Programs & Examples On #Cmdlet

How to get the current directory of the cmdlet being executed

I had similar problems and it made me a lot of trouble since I am making programs written in PowerShell (full end user GUI applications) and I have a lot of files and resources I need to load from disk. From my experience, using . to represent current directory is unreliable. It should represent current working directory, but it often does not. It appears that PowerShell saves location from which PowerShell has been invoked inside .. To be more precise, when PowerShell is first started, it starts, by default, inside your home user directory. That is usually directory of your user account, something like C:\USERS\YOUR USER NAME. After that, PowerShell changes directory to either directory from which you invoked it, or to directory where script you are executing is located before either presenting you with PowerShell prompt or running the script. But that happens after PowerShell app itself originally starts inside your home user directory.

And . represents that initial directory inside which PowerShell started. So . only represents current directory in case if you invoked PowerShell from the wanted directory. If you later change directory in PowerShell code, change appears not to be reflected inside . in every case. In some cases . represents current working directory, and in others directory from which PowerShell (itself, not the script) has been invoked, what can lead to inconsistent results. For this reason I use invoker script. PowerShell script with single command inside: POWERSHELL. That will ensure that PowerShell is invoked from the wanted directory and thus make . represent current directory. But it only works if you do not change directory later in PowerShell code. In case of a script, I use invoker script which is similar to last one I mentioned, except it contains a file option: POWERSHELL -FILE DRIVE:\PATH\SCRIPT NAME.PS1. That ensures that PowerShell is started inside current working directory.

Simply clicking on script invokes PowerShell from your home user directory no matter where script is located. It results with current working directory being directory where script is located, but PowerShell invocation directory being C:\USERS\YOUR USER NAME, and with . returning one of these two directories depending on the situation, what is ridiculous.

But to avoid all this fuss and using invoker script, you can simply use either $PWD or $PSSCRIPTROOT instead of . to represent current directory depending on weather you wish to represent current working directory or directory from which script has been invoked. And if you, for some reason, want to retrieve other of two directories which . returns, you can use $HOME.

I personally just have invoker script inside root directory of my apps I develop with PowerShell which invokes my main app script, and simply remember to never ever change current working directory inside my source code of my app, so I never have to worry about this, and I can use . to represent current directory and to support relative file addressing in my applications without any problems. This should work in newer versions of PowerShell (newer than version 2).

How can I throw CHECKED exceptions from inside Java 8 streams?

I wrote a library that extends the Stream API to allow you to throw checked exceptions. It uses Brian Goetz's trick.

Your code would become

public List<Class> getClasses() throws ClassNotFoundException {     
    Stream<String> classNames = 
        Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String");

    return ThrowingStream.of(classNames, ClassNotFoundException.class)
               .map(Class::forName)
               .collect(Collectors.toList());
}

How do you know a variable type in java?

I would like to expand on Martin's answer there...

His solution is rather nice, but it can be tweaked so any "variable type" can be printed like that.(It's actually Value Type, more on the topic). That said, "tweaked" may be a strong word for this. Regardless, it may be helpful.

Martins Solution:

a.getClass().getName()

However, If you want it to work with anything you can do this:

((Object) myVar).getClass().getName()
//OR
((Object) myInt).getClass().getSimpleName()

In this case, the primitive will simply be wrapped in a Wrapper. You will get the Object of the primitive in that case.

I myself used it like this:

private static String nameOf(Object o) {
    return o.getClass().getSimpleName();
}

Using Generics:

public static <T> String nameOf(T o) {
    return o.getClass().getSimpleName();
}

Importing project into Netbeans

You may try creating a new project in netbeans and then copy and and paste the files into it. I usually experience this problem when the project wasn't created in netbeans.

How to disable a link using only CSS?

The answer is already in the comments of the question. For more visibility, I am copying this solution here:

_x000D_
_x000D_
.not-active {_x000D_
  pointer-events: none;_x000D_
  cursor: default;_x000D_
  text-decoration: none;_x000D_
  color: black;_x000D_
}
_x000D_
<a href="link.html" class="not-active">Link</a>
_x000D_
_x000D_
_x000D_

For browser support, please see https://caniuse.com/#feat=pointer-events. If you need to support IE there is a workaround; see this answer.

Warning: The use of pointer-events in CSS for non-SVG elements is experimental. The feature used to be part of the CSS3 UI draft specification but, due to many open issues, has been postponed to CSS4.

convert string to char*

First of all, you would have to allocate memory:

char * S = new char[R.length() + 1];

then you can use strcpy with S and R.c_str():

std::strcpy(S,R.c_str());

You can also use R.c_str() if the string doesn't get changed or the c string is only used once. However, if S is going to be modified, you should copy the string, as writing to R.c_str() results in undefined behavior.

Note: Instead of strcpy you can also use str::copy.

How to rename a component in Angular CLI?

Here is a checklist I use to rename a component:

1.Rename the component class (VSCode Rename Symbool will update all the references)

<Old Name>Component => <New Name>Component

2.Rename @Component selector along with references (use VSCode's Replace in Files):

app-<old-name> => app-<new-name>

Result:
@Component({
  selector: 'app-<old-name>' => 'app-<new-name>',
  ...
})

<app-{old-name}></app-{old-name}> => <app-{new-name}></app-{new-name}>

3.Rename component folder (when renaming folder in VSCode, it will update references in module and other components)

src\app\<module>\<old-name> => src\app\<module>\<new-name>

4.Rename component files (renaming manually will be the fastest, but you can also use a terminal to rename all at once)

<old-name>.compoonent.* => <new-name>.compoonent.*

Bash:
find . -name "<old-name>.component.*" -exec rename 's/\/<old-name>\.component/\/<new-name>.component/' '{}' +

PowerShell: 
Get-Item <old-name>.component.* | % { Rename-Item $_ <new-name>.component.$($_.Extension) }

Cmd:
rename <old-name>.component.* <new-name>.component.*

5.Replace file references in @Component (use VSCode's Replace in Files):

<old-name>.component => <new-name>.component

Result:
@Component({
  ...
  templateUrl: './<old-name>.component.html' => './<old-name>.component.html',
  styleUrls: ['./<old-name>.component.scss'] => ['./<new-name>.component.scss']
})

That should be sufficient

Call parent method from child class c#

To access properties and methods of a parent class use the base keyword. So in your child class LoadData() method you would do this:

public class Child : Parent 
{
    public void LoadData() 
    {
        base.MyMethod(); // call method of parent class
        base.CurrentRow = 1; // set property of parent class
        // other stuff...
    }
}

Note that you would also have to change the access modifier of your parent MyMethod() to at least protected for the child class to access it.

Convert a String representation of a Dictionary to a dictionary?

Use json. the ast library consumes a lot of memory and and slower. I have a process that needs to read a text file of 156Mb. Ast with 5 minutes delay for the conversion dictionary json and 1 minutes using 60% less memory!

Turning Sonar off for certain code

Use //NOSONAR on the line you get warning if it is something you cannot help your code with. It works!

How can I open a Shell inside a Vim Window?

You may want to open a "screen" program, split screen, open shell on one and vim on another. Works for me.

How can I make an image transparent on Android?

For 20% transparency, this worked for me:

Button bu = (Button)findViewById(R.id.button1);
bu.getBackground().setAlpha(204);

Why is there no SortedList in Java?

Since all lists are already "sorted" by the order the items were added (FIFO ordering), you can "resort" them with another order, including the natural ordering of elements, using java.util.Collections.sort().

EDIT:

Lists as data structures are based in what is interesting is the ordering in which the items where inserted.

Sets do not have that information.

If you want to order by adding time, use List. If you want to order by other criteria, use SortedSet.

Check if a value is in an array (C#)

Something like this?

string[] printer = {"jupiter", "neptune", "pangea", "mercury", "sonic"};
PrinterSetup(printer);

// redefine PrinterSetup this way:
public void PrinterSetup(string[] printer)
{
    foreach (p in printer.Where(c => c == "jupiter"))
    {
        Process.Start("BLAH BLAH CODE TO ADD PRINTER VIA WINDOWS EXEC"");
    }
}

install / uninstall APKs programmatically (PackageManager vs Intents)

Android P+ requires this permission in AndroidManifest.xml

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

Then:

Intent intent = new Intent(Intent.ACTION_DELETE);
intent.setData(Uri.parse("package:com.example.mypackage"));
startActivity(intent);

to uninstall. Seems easier...

FontAwesome icons not showing. Why?

To whoever may be checking this out in 2018. I am using font awesome 4.7.0 and I got this issue solved by simply taking out the s in fas as seen in the code <i class="fa fa-[icon-name]"></i>. This was originally <i class="fas fa-[icon-name]"></i>.

Hope this helps.

Maven is not working in Java 8 when Javadoc tags are incomplete

So, save yourself some hours that I didn't and try this if it seems not to work:

 <additionalJOption>-Xdoclint:none</additionalJOption>

The tag is changed for newer versions.

How can I add new dimensions to a Numpy array?

There is no structure in numpy that allows you to append more data later.

Instead, numpy puts all of your data into a contiguous chunk of numbers (basically; a C array), and any resize requires allocating a new chunk of memory to hold it. Numpy's speed comes from being able to keep all the data in a numpy array in the same chunk of memory; e.g. mathematical operations can be parallelized for speed and you get less cache misses.

So you will have two kinds of solutions:

  1. Pre-allocate the memory for the numpy array and fill in the values, like in JoshAdel's answer, or
  2. Keep your data in a normal python list until it's actually needed to put them all together (see below)

images = []
for i in range(100):
    new_image = # pull image from somewhere
    images.append(new_image)
images = np.stack(images, axis=3)

Note that there is no need to expand the dimensions of the individual image arrays first, nor do you need to know how many images you expect ahead of time.

Example of Mockito's argumentCaptor

The steps in order to make a full check are:

Prepare the captor :

ArgumentCaptor<SomeArgumentClass> someArgumentCaptor = ArgumentCaptor.forClass(SomeArgumentClass.class);

verify the call to dependent on component (collaborator of subject under test). times(1) is the default value, so ne need to add it.

verify(dependentOnComponent, times(1)).send(someArgumentCaptor.capture());

Get the argument passed to collaborator

SomeArgumentClass someArgument = messageCaptor.getValue();

someArgument can be used for assertions

Can I perform a DNS lookup (hostname to IP address) using client-side Javascript?

I don't think this is allowed by most browsers for security reasons, in a pure JavaScript context as the question asks.

why are there two different kinds of for loops in java?

The second for loop is any easy way to iterate over the contents of an array, without having to manually specify the number of items in the array(manual enumeration). It is much more convenient than the first when dealing with arrays.

What does (function($) {})(jQuery); mean?

A little help:

_x000D_
_x000D_
// an anonymous function_x000D_
  _x000D_
(function () { console.log('allo') });_x000D_
_x000D_
// a self invoked anonymous function_x000D_
_x000D_
(function () { console.log('allo') })();_x000D_
  _x000D_
// a self invoked anonymous function with a parameter called "$"_x000D_
  _x000D_
var jQuery = 'I\'m not jQuery.';_x000D_
_x000D_
(function ($) { console.log($) })(jQuery);
_x000D_
_x000D_
_x000D_

jQuery Cross Domain Ajax

If you are planning to use JSONP you can use getJSON which made for that. jQuery has helper methods for JSONP.

$.getJSON( 'http://someotherdomain.com/service.svc&callback=?', function( result ) {
       console.log(result);
});

Read the below links

http://api.jquery.com/jQuery.getJSON/

Basic example of using .ajax() with JSONP?

Basic how-to for cross domain jsonp

How can I set a dynamic model name in AngularJS?

What I ended up doing is something like this:

In the controller:

link: function($scope, $element, $attr) {
  $scope.scope = $scope;  // or $scope.$parent, as needed
  $scope.field = $attr.field = '_suffix';
  $scope.subfield = $attr.sub_node;
  ...

so in the templates I could use totally dynamic names, and not just under a certain hard-coded element (like in your "Answers" case):

<textarea ng-model="scope[field][subfield]"></textarea>

Hope this helps.

XPath test if node value is number

The shortest possible way to test if the value contained in a variable $v can be used as a number is:

number($v) = number($v)

You only need to substitute the $v above with the expression whose value you want to test.

Explanation:

number($v) = number($v) is obviously true, if $v is a number, or a string that represents a number.

It is true also for a boolean value, because a number(true()) is 1 and number(false) is 0.

Whenever $v cannot be used as a number, then number($v) is NaN

and NaN is not equal to any other value, even to itself.

Thus, the above expression is true only for $v whose value can be used as a number, and false otherwise.

how to print json data in console.log

If you just want to print object then

console.log(JSON.stringify(data)); //this will convert json to string;

If you want to access value of field in object then use

console.log(data.input_data);

Read Variable from Web.Config

Given the following web.config:

<appSettings>
     <add key="ClientId" value="127605460617602"/>
     <add key="RedirectUrl" value="http://localhost:49548/Redirect.aspx"/>
</appSettings>

Example usage:

using System.Configuration;

string clientId = ConfigurationManager.AppSettings["ClientId"];
string redirectUrl = ConfigurationManager.AppSettings["RedirectUrl"];

Get GPS location from the web browser

There is the GeoLocation API, but browser support is rather thin on the ground at present. Most sites that care about such things use a GeoIP database (with the usual provisos about the inaccuracy of such a system). You could also look at third party services requiring user cooperation such as FireEagle.

getColor(int id) deprecated on Android 6.0 Marshmallow (API 23)

in activity used ContextCompat

ContextCompat.getColor(context, R.color.color_name)

in Adaper

private Context context;


context.getResources().getColor()

How to get the anchor from the URL using jQuery?

Use

window.location.hash

to retrieve everything beyond and including the #

Performance of Java matrix math libraries?

Just to add my 2 cents. I've compared some of these libraries. I attempted to matrix multiply a 3000 by 3000 matrix of doubles with itself. The results are as follows.

Using multithreaded ATLAS with C/C++, Octave, Python and R, the time taken was around 4 seconds.

Using Jama with Java, the time taken was 50 seconds.

Using Colt and Parallel Colt with Java, the time taken was 150 seconds!

Using JBLAS with Java, the time taken was again around 4 seconds as JBLAS uses multithreaded ATLAS.

So for me it was clear that the Java libraries didn't perform too well. However if someone has to code in Java, then the best option is JBLAS. Jama, Colt and Parallel Colt are not fast.

Press Enter to move to next control

In a KeyPress event, if the user pressed Enter, call

SendKeys.Send("{TAB}")

Nicest way to implement automatically selecting the text on receiving focus is to create a subclass of TextBox in your project with the following override:

Protected Overrides Sub OnGotFocus(ByVal e As System.EventArgs)
    SelectionStart = 0
    SelectionLength = Text.Length
    MyBase.OnGotFocus(e)
End Sub

Then use this custom TextBox in place of the WinForms standard TextBox on all your Forms.

Android design support library for API 28 (P) not working

Below code worked perfectly with me:

dependencies {
    api 'com.android.support:design:28.0.0-alpha3'

    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

    testImplementation 'junit:junit:4.12'

    androidTestImplementation 'androidx.test:runner:1.1.0-alpha2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha2'
}

Storing and displaying unicode string (??????) using PHP and MySQL

For those who are looking for PHP ( >5.3.5 ) PDO statement, we can set charset as per below:

$dbh = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');

Align a div to center

<div id="outer" style="z-index:10000;width:99%;height:200px;margin-top:300px;margin-left:auto;margin-right:auto;float:left;position:absolute;opacity:0.9;">

<div id="inner" style="opacity:1;background-color:White;width:300px;height:200px;margin-left:auto;margin-right:auto;">Inner</div></div>

Float the div in the background to the max width, set a div inside that that's not transparent and center it using margin auto.

How to disable editing of elements in combobox for c#?

This is another method I use because changing DropDownSyle to DropDownList makes it look 3D and sometimes its just plain ugly.

You can prevent user input by handling the KeyPress event of the ComboBox like this.

private void ComboBox1_KeyPress(object sender, KeyPressEventArgs e)
{
      e.Handled = true;
}

How to declare a variable in MySQL?

There are mainly three types of variables in MySQL:

  1. User-defined variables (prefixed with @):

    You can access any user-defined variable without declaring it or initializing it. If you refer to a variable that has not been initialized, it has a value of NULL and a type of string.

    SELECT @var_any_var_name
    

    You can initialize a variable using SET or SELECT statement:

    SET @start = 1, @finish = 10;    
    

    or

    SELECT @start := 1, @finish := 10;
    
    SELECT * FROM places WHERE place BETWEEN @start AND @finish;
    

    User variables can be assigned a value from a limited set of data types: integer, decimal, floating-point, binary or nonbinary string, or NULL value.

    User-defined variables are session-specific. That is, a user variable defined by one client cannot be seen or used by other clients.

    They can be used in SELECT queries using Advanced MySQL user variable techniques.

  2. Local Variables (no prefix) :

    Local variables needs to be declared using DECLARE before accessing it.

    They can be used as local variables and the input parameters inside a stored procedure:

    DELIMITER //
    
    CREATE PROCEDURE sp_test(var1 INT) 
    BEGIN   
        DECLARE start  INT unsigned DEFAULT 1;  
        DECLARE finish INT unsigned DEFAULT 10;
    
        SELECT  var1, start, finish;
    
        SELECT * FROM places WHERE place BETWEEN start AND finish; 
    END; //
    
    DELIMITER ;
    
    CALL sp_test(5);
    

    If the DEFAULT clause is missing, the initial value is NULL.

    The scope of a local variable is the BEGIN ... END block within which it is declared.

  3. Server System Variables (prefixed with @@):

    The MySQL server maintains many system variables configured to a default value. They can be of type GLOBAL, SESSION or BOTH.

    Global variables affect the overall operation of the server whereas session variables affect its operation for individual client connections.

    To see the current values used by a running server, use the SHOW VARIABLES statement or SELECT @@var_name.

    SHOW VARIABLES LIKE '%wait_timeout%';
    
    SELECT @@sort_buffer_size;
    

    They can be set at server startup using options on the command line or in an option file. Most of them can be changed dynamically while the server is running using SET GLOBAL or SET SESSION:

    -- Syntax to Set value to a Global variable:
    SET GLOBAL sort_buffer_size=1000000;
    SET @@global.sort_buffer_size=1000000;
    
    -- Syntax to Set value to a Session variable:
    SET sort_buffer_size=1000000;
    SET SESSION sort_buffer_size=1000000;
    SET @@sort_buffer_size=1000000;
    SET @@local.sort_buffer_size=10000;
    

How can I split a delimited string into an array in PHP?

What if you want your parts to contain commas? Well, quote them. And then what about the quotes? Well, double them up. In other words:

part1,"part2,with a comma and a quote "" in it",part3

PHP provides the https://php.net/str_getcsv function to parse a string as if it were a line in a CSV file which can be used with the above line instead of explode:

print_r(str_getcsv('part1,"part2,with a comma and a quote "" in it",part3'));
Array
(
    [0] => part1
    [1] => part2,with a comma and a quote " in it
    [2] => part3
)

How to get document height and width without using jquery

Get document size without jQuery

document.documentElement.clientWidth
document.documentElement.clientHeight

And use this if you need Screen size

screen.width
screen.height

Difference between variable declaration syntaxes in Javascript (including global variables)?

Yes, there are a couple of differences, though in practical terms they're not usually big ones.

There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:

var a = 0;     // 1
let a = 0;     // 1.1 (new with ES2015)
const a = 0;   // 1.2 (new with ES2015)
a = 0;         // 2
window.a = 0;  // 3
this.a = 0;    // 4

Those statements explained

#1 var a = 0;

This creates a global variable which is also a property of the global object, which we access as window on browsers (or via this a global scope, in non-strict code). Unlike some other properties, the property cannot be removed via delete.

In specification terms, it creates an identifier binding on the object Environment Record for the global environment. That makes it a property of the global object because the global object is where identifier bindings for the global environment's object Environment Record are held. This is why the property is non-deletable: It's not just a simple property, it's an identifier binding.

The binding (variable) is defined before the first line of code runs (see "When var happens" below).

Note that on IE8 and earlier, the property created on window is not enumerable (doesn't show up in for..in statements). In IE9, Chrome, Firefox, and Opera, it's enumerable.


#1.1 let a = 0;

This creates a global variable which is not a property of the global object. This is a new thing as of ES2015.

In specification terms, it creates an identifier binding on the declarative Environment Record for the global environment rather than the object Environment Record. The global environment is unique in having a split Environment Record, one for all the old stuff that goes on the global object (the object Environment Record) and another for all the new stuff (let, const, and the functions created by class) that don't go on the global object.

The binding is created before any step-by-step code in its enclosing block is executed (in this case, before any global code runs), but it's not accessible in any way until the step-by-step execution reaches the let statement. Once execution reaches the let statement, the variable is accessible. (See "When let and const happen" below.)


#1.2 const a = 0;

Creates a global constant, which is not a property of the global object.

const is exactly like let except that you must provide an initializer (the = value part), and you cannot change the value of the constant once it's created. Under the covers, it's exactly like let but with a flag on the identifier binding saying its value cannot be changed. Using const does three things for you:

  1. Makes it a parse-time error if you try to assign to the constant.
  2. Documents its unchanging nature for other programmers.
  3. Lets the JavaScript engine optimize on the basis that it won't change.

#2 a = 0;

This creates a property on the global object implicitly. As it's a normal property, you can delete it. I'd recommend not doing this, it can be unclear to anyone reading your code later. If you use ES5's strict mode, doing this (assigning to a non-existent variable) is an error. It's one of several reasons to use strict mode.

And interestingly, again on IE8 and earlier, the property created not enumerable (doesn't show up in for..in statements). That's odd, particularly given #3 below.


#3 window.a = 0;

This creates a property on the global object explicitly, using the window global that refers to the global object (on browsers; some non-browser environments have an equivalent global variable, such as global on NodeJS). As it's a normal property, you can delete it.

This property is enumerable, on IE8 and earlier, and on every other browser I've tried.


#4 this.a = 0;

Exactly like #3, except we're referencing the global object through this instead of the global window. This won't work in strict mode, though, because in strict mode global code, this doesn't have a reference to the global object (it has the value undefined instead).


Deleting properties

What do I mean by "deleting" or "removing" a? Exactly that: Removing the property (entirely) via the delete keyword:

window.a = 0;
display("'a' in window? " + ('a' in window)); // displays "true"
delete window.a;
display("'a' in window? " + ('a' in window)); // displays "false"

delete completely removes a property from an object. You can't do that with properties added to window indirectly via var, the delete is either silently ignored or throws an exception (depending on the JavaScript implementation and whether you're in strict mode).

Warning: IE8 again (and presumably earlier, and IE9-IE11 in the broken "compatibility" mode): It won't let you delete properties of the window object, even when you should be allowed to. Worse, it throws an exception when you try (try this experiment in IE8 and in other browsers). So when deleting from the window object, you have to be defensive:

try {
    delete window.prop;
}
catch (e) {
    window.prop = undefined;
}

That tries to delete the property, and if an exception is thrown it does the next best thing and sets the property to undefined.

This only applies to the window object, and only (as far as I know) to IE8 and earlier (or IE9-IE11 in the broken "compatibility" mode). Other browsers are fine with deleting window properties, subject to the rules above.


When var happens

The variables defined via the var statement are created before any step-by-step code in the execution context is run, and so the property exists well before the var statement.

This can be confusing, so let's take a look:

display("foo in window? " + ('foo' in window)); // displays "true"
display("window.foo = " + window.foo);          // displays "undefined"
display("bar in window? " + ('bar' in window)); // displays "false"
display("window.bar = " + window.bar);          // displays "undefined"
var foo = "f";
bar = "b";
display("foo in window? " + ('foo' in window)); // displays "true"
display("window.foo = " + window.foo);          // displays "f"
display("bar in window? " + ('bar' in window)); // displays "true"
display("window.bar = " + window.bar);          // displays "b"

Live example:

_x000D_
_x000D_
display("foo in window? " + ('foo' in window)); // displays "true"_x000D_
display("window.foo = " + window.foo);          // displays "undefined"_x000D_
display("bar in window? " + ('bar' in window)); // displays "false"_x000D_
display("window.bar = " + window.bar);          // displays "undefined"_x000D_
var foo = "f";_x000D_
bar = "b";_x000D_
display("foo in window? " + ('foo' in window)); // displays "true"_x000D_
display("window.foo = " + window.foo);          // displays "f"_x000D_
display("bar in window? " + ('bar' in window)); // displays "true"_x000D_
display("window.bar = " + window.bar);          // displays "b"_x000D_
_x000D_
function display(msg) {_x000D_
  var p = document.createElement('p');_x000D_
  p.innerHTML = msg;_x000D_
  document.body.appendChild(p);_x000D_
}
_x000D_
_x000D_
_x000D_

As you can see, the symbol foo is defined before the first line, but the symbol bar isn't. Where the var foo = "f"; statement is, there are really two things: defining the symbol, which happens before the first line of code is run; and doing an assignment to that symbol, which happens where the line is in the step-by-step flow. This is known as "var hoisting" because the var foo part is moved ("hoisted") to the top of the scope, but the foo = "f" part is left in its original location. (See Poor misunderstood var on my anemic little blog.)


When let and const happen

let and const are different from var in a couple of ways. The way that's relevant to the question is that although the binding they define is created before any step-by-step code runs, it's not accessible until the let or const statement is reached.

So while this runs:

display(a);    // undefined
var a = 0;
display(a);    // 0

This throws an error:

display(a);    // ReferenceError: a is not defined
let a = 0;
display(a);

The other two ways that let and const differ from var, which aren't really relevant to the question, are:

  1. var always applies to the entire execution context (throughout global code, or throughout function code in the function where it appears), but let and const apply only within the block where they appear. That is, var has function (or global) scope, but let and const have block scope.

  2. Repeating var a in the same context is harmless, but if you have let a (or const a), having another let a or a const a or a var a is a syntax error.

Here's an example demonstrating that let and const take effect immediately in their block before any code within that block runs, but aren't accessible until the let or const statement:

var a = 0;
console.log(a);
if (true)
{
  console.log(a); // ReferenceError: a is not defined
  let a = 1;
  console.log(a);
}

Note that the second console.log fails, instead of accessing the a from outside the block.


Off-topic: Avoid cluttering the global object (window)

The window object gets very, very cluttered with properties. Whenever possible, strongly recommend not adding to the mess. Instead, wrap up your symbols in a little package and export at most one symbol to the window object. (I frequently don't export any symbols to the window object.) You can use a function to contain all of your code in order to contain your symbols, and that function can be anonymous if you like:

(function() {
    var a = 0; // `a` is NOT a property of `window` now

    function foo() {
        alert(a);   // Alerts "0", because `foo` can access `a`
    }
})();

In that example, we define a function and have it executed right away (the () at the end).

A function used in this way is frequently called a scoping function. Functions defined within the scoping function can access variables defined in the scoping function because they're closures over that data (see: Closures are not complicated on my anemic little blog).

How to capture the android device screen content?

Framebuffer seems the way to go, it will not always contain 2+ frames like mentioned by Ryan Conrad. In my case it contained only one. I guess it depends on the frame/display size.

I tried to read the framebuffer continuously but it seems to return for a fixed amount of bytes read. In my case that is (3 410 432) bytes, which is enough to store a display frame of 854*480 RGBA (3 279 360 bytes). Yes, the frame in binary outputed from fb0 is RGBA in my device. This will most likely depend from device to device. This will be important for you to decode it =)

In my device /dev/graphics/fb0 permissions are so that only root and users from group graphics can read the fb0. graphics is a restricted group so you will probably only access fb0 with a rooted phone using su command.

Android apps have the user id (uid) app_## and group id (guid) app_## .

adb shell has uid shell and guid shell, which has much more permissions than an app. You can actually check those permissions at /system/permissions/platform.xml

This means you will be able to read fb0 in the adb shell without root but you will not read it within the app without root.

Also, giving READ_FRAME_BUFFER and/or ACCESS_SURFACE_FLINGER permissions on AndroidManifest.xml will do nothing for a regular app because these will only work for 'signature' apps.

Set database from SINGLE USER mode to MULTI USER

I googled for the solution for a while and finally came up with the below solution,

SSMS in general uses several connections to the database behind the scenes.

You will need to kill these connections before changing the access mode.(I have done it with EXEC(@kill); in the code template below.)

Then,

Run the following SQL to set the database in MULTI_USER mode.

USE master
GO
DECLARE @kill varchar(max) = '';
SELECT @kill = @kill + 'KILL ' + CONVERT(varchar(10), spid) + '; '
FROM master..sysprocesses 
WHERE spid > 50 AND dbid = DB_ID('<Your_DB_Name>')
EXEC(@kill);

GO
SET DEADLOCK_PRIORITY HIGH
ALTER DATABASE [<Your_DB_Name>] SET MULTI_USER WITH NO_WAIT
ALTER DATABASE [<Your_DB_Name>] SET MULTI_USER WITH ROLLBACK IMMEDIATE
GO

To switch back to Single User mode, you can use:

ALTER DATABASE [<Your_DB_Name>] SET SINGLE_USER

This should work. Happy coding!!

Thanks!!

How to avoid Python/Pandas creating an index in a saved csv?

If you want no index, read file using:

import pandas as pd
df = pd.read_csv('file.csv', index_col=0)

save it using

df.to_csv('file.csv', index=False)

Transform char array into String

I have search it again and search this question in baidu. Then I find 2 ways:

1,

_x000D_
_x000D_
char ch[]={'a','b','c','d','e','f','g','\0'};_x000D_
string s=ch;_x000D_
cout<<s;
_x000D_
_x000D_
_x000D_

Be aware to that '\0' is necessary for char array ch.

2,

_x000D_
_x000D_
#include<iostream>_x000D_
#include<string>_x000D_
#include<strstream>_x000D_
using namespace std;_x000D_
_x000D_
int main()_x000D_
{_x000D_
 char ch[]={'a','b','g','e','d','\0'};_x000D_
 strstream s;_x000D_
 s<<ch;_x000D_
 string str1;_x000D_
 s>>str1;_x000D_
 cout<<str1<<endl;_x000D_
 return 0;_x000D_
}
_x000D_
_x000D_
_x000D_

In this way, you also need to add the '\0' at the end of char array.

Also, strstream.h file will be abandoned and be replaced by stringstream

How to get local server host and port in Spring Boot?

You can get hostname from spring cloud property in spring-cloud-commons-2.1.0.RC2.jar

environment.getProperty("spring.cloud.client.ip-address");
environment.getProperty("spring.cloud.client.hostname");

spring.factories of spring-cloud-commons-2.1.0.RC2.jar

org.springframework.boot.env.EnvironmentPostProcessor=\
org.springframework.cloud.client.HostInfoEnvironmentPostProcessor

Random row selection in Pandas dataframe

Actually this will give you repeated indices np.random.random_integers(0, len(df), N) where N is a large number.

GIT commit as different user without email / or only email

Just supplement:

git commit --author="[email protected] " -m "Impersonation is evil."

In some cases the commit still fails and shows you the following message:

*** Please tell me who you are.

Run

git config --global user.email "[email protected]" git config --global user.name "Your Name"

to set your account's default identity. Omit --global to set the identity only in this repository.

fatal: unable to auto-detect email address (got xxxx)

So just run "git config", then "git commit"

.gitignore and "The following untracked working tree files would be overwritten by checkout"

It seems like you want the files ignored but they have already been commited. .gitignore has no effect on files that are already in the repo so they need to be removed with git rm --cached. The --cached will prevent it from having any effect on your working copy and it will just mark as removed the next time you commit. After the files are removed from the repo then the .gitignore will prevent them from being added again.

But you have another problem with your .gitignore, you are excessively using wildcards and its causing it to match less than you expect it to. Instead lets change the .gitignore and try this.

.bundle
.DS_Store
db/*.sqlite3
log/*.log
tmp/
public/system/images/
public/system/avatars/

font awesome icon in select option

I used this solution and it worked with Font Awesome 5: https://stackoverflow.com/a/50973559/3813846

What made the difference in my case was to add font-weight: 900;to the class. Keep in mind to 'fa' to the value.

Example of my code:

<select class="text-primary fa-select" name="class_logo" required>
  <option value="fa address-book">&#xf2b9; address-book</option>
  <option value="fa adjust">&#xf042; adjust</option>
  <option value="fa air-freshener">&#xf5d0; air-freshener</option>
</select>

CSS:

.fa-select {
    font-family: 'Lato', 'Font Awesome 5 Free';
    font-weight: 900;
}

Edit: If you are mixing Solid Icons with Brand Icons in the select, change the CSS as follows:

.fa-select {
    font-family: 'Lato', 'Font Awesome 5 Free', 'Font Awesome 5 Brands';
    font-weight: 900;
}

nvm is not compatible with the npm config "prefix" option:

It might be the problem if you have your home directory mounted somewhere, due nvm does not work properly with symlinks. Because I don't care where is my $NVM_DIR located I run this and all works fine:

$ mv ~/.nvm /tmp/
$ export NVM_DIR="/tmp/.nvm"
$ nvm use --delete-prefix v6.9.1

How to convert byte array to string and vice versa?

Why was the problem: As someone already specified: If you start with a byte[] and it does not in fact contain text data, there is no "proper conversion". Strings are for text, byte[] is for binary data, and the only really sensible thing to do is to avoid converting between them unless you absolutely have to.

I was observing this problem when I was trying to create byte[] from a pdf file and then converting it to String and then taking the String as input and converting back to file.

So make sure your encoding and decoding logic is same as I did. I explicitly encoded the byte[] to Base64 and decoded it to create the file again.

Use-case: Due to some limitation I was trying to sent byte[] in request(POST) and the process was as follows:

PDF File >> Base64.encodeBase64(byte[]) >> String >> Send in request(POST) >> receive String >> Base64.decodeBase64(byte[]) >> create binary

Try this and this worked for me..

File file = new File("filePath");

        byte[] byteArray = new byte[(int) file.length()];

        try {
            FileInputStream fileInputStream = new FileInputStream(file);
            fileInputStream.read(byteArray);

            String byteArrayStr= new String(Base64.encodeBase64(byteArray));

            FileOutputStream fos = new FileOutputStream("newFilePath");
            fos.write(Base64.decodeBase64(byteArrayStr.getBytes()));
            fos.close();
        } 
        catch (FileNotFoundException e) {
            System.out.println("File Not Found.");
            e.printStackTrace();
        }
        catch (IOException e1) {
            System.out.println("Error Reading The File.");
            e1.printStackTrace();
        }

How to test valid UUID/GUID?

regex to the rescue

/^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/.test('01234567-9ABC-DEF0-1234-56789ABCDEF0');

or with brackets

/^\{?[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}??\}?$/

How to call a View Controller programmatically?

main logic behind this is_,

NSString * storyboardIdentifier = @"SecondStoryBoard";

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardIdentifier bundle: nil];

UIViewController * UIVC = [storyboard instantiateViewControllerWithIdentifier:@"YourviewControllerIdentifer"];

[self presentViewController:UIVC animated:YES completion:nil];

Nested classes' scope?

I think you can simply do:

class OuterClass:
    outer_var = 1

    class InnerClass:
        pass
    InnerClass.inner_var = outer_var

The problem you encountered is due to this:

A block is a piece of Python program text that is executed as a unit. The following are blocks: a module, a function body, and a class definition.
(...)
A scope defines the visibility of a name within a block.
(...)
The scope of names defined in a class block is limited to the class block; it does not extend to the code blocks of methods – this includes generator expressions since they are implemented using a function scope. This means that the following will fail:

   class A:  

       a = 42  

       b = list(a + i for i in range(10))

http://docs.python.org/reference/executionmodel.html#naming-and-binding

The above means:
a function body is a code block and a method is a function, then names defined out of the function body present in a class definition do not extend to the function body.

Paraphrasing this for your case:
a class definition is a code block, then names defined out of the inner class definition present in an outer class definition do not extend to the inner class definition.

How do I POST a x-www-form-urlencoded request using Fetch?

No need to use jQuery, querystring or manually assemble the payload. URLSearchParams is a way to go and here is one of the most concise answers with the full request example:

fetch('https://example.com/login', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded'
  },
  body: new URLSearchParams({
    'param': 'Some value',
    'another_param': 'Another value'
  })
})
  .then(res => {
    // Do stuff with the result
  });

Yes, you can use Axios or whatever you want instead of fetch.

P.S. URLSearchParams is not supported in IE.

Forward declaration of a typedef in C++

Using forward declarations instead of a full #includes is possible only when you are not intending on using the type itself (in this file's scope) but a pointer or reference to it.

To use the type itself, the compiler must know its size - hence its full declaration must be seen - hence a full #include is needed.

However, the size of a pointer or reference is known to the compiler, regardless of the size of the pointee, so a forward declaration is sufficient - it declares a type identifier name.

Interestingly, when using pointer or reference to class or struct types, the compiler can handle incomplete types saving you the need to forward declare the pointee types as well:

// header.h

// Look Ma! No forward declarations!
typedef class A* APtr; // class A is an incomplete type - no fwd. decl. anywhere
typedef class A& ARef;

typedef struct B* BPtr; // struct B is an incomplete type - no fwd. decl. anywhere
typedef struct B& BRef;

// Using the name without the class/struct specifier requires fwd. decl. the type itself.    
class C;         // fwd. decl. type
typedef C* CPtr; // no class/struct specifier 
typedef C& CRef; // no class/struct specifier 

struct D;        // fwd. decl. type
typedef D* DPtr; // no class/struct specifier 
typedef D& DRef; // no class/struct specifier 

Android lollipop change navigation bar color

It can be done inside styles.xml using

<item name="android:navigationBarColor">@color/theme_color</item>

or

window.setNavigationBarColor(@ColorInt int color)

http://developer.android.com/reference/android/view/Window.html#setNavigationBarColor(int)

Note that the method was introduced in Android Lollipop and won't work on API version < 21.

The second method (works on KitKat) is to set windowTranslucentNavigation to true in the manifest and place a colored view beneath the navigation bar.

jQuery - checkbox enable/disable

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $('#InventoryMasterError').click(function(event) { //on click_x000D_
    if (this.checked) { // check select status_x000D_
      $('.checkerror').each(function() { //loop through each checkbox_x000D_
        $('#selecctall').attr('disabled', 'disabled');_x000D_
      });_x000D_
    } else {_x000D_
      $('.checkerror').each(function() { //loop through each checkbox_x000D_
        $('#selecctall').removeAttr('disabled', 'disabled');_x000D_
      });_x000D_
    }_x000D_
  });_x000D_
_x000D_
});_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $('#selecctall').click(function(event) { //on click_x000D_
    if (this.checked) { // check select status_x000D_
      $('.checkbox1').each(function() { //loop through each checkbox_x000D_
        $('#InventoryMasterError').attr('disabled', 'disabled');_x000D_
      });_x000D_
_x000D_
    } else {_x000D_
      $('.checkbox1').each(function() { //loop through each checkbox_x000D_
        $('#InventoryMasterError').removeAttr('disabled', 'disabled');_x000D_
      });_x000D_
    }_x000D_
  });_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<input type="checkbox" id="selecctall" name="selecctall" value="All" />_x000D_
<input type="checkbox" name="data[InventoryMaster][error]" label="" value="error" id="InventoryMasterError" />_x000D_
<input type="checkbox" name="checkid[]" class="checkbox1" value="1" id="InventoryMasterId" />_x000D_
<input type="checkbox" name="checkid[]" class="checkbox1" value="2" id="InventoryMasterId" />
_x000D_
_x000D_
_x000D_

How to print instances of a class using print()?

For Python 3:

If the specific format isn't important (e.g. for debugging) just inherit from the Printable class below. No need to write code for every object.

Inspired by this answer

class Printable:
    def __repr__(self):
        from pprint import pformat
        return "<" + type(self).__name__ + "> " + pformat(vars(self), indent=4, width=1)

# Example Usage
class MyClass(Printable):
    pass

my_obj = MyClass()
my_obj.msg = "Hello"
my_obj.number = "46"
print(my_obj)

How do I convert a list into a string with spaces in Python?

"".join([i for i in my_list])

This should work just like you asked!

Asynchronous Process inside a javascript for loop

ES2017: You can wrap the async code inside a function(say XHRPost) returning a promise( Async code inside the promise).

Then call the function(XHRPost) inside the for loop but with the magical Await keyword. :)

_x000D_
_x000D_
let http = new XMLHttpRequest();_x000D_
let url = 'http://sumersin/forum.social.json';_x000D_
_x000D_
function XHRpost(i) {_x000D_
  return new Promise(function(resolve) {_x000D_
    let params = 'id=nobot&%3Aoperation=social%3AcreateForumPost&subject=Demo' + i + '&message=Here%20is%20the%20Demo&_charset_=UTF-8';_x000D_
    http.open('POST', url, true);_x000D_
    http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');_x000D_
    http.onreadystatechange = function() {_x000D_
    console.log("Done " + i + "<<<<>>>>>" + http.readyState);_x000D_
          if(http.readyState == 4){_x000D_
              console.log('SUCCESS :',i);_x000D_
              resolve();_x000D_
          }_x000D_
         }_x000D_
    http.send(params);       _x000D_
    });_x000D_
 }_x000D_
 _x000D_
(async () => {_x000D_
    for (let i = 1; i < 5; i++) {_x000D_
        await XHRpost(i);_x000D_
       }_x000D_
})();
_x000D_
_x000D_
_x000D_

Laravel Eloquent ORM Transactions

If you want to avoid closures, and happy to use facades, the following keeps things nice and clean:

try {
    \DB::beginTransaction();

    $user = \Auth::user();
    $user->fill($request->all());
    $user->push();

    \DB::commit();

} catch (Throwable $e) {
    \DB::rollback();
}

If any statements fail, commit will never hit, and the transaction won't process.

Detect if HTML5 Video element is playing

It seems to me like you could just check for !stream.paused.

How to keep a git branch in sync with master

Whenever you want to get the changes from master into your work branch, do a git rebase <remote>/master. If there are any conflicts. resolve them.

When your work branch is ready, rebase again and then do git push <remote> HEAD:master. This will update the master branch on remote (central repo).

Does an HTTP Status code of 0 have any meaning?

Since iOS 9, you need to add "App Transport Security Settings" to your info.plist file and allow "Allow Arbitrary Loads" before making request to non-secure HTTP web service. I had this issue in one of my app.

JavaScript moving element in the DOM

jQuery.fn.swap = function(b){ 
    b = jQuery(b)[0]; 
    var a = this[0]; 
    var t = a.parentNode.insertBefore(document.createTextNode(''), a); 
    b.parentNode.insertBefore(a, b); 
    t.parentNode.insertBefore(b, t); 
    t.parentNode.removeChild(t); 
    return this; 
};

and use it like this:

$('#div1').swap('#div2');

if you don't want to use jQuery you could easily adapt the function.

Retrieving Android API version programmatically

Like this:

String versionRelease = BuildConfig.VERSION_NAME;

versionRelease :- 2.1.17

Please make sure your import package is correct ( import package your_application_package_name, otherwise it will not work properly).

Multiple ping script in Python

Thank you so much for this. I have modified it to work with Windows. I have also put a low timeout so, the IP's that have no return will not sit and wait for 5 seconds each. This is from hochl source code.

import subprocess
import os
with open(os.devnull, "wb") as limbo:
        for n in xrange(200, 240):
                ip="10.2.7.{0}".format(n)
                result=subprocess.Popen(["ping", "-n", "1", "-w", "200", ip],
                        stdout=limbo, stderr=limbo).wait()
                if result:
                        print ip, "inactive"
                else:
                        print ip, "active"

Just change the ip= for your scheme and the xrange for the hosts.

jQuery: Check if special characters exists in string

var specialChars = "<>@!#$%^&*()_+[]{}?:;|'\"\\,./~`-="
var check = function(string){
    for(i = 0; i < specialChars.length;i++){
        if(string.indexOf(specialChars[i]) > -1){
            return true
        }
    }
    return false;
}

if(check($('#Search').val()) == false){
    // Code that needs to execute when none of the above is in the string
}else{
    alert('Your search string contains illegal characters.');
}

Android M - check runtime permission - how to determine if the user checked "Never ask again"?

Instead you will receive callback on onRequestPermissionsResult() as PERMISSION_DENIED when you request permission again while falling in false condition of shouldShowRequestPermissionRationale()

From Android doc:

When the system asks the user to grant a permission, the user has the option of telling the system not to ask for that permission again. In that case, any time an app uses requestPermissions() to ask for that permission again, the system immediately denies the request. The system calls your onRequestPermissionsResult() callback method and passes PERMISSION_DENIED, the same way it would if the user had explicitly rejected your request again. This means that when you call requestPermissions(), you cannot assume that any direct interaction with the user has taken place.

What is the difference between min SDK version/target SDK version vs. compile SDK version?

The min sdk version is the earliest release of the Android SDK that your application can run on. Usually this is because of a problem with the earlier APIs, lacking functionality, or some other behavioural issue.

The target sdk version is the version your application was targeted to run on. Ideally, this is because of some sort of optimal run conditions. If you were to "make your app for version 19", this is where that would be specified. It may run on earlier or later releases, but this is what you were aiming for. This is mostly to indicate how current your application is for use in the marketplace, etc.

The compile sdk version is the version of android your IDE (or other means of compiling I suppose) uses to make your app when you publish a .apk file. This is useful for testing your application as it is a common need to compile your app as you develop it. As this will be the version to compile to an APK, it will naturally be the version of your release. Likewise, it is advisable to have this match your target sdk version.

How do I show a message in the foreach loop?

You are looking to see if a single value is in an array. Use in_array.

However note that case is important, as are any leading or trailing spaces. Use var_dump to find out the length of the strings too, and see if they fit.

How do I add a new sourceset to Gradle?

I'm new to Gradle, using Gradle 6.0.1 JUnit 4.12. Here's what I came up with to solve this problem.

apply plugin: 'java'
repositories { jcenter() }

dependencies {
    testImplementation 'junit:junit:4.12'
}

sourceSets {
  main {
    java {
       srcDirs = ['src']
    }
  }
  test {
    java {
      srcDirs = ['tests']
    }
  }
}

Notice that the main source and test source is referenced separately, one under main and one under test.

The testImplementation item under dependencies is only used for compiling the source in test. If your main code actually had a dependency on JUnit, then you would also specify implementation under dependencies.

I had to specify the repositories section to get this to work, I doubt that is the best/only way.

Understanding [TCP ACKed unseen segment] [TCP Previous segment not captured]

Acked Unseen sample

Hi guys! Just some observations from what I just found in my capture:

On many occasions, the packet capture reports “ACKed segment that wasn't captured” on the client side, which alerts of the condition that the client PC has sent a data packet, the server acknowledges receipt of that packet, but the packet capture made on the client does not include the packet sent by the client

Initially, I thought it indicates a failure of the PC to record into the capture a packet it sends because “e.g., machine which is running Wireshark is slow” (https://osqa-ask.wireshark.org/questions/25593/tcp-previous-segment-not-captured-is-that-a-connectivity-issue)
However, then I noticed every time I see this “ACKed segment that wasn't captured” alert I can see a record of an “invalid” packet sent by the client PC

  • In the capture example above, frame 67795 sends an ACK for 10384

  • Even though wireshark reports Bogus IP length (0), frame 67795 is reported to have length 13194

  • Frame 67800 sends an ACK for 23524
  • 10384+13194 = 23578
  • 23578 – 23524 = 54
  • 54 is in fact length of the Ethernet / IP / TCP headers (14 for Ethernt, 20 for IP, 20 for TCP)
  • So in fact, the frame 67796 does represent a large TCP packets (13194 bytes) which operating system tried to put on the wore
    • NIC driver will fragment it into smaller 1500 bytes pieces in order to transmit over the network
    • But Wireshark running on my PC fails to understand it is a valid packet and parse it. I believe Wireshark running on 2012 Windows server reads these captures correctly
  • So after all, these “Bogus IP length” and “ACKed segment that wasn't captured” alerts were in fact false positives in my case

How to connect with Java into Active Directory

You can use DDC (Domain Directory Controller). It is a new, easy to use, Java SDK. You don't even need to know LDAP to use it. It exposes an object-oriented API instead.

You can find it here.

How to recover stashed uncommitted changes

To make this simple, you have two options to reapply your stash:

  1. git stash pop - Restore back to the saved state, but it deletes the stash from the temporary storage.
  2. git stash apply - Restore back to the saved state and leaves the stash list for possible later reuse.

You can read in more detail about git stashes in this article.

Import txt file and having each line as a list

Create a list of lists:

with open("/path/to/file") as file:
    lines = []
    for line in file:
        # The rstrip method gets rid of the "\n" at the end of each line
        lines.append(line.rstrip().split(","))

Windows equivalent of 'touch' (i.e. the node.js way to create an index.html)

Windows does not natively include a touch command.

You can use any of the available public versions or you can use your own version. Save this code as touch.cmd and place it somewhere in your path

@echo off
    setlocal enableextensions disabledelayedexpansion

    (for %%a in (%*) do if exist "%%~a" (
        pushd "%%~dpa" && ( copy /b "%%~nxa"+,, & popd )
    ) else (
        type nul > "%%~fa"
    )) >nul 2>&1

It will iterate over it argument list, and for each element if it exists, update the file timestamp, else, create it.

How to check if a string contains an element from a list in Python

extensionsToCheck = ('.pdf', '.doc', '.xls')

'test.doc'.endswith(extensionsToCheck)   # returns True

'test.jpg'.endswith(extensionsToCheck)   # returns False

How to make a checkbox checked with jQuery?

You don't need to control your checkBoxes with jQuery. You can do it with some simple JavaScript.

This JS snippet should work fine:

document.TheFormHere.test.Value = true;

How to list all the roles existing in Oracle database?

all_roles.sql

SELECT SUBSTR(TRIM(rtp.role),1,12)          AS ROLE
     , SUBSTR(rp.grantee,1,16)              AS GRANTEE
     , SUBSTR(TRIM(rtp.privilege),1,12)     AS PRIVILEGE
     , SUBSTR(TRIM(rtp.owner),1,12)         AS OWNER
     , SUBSTR(TRIM(rtp.table_name),1,28)    AS TABLE_NAME
     , SUBSTR(TRIM(rtp.column_name),1,20)   AS COLUMN_NAME
     , SUBSTR(rtp.common,1,4)               AS COMMON
     , SUBSTR(rtp.grantable,1,4)            AS GRANTABLE
     , SUBSTR(rp.default_role,1,16)         AS DEFAULT_ROLE
     , SUBSTR(rp.admin_option,1,4)          AS ADMIN_OPTION
  FROM role_tab_privs rtp
  LEFT JOIN dba_role_privs rp
    ON (rtp.role = rp.granted_role)
 WHERE ('&1' IS NULL OR UPPER(rtp.role) LIKE UPPER('%&1%'))
   AND ('&2' IS NULL OR UPPER(rp.grantee) LIKE UPPER('%&2%'))
   AND ('&3' IS NULL OR UPPER(rtp.table_name) LIKE UPPER('%&3%'))
   AND ('&4' IS NULL OR UPPER(rtp.owner) LIKE UPPER('%&4%'))
 ORDER BY 1
        , 2
        , 3
        , 4
;

Usage

SQLPLUS> @all_roles '' '' '' '' '' ''
SQLPLUS> @all_roles 'somerol' '' '' '' '' ''
SQLPLUS> @all_roles 'roler' 'username' '' '' '' ''
SQLPLUS> @all_roles '' '' 'part-of-database-package-name' '' '' ''
etc.

Find substring in the string in TWIG

Just searched for the docs, and found this:

Containment Operator: The in operator performs containment test. It returns true if the left operand is contained in the right:

{# returns true #}

{{ 1 in [1, 2, 3] }}

{{ 'cd' in 'abcde' }}

NSOperation vs Grand Central Dispatch

Both NSQueueOperations and GCD allow executing heavy computation task in the background on separate threads by freeing the UI Application Main Tread.

Well, based previous post we see NSOperations has addDependency so that you can queue your operation one after another sequentially.

But I also read about GCD serial Queues you can create run your operations in the queue using dispatch_queue_create. This will allow running a set of operations one after another in a sequential manner.

NSQueueOperation Advantages over GCD:

  1. It allows to add dependency and allows you to remove dependency so for one transaction you can run sequential using dependency and for other transaction run concurrently while GCD doesn't allow to run this way.

  2. It is easy to cancel an operation if it is in the queue it can be stopped if it is running.

  3. You can define the maximum number of concurrent operations.

  4. You can suspend operation which they are in Queue

  5. You can find how many pending operations are there in queue.

Run AVD Emulator without Android Studio

(Only for Windows) Why to torture yourself? Make a Simple BAT file ! :

  1. Open Notepad
  2. Create the command as shown below
  3. Save as *.bat
  4. (Optional) Create a shortcut to that *.bat, rename shortcut and change icon

Here is the command:

cd /d yourSdkPath\emulator && emulator -avd yourAVDName

Example:

cd /d D:\Android_SDK\emulator && emulator -avd Nexus_5_API_28

android activity has leaked window com.android.internal.policy.impl.phonewindow$decorview Issue

 @Override
    protected void onPostExecute(final Boolean success) {
        mProgressDialog.dismiss();
        mProgressDialog = null;

setting the value null works for me

Nginx reverse proxy causing 504 Gateway Timeout

NGINX itself may not be the root cause.

IF "minimum ports per VM instance" set on the NAT Gateway -- which stand between your NGINX instance & the proxy_pass destination -- is too small for the number of concurrent requests, it has to be increased.

Solution: Increase the available number of ports per VM on NAT Gateway.

Context In my case, on Google Cloud, a reverse proxy NGINX was placed inside a subnet, with a NAT Gateway. The NGINX instance was redirecting requests to a domain associated with our backend API (upstream) through the NAT Gateway.

This documentation from GCP will help you understand how NAT is relevant to the NGINX 504 timeout.

How to trigger ngClick programmatically

Just in case everybody see's it, I added additional duplicating answer with an important line which will not break event propagation

$scope.clickOnUpload = function ($event) {    
    $event.stopPropagation(); // <-- this is important

    $timeout(function() {
        angular.element(domElement).trigger('click');
    }, 0);
};

How to check if curl is enabled or disabled

Just return your existing check from a function.

function _isCurl(){
    return function_exists('curl_version');
}

Fatal error in launcher: Unable to create process using ""C:\Program Files (x86)\Python33\python.exe" "C:\Program Files (x86)\Python33\pip.exe""

I was trying to install some site-packages like numpy, xgboost and so on, but this error showed up every time:

Fatal error in launcher: Unable to create process using

I've tried many ways to solve this problem and found this one, that successfully helped me:

python -m pip freeze

Hope it'll help someone too.

P.S. I found this solution here: https://stackoverflow.com/a/39733705/10310794

Convert UTC Epoch to local date

If you prefer to resolve timestamps and dates conversions from and to UTC and local time without libraries like moment.js, take a look at the option below.

For applications that use UTC timestamps, you may need to show the date in the browser considering the local timezone and daylight savings when applicable. Editing a date that is in a different daylight savings time even though in the same timezone can be tricky.

The Number and Date extensions below allow you to show and get dates in the timezone of the timestamps. For example, lets say you are in Vancouver, if you are editing a date in July or in December, it can mean you are editing a date in PST or PDT.

I recommend you to check the Code Snippet down below to test this solution.

Conversions from milliseconds

Number.prototype.toLocalDate = function () {
    var value = new Date(this);

    value.setHours(value.getHours() + (value.getTimezoneOffset() / 60));

    return value;
};

Number.prototype.toUTCDate = function () {
    var value = new Date(this);

    value.setHours(value.getHours() - (value.getTimezoneOffset() / 60));

    return value;
};

Conversions from dates

Date.prototype.getUTCTime = function () {
    return this.getTime() - (this.getTimezoneOffset() * 60000);
};

Usage

// Adds the timezone and daylight savings if applicable
(1499670000000).toLocalDate();

// Eliminates the timezone and daylight savings if applicable
new Date(2017, 6, 10).getUTCTime();

See it for yourself

_x000D_
_x000D_
// Extending Number_x000D_
_x000D_
Number.prototype.toLocalDate = function () {_x000D_
    var value = new Date(this);_x000D_
_x000D_
    value.setHours(value.getHours() + (value.getTimezoneOffset() / 60));_x000D_
_x000D_
    return value;_x000D_
};_x000D_
_x000D_
Number.prototype.toUTCDate = function () {_x000D_
    var value = new Date(this);_x000D_
_x000D_
    value.setHours(value.getHours() - (value.getTimezoneOffset() / 60));_x000D_
_x000D_
    return value;_x000D_
};_x000D_
_x000D_
// Extending Date_x000D_
_x000D_
Date.prototype.getUTCTime = function () {_x000D_
    return this.getTime() - (this.getTimezoneOffset() * 60000);_x000D_
};_x000D_
_x000D_
// Getting the demo to work_x000D_
document.getElementById('m-to-local-button').addEventListener('click', function () {_x000D_
  var displayElement = document.getElementById('m-to-local-display'),_x000D_
      value = document.getElementById('m-to-local').value,_x000D_
      milliseconds = parseInt(value);_x000D_
  _x000D_
  if (typeof milliseconds === 'number')_x000D_
    displayElement.innerText = (milliseconds).toLocalDate().toISOString();_x000D_
  else_x000D_
    displayElement.innerText = 'Set a value';_x000D_
}, false);_x000D_
_x000D_
document.getElementById('m-to-utc-button').addEventListener('click', function () {_x000D_
  var displayElement = document.getElementById('m-to-utc-display'),_x000D_
      value = document.getElementById('m-to-utc').value,_x000D_
      milliseconds = parseInt(value);_x000D_
  _x000D_
  if (typeof milliseconds === 'number')_x000D_
    displayElement.innerText = (milliseconds).toUTCDate().toISOString();_x000D_
  else_x000D_
    displayElement.innerText = 'Set a value';_x000D_
}, false);_x000D_
_x000D_
document.getElementById('date-to-utc-button').addEventListener('click', function () {_x000D_
  var displayElement = document.getElementById('date-to-utc-display'),_x000D_
      yearValue = document.getElementById('date-to-utc-year').value || '1970',_x000D_
      monthValue = document.getElementById('date-to-utc-month').value || '0',_x000D_
      dayValue = document.getElementById('date-to-utc-day').value || '1',_x000D_
      hourValue = document.getElementById('date-to-utc-hour').value || '0',_x000D_
      minuteValue = document.getElementById('date-to-utc-minute').value || '0',_x000D_
      secondValue = document.getElementById('date-to-utc-second').value || '0',_x000D_
      year = parseInt(yearValue),_x000D_
      month = parseInt(monthValue),_x000D_
      day = parseInt(dayValue),_x000D_
      hour = parseInt(hourValue),_x000D_
      minute = parseInt(minuteValue),_x000D_
      second = parseInt(secondValue);_x000D_
  _x000D_
  displayElement.innerText = new Date(year, month, day, hour, minute, second).getUTCTime();_x000D_
}, false);
_x000D_
<link href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.2.11/semantic.css" rel="stylesheet"/>_x000D_
_x000D_
<div class="ui container">_x000D_
  <p></p>_x000D_
  _x000D_
  <h3>Milliseconds to local date</h3>_x000D_
  <input id="m-to-local" placeholder="Timestamp" value="0" /> <button id="m-to-local-button">Convert</button>_x000D_
  <em id="m-to-local-display">Set a value</em>_x000D_
_x000D_
  <h3>Milliseconds to UTC date</h3>_x000D_
  <input id="m-to-utc" placeholder="Timestamp" value="0" /> <button id="m-to-utc-button">Convert</button>_x000D_
  <em id="m-to-utc-display">Set a value</em>_x000D_
  _x000D_
  <h3>Date to milliseconds in UTC</h3>_x000D_
  <input id="date-to-utc-year" placeholder="Year" style="width: 4em;" />_x000D_
  <input id="date-to-utc-month" placeholder="Month" style="width: 4em;" />_x000D_
  <input id="date-to-utc-day" placeholder="Day" style="width: 4em;" />_x000D_
  <input id="date-to-utc-hour" placeholder="Hour" style="width: 4em;" />_x000D_
  <input id="date-to-utc-minute" placeholder="Minute" style="width: 4em;" />_x000D_
  <input id="date-to-utc-second" placeholder="Second" style="width: 4em;" />_x000D_
  <button id="date-to-utc-button">Convert</button>_x000D_
  <em id="date-to-utc-display">Set the values</em>_x000D_
  _x000D_
</div>
_x000D_
_x000D_
_x000D_

Retrieve CPU usage and memory usage of a single process on Linux?

For those who struggled for a while wonderring why the selected answer does not work:

ps -p <pid> -o %cpu,%mem

No SPACE ibetween %cpu, and %mem.

SELECT INTO a table variable in T-SQL

One reason to use SELECT INTO is that it allows you to use IDENTITY:

SELECT IDENTITY(INT,1,1) AS Id, name
INTO #MyTable 
FROM (SELECT name FROM AnotherTable) AS t

This would not work with a table variable, which is too bad...

RelativeLayout center vertical

This is working for me.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rell_main_bg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#096d74" > 

<ImageView 
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:src="@drawable/img_logo_large"
    android:contentDescription="@null" />

</RelativeLayout>

What is a simple C or C++ TCP server and client example?

Although many year ago, clsocket seems a really nice small cross-platform (Windows, Linux, Mac OSX): https://github.com/DFHack/clsocket

Execute jar file with multiple classpath libraries from command prompt

Regardless of the OS the below command should work:

java -cp "MyJar.jar;lib/*" com.mainClass

Always use quotes and please take attention that lib/*.jar will not work.

Display / print all rows of a tibble (tbl_df)

You can use as.data.frame or print.data.frame.

If you want this to be the default, you can change the value of the dplyr.print_max option.

options(dplyr.print_max = 1e9)

How to put scroll bar only for modal-body?

Optional: If you don't want the modal to exceed the window height and use a scrollbar in the .modal-body, you can use this responsive solution. See a working demo here: http://codepen.io/dimbslmh/full/mKfCc/

function setModalMaxHeight(element) {
  this.$element     = $(element);
  this.$content     = this.$element.find('.modal-content');
  var borderWidth   = this.$content.outerHeight() - this.$content.innerHeight();
  var dialogMargin  = $(window).width() > 767 ? 60 : 20;
  var contentHeight = $(window).height() - (dialogMargin + borderWidth);
  var headerHeight  = this.$element.find('.modal-header').outerHeight() || 0;
  var footerHeight  = this.$element.find('.modal-footer').outerHeight() || 0;
  var maxHeight     = contentHeight - (headerHeight + footerHeight);

  this.$content.css({
      'overflow': 'hidden'
  });

  this.$element
    .find('.modal-body').css({
      'max-height': maxHeight,
      'overflow-y': 'auto'
  });
}

$('.modal').on('show.bs.modal', function() {
  $(this).show();
  setModalMaxHeight(this);
});

$(window).resize(function() {
  if ($('.modal.in').length != 0) {
    setModalMaxHeight($('.modal.in'));
  }
});

Save string to the NSUserDefaults?

more precisely

-(void)saveToUserDefaults:(NSString*)myString
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) {
        [standardUserDefaults setObject:myString forKey:@"timestamps"];
        [standardUserDefaults synchronize];
    }
}

How to install toolbox for MATLAB

first, you need to find the toolbox that you need. There are many people developing 3rd party toolboxes for Matlab, so there isn't just one single place where you can find "the image processing toolbox". That said, a good place to start looking is the Matlab Central which is a Mathworks-run site for exchanging all kinds of Matlab-related material.

Once you find a toolbox you want, it will be in some compressed format, and its developers might have a "readme" file that details on how to install it. If it isn't the case, a generic way to attempt installation is to place the toolbox in any directory on your drive, and then add it to Matlab path, e.g., going to File -> Set Path... -> Add Folder or Add with Subfolders (I'm writing for memory but this is definitely close).

Otherwise, you can extract all .m files in your working directory, if you don't want to use downloaded toolbox in more than one project.

How to redirect to Index from another controller?

Tag helpers:

<a asp-controller="OtherController" asp-action="Index" class="btn btn-primary"> Back to Other Controller View </a>

In the controller.cs have a method:

public async Task<IActionResult> Index()
{
    ViewBag.Title = "Titles";
    return View(await Your_Model or Service method);
}

What is the difference between varchar and varchar2 in Oracle?

After some experimentation (see below), I can confirm that as of September 2017, nothing has changed with regards to the functionality described in the accepted answer:-

  1. Rextester demo for Oracle 11g: Empty strings are inserted as NULLs for both VARCHAR and VARCHAR2.
  2. LiveSQL demo for Oracle 12c: Same results.

The historical reason for these two keywords is explained well in an answer to a different question.

Regular expression which matches a pattern, or is an empty string

An alternative would be to place your regexp in non-capturing parentheses. Then make that expression optional using the ? qualifier, which will look for 0 (i.e. empty string) or 1 instances of the non-captured group.

For example:

/(?: some regexp )?/

In your case the regular expression would look something like this:

/^(?:[\w\.\-]+@([\w\-]+\.)+[a-zA-Z]+)?$/

No | "or" operator necessary!

Here is the Mozilla documentation for JavaScript Regular Expression syntax.

Android Closing Activity Programmatically

You Can use just finish(); everywhere after Activity Start for clear that Activity from Stack.

setting y-axis limit in matplotlib

This should work. Your code works for me, like for Tamás and Manoj Govindan. It looks like you could try to update Matplotlib. If you can't update Matplotlib (for instance if you have insufficient administrative rights), maybe using a different backend with matplotlib.use() could help.

Difference between @Before, @BeforeClass, @BeforeEach and @BeforeAll

Before and BeforeClass in JUnit

The function @Before annotation will be executed before each of test function in the class having @Test annotation but the function with @BeforeClass will be execute only one time before all the test functions in the class.

Similarly function with @After annotation will be executed after each of test function in the class having @Test annotation but the function with @AfterClass will be execute only one time after all the test functions in the class.

SampleClass

public class SampleClass {
    public String initializeData(){
        return "Initialize";
    }

    public String processDate(){
        return "Process";
    }
 }

SampleTest

public class SampleTest {

    private SampleClass sampleClass;

    @BeforeClass
    public static void beforeClassFunction(){
        System.out.println("Before Class");
    }

    @Before
    public void beforeFunction(){
        sampleClass=new SampleClass();
        System.out.println("Before Function");
    }

    @After
    public void afterFunction(){
        System.out.println("After Function");
    }

    @AfterClass
    public static void afterClassFunction(){
        System.out.println("After Class");
    }

    @Test
    public void initializeTest(){
        Assert.assertEquals("Initailization check", "Initialize", sampleClass.initializeData() );
    }

    @Test
    public void processTest(){
        Assert.assertEquals("Process check", "Process", sampleClass.processDate() );
    }

}

Output

Before Class
Before Function
After Function
Before Function
After Function
After Class

In Junit 5

@Before = @BeforeEach
@BeforeClass = @BeforeAll
@After = @AfterEach
@AfterClass = @AfterAll

How to write some data to excel file(.xlsx)

Hope here is the exact what we are looking for.

private void button2_Click(object sender, RoutedEventArgs e)
{
    UpdateExcel("Sheet3", 4, 7, "Namachi@gmail");
}

private void UpdateExcel(string sheetName, int row, int col, string data)
{
    Microsoft.Office.Interop.Excel.Application oXL = null;
    Microsoft.Office.Interop.Excel._Workbook oWB = null;
    Microsoft.Office.Interop.Excel._Worksheet oSheet = null;

    try
    {
        oXL = new Microsoft.Office.Interop.Excel.Application();
        oWB = oXL.Workbooks.Open("d:\\MyExcel.xlsx");
        oSheet = String.IsNullOrEmpty(sheetName) ? (Microsoft.Office.Interop.Excel._Worksheet)oWB.ActiveSheet : (Microsoft.Office.Interop.Excel._Worksheet)oWB.Worksheets[sheetName];

        oSheet.Cells[row, col] = data;

        oWB.Save();

        MessageBox.Show("Done!");
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
    finally
    {
        if (oWB != null)
        oWB.Close();
    }
}

What's the difference between MyISAM and InnoDB?

The main differences between InnoDB and MyISAM ("with respect to designing a table or database" you asked about) are support for "referential integrity" and "transactions".

If you need the database to enforce foreign key constraints, or you need the database to support transactions (i.e. changes made by two or more DML operations handled as single unit of work, with all of the changes either applied, or all the changes reverted) then you would choose the InnoDB engine, since these features are absent from the MyISAM engine.

Those are the two biggest differences. Another big difference is concurrency. With MyISAM, a DML statement will obtain an exclusive lock on the table, and while that lock is held, no other session can perform a SELECT or a DML operation on the table.

Those two specific engines you asked about (InnoDB and MyISAM) have different design goals. MySQL also has other storage engines, with their own design goals.

So, in choosing between InnoDB and MyISAM, the first step is in determining if you need the features provided by InnoDB. If not, then MyISAM is up for consideration.

A more detailed discussion of differences is rather impractical (in this forum) absent a more detailed discussion of the problem space... how the application will use the database, how many tables, size of the tables, the transaction load, volumes of select, insert, updates, concurrency requirements, replication features, etc.


The logical design of the database should be centered around data analysis and user requirements; the choice to use a relational database would come later, and even later would the choice of MySQL as a relational database management system, and then the selection of a storage engine for each table.

What are the benefits of using C# vs F# or F# vs C#?

General benefits of functional programming over imperative languages:

You can formulate many problems much easier, closer to their definition and more concise in a functional programming language like F# and your code is less error-prone (immutability, more powerful type system, intuitive recurive algorithms). You can code what you mean instead of what the computer wants you to say ;-) You will find many discussions like this when you google it or even search for it at SO.

Special F#-advantages:

  • Asynchronous programming is extremely easy and intuitive with async {}-expressions - Even with ParallelFX, the corresponding C#-code is much bigger

  • Very easy integration of compiler compilers and domain-specific languages

  • Extending the language as you need it: LOP

  • Units of measure

  • More flexible syntax

  • Often shorter and more elegant solutions

Take a look at this document

The advantages of C# are that it's often more accurate to "imperative"-applications (User-interface, imperative algorithms) than a functional programming language, that the .NET-Framework it uses is designed imperatively and that it's more widespread.

Furthermore you can have F# and C# together in one solution, so you can combine the benefits of both languages and use them where they're needed.

Using ping in c#

Using ping in C# is achieved by using the method Ping.Send(System.Net.IPAddress), which runs a ping request to the provided (valid) IP address or URL and gets a response which is called an Internet Control Message Protocol (ICMP) Packet. The packet contains a header of 20 bytes which contains the response data from the server which received the ping request. The .Net framework System.Net.NetworkInformation namespace contains a class called PingReply that has properties designed to translate the ICMP response and deliver useful information about the pinged server such as:

  • IPStatus: Gets the address of the host that sends the Internet Control Message Protocol (ICMP) echo reply.
  • IPAddress: Gets the number of milliseconds taken to send an Internet Control Message Protocol (ICMP) echo request and receive the corresponding ICMP echo reply message.
  • RoundtripTime (System.Int64): Gets the options used to transmit the reply to an Internet Control Message Protocol (ICMP) echo request.
  • PingOptions (System.Byte[]): Gets the buffer of data received in an Internet Control Message Protocol (ICMP) echo reply message.

The following is a simple example using WinForms to demonstrate how ping works in c#. By providing a valid IP address in textBox1 and clicking button1, we are creating an instance of the Ping class, a local variable PingReply, and a string to store the IP or URL address. We assign PingReply to the ping Send method, then we inspect if the request was successful by comparing the status of the reply to the property IPAddress.Success status. Finally, we extract from PingReply the information we need to display for the user, which is described above.

    using System;
    using System.Net.NetworkInformation;
    using System.Windows.Forms;

    namespace PingTest1
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }

            private void button1_Click(object sender, EventArgs e)
            {
                Ping p = new Ping();
                PingReply r;
                string s;
                s = textBox1.Text;
                r = p.Send(s);

                if (r.Status == IPStatus.Success)
                {
                    lblResult.Text = "Ping to " + s.ToString() + "[" + r.Address.ToString() + "]" + " Successful"
                       + " Response delay = " + r.RoundtripTime.ToString() + " ms" + "\n";
                }
            }

            private void textBox1_Validated(object sender, EventArgs e)
            {
                if (string.IsNullOrWhiteSpace(textBox1.Text) || textBox1.Text == "")
                {
                    MessageBox.Show("Please use valid IP or web address!!");
                }
            }
        }
    }

How do I tell CMake to link in a static library in the source directory?

If you don't want to include the full path, you can do

add_executable(main main.cpp)
target_link_libraries(main bingitup)

bingitup is the same name you'd give a target if you create the static library in a CMake project:

add_library(bingitup STATIC bingitup.cpp)

CMake automatically adds the lib to the front and the .a at the end on Linux, and .lib at the end on Windows.

If the library is external, you might want to add the path to the library using

link_directories(/path/to/libraries/)

How to randomly select an item from a list?

foo = ['a', 'b', 'c', 'd', 'e']
number_of_samples = 1

In python 2:

random_items = random.sample(population=foo, k=number_of_samples)

In python 3:

random_items = random.choices(population=foo, k=number_of_samples)

How do I get the total number of unique pairs of a set in the database?

I was solving this algorithm and get stuck with the pairs part.

This explanation help me a lot https://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/

So to calculate the sum of series of numbers:

n(n+1)/2

But you need to calculate this

1 + 2 + ... + (n-1)

So in order to get this you can use

n(n+1)/2 - n

that is equal to

n(n-1)/2

How to get the date from jQuery UI datepicker

Try this, works like charm, gives the date you have selected. onsubmit form try to get this value:-

var date = $("#scheduleDate").datepicker({ dateFormat: 'dd,MM,yyyy' }).val();

Reference here

How can I add an item to a IEnumerable<T> collection?

Have you considered using ICollection<T> or IList<T> interfaces instead, they exist for the very reason that you want to have an Add method on an IEnumerable<T>.

IEnumerable<T> is used to 'mark' a type as being...well, enumerable or just a sequence of items without necessarily making any guarantees of whether the real underlying object supports adding/removing of items. Also remember that these interfaces implement IEnumerable<T> so you get all the extensions methods that you get with IEnumerable<T> as well.

Looking for a 'cmake clean' command to clear up CMake output

Simply issuing rm CMakeCache.txt works for me too.

iPhone 6 Plus resolution confusion: Xcode or Apple's website? for development

The iPhone 6+ renders internally using @3x assets at a virtual resolution of 2208×1242 (with 736x414 points), then samples that down for display. The same as using a scaled resolution on a Retina MacBook — it lets them hit an integral multiple for pixel assets while still having e.g. 12 pt text look the same size on the screen.

So, yes, the launch screens need to be that size.

The maths:

The 6, the 5s, the 5, the 4s and the 4 are all 326 pixels per inch, and use @2x assets to stick to the approximately 160 points per inch of all previous devices.

The 6+ is 401 pixels per inch. So it'd hypothetically need roughly @2.46x assets. Instead Apple uses @3x assets and scales the complete output down to about 84% of its natural size.

In practice Apple has decided to go with more like 87%, turning the 1080 into 1242. No doubt that was to find something as close as possible to 84% that still produced integral sizes in both directions — 1242/1080 = 2208/1920 exactly, whereas if you'd turned the 1080 into, say, 1286, you'd somehow need to render 2286.22 pixels vertically to scale well.

Iterate through dictionary values?

You could search for the corresponding key or you could "invert" the dictionary, but considering how you use it, it would be best if you just iterated over key/value pairs in the first place, which you can do with items(). Then you have both directly in variables and don't need a lookup at all:

for key, value in PIX0.items():
    NUM = input("What is the Resolution of %s?"  % key)
    if NUM == value:

You can of course use that both ways then.

Or if you don't actually need the dictionary for something else, you could ditch the dictionary and have an ordinary list of pairs.

Batch File: ( was unexpected at this time

You are getting that error because when the param1 if statements are evaluated, param is always null due to being scoped variables without delayed expansion.

When parentheses are used, all the commands and variables within those parentheses are expanded. And at that time, param1 has no value making the if statements invalid. When using delayed expansion, the variables are only expanded when the command is actually called.

Also I recommend using if not defined command to determine if a variable is set.

@echo off
setlocal EnableExtensions EnableDelayedExpansion
cls
title ~USB Wizard~
echo What do you want to do?
echo 1.Enable/Disable USB Storage Devices.
echo 2.Enable/Disable Writing Data onto USB Storage.
echo 3.~Yet to come~.

set "a=%globalparam1%"
goto :aCheck
:aPrompt
set /p "a=Enter Choice: "
:aCheck
if not defined a goto :aPrompt
echo %a%

IF "%a%"=="2" (
    title USB WRITE LOCK
    echo What do you want to do?
    echo 1.Apply USB Write Protection
    echo 2.Remove USB Write Protection

    ::param1
    set "param1=%globalparam2%"
    goto :param1Check
    :param1Prompt
    set /p "param1=Enter Choice: "
    :param1Check
    if not defined param1 goto :param1Prompt
    echo !param1!

    if "!param1!"=="1" (
        REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000001 
        echo USB Write is Locked!
    )
    if "!param1!"=="2" (
        REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000000
        echo USB Write is Unlocked! 
    )
)
pause
endlocal

Angular2 http.get() ,map(), subscribe() and observable pattern - basic understanding

Concepts

Observables in short tackles asynchronous processing and events. Comparing to promises this could be described as observables = promises + events.

What is great with observables is that they are lazy, they can be canceled and you can apply some operators in them (like map, ...). This allows to handle asynchronous things in a very flexible way.

A great sample describing the best the power of observables is the way to connect a filter input to a corresponding filtered list. When the user enters characters, the list is refreshed. Observables handle corresponding AJAX requests and cancel previous in-progress requests if another one is triggered by new value in the input. Here is the corresponding code:

this.textValue.valueChanges
    .debounceTime(500)
    .switchMap(data => this.httpService.getListValues(data))
    .subscribe(data => console.log('new list values', data));

(textValue is the control associated with the filter input).

Here is a wider description of such use case: How to watch for form changes in Angular 2?.

There are two great presentations at AngularConnect 2015 and EggHead:

Christoph Burgdorf also wrote some great blog posts on the subject:

In action

In fact regarding your code, you mixed two approaches ;-) Here are they:

  • Manage the observable by your own. In this case, you're responsible to call the subscribe method on the observable and assign the result into an attribute of the component. You can then use this attribute in the view for iterate over the collection:

    @Component({
      template: `
        <h1>My Friends</h1>
        <ul>
          <li *ngFor="#frnd of result">
            {{frnd.name}} is {{frnd.age}} years old.
          </li>
        </ul>
      `,
      directive:[CORE_DIRECTIVES]
    })
    export class FriendsList implement OnInit, OnDestroy {
      result:Array<Object>; 
    
      constructor(http: Http) {
      }
    
      ngOnInit() {
        this.friendsObservable = http.get('friends.json')
                      .map(response => response.json())
                      .subscribe(result => this.result = result);
       }
    
       ngOnDestroy() {
         this.friendsObservable.dispose();
       }
    }
    

    Returns from both get and map methods are the observable not the result (in the same way than with promises).

  • Let manage the observable by the Angular template. You can also leverage the async pipe to implicitly manage the observable. In this case, there is no need to explicitly call the subscribe method.

    @Component({
      template: `
        <h1>My Friends</h1>
        <ul>
          <li *ngFor="#frnd of (result | async)">
            {{frnd.name}} is {{frnd.age}} years old.
          </li>
        </ul>
      `,
      directive:[CORE_DIRECTIVES]
    })
    export class FriendsList implement OnInit {
      result:Array<Object>; 
    
      constructor(http: Http) {
      }
    
      ngOnInit() {
        this.result = http.get('friends.json')
                      .map(response => response.json());
       }
    }
    

You can notice that observables are lazy. So the corresponding HTTP request will be only called once a listener with attached on it using the subscribe method.

You can also notice that the map method is used to extract the JSON content from the response and use it then in the observable processing.

Hope this helps you, Thierry

How to install MySQLi on MacOS

I had the same issue, I went to EasyApache4 from the WHM clicked on customize button then PHP Extension tab.. I selected and installed the extension php72-php-mysqlnd and my was solved

How do I mount a host directory as a volume in docker compose

There are a few options

Short Syntax

Using the host : guest format you can do any of the following:

volumes:
  # Just specify a path and let the Engine create a volume
  - /var/lib/mysql

  # Specify an absolute path mapping
  - /opt/data:/var/lib/mysql

  # Path on the host, relative to the Compose file
  - ./cache:/tmp/cache

  # User-relative path
  - ~/configs:/etc/configs/:ro

  # Named volume
  - datavolume:/var/lib/mysql

Long Syntax

As of docker-compose v3.2 you can use long syntax which allows the configuration of additional fields that can be expressed in the short form such as mount type (volume, bind or tmpfs) and read_only.

version: "3.2"
services:
  web:
    image: nginx:alpine
    ports:
      - "80:80"
    volumes:
      - type: volume
        source: mydata
        target: /data
        volume:
          nocopy: true
      - type: bind
        source: ./static
        target: /opt/app/static

networks:
  webnet:

volumes:
  mydata:

Check out https://docs.docker.com/compose/compose-file/#long-syntax-3 for more info.

Sum a list of numbers in Python

Short and simple:

def ave(x,y):
  return (x + y) / 2.0

map(ave, a[:-1], a[1:])

And here's how it looks:

>>> a = range(10)
>>> map(ave, a[:-1], a[1:])
[0.5, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5]

Due to some stupidity in how Python handles a map over two lists, you do have to truncate the list, a[:-1]. It works more as you'd expect if you use itertools.imap:

>>> import itertools
>>> itertools.imap(ave, a, a[1:])
<itertools.imap object at 0x1005c3990>
>>> list(_)
[0.5, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5]

React - How to get parameter value from query string?

let data = new FormData();
data.append('file', values.file);

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

More simply in one line:

proxy=192.168.2.1:8080;curl -v example.com

eg. $proxy=192.168.2.1:8080;curl -v example.com

xxxxxxxxx-ASUS:~$ proxy=192.168.2.1:8080;curl -v https://google.com|head -c 15 % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

  • Trying 172.217.163.46:443...
  • TCP_NODELAY set
  • Connected to google.com (172.217.163.46) port 443 (#0)
  • ALPN, offering h2
  • ALPN, offering http/1.1
  • successfully set certificate verify locations:
  • CAfile: /etc/ssl/certs/ca-certificates.crt CApath: /etc/ssl/certs } [5 bytes data]
  • TLSv1.3 (OUT), TLS handshake, Client hello (1): } [512 bytes data]

Cannot import the keyfile 'blah.pfx' - error 'The keyfile may be password protected'

I got the same error. In my case, I tried all of the above, but I couldn't get the result.

I finally realized that in my case, the reason for the error was that the certificate password was not entered or entered incorrectly. The error disappeared when I entered the password dynamically correctly. successful

How to stop default link click behavior with jQuery

You can use e.preventDefault(); instead of e.stopPropagation();

How to check a not-defined variable in JavaScript

In JavaScript, null is an object. There's another value for things that don't exist, undefined. The DOM returns null for almost all cases where it fails to find some structure in the document, but in JavaScript itself undefined is the value used.

Second, no, there is not a direct equivalent. If you really want to check for specifically for null, do:

if (yourvar === null) // Does not execute if yourvar is `undefined`

If you want to check if a variable exists, that can only be done with try/catch, since typeof will treat an undeclared variable and a variable declared with the value of undefined as equivalent.

But, to check if a variable is declared and is not undefined:

if (yourvar !== undefined) // Any scope

Previously, it was necessary to use the typeof operator to check for undefined safely, because it was possible to reassign undefined just like a variable. The old way looked like this:

if (typeof yourvar !== 'undefined') // Any scope

The issue of undefined being re-assignable was fixed in ECMAScript 5, which was released in 2009. You can now safely use === and !== to test for undefined without using typeof as undefined has been read-only for some time.

If you want to know if a member exists independent but don't care what its value is:

if ('membername' in object) // With inheritance
if (object.hasOwnProperty('membername')) // Without inheritance

If you want to to know whether a variable is truthy:

if (yourvar)

Source

Find files in created between a date range

If you use GNU find, since version 4.3.3 you can do:

find -newerct "1 Aug 2013" ! -newerct "1 Sep 2013" -ls

It will accept any date string accepted by GNU date -d.

You can change the c in -newerct to any of a, B, c, or m for looking at atime/birth/ctime/mtime.

Another example - list files modified between 17:30 and 22:00 on Nov 6 2017:

find -newermt "2017-11-06 17:30:00" ! -newermt "2017-11-06 22:00:00" -ls

Full details from man find:

   -newerXY reference
          Compares the timestamp of the current file with reference.  The reference argument is normally the name of a file (and one of its timestamps  is  used
          for  the  comparison)  but  it may also be a string describing an absolute time.  X and Y are placeholders for other letters, and these letters select
          which time belonging to how reference is used for the comparison.

          a   The access time of the file reference
          B   The birth time of the file reference
          c   The inode status change time of reference
          m   The modification time of the file reference
          t   reference is interpreted directly as a time

          Some combinations are invalid; for example, it is invalid for X to be t.  Some combinations are not implemented on all systems; for example B  is  not
          supported on all systems.  If an invalid or unsupported combination of XY is specified, a fatal error results.  Time specifications are interpreted as
          for the argument to the -d option of GNU date.  If you try to use the birth time of a reference file, and the birth time cannot be determined, a fatal
          error  message  results.   If  you  specify a test which refers to the birth time of files being examined, this test will fail for any files where the
          birth time is unknown.

How do I use regex in a SQLite query?

A hacky way to solve it without regex is where ',' || x || ',' like '%,3,%'

jquery AJAX and json format

You aren't actually sending JSON. You are passing an object as the data, but you need to stringify the object and pass the string instead.

Your dataType: "json" only tells jQuery that you want it to parse the returned JSON, it does not mean that jQuery will automatically stringify your request data.

Change to:

$.ajax({
        type: "POST",
        url: hb_base_url + "consumer",
        contentType: "application/json",
        dataType: "json",
        data: JSON.stringify({
            first_name: $("#namec").val(),
            last_name: $("#surnamec").val(),
            email: $("#emailc").val(),
            mobile: $("#numberc").val(),
            password: $("#passwordc").val()
        }),
        success: function(response) {
            console.log(response);
        },
        error: function(response) {
            console.log(response);
        }
});

How to set Navigation Drawer to be opened from right to left

I did following modification to the Navigation Drawer Activity example in Android Studio. With support libraries 25.3.1.

MainActivity.java:

private DrawerLayout mDrawerLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

@Override
public void onBackPressed() {
    if (mDrawerLayout.isDrawerOpen(GravityCompat.END)) {
        mDrawerLayout.closeDrawer(GravityCompat.END);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int itemId = item.getItemId();
    switch (itemId) {
        case android.R.id.home:
            finish();
            return true;

        case R.id.action_right_drawer:
            if (mDrawerLayout.isDrawerOpen(GravityCompat.END)) {
                mDrawerLayout.closeDrawer(GravityCompat.END);
            } else {
                mDrawerLayout.openDrawer(GravityCompat.END);
            }
            return true;

        default:
            return super.onOptionsItemSelected(item);
    }
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.

    mDrawerLayout.closeDrawer(GravityCompat.END);
    return true;
}

main.xml (download ic_menu_white_24px from https://material.io/icons/):

<?xml version="1.0" encoding="utf-8"?>
    <menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item android:id="@+id/action_right_drawer"
        android:title="Drawer menu"
        android:icon="@drawable/ic_menu_white_24px"
        android:orderInCategory="100"
        app:showAsAction="always" />
</menu>

In activity_main.xml change

android:layout_gravity="start"

to

android:layout_gravity="end"

CSS hide scroll bar, but have element scrollable

if you use sass, you can try this

&::-webkit-scrollbar { 

}

Invalid date in safari

This is not the best solution, although I simply catch the error and send back current date. I personally feel like not solving Safari issues, if users want to use a sh*t non-standards compliant browser - they have to live with quirks.

function safeDate(dateString = "") {
  let date = new Date();
  try {
    if (Date.parse(dateString)) {
      date = new Date(Date.parse(dateString))
    }
  } catch (error) {
    // do nothing.
  }
  return date;
}

I'd suggest having your backend send ISO dates.

Add comma to numbers every three digits

You could try NumberFormatter.

$(this).format({format:"#,###.00", locale:"us"});

It also supports different locales, including of course US.

Here's a very simplified example of how to use it:

<html>
    <head>
        <script type="text/javascript" src="jquery.js"></script>
        <script type="text/javascript" src="jquery.numberformatter.js"></script>
        <script>
        $(document).ready(function() {
            $(".numbers").each(function() {
                $(this).format({format:"#,###", locale:"us"});
            });
        });
        </script>
    </head>
    <body>
        <div class="numbers">1000</div>
        <div class="numbers">2000000</div>
    </body>
</html>

Output:

1,000
2,000,000

Replace or delete certain characters from filenames of all files in a folder

I would recommend the rename command for this. Type ren /? at the command line for more help.

AttributeError: 'DataFrame' object has no attribute

To get all the counts for all the columns in a dataframe, it's just df.count()

How to check if a variable is a dictionary in Python?

The OP did not exclude the starting variable, so for completeness here is how to handle the generic case of processing a supposed dictionary that may include items as dictionaries.

Also following the pure Python(3.8) recommended way to test for dictionary in the above comments.

from collections.abc import Mapping

dict = {'abc': 'abc', 'def': {'ghi': 'ghi', 'jkl': 'jkl'}}

def parse_dict(in_dict): 
    if isinstance(in_dict, Mapping):
        for k_outer, v_outer in in_dict.items():
            if isinstance(v_outer, Mapping):
                for k_inner, v_inner in v_outer.items():
                    print(k_inner, v_inner)
            else:
                print(k_outer, v_outer)

parse_dict(dict)

Using Enum values as String literals

You can't. I think you have FOUR options here. All four offer a solution but with a slightly different approach...

Option One: use the built-in name() on an enum. This is perfectly fine if you don't need any special naming format.

    String name = Modes.mode1.name(); // Returns the name of this enum constant, exactly as declared in its enum declaration.

Option Two: add overriding properties to your enums if you want more control

public enum Modes {
    mode1 ("Fancy Mode 1"),
    mode2 ("Fancy Mode 2"),
    mode3 ("Fancy Mode 3");

    private final String name;       

    private Modes(String s) {
        name = s;
    }

    public boolean equalsName(String otherName) {
        // (otherName == null) check is not needed because name.equals(null) returns false 
        return name.equals(otherName);
    }

    public String toString() {
       return this.name;
    }
}

Option Three: use static finals instead of enums:

public final class Modes {

    public static final String MODE_1 = "Fancy Mode 1";
    public static final String MODE_2 = "Fancy Mode 2";
    public static final String MODE_3 = "Fancy Mode 3";

    private Modes() { }
}

Option Four: interfaces have every field public, static and final:

public interface Modes {

    String MODE_1 = "Fancy Mode 1";
    String MODE_2 = "Fancy Mode 2";
    String MODE_3 = "Fancy Mode 3";  
}

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

Add a link to an image in a css style sheet

You could do something like

<a href="http://home.com"><img src="images/logo.png" alt="" id="logo"></a>

in HTML

Clear History and Reload Page on Login/Logout Using Ionic Framework

Reload the page isn't the best approach.

you can handle state change events for reload data without reload the view itself.

read about ionicView life-cycle here:

http://blog.ionic.io/navigating-the-changes/

and handle the event beforeEnter for data reload.

$scope.$on('$ionicView.beforeEnter', function(){
  // Any thing you can think of
});

Convert hours:minutes:seconds into total minutes in excel

The only way is to use a formula or to format cells. The method i will use will be the following: Add another column next to these values. Then use the following formula:

=HOUR(A1)*60+MINUTE(A1)+SECOND(A1)/60

enter image description here

Change the Right Margin of a View Programmatically?

EDIT: A more generic way of doing this that doesn't rely on the layout type (other than that it is a layout type which supports margins):

public static void setMargins (View v, int l, int t, int r, int b) {
    if (v.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
        ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
        p.setMargins(l, t, r, b);
        v.requestLayout();
    }
}

You should check the docs for TextView. Basically, you'll want to get the TextView's LayoutParams object, and modify the margins, then set it back to the TextView. Assuming it's in a LinearLayout, try something like this:

TextView tv = (TextView)findViewById(R.id.my_text_view);
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams)tv.getLayoutParams();
params.setMargins(0, 0, 10, 0); //substitute parameters for left, top, right, bottom
tv.setLayoutParams(params);

I can't test it right now, so my casting may be off by a bit, but the LayoutParams are what need to be modified to change the margin.

NOTE

Don't forget that if your TextView is inside, for example, a RelativeLayout, one should use RelativeLayout.LayoutParams instead of LinearLayout.LayoutParams

Linux : Search for a Particular word in a List of files under a directory

You could club find with exec as follows to get the list of the files as well as the occurrence of the word/string that you are looking for

find . -exec grep "my word" '{}' \; -print

404 Not Found The requested URL was not found on this server

In httpd.conf file you need to remove #

#LoadModule rewrite_module modules/mod_rewrite.so

after removing # line will look like this:

LoadModule rewrite_module modules/mod_rewrite.so

I am sure your issue will be solved...

Displaying a webcam feed using OpenCV and Python

An update to show how to do it in the recent versions of OpenCV:

import cv2

cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)

if vc.isOpened(): # try to get the first frame
    rval, frame = vc.read()
else:
    rval = False

while rval:
    cv2.imshow("preview", frame)
    rval, frame = vc.read()
    key = cv2.waitKey(20)
    if key == 27: # exit on ESC
        break

cv2.destroyWindow("preview")
vc.release()

It works in OpenCV-2.4.2 for me.

Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0

It work for me in this issue in a project of react-native:

Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.

244 actionable tasks: 2 executed, 242 up-to-date D8: Cannot fit requested classes in a single dex file (# fields: 67296 > 65536) com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: The number of method references in a .dex file cannot exceed 64K. Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html ....

I Did this:

Custom ImageView with drop shadow

This works for me ...

public class ShadowImage extends Drawable {

Bitmap bm;

@Override
public void draw(Canvas canvas) {

    Paint mShadow = new Paint();
    Rect rect = new Rect(0,0,bm.getWidth(), bm.getHeight());

    mShadow.setAntiAlias(true);
    mShadow.setShadowLayer(5.5f, 4.0f, 4.0f, Color.BLACK);

    canvas.drawRect(rect, mShadow);
    canvas.drawBitmap(bm, 0.0f, 0.0f, null);

}

public ShadowImage(Bitmap bitmap) {
    super();
    this.bm = bitmap;
} ... }

How can I create directories recursively?

os.makedirs is what you need. For chmod or chown you'll have to use os.walk and use it on every file/dir yourself.

How to add an auto-incrementing primary key to an existing table, in PostgreSQL?

ALTER TABLE test1 ADD COLUMN id SERIAL PRIMARY KEY;

This is all you need to:

  1. Add the id column
  2. Populate it with a sequence from 1 to count(*).
  3. Set it as primary key / not null.

Credit is given to @resnyanskiy who gave this answer in a comment.

Converting an OpenCV Image to Black and White

Pay attention, if you use cv.CV_THRESH_BINARY means every pixel greater than threshold becomes the maxValue (in your case 255), otherwise the value is 0. Obviously if your threshold is 0 everything becomes white (maxValue = 255) and if the value is 255 everything becomes black (i.e. 0).

If you don't want to work out a threshold, you can use the Otsu's method. But this algorithm only works with 8bit images in the implementation of OpenCV. If your image is 8bit use the algorithm like this:

cv.Threshold(im_gray_mat, im_bw_mat, threshold, 255, cv.CV_THRESH_BINARY | cv.CV_THRESH_OTSU);

No matter the value of threshold if you have a 8bit image.

Why do I get "Pickle - EOFError: Ran out of input" reading an empty file?

Note that the mode of opening files is 'a' or some other have alphabet 'a' will also make error because of the overwritting.

pointer = open('makeaafile.txt', 'ab+')
tes = pickle.load(pointer, encoding='utf-8')

Difference between attr_accessor and attr_accessible

Many people on this thread and on google explain very well that attr_accessible specifies a whitelist of attributes that are allowed to be updated in bulk (all the attributes of an object model together at the same time) This is mainly (and only) to protect your application from "Mass assignment" pirate exploit.

This is explained here on the official Rails doc : Mass Assignment

attr_accessor is a ruby code to (quickly) create setter and getter methods in a Class. That's all.

Now, what is missing as an explanation is that when you create somehow a link between a (Rails) model with a database table, you NEVER, NEVER, NEVER need attr_accessor in your model to create setters and getters in order to be able to modify your table's records.

This is because your model inherits all methods from the ActiveRecord::Base Class, which already defines basic CRUD accessors (Create, Read, Update, Delete) for you. This is explained on the offical doc here Rails Model and here Overwriting default accessor (scroll down to the chapter "Overwrite default accessor")

Say for instance that: we have a database table called "users" that contains three columns "firstname", "lastname" and "role" :

SQL instructions :

CREATE TABLE users (
  firstname string,
  lastname string
  role string
);

I assumed that you set the option config.active_record.whitelist_attributes = true in your config/environment/production.rb to protect your application from Mass assignment exploit. This is explained here : Mass Assignment

Your Rails model will perfectly work with the Model here below :

class User < ActiveRecord::Base

end

However you will need to update each attribute of user separately in your controller for your form's View to work :

def update
    @user = User.find_by_id(params[:id])
    @user.firstname = params[:user][:firstname]
    @user.lastname = params[:user][:lastname]

    if @user.save
        # Use of I18 internationalization t method for the flash message
        flash[:success] = t('activerecord.successful.messages.updated', :model => User.model_name.human)
    end

    respond_with(@user)
end

Now to ease your life, you don't want to make a complicated controller for your User model. So you will use the attr_accessible special method in your Class model :

class User < ActiveRecord::Base

  attr_accessible :firstname, :lastname

end

So you can use the "highway" (mass assignment) to update :

def update
    @user = User.find_by_id(params[:id])

    if @user.update_attributes(params[:user])
        # Use of I18 internationlization t method for the flash message
        flash[:success] = t('activerecord.successful.messages.updated', :model => User.model_name.human)
    end

    respond_with(@user)
end

You didn't add the "role" attributes to the attr_accessible list because you don't let your users set their role by themselves (like admin). You do this yourself on another special admin View.

Though your user view doesn't show a "role" field, a pirate could easily send a HTTP POST request that include "role" in the params hash. The missing "role" attribute on the attr_accessible is to protect your application from that.

You can still modify your user.role attribute on its own like below, but not with all attributes together.

@user.role = DEFAULT_ROLE

Why the hell would you use the attr_accessor?

Well, this would be in the case that your user-form shows a field that doesn't exist in your users table as a column.

For instance, say your user view shows a "please-tell-the-admin-that-I'm-in-here" field. You don't want to store this info in your table. You just want that Rails send you an e-mail warning you that one "crazy" ;-) user has subscribed.

To be able to make use of this info you need to store it temporarily somewhere. What more easy than recover it in a user.peekaboo attribute ?

So you add this field to your model :

class User < ActiveRecord::Base

  attr_accessible :firstname, :lastname
  attr_accessor :peekaboo

end

So you will be able to make an educated use of the user.peekaboo attribute somewhere in your controller to send an e-mail or do whatever you want.

ActiveRecord will not save the "peekaboo" attribute in your table when you do a user.save because she don't see any column matching this name in her model.

How to use awk sort by column 3

To exclude the first line (header) from sorting, I split it out into two buffers.

df | awk 'BEGIN{header=""; $body=""} { if(NR==1){header=$0}else{body=body"\n"$0}} END{print header; print body|"sort -nk3"}'

Word wrap for a label in Windows Forms

From MSDN, Automatically Wrap Text in Label:

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

public class GrowLabel : Label {
    private bool mGrowing;
    public GrowLabel() {
        this.AutoSize = false;
    }
    private void resizeLabel() {
        if (mGrowing) 
            return;
        try {
            mGrowing = true;
            Size sz = new Size(this.Width, Int32.MaxValue);
            sz = TextRenderer.MeasureText(this.Text, this.Font, sz, TextFormatFlags.WordBreak);
            this.Height = sz.Height;
        }
        finally {
            mGrowing = false;
        }
    }
    protected override void OnTextChanged(EventArgs e) {
        base.OnTextChanged(e);
        resizeLabel();
    }
    protected override void OnFontChanged(EventArgs e) {
        base.OnFontChanged(e);
        resizeLabel();
    }
    protected override void OnSizeChanged(EventArgs e) {
        base.OnSizeChanged(e);
        resizeLabel();
    }
}

How to avoid reverse engineering of an APK file?

 1. How can I completely avoid reverse engineering of an Android APK? Is this possible?

AFAIK, there is not any trick for complete avoidance of reverse engineering.

And also very well said by @inazaruk: Whatever you do to your code, a potential attacker is able to change it in any way she or he finds it feasible. You basically can't protect your application from being modified. And any protection you put in there can be disabled/removed.

 2. How can I protect all the app's resources, assets and source code so that hackers can't hack the APK file in any way?

You can do different tricks to make hacking harder though. For example, use obfuscation (if it's Java code). This usually slows down reverse engineering significantly.

 3. Is there a way to make hacking more tough or even impossible? What more can I do to protect the source code in my APK file?

As everyone says, and as you probably know, there's no 100% security. But the place to start for Android, that Google has built in, is ProGuard. If you have the option of including shared libraries, you can include the needed code in C++ to verify file sizes, integration, etc. If you need to add an external native library to your APK's library folder on every build, then you can use it by the below suggestion.

Put the library in the native library path which defaults to "libs" in your project folder. If you built the native code for the 'armeabi' target then put it under libs/armeabi. If it was built with armeabi-v7a then put it under libs/armeabi-v7a.

<project>/libs/armeabi/libstuff.so

Fastest way to determine if record exists

For MySql you can use LIMIT like below (Example shows in PHP)

  $sql = "SELECT column_name FROM table_name WHERE column_name = 'your_value' LIMIT 1";
  $result = $conn->query($sql);
  if ($result -> num_rows > 0) {
      echo "Value exists" ;
  } else {
      echo "Value not found";
  }

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Correct expression is

"source " + (DT_STR,4,1252)DATEPART( "yyyy" , getdate() ) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "mm" , getdate() ), 2) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "dd" , getdate() ), 2) +".CSV"

Reading serial data in realtime in Python

You need to set the timeout to "None" when you open the serial port:

ser = serial.Serial(**bco_port**, timeout=None, baudrate=115000, xonxoff=False, rtscts=False, dsrdtr=False) 

This is a blocking command, so you are waiting until you receive data that has newline (\n or \r\n) at the end: line = ser.readline()

Once you have the data, it will return ASAP.

Send multiple checkbox data to PHP via jQuery ajax()

Check this out.

<script type="text/javascript">
    function submitForm() {
$(document).ready(function() {
$("form#myForm").submit(function() {

        var myCheckboxes = new Array();
        $("input:checked").each(function() {
           myCheckboxes.push($(this).val());
        });

        $.ajax({
            type: "POST",
            url: "myurl.php",
            dataType: 'html',
            data: 'myField='+$("textarea[name=myField]").val()+'&myCheckboxes='+myCheckboxes,
            success: function(data){
                $('#myResponse').html(data)
            }
        });
        return false;
});
});
}
</script>

And on myurl.php you can use print_r($_POST['myCheckboxes']);

sql insert into table with select case values

You have the alias inside of the case, it needs to be outside of the END:

Insert into TblStuff (FullName,Address,City,Zip)
Select
  Case
    When Middle is Null 
    Then Fname + LName
    Else Fname +' ' + Middle + ' '+ Lname
  End as FullName,
  Case
    When Address2 is Null Then Address1
    else Address1 +', ' + Address2 
  End as  Address,
  City as City,
  Zip as Zip
from tblImport

How to run python script with elevated privilege on windows

It worth mentioning that if you intend to package your application with PyInstaller and wise to avoid supporting that feature by yourself, you can pass the --uac-admin or --uac-uiaccess argument in order to request UAC elevation on start.

how to git commit a whole folder?

To Add a little to the above answers:

If you are wanting to commit a folder like the above

git add foldername
git commit -m "commit operation"

To add the folder you will need to be on the same level as, or above, the folder you are trying to add.

For example: App/Storage/Emails/email.php

If you are trying to add the "Storage" file but you have been working inside it on the email.php document you will not be able to add the "Storage" file unless you have 'changed directory' (cd ../) back up to the same level, or higher, as the Storage file itself

How to find path of active app.config file?

Strictly speaking, there is no single configuration file. Excluding ASP.NET1 there can be three configuration files using the inbuilt (System.Configuration) support. In addition to the machine config: app.exe.config, user roaming, and user local.

To get the "global" configuration (exe.config):

ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)
                    .FilePath

Use different ConfigurationUserLevel values for per-use roaming and non-roaming configuration files.


1 Which has a completely different model where the content of a child folders (IIS-virtual or file system) web.config can (depending on the setting) add to or override the parent's web.config.

Saving any file to in the database, just convert it to a byte array?

Confirming I was able to use the answer posted by MadBoy and edited by Otiel on both MS SQL Server 2012 and 2014 in addition to the versions previously listed using varbinary(MAX) columns.

If you are wondering why you cannot "Filestream" (noted in a separate answer) as a datatype in the SQL Server table designer or why you cannot set a column's datatype to "Filestream" using T-SQL, it is because FILESTREAM is a storage attribute of the varbinary(MAX) datatype. It is not a datatype on its own.

See these articles on setting up and enabling FILESTREAM on a database: https://msdn.microsoft.com/en-us/library/cc645923(v=sql.120).aspx

http://www.kodyaz.com/t-sql/default-filestream-filegroup-is-not-available-in-database.aspx

Once configured, a filestream enabled varbinary(max) column can be added as so:

ALTER TABLE TableName

ADD ColumnName varbinary(max) FILESTREAM NULL

GO

Why use Ruby's attr_accessor, attr_reader and attr_writer?

You don't always want your instance variables to be fully accessible from outside of the class. There are plenty of cases where allowing read access to an instance variable makes sense, but writing to it might not (e.g. a model that retrieves data from a read-only source). There are cases where you want the opposite, but I can't think of any that aren't contrived off the top of my head.

How to access static resources when mapping a global front controller servlet on /*

With Spring 3.0.4.RELEASE and higher you can use

<mvc:resources mapping="/resources/**" location="/public-resources/"/>

As seen in Spring Reference.

Understanding React-Redux and mapStateToProps()

I would like to re-structure the statement that you mentioned which is:

This means that the state as consumed by your target component can have a wildly different structure from the state as it is stored on your store

You can say that the state consumed by your target component has a small portion of the state that is stored on the redux store. In other words, the state consumed by your component would be the sub-set of the state of the redux store.

As far as understanding the connect() method is concerned, it's fairly simple! connect() method has the power to add new props to your component and even override existing props. It is through this connect method that we can access the state of the redux store as well which is thrown to us by the Provider. A combination of which works in your favor and you get to add the state of your redux store to the props of your component.

Above is some theory and I would suggest you look at this video once to understand the syntax better.

How can I remove all text after a character in bash?

An example might have been useful, but if I understood you correctly, this would work:

echo "Hello: world" | cut -f1 -d":"

This will convert Hello: world into Hello.

Disable LESS-CSS Overwriting calc()

Here's a cross-browser less mixin for using CSS's calc with any property:

.calc(@prop; @val) {
  @{prop}: calc(~'@{val}');
  @{prop}: -moz-calc(~'@{val}');
  @{prop}: -webkit-calc(~'@{val}');
  @{prop}: -o-calc(~'@{val}');
}

Example usage:

.calc(width; "100% - 200px");

And the CSS that's output:

width: calc(100% - 200px);
width: -moz-calc(100% - 200px);
width: -webkit-calc(100% - 200px);
width: -o-calc(100% - 200px);

A codepen of this example: http://codepen.io/patrickberkeley/pen/zobdp

ASP.NET Core configuration for .NET Core console application

You can use this code snippet. It includes Configuration and DI.

public class Program
{
    public static ILoggerFactory LoggerFactory;
    public static IConfigurationRoot Configuration;

    public static void Main(string[] args)
    {
        Console.OutputEncoding = Encoding.UTF8;

        string environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");

        if (String.IsNullOrWhiteSpace(environment))
            throw new ArgumentNullException("Environment not found in ASPNETCORE_ENVIRONMENT");

        Console.WriteLine("Environment: {0}", environment);

        var services = new ServiceCollection();

        // Set up configuration sources.
        var builder = new ConfigurationBuilder()
            .SetBasePath(Path.Combine(AppContext.BaseDirectory))
            .AddJsonFile("appsettings.json", optional: true);
        if (environment == "Development")
        {

            builder
                .AddJsonFile(
                    Path.Combine(AppContext.BaseDirectory, string.Format("..{0}..{0}..{0}", Path.DirectorySeparatorChar), $"appsettings.{environment}.json"),
                    optional: true
                );
        }
        else
        {
            builder
                .AddJsonFile($"appsettings.{environment}.json", optional: false);
        }

        Configuration = builder.Build();

        LoggerFactory = new LoggerFactory()
            .AddConsole(Configuration.GetSection("Logging"))
            .AddDebug();

        services
            .AddEntityFrameworkNpgsql()
            .AddDbContext<FmDataContext>(o => o.UseNpgsql(connectionString), ServiceLifetime.Transient);

        services.AddTransient<IPackageFileService, PackageFileServiceImpl>();

        var serviceProvider = services.BuildServiceProvider();

        var packageFileService = serviceProvider.GetRequiredService<IPackageFileService>();

        ............
    }
}

Oh, and don't forget to add in the project.json

{
  "version": "1.0.0-*",
  "buildOptions": {
    "emitEntryPoint": true,
    "copyToOutput": {
      "includeFiles": [
        "appsettings.json",
        "appsettings.Integration.json",
        "appsettings.Production.json",
        "appsettings.Staging.json"
      ]
    }
  },

  "publishOptions": {
    "copyToOutput": [
      "appsettings.json",
      "appsettings.Integration.json",
      "appsettings.Production.json",
      "appsettings.Staging.json"
    ]
  },
...
}

Why is json_encode adding backslashes?

Just use the "JSON_UNESCAPED_SLASHES" Option (added after version 5.4).

json_encode($array,JSON_UNESCAPED_SLASHES);

How to serve up a JSON response using Go?

You can do something like this in you getJsonResponse function -

jData, err := json.Marshal(Data)
if err != nil {
    // handle error
}
w.Header().Set("Content-Type", "application/json")
w.Write(jData)

Calling a Fragment method from a parent Activity

FragmentManager fm = getFragmentManager(); 
MainFragment frag = (MainFragment)fm.findFragmentById(R.id.main_fragment); 
frag.<specific_function_name>(); 

Inserting the iframe into react component

If you don't want to use dangerouslySetInnerHTML then you can use the below mentioned solution

var Iframe = React.createClass({     
  render: function() {
    return(         
      <div>          
        <iframe src={this.props.src} height={this.props.height} width={this.props.width}/>         
      </div>
    )
  }
});

ReactDOM.render(
  <Iframe src="http://plnkr.co/" height="500" width="500"/>,
  document.getElementById('example')
);

here live demo is available Demo

How to make Java honor the DNS Caching Timeout?

According to the official oracle java properties, sun.net.inetaddr.ttl is Sun implementation-specific property, which "may not be supported in future releases". "the preferred way is to use the security property" networkaddress.cache.ttl.

Tomcat: How to find out running tomcat version

You can find out the server information through its status page:

{running-tomcat-url}/manager/status

On that page you can see the version of Java on which your Tomcat runs

Note: I have also pasted this answer on Tomcat6 and JRE7 compatibility issue. Unsupported major.minor version 51.0

How do I dump an object's fields to the console?

p object

Ruby doc for p.

p(*args) public

For each object, directly writes obj.inspect followed by a newline to the program’s standard output.

Using a .php file to generate a MySQL dump

If you want to create a backup to download it via the browser, you also can do this without using a file.

The php function passthru() will directly redirect the output of mysqldump to the browser. In this example it also will be zipped.

Pro: You don't have to deal with temp files.

Con: Won't work on Windows. May have limits with huge datasets.

<?php

$DBUSER="user";
$DBPASSWD="password";
$DATABASE="user_db";

$filename = "backup-" . date("d-m-Y") . ".sql.gz";
$mime = "application/x-gzip";

header( "Content-Type: " . $mime );
header( 'Content-Disposition: attachment; filename="' . $filename . '"' );

$cmd = "mysqldump -u $DBUSER --password=$DBPASSWD $DATABASE | gzip --best";   

passthru( $cmd );

exit(0);
?>

Calculating moving average

In data.table 1.12.0 new frollmean function has been added to compute fast and exact rolling mean carefully handling NA, NaN and +Inf, -Inf values.

As there is no reproducible example in the question there is not much more to address here.

You can find more info about ?frollmean in manual, also available online at ?frollmean.

Examples from manual below:

library(data.table)
d = as.data.table(list(1:6/2, 3:8/4))

# rollmean of single vector and single window
frollmean(d[, V1], 3)

# multiple columns at once
frollmean(d, 3)

# multiple windows at once
frollmean(d[, .(V1)], c(3, 4))

# multiple columns and multiple windows at once
frollmean(d, c(3, 4))

## three above are embarrassingly parallel using openmp

What does 'synchronized' mean?

Synchronized normal method equivalent to Synchronized statement (use this)

class A {
    public synchronized void methodA() {
        // all function code
    }

    equivalent to

    public void methodA() {
        synchronized(this) {
             // all function code
        }
    } 
}

Synchronized static method equivalent to Synchronized statement (use class)

class A {
    public static synchronized void methodA() {
        // all function code
    }

    equivalent to

    public void methodA() {
        synchronized(A.class) {
             // all function code
        }
    } 
}

Synchronized statement (using variable)

class A {
    private Object lock1 = new Object();

    public void methodA() {
        synchronized(lock1 ) {
             // all function code
        }
    } 
}

For synchronized, we have both Synchronized Methods and Synchronized Statements. However, Synchronized Methods is similar to Synchronized Statements so we just need to understand Synchronized Statements.

=> Basically, we will have

synchronized(object or class) { // object/class use to provides the intrinsic lock
   // code 
}

Here is 2 think that help understanding synchronized

  • Every object/class have an intrinsic lock associated with it.
  • When a thread invokes a synchronized statement, it automatically acquires the intrinsic lock for that synchronized statement's object and releases it when the method returns. As long as a thread owns an intrinsic lock, NO other thread can acquire the SAME lock => thread safe.

=> When a thread A invokes synchronized(this){// code 1} => all the block code (inside class) where have synchronized(this) and all synchronized normal method (inside class) is locked because SAME lock. It will execute after thread A unlock ("// code 1" finished).

This behavior is similar to synchronized(a variable){// code 1} or synchronized(class).

SAME LOCK => lock (not depend on which method? or which statements?)

Use synchronized method or synchronized statements?

I prefer synchronized statements because it is more extendable. Example, in future, you only need synchronized a part of method. Example, you have 2 synchronized method and it don't have any relevant to each other, however when a thread run a method, it will block the other method (it can prevent by use synchronized(a variable)).

However, apply synchronized method is simple and the code look simple. For some class, there only 1 synchronized method, or all synchronized methods in the class in relevant to each other => we can use synchronized method to make code shorter and easy to understand

Note

(it not relevant to much to synchronized, it is the different between object and class or none-static and static).

  • When you use synchronized or normal method or synchronized(this) or synchronized(non-static variable) it will synchronized base on each object instance.
  • When you use synchronized or static method or synchronized(class) or synchronized(static variable) it will synchronized base on class

Reference

https://docs.oracle.com/javase/tutorial/essential/concurrency/syncmeth.html https://docs.oracle.com/javase/tutorial/essential/concurrency/locksync.html

Hope it help

T-SQL: Selecting rows to delete via joins

I would use this syntax

Delete a 
from TableA a
Inner Join TableB b
on  a.BId = b.BId
WHERE [filter condition]

Calling method using JavaScript prototype

I did not understand what exactly you're trying to do, but normally implementing object-specific behaviour is done along these lines:

function MyClass(name) {
    this.name = name;
}

MyClass.prototype.doStuff = function() {
    // generic behaviour
}

var myObj = new MyClass('foo');

var myObjSpecial = new MyClass('bar');
myObjSpecial.doStuff = function() {
    // do specialised stuff
    // how to call the generic implementation:
    MyClass.prototype.doStuff.call(this /*, args...*/);
}

"The certificate chain was issued by an authority that is not trusted" when connecting DB in VM Role from Azure website

If You are trying to access it through Data Connections in Visual Studio 2015, and getting the above Error, Then Go to Advanced and set TrustServerCertificate=True for error to go away.

Showing/Hiding Table Rows with Javascript - can do with ID - how to do with Class?

You can change the class of the entire table and use the cascade in the CSS: http://jsbin.com/oyunuy/1/

PLS-00103: Encountered the symbol when expecting one of the following:

begin
    var_number := 10;

    if var_number > 100 then
        dbms_output.put_line(var_number||' is greater than 100');
    else if var_number < 100 then
        dbms_output.put_line(var_number||' is less than 100');
    else
        dbms_output.put_line(var_number||' is equal to 100');
    end if;
end if;

How to check if a variable is NULL, then set it with a MySQL stored procedure?

@last_run_time is a 9.4. User-Defined Variables and last_run_time datetime one 13.6.4.1. Local Variable DECLARE Syntax, are different variables.

Try: SELECT last_run_time;

UPDATE

Example:

/* CODE FOR DEMONSTRATION PURPOSES */
DELIMITER $$

CREATE PROCEDURE `sp_test`()
BEGIN
    DECLARE current_procedure_name CHAR(60) DEFAULT 'accounts_general';
    DECLARE last_run_time DATETIME DEFAULT NULL;
    DECLARE current_run_time DATETIME DEFAULT NOW();

    -- Define the last run time
    SET last_run_time := (SELECT MAX(runtime) FROM dynamo.runtimes WHERE procedure_name = current_procedure_name);

    -- if there is no last run time found then use yesterday as starting point
    IF(last_run_time IS NULL) THEN
        SET last_run_time := DATE_SUB(NOW(), INTERVAL 1 DAY);
    END IF;

    SELECT last_run_time;

    -- Insert variables in table2
    INSERT INTO table2 (col0, col1, col2) VALUES (current_procedure_name, last_run_time, current_run_time);
END$$

DELIMITER ;

How can I match on an attribute that contains a certain string?

Be aware that bobince's answer might be overly complicated if you can assume that the class name you are interested in is not a substring of another possible class name. If this is true, you can simply use substring matching via the contains function. The following will match any element whose class contains the substring 'atag':

//*[contains(@class,'atag')]

If the assumption above does not hold, a substring match will match elements you don't intend. In this case, you have to find the word boundaries. By using the space delimiters to find the class name boundaries, bobince's second answer finds the exact matches:

//*[contains(concat(' ', normalize-space(@class), ' '), ' atag ')]

This will match atag and not matag.

Where can I download JSTL jar

You can download JSTL 1.1 here and JSTL 1.2 here.

See also:

How to change a TextView's style at runtime

TextView tvCompany = (TextView)findViewById(R.layout.tvCompany);
tvCompany.setTypeface(null,Typeface.BOLD);

You an set it from code. Typeface

Difference between DOMContentLoaded and load events

Here's some code that works for us. We found MSIE to be hit and miss with DomContentLoaded, there appears to be some delay when no additional resources are cached (up to 300ms based on our console logging), and it triggers too fast when they are cached. So we resorted to a fallback for MISE. You also want to trigger the doStuff() function whether DomContentLoaded triggers before or after your external JS files.

// detect MSIE 9,10,11, but not Edge
ua=navigator.userAgent.toLowerCase();isIE=/msie/.test(ua);

function doStuff(){
    //
}
if(isIE){
    // play it safe, very few users, exec ur JS when all resources are loaded
    window.onload=function(){doStuff();}
} else {
    // add event listener to trigger your function when DOMContentLoaded
    if(document.readyState==='loading'){
        document.addEventListener('DOMContentLoaded',doStuff);
    } else {
        // DOMContentLoaded already loaded, so better trigger your function
        doStuff();
    }
}

Troubleshooting "program does not contain a static 'Main' method" when it clearly does...?

If you have a WPF or Silverlight application, make sure that App.xaml has "ApplicationDefinition" as the BuildAction on the File Properties.

Set SSH connection timeout

The ConnectTimeout option allows you to tell your ssh client how long you're willing to wait for a connection before returning an error. By setting ConnectTimeout to 1, you're effectively saying "try for at most 1 second and then fail if you haven't connected yet".

The problem is that when you connect by name, the DNS lookup can take several seconds. Connecting by IP address is much faster, and may actually work in one second or less. What sinelaw is experiencing is that every attempt to connect by DNS name is failing to occur within one second. The default setting of ConnectTimeout defers to the linux kernel connect timeout, which is usually pretty long.

Convert String to Float in Swift

This is how I approached it. I did not want to "cross the bridge", as it has been removed from Xcode 6 beta 5 anyway, quick and dirty:

extension String {

    // converting a string to double
    func toDouble() -> Double? {

        // split the string into components
        var comps = self.componentsSeparatedByString(".")

        // we have nothing
        if comps.count == 0 {
            return nil
        }
        // if there is more than one decimal
        else if comps.count > 2 {
            return nil
        }
        else if comps[0] == "" || comps[1] == "" {
            return nil
        }

        // grab the whole portion
        var whole = 0.0
        // ensure we have a number for the whole
        if let w = comps[0].toInt() {
            whole = Double(w)
        }
        else {
            return nil
        }

        // we only got the whole
        if comps.count == 1 {

            return whole

        }

        // grab the fractional
        var fractional = 0.0
        // ensure we have a number for the fractional
        if let f = comps[1].toInt() {

            // use number of digits to get the power
            var toThePower = Double(countElements(comps[1]))

            // compute the fractional portion
            fractional = Double(f) / pow(10.0, toThePower)

        }
        else {
            return nil
        }

        // return the result
        return whole + fractional
    }

    // converting a string to float
    func toFloat() -> Float? {

        if let val = self.toDouble() {
            return Float(val)
        }
        else {
            return nil
        }

    }

}


// test it out
var str = "78.001"

if let val = str.toFloat() {
    println("Str in float: \(val)")
}
else {
    println("Unable to convert Str to float")
}

// now in double
if let val = str.toDouble() {
    println("Str in double: \(val)")
}
else {
    println("Unable to convert Str to double")
}

Adding a collaborator to my free GitHub account?

FYI for future readers. The instructions above are outdated, in particular step 2:
2. Click on Settings button

Bash script error [: !=: unary operator expected

Quotes!

if [ "$1" != -v ]; then

Otherwise, when $1 is completely empty, your test becomes:

[ != -v ]

instead of

[ "" != -v ]

...and != is not a unary operator (that is, one capable of taking only a single argument).

src absolute path problem

I think because C would be seen the C drive on the client pc, it wont let you. And if it could do this, it would be a big security hole.

How do I install Java on Mac OSX allowing version switching?

With Homebrew and jenv:

Assumption: Mac machine and you already have installed homebrew.

Install cask:

$ brew tap caskroom/cask
$ brew tap caskroom/versions

To install latest java:

$ brew cask install java

To install java 8:

$ brew cask install java8

To install java 9:

$ brew cask install java9

If you want to install/manage multiple version then you can use 'jenv':

Install and configure jenv:

$ brew install jenv
$ echo 'export PATH="$HOME/.jenv/bin:$PATH"' >> ~/.bash_profile
$ echo 'eval "$(jenv init -)"' >> ~/.bash_profile
$ source ~/.bash_profile

Add the installed java to jenv:

$ jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_202.jdk/Contents/Home
$ jenv add /Library/Java/JavaVirtualMachines/jdk1.11.0_2.jdk/Contents/Home

To see all the installed java:

$ jenv versions

Above command will give the list of installed java:

* system (set by /Users/lyncean/.jenv/version)
1.8
1.8.0.202-ea
oracle64-1.8.0.202-ea

Configure the java version which you want to use:

$ jenv global oracle64-1.6.0.39

How can I make the computer beep in C#?

The solution would be,

Console.Beep

Use jQuery to hide a DIV when the user clicks outside of it

dojo.query(document.body).connect('mouseup',function (e)
{
    var obj = dojo.position(dojo.query('div#divselector')[0]);
    if (!((e.clientX > obj.x && e.clientX <(obj.x+obj.w)) && (e.clientY > obj.y && e.clientY <(obj.y+obj.h))) ){
        MyDive.Hide(id);
    }
});