Programs & Examples On #Wmi service

Return value in a Bash function

The problem with other answers is they either use a global, which can be overwritten when several functions are in a call chain, or echo which means your function cannot output diagnostic info (you will forget your function does this and the "result", i.e. return value, will contain more info than your caller expects, leading to weird bug), or eval which is way too heavy and hacky.

The proper way to do this is to put the top level stuff in a function and use a local with bash's dynamic scoping rule. Example:

func1() 
{
    ret_val=hi
}

func2()
{
    ret_val=bye
}

func3()
{
    local ret_val=nothing
    echo $ret_val
    func1
    echo $ret_val
    func2
    echo $ret_val
}

func3

This outputs

nothing
hi
bye

Dynamic scoping means that ret_val points to a different object depending on the caller! This is different from lexical scoping, which is what most programming languages use. This is actually a documented feature, just easy to miss, and not very well explained, here is the documentation for it (emphasis is mine):

Variables local to the function may be declared with the local builtin. These variables are visible only to the function and the commands it invokes.

For someone with a C/C++/Python/Java/C#/javascript background, this is probably the biggest hurdle: functions in bash are not functions, they are commands, and behave as such: they can output to stdout/stderr, they can pipe in/out, they can return an exit code. Basically there is no difference between defining a command in a script and creating an executable that can be called from the command line.

So instead of writing your script like this:

top-level code 
bunch of functions
more top-level code

write it like this:

# define your main, containing all top-level code
main() 
bunch of functions
# call main
main  

where main() declares ret_val as local and all other functions return values via ret_val.

See also the following Unix & Linux question: Scope of Local Variables in Shell Functions.

Another, perhaps even better solution depending on situation, is the one posted by ya.teck which uses local -n.

Double free or corruption after queue::push

Um, shouldn't the destructor be calling delete, rather than delete[]?

Injecting @Autowired private field during testing

Look at this link

Then write your test case as

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"/applicationContext.xml"})
public class MyLauncherTest{

@Resource
private MyLauncher myLauncher ;

   @Test
   public void someTest() {
       //test code
   }
}

What exactly is "exit" in PowerShell?

It's a reserved keyword (like return, filter, function, break).

Reference

Also, as per Section 7.6.4 of Bruce Payette's Powershell in Action:

But what happens when you want a script to exit from within a function defined in that script? ... To make this easier, Powershell has the exit keyword.

Of course, as other have pointed out, it's not hard to do what you want by wrapping exit in a function:

PS C:\> function ex{exit}
PS C:\> new-alias ^D ex

How to import a new font into a project - Angular 5

You can try creating a css for your font with font-face (like explained here)

Step #1

Create a css file with font face and place it somewhere, like in assets/fonts

customfont.css

@font-face {
    font-family: YourFontFamily;
    src: url("/assets/font/yourFont.otf") format("truetype");
}

Step #2

Add the css to your .angular-cli.json in the styles config

"styles":[
 //...your other styles
 "assets/fonts/customFonts.css"
 ]

Do not forget to restart ng serve after doing this

Step #3

Use the font in your code

component.css

span {font-family: YourFontFamily; }

How to call a function from another controller in angularjs?

I wouldn't use function from one controller into another. A better approach would be to move the common function to a service and then inject the service in both controllers.

How to clone all remote branches in Git?

As of early 2017, the answer in this comment works:

git fetch <origin-name> <branch-name> brings the branch down for you. While this doesn't pull all branches at once, you can singularly execute this per-branch.

Why Java Calendar set(int year, int month, int date) not returning correct date?

Months in Calendar object start from 0

0 = January = Calendar.JANUARY
1 = february = Calendar.FEBRUARY

Kotlin - How to correctly concatenate a String

I agree with the accepted answer above but it is only good for known string values. For dynamic string values here is my suggestion.

// A list may come from an API JSON like
{
   "names": [
      "Person 1",
      "Person 2",
      "Person 3",
         ...
      "Person N"
   ]
}
var listOfNames = mutableListOf<String>() 

val stringOfNames = listOfNames.joinToString(", ") 
// ", " <- a separator for the strings, could be any string that you want

// Posible result
// Person 1, Person 2, Person 3, ..., Person N

This is useful for concatenating list of strings with separator.

Insert data into a view (SQL Server)

What is your Compatibility Level set to? If it's 90, it's working as designed. See this article.

In any case, why not just insert directly into the table?

Using Auto Layout in UITableView for dynamic cell layouts & variable row heights

An important enough gotcha I just ran into to post as an answer.

@smileyborg's answer is mostly correct. However, if you have any code in the layoutSubviews method of your custom cell class, for instance setting the preferredMaxLayoutWidth, then it won't be run with this code:

[cell.contentView setNeedsLayout];
[cell.contentView layoutIfNeeded];

It confounded me for awhile. Then I realized it's because those are only triggering layoutSubviews on the contentView, not the cell itself.

My working code looks like this:

TCAnswerDetailAppSummaryCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"TCAnswerDetailAppSummaryCell"];
[cell configureWithThirdPartyObject:self.app];
[cell layoutIfNeeded];
CGFloat height = [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
return height;

Note that if you are creating a new cell, I'm pretty sure you don't need to call setNeedsLayout as it should already be set. In cases where you save a reference to a cell, you should probably call it. Either way it shouldn't hurt anything.

Another tip if you are using cell subclasses where you are setting things like preferredMaxLayoutWidth. As @smileyborg mentions, "your table view cell hasn't yet had its width fixed to the table view's width". This is true, and trouble if you are doing your work in your subclass and not in the view controller. However you can simply set the cell frame at this point using the table width:

For instance in the calculation for height:

self.summaryCell = [self.tableView dequeueReusableCellWithIdentifier:@"TCAnswerDetailDefaultSummaryCell"];
CGRect oldFrame = self.summaryCell.frame;
self.summaryCell.frame = CGRectMake(oldFrame.origin.x, oldFrame.origin.y, self.tableView.frame.size.width, oldFrame.size.height);

(I happen to cache this particular cell for re-use, but that's irrelevant).

How to encrypt a large file in openssl using public key

You can't directly encrypt a large file using rsautl. instead, do something like the following:

  1. Generate a key using openssl rand, eg. openssl rand 32 -out keyfile
  2. Encrypt the key file using openssl rsautl
  3. Encrypt the data using openssl enc, using the generated key from step 1.
  4. Package the encrypted key file with the encrypted data. the recipient will need to decrypt the key with their private key, then decrypt the data with the resulting key.

If/else else if in Jquery for a condition

A few more things in addition to the existing answers. Have a look at this:

var seatsValid = true;
// cache the selector
var seatsVal = $("#seats").val();
if(seatsVal!=''){
    seatsValid = false;
    alert("Not a valid character")
    // convert seatsVal to an integer for comparison
}else if(parseInt(seatsVal) < 99999){
    seatsValid = false;
    alert("Not a valid Number");
}

The variable name setFlag is very generic, if your only using it in conjunction with the number of seats you should rename it (I called it seatsValid). I also initialized it to true which gets rid of the need for the final else in your original code. Next, I put the selector and call to .val() in a variable. It's good practice to cache your selectors so jquery doesn't need to traverse the DOM more than it needs to. Lastly when comparing two values you should try to make sure they are the same type, in this case seatsVal is a string so in order to properly compare it to 99999 you should use parseInt() on it.

Stop embedded youtube iframe?

Talvi's answer may still work, but that Youtube Javascript API has been marked as deprecated. You should now be using the newer Youtube IFrame API.

The documentation provides a few ways to accomplish video embedding, but for your goal, you'd include the following:

//load the IFrame Player API code asynchronously
var tag = document.createElement('script');

tag.src = "https://www.youtube.com/iframe_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

//will be youtube player references once API is loaded
var players = [];

//gets called once the player API has loaded
function onYouTubeIframeAPIReady() {
    $('.myiframeclass').each(function() {
        var frame = $(this);

        //create each instance using the individual iframe id
        var player = new YT.Player(frame.attr('id'));

        players.push(player);
    });
}

//global stop button click handler
$('#mybutton').click(function(){

    //loop through each Youtube player instance and call stopVideo()
    for (var i in players) {
        var player = players[i];
        player.stopVideo();
    }
});

Qt: How do I handle the event of the user pressing the 'X' (close) button?

also you can reimplement protected member QWidget::closeEvent()

void YourWidgetWithXButton::closeEvent(QCloseEvent *event)
{
    // do what you need here
    // then call parent's procedure
    QWidget::closeEvent(event);
}

Use own username/password with git and bitbucket

Are you sure you aren't pushing over SSH? Maybe check the email associated with your SSH key in bitbucket if you have one.

Check if an element has event listener on it. No jQuery

There is no JavaScript function to achieve this. However, you could set a boolean value to true when you add the listener, and false when you remove it. Then check against this boolean before potentially adding a duplicate event listener.

Possible duplicate: How to check whether dynamically attached event listener exists or not?

How do I 'foreach' through a two-dimensional array?

Here's a simple extension method that returns each row as an IEnumerable<T>. This has the advantage of not using any extra memory:

public static class Array2dExt
{
    public static IEnumerable<IEnumerable<T>> Rows<T>(this T[,] array)
    {
        for (int r = array.GetLowerBound(0); r <= array.GetUpperBound(0); ++r)
            yield return row(array, r);
    }

    static IEnumerable<T> row<T>(T[,] array, int r)
    {
        for (int c = array.GetLowerBound(1); c <= array.GetUpperBound(1); ++c)
            yield return array[r, c];
    }
}

Sample usage:

static void Main()
{
    string[,] siblings = { { "Mike", "Amy" }, { "Mary", "Albert" }, {"Fred", "Harry"} };

    foreach (var row in siblings.Rows())
        Console.WriteLine("{" + string.Join(", ", row) + "}");
}

how to make UITextView height dynamic according to text length?

Whenever you need to resize the textview according to the inside content size, like in messageing app. Use cocoapods(GrowingTextView), it will make your life easier, than coding the dynamic resizing of textview on your own.

delete a column with awk or sed

Try this :

awk '$3="";1' file.txt > new_file && mv new_file file.txt

or

awk '{$3="";print}' file.txt > new_file && mv new_file file.txt

Convert string to Date in java

it went OK when i used Locale.US parametre in SimpleDateFormat

String dateString = "15 May 2013 17:38:34 +0300";
System.out.println(dateString);

SimpleDateFormat dateFormat = new SimpleDateFormat("dd MMM yyyy HH:mm:ss Z", Locale.US);
DateFormat targetFormat = new SimpleDateFormat("dd MMM yyyy HH:mm", Locale.getDefault());
String formattedDate = null;
Date convertedDate = new Date();
try {
     convertedDate = dateFormat.parse(dateString);
System.out.println(dateString);
formattedDate = targetFormat.format(convertedDate);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 System.out.println(convertedDate);

SQL Server equivalent of MySQL's NOW()?

getdate() 

is the direct equivalent, but you should always use UTC datetimes

getutcdate()

whether your app operates across timezones or not - otherwise you run the risk of screwing up date math at the spring/fall transitions

get dictionary value by key

I use a similar method to dasblinkenlight's in a function to return a single key value from a Cookie containing a JSON array loaded into a Dictionary as follows:

    /// <summary>
    /// Gets a single key Value from a Json filled cookie with 'cookiename','key' 
    /// </summary>
    public static string GetSpecialCookieKeyVal(string _CookieName, string _key)
    {
        //CALL COOKIE VALUES INTO DICTIONARY
        Dictionary<string, string> dictCookie =
        JsonConvert.DeserializeObject<Dictionary<string, string>>
         (MyCookinator.Get(_CookieName));

        string value;
        if (dictCookie.TryGetValue( _key, out value))
        {
            return value;
        }
        else
        {
            return "0";
        }

    }

Where "MyCookinator.Get()" is another simple Cookie function getting an http cookie overall value.

Generating random integer from a range

assume min and max are int values, [ and ] means include this value, ( and ) means not include this value, using above to get the right value using c++ rand()

reference: for ()[] define, visit:

https://en.wikipedia.org/wiki/Interval_(mathematics)

for rand and srand function or RAND_MAX define, visit:

http://en.cppreference.com/w/cpp/numeric/random/rand

[min, max]

int randNum = rand() % (max - min + 1) + min

(min, max]

int randNum = rand() % (max - min) + min + 1

[min, max)

int randNum = rand() % (max - min) + min

(min, max)

int randNum = rand() % (max - min - 1) + min + 1

Git in Visual Studio - add existing project?

The process is greatly simplified for VS2017 / VS2019 (maybe even earlier, but I have not tested) in conjunction with GitHub:

  1. Create an empty repository in GitHub => https://github.com//.git

  2. Install GitHub extension for Visual Studio

  3. Follow these instructions: (optionally add to source control to git initialize) -> Team explorer -> Sync -> Publish to GitHub -> https://github.com//.git

How do I match any character across multiple lines in a regular expression?

([\s\S]*)<FooBar>

The dot matches all except newlines (\r\n). So use \s\S, which will match ALL characters.

PowerShell: Create Local User Account

Import-Csv C:\test.csv |
Foreach-Object {
  NET USER    $ _.username   $ _.password /ADD
  NET LOCALGROUP "group" $_.username  /ADD
}

edit csv as username,password and change "group" for your groupname

:) worked on 2012 R2

CSS: Position loading indicator in the center of the screen

This is what I've done for Angular 4:

<style type="text/css">  
  .centered {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    transform: -webkit-translate(-50%, -50%);
    transform: -moz-translate(-50%, -50%);
    transform: -ms-translate(-50%, -50%);
    color:darkred;
  }
</style>

</head>

<body>
  <app-root>
        <div class="centered">
          <h1>Loading...</h1>
        </div>
  </app-root>
</body>

getting the X/Y coordinates of a mouse click on an image with jQuery

You can use pageX and pageY to get the position of the mouse in the window. You can also use jQuery's offset to get the position of an element.

So, it should be pageX - offset.left for how far from the left of the image and pageY - offset.top for how far from the top of the image.

Here is an example:

$(document).ready(function() {
  $('img').click(function(e) {
    var offset = $(this).offset();
    alert(e.pageX - offset.left);
    alert(e.pageY - offset.top);
  });
});

I've made a live example here and here is the source.

To calculate how far from the bottom or right, you would have to use jQuery's width and height methods.

SVN Repository Search

There is sourceforge.net/projects/svn-search.

There is also a Windows application directly from the SVN home called SvnQuery available at http://svnquery.tigris.org

PHPMailer - SMTP ERROR: Password command failed when send mail from my server

If you are G Suit user it can be solved by Administrator

  1. Go to your Admin panel
  2. Type in top search bar «Security» (Select Security with Shield icon)
  3. Open Basic settings
  4. Goto Less secure apps section
  5. Press: Go to settings for less secure apps ››

And now select one of Radio Button a) Disable access to less secure apps for all users (Recommended) b) Allow users to manage their access to less secure apps c) Enforce access to less secure apps for all users (Not Recommended)

Usually It does not working because of a)! And will start working immediately with c) option. b) – option will need more configuration for each user in GSuit

Hope it helps

VBA Object doesn't support this property or method

Object doesn't support this property or method.

Think of it like if anything after the dot is called on an object. It's like a chain.

An object is a class instance. A class instance supports some properties defined in that class type definition. It exposes whatever intelli-sense in VBE tells you (there are some hidden members but it's not related to this). So after each dot . you get intelli-sense (that white dropdown) trying to help you pick the correct action.

(you can start either way - front to back or back to front, once you understand how this works you'll be able to identify where the problem occurs)

Type this much anywhere in your code area

Dim a As Worksheets
a.

you get help from VBE, it's a little dropdown called Intelli-sense

enter image description here

It lists all available actions that particular object exposes to any user. You can't see the .Selection member of the Worksheets() class. That's what the error tells you exactly.

Object doesn't support this property or method.

If you look at the example on MSDN

Worksheets("GRA").Activate
iAreaCount = Selection.Areas.Count

It activates the sheet first then calls the Selection... it's not connected together because Selection is not a member of Worksheets() class. Simply, you can't prefix the Selection

What about

Sub DisplayColumnCount()
    Dim iAreaCount As Integer
    Dim i As Integer

    Worksheets("GRA").Activate
    iAreaCount = Selection.Areas.Count

    If iAreaCount <= 1 Then
        MsgBox "The selection contains " & Selection.Columns.Count & " columns."
    Else
        For i = 1 To iAreaCount
        MsgBox "Area " & i & " of the selection contains " & _
        Selection.Areas(i).Columns.Count & " columns."
        Next i
    End If
End Sub

from HERE

How to draw an overlay on a SurfaceView used by Camera on Android?

I think you should call the super.draw() method first before you do anything in surfaceView's draw method.

Is it possible to start activity through adb shell?

You can also find the name of the current on screen activity using

adb shell dumpsys window windows | grep 'mCurrentFocus'

How to calculate mean, median, mode and range from a set of numbers

As already pointed out by Nico Huysamen, finding multiple mode in Java 1.8 can be done alternatively as below.

import java.util.ArrayList;
import java.util.List;
import java.util.HashMap;
import java.util.Map;

public static void mode(List<Integer> numArr) {
    Map<Integer, Integer> freq = new HashMap<Integer, Integer>();;
    Map<Integer, List<Integer>> mode = new HashMap<Integer, List<Integer>>();

    int modeFreq = 1; //record the highest frequence
    for(int x=0; x<numArr.size(); x++) { //1st for loop to record mode
        Integer curr = numArr.get(x); //O(1)
        freq.merge(curr, 1, (a, b) -> a + b); //increment the frequency for existing element, O(1)
        int currFreq = freq.get(curr); //get frequency for current element, O(1)

        //lazy instantiate a list if no existing list, then
        //record mapping of frequency to element (frequency, element), overall O(1)
        mode.computeIfAbsent(currFreq, k -> new ArrayList<>()).add(curr);

        if(modeFreq < currFreq) modeFreq = currFreq; //update highest frequency
    }
    mode.get(modeFreq).forEach(x -> System.out.println("Mode = " + x)); //pretty print the result //another for loop to return result
}

Happy coding!

How to override application.properties during production in Spring-Boot?

UPDATE: this is a bug in spring see here

the application properties outside of your jar must be in one of the following places, then everything should work.

21.2 Application property files
SpringApplication will load properties from application.properties files in the following    locations and add them to the Spring Environment:

A /config subdir of the current directory.
The current directory
A classpath /config package
The classpath root

so e.g. this should work, when you dont want to specify cmd line args and you dont use spring.config.location in your base app.props:

d:\yourExecutable.jar
d:\application.properties

or

d:\yourExecutable.jar
d:\config\application.properties

see spring external config doc

Update: you may use \@Configuration together with \@PropertySource. according to the doc here you can specify resources anywhere. you should just be careful, when which config is loaded to make sure your production one wins.

Laravel orderBy on a relationship

It is possible to extend the relation with query functions:

<?php
public function comments()
{
    return $this->hasMany('Comment')->orderBy('column');
}

[edit after comment]

<?php
class User
{
    public function comments()
    {
        return $this->hasMany('Comment');
    }
}

class Controller
{
    public function index()
    {
        $column = Input::get('orderBy', 'defaultColumn');
        $comments = User::find(1)->comments()->orderBy($column)->get();

        // use $comments in the template
    }
}

default User model + simple Controller example; when getting the list of comments, just apply the orderBy() based on Input::get(). (be sure to do some input-checking ;) )

Get Date in YYYYMMDD format in windows batch file

If, after reading the other questions and viewing the links mentioned in the comment sections, you still can't figure it out, read on.

First of all, where you're going wrong is the offset.

It should look more like this...

set mydate=%date:~10,4%%date:~6,2%/%date:~4,2%
echo %mydate%

If the date was Tue 12/02/2013 then it would display it as 2013/02/12.

To remove the slashes, the code would look more like

set mydate=%date:~10,4%%date:~7,2%%date:~4,2%
echo %mydate%

which would output 20130212

And a hint for doing it in the future, if mydate equals something like %date:~10,4%%date:~7,2% or the like, you probably forgot a tilde (~).

Best way to get value from Collection by index

I agree that this is generally a bad idea. However, Commons Collections had a nice routine for getting the value by index if you really need to:

CollectionUtils.get(collection, index)

error: package javax.servlet does not exist

I only put this code in my pom.xml and I executed the command maven install.

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.0.1</version>
    <scope>provided</scope>
</dependency>

Min/Max-value validators in asp.net mvc

jQuery Validation Plugin already implements min and max rules, we just need to create an adapter for our custom attribute:

public class MaxAttribute : ValidationAttribute, IClientValidatable
{
    private readonly int maxValue;

    public MaxAttribute(int maxValue)
    {
        this.maxValue = maxValue;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule();

        rule.ErrorMessage = ErrorMessageString, maxValue;

        rule.ValidationType = "max";
        rule.ValidationParameters.Add("max", maxValue);
        yield return rule;
    }

    public override bool IsValid(object value)
    {
        return (int)value <= maxValue;
    }
}

Adapter:

$.validator.unobtrusive.adapters.add(
   'max',
   ['max'],
   function (options) {
       options.rules['max'] = parseInt(options.params['max'], 10);
       options.messages['max'] = options.message;
   });

Min attribute would be very similar.

Unable to read data from the transport connection : An existing connection was forcibly closed by the remote host

I get that problem in the past. I'm using PostgreSQL and when I run my program, sometimes it connects and sometimes it throws an error like that.

When I experiment with my code, I put my Connection code at the very first line below the public Form. Here is an example:

BEFORE:

    public Form1()
        {
        //HERE LIES SOME CODES FOR RESIZING MY CONTROLS DURING RUNTIME
        //CODE
        //CODE AGAIN
        //ANOTHER CODE
        //CODE NA NAMAN
        //CODE PA RIN!





        //Connect to Database to generate auto number
        NpgsqlConnection iConnect = new NpgsqlConnection("Server=localhost;Port=5432;User ID=postgres;Password=pass;Database=DB");
        iConnect.Open();
        NpgsqlCommand iQuery = new NpgsqlCommand("Select * from table1", iConnect);
        NpgsqlDataReader iRead = iQuery.ExecuteReader();
        NpgsqlDataAdapter iAdapter = new NpgsqlDataAdapter(iQuery);

        DataSet iDataSet = new DataSet();
        iAdapter.Fill(iDataSet, "ID");

        MessageBox.Show(iDataSet.Tables["ID"].Rows.Count.ToString());
        }

NOW:

    public Form1()
        {
        //Connect to Database to generate auto number
        NpgsqlConnection iConnect = new NpgsqlConnection("Server=localhost;Port=5432;User ID=postgres;Password=pass;Database=DB");
        iConnect.Open();
        NpgsqlCommand iQuery = new NpgsqlCommand("Select * from table1", iConnect);
        NpgsqlDataReader iRead = iQuery.ExecuteReader();
        NpgsqlDataAdapter iAdapter = new NpgsqlDataAdapter(iQuery);

        DataSet iDataSet = new DataSet();
        iAdapter.Fill(iDataSet, "ID");

        MessageBox.Show(iDataSet.Tables["ID"].Rows.Count.ToString());





        //HERE LIES SOME CODES FOR RESIZING MY CONTROLS DURING RUNTIME
        //CODE
        //CODE AGAIN
        //ANOTHER CODE
        //CODE NA NAMAN
        //CODE PA RIN!

        }

I think that the program must read first the connection before doing anything, I don't know, correct me if I'm wrong. But according to my research, it's not a code problem - it was actually from the machine itself.

Happy Coding!

How to view changes made to files on a certain revision in Subversion

Call this in the project:

svn diff -r REVNO:HEAD --summarize

REVNO is the start revision number and HEAD is the end revision number. If HEAD is equal to the last revision number, it can skip it.

The command returns a list with all files that are changed/added/deleted in this revision period.

The command can be called with the URL revision parameter to check changes like this:

svn diff -r REVNO:HEAD --summarize SVN_URL

Delete all files of specific type (extension) recursively down a directory using a batch file

You can use this to delete ALL Files Inside a Folder and Subfolders:

DEL "C:\Folder\*.*" /S /Q

Or use this to Delete Certain File Types Only:

DEL "C:\Folder\*.mp4" /S /Q 
DEL "C:\Folder\*.dat" /S /Q 

C# Select elements in list as List of string

List<string> empnames = (from e in emplist select e.Enaame).ToList();

Or

string[] empnames = (from e in emplist select e.Enaame).ToArray();

Etc...

Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

I solved it by putting this:

@Override
protected void onDestroy() {
    accessTokenTracker.stopTracking();
    super.onDestroy();
}

List of <p:ajax> events

You might want to look at "JavaScript HTML DOM Events" for a general overview of events:

http://www.w3schools.com/jsref/dom_obj_event.asp

PrimeFaces is built on jQuery, so here's jQuery's "Events" documentation:

http://api.jquery.com/category/events/

http://api.jquery.com/category/events/form-events/

http://api.jquery.com/category/events/keyboard-events/

http://api.jquery.com/category/events/mouse-events/

http://api.jquery.com/category/events/browser-events/

Below, I've listed some of the more common events, with comments about where they can be used (taken from jQuery documentation).

Mouse Events

(Any HTML element can receive these events.)

click

dblclick

mousedown

mousemove

mouseover

mouseout

mouseup

Keyboard Events

(These events can be attached to any element, but the event is only sent to the element that has the focus. Focusable elements can vary between browsers, but form elements can always get focus so are reasonable candidates for these event types.)

keydown

keypress

keyup

Form Events

blur (In recent browsers, the domain of the event has been extended to include all element types.)

change (This event is limited to <input> elements, <textarea> boxes and <select> elements.)

focus (This event is implicitly applicable to a limited set of elements, such as form elements (<input>, <select>, etc.) and links (<a href>). In recent browser versions, the event can be extended to include all element types by explicitly setting the element's tabindex property. An element can gain focus via keyboard commands, such as the Tab key, or by mouse clicks on the element.)

select (This event is limited to <input type="text"> fields and <textarea> boxes.)

submit (It can only be attached to <form> elements.)

is vs typeof

They don't do the same thing. The first one works if obj is of type ClassA or of some subclass of ClassA. The second one will only match objects of type ClassA. The second one will be faster since it doesn't have to check the class hierarchy.

For those who want to know the reason, but don't want to read the article referenced in is vs typeof.

ReferenceError: document is not defined (in plain JavaScript)

It depends on when the self executing anonymous function is running. It is possible that it is running before window.document is defined.

In that case, try adding a listener

window.addEventListener('load', yourFunction, false);
// ..... or 
window.addEventListener('DOMContentLoaded', yourFunction, false);

yourFunction () {
  // some ocde

}

Update: (after the update of the question and inclusion of the code)

Read the following about the issues in referencing DOM elements from a JavaScript inserted and run in head element:
- “getElementsByTagName(…)[0]” is undefined?
- Traversing the DOM

What's an object file in C?

An object file is the real output from the compilation phase. It's mostly machine code, but has info that allows a linker to see what symbols are in it as well as symbols it requires in order to work. (For reference, "symbols" are basically names of global objects, functions, etc.)

A linker takes all these object files and combines them to form one executable (assuming that it can, ie: that there aren't any duplicate or undefined symbols). A lot of compilers will do this for you (read: they run the linker on their own) if you don't tell them to "just compile" using command-line options. (-c is a common "just compile; don't link" option.)

$(document).ready equivalent without jQuery

For IE9+:

function ready(fn) {
  if (document.readyState != 'loading'){
    fn();
  } else {
    document.addEventListener('DOMContentLoaded', fn);
  }
}

How to automatically allow blocked content in IE?

There is a code solution too. I saw it in a training video. You can add a line to tell IE that the local file is safe. I tested on IE8 and it works. That line is <!-- saved from url=(0014)about:internet -->

For more details, please refer to https://msdn.microsoft.com/en-us/library/ms537628(v=vs.85).aspx

<!DOCTYPE html>
<!-- saved from url=(0014)about:internet -->
<html lang="en">
    <title></title>
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
    <script>
        $(document).ready(function () {
            alert('hi');

        });
    </script>
</head>
<body>
</body>
</html>

Matplotlib color according to class labels

The accepted answer has it spot on, but if you might want to specify which class label should be assigned to a specific color or label you could do the following. I did a little label gymnastics with the colorbar, but making the plot itself reduces to a nice one-liner. This works great for plotting the results from classifications done with sklearn. Each label matches a (x,y) coordinate.

import matplotlib
import matplotlib.pyplot as plt
import numpy as np

x = [4,8,12,16,1,4,9,16]
y = [1,4,9,16,4,8,12,3]
label = [0,1,2,3,0,1,2,3]
colors = ['red','green','blue','purple']

fig = plt.figure(figsize=(8,8))
plt.scatter(x, y, c=label, cmap=matplotlib.colors.ListedColormap(colors))

cb = plt.colorbar()
loc = np.arange(0,max(label),max(label)/float(len(colors)))
cb.set_ticks(loc)
cb.set_ticklabels(colors)

Scatter plot color labels

Using a slightly modified version of this answer, one can generalise the above for N colors as follows:

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

N = 23 # Number of labels

# setup the plot
fig, ax = plt.subplots(1,1, figsize=(6,6))
# define the data
x = np.random.rand(1000)
y = np.random.rand(1000)
tag = np.random.randint(0,N,1000) # Tag each point with a corresponding label    

# define the colormap
cmap = plt.cm.jet
# extract all colors from the .jet map
cmaplist = [cmap(i) for i in range(cmap.N)]
# create the new map
cmap = cmap.from_list('Custom cmap', cmaplist, cmap.N)

# define the bins and normalize
bounds = np.linspace(0,N,N+1)
norm = mpl.colors.BoundaryNorm(bounds, cmap.N)

# make the scatter
scat = ax.scatter(x,y,c=tag,s=np.random.randint(100,500,N),cmap=cmap,     norm=norm)
# create the colorbar
cb = plt.colorbar(scat, spacing='proportional',ticks=bounds)
cb.set_label('Custom cbar')
ax.set_title('Discrete color mappings')
plt.show()

Which gives:

enter image description here

Apache shutdown unexpectedly

on your XAMPP control panel, next to apache, select the "Config" option and select the first file (httpd.conf):

there, look for the "listen" line (you may use the find tool in the notepad) and there must be a line stating "Listen 80". Note: there are other lines with "listen" on them but they should be commented (start with a #), the one you need to change is the one saying exactly "listen 80". Now change it to "Listen 1337".

Start apache now.

If the error subsists, it's because there's another port that's already in use. So, select the config option again (next to apache in your xampp control panel) and select the second option this time (httpd-ssl.conf):

there, look for the line "Listen 443" and change it to "Listen 7331".

Start apache, it should be working now.

SQL (MySQL) vs NoSQL (CouchDB)

One of the best options is to go for MongoDB(NOSql dB) that supports scalability.Stores large amounts of data nothing but bigdata in the form of documents unlike rows and tables in sql.This is fasters that follows sharding of the data.Uses replicasets to ensure data guarantee that maintains multiple servers having primary db server as the base. Language independent. Flexible to use

Force “landscape” orientation mode

I had the same problem, it was a missing manifest.json file, if not found the browser decide with orientation is best fit, if you don't specify the file or use a wrong path.

I fixed just calling the manifest.json correctly on html headers.

My html headers:

<meta name="application-name" content="App Name">
<meta name="mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-capable" content="yes" />
<meta name="apple-mobile-web-app-status-bar-style" content="black" />
<link rel="manifest" href="manifest.json">
<meta name="msapplication-starturl" content="/">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="theme-color" content="#">
<meta name="msapplication-TileColor" content="#">
<meta name="msapplication-config" content="browserconfig.xml">
<link rel="icon" type="image/png" sizes="192x192" href="android-chrome-192x192.png">
<link rel="apple-touch-icon" sizes="180x180" href="apple-touch-icon.png">
<link rel="mask-icon" href="safari-pinned-tab.svg" color="#ffffff">
<link rel="shortcut icon" href="favicon.ico">

And the manifest.json file content:

{
  "display": "standalone",
  "orientation": "portrait",
  "start_url": "/",
  "theme_color": "#000000",
  "background_color": "#ffffff",
  "icons": [
  {
    "src": "android-chrome-192x192.png",
    "sizes": "192x192",
    "type": "image/png"
  }
}

To generate your favicons and icons use this webtool: https://realfavicongenerator.net/

To generate your manifest file use: https://tomitm.github.io/appmanifest/

My PWA Works great, hope it helps!

Sort Dictionary by keys

I tried all of the above, in a nutshell all you need is

let sorted = dictionary.sorted { $0.key < $1.key }
let keysArraySorted = Array(sorted.map({ $0.key }))
let valuesArraySorted = Array(sorted.map({ $0.value }))

How to send POST request in JSON using HTTPClient in Android?

Too much code for this task, checkout this library https://github.com/kodart/Httpzoid Is uses GSON internally and provides API that works with objects. All JSON details are hidden.

Http http = HttpFactory.create(context);
http.get("http://example.com/users")
    .handler(new ResponseHandler<User[]>() {
        @Override
        public void success(User[] users, HttpResponse response) {
        }
    }).execute();

Test if a variable is a list or tuple

Python uses "Duck typing", i.e. if a variable kwaks like a duck, it must be a duck. In your case, you probably want it to be iterable, or you want to access the item at a certain index. You should just do this: i.e. use the object in for var: or var[idx] inside a try block, and if you get an exception it wasn't a duck...

How to include header files in GCC search path?

Using environment variable is sometimes more convenient when you do not control the build scripts / process.

For C includes use C_INCLUDE_PATH.

For C++ includes use CPLUS_INCLUDE_PATH.

See this link for other gcc environment variables.

Example usage in MacOS / Linux

# `pip install` will automatically run `gcc` using parameters
# specified in the `asyncpg` package (that I do not control)

C_INCLUDE_PATH=/home/scott/.pyenv/versions/3.7.9/include/python3.7m pip install asyncpg

Example usage in Windows

set C_INCLUDE_PATH="C:\Users\Scott\.pyenv\versions\3.7.9\include\python3.7m"

pip install asyncpg

# clear the environment variable so it doesn't affect other builds
set C_INCLUDE_PATH=

Calling UserForm_Initialize() in a Module

SOLUTION After all this time, I managed to resolve the problem.

In Module: UserForms(Name).Userform_Initialize

This method works best to dynamically init the current UserForm

Postgresql : Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections

The error you quote has nothing to do with pg_hba.conf; it's failing to connect, not failing to authorize the connection.

Do what the error message says:

Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections

You haven't shown the command that produces the error. Assuming you're connecting on localhost port 5432 (the defaults for a standard PostgreSQL install), then either:

  • PostgreSQL isn't running

  • PostgreSQL isn't listening for TCP/IP connections (listen_addresses in postgresql.conf)

  • PostgreSQL is only listening on IPv4 (0.0.0.0 or 127.0.0.1) and you're connecting on IPv6 (::1) or vice versa. This seems to be an issue on some older Mac OS X versions that have weird IPv6 socket behaviour, and on some older Windows versions.

  • PostgreSQL is listening on a different port to the one you're connecting on

  • (unlikely) there's an iptables rule blocking loopback connections

(If you are not connecting on localhost, it may also be a network firewall that's blocking TCP/IP connections, but I'm guessing you're using the defaults since you didn't say).

So ... check those:

  • ps -f -u postgres should list postgres processes

  • sudo lsof -n -u postgres |grep LISTEN or sudo netstat -ltnp | grep postgres should show the TCP/IP addresses and ports PostgreSQL is listening on

BTW, I think you must be on an old version. On my 9.3 install, the error is rather more detailed:

$ psql -h localhost -p 12345
psql: could not connect to server: Connection refused
        Is the server running on host "localhost" (::1) and accepting
        TCP/IP connections on port 12345?

Still Reachable Leak detected by Valgrind

For future readers, "Still Reachable" might mean you forgot to close something like a file. While it doesn't seem that way in the original question, you should always make sure you've done that.

Bootstrap 3 - jumbotron background image effect

I think what you are looking for is to keep the background image fixed and just move the content on scroll. For that you have to simply use the following css property :

background-attachment: fixed;

How can I create a correlation matrix in R?

The cor function will use the columns of the matrix in the calculation of correlation. So, the number of rows must be the same between your matrix x and matrix y. Ex.:

set.seed(1)
x <- matrix(rnorm(20), nrow=5, ncol=4)
y <- matrix(rnorm(15), nrow=5, ncol=3)
COR <- cor(x,y)
COR
image(x=seq(dim(x)[2]), y=seq(dim(y)[2]), z=COR, xlab="x column", ylab="y column")
text(expand.grid(x=seq(dim(x)[2]), y=seq(dim(y)[2])), labels=round(c(COR),2))

enter image description here

Edit:

Here is an example of custom row and column labels on a correlation matrix calculated with a single matrix:

png("corplot.png", width=5, height=5, units="in", res=200)
op <- par(mar=c(6,6,1,1), ps=10)
COR <- cor(iris[,1:4])
image(x=seq(nrow(COR)), y=seq(ncol(COR)), z=cor(iris[,1:4]), axes=F, xlab="", ylab="")
text(expand.grid(x=seq(dim(COR)[1]), y=seq(dim(COR)[2])), labels=round(c(COR),2))
box()
axis(1, at=seq(nrow(COR)), labels = rownames(COR), las=2)
axis(2, at=seq(ncol(COR)), labels = colnames(COR), las=1)
par(op)
dev.off()

enter image description here

How do I make Git use the editor of my choice for commits?

Setting Sublime Text 2 as Git commit editor in Mac OSX 10

Run this command:

$ git config --global core.editor "/Applications/Sublime\ Text\ 2.app/Contents/SharedSupport/bin/subl"

Or just:

$ git config --global core.editor "subl -w"

How to use \n new line in VB msgbox() ...?

msgbox "This is the first line" & vbcrlf & "and this is the second line"

or in .NET msgbox "This is the first line" & Environment.NewLine & "and this is the second line"

WPF ListView - detect when selected item is clicked

This worked for me.

Single-clicking a row triggers the code-behind.

XAML:

<ListView x:Name="MyListView" MouseLeftButtonUp="MyListView_MouseLeftButtonUp">
    <GridView>
        <!-- Declare GridViewColumns. -->
    </GridView>
</ListView.View>

Code-behind:

private void MyListView_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    System.Windows.Controls.ListView list = (System.Windows.Controls.ListView)sender;
    MyClass selectedObject = (MyClass)list.SelectedItem;
    // Do stuff with the selectedObject.
}

How to get a DOM Element from a JQuery Selector

You can access the raw DOM element with:

$("table").get(0);

or more simply:

$("table")[0];

There isn't actually a lot you need this for however (in my experience). Take your checkbox example:

$(":checkbox").click(function() {
  if ($(this).is(":checked")) {
    // do stuff
  }
});

is more "jquery'ish" and (imho) more concise. What if you wanted to number them?

$(":checkbox").each(function(i, elem) {
  $(elem).data("index", i);
});
$(":checkbox").click(function() {
  if ($(this).is(":checked") && $(this).data("index") == 0) {
    // do stuff
  }
});

Some of these features also help mask differences in browsers too. Some attributes can be different. The classic example is AJAX calls. To do this properly in raw Javascript has about 7 fallback cases for XmlHttpRequest.

Spark: Add column to dataframe conditionally

My bad, I had missed one part of the question.

Best, cleanest way is to use a UDF. Explanation within the code.

// create some example data...BY DataFrame
// note, third record has an empty string
case class Stuff(a:String,b:Int)
val d= sc.parallelize(Seq( ("a",1),("b",2),
     ("",3) ,("d",4)).map { x => Stuff(x._1,x._2)  }).toDF

// now the good stuff.
import org.apache.spark.sql.functions.udf
// function that returns 0 is string empty 
val func = udf( (s:String) => if(s.isEmpty) 0 else 1 )
// create new dataframe with added column named "notempty"
val r = d.select( $"a", $"b", func($"a").as("notempty") )

    scala> r.show
+---+---+--------+
|  a|  b|notempty|
+---+---+--------+
|  a|  1|    1111|
|  b|  2|    1111|
|   |  3|       0|
|  d|  4|    1111|
+---+---+--------+

What is the difference between join and merge in Pandas?

One of the difference is that merge is creating a new index, and join is keeping the left side index. It can have a big consequence on your later transformations if you wrongly assume that your index isn't changed with merge.

For example:

import pandas as pd

df1 = pd.DataFrame({'org_index': [101, 102, 103, 104],
                    'date': [201801, 201801, 201802, 201802],
                    'val': [1, 2, 3, 4]}, index=[101, 102, 103, 104])
df1

       date  org_index  val
101  201801        101    1
102  201801        102    2
103  201802        103    3
104  201802        104    4

-

df2 = pd.DataFrame({'date': [201801, 201802], 'dateval': ['A', 'B']}).set_index('date')
df2

       dateval
date          
201801       A
201802       B

-

df1.merge(df2, on='date')

     date  org_index  val dateval
0  201801        101    1       A
1  201801        102    2       A
2  201802        103    3       B
3  201802        104    4       B

-

df1.join(df2, on='date')
       date  org_index  val dateval
101  201801        101    1       A
102  201801        102    2       A
103  201802        103    3       B
104  201802        104    4       B

How does C compute sin() and other math functions?

Chebyshev polynomials, as mentioned in another answer, are the polynomials where the largest difference between the function and the polynomial is as small as possible. That is an excellent start.

In some cases, the maximum error is not what you are interested in, but the maximum relative error. For example for the sine function, the error near x = 0 should be much smaller than for larger values; you want a small relative error. So you would calculate the Chebyshev polynomial for sin x / x, and multiply that polynomial by x.

Next you have to figure out how to evaluate the polynomial. You want to evaluate it in such a way that the intermediate values are small and therefore rounding errors are small. Otherwise the rounding errors might become a lot larger than errors in the polynomial. And with functions like the sine function, if you are careless then it may be possible that the result that you calculate for sin x is greater than the result for sin y even when x < y. So careful choice of the calculation order and calculation of upper bounds for the rounding error are needed.

For example, sin x = x - x^3/6 + x^5 / 120 - x^7 / 5040... If you calculate naively sin x = x * (1 - x^2/6 + x^4/120 - x^6/5040...), then that function in parentheses is decreasing, and it will happen that if y is the next larger number to x, then sometimes sin y will be smaller than sin x. Instead, calculate sin x = x - x^3 * (1/6 - x^2 / 120 + x^4/5040...) where this cannot happen.

When calculating Chebyshev polynomials, you usually need to round the coefficients to double precision, for example. But while a Chebyshev polynomial is optimal, the Chebyshev polynomial with coefficients rounded to double precision is not the optimal polynomial with double precision coefficients!

For example for sin (x), where you need coefficients for x, x^3, x^5, x^7 etc. you do the following: Calculate the best approximation of sin x with a polynomial (ax + bx^3 + cx^5 + dx^7) with higher than double precision, then round a to double precision, giving A. The difference between a and A would be quite large. Now calculate the best approximation of (sin x - Ax) with a polynomial (b x^3 + cx^5 + dx^7). You get different coefficients, because they adapt to the difference between a and A. Round b to double precision B. Then approximate (sin x - Ax - Bx^3) with a polynomial cx^5 + dx^7 and so on. You will get a polynomial that is almost as good as the original Chebyshev polynomial, but much better than Chebyshev rounded to double precision.

Next you should take into account the rounding errors in the choice of polynomial. You found a polynomial with minimum error in the polynomial ignoring rounding error, but you want to optimise polynomial plus rounding error. Once you have the Chebyshev polynomial, you can calculate bounds for the rounding error. Say f (x) is your function, P (x) is the polynomial, and E (x) is the rounding error. You don't want to optimise | f (x) - P (x) |, you want to optimise | f (x) - P (x) +/- E (x) |. You will get a slightly different polynomial that tries to keep the polynomial errors down where the rounding error is large, and relaxes the polynomial errors a bit where the rounding error is small.

All this will get you easily rounding errors of at most 0.55 times the last bit, where +,-,*,/ have rounding errors of at most 0.50 times the last bit.

How can I make Bootstrap 4 columns all the same height?

You just have to use class="row-eq-height" with your class="row" to get equal height columns for previous bootstrap versions.

but with bootstrap 4 this comes natively.

check this link --http://getbootstrap.com.vn/examples/equal-height-columns/

HTML5 video (mp4 and ogv) problems in Safari and Firefox - but Chrome is all good

Just need to change one letter:), rename 640x360.ogv to 640x360.ogg, it will work for all the 3 browers.

What is Scala's yield?

Yes, as Earwicker said, it's pretty much the equivalent to LINQ's select and has very little to do with Ruby's and Python's yield. Basically, where in C# you would write

from ... select ??? 

in Scala you have instead

for ... yield ???

It's also important to understand that for-comprehensions don't just work with sequences, but with any type which defines certain methods, just like LINQ:

  • If your type defines just map, it allows for-expressions consisting of a single generator.
  • If it defines flatMap as well as map, it allows for-expressions consisting of several generators.
  • If it defines foreach, it allows for-loops without yield (both with single and multiple generators).
  • If it defines filter, it allows for-filter expressions starting with an if in the for expression.

How does a ArrayList's contains() method evaluate objects?

The ArrayList uses the equals method implemented in the class (your case Thing class) to do the equals comparison.

Visual Studio 2012 Web Publish doesn't copy files

Follow these steps to resolve:

Build > Publish > Profile > New

Create a new profile and configure it with the same settings as your existing profile.

The project will now publish correctly. This often occurs as a result of a source-controlled publish profile from another machine that was created in a newer version of Visual Studio.

How do I render a shadow?

I'm using Styled Components and created a helper function for myself.

It takes the given Android elevation and creates a fairly equivalent iOS shadow.

stylingTools.js

import { css } from 'styled-components/native';

/*
 REMINDER!!!!!!!!!!!!!
 Shadows do not show up on iOS if `overflow: hidden` is used.
 https://react-native.canny.io/feature-requests/p/shadow-does-not-appear-if-overflow-hidden-is-set-on-ios
*/

// eslint-disable-next-line import/prefer-default-export
export const crossPlatformElevation = (elevation: number = 0) => css`
  /* Android - native default is 4, we're setting to 0 to match iOS. */
  elevation: ${elevation};

  /* iOS - default is no shadow. Only add if above zero */
  ${elevation > 0
    && css`
      shadow-color: black;
      shadow-offset: 0px ${0.5 * elevation}px;
      shadow-opacity: 0.3;
      shadow-radius: ${0.8 * elevation}px;
    `}
`;

To use

import styled from 'styled-components/native';
import { crossPlatformElevation } from "../../lib/stylingTools";

export const ContentContainer = styled.View`
  background: white;
  ${crossPlatformElevation(10)};
`;

How to Set the Background Color of a JButton on the Mac OS

If you are not required to use Apple's look and feel, a simple fix is to put the following code in your application or applet, before you add any GUI components to your JFrame or JApplet:

 try {
    UIManager.setLookAndFeel( UIManager.getCrossPlatformLookAndFeelClassName() );
 } catch (Exception e) {
            e.printStackTrace();
 }

That will set the look and feel to the cross-platform look and feel, and the setBackground() method will then work to change a JButton's background color.

Newline in JLabel

You can do

JLabel l = new JLabel("<html><p>Hello World! blah blah blah</p></html>", SwingConstants.CENTER);

and it will automatically wrap it where appropriate.

import sun.misc.BASE64Encoder results in error compiled in Eclipse

Add base64decoder jar and try these imports:

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;

How do I resolve git saying "Commit your changes or stash them before you can merge"?

git stash
git pull <remote name> <remote branch name> (or) switch branch
git stash apply --index

The first command stores your changes temporarily in the stash and removes them from the working directory.

The second command switches branches.

The third command restores the changes which you have stored in the stash (the --index option is useful to make sure that staged files are still staged).

How to trigger event when a variable's value is changed?

just use a property

int  _theVariable;
public int TheVariable{
  get{return _theVariable;}
  set{
    _theVariable = value; 
    if ( _theVariable == 1){
      //Do stuff here.
    }
  }
}

Custom Date Format for Bootstrap-DatePicker

Perhaps you can check it here for the LATEST version always

http://bootstrap-datepicker.readthedocs.org/en/latest/

$('.datepicker').datepicker({
    format: 'mm/dd/yyyy',
    startDate: '-3d'
})

or

$.fn.datepicker.defaults.format = "mm/dd/yyyy";
$('.datepicker').datepicker({
    startDate: '-3d'
})

How to Convert Boolean to String

function ToStr($Val=null,$T=0){

    return is_string($Val)?"$Val"
    :
    (
        is_numeric($Val)?($T?"$Val":$Val)
        :
        (
            is_null($Val)?"NULL"
            :
            (
                is_bool($Val)?($Val?"TRUE":"FALSE")
                :
                (
                    is_array($Val)?@StrArr($Val,$T)
                    :
                    false
                )
            )
        )
    );

}
function StrArr($Arr,$T=0)
{
    $Str="";
    $i=-1;
    if(is_array($Arr))
    foreach($Arr AS $K => $V)
    $Str.=((++$i)?", ":null).(is_string($K)?"\"$K\"":$K)." => ".(is_string($V)?"\"$V\"":@ToStr($V,$T+1));
    return "array( ".($i?@ToStr($Arr):$Str)." )".($T?null:";");
}

$A = array(1,2,array('a'=>'b'),array('a','b','c'),true,false,ToStr(100));
echo StrArr($A); // OR ToStr($A) // OR ToStr(true) // OR StrArr(true)

typedef fixed length array

Building off the accepted answer, a multi-dimensional array type, that is a fixed-length array of fixed-length arrays, can't be declared with

typedef char[M] T[N];  // wrong!

instead, the intermediate 1D array type can be declared and used as in the accepted answer:

typedef char T_t[M];
typedef T_t T[N];

or, T can be declared in a single (arguably confusing) statement:

typedef char T[N][M];

which defines a type of N arrays of M chars (be careful about the order, here).

Installing jdk8 on ubuntu- "unable to locate package" update doesn't fix

I used another repository for oracle java.

sudo add-apt-repository ppa:linuxuprising/java
sudo apt-get update

sudo apt install  oracle-java11-installer

Python function overloading

You can use "roll-your-own" solution for function overloading. This one is copied from Guido van Rossum's article about multimethods (because there is little difference between multimethods and overloading in Python):

registry = {}

class MultiMethod(object):
    def __init__(self, name):
        self.name = name
        self.typemap = {}
    def __call__(self, *args):
        types = tuple(arg.__class__ for arg in args) # a generator expression!
        function = self.typemap.get(types)
        if function is None:
            raise TypeError("no match")
        return function(*args)
    def register(self, types, function):
        if types in self.typemap:
            raise TypeError("duplicate registration")
        self.typemap[types] = function


def multimethod(*types):
    def register(function):
        name = function.__name__
        mm = registry.get(name)
        if mm is None:
            mm = registry[name] = MultiMethod(name)
        mm.register(types, function)
        return mm
    return register

The usage would be

from multimethods import multimethod
import unittest

# 'overload' makes more sense in this case
overload = multimethod

class Sprite(object):
    pass

class Point(object):
    pass

class Curve(object):
    pass

@overload(Sprite, Point, Direction, int)
def add_bullet(sprite, start, direction, speed):
    # ...

@overload(Sprite, Point, Point, int, int)
def add_bullet(sprite, start, headto, speed, acceleration):
    # ...

@overload(Sprite, str)
def add_bullet(sprite, script):
    # ...

@overload(Sprite, Curve, speed)
def add_bullet(sprite, curve, speed):
    # ...

Most restrictive limitations at the moment are:

  • methods are not supported, only functions that are not class members;
  • inheritance is not handled;
  • kwargs are not supported;
  • registering new functions should be done at import time thing is not thread-safe

getResourceAsStream() is always returning null

I think this way you can get the file from "anywhere" (including server locations) and you do not need to care about where to put it.

It's usually a bad practice having to care about such things.

Thread.currentThread().getContextClassLoader().getResourceAsStream("abc.properties");

Create a batch file to run an .exe with an additional parameter

Found another solution for the same. It will be more helpful.

START C:\"Program Files (x86)"\Test\"Test Automation"\finger.exe ConfigFile="C:\Users\PCName\Desktop\Automation\Documents\Validation_ZoneWise_Default.finger.Config"

finger.exe is a parent program that is calling config solution. Note: if your path folder name consists of spaces, then do not forget to add "".

How can I find where Python is installed on Windows?

It would be either of

  • C:\Python36
  • C:\Users\(Your logged in User)\AppData\Local\Programs\Python\Python36

Difference between "on-heap" and "off-heap"

The heap is the place in memory where your dynamically allocated objects live. If you used new then it's on the heap. That's as opposed to stack space, which is where the function stack lives. If you have a local variable then that reference is on the stack. Java's heap is subject to garbage collection and the objects are usable directly.

EHCache's off-heap storage takes your regular object off the heap, serializes it, and stores it as bytes in a chunk of memory that EHCache manages. It's like storing it to disk but it's still in RAM. The objects are not directly usable in this state, they have to be deserialized first. Also not subject to garbage collection.

Which Python memory profiler is recommended?

I recommend Dowser. It is very easy to setup, and you need zero changes to your code. You can view counts of objects of each type through time, view list of live objects, view references to live objects, all from the simple web interface.

# memdebug.py

import cherrypy
import dowser

def start(port):
    cherrypy.tree.mount(dowser.Root())
    cherrypy.config.update({
        'environment': 'embedded',
        'server.socket_port': port
    })
    cherrypy.server.quickstart()
    cherrypy.engine.start(blocking=False)

You import memdebug, and call memdebug.start. That's all.

I haven't tried PySizer or Heapy. I would appreciate others' reviews.

UPDATE

The above code is for CherryPy 2.X, CherryPy 3.X the server.quickstart method has been removed and engine.start does not take the blocking flag. So if you are using CherryPy 3.X

# memdebug.py

import cherrypy
import dowser

def start(port):
    cherrypy.tree.mount(dowser.Root())
    cherrypy.config.update({
        'environment': 'embedded',
        'server.socket_port': port
    })
    cherrypy.engine.start()

Git: Pull from other remote

upstream in the github example is just the name they've chosen to refer to that repository. You may choose any that you like when using git remote add. Depending on what you select for this name, your git pull usage will change. For example, if you use:

git remote add upstream git://github.com/somename/original-project.git

then you would use this to pull changes:

git pull upstream master

But, if you choose origin for the name of the remote repo, your commands would be:

To name the remote repo in your local config: git remote add origin git://github.com/somename/original-project.git

And to pull: git pull origin master

Is it a good idea to index datetime field in mysql?

MySQL recommends using indexes for a variety of reasons including elimination of rows between conditions: http://dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html

This makes your datetime column an excellent candidate for an index if you are going to be using it in conditions frequently in queries. If your only condition is BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 30 DAY) and you have no other index in the condition, MySQL will have to do a full table scan on every query. I'm not sure how many rows are generated in 30 days, but as long as it's less than about 1/3 of the total rows it will be more efficient to use an index on the column.

Your question about creating an efficient database is very broad. I'd say to just make sure that it's normalized and all appropriate columns are indexed (i.e. ones used in joins and where clauses).

How to set Python's default version to 3.x on OS X?

You can solve it by symbolic link.

unlink /usr/local/bin/python
ln -s /usr/local/bin/python3.3 /usr/local/bin/python

Accessing certain pixel RGB value in openCV

Try the following:

cv::Mat image = ...do some stuff...;

image.at<cv::Vec3b>(y,x); gives you the RGB (it might be ordered as BGR) vector of type cv::Vec3b

image.at<cv::Vec3b>(y,x)[0] = newval[0];
image.at<cv::Vec3b>(y,x)[1] = newval[1];
image.at<cv::Vec3b>(y,x)[2] = newval[2];

How to square or raise to a power (elementwise) a 2D numpy array?

The fastest way is to do a*a or a**2 or np.square(a) whereas np.power(a, 2) showed to be considerably slower.

np.power() allows you to use different exponents for each element if instead of 2 you pass another array of exponents. From the comments of @GarethRees I just learned that this function will give you different results than a**2 or a*a, which become important in cases where you have small tolerances.

I've timed some examples using NumPy 1.9.0 MKL 64 bit, and the results are shown below:

In [29]: a = np.random.random((1000, 1000))

In [30]: timeit a*a
100 loops, best of 3: 2.78 ms per loop

In [31]: timeit a**2
100 loops, best of 3: 2.77 ms per loop

In [32]: timeit np.power(a, 2)
10 loops, best of 3: 71.3 ms per loop

Is Constructor Overriding Possible?

It is never possible. Constructor Overriding is never possible in Java.

This is because,

Constructor looks like a method but name should be as class name and no return value.

Overriding means what we have declared in Super class, that exactly we have to declare in Sub class it is called Overriding. Super class name and Sub class names are different.

If you trying to write Super class Constructor in Sub class, then Sub class will treat that as a method not constructor because name should not match with Sub class name. And it will give an compilation error that methods does not have return value. So we should declare as void, then only it will compile.


Have a look at the following code :

Class One
        {
         ....
         One() { // Super Class constructor
          .... 
        }

        One(int a) { // Super Class Constructor Overloading
          .... 
        }
 }

Class Two extends One
                   {
                    One() {    // this is a method not constructor 
                    .....      // because name should not match with Class name
                   }

                    Two() { // sub class constructor
                   ....  
                   }

                   Two(int b) { // sub class constructor overloading
                   ....
                  }
 }  

How to make g++ search for header files in a specific directory?

Headers included with #include <> will be searched in all default directories , but you can also add your own location in the search path with -I command line arg.

I saw your edit you could install your headers in default locations usually

 /usr/local/include
 libdir/gcc/target/version/include
 /usr/target/include
 /usr/include

Confirm with compiler docs though.

Best way to return a value from a python script

If you want your script to return values, just do return [1,2,3] from a function wrapping your code but then you'd have to import your script from another script to even have any use for that information:

Return values (from a wrapping-function)

(again, this would have to be run by a separate Python script and be imported in order to even do any good):

import ...
def main():
    # calculate stuff
    return [1,2,3]

Exit codes as indicators

(This is generally just good for when you want to indicate to a governor what went wrong or simply the number of bugs/rows counted or w/e. Normally 0 is a good exit and >=1 is a bad exit but you could inter-prate them in any way you want to get data out of it)

import sys
# calculate and stuff
sys.exit(100)

And exit with a specific exit code depending on what you want that to tell your governor. I used exit codes when running script by a scheduling and monitoring environment to indicate what has happened.

(os._exit(100) also works, and is a bit more forceful)

Stdout as your relay

If not you'd have to use stdout to communicate with the outside world (like you've described). But that's generally a bad idea unless it's a parser executing your script and can catch whatever it is you're reporting to.

import sys
# calculate stuff
sys.stdout.write('Bugs: 5|Other: 10\n')
sys.stdout.flush()
sys.exit(0)

Are you running your script in a controlled scheduling environment then exit codes are the best way to go.

Files as conveyors

There's also the option to simply write information to a file, and store the result there.

# calculate
with open('finish.txt', 'wb') as fh:
    fh.write(str(5)+'\n')

And pick up the value/result from there. You could even do it in a CSV format for others to read simplistically.

Sockets as conveyors

If none of the above work, you can also use network sockets locally *(unix sockets is a great way on nix systems). These are a bit more intricate and deserve their own post/answer. But editing to add it here as it's a good option to communicate between processes. Especially if they should run multiple tasks and return values.

What is an opaque response, and what purpose does it serve?

Consider the case in which a service worker acts as an agnostic cache. Your only goal is serve the same resources that you would get from the network, but faster. Of course you can't ensure all the resources will be part of your origin (consider libraries served from CDNs, for instance). As the service worker has the potential of altering network responses, you need to guarantee you are not interested in the contents of the response, nor on its headers, nor even on the result. You're only interested on the response as a black box to possibly cache it and serve it faster.

This is what { mode: 'no-cors' } was made for.

Clone Object without reference javascript

You could define a clone function.

I use this one :

function goclone(source) {
    if (Object.prototype.toString.call(source) === '[object Array]') {
        var clone = [];
        for (var i=0; i<source.length; i++) {
            clone[i] = goclone(source[i]);
        }
        return clone;
    } else if (typeof(source)=="object") {
        var clone = {};
        for (var prop in source) {
            if (source.hasOwnProperty(prop)) {
                clone[prop] = goclone(source[prop]);
            }
        }
        return clone;
    } else {
        return source;
    }
}

var B = goclone(A);

It doesn't copy the prototype, functions, and so on. But you should adapt it (and maybe simplify it) for you own need.

How to create user for a db in postgresql?

From CLI:

$ su - postgres 
$ psql template1
template1=# CREATE USER tester WITH PASSWORD 'test_password';
template1=# GRANT ALL PRIVILEGES ON DATABASE "test_database" to tester;
template1=# \q

PHP (as tested on localhost, it works as expected):

  $connString = 'port=5432 dbname=test_database user=tester password=test_password';
  $connHandler = pg_connect($connString);
  echo 'Connected to '.pg_dbname($connHandler);

Enable/Disable a dropdownbox in jquery

$("#chkdwn2").change(function(){
       $("#dropdown").slideToggle();
});

JsFiddle

Execute PowerShell Script from C# with Commandline Arguments

Mine is a bit more smaller and simpler:

/// <summary>
/// Runs a PowerShell script taking it's path and parameters.
/// </summary>
/// <param name="scriptFullPath">The full file path for the .ps1 file.</param>
/// <param name="parameters">The parameters for the script, can be null.</param>
/// <returns>The output from the PowerShell execution.</returns>
public static ICollection<PSObject> RunScript(string scriptFullPath, ICollection<CommandParameter> parameters = null)
{
    var runspace = RunspaceFactory.CreateRunspace();
    runspace.Open();
    var pipeline = runspace.CreatePipeline();
    var cmd = new Command(scriptFullPath);
    if (parameters != null)
    {
        foreach (var p in parameters)
        {
            cmd.Parameters.Add(p);
        }
    }
    pipeline.Commands.Add(cmd);
    var results = pipeline.Invoke();
    pipeline.Dispose();
    runspace.Dispose();
    return results;
}

The I/O operation has been aborted because of either a thread exit or an application request

995 is an error reported by the IO Completion Port. The error comes since you try to continue read from the socket when it has most likely been closed.

Receiving 0 bytes from EndRecieve means that the socket has been closed, as does most exceptions that EndRecieve will throw.

You need to start dealing with those situations.

Never ever ignore exceptions, they are thrown for a reason.

Update

There is nothing that says that the server does anything wrong. A connection can be lost for a lot of reasons such as idle connection being closed by a switch/router/firewall, shaky network, bad cables etc.

What I'm saying is that you MUST handle disconnections. The proper way of doing so is to dispose the socket and try to connect a new one at certain intervals.

As for the receive callback a more proper way of handling it is something like this (semi pseudo code):

public void OnDataReceived(IAsyncResult asyn)
{
    BLCommonFunctions.WriteLogger(0, "In :- OnDataReceived", ref swReceivedLogWriter, strLogPath, 0);

    try
    {
        SocketPacket client = (SocketPacket)asyn.AsyncState;

        int bytesReceived = client.thisSocket.EndReceive(asyn); //Here error is coming
        if (bytesReceived == 0)
        {
          HandleDisconnect(client);
          return;
        }
    }
    catch (Exception err)
    {
       HandleDisconnect(client);
    }

    try
    {
        string strHEX = BLCommonFunctions.ByteArrToHex(theSockId.dataBuffer);                    

        //do your handling here
    }
    catch (Exception err)
    {
        // Your logic threw an exception. handle it accordinhly
    }

    try
    {
       client.thisSocket.BeginRecieve(.. all parameters ..);
    }
    catch (Exception err)
    {
       HandleDisconnect(client);
    }
}

the reason to why I'm using three catch blocks is simply because the logic for the middle one is different from the other two. Exceptions from BeginReceive/EndReceive usually indicates socket disconnection while exceptions from your logic should not stop the socket receiving.

javascript password generator

Here's another approach based off Stephan Hoyer's solution

getRandomString (length) {
  var chars = 'abcdefghkmnpqrstuvwxyz23456789';
  return times(length, () => sample(chars)).join('');
}

#ifdef in C#

C# does have a preprocessor. It works just slightly differently than that of C++ and C.

Here is a MSDN links - the section on all preprocessor directives.

Call a "local" function within module.exports from another function in module.exports?

You can also save a reference to module's global scope outside the (module.)exports.somemodule definition:

var _this = this;

exports.somefunction = function() {
   console.log('hello');
}

exports.someotherfunction = function() {
   _this.somefunction();
}

What is a software framework?

A simple explanation is: A framework is a scaffold that you can you build applications around.

A framework generally provides some base functionality which you can use and extend to make more complex applications from, there are frameworks for all sorts of things. Microsofts MVC framework is a good example of this. It provides everything you need to get off the ground building website using the MVC pattern, it handles web requests, routes and the like. All you have to do is implement "Controllers" and provide "Views" which are two constructs defined by the MVC framework. The MVC framework then handles calling your controllers and rendering your views.

Perhaps not the best wording but I hope it helps

Last segment of URL in jquery

I don't really know if regex is the right way to solve this issue as it can really affect efficiency of your code, but the below regex will help you fetch the last segment and it will still give you the last segment even if the URL is followed by an empty /. The regex that I came up with is:

[^\/]+[\/]?$

Synchronization vs Lock

I would like to add some more things on top of Bert F answer.

Locks support various methods for finer grained lock control, which are more expressive than implicit monitors (synchronized locks)

A Lock provides exclusive access to a shared resource: only one thread at a time can acquire the lock and all access to the shared resource requires that the lock be acquired first. However, some locks may allow concurrent access to a shared resource, such as the read lock of a ReadWriteLock.

Advantages of Lock over Synchronization from documentation page

  1. The use of synchronized methods or statements provides access to the implicit monitor lock associated with every object, but forces all lock acquisition and release to occur in a block-structured way

  2. Lock implementations provide additional functionality over the use of synchronized methods and statements by providing a non-blocking attempt to acquire a lock (tryLock()), an attempt to acquire the lock that can be interrupted (lockInterruptibly(), and an attempt to acquire the lock that can timeout (tryLock(long, TimeUnit)).

  3. A Lock class can also provide behavior and semantics that is quite different from that of the implicit monitor lock, such as guaranteed ordering, non-reentrant usage, or deadlock detection

ReentrantLock: In simple terms as per my understanding, ReentrantLock allows an object to re-enter from one critical section to other critical section . Since you already have lock to enter one critical section, you can other critical section on same object by using current lock.

ReentrantLock key features as per this article

  1. Ability to lock interruptibly.
  2. Ability to timeout while waiting for lock.
  3. Power to create fair lock.
  4. API to get list of waiting thread for lock.
  5. Flexibility to try for lock without blocking.

You can use ReentrantReadWriteLock.ReadLock, ReentrantReadWriteLock.WriteLock to further acquire control on granular locking on read and write operations.

Apart from these three ReentrantLocks, java 8 provides one more Lock

StampedLock:

Java 8 ships with a new kind of lock called StampedLock which also support read and write locks just like in the example above. In contrast to ReadWriteLock the locking methods of a StampedLock return a stamp represented by a long value.

You can use these stamps to either release a lock or to check if the lock is still valid. Additionally stamped locks support another lock mode called optimistic locking.

Have a look at this article on usage of different type of ReentrantLock and StampedLock locks.

Generate HTML table from 2D JavaScript array

Based on the accepted solution:

function createTable (tableData) {
  const table = document.createElement('table').appendChild(
    tableData.reduce((tbody, rowData) => {
      tbody.appendChild(
        rowData.reduce((tr, cellData) => {
          tr.appendChild(
            document
              .createElement('td')
              .appendChild(document.createTextNode(cellData))
          )
          return tr
        }, document.createElement('tr'))
      )
      return tbody
    }, document.createElement('tbody'))
  )

  document.body.appendChild(table)
}

createTable([
  ['row 1, cell 1', 'row 1, cell 2'],
  ['row 2, cell 1', 'row 2, cell 2']
])

With a simple change it is possible to return the table as HTML element.

Why binary_crossentropy and categorical_crossentropy give different performances for the same problem?

The reason for this apparent performance discrepancy between categorical & binary cross entropy is what user xtof54 has already reported in his answer below, i.e.:

the accuracy computed with the Keras method evaluate is just plain wrong when using binary_crossentropy with more than 2 labels

I would like to elaborate more on this, demonstrate the actual underlying issue, explain it, and offer a remedy.

This behavior is not a bug; the underlying reason is a rather subtle & undocumented issue at how Keras actually guesses which accuracy to use, depending on the loss function you have selected, when you include simply metrics=['accuracy'] in your model compilation. In other words, while your first compilation option

model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])

is valid, your second one:

model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])

will not produce what you expect, but the reason is not the use of binary cross entropy (which, at least in principle, is an absolutely valid loss function).

Why is that? If you check the metrics source code, Keras does not define a single accuracy metric, but several different ones, among them binary_accuracy and categorical_accuracy. What happens under the hood is that, since you have selected binary cross entropy as your loss function and have not specified a particular accuracy metric, Keras (wrongly...) infers that you are interested in the binary_accuracy, and this is what it returns - while in fact you are interested in the categorical_accuracy.

Let's verify that this is the case, using the MNIST CNN example in Keras, with the following modification:

model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])  # WRONG way

model.fit(x_train, y_train,
          batch_size=batch_size,
          epochs=2,  # only 2 epochs, for demonstration purposes
          verbose=1,
          validation_data=(x_test, y_test))

# Keras reported accuracy:
score = model.evaluate(x_test, y_test, verbose=0) 
score[1]
# 0.9975801164627075

# Actual accuracy calculated manually:
import numpy as np
y_pred = model.predict(x_test)
acc = sum([np.argmax(y_test[i])==np.argmax(y_pred[i]) for i in range(10000)])/10000
acc
# 0.98780000000000001

score[1]==acc
# False    

To remedy this, i.e. to use indeed binary cross entropy as your loss function (as I said, nothing wrong with this, at least in principle) while still getting the categorical accuracy required by the problem at hand, you should ask explicitly for categorical_accuracy in the model compilation as follows:

from keras.metrics import categorical_accuracy
model.compile(loss='binary_crossentropy', optimizer='adam', metrics=[categorical_accuracy])

In the MNIST example, after training, scoring, and predicting the test set as I show above, the two metrics now are the same, as they should be:

# Keras reported accuracy:
score = model.evaluate(x_test, y_test, verbose=0) 
score[1]
# 0.98580000000000001

# Actual accuracy calculated manually:
y_pred = model.predict(x_test)
acc = sum([np.argmax(y_test[i])==np.argmax(y_pred[i]) for i in range(10000)])/10000
acc
# 0.98580000000000001

score[1]==acc
# True    

System setup:

Python version 3.5.3
Tensorflow version 1.2.1
Keras version 2.0.4

UPDATE: After my post, I discovered that this issue had already been identified in this answer.

How do I attach events to dynamic HTML elements with jQuery?

You want to use the live() function. See the docs.

For example:

$("#anchor1").live("click", function() {
    $("#anchor1").append('<a class="myclass" href="#">test4</a>');
});

Extract a subset of a dataframe based on a condition involving a field

Here are the two main approaches. I prefer this one for its readability:

bar <- subset(foo, location == "there")

Note that you can string together many conditionals with & and | to create complex subsets.

The second is the indexing approach. You can index rows in R with either numeric, or boolean slices. foo$location == "there" returns a vector of T and F values that is the same length as the rows of foo. You can do this to return only rows where the condition returns true.

foo[foo$location == "there", ]

Invoke native date picker from web-app on iOS/Android

On your form elements use input type="time". It will save you all the hassle of trying to use a data picker library.

Create a temporary table in MySQL with an index from a select

I wrestled quite a while with the proper syntax for CREATE TEMPORARY TABLE SELECT. Having figured out a few things, I wanted to share the answers with the rest of the community.

Basic information about the statement is available at the following MySQL links:

CREATE TABLE SELECT and CREATE TABLE.

At times it can be daunting to interpret the spec. Since most people learn best from examples, I will share how I have created a working statement, and how you can modify it to work for you.

  1. Add multiple indexes

    This statement shows how to add multiple indexes (note that index names - in lower case - are optional):

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (INDEX my_index_name (tag, time), UNIQUE my_unique_index_name (order_number))
    SELECT * FROM core.my_big_table
    WHERE my_val = 1
    
  2. Add a new primary key:

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (PRIMARY KEY my_pkey (order_number),
    INDEX cmpd_key (user_id, time))
    SELECT * FROM core.my_big_table
    
  3. Create additional columns

    You can create a new table with more columns than are specified in the SELECT statement. Specify the additional column in the table definition. Columns specified in the table definition and not found in select will be first columns in the new table, followed by the columns inserted by the SELECT statement.

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (my_new_id BIGINT NOT NULL AUTO_INCREMENT,  
    PRIMARY KEY my_pkey (my_new_id), INDEX my_unique_index_name (invoice_number))
    SELECT * FROM core.my_big_table
    
  4. Redefining data types for the columns from SELECT

    You can redefine the data type of a column being SELECTed. In the example below, column tag is a MEDIUMINT in core.my_big_table and I am redefining it to a BIGINT in core.my_tmp_table.

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (tag BIGINT,
    my_time DATETIME,  
    INDEX my_unique_index_name (tag) )
    SELECT * FROM core.my_big_table
    
  5. Advanced field definitions during create

    All the usual column definitions are available as when you create a normal table. Example:

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
    value BIGINT UNSIGNED NOT NULL DEFAULT 0 UNIQUE,
    location VARCHAR(20) DEFAULT "NEEDS TO BE SET",
    country CHAR(2) DEFAULT "XX" COMMENT "Two-letter country code",  
    INDEX my_index_name (location))
    ENGINE=MyISAM 
    SELECT * FROM core.my_big_table
    

Figure out size of UILabel based on String in Swift

This solution will help to calculate the height and width at runtime.

    let messageText = "Your Text String"
    let size = CGSize.init(width: 250, height: 1000)
    let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
    let estimateFrame = NSString(string: messageText).boundingRect(with:  size, options: options, attributes: [NSAttributedString.Key.font: UIFont(name: "HelveticaNeue", size: 17)!], context: nil)

Here you can calculate the estimated height that your string would take and pass it to the UILabel frame.

estimateFrame.Width
estimateFrame.Height 

Skip certain tables with mysqldump

Another example for ignoring multiple tables

/usr/bin/mysqldump -uUSER -pPASS --ignore-table={db_test.test1,db_test.test3} db_test> db_test.sql

using --ignore-table and create an array of tables, with syntaxs like

--ignore-table={db_test.table1,db_test.table3,db_test.table4}

Extra:

Import database

 # if file is .sql
 mysql -uUSER  -pPASS db_test < backup_database.sql
 # if file is .sql.gz
 gzip -dc < backup_database.sql.gz | mysql -uUSER -pPASSWORD db_test

Simple script to ignore tables and export in .sql.gz to save space

#!/bin/bash

#tables to ignore
_TIGNORE=(
my_database.table1
my_database.table2
my_database.tablex
)

#create text for ignore tables
_TDELIMITED="$(IFS=" "; echo "${_TIGNORE[*]/#/--ignore-table=}")"

#don't forget to include user and password
/usr/bin/mysqldump -uUSER -pPASSWORD --events ${_TDELIMITED} --databases my_database | gzip -v > backup_database.sql.gz

Links with information that will help you

Note: tested in ubuntu server with mysql Ver 14.14 Distrib 5.5.55

Java Swing revalidate() vs repaint()

revalidate() just request to layout the container, when you experienced simply call revalidate() works, it could be caused by the updating of child components bounds triggers the repaint() when their bounds are changed during the re-layout. In the case you mentioned, only component removed and no component bounds are changed, this case no repaint() is "accidentally" triggered.

How to count string occurrence in string?

Try it

<?php 
$str = "33,33,56,89,56,56";
echo substr_count($str, '56');
?>

<script type="text/javascript">
var temp = "33,33,56,89,56,56";
var count = temp.match(/56/g);  
alert(count.length);
</script>

Simple C example of doing an HTTP POST and consuming the response

A message has a header part and a message body separated by a blank line. The blank line is ALWAYS needed even if there is no message body. The header starts with a command and has additional lines of key value pairs separated by a colon and a space. If there is a message body, it can be anything you want it to be.

Lines in the header and the blank line at the end of the header must end with a carraige return and linefeed pair (see HTTP header line break style) so that's why those lines have \r\n at the end.

A URL has the form of http://host:port/path?query_string

There are two main ways of submitting a request to a website:

  • GET: The query string is optional but, if specified, must be reasonably short. Because of this the header could just be the GET command and nothing else. A sample message could be:

    GET /path?query_string HTTP/1.0\r\n
    \r\n
    
  • POST: What would normally be in the query string is in the body of the message instead. Because of this the header needs to include the Content-Type: and Content-Length: attributes as well as the POST command. A sample message could be:

    POST /path HTTP/1.0\r\n
    Content-Type: text/plain\r\n
    Content-Length: 12\r\n
    \r\n
    query_string
    

So, to answer your question: if the URL you are interested in POSTing to is http://api.somesite.com/apikey=ARG1&command=ARG2 then there is no body or query string and, consequently, no reason to POST because there is nothing to put in the body of the message and so nothing to put in the Content-Type: and Content-Length:

I guess you could POST if you really wanted to. In that case your message would look like:

POST /apikey=ARG1&command=ARG2 HTTP/1.0\r\n
\r\n

So to send the message the C program needs to:

  • create a socket
  • lookup the IP address
  • open the socket
  • send the request
  • wait for the response
  • close the socket

The send and receive calls won't necessarily send/receive ALL the data you give them - they will return the number of bytes actually sent/received. It is up to you to call them in a loop and send/receive the remainder of the message.

What I did not do in this sample is any sort of real error checking - when something fails I just exit the program. Let me know if it works for you:

#include <stdio.h> /* printf, sprintf */
#include <stdlib.h> /* exit */
#include <unistd.h> /* read, write, close */
#include <string.h> /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h> /* struct hostent, gethostbyname */

void error(const char *msg) { perror(msg); exit(0); }

int main(int argc,char *argv[])
{
    /* first what are we going to send and where are we going to send it? */
    int portno =        80;
    char *host =        "api.somesite.com";
    char *message_fmt = "POST /apikey=%s&command=%s HTTP/1.0\r\n\r\n";

    struct hostent *server;
    struct sockaddr_in serv_addr;
    int sockfd, bytes, sent, received, total;
    char message[1024],response[4096];

    if (argc < 3) { puts("Parameters: <apikey> <command>"); exit(0); }

    /* fill in the parameters */
    sprintf(message,message_fmt,argv[1],argv[2]);
    printf("Request:\n%s\n",message);

    /* create the socket */
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) error("ERROR opening socket");

    /* lookup the ip address */
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");

    /* fill in the structure */
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(portno);
    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);

    /* connect the socket */
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");

    /* send the request */
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(sockfd,message+sent,total-sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0)
            break;
        sent+=bytes;
    } while (sent < total);

    /* receive the response */
    memset(response,0,sizeof(response));
    total = sizeof(response)-1;
    received = 0;
    do {
        bytes = read(sockfd,response+received,total-received);
        if (bytes < 0)
            error("ERROR reading response from socket");
        if (bytes == 0)
            break;
        received+=bytes;
    } while (received < total);

    if (received == total)
        error("ERROR storing complete response from socket");

    /* close the socket */
    close(sockfd);

    /* process response */
    printf("Response:\n%s\n",response);

    return 0;
}

Like the other answer pointed out, 4096 bytes is not a very big response. I picked that number at random assuming that the response to your request would be short. If it can be big you have two choices:

  • read the Content-Length: header from the response and then dynamically allocate enough memory to hold the whole response.
  • write the response to a file as the pieces arrive

Additional information to answer the question asked in the comments:

What if you want to POST data in the body of the message? Then you do need to include the Content-Type: and Content-Length: headers. The Content-Length: is the actual length of everything after the blank line that separates the header from the body.

Here is a sample that takes the following command line arguments:

  • host
  • port
  • command (GET or POST)
  • path (not including the query data)
  • query data (put into the query string for GET and into the body for POST)
  • list of headers (Content-Length: is automatic if using POST)

So, for the original question you would run:

a.out api.somesite.com 80 GET "/apikey=ARG1&command=ARG2"

And for the question asked in the comments you would run:

a.out api.somesite.com 80 POST / "name=ARG1&value=ARG2" "Content-Type: application/x-www-form-urlencoded"

Here is the code:

#include <stdio.h> /* printf, sprintf */
#include <stdlib.h> /* exit, atoi, malloc, free */
#include <unistd.h> /* read, write, close */
#include <string.h> /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h> /* struct hostent, gethostbyname */

void error(const char *msg) { perror(msg); exit(0); }

int main(int argc,char *argv[])
{
    int i;

    /* first where are we going to send it? */
    int portno = atoi(argv[2])>0?atoi(argv[2]):80;
    char *host = strlen(argv[1])>0?argv[1]:"localhost";

    struct hostent *server;
    struct sockaddr_in serv_addr;
    int sockfd, bytes, sent, received, total, message_size;
    char *message, response[4096];

    if (argc < 5) { puts("Parameters: <host> <port> <method> <path> [<data> [<headers>]]"); exit(0); }

    /* How big is the message? */
    message_size=0;
    if(!strcmp(argv[3],"GET"))
    {
        message_size+=strlen("%s %s%s%s HTTP/1.0\r\n");        /* method         */
        message_size+=strlen(argv[3]);                         /* path           */
        message_size+=strlen(argv[4]);                         /* headers        */
        if(argc>5)
            message_size+=strlen(argv[5]);                     /* query string   */
        for(i=6;i<argc;i++)                                    /* headers        */
            message_size+=strlen(argv[i])+strlen("\r\n");
        message_size+=strlen("\r\n");                          /* blank line     */
    }
    else
    {
        message_size+=strlen("%s %s HTTP/1.0\r\n");
        message_size+=strlen(argv[3]);                         /* method         */
        message_size+=strlen(argv[4]);                         /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            message_size+=strlen(argv[i])+strlen("\r\n");
        if(argc>5)
            message_size+=strlen("Content-Length: %d\r\n")+10; /* content length */
        message_size+=strlen("\r\n");                          /* blank line     */
        if(argc>5)
            message_size+=strlen(argv[5]);                     /* body           */
    }

    /* allocate space for the message */
    message=malloc(message_size);

    /* fill in the parameters */
    if(!strcmp(argv[3],"GET"))
    {
        if(argc>5)
            sprintf(message,"%s %s%s%s HTTP/1.0\r\n",
                strlen(argv[3])>0?argv[3]:"GET",               /* method         */
                strlen(argv[4])>0?argv[4]:"/",                 /* path           */
                strlen(argv[5])>0?"?":"",                      /* ?              */
                strlen(argv[5])>0?argv[5]:"");                 /* query string   */
        else
            sprintf(message,"%s %s HTTP/1.0\r\n",
                strlen(argv[3])>0?argv[3]:"GET",               /* method         */
                strlen(argv[4])>0?argv[4]:"/");                /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            {strcat(message,argv[i]);strcat(message,"\r\n");}
        strcat(message,"\r\n");                                /* blank line     */
    }
    else
    {
        sprintf(message,"%s %s HTTP/1.0\r\n",
            strlen(argv[3])>0?argv[3]:"POST",                  /* method         */
            strlen(argv[4])>0?argv[4]:"/");                    /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            {strcat(message,argv[i]);strcat(message,"\r\n");}
        if(argc>5)
            sprintf(message+strlen(message),"Content-Length: %d\r\n",strlen(argv[5]));
        strcat(message,"\r\n");                                /* blank line     */
        if(argc>5)
            strcat(message,argv[5]);                           /* body           */
    }

    /* What are we going to send? */
    printf("Request:\n%s\n",message);

    /* create the socket */
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) error("ERROR opening socket");

    /* lookup the ip address */
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");

    /* fill in the structure */
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(portno);
    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);

    /* connect the socket */
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");

    /* send the request */
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(sockfd,message+sent,total-sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0)
            break;
        sent+=bytes;
    } while (sent < total);

    /* receive the response */
    memset(response,0,sizeof(response));
    total = sizeof(response)-1;
    received = 0;
    do {
        bytes = read(sockfd,response+received,total-received);
        if (bytes < 0)
            error("ERROR reading response from socket");
        if (bytes == 0)
            break;
        received+=bytes;
    } while (received < total);

    if (received == total)
        error("ERROR storing complete response from socket");

    /* close the socket */
    close(sockfd);

    /* process response */
    printf("Response:\n%s\n",response);

    free(message);
    return 0;
}

Show data on mouseover of circle

This concise example demonstrates common way how to create custom tooltip in d3.

_x000D_
_x000D_
var w = 500;_x000D_
var h = 150;_x000D_
_x000D_
var dataset = [5, 10, 15, 20, 25];_x000D_
_x000D_
// firstly we create div element that we can use as_x000D_
// tooltip container, it have absolute position and_x000D_
// visibility: hidden by default_x000D_
_x000D_
var tooltip = d3.select("body")_x000D_
  .append("div")_x000D_
  .attr('class', 'tooltip');_x000D_
_x000D_
var svg = d3.select("body")_x000D_
  .append("svg")_x000D_
  .attr("width", w)_x000D_
  .attr("height", h);_x000D_
_x000D_
// here we add some circles on the page_x000D_
_x000D_
var circles = svg.selectAll("circle")_x000D_
  .data(dataset)_x000D_
  .enter()_x000D_
  .append("circle");_x000D_
_x000D_
circles.attr("cx", function(d, i) {_x000D_
    return (i * 50) + 25;_x000D_
  })_x000D_
  .attr("cy", h / 2)_x000D_
  .attr("r", function(d) {_x000D_
    return d;_x000D_
  })_x000D_
  _x000D_
  // we define "mouseover" handler, here we change tooltip_x000D_
  // visibility to "visible" and add appropriate test_x000D_
  _x000D_
  .on("mouseover", function(d) {_x000D_
    return tooltip.style("visibility", "visible").text('radius = ' + d);_x000D_
  })_x000D_
  _x000D_
  // we move tooltip during of "mousemove"_x000D_
  _x000D_
  .on("mousemove", function() {_x000D_
    return tooltip.style("top", (event.pageY - 30) + "px")_x000D_
      .style("left", event.pageX + "px");_x000D_
  })_x000D_
  _x000D_
  // we hide our tooltip on "mouseout"_x000D_
  _x000D_
  .on("mouseout", function() {_x000D_
    return tooltip.style("visibility", "hidden");_x000D_
  });
_x000D_
.tooltip {_x000D_
    position: absolute;_x000D_
    z-index: 10;_x000D_
    visibility: hidden;_x000D_
    background-color: lightblue;_x000D_
    text-align: center;_x000D_
    padding: 4px;_x000D_
    border-radius: 4px;_x000D_
    font-weight: bold;_x000D_
    color: orange;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.11.0/d3.min.js"></script>
_x000D_
_x000D_
_x000D_

How to quit a java app from within the program

This should do it in the correct way:

mainFrame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
mainFrame.addWindowListener(new WindowListener() {

@Override
public void windowClosing(WindowEvent e) {
    if (doQuestion("Really want to exit?")) {
      mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      mainFrame.dispose();
    }
}

Get the item doubleclick event of listview

Was having a similar issue with a ListBox wanting to open a window (Different View) with the SelectedItem as the context (in my case, so I can edit it).

The three options I've found are: 1. Code Behind 2. Using Attached Behaviors 3. Using Blend's i:Interaction and EventToCommand using MVVM-Light.

I went with the 3rd option, and it looks something along these lines:

<ListBox x:Name="You_Need_This_Name"  
ItemsSource="{Binding Your_Collection_Name_Here}"
SelectedItem="{Binding Your_Property_Name_Here, UpdateSourceTrigger=PropertyChanged}"
... rest of your needed stuff here ...
>
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseDoubleClick">
    <Command:EventToCommand Command="{Binding Your_Command_Name_Here}" 
        CommandParameter="{Binding ElementName=You_Need_This_Name,Path=SelectedItem}"     />
    </i:EventTrigger>
</i:Interaction.Triggers>

That's about it ... when you double click on the item you want, your method on the ViewModel will be called with the SelectedItem as parameter, and you can do whatever you want there :)

How to obtain a QuerySet of all rows, with specific fields for each one of them?

Oskar Persson's answer is the best way to handle it because makes it easier to pass the data to the context and treat it normally from the template as we get the object instances (easily iterable to get props) instead of a plain value list.

After that you can just easily get the wanted prop:

for employee in employees:
    print(employee.eng_name)

Or in the template:

{% for employee in employees %}

    <p>{{ employee.eng_name }}</p>

{% endfor %}

How to animate button in android?

Dependency

Add it in your root build.gradle at the end of repositories:

allprojects {
repositories {
    ...
    maven { url "https://jitpack.io" }
}}

and then add dependency dependencies { compile 'com.github.varunest:sparkbutton:1.0.5' }

Usage

XML

<com.varunest.sparkbutton.SparkButton
        android:id="@+id/spark_button"
        android:layout_width="40dp"
        android:layout_height="40dp"
        app:sparkbutton_activeImage="@drawable/active_image"
        app:sparkbutton_inActiveImage="@drawable/inactive_image"
        app:sparkbutton_iconSize="40dp"
        app:sparkbutton_primaryColor="@color/primary_color"
        app:sparkbutton_secondaryColor="@color/secondary_color" />

Java (Optional)

SparkButton button  = new SparkButtonBuilder(context)
            .setActiveImage(R.drawable.active_image)
            .setInActiveImage(R.drawable.inactive_image)
            .setDisabledImage(R.drawable.disabled_image)
            .setImageSizePx(getResources().getDimensionPixelOffset(R.dimen.button_size))
            .setPrimaryColor(ContextCompat.getColor(context, R.color.primary_color))
            .setSecondaryColor(ContextCompat.getColor(context, R.color.secondary_color))
            .build();

Embed Youtube video inside an Android app

The video quality depends upon the Connection speed using API

alternatively for other than API means without YouTube app you can follow this link

How to view the dependency tree of a given npm module?

If you want to get the actually dependency path of specific package and want to know why you have it, you can simply ask yarn why <MODULE>. example:

    $> yarn why mime-db
    yarn why v1.5.1
    [1/4] Why do we have the module "mime-db"...?
    [2/4] Initialising dependency graph...
    [3/4] Finding dependency...
    [4/4] Calculating file sizes...
    => Found "[email protected]"
    info Reasons this module exists
       - "coveralls#request#mime-types" depends on it
       - Hoisted from "coveralls#request#mime-types#mime-db"
    info Disk size without dependencies: "196kB"
    info Disk size with unique dependencies: "196kB"
    info Disk size with transitive dependencies: "196kB"
    info Number of shared dependencies: 0
    Done in 0.65s.

Append an empty row in dataframe using pandas

You can add a new series, and name it at the same time. The name will be the index of the new row, and all the values will automatically be NaN.

df.append(pd.Series(name='Afterthought'))

How to pass multiple parameters in thread in VB

Dim evaluator As New Thread(Sub() Me.testthread(goodList, 1))
With evaluator
.IsBackground = True ' not necessary...
.Start()
End With

openpyxl - adjust column width size

I had to change @User3759685 above answer to this when the openpxyl updated. I was getting an error. Well @phihag reported this in the comments as well

for column_cells in ws.columns:
    new_column_length = max(len(as_text(cell.value)) for cell in column_cells)
    new_column_letter = (openpyxl.utils.get_column_letter(column_cells[0].column))
    if new_column_length > 0:
        ws.column_dimensions[new_column_letter].width = new_column_length + 1

How to disable <br> tags inside <div> by css?

I used it like this:

@media (max-width: 450px) {
  br {
    display: none;
  }
}

nb: media query via Foundation nb2: this is useful if one of the editor intend to use
tags in his/her copy and you need to deal with it specifically under some conditions—on mobile for example.

curl: (6) Could not resolve host: google.com; Name or service not known

I have today similar problem. But weirder.

  • host - works host pl.archive.ubuntu.com
  • dig - works on default and on all other DNS's dig pl.archive.ubuntu.com, dig @127.0.1.1 pl.archive.ubuntu.com
  • curl - doesn't work! but for some addresses it does. WEIRD! Same in Ruby, APT and many more.
$ curl -v http://google.com/
*   Trying 172.217.18.78...
* Connected to google.com (172.217.18.78) port 80 (#0)
> GET / HTTP/1.1
> Host: google.com
> User-Agent: curl/7.47.0
> Accept: */*
>
< HTTP/1.1 302 Found
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Referrer-Policy: no-referrer
< Location: http://www.google.pl/?gfe_rd=cr&ei=pt9UWfqXL4uBX_W5n8gB
< Content-Length: 256
< Date: Thu, 29 Jun 2017 11:08:22 GMT
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="http://www.google.pl/?gfe_rd=cr&ei=pt9UWfqXL4uBX_W5n8gB">here</A>.
</BODY></HTML>
* Connection #0 to host google.com left intact

$ curl -v http://pl.archive.ubuntu.com/
* Could not resolve host: pl.archive.ubuntu.com
* Closing connection 0
curl: (6) Could not resolve host: pl.archive.ubuntu.com

Revelation

Eventually I used strace on curl and found that it was connection to nscd deamon.

connect(4, {sa_family=AF_LOCAL, sun_path="/var/run/nscd/socket"}, 110) = 0

Solution

I've restarted the nscd service (Name Service Cache Daemon) and it helped to solve this issue!

systemctl restart nscd.service

How to create a file in memory for user to download, but not through server?

We can use the URL api, in particular URL.createObjectURL(), and the Blob api to encode and download pretty much anything.

If your download is small, this works fine:

_x000D_
_x000D_
document.body.innerHTML += 
`<a id="download" download="PATTERN.json" href="${URL.createObjectURL(new Blob([JSON.stringify("HELLO WORLD", null, 2)]))}"> Click me</a>`
download.click()
download.outerHTML = ""
_x000D_
_x000D_
_x000D_


If your download is huge, instead of using the DOM, a better way is to create a link element with the download parameters, and trigger a click.

Notice the link element isn't appended to the document but the click work anyway! This is possible to create a download of many hundreds of Mo this way.

_x000D_
_x000D_
const stack = {
 some: "stuffs",
 alot: "of them!"
}

BUTTONDOWNLOAD.onclick = (function(){
  let j = document.createElement("a")
  j.download = "stack_"+Date.now()+".json"
  j.href = URL.createObjectURL(new Blob([JSON.stringify(stack, null, 2)]))
  j.click()
})
_x000D_
<button id="BUTTONDOWNLOAD">DOWNLOAD!</button>
_x000D_
_x000D_
_x000D_


Bonus! Download any cyclic objects, avoid the errors:

TypeError: cyclic object value (Firefox) TypeError: Converting

circular structure to JSON (Chrome and Opera) TypeError: Circular

reference in value argument not supported (Edge)

Using https://github.com/douglascrockford/JSON-js/blob/master/cycle.js

On this example, downloading the document object as json.

_x000D_
_x000D_
/* JSON.decycle */
if(typeof JSON.decycle!=="function"){JSON.decycle=function decycle(object,replacer){"use strict";var objects=new WeakMap();return(function derez(value,path){var old_path;var nu;if(replacer!==undefined){value=replacer(value)}
if(typeof value==="object"&&value!==null&&!(value instanceof Boolean)&&!(value instanceof Date)&&!(value instanceof Number)&&!(value instanceof RegExp)&&!(value instanceof String)){old_path=objects.get(value);if(old_path!==undefined){return{$ref:old_path}}
objects.set(value,path);if(Array.isArray(value)){nu=[];value.forEach(function(element,i){nu[i]=derez(element,path+"["+i+"]")})}else{nu={};Object.keys(value).forEach(function(name){nu[name]=derez(value[name],path+"["+JSON.stringify(name)+"]")})}
return nu}
return value}(object,"$"))}}


document.body.innerHTML += 
`<a id="download" download="PATTERN.json" href="${URL.createObjectURL(new Blob([JSON.stringify(JSON.decycle(document), null, 2)]))}"></a>`
download.click()
_x000D_
_x000D_
_x000D_

What is the best way to measure execution time of a function?

Use a Profiler

Your approach will work nevertheless, but if you are looking for more sophisticated approaches. I'd suggest using a C# Profiler.

The advantages they have is:

  • You can even get a statement level breakup
  • No changes required in your codebase
  • Instrumentions generally have very less overhead, hence very accurate results can be obtained.

There are many available open-source as well.

SQL Server equivalent to MySQL enum data type?

IMHO Lookup tables is the way to go, with referential integrity. But only if you avoid "Evil Magic Numbers" by following an example such as this one: Generate enum from a database lookup table using T4

Have Fun!

How to quickly and conveniently disable all console.log statements in my code?

I know you asked how to disable console.log, but this might be what you're really after. This way you don't have to explicitly enable or disable the console. It simply prevents those pesky console errors for people who don't have it open or installed.

if(typeof(console) === 'undefined') {
    var console = {};
    console.log = console.error = console.info = console.debug = console.warn = console.trace = console.dir = console.dirxml = console.group = console.groupEnd = console.time = console.timeEnd = console.assert = console.profile = function() {};
}

Merging dictionaries in C#

I know this is an old question, but since we now have LINQ you can do it in a single line like this

Dictionary<T1,T2> merged;
Dictionary<T1,T2> mergee;
mergee.ToList().ForEach(kvp => merged.Add(kvp.Key, kvp.Value));

or

mergee.ToList().ForEach(kvp => merged.Append(kvp));

How to change text color of simple list item

try this code...

<RelativeLayout 
         xmlns:android="http://schemas.android.com/apk/res/android" 
         android:layout_width="fill_parent" 
         android:layout_height="fill_parent" 
         android:background="#ffff00"> 

    <ListView 
            android:id="@+id/android:list" 
            android:layout_marginTop="2px" 
            android:layout_marginLeft="2px" 
            android:layout_marginRight="2px"
            android:layout_width="fill_parent" 
            android:layout_height="wrap_content" 
            android:layout_weight="1" 
            android:background="@drawable/shape_1" 
            android:listSelector="@drawable/shape_3" 
            android:textColor="#ffff00" 
            android:layout_marginBottom="44px" /> 
</RelativeLayout>

Rails.env vs RAILS_ENV

Strange behaviour while debugging my app: require "active_support/notifications" (rdb:1) p ENV['RAILS_ENV'] "test" (rdb:1) p Rails.env "development"

I would say that you should stick to one or another (and preferably Rails.env)

ImageView in circular through xml

The following is one of the simplest ways to do it, use the following code:

Dependencies

dependencies {
    ...
    compile 'de.hdodenhof:circleimageview:2.1.0'      // use this or use the latest compile version. In case u get bug.
}

XML Code

<de.hdodenhof.circleimageview.CircleImageView
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/profile_image"
    android:layout_width="96dp"             //  here u can adjust the width 
    android:layout_height="96dp"            //  here u can adjust the height 
    android:src="@drawable/profile"         //  here u can change the image 
    app:civ_border_width="2dp"              //  here u can adjust the border of the circle.  
    app:civ_border_color="#FF000000"/>      //  here u can adjust the border color

Screenshot:

Screenshot

Source: Circular ImageView GitHub Repository

enter image description here

Batch - If, ElseIf, Else

@echo off
color 0a
set /p language=
if %language% == DE (
    goto LGDE
) else (
    if %language% == EN (
    goto LGEN
    ) else (
    echo N/A
)

:LGDE
(code)
:LGEN
(code)

How do I create a self-signed certificate for code signing on Windows?

Updated Answer

If you are using the following Windows versions or later: Windows Server 2012, Windows Server 2012 R2, or Windows 8.1 then MakeCert is now deprecated, and Microsoft recommends using the PowerShell Cmdlet New-SelfSignedCertificate.

If you're using an older version such as Windows 7, you'll need to stick with MakeCert or another solution. Some people suggest the Public Key Infrastructure Powershell (PSPKI) Module.

Original Answer

While you can create a self-signed code-signing certificate (SPC - Software Publisher Certificate) in one go, I prefer to do the following:

Creating a self-signed certificate authority (CA)

makecert -r -pe -n "CN=My CA" -ss CA -sr CurrentUser ^
         -a sha256 -cy authority -sky signature -sv MyCA.pvk MyCA.cer

(^ = allow batch command-line to wrap line)

This creates a self-signed (-r) certificate, with an exportable private key (-pe). It's named "My CA", and should be put in the CA store for the current user. We're using the SHA-256 algorithm. The key is meant for signing (-sky).

The private key should be stored in the MyCA.pvk file, and the certificate in the MyCA.cer file.

Importing the CA certificate

Because there's no point in having a CA certificate if you don't trust it, you'll need to import it into the Windows certificate store. You can use the Certificates MMC snapin, but from the command line:

certutil -user -addstore Root MyCA.cer

Creating a code-signing certificate (SPC)

makecert -pe -n "CN=My SPC" -a sha256 -cy end ^
         -sky signature ^
         -ic MyCA.cer -iv MyCA.pvk ^
         -sv MySPC.pvk MySPC.cer

It is pretty much the same as above, but we're providing an issuer key and certificate (the -ic and -iv switches).

We'll also want to convert the certificate and key into a PFX file:

pvk2pfx -pvk MySPC.pvk -spc MySPC.cer -pfx MySPC.pfx

If you want to protect the PFX file, add the -po switch, otherwise PVK2PFX creates a PFX file with no passphrase.

Using the certificate for signing code

signtool sign /v /f MySPC.pfx ^
              /t http://timestamp.url MyExecutable.exe

(See why timestamps may matter)

If you import the PFX file into the certificate store (you can use PVKIMPRT or the MMC snapin), you can sign code as follows:

signtool sign /v /n "Me" /s SPC ^
              /t http://timestamp.url MyExecutable.exe

Some possible timestamp URLs for signtool /t are:

  • http://timestamp.verisign.com/scripts/timstamp.dll
  • http://timestamp.globalsign.com/scripts/timstamp.dll
  • http://timestamp.comodoca.com/authenticode

Full Microsoft documentation

Downloads

For those who are not .NET developers, you will need a copy of the Windows SDK and .NET framework. A current link is available here: SDK & .NET (which installs makecert in C:\Program Files\Microsoft SDKs\Windows\v7.1). Your mileage may vary.

MakeCert is available from the Visual Studio Command Prompt. Visual Studio 2015 does have it, and it can be launched from the Start Menu in Windows 7 under "Developer Command Prompt for VS 2015" or "VS2015 x64 Native Tools Command Prompt" (probably all of them in the same folder).

How to add an event after close the modal window?

If you're using version 3.x of Bootstrap, the correct way to do this now is:

$('#myModal').on('hidden.bs.modal', function (e) {
  // do something...
})

Scroll down to the events section to learn more.

http://getbootstrap.com/javascript/#modals-usage

This appears to remain unchanged for whenever version 4 releases (http://v4-alpha.getbootstrap.com/components/modal/#events), but if it does I'll be sure to update this post with the relevant information.

How to Load Ajax in Wordpress

Use wp_localize_script and pass url there:

wp_localize_script( some_handle, 'admin_url', array('ajax_url' => admin_url( 'admin-ajax.php' ) ) );

then inside js, you can call it by

admin_url.ajax_url 

How do I get the picture size with PIL?

Followings gives dimensions as well as channels:

import numpy as np
from PIL import Image

with Image.open(filepath) as img:
    shape = np.array(img).shape

UIImage resize (Scale proportion)

This change worked for me:

// The size returned by CGImageGetWidth(imgRef) & CGImageGetHeight(imgRef) is incorrect as it doesn't respect the image orientation!
// CGImageRef imgRef = [image CGImage];
// CGFloat width = CGImageGetWidth(imgRef);
// CGFloat height = CGImageGetHeight(imgRef);
//
// This returns the actual width and height of the photo (and hence solves the problem
CGFloat width = image.size.width; 
CGFloat height = image.size.height;
CGRect bounds = CGRectMake(0, 0, width, height);

MIPS: Integer Multiplication and Division

To multiply, use mult for signed multiplication and multu for unsigned multiplication. Note that the result of the multiplication of two 32-bit numbers yields a 64-number. If you want the result back in $v0 that means that you assume the result will fit in 32 bits.

The 32 most significant bits will be held in the HI special register (accessible by mfhi instruction) and the 32 least significant bits will be held in the LO special register (accessible by the mflo instruction):

E.g.:

li $a0, 5
li $a1, 3
mult $a0, $a1
mfhi $a2 # 32 most significant bits of multiplication to $a2
mflo $v0 # 32 least significant bits of multiplication to $v0

To divide, use div for signed division and divu for unsigned division. In this case, the HI special register will hold the remainder and the LO special register will hold the quotient of the division.

E.g.:

div $a0, $a1
mfhi $a2 # remainder to $a2
mflo $v0 # quotient to $v0

100% width table overflowing div container

Well, given your constraints, I think setting overflow: scroll; on the .page div is probably your only option. 280 px is pretty narrow, and given your font size, word wrapping alone isn't going to do it. Some words are just long and can't be wrapped. You can either reduce your font size drastically or go with overflow: scroll.

String array initialization in Java

names[] = {"Ankit","Bohra","Xyz"};

is an initializer and used solely when constructing or creating a new array object. It cannot be used to set the array. You can use it when declared as:

String[] names= {"Ankit","Bohra","Xyz"};

You may also use:

names=new String[] {"Ankit","Bohra","Xyz"};

How to convert seconds to time format?

1 day = 86400000 milliseconds.

DecodeTime(milliseconds/86400000,hr,min,sec,msec)

Ups! I was thinking in delphi, there must be something similar in all languages.

Video format or MIME type is not supported

For Ubuntu 14.04

Just removed the package Oxideqt-dodecs then install flash or ubuntu restricted extras

and you are good to go!!

Jquery assiging class to th in a table

You had thead in your selector, but there is no thead in your table. Also you had your selectors backwards. As you mentioned above, you wanted to be adding the tr class to the th, not vice-versa (although your comment seems to contradict what you wrote up above).

$('tr th').each(function(index){     if($('tr td').eq(index).attr('class') != ''){         // get the class of the td         var tdClass = $('tr td').eq(index).attr('class');         // add it to this th         $(this).addClass(tdClass );     } }); 

Fiddle

How Can I Bypass the X-Frame-Options: SAMEORIGIN HTTP Header?

Yes Fiddler is an option for me:

  1. Open Fiddler menu > Rules > Customize Rules (this effectively edits CustomRules.js).
  2. Find the function OnBeforeResponse
  3. Add the following lines:

    oSession.oResponse.headers.Remove("X-Frame-Options");
    oSession.oResponse.headers.Add("Access-Control-Allow-Origin", "*");
    
  4. Remember to save the script!

AngularJS sorting rows by table header

Use a third-party JavaScript library. It will give you that and much more. A good example is datatables (if you are also using jQuery): https://datatables.net

Or just order your bound array in $scope.results when the header is clicked.

Efficient way to determine number of digits in an integer

sample console output

long long num = 123456789;
int digit = 1;
int result = 1;

while (result != 0) 
{
    result = num / 10;
    if (result != 0)
    {
        ++digit;
    }
    num = result;
}

cout << "Your number has " << digit << "digits" << endl;

Using XAMPP, how do I swap out PHP 5.3 for PHP 5.2?

I couldn't get this working. Started with PHP 5.3, then tried to switch to PHP 5.28 from xampp-win32-1.7.0.zip. Couldn't get it to work. Then, I got smart and figured out i was working with XAMPP and you can install it wherever you want, so I did a fresh install from scratch with xampp-win32-1.7.0.zip. The whole point of working with XAMPP is so you don't have to fuss with the sysadmin stuff. Using it in that context got me up and running in no time.

How can I Remove .DS_Store files from a Git repository?

Combining benzado and webmat's answers, updating with git rm, not failing on files found that aren't in repo, and making it paste-able generically for any user:

# remove any existing files from the repo, skipping over ones not in repo
find . -name .DS_Store -print0 | xargs -0 git rm --ignore-unmatch
# specify a global exclusion list
git config --global core.excludesfile ~/.gitignore
# adding .DS_Store to that list
echo .DS_Store >> ~/.gitignore

"document.getElementByClass is not a function"

Before jumping into any further error checking please first check whether its

document.getElementsByClassName() itself.

double check its getElements and not getElement

Oracle Date TO_CHAR('Month DD, YYYY') has extra spaces in it

if you use 'Month' in to_char it right pads to 9 characters; you have to use the abbreviated 'MON', or to_char then trim and concatenate it to avoid this. See, http://www.techonthenet.com/oracle/functions/to_char.php

select trim(to_char(date_field, 'month')) || ' ' || to_char(date_field,'dd, yyyy')
  from ...

or

select to_char(date_field,'mon dd, yyyy')
  from ...  

Scrolling an iframe with JavaScript?

I've also had trouble using any type of javascript "scrollTo" function in an iframe on an iPad. Finally found an "old" solution to the problem, just hash to an anchor.

In my situation after an ajax return my error messages were set to display at the top of the iframe but if the user had scrolled down in what is an admittedly long form the submission goes out and the error appears "above the fold". Additionally, assuming the user did scroll way down the top level page was scrolled away from 0,0 and was also hidden.

I added

<a name="ptop"></a>

to the top of my iframe document and

<a name="atop"></a>

to the top of my top level page

then

    $(document).ready(function(){
      $("form").bind("ajax:complete",
        function() {
          location.hash = "#";
          top.location.hash = "#";
          setTimeout('location.hash="#ptop"',150);
          setTimeout('top.location.hash="#atop"',350);
        }
      )
    });

in the iframe.

You have to hash the iframe before the top page or only the iframe will scroll and the top will remain hidden but while it's a tiny bit "jumpy" due to the timeout intervals it works. I imagine tags throughout would allow various "scrollTo" points.

Get current controller in view

Other way to get current Controller name in View

@ViewContext.Controller.ValueProvider.GetValue("controller").RawValue

Socket.IO handling disconnect event

Create a Map or a Set, and using "on connection" event set to it each connected socket, in reverse "once disconnect" event delete that socket from the Map we created earlier

import * as Server from 'socket.io';

const io = Server();
io.listen(3000);

const connections = new Set();

io.on('connection', function (s) {

  connections.add(s);

  s.once('disconnect', function () {
    connections.delete(s);
  });

});

How to install PyQt5 on Windows?

To install the GPL version of PyQt5, run (see PyQt5 Project):

pip3 install pyqt5

This will install the Python wheel for your platform and your version of Python (assuming both are supported).

(The wheel will be automatically downloaded from the Python Package Index.)

The PyQt5 wheel includes the necessary parts of the LGPL version of Qt. There is no need to install Qt yourself.

(The required sip is packaged as a separate wheel and will be downloaded and installed automatically.)


Note:

If you get an error message saying something as

No downloads could be found that satisfy the requirement 

then you are probably using an unsupported version of Python.

How to change the application launcher icon on Flutter?

I have changed it in the following steps:

1) please add this dependency on your pubspec.yaml page

 dev_dependencies:
  flutter_test:
    sdk: flutter
  flutter_launcher_icons: ^0.7.4

2) you have to upload an image/icon on your project which you want to see as a launcher icon. (i have created a folder name:image in my project then upload the logo.png in the image folder). Now you have to add the below codes and paste your image path on image_path: in pubspec.yaml page.

flutter_icons:
  image_path: "images/logo.png"
  android: true
  ios: true

3) Go to terminal and execute this command:

flutter pub get

4) After executing the command then enter below command:

flutter pub run flutter_launcher_icons:main

5) Done

N.B: (of course add an updated dependency from

https://pub.dev/packages/flutter_launcher_icons#-installing-tab-

)

Android Endless List

One solution is to implement an OnScrollListener and make changes (like adding items, etc.) to the ListAdapter at a convenient state in its onScroll method.

The following ListActivity shows a list of integers, starting with 40, adding items when the user scrolls to the end of the list.

public class Test extends ListActivity implements OnScrollListener {

    Aleph0 adapter = new Aleph0();

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setListAdapter(adapter); 
        getListView().setOnScrollListener(this);
    }

    public void onScroll(AbsListView view,
        int firstVisible, int visibleCount, int totalCount) {

        boolean loadMore = /* maybe add a padding */
            firstVisible + visibleCount >= totalCount;

        if(loadMore) {
            adapter.count += visibleCount; // or any other amount
            adapter.notifyDataSetChanged();
        }
    }

    public void onScrollStateChanged(AbsListView v, int s) { }    

    class Aleph0 extends BaseAdapter {
        int count = 40; /* starting amount */

        public int getCount() { return count; }
        public Object getItem(int pos) { return pos; }
        public long getItemId(int pos) { return pos; }

        public View getView(int pos, View v, ViewGroup p) {
                TextView view = new TextView(Test.this);
                view.setText("entry " + pos);
                return view;
        }
    }
}

You should obviously use separate threads for long running actions (like loading web-data) and might want to indicate progress in the last list item (like the market or gmail apps do).

Could not find module "@angular-devkit/build-angular"

you npm version is old, try to run the following command:

npm i npm@latest -g

How to delete a row from GridView?

Please try this code.....

DataRow dr = dtPrf_Mstr.NewRow();
dtPrf_Mstr.Rows.Add(dr);
GVGLCode.DataSource = dtPrf_Mstr;
GVGLCode.DataBind();
int iCount = GVGLCode.Rows.Count;
for (int i = 0; i < iCount; i++)
{
   GVGLCode.Rows.Remove(GVGLCode.Rows[i]);
}
GVGLCode.DataBind();

How can I convert a string with dot and comma into a float in Python

... Or instead of treating the commas as garbage to be filtered out, we could treat the overall string as a localized formatting of the float, and use the localization services:

from locale import atof, setlocale, LC_NUMERIC
setlocale(LC_NUMERIC, '') # set to your default locale; for me this is
# 'English_Canada.1252'. Or you could explicitly specify a locale in which floats
# are formatted the way that you describe, if that's not how your locale works :)
atof('123,456') # 123456.0
# To demonstrate, let's explicitly try a locale in which the comma is a
# decimal point:
setlocale(LC_NUMERIC, 'French_Canada.1252')
atof('123,456') # 123.456

How to change date format in JavaScript

Try -

var monthNames = [ "January", "February", "March", "April", "May", "June",
    "July", "August", "September", "October", "November", "December" ];

var newDate = new Date(form.startDate.value);
var formattedDate = monthNames[newDate.getMonth()] + ' ' + newDate.getFullYear();

Bootstrap Modal immediately disappearing

e.preventDefault(); with jquery ui

For me this problem occured with the click method override on a jquery ui button, causing a page reload on click by default.

Get a UTC timestamp

As wizzard pointed out, the correct method is,

new Date().getTime();

or under Javascript 1.5, just

Date.now();

From the documentation,

The value returned by the getTime method is the number of milliseconds since 1 January 1970 00:00:00 UTC.

If you wanted to make a time stamp without milliseconds you can use,

Math.floor(Date.now() / 1000);

I wanted to make this an answer so the correct method is more visible.

You can compare ExpExc's and Narendra Yadala's results to the method above at http://jsfiddle.net/JamesFM/bxEJd/, and verify with http://www.unixtimestamp.com/ or by running date +%s on a Unix terminal.

How to redirect to another page in node.js

In another way you can use window.location.href="your URL"

e.g.:

res.send('<script>window.location.href="your URL";</script>');

or:

return res.redirect("your url");

CSS set li indent

I found that doing it in two relatively simple steps seemed to work quite well. The first css definition for ul sets the base indent that you want for the list as a whole. The second definition sets the indent value for each nested list item within it. In my case they are the same, but you can obviously pick whatever you want.

ul {
    margin-left: 1.5em;
}

ul > ul {
    margin-left: 1.5em;
}

How can I disable notices and warnings in PHP within the .htaccess file?

Use:

ini_set('display_errors','off');

It is working fine in WordPress' config.php.

How to download a file using a Java REST service and a data stream

See example here: Input and Output binary streams using JERSEY?

Pseudo code would be something like this (there are a few other similar options in above mentioned post):

@Path("file/")
@GET
@Produces({"application/pdf"})
public StreamingOutput getFileContent() throws Exception {
     public void write(OutputStream output) throws IOException, WebApplicationException {
        try {
          //
          // 1. Get Stream to file from first server
          //
          while(<read stream from first server>) {
              output.write(<bytes read from first server>)
          }
        } catch (Exception e) {
            throw new WebApplicationException(e);
        } finally {
              // close input stream
        }
    }
}

Eclipse: Syntax Error, parameterized types are only if source level is 1.5

Right click your project and choose properties in the properties dialog check the Java Compiler settings, maybe you have different workspace settings.

error UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte

Use this solution it will strip out (ignore) the characters and return the string without them. Only use this if your need is to strip them not convert them.

with open(path, encoding="utf8", errors='ignore') as f:

Using errors='ignore' You'll just lose some characters. but if your don't care about them as they seem to be extra characters originating from a the bad formatting and programming of the clients connecting to my socket server. Then its a easy direct solution. reference

SQL: How to get the id of values I just INSERTed?

Simplest answer:

command.ExecuteScalar()

by default returns the first column

Return Value Type: System.Object The first column of the first row in the result set, or a null reference (Nothing in Visual Basic) if the result set is empty. Returns a maximum of 2033 characters.

Copied from MSDN

How to distinguish mouse "click" and "drag"

If you feel like using Rxjs:

_x000D_
_x000D_
var element = document;_x000D_
_x000D_
Rx.Observable_x000D_
  .merge(_x000D_
    Rx.Observable.fromEvent(element, 'mousedown').mapTo(0),_x000D_
    Rx.Observable.fromEvent(element, 'mousemove').mapTo(1)_x000D_
  )_x000D_
  .sample(Rx.Observable.fromEvent(element, 'mouseup'))_x000D_
  .subscribe(flag => {_x000D_
      console.clear();_x000D_
      console.log(flag ? "drag" : "click");_x000D_
  });
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://unpkg.com/@reactivex/[email protected]/dist/global/Rx.js"></script>
_x000D_
_x000D_
_x000D_

This is a direct clone of what @wong2 did in his answer, but converted to RxJs.

Also interesting use of sample. The sample operator will take the latest value from the source (the merge of mousedown and mousemove) and emit it when the inner observable (mouseup) emits.

Forking / Multi-Threaded Processes | Bash

Based on what you all shared I was able to put this together:

#!/usr/bin/env bash

VAR1="192.168.1.20 192.168.1.126 192.168.1.36"

for a in $VAR1; do { ssh -t -t $a -l Administrator "sudo softwareupdate -l"; } & done;
WAITPIDS="$WAITPIDS "$!;...; wait $WAITPIDS
echo "Script has finished"

Exit 1

This lists all the updates on the mac on three machines at once. Later on I used it to perform a software update for all machines when i CAT my ipaddress.txt

How to check if a specified key exists in a given S3 bucket using Java

Update:

It seems there's a new API to check just that. See another answer in this page: https://stackoverflow.com/a/36653034/435605

Original post:

Use errorCode.equals("NoSuchKey")

try {
    AmazonS3 s3 = new AmazonS3Client(new ClasspathPropertiesFileCredentialsProvider());
    String bucketName = getBucketName();
    s3.createBucket(bucketName);
    S3Object object = s3.getObject(bucketName, getKey());
} catch (AmazonServiceException e) {
    String errorCode = e.getErrorCode();
    if (!errorCode.equals("NoSuchKey")) {
        throw e;
    }
    Logger.getLogger(getClass()).debug("No such key!!!", e);
}

Note about the exception: I know exceptions should not be used for flow control. The problem is that Amazon didn't provide any api to check this flow - just documentation about the exception.

How to determine MIME type of file in android?

The MimeTypeMap solution above returned null in my usage. This works, and is easier:

Uri uri = Uri.fromFile(file);
ContentResolver cR = context.getContentResolver();
String mime = cR.getType(uri);

Fast and Lean PDF Viewer for iPhone / iPad / iOS - tips and hints?

Since iOS 11, you can use the native framework called PDFKit for displaying and manipulating PDFs.

After importing PDFKit, you should initialize a PDFView with a local or a remote URL and display it in your view.

if let url = Bundle.main.url(forResource: "example", withExtension: "pdf") {
    let pdfView = PDFView(frame: view.frame)
    pdfView.document = PDFDocument(url: url)
    view.addSubview(pdfView)
}

Read more about PDFKit in the Apple Developer documentation.

Mean filter for smoothing images in Matlab

I see good answers have already been given, but I thought it might be nice to just give a way to perform mean filtering in MATLAB using no special functions or toolboxes. This is also very good for understanding exactly how the process works as you are required to explicitly set the convolution kernel. The mean filter kernel is fortunately very easy:

I = imread(...)
kernel = ones(3, 3) / 9; % 3x3 mean kernel
J = conv2(I, kernel, 'same'); % Convolve keeping size of I

Note that for colour images you would have to apply this to each of the channels in the image.

What is the difference between screenX/Y, clientX/Y and pageX/Y?

The difference between those will depend largely on what browser you are currently referring to. Each one implements these properties differently, or not at all. Quirksmode has great documentation regarding browser differences in regards to W3C standards like the DOM and JavaScript Events.

How can I generate an apk that can run without server with react-native?

Try below, it will generate an app-debug.apk on your root/android/app/build/outputs/apk/debug folder

react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res

then go to android folder and run

./gradlew assembleDebug

Convert JsonObject to String

You can try Gson convertor, to get the exact conversion like json.stringify

val jsonString:String = jsonObject.toString()
val gson:Gson = GsonBuilder().setPrettyPrinting().create()
val json:JsonElement = gson.fromJson(jsonString,JsonElement.class)
val jsonInString:String= gson.toJson(json)
println(jsonInString)

javax.net.ssl.SSLException: Read error: ssl=0x9524b800: I/O error during system call, Connection reset by peer

If using Nginx and getting a similar problem, then this might help:

Scan your domain on this sslTesturl, and see if the connection is allowed for your device version.

If lower version devices(like < Android 4.4.2 etc) are not able to connect due to TLS support, then try adding this to your Nginx config file,

ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

How to convert a String to CharSequence?

Since String IS-A CharSequence, you can pass a String wherever you need a CharSequence, or assign a String to a CharSequence:

CharSequence cs = "string";
String s = cs.toString();
foo(s); // prints "string"

public void foo(CharSequence cs) { 
  System.out.println(cs);
}

If you want to convert a CharSequence to a String, just use the toString method that must be implemented by every concrete implementation of CharSequence.

Hope it helps.

Does Java have something like C#'s ref and out keywords?

Java passes parameters by value and doesn't have any mechanism to allow pass-by-reference. That means that whenever a parameter is passed, its value is copied into the stack frame handling the call.

The term value as I use it here needs a little clarification. In Java we have two kinds of variables - primitives and objects. A value of a primitive is the primitive itself, and the value of an object is its reference (and not the state of the object being referenced). Therefore, any change to the value inside the method will only change the copy of the value in the stack, and will not be seen by the caller. For example, there isn't any way to implement a real swap method, that receives two references and swaps them (not their content!).

How does Java import work?

Java's import statement is pure syntactical sugar. import is only evaluated at compile time to indicate to the compiler where to find the names in the code.

You may live without any import statement when you always specify the full qualified name of classes. Like this line needs no import statement at all:

javax.swing.JButton but = new  javax.swing.JButton();

The import statement will make your code more readable like this:

import javax.swing.*;

JButton but = new JButton();

iPhone UITextField - Change placeholder text color

For those using Monotouch (Xamarin.iOS), here's Adam's answer, translated to C#:

public class MyTextBox : UITextField
{
    public override void DrawPlaceholder(RectangleF rect)
    {
        UIColor.FromWhiteAlpha(0.5f, 1f).SetFill();
        new NSString(this.Placeholder).DrawString(rect, Font);
    }
}