")

You can also use:

@Scripts.RenderFormat("<script type=\"text/javascript\" src=\"{0}\"></script>", "~/bundles/mybundle")

To specify the format of your output in a scenario where you need to use Charset, Type, etc.

calling a java servlet from javascript

The code here will use AJAX to print text to an HTML5 document dynamically (Ajax code is similar to book Internet & WWW (Deitel)):

Javascript code:

var asyncRequest;    
function start(){
        asyncRequest = new XMLHttpRequest();
        asyncRequest.addEventListener("readystatechange", stateChange, false);'GET', '/Test', true);    //   /Test is url to Servlet!
    alert("Request failed");

function stateChange(){
if(asyncRequest.readyState == 4 && asyncRequest.status == 200)
    var text = document.getElementById("text");         //  text is an id of a 
    text.innerHTML = asyncRequest.responseText;         //  div in HTML document

window.addEventListener("load", start(), false);

Servlet java code:

public class Test extends HttpServlet{
public void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws IOException{
        resp.getWriter().println("Servlet wrote this! (");

HTML document

 <div id = "text"></div>


I wrote answer above when I was new with web programming. I let it stand, but the javascript part should definitely be in jQuery instead, it is 10 times easier than raw javascript.

How to call a stored procedure from Java and JPA

  1. For a simple stored procedure that using IN/OUT parameters like this

    CREATE OR REPLACE PROCEDURE count_comments (  
       postId IN NUMBER,  
       commentCount OUT NUMBER )  
        SELECT COUNT(*) INTO commentCount  
        FROM post_comment  
        WHERE post_id = postId; 

    You can call it from JPA as follows:

    StoredProcedureQuery query = entityManager
        .registerStoredProcedureParameter(1, Long.class, 
        .registerStoredProcedureParameter(2, Long.class, 
        .setParameter(1, 1L);
    Long commentCount = (Long) query.getOutputParameterValue(2);
  2. For a stored procedure which uses a SYS_REFCURSOR OUT parameter:

    CREATE OR REPLACE PROCEDURE post_comments ( 
       postId IN NUMBER, 
       postComments OUT SYS_REFCURSOR ) 
        OPEN postComments FOR
        SELECT *
        FROM post_comment 
        WHERE post_id = postId; 

    You can call it as follows:

    StoredProcedureQuery query = entityManager
        .registerStoredProcedureParameter(1, Long.class, 
        .registerStoredProcedureParameter(2, Class.class, 
        .setParameter(1, 1L);
    List<Object[]> postComments = query.getResultList();
  3. For a SQL function that looks as follows:

    CREATE OR REPLACE FUNCTION fn_count_comments ( 
        postId IN NUMBER ) 
        commentCount NUMBER; 
        SELECT COUNT(*) INTO commentCount 
        FROM post_comment 
        WHERE post_id = postId; 
        RETURN( commentCount ); 

    You can call it like this:

    BigDecimal commentCount = (BigDecimal) entityManager
        "SELECT fn_count_comments(:postId) FROM DUAL"
    .setParameter("postId", 1L)

    At least when using Hibernate 4.x and 5.x because the JPA StoredProcedureQuery does not work for SQL FUNCTIONS.

For more details about how to call stored procedures and functions when using JPA and Hibernate, check out the following articles

How to Round to the nearest whole number in C#

this will round up to the nearest 5 or not change if it already is divisible by 5

public static double R(double x)
    // markup to nearest 5
    return (((int)(x / 5)) * 5) + ((x % 5) > 0 ? 5 : 0);

Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }

I messed around with this for awhile. Here was my scenario:

I have two types, metrics1 and metrics2, each with different properties:

type metrics1 = {
    a: number;
    b: number;
    c: number;

type metrics2 = {
    d: number;
    e: number;
    f: number;

At a point in my code, I created an object that is the intersection of these two types because this object will hold all of their properties:

const myMetrics: metrics1 & metrics2 = {
    a: 10,
    b: 20,
    c: 30,
    d: 40,
    e: 50,
    f: 60

Now, I need to dynamically reference the properties of that object. This is where we run into index signature errors. Part of the issue can be broken down based on compile-time checking and runtime checking. If I reference the object using a const, I will not see that error because TypeScript can check if the property exists during compile time:

const myKey = 'a';
console.log(myMetrics[myKey]); // No issues, TypeScript has validated it exists

If, however, I am using a dynamic variable (e.g. let), then TypeScript will not be able to check if the property exists during compile time, and will require additional help during runtime. That is where the following typeguard comes in:

function isValidMetric(prop: string, obj: metrics1 & metrics2): prop is keyof (metrics1 & metrics2) {
    return prop in obj;

This reads as,"If the obj has the property prop then let TypeScript know that prop exists in the intersection of metrics1 & metrics2." Note: make sure you surround metrics1 & metrics2 in parentheses after keyof as shown above, or else you will end up with an intersection between the keys of metrics1 and the type of metrics2 (not its keys).

Now, I can use the typeguard and safely access my object during runtime:

let myKey:string = '';
myKey = 'a';
if (isValidMetric(myKey, myMetrics)) {

What GRANT USAGE ON SCHEMA exactly do?

GRANTs on different objects are separate. GRANTing on a database doesn't GRANT rights to the schema within. Similiarly, GRANTing on a schema doesn't grant rights on the tables within.

If you have rights to SELECT from a table, but not the right to see it in the schema that contains it then you can't access the table.

The rights tests are done in order:

Do you have `USAGE` on the schema? 
    No:  Reject access. 
    Yes: Do you also have the appropriate rights on the table? 
        No:  Reject access. 
        Yes: Check column privileges.

Your confusion may arise from the fact that the public schema has a default GRANT of all rights to the role public, which every user/group is a member of. So everyone already has usage on that schema.

The phrase:

(assuming that the objects' own privilege requirements are also met)

Is saying that you must have USAGE on a schema to use objects within it, but having USAGE on a schema is not by itself sufficient to use the objects within the schema, you must also have rights on the objects themselves.

It's like a directory tree. If you create a directory somedir with file somefile within it then set it so that only your own user can access the directory or the file (mode rwx------ on the dir, mode rw------- on the file) then nobody else can list the directory to see that the file exists.

If you were to grant world-read rights on the file (mode rw-r--r--) but not change the directory permissions it'd make no difference. Nobody could see the file in order to read it, because they don't have the rights to list the directory.

If you instead set rwx-r-xr-x on the directory, setting it so people can list and traverse the directory but not changing the file permissions, people could list the file but could not read it because they'd have no access to the file.

You need to set both permissions for people to actually be able to view the file.

Same thing in Pg. You need both schema USAGE rights and object rights to perform an action on an object, like SELECT from a table.

(The analogy falls down a bit in that PostgreSQL doesn't have row-level security yet, so the user can still "see" that the table exists in the schema by SELECTing from pg_class directly. They can't interact with it in any way, though, so it's just the "list" part that isn't quite the same.)

Custom Date/Time formatting in SQL Server

I'm adding this answer (for myself) as relevant to custom formatting.

For underscore yyyy_MM_dd

REPLACE(SUBSTRING(CONVERT(VARCHAR, @dt, 120), 1, 10),'-','_')

Are arrays passed by value or passed by reference in Java?

Kind of a trick realty... Even references are passed by value in Java, hence a change to the reference itself being scoped at the called function level. The compiler and/or JVM will often turn a value type into a reference.

What are the different types of keys in RDBMS?

From here and here: (after i googled your title)

  • Alternate key - An alternate key is any candidate key which is not selected to be the primary key
  • Candidate key - A candidate key is a field or combination of fields that can act as a primary key field for that table to uniquely identify each record in that table.
  • Compound key - compound key (also called a composite key or concatenated key) is a key that consists of 2 or more attributes.
  • Primary key - a primary key is a value that can be used to identify a unique row in a table. Attributes are associated with it. Examples of primary keys are Social Security numbers (associated to a specific person) or ISBNs (associated to a specific book). In the relational model of data, a primary key is a candidate key chosen as the main method of uniquely identifying a tuple in a relation.
  • Superkey - A superkey is defined in the relational model as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. Equivalently a superkey can also be defined as a set of attributes of a relvar upon which all attributes of the relvar are functionally dependent.
  • Foreign key - a foreign key (FK) is a field or group of fields in a database record that points to a key field or group of fields forming a key of another database record in some (usually different) table. Usually a foreign key in one table refers to the primary key (PK) of another table. This way references can be made to link information together and it is an essential part of database normalization

Push local Git repo to new remote including all branches and tags

I found that none of these seemed to work properly for me. Feel free to flame this to death but for some reason couldn't get the other options to work properly.

Expected result was a repo "cloned" to another remote (ie from Github to another provider):

  • All branches are created on new remote
  • All branch history are created on new remote
    • (this was missed on every solution I tried)
  • All tags are created on new remote
  • Source moves over (a given)
  • Non-destructive (giving pause to the --mirror option)

The major issue I was seeing was either all remote branches didn't get recreated in the new remote. If a command did, the new remote did not have the branch history (ie doing a git checkout branch; git log wouldn't show the expected branch commits).

I noticed git checkout -b branchname is NOT the same as git checkout branchname (the latter being what I needed). I notice git checkout --track branchname didn't appear to pull the branch history.

My Solution (powershell based):

Function Git-FetchRemoteBranches {
$originalbranch = (git symbolic-ref HEAD).split("/")[-1]

Foreach ($entry in (git branch -r)) {

If ($entry -like "*->*") {
  $branch = $entry.split("->")[2].split("/")[1]
  else {$branch = $entry.split("/")[1]}

Write-Host "--Trying git checkout " -NoNewline
Write-Host "$branch" -Foreground Yellow

git checkout $branch

Remove-Variable branch -Force


#Switch back to original branch, if needed
If ( ((git symbolic-ref HEAD).split("/")[-1]) -ne $originalbranch) {
"Switching back to original branch"
git checkout $originalbranch
Remove-Variable originalbranch -Force

git clone http://remoterepo
cd remoterepo
git remote add newremote
git push newremote --all
git push newremote --tags #Not sure if neeeded, but added for good measure

multiprocessing: How do I share a dict among multiple processes?

In addition to @senderle's here, some might also be wondering how to use the functionality of multiprocessing.Pool.

The nice thing is that there is a .Pool() method to the manager instance that mimics all the familiar API of the top-level multiprocessing.

from itertools import repeat
import multiprocessing as mp
import os
import pprint

def f(d: dict) -> None:
    pid = os.getpid()
    d[pid] = "Hi, I was written by process %d" % pid

if __name__ == '__main__':
    with mp.Manager() as manager:
        d = manager.dict()
        with manager.Pool() as pool:
  , repeat(d, 10))
        # `d` is a DictProxy object that can be converted to dict


$ python3 
{22562: 'Hi, I was written by process 22562',
 22563: 'Hi, I was written by process 22563',
 22564: 'Hi, I was written by process 22564',
 22565: 'Hi, I was written by process 22565',
 22566: 'Hi, I was written by process 22566',
 22567: 'Hi, I was written by process 22567',
 22568: 'Hi, I was written by process 22568',
 22569: 'Hi, I was written by process 22569',
 22570: 'Hi, I was written by process 22570',
 22571: 'Hi, I was written by process 22571'}

This is a slightly different example where each process just logs its process ID to the global DictProxy object d.

Check whether a path is valid

There are plenty of good solutions in here, but as none of then check if the path is rooted in an existing drive here's another one:

private bool IsValidPath(string path)
    // Check if the path is rooted in a driver
    if (path.Length < 3) return false;
    Regex driveCheck = new Regex(@"^[a-zA-Z]:\\$");
    if (!driveCheck.IsMatch(path.Substring(0, 3))) return false;

    // Check if such driver exists
    IEnumerable<string> allMachineDrivers = DriveInfo.GetDrives().Select(drive => drive.Name);
    if (!allMachineDrivers.Contains(path.Substring(0, 3))) return false;

    // Check if the rest of the path is valid
    string InvalidFileNameChars = new string(Path.GetInvalidPathChars());
    InvalidFileNameChars += @":/?*" + "\"";
    Regex containsABadCharacter = new Regex("[" + Regex.Escape(InvalidFileNameChars) + "]");
    if (containsABadCharacter.IsMatch(path.Substring(3, path.Length - 3)))
        return false;
    if (path[path.Length - 1] == '.') return false;

    return true;

This solution does not take relative paths into account.

How to add key,value pair to dictionary?

To insert/append to a dictionary

{"0": {"travelkey":"value", "travelkey2":"value"},"1":{"travelkey":"value","travelkey2":"value"}} 

travel_dict={} #initialize dicitionary 
travel_key=0 #initialize counter

if travel_key not in travel_dict: #for avoiding keyerror 0
    travel_dict[travel_key] = {}
travel_temp={val['key']:'no flexible'}  
travel_dict[travel_key].update(travel_temp) # Updates if val['key'] exists, else adds val['key']

Where can I find php.ini?

Best way to find this is: create a php file and add the following code:

<?php phpinfo(); ?>

and open it in browser, it will show the file which is actually being read!

Updates by OP:

  1. The previously accepted answer is likely to be faster and more convenient for you, but it is not always correct. See comments on that answer.
  2. Please also note the more convenient alternative <?php echo php_ini_loaded_file(); ?> mentioned in this answer.

Add space between HTML elements only using CSS

add these rules to the parent container:

display: grid
grid-auto-flow: column
grid-column-gap: 10px

Good reference:

Browser compatibility: