What is the difference between a URI, a URL and a URN?

Although the terms URI and URL are strictly defined, many use the terms for other things than they are defined for.

Let’s take Apache for example. If http://example.com/foo is requested from an Apache server, you’ll have the following environment variables set:

REDIRECT_URL: /foo
REQUEST_URI: /foo

With mod_rewrite enabled, you will also have these variables:

REDIRECT_SCRIPT_URL: /foo
REDIRECT_SCRIPT_URI: http://example.com/foo
SCRIPT_URL: /foo
SCRIPT_URI: http://example.com/foo

This might be the reason for some of the confusion.

What is the difference between URI, URL and URN?

Below I sum up Prateek Joshi's awesome explanation.

The theory:

URI (uniform resource identifier) identifies a resource (text document, image file, etc)
URL (uniform resource locator) is a subset of the URIs that include a network location
URN (uniform resource name) is a subset of URIs that include a name within a given space, but no location

That is:

enter image description here

And for an example:

enter image description here

Also, if you haven't already, I suggest reading Roger Pate's answer.

How to check what version of jQuery is loaded?

if (typeof jQuery != 'undefined') {  
    // jQuery is loaded => print the version
    alert(jQuery.fn.jquery);
}

Android WSDL/SOAP service client

private static  final  String NAMESPACE = "http://tempuri.org/";
private static  final String URL = "http://example.com/CRM/Service.svc";
private static  final  String SOAP_ACTION = "http://tempuri.org/Login";
private static  final String METHOD_NAME = "Login";


//calling web services method

String loginresult=callService(username,password,usertype);


//calling webservices
String callService(String a1,String b1,Integer c1) throws Exception {

            Boolean flag=true;
            do
            {
                try{
                    System.out.println(flag);

                SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);

                PropertyInfo pa1 = new PropertyInfo();
                pa1.setName("Username");
                pa1.setValue(a1.toString());

                PropertyInfo pb1 = new PropertyInfo();
                pb1.setName("Password");
                pb1.setValue(b1.toString());

                PropertyInfo pc1 = new PropertyInfo();
                pc1.setName("UserType");
                pc1.setValue(c1);
                System.out.println(c1+"this is integer****s");




                System.out.println("new");
                request.addProperty(pa1);
                request.addProperty(pb1);
                request.addProperty(pc1);



                System.out.println("new2");
                SoapSerializationEnvelope envelope = new    SoapSerializationEnvelope(SoapEnvelope.VER11);
                envelope.dotNet = true;
                System.out.println("new3");
                envelope.setOutputSoapObject(request);
                HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
                androidHttpTransport.setXmlVersionTag("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
                System.out.println("new4");
                try{
                androidHttpTransport.call(SOAP_ACTION, envelope);
                }
                catch(Exception e)
                {

                    System.out.println(e+"   this is exception");
                }
                System.out.println("new5");
                SoapObject response = (SoapObject)envelope.bodyIn;

                result = response.getProperty(0).toString(); 

                flag=false;
                System.out.println(flag);
                }catch (Exception e) {
                // TODO: handle exception
                    flag=false;
            }
            }
            while(flag);
            return result;

        }  
///

How do you use window.postMessage across domains?

Here is an example that works on Chrome 5.0.375.125.

The page B (iframe content):

<html>
    <head></head>
    <body>
        <script>
            top.postMessage('hello', 'A');
        </script>
    </body>
</html>

Note the use of top.postMessage or parent.postMessage not window.postMessage here

The page A:

<html>
<head></head>
<body>
    <iframe src="B"></iframe>
    <script>
        window.addEventListener( "message",
          function (e) {
                if(e.origin !== 'B'){ return; } 
                alert(e.data);
          },
          false);
    </script>
</body>
</html>

A and B must be something like http://domain.com

EDIT:

From another question, it looks the domains(A and B here) must have a / for the postMessage to work properly.

DIVs inside another DIV inside another DIV with CSS

What is the difference between char s[] and char *s?

char *s1 = "Hello world"; // Points to fixed character string which is not allowed to modify
char s2[] = "Hello world"; // As good as fixed array of characters in string so allowed to modify

// s1[0] = 'J'; // Illegal
s2[0] = 'J'; // Legal

Compare two files line by line and generate the difference in another file

Use the Diff utility and extract only the lines starting with < in the output

How do I get the base URL with PHP?

Try this. It works for me.

/*url.php file*/

trait URL {
    private $url = '';
    private $current_url = '';
    public $get = '';

    function __construct()
    {
        $this->url = $_SERVER['SERVER_NAME'];
        $this->current_url = $_SERVER['REQUEST_URI'];

        $clean_server = str_replace('', $this->url, $this->current_url);
        $clean_server = explode('/', $clean_server);

        $this->get = array('base_url' => "/".$clean_server[1]);
    }
}

Use like this:

<?php
/*
Test file

Tested for links:

http://localhost/index.php
http://localhost/
http://localhost/index.php/
http://localhost/url/index.php    
http://localhost/url/index.php/  
http://localhost/url/ab
http://localhost/url/ab/c
*/

require_once 'sys/url.php';

class Home
{
    use URL;
}

$h = new Home();

?>

<a href="<?=$h->get['base_url']?>">Base</a>

How to properly set Column Width upon creating Excel file? (Column properties)

Excel ColumnWidth from dataGridView:

           foreach (DataGridViewColumn co in dataGridView1.Columns)
           { worksheet.Columns[co.Index + 1].ColumnWidth = co.Width/8; }

How to embed HTML into IPython output?

This seems to work for me:

from IPython.core.display import display, HTML
display(HTML('<h1>Hello, world!</h1>'))

The trick is to wrap it in "display" as well.

Source: http://python.6.x6.nabble.com/Printing-HTML-within-IPython-Notebook-IPython-specific-prettyprint-tp5016624p5016631.html

How to get current local date and time in Kotlin

checkout these easy to use Kotlin extensions for date format

fun String.getStringDate(initialFormat: String, requiredFormat: String, locale: Locale = Locale.getDefault()): String {
    return this.toDate(initialFormat, locale).toString(requiredFormat, locale)
}

fun String.toDate(format: String, locale: Locale = Locale.getDefault()): Date = SimpleDateFormat(format, locale).parse(this)

fun Date.toString(format: String, locale: Locale = Locale.getDefault()): String {
    val formatter = SimpleDateFormat(format, locale)
    return formatter.format(this)
}

How to prove that a problem is NP complete?

In order to prove that a problem L is NP-complete, we need to do the following steps:

Prove your problem L belongs to NP (that is that given a solution you can verify it in polynomial time)
Select a known NP-complete problem L'
Describe an algorithm f that transforms L' into L
Prove that your algorithm is correct (formally: x ? L' if and only if f(x) ? L )
Prove that algo f runs in polynomial time

How to clear text area with a button in html using javascript?

You can simply use the ID attribute to the form and attach the <textarea> tag to the form like this:

<form name="commentform" action="#" method="post" target="_blank" id="1321">
    <textarea name="forcom" cols="40" rows="5" form="1321" maxlength="188">
        Enter your comment here...
    </textarea>
    <input type="submit" value="OK">
    <input type="reset" value="Clear">
</form>

Add timer to a Windows Forms application

Bit more detail:

    private void Form1_Load(object sender, EventArgs e)
    {
        Timer MyTimer = new Timer();
        MyTimer.Interval = (45 * 60 * 1000); // 45 mins
        MyTimer.Tick += new EventHandler(MyTimer_Tick);
        MyTimer.Start();
    }

    private void MyTimer_Tick(object sender, EventArgs e)
    {
        MessageBox.Show("The form will now be closed.", "Time Elapsed");
        this.Close();
    }

split string only on first instance of specified character

Use capturing parentheses:

"good_luck_buddy".split(/_(.+)/)[1]
"luck_buddy"

They are defined as

If separator contains capturing parentheses, matched results are returned in the array.

So in this case we want to split at _.+ (i.e. split separator being a sub string starting with _) but also let the result contain some part of our separator (i.e. everything after _).

In this example our separator (matching _(.+)) is _luck_buddy and the captured group (within the separator) is lucky_buddy. Without the capturing parenthesis the luck_buddy (matching .+) would've not been included in the result array as it is the case with simple split that separators are not included in the result.

Confused by python file mode "w+"

Both seems to be working same but there is a catch.

r+ :-

Open the file for Reading and Writing
Once Opened in the beginning file pointer will point to 0
Now if you will want to Read then it will start reading from beginning
if you want to Write then start writing, But the write process will begin from pointer 0. So there would be overwrite of characters, if there is any
In this case File should be present, either will FileNotFoundError will be raised.

w+ :-

Open the file for Reading and Writing
If file exist, File will be opened and all data will be erased,
If file does not exist, then new file will be created
In the beginning file pointer will point to 0 (as there is not data)
Now if you want to write something, then write
File pointer will be Now pointing to end of file (after write process)
If you want to read the data now, seek to specific point. (for beginning seek(0))

So, Overall saying both are meant to open the file to read and write but difference is whether we want to erase the data in the beginning and then do read/write or just start as it is.

abc.txt - in beginning

1234567
abcdefg
0987654
1234

Code for r+

with open('abc.txt', 'r+') as f:      # abc.txt should exist before opening
    print(f.tell())                   # Should give ==> 0
    f.write('abcd')                   
    print(f.read())                   # Pointer is pointing to index 3 => 4th position
    f.write('Sunny')                  # After read pointer is at End of file

Output

0
567
abcdefg
0987654
1234

abc.txt - After Run:

abcd567
abcdefg
0987654
1234Sunny

Resetting abc.txt as initial

Code for w+

with open('abc.txt', 'w+') as f:     
    print(f.tell())                   # Should give ==> 0
    f.write('abcd')                   
    print(f.read())                   # Pointer is pointing to index 3 => 4th position
    f.write('Sunny')                  # After read pointer is at End of file

Output

abc.txt - After Run:

abcdSunny

How can I fill out a Python string with spaces?

Use str.ljust():

>>> 'Hi'.ljust(6)
'Hi    '

You should also consider string.zfill(), str.ljust() and str.center() for string formatting. These can be chained and have the 'fill' character specified, thus:

>>> ('3'.zfill(8) + 'blind'.rjust(8) + 'mice'.ljust(8, '.')).center(40)
'        00000003   blindmice....        '

These string formatting operations have the advantage of working in Python v2 and v3.

Take a look at pydoc str sometime: there's a wealth of good stuff in there.

How to workaround 'FB is not defined'?

I had FB never being defined. Turned out that I was prototyping functions into the Object class called "merge" and another called "toArray". Both of these screwed up Facebook, no error messages but it wouldn't load.

I changed the names of my prototypes, it works now. Hey, if Facebook is going to prototype Object, shouldn't I be allowed to prototype it?

Vertically align text to top within a UILabel

for anyone reading this because the text inside your label is not vertically centered, keep in mind that some font types are not designed equally. for example, if you create a label with zapfino size 16, you will see the text is not perfectly centered vertically.

however, working with helvetica will vertically center your text.

Efficiently replace all accented characters in a string?

I can't speak to what you are trying to do specifically with the function itself, but if you don't like the regex being built every time, here are two solutions and some caveats about each.

Here is one way to do this:

function makeSortString(s) {
  if(!makeSortString.translate_re) makeSortString.translate_re = /[öäüÖÄÜ]/g;
  var translate = {
    "ä": "a", "ö": "o", "ü": "u",
    "Ä": "A", "Ö": "O", "Ü": "U"   // probably more to come
  };
  return ( s.replace(makeSortString.translate_re, function(match) { 
    return translate[match]; 
  }) );
}

This will obviously make the regex a property of the function itself. The only thing you may not like about this (or you may, I guess it depends) is that the regex can now be modified outside of the function's body. So, someone could do this to modify the interally-used regex:

makeSortString.translate_re = /[a-z]/g;

So, there is that option.

One way to get a closure, and thus prevent someone from modifying the regex, would be to define this as an anonymous function assignment like this:

var makeSortString = (function() {
  var translate_re = /[öäüÖÄÜ]/g;
  return function(s) {
    var translate = {
      "ä": "a", "ö": "o", "ü": "u",
      "Ä": "A", "Ö": "O", "Ü": "U"   // probably more to come
    };
    return ( s.replace(translate_re, function(match) { 
      return translate[match]; 
    }) );
  }
})();

Hopefully this is useful to you.

UPDATE: It's early and I don't know why I didn't see the obvious before, but it might also be useful to put you translate object in a closure as well:

var makeSortString = (function() {
  var translate_re = /[öäüÖÄÜ]/g;
  var translate = {
    "ä": "a", "ö": "o", "ü": "u",
    "Ä": "A", "Ö": "O", "Ü": "U"   // probably more to come
  };
  return function(s) {
    return ( s.replace(translate_re, function(match) { 
      return translate[match]; 
    }) );
  }
})();

Can’t delete docker image with dependent child images

Building on Simon Brady's brute force method here, if you don't have a ton of images you can use this shell function:

recursive_remove_image() {
  for image in $(docker images --quiet --filter "since=${1}")
  do
    if [ $(docker history --quiet ${image} | grep ${1}) ]
    then
      recursive_remove_image "${image}"
    fi
  done
  echo "Removing: ${1}"
  docker rmi -f ${1}
}

and then call it using recursive_remove_image <image-id>.

.net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible

The package is not fully compatible with dotnetcore 2.0 for now.

eg, for 'Microsoft.AspNet.WebApi.Client' it maybe supported in version (5.2.4). See Consume new Microsoft.AspNet.WebApi.Client.5.2.4 package for details.

You could try the standard Client package as Federico mentioned.

If that still not work, then as a workaround you can only create a Console App (.Net Framework) instead of the .net core 2.0 console app.

Reference this thread: Microsoft.AspNet.WebApi.Client supported in .NET Core or not?

Deserialize a json string to an object in python

Another way is to simply pass the json string as a dict to the constructor of your object. For example your object is:

class Payload(object):
    def __init__(self, action, method, data, *args, **kwargs):
        self.action = action
        self.method = method
        self.data = data

And the following two lines of python code will construct it:

j = json.loads(yourJsonString)
payload = Payload(**j)

Basically, we first create a generic json object from the json string. Then, we pass the generic json object as a dict to the constructor of the Payload class. The constructor of Payload class interprets the dict as keyword arguments and sets all the appropriate fields.

How do I erase an element from std::vector<> by index?

How about this?

void squeeze(vector<int> &v)
{
    int j = 0;
    for (int i = 1; i < v.size(); i++)
        if (v[i] != v[j] && ++j != i)
            v[j] = v[i];
    v.resize(j + 1);
}

Javascript search inside a JSON object

You could just loop through the array and find the matches:

var results = [];
var searchField = "name";
var searchVal = "my Name";
for (var i=0 ; i < obj.list.length ; i++)
{
    if (obj.list[i][searchField] == searchVal) {
        results.push(obj.list[i]);
    }
}

Should I Dispose() DataSet and DataTable?

You should assume it does something useful and call Dispose even if it does nothing in current .NET Framework incarnations. There's no guarantee it will stay that way in future versions leading to inefficient resource usage.

DateTime.Now.ToShortDateString(); replace month and day

Little addition to Jason's answer:

The ToShortDateString() is culture-sensitive.

From MSDN:

The string returned by the ToShortDateString method is culture-sensitive. It reflects the pattern defined by the current culture's DateTimeFormatInfo object. For example, for the en-US culture, the standard short date pattern is "M/d/yyyy"; for the de-DE culture, it is "dd.MM.yyyy"; for the ja-JP culture, it is "yyyy/M/d". The specific format string on a particular computer can also be customized so that it differs from the standard short date format string.

That's mean it's better to use the ToString() method and define format explicitly (as Jason said). Although if this string appeas in UI the ToShortDateString() is a good solution because it returns string which is familiar to a user.

If you need just today's date you can use DateTime.Today.

How to find whether MySQL is installed in Red Hat?

rpmquery <package Name> By this command you can check which package is installed.

For Example: rpmquery mysql

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare();

I got this error in a JobService from the following code:

    BluetoothLeScanner bluetoothLeScanner = getBluetoothLeScanner();
    if (BluetoothAdapter.STATE_ON == getBluetoothAdapter().getState() && null != bluetoothLeScanner) {
        // ...
    } else {
        Logger.debug(TAG, "BluetoothAdapter isn't on so will attempting to turn on and will retry starting scanning in a few seconds");
        getBluetoothAdapter().enable();
        (new Handler()).postDelayed(new Runnable() {
            @Override
            public void run() {
                startScanningBluetooth();
            }
        }, 5000);
    }

The service crashed:

2019-11-21 11:49:45.550 729-763/? D/BluetoothManagerService: MESSAGE_ENABLE(0): mBluetooth = null

    --------- beginning of crash
2019-11-21 11:49:45.556 8629-8856/com.locuslabs.android.sdk E/AndroidRuntime: FATAL EXCEPTION: Timer-1
    Process: com.locuslabs.android.sdk, PID: 8629
    java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
        at android.os.Handler.<init>(Handler.java:203)
        at android.os.Handler.<init>(Handler.java:117)
        at com.locuslabs.sdk.ibeacon.BeaconScannerJobService.startScanningBluetoothAndBroadcastAnyBeaconsFoundAndUpdatePersistentNotification(BeaconScannerJobService.java:120)
        at com.locuslabs.sdk.ibeacon.BeaconScannerJobService.access$500(BeaconScannerJobService.java:36)
        at com.locuslabs.sdk.ibeacon.BeaconScannerJobService$2$1.run(BeaconScannerJobService.java:96)
        at java.util.TimerThread.mainLoop(Timer.java:555)
        at java.util.TimerThread.run(Timer.java:505)

So I changed from Handler to Timer as follows:

   (new Timer()).schedule(new TimerTask() {
                @Override
                public void run() {
                    startScanningBluetooth();
                }
            }, 5000);

Now the code doesn't throw the RuntimeException anymore.

How to sort List of objects by some property

Since Java8 this can be done even cleaner using a combination of Comparator and Lambda expressions

For Example:

class Student{

    private String name;
    private List<Score> scores;

    // +accessor methods
}

class Score {

    private int grade;
    // +accessor methods
}

    Collections.sort(student.getScores(), Comparator.comparing(Score::getGrade);

How to set android layout to support all screen sizes?

Raise an event whenever a property's value changed?

The INotifyPropertyChanged interface is implemented with events. The interface has just one member, PropertyChanged, which is an event that consumers can subscribe to.

The version that Richard posted is not safe. Here is how to safely implement this interface:

public class MyClass : INotifyPropertyChanged
{
    private string imageFullPath;

    protected void OnPropertyChanged(PropertyChangedEventArgs e)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
            handler(this, e);
    }

    protected void OnPropertyChanged(string propertyName)
    {
        OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
    }

    public string ImageFullPath
    {
        get { return imageFullPath; }
        set
        {
            if (value != imageFullPath)
            {
                imageFullPath = value;
                OnPropertyChanged("ImageFullPath");
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
}

Note that this does the following things:

Abstracts the property-change notification methods so you can easily apply this to other properties;
Makes a copy of the PropertyChanged delegate before attempting to invoke it (failing to do this will create a race condition).
Correctly implements the INotifyPropertyChanged interface.

If you want to additionally create a notification for a specific property being changed, you can add the following code:

protected void OnImageFullPathChanged(EventArgs e)
{
    EventHandler handler = ImageFullPathChanged;
    if (handler != null)
        handler(this, e);
}

public event EventHandler ImageFullPathChanged;

Then add the line OnImageFullPathChanged(EventArgs.Empty) after the line OnPropertyChanged("ImageFullPath").

Since we have .Net 4.5 there exists the CallerMemberAttribute, which allows to get rid of the hard-coded string for the property name in the source code:

    protected void OnPropertyChanged(
        [System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
    {
        OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
    }

    public string ImageFullPath
    {
        get { return imageFullPath; }
        set
        {
            if (value != imageFullPath)
            {
                imageFullPath = value;
                OnPropertyChanged();
            }
        }
    }

Android: Create a toggle button with image and no text

create toggle_selector.xml in res/drawable

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@drawable/toggle_on" android:state_checked="true"/>
  <item android:drawable="@drawable/toggle_off" android:state_checked="false"/>
</selector>

apply the selector to your toggle button

<ToggleButton
            android:id="@+id/chkState"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/toggle_selector"
            android:textOff=""
            android:textOn=""/>

Note: for removing the text i used following in above code

textOff=""
textOn=""

Linq UNION query to select two elements

EDIT:

Ok I found why the int.ToString() in LINQtoEF fails, please read this post: Problem with converting int to string in Linq to entities

This works on my side :

        List<string> materialTypes = (from u in result.Users
                                      select u.LastName)
                       .Union(from u in result.Users
                               select SqlFunctions.StringConvert((double) u.UserId)).ToList();

On yours it should be like this:

    IList<String> materialTypes = ((from tom in context.MaterialTypes
                                       where tom.IsActive == true
                                       select tom.Name)
                                       .Union(from tom in context.MaterialTypes
                                       where tom.IsActive == true
                                       select SqlFunctions.StringConvert((double)tom.ID))).ToList();

Thanks, i've learnt something today :)

How do you use NSAttributedString?

An easier solution with attributed string extension.

extension NSMutableAttributedString {

    // this function attaches color to string    
    func setColorForText(textToFind: String, withColor color: UIColor) {
        let range: NSRange = self.mutableString.range(of: textToFind, options: .caseInsensitive)
        self.addAttribute(NSAttributedStringKey.foregroundColor, value: color, range: range)
    }

}

Try this and see (Tested in Swift 3 & 4)

let label = UILabel()
label.frame = CGRect(x: 120, y: 100, width: 200, height: 30)
let first = "first"
let second = "second"
let third = "third"
let stringValue = "\(first)\(second)\(third)"  // or direct assign single string value like "firstsecondthird"

let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: stringValue)
attributedString.setColorForText(textToFind: first, withColor: UIColor.red)   // use variable for string "first"
attributedString.setColorForText(textToFind: "second", withColor: UIColor.green) // or direct string like this "second"
attributedString.setColorForText(textToFind: third, withColor: UIColor.blue)
label.font = UIFont.systemFont(ofSize: 26)
label.attributedText = attributedString
self.view.addSubview(label)

Here is expected result:

enter image description here

sed with literal string--not input file

Works like you want:

echo "A,B,C" | sed s/,/\',\'/g

How to change node.js's console font color?

A handy one-liner I wrote for npm scripts that can't have dependencies:

_x000D_

const { r, g, b, w, c, m, y, k } = [
  ['r', 1], ['g', 2], ['b', 4], ['w', 7],
  ['c', 6], ['m', 5], ['y', 3], ['k', 0],
].reduce((cols, col) => ({
  ...cols,  [col[0]]: f => `\x1b[3${col[1]}m${f}\x1b[0m`
}), {})

console.log(`${g('I')} love ${r('Italy')}`)

_x000D_

r,g,b,w,c,m,y,k stands for red, green, blue, white, cyan, magenta, yellow and black.

Sheet.getRange(1,1,1,12) what does the numbers in bracket specify?

Found these docu on the google docu pages:

row --- int --- top row of the range
column --- int--- leftmost column of the range
optNumRows --- int --- number of rows in the range.
optNumColumns --- int --- number of columns in the range

In your example, you would get (if you picked the 3rd row) "C3:O3", cause C --> O is 12 columns

edit

Using the example on the docu:

// The code below will get the number of columns for the range C2:G8
// in the active spreadsheet, which happens to be "4"
var count = SpreadsheetApp.getActiveSheet().getRange(2, 3, 6, 4).getNumColumns(); Browser.msgBox(count);

The values between brackets:
2: the starting row = 2
3: the starting col = C
6: the number of rows = 6 so from 2 to 8
4: the number of cols = 4 so from C to G

So you come to the range: C2:G8

how to destroy an object in java?

Here is the code:

public static void main(String argso[]) {
int big_array[] = new int[100000];

// Do some computations with big_array and get a result. 
int result = compute(big_array);

// We no longer need big_array. It will get garbage collected when there
// are no more references to it. Since big_array is a local variable,
// it refers to the array until this method returns. But this method
// doesn't return. So we've got to explicitly get rid of the reference
// ourselves, so the garbage collector knows it can reclaim the array. 
big_array = null;

// Loop forever, handling the user's input
for(;;) handle_input(result);
}

How do I resolve "Please make sure that the file is accessible and that it is a valid assembly or COM component"?

I had the same program, I hope this could help.

I your using Windows 7, open Command Prompt-> run as Administrator. register your <...>.dll.

Why run as Administrator, you can register your <...>.dll using the run at the Windows Start, but still your dll only run as user even your account is administrator.

Now you can add your <...>.dll at the Project->Add Reference->Browse

Thanks

How do I check CPU and Memory Usage in Java?

The YourKit Java profiler is an excellent commercial solution. You can find further information in the docs on CPU profiling and memory profiling.

Update TensorFlow

For anaconda installation, first pick a channel which has the latest version of tensorflow binary. Usually, the latest versions are available at the channel conda-forge. Then simply do:

conda update -f -c conda-forge tensorflow

This will upgrade your existing tensorflow installation to the very latest version available. As of this writing, the latest version is 1.4.0-py36_0

How can I use std::maps with user-defined types as key?

You need to define operator < for the Class1.

Map needs to compare the values using operator < and hence you need to provide the same when user defined class are used as key.

class Class1
{
public:
    Class1(int id);

    bool operator <(const Class1& rhs) const
    {
        return id < rhs.id;
    }
private:
    int id;
};

org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException:

You are trying to access an XLS file. However, you are using XSSFWorkbook and XSSFSheet class objects. These classes are mainly used for XLSX files.

For XLS file: HSSFWorkbook & HSSFSheet
For XLSX file: XSSFSheet & XSSFSheet

So in place of XSSFWorkbook use HSSFWorkbook and in place of XSSFSheet use HSSFSheet.

So your code should look like this after the changes are made:

HSSFWorkbook workbook = new HSSFWorkbook(file);

HSSFSheet sheet = workbook.getSheetAt(0);

How can I check for Python version in a program that uses new language features?

Sets became part of the core language in Python 2.4, in order to stay backwards compatible. I did this back then, which will work for you as well:

if sys.version_info < (2, 4):
    from sets import Set as set

C++: what regex library should I use?

In C++ projects past, I have used PCRE with good success. It's very complete and well-tested since it's used in many high profile projects. And I see that Google has contributed a set of C++ wrappers for PCRE recently, too.

How should I remove all the leading spaces from a string? - swift

You can also use regex.

let trimmedString = myString.stringByReplacingOccurrencesOfString("\\s", withString: "", options: NSStringCompareOptions.RegularExpressionSearch, range: nil)

Visual Studio Code how to resolve merge conflicts with git?

For those who are having a hard time finding the "merge buttons".

The little lightbulp icon with merge options only shows up if you click precisely on the "merge conflict marker"

<<<<<<<

Steps (in VS Code 1.29.x):

Strange out of memory issue while loading an image to a Bitmap object

After setting an bitmap to imageview, recycle it like this:

bitmap.recycle();
bitmap=null;

How can I install a package with go get?

Command go

Download and install packages and dependencies

Usage:
go get [-d] [-f] [-t] [-u] [-v] [-fix] [-insecure] [build flags] [packages]
Get downloads the packages named by the import paths, along with their dependencies. It then installs the named packages, like 'go install'.

The -d flag instructs get to stop after downloading the packages; that is, it instructs get not to install the packages.

The -f flag, valid only when -u is set, forces get -u not to verify that each package has been checked out from the source control repository implied by its import path. This can be useful if the source is a local fork of the original.

The -fix flag instructs get to run the fix tool on the downloaded packages before resolving dependencies or building the code.

The -insecure flag permits fetching from repositories and resolving custom domains using insecure schemes such as HTTP. Use with caution.

The -t flag instructs get to also download the packages required to build the tests for the specified packages.

The -u flag instructs get to use the network to update the named packages and their dependencies. By default, get uses the network to check out missing packages but does not use it to look for updates to existing packages.

The -v flag enables verbose progress and debug output.

Get also accepts build flags to control the installation. See 'go help build'.

When checking out a new package, get creates the target directory GOPATH/src/. If the GOPATH contains multiple entries, get uses the first one. For more details see: 'go help gopath'.

When checking out or updating a package, get looks for a branch or tag that matches the locally installed version of Go. The most important rule is that if the local installation is running version "go1", get searches for a branch or tag named "go1". If no such version exists it retrieves the default branch of the package.

When go get checks out or updates a Git repository, it also updates any git submodules referenced by the repository.

Get never checks out or updates code stored in vendor directories.

For more about specifying packages, see 'go help packages'.

For more about how 'go get' finds source code to download, see 'go help importpath'.

This text describes the behavior of get when using GOPATH to manage source code and dependencies. If instead the go command is running in module-aware mode, the details of get's flags and effects change, as does 'go help get'. See 'go help modules' and 'go help module-get'.

See also: go build, go install, go clean.

For example, showing verbose output,

$ go get -v github.com/capotej/groupcache-db-experiment/...
github.com/capotej/groupcache-db-experiment (download)
github.com/golang/groupcache (download)
github.com/golang/protobuf (download)
github.com/capotej/groupcache-db-experiment/api
github.com/capotej/groupcache-db-experiment/client
github.com/capotej/groupcache-db-experiment/slowdb
github.com/golang/groupcache/consistenthash
github.com/golang/protobuf/proto
github.com/golang/groupcache/lru
github.com/capotej/groupcache-db-experiment/dbserver
github.com/capotej/groupcache-db-experiment/cli
github.com/golang/groupcache/singleflight
github.com/golang/groupcache/groupcachepb
github.com/golang/groupcache
github.com/capotej/groupcache-db-experiment/frontend
$

How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2

I also struggled finding articles on how to just generate the token part. I never found one and wrote my own. So if it helps:

The things to do are:

Create a new web application
Install the following NuGet packages:
- Microsoft.Owin
- Microsoft.Owin.Host.SystemWeb
- Microsoft.Owin.Security.OAuth
- Microsoft.AspNet.Identity.Owin
Add a OWIN startup class

Then create a HTML and a JavaScript (index.js) file with these contents:

var loginData = 'grant_type=password&[email protected]&password=test123';

var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
    if (xmlhttp.readyState === 4 && xmlhttp.status === 200) {
        alert(xmlhttp.responseText);
    }
}
xmlhttp.open("POST", "/token", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send(loginData);

<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
    <script type="text/javascript" src="index.js"></script>
</body>
</html>

The OWIN startup class should have this content:

using System;
using System.Security.Claims;
using Microsoft.Owin;
using Microsoft.Owin.Security.OAuth;
using OAuth20;
using Owin;

[assembly: OwinStartup(typeof(Startup))]

namespace OAuth20
{
    public class Startup
    {
        public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }

        public void Configuration(IAppBuilder app)
        {
            OAuthOptions = new OAuthAuthorizationServerOptions()
            {
                TokenEndpointPath = new PathString("/token"),
                Provider = new OAuthAuthorizationServerProvider()
                {
                    OnValidateClientAuthentication = async (context) =>
                    {
                        context.Validated();
                    },
                    OnGrantResourceOwnerCredentials = async (context) =>
                    {
                        if (context.UserName == "[email protected]" && context.Password == "test123")
                        {
                            ClaimsIdentity oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
                            context.Validated(oAuthIdentity);
                        }
                    }
                },
                AllowInsecureHttp = true,
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1)
            };

            app.UseOAuthBearerTokens(OAuthOptions);
        }
    }
}

Run your project. The token should be displayed in the pop-up.

Use table row coloring for cells in Bootstrap

With the current version of Bootstrap (3.3.7), it is possible to color a single cell of a table like so:

<td class = 'text-center col-md-4 success'>

Scrolling an iframe with JavaScript?

var $iframe = document.getElementByID('myIfreme');
var childDocument = iframe.contentDocument ? iframe.contentDocument : iframe.contentWindow.document;
 childDocument.documentElement.scrollTop = 0;

What does "control reaches end of non-void function" mean?

Always build with at least minimal optimization. With -O0, all analysis that the compiler could use to determine that execution cannot reach the end of the function has been disabled. This is why you're seeing the warning. The only time you should ever use -O0 is for step-by-line debugging, which is usually not a good debugging approach anyway, but it's what most people who got started with MSVC learned on...

Is it possible to start a shell session in a running container (without ssh)

Since things are achanging, at the moment the recommended way of accessing a running container is using nsenter.

You can find more information on this github repository. But in general you can use nsenter like this:

PID=$(docker inspect --format {{.State.Pid}} <container_name_or_ID>)
nsenter --target $PID --mount --uts --ipc --net --pid

or you can use the wrapper docker-enter:

docker-enter <container_name_or_ID>

A nice explanation on the topic can be found on Jérôme Petazzoni's blog entry: Why you don't need to run sshd in your docker containers

jQuery select all except first

_x000D_

$(document).ready(function(){_x000D_
_x000D_
  $(".btn1").click(function(){_x000D_
          $("div.test:not(:first)").hide();_x000D_
  });_x000D_
_x000D_
  $(".btn2").click(function(){_x000D_
           $("div.test").show();_x000D_
          $("div.test:not(:first):not(:last)").hide();_x000D_
  });_x000D_
_x000D_
  $(".btn3").click(function(){_x000D_
          $("div.test").hide();_x000D_
          $("div.test:not(:first):not(:last)").show();_x000D_
  });_x000D_
_x000D_
});

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<button class="btn1">Hide All except First</button>_x000D_
<button class="btn2">Hide All except First & Last</button>_x000D_
<button class="btn3">Hide First & Last</button>_x000D_
_x000D_
<br/>_x000D_
_x000D_
<div class='test'>First</div>_x000D_
<div class='test'>Second</div>_x000D_
<div class='test'>Third</div>_x000D_
<div class='test'>Last</div>

_x000D_

How to manually force a commit in a @Transactional method?

I know that due to this ugly anonymous inner class usage of TransactionTemplate doesn't look nice, but when for some reason we want to have a test method transactional IMHO it is the most flexible option.

In some cases (it depends on the application type) the best way to use transactions in Spring tests is a turned-off @Transactional on the test methods. Why? Because @Transactional may leads to many false-positive tests. You may look at this sample article to find out details. In such cases TransactionTemplate can be perfect for controlling transaction boundries when we want that control.

Missing `server' JVM (Java\jre7\bin\server\jvm.dll.)

To Fix The "Missing "server" JVM at C:\Program Files\Java\jre7\bin\server\jvm.dll, please install or use the JRE or JDK that contains these missing components.

Follow these steps:

Go to oracle.com and install Java JRE7 (Check if Java 6 is not installed already)

After that, go to C:/Program files/java/jre7/bin

Here, create an folder called Server

Now go into the C:/Program files/java/jre7/bin/client folder

Copy all the data in this folder into the new C:/Program files/java/jre7/bin/Server folder

How to embed matplotlib in pyqt - for Dummies

Below is an adaptation of previous code for using under PyQt5 and Matplotlib 2.0. There are a number of small changes: structure of PyQt submodules, other submodule from matplotlib, deprecated method has been replaced...


import sys
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt

import random

class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = plt.figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # instead of ax.hold(False)
        self.figure.clear()

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        # ax.hold(False) # deprecated, see above

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

how to "execute" make file

As paxdiablo said make -f pax.mk would execute the pax.mk makefile, if you directly execute it by typing ./pax.mk, then you would get syntax error.

Also you can just type make if your file name is makefile/Makefile.

Suppose you have two files named makefile and Makefile in the same directory then makefile is executed if make alone is given. You can even pass arguments to makefile.

Check out more about makefile at this Tutorial : Basic understanding of Makefile

Convert string to int array using LINQ

    public static int[] ConvertArray(string[] arrayToConvert)
    {
        int[] resultingArray = new int[arrayToConvert.Length];

        int itemValue;

        resultingArray = Array.ConvertAll<string, int>
            (
                arrayToConvert, 
                delegate(string intParameter) 
                {
                    int.TryParse(intParameter, out itemValue);
                    return itemValue;
                }
            );

        return resultingArray;
    }

Reference:

http://codepolice.net/convert-string-array-to-int-array-and-vice-versa-in-c/

Swift do-try-catch syntax

Swift is worry that your case statement is not covering all cases, to fix it you need to create a default case:

do {
    let sandwich = try makeMeSandwich(kitchen)
    print("i eat it \(sandwich)")
} catch SandwichError.NotMe {
    print("Not me error")
} catch SandwichError.DoItYourself {
    print("do it error")
} catch Default {
    print("Another Error")
}

JQuery $.each() JSON array object iteration

Assign the second variable for the $.each function() as well, makes it lot easier as it'll provide you the data (so you won't have to work with the indicies).

$.each(json, function(arrayID,group) {
            console.log('<a href="'+group.GROUP_ID+'">');
    $.each(group.EVENTS, function(eventID,eventData) {
            console.log('<p>'+eventData.SHORT_DESC+'</p>');
     });
});

Should print out everything you were trying in your question.

http://jsfiddle.net/niklasvh/hZsQS/

edit renamed the variables to make it bit easier to understand what is what.

What happens to a declared, uninitialized variable in C? Does it have a value?

It depends on the storage duration of the variable. A variable with static storage duration is always implicitly initialized with zero.

As for automatic (local) variables, an uninitialized variable has indeterminate value. Indeterminate value, among other things, mean that whatever "value" you might "see" in that variable is not only unpredictable, it is not even guaranteed to be stable. For example, in practice (i.e. ignoring the UB for a second) this code

int num;
int a = num;
int b = num;

does not guarantee that variables a and b will receive identical values. Interestingly, this is not some pedantic theoretical concept, this readily happens in practice as consequence of optimization.

So in general, the popular answer that "it is initialized with whatever garbage was in memory" is not even remotely correct. Uninitialized variable's behavior is different from that of a variable initialized with garbage.

How to programmatically set style attribute in a view

Yes, you can use for example in a button

Button b = new Button(this);
b.setBackgroundResource(R.drawable.selector_test);

What do >> and << mean in Python?

12 << 2

48

Actual binary value of 12 is "00 1100" when we execute the above statement Left shift ( 2 places shifted left) returns the value 48 its binary value is "11 0000".

48 >> 2

12

The binary value of 48 is "11 0000", after executing above statement Right shift ( 2 places shifted right) returns the value 12 its binary value is "00 1100".

Serializing with Jackson (JSON) - getting "No serializer found"?

adding setter and getter will also solve the issue as it fixed for me. For Ex:

public class TestA {
    String SomeString = "asd";

    public String getSomeString () {        return SomeString ;     }

    public void setSomeString (String SS ) {        SomeString = SS ;   } 
}

How do I change a PictureBox's image?

If you have an image imported as a resource in your project there is also this:

picPreview.Image = Properties.Resources.ImageName;

Where picPreview is the name of the picture box and ImageName is the name of the file you want to display.

*Resources are located by going to: Project --> Properties --> Resources

How to set Status Bar Style in Swift 3

To add to the great asnwer by @Krunal https://stackoverflow.com/a/49552326/4697535

In case you are using a UINavigationController, the preferredStatusBarStyle will have no effect on the UIViewController.

Xcode 10 and Swift 4.

Set a custom UINavigationController

Example:

class LightNavigationController: UINavigationController {

   open override var preferredStatusBarStyle: UIStatusBarStyle {
       return .lightContent
   }
}

Use an extension for an app level solution:

extension UINavigationController {

  open override var preferredStatusBarStyle: UIStatusBarStyle {
      guard let index = tabBarController?.selectedIndex else { return .default }
      switch index {
      case 0, 1, 2: return .lightContent // set lightContent for tabs 0-2
      default: return .default // set dark for tab 3
      }
  }
}

case in sql stored procedure on SQL Server

Try this

If @NewStatus  = 'InOffice' 
BEGIN
     Update tblEmployee set InOffice = -1 where EmpID = @EmpID
END
Else If @NewStatus  = 'OutOffice'
BEGIN
    Update tblEmployee set InOffice = -1 where EmpID = @EmpID
END
Else If @NewStatus  = 'Home'
BEGIN
    Update tblEmployee set Home = -1 where EmpID = @EmpID
END

Android - Center TextView Horizontally in LinearLayout

Just use: android:layout_centerHorizontal="true"

It will put the whole textview in the center

How can I add the sqlite3 module to Python?

You don't need to install sqlite3 module. It is included in the standard library (since Python 2.5).

Simple Popup by using Angular JS

If you are using bootstrap.js then the below code might be useful. This is very simple. Dont have to write anything in js to invoke the pop-up.

Source :http://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_modal&stacked=h

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
  <h2>Modal Example</h2>
  <!-- Trigger the modal with a button -->
  <button type="button" class="btn btn-info btn-lg" data-toggle="modal" data-target="#myModal">Open Modal</button>

  <!-- Modal -->
  <div class="modal fade" id="myModal" role="dialog">
    <div class="modal-dialog">

      <!-- Modal content-->
      <div class="modal-content">
        <div class="modal-header">
          <button type="button" class="close" data-dismiss="modal">&times;</button>
          <h4 class="modal-title">Modal Header</h4>
        </div>
        <div class="modal-body">
          <p>Some text in the modal.</p>
        </div>
        <div class="modal-footer">
          <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        </div>
      </div>

    </div>
  </div>

</div>

</body>
</html>

Bigger Glyphicons

You can just give the glyphicon a font-size to your liking:

span.glyphicon-link {
    font-size: 1.2em;
}

Python3 integer division

Try this:

a = 1
b = 2
int_div  = a // b

If statement within Where clause

You can't use IF like that. You can do what you want with AND and OR:

SELECT t.first_name,
       t.last_name,
       t.employid,
       t.status
  FROM employeetable t
 WHERE ((status_flag = STATUS_ACTIVE   AND t.status = 'A')
     OR (status_flag = STATUS_INACTIVE AND t.status = 'T')
     OR (source_flag = SOURCE_FUNCTION AND t.business_unit = 'production')
     OR (source_flag = SOURCE_USER     AND t.business_unit = 'users'))
   AND t.first_name LIKE firstname
   AND t.last_name  LIKE lastname
   AND t.employid   LIKE employeeid;

How to print the contents of RDD?

In python

   linesWithSessionIdCollect = linesWithSessionId.collect()
   linesWithSessionIdCollect

This will printout all the contents of the RDD

How to check if a file exists in a folder?

if (File.Exists(localUploadDirectory + "/" + fileName))
{                        
    `Your code here`
}

Insert text into textarea with jQuery

I know this is an old question but for people searching for this solution it's worth noting that you should not use append() to add content to a textarea. the append() method targets innerHTML not the value of the textarea. The content may appear in the textarea but it will not be added to the element's form value.

As noted above using:

$('#textarea').val($('#textarea').val()+'new content');

will work fine.

How to automatically generate unique id in SQL like UID12345678?

Table Creating

create table emp(eno int identity(100001,1),ename varchar(50))

Values inserting

insert into emp(ename)values('narendra'),('ajay'),('anil'),('raju')

Select Table

select * from emp

Output

eno     ename
100001  narendra
100002  rama
100003  ajay
100004  anil
100005  raju

Prevent multiple instances of a given app in .NET?

Normally it's done with a named Mutex (use new Mutex( "your app name", true ) and check the return value), but there's also some support classes in Microsoft.VisualBasic.dll that can do it for you.

jQuery map vs. each

The each method is meant to be an immutable iterator, where as the map method can be used as an iterator, but is really meant to manipulate the supplied array and return a new array.

Another important thing to note is that the each function returns the original array while the map function returns a new array. If you overuse the return value of the map function you can potentially waste a lot of memory.

For example:

var items = [1,2,3,4];

$.each(items, function() {
  alert('this is ' + this);
});

var newItems = $.map(items, function(i) {
  return i + 1;
});
// newItems is [2,3,4,5]

You can also use the map function to remove an item from an array. For example:

var items = [0,1,2,3,4,5,6,7,8,9];

var itemsLessThanEqualFive = $.map(items, function(i) {
  // removes all items > 5
  if (i > 5) 
    return null;
  return i;
});
// itemsLessThanEqualFive = [0,1,2,3,4,5]

You'll also note that the this is not mapped in the map function. You will have to supply the first parameter in the callback (eg we used i above). Ironically, the callback arguments used in the each method are the reverse of the callback arguments in the map function so be careful.

map(arr, function(elem, index) {});
// versus 
each(arr, function(index, elem) {});

MVC 4 Razor adding input type date

You will get it by tag type="date"...then it will render beautiful calendar and all...

@Html.TextBoxFor(model => model.EndTime, new { type = "date" })

init and arguments in Python

In Python:

Instance methods: require the self argument.
Class methods: take the class as a first argument.
Static methods: do not require either the instance (self) or the class (cls) argument.

__init__ is a special function and without overriding __new__ it will always be given the instance of the class as its first argument.

An example using the builtin classmethod and staticmethod decorators:

import sys

class Num:
    max = sys.maxint

    def __init__(self,num):
        self.n = num

    def getn(self):
        return self.n

    @staticmethod
    def getone():
        return 1

    @classmethod
    def getmax(cls):
        return cls.max

myObj = Num(3)
# with the appropriate decorator these should work fine
myObj.getone()
myObj.getmax()
myObj.getn()

That said, I would try to use @classmethod/@staticmethod sparingly. If you find yourself creating objects that consist of nothing but staticmethods the more pythonic thing to do would be to create a new module of related functions.

Cannot find Dumpbin.exe

A little refresh as for the Visual Studio 2015.

DUMPBIN is being shipped within Common Tools for Visual C++, so be sure to select this feature in the process of installation of Visual Studio. The utility resides at:

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\

It become available within Developer Command Prompt for VS 2015, which can be executed from Start Menu:

Visual Studio 2015 \ Visual Studio Tools \ Developer Command Prompt for VS2015

If you want to make it available in the regular command prompt, then add the utility's location to the PATH environment variable on your machine.

Open files always in a new tab

? Actually, VSCode shows you the preview of a file.

You can disable the preview with this:

"workbench.editor.enablePreview": false,

?? Basically just add these two settings and you're good to go.

How to select clear table contents without destroying the table?

There is a condition that most of these solutions do not address. I revised Patrick Honorez's solution to handle it. I felt I had to share this because I was pulling my hair out when the original function was occasionally clearing more data that I expected.

The situation happens when the table only has one column and the .SpecialCells(xlCellTypeConstants).ClearContents attempts to clear the contents of the top row. In this situation, only one cell is selected (the top row of the table that only has one column) and the SpecialCells command applies to the entire sheet instead of the selected range. What was happening to me was other cells on the sheet that were outside of my table were also getting cleared.

I did some digging and found this advice from Mathieu Guindon: Range SpecialCells ClearContents clears whole sheet

Range({any single cell}).SpecialCells({whatever}) seems to work off the entire sheet.

Range({more than one cell}).SpecialCells({whatever}) seems to work off the specified cells.

If the list/table only has one column (in row 1), this revision will check to see if the cell has a formula and if not, it will only clear the contents of that one cell.

Public Sub ClearList(lst As ListObject)
'Clears a listObject while leaving 1 empty row + formula
' https://stackoverflow.com/a/53856079/1898524
'
'With special help from this post to handle a single column table.
'   Range({any single cell}).SpecialCells({whatever}) seems to work off the entire sheet.
'   Range({more than one cell}).SpecialCells({whatever}) seems to work off the specified cells.
' https://stackoverflow.com/questions/40537537/range-specialcells-clearcontents-clears-whole-sheet-instead

    On Error Resume Next
    
    With lst
        '.Range.Worksheet.Activate ' Enable this if you are debugging 
    
        If .ShowAutoFilter Then .AutoFilter.ShowAllData
        If .DataBodyRange.Rows.Count = 1 Then Exit Sub ' Table is already clear
        .DataBodyRange.Offset(1).Rows.Clear
        
        If .DataBodyRange.Columns.Count > 1 Then ' Check to see if SpecialCells is going to evaluate just one cell.
            .DataBodyRange.Rows(1).SpecialCells(xlCellTypeConstants).ClearContents
        ElseIf Not .Range.HasFormula Then
            ' Only one cell in range and it does not contain a formula.
            .DataBodyRange.Rows(1).ClearContents
        End If

        .Resize .Range.Rows("1:2")
        
        .HeaderRowRange.Offset(1).Select

        ' Reset used range on the sheet
        Dim X
        X = .Range.Worksheet.UsedRange.Rows.Count 'see J-Walkenbach tip 73

    End With

End Sub

A final step I included is a tip that is attributed to John Walkenbach, sometimes noted as J-Walkenbach tip 73 Automatically Resetting The Last Cell

Adding hours to JavaScript Date object?

Another way to handle this is to convert the date to unixtime (epoch), then add the equivalent in (milli)seconds, then convert it back. This way you can handle day and month transitions, like adding 4 hours to 21, which should result in the next day, 01:00.

Laravel 5.4 Specific Table Migration

php artisan migrate --path=/database/migrations/fileName.php

You don't have to refresh for migration because refresh means Rollback all migrations and run them all again.

What's the difference between an id and a class?

When applying CSS, apply it to a class and try to avoid as much as you can to an id. The ID should only be used in JavaScript to fetch the element or for any event binding.

Classes should be used to apply CSS.

Sometimes you do have to use classes for event binding. In such cases, try to avoid classes which are being used for applying CSS and rather add new classes which doesn't have corresponding CSS. This will come to help when you need to change the CSS for any class or change the CSS class name all together for any element.

How can I use inverse or negative wildcards when pattern matching in a unix/linux shell?

If you want to avoid the mem cost of using the exec command, I believe you can do better with xargs. I think the following is a more efficient alternative to

find foo -type f ! -name '*Music*' -exec cp {} bar \; # new proc for each exec



find . -maxdepth 1 -name '*Music*' -prune -o -print0 | xargs -0 -i cp {} dest/

How to switch databases in psql?

You can connect using

\c dbname

If you would like to see all possible commands for POSTGRESQL or SQL follow this steps :

rails dbconsole (You will redericted to your current ENV database)
\? (For POSTGRESQL commands)

\h (For SQL commands)
Press Q to Exit

How to handle screen orientation change when progress dialog and background thread active?

I am a fresher in android and I tried this and it's worked.

public class loadTotalMemberByBranch extends AsyncTask<Void, Void,Void> {
        ProgressDialog progressDialog = new ProgressDialog(Login.this);
        int ranSucess=0;
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            super.onPreExecute();
            progressDialog.setTitle("");    
            progressDialog.isIndeterminate();
            progressDialog.setCancelable(false);
            progressDialog.show();
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);

        }
        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub

            return null;
        }
        @Override
        protected void onPostExecute(Void result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            progressDialog.dismiss();
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);
        }
}

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

After you edit /etc/php5/apache2/php.ini be sure to restart apache.

You can do so by running:

sudo service apache2 restart

Is key-value observation (KVO) available in Swift?

(Edited to add new info): consider whether using the Combine framework can help you accomplish what you wanted, rather than using KVO

Yes and no. KVO works on NSObject subclasses much as it always has. It does not work for classes that don't subclass NSObject. Swift does not (currently at least) have its own native observation system.

(See comments for how to expose other properties as ObjC so KVO works on them)

See the Apple Documentation for a full example.

Adding value to input field with jQuery

$.each(obj, function(index, value) {
    $('#looking_for_job_titles').tagsinput('add', value);
    console.log(value);
});

Trying to make bootstrap modal wider

If you need this solution for only few types of modals just use style="width:90%" attribute.

example:

div class="modal-dialog modal-lg" style="width:90%"

note: this will change only this particular modal

SQL error "ORA-01722: invalid number"

In my case the conversion error was in functional based index, that I had created for the table.

The data being inserted was OK. It took me a while to figure out that the actual error came from the buggy index.

Would be nice, if Oracle could have gave more precise error message in this case.

Can't connect to local MySQL server through socket '/tmp/mysql.sock

Check that your mysql has not reached maximum connections, or is not in some sort of booting loop as happens quite often if the settings are incorrect in my.cnf.

Use ps aux | grep mysql to check if the PID is changing.

What causes the Broken Pipe Error?

When peer close, you just do not know whether it just stop sending or both sending and receiving.Because TCP allows this, btw, you should know the difference between close and shutdown. If peer both stop sending and receiving, first you send some bytes, it will succeed. But the peer kernel will send you RST. So subsequently you send some bytes, your kernel will send you SIGPIPE signal, if you catch or ignore this signal, when your send returns, you just get Broken pipe error, or if you don't , the default behavior of your program is crashing.

'npm' is not recognized as internal or external command, operable program or batch file

Just add:

;C:\Program Files\nodejs\

To the end of your Path variable on the "User variable" section of the Environment Variables on the System Properties.

After that, reopen your command prompt and type

npm

This should work.

WHERE Clause to find all records in a specific month

One way would be to create a variable that represents the first of the month (ie 5/1/2009), either pass it into the proc or build it (concatenate month/1/year). Then use the DateDiff function.

WHERE DateDiff(m,@Date,DateField) = 0

This will return anything with a matching month and year.

How to format numbers as currency string?

Minimalistic approach that just meets the original requirements:

function formatMoney(n) {
    return "$ " + (Math.round(n * 100) / 100).toLocaleString();
}

@Daniel Magliola: You're right, the above was a hasty, incomplete implementation. Here's the corrected implementation:

function formatMoney(n) {
    return "$ " + n.toLocaleString().split(".")[0] + "."
        + n.toFixed(2).split(".")[1];
}

How to bind 'touchstart' and 'click' events but not respond to both?

I'm not sure if this works on all browsers and devices. I tested this using Google Chrome and Safari iOS.

$thing.on('click || touchend', function(e){

});

The OR opperand should fire only the first event (on desktop that should be click and on an iPhone that should be touchend).

hadoop copy a local file system folder to HDFS

To copy a folder file from local to hdfs, you can the below command

hadoop fs -put /path/localpath  /path/hdfspath

hadoop fs -copyFromLocal /path/localpath  /path/hdfspath

Get the data received in a Flask request

@app.route('/addData', methods=['POST'])
def add_data():
     data_in = mongo.db.Data
     id = request.values.get("id")
     name = request.values.get("name")
     newuser = {'id' : id, 'name' : name}
     if voter.find({'id' : id, 'name' : name}).count() > 0:
            return "Data Exists"
     else:
            data_in.insert(newuser)
            return "Data Added"

Determine direct shared object dependencies of a Linux binary?

ldd -v prints the dependency tree under "Version information:' section. The first block in that section are the direct dependencies of the binary.

See Hierarchical ldd(1)

How do I run Redis on Windows?

You can go through the below steps and get setup redis in windows.

Download the Redis zip file. Click here!
Extract the zip file to the prepared directory.
Run redis-server.exe, you can either directly run redis-server.exe by clicking or run via command prompt.

Run redis-cli.exe, after successfully running the redis-server. You can access it and test commands by running redis-cli.exe Test PING command is used to test if a connection is still alive.

Using LINQ to concatenate strings

This answer shows usage of LINQ (Aggregate) as requested in the question and is not intended for everyday use. Because this does not use a StringBuilder it will have horrible performance for very long sequences. For regular code use String.Join as shown in the other answer

Use aggregate queries like this:

string[] words = { "one", "two", "three" };
var res = words.Aggregate(
   "", // start with empty string to handle empty list case.
   (current, next) => current + ", " + next);
Console.WriteLine(res);

This outputs:

, one, two, three

An aggregate is a function that takes a collection of values and returns a scalar value. Examples from T-SQL include min, max, and sum. Both VB and C# have support for aggregates. Both VB and C# support aggregates as extension methods. Using the dot-notation, one simply calls a method on an IEnumerable object.

Remember that aggregate queries are executed immediately.

More information - MSDN: Aggregate Queries

If you really want to use Aggregate use variant using StringBuilder proposed in comment by CodeMonkeyKing which would be about the same code as regular String.Join including good performance for large number of objects:

 var res = words.Aggregate(
     new StringBuilder(), 
     (current, next) => current.Append(current.Length == 0? "" : ", ").Append(next))
     .ToString();

Calling a JSON API with Node.js

Problems with other answers:

unsafe JSON.parse
no response code checking

All of the answers here use JSON.parse() in an unsafe way. You should always put all calls to JSON.parse() in a try/catch block especially when you parse JSON coming from an external source, like you do here.

You can use request to parse the JSON automatically which wasn't mentioned here in other answers. There is already an answer using request module but it uses JSON.parse() to manually parse JSON - which should always be run inside a try {} catch {} block to handle errors of incorrect JSON or otherwise the entire app will crash. And incorrect JSON happens, trust me.

Other answers that use http also use JSON.parse() without checking for exceptions that can happen and crash your application.

Below I'll show few ways to handle it safely.

All examples use a public GitHub API so everyone can try that code safely.

Example with `request`

Here's a working example with request that automatically parses JSON:

'use strict';
var request = require('request');

var url = 'https://api.github.com/users/rsp';

request.get({
    url: url,
    json: true,
    headers: {'User-Agent': 'request'}
  }, (err, res, data) => {
    if (err) {
      console.log('Error:', err);
    } else if (res.statusCode !== 200) {
      console.log('Status:', res.statusCode);
    } else {
      // data is already parsed as JSON:
      console.log(data.html_url);
    }
});

Example with `http` and `try/catch`

This uses https - just change https to http if you want HTTP connections:

'use strict';
var https = require('https');

var options = {
    host: 'api.github.com',
    path: '/users/rsp',
    headers: {'User-Agent': 'request'}
};

https.get(options, function (res) {
    var json = '';
    res.on('data', function (chunk) {
        json += chunk;
    });
    res.on('end', function () {
        if (res.statusCode === 200) {
            try {
                var data = JSON.parse(json);
                // data is available here:
                console.log(data.html_url);
            } catch (e) {
                console.log('Error parsing JSON!');
            }
        } else {
            console.log('Status:', res.statusCode);
        }
    });
}).on('error', function (err) {
      console.log('Error:', err);
});

Example with `http` and `tryjson`

This example is similar to the above but uses the tryjson module. (Disclaimer: I am the author of that module.)

'use strict';
var https = require('https');
var tryjson = require('tryjson');

var options = {
    host: 'api.github.com',
    path: '/users/rsp',
    headers: {'User-Agent': 'request'}
};

https.get(options, function (res) {
    var json = '';

    res.on('data', function (chunk) {
        json += chunk;
    });

    res.on('end', function () {
        if (res.statusCode === 200) {
            var data = tryjson.parse(json);
            console.log(data ? data.html_url : 'Error parsing JSON!');
        } else {
            console.log('Status:', res.statusCode);
        }
    });
}).on('error', function (err) {
      console.log('Error:', err);
});

Summary

The example that uses request is the simplest. But if for some reason you don't want to use it then remember to always check the response code and to parse JSON safely.

Get controller and action name from within controller?

This seems to work nicely for me (so far), also works if you are using attribute routing.

public class BaseController : Controller
{
    protected string CurrentAction { get; private set; }
    protected string CurrentController { get; private set; }

    protected override void Initialize(RequestContext requestContext)
    {
        this.PopulateControllerActionInfo(requestContext);
    }

    private void PopulateControllerActionInfo(RequestContext requestContext)
    {
        RouteData routedata = requestContext.RouteData;

        object routes;

        if (routedata.Values.TryGetValue("MS_DirectRouteMatches", out routes))
        {
            routedata = (routes as List<RouteData>)?.FirstOrDefault();
        }

        if (routedata == null)
            return;

        Func<string, string> getValue = (s) =>
        {
            object o;
            return routedata.Values.TryGetValue(s, out o) ? o.ToString() : String.Empty;
        };

        this.CurrentAction = getValue("action");
        this.CurrentController = getValue("controller");
    }
}

convert strtotime to date time format in php

<?php
  echo date('d - m - Y',strtotime('2013-01-19 01:23:42'));
 ?>       
Out put : 19 - 01 - 2013

How to set HttpResponse timeout for Android in Java

If you're using the default http client, here's how to do it using the default http params:

HttpClient client = new DefaultHttpClient();
HttpParams params = client.getParams();
HttpConnectionParams.setConnectionTimeout(params, 3000);
HttpConnectionParams.setSoTimeout(params, 3000);

Original credit goes to http://www.jayway.com/2009/03/17/configuring-timeout-with-apache-httpclient-40/

What's the difference between JPA and Hibernate?

JPA is a Java API specification which describes the management of relational data in applications using Java Platform. where as Hibernate is a ORM (Object Relational Mapping) library which follows JPA specification.

You can think JPA as a set of Rules which is implemented by Hibernate.

Random numbers with Math.random() in Java

Google is right :-)

Google's formula creates numbers between: min and max Your formula creates numbers between: min and (min+max)

regex to match a single character that is anything but a space

The following should suffice:

[^ ]

If you want to expand that to anything but white-space (line breaks, tabs, spaces, hard spaces):

[^\s]

\S  # Note this is a CAPITAL 'S'!

Has anyone gotten HTML emails working with Twitter Bootstrap?

What about Bootstrap Email? This seems to really nice and compatible with bootstrap 4.

How do I create a constant in Python?

Can't help but provide my own very light minimalist metaclass implementation (which may appear as a variation from the previous metaclass answer).

Constants are stored inside a container class (no instantiation needed). Values can be set once, but cannot be changed (or deleted) once they are set.

Personally I currently have no use-case for this, but was a fun exercise.

class MetaConstant(type):
    ''' Metaclass that allows underlying class to store constants at class-level (subclass instance not needed).
        Non-existent attributes of underlying class (constants) can be set initially, but cannot be changed or deleted.
    '''

    def __setattr__(klass, attr, value):
        'If attribute (constant) doesn\'t exist, set value. If attribute exists, raise AttributeError.'
        if hasattr(klass, attr):
            raise AttributeError(f'Can\'t change the value of the constant {klass.__name__}.{attr} to {value}'
                                 f' (the value of {klass.__name__}.{attr} is already set to'
                                 f' {getattr(klass, attr)}).')
        super().__setattr__(attr, value)

    def __delattr__(klass, attr):
        if hasattr(klass, attr):
            raise AttributeError(f'Can\'t delete constant {klass.__name__}.{attr}'
                                 f' (set to {getattr(klass, attr)}).')


class Constants(metaclass=MetaConstant):
    'Container class for constants. No instantiation required.'
    #pass               # uncomment if no constants set upon class creation
    B = 'Six'           # sets Constants.B to 'Six'


Constants.B = 6         # AttributeError
del Constants.B         # AttributeError

Constants.A = 'Five'    # sets Constants.A to 'Five'
Constants.A = 5         # AttributeError
del Constants.A         # AttributeError

Feel free to suggest improvements.

Online SQL Query Syntax Checker

SQLFiddle will let you test out your queries, while it doesn't explicitly correct syntax etc. per se it does let you play around with the script and will definitely let you know if things are working or not.

Border Radius of Table is not working

<div class="leads-search-table">
                    <div class="row col-md-6 col-md-offset-2 custyle">
                    <table class="table custab bordered">
                    <thead>

                        <tr>
                            <th>ID</th>
                            <th>Title</th>
                            <th>Parent ID</th>
                            <th class="text-center">Action</th>
                        </tr>
                    </thead>
                            <tr>
                                <td>1</td>
                                <td>News</td>
                                <td>News Cate</td>
                                <td class="text-center"><a class='btn btn-info btn-xs' href="#"><span class="glyphicon glyphicon-edit"></span> Edit</a> <a href="#" class="btn btn-danger btn-xs"><span class="glyphicon glyphicon-remove"></span> Del</a></td>
                            </tr>
                            <tr>
                                <td>2</td>
                                <td>Products</td>
                                <td>Main Products</td>
                                <td class="text-center"><a class='btn btn-info btn-xs' href="#"><span class="glyphicon glyphicon-edit"></span> Edit</a> <a href="#" class="btn btn-danger btn-xs"><span class="glyphicon glyphicon-remove"></span> Del</a></td>
                            </tr>
                            <tr>
                                <td>3</td>
                                <td>Blogs</td>
                                <td>Parent Blogs</td>
                                <td class="text-center"><a class='btn btn-info btn-xs' href="#"><span class="glyphicon glyphicon-edit"></span> Edit</a> <a href="#" class="btn btn-danger btn-xs"><span class="glyphicon glyphicon-remove"></span> Del</a></td>
                            </tr>
                    </table>
                    </div>
                </div>

Css

.custab{
    border: 1px solid #ccc;
    margin: 5% 0;
    transition: 0.5s;
    background-color: #fff;
    -webkit-border-radius:4px;
    border-radius: 4px;
    border-collapse: separate;
}

oracle.jdbc.driver.OracleDriver ClassNotFoundException

Method 1: Download ojdbc.jar

add ojdbc6.jar to deployment assembly. Right click on project->properties->select deployment assembly->click on 'Add' ->select 'Archives from File System'->browse to the folder where ojdbc6.jar is saved.->add the jar->click finish->Apply/OK.

Method 2:

if you want to add ojdbc.jar to your maven dependencies you follow this link: http://www.mkyong.com/maven/how-to-add-oracle-jdbc-driver-in-your-maven-local-repository/ . . Even if you're using a maven project it is not necessary to add ojdbc to maven dependencies(method 2), method 1 (adding directly to deployment assembly) works just fine.

jQuery UI Dialog OnBeforeUnload

The correct way to display the alert is to simply return a string. Don't call the alert() method yourself.

<script type="text/javascript">
    $(window).on('beforeunload', function() {
        if (iWantTo) {
            return 'you are an idiot!';
        }
    }); 
</script>

Name [jdbc/mydb] is not bound in this Context

you put resource-ref in the description tag in web.xml

Custom circle button

With the official Material Components library you can use the MaterialButton applying a Widget.MaterialComponents.Button.Icon style.

Something like:

   <com.google.android.material.button.MaterialButton
            android:layout_width="48dp"
            android:layout_height="48dp"
            style="@style/Widget.MaterialComponents.Button.Icon"
            app:icon="@drawable/ic_add"
            app:iconSize="24dp"
            app:iconPadding="0dp"
            android:insetLeft="0dp"
            android:insetTop="0dp"
            android:insetRight="0dp"
            android:insetBottom="0dp"
            app:shapeAppearanceOverlay="@style/ShapeAppearanceOverlay.MyApp.Button.Rounded"
            />

Currently the app:iconPadding="0dp",android:insetLeft,android:insetTop,android:insetRight,android:insetBottom attributes are needed to center the icon on the button avoiding extra padding space.

Use the app:shapeAppearanceOverlay attribute to get rounded corners. In this case you will have a circle.

  <style name="ShapeAppearanceOverlay.MyApp.Button.Rounded" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
  </style>

The final result:

8080 port already taken issue when trying to redeploy project from Spring Tool Suite IDE

On Linux Machine, save the bash script and execute it. If you want to free port 8080, Input 8080 when prompted

echo "Enter port number to be closed :: "
read port
sudo kill $(sudo lsof -t -i:$port)

How to check version of a CocoaPods framework

pod outdated

When you run pod outdated, CocoaPods will list all pods that have newer versions that the ones listed in the Podfile.lock (the versions currently installed for each pod) and that could be updated (as long as it matches the restrictions like pod 'MyPod', '~>x.y' set in your Podfile)

Powershell script to see currently logged in users (domain and machine) + status (active, idle, away)

In search of this same solution, I found what I needed under a different question in stackoverflow: Powershell-log-off-remote-session. The below one line will return a list of logged on users.

query user /server:$SERVER

Setting values of input fields with Angular 6

As an alternate you can use reactive forms. Here is an example: https://stackblitz.com/edit/angular-pqb2xx

Template

<form [formGroup]="mainForm" ng-submit="submitForm()">
  Global Price: <input type="number" formControlName="globalPrice">
  <button type="button" [disabled]="mainForm.get('globalPrice').value === null" (click)="applyPriceToAll()">Apply to all</button>
  <table border formArrayName="orderLines">
  <ng-container *ngFor="let orderLine of orderLines let i=index" [formGroupName]="i">
    <tr>
       <td>{{orderLine.time | date}}</td>
       <td>{{orderLine.quantity}}</td>
       <td><input formControlName="price" type="number"></td>
    </tr>
</ng-container>
  </table>
</form>

Component

import { Component } from '@angular/core';
import { FormGroup, FormControl, FormArray } from '@angular/forms';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular 6';
  mainForm: FormGroup;
  orderLines = [
    {price: 10, time: new Date(), quantity: 2},
    {price: 20, time: new Date(), quantity: 3},
    {price: 30, time: new Date(), quantity: 3},
    {price: 40, time: new Date(), quantity: 5}
    ]
  constructor() {
    this.mainForm = this.getForm();
  }

  getForm(): FormGroup {
    return new FormGroup({
      globalPrice: new FormControl(),
      orderLines: new FormArray(this.orderLines.map(this.getFormGroupForLine))
    })
  }

  getFormGroupForLine(orderLine: any): FormGroup {
    return new FormGroup({
      price: new FormControl(orderLine.price)
    })
  }

  applyPriceToAll() {
    const formLines = this.mainForm.get('orderLines') as FormArray;
    const globalPrice = this.mainForm.get('globalPrice').value;
    formLines.controls.forEach(control => control.get('price').setValue(globalPrice));
    // optionally recheck value and validity without emit event.
  }

  submitForm() {

  }
}

How to create JSON string in C#

You could use the JavaScriptSerializer class, check this article to build an useful extension method.

Code from article:

namespace ExtensionMethods
{
    public static class JSONHelper
    {
        public static string ToJSON(this object obj)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            return serializer.Serialize(obj);
        }

        public static string ToJSON(this object obj, int recursionDepth)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            serializer.RecursionLimit = recursionDepth;
            return serializer.Serialize(obj);
        }
    }
}

Usage:

using ExtensionMethods;

...

List<Person> people = new List<Person>{
                   new Person{ID = 1, FirstName = "Scott", LastName = "Gurthie"},
                   new Person{ID = 2, FirstName = "Bill", LastName = "Gates"}
                   };


string jsonString = people.ToJSON();

How can I run MongoDB as a Windows service?

Unlike other answers this will ..

START THE SERVICE AUTOMATICALLY ON SYSTEM REBOOT / RESTART

MongoDB Install

Windows

(1) Install MongoDB

(2) Add bin to path

(3) Create c:\data\db

(4) Create c:\data\log

(5) Create c:\data\mongod.cfg with contents ..

systemLog:
    destination: file
    path: c:\data\log\mongod.log
storage:
    dbPath: c:\data\db

(6) To create service that will auto start on reboot .. RUN AS ADMIN ..

sc.exe create MongoDB binPath= "\"C:\Program Files\MongoDB\Server\3.4\bin\mongod.exe\" --service --config=\"C:\data\mongod.cfg\"" DisplayName= "MongoDB" start= "auto"

(7) Start the service .. RUN AS ADMIN ..

net start MongoDB

IMPORTANT: Even if this says 'The MongoDB service was started successfully' it can fail

To double check open Control Panel > Services, ensure the status of the MongoDB service is 'Running'

If not, check your log file at C:\data\log\mongod.log for the reason for failure and fix it

(Do not start MongoDB via Control Panel > Services, use .. net start MongoDB)

(8) Finally, restart your machine with MongoDB running and it will still be running on restart

If you ever want to kill it ..

net stop MongoDB

sc.exe delete MongoDB

Adding elements to a C# array

What's abaut this one:

List<int> tmpList = intArry.ToList(); tmpList.Add(anyInt); intArry = tmpList.ToArray();

Laravel 5.1 - Checking a Database Connection

Another Approach:

When Laravel tries to connect to database, if the connection fails or if it finds any errors it will return a PDOException error. We can catch this error and redirect the action

Add the following code in the app/filtes.php file.

App::error(function(PDOException $exception)
{
    Log::error("Error connecting to database: ".$exception->getMessage());

    return "Error connecting to database";
});

Hope this is helpful.

How to create major and minor gridlines with different linestyles in Python

Actually, it is as simple as setting major and minor separately:

In [9]: plot([23, 456, 676, 89, 906, 34, 2345])
Out[9]: [<matplotlib.lines.Line2D at 0x6112f90>]

In [10]: yscale('log')

In [11]: grid(b=True, which='major', color='b', linestyle='-')

In [12]: grid(b=True, which='minor', color='r', linestyle='--')

The gotcha with minor grids is that you have to have minor tick marks turned on too. In the above code this is done by yscale('log'), but it can also be done with plt.minorticks_on().

enter image description here

Why doesn't Python have multiline comments?

Besides, multiline comments are a bitch. Sorry to say, but regardless of the language, I don't use them for anything else than debugging purposes. Say you have code like this:

void someFunction()
{
    Something
    /*Some comments*/
    Something else
}

Then you find out that there is something in your code you can't fix with the debugger, so you start manually debugging it by commenting out smaller and smaller chuncks of code with theese multiline comments. This would then give the function:

void someFunction()
{ /*
    Something
   /* Comments */
   Something more*/
}

This is really irritating.

Git: "please tell me who you are" error

Have a look at the config file.

Repository > Repository Settings > Edit config file.

Check if the [user] section exists. If the user section is missing, add it.

Example:

[user]
name = "your name"
email = "your email"

Examples of good gotos in C or C++

@fizzer.myopenid.com: your posted code snippet is equivalent to the following:

    while (system_call() == -1)
    {
        if (errno != EINTR)
        {
            // handle real errors

            break;
        }
    }

I definitely prefer this form.

How can I check if a Perl array contains a particular value?

Simply turn the array into a hash:

my %params = map { $_ => 1 } @badparams;

if(exists($params{$someparam})) { ... }

You can also add more (unique) params to the list:

$params{$newparam} = 1;

And later get a list of (unique) params back:

@badparams = keys %params;

Dynamic instantiation from string name of a class in dynamically imported module?

I couldn't quite get there in my use case from the examples above, but Ahmad got me the closest (thank you). For those reading this in the future, here is the code that worked for me.

def get_class(fully_qualified_path, module_name, class_name, *instantiation):
    """
    Returns an instantiated class for the given string descriptors
    :param fully_qualified_path: The path to the module eg("Utilities.Printer")
    :param module_name: The module name eg("Printer")
    :param class_name: The class name eg("ScreenPrinter")
    :param instantiation: Any fields required to instantiate the class
    :return: An instance of the class
    """
    p = __import__(fully_qualified_path)
    m = getattr(p, module_name)
    c = getattr(m, class_name)
    instance = c(*instantiation)
    return instance

Are there any Open Source alternatives to Crystal Reports?

So far based on my research JasperSoft has turned out promising open source reporting tool… Matter of fact I am currently working on a huge project wherein I have started converting and building reports using JasperReports/iReports…

Every reporting tool has its own learning curve. The support group from and for Jasper and the quality of response that I have gotten so far is good.

Again at the end of the day it all comes down to what your business / organization needs.

How to set width and height dynamically using jQuery

or use this syntax:

$("#mainTable").css("width", "100px");
$("#mainTable").css("height", "200px");

Display a tooltip over a button using Windows Forms

You can use the ToolTip class:

Creating a ToolTip for a Control

Example:

private void Form1_Load(object sender, System.EventArgs e)
{
    System.Windows.Forms.ToolTip ToolTip1 = new System.Windows.Forms.ToolTip();
    ToolTip1.SetToolTip(this.Button1, "Hello");
}

How get the base URL via context path in JSF?

JSTL 1.2 variation leveraged from BalusC answer

<c:set var="baseURL" value="${pageContext.request.requestURL.substring(0, pageContext.request.requestURL.length() - pageContext.request.requestURI.length())}${pageContext.request.contextPath}/" />

<head>
  <base href="${baseURL}" />

Modular multiplicative inverse function in Python

To figure out the modular multiplicative inverse I recommend using the Extended Euclidean Algorithm like this:

def multiplicative_inverse(a, b):
    origA = a
    X = 0
    prevX = 1
    Y = 1
    prevY = 0
    while b != 0:
        temp = b
        quotient = a/b
        b = a%b
        a = temp
        temp = X
        a = prevX - quotient * X
        prevX = temp
        temp = Y
        Y = prevY - quotient * Y
        prevY = temp

    return origA + prevY

Error 'tunneling socket' while executing npm install

I also ran into the similar issue and was using CNTLM for proxy configuration. In my case HTTP_PROXY and HTTPS_PROXY are taking higher precedence over http_proxy and https_proxy so be aware of changing all proxy variables.

env|grep -i proxy

and make sure all of the below proxy variables should point to the same proxy.

HTTP-PROXY = "http://localhost:3128"
HTTPS-PROXY = "https://localhost:3128"
HTTPS_PROXY = "http://localhost:3128"
HTTP_PROXY = "http://localhost:3128"
PROXY = "http://localhost:3128"
http-proxy = "http://localhost:3128"
http_proxy = "http://localhost:3128"
https-proxy = "https://localhost:3128/"
https_proxy = "https://localhost:3128"
proxy = "http://localhost:3128/"

I know some variables are unneccessary but I'm not sure which is using what.

Angular 2 declaring an array of objects

type NumberArray = Array<{id: number, text: string}>;

const arr: NumberArray = [
    {id: 0, text: 'Number 0'},
    {id: 1, text: 'Number 1'},
    {id: 2, text: 'Number 2'},
    {id: 3, text: 'Number 3 '},
    {id: 4, text: 'Number 4 '},
    {id: 5, text: 'Number 5 '},
];

GIT clone repo across local file system in windows

the answer with the host name didn't work for me but this did :

git clone file:////home/git/repositories/MyProject.git/

SQL Server : Arithmetic overflow error converting expression to data type int

SELECT                          
    DATEPART(YEAR, dateTimeStamp) AS [Year]                         
    , DATEPART(MONTH, dateTimeStamp) AS [Month]                         
    , COUNT(*) AS NumStreams                        
    , [platform] AS [Platform]                      
    , deliverableName AS [Deliverable Name]                     
    , SUM(billableDuration) AS NumSecondsDelivered

Assuming that your quoted text is the exact text, one of these columns can't do the mathematical calculations that you want. Double click on the error and it will highlight the line that's causing the problems (if it's different than what's posted, it may not be up there); I tested your code with the variables and there was no problem, meaning that one of these columns (which we don't know more specific information about) is creating this error.

One of your expressions needs to be casted/converted to an int in order for this to go through, which is the meaning of Arithmetic overflow error converting expression to data type int.

Filtering a data frame by values in a column

Try this:

subset(studentdata, Drink=='water')

that should do it.

Change the class from factor to numeric of many columns in a data frame

Based on @SDahm's answer, this was an "optimal" solution for my tibble:

data %<>% lapply(type.convert) %>% as.data.table()

This requires dplyr and magrittr.

What is the difference between 0.0.0.0, 127.0.0.1 and localhost?

In current version of Jekyll, it defaults to http://127.0.0.1:4000/.
This is good, if you are connected to a network but do not want anyone else to access your application.

However it may happen that you want to see how your application runs on a mobile or from some other laptop/computer.

In that case, you can use

jekyll serve --host 0.0.0.0

This binds your application to the host & next use following to connect to it from some other host

http://host's IP adress/4000

How to skip the OPTIONS preflight request?

When performing certain types of cross-domain AJAX requests, modern browsers that support CORS will insert an extra "preflight" request to determine whether they have permission to perform the action. From example query:

$http.get( ‘https://example.com/api/v1/users/’ +userId,
  {params:{
           apiKey:’34d1e55e4b02e56a67b0b66’
          }
  } 
);

As a result of this fragment we can see that the address was sent two requests (OPTIONS and GET). The response from the server includes headers confirming the permissibility the query GET. If your server is not configured to process an OPTIONS request properly, client requests will fail. For example:

Access-Control-Allow-Credentials: true
Access-Control-Allow-Headers: accept, origin, x-requested-with, content-type
Access-Control-Allow-Methods: DELETE
Access-Control-Allow-Methods: OPTIONS
Access-Control-Allow-Methods: PUT
Access-Control-Allow-Methods: GET
Access-Control-Allow-Methods: POST
Access-Control-Allow-Orgin: *
Access-Control-Max-Age: 172800
Allow: PUT
Allow: OPTIONS
Allow: POST
Allow: DELETE
Allow: GET

How to run php files on my computer

I just put the content in the question in a file called test.php and ran php test.php. (In the folder where the test.php is.)

$ php foo.php                                                                                                                                                                                                                                                                                                                                    
15

Executing another application from Java

If you don't care about the return value you could just use Runtime.getRuntime().exec("path.to.your.batch.file");

c++ compile error: ISO C++ forbids comparison between pointer and integer

"y" is a string/array/pointer. 'y' is a char/integral type

REST API Token-based Authentication

In the web a stateful protocol is based on having a temporary token that is exchanged between a browser and a server (via cookie header or URI rewriting) on every request. That token is usually created on the server end, and it is a piece of opaque data that has a certain time-to-live, and it has the sole purpose of identifying a specific web user agent. That is, the token is temporary, and becomes a STATE that the web server has to maintain on behalf of a client user agent during the duration of that conversation. Therefore, the communication using a token in this way is STATEFUL. And if the conversation between client and server is STATEFUL it is not RESTful.

The username/password (sent on the Authorization header) is usually persisted on the database with the intent of identifying a user. Sometimes the user could mean another application; however, the username/password is NEVER intended to identify a specific web client user agent. The conversation between a web agent and server based on using the username/password in the Authorization header (following the HTTP Basic Authorization) is STATELESS because the web server front-end is not creating or maintaining any STATE information whatsoever on behalf of a specific web client user agent. And based on my understanding of REST, the protocol states clearly that the conversation between clients and server should be STATELESS. Therefore, if we want to have a true RESTful service we should use username/password (Refer to RFC mentioned in my previous post) in the Authorization header for every single call, NOT a sension kind of token (e.g. Session tokens created in web servers, OAuth tokens created in authorization servers, and so on).

I understand that several called REST providers are using tokens like OAuth1 or OAuth2 accept-tokens to be be passed as "Authorization: Bearer " in HTTP headers. However, it appears to me that using those tokens for RESTful services would violate the true STATELESS meaning that REST embraces; because those tokens are temporary piece of data created/maintained on the server side to identify a specific web client user agent for the valid duration of a that web client/server conversation. Therefore, any service that is using those OAuth1/2 tokens should not be called REST if we want to stick to the TRUE meaning of a STATELESS protocol.

Rubens

Uncaught TypeError: data.push is not a function

you can use push method only if the object is an array:

var data = new Array();
data.push({"country": "IN"}).

data['country'] = "IN"

if it's just an object you can use

data.country = "IN";

Expected response code 250 but got code "535", with message "535-5.7.8 Username and Password not accepted

I had everything fine. Less secure app option was also enabled. Still, I was getting the error. What I have done is:

Google will send you Critical security alert
Then you have to authorize that activity. ( Clicking on 'YES, THAT WAS ME' type thing )
Then you can try sending email again.

REST, HTTP DELETE and parameters

No, it is not RESTful. The only reason why you should be putting a verb (force_delete) into the URI is if you would need to overload GET/POST methods in an environment where PUT/DELETE methods are not available. Judging from your use of the DELETE method, this is not the case.

HTTP error code 409/Conflict should be used for situations where there is a conflict which prevents the RESTful service to perform the operation, but there is still a chance that the user might be able to resolve the conflict himself. A pre-deletion confirmation (where there are no real conflicts which would prevent deletion) is not a conflict per se, as nothing prevents the API from performing the requested operation.

As Alex said (I don't know who downvoted him, he is correct), this should be handled in the UI, because a RESTful service as such just processes requests and should be therefore stateless (i.e. it must not rely on confirmations by holding any server-side information about of a request).

Two examples how to do this in UI would be to:

pre-HTML5:* show a JS confirmation dialog to the user, and send the request only if the user confirms it
HTML5:* use a form with action DELETE where the form would contain only "Confirm" and "Cancel" buttons ("Confirm" would be the submit button)

(*) Please note that HTML versions prior to 5 do not support PUT and DELETE HTTP methods natively, however most modern browsers can do these two methods via AJAX calls. See this thread for details about cross-browser support.

Update (based on additional investigation and discussions):

The scenario where the service would require the force_delete=true flag to be present violates the uniform interface as defined in Roy Fielding's dissertation. Also, as per HTTP RFC, the DELETE method may be overridden on the origin server (client), implying that this is not done on the target server (service).

So once the service receives a DELETE request, it should process it without needing any additional confirmation (regardless if the service actually performs the operation).

Disable vertical sync for glxgears

For intel drivers, there is also this method

Disable Vertical Synchronization (VSYNC)

The intel-driver uses Triple Buffering for vertical synchronization, this allows for full performance and avoids tearing. To turn vertical synchronization off (e.g. for benchmarking) use this .drirc in your home directory:

<device screen="0" driver="dri2">
    <application name="Default">
        <option name="vblank_mode" value="0"/>
    </application>
</device>

How to redirect page after click on Ok button on sweet alert?

I wasn't able to do that with any swal(sweatAlert) default callback function, so I forced with jquery, got the Ok button class inspecting the element in chrome an made something like this:

<script>    
          sweetAlert({
                title:'Warning!',
                text: 'Invalid user or password!',
                type:'warning'
          },function(isConfirm){
                alert('ok');
          });
          $('.swal2-confirm').click(function(){
                window.location.href = 'index.php';
          });
</script>

The 'Ok' alert in function(isConfirm) was just a test to see if it would get into this function, if so I should be able to redirect from there, but I wasn't...

So I used jQuery to determine if the button "OK" of swal was clicked by getting it class: ".swal2-confirm' then I could redirect with success...

Hope this helps you all !

PS: I am using php echo to run the script, I din't have to leave php to run it, just use single quotes and you're done !

ALTER TABLE, set null in not null column, PostgreSQL 9.1

Execute the command in this format

ALTER TABLE tablename ALTER COLUMN columnname SET NOT NULL;

for setting the column to not null.

SQL state [99999]; error code [17004]; Invalid column type: 1111 With Spring SimpleJdbcCall

Probably, you need to insert schema identifier here:

in.addValue("po_system_users", null, OracleTypes.ARRAY, "your_schema.T_SYSTEM_USER_TAB");

What is the difference between background and background-color

They're both the same. There are multiple background selectors (i.e. background-color, background-image, background-position) and you can access them either through the simpler background selector or the more specific one. For example:

background: blue url(/myImage.jpg) no-repeat;

background-color: blue;
background-image: url(/myImage.jpg);
background-repeat: no-repeat;

What is the difference between Left, Right, Outer and Inner Joins?

There are only 4 kinds:

Inner join: The most common type. An output row is produced for every pair of input rows that match on the join conditions.
Left outer join: The same as an inner join, except that if there is any row for which no matching row in the table on the right can be found, a row is output containing the values from the table on the left, with NULL for each value in the table on the right. This means that every row from the table on the left will appear at least once in the output.
Right outer join: The same as a left outer join, except with the roles of the tables reversed.
Full outer join: A combination of left and right outer joins. Every row from both tables will appear in the output at least once.

A "cross join" or "cartesian join" is simply an inner join for which no join conditions have been specified, resulting in all pairs of rows being output.

Thanks to RusselH for pointing out FULL joins, which I'd omitted.

What are the safe characters for making URLs?

unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

How to check if a std::string is set or not?

Use empty():

std::string s;

if (s.empty())
    // nothing in s

Not able to launch IE browser using Selenium2 (Webdriver) with Java

The following snippet of WebDriver Java code should work to launch IE. The code will ignore the setup of Protected mode settings for all zone in the IE browser.

DesiredCapabilities capabilities = DesiredCapabilities.internetExplorer();
capabilities.setCapability(InternetExplorerDriver.INTRODUCE_FLAKINESS_BY_IGNORING_SECURITY_DOMAINS, true);
File file = new File("D:\\Ripon Al Wasim\\IEDriverServer.exe");
System.setProperty("webdriver.ie.driver", file.getAbsolutePath());
WebDriver driver = new InternetExplorerDriver(capabilities);
driver.get("https://www.google.com/");

Download IEDriverServer and extract it into your desired location and set the absolute path (In my above example it was "D:\Ripon Al Wasim\IEDriverServer.exe")

How to assign string to bytes array

For example,

package main

import "fmt"

func main() {
    s := "abc"
    var a [20]byte
    copy(a[:], s)
    fmt.Println("s:", []byte(s), "a:", a)
}

Output:

s: [97 98 99] a: [97 98 99 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

Why should I use a pointer rather than the object itself?

The key strength of object pointers in C++ is allowing for polymorphic arrays and maps of pointers of the same superclass. It allows, for example, to put parakeets, chickens, robins, ostriches, etc. in an array of Bird.

Additionally, dynamically allocated objects are more flexible, and can use HEAP memory whereas a locally allocated object will use the STACK memory unless it is static. Having large objects on the stack, especially when using recursion, will undoubtedly lead to stack overflow.

use regular expression in if-condition in bash

Use =~

for regular expression check Regular Expressions Tutorial Table of Contents

Adding a column to a data.frame

In addition to Roman's answer, something like this might be even simpler. Note that I haven't tested it because I do not have access to R right now.

# Note that I use a global variable here
# normally not advisable, but I liked the
# use here to make the code shorter
index <<- 0
new_column = sapply(df$h_no, function(x) {
  if(x == 1) index = index + 1
  return(index)
})

The function iterates over the values in n_ho and always returns the categorie that the current value belongs to. If a value of 1 is detected, we increase the global variable index and continue.

What is difference between Errors and Exceptions?

Error and Exception both extend Throwable, but mostly Error is thrown by JVM in a scenario which is fatal and there is no way for the application program to recover from that error. For instance OutOfMemoryError.

Though even application can raise an Error but its just not a good a practice, instead applications should use checked exceptions for recoverable conditions and runtime exceptions for programming errors.

UnicodeDecodeError: 'utf8' codec can't decode byte 0xa5 in position 0: invalid start byte

As of 2018-05 this is handled directly with decode, at least for Python 3.

I'm using the below snippet for invalid start byte and invalid continuation byte type errors. Adding errors='ignore' fixed it for me.

with open(out_file, 'rb') as f:
    for line in f:
        print(line.decode(errors='ignore'))

Oracle: How to filter by date and time in a where clause

In the example that you have provided there is nothing that would throw a SQL command not properly formed error. How are you executing this query? What are you not showing us?

This example script works fine:

create table tableName
(session_start_date_time DATE);

insert into tableName (session_start_date_time) 
values (sysdate+1);

select * from tableName
where session_start_date_time > to_date('12-Jan-2012 16:00', 'DD-MON-YYYY hh24:mi');

As does this example:

create table tableName2
(session_start_date_time TIMESTAMP);

insert into tableName2 (session_start_date_time) 
values (to_timestamp('01/12/2012 16:01:02.345678','mm/dd/yyyy hh24:mi:ss.ff'));

select * from tableName2
where session_start_date_time > to_date('12-Jan-2012 16:00', 'DD-MON-YYYY hh24:mi');

select * from tableName2
where session_start_date_time > to_timestamp('01/12/2012 14:01:02.345678','mm/dd/yyyy hh24:mi:ss.ff');

So there must be something else that is wrong.

How to style a div to have a background color for the entire width of the content, and not just for the width of the display?

.success { background-color: #cffccc; overflow: scroll; min-width: 100%; }

You can try scroll or auto.

What is content-type and datatype in an AJAX request?

contentType is the type of data you're sending, so application/json; charset=utf-8 is a common one, as is application/x-www-form-urlencoded; charset=UTF-8, which is the default.

dataType is what you're expecting back from the server: json, html, text, etc. jQuery will use this to figure out how to populate the success function's parameter.

If you're posting something like:

{"name":"John Doe"}

and expecting back:

{"success":true}

Then you should have:

var data = {"name":"John Doe"}
$.ajax({
    dataType : "json",
    contentType: "application/json; charset=utf-8",
    data : JSON.stringify(data),
    success : function(result) {
        alert(result.success); // result is an object which is created from the returned JSON
    },
});

If you're expecting the following:

<div>SUCCESS!!!</div>

Then you should do:

var data = {"name":"John Doe"}
$.ajax({
    dataType : "html",
    contentType: "application/json; charset=utf-8",
    data : JSON.stringify(data),
    success : function(result) {
        jQuery("#someContainer").html(result); // result is the HTML text
    },
});

One more - if you want to post:

name=John&age=34

Then don't stringify the data, and do:

var data = {"name":"John", "age": 34}
$.ajax({
    dataType : "html",
    contentType: "application/x-www-form-urlencoded; charset=UTF-8", // this is the default value, so it's optional
    data : data,
    success : function(result) {
        jQuery("#someContainer").html(result); // result is the HTML text
    },
});

When to use LinkedList over ArrayList in Java?

Both remove() and insert() have a runtime efficiency of O(n) for both ArrayLists and LinkedLists. However, the reason behind the linear processing time comes from two very different reasons:

In an ArrayList, you get to the element in O(1), but actually removing or inserting something makes it O(n) because all the following elements need to be changed.

In a LinkedList, it takes O(n) to actually get to the desired element, because we have to start at the very beginning until we reach the desired index. Actually removing or inserting is constant, because we only have to change 1 reference for remove() and 2 references for insert().

Which of the two is faster for inserting and removing depends on where it happens. If we are closer to the beginning the LinkedList will be faster, because we have to go through relatively few elements. If we are closer to the end an ArrayList will be faster, because we get there in constant time and only have to change the few remaining elements that follow it. When done precisely in the middle the LinkedList will be faster because going through n elements is quicker than moving n values.

Bonus: While there is no way of making these two methods O(1) for an ArrayList, there actually is a way to do this in LinkedLists. Let's say we want to go through the entire List removing and inserting elements on our way. Usually, you would start from the very beginning for each element using the LinkedList, we could also "save" the current element we're working on with an Iterator. With the help of the Iterator, we get an O(1) efficiency for remove() and insert() when working in a LinkedList. Making it the only performance benefit I'm aware of where a LinkedList is always better than an ArrayList.

How to convert a file to utf-8 in Python?

This worked for me in a small test:

sourceEncoding = "iso-8859-1"
targetEncoding = "utf-8"
source = open("source")
target = open("target", "w")

target.write(unicode(source.read(), sourceEncoding).encode(targetEncoding))

Import Maven dependencies in IntelliJ IDEA

Open IntelliJ Idea, Go to File > Other Settings > Default Settings... > Maven (Preferences) > Importing or| Preferences > Maven > Importing

enter image description here

Click on Enable Auto-import in the console.

enter image description here

javac: invalid target release: 1.8

Download JDK 8.
Edit your env var for JAVA_HOME to point to the new installed JDK 1.8: R-click on My Computer -> Properties -> Advanced System Settings -> Environment Variables find JAVA_HOME on the list and set it's value to something like that:
```
C:\Program Files\Java\jdk1.8.0_31
```
Find the old version and edit it in PATH variable aswell.
Probably you will need to restart the system.

Should be done.

How long is the SHA256 hash?

A sha256 is 256 bits long -- as its name indicates.

Since sha256 returns a hexadecimal representation, 4 bits are enough to encode each character (instead of 8, like for ASCII), so 256 bits would represent 64 hex characters, therefore you need a varchar(64), or even a char(64), as the length is always the same, not varying at all.

And the demo :

$hash = hash('sha256', 'hello, world!');
var_dump($hash);

Will give you :

$ php temp.php
string(64) "68e656b251e67e8358bef8483ab0d51c6619f3e7a1a9f0e75838d41ff368f728"

i.e. a string with 64 characters.

How to force NSLocalizedString to use a specific language

Maybe you should complement with this (on .pch file after #import ):

extern NSBundle* bundle; // Declared on Language.m

#ifdef NSLocalizedString
    #undef NSLocalizedString
    // Delete this line to avoid warning
    #warning "Undefining NSLocalizedString"
#endif

#define NSLocalizedString(key, comment) \
    [bundle localizedStringForKey:(key) value:@"" table:nil]

Android SDK Manager gives "Failed to fetch URL https://dl-ssl.google.com/android/repository/repository.xml" error when selecting repository

All that was necessary for me, a Ubuntu user, was to change the owner of the ~/.android directory. In a terminal type the following command:

sudo chown -R username:username ~/.android

Obviously, you must replace "username" (twice) with your username.

I wasn't sure if I should post this as an answer because the original poster's question was concerning Windows Vista, not Ubuntu. However I found this post whilst searching for the answer on Ubuntu so I believe it is pertinent. I don't have sufficient reputation to comment on +Maher Gamal's answer, though, which is what lead me to this answer. Hopefully someone else finds it useful!

Undefined columns selected when subsetting data frame

You want rows where that condition is true so you need a comma:

data[data$Ozone > 14, ]

What is the correct wget command syntax for HTTPS with username and password?

I have found that wget does not properly authenticate with some servers, perhaps because it is only HTTP 1.0 compliant. In such cases, curl (which is HTTP 1.1 compliant) usually does the trick:

curl -o <filename-to-save-as> -u <username>:<password> <url>

How do I close an open port from the terminal on the Mac?

I have created a function for this purpose.

function free_port() {
    if [ -z $1 ] 
    then
        echo no Port given
    else
        PORT=$1;
        PID=$(sudo lsof -i :$PORT) # store the PID, that is using this port 

        if [ -z $PID ] 
        then
            echo port: $PORT is already free.
        else
            sudo kill -9 $PID # kill the process, which frees the port
            echo port: $PORT is now free.
        fi
    fi
}

free_port 80 # you need to change this port number

Copy & pasting this block of code in your terminal should free your desired port. Just remember to change the port number in last line.

Android Percentage Layout Height

With introduction of ContraintLayout, it's possible to implement with Guidelines:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.eugene.test1.MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#AAA"
        android:text="TextView"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/guideline" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.5" />

</android.support.constraint.ConstraintLayout>

You can read more in this article Building interfaces with ConstraintLayout.

How to remove duplicate values from a multi-dimensional array in PHP

An easy to read solution, probably not the most efficient:

function arrayUnique($myArray){
    if(!is_array($myArray))
        return $myArray;

    foreach ($myArray as &$myvalue){
        $myvalue=serialize($myvalue);
    }

    $myArray=array_unique($myArray);

    foreach ($myArray as &$myvalue){
        $myvalue=unserialize($myvalue);
    }

    return $myArray;

}

Bootstrap: Use .pull-right without having to hardcode a negative margin-top

Float elements will be rendered at the line they are normally in the layout. To fix this, you have two choices:

Move the header and the p after the login box:

<div class='container'>
    <div class='hero-unit'>

        <div id='login-box' class='pull-right control-group'>
            <div class='clearfix'>
                <input type='text' placeholder='Username' />
            </div>
            <div class='clearfix'>
                <input type='password' placeholder='Password' />
            </div>
            <button type='button' class='btn btn-primary'>Log in</button>
        </div>

        <h2>Welcome</h2>

        <p>Please log in</p>

    </div>
</div>

Or enclose the left block in a pull-left div, and add a clearfix at the bottom

<div class='container'>
    <div class='hero-unit'>

        <div class="pull-left">

          <h2>Welcome</h2>

          <p>Please log in</p>

        </div>

        <div id='login-box' class='pull-right control-group'>
            <div class='clearfix'>
                <input type='text' placeholder='Username' />
            </div>
            <div class='clearfix'>
                <input type='password' placeholder='Password' />
            </div>
            <button type='button' class='btn btn-primary'>Log in</button>
        </div>

        <div class="clearfix"></div>

    </div>
</div>

How does python numpy.where() work?

Old Answer it is kind of confusing. It gives you the LOCATIONS (all of them) of where your statment is true.

so:

>>> a = np.arange(100)
>>> np.where(a > 30)
(array([31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64,
       65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81,
       82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98,
       99]),)
>>> np.where(a == 90)
(array([90]),)

a = a*40
>>> np.where(a > 1000)
(array([26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
       43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
       60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,
       77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,
       94, 95, 96, 97, 98, 99]),)
>>> a[25]
1000
>>> a[26]
1040

I use it as an alternative to list.index(), but it has many other uses as well. I have never used it with 2D arrays.

http://docs.scipy.org/doc/numpy/reference/generated/numpy.where.html

New Answer It seems that the person was asking something more fundamental.

The question was how could YOU implement something that allows a function (such as where) to know what was requested.

First note that calling any of the comparison operators do an interesting thing.

a > 1000
array([False, False, False, False, False, False, False, False, False,
       False, False, False, False, False, False, False, False, False,
       False, False, False, False, False, False, False, False,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True,  True,  True,  True,  True,  True,  True,  True,  True,
        True`,  True,  True,  True,  True,  True,  True,  True,  True,  True], dtype=bool)`

This is done by overloading the "__gt__" method. For instance:

>>> class demo(object):
    def __gt__(self, item):
        print item


>>> a = demo()
>>> a > 4
4

As you can see, "a > 4" was valid code.

You can get a full list and documentation of all overloaded functions here: http://docs.python.org/reference/datamodel.html

Something that is incredible is how simple it is to do this. ALL operations in python are done in such a way. Saying a > b is equivalent to a.gt(b)!

How to use the unsigned Integer in Java 8 and Java 9?

    // Java 8
    int vInt = Integer.parseUnsignedInt("4294967295");
    System.out.println(vInt); // -1
    String sInt = Integer.toUnsignedString(vInt);
    System.out.println(sInt); // 4294967295

    long vLong = Long.parseUnsignedLong("18446744073709551615");
    System.out.println(vLong); // -1
    String sLong = Long.toUnsignedString(vLong);
    System.out.println(sLong); // 18446744073709551615

    // Guava 18.0
    int vIntGu = UnsignedInts.parseUnsignedInt(UnsignedInteger.MAX_VALUE.toString());
    System.out.println(vIntGu); // -1
    String sIntGu = UnsignedInts.toString(vIntGu);
    System.out.println(sIntGu); // 4294967295

    long vLongGu = UnsignedLongs.parseUnsignedLong("18446744073709551615");
    System.out.println(vLongGu); // -1
    String sLongGu = UnsignedLongs.toString(vLongGu);
    System.out.println(sLongGu); // 18446744073709551615

    /**
     Integer - Max range
     Signed: From -2,147,483,648 to 2,147,483,647, from -(2^31) to 2^31 – 1
     Unsigned: From 0 to 4,294,967,295 which equals 2^32 - 1

     Long - Max range
     Signed: From -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, from -(2^63) to 2^63 - 1
     Unsigned: From 0 to 18,446,744,073,709,551,615 which equals 2^64 – 1
     */

Unable to set variables in bash script

Assignment in bash scripts cannot have spaces around the = and you probably want your date commands enclosed in ~~backticks~~ $():

#!/bin/bash
folder="ABC"
useracct='test'
day=$(date "+%d")
month=$(date "+%B")
year=$(date "+%Y")
folderToBeMoved="/users/$useracct/Documents/Archive/Primetime.eyetv"
newfoldername="/Volumes/Media/Network/$folder/$month$day$year"
ECHO "Network is $network" $network
ECHO "day is $day"
ECHO "Month is $month"
ECHO "YEAR is $year"
ECHO "source is $folderToBeMoved"
ECHO "dest is $newfoldername"
mkdir $newfoldername
cp -R $folderToBeMoved $newfoldername
if [-f $newfoldername/Primetime.eyetv]; then rm $folderToBeMoved; fi

With the last three lines commented out, for me this outputs:

Network is 
day is 16
Month is March
YEAR is 2010
source is /users/test/Documents/Archive/Primetime.eyetv
dest is /Volumes/Media/Network/ABC/March162010

How to spawn a process and capture its STDOUT in .NET?

I just tried this very thing and the following worked for me:

StringBuilder outputBuilder;
ProcessStartInfo processStartInfo;
Process process;

outputBuilder = new StringBuilder();

processStartInfo = new ProcessStartInfo();
processStartInfo.CreateNoWindow = true;
processStartInfo.RedirectStandardOutput = true;
processStartInfo.RedirectStandardInput = true;
processStartInfo.UseShellExecute = false;
processStartInfo.Arguments = "<insert command line arguments here>";
processStartInfo.FileName = "<insert tool path here>";

process = new Process();
process.StartInfo = processStartInfo;
// enable raising events because Process does not raise events by default
process.EnableRaisingEvents = true;
// attach the event handler for OutputDataReceived before starting the process
process.OutputDataReceived += new DataReceivedEventHandler
(
    delegate(object sender, DataReceivedEventArgs e)
    {
        // append the new data to the data already read-in
        outputBuilder.Append(e.Data);
    }
);
// start the process
// then begin asynchronously reading the output
// then wait for the process to exit
// then cancel asynchronously reading the output
process.Start();
process.BeginOutputReadLine();
process.WaitForExit();
process.CancelOutputRead();

// use the output
string output = outputBuilder.ToString();

NPM clean modules

For windows environment:

"scripts": {
    "clean": "rmdir /s /q node_modules",
    ...
}

Default values for Vue component props & how to check if a user did not set the prop?

Vue allows for you to specify a default prop value and type directly, by making props an object (see: https://vuejs.org/guide/components.html#Prop-Validation):

props: {
  year: {
    default: 2016,
    type: Number
  }
}

If the wrong type is passed then it throws an error and logs it in the console, here's the fiddle:

https://jsfiddle.net/cexbqe2q/

How do I correctly use "Not Equal" in MS Access?

Like this

SELECT DISTINCT Table1.Column1
FROM Table1
WHERE NOT EXISTS( SELECT * FROM Table2
    WHERE Table1.Column1 = Table2.Column1  )

You want NOT EXISTS, not "Not Equal"

By the way, you rarely want to write a FROM clause like this:

FROM Table1, Table2

as this means "FROM all combinations of every row in Table1 with every row in Table2..." Usually that's a lot more result rows than you ever want to see. And in the rare case that you really do want to do that, the more accepted syntax is:

FROM Table1 CROSS JOIN Table2

MongoDB Show all contents from all collections

Once you are in terminal/command line, access the database/collection you want to use as follows:

show dbs
use <db name>
show collections

choose your collection and type the following to see all contents of that collection:

db.collectionName.find()

More info here on the MongoDB Quick Reference Guide.

ReSharper "Cannot resolve symbol" even when project builds

What helped in my case after several of the suggestions above didn't:

Removed one project reference (of one of the libraries where ReSharper claimed not to be able to find it even though it was correctly referenced).
Use ReSharper’s "Resolve" on one of its usages to add the reference again.

After that, it worked fine, even though none of the project files were actually modified in the process.

laravel-5 passing variable to JavaScript

Let's say you have a collection named $services that you are passing to the view.

If you need a JS array with the names, you can iterate over this as follows:

<script>
    const myServices = [];
    @foreach ($services as $service)
        myServices.push('{{ $service->name }}');
    @endforeach
</script>

Note: If the string has special characters (like ó or HTML code), you can use {!! $service->name !!}.

If you need an array of objects (with all of the attributes), you can use:

<script>
  const myServices = @json($services);
  // ...
</script>

Note: This blade directive @json is not available for old Laravel versions. You can achieve the same result using json_encode as described in other answers.

Sometimes you don't need to pass a complete collection to the view, and just an array with 1 attribute. If that's your case, you better use $services = Service::pluck('name'); in your Controller.

Is there a way to get the git root directory in one command?

`git-extras`

adds $ git root
see https://github.com/tj/git-extras/blob/master/Commands.md#git-root

$ pwd
.../very-deep-from-root-directory
$ cd `git root`
$ git add . && git commit

Availability of git-extras

homebrew(osx)/linuxbrew(linux) $ brew install git-extras
debian/ubuntu repos (https://packages.debian.org/sid/git-extras) $ apt-get install git-extras

Mongoose: CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"

I was having the same problem.Turns out my Node.js was outdated. After upgrading it's working.

Programs & Examples On #Urn

What is the difference between a URI, a URL and a URN?

What is the difference between URI, URL and URN?

How to check what version of jQuery is loaded?

Android WSDL/SOAP service client

How do you use window.postMessage across domains?

DIVs inside another DIV inside another DIV with CSS

What is the difference between char s[] and char *s?

Compare two files line by line and generate the difference in another file

How do I get the base URL with PHP?

How to properly set Column Width upon creating Excel file? (Column properties)

How to embed HTML into IPython output?

How to get current local date and time in Kotlin

How to prove that a problem is NP complete?

How to clear text area with a button in html using javascript?

Add timer to a Windows Forms application

split string only on first instance of specified character

Confused by python file mode "w+"

How can I fill out a Python string with spaces?

How to workaround 'FB is not defined'?

Vertically align text to top within a UILabel

Efficiently replace all accented characters in a string?

Can’t delete docker image with dependent child images

.net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible

Deserialize a json string to an object in python

How do I erase an element from std::vector<> by index?

Javascript search inside a JSON object

Should I Dispose() DataSet and DataTable?

DateTime.Now.ToShortDateString(); replace month and day

How to find whether MySQL is installed in Red Hat?

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare();

How to sort List of objects by some property

How to set android layout to support all screen sizes?

Raise an event whenever a property's value changed?

Android: Create a toggle button with image and no text

Linq UNION query to select two elements

How do you use NSAttributedString?

sed with literal string--not input file

How to change node.js's console font color?

Sheet.getRange(1,1,1,12) what does the numbers in bracket specify?

how to destroy an object in java?

How do I resolve "Please make sure that the file is accessible and that it is a valid assembly or COM component"?

How do I check CPU and Memory Usage in Java?

Update TensorFlow

How can I use std::maps with user-defined types as key?

org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException:

How can I check for Python version in a program that uses new language features?

C++: what regex library should I use?

How should I remove all the leading spaces from a string? - swift

Visual Studio Code how to resolve merge conflicts with git?

Strange out of memory issue while loading an image to a Bitmap object

How can I install a package with go get?

How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2

Use table row coloring for cells in Bootstrap

Scrolling an iframe with JavaScript?

What does "control reaches end of non-void function" mean?

Is it possible to start a shell session in a running container (without ssh)

jQuery select all except first

How to manually force a commit in a @Transactional method?

Missing `server' JVM (Java\jre7\bin\server\jvm.dll.)

How to embed matplotlib in pyqt - for Dummies

how to "execute" make file

Convert string to int array using LINQ

Swift do-try-catch syntax

JQuery $.each() JSON array object iteration

What happens to a declared, uninitialized variable in C? Does it have a value?

How to programmatically set style attribute in a view

What do >> and << mean in Python?

Serializing with Jackson (JSON) - getting "No serializer found"?

How do I change a PictureBox's image?

How to set Status Bar Style in Swift 3

case in sql stored procedure on SQL Server

Android - Center TextView Horizontally in LinearLayout

How can I add the sqlite3 module to Python?

Simple Popup by using Angular JS

Bigger Glyphicons

Python3 integer division

If statement within Where clause

How to print the contents of RDD?

How to check if a file exists in a folder?

init and arguments in Python

Example with `request`

Example with `http` and `try/catch`

Example with `http` and `tryjson`