Bootstrap 4 Dropdown Menu not working?

Edit: In case anyone else is having this problem, I believe the solution for OP was that he had not imported popper.js.

Check that jQuery and all the relevant Bootstrap components are there. Also check the console and make sure there are no errors.

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<!DOCTYPE html>
<html lang="en">
<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS -->
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="anonymous">
</head>
<body>
  <nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#">Navbar</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNavDropdown">
      <ul class="navbar-nav">
        <li class="nav-item active">
          <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Features</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Pricing</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="http://example.com" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Dropdown link
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
        </li>
      </ul>
    </div>
  </nav>

  <!-- Optional JavaScript -->
  <!-- jQuery first, then Popper.js, then Bootstrap JS -->
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
<-- Always remember to call the above files first before calling the bootstrap.min.js file -->
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
</body>
</html>

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Fatal error: Call to a member function fetch_assoc() on a non-object

Most likely your query failed, and the query call returned a boolean FALSE (or an error object of some sort), which you then try to use as if was a resultset object, causing the error. Try something like var_dump($result) to see what you really got.

Check for errors after EVERY database query call. Even if the query itself is syntactically valid, there's far too many reasons for it to fail anyways - checking for errors every time will save you a lot of grief at some point.

Correct modification of state arrays in React.js

This code work for me:

fetch('http://localhost:8080')
  .then(response => response.json())
  .then(json => {
    this.setState({mystate: this.state.mystate.push.apply(this.state.mystate, json)})
  })

How do you display code snippets in MS Word preserving format and syntax highlighting?

Just paste your code in MS Words, select it -> then right click -> Numbering. In this case MS Word will interpret your code as marker/numbered list.

Here is the screens:

Screen1.

Screen2.

Git: Remove committed file after push

You can revert only one file to a specified revision.

First you can check on which commits the file was changed.

git log path/to/file.txt

Then you can checkout the file with the revision number.

git checkout 3cdc61015724f9965575ba954c8cd4232c8b42e4 /path/to/file.txt

After that you can commit and push it again.

Why is IoC / DI not common in Python?

I don't actually think that DI/IoC are that uncommon in Python. What is uncommon, however, are DI/IoC frameworks/containers.

Think about it: what does a DI container do? It allows you to

wire together independent components into a complete application ...
... at runtime.

We have names for "wiring together" and "at runtime":

scripting
dynamic

So, a DI container is nothing but an interpreter for a dynamic scripting language. Actually, let me rephrase that: a typical Java/.NET DI container is nothing but a crappy interpreter for a really bad dynamic scripting language with butt-ugly, sometimes XML-based, syntax.

When you program in Python, why would you want to use an ugly, bad scripting language when you have a beautiful, brilliant scripting language at your disposal? Actually, that's a more general question: when you program in pretty much any language, why would you want to use an ugly, bad scripting language when you have Jython and IronPython at your disposal?

So, to recap: the practice of DI/IoC is just as important in Python as it is in Java, for exactly the same reasons. The implementation of DI/IoC however, is built into the language and often so lightweight that it completely vanishes.

(Here's a brief aside for an analogy: in assembly, a subroutine call is a pretty major deal - you have to save your local variables and registers to memory, save your return address somewhere, change the instruction pointer to the subroutine you are calling, arrange for it to somehow jump back into your subroutine when it is finished, put the arguments somewhere where the callee can find them, and so on. IOW: in assembly, "subroutine call" is a Design Pattern, and before there were languages like Fortran which had subroutine calls built in, people were building their own "subroutine frameworks". Would you say that subroutine calls are "uncommon" in Python, just because you don't use subroutine frameworks?)

BTW: for an example of what it looks like to take DI to its logical conclusion, take a look at Gilad Bracha's Newspeak Programming Language and his writings on the subject:

Instantiating a generic type

You basically have two choices:

1.Require an instance:

public Navigation(T t) {     this("", "", t); }

2.Require a class instance:

public Navigation(Class<T> c) {     this("", "", c.newInstance()); }

You could use a factory pattern, but ultimately you'll face this same issue, but just push it elsewhere in the code.

Could not commit JPA transaction: Transaction marked as rollbackOnly

As explained @Yaroslav Stavnichiy if a service is marked as transactional spring tries to handle transaction itself. If any exception occurs then a rollback operation performed. If in your scenario ServiceUser.method() is not performing any transactional operation you can use @Transactional.TxType annotation. 'NEVER' option is used to manage that method outside transactional context.

Transactional.TxType reference doc is here.

Running bash script from within python

Adding an answer because I was directed here after asking how to run a bash script from python. You receive an error OSError: [Errno 2] file not found if your script takes in parameters. Lets say for instance your script took in a sleep time parameter: subprocess.call("sleep.sh 10") will not work, you must pass it as an array: subprocess.call(["sleep.sh", 10])

Execute php file from another php

exec('wget http://<url to the php script>') worked for me.

It enable me to integrate two php files that were designed as web pages and run them as code to do work without affecting the calling page

How to make parent wait for all child processes to finish?

pid_t child_pid, wpid;
int status = 0;

//Father code (before child processes start)

for (int id=0; id<n; id++) {
    if ((child_pid = fork()) == 0) {
        //child code
        exit(0);
    }
}

while ((wpid = wait(&status)) > 0); // this way, the father waits for all the child processes 

//Father code (After all child processes end)

wait waits for a child process to terminate, and returns that child process's pid. On error (eg when there are no child processes), -1 is returned. So, basically, the code keeps waiting for child processes to finish, until the waiting errors out, and then you know they are all finished.

Cannot load 64-bit SWT libraries on 32-bit JVM ( replacing SWT file )

Thanks a lot guys!

I overlooked my ECLIPSE VERSION it was 64Bit and 3.6

I had to make sure it's 32Bit Eclipse, 32 Bit JVM so i uninstalled Eclipse & all JVM for clean start. Installed 32Bit JDK1.6 from here and 32Bit Eclipse from here

How to easily import multiple sql files into a MySQL database?

The easiest solution is to copy/paste every sql files in one.

You can't add some sql markup for file importation (the imported files will be in your computer, not in the server, and I don't think MySQL manage some import markup for external sql files).

Delete all nodes and relationships in neo4j 1.8

It will do the trick..

Match (n)-[r]-()
Delete n,r;

no operator "<<" matches these operands

It looks like you're comparing strings incorrectly. To compare a string to another, use the std::string::compare function.

Example

     while ((wrong < MAX_WRONG) && (soFar.compare(THE_WORD) != 0))

How do I hide the bullets on my list for the sidebar?

its on you ul in the file http://ratest4.com/wp-content/themes/HarnettArts-BP-2010/style.css on line 252

add this to your css

ul{
     list-style:none;
}

Difference between Node object and Element object?

Best source of information for all of your DOM woes

http://www.w3.org/TR/dom/#nodes

"Objects implementing the Document, DocumentFragment, DocumentType, Element, Text, ProcessingInstruction, or Comment interface (simply called nodes) participate in a tree."

http://www.w3.org/TR/dom/#element

"Element nodes are simply known as elements."

How can I trigger the click event of another element in ng-click using angularjs?

I took the answer posted by Osiloke (Which was the easiest and most complete imho) and I added a change event listener. Works great! Thanks Osiloke. See below if you are interested:

HTML:

  <div file-button>
        <button class='btn btn-success btn-large'>Select your awesome file</button>
   </div>

Directive:

app.directive('fileButton', function() {
  return {
    link: function(scope, element, attributes) {

      var el = angular.element(element)
      var button = el.children()[0]

      el.css({
        position: 'relative',
        overflow: 'hidden',
        width: button.offsetWidth,
        height: button.offsetHeight
      })

      var fileInput = angular.element('<input id='+scope.file_button_id+' type="file" multiple />')
      fileInput.css({
        position: 'absolute',
        top: 0,
        left: 0,
        'z-index': '2',
        width: '100%',
        height: '100%',
        opacity: '0',
        cursor: 'pointer'
      })

      el.append(fileInput)
      document.getElementById(scope.file_button_id).addEventListener('change', scope.file_button_open, false); 
    }
  }
});

Controller:

$scope.file_button_id = "wo_files";    
$scope.file_button_open = function() 
{
  alert("Files are ready!");
}

Does a "Find in project..." feature exist in Eclipse IDE?

yes, but you need to open the global search panel. to do so, press the binoculars icon on the top right corner of the IDE.

you can even filter searches by function identifiers, method scopes an etc...

Choose File Search for plain text search in workspace/selected projects
For specific expression searches, choose the relevant tab (such as Java Search which allows to search for specific identifiers)

How can I use xargs to copy files that have spaces and quotes in their names?

For me, I was trying to do something a little different. I wanted to copy my .txt files into my tmp folder. The .txt filenames contain spaces and apostrophe characters. This worked on my Mac.

$ find . -type f -name '*.txt' | sed 's/'"'"'/\'"'"'/g' | sed 's/.*/"&"/'  | xargs -I{} cp -v {} ./tmp/

Scanner vs. StringTokenizer vs. String.Split

String.split seems to be much slower than StringTokenizer. The only advantage with split is that you get an array of the tokens. Also you can use any regular expressions in split. org.apache.commons.lang.StringUtils has a split method which works much more faster than any of two viz. StringTokenizer or String.split. But the CPU utilization for all the three is nearly the same. So we also need a method which is less CPU intensive, which I am still not able to find.

How do I push to GitHub under a different username?

This worked for me, it will prompt for username and password

git config --local credential.helper ""
git push origin master

Using "-Filter" with a variable

Try this:

$NameRegex = "chalmw-dm"  
$NameR = "$($NameRegex)*"
Get-ADComputer -Filter {name -like $NameR -and Enabled -eq $True}

How to Disable GUI Button in Java

Is there a reason you are not doing something like:

public class IPGUI extends JFrame implements ActionListener 
{
    private static JPanel contentPane;

    private JButton btnConvertDocuments;
    private JButton btnExtractImages;
    private JButton btnParseRIDValues;
    private JButton btnParseImageInfo;

    public IPGUI() 
    {
        ...

        btnConvertDocuments = new JButton("1. Convert Documents");

        ...

        btnExtractImages = new JButton("2. Extract Images");

        ...

        //etc.
    }

    public void actionPerformed(ActionEvent event) 
    {
        String command = event.getActionCommand();

        if (command.equals("w"))
        {
            FileConverter fc = new FileConverter();
            btnConvertDocuments.setEnabled( false );
        }
        else if (command.equals("x"))
        {
            ImageExtractor ie = new ImageExtractor();
            btnExtractImages.setEnabled( false );
        }

        // etc.
    }    
}

The if statement with your disabling code won't get called unless you keep calling the IPGUI constructor.

How to grep Git commit diffs or contents for a certain word?

vim-fugitive is versatile for that kind of examining in Vim.

Use :Ggrep to do that. For more information you can install vim-fugitive and look up the turorial by :help Grep. And this episode: exploring-the-history-of-a-git-repository will guide you to do all that.

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

json loads -> returns an object from a string representing a json object.

json dumps -> returns a string representing a json object from an object.

load and dump -> read/write from/to file instead of string

AngularJS : Custom filters and ng-repeat

One of the easiest ways to fix this is to use the $ which is the search all.

Here is a plunker that shows it working. I have changed the checkboxes to radio ( because I thought they should be complementary )..

http://plnkr.co/edit/dHzvm6hR5P8G4wPuTxoi?p=preview

If you want a very specific way of doing this ( instead of doing a generic search ) you need work with functions in the search.

The documentation is here

http://docs.angularjs.org/api/ng.filter:filter

How to stop the task scheduled in java.util.Timer class

timer.cancel();  //Terminates this timer,discarding any currently scheduled tasks.

timer.purge();   // Removes all cancelled tasks from this timer's task queue.

Spring Boot - Loading Initial Data

You can use something like this:

@SpringBootApplication  
public class Application {

@Autowired
private UserRepository userRepository;

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

@Bean
InitializingBean sendDatabase() {
    return () -> {
        userRepository.save(new User("John"));
        userRepository.save(new User("Rambo"));
      };
   }
}

yum error "Cannot retrieve metalink for repository: epel. Please verify its path and try again" updating ContextBroker

Check if you access internet through a proxy, and then your add internet proxy address to yum configuration.

add

proxy=http://ip:port

to /etc/yum.conf

Func vs. Action vs. Predicate

Action is a delegate (pointer) to a method, that takes zero, one or more input parameters, but does not return anything.

Func is a delegate (pointer) to a method, that takes zero, one or more input parameters, and returns a value (or reference).

Predicate is a special kind of Func often used for comparisons.

Though widely used with Linq, Action and Func are concepts logically independent of Linq. C++ already contained the basic concept in form of typed function pointers.

Here is a small example for Action and Func without using Linq:

class Program
{
    static void Main(string[] args)
    {
        Action<int> myAction = new Action<int>(DoSomething);
        myAction(123);           // Prints out "123"
                                 // can be also called as myAction.Invoke(123);

        Func<int, double> myFunc = new Func<int, double>(CalculateSomething);
        Console.WriteLine(myFunc(5));   // Prints out "2.5"
    }

    static void DoSomething(int i)
    {
        Console.WriteLine(i);
    }

    static double CalculateSomething(int i)
    {
        return (double)i/2;
    }
}

Which command in VBA can count the number of characters in a string variable?

Use the Len function

length = Len(myString)

Input group - two inputs close to each other

My solution requires no additional css and works with any combination of input-addon, input-btn and form-control. It just uses pre-existing bootstrap classes

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<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>_x000D_
<link href="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css" type="text/css" rel="stylesheet" />_x000D_
<form style="padding:10px; margin:10px" action="" class=" form-inline">_x000D_
  <div class="form-group">_x000D_
    <div class="input-group">_x000D_
    <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <input type="text" class="form-control" placeholder="MinVal">_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <input type="text" class="form-control" placeholder="MaxVal">_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</form>

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This will be inline if there is space and wrap for smaller screens.

Full Example ( input-addon, input-btn and form-control. )

jsfiddle

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<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>_x000D_
<link href="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css" type="text/css" rel="stylesheet" />_x000D_
<form style="padding:10px; margin:10px" action="" class=" form-inline">_x000D_
  <div class="form-group">_x000D_
    <div class="input-group">_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <span class="input-group-addon" id="basic-addon1">@</span>_x000D_
          <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">_x000D_
          <span></span>_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <span></span>_x000D_
          <span class="input-group-addon" id="basic-addon1">@</span>_x000D_
          <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">_x000D_
          <span></span>_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <span></span>_x000D_
          <span class="input-group-addon" id="basic-addon1">@</span>_x000D_
          <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">_x000D_
          <span></span>_x000D_
        </div>_x000D_
      </div>_x000D_
      <br>_x000D_
_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">_x000D_
          <span></span>_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="form-group">_x000D_
        <div class="input-group">_x000D_
          <span></span>_x000D_
          <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</form>

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POST data to a URL in PHP

If you're looking to post data to a URL from PHP code itself (without using an html form) it can be done with curl. It will look like this:

$url = 'http://www.someurl.com';
$myvars = 'myvar1=' . $myvar1 . '&myvar2=' . $myvar2;

$ch = curl_init( $url );
curl_setopt( $ch, CURLOPT_POST, 1);
curl_setopt( $ch, CURLOPT_POSTFIELDS, $myvars);
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt( $ch, CURLOPT_HEADER, 0);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);

$response = curl_exec( $ch );

This will send the post variables to the specified url, and what the page returns will be in $response.

get and set in TypeScript

TypeScript uses getter/setter syntax that is like ActionScript3.

class foo {
    private _bar: boolean = false;
    get bar(): boolean {
        return this._bar;
    }
    set bar(value: boolean) {
        this._bar = value;
    }
}

That will produce this JavaScript, using the ECMAScript 5 Object.defineProperty() feature.

var foo = (function () {
    function foo() {
        this._bar = false;
    }
    Object.defineProperty(foo.prototype, "bar", {
        get: function () {
            return this._bar;
        },
        set: function (value) {
            this._bar = value;
        },
        enumerable: true,
        configurable: true
    });
    return foo;
})();

So to use it,

var myFoo = new foo();
if(myFoo.bar) {         // calls the getter
    myFoo.bar = false;  // calls the setter and passes false
}

However, in order to use it at all, you must make sure the TypeScript compiler targets ECMAScript5. If you are running the command line compiler, use --target flag like this;

tsc --target ES5

If you are using Visual Studio, you must edit your project file to add the flag to the configuration for the TypeScriptCompile build tool. You can see that here:

As @DanFromGermany suggests below, if your are simply reading and writing a local property like foo.bar = true, then having a setter and getter pair is overkill. You can always add them later if you need to do something, like logging, whenever the property is read or written.

List of strings to one string

If you use .net 4.0 you can use a sorter way:

String.Join<string>(String.Empty, los);

Splitting string with pipe character ("|")

split takes regex as a parameter.| has special meaning in regex.. use \\| instead of | to escape it.

Difference between a SOAP message and a WSDL?

WSDL act as an interface between sender and receiver.
SOAP message is request and response in xml format.

comparing with java RMI

WSDL is the interface class
SOAP message is marshaled request and response message.

Axios having CORS issue

CORS issue can be simply resolved by following this:

Create a new shortcut of Google Chrome(update browser installation path accordingly) with following value:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-web-security --user-data-dir="D:\chrome\temp"

How do I return the response from an asynchronous call?

Here are some approaches to work with asynchronous requests:

Browser Promise object
Q - A promise library for JavaScript
A+ Promises.js
jQuery deferred
XMLHttpRequest API
Using callback concept - As implementation in first answer

Example: jQuery deferred implementation to work with multiple requests

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var App = App || {};

App = {
    getDataFromServer: function(){

      var self = this,
                 deferred = $.Deferred(),
                 requests = [];

      requests.push($.getJSON('request/ajax/url/1'));
      requests.push($.getJSON('request/ajax/url/2'));

      $.when.apply(jQuery, requests).done(function(xhrResponse) {
        return deferred.resolve(xhrResponse.result);
      });
      return deferred;
    },

    init: function(){

        this.getDataFromServer().done(_.bind(function(resp1, resp2) {

           // Do the operations which you wanted to do when you
           // get a response from Ajax, for example, log response.
        }, this));
    }
};
App.init();

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Adding items to a JComboBox

You can use String arrays to add jComboBox items

String [] items = { "First item", "Second item", "Third item", "Fourth item" };

JComboBox comboOne = new JComboBox (items);

Docker Networking - nginx: [emerg] host not found in upstream

My Workaround (after much trial and error):

In order to get around this issue, I had to get the full name of the 'upstream' Docker container, found by running docker network inspect my-special-docker-network and getting the full name property of the upstream container as such:
```
"Containers": {
     "39ad8199184f34585b556d7480dd47de965bc7b38ac03fc0746992f39afac338": {
          "Name": "my_upstream_container_name_1_2478f2b3aca0",
```
Then used this in the NGINX my-network.local.conf file in the location block of the proxy_pass property: (Note the addition of the GUID to the container name):
```
location / {
    proxy_pass http://my_upsteam_container_name_1_2478f2b3aca0:3000;
```

As opposed to the previously working, but now broken:

    location / {
        proxy_pass http://my_upstream_container_name_1:3000

Most likely cause is a recent change to Docker Compose, in their default naming scheme for containers, as listed here.

This seems to be happening for me and my team at work, with latest versions of the Docker nginx image:

I've opened issues with them on the docker/compose GitHub here

Violation of PRIMARY KEY constraint. Cannot insert duplicate key in object

I was getting the same error on a restored database when I tried to insert a new record using the EntityFramework. It turned out that the Indentity/Seed was screwing things up.

Using a reseed command fixed it.

DBCC CHECKIDENT ('[Prices]', RESEED, 4747030);GO

how to use JSON.stringify and json_decode() properly

None of the other answers worked in my case, most likely because the JSON array contained special characters. What fixed it for me:

Javascript (added encodeURIComponent)

var JSONstr = encodeURIComponent(JSON.stringify(fullInfoArray));
document.getElementById('JSONfullInfoArray').value = JSONstr;

PHP (unchanged from the question)

$data = json_decode($_POST["JSONfullInfoArray"]);
var_dump($data);

echo($_POST["JSONfullInfoArray"]);

Both echo and var_dump have been verified to work fine on a sample of more than 2000 user-entered datasets that included a URL field and a long text field, and that were returning NULL on var_dump for a subset that included URLs with the characters ?&#.

How to find the length of an array in shell?

In the Fish Shell the length of an array can be found with:

$ set a 1 2 3 4
$ count $a
4

check all socket opened in linux OS

Also you can use ss utility to dump sockets statistics.

To dump summary:

ss -s

Total: 91 (kernel 0)
TCP:   18 (estab 11, closed 0, orphaned 0, synrecv 0, timewait 0/0), ports 0

Transport Total     IP        IPv6
*         0         -         -        
RAW       0         0         0        
UDP       4         2         2        
TCP       18        16        2        
INET      22        18        4        
FRAG      0         0         0

To display all sockets:

ss -a

To display UDP sockets:

ss -u -a

To display TCP sockets:

ss -t -a

Here you can read ss man: ss

Apple Mach-O Linker Error when compiling for device

I had this same problem just a minute ago. which lead me here, which wasn't of any help. But I figured out what was the problem and fixed it. the problem was that in my header file i had declare one instance of the struct class named trig_node[SIZE]

my header...

struct TrigNode
{
    float msin;
    float mcos;
    float mtan;
}trig_node[SIZE];

and in my .cpp file i have a function that access this instance and return the answer.

float cos_table_(float deg)
{
    uint n = ((SIZE/DEGRE)*deg);
    return trig_node[n % DEGRE].mcos;
}

which is what as causing my linking error. So, to fix that i place the instance of the trig table class "trig_node[SIZE]" in the .cpp file which cleared the error. so now the new fix looked something like this

my header...

struct TrigNode
{
    float msin;
    float mcos;
    float mtan;
};

my .cpp file trig_node[SIZE]

float cos_table_(float deg)
{
    uint n = ((SIZE/DEGRE)*deg);
    return trig_node[n % DEGRE].mcos;
}

How do I include a newline character in a string in Delphi?

In the System.pas (which automatically gets used) the following is defined:

const
  sLineBreak = {$IFDEF LINUX} AnsiChar(#10) {$ENDIF} 
               {$IFDEF MSWINDOWS} AnsiString(#13#10) {$ENDIF};

This is from Delphi 2009 (notice the use of AnsiChar and AnsiString). (Line wrap added by me.)

So if you want to make your TLabel wrap, make sure AutoSize is set to true, and then use the following code:

label1.Caption := 'Line one'+sLineBreak+'Line two';

Works in all versions of Delphi since sLineBreak was introduced, which I believe was Delphi 6.

How do I empty an array in JavaScript?

To Empty a Current memory location of an array use: 'myArray.length = 0' or 'myArray.pop() UN-till its length is 0'

length : You can set the length property to truncate an array at any time. When you extend an array by changing its length property, the number of actual elements increases.
pop() : The pop method removes the last element from an array and returns that returns the removed value.
shift() : The shift method removes the element at the zeroeth index and shifts the values at consecutive indexes down, then returns the removed value.

Example:

var arr = ['77'];
arr.length = 20;
console.log("Increasing : ", arr); // (20) ["77", empty × 19]
arr.length = 12;
console.log("Truncating : ", arr); // (12) ["77", empty × 11]

var mainArr = new Array();
mainArr = ['1', '2', '3', '4'];

var refArr = mainArr;
console.log('Current', mainArr, 'Refered', refArr);

refArr.length = 3;
console.log('Length: ~ Current', mainArr, 'Refered', refArr);

mainArr.push('0');
console.log('Push to the End of Current Array Memory Location \n~ Current', mainArr, 'Refered', refArr);

mainArr.poptill_length(0);
console.log('Empty Array \n~ Current', mainArr, 'Refered', refArr);

Array.prototype.poptill_length = function (e) {
  while (this.length) {
    if( this.length == e ) break;

    console.log('removed last element:', this.pop());
  }
};

new Array() | [] Create an Array with new memory location by using Array constructor or array literal.

mainArr = []; // a new empty array is addressed to mainArr.

var arr = new Array('10'); // Array constructor
arr.unshift('1'); // add to the front
arr.push('15'); // add to the end
console.log("After Adding : ", arr); // ["1", "10", "15"]

arr.pop(); // remove from the end
arr.shift(); // remove from the front
console.log("After Removing : ", arr); // ["10"]

var arrLit = ['14', '17'];
console.log("array literal « ", indexedItem( arrLit ) ); // {0,14}{1,17}

function indexedItem( arr ) {
    var indexedStr = "";
    arr.forEach(function(item, index, array) {
        indexedStr += "{"+index+","+item+"}";
        console.log(item, index);
    });
    return indexedStr;
}

slice() : By using slice function we get an shallow copy of elements from the original array, with new memory address, So that any modification on cloneArr will not affect to an actual|original array.

var shallowCopy = mainArr.slice(); // this is how to make a copy

var cloneArr = mainArr.slice(0, 3); 
console.log('Main', mainArr, '\tCloned', cloneArr);

cloneArr.length = 0; // Clears current memory location of an array.
console.log('Main', mainArr, '\tCloned', cloneArr);

SqlDataAdapter vs SqlDataReader

The answer to that can be quite broad.

Essentially, the major difference for me that usually influences my decisions on which to use is that with a SQLDataReader, you are "streaming" data from the database. With a SQLDataAdapter, you are extracting the data from the database into an object that can itself be queried further, as well as performing CRUD operations on.

Obviously with a stream of data SQLDataReader is MUCH faster, but you can only process one record at a time. With a SQLDataAdapter, you have a complete collection of the matching rows to your query from the database to work with/pass through your code.

WARNING: If you are using a SQLDataReader, ALWAYS, ALWAYS, ALWAYS make sure that you write proper code to close the connection since you are keeping the connection open with the SQLDataReader. Failure to do this, or proper error handling to close the connection in case of an error in processing the results will CRIPPLE your application with connection leaks.

Pardon my VB, but this is the minimum amount of code you should have when using a SqlDataReader:

Using cn As New SqlConnection("..."), _
      cmd As New SqlCommand("...", cn)

    cn.Open()
    Using rdr As SqlDataReader = cmd.ExecuteReader()
        While rdr.Read()
            ''# ...
        End While
    End Using
End Using

equivalent C#:

using (var cn = new SqlConnection("..."))
using (var cmd = new SqlCommand("..."))
{
    cn.Open();
    using(var rdr = cmd.ExecuteReader())
    {
        while(rdr.Read())
        {
            //...
        }
    }
}

How to configure Docker port mapping to use Nginx as an upstream proxy?

@T0xicCode's answer is correct, but I thought I would expand on the details since it actually took me about 20 hours to finally get a working solution implemented.

If you're looking to run Nginx in its own container and use it as a reverse proxy to load balance multiple applications on the same server instance then the steps you need to follow are as such:

Link Your Containers

When you docker run your containers, typically by inputting a shell script into User Data, you can declare links to any other running containers. This means that you need to start your containers up in order and only the latter containers can link to the former ones. Like so:

#!/bin/bash
sudo docker run -p 3000:3000 --name API mydockerhub/api
sudo docker run -p 3001:3001 --link API:API --name App mydockerhub/app
sudo docker run -p 80:80 -p 443:443 --link API:API --link App:App --name Nginx mydockerhub/nginx

So in this example, the API container isn't linked to any others, but the App container is linked to API and Nginx is linked to both API and App.

The result of this is changes to the env vars and the /etc/hosts files that reside within the API and App containers. The results look like so:

/etc/hosts

Running cat /etc/hosts within your Nginx container will produce the following:

172.17.0.5  0fd9a40ab5ec
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.3  App
172.17.0.2  API

ENV Vars

Running env within your Nginx container will produce the following:

API_PORT=tcp://172.17.0.2:3000
API_PORT_3000_TCP_PROTO=tcp
API_PORT_3000_TCP_PORT=3000
API_PORT_3000_TCP_ADDR=172.17.0.2

APP_PORT=tcp://172.17.0.3:3001
APP_PORT_3001_TCP_PROTO=tcp
APP_PORT_3001_TCP_PORT=3001
APP_PORT_3001_TCP_ADDR=172.17.0.3

I've truncated many of the actual vars, but the above are the key values you need to proxy traffic to your containers.

To obtain a shell to run the above commands within a running container, use the following:

sudo docker exec -i -t Nginx bash

You can see that you now have both /etc/hosts file entries and env vars that contain the local IP address for any of the containers that were linked. So far as I can tell, this is all that happens when you run containers with link options declared. But you can now use this information to configure nginx within your Nginx container.

Configuring Nginx

This is where it gets a little tricky, and there's a couple of options. You can choose to configure your sites to point to an entry in the /etc/hosts file that docker created, or you can utilize the ENV vars and run a string replacement (I used sed) on your nginx.conf and any other conf files that may be in your /etc/nginx/sites-enabled folder to insert the IP values.

OPTION A: Configure Nginx Using ENV Vars

This is the option that I went with because I couldn't get the /etc/hosts file option to work. I'll be trying Option B soon enough and update this post with any findings.

The key difference between this option and using the /etc/hosts file option is how you write your Dockerfile to use a shell script as the CMD argument, which in turn handles the string replacement to copy the IP values from ENV to your conf file(s).

Here's the set of configuration files I ended up with:

Dockerfile

FROM ubuntu:14.04
MAINTAINER Your Name <[email protected]>

RUN apt-get update && apt-get install -y nano htop git nginx

ADD nginx.conf /etc/nginx/nginx.conf
ADD api.myapp.conf /etc/nginx/sites-enabled/api.myapp.conf
ADD app.myapp.conf /etc/nginx/sites-enabled/app.myapp.conf
ADD Nginx-Startup.sh /etc/nginx/Nginx-Startup.sh

EXPOSE 80 443

CMD ["/bin/bash","/etc/nginx/Nginx-Startup.sh"]

nginx.conf

daemon off;
user www-data;
pid /var/run/nginx.pid;
worker_processes 1;


events {
    worker_connections 1024;
}


http {

    # Basic Settings

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 33;
    types_hash_max_size 2048;

    server_tokens off;
    server_names_hash_bucket_size 64;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;


    # Logging Settings
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;


    # Gzip Settings

gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 3;
    gzip_buffers 16 8k;
    gzip_http_version 1.1;
    gzip_types text/plain text/xml text/css application/x-javascript application/json;
    gzip_disable "MSIE [1-6]\.(?!.*SV1)";

    # Virtual Host Configs  
    include /etc/nginx/sites-enabled/*;

    # Error Page Config
    #error_page 403 404 500 502 /srv/Splash;


}

NOTE: It's important to include daemon off; in your nginx.conf file to ensure that your container doesn't exit immediately after launching.

api.myapp.conf

upstream api_upstream{
    server APP_IP:3000;
}

server {
    listen 80;
    server_name api.myapp.com;
    return 301 https://api.myapp.com/$request_uri;
}

server {
    listen 443;
    server_name api.myapp.com;

    location / {
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
        proxy_pass http://api_upstream;
    }

}

Nginx-Startup.sh

#!/bin/bash
sed -i 's/APP_IP/'"$API_PORT_3000_TCP_ADDR"'/g' /etc/nginx/sites-enabled/api.myapp.com
sed -i 's/APP_IP/'"$APP_PORT_3001_TCP_ADDR"'/g' /etc/nginx/sites-enabled/app.myapp.com

service nginx start

I'll leave it up to you to do your homework about most of the contents of nginx.conf and api.myapp.conf.

The magic happens in Nginx-Startup.sh where we use sed to do string replacement on the APP_IP placeholder that we've written into the upstream block of our api.myapp.conf and app.myapp.conf files.

This ask.ubuntu.com question explains it very nicely: Find and replace text within a file using commands

GOTCHA On OSX, sed handles options differently, the -i flag specifically. On Ubuntu, the -i flag will handle the replacement 'in place'; it will open the file, change the text, and then 'save over' the same file. On OSX, the -i flag requires the file extension you'd like the resulting file to have. If you're working with a file that has no extension you must input '' as the value for the -i flag.

GOTCHA To use ENV vars within the regex that sed uses to find the string you want to replace you need to wrap the var within double-quotes. So the correct, albeit wonky-looking, syntax is as above.

So docker has launched our container and triggered the Nginx-Startup.sh script to run, which has used sed to change the value APP_IP to the corresponding ENV variable we provided in the sed command. We now have conf files within our /etc/nginx/sites-enabled directory that have the IP addresses from the ENV vars that docker set when starting up the container. Within your api.myapp.conf file you'll see the upstream block has changed to this:

upstream api_upstream{
    server 172.0.0.2:3000;
}

The IP address you see may be different, but I've noticed that it's usually 172.0.0.x.

You should now have everything routing appropriately.

GOTCHA You cannot restart/rerun any containers once you've run the initial instance launch. Docker provides each container with a new IP upon launch and does not seem to re-use any that its used before. So api.myapp.com will get 172.0.0.2 the first time, but then get 172.0.0.4 the next time. But Nginx will have already set the first IP into its conf files, or in its /etc/hosts file, so it won't be able to determine the new IP for api.myapp.com. The solution to this is likely to use CoreOS and its etcd service which, in my limited understanding, acts like a shared ENV for all machines registered into the same CoreOS cluster. This is the next toy I'm going to play with setting up.

OPTION B: Use /etc/hosts File Entries

This should be the quicker, easier way of doing this, but I couldn't get it to work. Ostensibly you just input the value of the /etc/hosts entry into your api.myapp.conf and app.myapp.conf files, but I couldn't get this method to work.

UPDATE: See @Wes Tod's answer for instructions on how to make this method work.

Here's the attempt that I made in api.myapp.conf:

upstream api_upstream{
    server API:3000;
}

Considering that there's an entry in my /etc/hosts file like so: 172.0.0.2 API I figured it would just pull in the value, but it doesn't seem to be.

I also had a couple of ancillary issues with my Elastic Load Balancer sourcing from all AZ's so that may have been the issue when I tried this route. Instead I had to learn how to handle replacing strings in Linux, so that was fun. I'll give this a try in a while and see how it goes.

Get/pick an image from Android's built-in Gallery app programmatically

I went through the solution from @hcpl & @mad. hcpl's solution supports well for local image in the gallery & mad provided a better solution on top of that - it helps to load OI/Astro/Dropbox image as well. But in my app, while working on picasa library that's now integrated in Android Gallery, both solution fail.

I searched & analyzed a bit & eventually have come with a better & elegant solution that overcomes this limitation. Thanks to Dimitar Darazhanski for his blog, that helped me in this case, I modified a bit to make it easier to understand. Here is my solution goes -

public class BrowsePicture extends Activity {

//YOU CAN EDIT THIS TO WHATEVER YOU WANT
private static final int SELECT_PICTURE = 1;

private String selectedImagePath;
//ADDED
private String filemanagerstring;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ((Button) findViewById(R.id.Button01))
    .setOnClickListener(new OnClickListener() {

        public void onClick(View arg0) {

            // in onCreate or any event where your want the user to
            // select a file
            Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent,
                    "Select Picture"), SELECT_PICTURE);
        }
    });
}

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        if (requestCode == SELECT_PICTURE) {
            Uri selectedImageUri = data.getData();
            Log.d("URI VAL", "selectedImageUri = " + selectedImageUri.toString());
            selectedImagePath = getPath(selectedImageUri);

            if(selectedImagePath!=null){         
                // IF LOCAL IMAGE, NO MATTER IF ITS DIRECTLY FROM GALLERY (EXCEPT PICASSA ALBUM),
                // OR OI/ASTRO FILE MANAGER. EVEN DROPBOX IS SUPPORTED BY THIS BECAUSE DROPBOX DOWNLOAD THE IMAGE 
                // IN THIS FORM - file:///storage/emulated/0/Android/data/com.dropbox.android/...
                System.out.println("local image"); 
            }
            else{
                System.out.println("picasa image!");
                loadPicasaImageFromGallery(selectedImageUri);
            }
        }
    }
}


// NEW METHOD FOR PICASA IMAGE LOAD
private void loadPicasaImageFromGallery(final Uri uri) {
    String[] projection = {  MediaColumns.DATA, MediaColumns.DISPLAY_NAME };
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
    if(cursor != null) {
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(MediaColumns.DISPLAY_NAME);
        if (columnIndex != -1) {
            new Thread(new Runnable() {
                // NEW THREAD BECAUSE NETWORK REQUEST WILL BE MADE THAT WILL BE A LONG PROCESS & BLOCK UI
                // IF CALLED IN UI THREAD 
                public void run() {
                    try {
                        Bitmap bitmap = android.provider.MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
                        // THIS IS THE BITMAP IMAGE WE ARE LOOKING FOR.
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }).start();
        }
    }
    cursor.close();
}


public String getPath(Uri uri) {
    String[] projection = {  MediaColumns.DATA};
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
    if(cursor != null) {
        //HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
        //THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
        cursor.moveToFirst();
        int columnIndex = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
        String filePath = cursor.getString(columnIndex);
        cursor.close();
        return filePath;
    }
    else 
        return uri.getPath();               // FOR OI/ASTRO/Dropbox etc
}

Check it & let me know if there's some issue with it. I have tested it & it works well in every case.

Hope this will help everyone.

MVC4 HTTP Error 403.14 - Forbidden

I have a bit different issue, on server 2012 somehow i forgot to enable asp.net 4.5 so if you have this issue, double check that you enable it.

Getting list of pixel values from PIL

I assume you are getting an error like.. TypeError: 'PixelAccess' object is not iterable...?

See the Image.load documentation for how to access pixels..

Basically, to get the list of pixels in an image, using PIL:

from PIL import Image
i = Image.open("myfile.png")

pixels = i.load() # this is not a list, nor is it list()'able
width, height = i.size

all_pixels = []
for x in range(width):
    for y in range(height):
        cpixel = pixels[x, y]
        all_pixels.append(cpixel)

That appends every pixel to the all_pixels - if the file is an RGB image (even if it only contains a black-and-white image) these will be a tuple, for example:

(255, 255, 255)

To convert the image to monochrome, you just average the three values - so, the last three lines of code would become..

cpixel = pixels[x, y]
bw_value = int(round(sum(cpixel) / float(len(cpixel))))
# the above could probably be bw_value = sum(cpixel)/len(cpixel)
all_pixels.append(bw_value)

Or to get the luminance (weighted average):

cpixel = pixels[x, y]
luma = (0.3 * cpixel[0]) + (0.59 * cpixel[1]) + (0.11 * cpixel[2])
all_pixels.append(luma)

Or pure 1-bit looking black and white:

cpixel = pixels[x, y]
if round(sum(cpixel)) / float(len(cpixel)) > 127:
    all_pixels.append(255)
else:
    all_pixels.append(0)

There is probably methods within PIL to do such RGB -> BW conversions quicker, but this works, and isn't particularly slow.

If you only want to perform calculations on each row, you could skip adding all the pixels to an intermediate list.. For example, to calculate the average value of each row:

from PIL import Image
i = Image.open("myfile.png")

pixels = i.load() # this is not a list
width, height = i.size
row_averages = []
for y in range(height):
    cur_row_ttl = 0
    for x in range(width):
        cur_pixel = pixels[x, y]
        cur_pixel_mono = sum(cur_pixel) / len(cur_pixel)
        cur_row_ttl += cur_pixel_mono

    cur_row_avg = cur_row_ttl / width
    row_averages.append(cur_row_avg)

print "Brighest row:",
print max(row_averages)

unix sort descending order

To list files based on size in asending order.

find ./ -size +1000M -exec ls -tlrh {} \; |awk -F" " '{print $5,$9}'  | sort -n\

Is it possible to play music during calls so that the partner can hear it ? Android

No, It is not possible. But if you want to dig it more, then you can visit Using Android phone as GSM Gateway for VoIP where author has concluded that

It's not possible to use Android as a GSM Gateway in its current form. Even after flashing custom ROM because they also depends on proprietary RIL (Radio Interface Layer) firmwares. Hurdles 1 and 2 (API limitation) can be removed because the source code is available for the open source community to make it possible. However, the hurdle 3 (proprietary RIL) is dependent on the hardware vendors. Hardware vendors do not usually make their device drivers code available.

NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

There is a bug filed for Eclipse:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=385680

You could try restarting Eclipse, it helped the original poster of the issue there.

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

krosenvold's answer inspired the following script which does the following:

get the dd dump via ssh from a remote server (as gz file)
unzip the dump
convert it to vmware

the script is restartable and checks the existence of the intermediate files. It also uses pv and qemu-img -p to show the progress of each step.

In my environment 2 x Ubuntu 12.04 LTS the steps took:

3 hours to get a 47 GByte disk dump of a 60 GByte partition
20 minutes to unpack to a 60 GByte dd file
45 minutes to create the vmware file

#!/bin/bash
# get a dd disk dump and convert it to vmware
#  see http://stackoverflow.com/questions/454899/how-to-convert-flat-raw-disk-image-to-vmdk-for-virtualbox-or-vmplayer
#  Author: wf  2014-10-1919

#
# get a dd dump from the given host's given disk and create a compressed
#   image at the given target 
#
#  1: host e.g. somehost.somedomain
#  2: disk e.g. sda
#  3: target e.g. image.gz
#
# http://unix.stackexchange.com/questions/132797/how-to-use-ssh-to-make-a-dd-copy-of-disk-a-from-host-b-and-save-on-disk-b
getdump() {
  local l_host="$1"
  local l_disk="$2"
  local l_target="$3"
  echo "getting disk dump of $l_disk from $l_host"
  ssh $l_host sudo fdisk -l  | egrep "^/dev/$l_disk"
  if [ $? -ne 0 ]
  then
    echo "device $l_disk does not exist on host $l_host" 1>&2
    exit 1
  else
    if [ ! -f $l_target ]
    then
      ssh $l_host "sudo dd if=/dev/$disk bs=1M | gzip -1 -" | pv | dd of=$l_target
    else
      echo "$l_target already exists"
    fi
  fi
}

#
# optionally install command from package if it is not available yet
# 1: command
# 2: package
#
opt_install() {
  l_command="$1"
  l_package="$2"
  echo "checking that $l_command from package $l_package  is installed ..."
  which $l_command
  if [ $? -ne 0 ]
  then
    echo "installing $l_package to make $l_command available ..."
    sudo apt-get install $l_package 
  fi
}

#
# convert the given image to vmware
#  1: the dd dump image
#  2: the vmware image file to convert to
#
vmware_convert() {
  local l_ddimage="$1"
  local l_vmwareimage="$2"
  echo "converting dd image $l_image to vmware $l_vmwareimage"
  #  convert to VMware disk format showing progess
  # see http://manpages.ubuntu.com/manpages/precise/man1/qemu-img.1.html
  qemu-img convert -p -O vmdk "$l_ddimage" "$l_vmwareimage"
}

#
# show usage
#
usage() {
  echo "usage: $0 host device"
  echo "      host: the host to get the disk dump from e.g. frodo.lotr.org"  
  echo "            you need ssh and sudo privileges on that host"
  echo "
  echo "    device: the disk to dump from e.g. sda"
  echo ""
  echo "  examples:
  echo "       $0 frodo.lotr.org sda"
  echo "       $0 gandalf.lotr.org sdb"
  echo ""
  echo "  the needed packages pv and qemu-utils will be installed if not available"
  echo "  you need local sudo rights for this to work"
  exit 1
}

# check arguments
if [ $# -lt 2 ]
then
  usage
fi

# get the command line parameters
host="$1"
disk="$2"

# calculate the names of the image files
ts=`date "+%Y-%m-%d"`
# prefix of all images
#   .gz the zipped dd
#   .dd the disk dump file
#   .vmware - the vmware disk file
image="${host}_${disk}_image_$ts"

echo "$0 $host/$disk ->  $image"

# first check/install necessary packages
opt_install qemu-img qemu-utils
opt_install pv pv

# check if dd files was already loaded
#  we don't want to start this tedious process twice if avoidable
if [ ! -f $image.gz ]
then
  getdump $host $disk $image.gz
else
  echo "$image.gz already downloaded"
fi

# check if the dd file was already uncompressed
# we don't want to start this tedious process twice if avoidable
if [ ! -f $image.dd ]
then
  echo "uncompressing $image.gz"
  zcat $image.gz | pv -cN zcat > $image.dd
else
  echo "image $image.dd already uncompressed"
fi
# check if the vmdk file was already converted
# we don't want to start this tedious process twice if avoidable
if [ ! -f $image.vmdk ]
then
  vmware_convert $image.dd $image.vmdk
else
  echo "vmware image $image.vmdk already converted"
fi

Getting Git to work with a proxy server - fails with "Request timed out"

For the git protocol (git://...), install socat and write a script such as:

#!/bin/sh

exec socat - socks4:your.company.com:$1:$2

make it executable, put it in your path, and in your ~/.gitconfig set core.gitproxy to the name of that script.

LogCat message: The Google Play services resources were not found. Check your project configuration to ensure that the resources are included

I have decompiled Google Play services revision 14 library. I think there is a bug in com.google.android.gms.common.GooglePlayServicesUtil.class. The aforementioned string appears only in one place:

public static int isGooglePlayServicesAvailable(Context context) {
    PackageManager localPackageManager = context.getPackageManager();
    try {
        Resources localResources = context.getResources();
        localResources.getString(R.string.common_google_play_services_unknown_issue);
    } catch (Throwable localThrowable1) {
        Log.e("GooglePlayServicesUtil", "The Google Play services resources were not found. "
                + "Check your project configuration to ensure that the resources are included.");
    }
....

There is no R.class in com.google.android.gms.common package.

There is an import com.google.android.gms.R.string;, but no usage of string.something, so I guess this is the error - there should be import com.google.android.gms.R;.

Nevertheless the isGooglePlayServicesAvailable method works as intended (except of logging that warning), but there are other methods in that class, which uses unimported R.class, so there may be some other errors. Although banners in my application works fine...

What is the difference between git pull and git fetch + git rebase?

It should be pretty obvious from your question that you're actually just asking about the difference between git merge and git rebase.

So let's suppose you're in the common case - you've done some work on your master branch, and you pull from origin's, which also has done some work. After the fetch, things look like this:

- o - o - o - H - A - B - C (master)
               \
                P - Q - R (origin/master)

If you merge at this point (the default behavior of git pull), assuming there aren't any conflicts, you end up with this:

- o - o - o - H - A - B - C - X (master)
               \             /
                P - Q - R --- (origin/master)

If on the other hand you did the appropriate rebase, you'd end up with this:

- o - o - o - H - P - Q - R - A' - B' - C' (master)
                          |
                          (origin/master)

The content of your work tree should end up the same in both cases; you've just created a different history leading up to it. The rebase rewrites your history, making it look as if you had committed on top of origin's new master branch (R), instead of where you originally committed (H). You should never use the rebase approach if someone else has already pulled from your master branch.

Finally, note that you can actually set up git pull for a given branch to use rebase instead of merge by setting the config parameter branch.<name>.rebase to true. You can also do this for a single pull using git pull --rebase.

Convert date yyyyMMdd to system.datetime format

have at look at the static methods DateTime.Parse() and DateTime.TryParse(). They will allow you to pass in your date string and a format string, and get a DateTime object in return.

http://msdn.microsoft.com/en-us/library/6fw7727c.aspx

Missing include "bits/c++config.h" when cross compiling 64 bit program on 32 bit in Ubuntu

On my 64 bit system I noticed that the following directory existed:

/usr/include/c++/4.4/x86_64-linux-gnu/32/bits

It would then make sense that on my 32 bit system that had been setup for 64bit cross compiling there should be a corresponding directory like:

/usr/include/c++/4.4/i686-linux-gnu/64/bits

I double checked and this directory did not exist. Running g++ with the verbose parameter showed that the compiler was actually looking for something in this location:

jesse@shalored:~/projects/test$ g++ -v -m64 main.cpp 
Using built-in specs.
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.4.4-14ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.4 --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5) 
COLLECT_GCC_OPTIONS='-v' '-m64' '-shared-libgcc' '-mtune=generic'
 /usr/lib/gcc/i686-linux-gnu/4.4.5/cc1plus -quiet -v -imultilib 64 -D_GNU_SOURCE main.cpp -D_FORTIFY_SOURCE=2 -quiet -dumpbase main.cpp -m64 -mtune=generic -auxbase main -version -fstack-protector -o /tmp/ccMvIfFH.s
ignoring nonexistent directory "/usr/include/c++/4.4/i686-linux-gnu/64"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/i686-linux-gnu/4.4.5/../../../../i686-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.4
 /usr/include/c++/4.4/backward
 /usr/local/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C++ (Ubuntu/Linaro 4.4.4-14ubuntu5) version 4.4.5 (i686-linux-gnu)
    compiled by GNU C version 4.4.5, GMP version 4.3.2, MPFR version 3.0.0-p3.
GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128197
Compiler executable checksum: 1fe36891f4a5f71e4a498e712867261c
In file included from main.cpp:1:
/usr/include/c++/4.4/iostream:39: fatal error: bits/c++config.h: No such file or directory
compilation terminated.

The error regarding the ignoring nonexistent directory was the clue. Unfortunately, I still don't know what package I need to install to have this directory show up so I just copied the /usr/include/c++/4.4/x86_64-linux-gnu/bits directory from my 64 bit machine to /usr/include/c++/4.4/i686-linux-gnu/64/bits on my 32 machine.

Now compiling with just the -m64 works correctly. The major drawback is that this is still not the correct way to do things and I am guessing the next time Update Manager installs and update to g++ things may break.

env: node: No such file or directory in mac

NOTE: Only mac users!

uninstall node completely with the commands

curl -ksO https://gist.githubusercontent.com/nicerobot/2697848/raw/uninstall-node.sh
chmod +x ./uninstall-node.sh
./uninstall-node.sh
rm uninstall-node.sh

Or you could check out this website: How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)

if this doesn't work, you need to remove node via control panel or any other method. As long as it gets removed.

Install node via this website: https://nodejs.org/en/download/

If you use nvm, you can use:

nvm install node

You can already check if it works, then you don't need to take the following steps with: npm -v and then node -v

if you have nvm installed: command -v nvm

Uninstall npm using the following command:

sudo npm uninstall npm -g

Or, if that fails, get the npm source code, and do:

sudo make uninstall

If you have nvm installed, then use: nvm uninstall npm

Install npm using the following command: npm install -g grunt

Time complexity of nested for-loop

Indeed, it is O(n^2). See also a very similar example with the same runtime here.

How to automatically generate unique id in SQL like UID12345678?

CREATE TABLE dbo.tblUsers
(
    ID INT IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
    UserID AS 'UID' + RIGHT('00000000' + CAST(ID AS VARCHAR(8)), 8) PERSISTED, 
    [Name] VARCHAR(50) NOT NULL,
)

marc_s's Answer Snap

React: trigger onChange if input value is changing by state?

I know what you mean, you want to trigger handleChange by click button.

But modify state value will not trigger onChange event, because onChange event is a form element event.

Go to first line in a file in vim?

Type "gg" in command mode. This brings the cursor to the first line.

How to use global variables in React Native?

You can consider leveraging React's Context feature.

class NavigationContainer extends React.Component {
    constructor(props) {
        super(props);
        this.goTo = this.goTo.bind(this);
    }
    goTo(location) {
        ...
    }
    getChildContext() {
        // returns the context to pass to children
        return {
            goTo: this.goTo
        }
    }
    ...
}

// defines the context available to children
NavigationContainer.childContextTypes = {
    goTo: PropTypes.func
}

class SomeViewContainer extends React.Component {
    render() {
        // grab the context provided by ancestors
        const {goTo} = this.context;
        return <button onClick={evt => goTo('somewhere')}>
            Hello
        </button>
    }
}

// Define the context we want from ancestors
SomeViewContainer.contextTypes = {
    goTo: PropTypes.func
}

With context, you can pass data through the component tree without having to pass the props down manually at every level. There is a big warning on this being an experimental feature and may break in the future, but I would imagine this feature to be around given the majority of the popular frameworks like Redux use context extensively.

The main advantage of using context v.s. a global variable is context is "scoped" to a subtree (this means you can define different scopes for different subtrees).

Do note that you should not pass your model data via context, as changes in context will not trigger React's component render cycle. However, I do find it useful in some use case, especially when implementing your own custom framework or workflow.

How to merge a transparent png image with another image using PIL

As olt already pointed out, Image.paste doesn't work properly, when source and destination both contain alpha.

Consider the following scenario:

Two test images, both contain alpha:

layer1 = Image.open("layer1.png")
layer2 = Image.open("layer2.png")

Compositing image using Image.paste like so:

final1 = Image.new("RGBA", layer1.size)
final1.paste(layer1, (0,0), layer1)
final1.paste(layer2, (0,0), layer2)

produces the following image (the alpha part of the overlayed red pixels is completely taken from the 2nd layer. The pixels are not blended correctly):

Compositing image using Image.alpha_composite like so:

final2 = Image.new("RGBA", layer1.size)
final2 = Image.alpha_composite(final2, layer1)
final2 = Image.alpha_composite(final2, layer2)

produces the following (correct) image:

ValueError when checking if variable is None or numpy.array

You can see if object has shape or not

def check_array(x):
    try:
        x.shape
        return True
    except:
        return False

How to clear https proxy setting of NPM?

In my case (Linux Mint 16 based on Ubuntu), I had to:

npm config delete https-proxy, and also
clear the https_proxy Bash environment parameter — oddly enough, although I cannot find this behavior documented anywhere, npm fallbacks to https_proxy:
```
$ http_proxy='' https_proxy='' npm config get https-proxy
null
$ http_proxy='' xxhttps_proxy='' npm config get https-proxy
https://1.2.3.4:8080
```

What is a Memory Heap?

A memory heap is a common structure for holding dynamically allocated memory. See Dynamic_memory_allocation on wikipedia.

There are other structures, like pools, stacks and piles.

How do I add a foreign key to an existing SQLite table?

If you use Db Browser for sqlite ,then it will be easy for you to modify the table. you can add foreign key in existing table without writing a query.

Open your database in Db browser,
Just right click on table and click modify,
At there scroll to foreign key column,
double click on field which you want to alter,
Then select table and it's field and click ok.

that's it. You successfully added foreign key in existing table.

How to set up a cron job to run an executable every hour?

Did you mean the executable fails to run , if invoked from any other directory? This is rather a bug on the executable. One potential reason could be the executable requires some shared libraires from the installed folder. You may check environment variable LD_LIBRARY_PATH

Docker Error bind: address already in use

In your case it was some other process that was using the port and as indicated in the comments, sudo netstat -pna | grep 3000 helped you in solving the problem.

While in other cases (I myself encountered it many times) it mostly is the same container running at some other instance. In that case docker ps was very helpful as often I left the same containers running in other directories and then tried running again at other places, where same container names were used.

How docker ps helped me: docker rm -f $(docker ps -aq) is a short command which I use to remove all containers.

Edit: Added how docker ps helped me.

How to click a href link using Selenium

You can use this method:

For the links if you use linkText(); it is more effective than the any other locator.

driver.findElement(By.linkText("App Configuration")).click();

what is the unsigned datatype?

unsigned really is a shorthand for unsigned int, and so defined in standard C.

Module not found: Error: Can't resolve 'core-js/es6'

If you use @babel/preset-env and useBuiltIns, then you just have to add corejs: 3 beside the useBuiltIns option, to specify which version to use, default is corejs: 2.

presets: [
  [
    "@babel/preset-env", {
      "useBuiltIns": "usage",
      "corejs": 3
    }
  ]
],

For further details see: https://github.com/zloirock/core-js/blob/master/docs/2019-03-19-core-js-3-babel-and-a-look-into-the-future.md#babelpreset-env

How to reduce a huge excel file

i Change the format of file to *.XLSX this change compress my file and reduce file size of 15%

Git error when trying to push -- pre-receive hook declined

Issue: "PUSH Failed refs/head/ - pre-receive hook declined"

I've faced the problem of unable to push my changes to my origin branch and anything to master branch of a particular project repository as the size of that repo was over hard limit of 2GB. It was throwing the error. That's because we had pushed the test data unknowingly to bitbucket from other testing branches.

PUSH Failed refs/head/ - pre-receive hook declined

So tried checking is that the same with other project repo's and they weren't having any issues.

Fix:

My colleague noticed that when we cloned the project back locally, the size of the project was 110MB. So then we started cleaning the branches we merged earlier and active branches which are no more required. Once that cleaning is done for couple of branches we realized the size of the repo went drastically down from 2GB to 120MB. Then we tried to push the changes to my branch and it worked.

What does upstream mean in nginx?

It's used for proxying requests to other servers.

An example from http://wiki.nginx.org/LoadBalanceExample is:

http {
  upstream myproject {
    server 127.0.0.1:8000 weight=3;
    server 127.0.0.1:8001;
    server 127.0.0.1:8002;    
    server 127.0.0.1:8003;
  }

  server {
    listen 80;
    server_name www.domain.com;
    location / {
      proxy_pass http://myproject;
    }
  }
}

This means all requests for / go to the any of the servers listed under upstream XXX, with a preference for port 8000.

Server unable to read htaccess file, denying access to be safe

I had same problem on Fedora, and found that problem was selinux. to test that it is problem run command: sudo setenforce 0

Otherwise or change in file /etc/sysconfig/selinux

SELINUX=enforcing
to
SELINUX=disabled

or add rules to selinux to allow http access

Amazon S3 upload file and get URL

a bit old but still for anyone stumbling upon this in the future:

you can do it with one line assuming you already wrote the CredentialProvider and the AmazonS3Client.

it will look like this:

 String ImageURL = String.valueOf(s3.getUrl(
                                  ConstantsAWS3.BUCKET_NAME, //The S3 Bucket To Upload To
                                  file.getName())); //The key for the uploaded object

and if you didn't wrote the CredentialProvider and the AmazonS3Client then just add them before getting the URL like this:

  CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
        getApplicationContext(),
        "POOL_ID", // Identity pool ID
        Regions.US_EAST_1 // Region
);

What does java.lang.Thread.interrupt() do?

For completeness, in addition to the other answers, if the thread is interrupted before it blocks on Object.wait(..) or Thread.sleep(..) etc., this is equivalent to it being interrupted immediately upon blocking on that method, as the following example shows.

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

        Thread.currentThread().interrupt();

        printInterrupted(1);

        Object o = new Object();
        try {
            synchronized (o) {
                printInterrupted(2);
                System.out.printf("A Time %d\n", System.currentTimeMillis());
                o.wait(100);
                System.out.printf("B Time %d\n", System.currentTimeMillis());
            }
        } catch (InterruptedException ie) {
            System.out.printf("WAS interrupted\n");
        }
        System.out.printf("C Time %d\n", System.currentTimeMillis());

        printInterrupted(3);

        Thread.currentThread().interrupt();

        printInterrupted(4);

        try {
            System.out.printf("D Time %d\n", System.currentTimeMillis());
            Thread.sleep(100);
            System.out.printf("E Time %d\n", System.currentTimeMillis());
        } catch (InterruptedException ie) {
            System.out.printf("WAS interrupted\n");
        }
        System.out.printf("F Time %d\n", System.currentTimeMillis());

        printInterrupted(5);

        try {
            System.out.printf("G Time %d\n", System.currentTimeMillis());
            Thread.sleep(100);
            System.out.printf("H Time %d\n", System.currentTimeMillis());
        } catch (InterruptedException ie) {
            System.out.printf("WAS interrupted\n");
        }
        System.out.printf("I Time %d\n", System.currentTimeMillis());

    }
    static void printInterrupted(int n) {
        System.out.printf("(%d) Am I interrupted? %s\n", n,
                Thread.currentThread().isInterrupted() ? "Yes" : "No");
    }
}

Output:

$ javac InterruptTest.java 

$ java -classpath "." InterruptTest
(1) Am I interrupted? Yes
(2) Am I interrupted? Yes
A Time 1399207408543
WAS interrupted
C Time 1399207408543
(3) Am I interrupted? No
(4) Am I interrupted? Yes
D Time 1399207408544
WAS interrupted
F Time 1399207408544
(5) Am I interrupted? No
G Time 1399207408545
H Time 1399207408668
I Time 1399207408669

Implication: if you loop like the following, and the interrupt occurs at the exact moment when control has left Thread.sleep(..) and is going around the loop, the exception is still going to occur. So it is perfectly safe to rely on the InterruptedException being reliably thrown after the thread has been interrupted:

while (true) {
    try {
        Thread.sleep(10);
    } catch (InterruptedException ie) {
        break;
    }
}

Show Console in Windows Application?

Easiest way is to start a WinForms application, go to settings and change the type to a console application.

What is a good regular expression to match a URL?

These are the droids you're looking for. This is taken from validator.js which is the library you should really use to do this. But if you want to roll your own, who am I to stop you? If you want pure regex then you can just take out the length check. I think it's a good idea to test the length of the URL though if you really want to determine compliance with the spec.

 function isURL(str) {
     var urlRegex = '^(?!mailto:)(?:(?:http|https|ftp)://)(?:\\S+(?::\\S*)?@)?(?:(?:(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[0-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[a-z\\u00a1-\\uffff]{2,})))|localhost)(?::\\d{2,5})?(?:(/|\\?|#)[^\\s]*)?$';
     var url = new RegExp(urlRegex, 'i');
     return str.length < 2083 && url.test(str);
}

Angular redirect to login page

1. Create a guard as seen below. 2. Install ngx-cookie-service to get cookies returned by external SSO. 3. Create ssoPath in environment.ts (SSO Login redirection). 4. Get the state.url and use encodeURIComponent.

import { Injectable } from '@angular/core';
import { CanActivate, Router, ActivatedRouteSnapshot, RouterStateSnapshot } from 
  '@angular/router';
import { CookieService } from 'ngx-cookie-service';
import { environment } from '../../../environments/environment.prod';

@Injectable()
export class AuthGuardService implements CanActivate {
  private returnUrl: string;
  constructor(private _router: Router, private cookie: CookieService) {}

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
    if (this.cookie.get('MasterSignOn')) {
      return true;
    } else {
      let uri = window.location.origin + '/#' + state.url;
      this.returnUrl = encodeURIComponent(uri);      
      window.location.href = environment.ssoPath +  this.returnUrl ;   
      return false;      
    }
  }
}

/lib/ld-linux.so.2: bad ELF interpreter: No such file or directory

looks to me yum install glibc.i686 should have worked. Unless Peter was not root. He has the 64 bit glib installed, he is installing a 32 bit package that requires the 32 bit glib which is glib.i686 for intel processors.

SyntaxError: Unexpected Identifier in Chrome's Javascript console

The comma got eaten by the quotes!

This part:

("username," visitorName);

Should be this:

("username", visitorName);

Aside: For pasting code into the console, you can paste them in one line at a time to help you pinpoint where things went wrong ;-)

Elasticsearch difference between MUST and SHOULD bool query

As said in the documentation:

Must: The clause (query) must appear in matching documents.

Should: The clause (query) should appear in the matching document. In a boolean query with no must clauses, one or more should clauses must match a document. The minimum number of should clauses to match can be set using the minimum_should_match parameter.

In other words, results will have to be matched by all the queries present in the must clause ( or match at least one of the should clauses if there is no must clause.

Since you want your results to satisfy all the queries, you should use must.

You can indeed use filters inside a boolean query.

import an array in python

Another option is numpy.genfromtxt, e.g:

import numpy as np
data = np.genfromtxt("myfile.dat",delimiter=",")

This will make data a numpy array with as many rows and columns as are in your file

C++: Print out enum value as text

Here is an example based on Boost.Preprocessor:

#include <iostream>

#include <boost/preprocessor/punctuation/comma.hpp>
#include <boost/preprocessor/control/iif.hpp>
#include <boost/preprocessor/comparison/equal.hpp>
#include <boost/preprocessor/stringize.hpp>
#include <boost/preprocessor/seq/for_each.hpp>
#include <boost/preprocessor/seq/size.hpp>
#include <boost/preprocessor/seq/seq.hpp>


#define DEFINE_ENUM(name, values)                               \
  enum name {                                                   \
    BOOST_PP_SEQ_FOR_EACH(DEFINE_ENUM_VALUE, , values)          \
  };                                                            \
  inline const char* format_##name(name val) {                  \
    switch (val) {                                              \
      BOOST_PP_SEQ_FOR_EACH(DEFINE_ENUM_FORMAT, , values)       \
    default:                                                    \
        return 0;                                               \
    }                                                           \
  }

#define DEFINE_ENUM_VALUE(r, data, elem)                        \
  BOOST_PP_SEQ_HEAD(elem)                                       \
  BOOST_PP_IIF(BOOST_PP_EQUAL(BOOST_PP_SEQ_SIZE(elem), 2),      \
               = BOOST_PP_SEQ_TAIL(elem), )                     \
  BOOST_PP_COMMA()

#define DEFINE_ENUM_FORMAT(r, data, elem)             \
  case BOOST_PP_SEQ_HEAD(elem):                       \
  return BOOST_PP_STRINGIZE(BOOST_PP_SEQ_HEAD(elem));


DEFINE_ENUM(Errors,
            ((ErrorA)(0))
            ((ErrorB))
            ((ErrorC)))

int main() {
  std::cout << format_Errors(ErrorB) << std::endl;
}

Maven artifact and groupId naming

Consider this to get a fully unique jar file:

GroupID - com.companyname.project
ArtifactId - com-companyname-project
Package - com.companyname.project

React JS get current date

OPTION 1: if you want to make a common utility function then you can use this

export function getCurrentDate(separator=''){

let newDate = new Date()
let date = newDate.getDate();
let month = newDate.getMonth() + 1;
let year = newDate.getFullYear();

return `${year}${separator}${month<10?`0${month}`:`${month}`}${separator}${date}`
}

and use it by just importing it as

import {getCurrentDate} from './utils'
console.log(getCurrentDate())

OPTION 2: or define and use in a class directly

getCurrentDate(separator=''){

let newDate = new Date()
let date = newDate.getDate();
let month = newDate.getMonth() + 1;
let year = newDate.getFullYear();

return `${year}${separator}${month<10?`0${month}`:`${month}`}${separator}${date}`
}

How to add include and lib paths to configure/make cycle?

Set LDFLAGS and CFLAGS when you run make:

$ LDFLAGS="-L/home/me/local/lib" CFLAGS="-I/home/me/local/include" make

If you don't want to do that a gazillion times, export these in your .bashrc (or your shell equivalent). Also set LD_LIBRARY_PATH to include /home/me/local/lib:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/me/local/lib

Replace Default Null Values Returned From Left Outer Join

That's as easy as

IsNull(FieldName, 0)

Or more completely:

SELECT iar.Description, 
  ISNULL(iai.Quantity,0) as Quantity, 
  ISNULL(iai.Quantity * rpl.RegularPrice,0) as 'Retail', 
  iar.Compliance 
FROM InventoryAdjustmentReason iar
LEFT OUTER JOIN InventoryAdjustmentItem iai  on (iar.Id = iai.InventoryAdjustmentReasonId)
LEFT OUTER JOIN Item i on (i.Id = iai.ItemId)
LEFT OUTER JOIN ReportPriceLookup rpl on (rpl.SkuNumber = i.SkuNo)
WHERE iar.StoreUse = 'yes'

How do I clear the dropdownlist values on button click event using jQuery?

A shorter alternative to the first solution given by Russ Cam would be:

$('#mySelect').val('');

This assumes you want to retain the list, but make it so that no option is selected.

If you wish to select a particular default value, just pass that value instead of an empty string.

$('#mySelect').val('someDefaultValue');

or to do it by the index of the option, you could do:

$('#mySelect option:eq(0)').attr('selected','selected'); // Select first option

C#: Printing all properties of an object

Regarding TypeDescriptor from Sean's reply (I can't comment because I have a bad reputation)... one advantage to using TypeDescriptor over GetProperties() is that TypeDescriptor has a mechanism for dynamically attaching properties to objects at runtime and normal reflection will miss these.

For example, when working with PowerShell's PSObject, which can have properties and methods added at runtime, they implemented a custom TypeDescriptor which merges these members in with the standard member set. By using TypeDescriptor, your code doesn't need to be aware of that fact.

Components, controls, and I think maybe DataSets also make use of this API.

Bootstrap datepicker hide after selection

You can use event changedate() to keep track of when the date is changed together with datepicker('hide') method to hide the datepicker after making selection:

$('yourpickerid').on('changeDate', function(ev){
    $(this).datepicker('hide');
});

Demo

UPDATE

This was the bug with autoclose: true. This bug was fixed in latest master. SEE THE COMMIT. Get the latest code from GitHub

Update Eclipse with Android development tools v. 23

DO NOT DO THIS

Warning: Please see the comments below this answer. These steps have had a negative impact for many people.

Click Help / Install new software...
Click on What is "already installed" (as in picture below)
In the new window you can uninstall the old ADT (uninstall Android Development Tools, Android DDMS, Android Hierarchy Viewer, Android TraceView, Android Native Development Tools and Tracer for OpenGL ES)
Restart Eclipse
Then again click on Help / Install New Software
Choose ADT... Install

I hope it helps!

Picture Demonstration

How to shutdown my Jenkins safely?

Immediately shuts down Jenkins server.

In Windows CMD.exe, Go to folder where jenkins-cli.jar file is located.

C:\Program Files (x86)\Jenkins\war\WEB-INF

Use Command to Safely Shutdown

java -jar jenkins-cli.jar -s http://localhost:8080 safe-shutdown --username "YourUsername" 
--password "YourPassword"

The full list of commands is available at http://localhost:8080/cli

Credits to Francisco post for cli commands.

Reference:

Hope helps someone.

Password masking console application

Console.Write("\b \b"); will delete the asterisk character from the screen, but you do not have any code within your else block that removes the previously entered character from your pass string variable.

Here's the relevant working code that should do what you require:

var pass = string.Empty;
ConsoleKey key;
do
{
    var keyInfo = Console.ReadKey(intercept: true);
    key = keyInfo.Key;

    if (key == ConsoleKey.Backspace && pass.Length > 0)
    {
        Console.Write("\b \b");
        pass = pass[0..^1];
    }
    else if (!char.IsControl(keyInfo.KeyChar))
    {
        Console.Write("*");
        pass += keyInfo.KeyChar;
    }
} while (key != ConsoleKey.Enter);

Create a asmx web service in C# using visual studio 2013

on the web site box, you have selected .NETFramework 4.5 and it doesn show, so click there and choose the 3.5...i hope it helps.

How can I safely create a nested directory?

Check os.makedirs: (It makes sure the complete path exists.)
To handle the fact the directory might exist, catch OSError. (If exist_ok is False (the default), an OSError is raised if the target directory already exists.)

import os
try:
    os.makedirs('./path/to/somewhere')
except OSError:
    pass

Differences between SP initiated SSO and IDP initiated SSO

SP Initiated SSO

Bill the user: "Hey Jimmy, show me that report"

Jimmy the SP: "Hey, I'm not sure who you are yet. We have a process here so you go get yourself verified with Bob the IdP first. I trust him."

Bob the IdP: "I see Jimmy sent you here. Please give me your credentials."

Bill the user: "Hi I'm Bill. Here are my credentials."

Bob the IdP: "Hi Bill. Looks like you check out."

Bob the IdP: "Hey Jimmy. This guy Bill checks out and here's some additional information about him. You do whatever you want from here."

Jimmy the SP: "Ok cool. Looks like Bill is also in our list of known guests. I'll let Bill in."

IdP Initiated SSO

Bill the user: "Hey Bob. I want to go to Jimmy's place. Security is tight over there."

Bob the IdP: "Hey Jimmy. I trust Bill. He checks out and here's some additional information about him. You do whatever you want from here."

Jimmy the SP: "Ok cool. Looks like Bill is also in our list of known guests. I'll let Bill in."

I go into more detail here, but still keeping things simple: https://jorgecolonconsulting.com/saml-sso-in-simple-terms/.

ActiveRecord: size vs count

The following strategies all make a call to the database to perform a COUNT(*) query.

Model.count

Model.all.size

records = Model.all
records.count

The following is not as efficient as it will load all records from the database into Ruby, which then counts the size of the collection.

records = Model.all
records.size

If your models have associations and you want to find the number of belonging objects (e.g. @customer.orders.size), you can avoid database queries (disk reads). Use a counter cache and Rails will keep the cache value up to date, and return that value in response to the size method.

Difference between the 'controller', 'link' and 'compile' functions when defining a directive

As complement to Mark's answer, the compile function does not have access to scope, but the link function does.

I really recommend this video; Writing Directives by Misko Hevery (the father of AngularJS), where he describes differences and some techniques. (Difference between compile function and link function at 14:41 mark in the video).

PHP Curl And Cookies

Here you can find some useful info about cURL & cookies http://docstore.mik.ua/orelly/webprog/pcook/ch11_04.htm .

You can also use this well done method https://github.com/alixaxel/phunction/blob/master/phunction/Net.php#L89 like a function:

function CURL($url, $data = null, $method = 'GET', $cookie = null, $options = null, $retries = 3)
{
    $result = false;

    if ((extension_loaded('curl') === true) && (is_resource($curl = curl_init()) === true))
    {
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_FAILONERROR, true);
        curl_setopt($curl, CURLOPT_AUTOREFERER, true);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

        if (preg_match('~^(?:DELETE|GET|HEAD|OPTIONS|POST|PUT)$~i', $method) > 0)
        {
            if (preg_match('~^(?:HEAD|OPTIONS)$~i', $method) > 0)
            {
                curl_setopt_array($curl, array(CURLOPT_HEADER => true, CURLOPT_NOBODY => true));
            }

            else if (preg_match('~^(?:POST|PUT)$~i', $method) > 0)
            {
                if (is_array($data) === true)
                {
                    foreach (preg_grep('~^@~', $data) as $key => $value)
                    {
                        $data[$key] = sprintf('@%s', rtrim(str_replace('\\', '/', realpath(ltrim($value, '@'))), '/') . (is_dir(ltrim($value, '@')) ? '/' : ''));
                    }

                    if (count($data) != count($data, COUNT_RECURSIVE))
                    {
                        $data = http_build_query($data, '', '&');
                    }
                }

                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            }

            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, strtoupper($method));

            if (isset($cookie) === true)
            {
                curl_setopt_array($curl, array_fill_keys(array(CURLOPT_COOKIEJAR, CURLOPT_COOKIEFILE), strval($cookie)));
            }

            if ((intval(ini_get('safe_mode')) == 0) && (ini_set('open_basedir', null) !== false))
            {
                curl_setopt_array($curl, array(CURLOPT_MAXREDIRS => 5, CURLOPT_FOLLOWLOCATION => true));
            }

            if (is_array($options) === true)
            {
                curl_setopt_array($curl, $options);
            }

            for ($i = 1; $i <= $retries; ++$i)
            {
                $result = curl_exec($curl);

                if (($i == $retries) || ($result !== false))
                {
                    break;
                }

                usleep(pow(2, $i - 2) * 1000000);
            }
        }

        curl_close($curl);
    }

    return $result;
}

And pass this as $cookie parameter:

$cookie_jar = tempnam('/tmp','cookie');

Generating random numbers in C

You should call srand() before calling rand to initialize the random number generator.

Either call it with a specific seed, and you will always get the same pseudo-random sequence

#include <stdlib.h>

int main ()
{
  srand ( 123 );
  int random_number = rand();
  return 0;
}

or call it with a changing sources, ie the time function

#include <stdlib.h>
#include <time.h>

int main ()
{
  srand ( time(NULL) );
  int random_number = rand();
  return 0;
}

In response to Moon's Comment rand() generates a random number with an equal probability between 0 and RAND_MAX (a macro pre-defined in stdlib.h)

You can then map this value to a smaller range, e.g.

int random_value = rand(); //between 0 and RAND_MAX

//you can mod the result
int N = 33;
int rand_capped = random_value % N;  //between 0 and 32
int S = 50;
int rand_range = rand_capped + S; //between 50 and 82

//you can convert it to a float
float unit_random = random_value / (float) RAND_MAX; //between 0 and 1 (floating point)

This might be sufficient for most uses, but its worth pointing out that in the first case using the mod operator introduces a slight bias if N does not divide evenly into RAND_MAX+1.

Random number generators are interesting and complex, it is widely said that the rand() generator in the C standard library is not a great quality random number generator, read (http://en.wikipedia.org/wiki/Random_number_generation for a definition of quality).

http://en.wikipedia.org/wiki/Mersenne_twister (source http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html ) is a popular high quality random number generator.

Also, I am not aware of arc4rand() or random() so I cannot comment.

Convert negative data into positive data in SQL Server

The best solution is: from positive to negative or from negative to positive

For negative:

SELECT ABS(a) * -1 AS AbsoluteA, ABS(b) * -1 AS AbsoluteB
FROM YourTable

For positive:

SELECT ABS(a) AS AbsoluteA, ABS(b)  AS AbsoluteB
FROM YourTable

How to check for a valid Base64 encoded string

All answers were been digested into 1 function that ensures 100% that its results will be accurate.

1) Use function as below:

    string encoded = "WW91ckJhc2U2NHN0cmluZw==";
    msgbox("Is string base64=" + IsBase64(encoded));

2) Below is the function:

public bool IsBase64(string base64String)
{
    try
    {
        if (!base64String.Length < 1)
        {
            if (!base64String.Equals(Convert.ToBase64String(Encoding.UTF8.GetBytes(Encoding.UTF8.GetString(Convert.FromBase64String(base64String)))), StringComparison.InvariantCultureIgnoreCase) & !System.Text.RegularExpressions.Regex.IsMatch(base64String, @"^[a-zA-Z0-9\+/]*={0,2}$"))
            {
                return false;
            }
            if ((base64String.Length % 4) != 0 || string.IsNullOrEmpty(base64String) || base64String.Length % 4 != 0 || base64String.Contains(" ") || base64String.Contains(Constants.vbTab) || base64String.Contains(Constants.vbCr) || base64String.Contains(Constants.vbLf))
            {
                return false;
            }
        }
        else
        {
            return false;
        }
                    
        return true;
    }
    catch (FormatException ex)
    {
            return false;
    }
}

What is sys.maxint in Python 3?

If you are looking for a number that is bigger than all others:

Method 1:

float('inf')

Method 2:

import sys
max = sys.maxsize

If you are looking for a number that is smaller than all others:

Method 1:

float('-inf')

Method 2:

import sys
min = -sys.maxsize - 1

Method 1 works in both Python2 and Python3. Method 2 works in Python3. I have not tried Method 2 in Python2.

Android intent for playing video?

I have come across this with the Hero, using what I thought was a published API. In the end, I used a test to see if the intent could be received:

private boolean isCallable(Intent intent) {
    List<ResolveInfo> list = getPackageManager().queryIntentActivities(intent, 
        PackageManager.MATCH_DEFAULT_ONLY);
    return list.size() > 0;
}

In use when I would usually just start the activity:

final Intent intent = new Intent("com.android.camera.action.CROP");
intent.setClassName("com.android.camera", "com.android.camera.CropImage");
if (isCallable(intent)) {
    // call the intent as you intended.
} else {
    // make alternative arrangements.
}

obvious: If you go down this route - using non-public APIs - you must absolutely provide a fallback which you know definitely works. It doesn't have to be perfect, it can be a Toast saying that this is unsupported for this handset/device, but you should avoid an uncaught exception. end obvious.

I find the Open Intents Registry of Intents Protocols quite useful, but I haven't found the equivalent of a TCK type list of intents which absolutely must be supported, and examples of what apps do different handsets.

PHP remove special character from string

Your dot is matching all characters. Escape it (and the other special characters), like this:

preg_replace('/[^a-zA-Z0-9_ %\[\]\.\(\)%&-]/s', '', $String);

Determine if 2 lists have the same elements, regardless of order?

As mentioned in comments above, the general case is a pain. It is fairly easy if all items are hashable or all items are sortable. However I have recently had to try solve the general case. Here is my solution. I realised after posting that this is a duplicate to a solution above that I missed on the first pass. Anyway, if you use slices rather than list.remove() you can compare immutable sequences.

def sequences_contain_same_items(a, b):
    for item in a:
        try:
            i = b.index(item)
        except ValueError:
            return False
        b = b[:i] + b[i+1:]
    return not b

ng-if check if array is empty

post.capabilities.items will still be defined because it's an empty array, if you check post.capabilities.items.length it should work fine because 0 is falsy.

What is WebKit and how is it related to CSS?

Update: So apparently, WebKit is a HTML/CSS web browser rendering engine for Safari/Chrome. Are there such engines for IE/Opera/Firefox and what are the differences, pros and cons of using one over the other? Can I use WebKit features in Firefox for example?

Every browser is backed by a rendering engine to draw the HTML/CSS web page.

~~IE → Trident~~ (discontinued)
Edge ? ~~EdgeHTML (clean-up fork of Trident)~~ (Edge switched to Blink in 2019)
Firefox → Gecko
~~Opera → Presto~~ (no longer uses Presto since Feb 2013, consider Opera = Chrome, therefore Blink nowadays)
Safari → WebKit
Chrome → Blink (a fork of Webkit).

See Comparison of web browser engines for a list of comparisons in different areas.

The ultimate question... is WebKit supported by IE?

Not natively.

Unable to launch the IIS Express Web server

The only solution that worked for me was to create another test project. Then following the next steps:

Right click the project and go to Properties -> Web
Under the project URL in the Use Local IIS Web Server section, copy the project URL(http:// localhost:59002/) - this is from the test project.
Navigate to the project which is giving this error. Right click the project and go to Properties -> Web.
Paste the project URL in the Use Local IIS Web Server section (URL copied from the test project). Close the test project and save.
Delete the test project and run the project that gave the error. Works after that...

Maybe not the best way but it was the only way I could get this to work. I received this error message after I reloaded my laptop (hard drive crashed) and got all of my projects from the server of where they where hosted.

Link entire table row?

I agree with Matti. Would be easy to do with some simple javascript. A quick jquery example would be something like this:

<tr>
  <td><a href="http://www.example.com/">example</a></td>
  <td>another cell</td>
  <td>one more</td>
</tr>

and

$('tr').click( function() {
    window.location = $(this).find('a').attr('href');
}).hover( function() {
    $(this).toggleClass('hover');
});

then in your CSS

tr.hover {
   cursor: pointer;
   /* whatever other hover styles you want */
}

What are .NumberFormat Options In Excel VBA?

Thanks to this question (and answers), I discovered an easy way to get at the exact NumberFormat string for virtually any format that Excel has to offer.

How to Obtain the NumberFormat String for Any Excel Number Format

Step 1: In the user interface, set a cell to the NumberFormat you want to use.

I manually formatted a cell to Chinese (PRC) currency

In my example, I selected the Chinese (PRC) Currency from the options contained in the "Account Numbers Format" combo box.

Step 2: Expand the Number Format dropdown and select "More Number Formats...".

Open the Number Format dropdown

Step 3: In the Number tab, in Category, click "Custom".

Click Custom

The "Sample" section shows the Chinese (PRC) currency formatting that I applied.

The "Type" input box contains the NumberFormat string that you can use programmatically.

So, in this example, the NumberFormat of my Chinese (PRC) Currency cell is as follows:

_ [$¥-804]* #,##0.00_ ;_ [$¥-804]* -#,##0.00_ ;_ [$¥-804]* "-"??_ ;_ @_

If you do these steps for each NumberFormat that you desire, then the world is yours.

I hope this helps.

Printing long int value in C

To take input " long int " and output " long int " in C is :

long int n;
scanf("%ld", &n);
printf("%ld", n);

To take input " long long int " and output " long long int " in C is :

long long int n;
scanf("%lld", &n);
printf("%lld", n);

Hope you've cleared..

typedef fixed length array

Here's a short example of why typedef array can be confusingly inconsistent. The other answers provide a workaround.

#include <stdio.h>
typedef char type24[3];

int func(type24 a) {
        type24 b;
        printf("sizeof(a) is %zu\n",sizeof(a));
        printf("sizeof(b) is %zu\n",sizeof(b));
        return 0;
}

int main(void) {
        type24 a;
        return func(a);
}

This produces the output

sizeof(a) is 8
sizeof(b) is 3

because type24 as a parameter is a pointer. (In C, arrays are always passed as pointers.) The gcc8 compiler will issue a warning by default, thankfully.

HSL to RGB color conversion

Php Implementation of Chris's C# Code

Also from here, which explains the math of it very well.

This is basically a bunch of functions to convert to and from HSL (Hue Saturation Lightness)

Tested and working on PHP 5.6.15

TL;DR: The full code can be found here on Pastebin.

Hex to HSL

Input: Hex color in format: [#]0f4 or [#]00ff44 (pound sign optional)
Output: HSL in Degrees, Percent, Percent

/**
 * Input: hex color
 * Output: hsl(in ranges from 0-1)
 * 
 * Takes the hex, converts it to RGB, and sends
 * it to RGBToHsl.  Returns the output.
 * 
*/
function hexToHsl($hex) {
    $r = "";
    $g = "";
    $b = "";

    $hex = str_replace('#', '', $hex);

    if (strlen($hex) == 3) {
        $r = substr($hex, 0, 1);
        $r = $r . $r;
        $g = substr($hex, 1, 1);
        $g = $g . $g;
        $b = substr($hex, 2, 1);
        $b = $b . $b;
    } elseif (strlen($hex) == 6) {
        $r = substr($hex, 0, 2);
        $g = substr($hex, 2, 2);
        $b = substr($hex, 4, 2);
    } else {
        return false;
    }

    $r = hexdec($r);
    $g = hexdec($g);
    $b = hexdec($b);

    $hsl =  rgbToHsl($r,$g,$b);
    return $hsl;
}

RGB to HSL

Input: RGB in range 0-255 Output: HSL in Degrees, Percent, Percent.

/**
 * 
 *Credits:
 * https://stackoverflow.com/questions/4793729/rgb-to-hsl-and-back-calculation-problems
 * http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/
 *
 * Called by hexToHsl by default.
 *
 * Converts an RGB color value to HSL. Conversion formula
 * adapted from http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/.
 * Assumes r, g, and b are contained in the range [0 - 255] and
 * returns h, s, and l in the format Degrees, Percent, Percent.
 *
 * @param   Number  r       The red color value
 * @param   Number  g       The green color value
 * @param   Number  b       The blue color value
 * @return  Array           The HSL representation
*/
function rgbToHsl($r, $g, $b){  
    //For the calculation, rgb needs to be in the range from 0 to 1. To convert, divide by 255 (ff). 
    $r /= 255;
    $g /= 255;
    $b /= 255;

    $myMax = max($r, $g, $b);
    $myMin = min($r, $g, $b);

    $maxAdd = ($myMax + $myMin);
    $maxSub = ($myMax - $myMin);

    //luminence is (max + min)/2
    $h = 0;
    $s = 0;
    $l = ($maxAdd / 2.0);

    //if all the numbers are equal, there is no saturation (greyscale).
    if($myMin != $myMax){
        if ($l < 0.5) {
            $s = ($maxSub / $maxAdd);
        } else {
            $s = (2.0 - $myMax - $myMin); //note order of opperations - can't use $maxSub here
            $s = ($maxSub / $s);
        }

        //find hue
        switch($myMax){
            case $r: 
                $h = ($g - $b);
                $h = ($h / $maxSub);
                break;
            case $g: 
                $h = ($b - $r); 
                $h = ($h / $maxSub);
                $h = ($h + 2.0);
                break;
            case $b: 
                $h = ($r - $g);
                $h = ($h / $maxSub); 
                $h = ($h + 4.0);
                break;
        } 
    }

    $hsl = hslToDegPercPerc($h, $s, $l);
    return $hsl;
}

HSL (0-1 range) to Degrees, Percent, Percent format

For the math calculations, HSL is easier to deal with in the 0-1 range, but for human readability, it's easier in Degrees, Percent, Percent. This function takes HSL in the ranges 0-1, and returns HSL in Degrees, Percent, Percent.

/**
 * Input: HSL in ranges 0-1.
 * Output: HSL in format Deg, Perc, Perc.
 * 
 * Note: rgbToHsl calls this function by default.
 * 
 * Multiplies $h by 60, and $s and $l by 100.
 */
function hslToDegPercPerc($h, $s, $l) {
    //convert h to degrees
    $h *= 60;

    if ($h < 0) {
        $h += 360;
    }

    //convert s and l to percentage
    $s *= 100;
    $l *= 100;

    $hsl['h'] = $h;
    $hsl['s'] = $s;
    $hsl['l'] = $l;
    return $hsl;
}

HSL (Degrees, Percent, Percent format) to HSL in range 0-1

This function converts HSL in the format Degrees, Percent, Percent, to the ranges 0-1 for easier computing.

/**
 * Input: HSL in format Deg, Perc, Perc
 * Output: An array containing HSL in ranges 0-1
 * 
 * Divides $h by 60, and $s and $l by 100.
 * 
 * hslToRgb calls this by default.
*/
function degPercPercToHsl($h, $s, $l) { 
    //convert h, s, and l back to the 0-1 range

    //convert the hue's 360 degrees in a circle to 1
    $h /= 360;

    //convert the saturation and lightness to the 0-1 
    //range by multiplying by 100
    $s /= 100;
    $l /= 100;

    $hsl['h'] =  $h;
    $hsl['s'] = $s;
    $hsl['l'] = $l;

    return $hsl;
}

HSL to RGB

Input: HSL in the format Degrees, Percent, Percent Output: RGB in the format 255, 255, 255.

/**
 * Converts an HSL color value to RGB. Conversion formula
 * adapted from http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/.
 * Assumes h, s, and l are in the format Degrees,
 * Percent, Percent, and returns r, g, and b in 
 * the range [0 - 255].
 *
 * Called by hslToHex by default.
 *
 * Calls: 
 *   degPercPercToHsl
 *   hueToRgb
 *
 * @param   Number  h       The hue value
 * @param   Number  s       The saturation level
 * @param   Number  l       The luminence
 * @return  Array           The RGB representation
 */
function hslToRgb($h, $s, $l){
    $hsl = degPercPercToHsl($h, $s, $l);
    $h = $hsl['h'];
    $s = $hsl['s'];
    $l = $hsl['l'];

    //If there's no saturation, the color is a greyscale,
    //so all three RGB values can be set to the lightness.
    //(Hue doesn't matter, because it's grey, not color)
    if ($s == 0) {
        $r = $l * 255;
        $g = $l * 255;
        $b = $l * 255;
    }
    else {
        //calculate some temperary variables to make the 
        //calculation eaisier.
        if ($l < 0.5) {
            $temp2 = $l * (1 + $s);
        } else {
            $temp2 = ($l + $s) - ($s * $l);
        }
        $temp1 = 2 * $l - $temp2;

        //run the calculated vars through hueToRgb to
        //calculate the RGB value.  Note that for the Red
        //value, we add a third (120 degrees), to adjust 
        //the hue to the correct section of the circle for
        //red.  Simalarly, for blue, we subtract 1/3.
        $r = 255 * hueToRgb($temp1, $temp2, $h + (1 / 3));
        $g = 255 * hueToRgb($temp1, $temp2, $h);
        $b = 255 * hueToRgb($temp1, $temp2, $h - (1 / 3));
    }

    $rgb['r'] = $r;
    $rgb['g'] = $g;
    $rgb['b'] = $b;

    return $rgb;
}

Hue to RGB

This function is called by hslToRgb to convert the hue into the separate RGB values.

/**
 * Converts an HSL hue to it's RGB value.  
 *
 * Input: $temp1 and $temp2 - temperary vars based on 
 * whether the lumanence is less than 0.5, and 
 * calculated using the saturation and luminence
 * values.
 *  $hue - the hue (to be converted to an RGB 
 * value)  For red, add 1/3 to the hue, green 
 * leave it alone, and blue you subtract 1/3 
 * from the hue.
 *
 * Output: One RGB value.
 *
 * Thanks to Easy RGB for this function (Hue_2_RGB).
 * http://www.easyrgb.com/index.php?X=MATH&$h=19#text19
 *
*/
function hueToRgb($temp1, $temp2, $hue) {
    if ($hue < 0) { 
        $hue += 1;
    }
    if ($hue > 1) {
        $hue -= 1;
    }

    if ((6 * $hue) < 1 ) {
        return ($temp1 + ($temp2 - $temp1) * 6 * $hue);
    } elseif ((2 * $hue) < 1 ) {
        return $temp2;
    } elseif ((3 * $hue) < 2 ) {
        return ($temp1 + ($temp2 - $temp1) * ((2 / 3) - $hue) * 6);
    }
    return $temp1;
}

HSL to Hex

Input: HSL in format Degrees, Percent, Percent Output: Hex in format 00ff22 (no pound sign).

Converts to RGB, then converts separately to hex.

/**
 * Converts HSL to Hex by converting it to 
 * RGB, then converting that to hex.
 * 
 * string hslToHex($h, $s, $l[, $prependPound = true]
 * 
 * $h is the Degrees value of the Hue
 * $s is the Percentage value of the Saturation
 * $l is the Percentage value of the Lightness
 * $prependPound is a bool, whether you want a pound 
 *  sign prepended. (optional - default=true)
 *
 * Calls: 
 *   hslToRgb
 *
 * Output: Hex in the format: #00ff88 (with 
 * pound sign).  Rounded to the nearest whole
 * number.
*/
function hslToHex($h, $s, $l, $prependPound = true) {
    //convert hsl to rgb
    $rgb = hslToRgb($h,$s,$l);

    //convert rgb to hex
    $hexR = $rgb['r'];
    $hexG = $rgb['g'];
    $hexB = $rgb['b'];

    //round to the nearest whole number
    $hexR = round($hexR);
    $hexG = round($hexG);
    $hexB = round($hexB);

    //convert to hex
    $hexR = dechex($hexR);
    $hexG = dechex($hexG);
    $hexB = dechex($hexB);

    //check for a non-two string length
    //if it's 1, we can just prepend a
    //0, but if it is anything else non-2,
    //it must return false, as we don't 
    //know what format it is in.
    if (strlen($hexR) != 2) {
        if (strlen($hexR) == 1) {
            //probably in format #0f4, etc.
            $hexR = "0" . $hexR;
        } else {
            //unknown format
            return false;
        }
    }
    if (strlen($hexG) != 2) {
        if (strlen($hexG) == 1) {
            $hexG = "0" . $hexG;
        } else {
            return false;
        }
    }
    if (strlen($hexB) != 2) {
        if (strlen($hexB) == 1) {
            $hexB = "0" . $hexB;
        } else {
            return false;
        }
    }

    //if prependPound is set, will prepend a
    //# sign to the beginning of the hex code.
    //(default = true)
    $hex = "";
    if ($prependPound) {
        $hex = "#";
    }

    $hex = $hex . $hexR . $hexG . $hexB;

    return $hex;
}

How to initialize var?

var just tells the compiler to infer the type you wanted at compile time...it cannot infer from null (though there are cases it could).

So, no you are not allowed to do this.

When you say "some empty value"...if you mean:

var s = string.Empty;
//
var s = "";

Then yes, you may do that, but not null.

Difference between git stash pop and git stash apply

In git stash is a storage area where current changed files can be moved.

stash area is useful when you want to pull some changes from git repository and detected some changes in some mutual files available in git repo.

git stash apply //apply the changes without removing stored files from stash area.

git stash pop  // apply the changes as well as remove stored files from stash area.

Note :- git apply only apply the changes from stash area while git pop apply as well as remove change from stash area.

cannot find zip-align when publishing app

i solved by RUN as Administrator @ your SDK Manager.exe in directory C:\Program Files\Android SDK

after that u'll get updated build tools an any repository

Paste multiple columns together

# your starting data..
data <- data.frame('a' = 1:3, 'b' = c('a','b','c'), 'c' = c('d', 'e', 'f'), 'd' = c('g', 'h', 'i')) 

# columns to paste together
cols <- c( 'b' , 'c' , 'd' )

# create a new column `x` with the three columns collapsed together
data$x <- apply( data[ , cols ] , 1 , paste , collapse = "-" )

# remove the unnecessary columns
data <- data[ , !( names( data ) %in% cols ) ]

How to set image for bar button with swift?

Similar to the accepted solution, but you can replace the

let button: UIButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton

with

let button = UIButton()

Here is the full solution, enjoy: (it's just a bit cleaner than the accepted solution)

let button = UIButton()
button.frame = CGRectMake(0, 0, 51, 31) //won't work if you don't set frame
button.setImage(UIImage(named: "fb"), forState: .Normal)
button.addTarget(self, action: Selector("fbButtonPressed"), forControlEvents: .TouchUpInside)

let barButton = UIBarButtonItem()
barButton.customView = button
self.navigationItem.rightBarButtonItem = barButton

How to show/hide if variable is null

In this case, myvar should be a boolean value. If this variable is true, it will show the div, if it's false.. It will hide.

Check this out.

Failed loading english.pickle with nltk.data.load

In Python-3.6 I can see the suggestion in the traceback. That's quite helpful. Hence I will say you guys to pay attention to the error you got, most of the time answers are within that problem ;).

And then as suggested by other folks here either using python terminal or using a command like python -c "import nltk; nltk.download('wordnet')" we can install them on the fly. You just need to run that command once and then it will save the data locally in your home directory.

What are the use cases for selecting CHAR over VARCHAR in SQL?

There is a difference between early performance optimization and using a best practice type of rule. If you are creating new tables where you will always have a fixed length field, it makes sense to use CHAR, you should be using it in that case. This isn't early optimization, but rather implementing a rule of thumb (or best practice).

i.e. - If you have a 2 letter state field, use CHAR(2). If you have a field with the actual state names, use VARCHAR.

Unit Testing: DateTime.Now

Add a fake assembly for System (right click on System reference=>Add fake assembly).

And write into your test method:

using (ShimsContext.Create())
{
   System.Fakes.ShimDateTime.NowGet = () => new DateTime(2014, 3, 10);
   MethodThatUsesDateTimeNow();
}

How to reset the state of a Redux store?

With Redux if have applied the following solution, which assumes I have set an initialState in all my reducers (e.g. { user: { name, email }}). In many components I check on these nested properties, so with this fix I prevent my renders methods are broken on coupled property conditions (e.g. if state.user.email, which will throw an error user is undefined if upper mentioned solutions).

const appReducer = combineReducers({
  tabs,
  user
})

const initialState = appReducer({}, {})

const rootReducer = (state, action) => {
  if (action.type === 'LOG_OUT') {
    state = initialState
  }

  return appReducer(state, action)
}

Bootstrap 3 - Responsive mp4-video

using that code wil give you a responsive video player with full control

<div class="embed-responsive embed-responsive-16by9">
    <iframe class="embed-responsive-item" width="640" height="480" src="https://www.youtube-nocookie.com/embed/Lw_e0vF1IB4" frameborder="0" allowfullscreen></iframe>
</div>

how to use python2.7 pip instead of default pip

An alternative is to call the pip module by using python2.7, as below:

python2.7 -m pip <commands>

For example, you could run python2.7 -m pip install <package> to install your favorite python modules. Here is a reference: https://stackoverflow.com/a/50017310/4256346.

In case the pip module has not yet been installed for this version of python, you can run the following:

python2.7 -m ensurepip

Running this command will "bootstrap the pip installer". Note that running this may require administrative privileges (i.e. sudo). Here is a reference: https://docs.python.org/2.7/library/ensurepip.html and another reference https://stackoverflow.com/a/46631019/4256346.

How to redirect output of systemd service to a file

Short answer:

StandardOutput=file:/var/log1.log
StandardError=file:/var/log2.log

If you don't want the files to be cleared every time the service is run, use append instead:

StandardOutput=append:/var/log1.log
StandardError=append:/var/log2.log

Include CSS,javascript file in Yii Framework

You can also add scripts from controller action. Just add this line in an action method then that script will apear only in that view:

Yii::app()->clientScript->registerScriptFile(Yii::app()->request->baseUrl . '/js/custom.js', CClientScript::POS_HEAD);

where POS_HEAD tell framework to put script in head section

Find the max of two or more columns with pandas

@DSM's answer is perfectly fine in almost any normal scenario. But if you're the type of programmer who wants to go a little deeper than the surface level, you might be interested to know that it is a little faster to call numpy functions on the underlying .to_numpy() (or .values for <0.24) array instead of directly calling the (cythonized) functions defined on the DataFrame/Series objects.

For example, you can use ndarray.max() along the first axis.

# Data borrowed from @DSM's post.
df = pd.DataFrame({"A": [1,2,3], "B": [-2, 8, 1]})
df
   A  B
0  1 -2
1  2  8
2  3  1

df['C'] = df[['A', 'B']].values.max(1)
# Or, assuming "A" and "B" are the only columns, 
# df['C'] = df.values.max(1) 
df

   A  B  C
0  1 -2  1
1  2  8  8
2  3  1  3

If your data has NaNs, you will need numpy.nanmax:

df['C'] = np.nanmax(df.values, axis=1)
df

   A  B  C
0  1 -2  1
1  2  8  8
2  3  1  3

You can also use numpy.maximum.reduce. numpy.maximum is a ufunc (Universal Function), and every ufunc has a reduce:

df['C'] = np.maximum.reduce(df['A', 'B']].values, axis=1)
# df['C'] = np.maximum.reduce(df[['A', 'B']], axis=1)
# df['C'] = np.maximum.reduce(df, axis=1)
df

   A  B  C
0  1 -2  1
1  2  8  8
2  3  1  3

np.maximum.reduce and np.max appear to be more or less the same (for most normal sized DataFrames)—and happen to be a shade faster than DataFrame.max. I imagine this difference roughly remains constant, and is due to internal overhead (indexing alignment, handling NaNs, etc).

The graph was generated using perfplot. Benchmarking code, for reference:

import pandas as pd
import perfplot

np.random.seed(0)
df_ = pd.DataFrame(np.random.randn(5, 1000))

perfplot.show(
    setup=lambda n: pd.concat([df_] * n, ignore_index=True),
    kernels=[
        lambda df: df.assign(new=df.max(axis=1)),
        lambda df: df.assign(new=df.values.max(1)),
        lambda df: df.assign(new=np.nanmax(df.values, axis=1)),
        lambda df: df.assign(new=np.maximum.reduce(df.values, axis=1)),
    ],
    labels=['df.max', 'np.max', 'np.maximum.reduce', 'np.nanmax'],
    n_range=[2**k for k in range(0, 15)],
    xlabel='N (* len(df))',
    logx=True,
    logy=True)

Concatenate columns in Apache Spark DataFrame

From Spark 2.3(SPARK-22771) Spark SQL supports the concatenation operator ||.

For example;

val df = spark.sql("select _c1 || _c2 as concat_column from <table_name>")

How to set a tkinter window to a constant size

Try parent_window.maxsize(x,x); to set the maximum size. It shouldn't get larger even if you set the background, etc.

Edit: use parent_window.minsize(x,x) also to set it to a constant size!

CSS @media print issues with background-color;

Got it:

CSS:

box-shadow: inset 0 0 0 1000px gold;

Works for all boxes - including table cells !!!

(If the PDF-printer output file is to be believed..?)
Only tested in Chrome + Firefox on Ubuntu...

Composer: The requested PHP extension ext-intl * is missing from your system

I have solved this problem by adding --ignore-platform-reqs command with composer install in ubuntu.

composer install --ignore-platform-reqs

Wrapping a react-router Link in an html button

You can use useHistory hook since react-router v5.1.0.

The useHistory hook gives you access to the history instance that you may use to navigate.

import React from 'react'
import { useHistory } from 'react-router-dom'

export default function SomeComponent() {
  const { push } = useHistory()
  ...
  <button
    type="button"
    onClick={() => push('/some-link')}
  >
    Some link
  </button>
  ...
}

case-insensitive matching in xpath?

matches() is an XPATH 2.0 function that allows for case-insensitive regex matching.

One of the flags is i for case-insensitive matching.

The following XPATH using the matches() function with the case-insensitive flag:

//CD[matches(@title,'empire burlesque','i')]

Python Requests and persistent sessions

snippet to retrieve json data, password protected

import requests

username = "my_user_name"
password = "my_super_secret"
url = "https://www.my_base_url.com"
the_page_i_want = "/my_json_data_page"

session = requests.Session()
# retrieve cookie value
resp = session.get(url+'/login')
csrf_token = resp.cookies['csrftoken']
# login, add referer
resp = session.post(url+"/login",
                  data={
                      'username': username,
                      'password': password,
                      'csrfmiddlewaretoken': csrf_token,
                      'next': the_page_i_want,
                  },
                  headers=dict(Referer=url+"/login"))
print(resp.json())

Importing images from a directory (Python) to list or dictionary

from PIL import Image
import os, os.path

imgs = []
path = "/home/tony/pictures"
valid_images = [".jpg",".gif",".png",".tga"]
for f in os.listdir(path):
    ext = os.path.splitext(f)[1]
    if ext.lower() not in valid_images:
        continue
    imgs.append(Image.open(os.path.join(path,f)))

Formatting floats without trailing zeros

>>> str(a if a % 1 else int(a))

Why is Android Studio reporting "URI is not registered"?

In Android Studio 3.1.2 this error occurs due to Wrong validation of the cache memory.,

Go to Project folder and delete all the contents in .idea folder

This will delete the cache memory and reloading the project will create new cache memory folder and makes it good to go.,

Deleting a SQL row ignoring all foreign keys and constraints

This is the way to disable foreign key checks in MySQL. Not relevant to OP's question since they use MS SQL Server, but google search results do turn this up so here's for reference:

SET FOREIGN_KEY_CHECKS = 0;

/ Run your script /

SET FOREIGN_KEY_CHECKS = 1;

See if this helps, This is for ignoring the foreign key checks. But deleting disabling this is very bad practice.

How to increase scrollback buffer size in tmux?

This builds on ntc2 and Chris Johnsen's answer. I am using this whenever I want to create a new session with a custom history-limit. I wanted a way to create sessions with limited scrollback without permanently changing my history-limit for future sessions.

tmux set-option -g history-limit 100 \; new-session -s mysessionname \; set-option -g history-limit 2000

This works whether or not there are existing sessions. After setting history-limit for the new session it resets it back to the default which for me is 2000.

I created an executable bash script that makes this a little more useful. The 1st parameter passed to the script sets the history-limit for the new session and the 2nd parameter sets its session name:

#!/bin/bash
tmux set-option -g history-limit "${1}" \; new-session -s "${2}" \; set-option -g history-limit 2000

Updating property value in properties file without deleting other values

Properties prop = new Properties();
prop.load(...); // FileInputStream 
prop.setProperty("key", "value");
prop.store(...); // FileOutputStream

Where is the .NET Framework 4.5 directory?

.NET 4.5 is an in place replacement for 4.0 - you will find the assemblies in the 4.0 directory.

See the blogs by Rick Strahl and Scott Hanselman on this topic.

You can also find the specific versions in:

C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework

Move top 1000 lines from text file to a new file using Unix shell commands

head -1000 file.txt > first100lines.txt
tail --lines=+1001 file.txt > restoffile.txt

How to get ip address of a server on Centos 7 in bash

Run this command to show ip4 and ip6:

ifconfig eth0 | grep inet | awk '{print $2}' | cut -d/ -f1

Get Root Directory Path of a PHP project

you can try: $_SERVER['PATH_TRANSLATED']

quote:

Filesystem- (not document root-) based path to the current script, after the server has done any virtual-to-real mapping. Note: As of PHP 4.3.2, PATH_TRANSLATED is no longer set implicitly under the Apache 2 SAPI in contrast to the situation in Apache 1, where it's set to the same value as the SCRIPT_FILENAME server variable when it's not populated by Apache.
This change was made to comply with the CGI specification that PATH_TRANSLATED should only exist if PATH_INFO is defined. Apache 2 users may use AcceptPathInfo = On inside httpd.conf to define PATH_INFO

source: php.net/manual

How to access a dictionary key value present inside a list?

First of all don't use 'list' as variable name.

If you have simple dictionaries with unique keys then you can do the following(note that new dictionary object with all items from sub-dictionaries will be created):

res  = {}
for line in listOfDicts:
   res.update(line)
res['d']
>>> 4

Otherwise:

getValues = lambda key,inputData: [subVal[key] for subVal in inputData if key in subVal]
getValues('d', listOfDicts)
>>> [4]

Or very base:

def get_value(listOfDicts, key):
    for subVal in listOfDicts:
        if key in subVal:
            return subVal[key]

Mod of negative number is melting my brain

For the more performance aware devs

uint wrap(int k, int n) ((uint)k)%n

A small performance comparison

Modulo: 00:00:07.2661827 ((n%x)+x)%x)
Cast:   00:00:03.2202334 ((uint)k)%n
If:     00:00:13.5378989 ((k %= n) < 0) ? k+n : k

As for performance cost of cast to uint have a look here

Visual Studio 6 Windows Common Controls 6.0 (sp6) Windows 7, 64 bit

=> just what jay said just delete those registry entries which are pointing to other paths other than on c:\windows\system32.Those are the culprits of the error.I got those errors on my vb6 IDE and after deleting those anomalous registry entries the problem was fixed. works like a charm.

java.rmi.ConnectException: Connection refused to host: 127.0.1.1;

I had the same exact problem and my issue was that I had 2 IP addresses from 2 different networks configured in the etc/hosts as below.

10.xxx.x.xxx    localhost
192.xxx.x.xxx   localhost

This should be because there was a conflict as to which IP to be used for the other devices to reach the rmiregistry over the network.

Once I removed the extra-record that is not required, I was able to solve the issue.

So my etc/hosts file had only the following record.

10.xxx.x.xxx    localhost

What does the question mark operator mean in Ruby?

Also note ? along with a character, will return the ASCII character code for A

For example:

?F # => will return 70

Alternately in ruby 1.8 you can do:

"F"[0]

or in ruby 1.9:

"F".ord

Also notice that ?F will return the string "F", so in order to make the code shorter, you can also use ?F.ord in Ruby 1.9 to get the same result as "F".ord.

How to push objects in AngularJS between ngRepeat arrays

Try this one also...

_x000D_

<!DOCTYPE html>_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
_x000D_
  <p>Click the button to join two arrays.</p>_x000D_
_x000D_
  <button onclick="myFunction()">Try it</button>_x000D_
_x000D_
  <p id="demo"></p>_x000D_
  <p id="demo1"></p>_x000D_
  <script>_x000D_
    function myFunction() {_x000D_
      var hege = [{_x000D_
        1: "Cecilie",_x000D_
        2: "Lone"_x000D_
      }];_x000D_
      var stale = [{_x000D_
        1: "Emil",_x000D_
        2: "Tobias"_x000D_
      }];_x000D_
      var hege = hege.concat(stale);_x000D_
      document.getElementById("demo1").innerHTML = hege;_x000D_
      document.getElementById("demo").innerHTML = stale;_x000D_
    }_x000D_
  </script>_x000D_
_x000D_
</body>_x000D_
_x000D_
</html>

_x000D_

How do I find the length (or dimensions, size) of a numpy matrix in python?

matrix.size according to the numpy docs returns the Number of elements in the array. Hope that helps.

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

_x000D_

select_x000D_
   c.owner,_x000D_
   c.object_name,_x000D_
   c.object_type,_x000D_
   b.sid,_x000D_
   b.serial#,_x000D_
   b.status,_x000D_
   b.osuser,_x000D_
   b.machine_x000D_
from_x000D_
   v$locked_object a,_x000D_
   v$session b,_x000D_
   dba_objects c_x000D_
where_x000D_
   b.sid = a.session_id_x000D_
and_x000D_
   a.object_id = c.object_id;_x000D_
   _x000D_
   ALTER SYSTEM KILL SESSION 'sid,serial#';

_x000D_

Integrate ZXing in Android Studio

buttion.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                new com.google.zxing.integration.android.IntentIntegrator(Fragment.this).initiateScan();
            }
        });

    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
        if(result != null) {
            if(result.getContents() == null) {
                Log.d("MainActivity", "Cancelled scan");
                Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
            } else {
                Log.d("MainActivity", "Scanned");
                Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();
            }
        } else {
            // This is important, otherwise the result will not be passed to the fragment
            super.onActivityResult(requestCode, resultCode, data);
        }
    }



dependencies {
    compile 'com.journeyapps:zxing-android-embedded:3.2.0@aar'
    compile 'com.google.zxing:core:3.2.1'
    compile 'com.android.support:appcompat-v7:23.1.0'
}

AttributeError: 'DataFrame' object has no attribute

value_counts() is now a DataFrame method since pandas 1.1.0

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.value_counts.html

Styles.Render in MVC4

It's calling the files included in that particular bundle which is declared inside the BundleConfig class in the App_Start folder.

In that particular case The call to @Styles.Render("~/Content/css") is calling "~/Content/site.css".

bundles.Add(new StyleBundle("~/Content/css").Include("~/Content/site.css"));

Can't connect to MySQL server on '127.0.0.1' (10061) (2003)

Looks like the mysql server is not started.

Look to the official documentation of MySQL how you can start a service under windows.

Install the server as a service using this command: C:> "C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqld" --install

How many values can be represented with n bits?

2⁹ = 512 values, because that's how many combinations of zeroes and ones you can have.

What those values represent however will depend on the system you are using. If it's an unsigned integer, you will have:

000000000 = 0 (min)
000000001 = 1
...
111111110 = 510
111111111 = 511 (max)

In two's complement, which is commonly used to represent integers in binary, you'll have:

000000000 = 0
000000001 = 1
...
011111110 = 254
011111111 = 255 (max)
100000000 = -256 (min) <- yay integer overflow
100000001 = -255
...
111111110 = -2
111111111 = -1

In general, with k bits you can represent 2^k values. Their range will depend on the system you are using:

Unsigned: 0 to 2^k-1
Signed: -2^k-1 to 2^k-1-1

How to resize JLabel ImageIcon?

Resizing the icon is not straightforward. You need to use Java's graphics 2D to scale the image. The first parameter is a Image class which you can easily get from ImageIcon class. You can use ImageIcon class to load your image file and then simply call getter method to get the image.

private Image getScaledImage(Image srcImg, int w, int h){
    BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D g2 = resizedImg.createGraphics();

    g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
    g2.drawImage(srcImg, 0, 0, w, h, null);
    g2.dispose();

    return resizedImg;
}

c# why can't a nullable int be assigned null as a value

What Harry S says is exactly right, but

int? accom = (accomStr == "noval" ? null : (int?)Convert.ToInt32(accomStr));

would also do the trick. (We Resharper users can always spot each other in crowds...)

Wait for shell command to complete

Use the WScript.Shell instead, because it has a waitOnReturn option:

Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1

wsh.Run "C:\folder\runbat.bat", windowStyle, waitOnReturn

(Idea copied from Wait for Shell to finish, then format cells - synchronously execute a command)

How to deal with persistent storage (e.g. databases) in Docker

When using Docker Compose, simply attach a named volume, for example:

version: '2'
services:
  db:
    image: mysql:5.6
    volumes:
      - db_data:/var/lib/mysql:rw
    environment:
      MYSQL_ROOT_PASSWORD: root
volumes:
  db_data:

Ignore mapping one property with Automapper

I'm perhaps a bit of a perfectionist; I don't really like the ForMember(..., x => x.Ignore()) syntax. It's a little thing, but it it matters to me. I wrote this extension method to make it a bit nicer:

public static IMappingExpression<TSource, TDestination> Ignore<TSource, TDestination>(
    this IMappingExpression<TSource, TDestination> map,
    Expression<Func<TDestination, object>> selector)
{
    map.ForMember(selector, config => config.Ignore());
    return map;
}

It can be used like so:

Mapper.CreateMap<JsonRecord, DatabaseRecord>()
        .Ignore(record => record.Field)
        .Ignore(record => record.AnotherField)
        .Ignore(record => record.Etc);

You could also rewrite it to work with params, but I don't like the look of a method with loads of lambdas.

Selecting only first-level elements in jquery

.add_to_cart >>> .form-item:eq(1)

the second .form-item at tree level child from the .add_to_cart

What is the iOS 6 user agent string?

iPhone:

Mozilla/5.0 (iPhone; CPU iPhone OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5376e Safari/8536.25

iPad:

Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5376e Safari/8536.25

For a complete list and more details about the iOS user agent check out these 2 resources:
Safari User Agent Strings (http://useragentstring.com/pages/Safari/)
Complete List of iOS User-Agent Strings (http://enterpriseios.com/wiki/UserAgent)

Reloading .env variables without restarting server (Laravel 5, shared hosting)

In config/database.php I changed the default DB connection from mysql to sqlite. I deleted the .env file (actually renamed it) and created the sqlite file with touch storage/database.sqlite. The migration worked with sqlite.

Then I switched back the config/database.php default DB connection to mysql and recovered the .env file. The migration worked with mysql.

It doesn't make sense I guess. Maybe was something serverside.

git status shows fatal: bad object HEAD

This is unlikely to be the source of your problem - but if you happen to be working in .NET you'll end up with a bunch of obj/ folders. Sometimes it is helpful to delete all of these obj/ folders in order to resolve a pesky build issue.

I received the same fatal: bad object HEAD on my current branch (master) and was unable to run git status or to checkout any other branch (I always got an error refs/remote/[branch] does not point to a valid object).

If you want to delete all of your obj folders, don't get lazy and allow .git/objects into the mix. That folder is where all of the actual contents of your git commits go.

After being close to giving up I decided to look at which files were in my recycle bin, and there it was. Restored the file and my local repository was like new.

C++ Structure Initialization

It is possible, but only if the struct you're initializing is a POD (plain old data) struct. It cannot contain any methods, constructors, or even default values.

java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlObject Error

For all that you add xmlbeans-2.3.0.jar and it is not working,you must use HSSFWorkbook instead of XSSFWorkbook after add jar.For instance;

    Workbook workbook = new HSSFWorkbook();
    Sheet listSheet = workbook.createSheet("Kisi Listesi");

    int rowIndex = 0;
    for (KayitParam kp : kayitList) {
        Row row = listSheet.createRow(rowIndex++);
        int cellIndex = 0;
        row.createCell(cellIndex++).setCellValue(kp.getAd());
        row.createCell(cellIndex++).setCellValue(kp.getSoyad());
        row.createCell(cellIndex++).setCellValue(kp.getEposta());
        row.createCell(cellIndex++).setCellValue(kp.getCinsiyet());
        row.createCell(cellIndex++).setCellValue(kp.getDogumtarihi());
        row.createCell(cellIndex++).setCellValue(kp.getTahsil());
    }

    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        workbook.write(baos);
        AMedia amedia = new AMedia("Kisiler.xls", "xls",
                "application/file", baos.toByteArray());
        Filedownload.save(amedia);
        baos.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

Is it better to use NOT or <> when comparing values?

Agreed, code readability is very important for others, but more importantly yourself. Imagine how difficult it would be to understand the first example in comparison to the second.

If code takes more than a few seconds to read (understand), perhaps there is a better way to write it. In this case, the second way.

How to make a JFrame button open another JFrame class in Netbeans?

This link works with me: video

The answer posted before didn't work for me until the second click

So what I did is Directly call:

        new NewForm().setVisible(true);

        this.dispose();//to close the current jframe

mysql datatype for telephone number and address

I usually store phone numbers as a BIGINT in E164 format.

E164 never start with a 0, with the first few digits being the country code.

+441234567890
+44 (0)1234 567890
01234 567890

etc. would be stored as 441234567890.

java.lang.NoSuchMethodError: org.apache.commons.codec.binary.Base64.encodeBase64String() in Java EE application

I faced the same problem with JBoss 4.2.3 GA when deploying my web application. I solved the issue by copying my commons-codec 1.6 jar into C:\jboss-4.2.3.GA\server\default\lib

how to convert .java file to a .class file

From the command line, run

javac ClassName.java

Mongoose query where value is not null

$ne

selects the documents where the value of the field is not equal to the specified value. This includes documents that do not contain the field.

User.find({ "username": { "$ne": 'admin' } })

$nin

$nin selects the documents where: the field value is not in the specified array or the field does not exist.

User.find({ "groups": { "$nin": ['admin', 'user'] } })

Iterating over Numpy matrix rows to apply a function each?

While you should certainly provide more information, if you are trying to go through each row, you can just iterate with a for loop:

import numpy
m = numpy.ones((3,5),dtype='int')
for row in m:
  print str(row)

Insert text into textarea with jQuery

This is similar to the answer given by @panchicore with a minor bug fixed.

function insertText(element, value) 
{
   var element_dom = document.getElementsByName(element)[0];
   if (document.selection) 
   {
      element_dom.focus();
      sel = document.selection.createRange();
      sel.text = value;
      return;
    } 
   if (element_dom.selectionStart || element_dom.selectionStart == "0") 
   {
     var t_start = element_dom.selectionStart;
     var t_end = element_dom.selectionEnd;
     var val_start = element_dom.value.substring(value, t_start);
     var val_end = element_dom.value.substring(t_end, element_dom.value.length);
     element_dom.value = val_start + value + val_end;
   } 
   else
   {
      element_dom.value += value;
   }
}

IIS error, Unable to start debugging on the webserver

I tried everything on here and finally discovered that it was the setup in my web.config. I removed that section and it worked fine; I will go back and troubleshoot later as to why it was busted.

*Edit: I removed the statusCode="503" because of an issue with the App_Offline.htm file and the way in which the errors were configured. I've removed the line below (it isn't needed locally), and everything is working perfectly.

<remove statusCode="503"/>

How can I include a YAML file inside another?

I think the solution used by @maxy-B looks great. However, it didn't succeed for me with nested inclusions. For example if config_1.yaml includes config_2.yaml, which includes config_3.yaml there was a problem with the loader. However, if you simply point the new loader class to itself on load, it works! Specifically, if we replace the old _include function with the very slightly modified version:

def _include(self, loader, node):                                    
     oldRoot = self.root                                              
     filename = os.path.join(self.root, loader.construct_scalar(node))
     self.root = os.path.dirname(filename)                           
     data = yaml.load(open(filename, 'r'), loader = IncludeLoader)                            
     self.root = oldRoot                                              
     return data

Upon reflection I agree with the other comments, that nested loading is not appropriate for yaml in general as the input stream may not be a file, but it is very useful!

WCF named pipe minimal example

~~I just found this excellent little tutorial.~~ broken link (Cached version)

I also followed Microsoft's tutorial which is nice, but I only needed pipes as well.

As you can see, you don't need configuration files and all that messy stuff.

By the way, he uses both HTTP and pipes. Just remove all code lines related to HTTP, and you'll get a pure pipe example.

Apache 2.4.3 (with XAMPP 1.8.1) not starting in windows 8

An error in your httpd.conf or other Apache config files will cause this. Revert httpd.conf et al to the pristine, installer versions and see if Apache runs again.

(I tried Skype and other suggestions here, no luck, but logs [XAMPP > Apache > Logs button] showed that it ran once when first installed. That was the giveaway.)

Likely errors:

Did you edit with a Windows text editor that changes line endings to non-Unix? (Solution here.)
Missing or invalid DSO files (.so)

Windows Bat file optional argument parsing

Dynamic variables creation

Pros

Works for >9 arguments
Keeps %1, %2, ... %* in tact
Works for both /arg and -arg style
No prior knowledge about arguments
Implementation is separate from main routine

Cons

Old arguments may leak into consecutive runs, therefore use setlocal for local scoping or write an accompanying :CLEAR-ARGS routine!
No alias support yet (like --force to -f)
No empty "" argument support

Usage

Here is an example how the following arguments relate to .bat variables:

>> testargs.bat /b 3 -c /d /e /f /g /h /i /j /k /bar 5 /foo "c:\"

echo %*        | /b 3 -c /d /e /f /g /h /i /j /k /bar 5 /foo "c:\"
echo %ARG_FOO% | c:\
echo %ARG_A%   |
echo %ARG_B%   | 3
echo %ARG_C%   | 1
echo %ARG_D%   | 1

Implementation

@echo off
setlocal

CALL :ARG-PARSER %*

::Print examples
echo: ALL: %*
echo: FOO: %ARG_FOO%
echo: A:   %ARG_A%
echo: B:   %ARG_B%
echo: C:   %ARG_C%
echo: D:   %ARG_D%


::*********************************************************
:: Parse commandline arguments into sane variables
:: See the following scenario as usage example:
:: >> thisfile.bat /a /b "c:\" /c /foo 5
:: >> CALL :ARG-PARSER %*
:: ARG_a=1
:: ARG_b=c:\
:: ARG_c=1
:: ARG_foo=5
::*********************************************************
:ARG-PARSER
    ::Loop until two consecutive empty args
    :loopargs
        IF "%~1%~2" EQU "" GOTO :EOF

        set "arg1=%~1" 
        set "arg2=%~2"
        shift

        ::Allow either / or -
        set "tst1=%arg1:-=/%"
        if "%arg1%" NEQ "" (
            set "tst1=%tst1:~0,1%"
        ) ELSE (
            set "tst1="
        )

        set "tst2=%arg2:-=/%"
        if "%arg2%" NEQ "" (
            set "tst2=%tst2:~0,1%"
        ) ELSE (
            set "tst2="
        )


        ::Capture assignments (eg. /foo bar)
        IF "%tst1%" EQU "/"  IF "%tst2%" NEQ "/" IF "%tst2%" NEQ "" (
            set "ARG_%arg1:~1%=%arg2%"
            GOTO loopargs
        )

        ::Capture flags (eg. /foo)
        IF "%tst1%" EQU "/" (
            set "ARG_%arg1:~1%=1"
            GOTO loopargs
        )
    goto loopargs
GOTO :EOF

Function passed as template argument

Came here with the additional requirement, that also parameter/return types should vary. Following Ben Supnik this would be for some type T

typedef T(*binary_T_op)(T, T);

instead of

typedef int(*binary_int_op)(int, int);

The solution here is to put the function type definition and the function template into a surrounding struct template.

template <typename T> struct BinOp
{
    typedef T(*binary_T_op )(T, T); // signature for all valid template params
    template<binary_T_op op>
    T do_op(T a, T b)
    {
       return op(a,b);
    }
};


double mulDouble(double a, double b)
{
    return a * b;
}


BinOp<double> doubleBinOp;

double res = doubleBinOp.do_op<&mulDouble>(4, 5);

Alternatively BinOp could be a class with static method template do_op(...), then called as

double res = BinOp<double>::do_op<&mulDouble>(4, 5);

IntelliJ: Error:java: error: release version 5 not supported

guys, I have also encountered this problem after having so much research on this issue I found 3 solutions to resolve this issue

Add these properties in your pom.xml; //Sorry for the formatting

<properties><java.version>1.8</java.version<maven.compiler.version>3.8.1</maven.compiler.version<maven.compiler.source>1.8</maven.compiler.source<maven.compiler.target>1.8</maven.compiler.target><java.version>11</java.version></properties>

Delete everything in the target byte version, you can find this in the java compiler setting of the IntelliJ

Remove everything below target byte version make it empty

Find the appium version you are using in the dependency. here I am using 7.3.0 find the version of the appium you are using in the dependency in pom.xml

Then write your version in the target byte version in java compiler enter image description here

ENJOY THE CODE>>>HOPE IT WORKED FOR YOU

Splitting a Java String by the pipe symbol using split("|")

You can also use .split("[|]").

(I used this instead of .split("\\|"), which didn't work for me.)

CSS hover vs. JavaScript mouseover

The problem with :hover is that IE6 only supports it on links. I use jQuery for this kind of thing these days:

$("div input").hover(function() {
  $(this).addClass("blue");
}, function() {
  $(this).removeClass("blue");
});

Makes things a lot easier. That'll work in IE6, FF, Chrome and Safari.

How to make a whole 'div' clickable in html and css without JavaScript?

Without JS, I am doing it like this:

My HTML:

<div class="container">
  <div class="sometext">Some text here</div>
  <div class="someothertext">Some other text here</div>
  <a href="#" class="mylink">text of my link</a>
</div>

My CSS:

.container{
  position: relative;
}

.container.a{
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  text-indent: -9999px; //these two lines are to hide my actual link text.
  overflow: hidden; //these two lines are to hide my actual link text.
}

How to make sure that a certain Port is not occupied by any other process

netstat -ano|find ":port_no" will give you the list.
a: Displays all connections and listening ports.
n: Displays addresses and port numbers in numerical form.
o: Displays the owning process ID associated with each connection .

example : netstat -ano | find ":1900" This gives you the result like this.

UDP    107.109.121.196:1900   *:*                                    1324  
UDP    127.0.0.1:1900         *:*                                    1324  
UDP    [::1]:1900             *:*                                    1324  
UDP    [fe80::8db8:d9cc:12a8:2262%13]:1900  *:*                      1324

sklearn plot confusion matrix with labels

I found a function that can plot the confusion matrix which generated from sklearn.

import numpy as np


def plot_confusion_matrix(cm,
                          target_names,
                          title='Confusion matrix',
                          cmap=None,
                          normalize=True):
    """
    given a sklearn confusion matrix (cm), make a nice plot

    Arguments
    ---------
    cm:           confusion matrix from sklearn.metrics.confusion_matrix

    target_names: given classification classes such as [0, 1, 2]
                  the class names, for example: ['high', 'medium', 'low']

    title:        the text to display at the top of the matrix

    cmap:         the gradient of the values displayed from matplotlib.pyplot.cm
                  see http://matplotlib.org/examples/color/colormaps_reference.html
                  plt.get_cmap('jet') or plt.cm.Blues

    normalize:    If False, plot the raw numbers
                  If True, plot the proportions

    Usage
    -----
    plot_confusion_matrix(cm           = cm,                  # confusion matrix created by
                                                              # sklearn.metrics.confusion_matrix
                          normalize    = True,                # show proportions
                          target_names = y_labels_vals,       # list of names of the classes
                          title        = best_estimator_name) # title of graph

    Citiation
    ---------
    http://scikit-learn.org/stable/auto_examples/model_selection/plot_confusion_matrix.html

    """
    import matplotlib.pyplot as plt
    import numpy as np
    import itertools

    accuracy = np.trace(cm) / np.sum(cm).astype('float')
    misclass = 1 - accuracy

    if cmap is None:
        cmap = plt.get_cmap('Blues')

    plt.figure(figsize=(8, 6))
    plt.imshow(cm, interpolation='nearest', cmap=cmap)
    plt.title(title)
    plt.colorbar()

    if target_names is not None:
        tick_marks = np.arange(len(target_names))
        plt.xticks(tick_marks, target_names, rotation=45)
        plt.yticks(tick_marks, target_names)

    if normalize:
        cm = cm.astype('float') / cm.sum(axis=1)[:, np.newaxis]


    thresh = cm.max() / 1.5 if normalize else cm.max() / 2
    for i, j in itertools.product(range(cm.shape[0]), range(cm.shape[1])):
        if normalize:
            plt.text(j, i, "{:0.4f}".format(cm[i, j]),
                     horizontalalignment="center",
                     color="white" if cm[i, j] > thresh else "black")
        else:
            plt.text(j, i, "{:,}".format(cm[i, j]),
                     horizontalalignment="center",
                     color="white" if cm[i, j] > thresh else "black")


    plt.tight_layout()
    plt.ylabel('True label')
    plt.xlabel('Predicted label\naccuracy={:0.4f}; misclass={:0.4f}'.format(accuracy, misclass))
    plt.show()

It will look like this

Programs & Examples On #Toolstripdropdown

Bootstrap 4 Dropdown Menu not working?

Fatal error: Call to a member function fetch_assoc() on a non-object

Correct modification of state arrays in React.js

How do you display code snippets in MS Word preserving format and syntax highlighting?

Git: Remove committed file after push

Why is IoC / DI not common in Python?

Instantiating a generic type

Could not commit JPA transaction: Transaction marked as rollbackOnly

Running bash script from within python

Execute php file from another php

How to make parent wait for all child processes to finish?

Cannot load 64-bit SWT libraries on 32-bit JVM ( replacing SWT file )

How to easily import multiple sql files into a MySQL database?

Delete all nodes and relationships in neo4j 1.8

no operator "<<" matches these operands

How do I hide the bullets on my list for the sidebar?

Difference between Node object and Element object?

How can I trigger the click event of another element in ng-click using angularjs?

Does a "Find in project..." feature exist in Eclipse IDE?

How can I use xargs to copy files that have spaces and quotes in their names?

Scanner vs. StringTokenizer vs. String.Split

How do I push to GitHub under a different username?

Using "-Filter" with a variable

How to Disable GUI Button in Java

How to grep Git commit diffs or contents for a certain word?

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

AngularJS : Custom filters and ng-repeat

How to stop the task scheduled in java.util.Timer class

Spring Boot - Loading Initial Data

yum error "Cannot retrieve metalink for repository: epel. Please verify its path and try again" updating ContextBroker

Func vs. Action vs. Predicate

Which command in VBA can count the number of characters in a string variable?

Input group - two inputs close to each other

POST data to a URL in PHP

get and set in TypeScript

List of strings to one string

Splitting string with pipe character ("|")

Difference between a SOAP message and a WSDL?

Axios having CORS issue

How do I return the response from an asynchronous call?

Here are some approaches to work with asynchronous requests:

Example: jQuery deferred implementation to work with multiple requests

Adding items to a JComboBox

Docker Networking - nginx: [emerg] host not found in upstream

Violation of PRIMARY KEY constraint. Cannot insert duplicate key in object

how to use JSON.stringify and json_decode() properly

How to find the length of an array in shell?

check all socket opened in linux OS

Apple Mach-O Linker Error when compiling for device

How do I include a newline character in a string in Delphi?

How do I empty an array in JavaScript?

SqlDataAdapter vs SqlDataReader

How to configure Docker port mapping to use Nginx as an upstream proxy?

Get/pick an image from Android's built-in Gallery app programmatically

MVC4 HTTP Error 403.14 - Forbidden

Getting list of pixel values from PIL

unix sort descending order

Is it possible to play music during calls so that the partner can hear it ? Android

NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

Getting Git to work with a proxy server - fails with "Request timed out"

LogCat message: The Google Play services resources were not found. Check your project configuration to ensure that the resources are included

What is the difference between git pull and git fetch + git rebase?

Convert date yyyyMMdd to system.datetime format

Missing include "bits/c++config.h" when cross compiling 64 bit program on 32 bit in Ubuntu

env: node: No such file or directory in mac

Time complexity of nested for-loop

How to automatically generate unique id in SQL like UID12345678?

React: trigger onChange if input value is changing by state?

Go to first line in a file in vim?

How to use global variables in React Native?

How to merge a transparent png image with another image using PIL

ValueError when checking if variable is None or numpy.array

How to clear https proxy setting of NPM?

What is a Memory Heap?

How do I add a foreign key to an existing SQLite table?

How to set up a cron job to run an executable every hour?

Docker Error bind: address already in use

How to click a href link using Selenium