Programs & Examples On #Volumes

docker mounting volumes on host

The VOLUME command will mount a directory inside your container and store any files created or edited inside that directory on your hosts disk outside the container file structure, bypassing the union file system.

The idea is that your volumes can be shared between your docker containers and they will stay around as long as there's a container (running or stopped) that references them.

You can have other containers mount existing volumes (effectively sharing them between containers) by using the --volumes-from command when you run a container.

The fundamental difference between VOLUME and -v is this: -v will mount existing files from your operating system inside your docker container and VOLUME will create a new, empty volume on your host and mount it inside your container.

Example:

  1. You have a Dockerfile that defines a VOLUME /var/lib/mysql.
  2. You build the docker image and tag it some-volume
  3. You run the container

And then,

  1. You have another docker image that you want to use this volume
  2. You run the docker container with the following: docker run --volumes-from some-volume docker-image-name:tag
  3. Now you have a docker container running that will have the volume from some-volume mounted in /var/lib/mysql

Note: Using --volumes-from will mount the volume over whatever exists in the location of the volume. I.e., if you had stuff in /var/lib/mysql, it will be replaced with the contents of the volume.

Copying files to a container with Docker Compose

Given

    volumes:
      - /dir/on/host:/var/www/html

if /dir/on/host doesn't exist, it is created on the host and the empty content is mounted in the container at /var/www/html. Whatever content you had before in /var/www/html inside the container is inaccessible, until you unmount the volume; the new mount is hiding the old content.

how to inherit Constructor from super class to sub class

Constructors are not inherited, you must create a new, identically prototyped constructor in the subclass that maps to its matching constructor in the superclass.

Here is an example of how this works:

class Foo {
    Foo(String str) { }
}

class Bar extends Foo {
    Bar(String str) {
        // Here I am explicitly calling the superclass 
        // constructor - since constructors are not inherited
        // you must chain them like this.
        super(str);
    }
}

Showing the stack trace from a running Python application

The suggestion to install a signal handler is a good one, and I use it a lot. For example, bzr by default installs a SIGQUIT handler that invokes pdb.set_trace() to immediately drop you into a pdb prompt. (See the bzrlib.breakin module's source for the exact details.) With pdb you can not only get the current stack trace (with the (w)here command) but also inspect variables, etc.

However, sometimes I need to debug a process that I didn't have the foresight to install the signal handler in. On linux, you can attach gdb to the process and get a python stack trace with some gdb macros. Put http://svn.python.org/projects/python/trunk/Misc/gdbinit in ~/.gdbinit, then:

  • Attach gdb: gdb -p PID
  • Get the python stack trace: pystack

It's not totally reliable unfortunately, but it works most of the time.

Finally, attaching strace can often give you a good idea what a process is doing.

CSS :: child set to change color on parent hover, but changes also when hovered itself

If you don't care about supporting old browsers, you can use :not() to exclude that element:

.parent:hover span:not(:hover) {
    border: 10px solid red;
}

Demo: http://jsfiddle.net/vz9A9/1/

If you do want to support them, the I guess you'll have to either use JavaScript or override the CSS properties again:

.parent span:hover {
    border: 10px solid green;
}

In reactJS, how to copy text to clipboard?

This work for me:

const handleCopyLink = useCallback(() => {
    const textField = document.createElement('textarea')
    textField.innerText = url
    document.body.appendChild(textField)
    if (window.navigator.platform === 'iPhone') {
      textField.setSelectionRange(0, 99999)
    } else {
      textField.select()
    }
    document.execCommand('copy')
    textField.remove()
    
    toast.success('Link successfully copied')
  }, [url])

error_reporting(E_ALL) does not produce error

That error is a parse error. The parser is throwing it while going through the code, trying to understand it. No code is being executed yet in the parsing stage. Because of that it hasn't yet executed the error_reporting line, therefore the error reporting settings aren't changed yet.

You cannot change error reporting settings (or really, do anything) in a file with syntax errors.

git status shows fatal: bad object HEAD

Running

git remote set-head origin --auto

followed by

git gc

Why can't I shrink a transaction log file, even after backup?

I've had the same issue in the past. Normally a shrink and a trn backup need to occur multiple times. In extreme cases I set the DB to "Simple" recovery and then run a shrink operation on the log file. That always works for me. However recently I had a situation where that would not work. The issue was caused by a long running query that did not complete, so any attempts to shrink were useless until I could kill that process then run my shrink operations. We are talking a log file that grew to 60 GB and is now shrunk to 500 MB.

Remember, as soon as you change from FULL to Simple recovery mode and do the shrink, dont forget to set it back to FULL. Then immediately afterward you must do a FULL DB backup.

SQL Server Case Statement when IS NULL

  case isnull(B.[stat],0)
  when 0 then dateadd(dd,10,(c.[Eventdate]))
  end

you can add in else statement if you want to add 30 days to the same .

Concatenate two PySpark dataframes

Maybe, you want to concatenate more of two Dataframes. I found a issue which use pandas Dataframe conversion.

Suppose you have 3 spark Dataframe who want to concatenate.

The code is the following:

list_dfs = []
list_dfs_ = []

df = spark.read.json('path_to_your_jsonfile.json',multiLine = True)
df2 = spark.read.json('path_to_your_jsonfile2.json',multiLine = True)
df3 = spark.read.json('path_to_your_jsonfile3.json',multiLine = True)

list_dfs.extend([df,df2,df3])

for df in list_dfs : 

    df = df.select([column for column in df.columns]).toPandas()
    list_dfs_.append(df)

list_dfs.clear()

df_ = sqlContext.createDataFrame(pd.concat(list_dfs_))

Exclude property from type

In Typescript 3.5+:

interface TypographyProps {
    variant: string
    fontSize: number
}

type TypographyPropsMinusVariant = Omit<TypographyProps, "variant">

jQuery find() method not working in AngularJS directive

find() - Limited to lookups by tag name you can see more information https://docs.angularjs.org/api/ng/function/angular.element

Also you can access by name or id or call please following example:

angular.element(document.querySelector('#txtName')).attr('class', 'error');

Center a column using Twitter Bootstrap 3

This works. A hackish way probably, but it works nicely. It was tested for responsive (Y).

.centered {
    background-color: teal;
    text-align: center;
}

Desktop

Responsive

Spring Boot War deployed to Tomcat

Hey make sure to do this changes to the pom.xml

<packaging>war</packaging>

in the dependencies section make sure to indicated the tomcat is provided so you dont need the embeded tomcat plugin.

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>       

    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>       

This is the whole pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <start-class>com.example.Application</start-class>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>       

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>       

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

And the Application class should be like this

Application.java

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
public class Application extends SpringBootServletInitializer {


    /**
     * Used when run as JAR
     */
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    /**
     * Used when run as WAR
     */
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(Application.class);
    }

}

And you can add a controller for testing MyController.java

package com.example;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class MyController {

    @RequestMapping("/hi")
    public @ResponseBody String hiThere(){
        return "hello world!";
    }
}

Then you can run the project in a tomcat 8 version and access the controller like this

http://localhost:8080/demo/hi

If for some reason you are not able to add the project to tomcat do a right click in the project and then go to the Build Path->configure build path->Project Faces

make sure only this 3 are selected

Dynamic web Module 3.1 Java 1.8 Javascript 1.0

How to play CSS3 transitions in a loop?

CSS transitions only animate from one set of styles to another; what you're looking for is CSS animations.

You need to define the animation keyframes and apply it to the element:

@keyframes changewidth {
  from {
    width: 100px;
  }

  to {
    width: 300px;
  }
}

div {
  animation-duration: 0.1s;
  animation-name: changewidth;
  animation-iteration-count: infinite;
  animation-direction: alternate;
}

Check out the link above to figure out how to customize it to your liking, and you'll have to add browser prefixes.

Prevent typing non-numeric in input type number

Based on Nrzonline's answer: I fixed the problem of the multiple "." at the end of the input by adding a

let lastCharacterEntered

outside of the input and then onKeyPress

e => {
          var allowedChars = "0123456789.";
          function contains(stringValue, charValue) {
            return stringValue.indexOf(charValue) > -1;
          }
          var invalidKey =
            (e.key.length === 1 && !contains(allowedChars, e.key)) ||
            (e.key === "." && contains(e.target.value, "."));
          console.log(e.target.value);
          invalidKey && e.preventDefault();
          if (!invalidKey) {
            if (lastCharacterEntered === "." && e.key === ".") {
              e.preventDefault();
            } else {
              lastCharacterEntered = e.key;
            }
          }
        }

CSS Inset Borders

To produce a border inset within an element the only solution I've found (and I've tried all the suggestions in this thread to no avail) is to use a pseudo-element such as :before

E.g.

.has-inset-border:before {
  content: "foo"; /* you need something or it will be invisible at least on Chrome */
  color: transparent;
  position: absolute;
  left: 10px;
  right: 10px;
  top: 10px;
  bottom: 10px;
  border: 4px dashed red;
}

The box-sizing property won't work, as the border always ends up outside everything.

The box-shadow options has the dual disadvantages of not really working and not being supported as widely (and costing more CPU cycles to render, if you care).

Using Oracle to_date function for date string with milliseconds

TO_DATE supports conversion to DATE datatype, which doesn't support milliseconds. If you want millisecond support in Oracle, you should look at TIMESTAMP datatype and TO_TIMESTAMP function.

Hope that helps.

Input from the keyboard in command line application

I have now been able to get Keyboard input in Swift by using the following:

In my main.swift file I declared a variable i and assigned to it the function GetInt() which I defined in Objective C. Through a so called Bridging Header where I declared the function prototype for GetInt I could link to main.swift. Here are the files:

main.swift:

var i: CInt = GetInt()
println("Your input is \(i) ");

Bridging Header:

#include "obj.m"

int GetInt();

obj.m:

#import <Foundation/Foundation.h>
#import <stdio.h>
#import <stdlib.h>

int GetInt()
{
    int i;
    scanf("%i", &i);
    return i;
}

In obj.m it is possible to include the c standard output and input, stdio.h, as well as the c standard library stdlib.h which enables you to program in C in Objective-C, which means there is no need for including a real swift file like user.c or something like that.

Hope I could help,

Edit: It is not possible to get String input through C because here I am using the CInt -> the integer type of C and not of Swift. There is no equivalent Swift type for the C char*. Therefore String is not convertible to string. But there are fairly enough solutions around here to get String input.

Raul

How to get the selected date value while using Bootstrap Datepicker?

You can try this

$('#startdate').val()

or

$('#startdate').data('date')

Make an Installation program for C# applications and include .NET Framework installer into the setup

WiX is the way to go for new installers. If WiX alone is too complicated or not flexible enough on the GUI side consider using SharpSetup - it allows you to create installer GUI in WinForms of WPF and has other nice features like translations, autoupdater, built-in prerequisites, improved autocompletion in VS and more.

(Disclaimer: I am the author of SharpSetup.)

Getting the error "Missing $ inserted" in LaTeX

I had this problem too. I solved it by removing the unnecessary blank line between equation tags. This gives the error:

\begin{equation}
P(\underline{\hat{X}} | \underline{Y}) = ...

\end{equation}

while this code compiles succesfully:

\begin{equation}
P(\underline{\hat{X}} | \underline{Y}) = ...
\end{equation}

Android Failed to install HelloWorld.apk on device (null) Error

When it shows the red writing - the error , don't close the emulator - leave it as is and run the application again.

Nesting CSS classes

No.

You can use grouping selectors and/or multiple classes on a single element, or you can use a template language and process it with software to write your CSS.

See also my article on CSS inheritance.

How to create a link for all mobile devices that opens google maps with a route starting at the current location, destinating a given place?

Based on the documentation the origin parameter is optional and it defaults to the user's location.

... Defaults to most relevant starting location, such as user location, if available. If none, the resulting map may provide a blank form to allow a user to enter the origin....

ex: https://www.google.com/maps/dir/?api=1&destination=Pike+Place+Market+Seattle+WA&travelmode=bicycling

For me this works on Desktop, IOS and Android.

How do I reformat HTML code using Sublime Text 2?

I am yet to have the privilege to comment so this is simply additional information related to @peter's answer above answer.

I found HTML did not align as expected if IE conditional comments in the header were not completely in-line e.g. flush to the left:

<!--[if lt IE 7]>
<p class='chromeframe'>Your browser is <em>unsupported</em>. <a href="http://browsehappy.com/">Upgrade to a different browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">install Google Chrome Frame</a> to experience this site.</p>
<![endif]-->
<!-- Le HTML5 shim, for IE6-8 support of HTML elements -->
<!--[if lt IE 9]>
<script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>
<![endif]--> 

How to limit depth for recursive file list?

tree -L 2 -u -g -p -d

Prints the directory tree in a pretty format up to depth 2 (-L 2). Print user (-u) and group (-g) and permissions (-p). Print only directories (-d). tree has a lot of other useful options.

How to copy an object by value, not by reference

Here are the few techniques I've heard of:

  1. Use clone() if the class implements Cloneable. This API is a bit flawed in java and I never quite understood why clone is not defined in the interface, but in Object. Still, it might work.

  2. Create a clone manually. If there is a constructor that accepts all parameters, it might be simple, e.g new User( user.ID, user.Age, ... ). You might even want a constructor that takes a User: new User( anotherUser ).

  3. Implement something to copy from/to a user. Instead of using a constructor, the class may have a method copy( User ). You can then first snapshot the object backupUser.copy( user ) and then restore it user.copy( backupUser ). You might have a variant with methods named backup/restore/snapshot.

  4. Use the state pattern.

  5. Use serialization. If your object is a graph, it might be easier to serialize/deserialize it to get a clone.

That all depends on the use case. Go for the simplest.

EDIT

I also recommend to have a look at these questions:

How to validate a form with multiple checkboxes to have atleast one checked

if (
  document.forms["form"]["mon"].checked==false &&
  document.forms["form"]["tues"].checked==false &&
  document.forms["form"]["wed"].checked==false &&
  document.forms["form"]["thrs"].checked==false &&
  document.forms["form"]["fri"].checked==false
) {
  alert("Select at least One Day into Five Days");
  return false; 
}

How can I concatenate a string within a loop in JSTL/JSP?

Is JSTL's join(), what you searched for?

<c:set var="myVar" value="${fn:join(myParams.items, ' ')}" />

Breaking/exit nested for in vb.net

Unfortunately, there's no exit two levels of for statement, but there are a few workarounds to do what you want:

  • Goto. In general, using goto is considered to be bad practice (and rightfully so), but using goto solely for a forward jump out of structured control statements is usually considered to be OK, especially if the alternative is to have more complicated code.

    For Each item In itemList
        For Each item1 In itemList1
            If item1.Text = "bla bla bla" Then
                Goto end_of_for
            End If
        Next
    Next
    
    end_of_for:
    
  • Dummy outer block

    Do
        For Each item In itemList
            For Each item1 In itemList1
                If item1.Text = "bla bla bla" Then
                    Exit Do
                End If
            Next
        Next
    Loop While False
    

    or

    Try
        For Each item In itemlist
            For Each item1 In itemlist1
                If item1 = "bla bla bla" Then
                    Exit Try
                End If
            Next
        Next
    Finally
    End Try
    
  • Separate function: Put the loops inside a separate function, which can be exited with return. This might require you to pass a lot of parameters, though, depending on how many local variables you use inside the loop. An alternative would be to put the block into a multi-line lambda, since this will create a closure over the local variables.

  • Boolean variable: This might make your code a bit less readable, depending on how many layers of nested loops you have:

    Dim done = False
    
    For Each item In itemList
        For Each item1 In itemList1
            If item1.Text = "bla bla bla" Then
                done = True
                Exit For
            End If
        Next
        If done Then Exit For
    Next
    

Laravel Request::all() Should Not Be Called Statically

I was facing this problem even with use Illuminate\Http\Request; line at the top of my controller. Kept pulling my hair till I realized that I was doing $request::ip() instead of $request->ip(). Can happen to you if you didn't sleep all night and are looking at the code at 6am with half-opened eyes.

Hope this helps someone down the road.

How to run a stored procedure in oracle sql developer?

Try to execute the procedure like this,

var c refcursor;
execute pkg_name.get_user('14232', '15', 'TDWL', 'SA', 1, :c);
print c;

How to execute a java .class from the command line

You need to specify the classpath. This should do it:

java -cp . Echo "hello"

This tells java to use . (the current directory) as its classpath, i.e. the place where it looks for classes. Note than when you use packages, the classpath has to contain the root directory, not the package subdirectories. e.g. if your class is my.package.Echo and the .class file is bin/my/package/Echo.class, the correct classpath directory is bin.

Generate random password string with requirements in javascript

My Crypto based take on the problem. Using ES6 and omitting any browser feature checks. Any comments on security or performance?

const generatePassword = (
  passwordLength = 12,
  passwordChars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
) =>
  [...window.crypto.getRandomValues(new Uint32Array(passwordLength))]
    .map(x => passwordChars[x % passwordChars.length])
    .join('');

How can I install MacVim on OS X?

  1. Download the latest build from https://github.com/macvim-dev/macvim/releases

  2. Expand the archive.

  3. Put MacVim.app into /Applications/.

Done.

need to test if sql query was successful

if the value is 0 then it wasn't successful, but if 1 then successful.

$this->db->affected_rows();

How to define a preprocessor symbol in Xcode

Go to your Target or Project settings, click the Gear icon at the bottom left, and select "Add User-Defined Setting". The new setting name should be GCC_PREPROCESSOR_DEFINITIONS, and you can type your definitions in the right-hand field.

Per Steph's comments, the full syntax is:

constant_1=VALUE constant_2=VALUE

Note that you don't need the '='s if you just want to #define a symbol, rather than giving it a value (for #ifdef statements)

Javascript .querySelector find <div> by innerTEXT

You best see if you have a parent element of the div you are querying. If so get the parent element and perform an element.querySelectorAll("div"). Once you get the nodeList apply a filter on it over the innerText property. Assume that a parent element of the div that we are querying has an id of container. You can normally access container directly from the id but let's do it the proper way.

var conty = document.getElementById("container"),
     divs = conty.querySelectorAll("div"),
    myDiv = [...divs].filter(e => e.innerText == "SomeText");

So that's it.

iOS Safari – How to disable overscroll but allow scrollable divs to scroll normally?

This solves the issue when you scroll past the beginning or end of the div

var selScrollable = '.scrollable';
// Uses document because document will be topmost level in bubbling
$(document).on('touchmove',function(e){
  e.preventDefault();
});
// Uses body because jQuery on events are called off of the element they are
// added to, so bubbling would not work if we used document instead.
$('body').on('touchstart', selScrollable, function(e) {
  if (e.currentTarget.scrollTop === 0) {
    e.currentTarget.scrollTop = 1;
  } else if (e.currentTarget.scrollHeight === e.currentTarget.scrollTop + e.currentTarget.offsetHeight) {
    e.currentTarget.scrollTop -= 1;
  }
});
// Stops preventDefault from being called on document if it sees a scrollable div
$('body').on('touchmove', selScrollable, function(e) {
  e.stopPropagation();
});

Note that this won't work if you want to block whole page scrolling when a div does not have overflow. To block that, use the following event handler instead of the one immediately above (adapted from this question):

$('body').on('touchmove', selScrollable, function(e) {
    // Only block default if internal div contents are large enough to scroll
    // Warning: scrollHeight support is not universal. (https://stackoverflow.com/a/15033226/40352)
    if($(this)[0].scrollHeight > $(this).innerHeight()) {
        e.stopPropagation();
    }
});

How do I add a ToolTip to a control?

  1. Add a ToolTip component to your form
  2. Select one of the controls that you want a tool tip for
  3. Open the property grid (F4), in the list you will find a property called "ToolTip on toolTip1" (or something similar). Set the desired tooltip text on that property.
  4. Repeat 2-3 for the other controls
  5. Done.

The trick here is that the ToolTip control is an extender control, which means that it will extend the set of properties for other controls on the form. Behind the scenes this is achieved by generating code like in Svetlozar's answer. There are other controls working in the same manner (such as the HelpProvider).

CSS set li indent

padding-left is what controls the indentation of ul not margin-left.

Compare: Here's setting padding-left to 0, notice all the indentation disappears.

_x000D_
_x000D_
ul {
  padding-left: 0;
}
_x000D_
<ul>
  <li>section a
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
<ul>
  <li>section b
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
_x000D_
_x000D_
_x000D_

and here's setting margin-left to 0px. Notice the indentation does NOT change.

_x000D_
_x000D_
ul {
  margin-left: 0;
}
_x000D_
<ul>
  <li>section a
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
<ul>
  <li>section b
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
_x000D_
_x000D_
_x000D_

How to find all tables that have foreign keys that reference particular table.column and have values for those foreign keys?

I wrote a little bash onliner that you can write to a script to get a friendly output:

mysql_references_to:

mysql -uUSER -pPASS -A DB_NAME -se "USE information_schema; SELECT * FROM KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_NAME = '$1' AND REFERENCED_COLUMN_NAME = 'id'\G" | sed 's/^[ \t]*//;s/[ \t]*$//' |egrep "\<TABLE_NAME|\<COLUMN_NAME" |sed 's/TABLE_NAME: /./g' |sed 's/COLUMN_NAME: //g' | paste -sd "," -| tr '.' '\n' |sed 's/,$//' |sed 's/,/./'

So the execution: mysql_references_to transaccion (where transaccion is a random table name) gives an output like this:

carrito_transaccion.transaccion_id
comanda_detalle.transaccion_id
comanda_detalle_devolucion.transaccion_positiva_id
comanda_detalle_devolucion.transaccion_negativa_id
comanda_transaccion.transaccion_id
cuenta_operacion.transaccion_id
...

Another Repeated column in mapping for entity error

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

Example:

Class Person {
    String name
}

Class Employee extends Person{
    String empId
}

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

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

Manually Triggering Form Validation using jQuery

Another way to resolve this problem:

$('input').oninvalid(function (event, errorMessage) {
    event.target.focus();
});

Verify External Script Is Loaded

If the script creates any variables or functions in the global space you can check for their existance:

External JS (in global scope) --

var myCustomFlag = true;

And to check if this has run:

if (typeof window.myCustomFlag == 'undefined') {
    //the flag was not found, so the code has not run
    $.getScript('<external JS>');
}

Update

You can check for the existence of the <script> tag in question by selecting all of the <script> elements and checking their src attributes:

//get the number of `<script>` elements that have the correct `src` attribute
var len = $('script').filter(function () {
    return ($(this).attr('src') == '<external JS>');
}).length;

//if there are no scripts that match, the load it
if (len === 0) {
    $.getScript('<external JS>');
}

Or you can just bake this .filter() functionality right into the selector:

var len = $('script[src="<external JS>"]').length;

Hide password with "•••••••" in a textField

You can achieve this directly in Xcode:

enter image description here

The very last checkbox, make sure secure is checked .

Or you can do it using code:

Identifies whether the text object should hide the text being entered.

Declaration

optional var secureTextEntry: Bool { get set }

Discussion

This property is set to false by default. Setting this property to true creates a password-style text object, which hides the text being entered.

example:

texfield.secureTextEntry = true

Detect Safari browser

Read many answers and posts and determined the most accurate solution. Tested in Safari, Chrome, Firefox (desktop and iOS versions). First we need to detect Apple vendor and then exclude Chrome and Firefox (for iOS).

let isSafari = navigator.vendor.match(/apple/i) &&
             !navigator.userAgent.match(/crios/i) &&
             !navigator.userAgent.match(/fxios/i);

if (isSafari) {
  //
} else {
  //
}

Setting UILabel text to bold

Use attributed string:

// Define attributes
let labelFont = UIFont(name: "HelveticaNeue-Bold", size: 18)
let attributes :Dictionary = [NSFontAttributeName : labelFont]

// Create attributed string
var attrString = NSAttributedString(string: "Foo", attributes:attributes)
label.attributedText = attrString

You need to define attributes.

Using attributed string you can mix colors, sizes, fonts etc within one text

How to change the data type of a column without dropping the column with query?

it's simple! just type bellow query

alter table table_Name alter column column_name datatype

alter table Message alter column message nvarchar(1024);

it will work happy programming

How do I install a color theme for IntelliJ IDEA 7.0.x

Go to File->Import Settings... and select the jar settings file

Update as of IntelliJ 2020:

Go to File -> Manage IDE Settings -> Import Settings...

Load local HTML file in a C# WebBrowser

  1. Somewhere, nearby the assembly you're going to run.
  2. Use reflection to get path to your executing assembly, then do some magic to locate your HTML file.

Like this:

var myAssembly = System.Reflection.Assembly.GetEntryAssembly();
var myAssemblyLocation = System.IO.Path.GetDirectoryName(a.Location);
var myHtmlPath = Path.Combine(myAssemblyLocation, "my.html");

How to search for a string in an arraylist

Loop through your list and do a contains or startswith.

ArrayList<String> resList = new ArrayList<String>();
String searchString = "bea";

for (String curVal : list){
  if (curVal.contains(searchString)){
    resList.add(curVal);
  }
}

You can wrap that in a method. The contains checks if its in the list. You could also go for startswith.

How do I get the XML SOAP request of an WCF Web service request?

There is an another way to see XML SOAP - custom MessageEncoder. The main difference from IClientMessageInspector is that it works on lower level, so it captures original byte content including any malformed xml.

In order to implement tracing using this approach you need to wrap a standard textMessageEncoding with custom message encoder as new binding element and apply that custom binding to endpoint in your config.

Also you can see as example how I did it in my project - wrapping textMessageEncoding, logging encoder, custom binding element and config.

What is ":-!!" in C code?

The : is a bitfield. As for !!, that is logical double negation and so returns 0 for false or 1 for true. And the - is a minus sign, i.e. arithmetic negation.

It's all just a trick to get the compiler to barf on invalid inputs.

Consider BUILD_BUG_ON_ZERO. When -!!(e) evaluates to a negative value, that produces a compile error. Otherwise -!!(e) evaluates to 0, and a 0 width bitfield has size of 0. And hence the macro evaluates to a size_t with value 0.

The name is weak in my view because the build in fact fails when the input is not zero.

BUILD_BUG_ON_NULL is very similar, but yields a pointer rather than an int.

Understanding repr( ) function in Python

>>> x = 'foo'
>>> x
'foo'

So the name x is attached to 'foo' string. When you call for example repr(x) the interpreter puts 'foo' instead of x and then calls repr('foo').

>>> repr(x)
"'foo'"
>>> x.__repr__()
"'foo'"

repr actually calls a magic method __repr__ of x, which gives the string containing the representation of the value 'foo' assigned to x. So it returns 'foo' inside the string "" resulting in "'foo'". The idea of repr is to give a string which contains a series of symbols which we can type in the interpreter and get the same value which was sent as an argument to repr.

>>> eval("'foo'")
'foo'

When we call eval("'foo'"), it's the same as we type 'foo' in the interpreter. It's as we directly type the contents of the outer string "" in the interpreter.

>>> eval('foo')

Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    eval('foo')
  File "<string>", line 1, in <module>
NameError: name 'foo' is not defined

If we call eval('foo'), it's the same as we type foo in the interpreter. But there is no foo variable available and an exception is raised.

>>> str(x)
'foo'
>>> x.__str__()
'foo'
>>> 

str is just the string representation of the object (remember, x variable refers to 'foo'), so this function returns string.

>>> str(5)
'5'

String representation of integer 5 is '5'.

>>> str('foo')
'foo'

And string representation of string 'foo' is the same string 'foo'.

How to get all selected values from <select multiple=multiple>?

Actually, I found the best, most-succinct, fastest, and most-compatible way using pure JavaScript (assuming you don't need to fully support IE lte 8) is the following:

var values = Array.prototype.slice.call(document.querySelectorAll('#select-meal-type option:checked'),0).map(function(v,i,a) { 
    return v.value; 
});

UPDATE (2017-02-14):

An even more succinct way using ES6/ES2015 (for the browsers that support it):

const selected = document.querySelectorAll('#select-meal-type option:checked');
const values = Array.from(selected).map(el => el.value);

How to open a folder in Windows Explorer from VBA?

Here's an answer that gives the switch-or-launch behaviour of Start, without the Command Prompt window. It does have the drawback that it can be fooled by an Explorer window that has a folder of the same name elsewhere opened. I might fix that by diving into the child windows and looking for the actual path, I need to figure out how to navigate that.

Usage (requires "Windows Script Host Object Model" in your project's References):

Dim mShell As wshShell

mDocPath = whatever_path & "\" & lastfoldername
mExplorerPath = mShell.ExpandEnvironmentStrings("%SystemRoot%") & "\Explorer.exe"

If Not SwitchToFolder(lastfoldername) Then
    Shell PathName:=mExplorerPath & " """ & mDocPath & """", WindowStyle:=vbNormalFocus
End If

Module:

Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
(ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" _
(ByVal hWnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" _
(ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Private Declare Function BringWindowToTop Lib "user32" _
(ByVal lngHWnd As Long) As Long

Function SwitchToFolder(pFolder As String) As Boolean

Dim hWnd As Long
Dim mRet As Long
Dim mText As String
Dim mWinClass As String
Dim mWinTitle As String

    SwitchToFolder = False

    hWnd = FindWindowEx(0, 0&, vbNullString, vbNullString)
    While hWnd <> 0 And SwitchToFolder = False
        mText = String(100, Chr(0))
        mRet = GetClassName(hWnd, mText, 100)
        mWinClass = Left(mText, mRet)
        If mWinClass = "CabinetWClass" Then
            mText = String(100, Chr(0))
            mRet = GetWindowText(hWnd, mText, 100)
            If mRet > 0 Then
                mWinTitle = Left(mText, mRet)
                If UCase(mWinTitle) = UCase(pFolder) Or _
                   UCase(Right(mWinTitle, Len(pFolder) + 1)) = "\" & UCase(pFolder) Then
                    BringWindowToTop hWnd
                    SwitchToFolder = True
                End If
            End If
        End If
        hWnd = FindWindowEx(0, hWnd, vbNullString, vbNullString)
    Wend

End Function

Get full path of a file with FileUpload Control

Check this post under FileUpload Control

Additionally, the “Include local directory path when uploading files” URLAction has been set to "Disable" for the Internet Zone. This change prevents leakage of potentially sensitive local file-system information to the Internet. For instance, rather than submitting the full path C:\users\ericlaw\documents\secret\image.png, Internet Explorer 8 will now submit only the filename image.png.

Its an option under Internet security that can be enabled

VB.Net: Dynamically Select Image from My.Resources

Make sure you don't include extension of the resource, nor path to it. It's only the resource file name.

PictureBoxName.Image = My.Resources.ResourceManager.GetObject("object_name") 

Pure CSS collapse/expand div

You just need to iterate the anchors in the two links.

<a href="#hide2" class="hide" id="hide2">+</a>
<a href="#show2" class="show" id="show2">-</a>

See this jsfiddle http://jsfiddle.net/eJX8z/

I also added some margin to the FAQ call to improve the format.

How do I convert a Python 3 byte-string variable into a regular string?

Call decode() on a bytes instance to get the text which it encodes.

str = bytes.decode()

How do I break a string across more than one line of code in JavaScript?

In your example, you can break the string into two pieces:

alert ( "Please Select file"
 + " to delete");

Or, when it's a string, as in your case, you can use a backslash as @Gumbo suggested:

alert ( "Please Select file\
 to delete");

Note that this backslash approach is not necessarily preferred, and possibly not universally supported (I had trouble finding hard data on this). It is not in the ECMA 5.1 spec.

When working with other code (not in quotes), line breaks are ignored, and perfectly acceptable. For example:

if(SuperLongConditionWhyIsThisSoLong
  && SuperLongConditionOnAnotherLine
  && SuperLongConditionOnThirdLineSheesh)
{
    // launch_missiles();
}

A SQL Query to select a string between two known strings

Hope this helps : Declared a variable , in case of any changes need to be made thats only once .

declare @line  varchar(100)

set @line ='[email protected]'

select SUBSTRING(@line ,(charindex('-',@line)+1), CHARINDEX('@',@line)-charindex('-',@line)-1)

Free XML Formatting tool

Try http://prettydiff.com/ The algorithm is similar to HTML Tidy, but is more complete. The program is written entirely in JavaScript, so you don't have to install anything.

Phone validation regex

I have a more generic regex to allow the user to enter only numbers, +, -, whitespace and (). It respects the parenthesis balance and there is always a number after a symbol.

^([+]?[\s0-9]+)?(\d{3}|[(]?[0-9]+[)])?([-]?[\s]?[0-9])+$

false, ""
false, "+48 504 203 260@@"
false, "+48.504.203.260"
false, "+55(123) 456-78-90-"
false, "+55(123) - 456-78-90"
false, "504.203.260"
false, " "
false, "-"
false, "()"
false, "() + ()"
false, "(21 7777"
false, "+48 (21)"
false, "+"
true , " 1"
true , "1"
true, "555-5555-555"
true, "+48 504 203 260"
true, "+48 (12) 504 203 260"
true, "+48 (12) 504-203-260"
true, "+48(12)504203260"
true, "+4812504203260"
true, "4812504203260

ValueError: unsupported pickle protocol: 3, python2 pickle can not load the file dumped by python 3 pickle?

Pickle uses different protocols to convert your data to a binary stream.

You must specify in python 3 a protocol lower than 3 in order to be able to load the data in python 2. You can specify the protocol parameter when invoking pickle.dump.

How do I instantiate a Queue object in java?

Queue is an interface in java, you can not do that.

Instead you have two options:

option1:

Queue<Integer> Q = new LinkedList<>();

option2:

Queue<Integer> Q = new ArrayDeque<>();

I recommend using option2 as it is bit faster than the other

pip install mysql-python fails with EnvironmentError: mysql_config not found

Your sudo path does not know about your local path... go into superuser mode, add the path, and install it from there.

sudo su
export PATH=$PATH:/usr/local/mysql/bin/
pip install mysql-python
exit

And you're up and running on OSX. Now you have an updated global python.

Grid of responsive squares

You can make responsive grid of squares with verticaly and horizontaly centered content only with CSS. I will explain how in a step by step process but first here are 2 demos of what you can achieve :

Responsive 3x3 square grid Responsive square images in a 3x3 grid

Now let's see how to make these fancy responsive squares!



1. Making the responsive squares :

The trick for keeping elements square (or whatever other aspect ratio) is to use percent padding-bottom.
Side note: you can use top padding too or top/bottom margin but the background of the element won't display.

As top padding is calculated according to the width of the parent element (See MDN for reference), the height of the element will change according to its width. You can now Keep its aspect ratio according to its width.
At this point you can code :

HTML :

 <div></div>

CSS

div {
    width: 30%;
    padding-bottom: 30%; /* = width for a square aspect ratio */
}

Here is a simple layout example of 3*3 squares grid using the code above.

With this technique, you can make any other aspect ratio, here is a table giving the values of bottom padding according to the aspect ratio and a 30% width.

 Aspect ratio  |  padding-bottom  |  for 30% width
------------------------------------------------
    1:1        |  = width         |    30%
    1:2        |  width x 2       |    60%
    2:1        |  width x 0.5     |    15%
    4:3        |  width x 0.75    |    22.5%
    16:9       |  width x 0.5625  |    16.875%




2. Adding content inside the squares

As you can't add content directly inside the squares (it would expand their height and squares wouldn't be squares anymore) you need to create child elements (for this example I am using divs) inside them with position: absolute; and put the content inside them. This will take the content out of the flow and keep the size of the square.

Don't forget to add position:relative; on the parent divs so the absolute children are positioned/sized relatively to their parent.

Let's add some content to our 3x3 grid of squares :

HTML :

<div class="square">
    <div class="content">
        .. CONTENT HERE ..
    </div>
</div>
... and so on 9 times for 9 squares ...

CSS :

.square {
    float:left;
    position: relative;
    width: 30%;
    padding-bottom: 30%; /* = width for a 1:1 aspect ratio */
    margin:1.66%;
    overflow:hidden;
}

.content {
    position:absolute;
    height:80%; /* = 100% - 2*10% padding */
    width:90%; /* = 100% - 2*5% padding */
    padding: 10% 5%;
}

RESULT <-- with some formatting to make it pretty!



3.Centering the content

Horizontally :

This is pretty easy, you just need to add text-align:center to .content.
RESULT

Vertical alignment

This becomes serious! The trick is to use

display:table;
/* and */
display:table-cell;
vertical-align:middle;

but we can't use display:table; on .square or .content divs because it conflicts with position:absolute; so we need to create two children inside .content divs. Our code will be updated as follow :

HTML :

<div class="square">
    <div class="content">
        <div class="table">
            <div class="table-cell">
                ... CONTENT HERE ...
            </div>
        </div>
    </div>
</div>
... and so on 9 times for 9 squares ...

CSS :

.square {
    float:left;
    position: relative;
    width: 30%;
    padding-bottom : 30%; /* = width for a 1:1 aspect ratio */
    margin:1.66%;
    overflow:hidden;
}

.content {
    position:absolute;
    height:80%; /* = 100% - 2*10% padding */
    width:90%; /* = 100% - 2*5% padding */
    padding: 10% 5%;
}
.table{
    display:table;
    height:100%;
    width:100%;
}
.table-cell{
    display:table-cell;
    vertical-align:middle;
    height:100%;
    width:100%;
}




We have now finished and we can take a look at the result here :

LIVE FULLSCREEN RESULT

editable fiddle here


How to commit a change with both "message" and "description" from the command line?

In case you want to improve the commit message with header and body after you created the commit, you can reword it. This approach is more useful because you know what the code does only after you wrote it.

git rebase -i origin/master

Then, your commits will appear:

pick e152ce2 Update framework
pick ffcf91e Some magic
pick fa672e1 Update comments

Select the commit you want to reword and save.

pick e152ce2 Update framework
reword ffcf91e Some magic
pick fa672e1 Update comments

Now, you have the opportunity to add header and body, where the first line will be the header.

Create perpetuum mobile

Redesign laws of physics with a pinch of imagination. Open a wormhole in 23 dimensions. Add protection to avoid high instability.

Android: Difference between onInterceptTouchEvent and dispatchTouchEvent?

ViewGroup's onInterceptTouchEvent() is always the entry point for ACTION_DOWN event which is first event to occur.

If you want ViewGroup to process this gesture, return true from onInterceptTouchEvent(). On returning true, ViewGroup's onTouchEvent() will receive all subsequent events till next ACTION_UP or ACTION_CANCEL, and in most cases, the touch events between ACTION_DOWN and ACTION_UP or ACTION_CANCEL are ACTION_MOVE, which will normally be recognized as scrolling/fling gestures.

If you return false from onInterceptTouchEvent(), the target view's onTouchEvent() will be called. It will be repeated for subsequent messages till you return true from onInterceptTouchEvent().

Source: http://neevek.net/posts/2013/10/13/implementing-onInterceptTouchEvent-and-onTouchEvent-for-ViewGroup.html

How to connect wireless network adapter to VMWare workstation?

Since there is only one WiFi hardware on the computer its not possible to connect one WiFi hardware to multiple WiFi networks, if you want to that I think you have to map WiFi hardware to guest OS and how host you'll have to use some other hardware (may be Ethernet) but I'm sure that it will work in that way as no VM software allow us to allocate Hardware to Guest except for USB, you can also get USB WiFI and allocate that to VM only.

Loop through JSON in EJS

JSON.stringify returns a String. So, for example:

var data = [
    { id: 1, name: "bob" },
    { id: 2, name: "john" },
    { id: 3, name: "jake" },
];

JSON.stringify(data)

will return the equivalent of:

"[{\"id\":1,\"name\":\"bob\"},{\"id\":2,\"name\":\"john\"},{\"id\":3,\"name\":\"jake\"}]"

as a String value.

So when you have

<% for(var i=0; i<JSON.stringify(data).length; i++) {%>

what that ends up looking like is:

<% for(var i=0; i<"[{\"id\":1,\"name\":\"bob\"},{\"id\":2,\"name\":\"john\"},{\"id\":3,\"name\":\"jake\"}]".length; i++) {%>

which is probably not what you want. What you probably do want is something like this:

<table>
<% for(var i=0; i < data.length; i++) { %>
   <tr>
     <td><%= data[i].id %></td>
     <td><%= data[i].name %></td>
   </tr>
<% } %>
</table>

This will output the following table (using the example data from above):

<table>
  <tr>
    <td>1</td>
    <td>bob</td>
  </tr>
  <tr>
    <td>2</td>
    <td>john</td>
  </tr>
  <tr>
    <td>3</td>
    <td>jake</td>
  </tr>
</table>

Can there exist two main methods in a Java program?

Here you can see that there are 2 public static void main (String args[]) in a single file with the name Test.java (specifically didn't use the name of file as either of the 2 classes names) and the 2 classes are with the default access specifier.

class Sum {

    int add(int a, int b) {
        return (a+b);   
    }

    public static void main (String args[]) {
        System.out.println(" using Sum class");
        Sum a = new Sum();
        System.out.println("Sum is :" + a.add(5, 10));
    }

    public static void main (int i) {
        System.out.println(" Using Sum class main function with integer argument");
        Sum a = new Sum();
        System.out.println("Sum is :" + a.add(20, 10));
    }
}

class DefClass {

    public static void main (String args[]) {
        System.out.println(" using DefClass");
        Sum a = new Sum();
        System.out.println("Sum is :" + a.add(5, 10));
        Sum.main(null);
        Sum.main(1);
    }
}

When we compile the code Test.java it will generate 2 .class files (viz Sum.class and DefClass.class) and if we run Test.java we cannot run it as it won't find any main class with the name Test. Instead if we do java Sum or java DefClass both will give different outputs using different main(). To use the main method of Sum class we can use the class name Sum.main(null) or Sum.main(1)//Passing integer value in the DefClass main().

In a class scope we can have only one public static void main (String args[]) per class since a static method of a class belongs to a class and not to its objects and is called using its class name. Even if we create multiple objects and call the same static methods using them then the instance of the static method to which these call will refer will be the same.

We can also do the overloading of the main method by passing different set of arguments in the main. The Similar example is provided in the above code but by default the control flow will start with the public static void main (String args[]) of the class file which we have invoked using java classname. To invoke the main method with other set of arguments we have to explicitly call it from other classes.

Changing default shell in Linux

You should have a 'skeleton' somewhere in /etc, probably /etc/skeleton, or check the default settings, probably /etc/default or something. Those are scripts that define standard environment variables getting set during a login.

If it is just for your own account: check the (hidden) file ~/.profile and ~/.login. Or generate them, if they don't exist. These are also evaluated by the login process.

Inserting Data into Hive Table

What ever data you have inserted into one text file or log file that can put on one path in hdfs and then write a query as follows in hive

  hive>load data inpath<<specify inputpath>> into table <<tablename>>;

EXAMPLE:

hive>create table foo (id int, name string)
row format delimited
fields terminated by '\t' or '|'or ','
stored as text file;
table created..
    DATA INSERTION::
    hive>load data inpath '/home/hive/foodata.log' into table foo;

Get the full URL in PHP

This is quite easy to do with your Apache environment variables. This only works with Apache 2, which I assume you are using.

Simply use the following PHP code:

<?php
    $request_url = apache_getenv("HTTP_HOST") . apache_getenv("REQUEST_URI");
    echo $request_url;
?>

break out of if and foreach

foreach($equipxml as $equip) {
    $current_device = $equip->xpath("name");
    if ( $current_device[0] == $device ) {
        // found a match in the file            
        $nodeid = $equip->id;
        break;
    }
}

Simply use break. That will do it.

Clicking HTML 5 Video element to play, pause video, breaks play button

How about this one

<video class="play-video" muted onclick="this.paused?this.play():this.pause();">
   <source src="" type="video/mp4">
</video>

expected assignment or function call: no-unused-expressions ReactJS

The error - "Expected an assignment or function call and instead saw an expression no-unused-expressions" comes when we use curly braces i.e {} to return an object literal expression. In such case we can fix it with 2 options

  1. Use the parentheses i.e ()
  2. Use return statement with curly braces i.e {}

Example :

const items = ["Test1", "Test2", "Test3", "Test4"];
console.log(articles.map(item => { `this is ${item}` })); // wrong
console.log(items.map(item => (`this is ${item}`))); // Option1
console.log(items.map(item => { return `this is ${item}` })); // Option2

What exactly does numpy.exp() do?

exp(x) = e^x where e= 2.718281(approx)

import numpy as np

ar=np.array([1,2,3])
ar=np.exp(ar)
print ar

outputs:

[ 2.71828183  7.3890561  20.08553692]

Warning: mysqli_connect(): (HY000/1045): Access denied for user 'username'@'localhost' (using password: YES)

That combination of username, host, and password is not allowed to connect to the server. Verify the permission tables (reloading grants if required) on the server and that you're connecting to the correct server.

JQuery datepicker language

Try Adding this

$('input[name="daterangepicker"]').daterangepicker({

   "locale": {
    "firstDay" :1 // 0 Tuesday - 6 - Monday between
         }});

It must be completed within the locale object of the defined daterangepicker. detailed information can be found here.

mysqli or PDO - what are the pros and cons?

In my benchmark script, each method is tested 10000 times and the difference of the total time for each method is printed. You should this on your own configuration, I'm sure results will vary!

These are my results:

  • "SELECT NULL" -> PGO() faster by ~ 0.35 seconds
  • "SHOW TABLE STATUS" -> mysqli() faster by ~ 2.3 seconds
  • "SELECT * FROM users" -> mysqli() faster by ~ 33 seconds

Note: by using ->fetch_row() for mysqli, the column names are not added to the array, I didn't find a way to do that in PGO. But even if I use ->fetch_array() , mysqli is slightly slower but still faster than PGO (except for SELECT NULL).

What's the best way to dedupe a table?

Adding the actual code here for future reference

So, there are 3 steps, and therefore 3 SQL statements:

Step 1: Move the non duplicates (unique tuples) into a temporary table

CREATE TABLE new_table as
SELECT * FROM old_table WHERE 1 GROUP BY [column to remove duplicates by];

Step 2: delete the old table (or rename it) We no longer need the table with all the duplicate entries, so drop it!

DROP TABLE old_table;

Step 3: rename the new_table to the name of the old_table

RENAME TABLE new_table TO old_table;

And of course, don't forget to fix your buggy code to stop inserting duplicates!

Javascript Src Path

If you have

<base href="/" />

It's will not load file right. Just delete it.

How do I create a pause/wait function using Qt?

If you want a cross-platform method of doing this, the general pattern is to derive from QThread and create a function (static, if you'd like) in your derived class that will call one of the sleep functions in QThread.

How to make a variadic macro (variable number of arguments)

#define DEBUG

#ifdef DEBUG
  #define PRINT print
#else
  #define PRINT(...) ((void)0) //strip out PRINT instructions from code
#endif 

void print(const char *fmt, ...) {

    va_list args;
    va_start(args, fmt);
    vsprintf(str, fmt, args);
        va_end(args);

        printf("%s\n", str);

}

int main() {
   PRINT("[%s %d, %d] Hello World", "March", 26, 2009);
   return 0;
}

If the compiler does not understand variadic macros, you can also strip out PRINT with either of the following:

#define PRINT //

or

#define PRINT if(0)print

The first comments out the PRINT instructions, the second prevents PRINT instruction because of a NULL if condition. If optimization is set, the compiler should strip out never executed instructions like: if(0) print("hello world"); or ((void)0);

How to check if MySQL returns null/empty?

Use empty() and/or is_null()

http://www.php.net/empty http://www.php.net/is_null

Empty alone will achieve your current usage, is_null would just make more control possible if you wanted to distinguish between a field that is null and a field that is empty.

Java collections convert a string to a list of characters

Using Java 8 - Stream Funtion:

Converting A String into Character List:

ArrayList<Character> characterList =  givenStringVariable
                                                         .chars()
                                                         .mapToObj(c-> (char)c)
                                                         .collect(collectors.toList());

Converting A Character List into String:

 String givenStringVariable =  characterList
                                            .stream()
                                            .map(String::valueOf)
                                            .collect(Collectors.joining())

Java code To convert byte to Hexadecimal

BigInteger n = new BigInteger(byteArray);
String hexa = n.toString(16));

Getting Gradle dependencies in IntelliJ IDEA using Gradle build

When importing an existing Gradle project (one with a build.gradle) into IntelliJ IDEA, when presented with the following screen, select Import from external model -> Gradle.

Import project from external model

Optionally, select Auto Import on the next screen to automatically import new dependencies.

How do I make a file:// hyperlink that works in both IE and Firefox?

just use

file:///

works in IE, Firefox and Chrome as far as I can tell.

see http://msdn.microsoft.com/en-us/library/aa767731(VS.85).aspx for more info

How to get distinct values for non-key column fields in Laravel?

Note that groupBy as used above won't work for postgres.

Using distinct is probably a better option - e.g. $users = User::query()->distinct()->get();

If you use query you can select all the columns as requested.

Selecting/excluding sets of columns in pandas

Here's how to create a copy of a DataFrame excluding a list of columns:

df = pd.DataFrame(np.random.randn(100, 4), columns=list('ABCD'))
df2 = df.drop(['B', 'D'], axis=1)

But be careful! You mention views in your question, suggesting that if you changed df, you'd want df2 to change too. (Like a view would in a database.)

This method doesn't achieve that:

>>> df.loc[0, 'A'] = 999 # Change the first value in df
>>> df.head(1)
     A         B         C         D
0  999 -0.742688 -1.980673 -0.920133
>>> df2.head(1) # df2 is unchanged. It's not a view, it's a copy!
          A         C
0  0.251262 -1.980673

Note also that this is also true of @piggybox's method. (Although that method is nice and slick and Pythonic. I'm not doing it down!!)

For more on views vs. copies see this SO answer and this part of the Pandas docs which that answer refers to.

Writing a VLOOKUP function in vba

Please find the code below for Vlookup:

Function vlookupVBA(lookupValue, rangeString, colOffset)
vlookupVBA = "#N/A"
On Error Resume Next
Dim table_lookup As range
Set table_lookup = range(rangeString)
vlookupVBA = Application.WorksheetFunction.vlookup(lookupValue, table_lookup, colOffset, False)
End Function

How to restore a SQL Server 2012 database to SQL Server 2008 R2?

The only built-in way to "downgrade" a database from one SQL Server version to a lower one is the hard way: Script out the whole database, schema and data, then execute the script on the target server.

This is do-able but tends to be brutal.

What's the difference between using CGFloat and float?

CGFloat is a regular float on 32-bit systems and a double on 64-bit systems

typedef float CGFloat;// 32-bit
typedef double CGFloat;// 64-bit

So you won't get any performance penalty.

Count rows with not empty value

A very flexible way to do that kind of things is using ARRAYFORMULA.

As an example imagine you want to count non empty strings (text fields) you can use this code:

=ARRAYFORMULA(SUM(IF(Len(B3:B14)>0, 1, 0)))

What happens here is that "ArrayFormula" let you operate over a set of values. Using the SUM function you indicates "ArrayFormula" to sum any value of the set. The "If" clause is only used to check "empty" or "not empty", 1 for not empty and 0 otherwise. "Len" returns the length of the different text fields, there is where you define the set (range) you want to check. Finally "ArrayFormula" will sum 1 for each field inside the set(range) in which "len" returns more than 0.

If you want to check any other condition, just modify the first argument of the IF clause.

USB Debugging option greyed out

After countless attempts, I found the following quote:

If you are using My KNOX, you cannot enable USB debugging mode while the container is installed. Unfortunately, you have to root your device ... - continue reading

Furthermore make sure:

  • your USB-cable works
  • your connection type is MTP (or PTP in some cases)
  • to enable USB debugging before pluging your device via USB-cable

I switched to another device without KNOX (not rooted as well) to save time. Maybe this quote will save someone some time. It was the only explanation to me in this case.

Cheers!

What is the documents directory (NSDocumentDirectory)?

It can be cleaner to add an extension to FileManager for this kind of awkward call, for tidiness if nothing else. Something like:

extension FileManager {
    static var documentDir : URL {
        return FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
    }
}

Conditionally formatting cells if their value equals any value of another column

Here is the formula

create a new rule in conditional formating based on a formula. Use the following formula and apply it to $A:$A

=NOT(ISERROR(MATCH(A1,$B$1:$B$1000,0)))


enter image description here

here is the example sheet to download if you encounter problems


UPDATE
here is @pnuts's suggestion which works perfect as well:

=MATCH(A1,B:B,0)>0


Use JAXB to create Object from XML String

If you already have the xml, and comes more than one attribute, you can handle it as follows:

String output = "<ciudads><ciudad><idCiudad>1</idCiudad>
<nomCiudad>BOGOTA</nomCiudad></ciudad><ciudad><idCiudad>6</idCiudad>
<nomCiudad>Pereira</nomCiudad></ciudads>";
DocumentBuilder db = DocumentBuilderFactory.newInstance()
    .newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(output));

Document doc = db.parse(is);
NodeList nodes = ((org.w3c.dom.Document) doc)
    .getElementsByTagName("ciudad");

for (int i = 0; i < nodes.getLength(); i++) {           
    Ciudad ciudad = new Ciudad();
    Element element = (Element) nodes.item(i);

    NodeList name = element.getElementsByTagName("idCiudad");
    Element element2 = (Element) name.item(0);
    ciudad.setIdCiudad(Integer
        .valueOf(getCharacterDataFromElement(element2)));

    NodeList title = element.getElementsByTagName("nomCiudad");
    element2 = (Element) title.item(0);
    ciudad.setNombre(getCharacterDataFromElement(element2));

    ciudades.getPartnerAccount().add(ciudad);
}
}

for (Ciudad ciudad1 : ciudades.getPartnerAccount()) {
System.out.println(ciudad1.getIdCiudad());
System.out.println(ciudad1.getNombre());
}

the method getCharacterDataFromElement is

public static String getCharacterDataFromElement(Element e) {
Node child = e.getFirstChild();
if (child instanceof CharacterData) {
CharacterData cd = (CharacterData) child;

return cd.getData();
}
return "";
}

Exposing the current state name with ui router

this is how I do it

JAVASCRIPT:

var module = angular.module('yourModuleName', ['ui.router']);

module.run( ['$rootScope', '$state', '$stateParams',
                      function ($rootScope,   $state,   $stateParams) {
    $rootScope.$state = $state;
    $rootScope.$stateParams = $stateParams; 
}
]);

HTML:

<pre id="uiRouterInfo">
      $state = {{$state.current.name}}
      $stateParams = {{$stateParams}}
      $state full url = {{ $state.$current.url.source }}    
</pre>

EXAMPLE

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

How do I find a list of Homebrew's installable packages?

Please use Homebrew Formulae page to see the list of installable packages. https://formulae.brew.sh/formula/

To install any package => command to use is :

brew install node

Getting "Lock wait timeout exceeded; try restarting transaction" even though I'm not using a transaction

HOW TO FORCE UNLOCK for locked tables in MySQL:

Breaking locks like this may cause atomicity in the database to not be enforced on the sql statements that caused the lock.

This is hackish, and the proper solution is to fix your application that caused the locks. However, when dollars are on the line, a swift kick will get things moving again.

1) Enter MySQL

mysql -u your_user -p

2) Let's see the list of locked tables

mysql> show open tables where in_use>0;

3) Let's see the list of the current processes, one of them is locking your table(s)

mysql> show processlist;

4) Kill one of these processes

mysql> kill <put_process_id_here>;

How to create a drop-down list?

You need a Spinner. Here it is an example:

spinner_1 = (Spinner) findViewById(R.id.spinner1);
spinner_1.setOnItemSelectedListener(this);
List<String> list = new ArrayList<String>(); 
list.add("RANJITH");
list.add("ARUN");
list.add("JEESMON");
list.add("NISAM");
list.add("SREEJITH");
list.add("SANJAY");
list.add("AKSHY");
list.add("FIROZ");
list.add("RAHUL");
list.add("ARJUN");
list.add("SAVIYO");
list.add("VISHNU");

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_1.setAdapter(adapter);


spinner_2 = (Spinner) findViewById(R.id.spinner_two);
spinner_2.setOnItemSelectedListener(this);
List<String> city = new ArrayList<String>();
city.add("KASARGOD");
city.add("KANNUR");
city.add("THRISSUR");
city.add("KOZHIKODE");
city.add("TRIVANDRUM");
city.add("ERNAMKULLAM");
city.add("WAYANAD");
city.add("PALAKKAD");
city.add("ALAPUZHA");
city.add("IDUKKI");
city.add("KOTTAYAM");
city.add("PATHANAMTHITTA");
city.add("KOLLAM");
city.add("MALAPPURAM");
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, city);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_2.setAdapter(adapter2);

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position,
        long id) {
    // TODO Auto-generated method stub
    Toast.makeText(this, "YOUR SELECTION IS : " + parent.getItemAtPosition(position).toString(), Toast.LENGTH_SHORT).show();


}

@Override
public void onNothingSelected(AdapterView<?> parent) {
    // TODO Auto-generated method stub

}

HTML email with Javascript

Here's what you CAN do:

You can attach (to the email) an html document that contains javascript.

Then, when the recipient opens the attachment, their web browser will facilitate the dynamic features you've implemented.

What is the difference between cssSelector & Xpath and which is better with respect to performance for cross browser testing?

I’m going to hold the unpopular on SO selenium tag opinion that XPath is preferable to CSS in the longer run.

This long post has two sections - first I'll put a back-of-the-napkin proof the performance difference between the two is 0.1-0.3 milliseconds (yes; that's 100 microseconds), and then I'll share my opinion why XPath is more powerful.


Performance difference

Let's first tackle "the elephant in the room" – that xpath is slower than css.

With the current cpu power (read: anything x86 produced since 2013), even on browserstack/saucelabs/aws VMs, and the development of the browsers (read: all the popular ones in the last 5 years) that is hardly the case. The browser's engines have developed, the support of xpath is uniform, IE is out of the picture (hopefully for most of us). This comparison in the other answer is being cited all over the place, but it is very contextual – how many are running – or care about – automation against IE8?

If there is a difference, it is in a fraction of a millisecond.

Yet, most higher-level frameworks add at least 1ms of overhead over the raw selenium call anyways (wrappers, handlers, state storing etc); my personal weapon of choice – RobotFramework – adds at least 2ms, which I am more than happy to sacrifice for what it provides. A network roundtrip from an AWS us-east-1 to BrowserStack's hub is usually 11 milliseconds.

So with remote browsers if there is a difference between xpath and css, it is overshadowed by everything else, in orders of magnitude.


The measurements

There are not that many public comparisons (I've really seen only the cited one), so – here's a rough single-case, dummy and simple one.
It will locate an element by the two strategies X times, and compare the average time for that.

The target – BrowserStack's landing page, and its "Sign Up" button; a screenshot of the html as writing this post:

enter image description here

Here's the test code (python):

from selenium import webdriver
import timeit


if __name__ == '__main__':

    xpath_locator = '//div[@class="button-section col-xs-12 row"]'
    css_locator = 'div.button-section.col-xs-12.row'

    repetitions = 1000

    driver = webdriver.Chrome()
    driver.get('https://www.browserstack.com/')

    css_time = timeit.timeit("driver.find_element_by_css_selector(css_locator)", 
                             number=repetitions, globals=globals())
    xpath_time = timeit.timeit('driver.find_element_by_xpath(xpath_locator)', 
                             number=repetitions, globals=globals())

    driver.quit()

    print("css total time {} repeats: {:.2f}s, per find: {:.2f}ms".
          format(repetitions, css_time, (css_time/repetitions)*1000))
    print("xpath total time for {} repeats: {:.2f}s, per find: {:.2f}ms".
          format(repetitions, xpath_time, (xpath_time/repetitions)*1000))

For those not familiar with Python – it opens the page, and finds the element – first with the css locator, then with the xpath; the find operation is repeated 1,000 times. The output is the total time in seconds for the 1,000 repetitions, and average time for one find in milliseconds.

The locators are:

  • for xpath – "a div element having this exact class value, somewhere in the DOM";
  • the css is similar – "a div element with this class, somewhere in the DOM".

Deliberately chosen not to be over-tuned; also, the class selector is cited for the css as "the second fastest after an id".

The environment – Chrome v66.0.3359.139, chromedriver v2.38, cpu: ULV Core M-5Y10 usually running at 1.5GHz (yes, a "word-processing" one, not even a regular i7 beast).

Here's the output:

css total time 1000 repeats: 8.84s, per find: 8.84ms

xpath total time for 1000 repeats: 8.52s, per find: 8.52ms

Obviously the per find timings are pretty close; the difference is 0.32 milliseconds. Don't jump "the xpath is faster" – sometimes it is, sometimes it's css.


Let's try with another set of locators, a tiny-bit more complicated – an attribute having a substring (common approach at least for me, going after an element's class when a part of it bears functional meaning):

xpath_locator = '//div[contains(@class, "button-section")]'
css_locator = 'div[class~=button-section]'

The two locators are again semantically the same – "find a div element having in its class attribute this substring".
Here are the results:

css total time 1000 repeats: 8.60s, per find: 8.60ms

xpath total time for 1000 repeats: 8.75s, per find: 8.75ms

Diff of 0.15ms.


As an exercise - the same test as done in the linked blog in the comments/other answer - the test page is public, and so is the testing code.

They are doing a couple of things in the code - clicking on a column to sort by it, then getting the values, and checking the UI sort is correct.
I'll cut it - just get the locators, after all - this is the root test, right?

The same code as above, with these changes in:

  • The url is now http://the-internet.herokuapp.com/tables; there are 2 tests.

  • The locators for the first one - "Finding Elements By ID and Class" - are:

css_locator = '#table2 tbody .dues'
xpath_locator = "//table[@id='table2']//tr/td[contains(@class,'dues')]"

And here is the outcome:

css total time 1000 repeats: 8.24s, per find: 8.24ms

xpath total time for 1000 repeats: 8.45s, per find: 8.45ms

Diff of 0.2 milliseconds.

The "Finding Elements By Traversing":

css_locator = '#table1 tbody tr td:nth-of-type(4)'
xpath_locator = "//table[@id='table1']//tr/td[4]"

The result:

css total time 1000 repeats: 9.29s, per find: 9.29ms

xpath total time for 1000 repeats: 8.79s, per find: 8.79ms

This time it is 0.5 ms (in reverse, xpath turned out "faster" here).

So 5 years later (better browsers engines) and focusing only on the locators performance (no actions like sorting in the UI, etc), the same testbed - there is practically no difference between CSS and XPath.


So, out of xpath and css, which of the two to choose for performance? The answer is simple – choose locating by id.

Long story short, if the id of an element is unique (as it's supposed to be according to the specs), its value plays an important role in the browser's internal representation of the DOM, and thus is usually the fastest.

Yet, unique and constant (e.g. not auto-generated) ids are not always available, which brings us to "why XPath if there's CSS?"


The XPath advantage

With the performance out of the picture, why do I think xpath is better? Simple – versatility, and power.

Xpath is a language developed for working with XML documents; as such, it allows for much more powerful constructs than css.
For example, navigation in every direction in the tree – find an element, then go to its grandparent and search for a child of it having certain properties.
It allows embedded boolean conditions – cond1 and not(cond2 or not(cond3 and cond4)); embedded selectors – "find a div having these children with these attributes, and then navigate according to it".
XPath allows searching based on a node's value (its text) – however frowned upon this practice is, it does come in handy especially in badly structured documents (no definite attributes to step on, like dynamic ids and classes - locate the element by its text content).

The stepping in css is definitely easier – one can start writing selectors in a matter of minutes; but after a couple of days of usage, the power and possibilities xpath has quickly overcomes css.
And purely subjective – a complex css is much harder to read than a complex xpath expression.

Outro ;)

Finally, again very subjective - which one to chose?

IMO, there is no right or wrong choice - they are different solutions to the same problem, and whatever is more suitable for the job should be picked.

Being "a fan" of XPath I'm not shy to use in my projects a mix of both - heck, sometimes it is much faster to just throw a CSS one, if I know it will do the work just fine.

Reset Windows Activation/Remove license key

On Windows XP -

  1. Reboot into "Safe mode with Command Prompt"
  2. Type "explorer" in the command prompt that comes up and push [Enter]
  3. Click on Start>Run, and type the following :

    rundll32.exe syssetup,SetupOobeBnk

Reboot, and login as normal.

This will reset the 30 day timer for activation back to 30 days so you can enter in the key normally.

How to utilize date add function in Google spreadsheet?

In a fresh spreadsheet (US locale) with 12/19/11 in A1 and DT 30 in B1 then:

=A1+right(B1,2)

in say C1 returns 1/18/12.

As a string function RIGHT returns Text but that can be coerced into a number when adding. In adding a number to dates unity is treated as one day. Within (very wide) limits, months and even years are adjusted automatically.

Cannot push to GitHub - keeps saying need merge

If by any chance git pull prints Already up-to-date then you might want to check the global git push.default param (In ~/.gitconfig). Set it to simple if it was in matching. The below answer explains why:

Git - What is the difference between push.default "matching" and "simple"

Also, it is worth checking if your local branch is out of date using git remote show origin and do a pull if needed

Add regression line equation and R^2 on graph

Here's the most simplest code for everyone

Note: Showing Pearson's Rho and not R^2.

library(ggplot2)
library(ggpubr)

df <- data.frame(x = c(1:100)
df$y <- 2 + 3 * df$x + rnorm(100, sd = 40)
p <- ggplot(data = df, aes(x = x, y = y)) +
        geom_smooth(method = "lm", se=FALSE, color="black", formula = y ~ x) +
        geom_point()+
        stat_cor(label.y = 35)+ #this means at 35th unit in the y axis, the r squared and p value will be shown
        stat_regline_equation(label.y = 30) #this means at 30th unit regresion line equation will be shown

p

One such example with my own dataset

Why does make think the target is up to date?

It happens when you have a file with the same name as Makefile target name in the directory where the Makefile is present.

enter image description here

Wipe data/Factory reset through ADB

After a lot of digging around I finally ended up downloading the source code of the recovery section of Android. Turns out you can actually send commands to the recovery.

 * The arguments which may be supplied in the recovery.command file:
 *   --send_intent=anystring - write the text out to recovery.intent
 *   --update_package=path - verify install an OTA package file
 *   --wipe_data - erase user data (and cache), then reboot
 *   --wipe_cache - wipe cache (but not user data), then reboot
 *   --set_encrypted_filesystem=on|off - enables / diasables encrypted fs

Those are the commands you can use according to the one I found but that might be different for modded files. So using adb you can do this:

adb shell
recovery --wipe_data

Using --wipe_data seemed to do what I was looking for which was handy although I have not fully tested this as of yet.

EDIT:

For anyone still using this topic, these commands may change based on which recovery you are using. If you are using Clockword recovery, these commands should still work. You can find other commands in /cache/recovery/command

For more information please see here: https://github.com/CyanogenMod/android_bootable_recovery/blob/cm-10.2/recovery.c

Can I nest a <button> element inside an <a> using HTML5?

_x000D_
_x000D_
<a href="index.html">_x000D_
  <button type="button">Submit</button>_x000D_
</a>
_x000D_
_x000D_
_x000D_ Or you can use java script in button as:

_x000D_
_x000D_
<button type="submit" onclick="myFunction()">Submit</button>_x000D_
<script>_x000D_
  function myFunction() {_x000D_
      var w = window.open(file:///E:/Aditya%20panchal/index.html);_x000D_
    }_x000D_
</script>
_x000D_
_x000D_
_x000D_

Angular2 change detection: ngOnChanges not firing for nested object

When you are manipulating the data like:

this.data.profiles[i].icon.url = '';

Then you should use in order to detect changes:

let array = this.data.profiles.map(x => Object.assign({}, x)); // It will detect changes

Since angular ngOnchanges not be able to detect changes in array, objects then we have to assign a new reference. Works everytime!

How to align this span to the right of the div?

The solution using flexbox without justify-content: space-between.

<div class="title">
  <span>Cumulative performance</span>
  <span>20/02/2011</span>
</div>

.title {
  display: flex;
}

span:first-of-type {
  flex: 1;
}

When we use flex:1 on the first <span>, it takes up the entire remaining space and moves the second <span> to the right. The Fiddle with this solution: https://jsfiddle.net/2k1vryn7/

Here https://jsfiddle.net/7wvx2uLp/3/ you can see the difference between two flexbox approaches: flexbox with justify-content: space-between and flexbox with flex:1 on the first <span>.

Angular 2 router.navigate

_x000D_
_x000D_
import { ActivatedRoute } from '@angular/router';_x000D_
_x000D_
export class ClassName {_x000D_
  _x000D_
  private router = ActivatedRoute;_x000D_
_x000D_
    constructor(r: ActivatedRoute) {_x000D_
        this.router =r;_x000D_
    }_x000D_
_x000D_
onSuccess() {_x000D_
     this.router.navigate(['/user_invitation'],_x000D_
         {queryParams: {email: loginEmail, code: userCode}});_x000D_
}_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
Get this values:_x000D_
---------------_x000D_
_x000D_
ngOnInit() {_x000D_
    this.route_x000D_
        .queryParams_x000D_
        .subscribe(params => {_x000D_
            let code = params['code'];_x000D_
            let userEmail = params['email'];_x000D_
        });_x000D_
}
_x000D_
_x000D_
_x000D_

Ref: https://angular.io/docs/ts/latest/api/router/index/NavigationExtras-interface.html

continuing execution after an exception is thrown in java

If you have a method that you want to throw an error but you want to do some cleanup in your method beforehand you can put the code that will throw the exception inside a try block, then put the cleanup in the catch block, then throw the error.

try {

    //Dangerous code: could throw an error

} catch (Exception e) {

    //Cleanup: make sure that this methods variables and such are in the desired state

    throw e;
}

This way the try/catch block is not actually handling the error but it gives you time to do stuff before the method terminates and still ensures that the error is passed on to the caller.

An example of this would be if a variable changed in the method then that variable was the cause of an error. It may be desirable to revert the variable.

How do I find the current executable filename?

This one was not included:

System.Windows.Forms.Application.ExecutablePath;

~Joe

Exit a while loop in VBS/VBA

While Loop is an obsolete structure, I would recommend you to replace "While loop" to "Do While..loop", and you will able to use Exit clause.

check = 0 

Do while not rs.EOF 
   if rs("reg_code") = rcode then 
      check = 1 
      Response.Write ("Found") 
      Exit do
   else 
      rs.MoveNext 
    end if 
Loop 

if check = 0 then 
   Response.Write "Not Found" 
end if}

what is the use of xsi:schemaLocation?

According to the spec for locating Schemas

there may or may not be a schema retrievable via the namespace name... User community and/or consumer/provider agreements may establish circumstances in which [trying to retrieve an xsd from the namespace url] is a sensible default strategy

(thanks for being unambiguous, spec!)

and

in case a document author (human or not) created a document with a particular schema in view, and warrants that some or all of the document conforms to that schema, the schemaLocation and noNamespaceSchemaLocation [attributes] are provided.

So basically with specifying just a namespace, your XML "might" be attempted to be validated against an xsd at that location (even if it lacks a schemaLocation attribute), depending on your "community." If you specify a specific schemaLocation, then it basically is implying that the xml document "should" be conformant to said xsd, so "please validate it" (as I read it). My guess is that if you don't do a schemaLocation or noNamespaceSchemaLocation attribute it just "isn't validated" most of the time (based on the other answers, appears java does it this way).

Another wrinkle here is that typically, with xsd validation in java libraries [ex: spring config xml files], if your XML files specifies a particular schemaLocation xsd url in an XML file, like xsi:schemaLocation="http://somewhere http://somewhere/something.xsd" typically within one of your dependency jars it will contain a copy of that xsd file, in its resources section, and spring has a "mapping" capability saying to treat that xsd file as if it maps to the url http://somewhere/something.xsd (so you never end up going to web and downloading the file, it just exists locally). See also https://stackoverflow.com/a/41225329/32453 for slightly more info.

Difference between 'struct' and 'typedef struct' in C++?

An important difference between a 'typedef struct' and a 'struct' in C++ is that inline member initialisation in 'typedef structs' will not work.

// the 'x' in this struct will NOT be initialised to zero
typedef struct { int x = 0; } Foo;

// the 'x' in this struct WILL be initialised to zero
struct Foo { int x = 0; };

How to convert a string Date to long millseconds

Easiest way is used the Date Using Date() and getTime()

    Date dte=new Date();
    long milliSeconds = dte.getTime();
    String strLong = Long.toString(milliSeconds);
    System.out.println(milliSeconds)

nullable object must have a value

When using LINQ extension methods (e.g. Select, Where), the lambda function might be converted to SQL that might not behave identically to your C# code. For instance, C#'s short-circuit evaluated && and || are converted to SQL's eager AND and OR. This can cause problems when you're checking for null in your lambda.

Example:

MyEnum? type = null;
Entities.Table.Where(a => type == null || 
    a.type == (int)type).ToArray();  // Exception: Nullable object must have a value

Notification bar icon turns white in Android 5 Lollipop

remove the android:targetSdkVersion="21" from manifest.xml. it will work! and from this there is no prob at all in your apk it just a trick i apply this and i found colorful icon in notification

Android Studio: Gradle - build fails -- Execution failed for task ':dexDebug'

I found a very interesting issue with Android Studio and the mircrosoft upgrade to the web browser. I upgraded "stupidly" to the latest version of ie. of course Microsoft in their infinite wisdom knows exactly what to do with security. When I tried to compile my app I kept getting the error Gradle - build fails -- Execution failed for task. looking in the stack I saw that it did not recognize the path to java.exe. I found that odd as I was just able to compile the day before. I added JAVA_HOME to the env vars for the system, closed Android Studio and reopened it. Low and behold if the fire wall nag screen did not pop asking if I wanted to all jave.exe through.

What a cluster!

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

Here's a picture explaining the difference between pageY and clientY.

pageY vs clientY

Same for pageX and clientX, respectively.


pageX/Y coordinates are relative to the top left corner of the whole rendered page (including parts hidden by scrolling),

while clientX/Y coordinates are relative to the top left corner of the visible part of the page, "seen" through browser window.

See Demo

You'll probably never need screenX/Y

Using ng-if as a switch inside ng-repeat?

I will suggest move all templates to separate files, and don't do spagetti inside repeat

take a look here:

html:

<div ng-repeat = "data in comments">
    <div ng-include src="buildUrl(data.type)"></div>
 </div>

js:

var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {

  $scope.comments = [
    {"_id":"52fb84fac6b93c152d8b4569",
       "post_id":"52fb84fac6b93c152d8b4567",
       "user_id":"52df9ab5c6b93c8e2a8b4567",
       "type":"hoot"},  
    {"_id":"52fb798cc6b93c74298b4568",
       "post_id":"52fb798cc6b93c74298b4567",
       "user_id":"52df9ab5c6b93c8e2a8b4567",
       "type":"story"},        
    {"_id":"52fb7977c6b93c5c2c8b456b",
       "post_id":"52fb7977c6b93c5c2c8b456a",
       "user_id":"52df9ab5c6b93c8e2a8b4567",
       "type":"article"}
  ];

  $scope.buildUrl = function(type) {
    return type + '.html';
  }
});

http://plnkr.co/edit/HxnirSvMHNQ748M2WeRt?p=preview

How to write a UTF-8 file with Java?

Below sample code can read file line by line and write new file in UTF-8 format. Also, i am explicitly specifying Cp1252 encoding.

    public static void main(String args[]) throws IOException {

    BufferedReader br = new BufferedReader(new InputStreamReader(
            new FileInputStream("c:\\filenonUTF.txt"),
            "Cp1252"));
    String line;

    Writer out = new BufferedWriter(
            new OutputStreamWriter(new FileOutputStream(
                    "c:\\fileUTF.txt"), "UTF-8"));

    try {

        while ((line = br.readLine()) != null) {

            out.write(line);
            out.write("\n");

        }

    } finally {

        br.close();
        out.close();

    }
}

link button property to open in new tab?

  1. LinkButton executes HTTP POST operation, you cant change post target here.
  2. Not all the browsers support posting form to a new target window.
  3. In order to have it post, you have to change target of your "FORM".
  4. You can use some javascript workaround to change your POST target, by changing form's target attribute, but browser will give a warning to user (IE Does), that this page is trying to post data on a new window, do you want to continue etc.

Try to find out ID of your form element in generated aspx, and you can change target like...

getElementByID('theForm').target = '_blank' or 'myNewWindow'

Didn't find class "com.google.firebase.provider.FirebaseInitProvider"?

If you are using MultiDex in your App Gradle then change extends application to extends MultiDexApplication in your application class. It will defiantly work

C++, How to determine if a Windows Process is running?

The solution provided by @user152949, as it was noted in commentaries, skips the first process and doesn't break when "exists" is set to true. Let me provide a fixed version:

#include <windows.h>
#include <tlhelp32.h>
#include <tchar.h>

bool IsProcessRunning(const TCHAR* const executableName) {
    PROCESSENTRY32 entry;
    entry.dwSize = sizeof(PROCESSENTRY32);

    const auto snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

    if (!Process32First(snapshot, &entry)) {
        CloseHandle(snapshot);
        return false;
    }

    do {
        if (!_tcsicmp(entry.szExeFile, executableName)) {
            CloseHandle(snapshot);
            return true;
        }
    } while (Process32Next(snapshot, &entry));

    CloseHandle(snapshot);
    return false;
}

Horizontal Scroll Table in Bootstrap/CSS

@Ciwan. You're right. The table goes to full width (much too wide). Not a good solution. Better to do this:

css:

.scrollme {
    overflow-x: auto;
}

html:

<div class="scrollme">                        
  <table class="table table-responsive"> ...
  </table>
</div>

Edit: changing scroll-y to scroll-x

XSL xsl:template match="/"

The value of the match attribute of the <xsl:template> instruction must be a match pattern.

Match patterns form a subset of the set of all possible XPath expressions. The first, natural, limitation is that a match pattern must select a set of nodes. There are also other limitations. In particular, reverse axes are not allowed in the location steps (but can be specified within the predicates). Also, no variable or parameter references are allowed in XSLT 1.0, but using these is legal in XSLT 2.x.

/ in XPath denotes the root or document node. In XPath 2.0 (and hence XSLT 2.x) this can also be written as document-node().

A match pattern can contain the // abbreviation.

Examples of match patterns:

<xsl:template match="table">

can be applied on any element named table.

<xsl:template match="x/y">

can be applied on any element named y whose parent is an element named x.

<xsl:template match="*">

can be applied to any element.

<xsl:template match="/*">

can be applied only to the top element of an XML document.

<xsl:template match="@*">

can be applied to any attribute.

<xsl:template match="text()">

can be applied to any text node.

<xsl:template match="comment()">

can be applied to any comment node.

<xsl:template match="processing-instruction()">

can be applied to any processing instruction node.

<xsl:template match="node()">

can be applied to any node: element, text, comment or processing instructon.

How is malloc() implemented internally?

It's also important to realize that simply moving the program break pointer around with brk and sbrk doesn't actually allocate the memory, it just sets up the address space. On Linux, for example, the memory will be "backed" by actual physical pages when that address range is accessed, which will result in a page fault, and will eventually lead to the kernel calling into the page allocator to get a backing page.

Laravel update model with unique validation rule for attribute

You can trying code bellow

return [
    'email' => 'required|email|max:255|unique:users,email,' .$this->get('id'),
    'username' => 'required|alpha_dash|max:50|unique:users,username,'.$this->get('id'),
    'password' => 'required|min:6',
    'confirm-password' => 'required|same:password',
];

Upload file to FTP using C#

I have observed that -

  1. FtpwebRequest is missing.
  2. As the target is FTP, so the NetworkCredential required.

I have prepared a method that works like this, you can replace the value of the variable ftpurl with the parameter TargetDestinationPath. I had tested this method on winforms application :

private void UploadProfileImage(string TargetFileName, string TargetDestinationPath, string FiletoUpload)
        {
            //Get the Image Destination path
            string imageName = TargetFileName; //you can comment this
            string imgPath = TargetDestinationPath; 

            string ftpurl = "ftp://downloads.abc.com/downloads.abc.com/MobileApps/SystemImages/ProfileImages/" + imgPath;
            string ftpusername = krayknot_DAL.clsGlobal.FTPUsername;
            string ftppassword = krayknot_DAL.clsGlobal.FTPPassword;
            string fileurl = FiletoUpload;

            FtpWebRequest ftpClient = (FtpWebRequest)FtpWebRequest.Create(ftpurl);
            ftpClient.Credentials = new System.Net.NetworkCredential(ftpusername, ftppassword);
            ftpClient.Method = System.Net.WebRequestMethods.Ftp.UploadFile;
            ftpClient.UseBinary = true;
            ftpClient.KeepAlive = true;
            System.IO.FileInfo fi = new System.IO.FileInfo(fileurl);
            ftpClient.ContentLength = fi.Length;
            byte[] buffer = new byte[4097];
            int bytes = 0;
            int total_bytes = (int)fi.Length;
            System.IO.FileStream fs = fi.OpenRead();
            System.IO.Stream rs = ftpClient.GetRequestStream();
            while (total_bytes > 0)
            {
                bytes = fs.Read(buffer, 0, buffer.Length);
                rs.Write(buffer, 0, bytes);
                total_bytes = total_bytes - bytes;
            }
            //fs.Flush();
            fs.Close();
            rs.Close();
            FtpWebResponse uploadResponse = (FtpWebResponse)ftpClient.GetResponse();
            string value = uploadResponse.StatusDescription;
            uploadResponse.Close();
        }

Let me know in case of any issue, or here is one more link that can help you:

https://msdn.microsoft.com/en-us/library/ms229715(v=vs.110).aspx

How to count the number of set bits in a 32-bit integer?

This will also work fine :

int ans = 0;
while(num){
 ans += (num &1);
 num = num >>1;
}    
return ans;

How do I make a dictionary with multiple keys to one value?

I guess you mean this:

class Value:
    def __init__(self, v=None):
        self.v = v

v1 = Value(1)
v2 = Value(2)

d = {'a': v1, 'b': v1, 'c': v2, 'd': v2}
d['a'].v += 1

d['b'].v == 2 # True
  • Python's strings and numbers are immutable objects,
  • So, if you want d['a'] and d['b'] to point to the same value that "updates" as it changes, make the value refer to a mutable object (user-defined class like above, or a dict, list, set).
  • Then, when you modify the object at d['a'], d['b'] changes at same time because they both point to same object.

How to create a generic array in Java?

You could use a cast:

public class GenSet<Item> {
    private Item[] a;

    public GenSet(int s) {
        a = (Item[]) new Object[s];
    }
}

Looping through dictionary object

public class TestModels
{
    public Dictionary<int, dynamic> sp = new Dictionary<int, dynamic>();

    public TestModels()
    {
        sp.Add(0, new {name="Test One", age=5});
        sp.Add(1, new {name="Test Two", age=7});
    }
}

Use xml.etree.ElementTree to print nicely formatted xml files

You could use the library lxml (Note top level link is now spam) , which is a superset of ElementTree. Its tostring() method includes a parameter pretty_print - for example:

>>> print(etree.tostring(root, pretty_print=True))
<root>
  <child1/>
  <child2/>
  <child3/>
</root>

Is it possible to use vh minus pixels in a CSS calc()?

It does work indeed. Issue was with my less compiler. It was compiled in to:

.container {
  min-height: calc(-51vh);
}

Fixed with the following code in less file:

.container {
  min-height: calc(~"100vh - 150px");
}

Thanks to this link: Less Aggressive Compilation with CSS3 calc

How can I limit possible inputs in a HTML5 "number" element?

HTML Input

 <input class="minutesInput" type="number" min="10" max="120" value="" />

jQuery

 $(".minutesInput").on('keyup keypress blur change', function(e) {

    if($(this).val() > 120){
      $(this).val('120');
      return false;
    }

  });

php form action php self

Leaving the action value blank will cause the form to post back to itself.

Redirect in Spring MVC

try to change this in your dispatcher-servlet.xml

<!-- Your View Resolver -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.ResourceBundleViewResolver">
    <property name="basenames" value="views" />
    <property name="order" value="1" />
</bean>   
<!-- UrlBasedViewResolver to Handle Redirects & Forward -->
<bean id="urlViewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" />
    <property name="order" value="2" />
</bean>        

What happens is clearly explained here http://projects.nigelsim.org/wiki/RedirectWithSpringWebMvc

Passing Arrays to Function in C++

The syntaxes

int[]

and

int[X] // Where X is a compile-time positive integer

are exactly the same as

int*

when in a function parameter list (I left out the optional names).

Additionally, an array name decays to a pointer to the first element when passed to a function (and not passed by reference) so both int firstarray[3] and int secondarray[5] decay to int*s.

It also happens that both an array dereference and a pointer dereference with subscript syntax (subscript syntax is x[y]) yield an lvalue to the same element when you use the same index.

These three rules combine to make the code legal and work how you expect; it just passes pointers to the function, along with the length of the arrays which you cannot know after the arrays decay to pointers.

Proper way to initialize C++ structs

From what you've told us it does appear to be a false positive in valgrind. The new syntax with () should value-initialize the object, assuming it is POD.

Is it possible that some subpart of your struct isn't actually POD and that's preventing the expected initialization? Are you able to simplify your code into a postable example that still flags the valgrind error?

Alternately perhaps your compiler doesn't actually value-initialize POD structures.

In any case probably the simplest solution is to write constructor(s) as needed for the struct/subparts.

Substitute a comma with a line break in a cell

Windows (unlike some other OS's, like Linux), uses CR+LF for line breaks:

  • CR = 13 = 0x0D = ^M = \r = carriage return

  • LF = 10 = 0x0A = ^J = \n = new line

The characters need to be in that order, if you want the line breaks to be consistently visible when copied to other Windows programs. So the Excel function would be:

=SUBSTITUTE(A1,",",CHAR(13) & CHAR(10))

adding 30 minutes to datetime php/mysql

Try this one

DATE_ADD(datefield, INTERVAL 30 MINUTE)

How to create Select List for Country and States/province in MVC

Thank You All! I am able to to load Select List as per MVC now My Working Code is below:

HTML+MVC Code in View:-

    <tr>
        <th>@Html.Label("Country")</th>
        <td>@Html.DropDownListFor(x =>x.Province,SelectListItemHelper.GetCountryList())<span class="required">*</span></td>
    </tr>
    <tr>
        <th>@Html.LabelFor(x=>x.Province)</th>
        <td>@Html.DropDownListFor(x =>x.Province,SelectListItemHelper.GetProvincesList())<span class="required">*</span></td>
    </tr>

Created a Controller under "UTIL" folder: Code:-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MedAvail.Applications.MedProvision.Web.Util
{
    public class SelectListItemHelper
    {
        public static IEnumerable<SelectListItem> GetProvincesList()
        {
            IList<SelectListItem> items = new List<SelectListItem>
            {
                new SelectListItem{Text = "California", Value = "B"},
                new SelectListItem{Text = "Alaska", Value = "B"},
                new SelectListItem{Text = "Illinois", Value = "B"},
                new SelectListItem{Text = "Texas", Value = "B"},
                new SelectListItem{Text = "Washington", Value = "B"}

            };
            return items;
        }


        public static IEnumerable<SelectListItem> GetCountryList()
        {
            IList<SelectListItem> items = new List<SelectListItem>
            {
                new SelectListItem{Text = "United States", Value = "B"},
                new SelectListItem{Text = "Canada", Value = "B"},
                new SelectListItem{Text = "United Kingdom", Value = "B"},
                new SelectListItem{Text = "Texas", Value = "B"},
                new SelectListItem{Text = "Washington", Value = "B"}

            };
            return items;
        }


    }
}

And its working COOL now :-)

Thank you!!

Git 'fatal: Unable to write new index file'

Here is what worked for me:

Context:

  1. Building a project on a server

  2. git status returns a HEAD detached at <commit-SHA>

  3. What ever operation I did locally, I had this error. More specifically:

    • git checkout
    • git reset HEAD --hard

Solution

  1. Simply removed file <work-dir>/.git/index.
  2. A git status would indicate that all files in the projet are not tracked (no surprise here).
  3. git reset HEAD --hard
  4. Back to HEAD detached at <commit-SHA> when doing a git status, but then you should be able to
  5. git checkout <some-branch>

and you're back on track!

!! IMPORTANT !!

This works only because I am "merly" building. No precious modification has been performed on the code. If you are actually in "dev-time", then I would recommand to save your work first or go for another method.

Hope it will help :).

Drop rows with all zeros in pandas data frame

It turns out this can be nicely expressed in a vectorized fashion:

> df = pd.DataFrame({'a':[0,0,1,1], 'b':[0,1,0,1]})
> df = df[(df.T != 0).any()]
> df
   a  b
1  0  1
2  1  0
3  1  1

Angular 2 Show and Hide an element

When you don't care about removing the Html Dom-Element, use *ngIf.

Otherwise, use this:

<div [style.visibility]="(numberOfUnreadAlerts == 0) ? 'hidden' : 'visible' ">
   COUNTER: {{numberOfUnreadAlerts}} 
</div>

How to set JAVA_HOME for multiple Tomcat instances?

Also, note that there shouldn't be any space after =:

set JAVA_HOME=C:\Program Files\Java\jdk1.6.0_27

Importing Excel into a DataTable Quickly

MS Office Interop is slow and even Microsoft does not recommend Interop usage on server side and cannot be use to import large Excel files. For more details see why not to use OLE Automation from Microsoft point of view.

Instead, you can use any Excel library, like EasyXLS for example. This is a code sample that shows how to read the Excel file:

ExcelDocument workbook = new ExcelDocument();
DataSet ds = workbook.easy_ReadXLSActiveSheet_AsDataSet("excel.xls");
DataTable dataTable = ds.Tables[0];

If your Excel file has multiple sheets or for importing only ranges of cells (for better performances) take a look to more code samples on how to import Excel to DataTable in C# using EasyXLS.

Working with SQL views in Entity Framework Core

Here is a new way to work with SQL views in EF Core: Query Types.

How do I manually create a file with a . (dot) prefix in Windows? For example, .htaccess

Use something like Notepad++ (or even Notepad), 'Save As', and enter the name .htaccess that way. I always found it weird, but it lets you do it from a program!

Is the MIME type 'image/jpg' the same as 'image/jpeg'?

tl;dr the "standards" are a hodge-podge mess; it depends who you ask!

Overall, there appears to be no MIME type image/jpg. Yet, in practice, nearly all software handles image files named "*.jpg" just fine.
This particular topic is confusing because the varying association of file name extension associated to a MIME type depends which organization created the table of file name extensions to MIME types. In other words, file name extension .jpg could be many different things.

For example, here are three "complete lists" and one RFC that with varying JPEG Image format file name extensions and the associated MIME types.

These "complete lists" and RFC do not have MIME type image/jpg! But for MIME type image/jpeg some lists do have varying file name extensions (.jpeg, .jpg, …). Other lists do not mention image/jpeg.

Also, there are different types of JPEG Image formats (e.g. Progressive JPEG Image format, JPEG 2000, etcetera) and "JPEG Extensions" that may or may not overlap in file name extension and declared MIME type.

Another confusing thing is RFC 3745 does not appear to match IANA Media Types yet the same RFC is supposed to inform the IANA Media Types document. For example, in RFC 3745 .jpf is preferred file extension for image/jpx but in IANA Media Types the name jpf is not present (and that IANA document references RFC 3745!).

Another confusing thing is IANA Media Types lists "names" but does not list "file name extensions". This is on purpose, but confuses the endeavor of mapping file name extensions to MIME types.

Another confusing thing: is it "mime", or "MIME", or "MIME type", or "mime type", or "mime/type", or "media type"?


The most official seeming document by IANA is surprisingly inadequate. No MIME type is registered for file extension .jpg yet there exists the odd vnd.sealedmedia.softseal.jpg. File extension.JPEG is only known as a video type while file extension .jpeg is an image type (when did lowercase and uppercase letters start mattering!?). At the same time, jpeg2000 is type video yet RFC 3745 considers JPEG 2000 an image type! The IANA list seems to cater to company-specific jpeg formats (e.g. vnd.sealedmedia.softseal.jpg).


In summary...

Because of the prior confusions, it is difficult to find an industry-accepted canonical document that maps file name extensions to MIME types, particularly for the JPEG Image File Format.



Related question "List of ALL MimeTypes on the Planet, mapped to File Extensions?".

Write HTML file using Java

Templates and other methods based on preliminary creation of the document in memory are likely to impose certain limits on resulting document size.

Meanwhile a very straightforward and reliable write-on-the-fly approach to creation of plain HTML exists, based on a SAX handler and default XSLT transformer, the latter having intrinsic capability of HTML output:

String encoding = "UTF-8";
FileOutputStream fos = new FileOutputStream("myfile.html");
OutputStreamWriter writer = new OutputStreamWriter(fos, encoding);
StreamResult streamResult = new StreamResult(writer);

SAXTransformerFactory saxFactory =
    (SAXTransformerFactory) TransformerFactory.newInstance();
TransformerHandler tHandler = saxFactory.newTransformerHandler();
tHandler.setResult(streamResult);

Transformer transformer = tHandler.getTransformer();
transformer.setOutputProperty(OutputKeys.METHOD, "html");
transformer.setOutputProperty(OutputKeys.ENCODING, encoding);
transformer.setOutputProperty(OutputKeys.INDENT, "yes");

writer.write("<!DOCTYPE html>\n");
writer.flush();
tHandler.startDocument();
    tHandler.startElement("", "", "html", new AttributesImpl());
        tHandler.startElement("", "", "head", new AttributesImpl());
            tHandler.startElement("", "", "title", new AttributesImpl());
                tHandler.characters("Hello".toCharArray(), 0, 5);
            tHandler.endElement("", "", "title");
        tHandler.endElement("", "", "head");
        tHandler.startElement("", "", "body", new AttributesImpl());
            tHandler.startElement("", "", "p", new AttributesImpl());
                tHandler.characters("5 > 3".toCharArray(), 0, 5); // note '>' character
            tHandler.endElement("", "", "p");
        tHandler.endElement("", "", "body");
    tHandler.endElement("", "", "html");
tHandler.endDocument();
writer.close();

Note that XSLT transformer will release you from the burden of escaping special characters like >, as it takes necessary care of it by itself.

And it is easy to wrap SAX methods like startElement() and characters() to something more convenient to one's taste...

pretty-print JSON using JavaScript

Here's user123444555621's awesome HTML one adapted for terminals. Handy for debugging Node scripts:

function prettyJ(json) {
  if (typeof json !== 'string') {
    json = JSON.stringify(json, undefined, 2);
  }
  return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, 
    function (match) {
      let cls = "\x1b[36m";
      if (/^"/.test(match)) {
        if (/:$/.test(match)) {
          cls = "\x1b[34m";
        } else {
          cls = "\x1b[32m";
        }
      } else if (/true|false/.test(match)) {
        cls = "\x1b[35m"; 
      } else if (/null/.test(match)) {
        cls = "\x1b[31m";
      }
      return cls + match + "\x1b[0m";
    }
  );
}

Usage:

// thing = any json OR string of json
prettyJ(thing);

How does Python's super() work with multiple inheritance?

This is detailed with a reasonable amount of detail by Guido himself in his blog post Method Resolution Order (including two earlier attempts).

In your example, Third() will call First.__init__. Python looks for each attribute in the class's parents as they are listed left to right. In this case, we are looking for __init__. So, if you define

class Third(First, Second):
    ...

Python will start by looking at First, and, if First doesn't have the attribute, then it will look at Second.

This situation becomes more complex when inheritance starts crossing paths (for example if First inherited from Second). Read the link above for more details, but, in a nutshell, Python will try to maintain the order in which each class appears on the inheritance list, starting with the child class itself.

So, for instance, if you had:

class First(object):
    def __init__(self):
        print "first"

class Second(First):
    def __init__(self):
        print "second"

class Third(First):
    def __init__(self):
        print "third"

class Fourth(Second, Third):
    def __init__(self):
        super(Fourth, self).__init__()
        print "that's it"

the MRO would be [Fourth, Second, Third, First].

By the way: if Python cannot find a coherent method resolution order, it'll raise an exception, instead of falling back to behavior which might surprise the user.

Edited to add an example of an ambiguous MRO:

class First(object):
    def __init__(self):
        print "first"

class Second(First):
    def __init__(self):
        print "second"

class Third(First, Second):
    def __init__(self):
        print "third"

Should Third's MRO be [First, Second] or [Second, First]? There's no obvious expectation, and Python will raise an error:

TypeError: Error when calling the metaclass bases
    Cannot create a consistent method resolution order (MRO) for bases Second, First

Edit: I see several people arguing that the examples above lack super() calls, so let me explain: The point of the examples is to show how the MRO is constructed. They are not intended to print "first\nsecond\third" or whatever. You can – and should, of course, play around with the example, add super() calls, see what happens, and gain a deeper understanding of Python's inheritance model. But my goal here is to keep it simple and show how the MRO is built. And it is built as I explained:

>>> Fourth.__mro__
(<class '__main__.Fourth'>,
 <class '__main__.Second'>, <class '__main__.Third'>,
 <class '__main__.First'>,
 <type 'object'>)

How do I change the background of a Frame in Tkinter?

The root of the problem is that you are unknowingly using the Frame class from the ttk package rather than from the tkinter package. The one from ttk does not support the background option.

This is the main reason why you shouldn't do global imports -- you can overwrite the definition of classes and commands.

I recommend doing imports like this:

import tkinter as tk
import ttk

Then you prefix the widgets with either tk or ttk :

f1 = tk.Frame(..., bg=..., fg=...)
f2 = ttk.Frame(..., style=...)

It then becomes instantly obvious which widget you are using, at the expense of just a tiny bit more typing. If you had done this, this error in your code would never have happened.

PHP Fatal error: Class 'PDO' not found

I had to run the following on AWS EC2 Linux instance (PHP Version 7.3):

sudo yum install php73-php-pdo php73-php-mysqlnd

Confirm password validation in Angular 6

You can use this way to fulfill this requirement. I use the below method to validate the Password and Confirm Password.

To use this method you have to import FormGroup from @angular/forms library.

import { FormBuilder, Validators, FormGroup } from '@angular/forms';

FormBuilder Group:

this.myForm= this.formBuilder.group({
  password    : ['', Validators.compose([Validators.required])],
  confirmPassword    : ['',  Validators.compose([Validators.required])],
},
{validator: this.checkPassword('password', 'confirmPassword') }
);

Method to Validate two fields:

 checkPassword(controlName: string, matchingControlName: string) {
    return (formGroup: FormGroup) => {
        const control = formGroup.controls[controlName];
        const matchingControl = formGroup.controls[matchingControlName];
        if (matchingControl.errors && !matchingControl.errors.mustMatch) {
            // return if another validator has already found an error on the matchingControl
            return;
        }
        // set error on matchingControl if validation fails
        if (control.value !== matchingControl.value) {
            matchingControl.setErrors({ mustMatch: true });
            this.isPasswordSame = (matchingControl.status == 'VALID') ? true : false;
        } else {
            matchingControl.setErrors(null);
            this.isPasswordSame = (matchingControl.status == 'VALID') ? true : false;
        }
    }
  }

HTML: Here I am use personalized isPasswordSame variable you can use the inbuilt hasError or any other.

<form [formGroup]="myForm">
  <ion-item>
    <ion-label position="floating">Password</ion-label>
    <ion-input required type="text" formControlName="password" placeholder="Enter Password"></ion-input>
  </ion-item>
  <ion-label *ngIf="myForm.controls.password.valid">
      <p class="error">Please enter password!!</p>
  </ion-label>
  <ion-item>
    <ion-label position="floating">Confirm Password</ion-label>
    <ion-input required type="text" formControlName="confirmPassword" placeholder="Enter Confirm Password"></ion-input>
  </ion-item>
  <ion-label *ngIf="isPasswordSame">
      <p class="error">Password and Confrim Password must be same!!</p>
  </ion-label>
</form>

Android WebView Cookie Problem

Encountered this too also. Here's what I did.

On my LoginActivity, inside my AsyncTask, I have the following:

CookieStoreHelper.cookieStore = new BasicCookieStore();
BasicHttpContext localContext = new BasicHttpContext();
localContext.setAttribute(ClientContext.COOKIE_STORE, CookieStoreHelper.cookieStore);

HttpResponse postResponse = client.execute(httpPost,localContext);
CookieStoreHelper.sessionCookie = CookieStoreHelper.cookieStore.getCookies();

//WHERE CookieStoreHelper.sessionCookie is another class containing the variable sessionCookie defined as List cookies; and cookieStore define as BasicCookieStore cookieStore;

Then on my Fragment, where my WebView is located i have the following:

//DECLARE LIST OF COOKIE
List<Cookie> sessionCookie;

inside my method or just before you are setting the WebViewClient()

WebSettings settings = webView.getSettings();
settings.setJavaScriptEnabled(true);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);

sessionCookie = CookieStoreHelper.cookieStore.getCookies();
CookieSyncManager.createInstance(webView.getContext());
CookieSyncManager.getInstance().startSync();
CookieManager cookieManager = CookieManager.getInstance();
CookieManager.getInstance().setAcceptCookie(true);
if (sessionCookie != null) {
   for(Cookie c:  sessionCookie){
      cookieManager.setCookie(CookieStoreHelper.DOMAIN, c.getName() + "=" + c.getValue());
   }
   CookieSyncManager.getInstance().sync();

 }

 webView.setWebViewClient(new WebViewClient() {
    //AND SO ON, YOUR CODE
 }

Quick Tip: Have firebug installed on firefox or use developer console on chrome and test first your webpage, capture the Cookie and check the domain so you can store it somewhere and be sure that you are correctly setting the right domain.

Edit: edited CookieStoreHelper.cookies to CookieStoreHelper.sessionCookie

How to uninstall jupyter

When you $ pip install jupyter several dependencies are installed. The best way to uninstall it completely is by running:

  1. $ pip install pip-autoremove
  2. $ pip-autoremove jupyter -y

Kindly refer to this related question.

pip-autoremove removes a package and its unused dependencies. Here are the docs.

How to show multiline text in a table cell

On your server-side code, replace the new lines (\n) with <br/>.

If you're using PHP, you can use nl2br()

How to write html code inside <?php ?>, I want write html code within the PHP script so that it can be echoed from Backend

You can drop in and out of the PHP context using the <?php and ?> tags. For example...

<?php
$array = array(1, 2, 3, 4);
?>

<table>
<thead><tr><th>Number</th></tr></thead>
<tbody>
<?php foreach ($array as $num) : ?>
<tr><td><?= htmlspecialchars($num) ?></td></tr>
<?php endforeach ?>
</tbody>
</table>

Also see Alternative syntax for control structures

What exactly does the T and Z mean in timestamp?

The T doesn't really stand for anything. It is just the separator that the ISO 8601 combined date-time format requires. You can read it as an abbreviation for Time.

The Z stands for the Zero timezone, as it is offset by 0 from the Coordinated Universal Time (UTC).

Both characters are just static letters in the format, which is why they are not documented by the datetime.strftime() method. You could have used Q or M or Monty Python and the method would have returned them unchanged as well; the method only looks for patterns starting with % to replace those with information from the datetime object.

Find IP address of directly connected device

Windows 7 has the arp command within it. arp -a should show you the static and dynamic type interfaces connected to your system.

Assigning the output of a command to a variable

Try:

output=$(ps -ef | awk '/siebsvc –s siebsrvr/ && !/awk/ { a++ } END { print a }'); echo $output

Wrapping your command in $( ) tells the shell to run that command, instead of attempting to set the command itself to the variable named "output". (Note that you could also use backticks `command`.)

I can highly recommend http://tldp.org/LDP/abs/html/commandsub.html to learn more about command substitution.

Also, as 1_CR correctly points out in a comment, the extra space between the equals sign and the assignment is causing it to fail. Here is a simple example on my machine of the behavior you are experiencing:

jed@MBP:~$ foo=$(ps -ef |head -1);echo $foo
UID PID PPID C STIME TTY TIME CMD

jed@MBP:~$ foo= $(ps -ef |head -1);echo $foo
-bash: UID: command not found
UID PID PPID C STIME TTY TIME CMD

Formula px to dp, dp to px android

In most of the cases, conversion functions are called frequently. We can optimize it by adding memoization. So,it does not calculate every-time the function is called.

Let's declare a HashMap which will store the calculated values.

private static Map<Float, Float> pxCache = new HashMap<>();

A function which calculates pixel values :

public static float calculateDpToPixel(float dp, Context context) {

        Resources resources = context.getResources();
        DisplayMetrics metrics = resources.getDisplayMetrics();
        float px = dp * (metrics.densityDpi / 160f);
        return px;

    }

A memoization function which returns the value from HashMap and maintains the record of previous values.

Memoization can be implemented in different ways in Java. For Java 7 :

public static float convertDpToPixel(float dp, final Context context) {

        Float f = pxCache.get(dp);
        if (f == null) {
            synchronized (pxCache) {
                f = calculateDpToPixel(dp, context);
                pxCache.put(dp, f);
            }

        }

        return f;
    }

Java 8 supports Lambda function :

public static float convertDpToPixel(float dp, final Context context) {

        pxCache.computeIfAbsent(dp, y ->calculateDpToPixel(dp,context));
}

Thanks.

php multidimensional array get values

This is the way to iterate on this array:

foreach($hotels as $row) {
       foreach($row['rooms'] as $k) {
             echo $k['boards']['board_id'];
             echo $k['boards']['price'];
       }
}

You want to iterate on the hotels and the rooms (the ones with numeric indexes), because those seem to be the "collections" in this case. The other arrays only hold and group properties.

Assert an object is a specific type

Solution for JUnit 5

The documentation says:

However, JUnit Jupiter’s org.junit.jupiter.Assertions class does not provide an assertThat() method like the one found in JUnit 4’s org.junit.Assert class which accepts a Hamcrest Matcher. Instead, developers are encouraged to use the built-in support for matchers provided by third-party assertion libraries.

Example for Hamcrest:

import static org.hamcrest.CoreMatchers.instanceOf;
import static org.hamcrest.MatcherAssert.assertThat;

import org.junit.jupiter.api.Test;

class HamcrestAssertionDemo {

    @Test
    void assertWithHamcrestMatcher() {
        SubClass subClass = new SubClass();
        assertThat(subClass, instanceOf(BaseClass.class));
    }

}

Example for AssertJ:

import static org.assertj.core.api.Assertions.assertThat;

import org.junit.jupiter.api.Test;

class AssertJDemo {

    @Test
    void assertWithAssertJ() {
        SubClass subClass = new SubClass();
        assertThat(subClass).isInstanceOf(BaseClass.class);
    }

}

Note that this assumes you want to test behaviors similar to instanceof (which accepts subclasses). If you want exact equal type, I don’t see a better way than asserting the two class to be equal like you mentioned in the question.

How to evaluate a boolean variable in an if block in bash?

bash doesn't know boolean variables, nor does test (which is what gets called when you use [).

A solution would be:

if $myVar ; then ... ; fi

because true and false are commands that return 0 or 1 respectively which is what if expects.

Note that the values are "swapped". The command after if must return 0 on success while 0 means "false" in most programming languages.

SECURITY WARNING: This works because BASH expands the variable, then tries to execute the result as a command! Make sure the variable can't contain malicious code like rm -rf /

How do I change the string representation of a Python class?

This is not as easy as it seems, some core library functions don't work when only str is overwritten (checked with Python 2.7), see this thread for examples How to make a class JSON serializable Also, try this

import json

class A(unicode):
    def __str__(self):
        return 'a'
    def __unicode__(self):
        return u'a'
    def __repr__(self):
        return 'a'

a = A()
json.dumps(a)

produces

'""'

and not

'"a"'

as would be expected.

EDIT: answering mchicago's comment:

unicode does not have any attributes -- it is an immutable string, the value of which is hidden and not available from high-level Python code. The json module uses re for generating the string representation which seems to have access to this internal attribute. Here's a simple example to justify this:

b = A('b') print b

produces

'a'

while

json.dumps({'b': b})

produces

{"b": "b"}

so you see that the internal representation is used by some native libraries, probably for performance reasons.

See also this for more details: http://www.laurentluce.com/posts/python-string-objects-implementation/

How to check Grants Permissions at Run-Time?

fun hasPermission(permission: String): Boolean {
      if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) return true // must be granted after installed.
      return mAppSet.appContext.checkSelfPermission(permission) == PackageManager.PERMISSION_GRANTED
}

c - warning: implicit declaration of function ‘printf’

You need to include a declaration of the printf() function.

#include <stdio.h>

How to reverse MD5 to get the original string?

No, that's not really possible, as

  • there can be more than one string giving the same MD5
  • it was designed to be hard to "reverse"

The goal of the MD5 and its family of hashing functions is

  • to get short "extracts" from long string
  • to make it hard to guess where they come from
  • to make it hard to find collisions, that is other words having the same hash (which is a very similar exigence as the second one)

Think that you can get the MD5 of any string, even very long. And the MD5 is only 16 bytes long (32 if you write it in hexa to store or distribute it more easily). If you could reverse them, you'd have a magical compacting scheme.

This being said, as there aren't so many short strings (passwords...) used in the world, you can test them from a dictionary (that's called "brute force attack") or even google for your MD5. If the word is common and wasn't salted, you have a reasonable chance to succeed...

JS - window.history - Delete a state

You may have moved on by now, but... as far as I know there's no way to delete a history entry (or state).

One option I've been looking into is to handle the history yourself in JavaScript and use the window.history object as a carrier of sorts.

Basically, when the page first loads you create your custom history object (we'll go with an array here, but use whatever makes sense for your situation), then do your initial pushState. I would pass your custom history object as the state object, as it may come in handy if you also need to handle users navigating away from your app and coming back later.

var myHistory = [];

function pageLoad() {
    window.history.pushState(myHistory, "<name>", "<url>");

    //Load page data.
}

Now when you navigate, you add to your own history object (or don't - the history is now in your hands!) and use replaceState to keep the browser out of the loop.

function nav_to_details() {
    myHistory.push("page_im_on_now");
    window.history.replaceState(myHistory, "<name>", "<url>");

    //Load page data.
}

When the user navigates backwards, they'll be hitting your "base" state (your state object will be null) and you can handle the navigation according to your custom history object. Afterward, you do another pushState.

function on_popState() {
    // Note that some browsers fire popState on initial load,
    // so you should check your state object and handle things accordingly.
    // (I did not do that in these examples!)

    if (myHistory.length > 0) {
        var pg = myHistory.pop();
        window.history.pushState(myHistory, "<name>", "<url>");

        //Load page data for "pg".
    } else {
        //No "history" - let them exit or keep them in the app.
    }
}

The user will never be able to navigate forward using their browser buttons because they are always on the newest page.

From the browser's perspective, every time they go "back", they've immediately pushed forward again.

From the user's perspective, they're able to navigate backwards through the pages but not forward (basically simulating the smartphone "page stack" model).

From the developer's perspective, you now have a high level of control over how the user navigates through your application, while still allowing them to use the familiar navigation buttons on their browser. You can add/remove items from anywhere in the history chain as you please. If you use objects in your history array, you can track extra information about the pages as well (like field contents and whatnot).

If you need to handle user-initiated navigation (like the user changing the URL in a hash-based navigation scheme), then you might use a slightly different approach like...

var myHistory = [];

function pageLoad() {
    // When the user first hits your page...
    // Check the state to see what's going on.

    if (window.history.state === null) {
        // If the state is null, this is a NEW navigation,
        //    the user has navigated to your page directly (not using back/forward).

        // First we establish a "back" page to catch backward navigation.
        window.history.replaceState(
            { isBackPage: true },
            "<back>",
            "<back>"
        );

        // Then push an "app" page on top of that - this is where the user will sit.
        // (As browsers vary, it might be safer to put this in a short setTimeout).
        window.history.pushState(
            { isBackPage: false },
            "<name>",
            "<url>"
        );

        // We also need to start our history tracking.
        myHistory.push("<whatever>");

        return;
    }

    // If the state is NOT null, then the user is returning to our app via history navigation.

    // (Load up the page based on the last entry of myHistory here)

    if (window.history.state.isBackPage) {
        // If the user came into our app via the back page,
        //     you can either push them forward one more step or just use pushState as above.

        window.history.go(1);
        // or window.history.pushState({ isBackPage: false }, "<name>", "<url>");
    }

    setTimeout(function() {
        // Add our popstate event listener - doing it here should remove
        //     the issue of dealing with the browser firing it on initial page load.
        window.addEventListener("popstate", on_popstate);
    }, 100);
}

function on_popstate(e) {
    if (e.state === null) {
        // If there's no state at all, then the user must have navigated to a new hash.

        // <Look at what they've done, maybe by reading the hash from the URL>
        // <Change/load the new page and push it onto the myHistory stack>
        // <Alternatively, ignore their navigation attempt by NOT loading anything new or adding to myHistory>

        // Undo what they've done (as far as navigation) by kicking them backwards to the "app" page
        window.history.go(-1);

        // Optionally, you can throw another replaceState in here, e.g. if you want to change the visible URL.
        // This would also prevent them from using the "forward" button to return to the new hash.
        window.history.replaceState(
            { isBackPage: false },
            "<new name>",
            "<new url>"
        );
    } else {
        if (e.state.isBackPage) {
            // If there is state and it's the 'back' page...

            if (myHistory.length > 0) {
                // Pull/load the page from our custom history...
                var pg = myHistory.pop();
                // <load/render/whatever>

                // And push them to our "app" page again
                window.history.pushState(
                    { isBackPage: false },
                    "<name>",
                    "<url>"
                );
            } else {
                // No more history - let them exit or keep them in the app.
            }
        }

        // Implied 'else' here - if there is state and it's NOT the 'back' page
        //     then we can ignore it since we're already on the page we want.
        //     (This is the case when we push the user back with window.history.go(-1) above)
    }
}

Converting a list to a set changes element order

In Python 3.6, set() now should keep the order, but there is another solution for Python 2 and 3:

>>> x = [1, 2, 20, 6, 210]
>>> sorted(set(x), key=x.index)
[1, 2, 20, 6, 210]

Disable button in angular with two conditions?

It sounds like you need an OR instead:

<button type="submit" [disabled]="!validate || !SAForm.valid">Add</button>

This will disable the button if not validate or if not SAForm.valid.

Find the max of 3 numbers in Java with different data types

Java 8 way. Works for multiple parameters:

Stream.of(first, second, third).max(Integer::compareTo).get()

Setting up Gradle for api 26 (Android)

Have you added the google maven endpoint?

Important: The support libraries are now available through Google's Maven repository. You do not need to download the support repository from the SDK Manager. For more information, see Support Library Setup.

Add the endpoint to your build.gradle file:

allprojects {
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com'
        }
    }
}

Which can be replaced by the shortcut google() since Android Gradle v3:

allprojects {
    repositories {
        jcenter()
        google()
    }
}

If you already have any maven url inside repositories, you can add the reference after them, i.e.:

allprojects {
    repositories {
        jcenter()
        maven {
            url 'https://jitpack.io'
        }
        maven {
            url 'https://maven.google.com'
        }
    }
}

Why am I getting error CS0246: The type or namespace name could not be found?

I resolved this by making sure my project shared the same .Net Framework version as the projects/libraries it depended on.

It turned out the libraries (projects within the solution) used .Net 4.6.1 and my project was using 4.5.2

HTTP Error 403.14 - Forbidden The Web server is configured to not list the contents

In my case ASP.NET not registered on server. try to execute this in command prompt:

Windows 32bit

%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -ir

Windows 64bit

%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir 

accepting HTTPS connections with self-signed certificates

Google recommends the usage of Android Volley for HTTP/HTTPS connections, since that HttpClient is deprecated. So, you know the right choice :).

And also, NEVER NUKE SSL Certificates (NEVER!!!).

To nuke SSL Certificates, is totally against the purpose of SSL, which is promoting security. There's no sense of using SSL, if you're planning to bomb all SSL certificates that comes. A better solution would be creating a custom TrustManager on your App + using Android Volley for HTTP/HTTPS connections.

Here's a Gist which I created, with a basic LoginApp, performing HTTPS connections, using a Self-Signed Certificate on the server-side, accepted on the App.

Here's also another Gist that may help, for creating Self-Signed SSL Certificates for setting up on your Server and also using the certificate on your App. Very important: you must copy the .crt file which was generated by the script above, to the "raw" directory from your Android project.

What does LINQ return when the results are empty

It won't throw exception, you'll get an empty list.

Example of a strong and weak entity types

Weak Entity Type: An entity whose instances cannot exits without being linked with instances of some other entity is called weak entity type. It cannot exist independently. For example: Our PC is depend on us it will not open or close with its own.

Strong Entity Type: An entity whose linked to the instances of any other entity type is called strong entity type. It can exit independently. For example: A person can do every thing can go everywhere and use ever thing

Creating a URL in the controller .NET MVC

If you need the full url (for instance to send by email) consider using one of the following built-in methods:

With this you create the route to use to build the url:

Url.RouteUrl("OpinionByCompany", new RouteValueDictionary(new{cid=newop.CompanyID,oid=newop.ID}), HttpContext.Request.Url.Scheme, HttpContext.Request.Url.Authority)

Here the url is built after the route engine determine the correct one:

Url.Action("Detail","Opinion",new RouteValueDictionary(new{cid=newop.CompanyID,oid=newop.ID}),HttpContext.Request.Url.Scheme, HttpContext.Request.Url.Authority)

In both methods, the last 2 parameters specifies the protocol and hostname.

Regards.

How to get duplicate items from a list using LINQ?

Here is one way to do it:

List<String> duplicates = lst.GroupBy(x => x)
                             .Where(g => g.Count() > 1)
                             .Select(g => g.Key)
                             .ToList();

The GroupBy groups the elements that are the same together, and the Where filters out those that only appear once, leaving you with only the duplicates.

Android Studio Gradle DSL method not found: 'android()' -- Error(17,0)

I got this same error when I was trying to import an Eclipse NDK project into Android Studio. It turns out, for NDK support in Android Studio, you need to use a new gradle and android plugin (and gradle version 2.5+ for that matter). This plugin, requires changes in the module's build.gradle file. Specifically the "android{...}" object should be inside "model{...}" object like this:

apply plugin: 'com.android.model.application'
model {
    android {
    ....
    }
}

So if you have updated your gradle configuration to use the new gradle plugin, and the new android plugin, but didn't change the module's build.gradle syntax, you could get "Gradle DSL method not found: 'android()'" error.

I prepared a patch file here that has some further explanations in the comments: https://gist.github.com/shumoapp/91d815de6e01f5921d1f These are the changes I had to do after importing the native-audio ndk project into Android Studio.

error: Libtool library used but 'LIBTOOL' is undefined

A good answer for me was to install libtool:

sudo apt-get install libtool

How to get a view table query (code) in SQL Server 2008 Management Studio

Use sp_helptext before the view_name. Example:

sp_helptext Example_1

Hence you will get the query:

CREATE VIEW dbo.Example_1
AS
SELECT       a, b, c
FROM         dbo.table_name JOIN blah blah blah
WHERE        blah blah blah

sp_helptext will give stored procedures.

How to insert a character in a string at a certain position?

// Create given String and make with size 30
String str = "Hello How Are You";

// Creating StringBuffer Object for right padding
StringBuffer stringBufferRightPad = new StringBuffer(str);
while (stringBufferRightPad.length() < 30) {
    stringBufferRightPad.insert(stringBufferRightPad.length(), "*");
}

System.out.println("after Left padding : " + stringBufferRightPad);
System.out.println("after Left padding : " + stringBufferRightPad.toString());

// Creating StringBuffer Object for right padding
StringBuffer stringBufferLeftPad = new StringBuffer(str);
while (stringBufferLeftPad.length() < 30) {
    stringBufferLeftPad.insert(0, "*");
}
System.out.println("after Left padding : " + stringBufferLeftPad);
System.out.println("after Left padding : " + stringBufferLeftPad.toString());

How to overwrite the output directory in spark

If you are willing to use your own custom output format, you would be able to get the desired behaviour with RDD as well.

Have a look at the following classes: FileOutputFormat, FileOutputCommitter

In file output format you have a method named checkOutputSpecs, which is checking whether the output directory exists. In FileOutputCommitter you have the commitJob which is usually transferring data from the temporary directory to its final place.

I wasn't able to verify it yet (would do it, as soon as I have few free minutes) but theoretically: If I extend FileOutputFormat and override checkOutputSpecs to a method that doesn't throw exception on directory already exists, and adjust the commitJob method of my custom output committer to perform which ever logic that I want (e.g. Override some of the files, append others) than I may be able to achieve the desired behaviour with RDDs as well.

The output format is passed to: saveAsNewAPIHadoopFile (which is the method saveAsTextFile called as well to actually save the files). And the Output committer is configured at the application level.