Programs & Examples On #Query cache

Query Cache is the cache, that stores the database queries and their results.

apache server reached MaxClients setting, consider raising the MaxClients setting

Did you consider using nginx (or other event based web server) instead of apache?

nginx shall allow higher number of connections and consume much less resources (as it is event based and does not create separate process per connection). Anyway, you will need some processes, doing real work (like WSGI servers or so) and if they stay on the same server as the front end web server, you only shift the performance problem to a bit different place.

Latest apache version shall allow similar solution (configure it in event based manner), but this is not my area of expertise.

subtract time from date - moment js

I might be missing something in your question here... but from what I can gather, by using the subtract method this should be what you're looking to do:

var timeStr = "00:03:15";
    timeStr = timeStr.split(':');

var h = timeStr[1],
    m = timeStr[2];

var newTime = moment("01:20:00 06-26-2014")
    .subtract({'hours': h, 'minutes': m})
    .format('hh:mm');

var str = h + " hours and " + m + " minutes earlier: " + newTime;

console.log(str); // 3 hours and 15 minutes earlier: 10:05

_x000D_
_x000D_
$(document).ready(function(){    _x000D_
     var timeStr = "00:03:15";_x000D_
        timeStr = timeStr.split(':');_x000D_
_x000D_
    var h = timeStr[1],_x000D_
        m = timeStr[2];_x000D_
_x000D_
    var newTime = moment("01:20:00 06-26-2014")_x000D_
        .subtract({'hours': h, 'minutes': m})_x000D_
        .format('hh:mm');_x000D_
_x000D_
    var str = h + " hours and " + m + " minutes earlier: " + newTime;_x000D_
_x000D_
    $('#new-time').html(str);_x000D_
})
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.9.0/moment.min.js"></script>_x000D_
_x000D_
_x000D_
<p id="new-time"></p>
_x000D_
_x000D_
_x000D_

Is there a way to add a gif to a Markdown file?

just upload the .gif file into your base folder of GitHub and edit README.md just use this code

![](name-of-giphy.gif)

Remove all whitespace in a string

eliminate all the whitespace from a string, on both ends, and in between words.

>>> import re
>>> re.sub("\s+", # one or more repetition of whitespace
    '', # replace with empty string (->remove)
    ''' hello
...    apple
... ''')
'helloapple'

Python docs:

How do I convert a file path to a URL in ASP.NET

The simple solution seems to be to have a temporary location within the website that you can access easily with URL and then you can move files to the physical location when you need to save them.

How to Generate a random number of fixed length using JavaScript?

parseInt(Math.random().toString().slice(2,Math.min(length+2, 18)), 10); // 18 -> due to max digits in Math.random

Update: This method has few flaws: - Sometimes the number of digits might be lesser if its left padded with zeroes.

Efficiently replace all accented characters in a string?

I made a Prototype Version of this:

String.prototype.strip = function() {
  var translate_re = /[öäüÖÄÜß ]/g;
  var translate = {
    "ä":"a", "ö":"o", "ü":"u",
    "Ä":"A", "Ö":"O", "Ü":"U",
    " ":"_", "ß":"ss"   // probably more to come
  };
    return (this.replace(translate_re, function(match){
        return translate[match];})
    );
};

Use like:

var teststring = 'ä ö ü Ä Ö Ü ß';
teststring.strip();

This will will change the String to a_o_u_A_O_U_ss

change figure size and figure format in matplotlib

The first part (setting the output size explictly) isn't too hard:

import matplotlib.pyplot as plt
list1 = [3,4,5,6,9,12]
list2 = [8,12,14,15,17,20]
fig = plt.figure(figsize=(4,3))
ax = fig.add_subplot(111)
ax.plot(list1, list2)
fig.savefig('fig1.png', dpi = 300)
fig.close()

But after a quick google search on matplotlib + tiff, I'm not convinced that matplotlib can make tiff plots. There is some mention of the GDK backend being able to do it.

One option would be to convert the output with a tool like imagemagick's convert.

(Another option is to wait around here until a real matplotlib expert shows up and proves me wrong ;-)

How to generate an entity-relationship (ER) diagram using Oracle SQL Developer

Create a diagram for existing database schema or its subset as follows:

  1. Click File ? Data Modeler ? Import ? Data Dictionary.
  2. Select a DB connection (add one if none).
  3. Click Next.
  4. Check one or more schema names.
  5. Click Next.
  6. Check one or more objects to import.
  7. Click Next.
  8. Click Finish.

The ERD is displayed.

Export the diagram as follows:

  1. Click File ? Data Modeler ? Print Diagram ? To Image File.
  2. Browse to and select the export file location.
  3. Click Save.

The diagram is exported. To export in a vector format, use To PDF File, instead. This allows for simplified editing using Inkscape (or other vector image editor).

These instructions may work for SQL Developer 3.2.09.23 to 4.1.3.20.

Jquery Ajax Posting json to webservice

I have query,

$("#login-button").click(function(e){ alert("hiii");

        var username = $("#username-field").val();
        var password = $("#username-field").val();

        alert(username);
        alert("password" + password);



        var markers = { "userName" : "admin","password" : "admin123"};
        $.ajax({
            type: "POST",
            url: url,
            // The key needs to match your method's input parameter (case-sensitive).
            data: JSON.stringify(markers),
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function(data){alert("got the data"+data);},
            failure: function(errMsg) {
                alert(errMsg);
            }
        });

    });

I'm posting the the login details in json and getting a string as "Success",but I'm not getting the response.

Get JSON data from external URL and display it in a div as plain text

You can use $.ajax call to get the value and then put it in the div you want to. One thing you must know is you cannot receive JSON Data. You have to use JSONP.

Code would be like this:

function CallURL()  {
    $.ajax({
        url: 'https://www.googleapis.com/freebase/v1/text/en/bob_dylan',
        type: "GET",
        dataType: "jsonp",
        async: false,
        success: function(msg)  {
            JsonpCallback(msg);
        },
        error: function()  {
            ErrorFunction();
        }
    });
}

function JsonpCallback(json)  {
    document.getElementById('summary').innerHTML = json.result;
}

Get textarea text with javascript or Jquery

Try This:

var info = document.getElementById("area1").value; // Javascript
var info = $("#area1").val(); // jQuery

Replace line break characters with <br /> in ASP.NET MVC Razor view

Split on newlines (environment agnostic) and print regularly -- no need to worry about encoding or xss:

@if (!string.IsNullOrWhiteSpace(text)) 
{
    var lines = text.Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries);
    foreach (var line in lines)
    {
        <p>@line</p>
    }
}

(remove empty entries is optional)

simple HTTP server in Java using only Java SE API

The com.sun.net.httpserver solution is not portable across JREs. Its better to use the official webservices API in javax.xml.ws to bootstrap a minimal HTTP server...

import java.io._
import javax.xml.ws._
import javax.xml.ws.http._
import javax.xml.transform._
import javax.xml.transform.stream._

@WebServiceProvider
@ServiceMode(value=Service.Mode.PAYLOAD) 
class P extends Provider[Source] {
  def invoke(source: Source) = new StreamSource( new StringReader("<p>Hello There!</p>"));
}

val address = "http://127.0.0.1:8080/"
Endpoint.create(HTTPBinding.HTTP_BINDING, new P()).publish(address)

println("Service running at "+address)
println("Type [CTRL]+[C] to quit!")

Thread.sleep(Long.MaxValue)

EDIT: this actually works! The above code looks like Groovy or something. Here is a translation to Java which I tested:

import java.io.*;
import javax.xml.ws.*;
import javax.xml.ws.http.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;

@WebServiceProvider
@ServiceMode(value = Service.Mode.PAYLOAD)
public class Server implements Provider<Source> {

    public Source invoke(Source request) {
        return  new StreamSource(new StringReader("<p>Hello There!</p>"));
    }

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

        String address = "http://127.0.0.1:8080/";
        Endpoint.create(HTTPBinding.HTTP_BINDING, new Server()).publish(address);

        System.out.println("Service running at " + address);
        System.out.println("Type [CTRL]+[C] to quit!");

        Thread.sleep(Long.MAX_VALUE);
    }
}

CSS transition effect makes image blurry / moves image 1px, in Chrome?

Had the same problem with embeded youtube iframe (Translations were used for centering iframe element). None of the solutions above worked until tried reset css filters and magic happened.

Structure:

<div class="translate">
     <iframe/>
</div>

Style [before]

.translate {
  transform: translateX(-50%);
  -webkit-transform: translateX(-50%);
}

Style [after]

.translate {
  transform: translateX(-50%);
  -webkit-transform: translateX(-50%);
  filter: blur(0);
  -webkit-filter: blur(0);
}

Get the first element of each tuple in a list in Python

res_list = [x[0] for x in rows]

c.f. http://docs.python.org/3/tutorial/datastructures.html#list-comprehensions

For a discussion on why to prefer comprehensions over higher-order functions such as map, go to http://www.artima.com/weblogs/viewpost.jsp?thread=98196.

How to check for the type of a template parameter?

I think todays, it is better to use, but only with C++17.

#include <type_traits>

template <typename T>
void foo() {
    if constexpr (std::is_same_v<T, animal>) {
        // use type specific operations... 
    } 
}

If you use some type specific operations in if expression body without constexpr, this code will not compile.

How do I round a double to two decimal places in Java?

If you want the result to two decimal places you can do

// assuming you want to round to Infinity.
double tip = (long) (amount * percent + 0.5) / 100.0; 

This result is not precise but Double.toString(double) will correct for this and print one to two decimal places. However as soon as you perform another calculation, you can get a result which will not be implicitly rounded. ;)

Carousel with Thumbnails in Bootstrap 3.0

Bootstrap 4 (update 2019)

A multi-item carousel can be accomplished in several ways as explained here. Another option is to use separate thumbnails to navigate the carousel slides.

Bootstrap 3 (original answer)

This can be done using the grid inside each carousel item.

       <div id="myCarousel" class="carousel slide">
                <div class="carousel-inner">
                    <div class="item active">
                        <div class="row">
                            <div class="col-sm-3">..
                            </div>
                            <div class="col-sm-3">..
                            </div>
                            <div class="col-sm-3">..
                            </div>
                            <div class="col-sm-3">..
                            </div>
                        </div>
                        <!--/row-->
                    </div>
                    ...add more item(s)
                 </div>
        </div>

Demo example thumbnail slider using the carousel:
http://www.bootply.com/81478

Another example with carousel indicators as thumbnails: http://www.bootply.com/79859

nginx error "conflicting server name" ignored

You have another server_name ec2-xx-xx-xxx-xxx.us-west-1.compute.amazonaws.com somewhere in the config.

Changing the Git remote 'push to' default

git remote set-url --push origin should work, as you mentioned, but you need to explicitly provide the url instead of an alternative remote name, e.g.

git remote set-url --push origin [email protected]:contributor/repo.git

You can confirm whether this worked by doing a git remote -v. E.g.

? ~/go/src/github.com/stretchr/testify/ master git remote -v
fork    [email protected]:contributor/testify.git (fetch)
fork    [email protected]:contributor/testify.git (push)
origin  [email protected]:stretchr/testify (fetch)
origin  [email protected]:contributor/testify.git (push)

Converting A String To Hexadecimal In Java

I would suggest something like this, where str is your input string:

StringBuffer hex = new StringBuffer();
char[] raw = tokens[0].toCharArray();
for (int i=0;i<raw.length;i++) {
    if     (raw[i]<=0x000F) { hex.append("000"); }
    else if(raw[i]<=0x00FF) { hex.append("00" ); }
    else if(raw[i]<=0x0FFF) { hex.append("0"  ); }
    hex.append(Integer.toHexString(raw[i]).toUpperCase());
}

How to multiply individual elements of a list with a number?

You can use built-in map function:

result = map(lambda x: x * P, S)

or list comprehensions that is a bit more pythonic:

result = [x * P for x in S]

Rotate axis text in python matplotlib

It will depend on what are you plotting.

import matplotlib.pyplot as plt

 x=['long_text_for_a_label_a',
    'long_text_for_a_label_b',
    'long_text_for_a_label_c']
y=[1,2,3]
myplot = plt.plot(x,y)
for item in myplot.axes.get_xticklabels():
    item.set_rotation(90)

For pandas and seaborn that give you an Axes object:

df = pd.DataFrame(x,y)
#pandas
myplot = df.plot.bar()
#seaborn 
myplotsns =sns.barplot(y='0',  x=df.index, data=df)
# you can get xticklabels without .axes cause the object are already a 
# isntance of it
for item in myplot.get_xticklabels():
    item.set_rotation(90)

If you need to rotate labels you may need change the font size too, you can use font_scale=1.0 to do that.

Resource leak: 'in' is never closed

It is telling you that you need to close the Scanner you instantiated on System.in with Scanner.close(). Normally every reader should be closed.

Note that if you close System.in, you won't be able to read from it again. You may also take a look at the Console class.

public void readShapeData() {
    Console console = System.console();
    double width = Double.parseDouble(console.readLine("Enter the width of the Rectangle: "));
    double height = Double.parseDouble(console.readLine("Enter the height of the Rectangle: "));
    ...
}

What's the difference between .NET Core, .NET Framework, and Xamarin?

You should use .NET Core, instead of .NET Framework or Xamarin, in the following 6 typical scenarios according to the documentation here.

1. Cross-Platform needs

Clearly, if your goal is to have an application (web/service) that should be able to run across platforms (Windows, Linux and MacOS), the best choice in the .NET ecosystem is to use .NET Core as its runtime (CoreCLR) and libraries are cross-platform. The other choice is to use the Mono Project.

Both choices are open source, but .NET Core is directly and officially supported by Microsoft and will have a heavy investment moving forward.

When using .NET Core across platforms, the best development experience exists on Windows with the Visual Studio IDE which supports many productivity features including project management, debugging, source control, refactoring, rich editing including Intellisense, testing and much more. But rich development is also supported using Visual Studio Code on Mac, Linux and Windows including intellisense and debugging. Even third party editors like Sublime, Emacs, VI and more work well and can get editor intellisense using the open source Omnisharp project.

2. Microservices

When you are building a microservices oriented system composed of multiple independent, dynamically scalable, stateful or stateless microservices, the great advantage that you have here is that you can use different technologies/frameworks/languages at a microservice level. That allows you to use the best approach and technology per micro areas in your system, so if you want to build very performant and scalable microservices, you should use .NET Core. Eventually, if you need to use any .NET Framework library that is not compatible with .NET Core, there’s no issue, you can build that microservice with the .NET Framework and in the future you might be able to substitute it with the .NET Core.

The infrastructure platform you could use are many. Ideally, for large and complex microservice systems, you should use Azure Service Fabric. But for stateless microservices you can also use other products like Azure App Service or Azure Functions.

Note that as of June 2016, not every technology within Azure supports the .NET Core, but .NET Core support in Azure will be increasing dramatically now that .NET Core is RTM released.

3. Best performant and scalable systems

When your system needs the best possible performance and scalability so you get the best responsiveness no matter how many users you have, then is where .NET Core and ASP.NET Core really shine. The more you can do with the same amount of infrastructure/hardware, the richer the experience you’ll have for your end users – at a lower cost.

The days of Moore’s law performance improvements for single CPUs does not apply anymore; yet you need to do more while your system is growing and need higher scalability and performance for everyday’ s more demanding users which are growing exponentially in numbers. You need to get more efficient, optimize everywhere, and scale better across clusters of machines, VMs and CPU cores, ultimately. It is not just a matter of user’s satisfaction; it can also make a huge difference in cost/TCO. This is why it is important to strive for performance and scalability.

As mentioned, if you can isolate small pieces of your system as microservices or any other loosely-coupled approach, it’ll be better as you’ll be able to not just evolve each small piece/microservice independently and have a better long-term agility and maintenance, but also you’ll be able to use any other technology at a microservice level if what you need to do is not compatible with .NET Core. And eventually you’d be able to refactor it and bring it to .NET Core when possible.

4. Command line style development for Mac, Linux or Windows.

This approach is optional when using .NET Core. You can also use the full Visual Studio IDE, of course. But if you are a developer that wants to develop with lightweight editors and heavy use of command line, .NET Core is designed for CLI. It provides simple command line tools available on all supported platforms, enabling developers to build and test applications with a minimal installation on developer, lab or production machines. Editors like Visual Studio Code use the same command line tools for their development experiences. And IDE’s like Visual Studio use the same CLI tools but hide them behind a rich IDE experience. Developers can now choose the level they want to interact with the tool chain from CLI to editor to IDE.

5. Need side by side of .NET versions per application level.

If you want to be able to install applications with dependencies on different versions of frameworks in .NET, you need to use .NET Core which provides 100% side-by side as explained previously in this document.

6. Windows 10 UWP .NET apps.

In addition, you may also want to read:

  1. When should I NOT use .NET Core?
  2. When should I still use .NET Framework 4.x, instead of .NET Core?
  3. When should I use Xamarin, instead of .NET Core?

Insert Data Into Temp Table with Query

SELECT * INTO #TempTable 
FROM SampleTable
WHERE...

SELECT * FROM #TempTable
DROP TABLE #TempTable

How to get row count using ResultSet in Java?

Your function will return the size of a ResultSet, but its cursor will be set after last record, so without rewinding it by calling beforeFirst(), first() or previous() you won't be able to read its rows, and rewinding methods won't work with forward only ResultSet (you'll get the same exception you're getting in your second code fragment).

Prevent screen rotation on Android

Add the following to your AndroidManifest.xml

[ app > src > main > AndroidManifest.xml ]

<activity android:name=".MainActivity"
          android:configChanges="orientation"
          android:screenOrientation="portrait"/>

Example:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xxx.zzzzzz.yyyyy">

   <uses-permission android:name="A-PERMISSION" />

   <application>
      <activity android:name=".MainActivity"
                android:screenOrientation="portrait"
                android:configChanges="orientation">
      </activity>
   </application>

</manifest>

Why does C# XmlDocument.LoadXml(string) fail when an XML header is included?

I figured it out. Read the MSDN documentation and it says to use .Load instead of LoadXml when reading from strings. Found out this works 100% of time. Oddly enough using StringReader causes problems. I think the main reason is that this is a Unicode encoded string and that could cause problems because StringReader is UTF-8 only.

MemoryStream stream = new MemoryStream();
            byte[] data = body.PayloadEncoding.GetBytes(body.Payload);
            stream.Write(data, 0, data.Length);
            stream.Seek(0, SeekOrigin.Begin);

            XmlTextReader reader = new XmlTextReader(stream);

            // MSDN reccomends we use Load instead of LoadXml when using in memory XML payloads
            bodyDoc.Load(reader);

undefined reference to 'vtable for class' constructor

You're declaring a virtual function and not defining it:

virtual void calculateCredits();

Either define it or declare it as:

virtual void calculateCredits() = 0;

Or simply:

virtual void calculateCredits() { };

Read more about vftable: http://en.wikipedia.org/wiki/Virtual_method_table

How to fill the whole canvas with specific color?

We don't need to access the canvas context.

Implementing hednek in pure JS you would get canvas.setAttribute('style', 'background-color:#00F8'). But my preferred method requires converting the kabab-case to camelCase.

canvas.style.backgroundColor = '#00F8'

How do I declare an array of undefined or no initial size?

This can be done by using a pointer, and allocating memory on the heap using malloc. Note that there is no way to later ask how big that memory block is. You have to keep track of the array size yourself.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char** argv)
{
  /* declare a pointer do an integer */
  int *data; 
  /* we also have to keep track of how big our array is - I use 50 as an example*/
  const int datacount = 50;
  data = malloc(sizeof(int) * datacount); /* allocate memory for 50 int's */
  if (!data) { /* If data == 0 after the call to malloc, allocation failed for some reason */
    perror("Error allocating memory");
    abort();
  }
  /* at this point, we know that data points to a valid block of memory.
     Remember, however, that this memory is not initialized in any way -- it contains garbage.
     Let's start by clearing it. */
  memset(data, 0, sizeof(int)*datacount);
  /* now our array contains all zeroes. */
  data[0] = 1;
  data[2] = 15;
  data[49] = 66; /* the last element in our array, since we start counting from 0 */
  /* Loop through the array, printing out the values (mostly zeroes, but even so) */
  for(int i = 0; i < datacount; ++i) {
    printf("Element %d: %d\n", i, data[i]);
  }
}

That's it. What follows is a more involved explanation of why this works :)

I don't know how well you know C pointers, but array access in C (like array[2]) is actually a shorthand for accessing memory via a pointer. To access the memory pointed to by data, you write *data. This is known as dereferencing the pointer. Since data is of type int *, then *data is of type int. Now to an important piece of information: (data + 2) means "add the byte size of 2 ints to the adress pointed to by data".

An array in C is just a sequence of values in adjacent memory. array[1] is just next to array[0]. So when we allocate a big block of memory and want to use it as an array, we need an easy way of getting the direct adress to every element inside. Luckily, C lets us use the array notation on pointers as well. data[0] means the same thing as *(data+0), namely "access the memory pointed to by data". data[2] means *(data+2), and accesses the third int in the memory block.

How to simulate a mouse click using JavaScript?

(Modified version to make it work without prototype.js)

function simulate(element, eventName)
{
    var options = extend(defaultOptions, arguments[2] || {});
    var oEvent, eventType = null;

    for (var name in eventMatchers)
    {
        if (eventMatchers[name].test(eventName)) { eventType = name; break; }
    }

    if (!eventType)
        throw new SyntaxError('Only HTMLEvents and MouseEvents interfaces are supported');

    if (document.createEvent)
    {
        oEvent = document.createEvent(eventType);
        if (eventType == 'HTMLEvents')
        {
            oEvent.initEvent(eventName, options.bubbles, options.cancelable);
        }
        else
        {
            oEvent.initMouseEvent(eventName, options.bubbles, options.cancelable, document.defaultView,
            options.button, options.pointerX, options.pointerY, options.pointerX, options.pointerY,
            options.ctrlKey, options.altKey, options.shiftKey, options.metaKey, options.button, element);
        }
        element.dispatchEvent(oEvent);
    }
    else
    {
        options.clientX = options.pointerX;
        options.clientY = options.pointerY;
        var evt = document.createEventObject();
        oEvent = extend(evt, options);
        element.fireEvent('on' + eventName, oEvent);
    }
    return element;
}

function extend(destination, source) {
    for (var property in source)
      destination[property] = source[property];
    return destination;
}

var eventMatchers = {
    'HTMLEvents': /^(?:load|unload|abort|error|select|change|submit|reset|focus|blur|resize|scroll)$/,
    'MouseEvents': /^(?:click|dblclick|mouse(?:down|up|over|move|out))$/
}
var defaultOptions = {
    pointerX: 0,
    pointerY: 0,
    button: 0,
    ctrlKey: false,
    altKey: false,
    shiftKey: false,
    metaKey: false,
    bubbles: true,
    cancelable: true
}

You can use it like this:

simulate(document.getElementById("btn"), "click");

Note that as a third parameter you can pass in 'options'. The options you don't specify are taken from the defaultOptions (see bottom of the script). So if you for example want to specify mouse coordinates you can do something like:

simulate(document.getElementById("btn"), "click", { pointerX: 123, pointerY: 321 })

You can use a similar approach to override other default options.

Credits should go to kangax. Here's the original source (prototype.js specific).

Trigger validation of all fields in Angular Form submit

Note: I know this is a hack, but it was useful for Angular 1.2 and earlier that didn't provide a simple mechanism.

The validation kicks in on the change event, so some things like changing the values programmatically won't trigger it. But triggering the change event will trigger the validation. For example, with jQuery:

$('#formField1, #formField2').trigger('change');

Convert String to Float in Swift

For the sake of completeness this is a solution using an extension of UITextField which can also consider a different locale.

For Swift 3+

extension UITextField {
    func floatValue(locale : Locale = Locale.current) -> Float {
        let numberFormatter = NumberFormatter()
        numberFormatter.numberStyle = .decimal
        numberFormatter.locale = locale

        let nsNumber = numberFormatter.number(from: text!)
        return nsNumber == nil ? 0.0 : nsNumber!.floatValue
    }
}

jquery equivalent for JSON.stringify

There is no such functionality in jQuery. Use JSON.stringify or alternatively any jQuery plugin with similar functionality (e.g jquery-json).

Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory

I copied some code and created a TC. Basically converted a normal java class to JUnit TC. I was gettgig error. Later I created a new JUnit Class from New -> Junit TC. Copied the same code. It works fine and error vanished.

How to retrieve a user environment variable in CMake (Windows)

Getting variables into your CMake script

You can pass a variable on the line with the cmake invocation:

FOO=1 cmake

or by exporting a variable in BASH:

export FOO=1

Then you can pick it up in a cmake script using:

$ENV{FOO}

Find a private field with Reflection?

Use BindingFlags.NonPublic and BindingFlags.Instance flags

FieldInfo[] fields = myType.GetFields(
                         BindingFlags.NonPublic | 
                         BindingFlags.Instance);

Remove sensitive files and their commits from Git history

To be clear: The accepted answer is correct. Try it first. However, it may be unnecessarily complex for some use cases, particularly if you encounter obnoxious errors such as 'fatal: bad revision --prune-empty', or really don't care about the history of your repo.

An alternative would be:

  1. cd to project's base branch
  2. Remove the sensitive code / file
  3. rm -rf .git/ # Remove all git info from your code
  4. Go to github and delete your repository
  5. Follow this guide to push your code to a new repository as you normally would - https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/

This will of course remove all commit history branches, and issues from both your github repo, and your local git repo. If this is unacceptable you will have to use an alternate approach.

Call this the nuclear option.

System.BadImageFormatException: Could not load file or assembly (from installutil.exe)

I have faced this issue today. In my case, my application's (had a reference to a 64-bit dll) platform target was set to AnyCPU but Prefer 32-bit check box under platform target section was ticked by default. This was the problem and worked all fine after un-checking Prefer 32-bit option.

svn: E155004: ..(path of resource).. is already locked

Just cleanup. Happened in JetBrains PhpStorm

How can I know if Object is String type object?

Use the instanceof syntax.

Like so:

Object foo = "";

if( foo instanceof String ) {
  // do something String related to foo
}

Attempt to present UIViewController on UIViewController whose view is not in the window hierarchy

With Swift 3...

Another possible cause to this, which happened to me, was having a segue from a tableViewCell to another ViewController on the Storyboard. I also used override func prepare(for segue: UIStoryboardSegue, sender: Any?) {} when the cell was clicked.

I fixed this issue by making a segue from ViewController to ViewController.

What is an MDF file?

SQL Server databases use two files - an MDF file, known as the primary database file, which contains the schema and data, and a LDF file, which contains the logs. See wikipedia. A database may also use secondary database file, which normally uses a .ndf extension.

As John S. indicates, these file extensions are purely convention - you can use whatever you want, although I can't think of a good reason to do that.

More info on MSDN here and in Beginning SQL Server 2005 Administation (Google Books) here.

Notification not showing in Oreo

In android Oreo,notification app is done by using channels and NotificationHelper class.It should have a channel id and channel name.

First u have to create a NotificationHelper Class

public class NotificationHelper extends ContextWrapper {

private static final String EDMT_CHANNEL_ID="com.example.safna.notifier1.EDMTDEV";
private static final String EDMT_CHANNEL_NAME="EDMTDEV Channel";
private NotificationManager manager;

public  NotificationHelper(Context base)
{
    super(base);
    createChannels();
}
private void createChannels()
{
    NotificationChannel edmtChannel=new NotificationChannel(EDMT_CHANNEL_ID,EDMT_CHANNEL_NAME,NotificationManager.IMPORTANCE_DEFAULT);
    edmtChannel.enableLights(true);
    edmtChannel.enableVibration(true);
    edmtChannel.setLightColor(Color.GREEN);
    edmtChannel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);

    getManager().createNotificationChannel(edmtChannel);

}
public NotificationManager getManager()
{
   if (manager==null)
       manager=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
   return manager;

}
public NotificationCompat.Builder getEDMTChannelNotification(String title,String body)
{
    return new NotificationCompat.Builder(getApplicationContext(),EDMT_CHANNEL_ID)
            .setContentText(body)
            .setContentTitle(title)
            .setSmallIcon(R.mipmap.ic_launcher_round)
            .setAutoCancel(true);
    }
}

Create a button in activity xml file,then In the main activity

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    helper=new NotificationHelper(this);

    btnSend=(Button)findViewById(R.id.btnSend);

    btnSend.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String title="Title";
            String content="Content";
            Notification.Builder builder=helper.getEDMTChannelNotification(title,content);
            helper.getManager().notify(new Random().nextInt(),builder.build());
        }
    });

}

Then run ur project

Detecting when Iframe content has loaded (Cross browser)

See this blog post. It uses jQuery, but it should help you even if you are not using it.

Basically you add this to your document.ready()

$('iframe').load(function() {
    RunAfterIFrameLoaded();
});

make iframe height dynamic based on content inside- JQUERY/Javascript

Add this to the iframe, this worked for me:

onload="this.height=this.contentWindow.document.body.scrollHeight;"

And if you use jQuery try this code:

onload="$(this).height($(this.contentWindow.document.body).find(\'div\').first().height());"

Tomcat Servlet: Error 404 - The requested resource is not available

try this (if the Java EE V6)

package crunch;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
@WebServlet(name="hello",urlPatterns={"/hello"})
public class HelloWorld extends HttpServlet {
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
      throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    out.println("Hello World");
  }
}

now reach the servlet by http://127.0.0.1:8080/yourapp/hello

where 8080 is default tomcat port, and yourapp is the context name of your applciation

How to copy files from 'assets' folder to sdcard?

I know this has been answered but I have a slightly more elegant way to copy from asset directory to a file on the sdcard. It requires no "for" loop but instead uses File Streams and Channels to do the work.

(Note) If using any type of compressed file, APK, PDF, ... you may want to rename the file extension before inserting into asset and then rename once you copy it to SDcard)

AssetManager am = context.getAssets();
AssetFileDescriptor afd = null;
try {
    afd = am.openFd( "MyFile.dat");

    // Create new file to copy into.
    File file = new File(Environment.getExternalStorageDirectory() + java.io.File.separator + "NewFile.dat");
    file.createNewFile();

    copyFdToFile(afd.getFileDescriptor(), file);

} catch (IOException e) {
    e.printStackTrace();
}

A way to copy a file without having to loop through it.

public static void copyFdToFile(FileDescriptor src, File dst) throws IOException {
    FileChannel inChannel = new FileInputStream(src).getChannel();
    FileChannel outChannel = new FileOutputStream(dst).getChannel();
    try {
        inChannel.transferTo(0, inChannel.size(), outChannel);
    } finally {
        if (inChannel != null)
            inChannel.close();
        if (outChannel != null)
            outChannel.close();
    }
}

How to deselect all selected rows in a DataGridView control?

i have ran into the same problem and found a solution (not totally by myself, but there is the internet for)

Color blue  = ColorTranslator.FromHtml("#CCFFFF");
Color red = ColorTranslator.FromHtml("#FFCCFF");
Color letters = Color.Black;

foreach (DataGridViewRow r in datagridIncome.Rows)
{
    if (r.Cells[5].Value.ToString().Contains("1")) { 
        r.DefaultCellStyle.BackColor = blue;
        r.DefaultCellStyle.SelectionBackColor = blue;
        r.DefaultCellStyle.SelectionForeColor = letters;
    }
    else { 
        r.DefaultCellStyle.BackColor = red;
        r.DefaultCellStyle.SelectionBackColor = red;
        r.DefaultCellStyle.SelectionForeColor = letters;
    }
}

This is a small trick, the only way you can see a row is selected, is by the very first column (not column[0], but the one therefore). When you click another row, you will not see the blue selection anymore, only the arrow indicates which row have selected. As you understand, I use rowSelection in my gridview.

Get the selected value in a dropdown using jQuery.

I have gone through all the answers provided above. This is the easiest way which I used to get the selected value from the drop down list

$('#searchType').val() // for the value

SQL JOIN and different types of JOINs

What is SQL JOIN ?

SQL JOIN is a method to retrieve data from two or more database tables.

What are the different SQL JOINs ?

There are a total of five JOINs. They are :

  1. JOIN or INNER JOIN
  2. OUTER JOIN

     2.1 LEFT OUTER JOIN or LEFT JOIN
     2.2 RIGHT OUTER JOIN or RIGHT JOIN
     2.3 FULL OUTER JOIN or FULL JOIN

  3. NATURAL JOIN
  4. CROSS JOIN
  5. SELF JOIN

1. JOIN or INNER JOIN :

In this kind of a JOIN, we get all records that match the condition in both tables, and records in both tables that do not match are not reported.

In other words, INNER JOIN is based on the single fact that: ONLY the matching entries in BOTH the tables SHOULD be listed.

Note that a JOIN without any other JOIN keywords (like INNER, OUTER, LEFT, etc) is an INNER JOIN. In other words, JOIN is a Syntactic sugar for INNER JOIN (see: Difference between JOIN and INNER JOIN).

2. OUTER JOIN :

OUTER JOIN retrieves

Either, the matched rows from one table and all rows in the other table Or, all rows in all tables (it doesn't matter whether or not there is a match).

There are three kinds of Outer Join :

2.1 LEFT OUTER JOIN or LEFT JOIN

This join returns all the rows from the left table in conjunction with the matching rows from the right table. If there are no columns matching in the right table, it returns NULL values.

2.2 RIGHT OUTER JOIN or RIGHT JOIN

This JOIN returns all the rows from the right table in conjunction with the matching rows from the left table. If there are no columns matching in the left table, it returns NULL values.

2.3 FULL OUTER JOIN or FULL JOIN

This JOIN combines LEFT OUTER JOIN and RIGHT OUTER JOIN. It returns rows from either table when the conditions are met and returns NULL value when there is no match.

In other words, OUTER JOIN is based on the fact that: ONLY the matching entries in ONE OF the tables (RIGHT or LEFT) or BOTH of the tables(FULL) SHOULD be listed.

Note that `OUTER JOIN` is a loosened form of `INNER JOIN`.

3. NATURAL JOIN :

It is based on the two conditions :

  1. the JOIN is made on all the columns with the same name for equality.
  2. Removes duplicate columns from the result.

This seems to be more of theoretical in nature and as a result (probably) most DBMS don't even bother supporting this.

4. CROSS JOIN :

It is the Cartesian product of the two tables involved. The result of a CROSS JOIN will not make sense in most of the situations. Moreover, we won't need this at all (or needs the least, to be precise).

5. SELF JOIN :

It is not a different form of JOIN, rather it is a JOIN (INNER, OUTER, etc) of a table to itself.

JOINs based on Operators

Depending on the operator used for a JOIN clause, there can be two types of JOINs. They are

  1. Equi JOIN
  2. Theta JOIN

1. Equi JOIN :

For whatever JOIN type (INNER, OUTER, etc), if we use ONLY the equality operator (=), then we say that the JOIN is an EQUI JOIN.

2. Theta JOIN :

This is same as EQUI JOIN but it allows all other operators like >, <, >= etc.

Many consider both EQUI JOIN and Theta JOIN similar to INNER, OUTER etc JOINs. But I strongly believe that its a mistake and makes the ideas vague. Because INNER JOIN, OUTER JOIN etc are all connected with the tables and their data whereas EQUI JOIN and THETA JOIN are only connected with the operators we use in the former.

Again, there are many who consider NATURAL JOIN as some sort of "peculiar" EQUI JOIN. In fact, it is true, because of the first condition I mentioned for NATURAL JOIN. However, we don't have to restrict that simply to NATURAL JOINs alone. INNER JOINs, OUTER JOINs etc could be an EQUI JOIN too.

What should be the values of GOPATH and GOROOT?

As of 2020 and Go version 1.13+, in Windows the best way for updating GOPATH is just typing in command prompt:

setx GOPATH C:\mynewgopath

SQL to search objects, including stored procedures, in Oracle

I'm not sure I quite understand the question but if you want to search objects on the database for a particular search string try:

SELECT owner, name, type, line, text 
FROM dba_source
WHERE instr(UPPER(text), UPPER(:srch_str)) > 0;

From there if you need any more info you can just look up the object / line number.

How to convert a PNG image to a SVG?

Easy

  1. Download Inkscape (it's completely free)
  2. Follow the instructions in this short youtube video

As you'll see, if you want to do a whole lot of other clever .svg stuff you can do it using Inkscape also.

A non-technical observation: I personally prefer this method over "free" website offerings because, aside from often requiring registration, by uploading the image, in all practical terms, one is giving the image to the website owner.

How to run only one task in ansible playbook?

See my answer here: Run only one task and handler from ansible playbook

It is possible to run separate role (from roles/ dir):

ansible -i stage.yml -m include_role -a name=create-os-user localhost

and separate task file:

ansible -i stage.yml -m include_tasks -a file=tasks/create-os-user.yml localhost

If you externalize tasks from role to root tasks/ directory (reuse is achieved by import_tasks: ../../../tasks/create-os-user.yml) you can run it independently from playbook/role.

Get JSON object from URL

file_get_contents() is not fetching the data from url,then i tried curl and it's working fine.

How to get the selected value from drop down list in jsp?

I know that this is an old question, but as I was googling it was the first link in a results. So here is the jsp solution:

<form action="some.jsp">
  <select name="item">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
  </select>
  <input type="submit" value="Submit">
</form>

in some.jsp

request.getParameter("item");

this line will return the selected option (from the example it is: 1, 2 or 3)

Chart.js canvas resize

I had the same kind of scaling issue's using Angular CLI. Was able to get it working by removing this line from the index.html:

<script src="node_modules/chart.js/dist/Chart.bundle.min.js"></script>

and then in the angular-cli.json file, in the scripts section, using this:

"scripts": ["../node_modules/chart.js/dist/Chart.bundle.min.js"]

Source: mikebarr58

Download file through an ajax call php

A very simple solution using jQuery:

on the client side:

$('.act_download_statement').click(function(e){
    e.preventDefault();
    form = $('#my_form');
    form.submit();
});

and on the server side, make sure you send back the correct Content-Type header, so the browser will know its an attachment and the download will begin.

browser.msie error after update to jQuery 1.9.1

Instead of having the whole migration script added, you could simply add the following (extracted from the migration script)

$.uaMatch = function( ua ) {
    ua = ua.toLowerCase();

    var match = /(chrome)[ \/]([\w.]+)/.exec( ua ) ||
        /(webkit)[ \/]([\w.]+)/.exec( ua ) ||
        /(opera)(?:.*version|)[ \/]([\w.]+)/.exec( ua ) ||
        /(msie) ([\w.]+)/.exec( ua ) ||
        ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec( ua ) ||
        [];

    return {
        browser: match[ 1 ] || "",
        version: match[ 2 ] || "0"
    };
};

and then use it like so

$.uaMatch(navigator.userAgent)

How can I "reset" an Arduino board?

Make sure you plug the Arduino directly into the computer and not through a hub. Using a hub will give you this error.

Darken CSS background image?

You can use the CSS3 Linear Gradient property along with your background-image like this:

#landing-wrapper {
    display:table;
    width:100%;
    background: linear-gradient( rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5) ), url('landingpagepic.jpg');
    background-position:center top;
    height:350px;
}

Here's a demo:

_x000D_
_x000D_
#landing-wrapper {_x000D_
  display: table;_x000D_
  width: 100%;_x000D_
  background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('http://placehold.it/350x150');_x000D_
  background-position: center top;_x000D_
  height: 350px;_x000D_
  color: white;_x000D_
}
_x000D_
<div id="landing-wrapper">Lorem ipsum dolor ismet.</div>
_x000D_
_x000D_
_x000D_

How to cherry pick from 1 branch to another

When you cherry-pick, it creates a new commit with a new SHA. If you do:

git cherry-pick -x <sha>

then at least you'll get the commit message from the original commit appended to your new commit, along with the original SHA, which is very useful for tracking cherry-picks.

How to see which flags -march=native will activate?

To see command-line flags, use:

gcc -march=native -E -v - </dev/null 2>&1 | grep cc1

If you want to see the compiler/precompiler defines set by certain parameters, do this:

echo | gcc -dM -E - -march=native

How to install package from github repo in Yarn

For GitHub (or similar) private repository:

yarn add 'ssh://[email protected]:myproject.git#<branch,tag,commit>'
npm install 'ssh://[email protected]:myproject.git#<branch,tag,commit>'

slashes in url variables

You need to escape the slashes as %2F.

Why is SQL server throwing this error: Cannot insert the value NULL into column 'id'?

if you can't or don't want to set the autoincrement property of the id, you can set value for the id for each row, like this:

INSERT INTO role (id, name, created)
SELECT 
      (select max(id) from role) + ROW_NUMBER() OVER (ORDER BY name)
    , name
    , created
FROM (
    VALUES 
      ('Content Coordinator', GETDATE())
    , ('Content Viewer', GETDATE())
) AS x(name, created)

ascending/descending in LINQ - can one change the order via parameter?

You can easily create your own extension method on IEnumerable or IQueryable:

public static IOrderedEnumerable<TSource> OrderByWithDirection<TSource,TKey>
    (this IEnumerable<TSource> source,
     Func<TSource, TKey> keySelector,
     bool descending)
{
    return descending ? source.OrderByDescending(keySelector)
                      : source.OrderBy(keySelector);
}

public static IOrderedQueryable<TSource> OrderByWithDirection<TSource,TKey>
    (this IQueryable<TSource> source,
     Expression<Func<TSource, TKey>> keySelector,
     bool descending)
{
    return descending ? source.OrderByDescending(keySelector)
                      : source.OrderBy(keySelector);
}

Yes, you lose the ability to use a query expression here - but frankly I don't think you're actually benefiting from a query expression anyway in this case. Query expressions are great for complex things, but if you're only doing a single operation it's simpler to just put that one operation:

var query = dataList.OrderByWithDirection(x => x.Property, direction);

How to create a secure random AES key in Java?

I would use your suggested code, but with a slight simplification:

KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(256); // for example
SecretKey secretKey = keyGen.generateKey();

Let the provider select how it plans to obtain randomness - don't define something that may not be as good as what the provider has already selected.

This code example assumes (as Maarten points out below) that you've configured your java.security file to include your preferred provider at the top of the list. If you want to manually specify the provider, just call KeyGenerator.getInstance("AES", "providerName");.

For a truly secure key, you need to be using a hardware security module (HSM) to generate and protect the key. HSM manufacturers will typically supply a JCE provider that will do all the key generation for you, using the code above.

Remove specific characters from a string in Python

Below one.. with out using regular expression concept..

ipstring ="text with symbols!@#$^&*( ends here"
opstring=''
for i in ipstring:
    if i.isalnum()==1 or i==' ':
        opstring+=i
    pass
print opstring

Remove Last Comma from a string

The problem is that you remove the last comma in the string, not the comma if it's the last thing in the string. So you should put an if to check if the last char is ',' and change it if it is.

EDIT: Is it really that confusing?

'This, is a random string'

Your code finds the last comma from the string and stores only 'This, ' because, the last comma is after 'This' not at the end of the string.

Unprotect workbook without password

Try the below code to unprotect the workbook. It works for me just fine in excel 2010 but I am not sure if it will work in 2013.

Sub PasswordBreaker()
    'Breaks worksheet password protection.
    Dim i As Integer, j As Integer, k As Integer
    Dim l As Integer, m As Integer, n As Integer
    Dim i1 As Integer, i2 As Integer, i3 As Integer
    Dim i4 As Integer, i5 As Integer, i6 As Integer
    On Error Resume Next
    For i = 65 To 66: For j = 65 To 66: For k = 65 To 66
    For l = 65 To 66: For m = 65 To 66: For i1 = 65 To 66
    For i2 = 65 To 66: For i3 = 65 To 66: For i4 = 65 To 66
    For i5 = 65 To 66: For i6 = 65 To 66: For n = 32 To 126
    ThisWorkbook.Unprotect Chr(i) & Chr(j) & Chr(k) & _
        Chr(l) & Chr(m) & Chr(i1) & Chr(i2) & Chr(i3) & _
        Chr(i4) & Chr(i5) & Chr(i6) & Chr(n)
    If ThisWorkbook.ProtectStructure = False Then
        MsgBox "One usable password is " & Chr(i) & Chr(j) & _
            Chr(k) & Chr(l) & Chr(m) & Chr(i1) & Chr(i2) & _
            Chr(i3) & Chr(i4) & Chr(i5) & Chr(i6) & Chr(n)
         Exit Sub
    End If
    Next: Next: Next: Next: Next: Next
    Next: Next: Next: Next: Next: Next
End Sub

How can I get the baseurl of site?

I believe that the answers above doesn't consider when the site is not in the root of the website.

This is a for WebApi controller:

string baseUrl = (Url.Request.RequestUri.GetComponents(
                    UriComponents.SchemeAndServer, UriFormat.Unescaped).TrimEnd('/') 
                 + HttpContext.Current.Request.ApplicationPath).TrimEnd('/') ;

Global variables in header file

There are 3 scenarios, you describe:

  1. with 2 .c files and with int i; in the header.
  2. With 2 .c files and with int i=100; in the header (or any other value; that doesn't matter).
  3. With 1 .c file and with int i=100; in the header.

In each scenario, imagine the contents of the header file inserted into the .c file and this .c file compiled into a .o file and then these linked together.

Then following happens:

  1. works fine because of the already mentioned "tentative definitions": every .o file contains one of them, so the linker says "ok".

  2. doesn't work, because both .o files contain a definition with a value, which collide (even if they have the same value) - there may be only one with any given name in all .o files which are linked together at a given time.

  3. works of course, because you have only one .o file and so no possibility for collision.

IMHO a clean thing would be

  • to put either extern int i; or just int i; into the header file,
  • and then to put the "real" definition of i (namely int i = 100;) into file1.c. In this case, this initialization gets used at the start of the program and the corresponding line in main() can be omitted. (Besides, I hope the naming is only an example; please don't name any global variables as i in real programs.)

Android Imagebutton change Image OnClick

This misled me a bit - it should be setImageResource instead of setBackgroundResource :) !!

The following works fine :

ImageButton btn = (ImageButton)findViewById(R.id.imageButton1);       
 btn.setImageResource(R.drawable.actions_record);

while when using the setBackgroundResource the actual imagebutton's image stays while the background image is changed which leads to a ugly looking imageButton object

Thanks.

In Laravel, the best way to pass different types of flash messages in the session

One solution would be to flash two variables into the session:

  1. The message itself
  2. The "class" of your alert

for example:

Session::flash('message', 'This is a message!'); 
Session::flash('alert-class', 'alert-danger'); 

Then in your view:

@if(Session::has('message'))
<p class="alert {{ Session::get('alert-class', 'alert-info') }}">{{ Session::get('message') }}</p>
@endif

Note I've put a default value into the Session::get(). that way you only need to override it if the warning should be something other than the alert-info class.

(that is a quick example, and untested :) )

Differences in string compare methods in C#

Not that performance usually matters with 99% of the times you need to do this, but if you had to do this in a loop several million times I would highly suggest that you use .Equals or == because as soon as it finds a character that doesn't match it throws the whole thing out as false, but if you use the CompareTo it will have to figure out which character is less than the other, leading to slightly worse performance time.

If your app will be running in different countries, I'd recommend that you take a look at the CultureInfo implications and possibly use .Equals. Since I only really write apps for the US (and don't care if it doesn't work properly by someone), I always just use ==.

What are the complexity guarantees of the standard containers?

Another quick lookup table is available at this github page

Note : This does not consider all the containers such as, unordered_map etc. but is still great to look at. It is just a cleaner version of this

Linux command to check if a shell script is running or not

here a quick script to test if a shell script is running

#!/bin/sh

scripToTest="your_script_here.sh"
scriptExist=$(pgrep -f "$scripToTest")
[ -z "$scriptExist" ] && echo "$scripToTest : not running" || echo "$scripToTest : runnning"

How to change to an older version of Node.js

On windows 7 I used the general 'Uninstall Node.js' (just started typing in the search bottom left ,main menu field) followed by clicking the link to the older version which complies with the project, for instance: Windows 64-bit Installer: https://nodejs.org/dist/v4.4.6/node-v4.4.6-x64.msi

When should I use git pull --rebase?

Perhaps the best way to explain it is with an example:

  1. Alice creates topic branch A, and works on it
  2. Bob creates unrelated topic branch B, and works on it
  3. Alice does git checkout master && git pull. Master is already up to date.
  4. Bob does git checkout master && git pull. Master is already up to date.
  5. Alice does git merge topic-branch-A
  6. Bob does git merge topic-branch-B
  7. Bob does git push origin master before Alice
  8. Alice does git push origin master, which is rejected because it's not a fast-forward merge.
  9. Alice looks at origin/master's log, and sees that the commit is unrelated to hers.
  10. Alice does git pull --rebase origin master
  11. Alice's merge commit is unwound, Bob's commit is pulled, and Alice's commit is applied after Bob's commit.
  12. Alice does git push origin master, and everyone is happy they don't have to read a useless merge commit when they look at the logs in the future.

Note that the specific branch being merged into is irrelevant to the example. Master in this example could just as easily be a release branch or dev branch. The key point is that Alice & Bob are simultaneously merging their local branches to a shared remote branch.

"java.lang.OutOfMemoryError : unable to create new native Thread"

I had this same issue and it turned out to be an improper usage of an java API. I was initializing a builder in a batch processing method that was that not supposed to be initiallized more than once.

Basically I was doing something like:

for (batch in batches) {
    process_batch(batch)
}

def process_batch(batch) {
    var client = TransportClient.builder().build()
    client.processList(batch)
}

when I should have done this:

for (batch in batches) {
    var client = TransportClient.builder().build()
    process_batch(batch, client)
}

def process_batch(batch, client) {
    client.processList(batch)
}

How to determine if a number is positive or negative?

It's easy to do this like

private static boolean isNeg(T l) {
        return (Math.abs(l-1)>Math.abs(l));
 }

Sorting std::map using value

To build on Oli's solution (https://stackoverflow.com/a/5056797/2472351) using multimaps, you can replace the two template functions he used with the following:

template <typename A, typename B>
multimap<B, A> flip_map(map<A,B> & src) {

    multimap<B,A> dst;

    for(map<A, B>::const_iterator it = src.begin(); it != src.end(); ++it)
        dst.insert(pair<B, A>(it -> second, it -> first));

    return dst;
}

Here is an example program that shows all the key-value pairs being preserved after performing the flip.

#include <iostream>
#include <map>
#include <string>
#include <algorithm>

using namespace std;

template <typename A, typename B>
multimap<B, A> flip_map(map<A,B> & src) {

    multimap<B,A> dst;

    for(typename map<A, B>::const_iterator it = src.begin(); it != src.end(); ++it)
        dst.insert(pair<B, A>(it -> second, it -> first));

    return dst;
}

int main() {

    map<string, int> test;
    test["word"] = 1;
    test["spark"] = 15;
    test["the"] = 2;
    test["mail"] = 3;
    test["info"] = 3;
    test["sandwich"] = 15;

    cout << "Contents of original map:\n" << endl;
    for(map<string, int>::const_iterator it = test.begin(); it != test.end(); ++it)
        cout << it -> first << " " << it -> second << endl; 

    multimap<int, string> reverseTest = flip_map(test);

    cout << "\nContents of flipped map in descending order:\n" << endl;
    for(multimap<int, string>::const_reverse_iterator it = reverseTest.rbegin(); it != reverseTest.rend(); ++it)
        cout << it -> first << " " << it -> second << endl; 

    cout << endl;
}

Result:

enter image description here

Convert Month Number to Month Name Function in SQL

i think this is enough to get month name when u have date.

SELECT DATENAME(month ,GETDATE())

Fixed header, footer with scrollable content

Something like this

<html>
  <body style="height:100%; width:100%">
    <div id="header" style="position:absolute; top:0px; left:0px; height:200px; right:0px;overflow:hidden;"> 
    </div> 
    <div id="content" style="position:absolute; top:200px; bottom:200px; left:0px; right:0px; overflow:auto;"> 
    </div> 
    <div id="footer" style="position:absolute; bottom:0px; height:200px; left:0px; right:0px; overflow:hidden;"> 
    </div>
  </body>
</html> 

How to move up a directory with Terminal in OS X

Typing cd will take you back to your home directory. Whereas typing cd .. will move you up only one directory (the direct parent of the current directory).

How can you get the first digit in an int (C#)?

Try this

public int GetFirstDigit(int number) {
  if ( number < 10 ) {
    return number;
  }
  return GetFirstDigit ( (number - (number % 10)) / 10);
}

EDIT

Several people have requested the loop version

public static int GetFirstDigitLoop(int number)
{
    while (number >= 10)
    {
        number = (number - (number % 10)) / 10;
    }
    return number;
}

Google Maps JS API v3 - Simple Multiple Marker Example

Accepted answer, rewritten in ES6:

$(document).ready(() => {
  const mapEl = $('#our_map').get(0); // OR document.getElementById('our_map');

  // Display a map on the page
  const map = new google.maps.Map(mapEl, { mapTypeId: 'roadmap' });

  const buildings = [
    {
      title: 'London Eye, London', 
      coordinates: [51.503454, -0.119562],
      info: 'carousel'
    },
    {
      title: 'Palace of Westminster, London', 
      coordinates: [51.499633, -0.124755],
      info: 'palace'
    }
  ];

  placeBuildingsOnMap(buildings, map);
});


const placeBuildingsOnMap = (buildings, map) => {
  // Loop through our array of buildings & place each one on the map  
  const bounds = new google.maps.LatLngBounds();
  buildings.forEach((building) => {
    const position = { lat: building.coordinates[0], lng: building.coordinates[1] }
    // Stretch our bounds to the newly found marker position
    bounds.extend(position);

    const marker = new google.maps.Marker({
      position: position,
      map: map,
      title: building.title
    });

    const infoWindow = new google.maps.InfoWindow();
    // Allow each marker to have an info window
    google.maps.event.addListener(marker, 'click', () => {
      infoWindow.setContent(building.info);
      infoWindow.open(map, marker);
    })

    // Automatically center the map fitting all markers on the screen
    map.fitBounds(bounds);
  })
})

Variable not accessible when initialized outside function

A global variable would be best expressed in an external JavaScript file:

var system_status;

Make sure that this has not been used anywhere else. Then to access the variable on your page, just reference it as such. Say, for example, you wanted to fill in the results on a textbox,

document.getElementById("textbox1").value = system_status;

To ensure that the object exists, use the document ready feature of jQuery.

Example:

$(function() {
    $("#textbox1")[0].value = system_status;
});

AES vs Blowfish for file encryption

Both algorithms (AES and twofish) are considered very secure. This has been widely covered in other answers.

However, since AES is much widely used now in 2016, it has been specifically hardware-accelerated in several platforms such as ARM and x86. While not significantly faster than twofish before hardware acceleration, AES is now much faster thanks to the dedicated CPU instructions.

How to display the value of the bar on each bar with pyplot.barh()?

For pandas people :

ax = s.plot(kind='barh') # s is a Series (float) in [0,1]
[ax.text(v, i, '{:.2f}%'.format(100*v)) for i, v in enumerate(s)];

That's it. Alternatively, for those who prefer apply over looping with enumerate:

it = iter(range(len(s)))
s.apply(lambda x: ax.text(x, next(it),'{:.2f}%'.format(100*x)));

Also, ax.patches will give you the bars that you would get with ax.bar(...). In case you want to apply the functions of @SaturnFromTitan or techniques of others.

Remove the last three characters from a string

str= str.Remove(str.Length - 3);

Change "on" color of a Switch

Solution for Android Studio 3.6:

yourSwitch.setTextColor(getResources().getColor(R.color.yourColor));

Changes the text color of a in the color XML file defined value (yourColor).

Script parameters in Bash

I needed to make sure that my scripts are entirely portable between various machines, shells and even cygwin versions. Further, my colleagues who were the ones I had to write the scripts for, are programmers, so I ended up using this:

for ((i=1;i<=$#;i++)); 
do

    if [ ${!i} = "-s" ] 
    then ((i++)) 
        var1=${!i};

    elif [ ${!i} = "-log" ];
    then ((i++)) 
        logFile=${!i};  

    elif [ ${!i} = "-x" ];
    then ((i++)) 
        var2=${!i};    

    elif [ ${!i} = "-p" ]; 
    then ((i++)) 
        var3=${!i};

    elif [ ${!i} = "-b" ];
    then ((i++)) 
        var4=${!i};

    elif [ ${!i} = "-l" ];
    then ((i++)) 
        var5=${!i}; 

    elif [ ${!i} = "-a" ];
    then ((i++)) 
        var6=${!i};
    fi

done;

Rationale: I included a launcher.sh script as well, since the whole operation had several steps which were quasi independent on each other (I'm saying "quasi", because even though each script could be run on its own, they were usually all run together), and in two days I found out, that about half of my colleagues, being programmers and all, were too good to be using the launcher file, follow the "usage", or read the HELP which was displayed every time they did something wrong and they were making a mess of the whole thing, running scripts with arguments in the wrong order and complaining that the scripts didn't work properly. Being the choleric I am I decided to overhaul all my scripts to make sure that they are colleague-proof. The code segment above was the first thing.

Send Email to multiple Recipients with MailMessage?

According to the Documentation :

MailMessage.To property - Returns MailAddressCollection that contains the list of recipients of this email message

Here MailAddressCollection has a in built method called

   public void Add(string addresses)

   1. Summary:
          Add a list of email addresses to the collection.

   2. Parameters:
          addresses: 
                *The email addresses to add to the System.Net.Mail.MailAddressCollection. Multiple
                *email addresses must be separated with a comma character (",").     

Therefore requirement in case of multiple recipients : Pass a string that contains email addresses separated by comma

In your case :

simply replace all the ; with ,

Msg.To.Add(toEmail.replace(";", ","));

For reference :

  1. https://docs.microsoft.com/en-us/dotnet/api/system.net.mail.mailmessage?view=netframework-4.8
  2. https://www.geeksforgeeks.org/c-sharp-replace-method/

Exception is never thrown in body of corresponding try statement

A catch-block in a try statement needs to catch exactly the exception that the code inside the try {}-block can throw (or a super class of that).

try {
    //do something that throws ExceptionA, e.g.
    throw new ExceptionA("I am Exception Alpha!");
}
catch(ExceptionA e) {
    //do something to handle the exception, e.g.
    System.out.println("Message: " + e.getMessage());
}

What you are trying to do is this:

try {
    throw new ExceptionB("I am Exception Bravo!");
}
catch(ExceptionA e) {
    System.out.println("Message: " + e.getMessage());
}

This will lead to an compiler error, because your java knows that you are trying to catch an exception that will NEVER EVER EVER occur. Thus you would get: exception ExceptionA is never thrown in body of corresponding try statement.

How to have click event ONLY fire on parent DIV, not children?

I had the same problem and came up with this solution (based on the other answers)

 $( ".newsletter_background" ).click(function(e) {
    if (e.target == this) {
        $(".newsletter_background").hide();
    } 
});

Basically it says if the target is the div then run the code otherwise do nothing (don't hide it)

jQuery vs. javascript?

Jquery like any other good JavaScript frameworks supplies you with functionality independent of browser platform wrapping all the intricacies, which you may not care about or don't want to care about.

I think using a framework is better instead of using pure JavaScript and doing all the stuff from scratch, unless you usage is very limited.

I definitely recommend JQuery!

Thanks

Display only 10 characters of a long string?

If I understand correctly you want to limit a string to 10 characters?

var str = 'Some very long string';
if(str.length > 10) str = str.substring(0,10);

Something like that?

how to show confirmation alert with three buttons 'Yes' 'No' and 'Cancel' as it shows in MS Word

This cannot be done with the native javascript dialog box, but a lot of javascript libraries include more flexible dialogs. You can use something like jQuery UI's dialog box for this.

See also these very similar questions:

Here's an example, as demonstrated in this jsFiddle:

<html><head>
    <script type="text/javascript" src="http://code.jquery.com/jquery-1.7.1.js"></script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.js"></script>
    <link rel="stylesheet" type="text/css" href="/css/normalize.css">
    <link rel="stylesheet" type="text/css" href="/css/result-light.css">
    <link rel="stylesheet" type="text/css" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.17/themes/base/jquery-ui.css">
</head>
<body>
    <a class="checked" href="http://www.google.com">Click here</a>
    <script type="text/javascript">

        $(function() {
            $('.checked').click(function(e) {
                e.preventDefault();
                var dialog = $('<p>Are you sure?</p>').dialog({
                    buttons: {
                        "Yes": function() {alert('you chose yes');},
                        "No":  function() {alert('you chose no');},
                        "Cancel":  function() {
                            alert('you chose cancel');
                            dialog.dialog('close');
                        }
                    }
                });
            });
        });

    </script>
</body><html>

How to make a local variable (inside a function) global

Here are two methods to achieve the same thing:

Using parameters and return (recommended)

def other_function(parameter):
    return parameter + 5

def main_function():
    x = 10
    print(x)    
    x = other_function(x)
    print(x)

When you run main_function, you'll get the following output

>>> 10
>>> 15

Using globals (never do this)

x = 0   # The initial value of x, with global scope

def other_function():
    global x
    x = x + 5

def main_function():
    print(x)    # Just printing - no need to declare global yet
    global x   # So we can change the global x
    x = 10
    print(x)
    other_function()
    print(x)

Now you will get:

>>> 0    # Initial global value
>>> 10   # Now we've set it to 10 in `main_function()`
>>> 15   # Now we've added 5 in `other_function()`

Spring Data JPA - "No Property Found for Type" Exception

If you are using a composite key in your bean, your parameter will be an object. You need to adjust your findBy method according to the new combination.

@Embeddable
public class CombinationId implements Serializable {

  private String xId;
  private String yId;
}

public class RealObject implements Serializable, Persistable<CombinationId> {

  @EmbeddedId private CombinationId id;
}

In that case, your repository findBy method should be as this

@Repository
public interface PaymentProfileRepository extends JpaRepository<RealObject, String> {

  List<RealObject> findById_XId(String someString);
}

Programmatically Add CenterX/CenterY Constraints

Programmatically you can do it by adding the following constraints.

NSLayoutConstraint *constraintHorizontal = [NSLayoutConstraint constraintWithItem:self  
                                                                      attribute:NSLayoutAttributeCenterX 
                                                                      relatedBy:NSLayoutRelationEqual 
                                                                         toItem:self.superview 
                                                                      attribute:attribute 
                                                                     multiplier:1.0f 
                                                                       constant:0.0f];

NSLayoutConstraint *constraintVertical = [NSLayoutConstraint constraintWithItem:self
                                                                        attribute:NSLayoutAttributeCenterY 
                                                                        relatedBy:NSLayoutRelationEqual
                                                                           toItem:self.superview 
                                                                        attribute:attribute 
                                                                       multiplier:1.0f
                                                                         constant:0.0f];

CSS: Change image src on img:hover

I have one more solution. If anybody uses AngularJs : http://jsfiddle.net/ec9gn/30/

<div ng-controller='ctrl'>
    <img ng-mouseover="img='eb00eb'"  ng-mouseleave="img='000'"
         ng-src='http://dummyimage.com/100x100/{{img}}/fff' />
</div>

The Javascript :

function ctrl($scope){
    $scope.img= '000';
}

No CSS ^^.

Difference between window.location.href, window.location.replace and window.location.assign

The part about not being able to use the Back button is a common misinterpretation. window.location.replace(URL) throws out the top ONE entry from the page history list, by overwriting it with the new entry, so the user can't easily go Back to that ONE particular webpage. The function does NOT wipe out the entire page history list, nor does it make the Back button completely non-functional.

(NO function nor combination of parameters that I know of can change or overwrite history list entries that you don't own absolutely for certain - browsers generally impelement this security limitation by simply not even defining any operation that might at all affect any entry other than the top one in the page history list. I shudder to think what sorts of dastardly things malware might do if such a function existed.)

If you really want to make the Back button non-functional (probably not "user friendly": think again if that's really what you want to do), "open" a brand new window. (You can "open" a popup that doesn't even have a "Back" button too ...but popups aren't very popular these days:-) If you want to keep your page showing no matter what the user does (again the "user friendliness" is questionable), set up a window.onunload handler that just reloads your page all over again clear from the very beginning every time.

How to set JVM parameters for Junit Unit Tests?

According to this support question https://intellij-support.jetbrains.com/hc/en-us/community/posts/206165789-JUnit-default-heap-size-overridden-

the -Xmx argument for an IntelliJ junit test run will come from the maven-surefire-plugin, if it's set.

This pom.xml snippet

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
                <argLine>-Xmx1024m</argLine>
            </configuration>
        </plugin>

seems to pass the -Xmx1024 argument to the junit test run, with IntelliJ 2016.2.4.

Pipe subprocess standard output to a variable

If you are using python 2.7 or later, the easiest way to do this is to use the subprocess.check_output() command. Here is an example:

output = subprocess.check_output('ls')

To also redirect stderr you can use the following:

output = subprocess.check_output('ls', stderr=subprocess.STDOUT)



In the case that you want to pass parameters to the command, you can either use a list or use invoke a shell and use a single string.

output = subprocess.check_output(['ls', '-a'])
output = subprocess.check_output('ls -a', shell=True)

if block inside echo statement?

Use a ternary operator:

echo '<option value="'.$value.'"'.($value=='United States' ? 'selected="selected"' : '').'>'.$value.'</option>';

And while you're at it, you could use printf to make your code more readable/manageable:

printf('<option value="%s" %s>%s</option>',
    $value,
    $value == 'United States' ? 'selected="selected"' : ''
    $value);

Python Requests - No connection adapters

One more reason, maybe your url include some hiden characters, such as '\n'.

If you define your url like below, this exception will raise:

url = '''
http://google.com
'''

because there are '\n' hide in the string. The url in fact become:

\nhttp://google.com\n

Disable and later enable all table indexes in Oracle

combining 3 answers together: (because a select statement does not execute the DDL)

set pagesize 0

alter session set skip_unusable_indexes = true;
spool c:\temp\disable_indexes.sql
select 'alter index ' || u.index_name || ' unusable;' from user_indexes u;
spool off
@c:\temp\disable_indexes.sql

Do import...

select 'alter index ' || u.index_name || 
' rebuild online;' from user_indexes u;

Note this assumes that the import is going to happen in the same (sqlplus) session.
If you are calling "imp" it will run in a separate session so you would need to use "ALTER SYSTEM" instead of "ALTER SESSION" (and remember to put the parameter back the way you found it.

How to build a JSON array from mysql database

Use this

$array = array();
$subArray=array();
$sql_results = mysql_query('SELECT * FROM `location`');

while($row = mysql_fetch_array($sql_results))
{
    $subArray[location_id]=$row['location'];  //location_id is key and $row['location'] is value which come fron database.
    $subArray[x]=$row['x'];
    $subArray[y]=$row['y'];


 $array[] =  $subArray ;
}
echo'{"ProductsData":'.json_encode($array).'}';

Git Stash vs Shelve in IntelliJ IDEA

When using JetBrains IDE's with Git, "stashing and unstashing actions are supported in addition to shelving and unshelving. These features have much in common; the major difference is in the way patches are generated and applied. Shelve can operate with either individual files or bunch of files, while Stash can only operate with a whole bunch of changed files at once. Here are some more details on the differences between them."

Select N random elements from a List<T> in C#

Iterate through and for each element make the probability of selection = (number needed)/(number left)

So if you had 40 items, the first would have a 5/40 chance of being selected. If it is, the next has a 4/39 chance, otherwise it has a 5/39 chance. By the time you get to the end you will have your 5 items, and often you'll have all of them before that.

This technique is called selection sampling, a special case of Reservoir Sampling. It's similar in performance to shuffling the input, but of course allows the sample to be generated without modifying the original data.

Getting data from Yahoo Finance

To your first question, you can't really do any query through YQL to get data for all companies. It's more oriented towards obtaining data for a smaller query. (I.e., it's not going to give you a full data dump of the whole Yahoo! Finance database.)

To your second question, here's how you can get started exploring the Yahoo! Finance tables in YQL:

  1. Start at the YQL Console
  2. In the upper left corner, make sure Show Community Tables is checked
  3. Type finance in the search field
  4. You'll see all the Yahoo Finance tables (about 15)

Then you can try some example queries like the following:

select * from yahoo.finance.quote where symbol in ("YHOO","AAPL","GOOG","MSFT")

Update 2016-04-04: Here's a current screenshot showing the location of the Show Community Tables checkbox which must be clicked to see these finance tables: enter image description here

Flask - Calling python function on button OnClick event

You can simply do this with help of AJAX... Here is a example which calls a python function which prints hello without redirecting or refreshing the page.

In app.py put below code segment.

#rendering the HTML page which has the button
@app.route('/json')
def json():
    return render_template('json.html')

#background process happening without any refreshing
@app.route('/background_process_test')
def background_process_test():
    print ("Hello")
    return ("nothing")

And your json.html page should look like below.

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type=text/javascript>
        $(function() {
          $('a#test').on('click', function(e) {
            e.preventDefault()
            $.getJSON('/background_process_test',
                function(data) {
              //do nothing
            });
            return false;
          });
        });
</script>


//button
<div class='container'>
    <h3>Test</h3>
        <form>
            <a href=# id=test><button class='btn btn-default'>Test</button></a>
        </form>

</div>

Here when you press the button Test simple in the console you can see "Hello" is displaying without any refreshing.

Can you blur the content beneath/behind a div?

you can do this with css3, this blurs the whole element

div (or whatever element) {
  -webkit-filter: blur(5px);
  -moz-filter: blur(5px);
  -o-filter: blur(5px);
  -ms-filter: blur(5px);
  filter: blur(5px);
}

Fiddle: http://jsfiddle.net/H4DU4/

Server certificate verification failed: issuer is not trusted

I wouldn't use:

svn checkout

just to authorizes the server authentication, I rather use:

svn list https://your.repository.url

which will ask you to do the authentication as well.

If this is needed to get authorization to a user that can't login, run:

sudo -u username svn list https://your.repository.url

Open URL in Java to get the content

Are you sure using the java.net.URL class? Check your import statements.

Convert array of strings into a string in Java

Following is an example of Array to String conversion.

    public class ArrayToString
    {
public static void main(String[] args) { String[] strArray = new String[]{"Java", "PHP", ".NET", "PERL", "C", "COBOL"};

        String newString = Arrays.toString(strArray);

        newString = newString.substring(1, newString.length()-1);

        System.out.println("New New String: " + newString);
    }
}

How can I add a column that doesn't allow nulls in a Postgresql database?

Since rows already exist in the table, the ALTER statement is trying to insert NULL into the newly created column for all of the existing rows. You would have to add the column as allowing NULL, then fill the column with the values you want, and then set it to NOT NULL afterwards.

HTML/CSS font color vs span style

<span style="color:#ffffff; font-size:18px; line-height:35px; font-family: Calibri;">Our Activities </span>

This works for me well:) As it has been already mentioned above "The font tag has been deprecated, at least in XHTML. It always safe to use span tag. font may not give you desire results, at least in my case it didn't.

How to loop through a directory recursively to delete files with certain extensions

This method handles spaces well.

files="$(find -L "$dir" -type f)"
echo "Count: $(echo -n "$files" | wc -l)"
echo "$files" | while read file; do
  echo "$file"
done

Edit, fixes off-by-one

function count() {
    files="$(find -L "$1" -type f)";
    if [[ "$files" == "" ]]; then
        echo "No files";
        return 0;
    fi
    file_count=$(echo "$files" | wc -l)
    echo "Count: $file_count"
    echo "$files" | while read file; do
        echo "$file"
    done
}

Run a controller function whenever a view is opened/shown

I faced at the same problem, and here i leave the reason of this behavior for everyone else with the same issue.

View LifeCycle

In order to improve performance, we've improved Ionic's ability to cache view elements and scope data. Once a controller is initialized, it may persist throughout the app’s life; it’s just hidden and removed from the watch cycle. Since we aren’t rebuilding scope, we’ve added events for which we should listen when entering the watch cycle again.

To see full description and $ionicView events go to: http://ionicframework.com/blog/navigating-the-changes/

call javascript function on hyperlink click

The JQuery answer. Since JavaScript was invented in order to develop JQuery, I am giving you an example in JQuery doing this:

<div class="menu">
    <a href="http://example.org">Example</a>
    <a href="http://foobar.com">Foobar.com</a>
</div>

<script>
jQuery( 'div.menu a' )
    .click(function() {
        do_the_click( this.href );
        return false;
    });

// play the funky music white boy
function do_the_click( url )
{
    alert( url );
}
</script>

Facebook share link without JavaScript

How to share content: https://developers.facebook.com/docs/share/

You have to choose use the deprecated function without JS, and check every day, or follow the way use JS and have fun.

Difference between long and int data types

From this reference:

An int was originally intended to be the "natural" word size of the processor. Many modern processors can handle different word sizes with equal ease.

Also, this bit:

On many (but not all) C and C++ implementations, a long is larger than an int. Today's most popular desktop platforms, such as Windows and Linux, run primarily on 32 bit processors and most compilers for these platforms use a 32 bit int which has the same size and representation as a long.

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

In advanced development ids we can basically use JavaScript.

For repeatable purposes, classes come handy contrary to ids which supposed to be unique.

Below is an example illustrating the expressions above:

<div id="box" class="box bg-color-red">this is a box</div>
<div id="box1" class="box bg-color-red">this is a box</div>

Now you can see in here box and box1 are two (2) different <div> elements, but we can apply the box and bg-color-red classes to both of them.

The concept is inheritance in an OOP language.

How is CountDownLatch used in Java Multithreading?

One good example of when to use something like this is with Java Simple Serial Connector, accessing serial ports. Typically you'll write something to the port, and asyncronously, on another thread, the device will respond on a SerialPortEventListener. Typically, you'll want to pause after writing to the port to wait for the response. Handling the thread locks for this scenario manually is extremely tricky, but using Countdownlatch is easy. Before you go thinking you can do it another way, be careful about race conditions you never thought of!!

Pseudocode:

CountDownLatch latch;
void writeData() { 
   latch = new CountDownLatch(1);
   serialPort.writeBytes(sb.toString().getBytes())
   try {
      latch.await(4, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
   }
}
class SerialPortReader implements SerialPortEventListener {
    public void serialEvent(SerialPortEvent event) {
        if(event.isRXCHAR()){//If data is available
            byte buffer[] = serialPort.readBytes(event.getEventValue());
            latch.countDown();
         }
     }
}

Distinct by property of class with LINQ

Same approach as Guffa but as an extension method:

public static IEnumerable<T> DistinctBy<T, TKey>(this IEnumerable<T> items, Func<T, TKey> property)
{
    return items.GroupBy(property).Select(x => x.First());
}

Used as:

var uniqueCars = cars.DistinctBy(x => x.CarCode);

Free ASP.Net and/or CSS Themes

Microsoft hired one fo the kids from A List Apart to whip some out. The .Net projects are free of charge for download.

http://msdn.microsoft.com/en-us/asp.net/aa336613.aspx

list all files in the folder and also sub folders

Use FileUtils from Apache commons.

listFiles

public static Collection<File> listFiles(File directory,
                                         String[] extensions,
                                         boolean recursive)
Finds files within a given directory (and optionally its subdirectories) which match an array of extensions.
Parameters:
directory - the directory to search in
extensions - an array of extensions, ex. {"java","xml"}. If this parameter is null, all files are returned.
recursive - if true all subdirectories are searched as well
Returns:
an collection of java.io.File with the matching files

How to install 2 Anacondas (Python 2 and 3) on Mac OS

This may be helpful if you have more than one python versions installed and dont know how to tell your ide's to use a specific version.

  1. Install anaconda. Latest version can be found here
  2. Open the navigator by typing anaconda-navigator in terminal
  3. Open environments. Click on create and then choose your python version in that.
  4. Now new environment will be created for your python version and you can install the IDE's(which are listed there) just by clicking install in that.
  5. Launch the IDE in your environment so that that IDE will use the specified version for that environment.

Hope it helps!!

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

This is a bit indirect, but it works very nicely. Get LiveWriter and install this plugin:

http://lvildosola.blogspot.com/2007/02/code-snippet-plugin-for-windows-live.html

Insert your code using the plugin into a blog post. Select all and copy it to Word.

It looks great and can include line numbers. It also spans pages decently.

HTH

Colby Africa

Create an ArrayList of unique values

You can read from file to map, where the key is the date and skip if the the whole row if the date is already in map

        Map<String, List<String>> map = new HashMap<String, List<String>>();

        int i = 0;
        String lastData = null;
        while (s.hasNext()) {
            String str = s.next();
            if (i % 13 == 0) {
                if (map.containsKey(str)) {
                    //skip the whole row
                    lastData = null;
                } else {
                    lastData = str;
                    map.put(lastData, new ArrayList<String>());
                }
            } else if (lastData != null) {
                map.get(lastData).add(str);
            }


            i++;
        }

Is it possible to capture the stdout from the sh DSL command in the pipeline

Now, the sh step supports returning stdout by supplying the parameter returnStdout.

// These should all be performed at the point where you've
// checked out your sources on the slave. A 'git' executable
// must be available.
// Most typical, if you're not cloning into a sub directory
gitCommit = sh(returnStdout: true, script: 'git rev-parse HEAD').trim()
// short SHA, possibly better for chat notifications, etc.
shortCommit = gitCommit.take(6)

See this example.

How to ignore conflicts in rpm installs

Try Freshen command:

rpm -Fvh *.rpm

How to write a JSON file in C#?

The example in Liam's answer saves the file as string in a single line. I prefer to add formatting. Someone in the future may want to change some value manually in the file. If you add formatting it's easier to do so.

The following adds basic JSON indentation:

 string json = JsonConvert.SerializeObject(_data.ToArray(), Formatting.Indented);

How to add elements to a list in R (loop)

You should not add to your list using c inside the loop, because that can result in very very slow code. Basically when you do c(l, new_element), the whole contents of the list are copied. Instead of that, you need to access the elements of the list by index. If you know how long your list is going to be, it's best to initialise it to this size using l <- vector("list", N). If you don't you can initialise it to have length equal to some large number (e.g if you have an upper bound on the number of iterations) and then just pick the non-NULL elements after the loop has finished. Anyway, the basic point is that you should have an index to keep track of the list element and add using that eg

i <- 1
while(...) {
    l[[i]] <- new_element
    i <- i + 1
}

For more info have a look at Patrick Burns' The R Inferno (Chapter 2).

How to drop columns using Rails migration

In a rails4 app it is possible to use the change method also for removing columns. The third param is the data_type and in the optional forth you can give options. It is a bit hidden in the section 'Available transformations' on the documentation .

class RemoveFieldFromTableName < ActiveRecord::Migration
  def change
    remove_column :table_name, :field_name, :data_type, {}
  end
end

How does one add keyboard languages and switch between them in Linux Mint 16?

This assumes you have other languages already added in Language Support. (To check this, Menu > Language Support)

Now to make the keyboard language appear in the Panel:

  • Menu > Keyboard > Layouts > Add (+)

The icon 'en' or your language should now appear in the right panel tray. Click it to switch language.

In previous Mint versions, the shortcut for switching language was LEFT SHIFT + CAPS.

It seems now there is no default, and it must be added:

  • System settings > Keyboard > Layouts > Options > Switching to another layout

Keyboard Preferences is also accessible by right-clicking the language icon in the Panel.

IntelliJ: Never use wildcard imports

This applies to "IntelliJ IDEA-2019.2.4" on Mac.

  1. Navigate to "IntelliJ IDEA->Preferences->Editor->Code Style->Kotlin".
  2. The "Packages to use Import with '' section on the screen will list "import java.util."

Before

  1. Click anywhere in that box and clear that entry.
  2. Hit Apply and OK.

After

How to "perfectly" override a dict?

You can write an object that behaves like a dict quite easily with ABCs (Abstract Base Classes) from the collections.abc module. It even tells you if you missed a method, so below is the minimal version that shuts the ABC up.

from collections.abc import MutableMapping


class TransformedDict(MutableMapping):
    """A dictionary that applies an arbitrary key-altering
       function before accessing the keys"""

    def __init__(self, *args, **kwargs):
        self.store = dict()
        self.update(dict(*args, **kwargs))  # use the free update to set keys

    def __getitem__(self, key):
        return self.store[self._keytransform(key)]

    def __setitem__(self, key, value):
        self.store[self._keytransform(key)] = value

    def __delitem__(self, key):
        del self.store[self._keytransform(key)]

    def __iter__(self):
        return iter(self.store)
    
    def __len__(self):
        return len(self.store)

    def _keytransform(self, key):
        return key

You get a few free methods from the ABC:

class MyTransformedDict(TransformedDict):

    def _keytransform(self, key):
        return key.lower()


s = MyTransformedDict([('Test', 'test')])

assert s.get('TEST') is s['test']   # free get
assert 'TeSt' in s                  # free __contains__
                                    # free setdefault, __eq__, and so on

import pickle
# works too since we just use a normal dict
assert pickle.loads(pickle.dumps(s)) == s

I wouldn't subclass dict (or other builtins) directly. It often makes no sense, because what you actually want to do is implement the interface of a dict. And that is exactly what ABCs are for.

How do you convert a DataTable into a generic list?

If anyone want's to create custom function to convert datatable to list

class Program
{
    static void Main(string[] args)
    {
        DataTable table = GetDataTable();
        var sw = new Stopwatch();

        sw.Start();
        LinqMethod(table);
        sw.Stop();
        Console.WriteLine("Elapsed time for Linq Method={0}", sw.ElapsedMilliseconds);

        sw.Reset();

        sw.Start();
        ForEachMethod(table);
        sw.Stop();
        Console.WriteLine("Elapsed time for Foreach method={0}", sw.ElapsedMilliseconds);

        Console.ReadKey();
    }

    private static DataTable GetDataTable()
    {
        var table = new DataTable();
        table.Columns.Add("ID", typeof(double));
        table.Columns.Add("CategoryName", typeof(string));
        table.Columns.Add("Active", typeof(double));

        var rand = new Random();

        for (int i = 0; i < 100000; i++)
        {
            table.Rows.Add(i, "name" + i,  rand.Next(0, 2));
        }
        return table;
    }

    private static void LinqMethod(DataTable table)
    {
        var list = table.AsEnumerable()
            .Skip(1)
            .Select(dr =>
                new Category
                {
                    Id = Convert.ToInt32(dr.Field<double>("ID")),
                    CategoryName = dr.Field<string>("CategoryName"),                      
                    IsActive =
                            dr.Field<double>("Active") == 1 ? true : false
                }).ToList();
    }
    private static void ForEachMethod(DataTable table)
    {
        var categoryList = new List<Category>(table.Rows.Count);
        foreach (DataRow row in table.Rows)
        {
            var values = row.ItemArray;
            var category = new Category()
            {
                Id = Convert.ToInt32(values[0]),
                CategoryName = Convert.ToString(values[1]),                   
                IsActive = (double)values[2] == 1 ? true : false
            };
            categoryList.Add(category);
        }
    }

    private class Category
    {
        public int Id { get; set; }
        public string CategoryName { get; set; }
        public bool IsActive { get; set; }
    }
}

If we execute above code, Foreach method finishes in 56ms while linq one takes 101ms ( for 1000 records). So Foreach method is better to use. Source:Ways to Convert Datatable to List in C# (with performance test example)

How do I check if a string contains a specific word?

if (preg_match('/(are)/', $a)) {
   echo 'true';
}

position: fixed doesn't work on iPad and iPhone

here is my solution to this...

CSS

#bgimg_top {
    background: url(images/bg.jpg) no-repeat 50% 0%; 
    position: fixed; 
    top:0; 
    left: 0; 
    right:0 ; 
    bottom:0;
}

HTML

<body>
<div id="bgimg_top"></div>
....
</body>

Explanation is that position fixed for the div will keep the div on the background at all time, then we stretch the div to go on all corners of the browser (provided the body margin = 0) using the (left,right,top,bottom) simultaneously.

Please make sure you do not use the width and height as this will override the top,left,right,bottom options.

print highest value in dict with key

The clue is to work with the dict's items (i.e. key-value pair tuples). Then by using the second element of the item as the max key (as opposed to the dict key) you can easily extract the highest value and its associated key.

 mydict = {'A':4,'B':10,'C':0,'D':87}
>>> max(mydict.items(), key=lambda k: k[1])
('D', 87)
>>> min(mydict.items(), key=lambda k: k[1])
('C', 0)

TypeError: method() takes 1 positional argument but 2 were given

In my case, I forgot to add the ()

I was calling the method like this

obj = className.myMethod

But it should be is like this

obj = className.myMethod()

How to run ssh-add on windows?

One could install Git for Windows and subsequently run ssh-add:

Step 3: Add your key to the ssh-agent

To configure the ssh-agent program to use your SSH key:

If you have GitHub for Windows installed, you can use it to clone repositories and not deal with SSH keys. It also comes with the Git Bash tool, which is the preferred way of running git commands on Windows.

  1. Ensure ssh-agent is enabled:

    • If you are using Git Bash, turn on ssh-agent:

      # start the ssh-agent in the background
      ssh-agent -s
      # Agent pid 59566
      
    • If you are using another terminal prompt, such as msysgit, turn on ssh-agent:

      # start the ssh-agent in the background
      eval $(ssh-agent -s)
      # Agent pid 59566
      
  2. Add your SSH key to the ssh-agent:

    ssh-add ~/.ssh/id_rsa
    

How can I combine flexbox and vertical scroll in a full-height app?

Thanks to https://stackoverflow.com/users/1652962/cimmanon that gave me the answer.

The solution is setting a height to the vertical scrollable element. For example:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 0px;
}

The element will have height because flexbox recalculates it unless you want a min-height so you can use height: 100px; that it is exactly the same as: min-height: 100px;

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 100px; /* == min-height: 100px*/
}

So the best solution if you want a min-height in the vertical scroll:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 100px;
}

If you just want full vertical scroll in case there is no enough space to see the article:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 0px;
}

The final code: http://jsfiddle.net/ch7n6/867/

Different ways of clearing lists

It appears to me that del will give you the memory back, while assigning a new list will make the old one be deleted only when the gc runs.matter.

This may be useful for large lists, but for small list it should be negligible.

Edit: As Algorias, it doesn't matter.

Note that

del old_list[ 0:len(old_list) ]

is equivalent to

del old_list[:]

Why does instanceof return false for some literals?

Primitives are a different kind of type than objects created from within Javascript. From the Mozilla API docs:

var color1 = new String("green");
color1 instanceof String; // returns true
var color2 = "coral";
color2 instanceof String; // returns false (color2 is not a String object)

I can't find any way to construct primitive types with code, perhaps it's not possible. This is probably why people use typeof "foo" === "string" instead of instanceof.

An easy way to remember things like this is asking yourself "I wonder what would be sane and easy to learn"? Whatever the answer is, Javascript does the other thing.

How can I find the number of days between two Date objects in Ruby?

Subtract the beginning date from the end date:

endDate - beginDate 

$(document).ready shorthand

The shorthand is:

$(function() {
    // Code here
});

android edittext onchange listener

First, you can see if the user finished editing the text if the EditText loses focus or if the user presses the done button (this depends on your implementation and on what fits the best for you). Second, you can't get an EditText instance within the TextWatcher only if you have declared the EditText as an instance object. Even though you shouldn't edit the EditText within the TextWatcher because it is not safe.

EDIT:

To be able to get the EditText instance into your TextWatcher implementation, you should try something like this:

public class YourClass extends Activity {

    private EditText yourEditText;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);
        yourEditText = (EditText) findViewById(R.id.yourEditTextId);

        yourEditText.addTextChangedListener(new TextWatcher() {

            public void afterTextChanged(Editable s) {

                // you can call or do what you want with your EditText here

                // yourEditText... 
            }

            public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

            public void onTextChanged(CharSequence s, int start, int before, int count) {}
        });
    }
}

Note that the above sample might have some errors but I just wanted to show you an example.

How to round up a number to nearest 10?

to nearest 10 , should be as below

$number = ceil($input * 0.1)/0.1 ;

How to do the equivalent of pass by reference for primitives in Java

public static void main(String[] args) {
    int[] toyNumber = new int[] {5};
    NewClass temp = new NewClass();
    temp.play(toyNumber);
    System.out.println("Toy number in main " + toyNumber[0]);
}

void play(int[] toyNumber){
    System.out.println("Toy number in play " + toyNumber[0]);
    toyNumber[0]++;
    System.out.println("Toy number in play after increement " + toyNumber[0]);
}

How to compare two java objects

You need to implement the equals() method in your MyClass.

The reason that == didn't work is this is checking that they refer to the same instance. Since you did new for each, each one is a different instance.

The reason that equals() didn't work is because you didn't implement it yourself yet. I believe it's default behavior is the same thing as ==.

Note that you should also implement hashcode() if you're going to implement equals() because a lot of java.util Collections expect that.

How to mock private method for testing using PowerMock?

A generic solution that will work with any testing framework (if your class is non-final) is to manually create your own mock.

  1. Change your private method to protected.
  2. In your test class extend the class
  3. override the previously-private method to return whatever constant you want

This doesn't use any framework so its not as elegant but it will always work: even without PowerMock. Alternatively, you can use Mockito to do steps #2 & #3 for you, if you've done step #1 already.

To mock a private method directly, you'll need to use PowerMock as shown in the other answer.

jquery change div text

Put the title in its own span.

<span id="dialog_title_span">'+dialog_title+'</span>
$('#dialog_title_span').text("new dialog title");

Changing Vim indentation behavior by file type

I use a utility that I wrote in C called autotab. It analyzes the first few thousand lines of a file which you load and determines values for the Vim parameters shiftwidth, tabstop and expandtab.

This is compiled using, for instance, gcc -O autotab.c -o autotab. Instructions for integrating with Vim are in the comment header at the top.

Autotab is fairly clever, but can get confused from time to time, in particular by that have been inconsistently maintained using different indentation styles.

If a file evidently uses tabs, or a combination of tabs and spaces, for indentation, Autotab will figure out what tab size is being used by considering factors like alignment of internal elements across successive lines, such as comments.

It works for a variety of programming languages, and is forgiving for "out of band" elements which do not obey indentation increments, such as C preprocessing directives, C statement labels, not to mention the obvious blank lines.

How to clear the Entry widget after a button is pressed in Tkinter?

I'm unclear about your question. From http://effbot.org/tkinterbook/entry.htm#patterns, it seems you just need to do an assignment after you called the delete. To add entry text to the widget, use the insert method. To replace the current text, you can call delete before you insert the new text.

e = Entry(master)
e.pack()

e.delete(0, END)
e.insert(0, "")

Could you post a bit more code?

How to save LogCat contents to file?

In addition to answer by Dinesh Prajapati, Use

 adb -d logcat <your package name>:<log level>

where -d is for device and you may also choose -e instead for emulator log and log level is a/d/i/v/e/w etc.

Now your command goes like:

adb -d logcat com.example.example:V > logfileName_WithPath.txt

C# Parsing JSON array of objects

string jsonData1=@"[{""name"":""0"",""price"":""40"",""count"":""1"",""productId"":""4"",""catid"":""4"",""productTotal"":""40"",""orderstatus"":""0"",""orderkey"":""123456789""}]";

                  string jsonData = jsonData1.Replace("\"", "");


                  DataSet ds = new DataSet();
                  DataTable dt = new DataTable();
       JArray array= JArray.Parse(jsonData);

couldnot parse , if the vaule is a string..

look at name : meals , if name : 1 then it will parse

JavaScript: Is there a way to get Chrome to break on all errors?

I got trouble to get it so I post pictures showing different options:

Chrome 75.0.3770.142 [29 July 2018]

Very very similar UI since at least Chrome 38.0.2125.111 [11 December 2014]

In tab Sources :

enter image description here

When button is activated, you can Pause On Caught Exceptions with the checkbox below: enter image description here


Previous versions

Chrome 32.0.1700.102 [03 feb 2014]

enter image description here

enter image description here enter image description here enter image description here

Chrome 27.0.1453.93 Stable

Debug options

Mongodb: failed to connect to server on first connect

In case of remote db in cloud such as ATLAS, you should create whitelist entry 0.0.0.0/0. This allows you to access your cluster ATLAS from any IP address.

enter image description here

How can I get the IP address from NIC in Python?

Two methods:

Method #1 (use external package)

You need to ask for the IP address that is bound to your eth0 interface. This is available from the netifaces package

import netifaces as ni
ni.ifaddresses('eth0')
ip = ni.ifaddresses('eth0')[ni.AF_INET][0]['addr']
print ip  # should print "192.168.100.37"

You can also get a list of all available interfaces via

ni.interfaces()

Method #2 (no external package)

Here's a way to get the IP address without using a python package:

import socket
import fcntl
import struct

def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,  # SIOCGIFADDR
        struct.pack('256s', ifname[:15])
    )[20:24])

get_ip_address('eth0')  # '192.168.0.110'

Note: detecting the IP address to determine what environment you are using is quite a hack. Almost all frameworks provide a very simple way to set/modify an environment variable to indicate the current environment. Try and take a look at your documentation for this. It should be as simple as doing

if app.config['ENV'] == 'production':
  #send production email
else:
  #send development email

What is external linkage and internal linkage?

As dudewat said external linkage means the symbol (function or global variable) is accessible throughout your program and internal linkage means that it is only accessible in one translation unit.

You can explicitly control the linkage of a symbol by using the extern and static keywords. If the linkage is not specified then the default linkage is extern (external linkage) for non-const symbols and static (internal linkage) for const symbols.

// In namespace scope or global scope.
int i; // extern by default
const int ci; // static by default
extern const int eci; // explicitly extern
static int si; // explicitly static

// The same goes for functions (but there are no const functions).
int f(); // extern by default
static int sf(); // explicitly static 

Note that instead of using static (internal linkage), it is better to use anonymous namespaces into which you can also put classes. Though they allow extern linkage, anonymous namespaces are unreachable from other translation units, making linkage effectively static.

namespace {
  int i; // extern by default but unreachable from other translation units
  class C; // extern by default but unreachable from other translation units
}

Can I use a case/switch statement with two variables?

How about a bitwise operator? Instead of strings, you're dealing with "enums", which looks more "elegant."

// Declare slider's state "enum"
var SliderOne = {
    A: 1,
    B: 2,
    C: 4,
    D: 8,
    E: 16
};

var SliderTwo = {
    A: 32,
    B: 64,
    C: 128,
    D: 256,
    E: 512
};

// Set state
var s1 = SliderOne.A,
    s2 = SliderTwo.B;

// Switch state
switch (s1 | s2) {
    case SliderOne.A | SliderTwo.A :
    case SliderOne.A | SliderTwo.C :
        // Logic when State #1 is A, and State #2 is either A or C
        break;
    case SliderOne.B | SliderTwo.C :
        // Logic when State #1 is B, and State #2 is C
        break;
    case SliderOne.E | SliderTwo.E :
    default:
        // Logic when State #1 is E, and State #2 is E or
        // none of above match
        break;


}

I however agree with others, 25 cases in a switch-case logic is not too pretty, and if-else might, in some cases, "look" better. Anyway.

How to overcome the CORS issue in ReactJS

the simplest way what I found from a tutorial of "TraversyMedia" is that just use https://cors-anywhere.herokuapp.com in 'axios' or 'fetch' api

https://cors-anywhere.herokuapp.com/{type_your_url_here} 

e.g.

axios.get(`https://cors-anywhere.herokuapp.com/https://www.api.com/`)

and in your case edit url as

url: 'https://cors-anywhere.herokuapp.com/https://www.api.com',

What are the differences and similarities between ffmpeg, libav, and avconv?

Confusing messages

These messages are rather misleading and understandably a source of confusion. Older Ubuntu versions used Libav which is a fork of the FFmpeg project. FFmpeg returned in Ubuntu 15.04 "Vivid Vervet".

The fork was basically a non-amicable result of conflicting personalities and development styles within the FFmpeg community. It is worth noting that the maintainer for Debian/Ubuntu switched from FFmpeg to Libav on his own accord due to being involved with the Libav fork.

The real ffmpeg vs the fake one

For a while both Libav and FFmpeg separately developed their own version of ffmpeg.

Libav then renamed their bizarro ffmpeg to avconv to distance themselves from the FFmpeg project. During the transition period the "not developed anymore" message was displayed to tell users to start using avconv instead of their counterfeit version of ffmpeg. This confused users into thinking that FFmpeg (the project) is dead, which is not true. A bad choice of words, but I can't imagine Libav not expecting such a response by general users.

This message was removed upstream when the fake "ffmpeg" was finally removed from the Libav source, but, depending on your version, it can still show up in Ubuntu because the Libav source Ubuntu uses is from the ffmpeg-to-avconv transition period.

In June 2012, the message was re-worded for the package libav - 4:0.8.3-0ubuntu0.12.04.1. Unfortunately the new "deprecated" message has caused additional user confusion.

Starting with Ubuntu 15.04 "Vivid Vervet", FFmpeg's ffmpeg is back in the repositories again.

libav vs Libav

To further complicate matters, Libav chose a name that was historically used by FFmpeg to refer to its libraries (libavcodec, libavformat, etc). For example the libav-user mailing list, for questions and discussions about using the FFmpeg libraries, is unrelated to the Libav project.

How to tell the difference

If you are using avconv then you are using Libav. If you are using ffmpeg you could be using FFmpeg or Libav. Refer to the first line in the console output to tell the difference: the copyright notice will either mention FFmpeg or Libav.

Secondly, the version numbering schemes differ. Each of the FFmpeg or Libav libraries contains a version.h header which shows a version number. FFmpeg will end in three digits, such as 57.67.100, and Libav will end in one digit such as 57.67.0. You can also view the library version numbers by running ffmpeg or avconv and viewing the console output.

If you want to use the real ffmpeg

Ubuntu 15.04 "Vivid Vervet" or newer

The real ffmpeg is in the repository, so you can install it with:

apt-get install ffmpeg

For older Ubuntu versions

Your options are:

These methods are non-intrusive, reversible, and will not interfere with the system or any repository packages.

Another possible option is to upgrade to Ubuntu 15.04 "Vivid Vervet" or newer and just use ffmpeg from the repository.

Also see

For an interesting blog article on the situation, as well as a discussion about the main technical differences between the projects, see The FFmpeg/Libav situation.

How to check if a line has one of the strings in a list?

This still loops through the cartesian product of the two lists, but it does it one line:

>>> lines1 = ['soup', 'butter', 'venison']
>>> lines2 = ['prune', 'rye', 'turkey']
>>> search_strings = ['a', 'b', 'c']
>>> any(s in l for l in lines1 for s in search_strings)
True
>>> any(s in l for l in lines2 for s in search_strings)
False

This also have the advantage that any short-circuits, and so the looping stops as soon as a match is found. Also, this only finds the first occurrence of a string from search_strings in linesX. If you want to find multiple occurrences you could do something like this:

>>> lines3 = ['corn', 'butter', 'apples']
>>> [(s, l) for l in lines3 for s in search_strings if s in l]
[('c', 'corn'), ('b', 'butter'), ('a', 'apples')]

If you feel like coding something more complex, it seems the Aho-Corasick algorithm can test for the presence of multiple substrings in a given input string. (Thanks to Niklas B. for pointing that out.) I still think it would result in quadratic performance for your use-case since you'll still have to call it multiple times to search multiple lines. However, it would beat the above (cubic, on average) algorithm.

Creating a custom JButton in Java

When I was first learning Java we had to make Yahtzee and I thought it would be cool to create custom Swing components and containers instead of just drawing everything on one JPanel. The benefit of extending Swing components, of course, is to have the ability to add support for keyboard shortcuts and other accessibility features that you can't do just by having a paint() method print a pretty picture. It may not be done the best way however, but it may be a good starting point for you.

Edit 8/6 - If it wasn't apparent from the images, each Die is a button you can click. This will move it to the DiceContainer below. Looking at the source code you can see that each Die button is drawn dynamically, based on its value.

alt text
alt text
alt text

Here are the basic steps:

  1. Create a class that extends JComponent
  2. Call parent constructor super() in your constructors
  3. Make sure you class implements MouseListener
  4. Put this in the constructor:

    enableInputMethods(true);   
    addMouseListener(this);
    
  5. Override these methods:

    public Dimension getPreferredSize()  
    public Dimension getMinimumSize()  
    public Dimension getMaximumSize()
    
  6. Override this method:

    public void paintComponent(Graphics g)
    

The amount of space you have to work with when drawing your button is defined by getPreferredSize(), assuming getMinimumSize() and getMaximumSize() return the same value. I haven't experimented too much with this but, depending on the layout you use for your GUI your button could look completely different.

And finally, the source code. In case I missed anything.

Provisioning Profiles menu item missing from Xcode 5

These settings have now moved to Preferences > Accounts:

enter image description here

Git Cherry-pick vs Merge Workflow

In my opinion cherry-picking should be reserved for rare situations where it is required, for example if you did some fix on directly on 'master' branch (trunk, main development branch) and then realized that it should be applied also to 'maint'. You should base workflow either on merge, or on rebase (or "git pull --rebase").

Please remember that cherry-picked or rebased commit is different from the point of view of Git (has different SHA-1 identifier) than the original, so it is different than the commit in remote repository. (Rebase can usually deal with this, as it checks patch id i.e. the changes, not a commit id).

Also in git you can merge many branches at once: so called octopus merge. Note that octopus merge has to succeed without conflicts. Nevertheless it might be useful.

HTH.

Find and replace with sed in directory and sub directories

I think we can do this with one line simple command

for i in `grep -rl eth0 . 2> /dev/null`; do sed -i ‘s/eth0/eth1/’ $i; done

Refer to this page.

Access localhost from the internet

You are accesing localhost, meaning you have a web server running on your machine. To access it from Internet, you need to assign a public IP address to your machine. Then you can access http://<public_ip>:<port>/. Port number is normally 80.

NGINX - No input file specified. - php Fast/CGI

use in windows

fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

wasn't putting -b

php-cgi.exe -b 127.0.0.1:9000

checking if a number is divisible by 6 PHP

if ($number % 6 != 0) {
  $number += 6 - ($number % 6);
}

The modulus operator gives the remainder of the division, so $number % 6 is the amount left over when dividing by 6. This will be faster than doing a loop and continually rechecking.

If decreasing is acceptable then this is even faster:

$number -= $number % 6;

Reading a binary input stream into a single byte array in Java

You can read it by chunks (byte buffer[] = new byte[2048]) and write the chunks to a ByteArrayOutputStream. From the ByteArrayOutputStream you can retrieve the contents as a byte[], without needing to determine its size beforehand.

Difference between INNER JOIN and LEFT SEMI JOIN

Suppose there are 2 tables TableA and TableB with only 2 columns (Id, Data) and following data:

TableA:

+----+---------+
| Id |  Data   |
+----+---------+
|  1 | DataA11 |
|  1 | DataA12 |
|  1 | DataA13 |
|  2 | DataA21 |
|  3 | DataA31 |
+----+---------+

TableB:

+----+---------+
| Id |  Data   |
+----+---------+
|  1 | DataB11 |
|  2 | DataB21 |
|  2 | DataB22 |
|  2 | DataB23 |
|  4 | DataB41 |
+----+---------+

Inner Join on column Id will return columns from both the tables and only the matching records:

.----.---------.----.---------.
| Id |  Data   | Id |  Data   |
:----+---------+----+---------:
|  1 | DataA11 |  1 | DataB11 |
:----+---------+----+---------:
|  1 | DataA12 |  1 | DataB11 |
:----+---------+----+---------:
|  1 | DataA13 |  1 | DataB11 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB21 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB22 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB23 |
'----'---------'----'---------'

Left Join (or Left Outer join) on column Id will return columns from both the tables and matching records with records from left table (Null values from right table):

.----.---------.----.---------.
| Id |  Data   | Id |  Data   |
:----+---------+----+---------:
|  1 | DataA11 |  1 | DataB11 |
:----+---------+----+---------:
|  1 | DataA12 |  1 | DataB11 |
:----+---------+----+---------:
|  1 | DataA13 |  1 | DataB11 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB21 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB22 |
:----+---------+----+---------:
|  2 | DataA21 |  2 | DataB23 |
:----+---------+----+---------:
|  3 | DataA31 |    |         |
'----'---------'----'---------'

Right Join (or Right Outer join) on column Id will return columns from both the tables and matching records with records from right table (Null values from left table):

+-----------------------------+
¦ Id ¦  Data   ¦ Id ¦  Data   ¦
+----+---------+----+---------¦
¦  1 ¦ DataA11 ¦  1 ¦ DataB11 ¦
¦  1 ¦ DataA12 ¦  1 ¦ DataB11 ¦
¦  1 ¦ DataA13 ¦  1 ¦ DataB11 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB21 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB22 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB23 ¦
¦    ¦         ¦  4 ¦ DataB41 ¦
+-----------------------------+

Full Outer Join on column Id will return columns from both the tables and matching records with records from left table (Null values from right table) and records from right table (Null values from left table):

+-----------------------------+
¦ Id ¦  Data   ¦ Id ¦  Data   ¦
¦----+---------+----+---------¦
¦  - ¦         ¦    ¦         ¦
¦  1 ¦ DataA11 ¦  1 ¦ DataB11 ¦
¦  1 ¦ DataA12 ¦  1 ¦ DataB11 ¦
¦  1 ¦ DataA13 ¦  1 ¦ DataB11 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB21 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB22 ¦
¦  2 ¦ DataA21 ¦  2 ¦ DataB23 ¦
¦  3 ¦ DataA31 ¦    ¦         ¦
¦    ¦         ¦  4 ¦ DataB41 ¦
+-----------------------------+

Left Semi Join on column Id will return columns only from left table and matching records only from left table:

+--------------+
¦ Id ¦  Data   ¦
+----+---------¦
¦  1 ¦ DataA11 ¦
¦  1 ¦ DataA12 ¦
¦  1 ¦ DataA13 ¦
¦  2 ¦ DataA21 ¦
+--------------+

Return row of Data Frame based on value in a column - R

You could use dplyr:

df %>% group_by("Amount") %>% slice(which.min(x))

How can I make an entire HTML form "readonly"?

You can use this function to disable the form:

function disableForm(formID){
  $('#' + formID).children(':input').attr('disabled', 'disabled');
}

See the working demo here

Note that it uses jQuery.

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

Update 2015-06

Based on antoinepairet's comment/example:

Using uib-collapse attribute provides animations: http://plnkr.co/edit/omyoOxYnCdWJP8ANmTc6?p=preview

<nav class="navbar navbar-default" role="navigation">
    <div class="navbar-header">

        <!-- note the ng-init and ng-click here: -->
        <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </button>
        <a class="navbar-brand" href="#">Brand</a>
    </div>

    <div class="collapse navbar-collapse" uib-collapse="navCollapsed">
        <ul class="nav navbar-nav">
        ...
        </ul>
    </div>
</nav>

Ancient..

I see that the question is framed around BS2, but I thought I'd pitch in with a solution for Bootstrap 3 using ng-class solution based on suggestions in ui.bootstrap issue 394:

The only variation from the official bootstrap example is the addition of ng- attributes noted by comments, below:

<nav class="navbar navbar-default" role="navigation">
  <div class="navbar-header">

    <!-- note the ng-init and ng-click here: -->
    <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a class="navbar-brand" href="#">Brand</a>
  </div>

  <!-- note the ng-class here -->
  <div class="collapse navbar-collapse" ng-class="{'in':!navCollapsed}">

    <ul class="nav navbar-nav">
    ...

Here is an updated working example: http://plnkr.co/edit/OlCCnbGlYWeO7Nxwfj5G?p=preview (hat tip Lars)

This seems to works for me in simple use cases, but you'll note in the example that the second dropdown is cut off… good luck!

Android Studio-No Module

I had the same issue since I changed my app ID in config.xml file.

I used to open my Android project by choosing among recent projects of Android Studio.

I just File > Open > My project to get it working again.

Get individual query parameters from Uri

Use this:

string uri = ...;
string queryString = new System.Uri(uri).Query;
var queryDictionary = System.Web.HttpUtility.ParseQueryString(queryString);

This code by Tejs isn't the 'proper' way to get the query string from the URI:

string.Join(string.Empty, uri.Split('?').Skip(1));

Changing cursor to waiting in javascript/jquery

Here is something else interesting you can do. Define a function to call just before each ajax call. Also assign a function to call after each ajax call is complete. The first function will set the wait cursor and the second will clear it. They look like the following:

$(document).ajaxComplete(function(event, request, settings) {
    $('*').css('cursor', 'default');
  });

function waitCursor() {
    $('*').css('cursor', 'progress');
  }

How to publish a Web Service from Visual Studio into IIS?

If using Visual Studio 2010 you can right-click on the project for the service, and select properties. Then select the Web tab. Under the Servers section you can configure the URL. There is also a button to create the virtual directory.

Recursive Fibonacci

int fib(int x) 
{
    if (x < 2)
      return x;
    else 
      return (fib(x - 1) + fib(x - 2));
}

How to have Android Service communicate with Activity

Binding is another way to communicate

Create a callback

public interface MyCallBack{

   public void getResult(String result);

}

Activity side:

  1. Implement the interface in the Activity

  2. Provide the implementation for the method

  3. Bind the Activity to Service

  4. Register and Unregister Callback when the Service gets bound and unbound with Activity.

    public class YourActivity extends AppCompatActivity implements MyCallBack{
    
          private Intent notifyMeIntent;
          private GPSService gpsService;
          private boolean bound = false;
    
          @Override
          public void onCreate(Bundle sis){
    
              // activity code ...
    
              startGPSService();
    
          }
    
          @Override
          public void getResult(String result){
           // show in textView textView.setText(result);
          }
    
          @Override
          protected void onStart()
          {
              super.onStart();
              bindService();
          }
    
          @Override
          protected void onStop() {
              super.onStop();
              unbindService();
          }
    
          private ServiceConnection serviceConnection = new ServiceConnection() {
    
                @Override
                public void onServiceConnected(ComponentName className, IBinder service) {
    
                      GPSService.GPSBinder binder = (GPSService.GPSBinder) service;
                      gpsService= binder.getService();
                      bound = true;
                      gpsService.registerCallBack(YourActivity.this); // register
    
               }
    
               @Override
               public void onServiceDisconnected(ComponentName arg0) {
                      bound = false;
               }
          };
    
          private void bindService() {
    
               bindService(notifyMeIntent, serviceConnection, Context.BIND_AUTO_CREATE);
          }
    
          private void unbindService(){
               if (bound) {
                     gpsService.registerCallBack(null); // unregister            
                     unbindService(serviceConnection);
                     bound = false;
                }
          }
    
          // Call this method somewhere to start Your GPSService
          private void startGPSService(){
               notifyMeIntent = new Intent(this, GPSService.class);
               startService(myIntent );
          }
    
     }
    

Service Side:

  1. Initialize callback

  2. Invoke the callback method whenever needed

     public class GPSService extends Service{
    
         private MyCallBack myCallback;
         private IBinder serviceBinder = new GPSBinder();
    
         public void registerCallBack(MyCallBack myCallback){
              this.myCallback= myCallback;
         }
    
         public class GPSBinder extends Binder{
    
             public GPSService getService(){
                  return GPSService.this;
             }
        }
    
        @Nullable
        @Override
        public IBinder onBind(Intent intent){
             return serviceBinder;
        }
     }
    

Uncaught ReferenceError: function is not defined with onclick

If the function is not defined when using that function in html, such as onclick = ‘function () ', it means function is in a callback, in my case is 'DOMContentLoaded'.

How to get duplicate items from a list using LINQ?

Here's another option:

var list = new List<string> { "6", "1", "2", "4", "6", "5", "1" };

var set = new HashSet<string>();
var duplicates = list.Where(x => !set.Add(x));

Installing OpenCV for Python on Ubuntu, getting ImportError: No module named cv2.cv

Find where the cv2.so is, for example /usr/local/lib/python2.7/dist-packages, then add this into your ~/.bashrc by doing:

sudo gedit ~/.bashrc

and add

export PYTHONPATH=/usr/local/lib/python2.7/dist-packages:$PYTHONPATH

In the last line

And then remember to open another terminal, this can be work, and I have solve my problem. Hope it can help you.

php random x digit number

you people really likes to complicate things :)

the real problem is that the OP wants to, probably, add that to the end of some really big number. if not, there is no need I can think of for that to be required. as left zeros in any number is just, well, left zeroes.

so, just append the larger portion of that number as a math sum, not string.

e.g.

$x = "102384129" . complex_3_digit_random_string();

simply becomes

$x = 102384129000 + rand(0, 999);

done.

Adding an onclicklistener to listview (android)

The prestListView.getItemAtPosition(position); returns the UI widget: Text, Icon, ...

Try this instead:

Object o = prestationAdapterEco.getItemAtPosition(position);

or

Object o = arg0.getItemAtPosition(position);

Get the object from the adapter. Not from the list-view.

2. Object o is a prestationEco object. Not a String.